diff options
76 files changed, 5930 insertions, 2780 deletions
diff --git a/Documentation/atomic_t.txt b/Documentation/atomic_t.txt index 0f1fdedf36bb..0f1ffa03db09 100644 --- a/Documentation/atomic_t.txt +++ b/Documentation/atomic_t.txt @@ -271,3 +271,97 @@ WRITE_ONCE. Thus: SC *y, t; is allowed. + + +CMPXCHG vs TRY_CMPXCHG +---------------------- + + int atomic_cmpxchg(atomic_t *ptr, int old, int new); + bool atomic_try_cmpxchg(atomic_t *ptr, int *oldp, int new); + +Both provide the same functionality, but try_cmpxchg() can lead to more +compact code. The functions relate like: + + bool atomic_try_cmpxchg(atomic_t *ptr, int *oldp, int new) + { + int ret, old = *oldp; + ret = atomic_cmpxchg(ptr, old, new); + if (ret != old) + *oldp = ret; + return ret == old; + } + +and: + + int atomic_cmpxchg(atomic_t *ptr, int old, int new) + { + (void)atomic_try_cmpxchg(ptr, &old, new); + return old; + } + +Usage: + + old = atomic_read(&v); old = atomic_read(&v); + for (;;) { do { + new = func(old); new = func(old); + tmp = atomic_cmpxchg(&v, old, new); } while (!atomic_try_cmpxchg(&v, &old, new)); + if (tmp == old) + break; + old = tmp; + } + +NB. try_cmpxchg() also generates better code on some platforms (notably x86) +where the function more closely matches the hardware instruction. + + +FORWARD PROGRESS +---------------- + +In general strong forward progress is expected of all unconditional atomic +operations -- those in the Arithmetic and Bitwise classes and xchg(). However +a fair amount of code also requires forward progress from the conditional +atomic operations. + +Specifically 'simple' cmpxchg() loops are expected to not starve one another +indefinitely. However, this is not evident on LL/SC architectures, because +while an LL/SC architecure 'can/should/must' provide forward progress +guarantees between competing LL/SC sections, such a guarantee does not +transfer to cmpxchg() implemented using LL/SC. Consider: + + old = atomic_read(&v); + do { + new = func(old); + } while (!atomic_try_cmpxchg(&v, &old, new)); + +which on LL/SC becomes something like: + + old = atomic_read(&v); + do { + new = func(old); + } while (!({ + volatile asm ("1: LL %[oldval], %[v]\n" + " CMP %[oldval], %[old]\n" + " BNE 2f\n" + " SC %[new], %[v]\n" + " BNE 1b\n" + "2:\n" + : [oldval] "=&r" (oldval), [v] "m" (v) + : [old] "r" (old), [new] "r" (new) + : "memory"); + success = (oldval == old); + if (!success) + old = oldval; + success; })); + +However, even the forward branch from the failed compare can cause the LL/SC +to fail on some architectures, let alone whatever the compiler makes of the C +loop body. As a result there is no guarantee what so ever the cacheline +containing @v will stay on the local CPU and progress is made. + +Even native CAS architectures can fail to provide forward progress for their +primitive (See Sparc64 for an example). + +Such implementations are strongly encouraged to add exponential backoff loops +to a failed CAS in order to ensure some progress. Affected architectures are +also strongly encouraged to inspect/audit the atomic fallbacks, refcount_t and +their locking primitives. diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c index 6f5fe5092154..c8a625667e81 100644 --- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c +++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c @@ -1904,8 +1904,8 @@ int __atomisp_streamoff(struct file *file, void *fh, enum v4l2_buf_type type) dev_dbg(isp->dev, "Stop stream on pad %d for asd%d\n", atomisp_subdev_source_pad(vdev), asd->index); - BUG_ON(!rt_mutex_is_locked(&isp->mutex)); - BUG_ON(!mutex_is_locked(&isp->streamoff_mutex)); + lockdep_assert_held(&isp->mutex); + lockdep_assert_held(&isp->streamoff_mutex); if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE) { dev_dbg(isp->dev, "unsupported v4l2 buf type\n"); diff --git a/include/asm-generic/atomic-long.h b/include/asm-generic/atomic-long.h deleted file mode 100644 index 073cf40f431b..000000000000 --- a/include/asm-generic/atomic-long.h +++ /dev/null @@ -1,1014 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -// Generated by scripts/atomic/gen-atomic-long.sh -// DO NOT MODIFY THIS FILE DIRECTLY - -#ifndef _ASM_GENERIC_ATOMIC_LONG_H -#define _ASM_GENERIC_ATOMIC_LONG_H - -#include <linux/compiler.h> -#include <asm/types.h> - -#ifdef CONFIG_64BIT -typedef atomic64_t atomic_long_t; -#define ATOMIC_LONG_INIT(i) ATOMIC64_INIT(i) -#define atomic_long_cond_read_acquire atomic64_cond_read_acquire -#define atomic_long_cond_read_relaxed atomic64_cond_read_relaxed -#else -typedef atomic_t atomic_long_t; -#define ATOMIC_LONG_INIT(i) ATOMIC_INIT(i) -#define atomic_long_cond_read_acquire atomic_cond_read_acquire -#define atomic_long_cond_read_relaxed atomic_cond_read_relaxed -#endif - -#ifdef CONFIG_64BIT - -static __always_inline long -atomic_long_read(const atomic_long_t *v) -{ - return atomic64_read(v); -} - -static __always_inline long -atomic_long_read_acquire(const atomic_long_t *v) -{ - return atomic64_read_acquire(v); -} - -static __always_inline void -atomic_long_set(atomic_long_t *v, long i) -{ - atomic64_set(v, i); -} - -static __always_inline void -atomic_long_set_release(atomic_long_t *v, long i) -{ - atomic64_set_release(v, i); -} - -static __always_inline void -atomic_long_add(long i, atomic_long_t *v) -{ - atomic64_add(i, v); -} - -static __always_inline long -atomic_long_add_return(long i, atomic_long_t *v) -{ - return atomic64_add_return(i, v); -} - -static __always_inline long -atomic_long_add_return_acquire(long i, atomic_long_t *v) -{ - return atomic64_add_return_acquire(i, v); -} - -static __always_inline long -atomic_long_add_return_release(long i, atomic_long_t *v) -{ - return atomic64_add_return_release(i, v); -} - -static __always_inline long -atomic_long_add_return_relaxed(long i, atomic_long_t *v) -{ - return atomic64_add_return_relaxed(i, v); -} - -static __always_inline long -atomic_long_fetch_add(long i, atomic_long_t *v) -{ - return atomic64_fetch_add(i, v); -} - -static __always_inline long -atomic_long_fetch_add_acquire(long i, atomic_long_t *v) -{ - return atomic64_fetch_add_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_add_release(long i, atomic_long_t *v) -{ - return atomic64_fetch_add_release(i, v); -} - -static __always_inline long -atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) -{ - return atomic64_fetch_add_relaxed(i, v); -} - -static __always_inline void -atomic_long_sub(long i, atomic_long_t *v) -{ - atomic64_sub(i, v); -} - -static __always_inline long -atomic_long_sub_return(long i, atomic_long_t *v) -{ - return atomic64_sub_return(i, v); -} - -static __always_inline long -atomic_long_sub_return_acquire(long i, atomic_long_t *v) -{ - return atomic64_sub_return_acquire(i, v); -} - -static __always_inline long -atomic_long_sub_return_release(long i, atomic_long_t *v) -{ - return atomic64_sub_return_release(i, v); -} - -static __always_inline long -atomic_long_sub_return_relaxed(long i, atomic_long_t *v) -{ - return atomic64_sub_return_relaxed(i, v); -} - -static __always_inline long -atomic_long_fetch_sub(long i, atomic_long_t *v) -{ - return atomic64_fetch_sub(i, v); -} - -static __always_inline long -atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) -{ - return atomic64_fetch_sub_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_sub_release(long i, atomic_long_t *v) -{ - return atomic64_fetch_sub_release(i, v); -} - -static __always_inline long -atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) -{ - return atomic64_fetch_sub_relaxed(i, v); -} - -static __always_inline void -atomic_long_inc(atomic_long_t *v) -{ - atomic64_inc(v); -} - -static __always_inline long -atomic_long_inc_return(atomic_long_t *v) -{ - return atomic64_inc_return(v); -} - -static __always_inline long -atomic_long_inc_return_acquire(atomic_long_t *v) -{ - return atomic64_inc_return_acquire(v); -} - -static __always_inline long -atomic_long_inc_return_release(atomic_long_t *v) -{ - return atomic64_inc_return_release(v); -} - -static __always_inline long -atomic_long_inc_return_relaxed(atomic_long_t *v) -{ - return atomic64_inc_return_relaxed(v); -} - -static __always_inline long -atomic_long_fetch_inc(atomic_long_t *v) -{ - return atomic64_fetch_inc(v); -} - -static __always_inline long -atomic_long_fetch_inc_acquire(atomic_long_t *v) -{ - return atomic64_fetch_inc_acquire(v); -} - -static __always_inline long -atomic_long_fetch_inc_release(atomic_long_t *v) -{ - return atomic64_fetch_inc_release(v); -} - -static __always_inline long -atomic_long_fetch_inc_relaxed(atomic_long_t *v) -{ - return atomic64_fetch_inc_relaxed(v); -} - -static __always_inline void -atomic_long_dec(atomic_long_t *v) -{ - atomic64_dec(v); -} - -static __always_inline long -atomic_long_dec_return(atomic_long_t *v) -{ - return atomic64_dec_return(v); -} - -static __always_inline long -atomic_long_dec_return_acquire(atomic_long_t *v) -{ - return atomic64_dec_return_acquire(v); -} - -static __always_inline long -atomic_long_dec_return_release(atomic_long_t *v) -{ - return atomic64_dec_return_release(v); -} - -static __always_inline long -atomic_long_dec_return_relaxed(atomic_long_t *v) -{ - return atomic64_dec_return_relaxed(v); -} - -static __always_inline long -atomic_long_fetch_dec(atomic_long_t *v) -{ - return atomic64_fetch_dec(v); -} - -static __always_inline long -atomic_long_fetch_dec_acquire(atomic_long_t *v) -{ - return atomic64_fetch_dec_acquire(v); -} - -static __always_inline long -atomic_long_fetch_dec_release(atomic_long_t *v) -{ - return atomic64_fetch_dec_release(v); -} - -static __always_inline long -atomic_long_fetch_dec_relaxed(atomic_long_t *v) -{ - return atomic64_fetch_dec_relaxed(v); -} - -static __always_inline void -atomic_long_and(long i, atomic_long_t *v) -{ - atomic64_and(i, v); -} - -static __always_inline long -atomic_long_fetch_and(long i, atomic_long_t *v) -{ - return atomic64_fetch_and(i, v); -} - -static __always_inline long -atomic_long_fetch_and_acquire(long i, atomic_long_t *v) -{ - return atomic64_fetch_and_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_and_release(long i, atomic_long_t *v) -{ - return atomic64_fetch_and_release(i, v); -} - -static __always_inline long -atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) -{ - return atomic64_fetch_and_relaxed(i, v); -} - -static __always_inline void -atomic_long_andnot(long i, atomic_long_t *v) -{ - atomic64_andnot(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot(long i, atomic_long_t *v) -{ - return atomic64_fetch_andnot(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) -{ - return atomic64_fetch_andnot_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot_release(long i, atomic_long_t *v) -{ - return atomic64_fetch_andnot_release(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) -{ - return atomic64_fetch_andnot_relaxed(i, v); -} - -static __always_inline void -atomic_long_or(long i, atomic_long_t *v) -{ - atomic64_or(i, v); -} - -static __always_inline long -atomic_long_fetch_or(long i, atomic_long_t *v) -{ - return atomic64_fetch_or(i, v); -} - -static __always_inline long -atomic_long_fetch_or_acquire(long i, atomic_long_t *v) -{ - return atomic64_fetch_or_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_or_release(long i, atomic_long_t *v) -{ - return atomic64_fetch_or_release(i, v); -} - -static __always_inline long -atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) -{ - return atomic64_fetch_or_relaxed(i, v); -} - -static __always_inline void -atomic_long_xor(long i, atomic_long_t *v) -{ - atomic64_xor(i, v); -} - -static __always_inline long -atomic_long_fetch_xor(long i, atomic_long_t *v) -{ - return atomic64_fetch_xor(i, v); -} - -static __always_inline long -atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) -{ - return atomic64_fetch_xor_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_xor_release(long i, atomic_long_t *v) -{ - return atomic64_fetch_xor_release(i, v); -} - -static __always_inline long -atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) -{ - return atomic64_fetch_xor_relaxed(i, v); -} - -static __always_inline long -atomic_long_xchg(atomic_long_t *v, long i) -{ - return atomic64_xchg(v, i); -} - -static __always_inline long -atomic_long_xchg_acquire(atomic_long_t *v, long i) -{ - return atomic64_xchg_acquire(v, i); -} - -static __always_inline long -atomic_long_xchg_release(atomic_long_t *v, long i) -{ - return atomic64_xchg_release(v, i); -} - -static __always_inline long -atomic_long_xchg_relaxed(atomic_long_t *v, long i) -{ - return atomic64_xchg_relaxed(v, i); -} - -static __always_inline long -atomic_long_cmpxchg(atomic_long_t *v, long old, long new) -{ - return atomic64_cmpxchg(v, old, new); -} - -static __always_inline long -atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) -{ - return atomic64_cmpxchg_acquire(v, old, new); -} - -static __always_inline long -atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) -{ - return atomic64_cmpxchg_release(v, old, new); -} - -static __always_inline long -atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) -{ - return atomic64_cmpxchg_relaxed(v, old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) -{ - return atomic64_try_cmpxchg(v, (s64 *)old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) -{ - return atomic64_try_cmpxchg_acquire(v, (s64 *)old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) -{ - return atomic64_try_cmpxchg_release(v, (s64 *)old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) -{ - return atomic64_try_cmpxchg_relaxed(v, (s64 *)old, new); -} - -static __always_inline bool -atomic_long_sub_and_test(long i, atomic_long_t *v) -{ - return atomic64_sub_and_test(i, v); -} - -static __always_inline bool -atomic_long_dec_and_test(atomic_long_t *v) -{ - return atomic64_dec_and_test(v); -} - -static __always_inline bool -atomic_long_inc_and_test(atomic_long_t *v) -{ - return atomic64_inc_and_test(v); -} - -static __always_inline bool -atomic_long_add_negative(long i, atomic_long_t *v) -{ - return atomic64_add_negative(i, v); -} - -static __always_inline long -atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) -{ - return atomic64_fetch_add_unless(v, a, u); -} - -static __always_inline bool -atomic_long_add_unless(atomic_long_t *v, long a, long u) -{ - return atomic64_add_unless(v, a, u); -} - -static __always_inline bool -atomic_long_inc_not_zero(atomic_long_t *v) -{ - return atomic64_inc_not_zero(v); -} - -static __always_inline bool -atomic_long_inc_unless_negative(atomic_long_t *v) -{ - return atomic64_inc_unless_negative(v); -} - -static __always_inline bool -atomic_long_dec_unless_positive(atomic_long_t *v) -{ - return atomic64_dec_unless_positive(v); -} - -static __always_inline long -atomic_long_dec_if_positive(atomic_long_t *v) -{ - return atomic64_dec_if_positive(v); -} - -#else /* CONFIG_64BIT */ - -static __always_inline long -atomic_long_read(const atomic_long_t *v) -{ - return atomic_read(v); -} - -static __always_inline long -atomic_long_read_acquire(const atomic_long_t *v) -{ - return atomic_read_acquire(v); -} - -static __always_inline void -atomic_long_set(atomic_long_t *v, long i) -{ - atomic_set(v, i); -} - -static __always_inline void -atomic_long_set_release(atomic_long_t *v, long i) -{ - atomic_set_release(v, i); -} - -static __always_inline void -atomic_long_add(long i, atomic_long_t *v) -{ - atomic_add(i, v); -} - -static __always_inline long -atomic_long_add_return(long i, atomic_long_t *v) -{ - return atomic_add_return(i, v); -} - -static __always_inline long -atomic_long_add_return_acquire(long i, atomic_long_t *v) -{ - return atomic_add_return_acquire(i, v); -} - -static __always_inline long -atomic_long_add_return_release(long i, atomic_long_t *v) -{ - return atomic_add_return_release(i, v); -} - -static __always_inline long -atomic_long_add_return_relaxed(long i, atomic_long_t *v) -{ - return atomic_add_return_relaxed(i, v); -} - -static __always_inline long -atomic_long_fetch_add(long i, atomic_long_t *v) -{ - return atomic_fetch_add(i, v); -} - -static __always_inline long -atomic_long_fetch_add_acquire(long i, atomic_long_t *v) -{ - return atomic_fetch_add_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_add_release(long i, atomic_long_t *v) -{ - return atomic_fetch_add_release(i, v); -} - -static __always_inline long -atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) -{ - return atomic_fetch_add_relaxed(i, v); -} - -static __always_inline void -atomic_long_sub(long i, atomic_long_t *v) -{ - atomic_sub(i, v); -} - -static __always_inline long -atomic_long_sub_return(long i, atomic_long_t *v) -{ - return atomic_sub_return(i, v); -} - -static __always_inline long -atomic_long_sub_return_acquire(long i, atomic_long_t *v) -{ - return atomic_sub_return_acquire(i, v); -} - -static __always_inline long -atomic_long_sub_return_release(long i, atomic_long_t *v) -{ - return atomic_sub_return_release(i, v); -} - -static __always_inline long -atomic_long_sub_return_relaxed(long i, atomic_long_t *v) -{ - return atomic_sub_return_relaxed(i, v); -} - -static __always_inline long -atomic_long_fetch_sub(long i, atomic_long_t *v) -{ - return atomic_fetch_sub(i, v); -} - -static __always_inline long -atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) -{ - return atomic_fetch_sub_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_sub_release(long i, atomic_long_t *v) -{ - return atomic_fetch_sub_release(i, v); -} - -static __always_inline long -atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) -{ - return atomic_fetch_sub_relaxed(i, v); -} - -static __always_inline void -atomic_long_inc(atomic_long_t *v) -{ - atomic_inc(v); -} - -static __always_inline long -atomic_long_inc_return(atomic_long_t *v) -{ - return atomic_inc_return(v); -} - -static __always_inline long -atomic_long_inc_return_acquire(atomic_long_t *v) -{ - return atomic_inc_return_acquire(v); -} - -static __always_inline long -atomic_long_inc_return_release(atomic_long_t *v) -{ - return atomic_inc_return_release(v); -} - -static __always_inline long -atomic_long_inc_return_relaxed(atomic_long_t *v) -{ - return atomic_inc_return_relaxed(v); -} - -static __always_inline long -atomic_long_fetch_inc(atomic_long_t *v) -{ - return atomic_fetch_inc(v); -} - -static __always_inline long -atomic_long_fetch_inc_acquire(atomic_long_t *v) -{ - return atomic_fetch_inc_acquire(v); -} - -static __always_inline long -atomic_long_fetch_inc_release(atomic_long_t *v) -{ - return atomic_fetch_inc_release(v); -} - -static __always_inline long -atomic_long_fetch_inc_relaxed(atomic_long_t *v) -{ - return atomic_fetch_inc_relaxed(v); -} - -static __always_inline void -atomic_long_dec(atomic_long_t *v) -{ - atomic_dec(v); -} - -static __always_inline long -atomic_long_dec_return(atomic_long_t *v) -{ - return atomic_dec_return(v); -} - -static __always_inline long -atomic_long_dec_return_acquire(atomic_long_t *v) -{ - return atomic_dec_return_acquire(v); -} - -static __always_inline long -atomic_long_dec_return_release(atomic_long_t *v) -{ - return atomic_dec_return_release(v); -} - -static __always_inline long -atomic_long_dec_return_relaxed(atomic_long_t *v) -{ - return atomic_dec_return_relaxed(v); -} - -static __always_inline long -atomic_long_fetch_dec(atomic_long_t *v) -{ - return atomic_fetch_dec(v); -} - -static __always_inline long -atomic_long_fetch_dec_acquire(atomic_long_t *v) -{ - return atomic_fetch_dec_acquire(v); -} - -static __always_inline long -atomic_long_fetch_dec_release(atomic_long_t *v) -{ - return atomic_fetch_dec_release(v); -} - -static __always_inline long -atomic_long_fetch_dec_relaxed(atomic_long_t *v) -{ - return atomic_fetch_dec_relaxed(v); -} - -static __always_inline void -atomic_long_and(long i, atomic_long_t *v) -{ - atomic_and(i, v); -} - -static __always_inline long -atomic_long_fetch_and(long i, atomic_long_t *v) -{ - return atomic_fetch_and(i, v); -} - -static __always_inline long -atomic_long_fetch_and_acquire(long i, atomic_long_t *v) -{ - return atomic_fetch_and_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_and_release(long i, atomic_long_t *v) -{ - return atomic_fetch_and_release(i, v); -} - -static __always_inline long -atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) -{ - return atomic_fetch_and_relaxed(i, v); -} - -static __always_inline void -atomic_long_andnot(long i, atomic_long_t *v) -{ - atomic_andnot(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot(long i, atomic_long_t *v) -{ - return atomic_fetch_andnot(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) -{ - return atomic_fetch_andnot_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot_release(long i, atomic_long_t *v) -{ - return atomic_fetch_andnot_release(i, v); -} - -static __always_inline long -atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) -{ - return atomic_fetch_andnot_relaxed(i, v); -} - -static __always_inline void -atomic_long_or(long i, atomic_long_t *v) -{ - atomic_or(i, v); -} - -static __always_inline long -atomic_long_fetch_or(long i, atomic_long_t *v) -{ - return atomic_fetch_or(i, v); -} - -static __always_inline long -atomic_long_fetch_or_acquire(long i, atomic_long_t *v) -{ - return atomic_fetch_or_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_or_release(long i, atomic_long_t *v) -{ - return atomic_fetch_or_release(i, v); -} - -static __always_inline long -atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) -{ - return atomic_fetch_or_relaxed(i, v); -} - -static __always_inline void -atomic_long_xor(long i, atomic_long_t *v) -{ - atomic_xor(i, v); -} - -static __always_inline long -atomic_long_fetch_xor(long i, atomic_long_t *v) -{ - return atomic_fetch_xor(i, v); -} - -static __always_inline long -atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) -{ - return atomic_fetch_xor_acquire(i, v); -} - -static __always_inline long -atomic_long_fetch_xor_release(long i, atomic_long_t *v) -{ - return atomic_fetch_xor_release(i, v); -} - -static __always_inline long -atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) -{ - return atomic_fetch_xor_relaxed(i, v); -} - -static __always_inline long -atomic_long_xchg(atomic_long_t *v, long i) -{ - return atomic_xchg(v, i); -} - -static __always_inline long -atomic_long_xchg_acquire(atomic_long_t *v, long i) -{ - return atomic_xchg_acquire(v, i); -} - -static __always_inline long -atomic_long_xchg_release(atomic_long_t *v, long i) -{ - return atomic_xchg_release(v, i); -} - -static __always_inline long -atomic_long_xchg_relaxed(atomic_long_t *v, long i) -{ - return atomic_xchg_relaxed(v, i); -} - -static __always_inline long -atomic_long_cmpxchg(atomic_long_t *v, long old, long new) -{ - return atomic_cmpxchg(v, old, new); -} - -static __always_inline long -atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) -{ - return atomic_cmpxchg_acquire(v, old, new); -} - -static __always_inline long -atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) -{ - return atomic_cmpxchg_release(v, old, new); -} - -static __always_inline long -atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) -{ - return atomic_cmpxchg_relaxed(v, old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) -{ - return atomic_try_cmpxchg(v, (int *)old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) -{ - return atomic_try_cmpxchg_acquire(v, (int *)old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) -{ - return atomic_try_cmpxchg_release(v, (int *)old, new); -} - -static __always_inline bool -atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) -{ - return atomic_try_cmpxchg_relaxed(v, (int *)old, new); -} - -static __always_inline bool -atomic_long_sub_and_test(long i, atomic_long_t *v) -{ - return atomic_sub_and_test(i, v); -} - -static __always_inline bool -atomic_long_dec_and_test(atomic_long_t *v) -{ - return atomic_dec_and_test(v); -} - -static __always_inline bool -atomic_long_inc_and_test(atomic_long_t *v) -{ - return atomic_inc_and_test(v); -} - -static __always_inline bool -atomic_long_add_negative(long i, atomic_long_t *v) -{ - return atomic_add_negative(i, v); -} - -static __always_inline long -atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) -{ - return atomic_fetch_add_unless(v, a, u); -} - -static __always_inline bool -atomic_long_add_unless(atomic_long_t *v, long a, long u) -{ - return atomic_add_unless(v, a, u); -} - -static __always_inline bool -atomic_long_inc_not_zero(atomic_long_t *v) -{ - return atomic_inc_not_zero(v); -} - -static __always_inline bool -atomic_long_inc_unless_negative(atomic_long_t *v) -{ - return atomic_inc_unless_negative(v); -} - -static __always_inline bool -atomic_long_dec_unless_positive(atomic_long_t *v) -{ - return atomic_dec_unless_positive(v); -} - -static __always_inline long -atomic_long_dec_if_positive(atomic_long_t *v) -{ - return atomic_dec_if_positive(v); -} - -#endif /* CONFIG_64BIT */ -#endif /* _ASM_GENERIC_ATOMIC_LONG_H */ -// a624200981f552b2c6be4f32fe44da8289f30d87 diff --git a/include/asm-generic/bitops/atomic.h b/include/asm-generic/bitops/atomic.h index 0e7316a86240..3096f086b5a3 100644 --- a/include/asm-generic/bitops/atomic.h +++ b/include/asm-generic/bitops/atomic.h @@ -11,25 +11,29 @@ * See Documentation/atomic_bitops.txt for details. */ -static __always_inline void set_bit(unsigned int nr, volatile unsigned long *p) +static __always_inline void +arch_set_bit(unsigned int nr, volatile unsigned long *p) { p += BIT_WORD(nr); - atomic_long_or(BIT_MASK(nr), (atomic_long_t *)p); + arch_atomic_long_or(BIT_MASK(nr), (atomic_long_t *)p); } -static __always_inline void clear_bit(unsigned int nr, volatile unsigned long *p) +static __always_inline void +arch_clear_bit(unsigned int nr, volatile unsigned long *p) { p += BIT_WORD(nr); - atomic_long_andnot(BIT_MASK(nr), (atomic_long_t *)p); + arch_atomic_long_andnot(BIT_MASK(nr), (atomic_long_t *)p); } -static __always_inline void change_bit(unsigned int nr, volatile unsigned long *p) +static __always_inline void +arch_change_bit(unsigned int nr, volatile unsigned long *p) { p += BIT_WORD(nr); - atomic_long_xor(BIT_MASK(nr), (atomic_long_t *)p); + arch_atomic_long_xor(BIT_MASK(nr), (atomic_long_t *)p); } -static inline int test_and_set_bit(unsigned int nr, volatile unsigned long *p) +static __always_inline int +arch_test_and_set_bit(unsigned int nr, volatile unsigned long *p) { long old; unsigned long mask = BIT_MASK(nr); @@ -38,11 +42,12 @@ static inline int test_and_set_bit(unsigned int nr, volatile unsigned long *p) if (READ_ONCE(*p) & mask) return 1; - old = atomic_long_fetch_or(mask, (atomic_long_t *)p); + old = arch_atomic_long_fetch_or(mask, (atomic_long_t *)p); return !!(old & mask); } -static inline int test_and_clear_bit(unsigned int nr, volatile unsigned long *p) +static __always_inline int +arch_test_and_clear_bit(unsigned int nr, volatile unsigned long *p) { long old; unsigned long mask = BIT_MASK(nr); @@ -51,18 +56,21 @@ static inline int test_and_clear_bit(unsigned int nr, volatile unsigned long *p) if (!(READ_ONCE(*p) & mask)) return 0; - old = atomic_long_fetch_andnot(mask, (atomic_long_t *)p); + old = arch_atomic_long_fetch_andnot(mask, (atomic_long_t *)p); return !!(old & mask); } -static inline int test_and_change_bit(unsigned int nr, volatile unsigned long *p) +static __always_inline int +arch_test_and_change_bit(unsigned int nr, volatile unsigned long *p) { long old; unsigned long mask = BIT_MASK(nr); p += BIT_WORD(nr); - old = atomic_long_fetch_xor(mask, (atomic_long_t *)p); + old = arch_atomic_long_fetch_xor(mask, (atomic_long_t *)p); return !!(old & mask); } +#include <asm-generic/bitops/instrumented-atomic.h> + #endif /* _ASM_GENERIC_BITOPS_ATOMIC_H */ diff --git a/include/asm-generic/bitops/lock.h b/include/asm-generic/bitops/lock.h index 3ae021368f48..630f2f6b9595 100644 --- a/include/asm-generic/bitops/lock.h +++ b/include/asm-generic/bitops/lock.h @@ -7,7 +7,7 @@ #include <asm/barrier.h> /** - * test_and_set_bit_lock - Set a bit and return its old value, for lock + * arch_test_and_set_bit_lock - Set a bit and return its old value, for lock * @nr: Bit to set * @addr: Address to count from * @@ -15,8 +15,8 @@ * the returned value is 0. * It can be used to implement bit locks. */ -static inline int test_and_set_bit_lock(unsigned int nr, - volatile unsigned long *p) +static __always_inline int +arch_test_and_set_bit_lock(unsigned int nr, volatile unsigned long *p) { long old; unsigned long mask = BIT_MASK(nr); @@ -25,26 +25,27 @@ static inline int test_and_set_bit_lock(unsigned int nr, if (READ_ONCE(*p) & mask) return 1; - old = atomic_long_fetch_or_acquire(mask, (atomic_long_t *)p); + old = arch_atomic_long_fetch_or_acquire(mask, (atomic_long_t *)p); return !!(old & mask); } /** - * clear_bit_unlock - Clear a bit in memory, for unlock + * arch_clear_bit_unlock - Clear a bit in memory, for unlock * @nr: the bit to set * @addr: the address to start counting from * * This operation is atomic and provides release barrier semantics. */ -static inline void clear_bit_unlock(unsigned int nr, volatile unsigned long *p) +static __always_inline void +arch_clear_bit_unlock(unsigned int nr, volatile unsigned long *p) { p += BIT_WORD(nr); - atomic_long_fetch_andnot_release(BIT_MASK(nr), (atomic_long_t *)p); + arch_atomic_long_fetch_andnot_release(BIT_MASK(nr), (atomic_long_t *)p); } /** - * __clear_bit_unlock - Clear a bit in memory, for unlock + * arch___clear_bit_unlock - Clear a bit in memory, for unlock * @nr: the bit to set * @addr: the address to start counting from * @@ -54,38 +55,40 @@ static inline void clear_bit_unlock(unsigned int nr, volatile unsigned long *p) * * See for example x86's implementation. */ -static inline void __clear_bit_unlock(unsigned int nr, - volatile unsigned long *p) +static inline void +arch___clear_bit_unlock(unsigned int nr, volatile unsigned long *p) { unsigned long old; p += BIT_WORD(nr); old = READ_ONCE(*p); old &= ~BIT_MASK(nr); - atomic_long_set_release((atomic_long_t *)p, old); + arch_atomic_long_set_release((atomic_long_t *)p, old); } /** - * clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom - * byte is negative, for unlock. + * arch_clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom + * byte is negative, for unlock. * @nr: the bit to clear * @addr: the address to start counting from * * This is a bit of a one-trick-pony for the filemap code, which clears * PG_locked and tests PG_waiters, */ -#ifndef clear_bit_unlock_is_negative_byte -static inline bool clear_bit_unlock_is_negative_byte(unsigned int nr, - volatile unsigned long *p) +#ifndef arch_clear_bit_unlock_is_negative_byte +static inline bool arch_clear_bit_unlock_is_negative_byte(unsigned int nr, + volatile unsigned long *p) { long old; unsigned long mask = BIT_MASK(nr); p += BIT_WORD(nr); - old = atomic_long_fetch_andnot_release(mask, (atomic_long_t *)p); + old = arch_atomic_long_fetch_andnot_release(mask, (atomic_long_t *)p); return !!(old & BIT(7)); } -#define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte +#define arch_clear_bit_unlock_is_negative_byte arch_clear_bit_unlock_is_negative_byte #endif +#include <asm-generic/bitops/instrumented-lock.h> + #endif /* _ASM_GENERIC_BITOPS_LOCK_H_ */ diff --git a/include/asm-generic/bitops/non-atomic.h b/include/asm-generic/bitops/non-atomic.h index 7e10c4b50c5d..365377fb104b 100644 --- a/include/asm-generic/bitops/non-atomic.h +++ b/include/asm-generic/bitops/non-atomic.h @@ -5,7 +5,7 @@ #include <asm/types.h> /** - * __set_bit - Set a bit in memory + * arch___set_bit - Set a bit in memory * @nr: the bit to set * @addr: the address to start counting from * @@ -13,24 +13,28 @@ * If it's called on the same region of memory simultaneously, the effect * may be that only one operation succeeds. */ -static inline void __set_bit(int nr, volatile unsigned long *addr) +static __always_inline void +arch___set_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); *p |= mask; } +#define __set_bit arch___set_bit -static inline void __clear_bit(int nr, volatile unsigned long *addr) +static __always_inline void +arch___clear_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); *p &= ~mask; } +#define __clear_bit arch___clear_bit /** - * __change_bit - Toggle a bit in memory + * arch___change_bit - Toggle a bit in memory * @nr: the bit to change * @addr: the address to start counting from * @@ -38,16 +42,18 @@ static inline void __clear_bit(int nr, volatile unsigned long *addr) * If it's called on the same region of memory simultaneously, the effect * may be that only one operation succeeds. */ -static inline void __change_bit(int nr, volatile unsigned long *addr) +static __always_inline +void arch___change_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); *p ^= mask; } +#define __change_bit arch___change_bit /** - * __test_and_set_bit - Set a bit and return its old value + * arch___test_and_set_bit - Set a bit and return its old value * @nr: Bit to set * @addr: Address to count from * @@ -55,7 +61,8 @@ static inline void __change_bit(int nr, volatile unsigned long *addr) * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. */ -static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) +static __always_inline int +arch___test_and_set_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); @@ -64,9 +71,10 @@ static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) *p = old | mask; return (old & mask) != 0; } +#define __test_and_set_bit arch___test_and_set_bit /** - * __test_and_clear_bit - Clear a bit and return its old value + * arch___test_and_clear_bit - Clear a bit and return its old value * @nr: Bit to clear * @addr: Address to count from * @@ -74,7 +82,8 @@ static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) * If two examples of this operation race, one can appear to succeed * but actually fail. You must protect multiple accesses with a lock. */ -static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) +static __always_inline int +arch___test_and_clear_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); @@ -83,10 +92,11 @@ static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) *p = old & ~mask; return (old & mask) != 0; } +#define __test_and_clear_bit arch___test_and_clear_bit /* WARNING: non atomic and it can be reordered! */ -static inline int __test_and_change_bit(int nr, - volatile unsigned long *addr) +static __always_inline int +arch___test_and_change_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); @@ -95,15 +105,18 @@ static inline int __test_and_change_bit(int nr, *p = old ^ mask; return (old & mask) != 0; } +#define __test_and_change_bit arch___test_and_change_bit /** - * test_bit - Determine whether a bit is set + * arch_test_bit - Determine whether a bit is set * @nr: bit number to test * @addr: Address to start counting from */ -static inline int test_bit(int nr, const volatile unsigned long *addr) +static __always_inline int +arch_test_bit(int nr, const volatile unsigned long *addr) { return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); } +#define test_bit arch_test_bit #endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */ diff --git a/include/linux/atomic.h b/include/linux/atomic.h index ed1d3ffd5b9d..8dd57c3a99e9 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -77,9 +77,8 @@ __ret; \ }) -#include <linux/atomic-arch-fallback.h> -#include <asm-generic/atomic-instrumented.h> - -#include <asm-generic/atomic-long.h> +#include <linux/atomic/atomic-arch-fallback.h> +#include <linux/atomic/atomic-long.h> +#include <linux/atomic/atomic-instrumented.h> #endif /* _LINUX_ATOMIC_H */ diff --git a/include/linux/atomic-arch-fallback.h b/include/linux/atomic/atomic-arch-fallback.h index a3dba31df01e..a3dba31df01e 100644 --- a/include/linux/atomic-arch-fallback.h +++ b/include/linux/atomic/atomic-arch-fallback.h diff --git a/include/asm-generic/atomic-instrumented.h b/include/linux/atomic/atomic-instrumented.h index bc45af52c93b..a0f654370da3 100644 --- a/include/asm-generic/atomic-instrumented.h +++ b/include/linux/atomic/atomic-instrumented.h @@ -14,8 +14,8 @@ * arch_ variants (i.e. arch_atomic_read()/arch_atomic_cmpxchg()) to avoid * double instrumentation. */ -#ifndef _ASM_GENERIC_ATOMIC_INSTRUMENTED_H -#define _ASM_GENERIC_ATOMIC_INSTRUMENTED_H +#ifndef _LINUX_ATOMIC_INSTRUMENTED_H +#define _LINUX_ATOMIC_INSTRUMENTED_H #include <linux/build_bug.h> #include <linux/compiler.h> @@ -1177,6 +1177,584 @@ atomic64_dec_if_positive(atomic64_t *v) return arch_atomic64_dec_if_positive(v); } +static __always_inline long +atomic_long_read(const atomic_long_t *v) +{ + instrument_atomic_read(v, sizeof(*v)); + return arch_atomic_long_read(v); +} + +static __always_inline long +atomic_long_read_acquire(const atomic_long_t *v) +{ + instrument_atomic_read(v, sizeof(*v)); + return arch_atomic_long_read_acquire(v); +} + +static __always_inline void +atomic_long_set(atomic_long_t *v, long i) +{ + instrument_atomic_write(v, sizeof(*v)); + arch_atomic_long_set(v, i); +} + +static __always_inline void +atomic_long_set_release(atomic_long_t *v, long i) +{ + instrument_atomic_write(v, sizeof(*v)); + arch_atomic_long_set_release(v, i); +} + +static __always_inline void +atomic_long_add(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_add(i, v); +} + +static __always_inline long +atomic_long_add_return(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_add_return(i, v); +} + +static __always_inline long +atomic_long_add_return_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_add_return_acquire(i, v); +} + +static __always_inline long +atomic_long_add_return_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_add_return_release(i, v); +} + +static __always_inline long +atomic_long_add_return_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_add_return_relaxed(i, v); +} + +static __always_inline long +atomic_long_fetch_add(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_add(i, v); +} + +static __always_inline long +atomic_long_fetch_add_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_add_acquire(i, v); +} + +static __always_inline long +atomic_long_fetch_add_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_add_release(i, v); +} + +static __always_inline long +atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_add_relaxed(i, v); +} + +static __always_inline void +atomic_long_sub(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_sub(i, v); +} + +static __always_inline long +atomic_long_sub_return(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_sub_return(i, v); +} + +static __always_inline long +atomic_long_sub_return_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_sub_return_acquire(i, v); +} + +static __always_inline long +atomic_long_sub_return_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_sub_return_release(i, v); +} + +static __always_inline long +atomic_long_sub_return_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_sub_return_relaxed(i, v); +} + +static __always_inline long +atomic_long_fetch_sub(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_sub(i, v); +} + +static __always_inline long +atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_sub_acquire(i, v); +} + +static __always_inline long +atomic_long_fetch_sub_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_sub_release(i, v); +} + +static __always_inline long +atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_sub_relaxed(i, v); +} + +static __always_inline void +atomic_long_inc(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_inc(v); +} + +static __always_inline long +atomic_long_inc_return(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_return(v); +} + +static __always_inline long +atomic_long_inc_return_acquire(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_return_acquire(v); +} + +static __always_inline long +atomic_long_inc_return_release(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_return_release(v); +} + +static __always_inline long +atomic_long_inc_return_relaxed(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_return_relaxed(v); +} + +static __always_inline long +atomic_long_fetch_inc(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_inc(v); +} + +static __always_inline long +atomic_long_fetch_inc_acquire(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_inc_acquire(v); +} + +static __always_inline long +atomic_long_fetch_inc_release(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_inc_release(v); +} + +static __always_inline long +atomic_long_fetch_inc_relaxed(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_inc_relaxed(v); +} + +static __always_inline void +atomic_long_dec(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_dec(v); +} + +static __always_inline long +atomic_long_dec_return(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_return(v); +} + +static __always_inline long +atomic_long_dec_return_acquire(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_return_acquire(v); +} + +static __always_inline long +atomic_long_dec_return_release(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_return_release(v); +} + +static __always_inline long +atomic_long_dec_return_relaxed(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_return_relaxed(v); +} + +static __always_inline long +atomic_long_fetch_dec(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_dec(v); +} + +static __always_inline long +atomic_long_fetch_dec_acquire(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_dec_acquire(v); +} + +static __always_inline long +atomic_long_fetch_dec_release(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_dec_release(v); +} + +static __always_inline long +atomic_long_fetch_dec_relaxed(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_dec_relaxed(v); +} + +static __always_inline void +atomic_long_and(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_and(i, v); +} + +static __always_inline long +atomic_long_fetch_and(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_and(i, v); +} + +static __always_inline long +atomic_long_fetch_and_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_and_acquire(i, v); +} + +static __always_inline long +atomic_long_fetch_and_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_and_release(i, v); +} + +static __always_inline long +atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_and_relaxed(i, v); +} + +static __always_inline void +atomic_long_andnot(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_andnot(i, v); +} + +static __always_inline long +atomic_long_fetch_andnot(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_andnot(i, v); +} + +static __always_inline long +atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_andnot_acquire(i, v); +} + +static __always_inline long +atomic_long_fetch_andnot_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_andnot_release(i, v); +} + +static __always_inline long +atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_andnot_relaxed(i, v); +} + +static __always_inline void +atomic_long_or(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_or(i, v); +} + +static __always_inline long +atomic_long_fetch_or(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_or(i, v); +} + +static __always_inline long +atomic_long_fetch_or_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_or_acquire(i, v); +} + +static __always_inline long +atomic_long_fetch_or_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_or_release(i, v); +} + +static __always_inline long +atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_or_relaxed(i, v); +} + +static __always_inline void +atomic_long_xor(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + arch_atomic_long_xor(i, v); +} + +static __always_inline long +atomic_long_fetch_xor(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_xor(i, v); +} + +static __always_inline long +atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_xor_acquire(i, v); +} + +static __always_inline long +atomic_long_fetch_xor_release(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_xor_release(i, v); +} + +static __always_inline long +atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_xor_relaxed(i, v); +} + +static __always_inline long +atomic_long_xchg(atomic_long_t *v, long i) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_xchg(v, i); +} + +static __always_inline long +atomic_long_xchg_acquire(atomic_long_t *v, long i) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_xchg_acquire(v, i); +} + +static __always_inline long +atomic_long_xchg_release(atomic_long_t *v, long i) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_xchg_release(v, i); +} + +static __always_inline long +atomic_long_xchg_relaxed(atomic_long_t *v, long i) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_xchg_relaxed(v, i); +} + +static __always_inline long +atomic_long_cmpxchg(atomic_long_t *v, long old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_cmpxchg(v, old, new); +} + +static __always_inline long +atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_cmpxchg_acquire(v, old, new); +} + +static __always_inline long +atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_cmpxchg_release(v, old, new); +} + +static __always_inline long +atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_cmpxchg_relaxed(v, old, new); +} + +static __always_inline bool +atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + instrument_atomic_read_write(old, sizeof(*old)); + return arch_atomic_long_try_cmpxchg(v, old, new); +} + +static __always_inline bool +atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + instrument_atomic_read_write(old, sizeof(*old)); + return arch_atomic_long_try_cmpxchg_acquire(v, old, new); +} + +static __always_inline bool +atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + instrument_atomic_read_write(old, sizeof(*old)); + return arch_atomic_long_try_cmpxchg_release(v, old, new); +} + +static __always_inline bool +atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) +{ + instrument_atomic_read_write(v, sizeof(*v)); + instrument_atomic_read_write(old, sizeof(*old)); + return arch_atomic_long_try_cmpxchg_relaxed(v, old, new); +} + +static __always_inline bool +atomic_long_sub_and_test(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_sub_and_test(i, v); +} + +static __always_inline bool +atomic_long_dec_and_test(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_and_test(v); +} + +static __always_inline bool +atomic_long_inc_and_test(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_and_test(v); +} + +static __always_inline bool +atomic_long_add_negative(long i, atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_add_negative(i, v); +} + +static __always_inline long +atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_fetch_add_unless(v, a, u); +} + +static __always_inline bool +atomic_long_add_unless(atomic_long_t *v, long a, long u) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_add_unless(v, a, u); +} + +static __always_inline bool +atomic_long_inc_not_zero(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_not_zero(v); +} + +static __always_inline bool +atomic_long_inc_unless_negative(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_inc_unless_negative(v); +} + +static __always_inline bool +atomic_long_dec_unless_positive(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_unless_positive(v); +} + +static __always_inline long +atomic_long_dec_if_positive(atomic_long_t *v) +{ + instrument_atomic_read_write(v, sizeof(*v)); + return arch_atomic_long_dec_if_positive(v); +} + #define xchg(ptr, ...) \ ({ \ typeof(ptr) __ai_ptr = (ptr); \ @@ -1333,5 +1911,5 @@ atomic64_dec_if_positive(atomic64_t *v) arch_cmpxchg_double_local(__ai_ptr, __VA_ARGS__); \ }) -#endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */ -// 1d7c3a25aca5c7fb031c307be4c3d24c7b48fcd5 +#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */ +// 2a9553f0a9d5619f19151092df5cabbbf16ce835 diff --git a/include/linux/atomic/atomic-long.h b/include/linux/atomic/atomic-long.h new file mode 100644 index 000000000000..800b8c35992d --- /dev/null +++ b/include/linux/atomic/atomic-long.h @@ -0,0 +1,1014 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Generated by scripts/atomic/gen-atomic-long.sh +// DO NOT MODIFY THIS FILE DIRECTLY + +#ifndef _LINUX_ATOMIC_LONG_H +#define _LINUX_ATOMIC_LONG_H + +#include <linux/compiler.h> +#include <asm/types.h> + +#ifdef CONFIG_64BIT +typedef atomic64_t atomic_long_t; +#define ATOMIC_LONG_INIT(i) ATOMIC64_INIT(i) +#define atomic_long_cond_read_acquire atomic64_cond_read_acquire +#define atomic_long_cond_read_relaxed atomic64_cond_read_relaxed +#else +typedef atomic_t atomic_long_t; +#define ATOMIC_LONG_INIT(i) ATOMIC_INIT(i) +#define atomic_long_cond_read_acquire atomic_cond_read_acquire +#define atomic_long_cond_read_relaxed atomic_cond_read_relaxed +#endif + +#ifdef CONFIG_64BIT + +static __always_inline long +arch_atomic_long_read(const atomic_long_t *v) +{ + return arch_atomic64_read(v); +} + +static __always_inline long +arch_atomic_long_read_acquire(const atomic_long_t *v) +{ + return arch_atomic64_read_acquire(v); +} + +static __always_inline void +arch_atomic_long_set(atomic_long_t *v, long i) +{ + arch_atomic64_set(v, i); +} + +static __always_inline void +arch_atomic_long_set_release(atomic_long_t *v, long i) +{ + arch_atomic64_set_release(v, i); +} + +static __always_inline void +arch_atomic_long_add(long i, atomic_long_t *v) +{ + arch_atomic64_add(i, v); +} + +static __always_inline long +arch_atomic_long_add_return(long i, atomic_long_t *v) +{ + return arch_atomic64_add_return(i, v); +} + +static __always_inline long +arch_atomic_long_add_return_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_add_return_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_add_return_release(long i, atomic_long_t *v) +{ + return arch_atomic64_add_return_release(i, v); +} + +static __always_inline long +arch_atomic_long_add_return_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_add_return_relaxed(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_add(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_add_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_release(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_add_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_add_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_sub(long i, atomic_long_t *v) +{ + arch_atomic64_sub(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return(long i, atomic_long_t *v) +{ + return arch_atomic64_sub_return(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_sub_return_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return_release(long i, atomic_long_t *v) +{ + return arch_atomic64_sub_return_release(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_sub_return_relaxed(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_sub(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_sub_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub_release(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_sub_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_sub_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_inc(atomic_long_t *v) +{ + arch_atomic64_inc(v); +} + +static __always_inline long +arch_atomic_long_inc_return(atomic_long_t *v) +{ + return arch_atomic64_inc_return(v); +} + +static __always_inline long +arch_atomic_long_inc_return_acquire(atomic_long_t *v) +{ + return arch_atomic64_inc_return_acquire(v); +} + +static __always_inline long +arch_atomic_long_inc_return_release(atomic_long_t *v) +{ + return arch_atomic64_inc_return_release(v); +} + +static __always_inline long +arch_atomic_long_inc_return_relaxed(atomic_long_t *v) +{ + return arch_atomic64_inc_return_relaxed(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc(atomic_long_t *v) +{ + return arch_atomic64_fetch_inc(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc_acquire(atomic_long_t *v) +{ + return arch_atomic64_fetch_inc_acquire(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc_release(atomic_long_t *v) +{ + return arch_atomic64_fetch_inc_release(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc_relaxed(atomic_long_t *v) +{ + return arch_atomic64_fetch_inc_relaxed(v); +} + +static __always_inline void +arch_atomic_long_dec(atomic_long_t *v) +{ + arch_atomic64_dec(v); +} + +static __always_inline long +arch_atomic_long_dec_return(atomic_long_t *v) +{ + return arch_atomic64_dec_return(v); +} + +static __always_inline long +arch_atomic_long_dec_return_acquire(atomic_long_t *v) +{ + return arch_atomic64_dec_return_acquire(v); +} + +static __always_inline long +arch_atomic_long_dec_return_release(atomic_long_t *v) +{ + return arch_atomic64_dec_return_release(v); +} + +static __always_inline long +arch_atomic_long_dec_return_relaxed(atomic_long_t *v) +{ + return arch_atomic64_dec_return_relaxed(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec(atomic_long_t *v) +{ + return arch_atomic64_fetch_dec(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec_acquire(atomic_long_t *v) +{ + return arch_atomic64_fetch_dec_acquire(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec_release(atomic_long_t *v) +{ + return arch_atomic64_fetch_dec_release(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec_relaxed(atomic_long_t *v) +{ + return arch_atomic64_fetch_dec_relaxed(v); +} + +static __always_inline void +arch_atomic_long_and(long i, atomic_long_t *v) +{ + arch_atomic64_and(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_and(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_and_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and_release(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_and_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_and_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_andnot(long i, atomic_long_t *v) +{ + arch_atomic64_andnot(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_andnot(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_andnot_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot_release(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_andnot_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_andnot_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_or(long i, atomic_long_t *v) +{ + arch_atomic64_or(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_or(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_or_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or_release(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_or_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_or_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_xor(long i, atomic_long_t *v) +{ + arch_atomic64_xor(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_xor(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_xor_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor_release(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_xor_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic64_fetch_xor_relaxed(i, v); +} + +static __always_inline long +arch_atomic_long_xchg(atomic_long_t *v, long i) +{ + return arch_atomic64_xchg(v, i); +} + +static __always_inline long +arch_atomic_long_xchg_acquire(atomic_long_t *v, long i) +{ + return arch_atomic64_xchg_acquire(v, i); +} + +static __always_inline long +arch_atomic_long_xchg_release(atomic_long_t *v, long i) +{ + return arch_atomic64_xchg_release(v, i); +} + +static __always_inline long +arch_atomic_long_xchg_relaxed(atomic_long_t *v, long i) +{ + return arch_atomic64_xchg_relaxed(v, i); +} + +static __always_inline long +arch_atomic_long_cmpxchg(atomic_long_t *v, long old, long new) +{ + return arch_atomic64_cmpxchg(v, old, new); +} + +static __always_inline long +arch_atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) +{ + return arch_atomic64_cmpxchg_acquire(v, old, new); +} + +static __always_inline long +arch_atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) +{ + return arch_atomic64_cmpxchg_release(v, old, new); +} + +static __always_inline long +arch_atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) +{ + return arch_atomic64_cmpxchg_relaxed(v, old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) +{ + return arch_atomic64_try_cmpxchg(v, (s64 *)old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) +{ + return arch_atomic64_try_cmpxchg_acquire(v, (s64 *)old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) +{ + return arch_atomic64_try_cmpxchg_release(v, (s64 *)old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) +{ + return arch_atomic64_try_cmpxchg_relaxed(v, (s64 *)old, new); +} + +static __always_inline bool +arch_atomic_long_sub_and_test(long i, atomic_long_t *v) +{ + return arch_atomic64_sub_and_test(i, v); +} + +static __always_inline bool +arch_atomic_long_dec_and_test(atomic_long_t *v) +{ + return arch_atomic64_dec_and_test(v); +} + +static __always_inline bool +arch_atomic_long_inc_and_test(atomic_long_t *v) +{ + return arch_atomic64_inc_and_test(v); +} + +static __always_inline bool +arch_atomic_long_add_negative(long i, atomic_long_t *v) +{ + return arch_atomic64_add_negative(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) +{ + return arch_atomic64_fetch_add_unless(v, a, u); +} + +static __always_inline bool +arch_atomic_long_add_unless(atomic_long_t *v, long a, long u) +{ + return arch_atomic64_add_unless(v, a, u); +} + +static __always_inline bool +arch_atomic_long_inc_not_zero(atomic_long_t *v) +{ + return arch_atomic64_inc_not_zero(v); +} + +static __always_inline bool +arch_atomic_long_inc_unless_negative(atomic_long_t *v) +{ + return arch_atomic64_inc_unless_negative(v); +} + +static __always_inline bool +arch_atomic_long_dec_unless_positive(atomic_long_t *v) +{ + return arch_atomic64_dec_unless_positive(v); +} + +static __always_inline long +arch_atomic_long_dec_if_positive(atomic_long_t *v) +{ + return arch_atomic64_dec_if_positive(v); +} + +#else /* CONFIG_64BIT */ + +static __always_inline long +arch_atomic_long_read(const atomic_long_t *v) +{ + return arch_atomic_read(v); +} + +static __always_inline long +arch_atomic_long_read_acquire(const atomic_long_t *v) +{ + return arch_atomic_read_acquire(v); +} + +static __always_inline void +arch_atomic_long_set(atomic_long_t *v, long i) +{ + arch_atomic_set(v, i); +} + +static __always_inline void +arch_atomic_long_set_release(atomic_long_t *v, long i) +{ + arch_atomic_set_release(v, i); +} + +static __always_inline void +arch_atomic_long_add(long i, atomic_long_t *v) +{ + arch_atomic_add(i, v); +} + +static __always_inline long +arch_atomic_long_add_return(long i, atomic_long_t *v) +{ + return arch_atomic_add_return(i, v); +} + +static __always_inline long +arch_atomic_long_add_return_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_add_return_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_add_return_release(long i, atomic_long_t *v) +{ + return arch_atomic_add_return_release(i, v); +} + +static __always_inline long +arch_atomic_long_add_return_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_add_return_relaxed(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_add(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_add_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_release(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_add_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_add_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_sub(long i, atomic_long_t *v) +{ + arch_atomic_sub(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return(long i, atomic_long_t *v) +{ + return arch_atomic_sub_return(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_sub_return_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return_release(long i, atomic_long_t *v) +{ + return arch_atomic_sub_return_release(i, v); +} + +static __always_inline long +arch_atomic_long_sub_return_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_sub_return_relaxed(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_sub(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_sub_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub_release(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_sub_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_sub_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_sub_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_inc(atomic_long_t *v) +{ + arch_atomic_inc(v); +} + +static __always_inline long +arch_atomic_long_inc_return(atomic_long_t *v) +{ + return arch_atomic_inc_return(v); +} + +static __always_inline long +arch_atomic_long_inc_return_acquire(atomic_long_t *v) +{ + return arch_atomic_inc_return_acquire(v); +} + +static __always_inline long +arch_atomic_long_inc_return_release(atomic_long_t *v) +{ + return arch_atomic_inc_return_release(v); +} + +static __always_inline long +arch_atomic_long_inc_return_relaxed(atomic_long_t *v) +{ + return arch_atomic_inc_return_relaxed(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc(atomic_long_t *v) +{ + return arch_atomic_fetch_inc(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc_acquire(atomic_long_t *v) +{ + return arch_atomic_fetch_inc_acquire(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc_release(atomic_long_t *v) +{ + return arch_atomic_fetch_inc_release(v); +} + +static __always_inline long +arch_atomic_long_fetch_inc_relaxed(atomic_long_t *v) +{ + return arch_atomic_fetch_inc_relaxed(v); +} + +static __always_inline void +arch_atomic_long_dec(atomic_long_t *v) +{ + arch_atomic_dec(v); +} + +static __always_inline long +arch_atomic_long_dec_return(atomic_long_t *v) +{ + return arch_atomic_dec_return(v); +} + +static __always_inline long +arch_atomic_long_dec_return_acquire(atomic_long_t *v) +{ + return arch_atomic_dec_return_acquire(v); +} + +static __always_inline long +arch_atomic_long_dec_return_release(atomic_long_t *v) +{ + return arch_atomic_dec_return_release(v); +} + +static __always_inline long +arch_atomic_long_dec_return_relaxed(atomic_long_t *v) +{ + return arch_atomic_dec_return_relaxed(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec(atomic_long_t *v) +{ + return arch_atomic_fetch_dec(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec_acquire(atomic_long_t *v) +{ + return arch_atomic_fetch_dec_acquire(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec_release(atomic_long_t *v) +{ + return arch_atomic_fetch_dec_release(v); +} + +static __always_inline long +arch_atomic_long_fetch_dec_relaxed(atomic_long_t *v) +{ + return arch_atomic_fetch_dec_relaxed(v); +} + +static __always_inline void +arch_atomic_long_and(long i, atomic_long_t *v) +{ + arch_atomic_and(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_and(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_and_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and_release(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_and_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_and_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_and_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_andnot(long i, atomic_long_t *v) +{ + arch_atomic_andnot(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_andnot(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_andnot_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot_release(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_andnot_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_andnot_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_andnot_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_or(long i, atomic_long_t *v) +{ + arch_atomic_or(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_or(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_or_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or_release(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_or_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_or_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_or_relaxed(i, v); +} + +static __always_inline void +arch_atomic_long_xor(long i, atomic_long_t *v) +{ + arch_atomic_xor(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_xor(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor_acquire(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_xor_acquire(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor_release(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_xor_release(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_xor_relaxed(long i, atomic_long_t *v) +{ + return arch_atomic_fetch_xor_relaxed(i, v); +} + +static __always_inline long +arch_atomic_long_xchg(atomic_long_t *v, long i) +{ + return arch_atomic_xchg(v, i); +} + +static __always_inline long +arch_atomic_long_xchg_acquire(atomic_long_t *v, long i) +{ + return arch_atomic_xchg_acquire(v, i); +} + +static __always_inline long +arch_atomic_long_xchg_release(atomic_long_t *v, long i) +{ + return arch_atomic_xchg_release(v, i); +} + +static __always_inline long +arch_atomic_long_xchg_relaxed(atomic_long_t *v, long i) +{ + return arch_atomic_xchg_relaxed(v, i); +} + +static __always_inline long +arch_atomic_long_cmpxchg(atomic_long_t *v, long old, long new) +{ + return arch_atomic_cmpxchg(v, old, new); +} + +static __always_inline long +arch_atomic_long_cmpxchg_acquire(atomic_long_t *v, long old, long new) +{ + return arch_atomic_cmpxchg_acquire(v, old, new); +} + +static __always_inline long +arch_atomic_long_cmpxchg_release(atomic_long_t *v, long old, long new) +{ + return arch_atomic_cmpxchg_release(v, old, new); +} + +static __always_inline long +arch_atomic_long_cmpxchg_relaxed(atomic_long_t *v, long old, long new) +{ + return arch_atomic_cmpxchg_relaxed(v, old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new) +{ + return arch_atomic_try_cmpxchg(v, (int *)old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg_acquire(atomic_long_t *v, long *old, long new) +{ + return arch_atomic_try_cmpxchg_acquire(v, (int *)old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg_release(atomic_long_t *v, long *old, long new) +{ + return arch_atomic_try_cmpxchg_release(v, (int *)old, new); +} + +static __always_inline bool +arch_atomic_long_try_cmpxchg_relaxed(atomic_long_t *v, long *old, long new) +{ + return arch_atomic_try_cmpxchg_relaxed(v, (int *)old, new); +} + +static __always_inline bool +arch_atomic_long_sub_and_test(long i, atomic_long_t *v) +{ + return arch_atomic_sub_and_test(i, v); +} + +static __always_inline bool +arch_atomic_long_dec_and_test(atomic_long_t *v) +{ + return arch_atomic_dec_and_test(v); +} + +static __always_inline bool +arch_atomic_long_inc_and_test(atomic_long_t *v) +{ + return arch_atomic_inc_and_test(v); +} + +static __always_inline bool +arch_atomic_long_add_negative(long i, atomic_long_t *v) +{ + return arch_atomic_add_negative(i, v); +} + +static __always_inline long +arch_atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u) +{ + return arch_atomic_fetch_add_unless(v, a, u); +} + +static __always_inline bool +arch_atomic_long_add_unless(atomic_long_t *v, long a, long u) +{ + return arch_atomic_add_unless(v, a, u); +} + +static __always_inline bool +arch_atomic_long_inc_not_zero(atomic_long_t *v) +{ + return arch_atomic_inc_not_zero(v); +} + +static __always_inline bool +arch_atomic_long_inc_unless_negative(atomic_long_t *v) +{ + return arch_atomic_inc_unless_negative(v); +} + +static __always_inline bool +arch_atomic_long_dec_unless_positive(atomic_long_t *v) +{ + return arch_atomic_dec_unless_positive(v); +} + +static __always_inline long +arch_atomic_long_dec_if_positive(atomic_long_t *v) +{ + return arch_atomic_dec_if_positive(v); +} + +#endif /* CONFIG_64BIT */ +#endif /* _LINUX_ATOMIC_LONG_H */ +// e8f0e08ff072b74d180eabe2ad001282b38c2c88 diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h index edb5c186b0b7..3f49e65169c6 100644 --- a/include/linux/debug_locks.h +++ b/include/linux/debug_locks.h @@ -3,8 +3,7 @@ #define __LINUX_DEBUG_LOCKING_H #include <linux/atomic.h> -#include <linux/bug.h> -#include <linux/printk.h> +#include <linux/cache.h> struct task_struct; diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h index ded90b097e6e..975e33b793a7 100644 --- a/include/linux/local_lock_internal.h +++ b/include/linux/local_lock_internal.h @@ -6,6 +6,8 @@ #include <linux/percpu-defs.h> #include <linux/lockdep.h> +#ifndef CONFIG_PREEMPT_RT + typedef struct { #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; @@ -14,29 +16,14 @@ typedef struct { } local_lock_t; #ifdef CONFIG_DEBUG_LOCK_ALLOC -# define LL_DEP_MAP_INIT(lockname) \ +# define LOCAL_LOCK_DEBUG_INIT(lockname) \ .dep_map = { \ .name = #lockname, \ .wait_type_inner = LD_WAIT_CONFIG, \ - .lock_type = LD_LOCK_PERCPU, \ - } -#else -# define LL_DEP_MAP_INIT(lockname) -#endif - -#define INIT_LOCAL_LOCK(lockname) { LL_DEP_MAP_INIT(lockname) } - -#define __local_lock_init(lock) \ -do { \ - static struct lock_class_key __key; \ - \ - debug_check_no_locks_freed((void *)lock, sizeof(*lock));\ - lockdep_init_map_type(&(lock)->dep_map, #lock, &__key, 0, \ - LD_WAIT_CONFIG, LD_WAIT_INV, \ - LD_LOCK_PERCPU); \ -} while (0) + .lock_type = LD_LOCK_PERCPU, \ + }, \ + .owner = NULL, -#ifdef CONFIG_DEBUG_LOCK_ALLOC static inline void local_lock_acquire(local_lock_t *l) { lock_map_acquire(&l->dep_map); @@ -51,11 +38,30 @@ static inline void local_lock_release(local_lock_t *l) lock_map_release(&l->dep_map); } +static inline void local_lock_debug_init(local_lock_t *l) +{ + l->owner = NULL; +} #else /* CONFIG_DEBUG_LOCK_ALLOC */ +# define LOCAL_LOCK_DEBUG_INIT(lockname) static inline void local_lock_acquire(local_lock_t *l) { } static inline void local_lock_release(local_lock_t *l) { } +static inline void local_lock_debug_init(local_lock_t *l) { } #endif /* !CONFIG_DEBUG_LOCK_ALLOC */ +#define INIT_LOCAL_LOCK(lockname) { LOCAL_LOCK_DEBUG_INIT(lockname) } + +#define __local_lock_init(lock) \ +do { \ + static struct lock_class_key __key; \ + \ + debug_check_no_locks_freed((void *)lock, sizeof(*lock));\ + lockdep_init_map_type(&(lock)->dep_map, #lock, &__key, \ + 0, LD_WAIT_CONFIG, LD_WAIT_INV, \ + LD_LOCK_PERCPU); \ + local_lock_debug_init(lock); \ +} while (0) + #define __local_lock(lock) \ do { \ preempt_disable(); \ @@ -91,3 +97,45 @@ static inline void local_lock_release(local_lock_t *l) { } local_lock_release(this_cpu_ptr(lock)); \ local_irq_restore(flags); \ } while (0) + +#else /* !CONFIG_PREEMPT_RT */ + +/* + * On PREEMPT_RT local_lock maps to a per CPU spinlock, which protects the + * critical section while staying preemptible. + */ +typedef spinlock_t local_lock_t; + +#define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname)) + +#define __local_lock_init(l) \ + do { \ + local_spin_lock_init((l)); \ + } while (0) + +#define __local_lock(__lock) \ + do { \ + migrate_disable(); \ + spin_lock(this_cpu_ptr((__lock))); \ + } while (0) + +#define __local_lock_irq(lock) __local_lock(lock) + +#define __local_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + flags = 0; \ + __local_lock(lock); \ + } while (0) + +#define __local_unlock(__lock) \ + do { \ + spin_unlock(this_cpu_ptr((__lock))); \ + migrate_enable(); \ + } while (0) + +#define __local_unlock_irq(lock) __local_unlock(lock) + +#define __local_unlock_irqrestore(lock, flags) __local_unlock(lock) + +#endif /* CONFIG_PREEMPT_RT */ diff --git a/include/linux/mutex.h b/include/linux/mutex.h index e19323521f9c..8f226d460f51 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -20,8 +20,17 @@ #include <linux/osq_lock.h> #include <linux/debug_locks.h> -struct ww_class; -struct ww_acquire_ctx; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ + , .dep_map = { \ + .name = #lockname, \ + .wait_type_inner = LD_WAIT_SLEEP, \ + } +#else +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) +#endif + +#ifndef CONFIG_PREEMPT_RT /* * Simple, straightforward mutexes with strict semantics: @@ -53,7 +62,7 @@ struct ww_acquire_ctx; */ struct mutex { atomic_long_t owner; - spinlock_t wait_lock; + raw_spinlock_t wait_lock; #ifdef CONFIG_MUTEX_SPIN_ON_OWNER struct optimistic_spin_queue osq; /* Spinner MCS lock */ #endif @@ -66,27 +75,6 @@ struct mutex { #endif }; -struct ww_mutex { - struct mutex base; - struct ww_acquire_ctx *ctx; -#ifdef CONFIG_DEBUG_MUTEXES - struct ww_class *ww_class; -#endif -}; - -/* - * This is the control structure for tasks blocked on mutex, - * which resides on the blocked task's kernel stack: - */ -struct mutex_waiter { - struct list_head list; - struct task_struct *task; - struct ww_acquire_ctx *ww_ctx; -#ifdef CONFIG_DEBUG_MUTEXES - void *magic; -#endif -}; - #ifdef CONFIG_DEBUG_MUTEXES #define __DEBUG_MUTEX_INITIALIZER(lockname) \ @@ -117,19 +105,9 @@ do { \ __mutex_init((mutex), #mutex, &__key); \ } while (0) -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ - , .dep_map = { \ - .name = #lockname, \ - .wait_type_inner = LD_WAIT_SLEEP, \ - } -#else -# define __DEP_MAP_MUTEX_INITIALIZER(lockname) -#endif - #define __MUTEX_INITIALIZER(lockname) \ { .owner = ATOMIC_LONG_INIT(0) \ - , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ + , .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ __DEBUG_MUTEX_INITIALIZER(lockname) \ __DEP_MAP_MUTEX_INITIALIZER(lockname) } @@ -148,6 +126,50 @@ extern void __mutex_init(struct mutex *lock, const char *name, */ extern bool mutex_is_locked(struct mutex *lock); +#else /* !CONFIG_PREEMPT_RT */ +/* + * Preempt-RT variant based on rtmutexes. + */ +#include <linux/rtmutex.h> + +struct mutex { + struct rt_mutex_base rtmutex; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#define __MUTEX_INITIALIZER(mutexname) \ +{ \ + .rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex) \ + __DEP_MAP_MUTEX_INITIALIZER(mutexname) \ +} + +#define DEFINE_MUTEX(mutexname) \ + struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) + +extern void __mutex_rt_init(struct mutex *lock, const char *name, + struct lock_class_key *key); +extern int mutex_trylock(struct mutex *lock); + +static inline void mutex_destroy(struct mutex *lock) { } + +#define mutex_is_locked(l) rt_mutex_base_is_locked(&(l)->rtmutex) + +#define __mutex_init(mutex, name, key) \ +do { \ + rt_mutex_base_init(&(mutex)->rtmutex); \ + __mutex_rt_init((mutex), name, key); \ +} while (0) + +#define mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + \ + __mutex_init((mutex), #mutex, &__key); \ +} while (0) +#endif /* CONFIG_PREEMPT_RT */ + /* * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/locking/mutex-design.rst. diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 9881eac0698f..4d244e295e85 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -121,7 +121,11 @@ /* * The preempt_count offset after spin_lock() */ +#if !defined(CONFIG_PREEMPT_RT) #define PREEMPT_LOCK_OFFSET PREEMPT_DISABLE_OFFSET +#else +#define PREEMPT_LOCK_OFFSET 0 +#endif /* * The preempt_count offset needed for things like: diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h index d31ecaf4fdd3..235047d7a1b5 100644 --- a/include/linux/rbtree.h +++ b/include/linux/rbtree.h @@ -17,24 +17,14 @@ #ifndef _LINUX_RBTREE_H #define _LINUX_RBTREE_H +#include <linux/rbtree_types.h> + #include <linux/kernel.h> #include <linux/stddef.h> #include <linux/rcupdate.h> -struct rb_node { - unsigned long __rb_parent_color; - struct rb_node *rb_right; - struct rb_node *rb_left; -} __attribute__((aligned(sizeof(long)))); - /* The alignment might seem pointless, but allegedly CRIS needs it */ - -struct rb_root { - struct rb_node *rb_node; -}; - #define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3)) -#define RB_ROOT (struct rb_root) { NULL, } #define rb_entry(ptr, type, member) container_of(ptr, type, member) #define RB_EMPTY_ROOT(root) (READ_ONCE((root)->rb_node) == NULL) @@ -112,23 +102,6 @@ static inline void rb_link_node_rcu(struct rb_node *node, struct rb_node *parent typeof(*pos), field); 1; }); \ pos = n) -/* - * Leftmost-cached rbtrees. - * - * We do not cache the rightmost node based on footprint - * size vs number of potential users that could benefit - * from O(1) rb_last(). Just not worth it, users that want - * this feature can always implement the logic explicitly. - * Furthermore, users that want to cache both pointers may - * find it a bit asymmetric, but that's ok. - */ -struct rb_root_cached { - struct rb_root rb_root; - struct rb_node *rb_leftmost; -}; - -#define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL } - /* Same as rb_first(), but O(1) */ #define rb_first_cached(root) (root)->rb_leftmost diff --git a/include/linux/rbtree_types.h b/include/linux/rbtree_types.h new file mode 100644 index 000000000000..45b6ecde3665 --- /dev/null +++ b/include/linux/rbtree_types.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _LINUX_RBTREE_TYPES_H +#define _LINUX_RBTREE_TYPES_H + +struct rb_node { + unsigned long __rb_parent_color; + struct rb_node *rb_right; + struct rb_node *rb_left; +} __attribute__((aligned(sizeof(long)))); +/* The alignment might seem pointless, but allegedly CRIS needs it */ + +struct rb_root { + struct rb_node *rb_node; +}; + +/* + * Leftmost-cached rbtrees. + * + * We do not cache the rightmost node based on footprint + * size vs number of potential users that could benefit + * from O(1) rb_last(). Just not worth it, users that want + * this feature can always implement the logic explicitly. + * Furthermore, users that want to cache both pointers may + * find it a bit asymmetric, but that's ok. + */ +struct rb_root_cached { + struct rb_root rb_root; + struct rb_node *rb_leftmost; +}; + +#define RB_ROOT (struct rb_root) { NULL, } +#define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL } + +#endif diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h index d1672de9ca89..9deedfeec2b1 100644 --- a/include/linux/rtmutex.h +++ b/include/linux/rtmutex.h @@ -13,12 +13,39 @@ #ifndef __LINUX_RT_MUTEX_H #define __LINUX_RT_MUTEX_H +#include <linux/compiler.h> #include <linux/linkage.h> -#include <linux/rbtree.h> -#include <linux/spinlock_types.h> +#include <linux/rbtree_types.h> +#include <linux/spinlock_types_raw.h> extern int max_lock_depth; /* for sysctl */ +struct rt_mutex_base { + raw_spinlock_t wait_lock; + struct rb_root_cached waiters; + struct task_struct *owner; +}; + +#define __RT_MUTEX_BASE_INITIALIZER(rtbasename) \ +{ \ + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(rtbasename.wait_lock), \ + .waiters = RB_ROOT_CACHED, \ + .owner = NULL \ +} + +/** + * rt_mutex_base_is_locked - is the rtmutex locked + * @lock: the mutex to be queried + * + * Returns true if the mutex is locked, false if unlocked. + */ +static inline bool rt_mutex_base_is_locked(struct rt_mutex_base *lock) +{ + return READ_ONCE(lock->owner) != NULL; +} + +extern void rt_mutex_base_init(struct rt_mutex_base *rtb); + /** * The rt_mutex structure * @@ -28,9 +55,7 @@ extern int max_lock_depth; /* for sysctl */ * @owner: the mutex owner */ struct rt_mutex { - raw_spinlock_t wait_lock; - struct rb_root_cached waiters; - struct task_struct *owner; + struct rt_mutex_base rtmutex; #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif @@ -52,32 +77,24 @@ do { \ } while (0) #ifdef CONFIG_DEBUG_LOCK_ALLOC -#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ - , .dep_map = { .name = #mutexname } +#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ + .dep_map = { \ + .name = #mutexname, \ + .wait_type_inner = LD_WAIT_SLEEP, \ + } #else #define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) #endif -#define __RT_MUTEX_INITIALIZER(mutexname) \ - { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ - , .waiters = RB_ROOT_CACHED \ - , .owner = NULL \ - __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)} +#define __RT_MUTEX_INITIALIZER(mutexname) \ +{ \ + .rtmutex = __RT_MUTEX_BASE_INITIALIZER(mutexname.rtmutex), \ + __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ +} #define DEFINE_RT_MUTEX(mutexname) \ struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) -/** - * rt_mutex_is_locked - is the mutex locked - * @lock: the mutex to be queried - * - * Returns 1 if the mutex is locked, 0 if unlocked. - */ -static inline int rt_mutex_is_locked(struct rt_mutex *lock) -{ - return lock->owner != NULL; -} - extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key); #ifdef CONFIG_DEBUG_LOCK_ALLOC diff --git a/include/linux/rwbase_rt.h b/include/linux/rwbase_rt.h new file mode 100644 index 000000000000..1d264dd08625 --- /dev/null +++ b/include/linux/rwbase_rt.h @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0-only +#ifndef _LINUX_RWBASE_RT_H +#define _LINUX_RWBASE_RT_H + +#include <linux/rtmutex.h> +#include <linux/atomic.h> + +#define READER_BIAS (1U << 31) +#define WRITER_BIAS (1U << 30) + +struct rwbase_rt { + atomic_t readers; + struct rt_mutex_base rtmutex; +}; + +#define __RWBASE_INITIALIZER(name) \ +{ \ + .readers = ATOMIC_INIT(READER_BIAS), \ + .rtmutex = __RT_MUTEX_BASE_INITIALIZER(name.rtmutex), \ +} + +#define init_rwbase_rt(rwbase) \ + do { \ + rt_mutex_base_init(&(rwbase)->rtmutex); \ + atomic_set(&(rwbase)->readers, READER_BIAS); \ + } while (0) + + +static __always_inline bool rw_base_is_locked(struct rwbase_rt *rwb) +{ + return atomic_read(&rwb->readers) != READER_BIAS; +} + +static __always_inline bool rw_base_is_contended(struct rwbase_rt *rwb) +{ + return atomic_read(&rwb->readers) > 0; +} + +#endif /* _LINUX_RWBASE_RT_H */ diff --git a/include/linux/rwlock_rt.h b/include/linux/rwlock_rt.h new file mode 100644 index 000000000000..49c1f3842ed5 --- /dev/null +++ b/include/linux/rwlock_rt.h @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-only +#ifndef __LINUX_RWLOCK_RT_H +#define __LINUX_RWLOCK_RT_H + +#ifndef __LINUX_SPINLOCK_RT_H +#error Do not #include directly. Use <linux/spinlock.h>. +#endif + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern void __rt_rwlock_init(rwlock_t *rwlock, const char *name, + struct lock_class_key *key); +#else +static inline void __rt_rwlock_init(rwlock_t *rwlock, char *name, + struct lock_class_key *key) +{ +} +#endif + +#define rwlock_init(rwl) \ +do { \ + static struct lock_class_key __key; \ + \ + init_rwbase_rt(&(rwl)->rwbase); \ + __rt_rwlock_init(rwl, #rwl, &__key); \ +} while (0) + +extern void rt_read_lock(rwlock_t *rwlock); +extern int rt_read_trylock(rwlock_t *rwlock); +extern void rt_read_unlock(rwlock_t *rwlock); +extern void rt_write_lock(rwlock_t *rwlock); +extern int rt_write_trylock(rwlock_t *rwlock); +extern void rt_write_unlock(rwlock_t *rwlock); + +static __always_inline void read_lock(rwlock_t *rwlock) +{ + rt_read_lock(rwlock); +} + +static __always_inline void read_lock_bh(rwlock_t *rwlock) +{ + local_bh_disable(); + rt_read_lock(rwlock); +} + +static __always_inline void read_lock_irq(rwlock_t *rwlock) +{ + rt_read_lock(rwlock); +} + +#define read_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + rt_read_lock(lock); \ + flags = 0; \ + } while (0) + +#define read_trylock(lock) __cond_lock(lock, rt_read_trylock(lock)) + +static __always_inline void read_unlock(rwlock_t *rwlock) +{ + rt_read_unlock(rwlock); +} + +static __always_inline void read_unlock_bh(rwlock_t *rwlock) +{ + rt_read_unlock(rwlock); + local_bh_enable(); +} + +static __always_inline void read_unlock_irq(rwlock_t *rwlock) +{ + rt_read_unlock(rwlock); +} + +static __always_inline void read_unlock_irqrestore(rwlock_t *rwlock, + unsigned long flags) +{ + rt_read_unlock(rwlock); +} + +static __always_inline void write_lock(rwlock_t *rwlock) +{ + rt_write_lock(rwlock); +} + +static __always_inline void write_lock_bh(rwlock_t *rwlock) +{ + local_bh_disable(); + rt_write_lock(rwlock); +} + +static __always_inline void write_lock_irq(rwlock_t *rwlock) +{ + rt_write_lock(rwlock); +} + +#define write_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + rt_write_lock(lock); \ + flags = 0; \ + } while (0) + +#define write_trylock(lock) __cond_lock(lock, rt_write_trylock(lock)) + +#define write_trylock_irqsave(lock, flags) \ +({ \ + int __locked; \ + \ + typecheck(unsigned long, flags); \ + flags = 0; \ + __locked = write_trylock(lock); \ + __locked; \ +}) + +static __always_inline void write_unlock(rwlock_t *rwlock) +{ + rt_write_unlock(rwlock); +} + +static __always_inline void write_unlock_bh(rwlock_t *rwlock) +{ + rt_write_unlock(rwlock); + local_bh_enable(); +} + +static __always_inline void write_unlock_irq(rwlock_t *rwlock) +{ + rt_write_unlock(rwlock); +} + +static __always_inline void write_unlock_irqrestore(rwlock_t *rwlock, + unsigned long flags) +{ + rt_write_unlock(rwlock); +} + +#define rwlock_is_contended(lock) (((void)(lock), 0)) + +#endif /* __LINUX_RWLOCK_RT_H */ diff --git a/include/linux/rwlock_types.h b/include/linux/rwlock_types.h index 3bd03e18061c..1948442e7750 100644 --- a/include/linux/rwlock_types.h +++ b/include/linux/rwlock_types.h @@ -1,9 +1,23 @@ #ifndef __LINUX_RWLOCK_TYPES_H #define __LINUX_RWLOCK_TYPES_H +#if !defined(__LINUX_SPINLOCK_TYPES_H) +# error "Do not include directly, include spinlock_types.h" +#endif + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define RW_DEP_MAP_INIT(lockname) \ + .dep_map = { \ + .name = #lockname, \ + .wait_type_inner = LD_WAIT_CONFIG, \ + } +#else +# define RW_DEP_MAP_INIT(lockname) +#endif + +#ifndef CONFIG_PREEMPT_RT /* - * include/linux/rwlock_types.h - generic rwlock type definitions - * and initializers + * generic rwlock type definitions and initializers * * portions Copyright 2005, Red Hat, Inc., Ingo Molnar * Released under the General Public License (GPL). @@ -21,16 +35,6 @@ typedef struct { #define RWLOCK_MAGIC 0xdeaf1eed -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define RW_DEP_MAP_INIT(lockname) \ - .dep_map = { \ - .name = #lockname, \ - .wait_type_inner = LD_WAIT_CONFIG, \ - } -#else -# define RW_DEP_MAP_INIT(lockname) -#endif - #ifdef CONFIG_DEBUG_SPINLOCK #define __RW_LOCK_UNLOCKED(lockname) \ (rwlock_t) { .raw_lock = __ARCH_RW_LOCK_UNLOCKED, \ @@ -46,4 +50,29 @@ typedef struct { #define DEFINE_RWLOCK(x) rwlock_t x = __RW_LOCK_UNLOCKED(x) +#else /* !CONFIG_PREEMPT_RT */ + +#include <linux/rwbase_rt.h> + +typedef struct { + struct rwbase_rt rwbase; + atomic_t readers; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} rwlock_t; + +#define __RWLOCK_RT_INITIALIZER(name) \ +{ \ + .rwbase = __RWBASE_INITIALIZER(name), \ + RW_DEP_MAP_INIT(name) \ +} + +#define __RW_LOCK_UNLOCKED(name) __RWLOCK_RT_INITIALIZER(name) + +#define DEFINE_RWLOCK(name) \ + rwlock_t name = __RW_LOCK_UNLOCKED(name) + +#endif /* CONFIG_PREEMPT_RT */ + #endif /* __LINUX_RWLOCK_TYPES_H */ diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index a66038d88878..426e98e0b675 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -16,6 +16,19 @@ #include <linux/spinlock.h> #include <linux/atomic.h> #include <linux/err.h> + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __RWSEM_DEP_MAP_INIT(lockname) \ + .dep_map = { \ + .name = #lockname, \ + .wait_type_inner = LD_WAIT_SLEEP, \ + }, +#else +# define __RWSEM_DEP_MAP_INIT(lockname) +#endif + +#ifndef CONFIG_PREEMPT_RT + #ifdef CONFIG_RWSEM_SPIN_ON_OWNER #include <linux/osq_lock.h> #endif @@ -64,16 +77,6 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) /* Common initializer macros and functions */ -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define __RWSEM_DEP_MAP_INIT(lockname) \ - .dep_map = { \ - .name = #lockname, \ - .wait_type_inner = LD_WAIT_SLEEP, \ - }, -#else -# define __RWSEM_DEP_MAP_INIT(lockname) -#endif - #ifdef CONFIG_DEBUG_RWSEMS # define __RWSEM_DEBUG_INIT(lockname) .magic = &lockname, #else @@ -119,6 +122,61 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem) return !list_empty(&sem->wait_list); } +#else /* !CONFIG_PREEMPT_RT */ + +#include <linux/rwbase_rt.h> + +struct rw_semaphore { + struct rwbase_rt rwbase; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#define __RWSEM_INITIALIZER(name) \ + { \ + .rwbase = __RWBASE_INITIALIZER(name), \ + __RWSEM_DEP_MAP_INIT(name) \ + } + +#define DECLARE_RWSEM(lockname) \ + struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname) + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern void __rwsem_init(struct rw_semaphore *rwsem, const char *name, + struct lock_class_key *key); +#else +static inline void __rwsem_init(struct rw_semaphore *rwsem, const char *name, + struct lock_class_key *key) +{ +} +#endif + +#define init_rwsem(sem) \ +do { \ + static struct lock_class_key __key; \ + \ + init_rwbase_rt(&(sem)->rwbase); \ + __rwsem_init((sem), #sem, &__key); \ +} while (0) + +static __always_inline int rwsem_is_locked(struct rw_semaphore *sem) +{ + return rw_base_is_locked(&sem->rwbase); +} + +static __always_inline int rwsem_is_contended(struct rw_semaphore *sem) +{ + return rw_base_is_contended(&sem->rwbase); +} + +#endif /* CONFIG_PREEMPT_RT */ + +/* + * The functions below are the same for all rwsem implementations including + * the RT specific variant. + */ + /* * lock for reading */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 7c6a77da8b10..af7179f8572c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -95,7 +95,9 @@ struct task_group; #define TASK_WAKING 0x0200 #define TASK_NOLOAD 0x0400 #define TASK_NEW 0x0800 -#define TASK_STATE_MAX 0x1000 +/* RT specific auxilliary flag to mark RT lock waiters */ +#define TASK_RTLOCK_WAIT 0x1000 +#define TASK_STATE_MAX 0x2000 /* Convenience macros for the sake of set_current_state: */ #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) @@ -121,8 +123,6 @@ struct task_group; #define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0) -#ifdef CONFIG_DEBUG_ATOMIC_SLEEP - /* * Special states are those that do not use the normal wait-loop pattern. See * the comment with set_special_state(). @@ -130,30 +130,37 @@ struct task_group; #define is_special_task_state(state) \ ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) -#define __set_current_state(state_value) \ - do { \ - WARN_ON_ONCE(is_special_task_state(state_value));\ - current->task_state_change = _THIS_IP_; \ - WRITE_ONCE(current->__state, (state_value)); \ - } while (0) - -#define set_current_state(state_value) \ - do { \ - WARN_ON_ONCE(is_special_task_state(state_value));\ - current->task_state_change = _THIS_IP_; \ - smp_store_mb(current->__state, (state_value)); \ +#ifdef CONFIG_DEBUG_ATOMIC_SLEEP +# define debug_normal_state_change(state_value) \ + do { \ + WARN_ON_ONCE(is_special_task_state(state_value)); \ + current->task_state_change = _THIS_IP_; \ } while (0) -#define set_special_state(state_value) \ +# define debug_special_state_change(state_value) \ do { \ - unsigned long flags; /* may shadow */ \ WARN_ON_ONCE(!is_special_task_state(state_value)); \ - raw_spin_lock_irqsave(¤t->pi_lock, flags); \ current->task_state_change = _THIS_IP_; \ - WRITE_ONCE(current->__state, (state_value)); \ - raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ } while (0) + +# define debug_rtlock_wait_set_state() \ + do { \ + current->saved_state_change = current->task_state_change;\ + current->task_state_change = _THIS_IP_; \ + } while (0) + +# define debug_rtlock_wait_restore_state() \ + do { \ + current->task_state_change = current->saved_state_change;\ + } while (0) + #else +# define debug_normal_state_change(cond) do { } while (0) +# define debug_special_state_change(cond) do { } while (0) +# define debug_rtlock_wait_set_state() do { } while (0) +# define debug_rtlock_wait_restore_state() do { } while (0) +#endif + /* * set_current_state() includes a barrier so that the write of current->state * is correctly serialised wrt the caller's subsequent test of whether to @@ -192,26 +199,77 @@ struct task_group; * Also see the comments of try_to_wake_up(). */ #define __set_current_state(state_value) \ - WRITE_ONCE(current->__state, (state_value)) + do { \ + debug_normal_state_change((state_value)); \ + WRITE_ONCE(current->__state, (state_value)); \ + } while (0) #define set_current_state(state_value) \ - smp_store_mb(current->__state, (state_value)) + do { \ + debug_normal_state_change((state_value)); \ + smp_store_mb(current->__state, (state_value)); \ + } while (0) /* * set_special_state() should be used for those states when the blocking task * can not use the regular condition based wait-loop. In that case we must - * serialize against wakeups such that any possible in-flight TASK_RUNNING stores - * will not collide with our state change. + * serialize against wakeups such that any possible in-flight TASK_RUNNING + * stores will not collide with our state change. */ #define set_special_state(state_value) \ do { \ unsigned long flags; /* may shadow */ \ + \ raw_spin_lock_irqsave(¤t->pi_lock, flags); \ + debug_special_state_change((state_value)); \ WRITE_ONCE(current->__state, (state_value)); \ raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ } while (0) -#endif +/* + * PREEMPT_RT specific variants for "sleeping" spin/rwlocks + * + * RT's spin/rwlock substitutions are state preserving. The state of the + * task when blocking on the lock is saved in task_struct::saved_state and + * restored after the lock has been acquired. These operations are + * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT + * lock related wakeups while the task is blocked on the lock are + * redirected to operate on task_struct::saved_state to ensure that these + * are not dropped. On restore task_struct::saved_state is set to + * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. + * + * The lock operation looks like this: + * + * current_save_and_set_rtlock_wait_state(); + * for (;;) { + * if (try_lock()) + * break; + * raw_spin_unlock_irq(&lock->wait_lock); + * schedule_rtlock(); + * raw_spin_lock_irq(&lock->wait_lock); + * set_current_state(TASK_RTLOCK_WAIT); + * } + * current_restore_rtlock_saved_state(); + */ +#define current_save_and_set_rtlock_wait_state() \ + do { \ + lockdep_assert_irqs_disabled(); \ + raw_spin_lock(¤t->pi_lock); \ + current->saved_state = current->__state; \ + debug_rtlock_wait_set_state(); \ + WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ + raw_spin_unlock(¤t->pi_lock); \ + } while (0); + +#define current_restore_rtlock_saved_state() \ + do { \ + lockdep_assert_irqs_disabled(); \ + raw_spin_lock(¤t->pi_lock); \ + debug_rtlock_wait_restore_state(); \ + WRITE_ONCE(current->__state, current->saved_state); \ + current->saved_state = TASK_RUNNING; \ + raw_spin_unlock(¤t->pi_lock); \ + } while (0); #define get_current_state() READ_ONCE(current->__state) @@ -230,6 +288,9 @@ extern long schedule_timeout_idle(long timeout); asmlinkage void schedule(void); extern void schedule_preempt_disabled(void); asmlinkage void preempt_schedule_irq(void); +#ifdef CONFIG_PREEMPT_RT + extern void schedule_rtlock(void); +#endif extern int __must_check io_schedule_prepare(void); extern void io_schedule_finish(int token); @@ -668,6 +729,11 @@ struct task_struct { #endif unsigned int __state; +#ifdef CONFIG_PREEMPT_RT + /* saved state for "spinlock sleepers" */ + unsigned int saved_state; +#endif + /* * This begins the randomizable portion of task_struct. Only * scheduling-critical items should be added above here. @@ -1362,6 +1428,9 @@ struct task_struct { struct kmap_ctrl kmap_ctrl; #ifdef CONFIG_DEBUG_ATOMIC_SLEEP unsigned long task_state_change; +# ifdef CONFIG_PREEMPT_RT + unsigned long saved_state_change; +# endif #endif int pagefault_disabled; #ifdef CONFIG_MMU diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h index 26a2013ac39c..06cd8fb2f409 100644 --- a/include/linux/sched/wake_q.h +++ b/include/linux/sched/wake_q.h @@ -42,8 +42,11 @@ struct wake_q_head { #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01) -#define DEFINE_WAKE_Q(name) \ - struct wake_q_head name = { WAKE_Q_TAIL, &name.first } +#define WAKE_Q_HEAD_INITIALIZER(name) \ + { WAKE_Q_TAIL, &name.first } + +#define DEFINE_WAKE_Q(name) \ + struct wake_q_head name = WAKE_Q_HEAD_INITIALIZER(name) static inline void wake_q_init(struct wake_q_head *head) { diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 79897841a2cc..45310ea1b1d7 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -12,6 +12,8 @@ * asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the * initializers * + * linux/spinlock_types_raw: + * The raw types and initializers * linux/spinlock_types.h: * defines the generic type and initializers * @@ -31,6 +33,8 @@ * contains the generic, simplified UP spinlock type. * (which is an empty structure on non-debug builds) * + * linux/spinlock_types_raw: + * The raw RT types and initializers * linux/spinlock_types.h: * defines the generic type and initializers * @@ -308,8 +312,10 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) 1 : ({ local_irq_restore(flags); 0; }); \ }) -/* Include rwlock functions */ +#ifndef CONFIG_PREEMPT_RT +/* Include rwlock functions for !RT */ #include <linux/rwlock.h> +#endif /* * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: @@ -320,6 +326,9 @@ static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) # include <linux/spinlock_api_up.h> #endif +/* Non PREEMPT_RT kernel, map to raw spinlocks: */ +#ifndef CONFIG_PREEMPT_RT + /* * Map the spin_lock functions to the raw variants for PREEMPT_RT=n */ @@ -454,6 +463,10 @@ static __always_inline int spin_is_contended(spinlock_t *lock) #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) +#else /* !CONFIG_PREEMPT_RT */ +# include <linux/spinlock_rt.h> +#endif /* CONFIG_PREEMPT_RT */ + /* * Pull the atomic_t declaration: * (asm-mips/atomic.h needs above definitions) diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h index 19a9be9d97ee..6b8e1a0b137b 100644 --- a/include/linux/spinlock_api_smp.h +++ b/include/linux/spinlock_api_smp.h @@ -187,6 +187,9 @@ static inline int __raw_spin_trylock_bh(raw_spinlock_t *lock) return 0; } +/* PREEMPT_RT has its own rwlock implementation */ +#ifndef CONFIG_PREEMPT_RT #include <linux/rwlock_api_smp.h> +#endif #endif /* __LINUX_SPINLOCK_API_SMP_H */ diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h new file mode 100644 index 000000000000..835aedaf68ac --- /dev/null +++ b/include/linux/spinlock_rt.h @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0-only +#ifndef __LINUX_SPINLOCK_RT_H +#define __LINUX_SPINLOCK_RT_H + +#ifndef __LINUX_SPINLOCK_H +#error Do not include directly. Use spinlock.h +#endif + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern void __rt_spin_lock_init(spinlock_t *lock, const char *name, + struct lock_class_key *key, bool percpu); +#else +static inline void __rt_spin_lock_init(spinlock_t *lock, const char *name, + struct lock_class_key *key, bool percpu) +{ +} +#endif + +#define spin_lock_init(slock) \ +do { \ + static struct lock_class_key __key; \ + \ + rt_mutex_base_init(&(slock)->lock); \ + __rt_spin_lock_init(slock, #slock, &__key, false); \ +} while (0) + +#define local_spin_lock_init(slock) \ +do { \ + static struct lock_class_key __key; \ + \ + rt_mutex_base_init(&(slock)->lock); \ + __rt_spin_lock_init(slock, #slock, &__key, true); \ +} while (0) + +extern void rt_spin_lock(spinlock_t *lock); +extern void rt_spin_lock_nested(spinlock_t *lock, int subclass); +extern void rt_spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *nest_lock); +extern void rt_spin_unlock(spinlock_t *lock); +extern void rt_spin_lock_unlock(spinlock_t *lock); +extern int rt_spin_trylock_bh(spinlock_t *lock); +extern int rt_spin_trylock(spinlock_t *lock); + +static __always_inline void spin_lock(spinlock_t *lock) +{ + rt_spin_lock(lock); +} + +#ifdef CONFIG_LOCKDEP +# define __spin_lock_nested(lock, subclass) \ + rt_spin_lock_nested(lock, subclass) + +# define __spin_lock_nest_lock(lock, nest_lock) \ + do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \ + rt_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ + } while (0) +# define __spin_lock_irqsave_nested(lock, flags, subclass) \ + do { \ + typecheck(unsigned long, flags); \ + flags = 0; \ + __spin_lock_nested(lock, subclass); \ + } while (0) + +#else + /* + * Always evaluate the 'subclass' argument to avoid that the compiler + * warns about set-but-not-used variables when building with + * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. + */ +# define __spin_lock_nested(lock, subclass) spin_lock(((void)(subclass), (lock))) +# define __spin_lock_nest_lock(lock, subclass) spin_lock(((void)(subclass), (lock))) +# define __spin_lock_irqsave_nested(lock, flags, subclass) \ + spin_lock_irqsave(((void)(subclass), (lock)), flags) +#endif + +#define spin_lock_nested(lock, subclass) \ + __spin_lock_nested(lock, subclass) + +#define spin_lock_nest_lock(lock, nest_lock) \ + __spin_lock_nest_lock(lock, nest_lock) + +#define spin_lock_irqsave_nested(lock, flags, subclass) \ + __spin_lock_irqsave_nested(lock, flags, subclass) + +static __always_inline void spin_lock_bh(spinlock_t *lock) +{ + /* Investigate: Drop bh when blocking ? */ + local_bh_disable(); + rt_spin_lock(lock); +} + +static __always_inline void spin_lock_irq(spinlock_t *lock) +{ + rt_spin_lock(lock); +} + +#define spin_lock_irqsave(lock, flags) \ + do { \ + typecheck(unsigned long, flags); \ + flags = 0; \ + spin_lock(lock); \ + } while (0) + +static __always_inline void spin_unlock(spinlock_t *lock) +{ + rt_spin_unlock(lock); +} + +static __always_inline void spin_unlock_bh(spinlock_t *lock) +{ + rt_spin_unlock(lock); + local_bh_enable(); +} + +static __always_inline void spin_unlock_irq(spinlock_t *lock) +{ + rt_spin_unlock(lock); +} + +static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, + unsigned long flags) +{ + rt_spin_unlock(lock); +} + +#define spin_trylock(lock) \ + __cond_lock(lock, rt_spin_trylock(lock)) + +#define spin_trylock_bh(lock) \ + __cond_lock(lock, rt_spin_trylock_bh(lock)) + +#define spin_trylock_irq(lock) \ + __cond_lock(lock, rt_spin_trylock(lock)) + +#define __spin_trylock_irqsave(lock, flags) \ +({ \ + int __locked; \ + \ + typecheck(unsigned long, flags); \ + flags = 0; \ + __locked = spin_trylock(lock); \ + __locked; \ +}) + +#define spin_trylock_irqsave(lock, flags) \ + __cond_lock(lock, __spin_trylock_irqsave(lock, flags)) + +#define spin_is_contended(lock) (((void)(lock), 0)) + +static inline int spin_is_locked(spinlock_t *lock) +{ + return rt_mutex_base_is_locked(&lock->lock); +} + +#define assert_spin_locked(lock) BUG_ON(!spin_is_locked(lock)) + +#include <linux/rwlock_rt.h> + +#endif diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h index b981caafe8bf..2dfa35ffec76 100644 --- a/include/linux/spinlock_types.h +++ b/include/linux/spinlock_types.h @@ -9,65 +9,11 @@ * Released under the General Public License (GPL). */ -#if defined(CONFIG_SMP) -# include <asm/spinlock_types.h> -#else -# include <linux/spinlock_types_up.h> -#endif - -#include <linux/lockdep_types.h> +#include <linux/spinlock_types_raw.h> -typedef struct raw_spinlock { - arch_spinlock_t raw_lock; -#ifdef CONFIG_DEBUG_SPINLOCK - unsigned int magic, owner_cpu; - void *owner; -#endif -#ifdef CONFIG_DEBUG_LOCK_ALLOC - struct lockdep_map dep_map; -#endif -} raw_spinlock_t; - -#define SPINLOCK_MAGIC 0xdead4ead - -#define SPINLOCK_OWNER_INIT ((void *)-1L) - -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define RAW_SPIN_DEP_MAP_INIT(lockname) \ - .dep_map = { \ - .name = #lockname, \ - .wait_type_inner = LD_WAIT_SPIN, \ - } -# define SPIN_DEP_MAP_INIT(lockname) \ - .dep_map = { \ - .name = #lockname, \ - .wait_type_inner = LD_WAIT_CONFIG, \ - } -#else -# define RAW_SPIN_DEP_MAP_INIT(lockname) -# define SPIN_DEP_MAP_INIT(lockname) -#endif - -#ifdef CONFIG_DEBUG_SPINLOCK -# define SPIN_DEBUG_INIT(lockname) \ - .magic = SPINLOCK_MAGIC, \ - .owner_cpu = -1, \ - .owner = SPINLOCK_OWNER_INIT, -#else -# define SPIN_DEBUG_INIT(lockname) -#endif - -#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \ - { \ - .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ - SPIN_DEBUG_INIT(lockname) \ - RAW_SPIN_DEP_MAP_INIT(lockname) } - -#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \ - (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname) - -#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x) +#ifndef CONFIG_PREEMPT_RT +/* Non PREEMPT_RT kernels map spinlock to raw_spinlock */ typedef struct spinlock { union { struct raw_spinlock rlock; @@ -96,6 +42,35 @@ typedef struct spinlock { #define DEFINE_SPINLOCK(x) spinlock_t x = __SPIN_LOCK_UNLOCKED(x) +#else /* !CONFIG_PREEMPT_RT */ + +/* PREEMPT_RT kernels map spinlock to rt_mutex */ +#include <linux/rtmutex.h> + +typedef struct spinlock { + struct rt_mutex_base lock; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} spinlock_t; + +#define __SPIN_LOCK_UNLOCKED(name) \ + { \ + .lock = __RT_MUTEX_BASE_INITIALIZER(name.lock), \ + SPIN_DEP_MAP_INIT(name) \ + } + +#define __LOCAL_SPIN_LOCK_UNLOCKED(name) \ + { \ + .lock = __RT_MUTEX_BASE_INITIALIZER(name.lock), \ + LOCAL_SPIN_DEP_MAP_INIT(name) \ + } + +#define DEFINE_SPINLOCK(name) \ + spinlock_t name = __SPIN_LOCK_UNLOCKED(name) + +#endif /* CONFIG_PREEMPT_RT */ + #include <linux/rwlock_types.h> #endif /* __LINUX_SPINLOCK_TYPES_H */ diff --git a/include/linux/spinlock_types_raw.h b/include/linux/spinlock_types_raw.h new file mode 100644 index 000000000000..91cb36b65a17 --- /dev/null +++ b/include/linux/spinlock_types_raw.h @@ -0,0 +1,73 @@ +#ifndef __LINUX_SPINLOCK_TYPES_RAW_H +#define __LINUX_SPINLOCK_TYPES_RAW_H + +#include <linux/types.h> + +#if defined(CONFIG_SMP) +# include <asm/spinlock_types.h> +#else +# include <linux/spinlock_types_up.h> +#endif + +#include <linux/lockdep_types.h> + +typedef struct raw_spinlock { + arch_spinlock_t raw_lock; +#ifdef CONFIG_DEBUG_SPINLOCK + unsigned int magic, owner_cpu; + void *owner; +#endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} raw_spinlock_t; + +#define SPINLOCK_MAGIC 0xdead4ead + +#define SPINLOCK_OWNER_INIT ((void *)-1L) + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define RAW_SPIN_DEP_MAP_INIT(lockname) \ + .dep_map = { \ + .name = #lockname, \ + .wait_type_inner = LD_WAIT_SPIN, \ + } +# define SPIN_DEP_MAP_INIT(lockname) \ + .dep_map = { \ + .name = #lockname, \ + .wait_type_inner = LD_WAIT_CONFIG, \ + } + +# define LOCAL_SPIN_DEP_MAP_INIT(lockname) \ + .dep_map = { \ + .name = #lockname, \ + .wait_type_inner = LD_WAIT_CONFIG, \ + .lock_type = LD_LOCK_PERCPU, \ + } +#else +# define RAW_SPIN_DEP_MAP_INIT(lockname) +# define SPIN_DEP_MAP_INIT(lockname) +# define LOCAL_SPIN_DEP_MAP_INIT(lockname) +#endif + +#ifdef CONFIG_DEBUG_SPINLOCK +# define SPIN_DEBUG_INIT(lockname) \ + .magic = SPINLOCK_MAGIC, \ + .owner_cpu = -1, \ + .owner = SPINLOCK_OWNER_INIT, +#else +# define SPIN_DEBUG_INIT(lockname) +#endif + +#define __RAW_SPIN_LOCK_INITIALIZER(lockname) \ +{ \ + .raw_lock = __ARCH_SPIN_LOCK_UNLOCKED, \ + SPIN_DEBUG_INIT(lockname) \ + RAW_SPIN_DEP_MAP_INIT(lockname) } + +#define __RAW_SPIN_LOCK_UNLOCKED(lockname) \ + (raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname) + +#define DEFINE_RAW_SPINLOCK(x) raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x) + +#endif /* __LINUX_SPINLOCK_TYPES_RAW_H */ diff --git a/include/linux/static_call.h b/include/linux/static_call.h index fc94faa53b5b..3e56a9751c06 100644 --- a/include/linux/static_call.h +++ b/include/linux/static_call.h @@ -17,11 +17,17 @@ * DECLARE_STATIC_CALL(name, func); * DEFINE_STATIC_CALL(name, func); * DEFINE_STATIC_CALL_NULL(name, typename); + * DEFINE_STATIC_CALL_RET0(name, typename); + * + * __static_call_return0; + * * static_call(name)(args...); * static_call_cond(name)(args...); * static_call_update(name, func); * static_call_query(name); * + * EXPORT_STATIC_CALL{,_TRAMP}{,_GPL}() + * * Usage example: * * # Start with the following functions (with identical prototypes): @@ -96,6 +102,33 @@ * To query which function is currently set to be called, use: * * func = static_call_query(name); + * + * + * DEFINE_STATIC_CALL_RET0 / __static_call_return0: + * + * Just like how DEFINE_STATIC_CALL_NULL() / static_call_cond() optimize the + * conditional void function call, DEFINE_STATIC_CALL_RET0 / + * __static_call_return0 optimize the do nothing return 0 function. + * + * This feature is strictly UB per the C standard (since it casts a function + * pointer to a different signature) and relies on the architecture ABI to + * make things work. In particular it relies on Caller Stack-cleanup and the + * whole return register being clobbered for short return values. All normal + * CDECL style ABIs conform. + * + * In particular the x86_64 implementation replaces the 5 byte CALL + * instruction at the callsite with a 5 byte clear of the RAX register, + * completely eliding any function call overhead. + * + * Notably argument setup is unconditional. + * + * + * EXPORT_STATIC_CALL() vs EXPORT_STATIC_CALL_TRAMP(): + * + * The difference is that the _TRAMP variant tries to only export the + * trampoline with the result that a module can use static_call{,_cond}() but + * not static_call_update(). + * */ #include <linux/types.h> diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h index b77f39f319ad..29db736af86d 100644 --- a/include/linux/ww_mutex.h +++ b/include/linux/ww_mutex.h @@ -18,6 +18,24 @@ #define __LINUX_WW_MUTEX_H #include <linux/mutex.h> +#include <linux/rtmutex.h> + +#if defined(CONFIG_DEBUG_MUTEXES) || \ + (defined(CONFIG_PREEMPT_RT) && defined(CONFIG_DEBUG_RT_MUTEXES)) +#define DEBUG_WW_MUTEXES +#endif + +#ifndef CONFIG_PREEMPT_RT +#define WW_MUTEX_BASE mutex +#define ww_mutex_base_init(l,n,k) __mutex_init(l,n,k) +#define ww_mutex_base_trylock(l) mutex_trylock(l) +#define ww_mutex_base_is_locked(b) mutex_is_locked((b)) +#else +#define WW_MUTEX_BASE rt_mutex +#define ww_mutex_base_init(l,n,k) __rt_mutex_init(l,n,k) +#define ww_mutex_base_trylock(l) rt_mutex_trylock(l) +#define ww_mutex_base_is_locked(b) rt_mutex_base_is_locked(&(b)->rtmutex) +#endif struct ww_class { atomic_long_t stamp; @@ -28,16 +46,24 @@ struct ww_class { unsigned int is_wait_die; }; +struct ww_mutex { + struct WW_MUTEX_BASE base; + struct ww_acquire_ctx *ctx; +#ifdef DEBUG_WW_MUTEXES + struct ww_class *ww_class; +#endif +}; + struct ww_acquire_ctx { struct task_struct *task; unsigned long stamp; unsigned int acquired; unsigned short wounded; unsigned short is_wait_die; -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES unsigned int done_acquire; struct ww_class *ww_class; - struct ww_mutex *contending_lock; + void *contending_lock; #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; @@ -74,9 +100,9 @@ struct ww_acquire_ctx { static inline void ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class) { - __mutex_init(&lock->base, ww_class->mutex_name, &ww_class->mutex_key); + ww_mutex_base_init(&lock->base, ww_class->mutex_name, &ww_class->mutex_key); lock->ctx = NULL; -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES lock->ww_class = ww_class; #endif } @@ -113,7 +139,7 @@ static inline void ww_acquire_init(struct ww_acquire_ctx *ctx, ctx->acquired = 0; ctx->wounded = false; ctx->is_wait_die = ww_class->is_wait_die; -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES ctx->ww_class = ww_class; ctx->done_acquire = 0; ctx->contending_lock = NULL; @@ -143,7 +169,7 @@ static inline void ww_acquire_init(struct ww_acquire_ctx *ctx, */ static inline void ww_acquire_done(struct ww_acquire_ctx *ctx) { -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES lockdep_assert_held(ctx); DEBUG_LOCKS_WARN_ON(ctx->done_acquire); @@ -163,7 +189,7 @@ static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx) #ifdef CONFIG_DEBUG_LOCK_ALLOC mutex_release(&ctx->dep_map, _THIS_IP_); #endif -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES DEBUG_LOCKS_WARN_ON(ctx->acquired); if (!IS_ENABLED(CONFIG_PROVE_LOCKING)) /* @@ -269,7 +295,7 @@ static inline void ww_mutex_lock_slow(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { int ret; -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES DEBUG_LOCKS_WARN_ON(!ctx->contending_lock); #endif ret = ww_mutex_lock(lock, ctx); @@ -305,7 +331,7 @@ static inline int __must_check ww_mutex_lock_slow_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { -#ifdef CONFIG_DEBUG_MUTEXES +#ifdef DEBUG_WW_MUTEXES DEBUG_LOCKS_WARN_ON(!ctx->contending_lock); #endif return ww_mutex_lock_interruptible(lock, ctx); @@ -322,7 +348,7 @@ extern void ww_mutex_unlock(struct ww_mutex *lock); */ static inline int __must_check ww_mutex_trylock(struct ww_mutex *lock) { - return mutex_trylock(&lock->base); + return ww_mutex_base_trylock(&lock->base); } /*** @@ -335,7 +361,9 @@ static inline int __must_check ww_mutex_trylock(struct ww_mutex *lock) */ static inline void ww_mutex_destroy(struct ww_mutex *lock) { +#ifndef CONFIG_PREEMPT_RT mutex_destroy(&lock->base); +#endif } /** @@ -346,7 +374,7 @@ static inline void ww_mutex_destroy(struct ww_mutex *lock) */ static inline bool ww_mutex_is_locked(struct ww_mutex *lock) { - return mutex_is_locked(&lock->base); + return ww_mutex_base_is_locked(&lock->base); } #endif diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 3de8fd11873b..4198f0273ecd 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -251,7 +251,7 @@ config ARCH_USE_QUEUED_RWLOCKS config QUEUED_RWLOCKS def_bool y if ARCH_USE_QUEUED_RWLOCKS - depends on SMP + depends on SMP && !PREEMPT_RT config ARCH_HAS_MMIOWB bool diff --git a/kernel/futex.c b/kernel/futex.c index 2ecb07575055..e7b4c6121da4 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -179,7 +179,7 @@ struct futex_pi_state { /* * The PI object: */ - struct rt_mutex pi_mutex; + struct rt_mutex_base pi_mutex; struct task_struct *owner; refcount_t refcount; @@ -197,6 +197,8 @@ struct futex_pi_state { * @rt_waiter: rt_waiter storage for use with requeue_pi * @requeue_pi_key: the requeue_pi target futex key * @bitset: bitset for the optional bitmasked wakeup + * @requeue_state: State field for futex_requeue_pi() + * @requeue_wait: RCU wait for futex_requeue_pi() (RT only) * * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so * we can wake only the relevant ones (hashed queues may be shared). @@ -219,12 +221,68 @@ struct futex_q { struct rt_mutex_waiter *rt_waiter; union futex_key *requeue_pi_key; u32 bitset; + atomic_t requeue_state; +#ifdef CONFIG_PREEMPT_RT + struct rcuwait requeue_wait; +#endif } __randomize_layout; +/* + * On PREEMPT_RT, the hash bucket lock is a 'sleeping' spinlock with an + * underlying rtmutex. The task which is about to be requeued could have + * just woken up (timeout, signal). After the wake up the task has to + * acquire hash bucket lock, which is held by the requeue code. As a task + * can only be blocked on _ONE_ rtmutex at a time, the proxy lock blocking + * and the hash bucket lock blocking would collide and corrupt state. + * + * On !PREEMPT_RT this is not a problem and everything could be serialized + * on hash bucket lock, but aside of having the benefit of common code, + * this allows to avoid doing the requeue when the task is already on the + * way out and taking the hash bucket lock of the original uaddr1 when the + * requeue has been completed. + * + * The following state transitions are valid: + * + * On the waiter side: + * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IGNORE + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT + * + * On the requeue side: + * Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_INPROGRESS + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_DONE/LOCKED + * Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_NONE (requeue failed) + * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_DONE/LOCKED + * Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_IGNORE (requeue failed) + * + * The requeue side ignores a waiter with state Q_REQUEUE_PI_IGNORE as this + * signals that the waiter is already on the way out. It also means that + * the waiter is still on the 'wait' futex, i.e. uaddr1. + * + * The waiter side signals early wakeup to the requeue side either through + * setting state to Q_REQUEUE_PI_IGNORE or to Q_REQUEUE_PI_WAIT depending + * on the current state. In case of Q_REQUEUE_PI_IGNORE it can immediately + * proceed to take the hash bucket lock of uaddr1. If it set state to WAIT, + * which means the wakeup is interleaving with a requeue in progress it has + * to wait for the requeue side to change the state. Either to DONE/LOCKED + * or to IGNORE. DONE/LOCKED means the waiter q is now on the uaddr2 futex + * and either blocked (DONE) or has acquired it (LOCKED). IGNORE is set by + * the requeue side when the requeue attempt failed via deadlock detection + * and therefore the waiter q is still on the uaddr1 futex. + */ +enum { + Q_REQUEUE_PI_NONE = 0, + Q_REQUEUE_PI_IGNORE, + Q_REQUEUE_PI_IN_PROGRESS, + Q_REQUEUE_PI_WAIT, + Q_REQUEUE_PI_DONE, + Q_REQUEUE_PI_LOCKED, +}; + static const struct futex_q futex_q_init = { /* list gets initialized in queue_me()*/ - .key = FUTEX_KEY_INIT, - .bitset = FUTEX_BITSET_MATCH_ANY + .key = FUTEX_KEY_INIT, + .bitset = FUTEX_BITSET_MATCH_ANY, + .requeue_state = ATOMIC_INIT(Q_REQUEUE_PI_NONE), }; /* @@ -1299,27 +1357,6 @@ static int attach_to_pi_owner(u32 __user *uaddr, u32 uval, union futex_key *key, return 0; } -static int lookup_pi_state(u32 __user *uaddr, u32 uval, - struct futex_hash_bucket *hb, - union futex_key *key, struct futex_pi_state **ps, - struct task_struct **exiting) -{ - struct futex_q *top_waiter = futex_top_waiter(hb, key); - - /* - * If there is a waiter on that futex, validate it and - * attach to the pi_state when the validation succeeds. - */ - if (top_waiter) - return attach_to_pi_state(uaddr, uval, top_waiter->pi_state, ps); - - /* - * We are the first waiter - try to look up the owner based on - * @uval and attach to it. - */ - return attach_to_pi_owner(uaddr, uval, key, ps, exiting); -} - static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval) { int err; @@ -1354,7 +1391,7 @@ static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval) * - 1 - acquired the lock; * - <0 - error * - * The hb->lock and futex_key refs shall be held by the caller. + * The hb->lock must be held by the caller. * * @exiting is only set when the return value is -EBUSY. If so, this holds * a refcount on the exiting task on return and the caller needs to drop it @@ -1493,11 +1530,11 @@ static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q) */ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_state) { - u32 curval, newval; struct rt_mutex_waiter *top_waiter; struct task_struct *new_owner; bool postunlock = false; - DEFINE_WAKE_Q(wake_q); + DEFINE_RT_WAKE_Q(wqh); + u32 curval, newval; int ret = 0; top_waiter = rt_mutex_top_waiter(&pi_state->pi_mutex); @@ -1549,14 +1586,14 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ * not fail. */ pi_state_update_owner(pi_state, new_owner); - postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q); + postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wqh); } out_unlock: raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); if (postunlock) - rt_mutex_postunlock(&wake_q); + rt_mutex_postunlock(&wqh); return ret; } @@ -1793,6 +1830,108 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1, q->key = *key2; } +static inline bool futex_requeue_pi_prepare(struct futex_q *q, + struct futex_pi_state *pi_state) +{ + int old, new; + + /* + * Set state to Q_REQUEUE_PI_IN_PROGRESS unless an early wakeup has + * already set Q_REQUEUE_PI_IGNORE to signal that requeue should + * ignore the waiter. + */ + old = atomic_read_acquire(&q->requeue_state); + do { + if (old == Q_REQUEUE_PI_IGNORE) + return false; + + /* + * futex_proxy_trylock_atomic() might have set it to + * IN_PROGRESS and a interleaved early wake to WAIT. + * + * It was considered to have an extra state for that + * trylock, but that would just add more conditionals + * all over the place for a dubious value. + */ + if (old != Q_REQUEUE_PI_NONE) + break; + + new = Q_REQUEUE_PI_IN_PROGRESS; + } while (!atomic_try_cmpxchg(&q->requeue_state, &old, new)); + + q->pi_state = pi_state; + return true; +} + +static inline void futex_requeue_pi_complete(struct futex_q *q, int locked) +{ + int old, new; + + old = atomic_read_acquire(&q->requeue_state); + do { + if (old == Q_REQUEUE_PI_IGNORE) + return; + + if (locked >= 0) { + /* Requeue succeeded. Set DONE or LOCKED */ + WARN_ON_ONCE(old != Q_REQUEUE_PI_IN_PROGRESS && + old != Q_REQUEUE_PI_WAIT); + new = Q_REQUEUE_PI_DONE + locked; + } else if (old == Q_REQUEUE_PI_IN_PROGRESS) { + /* Deadlock, no early wakeup interleave */ + new = Q_REQUEUE_PI_NONE; + } else { + /* Deadlock, early wakeup interleave. */ + WARN_ON_ONCE(old != Q_REQUEUE_PI_WAIT); + new = Q_REQUEUE_PI_IGNORE; + } + } while (!atomic_try_cmpxchg(&q->requeue_state, &old, new)); + +#ifdef CONFIG_PREEMPT_RT + /* If the waiter interleaved with the requeue let it know */ + if (unlikely(old == Q_REQUEUE_PI_WAIT)) + rcuwait_wake_up(&q->requeue_wait); +#endif +} + +static inline int futex_requeue_pi_wakeup_sync(struct futex_q *q) +{ + int old, new; + + old = atomic_read_acquire(&q->requeue_state); + do { + /* Is requeue done already? */ + if (old >= Q_REQUEUE_PI_DONE) + return old; + + /* + * If not done, then tell the requeue code to either ignore + * the waiter or to wake it up once the requeue is done. + */ + new = Q_REQUEUE_PI_WAIT; + if (old == Q_REQUEUE_PI_NONE) + new = Q_REQUEUE_PI_IGNORE; + } while (!atomic_try_cmpxchg(&q->requeue_state, &old, new)); + + /* If the requeue was in progress, wait for it to complete */ + if (old == Q_REQUEUE_PI_IN_PROGRESS) { +#ifdef CONFIG_PREEMPT_RT + rcuwait_wait_event(&q->requeue_wait, + atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT, + TASK_UNINTERRUPTIBLE); +#else + (void)atomic_cond_read_relaxed(&q->requeue_state, VAL != Q_REQUEUE_PI_WAIT); +#endif + } + + /* + * Requeue is now either prohibited or complete. Reread state + * because during the wait above it might have changed. Nothing + * will modify q->requeue_state after this point. + */ + return atomic_read(&q->requeue_state); +} + /** * requeue_pi_wake_futex() - Wake a task that acquired the lock during requeue * @q: the futex_q @@ -1820,6 +1959,8 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key, q->lock_ptr = &hb->lock; + /* Signal locked state to the waiter */ + futex_requeue_pi_complete(q, 1); wake_up_state(q->task, TASK_NORMAL); } @@ -1879,10 +2020,21 @@ futex_proxy_trylock_atomic(u32 __user *pifutex, struct futex_hash_bucket *hb1, if (!top_waiter) return 0; + /* + * Ensure that this is a waiter sitting in futex_wait_requeue_pi() + * and waiting on the 'waitqueue' futex which is always !PI. + */ + if (!top_waiter->rt_waiter || top_waiter->pi_state) + ret = -EINVAL; + /* Ensure we requeue to the expected futex. */ if (!match_futex(top_waiter->requeue_pi_key, key2)) return -EINVAL; + /* Ensure that this does not race against an early wakeup */ + if (!futex_requeue_pi_prepare(top_waiter, NULL)) + return -EAGAIN; + /* * Try to take the lock for top_waiter. Set the FUTEX_WAITERS bit in * the contended case or if set_waiters is 1. The pi_state is returned @@ -1892,8 +2044,22 @@ futex_proxy_trylock_atomic(u32 __user *pifutex, struct futex_hash_bucket *hb1, ret = futex_lock_pi_atomic(pifutex, hb2, key2, ps, top_waiter->task, exiting, set_waiters); if (ret == 1) { + /* Dequeue, wake up and update top_waiter::requeue_state */ requeue_pi_wake_futex(top_waiter, key2, hb2); return vpid; + } else if (ret < 0) { + /* Rewind top_waiter::requeue_state */ + futex_requeue_pi_complete(top_waiter, ret); + } else { + /* + * futex_lock_pi_atomic() did not acquire the user space + * futex, but managed to establish the proxy lock and pi + * state. top_waiter::requeue_state cannot be fixed up here + * because the waiter is not enqueued on the rtmutex + * yet. This is handled at the callsite depending on the + * result of rt_mutex_start_proxy_lock() which is + * guaranteed to be reached with this function returning 0. + */ } return ret; } @@ -1948,23 +2114,35 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, return -EINVAL; /* + * futex_requeue() allows the caller to define the number + * of waiters to wake up via the @nr_wake argument. With + * REQUEUE_PI, waking up more than one waiter is creating + * more problems than it solves. Waking up a waiter makes + * only sense if the PI futex @uaddr2 is uncontended as + * this allows the requeue code to acquire the futex + * @uaddr2 before waking the waiter. The waiter can then + * return to user space without further action. A secondary + * wakeup would just make the futex_wait_requeue_pi() + * handling more complex, because that code would have to + * look up pi_state and do more or less all the handling + * which the requeue code has to do for the to be requeued + * waiters. So restrict the number of waiters to wake to + * one, and only wake it up when the PI futex is + * uncontended. Otherwise requeue it and let the unlock of + * the PI futex handle the wakeup. + * + * All REQUEUE_PI users, e.g. pthread_cond_signal() and + * pthread_cond_broadcast() must use nr_wake=1. + */ + if (nr_wake != 1) + return -EINVAL; + + /* * requeue_pi requires a pi_state, try to allocate it now * without any locks in case it fails. */ if (refill_pi_state_cache()) return -ENOMEM; - /* - * requeue_pi must wake as many tasks as it can, up to nr_wake - * + nr_requeue, since it acquires the rt_mutex prior to - * returning to userspace, so as to not leave the rt_mutex with - * waiters and no owner. However, second and third wake-ups - * cannot be predicted as they involve race conditions with the - * first wake and a fault while looking up the pi_state. Both - * pthread_cond_signal() and pthread_cond_broadcast() should - * use nr_wake=1. - */ - if (nr_wake != 1) - return -EINVAL; } retry: @@ -2014,7 +2192,7 @@ retry_private: } } - if (requeue_pi && (task_count - nr_wake < nr_requeue)) { + if (requeue_pi) { struct task_struct *exiting = NULL; /* @@ -2022,6 +2200,8 @@ retry_private: * intend to requeue waiters, force setting the FUTEX_WAITERS * bit. We force this here where we are able to easily handle * faults rather in the requeue loop below. + * + * Updates topwaiter::requeue_state if a top waiter exists. */ ret = futex_proxy_trylock_atomic(uaddr2, hb1, hb2, &key1, &key2, &pi_state, @@ -2031,28 +2211,52 @@ retry_private: * At this point the top_waiter has either taken uaddr2 or is * waiting on it. If the former, then the pi_state will not * exist yet, look it up one more time to ensure we have a - * reference to it. If the lock was taken, ret contains the - * vpid of the top waiter task. + * reference to it. If the lock was taken, @ret contains the + * VPID of the top waiter task. * If the lock was not taken, we have pi_state and an initial * refcount on it. In case of an error we have nothing. + * + * The top waiter's requeue_state is up to date: + * + * - If the lock was acquired atomically (ret > 0), then + * the state is Q_REQUEUE_PI_LOCKED. + * + * - If the trylock failed with an error (ret < 0) then + * the state is either Q_REQUEUE_PI_NONE, i.e. "nothing + * happened", or Q_REQUEUE_PI_IGNORE when there was an + * interleaved early wakeup. + * + * - If the trylock did not succeed (ret == 0) then the + * state is either Q_REQUEUE_PI_IN_PROGRESS or + * Q_REQUEUE_PI_WAIT if an early wakeup interleaved. + * This will be cleaned up in the loop below, which + * cannot fail because futex_proxy_trylock_atomic() did + * the same sanity checks for requeue_pi as the loop + * below does. */ if (ret > 0) { WARN_ON(pi_state); task_count++; /* - * If we acquired the lock, then the user space value - * of uaddr2 should be vpid. It cannot be changed by - * the top waiter as it is blocked on hb2 lock if it - * tries to do so. If something fiddled with it behind - * our back the pi state lookup might unearth it. So - * we rather use the known value than rereading and - * handing potential crap to lookup_pi_state. + * If futex_proxy_trylock_atomic() acquired the + * user space futex, then the user space value + * @uaddr2 has been set to the @hb1's top waiter + * task VPID. This task is guaranteed to be alive + * and cannot be exiting because it is either + * sleeping or blocked on @hb2 lock. + * + * The @uaddr2 futex cannot have waiters either as + * otherwise futex_proxy_trylock_atomic() would not + * have succeeded. * - * If that call succeeds then we have pi_state and an - * initial refcount on it. + * In order to requeue waiters to @hb2, pi state is + * required. Hand in the VPID value (@ret) and + * allocate PI state with an initial refcount on + * it. */ - ret = lookup_pi_state(uaddr2, ret, hb2, &key2, - &pi_state, &exiting); + ret = attach_to_pi_owner(uaddr2, ret, &key2, &pi_state, + &exiting); + WARN_ON(ret); } switch (ret) { @@ -2060,7 +2264,10 @@ retry_private: /* We hold a reference on the pi state. */ break; - /* If the above failed, then pi_state is NULL */ + /* + * If the above failed, then pi_state is NULL and + * waiter::requeue_state is correct. + */ case -EFAULT: double_unlock_hb(hb1, hb2); hb_waiters_dec(hb2); @@ -2112,18 +2319,17 @@ retry_private: break; } - /* - * Wake nr_wake waiters. For requeue_pi, if we acquired the - * lock, we already woke the top_waiter. If not, it will be - * woken by futex_unlock_pi(). - */ - if (++task_count <= nr_wake && !requeue_pi) { - mark_wake_futex(&wake_q, this); + /* Plain futexes just wake or requeue and are done */ + if (!requeue_pi) { + if (++task_count <= nr_wake) + mark_wake_futex(&wake_q, this); + else + requeue_futex(this, hb1, hb2, &key2); continue; } /* Ensure we requeue to the expected futex for requeue_pi. */ - if (requeue_pi && !match_futex(this->requeue_pi_key, &key2)) { + if (!match_futex(this->requeue_pi_key, &key2)) { ret = -EINVAL; break; } @@ -2131,54 +2337,67 @@ retry_private: /* * Requeue nr_requeue waiters and possibly one more in the case * of requeue_pi if we couldn't acquire the lock atomically. + * + * Prepare the waiter to take the rt_mutex. Take a refcount + * on the pi_state and store the pointer in the futex_q + * object of the waiter. */ - if (requeue_pi) { + get_pi_state(pi_state); + + /* Don't requeue when the waiter is already on the way out. */ + if (!futex_requeue_pi_prepare(this, pi_state)) { /* - * Prepare the waiter to take the rt_mutex. Take a - * refcount on the pi_state and store the pointer in - * the futex_q object of the waiter. + * Early woken waiter signaled that it is on the + * way out. Drop the pi_state reference and try the + * next waiter. @this->pi_state is still NULL. */ - get_pi_state(pi_state); - this->pi_state = pi_state; - ret = rt_mutex_start_proxy_lock(&pi_state->pi_mutex, - this->rt_waiter, - this->task); - if (ret == 1) { - /* - * We got the lock. We do neither drop the - * refcount on pi_state nor clear - * this->pi_state because the waiter needs the - * pi_state for cleaning up the user space - * value. It will drop the refcount after - * doing so. - */ - requeue_pi_wake_futex(this, &key2, hb2); - continue; - } else if (ret) { - /* - * rt_mutex_start_proxy_lock() detected a - * potential deadlock when we tried to queue - * that waiter. Drop the pi_state reference - * which we took above and remove the pointer - * to the state from the waiters futex_q - * object. - */ - this->pi_state = NULL; - put_pi_state(pi_state); - /* - * We stop queueing more waiters and let user - * space deal with the mess. - */ - break; - } + put_pi_state(pi_state); + continue; + } + + ret = rt_mutex_start_proxy_lock(&pi_state->pi_mutex, + this->rt_waiter, + this->task); + + if (ret == 1) { + /* + * We got the lock. We do neither drop the refcount + * on pi_state nor clear this->pi_state because the + * waiter needs the pi_state for cleaning up the + * user space value. It will drop the refcount + * after doing so. this::requeue_state is updated + * in the wakeup as well. + */ + requeue_pi_wake_futex(this, &key2, hb2); + task_count++; + } else if (!ret) { + /* Waiter is queued, move it to hb2 */ + requeue_futex(this, hb1, hb2, &key2); + futex_requeue_pi_complete(this, 0); + task_count++; + } else { + /* + * rt_mutex_start_proxy_lock() detected a potential + * deadlock when we tried to queue that waiter. + * Drop the pi_state reference which we took above + * and remove the pointer to the state from the + * waiters futex_q object. + */ + this->pi_state = NULL; + put_pi_state(pi_state); + futex_requeue_pi_complete(this, ret); + /* + * We stop queueing more waiters and let user space + * deal with the mess. + */ + break; } - requeue_futex(this, hb1, hb2, &key2); } /* - * We took an extra initial reference to the pi_state either - * in futex_proxy_trylock_atomic() or in lookup_pi_state(). We - * need to drop it here again. + * We took an extra initial reference to the pi_state either in + * futex_proxy_trylock_atomic() or in attach_to_pi_owner(). We need + * to drop it here again. */ put_pi_state(pi_state); @@ -2357,7 +2576,7 @@ static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, * Modifying pi_state _before_ the user space value would leave the * pi_state in an inconsistent state when we fault here, because we * need to drop the locks to handle the fault. This might be observed - * in the PID check in lookup_pi_state. + * in the PID checks when attaching to PI state . */ retry: if (!argowner) { @@ -2614,8 +2833,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, * * Setup the futex_q and locate the hash_bucket. Get the futex value and * compare it with the expected value. Handle atomic faults internally. - * Return with the hb lock held and a q.key reference on success, and unlocked - * with no q.key reference on failure. + * Return with the hb lock held on success, and unlocked on failure. * * Return: * - 0 - uaddr contains val and hb has been locked; @@ -2693,8 +2911,8 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, current->timer_slack_ns); retry: /* - * Prepare to wait on uaddr. On success, holds hb lock and increments - * q.key refs. + * Prepare to wait on uaddr. On success, it holds hb->lock and q + * is initialized. */ ret = futex_wait_setup(uaddr, val, flags, &q, &hb); if (ret) @@ -2705,7 +2923,6 @@ retry: /* If we were woken (and unqueued), we succeeded, whatever. */ ret = 0; - /* unqueue_me() drops q.key ref */ if (!unqueue_me(&q)) goto out; ret = -ETIMEDOUT; @@ -3072,27 +3289,22 @@ pi_faulted: } /** - * handle_early_requeue_pi_wakeup() - Detect early wakeup on the initial futex + * handle_early_requeue_pi_wakeup() - Handle early wakeup on the initial futex * @hb: the hash_bucket futex_q was original enqueued on * @q: the futex_q woken while waiting to be requeued - * @key2: the futex_key of the requeue target futex * @timeout: the timeout associated with the wait (NULL if none) * - * Detect if the task was woken on the initial futex as opposed to the requeue - * target futex. If so, determine if it was a timeout or a signal that caused - * the wakeup and return the appropriate error code to the caller. Must be - * called with the hb lock held. + * Determine the cause for the early wakeup. * * Return: - * - 0 = no early wakeup detected; - * - <0 = -ETIMEDOUT or -ERESTARTNOINTR + * -EWOULDBLOCK or -ETIMEDOUT or -ERESTARTNOINTR */ static inline int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, - struct futex_q *q, union futex_key *key2, + struct futex_q *q, struct hrtimer_sleeper *timeout) { - int ret = 0; + int ret; /* * With the hb lock held, we avoid races while we process the wakeup. @@ -3101,22 +3313,21 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * It can't be requeued from uaddr2 to something else since we don't * support a PI aware source futex for requeue. */ - if (!match_futex(&q->key, key2)) { - WARN_ON(q->lock_ptr && (&hb->lock != q->lock_ptr)); - /* - * We were woken prior to requeue by a timeout or a signal. - * Unqueue the futex_q and determine which it was. - */ - plist_del(&q->list, &hb->chain); - hb_waiters_dec(hb); + WARN_ON_ONCE(&hb->lock != q->lock_ptr); - /* Handle spurious wakeups gracefully */ - ret = -EWOULDBLOCK; - if (timeout && !timeout->task) - ret = -ETIMEDOUT; - else if (signal_pending(current)) - ret = -ERESTARTNOINTR; - } + /* + * We were woken prior to requeue by a timeout or a signal. + * Unqueue the futex_q and determine which it was. + */ + plist_del(&q->list, &hb->chain); + hb_waiters_dec(hb); + + /* Handle spurious wakeups gracefully */ + ret = -EWOULDBLOCK; + if (timeout && !timeout->task) + ret = -ETIMEDOUT; + else if (signal_pending(current)) + ret = -ERESTARTNOINTR; return ret; } @@ -3169,6 +3380,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, struct futex_hash_bucket *hb; union futex_key key2 = FUTEX_KEY_INIT; struct futex_q q = futex_q_init; + struct rt_mutex_base *pi_mutex; int res, ret; if (!IS_ENABLED(CONFIG_FUTEX_PI)) @@ -3198,8 +3410,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, q.requeue_pi_key = &key2; /* - * Prepare to wait on uaddr. On success, increments q.key (key1) ref - * count. + * Prepare to wait on uaddr. On success, it holds hb->lock and q + * is initialized. */ ret = futex_wait_setup(uaddr, val, flags, &q, &hb); if (ret) @@ -3218,32 +3430,22 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, /* Queue the futex_q, drop the hb lock, wait for wakeup. */ futex_wait_queue_me(hb, &q, to); - spin_lock(&hb->lock); - ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to); - spin_unlock(&hb->lock); - if (ret) - goto out; - - /* - * In order for us to be here, we know our q.key == key2, and since - * we took the hb->lock above, we also know that futex_requeue() has - * completed and we no longer have to concern ourselves with a wakeup - * race with the atomic proxy lock acquisition by the requeue code. The - * futex_requeue dropped our key1 reference and incremented our key2 - * reference count. - */ + switch (futex_requeue_pi_wakeup_sync(&q)) { + case Q_REQUEUE_PI_IGNORE: + /* The waiter is still on uaddr1 */ + spin_lock(&hb->lock); + ret = handle_early_requeue_pi_wakeup(hb, &q, to); + spin_unlock(&hb->lock); + break; - /* - * Check if the requeue code acquired the second futex for us and do - * any pertinent fixup. - */ - if (!q.rt_waiter) { + case Q_REQUEUE_PI_LOCKED: + /* The requeue acquired the lock */ if (q.pi_state && (q.pi_state->owner != current)) { spin_lock(q.lock_ptr); ret = fixup_owner(uaddr2, &q, true); /* - * Drop the reference to the pi state which - * the requeue_pi() code acquired for us. + * Drop the reference to the pi state which the + * requeue_pi() code acquired for us. */ put_pi_state(q.pi_state); spin_unlock(q.lock_ptr); @@ -3253,18 +3455,14 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, */ ret = ret < 0 ? ret : 0; } - } else { - struct rt_mutex *pi_mutex; + break; - /* - * We have been woken up by futex_unlock_pi(), a timeout, or a - * signal. futex_unlock_pi() will not destroy the lock_ptr nor - * the pi_state. - */ - WARN_ON(!q.pi_state); + case Q_REQUEUE_PI_DONE: + /* Requeue completed. Current is 'pi_blocked_on' the rtmutex */ pi_mutex = &q.pi_state->pi_mutex; ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); + /* Current is not longer pi_blocked_on */ spin_lock(q.lock_ptr); if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) ret = 0; @@ -3284,17 +3482,21 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, unqueue_me_pi(&q); spin_unlock(q.lock_ptr); - } - if (ret == -EINTR) { - /* - * We've already been requeued, but cannot restart by calling - * futex_lock_pi() directly. We could restart this syscall, but - * it would detect that the user space "val" changed and return - * -EWOULDBLOCK. Save the overhead of the restart and return - * -EWOULDBLOCK directly. - */ - ret = -EWOULDBLOCK; + if (ret == -EINTR) { + /* + * We've already been requeued, but cannot restart + * by calling futex_lock_pi() directly. We could + * restart this syscall, but it would detect that + * the user space "val" changed and return + * -EWOULDBLOCK. Save the overhead of the restart + * and return -EWOULDBLOCK directly. + */ + ret = -EWOULDBLOCK; + } + break; + default: + BUG(); } out: diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile index 3572808223e4..d51cabf28f38 100644 --- a/kernel/locking/Makefile +++ b/kernel/locking/Makefile @@ -24,7 +24,8 @@ obj-$(CONFIG_SMP) += spinlock.o obj-$(CONFIG_LOCK_SPIN_ON_OWNER) += osq_lock.o obj-$(CONFIG_PROVE_LOCKING) += spinlock.o obj-$(CONFIG_QUEUED_SPINLOCKS) += qspinlock.o -obj-$(CONFIG_RT_MUTEXES) += rtmutex.o +obj-$(CONFIG_RT_MUTEXES) += rtmutex_api.o +obj-$(CONFIG_PREEMPT_RT) += spinlock_rt.o ww_rt_mutex.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o diff --git a/kernel/locking/mutex-debug.c b/kernel/locking/mutex-debug.c index db9301591e3f..bc8abb8549d2 100644 --- a/kernel/locking/mutex-debug.c +++ b/kernel/locking/mutex-debug.c @@ -1,6 +1,4 @@ /* - * kernel/mutex-debug.c - * * Debugging code for mutexes * * Started by Ingo Molnar: @@ -22,7 +20,7 @@ #include <linux/interrupt.h> #include <linux/debug_locks.h> -#include "mutex-debug.h" +#include "mutex.h" /* * Must be called with lock->wait_lock held. @@ -32,6 +30,7 @@ void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); + waiter->ww_ctx = MUTEX_POISON_WW_CTX; } void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) diff --git a/kernel/locking/mutex-debug.h b/kernel/locking/mutex-debug.h deleted file mode 100644 index 53e631e1d76d..000000000000 --- a/kernel/locking/mutex-debug.h +++ /dev/null @@ -1,29 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Mutexes: blocking mutual exclusion locks - * - * started by Ingo Molnar: - * - * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> - * - * This file contains mutex debugging related internal declarations, - * prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case. - * More details are in kernel/mutex-debug.c. - */ - -/* - * This must be called with lock->wait_lock held. - */ -extern void debug_mutex_lock_common(struct mutex *lock, - struct mutex_waiter *waiter); -extern void debug_mutex_wake_waiter(struct mutex *lock, - struct mutex_waiter *waiter); -extern void debug_mutex_free_waiter(struct mutex_waiter *waiter); -extern void debug_mutex_add_waiter(struct mutex *lock, - struct mutex_waiter *waiter, - struct task_struct *task); -extern void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, - struct task_struct *task); -extern void debug_mutex_unlock(struct mutex *lock); -extern void debug_mutex_init(struct mutex *lock, const char *name, - struct lock_class_key *key); diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index d2df5e68b503..d456579d0952 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -30,17 +30,20 @@ #include <linux/debug_locks.h> #include <linux/osq_lock.h> +#ifndef CONFIG_PREEMPT_RT +#include "mutex.h" + #ifdef CONFIG_DEBUG_MUTEXES -# include "mutex-debug.h" +# define MUTEX_WARN_ON(cond) DEBUG_LOCKS_WARN_ON(cond) #else -# include "mutex.h" +# define MUTEX_WARN_ON(cond) #endif void __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) { atomic_long_set(&lock->owner, 0); - spin_lock_init(&lock->wait_lock); + raw_spin_lock_init(&lock->wait_lock); INIT_LIST_HEAD(&lock->wait_list); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER osq_lock_init(&lock->osq); @@ -91,55 +94,56 @@ static inline unsigned long __owner_flags(unsigned long owner) return owner & MUTEX_FLAGS; } -/* - * Trylock variant that returns the owning task on failure. - */ -static inline struct task_struct *__mutex_trylock_or_owner(struct mutex *lock) +static inline struct task_struct *__mutex_trylock_common(struct mutex *lock, bool handoff) { unsigned long owner, curr = (unsigned long)current; owner = atomic_long_read(&lock->owner); for (;;) { /* must loop, can race against a flag */ - unsigned long old, flags = __owner_flags(owner); + unsigned long flags = __owner_flags(owner); unsigned long task = owner & ~MUTEX_FLAGS; if (task) { - if (likely(task != curr)) - break; - - if (likely(!(flags & MUTEX_FLAG_PICKUP))) + if (flags & MUTEX_FLAG_PICKUP) { + if (task != curr) + break; + flags &= ~MUTEX_FLAG_PICKUP; + } else if (handoff) { + if (flags & MUTEX_FLAG_HANDOFF) + break; + flags |= MUTEX_FLAG_HANDOFF; + } else { break; - - flags &= ~MUTEX_FLAG_PICKUP; + } } else { -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(flags & MUTEX_FLAG_PICKUP); -#endif + MUTEX_WARN_ON(flags & (MUTEX_FLAG_HANDOFF | MUTEX_FLAG_PICKUP)); + task = curr; } - /* - * We set the HANDOFF bit, we must make sure it doesn't live - * past the point where we acquire it. This would be possible - * if we (accidentally) set the bit on an unlocked mutex. - */ - flags &= ~MUTEX_FLAG_HANDOFF; - - old = atomic_long_cmpxchg_acquire(&lock->owner, owner, curr | flags); - if (old == owner) - return NULL; - - owner = old; + if (atomic_long_try_cmpxchg_acquire(&lock->owner, &owner, task | flags)) { + if (task == curr) + return NULL; + break; + } } return __owner_task(owner); } /* + * Trylock or set HANDOFF + */ +static inline bool __mutex_trylock_or_handoff(struct mutex *lock, bool handoff) +{ + return !__mutex_trylock_common(lock, handoff); +} + +/* * Actual trylock that will work on any unlocked state. */ static inline bool __mutex_trylock(struct mutex *lock) { - return !__mutex_trylock_or_owner(lock); + return !__mutex_trylock_common(lock, false); } #ifndef CONFIG_DEBUG_LOCK_ALLOC @@ -168,10 +172,7 @@ static __always_inline bool __mutex_unlock_fast(struct mutex *lock) { unsigned long curr = (unsigned long)current; - if (atomic_long_cmpxchg_release(&lock->owner, curr, 0UL) == curr) - return true; - - return false; + return atomic_long_try_cmpxchg_release(&lock->owner, &curr, 0UL); } #endif @@ -226,23 +227,18 @@ static void __mutex_handoff(struct mutex *lock, struct task_struct *task) unsigned long owner = atomic_long_read(&lock->owner); for (;;) { - unsigned long old, new; + unsigned long new; -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(__owner_task(owner) != current); - DEBUG_LOCKS_WARN_ON(owner & MUTEX_FLAG_PICKUP); -#endif + MUTEX_WARN_ON(__owner_task(owner) != current); + MUTEX_WARN_ON(owner & MUTEX_FLAG_PICKUP); new = (owner & MUTEX_FLAG_WAITERS); new |= (unsigned long)task; if (task) new |= MUTEX_FLAG_PICKUP; - old = atomic_long_cmpxchg_release(&lock->owner, owner, new); - if (old == owner) + if (atomic_long_try_cmpxchg_release(&lock->owner, &owner, new)) break; - - owner = old; } } @@ -286,218 +282,18 @@ void __sched mutex_lock(struct mutex *lock) EXPORT_SYMBOL(mutex_lock); #endif -/* - * Wait-Die: - * The newer transactions are killed when: - * It (the new transaction) makes a request for a lock being held - * by an older transaction. - * - * Wound-Wait: - * The newer transactions are wounded when: - * An older transaction makes a request for a lock being held by - * the newer transaction. - */ - -/* - * Associate the ww_mutex @ww with the context @ww_ctx under which we acquired - * it. - */ -static __always_inline void -ww_mutex_lock_acquired(struct ww_mutex *ww, struct ww_acquire_ctx *ww_ctx) -{ -#ifdef CONFIG_DEBUG_MUTEXES - /* - * If this WARN_ON triggers, you used ww_mutex_lock to acquire, - * but released with a normal mutex_unlock in this call. - * - * This should never happen, always use ww_mutex_unlock. - */ - DEBUG_LOCKS_WARN_ON(ww->ctx); - - /* - * Not quite done after calling ww_acquire_done() ? - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire); +#include "ww_mutex.h" - if (ww_ctx->contending_lock) { - /* - * After -EDEADLK you tried to - * acquire a different ww_mutex? Bad! - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww); - - /* - * You called ww_mutex_lock after receiving -EDEADLK, - * but 'forgot' to unlock everything else first? - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0); - ww_ctx->contending_lock = NULL; - } - - /* - * Naughty, using a different class will lead to undefined behavior! - */ - DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class); -#endif - ww_ctx->acquired++; - ww->ctx = ww_ctx; -} - -/* - * Determine if context @a is 'after' context @b. IOW, @a is a younger - * transaction than @b and depending on algorithm either needs to wait for - * @b or die. - */ -static inline bool __sched -__ww_ctx_stamp_after(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b) -{ - - return (signed long)(a->stamp - b->stamp) > 0; -} - -/* - * Wait-Die; wake a younger waiter context (when locks held) such that it can - * die. - * - * Among waiters with context, only the first one can have other locks acquired - * already (ctx->acquired > 0), because __ww_mutex_add_waiter() and - * __ww_mutex_check_kill() wake any but the earliest context. - */ -static bool __sched -__ww_mutex_die(struct mutex *lock, struct mutex_waiter *waiter, - struct ww_acquire_ctx *ww_ctx) -{ - if (!ww_ctx->is_wait_die) - return false; - - if (waiter->ww_ctx->acquired > 0 && - __ww_ctx_stamp_after(waiter->ww_ctx, ww_ctx)) { - debug_mutex_wake_waiter(lock, waiter); - wake_up_process(waiter->task); - } - - return true; -} - -/* - * Wound-Wait; wound a younger @hold_ctx if it holds the lock. - * - * Wound the lock holder if there are waiters with older transactions than - * the lock holders. Even if multiple waiters may wound the lock holder, - * it's sufficient that only one does. - */ -static bool __ww_mutex_wound(struct mutex *lock, - struct ww_acquire_ctx *ww_ctx, - struct ww_acquire_ctx *hold_ctx) -{ - struct task_struct *owner = __mutex_owner(lock); - - lockdep_assert_held(&lock->wait_lock); - - /* - * Possible through __ww_mutex_add_waiter() when we race with - * ww_mutex_set_context_fastpath(). In that case we'll get here again - * through __ww_mutex_check_waiters(). - */ - if (!hold_ctx) - return false; - - /* - * Can have !owner because of __mutex_unlock_slowpath(), but if owner, - * it cannot go away because we'll have FLAG_WAITERS set and hold - * wait_lock. - */ - if (!owner) - return false; - - if (ww_ctx->acquired > 0 && __ww_ctx_stamp_after(hold_ctx, ww_ctx)) { - hold_ctx->wounded = 1; - - /* - * wake_up_process() paired with set_current_state() - * inserts sufficient barriers to make sure @owner either sees - * it's wounded in __ww_mutex_check_kill() or has a - * wakeup pending to re-read the wounded state. - */ - if (owner != current) - wake_up_process(owner); - - return true; - } - - return false; -} - -/* - * We just acquired @lock under @ww_ctx, if there are later contexts waiting - * behind us on the wait-list, check if they need to die, or wound us. - * - * See __ww_mutex_add_waiter() for the list-order construction; basically the - * list is ordered by stamp, smallest (oldest) first. - * - * This relies on never mixing wait-die/wound-wait on the same wait-list; - * which is currently ensured by that being a ww_class property. - * - * The current task must not be on the wait list. - */ -static void __sched -__ww_mutex_check_waiters(struct mutex *lock, struct ww_acquire_ctx *ww_ctx) -{ - struct mutex_waiter *cur; - - lockdep_assert_held(&lock->wait_lock); - - list_for_each_entry(cur, &lock->wait_list, list) { - if (!cur->ww_ctx) - continue; - - if (__ww_mutex_die(lock, cur, ww_ctx) || - __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx)) - break; - } -} +#ifdef CONFIG_MUTEX_SPIN_ON_OWNER /* - * After acquiring lock with fastpath, where we do not hold wait_lock, set ctx - * and wake up any waiters so they can recheck. + * Trylock variant that returns the owning task on failure. */ -static __always_inline void -ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +static inline struct task_struct *__mutex_trylock_or_owner(struct mutex *lock) { - ww_mutex_lock_acquired(lock, ctx); - - /* - * The lock->ctx update should be visible on all cores before - * the WAITERS check is done, otherwise contended waiters might be - * missed. The contended waiters will either see ww_ctx == NULL - * and keep spinning, or it will acquire wait_lock, add itself - * to waiter list and sleep. - */ - smp_mb(); /* See comments above and below. */ - - /* - * [W] ww->ctx = ctx [W] MUTEX_FLAG_WAITERS - * MB MB - * [R] MUTEX_FLAG_WAITERS [R] ww->ctx - * - * The memory barrier above pairs with the memory barrier in - * __ww_mutex_add_waiter() and makes sure we either observe ww->ctx - * and/or !empty list. - */ - if (likely(!(atomic_long_read(&lock->base.owner) & MUTEX_FLAG_WAITERS))) - return; - - /* - * Uh oh, we raced in fastpath, check if any of the waiters need to - * die or wound us. - */ - spin_lock(&lock->base.wait_lock); - __ww_mutex_check_waiters(&lock->base, ctx); - spin_unlock(&lock->base.wait_lock); + return __mutex_trylock_common(lock, false); } -#ifdef CONFIG_MUTEX_SPIN_ON_OWNER - static inline bool ww_mutex_spin_on_owner(struct mutex *lock, struct ww_acquire_ctx *ww_ctx, struct mutex_waiter *waiter) @@ -754,171 +550,11 @@ EXPORT_SYMBOL(mutex_unlock); */ void __sched ww_mutex_unlock(struct ww_mutex *lock) { - /* - * The unlocking fastpath is the 0->1 transition from 'locked' - * into 'unlocked' state: - */ - if (lock->ctx) { -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired); -#endif - if (lock->ctx->acquired > 0) - lock->ctx->acquired--; - lock->ctx = NULL; - } - + __ww_mutex_unlock(lock); mutex_unlock(&lock->base); } EXPORT_SYMBOL(ww_mutex_unlock); - -static __always_inline int __sched -__ww_mutex_kill(struct mutex *lock, struct ww_acquire_ctx *ww_ctx) -{ - if (ww_ctx->acquired > 0) { -#ifdef CONFIG_DEBUG_MUTEXES - struct ww_mutex *ww; - - ww = container_of(lock, struct ww_mutex, base); - DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock); - ww_ctx->contending_lock = ww; -#endif - return -EDEADLK; - } - - return 0; -} - - -/* - * Check the wound condition for the current lock acquire. - * - * Wound-Wait: If we're wounded, kill ourself. - * - * Wait-Die: If we're trying to acquire a lock already held by an older - * context, kill ourselves. - * - * Since __ww_mutex_add_waiter() orders the wait-list on stamp, we only have to - * look at waiters before us in the wait-list. - */ -static inline int __sched -__ww_mutex_check_kill(struct mutex *lock, struct mutex_waiter *waiter, - struct ww_acquire_ctx *ctx) -{ - struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); - struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx); - struct mutex_waiter *cur; - - if (ctx->acquired == 0) - return 0; - - if (!ctx->is_wait_die) { - if (ctx->wounded) - return __ww_mutex_kill(lock, ctx); - - return 0; - } - - if (hold_ctx && __ww_ctx_stamp_after(ctx, hold_ctx)) - return __ww_mutex_kill(lock, ctx); - - /* - * If there is a waiter in front of us that has a context, then its - * stamp is earlier than ours and we must kill ourself. - */ - cur = waiter; - list_for_each_entry_continue_reverse(cur, &lock->wait_list, list) { - if (!cur->ww_ctx) - continue; - - return __ww_mutex_kill(lock, ctx); - } - - return 0; -} - -/* - * Add @waiter to the wait-list, keep the wait-list ordered by stamp, smallest - * first. Such that older contexts are preferred to acquire the lock over - * younger contexts. - * - * Waiters without context are interspersed in FIFO order. - * - * Furthermore, for Wait-Die kill ourself immediately when possible (there are - * older contexts already waiting) to avoid unnecessary waiting and for - * Wound-Wait ensure we wound the owning context when it is younger. - */ -static inline int __sched -__ww_mutex_add_waiter(struct mutex_waiter *waiter, - struct mutex *lock, - struct ww_acquire_ctx *ww_ctx) -{ - struct mutex_waiter *cur; - struct list_head *pos; - bool is_wait_die; - - if (!ww_ctx) { - __mutex_add_waiter(lock, waiter, &lock->wait_list); - return 0; - } - - is_wait_die = ww_ctx->is_wait_die; - - /* - * Add the waiter before the first waiter with a higher stamp. - * Waiters without a context are skipped to avoid starving - * them. Wait-Die waiters may die here. Wound-Wait waiters - * never die here, but they are sorted in stamp order and - * may wound the lock holder. - */ - pos = &lock->wait_list; - list_for_each_entry_reverse(cur, &lock->wait_list, list) { - if (!cur->ww_ctx) - continue; - - if (__ww_ctx_stamp_after(ww_ctx, cur->ww_ctx)) { - /* - * Wait-Die: if we find an older context waiting, there - * is no point in queueing behind it, as we'd have to - * die the moment it would acquire the lock. - */ - if (is_wait_die) { - int ret = __ww_mutex_kill(lock, ww_ctx); - - if (ret) - return ret; - } - - break; - } - - pos = &cur->list; - - /* Wait-Die: ensure younger waiters die. */ - __ww_mutex_die(lock, cur, ww_ctx); - } - - __mutex_add_waiter(lock, waiter, pos); - - /* - * Wound-Wait: if we're blocking on a mutex owned by a younger context, - * wound that such that we might proceed. - */ - if (!is_wait_die) { - struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); - - /* - * See ww_mutex_set_context_fastpath(). Orders setting - * MUTEX_FLAG_WAITERS vs the ww->ctx load, - * such that either we or the fastpath will wound @ww->ctx. - */ - smp_mb(); - __ww_mutex_wound(lock, ww_ctx, ww->ctx); - } - - return 0; -} - /* * Lock a mutex (possibly interruptible), slowpath: */ @@ -928,7 +564,6 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx) { struct mutex_waiter waiter; - bool first = false; struct ww_mutex *ww; int ret; @@ -937,9 +572,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas might_sleep(); -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(lock->magic != lock); -#endif + MUTEX_WARN_ON(lock->magic != lock); ww = container_of(lock, struct ww_mutex, base); if (ww_ctx) { @@ -953,6 +586,10 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas */ if (ww_ctx->acquired == 0) ww_ctx->wounded = 0; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + nest_lock = &ww_ctx->dep_map; +#endif } preempt_disable(); @@ -968,7 +605,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas return 0; } - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); /* * After waiting to acquire the wait_lock, try again. */ @@ -980,17 +617,15 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas } debug_mutex_lock_common(lock, &waiter); + waiter.task = current; + if (use_ww_ctx) + waiter.ww_ctx = ww_ctx; lock_contended(&lock->dep_map, ip); if (!use_ww_ctx) { /* add waiting tasks to the end of the waitqueue (FIFO): */ __mutex_add_waiter(lock, &waiter, &lock->wait_list); - - -#ifdef CONFIG_DEBUG_MUTEXES - waiter.ww_ctx = MUTEX_POISON_WW_CTX; -#endif } else { /* * Add in stamp order, waking up waiters that must kill @@ -999,14 +634,12 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas ret = __ww_mutex_add_waiter(&waiter, lock, ww_ctx); if (ret) goto err_early_kill; - - waiter.ww_ctx = ww_ctx; } - waiter.task = current; - set_current_state(state); for (;;) { + bool first; + /* * Once we hold wait_lock, we're serialized against * mutex_unlock() handing the lock off to us, do a trylock @@ -1032,18 +665,10 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas goto err; } - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); schedule_preempt_disabled(); - /* - * ww_mutex needs to always recheck its position since its waiter - * list is not FIFO ordered. - */ - if (ww_ctx || !first) { - first = __mutex_waiter_is_first(lock, &waiter); - if (first) - __mutex_set_flag(lock, MUTEX_FLAG_HANDOFF); - } + first = __mutex_waiter_is_first(lock, &waiter); set_current_state(state); /* @@ -1051,13 +676,13 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas * state back to RUNNING and fall through the next schedule(), * or we must see its unlock and acquire. */ - if (__mutex_trylock(lock) || + if (__mutex_trylock_or_handoff(lock, first) || (first && mutex_optimistic_spin(lock, ww_ctx, &waiter))) break; - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); } - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); acquired: __set_current_state(TASK_RUNNING); @@ -1082,7 +707,7 @@ skip_wait: if (ww_ctx) ww_mutex_lock_acquired(ww, ww_ctx); - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); preempt_enable(); return 0; @@ -1090,7 +715,7 @@ err: __set_current_state(TASK_RUNNING); __mutex_remove_waiter(lock, &waiter); err_early_kill: - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); debug_mutex_free_waiter(&waiter); mutex_release(&lock->dep_map, ip); preempt_enable(); @@ -1106,10 +731,9 @@ __mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass, static int __sched __ww_mutex_lock(struct mutex *lock, unsigned int state, unsigned int subclass, - struct lockdep_map *nest_lock, unsigned long ip, - struct ww_acquire_ctx *ww_ctx) + unsigned long ip, struct ww_acquire_ctx *ww_ctx) { - return __mutex_lock_common(lock, state, subclass, nest_lock, ip, ww_ctx, true); + return __mutex_lock_common(lock, state, subclass, NULL, ip, ww_ctx, true); } #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -1189,8 +813,7 @@ ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) might_sleep(); ret = __ww_mutex_lock(&lock->base, TASK_UNINTERRUPTIBLE, - 0, ctx ? &ctx->dep_map : NULL, _RET_IP_, - ctx); + 0, _RET_IP_, ctx); if (!ret && ctx && ctx->acquired > 1) return ww_mutex_deadlock_injection(lock, ctx); @@ -1205,8 +828,7 @@ ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) might_sleep(); ret = __ww_mutex_lock(&lock->base, TASK_INTERRUPTIBLE, - 0, ctx ? &ctx->dep_map : NULL, _RET_IP_, - ctx); + 0, _RET_IP_, ctx); if (!ret && ctx && ctx->acquired > 1) return ww_mutex_deadlock_injection(lock, ctx); @@ -1237,29 +859,21 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne */ owner = atomic_long_read(&lock->owner); for (;;) { - unsigned long old; - -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(__owner_task(owner) != current); - DEBUG_LOCKS_WARN_ON(owner & MUTEX_FLAG_PICKUP); -#endif + MUTEX_WARN_ON(__owner_task(owner) != current); + MUTEX_WARN_ON(owner & MUTEX_FLAG_PICKUP); if (owner & MUTEX_FLAG_HANDOFF) break; - old = atomic_long_cmpxchg_release(&lock->owner, owner, - __owner_flags(owner)); - if (old == owner) { + if (atomic_long_try_cmpxchg_release(&lock->owner, &owner, __owner_flags(owner))) { if (owner & MUTEX_FLAG_WAITERS) break; return; } - - owner = old; } - spin_lock(&lock->wait_lock); + raw_spin_lock(&lock->wait_lock); debug_mutex_unlock(lock); if (!list_empty(&lock->wait_list)) { /* get the first entry from the wait-list: */ @@ -1276,7 +890,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne if (owner & MUTEX_FLAG_HANDOFF) __mutex_handoff(lock, next); - spin_unlock(&lock->wait_lock); + raw_spin_unlock(&lock->wait_lock); wake_up_q(&wake_q); } @@ -1380,7 +994,7 @@ __mutex_lock_interruptible_slowpath(struct mutex *lock) static noinline int __sched __ww_mutex_lock_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { - return __ww_mutex_lock(&lock->base, TASK_UNINTERRUPTIBLE, 0, NULL, + return __ww_mutex_lock(&lock->base, TASK_UNINTERRUPTIBLE, 0, _RET_IP_, ctx); } @@ -1388,7 +1002,7 @@ static noinline int __sched __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { - return __ww_mutex_lock(&lock->base, TASK_INTERRUPTIBLE, 0, NULL, + return __ww_mutex_lock(&lock->base, TASK_INTERRUPTIBLE, 0, _RET_IP_, ctx); } @@ -1412,9 +1026,7 @@ int __sched mutex_trylock(struct mutex *lock) { bool locked; -#ifdef CONFIG_DEBUG_MUTEXES - DEBUG_LOCKS_WARN_ON(lock->magic != lock); -#endif + MUTEX_WARN_ON(lock->magic != lock); locked = __mutex_trylock(lock); if (locked) @@ -1455,7 +1067,8 @@ ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) } EXPORT_SYMBOL(ww_mutex_lock_interruptible); -#endif +#endif /* !CONFIG_DEBUG_LOCK_ALLOC */ +#endif /* !CONFIG_PREEMPT_RT */ /** * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0 diff --git a/kernel/locking/mutex.h b/kernel/locking/mutex.h index f0c710b1d192..0b2a79c4013b 100644 --- a/kernel/locking/mutex.h +++ b/kernel/locking/mutex.h @@ -5,19 +5,41 @@ * started by Ingo Molnar: * * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> - * - * This file contains mutex debugging related internal prototypes, for the - * !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs: */ -#define debug_mutex_wake_waiter(lock, waiter) do { } while (0) -#define debug_mutex_free_waiter(waiter) do { } while (0) -#define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0) -#define debug_mutex_remove_waiter(lock, waiter, ti) do { } while (0) -#define debug_mutex_unlock(lock) do { } while (0) -#define debug_mutex_init(lock, name, key) do { } while (0) +/* + * This is the control structure for tasks blocked on mutex, which resides + * on the blocked task's kernel stack: + */ +struct mutex_waiter { + struct list_head list; + struct task_struct *task; + struct ww_acquire_ctx *ww_ctx; +#ifdef CONFIG_DEBUG_MUTEXES + void *magic; +#endif +}; -static inline void -debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) -{ -} +#ifdef CONFIG_DEBUG_MUTEXES +extern void debug_mutex_lock_common(struct mutex *lock, + struct mutex_waiter *waiter); +extern void debug_mutex_wake_waiter(struct mutex *lock, + struct mutex_waiter *waiter); +extern void debug_mutex_free_waiter(struct mutex_waiter *waiter); +extern void debug_mutex_add_waiter(struct mutex *lock, + struct mutex_waiter *waiter, + struct task_struct *task); +extern void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, + struct task_struct *task); +extern void debug_mutex_unlock(struct mutex *lock); +extern void debug_mutex_init(struct mutex *lock, const char *name, + struct lock_class_key *key); +#else /* CONFIG_DEBUG_MUTEXES */ +# define debug_mutex_lock_common(lock, waiter) do { } while (0) +# define debug_mutex_wake_waiter(lock, waiter) do { } while (0) +# define debug_mutex_free_waiter(waiter) do { } while (0) +# define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0) +# define debug_mutex_remove_waiter(lock, waiter, ti) do { } while (0) +# define debug_mutex_unlock(lock) do { } while (0) +# define debug_mutex_init(lock, name, key) do { } while (0) +#endif /* !CONFIG_DEBUG_MUTEXES */ diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index ad0db322ed3b..8eabdc79602b 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -8,20 +8,58 @@ * Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com> * Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt * Copyright (C) 2006 Esben Nielsen + * Adaptive Spinlocks: + * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich, + * and Peter Morreale, + * Adaptive Spinlocks simplification: + * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com> * * See Documentation/locking/rt-mutex-design.rst for details. */ -#include <linux/spinlock.h> -#include <linux/export.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/sched/deadline.h> #include <linux/sched/signal.h> #include <linux/sched/rt.h> -#include <linux/sched/deadline.h> #include <linux/sched/wake_q.h> -#include <linux/sched/debug.h> -#include <linux/timer.h> +#include <linux/ww_mutex.h> #include "rtmutex_common.h" +#ifndef WW_RT +# define build_ww_mutex() (false) +# define ww_container_of(rtm) NULL + +static inline int __ww_mutex_add_waiter(struct rt_mutex_waiter *waiter, + struct rt_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ + return 0; +} + +static inline void __ww_mutex_check_waiters(struct rt_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ +} + +static inline void ww_mutex_lock_acquired(struct ww_mutex *lock, + struct ww_acquire_ctx *ww_ctx) +{ +} + +static inline int __ww_mutex_check_kill(struct rt_mutex *lock, + struct rt_mutex_waiter *waiter, + struct ww_acquire_ctx *ww_ctx) +{ + return 0; +} + +#else +# define build_ww_mutex() (true) +# define ww_container_of(rtm) container_of(rtm, struct ww_mutex, base) +# include "ww_mutex.h" +#endif + /* * lock->owner state tracking: * @@ -50,7 +88,7 @@ */ static __always_inline void -rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner) +rt_mutex_set_owner(struct rt_mutex_base *lock, struct task_struct *owner) { unsigned long val = (unsigned long)owner; @@ -60,13 +98,13 @@ rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner) WRITE_ONCE(lock->owner, (struct task_struct *)val); } -static __always_inline void clear_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline void clear_rt_mutex_waiters(struct rt_mutex_base *lock) { lock->owner = (struct task_struct *) ((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS); } -static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex_base *lock) { unsigned long owner, *p = (unsigned long *) &lock->owner; @@ -141,15 +179,26 @@ static __always_inline void fixup_rt_mutex_waiters(struct rt_mutex *lock) * set up. */ #ifndef CONFIG_DEBUG_RT_MUTEXES -# define rt_mutex_cmpxchg_acquire(l,c,n) (cmpxchg_acquire(&l->owner, c, n) == c) -# define rt_mutex_cmpxchg_release(l,c,n) (cmpxchg_release(&l->owner, c, n) == c) +static __always_inline bool rt_mutex_cmpxchg_acquire(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return try_cmpxchg_acquire(&lock->owner, &old, new); +} + +static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return try_cmpxchg_release(&lock->owner, &old, new); +} /* * Callers must hold the ->wait_lock -- which is the whole purpose as we force * all future threads that attempt to [Rmw] the lock to the slowpath. As such * relaxed semantics suffice. */ -static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline void mark_rt_mutex_waiters(struct rt_mutex_base *lock) { unsigned long owner, *p = (unsigned long *) &lock->owner; @@ -165,7 +214,7 @@ static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) * 2) Drop lock->wait_lock * 3) Try to unlock the lock with cmpxchg */ -static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, +static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex_base *lock, unsigned long flags) __releases(lock->wait_lock) { @@ -201,10 +250,22 @@ static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, } #else -# define rt_mutex_cmpxchg_acquire(l,c,n) (0) -# define rt_mutex_cmpxchg_release(l,c,n) (0) +static __always_inline bool rt_mutex_cmpxchg_acquire(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return false; + +} -static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) +static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex_base *lock, + struct task_struct *old, + struct task_struct *new) +{ + return false; +} + +static __always_inline void mark_rt_mutex_waiters(struct rt_mutex_base *lock) { lock->owner = (struct task_struct *) ((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS); @@ -213,7 +274,7 @@ static __always_inline void mark_rt_mutex_waiters(struct rt_mutex *lock) /* * Simple slow path only version: lock->owner is protected by lock->wait_lock. */ -static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, +static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex_base *lock, unsigned long flags) __releases(lock->wait_lock) { @@ -223,11 +284,28 @@ static __always_inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, } #endif +static __always_inline int __waiter_prio(struct task_struct *task) +{ + int prio = task->prio; + + if (!rt_prio(prio)) + return DEFAULT_PRIO; + + return prio; +} + +static __always_inline void +waiter_update_prio(struct rt_mutex_waiter *waiter, struct task_struct *task) +{ + waiter->prio = __waiter_prio(task); + waiter->deadline = task->dl.deadline; +} + /* * Only use with rt_mutex_waiter_{less,equal}() */ #define task_to_waiter(p) \ - &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline } + &(struct rt_mutex_waiter){ .prio = __waiter_prio(p), .deadline = (p)->dl.deadline } static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, struct rt_mutex_waiter *right) @@ -265,22 +343,63 @@ static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left, return 1; } +static inline bool rt_mutex_steal(struct rt_mutex_waiter *waiter, + struct rt_mutex_waiter *top_waiter) +{ + if (rt_mutex_waiter_less(waiter, top_waiter)) + return true; + +#ifdef RT_MUTEX_BUILD_SPINLOCKS + /* + * Note that RT tasks are excluded from same priority (lateral) + * steals to prevent the introduction of an unbounded latency. + */ + if (rt_prio(waiter->prio) || dl_prio(waiter->prio)) + return false; + + return rt_mutex_waiter_equal(waiter, top_waiter); +#else + return false; +#endif +} + #define __node_2_waiter(node) \ rb_entry((node), struct rt_mutex_waiter, tree_entry) static __always_inline bool __waiter_less(struct rb_node *a, const struct rb_node *b) { - return rt_mutex_waiter_less(__node_2_waiter(a), __node_2_waiter(b)); + struct rt_mutex_waiter *aw = __node_2_waiter(a); + struct rt_mutex_waiter *bw = __node_2_waiter(b); + + if (rt_mutex_waiter_less(aw, bw)) + return 1; + + if (!build_ww_mutex()) + return 0; + + if (rt_mutex_waiter_less(bw, aw)) + return 0; + + /* NOTE: relies on waiter->ww_ctx being set before insertion */ + if (aw->ww_ctx) { + if (!bw->ww_ctx) + return 1; + + return (signed long)(aw->ww_ctx->stamp - + bw->ww_ctx->stamp) < 0; + } + + return 0; } static __always_inline void -rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter) +rt_mutex_enqueue(struct rt_mutex_base *lock, struct rt_mutex_waiter *waiter) { rb_add_cached(&waiter->tree_entry, &lock->waiters, __waiter_less); } static __always_inline void -rt_mutex_dequeue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter) +rt_mutex_dequeue(struct rt_mutex_base *lock, struct rt_mutex_waiter *waiter) { if (RB_EMPTY_NODE(&waiter->tree_entry)) return; @@ -326,6 +445,35 @@ static __always_inline void rt_mutex_adjust_prio(struct task_struct *p) rt_mutex_setprio(p, pi_task); } +/* RT mutex specific wake_q wrappers */ +static __always_inline void rt_mutex_wake_q_add(struct rt_wake_q_head *wqh, + struct rt_mutex_waiter *w) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && w->wake_state != TASK_NORMAL) { + if (IS_ENABLED(CONFIG_PROVE_LOCKING)) + WARN_ON_ONCE(wqh->rtlock_task); + get_task_struct(w->task); + wqh->rtlock_task = w->task; + } else { + wake_q_add(&wqh->head, w->task); + } +} + +static __always_inline void rt_mutex_wake_up_q(struct rt_wake_q_head *wqh) +{ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && wqh->rtlock_task) { + wake_up_state(wqh->rtlock_task, TASK_RTLOCK_WAIT); + put_task_struct(wqh->rtlock_task); + wqh->rtlock_task = NULL; + } + + if (!wake_q_empty(&wqh->head)) + wake_up_q(&wqh->head); + + /* Pairs with preempt_disable() in mark_wakeup_next_waiter() */ + preempt_enable(); +} + /* * Deadlock detection is conditional: * @@ -348,12 +496,7 @@ rt_mutex_cond_detect_deadlock(struct rt_mutex_waiter *waiter, return chwalk == RT_MUTEX_FULL_CHAINWALK; } -/* - * Max number of times we'll walk the boosting chain: - */ -int max_lock_depth = 1024; - -static __always_inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p) +static __always_inline struct rt_mutex_base *task_blocked_on_lock(struct task_struct *p) { return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL; } @@ -423,15 +566,15 @@ static __always_inline struct rt_mutex *task_blocked_on_lock(struct task_struct */ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, enum rtmutex_chainwalk chwalk, - struct rt_mutex *orig_lock, - struct rt_mutex *next_lock, + struct rt_mutex_base *orig_lock, + struct rt_mutex_base *next_lock, struct rt_mutex_waiter *orig_waiter, struct task_struct *top_task) { struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter; struct rt_mutex_waiter *prerequeue_top_waiter; int ret = 0, depth = 0; - struct rt_mutex *lock; + struct rt_mutex_base *lock; bool detect_deadlock; bool requeue = true; @@ -514,6 +657,31 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, goto out_unlock_pi; /* + * There could be 'spurious' loops in the lock graph due to ww_mutex, + * consider: + * + * P1: A, ww_A, ww_B + * P2: ww_B, ww_A + * P3: A + * + * P3 should not return -EDEADLK because it gets trapped in the cycle + * created by P1 and P2 (which will resolve -- and runs into + * max_lock_depth above). Therefore disable detect_deadlock such that + * the below termination condition can trigger once all relevant tasks + * are boosted. + * + * Even when we start with ww_mutex we can disable deadlock detection, + * since we would supress a ww_mutex induced deadlock at [6] anyway. + * Supressing it here however is not sufficient since we might still + * hit [6] due to adjustment driven iteration. + * + * NOTE: if someone were to create a deadlock between 2 ww_classes we'd + * utterly fail to report it; lockdep should. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && waiter->ww_ctx && detect_deadlock) + detect_deadlock = false; + + /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! @@ -574,8 +742,21 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * walk, we detected a deadlock. */ if (lock == orig_lock || rt_mutex_owner(lock) == top_task) { - raw_spin_unlock(&lock->wait_lock); ret = -EDEADLK; + + /* + * When the deadlock is due to ww_mutex; also see above. Don't + * report the deadlock and instead let the ww_mutex wound/die + * logic pick which of the contending threads gets -EDEADLK. + * + * NOTE: assumes the cycle only contains a single ww_class; any + * other configuration and we fail to report; also, see + * lockdep. + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && orig_waiter->ww_ctx) + ret = 0; + + raw_spin_unlock(&lock->wait_lock); goto out_unlock_pi; } @@ -653,8 +834,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * serializes all pi_waiters access and rb_erase() does not care about * the values of the node being removed. */ - waiter->prio = task->prio; - waiter->deadline = task->dl.deadline; + waiter_update_prio(waiter, task); rt_mutex_enqueue(lock, waiter); @@ -676,7 +856,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * to get the lock. */ if (prerequeue_top_waiter != rt_mutex_top_waiter(lock)) - wake_up_process(rt_mutex_top_waiter(lock)->task); + wake_up_state(waiter->task, waiter->wake_state); raw_spin_unlock_irq(&lock->wait_lock); return 0; } @@ -779,7 +959,7 @@ static int __sched rt_mutex_adjust_prio_chain(struct task_struct *task, * callsite called task_blocked_on_lock(), otherwise NULL */ static int __sched -try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, +try_to_take_rt_mutex(struct rt_mutex_base *lock, struct task_struct *task, struct rt_mutex_waiter *waiter) { lockdep_assert_held(&lock->wait_lock); @@ -815,19 +995,21 @@ try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, * trylock attempt. */ if (waiter) { - /* - * If waiter is not the highest priority waiter of - * @lock, give up. - */ - if (waiter != rt_mutex_top_waiter(lock)) - return 0; + struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock); /* - * We can acquire the lock. Remove the waiter from the - * lock waiters tree. + * If waiter is the highest priority waiter of @lock, + * or allowed to steal it, take it over. */ - rt_mutex_dequeue(lock, waiter); - + if (waiter == top_waiter || rt_mutex_steal(waiter, top_waiter)) { + /* + * We can acquire the lock. Remove the waiter from the + * lock waiters tree. + */ + rt_mutex_dequeue(lock, waiter); + } else { + return 0; + } } else { /* * If the lock has waiters already we check whether @task is @@ -838,13 +1020,9 @@ try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task, * not need to be dequeued. */ if (rt_mutex_has_waiters(lock)) { - /* - * If @task->prio is greater than or equal to - * the top waiter priority (kernel view), - * @task lost. - */ - if (!rt_mutex_waiter_less(task_to_waiter(task), - rt_mutex_top_waiter(lock))) + /* Check whether the trylock can steal it. */ + if (!rt_mutex_steal(task_to_waiter(task), + rt_mutex_top_waiter(lock))) return 0; /* @@ -897,14 +1075,15 @@ takeit: * * This must be called with lock->wait_lock held and interrupts disabled */ -static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, +static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock, struct rt_mutex_waiter *waiter, struct task_struct *task, + struct ww_acquire_ctx *ww_ctx, enum rtmutex_chainwalk chwalk) { struct task_struct *owner = rt_mutex_owner(lock); struct rt_mutex_waiter *top_waiter = waiter; - struct rt_mutex *next_lock; + struct rt_mutex_base *next_lock; int chain_walk = 0, res; lockdep_assert_held(&lock->wait_lock); @@ -924,8 +1103,7 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, raw_spin_lock(&task->pi_lock); waiter->task = task; waiter->lock = lock; - waiter->prio = task->prio; - waiter->deadline = task->dl.deadline; + waiter_update_prio(waiter, task); /* Get the top priority waiter on the lock */ if (rt_mutex_has_waiters(lock)) @@ -936,6 +1114,21 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, raw_spin_unlock(&task->pi_lock); + if (build_ww_mutex() && ww_ctx) { + struct rt_mutex *rtm; + + /* Check whether the waiter should back out immediately */ + rtm = container_of(lock, struct rt_mutex, rtmutex); + res = __ww_mutex_add_waiter(waiter, rtm, ww_ctx); + if (res) { + raw_spin_lock(&task->pi_lock); + rt_mutex_dequeue(lock, waiter); + task->pi_blocked_on = NULL; + raw_spin_unlock(&task->pi_lock); + return res; + } + } + if (!owner) return 0; @@ -986,8 +1179,8 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex *lock, * * Called with lock->wait_lock held and interrupts disabled. */ -static void __sched mark_wakeup_next_waiter(struct wake_q_head *wake_q, - struct rt_mutex *lock) +static void __sched mark_wakeup_next_waiter(struct rt_wake_q_head *wqh, + struct rt_mutex_base *lock) { struct rt_mutex_waiter *waiter; @@ -1023,235 +1216,14 @@ static void __sched mark_wakeup_next_waiter(struct wake_q_head *wake_q, * deboost but before waking our donor task, hence the preempt_disable() * before unlock. * - * Pairs with preempt_enable() in rt_mutex_postunlock(); + * Pairs with preempt_enable() in rt_mutex_wake_up_q(); */ preempt_disable(); - wake_q_add(wake_q, waiter->task); - raw_spin_unlock(¤t->pi_lock); -} - -/* - * Remove a waiter from a lock and give up - * - * Must be called with lock->wait_lock held and interrupts disabled. I must - * have just failed to try_to_take_rt_mutex(). - */ -static void __sched remove_waiter(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter) -{ - bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); - struct task_struct *owner = rt_mutex_owner(lock); - struct rt_mutex *next_lock; - - lockdep_assert_held(&lock->wait_lock); - - raw_spin_lock(¤t->pi_lock); - rt_mutex_dequeue(lock, waiter); - current->pi_blocked_on = NULL; + rt_mutex_wake_q_add(wqh, waiter); raw_spin_unlock(¤t->pi_lock); - - /* - * Only update priority if the waiter was the highest priority - * waiter of the lock and there is an owner to update. - */ - if (!owner || !is_top_waiter) - return; - - raw_spin_lock(&owner->pi_lock); - - rt_mutex_dequeue_pi(owner, waiter); - - if (rt_mutex_has_waiters(lock)) - rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock)); - - rt_mutex_adjust_prio(owner); - - /* Store the lock on which owner is blocked or NULL */ - next_lock = task_blocked_on_lock(owner); - - raw_spin_unlock(&owner->pi_lock); - - /* - * Don't walk the chain, if the owner task is not blocked - * itself. - */ - if (!next_lock) - return; - - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(owner); - - raw_spin_unlock_irq(&lock->wait_lock); - - rt_mutex_adjust_prio_chain(owner, RT_MUTEX_MIN_CHAINWALK, lock, - next_lock, NULL, current); - - raw_spin_lock_irq(&lock->wait_lock); -} - -/* - * Recheck the pi chain, in case we got a priority setting - * - * Called from sched_setscheduler - */ -void __sched rt_mutex_adjust_pi(struct task_struct *task) -{ - struct rt_mutex_waiter *waiter; - struct rt_mutex *next_lock; - unsigned long flags; - - raw_spin_lock_irqsave(&task->pi_lock, flags); - - waiter = task->pi_blocked_on; - if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { - raw_spin_unlock_irqrestore(&task->pi_lock, flags); - return; - } - next_lock = waiter->lock; - raw_spin_unlock_irqrestore(&task->pi_lock, flags); - - /* gets dropped in rt_mutex_adjust_prio_chain()! */ - get_task_struct(task); - - rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL, - next_lock, NULL, task); } -void __sched rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) -{ - debug_rt_mutex_init_waiter(waiter); - RB_CLEAR_NODE(&waiter->pi_tree_entry); - RB_CLEAR_NODE(&waiter->tree_entry); - waiter->task = NULL; -} - -/** - * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop - * @lock: the rt_mutex to take - * @state: the state the task should block in (TASK_INTERRUPTIBLE - * or TASK_UNINTERRUPTIBLE) - * @timeout: the pre-initialized and started timer, or NULL for none - * @waiter: the pre-initialized rt_mutex_waiter - * - * Must be called with lock->wait_lock held and interrupts disabled - */ -static int __sched __rt_mutex_slowlock(struct rt_mutex *lock, unsigned int state, - struct hrtimer_sleeper *timeout, - struct rt_mutex_waiter *waiter) -{ - int ret = 0; - - for (;;) { - /* Try to acquire the lock: */ - if (try_to_take_rt_mutex(lock, current, waiter)) - break; - - if (timeout && !timeout->task) { - ret = -ETIMEDOUT; - break; - } - if (signal_pending_state(state, current)) { - ret = -EINTR; - break; - } - - raw_spin_unlock_irq(&lock->wait_lock); - - schedule(); - - raw_spin_lock_irq(&lock->wait_lock); - set_current_state(state); - } - - __set_current_state(TASK_RUNNING); - return ret; -} - -static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, - struct rt_mutex_waiter *w) -{ - /* - * If the result is not -EDEADLOCK or the caller requested - * deadlock detection, nothing to do here. - */ - if (res != -EDEADLOCK || detect_deadlock) - return; - - /* - * Yell loudly and stop the task right here. - */ - WARN(1, "rtmutex deadlock detected\n"); - while (1) { - set_current_state(TASK_INTERRUPTIBLE); - schedule(); - } -} - -/* - * Slow path lock function: - */ -static int __sched rt_mutex_slowlock(struct rt_mutex *lock, unsigned int state, - struct hrtimer_sleeper *timeout, - enum rtmutex_chainwalk chwalk) -{ - struct rt_mutex_waiter waiter; - unsigned long flags; - int ret = 0; - - rt_mutex_init_waiter(&waiter); - - /* - * Technically we could use raw_spin_[un]lock_irq() here, but this can - * be called in early boot if the cmpxchg() fast path is disabled - * (debug, no architecture support). In this case we will acquire the - * rtmutex with lock->wait_lock held. But we cannot unconditionally - * enable interrupts in that early boot case. So we need to use the - * irqsave/restore variants. - */ - raw_spin_lock_irqsave(&lock->wait_lock, flags); - - /* Try to acquire the lock again: */ - if (try_to_take_rt_mutex(lock, current, NULL)) { - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - return 0; - } - - set_current_state(state); - - /* Setup the timer, when timeout != NULL */ - if (unlikely(timeout)) - hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS); - - ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk); - - if (likely(!ret)) - /* sleep on the mutex */ - ret = __rt_mutex_slowlock(lock, state, timeout, &waiter); - - if (unlikely(ret)) { - __set_current_state(TASK_RUNNING); - remove_waiter(lock, &waiter); - rt_mutex_handle_deadlock(ret, chwalk, &waiter); - } - - /* - * try_to_take_rt_mutex() sets the waiter bit - * unconditionally. We might have to fix that up. - */ - fixup_rt_mutex_waiters(lock); - - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - - /* Remove pending timer: */ - if (unlikely(timeout)) - hrtimer_cancel(&timeout->timer); - - debug_rt_mutex_free_waiter(&waiter); - - return ret; -} - -static int __sched __rt_mutex_slowtrylock(struct rt_mutex *lock) +static int __sched __rt_mutex_slowtrylock(struct rt_mutex_base *lock) { int ret = try_to_take_rt_mutex(lock, current, NULL); @@ -1267,7 +1239,7 @@ static int __sched __rt_mutex_slowtrylock(struct rt_mutex *lock) /* * Slow path try-lock function: */ -static int __sched rt_mutex_slowtrylock(struct rt_mutex *lock) +static int __sched rt_mutex_slowtrylock(struct rt_mutex_base *lock) { unsigned long flags; int ret; @@ -1293,25 +1265,20 @@ static int __sched rt_mutex_slowtrylock(struct rt_mutex *lock) return ret; } -/* - * Performs the wakeup of the top-waiter and re-enables preemption. - */ -void __sched rt_mutex_postunlock(struct wake_q_head *wake_q) +static __always_inline int __rt_mutex_trylock(struct rt_mutex_base *lock) { - wake_up_q(wake_q); + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) + return 1; - /* Pairs with preempt_disable() in mark_wakeup_next_waiter() */ - preempt_enable(); + return rt_mutex_slowtrylock(lock); } /* * Slow path to release a rt-mutex. - * - * Return whether the current task needs to call rt_mutex_postunlock(). */ -static void __sched rt_mutex_slowunlock(struct rt_mutex *lock) +static void __sched rt_mutex_slowunlock(struct rt_mutex_base *lock) { - DEFINE_WAKE_Q(wake_q); + DEFINE_RT_WAKE_Q(wqh); unsigned long flags; /* irqsave required to support early boot calls */ @@ -1364,422 +1331,387 @@ static void __sched rt_mutex_slowunlock(struct rt_mutex *lock) * * Queue the next waiter for wakeup once we release the wait_lock. */ - mark_wakeup_next_waiter(&wake_q, lock); + mark_wakeup_next_waiter(&wqh, lock); raw_spin_unlock_irqrestore(&lock->wait_lock, flags); - rt_mutex_postunlock(&wake_q); + rt_mutex_wake_up_q(&wqh); } -/* - * debug aware fast / slowpath lock,trylock,unlock - * - * The atomic acquire/release ops are compiled away, when either the - * architecture does not support cmpxchg or when debugging is enabled. - */ -static __always_inline int __rt_mutex_lock(struct rt_mutex *lock, long state, - unsigned int subclass) +static __always_inline void __rt_mutex_unlock(struct rt_mutex_base *lock) { - int ret; - - might_sleep(); - mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); - - if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) - return 0; + if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) + return; - ret = rt_mutex_slowlock(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK); - if (ret) - mutex_release(&lock->dep_map, _RET_IP_); - return ret; + rt_mutex_slowunlock(lock); } -#ifdef CONFIG_DEBUG_LOCK_ALLOC -/** - * rt_mutex_lock_nested - lock a rt_mutex - * - * @lock: the rt_mutex to be locked - * @subclass: the lockdep subclass - */ -void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass) +#ifdef CONFIG_SMP +static bool rtmutex_spin_on_owner(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *owner) { - __rt_mutex_lock(lock, TASK_UNINTERRUPTIBLE, subclass); -} -EXPORT_SYMBOL_GPL(rt_mutex_lock_nested); - -#else /* !CONFIG_DEBUG_LOCK_ALLOC */ + bool res = true; -/** - * rt_mutex_lock - lock a rt_mutex - * - * @lock: the rt_mutex to be locked - */ -void __sched rt_mutex_lock(struct rt_mutex *lock) + rcu_read_lock(); + for (;;) { + /* If owner changed, trylock again. */ + if (owner != rt_mutex_owner(lock)) + break; + /* + * Ensure that @owner is dereferenced after checking that + * the lock owner still matches @owner. If that fails, + * @owner might point to freed memory. If it still matches, + * the rcu_read_lock() ensures the memory stays valid. + */ + barrier(); + /* + * Stop spinning when: + * - the lock owner has been scheduled out + * - current is not longer the top waiter + * - current is requested to reschedule (redundant + * for CONFIG_PREEMPT_RCU=y) + * - the VCPU on which owner runs is preempted + */ + if (!owner->on_cpu || need_resched() || + rt_mutex_waiter_is_top_waiter(lock, waiter) || + vcpu_is_preempted(task_cpu(owner))) { + res = false; + break; + } + cpu_relax(); + } + rcu_read_unlock(); + return res; +} +#else +static bool rtmutex_spin_on_owner(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *owner) { - __rt_mutex_lock(lock, TASK_UNINTERRUPTIBLE, 0); + return false; } -EXPORT_SYMBOL_GPL(rt_mutex_lock); #endif -/** - * rt_mutex_lock_interruptible - lock a rt_mutex interruptible - * - * @lock: the rt_mutex to be locked - * - * Returns: - * 0 on success - * -EINTR when interrupted by a signal +#ifdef RT_MUTEX_BUILD_MUTEX +/* + * Functions required for: + * - rtmutex, futex on all kernels + * - mutex and rwsem substitutions on RT kernels */ -int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock) -{ - return __rt_mutex_lock(lock, TASK_INTERRUPTIBLE, 0); -} -EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); -/** - * rt_mutex_trylock - try to lock a rt_mutex - * - * @lock: the rt_mutex to be locked - * - * This function can only be called in thread context. It's safe to call it - * from atomic regions, but not from hard or soft interrupt context. +/* + * Remove a waiter from a lock and give up * - * Returns: - * 1 on success - * 0 on contention + * Must be called with lock->wait_lock held and interrupts disabled. It must + * have just failed to try_to_take_rt_mutex(). */ -int __sched rt_mutex_trylock(struct rt_mutex *lock) +static void __sched remove_waiter(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter) { - int ret; + bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); + struct task_struct *owner = rt_mutex_owner(lock); + struct rt_mutex_base *next_lock; - if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) - return 0; + lockdep_assert_held(&lock->wait_lock); + + raw_spin_lock(¤t->pi_lock); + rt_mutex_dequeue(lock, waiter); + current->pi_blocked_on = NULL; + raw_spin_unlock(¤t->pi_lock); /* - * No lockdep annotation required because lockdep disables the fast - * path. + * Only update priority if the waiter was the highest priority + * waiter of the lock and there is an owner to update. */ - if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) - return 1; - - ret = rt_mutex_slowtrylock(lock); - if (ret) - mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); - - return ret; -} -EXPORT_SYMBOL_GPL(rt_mutex_trylock); - -/** - * rt_mutex_unlock - unlock a rt_mutex - * - * @lock: the rt_mutex to be unlocked - */ -void __sched rt_mutex_unlock(struct rt_mutex *lock) -{ - mutex_release(&lock->dep_map, _RET_IP_); - if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) + if (!owner || !is_top_waiter) return; - rt_mutex_slowunlock(lock); -} -EXPORT_SYMBOL_GPL(rt_mutex_unlock); + raw_spin_lock(&owner->pi_lock); -/* - * Futex variants, must not use fastpath. - */ -int __sched rt_mutex_futex_trylock(struct rt_mutex *lock) -{ - return rt_mutex_slowtrylock(lock); -} + rt_mutex_dequeue_pi(owner, waiter); -int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock) -{ - return __rt_mutex_slowtrylock(lock); -} + if (rt_mutex_has_waiters(lock)) + rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock)); -/** - * __rt_mutex_futex_unlock - Futex variant, that since futex variants - * do not use the fast-path, can be simple and will not need to retry. - * - * @lock: The rt_mutex to be unlocked - * @wake_q: The wake queue head from which to get the next lock waiter - */ -bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wake_q) -{ - lockdep_assert_held(&lock->wait_lock); + rt_mutex_adjust_prio(owner); - debug_rt_mutex_unlock(lock); + /* Store the lock on which owner is blocked or NULL */ + next_lock = task_blocked_on_lock(owner); - if (!rt_mutex_has_waiters(lock)) { - lock->owner = NULL; - return false; /* done */ - } + raw_spin_unlock(&owner->pi_lock); /* - * We've already deboosted, mark_wakeup_next_waiter() will - * retain preempt_disabled when we drop the wait_lock, to - * avoid inversion prior to the wakeup. preempt_disable() - * therein pairs with rt_mutex_postunlock(). + * Don't walk the chain, if the owner task is not blocked + * itself. */ - mark_wakeup_next_waiter(wake_q, lock); + if (!next_lock) + return; - return true; /* call postunlock() */ -} + /* gets dropped in rt_mutex_adjust_prio_chain()! */ + get_task_struct(owner); -void __sched rt_mutex_futex_unlock(struct rt_mutex *lock) -{ - DEFINE_WAKE_Q(wake_q); - unsigned long flags; - bool postunlock; + raw_spin_unlock_irq(&lock->wait_lock); - raw_spin_lock_irqsave(&lock->wait_lock, flags); - postunlock = __rt_mutex_futex_unlock(lock, &wake_q); - raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + rt_mutex_adjust_prio_chain(owner, RT_MUTEX_MIN_CHAINWALK, lock, + next_lock, NULL, current); - if (postunlock) - rt_mutex_postunlock(&wake_q); + raw_spin_lock_irq(&lock->wait_lock); } /** - * __rt_mutex_init - initialize the rt_mutex - * - * @lock: The rt_mutex to be initialized - * @name: The lock name used for debugging - * @key: The lock class key used for debugging - * - * Initialize the rt_mutex to unlocked state. + * rt_mutex_slowlock_block() - Perform the wait-wake-try-to-take loop + * @lock: the rt_mutex to take + * @ww_ctx: WW mutex context pointer + * @state: the state the task should block in (TASK_INTERRUPTIBLE + * or TASK_UNINTERRUPTIBLE) + * @timeout: the pre-initialized and started timer, or NULL for none + * @waiter: the pre-initialized rt_mutex_waiter * - * Initializing of a locked rt_mutex is not allowed + * Must be called with lock->wait_lock held and interrupts disabled */ -void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name, - struct lock_class_key *key) +static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state, + struct hrtimer_sleeper *timeout, + struct rt_mutex_waiter *waiter) { - debug_check_no_locks_freed((void *)lock, sizeof(*lock)); - lockdep_init_map(&lock->dep_map, name, key, 0); + struct rt_mutex *rtm = container_of(lock, struct rt_mutex, rtmutex); + struct task_struct *owner; + int ret = 0; - __rt_mutex_basic_init(lock); -} -EXPORT_SYMBOL_GPL(__rt_mutex_init); + for (;;) { + /* Try to acquire the lock: */ + if (try_to_take_rt_mutex(lock, current, waiter)) + break; -/** - * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a - * proxy owner - * - * @lock: the rt_mutex to be locked - * @proxy_owner:the task to set as owner - * - * No locking. Caller has to do serializing itself - * - * Special API call for PI-futex support. This initializes the rtmutex and - * assigns it to @proxy_owner. Concurrent operations on the rtmutex are not - * possible at this point because the pi_state which contains the rtmutex - * is not yet visible to other tasks. - */ -void __sched rt_mutex_init_proxy_locked(struct rt_mutex *lock, - struct task_struct *proxy_owner) -{ - __rt_mutex_basic_init(lock); - rt_mutex_set_owner(lock, proxy_owner); + if (timeout && !timeout->task) { + ret = -ETIMEDOUT; + break; + } + if (signal_pending_state(state, current)) { + ret = -EINTR; + break; + } + + if (build_ww_mutex() && ww_ctx) { + ret = __ww_mutex_check_kill(rtm, waiter, ww_ctx); + if (ret) + break; + } + + if (waiter == rt_mutex_top_waiter(lock)) + owner = rt_mutex_owner(lock); + else + owner = NULL; + raw_spin_unlock_irq(&lock->wait_lock); + + if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner)) + schedule(); + + raw_spin_lock_irq(&lock->wait_lock); + set_current_state(state); + } + + __set_current_state(TASK_RUNNING); + return ret; } -/** - * rt_mutex_proxy_unlock - release a lock on behalf of owner - * - * @lock: the rt_mutex to be locked - * - * No locking. Caller has to do serializing itself - * - * Special API call for PI-futex support. This merrily cleans up the rtmutex - * (debugging) state. Concurrent operations on this rt_mutex are not - * possible because it belongs to the pi_state which is about to be freed - * and it is not longer visible to other tasks. - */ -void __sched rt_mutex_proxy_unlock(struct rt_mutex *lock) +static void __sched rt_mutex_handle_deadlock(int res, int detect_deadlock, + struct rt_mutex_waiter *w) { - debug_rt_mutex_proxy_unlock(lock); - rt_mutex_set_owner(lock, NULL); + /* + * If the result is not -EDEADLOCK or the caller requested + * deadlock detection, nothing to do here. + */ + if (res != -EDEADLOCK || detect_deadlock) + return; + + if (build_ww_mutex() && w->ww_ctx) + return; + + /* + * Yell loudly and stop the task right here. + */ + WARN(1, "rtmutex deadlock detected\n"); + while (1) { + set_current_state(TASK_INTERRUPTIBLE); + schedule(); + } } /** - * __rt_mutex_start_proxy_lock() - Start lock acquisition for another task - * @lock: the rt_mutex to take - * @waiter: the pre-initialized rt_mutex_waiter - * @task: the task to prepare - * - * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock - * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. - * - * NOTE: does _NOT_ remove the @waiter on failure; must either call - * rt_mutex_wait_proxy_lock() or rt_mutex_cleanup_proxy_lock() after this. - * - * Returns: - * 0 - task blocked on lock - * 1 - acquired the lock for task, caller should wake it up - * <0 - error - * - * Special API call for PI-futex support. + * __rt_mutex_slowlock - Locking slowpath invoked with lock::wait_lock held + * @lock: The rtmutex to block lock + * @ww_ctx: WW mutex context pointer + * @state: The task state for sleeping + * @chwalk: Indicator whether full or partial chainwalk is requested + * @waiter: Initializer waiter for blocking */ -int __sched __rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task) +static int __sched __rt_mutex_slowlock(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state, + enum rtmutex_chainwalk chwalk, + struct rt_mutex_waiter *waiter) { + struct rt_mutex *rtm = container_of(lock, struct rt_mutex, rtmutex); + struct ww_mutex *ww = ww_container_of(rtm); int ret; lockdep_assert_held(&lock->wait_lock); - if (try_to_take_rt_mutex(lock, task, NULL)) - return 1; + /* Try to acquire the lock again: */ + if (try_to_take_rt_mutex(lock, current, NULL)) { + if (build_ww_mutex() && ww_ctx) { + __ww_mutex_check_waiters(rtm, ww_ctx); + ww_mutex_lock_acquired(ww, ww_ctx); + } + return 0; + } - /* We enforce deadlock detection for futexes */ - ret = task_blocks_on_rt_mutex(lock, waiter, task, - RT_MUTEX_FULL_CHAINWALK); + set_current_state(state); - if (ret && !rt_mutex_owner(lock)) { - /* - * Reset the return value. We might have - * returned with -EDEADLK and the owner - * released the lock while we were walking the - * pi chain. Let the waiter sort it out. - */ - ret = 0; + ret = task_blocks_on_rt_mutex(lock, waiter, current, ww_ctx, chwalk); + if (likely(!ret)) + ret = rt_mutex_slowlock_block(lock, ww_ctx, state, NULL, waiter); + + if (likely(!ret)) { + /* acquired the lock */ + if (build_ww_mutex() && ww_ctx) { + if (!ww_ctx->is_wait_die) + __ww_mutex_check_waiters(rtm, ww_ctx); + ww_mutex_lock_acquired(ww, ww_ctx); + } + } else { + __set_current_state(TASK_RUNNING); + remove_waiter(lock, waiter); + rt_mutex_handle_deadlock(ret, chwalk, waiter); } + /* + * try_to_take_rt_mutex() sets the waiter bit + * unconditionally. We might have to fix that up. + */ + fixup_rt_mutex_waiters(lock); return ret; } -/** - * rt_mutex_start_proxy_lock() - Start lock acquisition for another task - * @lock: the rt_mutex to take - * @waiter: the pre-initialized rt_mutex_waiter - * @task: the task to prepare - * - * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock - * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. - * - * NOTE: unlike __rt_mutex_start_proxy_lock this _DOES_ remove the @waiter - * on failure. - * - * Returns: - * 0 - task blocked on lock - * 1 - acquired the lock for task, caller should wake it up - * <0 - error - * - * Special API call for PI-futex support. - */ -int __sched rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task) +static inline int __rt_mutex_slowlock_locked(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state) { + struct rt_mutex_waiter waiter; int ret; - raw_spin_lock_irq(&lock->wait_lock); - ret = __rt_mutex_start_proxy_lock(lock, waiter, task); - if (unlikely(ret)) - remove_waiter(lock, waiter); - raw_spin_unlock_irq(&lock->wait_lock); + rt_mutex_init_waiter(&waiter); + waiter.ww_ctx = ww_ctx; + ret = __rt_mutex_slowlock(lock, ww_ctx, state, RT_MUTEX_MIN_CHAINWALK, + &waiter); + + debug_rt_mutex_free_waiter(&waiter); return ret; } -/** - * rt_mutex_wait_proxy_lock() - Wait for lock acquisition - * @lock: the rt_mutex we were woken on - * @to: the timeout, null if none. hrtimer should already have - * been started. - * @waiter: the pre-initialized rt_mutex_waiter - * - * Wait for the lock acquisition started on our behalf by - * rt_mutex_start_proxy_lock(). Upon failure, the caller must call - * rt_mutex_cleanup_proxy_lock(). - * - * Returns: - * 0 - success - * <0 - error, one of -EINTR, -ETIMEDOUT - * - * Special API call for PI-futex support +/* + * rt_mutex_slowlock - Locking slowpath invoked when fast path fails + * @lock: The rtmutex to block lock + * @ww_ctx: WW mutex context pointer + * @state: The task state for sleeping */ -int __sched rt_mutex_wait_proxy_lock(struct rt_mutex *lock, - struct hrtimer_sleeper *to, - struct rt_mutex_waiter *waiter) +static int __sched rt_mutex_slowlock(struct rt_mutex_base *lock, + struct ww_acquire_ctx *ww_ctx, + unsigned int state) { + unsigned long flags; int ret; - raw_spin_lock_irq(&lock->wait_lock); - /* sleep on the mutex */ - set_current_state(TASK_INTERRUPTIBLE); - ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter); /* - * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might - * have to fix that up. + * Technically we could use raw_spin_[un]lock_irq() here, but this can + * be called in early boot if the cmpxchg() fast path is disabled + * (debug, no architecture support). In this case we will acquire the + * rtmutex with lock->wait_lock held. But we cannot unconditionally + * enable interrupts in that early boot case. So we need to use the + * irqsave/restore variants. */ - fixup_rt_mutex_waiters(lock); - raw_spin_unlock_irq(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); + ret = __rt_mutex_slowlock_locked(lock, ww_ctx, state); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); return ret; } +static __always_inline int __rt_mutex_lock(struct rt_mutex_base *lock, + unsigned int state) +{ + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) + return 0; + + return rt_mutex_slowlock(lock, NULL, state); +} +#endif /* RT_MUTEX_BUILD_MUTEX */ + +#ifdef RT_MUTEX_BUILD_SPINLOCKS +/* + * Functions required for spin/rw_lock substitution on RT kernels + */ + /** - * rt_mutex_cleanup_proxy_lock() - Cleanup failed lock acquisition - * @lock: the rt_mutex we were woken on - * @waiter: the pre-initialized rt_mutex_waiter - * - * Attempt to clean up after a failed __rt_mutex_start_proxy_lock() or - * rt_mutex_wait_proxy_lock(). - * - * Unless we acquired the lock; we're still enqueued on the wait-list and can - * in fact still be granted ownership until we're removed. Therefore we can - * find we are in fact the owner and must disregard the - * rt_mutex_wait_proxy_lock() failure. - * - * Returns: - * true - did the cleanup, we done. - * false - we acquired the lock after rt_mutex_wait_proxy_lock() returned, - * caller should disregards its return value. - * - * Special API call for PI-futex support + * rtlock_slowlock_locked - Slow path lock acquisition for RT locks + * @lock: The underlying RT mutex */ -bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter) +static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock) { - bool cleanup = false; + struct rt_mutex_waiter waiter; + struct task_struct *owner; - raw_spin_lock_irq(&lock->wait_lock); - /* - * Do an unconditional try-lock, this deals with the lock stealing - * state where __rt_mutex_futex_unlock() -> mark_wakeup_next_waiter() - * sets a NULL owner. - * - * We're not interested in the return value, because the subsequent - * test on rt_mutex_owner() will infer that. If the trylock succeeded, - * we will own the lock and it will have removed the waiter. If we - * failed the trylock, we're still not owner and we need to remove - * ourselves. - */ - try_to_take_rt_mutex(lock, current, waiter); - /* - * Unless we're the owner; we're still enqueued on the wait_list. - * So check if we became owner, if not, take us off the wait_list. - */ - if (rt_mutex_owner(lock) != current) { - remove_waiter(lock, waiter); - cleanup = true; + lockdep_assert_held(&lock->wait_lock); + + if (try_to_take_rt_mutex(lock, current, NULL)) + return; + + rt_mutex_init_rtlock_waiter(&waiter); + + /* Save current state and set state to TASK_RTLOCK_WAIT */ + current_save_and_set_rtlock_wait_state(); + + task_blocks_on_rt_mutex(lock, &waiter, current, NULL, RT_MUTEX_MIN_CHAINWALK); + + for (;;) { + /* Try to acquire the lock again */ + if (try_to_take_rt_mutex(lock, current, &waiter)) + break; + + if (&waiter == rt_mutex_top_waiter(lock)) + owner = rt_mutex_owner(lock); + else + owner = NULL; + raw_spin_unlock_irq(&lock->wait_lock); + + if (!owner || !rtmutex_spin_on_owner(lock, &waiter, owner)) + schedule_rtlock(); + + raw_spin_lock_irq(&lock->wait_lock); + set_current_state(TASK_RTLOCK_WAIT); } + + /* Restore the task state */ + current_restore_rtlock_saved_state(); + /* - * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might - * have to fix that up. + * try_to_take_rt_mutex() sets the waiter bit unconditionally. + * We might have to fix that up: */ fixup_rt_mutex_waiters(lock); - - raw_spin_unlock_irq(&lock->wait_lock); - - return cleanup; + debug_rt_mutex_free_waiter(&waiter); } -#ifdef CONFIG_DEBUG_RT_MUTEXES -void rt_mutex_debug_task_free(struct task_struct *task) +static __always_inline void __sched rtlock_slowlock(struct rt_mutex_base *lock) { - DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root)); - DEBUG_LOCKS_WARN_ON(task->pi_blocked_on); + unsigned long flags; + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + rtlock_slowlock_locked(lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); } -#endif + +#endif /* RT_MUTEX_BUILD_SPINLOCKS */ diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c new file mode 100644 index 000000000000..5c9299aaabae --- /dev/null +++ b/kernel/locking/rtmutex_api.c @@ -0,0 +1,590 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtmutex API + */ +#include <linux/spinlock.h> +#include <linux/export.h> + +#define RT_MUTEX_BUILD_MUTEX +#include "rtmutex.c" + +/* + * Max number of times we'll walk the boosting chain: + */ +int max_lock_depth = 1024; + +/* + * Debug aware fast / slowpath lock,trylock,unlock + * + * The atomic acquire/release ops are compiled away, when either the + * architecture does not support cmpxchg or when debugging is enabled. + */ +static __always_inline int __rt_mutex_lock_common(struct rt_mutex *lock, + unsigned int state, + unsigned int subclass) +{ + int ret; + + might_sleep(); + mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + ret = __rt_mutex_lock(&lock->rtmutex, state); + if (ret) + mutex_release(&lock->dep_map, _RET_IP_); + return ret; +} + +void rt_mutex_base_init(struct rt_mutex_base *rtb) +{ + __rt_mutex_base_init(rtb); +} +EXPORT_SYMBOL(rt_mutex_base_init); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +/** + * rt_mutex_lock_nested - lock a rt_mutex + * + * @lock: the rt_mutex to be locked + * @subclass: the lockdep subclass + */ +void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass) +{ + __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock_nested); + +#else /* !CONFIG_DEBUG_LOCK_ALLOC */ + +/** + * rt_mutex_lock - lock a rt_mutex + * + * @lock: the rt_mutex to be locked + */ +void __sched rt_mutex_lock(struct rt_mutex *lock) +{ + __rt_mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock); +#endif + +/** + * rt_mutex_lock_interruptible - lock a rt_mutex interruptible + * + * @lock: the rt_mutex to be locked + * + * Returns: + * 0 on success + * -EINTR when interrupted by a signal + */ +int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock) +{ + return __rt_mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0); +} +EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); + +/** + * rt_mutex_trylock - try to lock a rt_mutex + * + * @lock: the rt_mutex to be locked + * + * This function can only be called in thread context. It's safe to call it + * from atomic regions, but not from hard or soft interrupt context. + * + * Returns: + * 1 on success + * 0 on contention + */ +int __sched rt_mutex_trylock(struct rt_mutex *lock) +{ + int ret; + + if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) + return 0; + + ret = __rt_mutex_trylock(&lock->rtmutex); + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; +} +EXPORT_SYMBOL_GPL(rt_mutex_trylock); + +/** + * rt_mutex_unlock - unlock a rt_mutex + * + * @lock: the rt_mutex to be unlocked + */ +void __sched rt_mutex_unlock(struct rt_mutex *lock) +{ + mutex_release(&lock->dep_map, _RET_IP_); + __rt_mutex_unlock(&lock->rtmutex); +} +EXPORT_SYMBOL_GPL(rt_mutex_unlock); + +/* + * Futex variants, must not use fastpath. + */ +int __sched rt_mutex_futex_trylock(struct rt_mutex_base *lock) +{ + return rt_mutex_slowtrylock(lock); +} + +int __sched __rt_mutex_futex_trylock(struct rt_mutex_base *lock) +{ + return __rt_mutex_slowtrylock(lock); +} + +/** + * __rt_mutex_futex_unlock - Futex variant, that since futex variants + * do not use the fast-path, can be simple and will not need to retry. + * + * @lock: The rt_mutex to be unlocked + * @wqh: The wake queue head from which to get the next lock waiter + */ +bool __sched __rt_mutex_futex_unlock(struct rt_mutex_base *lock, + struct rt_wake_q_head *wqh) +{ + lockdep_assert_held(&lock->wait_lock); + + debug_rt_mutex_unlock(lock); + + if (!rt_mutex_has_waiters(lock)) { + lock->owner = NULL; + return false; /* done */ + } + + /* + * We've already deboosted, mark_wakeup_next_waiter() will + * retain preempt_disabled when we drop the wait_lock, to + * avoid inversion prior to the wakeup. preempt_disable() + * therein pairs with rt_mutex_postunlock(). + */ + mark_wakeup_next_waiter(wqh, lock); + + return true; /* call postunlock() */ +} + +void __sched rt_mutex_futex_unlock(struct rt_mutex_base *lock) +{ + DEFINE_RT_WAKE_Q(wqh); + unsigned long flags; + bool postunlock; + + raw_spin_lock_irqsave(&lock->wait_lock, flags); + postunlock = __rt_mutex_futex_unlock(lock, &wqh); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); + + if (postunlock) + rt_mutex_postunlock(&wqh); +} + +/** + * __rt_mutex_init - initialize the rt_mutex + * + * @lock: The rt_mutex to be initialized + * @name: The lock name used for debugging + * @key: The lock class key used for debugging + * + * Initialize the rt_mutex to unlocked state. + * + * Initializing of a locked rt_mutex is not allowed + */ +void __sched __rt_mutex_init(struct rt_mutex *lock, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + __rt_mutex_base_init(&lock->rtmutex); + lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP); +} +EXPORT_SYMBOL_GPL(__rt_mutex_init); + +/** + * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a + * proxy owner + * + * @lock: the rt_mutex to be locked + * @proxy_owner:the task to set as owner + * + * No locking. Caller has to do serializing itself + * + * Special API call for PI-futex support. This initializes the rtmutex and + * assigns it to @proxy_owner. Concurrent operations on the rtmutex are not + * possible at this point because the pi_state which contains the rtmutex + * is not yet visible to other tasks. + */ +void __sched rt_mutex_init_proxy_locked(struct rt_mutex_base *lock, + struct task_struct *proxy_owner) +{ + static struct lock_class_key pi_futex_key; + + __rt_mutex_base_init(lock); + /* + * On PREEMPT_RT the futex hashbucket spinlock becomes 'sleeping' + * and rtmutex based. That causes a lockdep false positive, because + * some of the futex functions invoke spin_unlock(&hb->lock) with + * the wait_lock of the rtmutex associated to the pi_futex held. + * spin_unlock() in turn takes wait_lock of the rtmutex on which + * the spinlock is based, which makes lockdep notice a lock + * recursion. Give the futex/rtmutex wait_lock a separate key. + */ + lockdep_set_class(&lock->wait_lock, &pi_futex_key); + rt_mutex_set_owner(lock, proxy_owner); +} + +/** + * rt_mutex_proxy_unlock - release a lock on behalf of owner + * + * @lock: the rt_mutex to be locked + * + * No locking. Caller has to do serializing itself + * + * Special API call for PI-futex support. This just cleans up the rtmutex + * (debugging) state. Concurrent operations on this rt_mutex are not + * possible because it belongs to the pi_state which is about to be freed + * and it is not longer visible to other tasks. + */ +void __sched rt_mutex_proxy_unlock(struct rt_mutex_base *lock) +{ + debug_rt_mutex_proxy_unlock(lock); + rt_mutex_set_owner(lock, NULL); +} + +/** + * __rt_mutex_start_proxy_lock() - Start lock acquisition for another task + * @lock: the rt_mutex to take + * @waiter: the pre-initialized rt_mutex_waiter + * @task: the task to prepare + * + * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock + * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. + * + * NOTE: does _NOT_ remove the @waiter on failure; must either call + * rt_mutex_wait_proxy_lock() or rt_mutex_cleanup_proxy_lock() after this. + * + * Returns: + * 0 - task blocked on lock + * 1 - acquired the lock for task, caller should wake it up + * <0 - error + * + * Special API call for PI-futex support. + */ +int __sched __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task) +{ + int ret; + + lockdep_assert_held(&lock->wait_lock); + + if (try_to_take_rt_mutex(lock, task, NULL)) + return 1; + + /* We enforce deadlock detection for futexes */ + ret = task_blocks_on_rt_mutex(lock, waiter, task, NULL, + RT_MUTEX_FULL_CHAINWALK); + + if (ret && !rt_mutex_owner(lock)) { + /* + * Reset the return value. We might have + * returned with -EDEADLK and the owner + * released the lock while we were walking the + * pi chain. Let the waiter sort it out. + */ + ret = 0; + } + + return ret; +} + +/** + * rt_mutex_start_proxy_lock() - Start lock acquisition for another task + * @lock: the rt_mutex to take + * @waiter: the pre-initialized rt_mutex_waiter + * @task: the task to prepare + * + * Starts the rt_mutex acquire; it enqueues the @waiter and does deadlock + * detection. It does not wait, see rt_mutex_wait_proxy_lock() for that. + * + * NOTE: unlike __rt_mutex_start_proxy_lock this _DOES_ remove the @waiter + * on failure. + * + * Returns: + * 0 - task blocked on lock + * 1 - acquired the lock for task, caller should wake it up + * <0 - error + * + * Special API call for PI-futex support. + */ +int __sched rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task) +{ + int ret; + + raw_spin_lock_irq(&lock->wait_lock); + ret = __rt_mutex_start_proxy_lock(lock, waiter, task); + if (unlikely(ret)) + remove_waiter(lock, waiter); + raw_spin_unlock_irq(&lock->wait_lock); + + return ret; +} + +/** + * rt_mutex_wait_proxy_lock() - Wait for lock acquisition + * @lock: the rt_mutex we were woken on + * @to: the timeout, null if none. hrtimer should already have + * been started. + * @waiter: the pre-initialized rt_mutex_waiter + * + * Wait for the lock acquisition started on our behalf by + * rt_mutex_start_proxy_lock(). Upon failure, the caller must call + * rt_mutex_cleanup_proxy_lock(). + * + * Returns: + * 0 - success + * <0 - error, one of -EINTR, -ETIMEDOUT + * + * Special API call for PI-futex support + */ +int __sched rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock, + struct hrtimer_sleeper *to, + struct rt_mutex_waiter *waiter) +{ + int ret; + + raw_spin_lock_irq(&lock->wait_lock); + /* sleep on the mutex */ + set_current_state(TASK_INTERRUPTIBLE); + ret = rt_mutex_slowlock_block(lock, NULL, TASK_INTERRUPTIBLE, to, waiter); + /* + * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might + * have to fix that up. + */ + fixup_rt_mutex_waiters(lock); + raw_spin_unlock_irq(&lock->wait_lock); + + return ret; +} + +/** + * rt_mutex_cleanup_proxy_lock() - Cleanup failed lock acquisition + * @lock: the rt_mutex we were woken on + * @waiter: the pre-initialized rt_mutex_waiter + * + * Attempt to clean up after a failed __rt_mutex_start_proxy_lock() or + * rt_mutex_wait_proxy_lock(). + * + * Unless we acquired the lock; we're still enqueued on the wait-list and can + * in fact still be granted ownership until we're removed. Therefore we can + * find we are in fact the owner and must disregard the + * rt_mutex_wait_proxy_lock() failure. + * + * Returns: + * true - did the cleanup, we done. + * false - we acquired the lock after rt_mutex_wait_proxy_lock() returned, + * caller should disregards its return value. + * + * Special API call for PI-futex support + */ +bool __sched rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter) +{ + bool cleanup = false; + + raw_spin_lock_irq(&lock->wait_lock); + /* + * Do an unconditional try-lock, this deals with the lock stealing + * state where __rt_mutex_futex_unlock() -> mark_wakeup_next_waiter() + * sets a NULL owner. + * + * We're not interested in the return value, because the subsequent + * test on rt_mutex_owner() will infer that. If the trylock succeeded, + * we will own the lock and it will have removed the waiter. If we + * failed the trylock, we're still not owner and we need to remove + * ourselves. + */ + try_to_take_rt_mutex(lock, current, waiter); + /* + * Unless we're the owner; we're still enqueued on the wait_list. + * So check if we became owner, if not, take us off the wait_list. + */ + if (rt_mutex_owner(lock) != current) { + remove_waiter(lock, waiter); + cleanup = true; + } + /* + * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might + * have to fix that up. + */ + fixup_rt_mutex_waiters(lock); + + raw_spin_unlock_irq(&lock->wait_lock); + + return cleanup; +} + +/* + * Recheck the pi chain, in case we got a priority setting + * + * Called from sched_setscheduler + */ +void __sched rt_mutex_adjust_pi(struct task_struct *task) +{ + struct rt_mutex_waiter *waiter; + struct rt_mutex_base *next_lock; + unsigned long flags; + + raw_spin_lock_irqsave(&task->pi_lock, flags); + + waiter = task->pi_blocked_on; + if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) { + raw_spin_unlock_irqrestore(&task->pi_lock, flags); + return; + } + next_lock = waiter->lock; + raw_spin_unlock_irqrestore(&task->pi_lock, flags); + + /* gets dropped in rt_mutex_adjust_prio_chain()! */ + get_task_struct(task); + + rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL, + next_lock, NULL, task); +} + +/* + * Performs the wakeup of the top-waiter and re-enables preemption. + */ +void __sched rt_mutex_postunlock(struct rt_wake_q_head *wqh) +{ + rt_mutex_wake_up_q(wqh); +} + +#ifdef CONFIG_DEBUG_RT_MUTEXES +void rt_mutex_debug_task_free(struct task_struct *task) +{ + DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root)); + DEBUG_LOCKS_WARN_ON(task->pi_blocked_on); +} +#endif + +#ifdef CONFIG_PREEMPT_RT +/* Mutexes */ +void __mutex_rt_init(struct mutex *mutex, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)mutex, sizeof(*mutex)); + lockdep_init_map_wait(&mutex->dep_map, name, key, 0, LD_WAIT_SLEEP); +} +EXPORT_SYMBOL(__mutex_rt_init); + +static __always_inline int __mutex_lock_common(struct mutex *lock, + unsigned int state, + unsigned int subclass, + struct lockdep_map *nest_lock, + unsigned long ip) +{ + int ret; + + might_sleep(); + mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip); + ret = __rt_mutex_lock(&lock->rtmutex, state); + if (ret) + mutex_release(&lock->dep_map, ip); + else + lock_acquired(&lock->dep_map, ip); + return ret; +} + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __sched mutex_lock_nested(struct mutex *lock, unsigned int subclass) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_nested); + +void __sched _mutex_lock_nest_lock(struct mutex *lock, + struct lockdep_map *nest_lock) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, nest_lock, _RET_IP_); +} +EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock); + +int __sched mutex_lock_interruptible_nested(struct mutex *lock, + unsigned int subclass) +{ + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); + +int __sched mutex_lock_killable_nested(struct mutex *lock, + unsigned int subclass) +{ + return __mutex_lock_common(lock, TASK_KILLABLE, subclass, NULL, _RET_IP_); +} +EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); + +void __sched mutex_lock_io_nested(struct mutex *lock, unsigned int subclass) +{ + int token; + + might_sleep(); + + token = io_schedule_prepare(); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); + io_schedule_finish(token); +} +EXPORT_SYMBOL_GPL(mutex_lock_io_nested); + +#else /* CONFIG_DEBUG_LOCK_ALLOC */ + +void __sched mutex_lock(struct mutex *lock) +{ + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock); + +int __sched mutex_lock_interruptible(struct mutex *lock) +{ + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock_interruptible); + +int __sched mutex_lock_killable(struct mutex *lock) +{ + return __mutex_lock_common(lock, TASK_KILLABLE, 0, NULL, _RET_IP_); +} +EXPORT_SYMBOL(mutex_lock_killable); + +void __sched mutex_lock_io(struct mutex *lock) +{ + int token = io_schedule_prepare(); + + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); + io_schedule_finish(token); +} +EXPORT_SYMBOL(mutex_lock_io); +#endif /* !CONFIG_DEBUG_LOCK_ALLOC */ + +int __sched mutex_trylock(struct mutex *lock) +{ + int ret; + + if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task())) + return 0; + + ret = __rt_mutex_trylock(&lock->rtmutex); + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; +} +EXPORT_SYMBOL(mutex_trylock); + +void __sched mutex_unlock(struct mutex *lock) +{ + mutex_release(&lock->dep_map, _RET_IP_); + __rt_mutex_unlock(&lock->rtmutex); +} +EXPORT_SYMBOL(mutex_unlock); + +#endif /* CONFIG_PREEMPT_RT */ diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index a90c22abdbca..c47e8361bfb5 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -25,29 +25,90 @@ * @pi_tree_entry: pi node to enqueue into the mutex owner waiters tree * @task: task reference to the blocked task * @lock: Pointer to the rt_mutex on which the waiter blocks + * @wake_state: Wakeup state to use (TASK_NORMAL or TASK_RTLOCK_WAIT) * @prio: Priority of the waiter * @deadline: Deadline of the waiter if applicable + * @ww_ctx: WW context pointer */ struct rt_mutex_waiter { struct rb_node tree_entry; struct rb_node pi_tree_entry; struct task_struct *task; - struct rt_mutex *lock; + struct rt_mutex_base *lock; + unsigned int wake_state; int prio; u64 deadline; + struct ww_acquire_ctx *ww_ctx; }; +/** + * rt_wake_q_head - Wrapper around regular wake_q_head to support + * "sleeping" spinlocks on RT + * @head: The regular wake_q_head for sleeping lock variants + * @rtlock_task: Task pointer for RT lock (spin/rwlock) wakeups + */ +struct rt_wake_q_head { + struct wake_q_head head; + struct task_struct *rtlock_task; +}; + +#define DEFINE_RT_WAKE_Q(name) \ + struct rt_wake_q_head name = { \ + .head = WAKE_Q_HEAD_INITIALIZER(name.head), \ + .rtlock_task = NULL, \ + } + +/* + * PI-futex support (proxy locking functions, etc.): + */ +extern void rt_mutex_init_proxy_locked(struct rt_mutex_base *lock, + struct task_struct *proxy_owner); +extern void rt_mutex_proxy_unlock(struct rt_mutex_base *lock); +extern int __rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task); +extern int rt_mutex_start_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter, + struct task_struct *task); +extern int rt_mutex_wait_proxy_lock(struct rt_mutex_base *lock, + struct hrtimer_sleeper *to, + struct rt_mutex_waiter *waiter); +extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter); + +extern int rt_mutex_futex_trylock(struct rt_mutex_base *l); +extern int __rt_mutex_futex_trylock(struct rt_mutex_base *l); + +extern void rt_mutex_futex_unlock(struct rt_mutex_base *lock); +extern bool __rt_mutex_futex_unlock(struct rt_mutex_base *lock, + struct rt_wake_q_head *wqh); + +extern void rt_mutex_postunlock(struct rt_wake_q_head *wqh); + /* * Must be guarded because this header is included from rcu/tree_plugin.h * unconditionally. */ #ifdef CONFIG_RT_MUTEXES -static inline int rt_mutex_has_waiters(struct rt_mutex *lock) +static inline int rt_mutex_has_waiters(struct rt_mutex_base *lock) { return !RB_EMPTY_ROOT(&lock->waiters.rb_root); } -static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex *lock) +/* + * Lockless speculative check whether @waiter is still the top waiter on + * @lock. This is solely comparing pointers and not derefencing the + * leftmost entry which might be about to vanish. + */ +static inline bool rt_mutex_waiter_is_top_waiter(struct rt_mutex_base *lock, + struct rt_mutex_waiter *waiter) +{ + struct rb_node *leftmost = rb_first_cached(&lock->waiters); + + return rb_entry(leftmost, struct rt_mutex_waiter, tree_entry) == waiter; +} + +static inline struct rt_mutex_waiter *rt_mutex_top_waiter(struct rt_mutex_base *lock) { struct rb_node *leftmost = rb_first_cached(&lock->waiters); struct rt_mutex_waiter *w = NULL; @@ -72,19 +133,12 @@ static inline struct rt_mutex_waiter *task_top_pi_waiter(struct task_struct *p) #define RT_MUTEX_HAS_WAITERS 1UL -static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) +static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock) { unsigned long owner = (unsigned long) READ_ONCE(lock->owner); return (struct task_struct *) (owner & ~RT_MUTEX_HAS_WAITERS); } -#else /* CONFIG_RT_MUTEXES */ -/* Used in rcu/tree_plugin.h */ -static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock) -{ - return NULL; -} -#endif /* !CONFIG_RT_MUTEXES */ /* * Constants for rt mutex functions which have a selectable deadlock @@ -101,49 +155,21 @@ enum rtmutex_chainwalk { RT_MUTEX_FULL_CHAINWALK, }; -static inline void __rt_mutex_basic_init(struct rt_mutex *lock) +static inline void __rt_mutex_base_init(struct rt_mutex_base *lock) { - lock->owner = NULL; raw_spin_lock_init(&lock->wait_lock); lock->waiters = RB_ROOT_CACHED; + lock->owner = NULL; } -/* - * PI-futex support (proxy locking functions, etc.): - */ -extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock, - struct task_struct *proxy_owner); -extern void rt_mutex_proxy_unlock(struct rt_mutex *lock); -extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter); -extern int __rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task); -extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter, - struct task_struct *task); -extern int rt_mutex_wait_proxy_lock(struct rt_mutex *lock, - struct hrtimer_sleeper *to, - struct rt_mutex_waiter *waiter); -extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, - struct rt_mutex_waiter *waiter); - -extern int rt_mutex_futex_trylock(struct rt_mutex *l); -extern int __rt_mutex_futex_trylock(struct rt_mutex *l); - -extern void rt_mutex_futex_unlock(struct rt_mutex *lock); -extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wqh); - -extern void rt_mutex_postunlock(struct wake_q_head *wake_q); - /* Debug functions */ -static inline void debug_rt_mutex_unlock(struct rt_mutex *lock) +static inline void debug_rt_mutex_unlock(struct rt_mutex_base *lock) { if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES)) DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current); } -static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock) +static inline void debug_rt_mutex_proxy_unlock(struct rt_mutex_base *lock) { if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES)) DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock)); @@ -161,4 +187,27 @@ static inline void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter) memset(waiter, 0x22, sizeof(*waiter)); } +static inline void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter) +{ + debug_rt_mutex_init_waiter(waiter); + RB_CLEAR_NODE(&waiter->pi_tree_entry); + RB_CLEAR_NODE(&waiter->tree_entry); + waiter->wake_state = TASK_NORMAL; + waiter->task = NULL; +} + +static inline void rt_mutex_init_rtlock_waiter(struct rt_mutex_waiter *waiter) +{ + rt_mutex_init_waiter(waiter); + waiter->wake_state = TASK_RTLOCK_WAIT; +} + +#else /* CONFIG_RT_MUTEXES */ +/* Used in rcu/tree_plugin.h */ +static inline struct task_struct *rt_mutex_owner(struct rt_mutex_base *lock) +{ + return NULL; +} +#endif /* !CONFIG_RT_MUTEXES */ + #endif diff --git a/kernel/locking/rwbase_rt.c b/kernel/locking/rwbase_rt.c new file mode 100644 index 000000000000..4ba15088e640 --- /dev/null +++ b/kernel/locking/rwbase_rt.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0-only + +/* + * RT-specific reader/writer semaphores and reader/writer locks + * + * down_write/write_lock() + * 1) Lock rtmutex + * 2) Remove the reader BIAS to force readers into the slow path + * 3) Wait until all readers have left the critical section + * 4) Mark it write locked + * + * up_write/write_unlock() + * 1) Remove the write locked marker + * 2) Set the reader BIAS, so readers can use the fast path again + * 3) Unlock rtmutex, to release blocked readers + * + * down_read/read_lock() + * 1) Try fast path acquisition (reader BIAS is set) + * 2) Take tmutex::wait_lock, which protects the writelocked flag + * 3) If !writelocked, acquire it for read + * 4) If writelocked, block on tmutex + * 5) unlock rtmutex, goto 1) + * + * up_read/read_unlock() + * 1) Try fast path release (reader count != 1) + * 2) Wake the writer waiting in down_write()/write_lock() #3 + * + * down_read/read_lock()#3 has the consequence, that rw semaphores and rw + * locks on RT are not writer fair, but writers, which should be avoided in + * RT tasks (think mmap_sem), are subject to the rtmutex priority/DL + * inheritance mechanism. + * + * It's possible to make the rw primitives writer fair by keeping a list of + * active readers. A blocked writer would force all newly incoming readers + * to block on the rtmutex, but the rtmutex would have to be proxy locked + * for one reader after the other. We can't use multi-reader inheritance + * because there is no way to support that with SCHED_DEADLINE. + * Implementing the one by one reader boosting/handover mechanism is a + * major surgery for a very dubious value. + * + * The risk of writer starvation is there, but the pathological use cases + * which trigger it are not necessarily the typical RT workloads. + * + * Common code shared between RT rw_semaphore and rwlock + */ + +static __always_inline int rwbase_read_trylock(struct rwbase_rt *rwb) +{ + int r; + + /* + * Increment reader count, if sem->readers < 0, i.e. READER_BIAS is + * set. + */ + for (r = atomic_read(&rwb->readers); r < 0;) { + if (likely(atomic_try_cmpxchg(&rwb->readers, &r, r + 1))) + return 1; + } + return 0; +} + +static int __sched __rwbase_read_lock(struct rwbase_rt *rwb, + unsigned int state) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + int ret; + + raw_spin_lock_irq(&rtm->wait_lock); + /* + * Allow readers, as long as the writer has not completely + * acquired the semaphore for write. + */ + if (atomic_read(&rwb->readers) != WRITER_BIAS) { + atomic_inc(&rwb->readers); + raw_spin_unlock_irq(&rtm->wait_lock); + return 0; + } + + /* + * Call into the slow lock path with the rtmutex->wait_lock + * held, so this can't result in the following race: + * + * Reader1 Reader2 Writer + * down_read() + * down_write() + * rtmutex_lock(m) + * wait() + * down_read() + * unlock(m->wait_lock) + * up_read() + * wake(Writer) + * lock(m->wait_lock) + * sem->writelocked=true + * unlock(m->wait_lock) + * + * up_write() + * sem->writelocked=false + * rtmutex_unlock(m) + * down_read() + * down_write() + * rtmutex_lock(m) + * wait() + * rtmutex_lock(m) + * + * That would put Reader1 behind the writer waiting on + * Reader2 to call up_read(), which might be unbound. + */ + + /* + * For rwlocks this returns 0 unconditionally, so the below + * !ret conditionals are optimized out. + */ + ret = rwbase_rtmutex_slowlock_locked(rtm, state); + + /* + * On success the rtmutex is held, so there can't be a writer + * active. Increment the reader count and immediately drop the + * rtmutex again. + * + * rtmutex->wait_lock has to be unlocked in any case of course. + */ + if (!ret) + atomic_inc(&rwb->readers); + raw_spin_unlock_irq(&rtm->wait_lock); + if (!ret) + rwbase_rtmutex_unlock(rtm); + return ret; +} + +static __always_inline int rwbase_read_lock(struct rwbase_rt *rwb, + unsigned int state) +{ + if (rwbase_read_trylock(rwb)) + return 0; + + return __rwbase_read_lock(rwb, state); +} + +static void __sched __rwbase_read_unlock(struct rwbase_rt *rwb, + unsigned int state) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + struct task_struct *owner; + + raw_spin_lock_irq(&rtm->wait_lock); + /* + * Wake the writer, i.e. the rtmutex owner. It might release the + * rtmutex concurrently in the fast path (due to a signal), but to + * clean up rwb->readers it needs to acquire rtm->wait_lock. The + * worst case which can happen is a spurious wakeup. + */ + owner = rt_mutex_owner(rtm); + if (owner) + wake_up_state(owner, state); + + raw_spin_unlock_irq(&rtm->wait_lock); +} + +static __always_inline void rwbase_read_unlock(struct rwbase_rt *rwb, + unsigned int state) +{ + /* + * rwb->readers can only hit 0 when a writer is waiting for the + * active readers to leave the critical section. + */ + if (unlikely(atomic_dec_and_test(&rwb->readers))) + __rwbase_read_unlock(rwb, state); +} + +static inline void __rwbase_write_unlock(struct rwbase_rt *rwb, int bias, + unsigned long flags) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + + atomic_add(READER_BIAS - bias, &rwb->readers); + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + rwbase_rtmutex_unlock(rtm); +} + +static inline void rwbase_write_unlock(struct rwbase_rt *rwb) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + __rwbase_write_unlock(rwb, WRITER_BIAS, flags); +} + +static inline void rwbase_write_downgrade(struct rwbase_rt *rwb) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + /* Release it and account current as reader */ + __rwbase_write_unlock(rwb, WRITER_BIAS - 1, flags); +} + +static int __sched rwbase_write_lock(struct rwbase_rt *rwb, + unsigned int state) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + /* Take the rtmutex as a first step */ + if (rwbase_rtmutex_lock_state(rtm, state)) + return -EINTR; + + /* Force readers into slow path */ + atomic_sub(READER_BIAS, &rwb->readers); + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + /* + * set_current_state() for rw_semaphore + * current_save_and_set_rtlock_wait_state() for rwlock + */ + rwbase_set_and_save_current_state(state); + + /* Block until all readers have left the critical section. */ + for (; atomic_read(&rwb->readers);) { + /* Optimized out for rwlocks */ + if (rwbase_signal_pending_state(state, current)) { + __set_current_state(TASK_RUNNING); + __rwbase_write_unlock(rwb, 0, flags); + return -EINTR; + } + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + + /* + * Schedule and wait for the readers to leave the critical + * section. The last reader leaving it wakes the waiter. + */ + if (atomic_read(&rwb->readers) != 0) + rwbase_schedule(); + set_current_state(state); + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + } + + atomic_set(&rwb->readers, WRITER_BIAS); + rwbase_restore_current_state(); + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + return 0; +} + +static inline int rwbase_write_trylock(struct rwbase_rt *rwb) +{ + struct rt_mutex_base *rtm = &rwb->rtmutex; + unsigned long flags; + + if (!rwbase_rtmutex_trylock(rtm)) + return 0; + + atomic_sub(READER_BIAS, &rwb->readers); + + raw_spin_lock_irqsave(&rtm->wait_lock, flags); + if (!atomic_read(&rwb->readers)) { + atomic_set(&rwb->readers, WRITER_BIAS); + raw_spin_unlock_irqrestore(&rtm->wait_lock, flags); + return 1; + } + __rwbase_write_unlock(rwb, 0, flags); + return 0; +} diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 16bfbb10c74d..9215b4d6a9de 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -28,6 +28,7 @@ #include <linux/rwsem.h> #include <linux/atomic.h> +#ifndef CONFIG_PREEMPT_RT #include "lock_events.h" /* @@ -1165,7 +1166,7 @@ out_nolock: * handle waking up a waiter on the semaphore * - up_read/up_write has decremented the active part of count if we come here */ -static struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem, long count) +static struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem) { unsigned long flags; DEFINE_WAKE_Q(wake_q); @@ -1297,7 +1298,7 @@ static inline void __up_read(struct rw_semaphore *sem) if (unlikely((tmp & (RWSEM_LOCK_MASK|RWSEM_FLAG_WAITERS)) == RWSEM_FLAG_WAITERS)) { clear_nonspinnable(sem); - rwsem_wake(sem, tmp); + rwsem_wake(sem); } } @@ -1319,7 +1320,7 @@ static inline void __up_write(struct rw_semaphore *sem) rwsem_clear_owner(sem); tmp = atomic_long_fetch_add_release(-RWSEM_WRITER_LOCKED, &sem->count); if (unlikely(tmp & RWSEM_FLAG_WAITERS)) - rwsem_wake(sem, tmp); + rwsem_wake(sem); } /* @@ -1344,6 +1345,114 @@ static inline void __downgrade_write(struct rw_semaphore *sem) rwsem_downgrade_wake(sem); } +#else /* !CONFIG_PREEMPT_RT */ + +#define RT_MUTEX_BUILD_MUTEX +#include "rtmutex.c" + +#define rwbase_set_and_save_current_state(state) \ + set_current_state(state) + +#define rwbase_restore_current_state() \ + __set_current_state(TASK_RUNNING) + +#define rwbase_rtmutex_lock_state(rtm, state) \ + __rt_mutex_lock(rtm, state) + +#define rwbase_rtmutex_slowlock_locked(rtm, state) \ + __rt_mutex_slowlock_locked(rtm, NULL, state) + +#define rwbase_rtmutex_unlock(rtm) \ + __rt_mutex_unlock(rtm) + +#define rwbase_rtmutex_trylock(rtm) \ + __rt_mutex_trylock(rtm) + +#define rwbase_signal_pending_state(state, current) \ + signal_pending_state(state, current) + +#define rwbase_schedule() \ + schedule() + +#include "rwbase_rt.c" + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __rwsem_init(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map_wait(&sem->dep_map, name, key, 0, LD_WAIT_SLEEP); +} +EXPORT_SYMBOL(__rwsem_init); +#endif + +static inline void __down_read(struct rw_semaphore *sem) +{ + rwbase_read_lock(&sem->rwbase, TASK_UNINTERRUPTIBLE); +} + +static inline int __down_read_interruptible(struct rw_semaphore *sem) +{ + return rwbase_read_lock(&sem->rwbase, TASK_INTERRUPTIBLE); +} + +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + return rwbase_read_lock(&sem->rwbase, TASK_KILLABLE); +} + +static inline int __down_read_trylock(struct rw_semaphore *sem) +{ + return rwbase_read_trylock(&sem->rwbase); +} + +static inline void __up_read(struct rw_semaphore *sem) +{ + rwbase_read_unlock(&sem->rwbase, TASK_NORMAL); +} + +static inline void __sched __down_write(struct rw_semaphore *sem) +{ + rwbase_write_lock(&sem->rwbase, TASK_UNINTERRUPTIBLE); +} + +static inline int __sched __down_write_killable(struct rw_semaphore *sem) +{ + return rwbase_write_lock(&sem->rwbase, TASK_KILLABLE); +} + +static inline int __down_write_trylock(struct rw_semaphore *sem) +{ + return rwbase_write_trylock(&sem->rwbase); +} + +static inline void __up_write(struct rw_semaphore *sem) +{ + rwbase_write_unlock(&sem->rwbase); +} + +static inline void __downgrade_write(struct rw_semaphore *sem) +{ + rwbase_write_downgrade(&sem->rwbase); +} + +/* Debug stubs for the common API */ +#define DEBUG_RWSEMS_WARN_ON(c, sem) + +static inline void __rwsem_set_reader_owned(struct rw_semaphore *sem, + struct task_struct *owner) +{ +} + +static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem) +{ + int count = atomic_read(&sem->rwbase.readers); + + return count < 0 && count != READER_BIAS; +} + +#endif /* CONFIG_PREEMPT_RT */ + /* * lock for reading */ diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c index 9aa855a96c4a..9ee381e4d2a4 100644 --- a/kernel/locking/semaphore.c +++ b/kernel/locking/semaphore.c @@ -54,6 +54,7 @@ void down(struct semaphore *sem) { unsigned long flags; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -77,6 +78,7 @@ int down_interruptible(struct semaphore *sem) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -103,6 +105,7 @@ int down_killable(struct semaphore *sem) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; @@ -157,6 +160,7 @@ int down_timeout(struct semaphore *sem, long timeout) unsigned long flags; int result = 0; + might_sleep(); raw_spin_lock_irqsave(&sem->lock, flags); if (likely(sem->count > 0)) sem->count--; diff --git a/kernel/locking/spinlock.c b/kernel/locking/spinlock.c index c8d7ad9fb9b2..c5830cfa379a 100644 --- a/kernel/locking/spinlock.c +++ b/kernel/locking/spinlock.c @@ -124,8 +124,11 @@ void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \ * __[spin|read|write]_lock_bh() */ BUILD_LOCK_OPS(spin, raw_spinlock); + +#ifndef CONFIG_PREEMPT_RT BUILD_LOCK_OPS(read, rwlock); BUILD_LOCK_OPS(write, rwlock); +#endif #endif @@ -209,6 +212,8 @@ void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock) EXPORT_SYMBOL(_raw_spin_unlock_bh); #endif +#ifndef CONFIG_PREEMPT_RT + #ifndef CONFIG_INLINE_READ_TRYLOCK int __lockfunc _raw_read_trylock(rwlock_t *lock) { @@ -353,6 +358,8 @@ void __lockfunc _raw_write_unlock_bh(rwlock_t *lock) EXPORT_SYMBOL(_raw_write_unlock_bh); #endif +#endif /* !CONFIG_PREEMPT_RT */ + #ifdef CONFIG_DEBUG_LOCK_ALLOC void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass) diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index b9d93087ee66..14235671a1a7 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -31,6 +31,7 @@ void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, EXPORT_SYMBOL(__raw_spin_lock_init); +#ifndef CONFIG_PREEMPT_RT void __rwlock_init(rwlock_t *lock, const char *name, struct lock_class_key *key) { @@ -48,6 +49,7 @@ void __rwlock_init(rwlock_t *lock, const char *name, } EXPORT_SYMBOL(__rwlock_init); +#endif static void spin_dump(raw_spinlock_t *lock, const char *msg) { @@ -139,6 +141,7 @@ void do_raw_spin_unlock(raw_spinlock_t *lock) arch_spin_unlock(&lock->raw_lock); } +#ifndef CONFIG_PREEMPT_RT static void rwlock_bug(rwlock_t *lock, const char *msg) { if (!debug_locks_off()) @@ -228,3 +231,5 @@ void do_raw_write_unlock(rwlock_t *lock) debug_write_unlock(lock); arch_write_unlock(&lock->raw_lock); } + +#endif /* !CONFIG_PREEMPT_RT */ diff --git a/kernel/locking/spinlock_rt.c b/kernel/locking/spinlock_rt.c new file mode 100644 index 000000000000..d2912e44d61f --- /dev/null +++ b/kernel/locking/spinlock_rt.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PREEMPT_RT substitution for spin/rw_locks + * + * spinlocks and rwlocks on RT are based on rtmutexes, with a few twists to + * resemble the non RT semantics: + * + * - Contrary to plain rtmutexes, spinlocks and rwlocks are state + * preserving. The task state is saved before blocking on the underlying + * rtmutex, and restored when the lock has been acquired. Regular wakeups + * during that time are redirected to the saved state so no wake up is + * missed. + * + * - Non RT spin/rwlocks disable preemption and eventually interrupts. + * Disabling preemption has the side effect of disabling migration and + * preventing RCU grace periods. + * + * The RT substitutions explicitly disable migration and take + * rcu_read_lock() across the lock held section. + */ +#include <linux/spinlock.h> +#include <linux/export.h> + +#define RT_MUTEX_BUILD_SPINLOCKS +#include "rtmutex.c" + +static __always_inline void rtlock_lock(struct rt_mutex_base *rtm) +{ + if (unlikely(!rt_mutex_cmpxchg_acquire(rtm, NULL, current))) + rtlock_slowlock(rtm); +} + +static __always_inline void __rt_spin_lock(spinlock_t *lock) +{ + ___might_sleep(__FILE__, __LINE__, 0); + rtlock_lock(&lock->lock); + rcu_read_lock(); + migrate_disable(); +} + +void __sched rt_spin_lock(spinlock_t *lock) +{ + spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); + __rt_spin_lock(lock); +} +EXPORT_SYMBOL(rt_spin_lock); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __sched rt_spin_lock_nested(spinlock_t *lock, int subclass) +{ + spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); + __rt_spin_lock(lock); +} +EXPORT_SYMBOL(rt_spin_lock_nested); + +void __sched rt_spin_lock_nest_lock(spinlock_t *lock, + struct lockdep_map *nest_lock) +{ + spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_); + __rt_spin_lock(lock); +} +EXPORT_SYMBOL(rt_spin_lock_nest_lock); +#endif + +void __sched rt_spin_unlock(spinlock_t *lock) +{ + spin_release(&lock->dep_map, _RET_IP_); + migrate_enable(); + rcu_read_unlock(); + + if (unlikely(!rt_mutex_cmpxchg_release(&lock->lock, current, NULL))) + rt_mutex_slowunlock(&lock->lock); +} +EXPORT_SYMBOL(rt_spin_unlock); + +/* + * Wait for the lock to get unlocked: instead of polling for an unlock + * (like raw spinlocks do), lock and unlock, to force the kernel to + * schedule if there's contention: + */ +void __sched rt_spin_lock_unlock(spinlock_t *lock) +{ + spin_lock(lock); + spin_unlock(lock); +} +EXPORT_SYMBOL(rt_spin_lock_unlock); + +static __always_inline int __rt_spin_trylock(spinlock_t *lock) +{ + int ret = 1; + + if (unlikely(!rt_mutex_cmpxchg_acquire(&lock->lock, NULL, current))) + ret = rt_mutex_slowtrylock(&lock->lock); + + if (ret) { + spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); + rcu_read_lock(); + migrate_disable(); + } + return ret; +} + +int __sched rt_spin_trylock(spinlock_t *lock) +{ + return __rt_spin_trylock(lock); +} +EXPORT_SYMBOL(rt_spin_trylock); + +int __sched rt_spin_trylock_bh(spinlock_t *lock) +{ + int ret; + + local_bh_disable(); + ret = __rt_spin_trylock(lock); + if (!ret) + local_bh_enable(); + return ret; +} +EXPORT_SYMBOL(rt_spin_trylock_bh); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __rt_spin_lock_init(spinlock_t *lock, const char *name, + struct lock_class_key *key, bool percpu) +{ + u8 type = percpu ? LD_LOCK_PERCPU : LD_LOCK_NORMAL; + + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map_type(&lock->dep_map, name, key, 0, LD_WAIT_CONFIG, + LD_WAIT_INV, type); +} +EXPORT_SYMBOL(__rt_spin_lock_init); +#endif + +/* + * RT-specific reader/writer locks + */ +#define rwbase_set_and_save_current_state(state) \ + current_save_and_set_rtlock_wait_state() + +#define rwbase_restore_current_state() \ + current_restore_rtlock_saved_state() + +static __always_inline int +rwbase_rtmutex_lock_state(struct rt_mutex_base *rtm, unsigned int state) +{ + if (unlikely(!rt_mutex_cmpxchg_acquire(rtm, NULL, current))) + rtlock_slowlock(rtm); + return 0; +} + +static __always_inline int +rwbase_rtmutex_slowlock_locked(struct rt_mutex_base *rtm, unsigned int state) +{ + rtlock_slowlock_locked(rtm); + return 0; +} + +static __always_inline void rwbase_rtmutex_unlock(struct rt_mutex_base *rtm) +{ + if (likely(rt_mutex_cmpxchg_acquire(rtm, current, NULL))) + return; + + rt_mutex_slowunlock(rtm); +} + +static __always_inline int rwbase_rtmutex_trylock(struct rt_mutex_base *rtm) +{ + if (likely(rt_mutex_cmpxchg_acquire(rtm, NULL, current))) + return 1; + + return rt_mutex_slowtrylock(rtm); +} + +#define rwbase_signal_pending_state(state, current) (0) + +#define rwbase_schedule() \ + schedule_rtlock() + +#include "rwbase_rt.c" +/* + * The common functions which get wrapped into the rwlock API. + */ +int __sched rt_read_trylock(rwlock_t *rwlock) +{ + int ret; + + ret = rwbase_read_trylock(&rwlock->rwbase); + if (ret) { + rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_); + rcu_read_lock(); + migrate_disable(); + } + return ret; +} +EXPORT_SYMBOL(rt_read_trylock); + +int __sched rt_write_trylock(rwlock_t *rwlock) +{ + int ret; + + ret = rwbase_write_trylock(&rwlock->rwbase); + if (ret) { + rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_); + rcu_read_lock(); + migrate_disable(); + } + return ret; +} +EXPORT_SYMBOL(rt_write_trylock); + +void __sched rt_read_lock(rwlock_t *rwlock) +{ + ___might_sleep(__FILE__, __LINE__, 0); + rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_); + rwbase_read_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT); + rcu_read_lock(); + migrate_disable(); +} +EXPORT_SYMBOL(rt_read_lock); + +void __sched rt_write_lock(rwlock_t *rwlock) +{ + ___might_sleep(__FILE__, __LINE__, 0); + rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_); + rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT); + rcu_read_lock(); + migrate_disable(); +} +EXPORT_SYMBOL(rt_write_lock); + +void __sched rt_read_unlock(rwlock_t *rwlock) +{ + rwlock_release(&rwlock->dep_map, _RET_IP_); + migrate_enable(); + rcu_read_unlock(); + rwbase_read_unlock(&rwlock->rwbase, TASK_RTLOCK_WAIT); +} +EXPORT_SYMBOL(rt_read_unlock); + +void __sched rt_write_unlock(rwlock_t *rwlock) +{ + rwlock_release(&rwlock->dep_map, _RET_IP_); + rcu_read_unlock(); + migrate_enable(); + rwbase_write_unlock(&rwlock->rwbase); +} +EXPORT_SYMBOL(rt_write_unlock); + +int __sched rt_rwlock_is_contended(rwlock_t *rwlock) +{ + return rw_base_is_contended(&rwlock->rwbase); +} +EXPORT_SYMBOL(rt_rwlock_is_contended); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __rt_rwlock_init(rwlock_t *rwlock, const char *name, + struct lock_class_key *key) +{ + debug_check_no_locks_freed((void *)rwlock, sizeof(*rwlock)); + lockdep_init_map_wait(&rwlock->dep_map, name, key, 0, LD_WAIT_CONFIG); +} +EXPORT_SYMBOL(__rt_rwlock_init); +#endif diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h new file mode 100644 index 000000000000..56f139201f24 --- /dev/null +++ b/kernel/locking/ww_mutex.h @@ -0,0 +1,569 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef WW_RT + +#define MUTEX mutex +#define MUTEX_WAITER mutex_waiter + +static inline struct mutex_waiter * +__ww_waiter_first(struct mutex *lock) +{ + struct mutex_waiter *w; + + w = list_first_entry(&lock->wait_list, struct mutex_waiter, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline struct mutex_waiter * +__ww_waiter_next(struct mutex *lock, struct mutex_waiter *w) +{ + w = list_next_entry(w, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline struct mutex_waiter * +__ww_waiter_prev(struct mutex *lock, struct mutex_waiter *w) +{ + w = list_prev_entry(w, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline struct mutex_waiter * +__ww_waiter_last(struct mutex *lock) +{ + struct mutex_waiter *w; + + w = list_last_entry(&lock->wait_list, struct mutex_waiter, list); + if (list_entry_is_head(w, &lock->wait_list, list)) + return NULL; + + return w; +} + +static inline void +__ww_waiter_add(struct mutex *lock, struct mutex_waiter *waiter, struct mutex_waiter *pos) +{ + struct list_head *p = &lock->wait_list; + if (pos) + p = &pos->list; + __mutex_add_waiter(lock, waiter, p); +} + +static inline struct task_struct * +__ww_mutex_owner(struct mutex *lock) +{ + return __mutex_owner(lock); +} + +static inline bool +__ww_mutex_has_waiters(struct mutex *lock) +{ + return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS; +} + +static inline void lock_wait_lock(struct mutex *lock) +{ + raw_spin_lock(&lock->wait_lock); +} + +static inline void unlock_wait_lock(struct mutex *lock) +{ + raw_spin_unlock(&lock->wait_lock); +} + +static inline void lockdep_assert_wait_lock_held(struct mutex *lock) +{ + lockdep_assert_held(&lock->wait_lock); +} + +#else /* WW_RT */ + +#define MUTEX rt_mutex +#define MUTEX_WAITER rt_mutex_waiter + +static inline struct rt_mutex_waiter * +__ww_waiter_first(struct rt_mutex *lock) +{ + struct rb_node *n = rb_first(&lock->rtmutex.waiters.rb_root); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline struct rt_mutex_waiter * +__ww_waiter_next(struct rt_mutex *lock, struct rt_mutex_waiter *w) +{ + struct rb_node *n = rb_next(&w->tree_entry); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline struct rt_mutex_waiter * +__ww_waiter_prev(struct rt_mutex *lock, struct rt_mutex_waiter *w) +{ + struct rb_node *n = rb_prev(&w->tree_entry); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline struct rt_mutex_waiter * +__ww_waiter_last(struct rt_mutex *lock) +{ + struct rb_node *n = rb_last(&lock->rtmutex.waiters.rb_root); + if (!n) + return NULL; + return rb_entry(n, struct rt_mutex_waiter, tree_entry); +} + +static inline void +__ww_waiter_add(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, struct rt_mutex_waiter *pos) +{ + /* RT unconditionally adds the waiter first and then removes it on error */ +} + +static inline struct task_struct * +__ww_mutex_owner(struct rt_mutex *lock) +{ + return rt_mutex_owner(&lock->rtmutex); +} + +static inline bool +__ww_mutex_has_waiters(struct rt_mutex *lock) +{ + return rt_mutex_has_waiters(&lock->rtmutex); +} + +static inline void lock_wait_lock(struct rt_mutex *lock) +{ + raw_spin_lock(&lock->rtmutex.wait_lock); +} + +static inline void unlock_wait_lock(struct rt_mutex *lock) +{ + raw_spin_unlock(&lock->rtmutex.wait_lock); +} + +static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock) +{ + lockdep_assert_held(&lock->rtmutex.wait_lock); +} + +#endif /* WW_RT */ + +/* + * Wait-Die: + * The newer transactions are killed when: + * It (the new transaction) makes a request for a lock being held + * by an older transaction. + * + * Wound-Wait: + * The newer transactions are wounded when: + * An older transaction makes a request for a lock being held by + * the newer transaction. + */ + +/* + * Associate the ww_mutex @ww with the context @ww_ctx under which we acquired + * it. + */ +static __always_inline void +ww_mutex_lock_acquired(struct ww_mutex *ww, struct ww_acquire_ctx *ww_ctx) +{ +#ifdef DEBUG_WW_MUTEXES + /* + * If this WARN_ON triggers, you used ww_mutex_lock to acquire, + * but released with a normal mutex_unlock in this call. + * + * This should never happen, always use ww_mutex_unlock. + */ + DEBUG_LOCKS_WARN_ON(ww->ctx); + + /* + * Not quite done after calling ww_acquire_done() ? + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire); + + if (ww_ctx->contending_lock) { + /* + * After -EDEADLK you tried to + * acquire a different ww_mutex? Bad! + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww); + + /* + * You called ww_mutex_lock after receiving -EDEADLK, + * but 'forgot' to unlock everything else first? + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0); + ww_ctx->contending_lock = NULL; + } + + /* + * Naughty, using a different class will lead to undefined behavior! + */ + DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class); +#endif + ww_ctx->acquired++; + ww->ctx = ww_ctx; +} + +/* + * Determine if @a is 'less' than @b. IOW, either @a is a lower priority task + * or, when of equal priority, a younger transaction than @b. + * + * Depending on the algorithm, @a will either need to wait for @b, or die. + */ +static inline bool +__ww_ctx_less(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b) +{ +/* + * Can only do the RT prio for WW_RT, because task->prio isn't stable due to PI, + * so the wait_list ordering will go wobbly. rt_mutex re-queues the waiter and + * isn't affected by this. + */ +#ifdef WW_RT + /* kernel prio; less is more */ + int a_prio = a->task->prio; + int b_prio = b->task->prio; + + if (rt_prio(a_prio) || rt_prio(b_prio)) { + + if (a_prio > b_prio) + return true; + + if (a_prio < b_prio) + return false; + + /* equal static prio */ + + if (dl_prio(a_prio)) { + if (dl_time_before(b->task->dl.deadline, + a->task->dl.deadline)) + return true; + + if (dl_time_before(a->task->dl.deadline, + b->task->dl.deadline)) + return false; + } + + /* equal prio */ + } +#endif + + /* FIFO order tie break -- bigger is younger */ + return (signed long)(a->stamp - b->stamp) > 0; +} + +/* + * Wait-Die; wake a lesser waiter context (when locks held) such that it can + * die. + * + * Among waiters with context, only the first one can have other locks acquired + * already (ctx->acquired > 0), because __ww_mutex_add_waiter() and + * __ww_mutex_check_kill() wake any but the earliest context. + */ +static bool +__ww_mutex_die(struct MUTEX *lock, struct MUTEX_WAITER *waiter, + struct ww_acquire_ctx *ww_ctx) +{ + if (!ww_ctx->is_wait_die) + return false; + + if (waiter->ww_ctx->acquired > 0 && __ww_ctx_less(waiter->ww_ctx, ww_ctx)) { +#ifndef WW_RT + debug_mutex_wake_waiter(lock, waiter); +#endif + wake_up_process(waiter->task); + } + + return true; +} + +/* + * Wound-Wait; wound a lesser @hold_ctx if it holds the lock. + * + * Wound the lock holder if there are waiters with more important transactions + * than the lock holders. Even if multiple waiters may wound the lock holder, + * it's sufficient that only one does. + */ +static bool __ww_mutex_wound(struct MUTEX *lock, + struct ww_acquire_ctx *ww_ctx, + struct ww_acquire_ctx *hold_ctx) +{ + struct task_struct *owner = __ww_mutex_owner(lock); + + lockdep_assert_wait_lock_held(lock); + + /* + * Possible through __ww_mutex_add_waiter() when we race with + * ww_mutex_set_context_fastpath(). In that case we'll get here again + * through __ww_mutex_check_waiters(). + */ + if (!hold_ctx) + return false; + + /* + * Can have !owner because of __mutex_unlock_slowpath(), but if owner, + * it cannot go away because we'll have FLAG_WAITERS set and hold + * wait_lock. + */ + if (!owner) + return false; + + if (ww_ctx->acquired > 0 && __ww_ctx_less(hold_ctx, ww_ctx)) { + hold_ctx->wounded = 1; + + /* + * wake_up_process() paired with set_current_state() + * inserts sufficient barriers to make sure @owner either sees + * it's wounded in __ww_mutex_check_kill() or has a + * wakeup pending to re-read the wounded state. + */ + if (owner != current) + wake_up_process(owner); + + return true; + } + + return false; +} + +/* + * We just acquired @lock under @ww_ctx, if there are more important contexts + * waiting behind us on the wait-list, check if they need to die, or wound us. + * + * See __ww_mutex_add_waiter() for the list-order construction; basically the + * list is ordered by stamp, smallest (oldest) first. + * + * This relies on never mixing wait-die/wound-wait on the same wait-list; + * which is currently ensured by that being a ww_class property. + * + * The current task must not be on the wait list. + */ +static void +__ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx) +{ + struct MUTEX_WAITER *cur; + + lockdep_assert_wait_lock_held(lock); + + for (cur = __ww_waiter_first(lock); cur; + cur = __ww_waiter_next(lock, cur)) { + + if (!cur->ww_ctx) + continue; + + if (__ww_mutex_die(lock, cur, ww_ctx) || + __ww_mutex_wound(lock, cur->ww_ctx, ww_ctx)) + break; + } +} + +/* + * After acquiring lock with fastpath, where we do not hold wait_lock, set ctx + * and wake up any waiters so they can recheck. + */ +static __always_inline void +ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + ww_mutex_lock_acquired(lock, ctx); + + /* + * The lock->ctx update should be visible on all cores before + * the WAITERS check is done, otherwise contended waiters might be + * missed. The contended waiters will either see ww_ctx == NULL + * and keep spinning, or it will acquire wait_lock, add itself + * to waiter list and sleep. + */ + smp_mb(); /* See comments above and below. */ + + /* + * [W] ww->ctx = ctx [W] MUTEX_FLAG_WAITERS + * MB MB + * [R] MUTEX_FLAG_WAITERS [R] ww->ctx + * + * The memory barrier above pairs with the memory barrier in + * __ww_mutex_add_waiter() and makes sure we either observe ww->ctx + * and/or !empty list. + */ + if (likely(!__ww_mutex_has_waiters(&lock->base))) + return; + + /* + * Uh oh, we raced in fastpath, check if any of the waiters need to + * die or wound us. + */ + lock_wait_lock(&lock->base); + __ww_mutex_check_waiters(&lock->base, ctx); + unlock_wait_lock(&lock->base); +} + +static __always_inline int +__ww_mutex_kill(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx) +{ + if (ww_ctx->acquired > 0) { +#ifdef DEBUG_WW_MUTEXES + struct ww_mutex *ww; + + ww = container_of(lock, struct ww_mutex, base); + DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock); + ww_ctx->contending_lock = ww; +#endif + return -EDEADLK; + } + + return 0; +} + +/* + * Check the wound condition for the current lock acquire. + * + * Wound-Wait: If we're wounded, kill ourself. + * + * Wait-Die: If we're trying to acquire a lock already held by an older + * context, kill ourselves. + * + * Since __ww_mutex_add_waiter() orders the wait-list on stamp, we only have to + * look at waiters before us in the wait-list. + */ +static inline int +__ww_mutex_check_kill(struct MUTEX *lock, struct MUTEX_WAITER *waiter, + struct ww_acquire_ctx *ctx) +{ + struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); + struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx); + struct MUTEX_WAITER *cur; + + if (ctx->acquired == 0) + return 0; + + if (!ctx->is_wait_die) { + if (ctx->wounded) + return __ww_mutex_kill(lock, ctx); + + return 0; + } + + if (hold_ctx && __ww_ctx_less(ctx, hold_ctx)) + return __ww_mutex_kill(lock, ctx); + + /* + * If there is a waiter in front of us that has a context, then its + * stamp is earlier than ours and we must kill ourself. + */ + for (cur = __ww_waiter_prev(lock, waiter); cur; + cur = __ww_waiter_prev(lock, cur)) { + + if (!cur->ww_ctx) + continue; + + return __ww_mutex_kill(lock, ctx); + } + + return 0; +} + +/* + * Add @waiter to the wait-list, keep the wait-list ordered by stamp, smallest + * first. Such that older contexts are preferred to acquire the lock over + * younger contexts. + * + * Waiters without context are interspersed in FIFO order. + * + * Furthermore, for Wait-Die kill ourself immediately when possible (there are + * older contexts already waiting) to avoid unnecessary waiting and for + * Wound-Wait ensure we wound the owning context when it is younger. + */ +static inline int +__ww_mutex_add_waiter(struct MUTEX_WAITER *waiter, + struct MUTEX *lock, + struct ww_acquire_ctx *ww_ctx) +{ + struct MUTEX_WAITER *cur, *pos = NULL; + bool is_wait_die; + + if (!ww_ctx) { + __ww_waiter_add(lock, waiter, NULL); + return 0; + } + + is_wait_die = ww_ctx->is_wait_die; + + /* + * Add the waiter before the first waiter with a higher stamp. + * Waiters without a context are skipped to avoid starving + * them. Wait-Die waiters may die here. Wound-Wait waiters + * never die here, but they are sorted in stamp order and + * may wound the lock holder. + */ + for (cur = __ww_waiter_last(lock); cur; + cur = __ww_waiter_prev(lock, cur)) { + + if (!cur->ww_ctx) + continue; + + if (__ww_ctx_less(ww_ctx, cur->ww_ctx)) { + /* + * Wait-Die: if we find an older context waiting, there + * is no point in queueing behind it, as we'd have to + * die the moment it would acquire the lock. + */ + if (is_wait_die) { + int ret = __ww_mutex_kill(lock, ww_ctx); + + if (ret) + return ret; + } + + break; + } + + pos = cur; + + /* Wait-Die: ensure younger waiters die. */ + __ww_mutex_die(lock, cur, ww_ctx); + } + + __ww_waiter_add(lock, waiter, pos); + + /* + * Wound-Wait: if we're blocking on a mutex owned by a younger context, + * wound that such that we might proceed. + */ + if (!is_wait_die) { + struct ww_mutex *ww = container_of(lock, struct ww_mutex, base); + + /* + * See ww_mutex_set_context_fastpath(). Orders setting + * MUTEX_FLAG_WAITERS vs the ww->ctx load, + * such that either we or the fastpath will wound @ww->ctx. + */ + smp_mb(); + __ww_mutex_wound(lock, ww_ctx, ww->ctx); + } + + return 0; +} + +static inline void __ww_mutex_unlock(struct ww_mutex *lock) +{ + if (lock->ctx) { +#ifdef DEBUG_WW_MUTEXES + DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired); +#endif + if (lock->ctx->acquired > 0) + lock->ctx->acquired--; + lock->ctx = NULL; + } +} diff --git a/kernel/locking/ww_rt_mutex.c b/kernel/locking/ww_rt_mutex.c new file mode 100644 index 000000000000..3f1fff7d2780 --- /dev/null +++ b/kernel/locking/ww_rt_mutex.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtmutex API + */ +#include <linux/spinlock.h> +#include <linux/export.h> + +#define RT_MUTEX_BUILD_MUTEX +#define WW_RT +#include "rtmutex.c" + +static int __sched +__ww_rt_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx, + unsigned int state, unsigned long ip) +{ + struct lockdep_map __maybe_unused *nest_lock = NULL; + struct rt_mutex *rtm = &lock->base; + int ret; + + might_sleep(); + + if (ww_ctx) { + if (unlikely(ww_ctx == READ_ONCE(lock->ctx))) + return -EALREADY; + + /* + * Reset the wounded flag after a kill. No other process can + * race and wound us here, since they can't have a valid owner + * pointer if we don't have any locks held. + */ + if (ww_ctx->acquired == 0) + ww_ctx->wounded = 0; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + nest_lock = &ww_ctx->dep_map; +#endif + } + mutex_acquire_nest(&rtm->dep_map, 0, 0, nest_lock, ip); + + if (likely(rt_mutex_cmpxchg_acquire(&rtm->rtmutex, NULL, current))) { + if (ww_ctx) + ww_mutex_set_context_fastpath(lock, ww_ctx); + return 0; + } + + ret = rt_mutex_slowlock(&rtm->rtmutex, ww_ctx, state); + + if (ret) + mutex_release(&rtm->dep_map, ip); + return ret; +} + +int __sched +ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + return __ww_rt_mutex_lock(lock, ctx, TASK_UNINTERRUPTIBLE, _RET_IP_); +} +EXPORT_SYMBOL(ww_mutex_lock); + +int __sched +ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + return __ww_rt_mutex_lock(lock, ctx, TASK_INTERRUPTIBLE, _RET_IP_); +} +EXPORT_SYMBOL(ww_mutex_lock_interruptible); + +void __sched ww_mutex_unlock(struct ww_mutex *lock) +{ + struct rt_mutex *rtm = &lock->base; + + __ww_mutex_unlock(lock); + + mutex_release(&rtm->dep_map, _RET_IP_); + __rt_mutex_unlock(&rtm->rtmutex); +} +EXPORT_SYMBOL(ww_mutex_unlock); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 7a4876a3a882..d070059163d7 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -529,7 +529,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) WRITE_ONCE(rnp->exp_tasks, np); if (IS_ENABLED(CONFIG_RCU_BOOST)) { /* Snapshot ->boost_mtx ownership w/rnp->lock held. */ - drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t; + drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx.rtmutex) == t; if (&t->rcu_node_entry == rnp->boost_tasks) WRITE_ONCE(rnp->boost_tasks, np); } @@ -556,7 +556,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) /* Unboost if we were boosted. */ if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex) - rt_mutex_futex_unlock(&rnp->boost_mtx); + rt_mutex_futex_unlock(&rnp->boost_mtx.rtmutex); /* * If this was the last task on the expedited lists, @@ -1053,7 +1053,7 @@ static int rcu_boost(struct rcu_node *rnp) * section. */ t = container_of(tb, struct task_struct, rcu_node_entry); - rt_mutex_init_proxy_locked(&rnp->boost_mtx, t); + rt_mutex_init_proxy_locked(&rnp->boost_mtx.rtmutex, t); raw_spin_unlock_irqrestore_rcu_node(rnp, flags); /* Lock only for side effect: boosts task t's priority. */ rt_mutex_lock(&rnp->boost_mtx); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 37bec9b05e31..c4462c454ab9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3776,6 +3776,55 @@ static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) } /* + * Invoked from try_to_wake_up() to check whether the task can be woken up. + * + * The caller holds p::pi_lock if p != current or has preemption + * disabled when p == current. + * + * The rules of PREEMPT_RT saved_state: + * + * The related locking code always holds p::pi_lock when updating + * p::saved_state, which means the code is fully serialized in both cases. + * + * The lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. No other + * bits set. This allows to distinguish all wakeup scenarios. + */ +static __always_inline +bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) +{ + if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) { + WARN_ON_ONCE((state & TASK_RTLOCK_WAIT) && + state != TASK_RTLOCK_WAIT); + } + + if (READ_ONCE(p->__state) & state) { + *success = 1; + return true; + } + +#ifdef CONFIG_PREEMPT_RT + /* + * Saved state preserves the task state across blocking on + * an RT lock. If the state matches, set p::saved_state to + * TASK_RUNNING, but do not wake the task because it waits + * for a lock wakeup. Also indicate success because from + * the regular waker's point of view this has succeeded. + * + * After acquiring the lock the task will restore p::__state + * from p::saved_state which ensures that the regular + * wakeup is not lost. The restore will also set + * p::saved_state to TASK_RUNNING so any further tests will + * not result in false positives vs. @success + */ + if (p->saved_state & state) { + p->saved_state = TASK_RUNNING; + *success = 1; + } +#endif + return false; +} + +/* * Notes on Program-Order guarantees on SMP systems. * * MIGRATION @@ -3914,10 +3963,9 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) * - we're serialized against set_special_state() by virtue of * it disabling IRQs (this allows not taking ->pi_lock). */ - if (!(READ_ONCE(p->__state) & state)) + if (!ttwu_state_match(p, state, &success)) goto out; - success = 1; trace_sched_waking(p); WRITE_ONCE(p->__state, TASK_RUNNING); trace_sched_wakeup(p); @@ -3932,14 +3980,11 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) */ raw_spin_lock_irqsave(&p->pi_lock, flags); smp_mb__after_spinlock(); - if (!(READ_ONCE(p->__state) & state)) + if (!ttwu_state_match(p, state, &success)) goto unlock; trace_sched_waking(p); - /* We're going to change ->state: */ - success = 1; - /* * Ensure we load p->on_rq _after_ p->state, otherwise it would * be possible to, falsely, observe p->on_rq == 0 and get stuck @@ -6061,6 +6106,24 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) #endif /* CONFIG_SCHED_CORE */ /* + * Constants for the sched_mode argument of __schedule(). + * + * The mode argument allows RT enabled kernels to differentiate a + * preemption from blocking on an 'sleeping' spin/rwlock. Note that + * SM_MASK_PREEMPT for !RT has all bits set, which allows the compiler to + * optimize the AND operation out and just check for zero. + */ +#define SM_NONE 0x0 +#define SM_PREEMPT 0x1 +#define SM_RTLOCK_WAIT 0x2 + +#ifndef CONFIG_PREEMPT_RT +# define SM_MASK_PREEMPT (~0U) +#else +# define SM_MASK_PREEMPT SM_PREEMPT +#endif + +/* * __schedule() is the main scheduler function. * * The main means of driving the scheduler and thus entering this function are: @@ -6099,7 +6162,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) * * WARNING: must be called with preemption disabled! */ -static void __sched notrace __schedule(bool preempt) +static void __sched notrace __schedule(unsigned int sched_mode) { struct task_struct *prev, *next; unsigned long *switch_count; @@ -6112,13 +6175,13 @@ static void __sched notrace __schedule(bool preempt) rq = cpu_rq(cpu); prev = rq->curr; - schedule_debug(prev, preempt); + schedule_debug(prev, !!sched_mode); if (sched_feat(HRTICK) || sched_feat(HRTICK_DL)) hrtick_clear(rq); local_irq_disable(); - rcu_note_context_switch(preempt); + rcu_note_context_switch(!!sched_mode); /* * Make sure that signal_pending_state()->signal_pending() below @@ -6152,7 +6215,7 @@ static void __sched notrace __schedule(bool preempt) * - ptrace_{,un}freeze_traced() can change ->state underneath us. */ prev_state = READ_ONCE(prev->__state); - if (!preempt && prev_state) { + if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { if (signal_pending_state(prev_state, prev)) { WRITE_ONCE(prev->__state, TASK_RUNNING); } else { @@ -6218,7 +6281,7 @@ static void __sched notrace __schedule(bool preempt) migrate_disable_switch(rq, prev); psi_sched_switch(prev, next, !task_on_rq_queued(prev)); - trace_sched_switch(preempt, prev, next); + trace_sched_switch(sched_mode & SM_MASK_PREEMPT, prev, next); /* Also unlocks the rq: */ rq = context_switch(rq, prev, next, &rf); @@ -6239,7 +6302,7 @@ void __noreturn do_task_dead(void) /* Tell freezer to ignore us: */ current->flags |= PF_NOFREEZE; - __schedule(false); + __schedule(SM_NONE); BUG(); /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */ @@ -6300,7 +6363,7 @@ asmlinkage __visible void __sched schedule(void) sched_submit_work(tsk); do { preempt_disable(); - __schedule(false); + __schedule(SM_NONE); sched_preempt_enable_no_resched(); } while (need_resched()); sched_update_worker(tsk); @@ -6328,7 +6391,7 @@ void __sched schedule_idle(void) */ WARN_ON_ONCE(current->__state); do { - __schedule(false); + __schedule(SM_NONE); } while (need_resched()); } @@ -6363,6 +6426,18 @@ void __sched schedule_preempt_disabled(void) preempt_disable(); } +#ifdef CONFIG_PREEMPT_RT +void __sched notrace schedule_rtlock(void) +{ + do { + preempt_disable(); + __schedule(SM_RTLOCK_WAIT); + sched_preempt_enable_no_resched(); + } while (need_resched()); +} +NOKPROBE_SYMBOL(schedule_rtlock); +#endif + static void __sched notrace preempt_schedule_common(void) { do { @@ -6381,7 +6456,7 @@ static void __sched notrace preempt_schedule_common(void) */ preempt_disable_notrace(); preempt_latency_start(1); - __schedule(true); + __schedule(SM_PREEMPT); preempt_latency_stop(1); preempt_enable_no_resched_notrace(); @@ -6460,7 +6535,7 @@ asmlinkage __visible void __sched notrace preempt_schedule_notrace(void) * an infinite recursion. */ prev_ctx = exception_enter(); - __schedule(true); + __schedule(SM_PREEMPT); exception_exit(prev_ctx); preempt_latency_stop(1); @@ -6609,7 +6684,7 @@ asmlinkage __visible void __sched preempt_schedule_irq(void) do { preempt_disable(); local_irq_enable(); - __schedule(true); + __schedule(SM_PREEMPT); local_irq_disable(); sched_preempt_enable_no_resched(); } while (need_resched()); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 5ddd575159fb..e5cdf98f50c2 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1235,7 +1235,7 @@ config PROVE_LOCKING depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select LOCKDEP select DEBUG_SPINLOCK - select DEBUG_MUTEXES + select DEBUG_MUTEXES if !PREEMPT_RT select DEBUG_RT_MUTEXES if RT_MUTEXES select DEBUG_RWSEMS select DEBUG_WW_MUTEX_SLOWPATH @@ -1299,7 +1299,7 @@ config LOCK_STAT depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select LOCKDEP select DEBUG_SPINLOCK - select DEBUG_MUTEXES + select DEBUG_MUTEXES if !PREEMPT_RT select DEBUG_RT_MUTEXES if RT_MUTEXES select DEBUG_LOCK_ALLOC default n @@ -1335,7 +1335,7 @@ config DEBUG_SPINLOCK config DEBUG_MUTEXES bool "Mutex debugging: basic checks" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL && !PREEMPT_RT help This feature allows mutex semantics violations to be detected and reported. @@ -1345,7 +1345,8 @@ config DEBUG_WW_MUTEX_SLOWPATH depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select DEBUG_LOCK_ALLOC select DEBUG_SPINLOCK - select DEBUG_MUTEXES + select DEBUG_MUTEXES if !PREEMPT_RT + select DEBUG_RT_MUTEXES if PREEMPT_RT help This feature enables slowpath testing for w/w mutex users by injecting additional -EDEADLK wound/backoff cases. Together with @@ -1368,7 +1369,7 @@ config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks" depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT select DEBUG_SPINLOCK - select DEBUG_MUTEXES + select DEBUG_MUTEXES if !PREEMPT_RT select DEBUG_RT_MUTEXES if RT_MUTEXES select LOCKDEP help diff --git a/lib/test_lockup.c b/lib/test_lockup.c index 864554e76973..906b598740a7 100644 --- a/lib/test_lockup.c +++ b/lib/test_lockup.c @@ -485,13 +485,13 @@ static int __init test_lockup_init(void) offsetof(spinlock_t, lock.wait_lock.magic), SPINLOCK_MAGIC) || test_magic(lock_rwlock_ptr, - offsetof(rwlock_t, rtmutex.wait_lock.magic), + offsetof(rwlock_t, rwbase.rtmutex.wait_lock.magic), SPINLOCK_MAGIC) || test_magic(lock_mutex_ptr, - offsetof(struct mutex, lock.wait_lock.magic), + offsetof(struct mutex, rtmutex.wait_lock.magic), SPINLOCK_MAGIC) || test_magic(lock_rwsem_ptr, - offsetof(struct rw_semaphore, rtmutex.wait_lock.magic), + offsetof(struct rw_semaphore, rwbase.rtmutex.wait_lock.magic), SPINLOCK_MAGIC)) return -EINVAL; #else @@ -502,7 +502,7 @@ static int __init test_lockup_init(void) offsetof(rwlock_t, magic), RWLOCK_MAGIC) || test_magic(lock_mutex_ptr, - offsetof(struct mutex, wait_lock.rlock.magic), + offsetof(struct mutex, wait_lock.magic), SPINLOCK_MAGIC) || test_magic(lock_rwsem_ptr, offsetof(struct rw_semaphore, wait_lock.magic), diff --git a/scripts/atomic/check-atomics.sh b/scripts/atomic/check-atomics.sh index 9c7fbd4bcbce..0e7bab3eb0d1 100755 --- a/scripts/atomic/check-atomics.sh +++ b/scripts/atomic/check-atomics.sh @@ -14,9 +14,9 @@ if [ $? -ne 0 ]; then fi cat <<EOF | -asm-generic/atomic-instrumented.h -asm-generic/atomic-long.h -linux/atomic-arch-fallback.h +linux/atomic/atomic-instrumented.h +linux/atomic/atomic-long.h +linux/atomic/atomic-arch-fallback.h EOF while read header; do OLDSUM="$(tail -n 1 ${LINUXDIR}/include/${header})" diff --git a/scripts/atomic/fallbacks/acquire b/scripts/atomic/fallbacks/acquire index 59c00529dc7c..ef764085c79a 100755 --- a/scripts/atomic/fallbacks/acquire +++ b/scripts/atomic/fallbacks/acquire @@ -1,8 +1,8 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_${pfx}${name}${sfx}_acquire(${params}) +arch_${atomic}_${pfx}${name}${sfx}_acquire(${params}) { - ${ret} ret = ${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args}); + ${ret} ret = arch_${atomic}_${pfx}${name}${sfx}_relaxed(${args}); __atomic_acquire_fence(); return ret; } diff --git a/scripts/atomic/fallbacks/add_negative b/scripts/atomic/fallbacks/add_negative index a66635bceefb..15caa2eb2371 100755 --- a/scripts/atomic/fallbacks/add_negative +++ b/scripts/atomic/fallbacks/add_negative @@ -1,6 +1,6 @@ cat <<EOF /** - * ${arch}${atomic}_add_negative - add and test if negative + * arch_${atomic}_add_negative - add and test if negative * @i: integer value to add * @v: pointer of type ${atomic}_t * @@ -9,8 +9,8 @@ cat <<EOF * result is greater than or equal to zero. */ static __always_inline bool -${arch}${atomic}_add_negative(${int} i, ${atomic}_t *v) +arch_${atomic}_add_negative(${int} i, ${atomic}_t *v) { - return ${arch}${atomic}_add_return(i, v) < 0; + return arch_${atomic}_add_return(i, v) < 0; } EOF diff --git a/scripts/atomic/fallbacks/add_unless b/scripts/atomic/fallbacks/add_unless index 2ff598a3f9ec..9e5159c2ccfc 100755 --- a/scripts/atomic/fallbacks/add_unless +++ b/scripts/atomic/fallbacks/add_unless @@ -1,6 +1,6 @@ cat << EOF /** - * ${arch}${atomic}_add_unless - add unless the number is already a given value + * arch_${atomic}_add_unless - add unless the number is already a given value * @v: pointer of type ${atomic}_t * @a: the amount to add to v... * @u: ...unless v is equal to u. @@ -9,8 +9,8 @@ cat << EOF * Returns true if the addition was done. */ static __always_inline bool -${arch}${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u) +arch_${atomic}_add_unless(${atomic}_t *v, ${int} a, ${int} u) { - return ${arch}${atomic}_fetch_add_unless(v, a, u) != u; + return arch_${atomic}_fetch_add_unless(v, a, u) != u; } EOF diff --git a/scripts/atomic/fallbacks/andnot b/scripts/atomic/fallbacks/andnot index 3f18663dcefb..5a42f54a3595 100755 --- a/scripts/atomic/fallbacks/andnot +++ b/scripts/atomic/fallbacks/andnot @@ -1,7 +1,7 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_${pfx}andnot${sfx}${order}(${int} i, ${atomic}_t *v) +arch_${atomic}_${pfx}andnot${sfx}${order}(${int} i, ${atomic}_t *v) { - ${retstmt}${arch}${atomic}_${pfx}and${sfx}${order}(~i, v); + ${retstmt}arch_${atomic}_${pfx}and${sfx}${order}(~i, v); } EOF diff --git a/scripts/atomic/fallbacks/dec b/scripts/atomic/fallbacks/dec index e2e01f0574bb..8c144c818e9e 100755 --- a/scripts/atomic/fallbacks/dec +++ b/scripts/atomic/fallbacks/dec @@ -1,7 +1,7 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v) +arch_${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v) { - ${retstmt}${arch}${atomic}_${pfx}sub${sfx}${order}(1, v); + ${retstmt}arch_${atomic}_${pfx}sub${sfx}${order}(1, v); } EOF diff --git a/scripts/atomic/fallbacks/dec_and_test b/scripts/atomic/fallbacks/dec_and_test index e8a5e492eb5f..8549f359bd0e 100755 --- a/scripts/atomic/fallbacks/dec_and_test +++ b/scripts/atomic/fallbacks/dec_and_test @@ -1,6 +1,6 @@ cat <<EOF /** - * ${arch}${atomic}_dec_and_test - decrement and test + * arch_${atomic}_dec_and_test - decrement and test * @v: pointer of type ${atomic}_t * * Atomically decrements @v by 1 and @@ -8,8 +8,8 @@ cat <<EOF * cases. */ static __always_inline bool -${arch}${atomic}_dec_and_test(${atomic}_t *v) +arch_${atomic}_dec_and_test(${atomic}_t *v) { - return ${arch}${atomic}_dec_return(v) == 0; + return arch_${atomic}_dec_return(v) == 0; } EOF diff --git a/scripts/atomic/fallbacks/dec_if_positive b/scripts/atomic/fallbacks/dec_if_positive index 527adec89c37..86bdced3428d 100755 --- a/scripts/atomic/fallbacks/dec_if_positive +++ b/scripts/atomic/fallbacks/dec_if_positive @@ -1,14 +1,14 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_dec_if_positive(${atomic}_t *v) +arch_${atomic}_dec_if_positive(${atomic}_t *v) { - ${int} dec, c = ${arch}${atomic}_read(v); + ${int} dec, c = arch_${atomic}_read(v); do { dec = c - 1; if (unlikely(dec < 0)) break; - } while (!${arch}${atomic}_try_cmpxchg(v, &c, dec)); + } while (!arch_${atomic}_try_cmpxchg(v, &c, dec)); return dec; } diff --git a/scripts/atomic/fallbacks/dec_unless_positive b/scripts/atomic/fallbacks/dec_unless_positive index dcab6848ca1e..c531d5afecc4 100755 --- a/scripts/atomic/fallbacks/dec_unless_positive +++ b/scripts/atomic/fallbacks/dec_unless_positive @@ -1,13 +1,13 @@ cat <<EOF static __always_inline bool -${arch}${atomic}_dec_unless_positive(${atomic}_t *v) +arch_${atomic}_dec_unless_positive(${atomic}_t *v) { - ${int} c = ${arch}${atomic}_read(v); + ${int} c = arch_${atomic}_read(v); do { if (unlikely(c > 0)) return false; - } while (!${arch}${atomic}_try_cmpxchg(v, &c, c - 1)); + } while (!arch_${atomic}_try_cmpxchg(v, &c, c - 1)); return true; } diff --git a/scripts/atomic/fallbacks/fence b/scripts/atomic/fallbacks/fence index 3764fc8ce945..07757d8e338e 100755 --- a/scripts/atomic/fallbacks/fence +++ b/scripts/atomic/fallbacks/fence @@ -1,10 +1,10 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_${pfx}${name}${sfx}(${params}) +arch_${atomic}_${pfx}${name}${sfx}(${params}) { ${ret} ret; __atomic_pre_full_fence(); - ret = ${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args}); + ret = arch_${atomic}_${pfx}${name}${sfx}_relaxed(${args}); __atomic_post_full_fence(); return ret; } diff --git a/scripts/atomic/fallbacks/fetch_add_unless b/scripts/atomic/fallbacks/fetch_add_unless index 0e0b9aef1515..68ce13c8b9da 100755 --- a/scripts/atomic/fallbacks/fetch_add_unless +++ b/scripts/atomic/fallbacks/fetch_add_unless @@ -1,6 +1,6 @@ cat << EOF /** - * ${arch}${atomic}_fetch_add_unless - add unless the number is already a given value + * arch_${atomic}_fetch_add_unless - add unless the number is already a given value * @v: pointer of type ${atomic}_t * @a: the amount to add to v... * @u: ...unless v is equal to u. @@ -9,14 +9,14 @@ cat << EOF * Returns original value of @v */ static __always_inline ${int} -${arch}${atomic}_fetch_add_unless(${atomic}_t *v, ${int} a, ${int} u) +arch_${atomic}_fetch_add_unless(${atomic}_t *v, ${int} a, ${int} u) { - ${int} c = ${arch}${atomic}_read(v); + ${int} c = arch_${atomic}_read(v); do { if (unlikely(c == u)) break; - } while (!${arch}${atomic}_try_cmpxchg(v, &c, c + a)); + } while (!arch_${atomic}_try_cmpxchg(v, &c, c + a)); return c; } diff --git a/scripts/atomic/fallbacks/inc b/scripts/atomic/fallbacks/inc index 15ec62946e8c..3c2c3739169e 100755 --- a/scripts/atomic/fallbacks/inc +++ b/scripts/atomic/fallbacks/inc @@ -1,7 +1,7 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_${pfx}inc${sfx}${order}(${atomic}_t *v) +arch_${atomic}_${pfx}inc${sfx}${order}(${atomic}_t *v) { - ${retstmt}${arch}${atomic}_${pfx}add${sfx}${order}(1, v); + ${retstmt}arch_${atomic}_${pfx}add${sfx}${order}(1, v); } EOF diff --git a/scripts/atomic/fallbacks/inc_and_test b/scripts/atomic/fallbacks/inc_and_test index cecc8322a21f..0cf23fe1efb8 100755 --- a/scripts/atomic/fallbacks/inc_and_test +++ b/scripts/atomic/fallbacks/inc_and_test @@ -1,6 +1,6 @@ cat <<EOF /** - * ${arch}${atomic}_inc_and_test - increment and test + * arch_${atomic}_inc_and_test - increment and test * @v: pointer of type ${atomic}_t * * Atomically increments @v by 1 @@ -8,8 +8,8 @@ cat <<EOF * other cases. */ static __always_inline bool -${arch}${atomic}_inc_and_test(${atomic}_t *v) +arch_${atomic}_inc_and_test(${atomic}_t *v) { - return ${arch}${atomic}_inc_return(v) == 0; + return arch_${atomic}_inc_return(v) == 0; } EOF diff --git a/scripts/atomic/fallbacks/inc_not_zero b/scripts/atomic/fallbacks/inc_not_zero index 50f2d4d48279..ed8a1f562667 100755 --- a/scripts/atomic/fallbacks/inc_not_zero +++ b/scripts/atomic/fallbacks/inc_not_zero @@ -1,14 +1,14 @@ cat <<EOF /** - * ${arch}${atomic}_inc_not_zero - increment unless the number is zero + * arch_${atomic}_inc_not_zero - increment unless the number is zero * @v: pointer of type ${atomic}_t * * Atomically increments @v by 1, if @v is non-zero. * Returns true if the increment was done. */ static __always_inline bool -${arch}${atomic}_inc_not_zero(${atomic}_t *v) +arch_${atomic}_inc_not_zero(${atomic}_t *v) { - return ${arch}${atomic}_add_unless(v, 1, 0); + return arch_${atomic}_add_unless(v, 1, 0); } EOF diff --git a/scripts/atomic/fallbacks/inc_unless_negative b/scripts/atomic/fallbacks/inc_unless_negative index 87629e0d4a80..95d8ce48233f 100755 --- a/scripts/atomic/fallbacks/inc_unless_negative +++ b/scripts/atomic/fallbacks/inc_unless_negative @@ -1,13 +1,13 @@ cat <<EOF static __always_inline bool -${arch}${atomic}_inc_unless_negative(${atomic}_t *v) +arch_${atomic}_inc_unless_negative(${atomic}_t *v) { - ${int} c = ${arch}${atomic}_read(v); + ${int} c = arch_${atomic}_read(v); do { if (unlikely(c < 0)) return false; - } while (!${arch}${atomic}_try_cmpxchg(v, &c, c + 1)); + } while (!arch_${atomic}_try_cmpxchg(v, &c, c + 1)); return true; } diff --git a/scripts/atomic/fallbacks/read_acquire b/scripts/atomic/fallbacks/read_acquire index 341a88dccaa7..803ba7561076 100755 --- a/scripts/atomic/fallbacks/read_acquire +++ b/scripts/atomic/fallbacks/read_acquire @@ -1,6 +1,6 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_read_acquire(const ${atomic}_t *v) +arch_${atomic}_read_acquire(const ${atomic}_t *v) { return smp_load_acquire(&(v)->counter); } diff --git a/scripts/atomic/fallbacks/release b/scripts/atomic/fallbacks/release index f8906d537c0f..b46feb56d69c 100755 --- a/scripts/atomic/fallbacks/release +++ b/scripts/atomic/fallbacks/release @@ -1,8 +1,8 @@ cat <<EOF static __always_inline ${ret} -${arch}${atomic}_${pfx}${name}${sfx}_release(${params}) +arch_${atomic}_${pfx}${name}${sfx}_release(${params}) { __atomic_release_fence(); - ${retstmt}${arch}${atomic}_${pfx}${name}${sfx}_relaxed(${args}); + ${retstmt}arch_${atomic}_${pfx}${name}${sfx}_relaxed(${args}); } EOF diff --git a/scripts/atomic/fallbacks/set_release b/scripts/atomic/fallbacks/set_release index 76068272d5f5..86ede759f24e 100755 --- a/scripts/atomic/fallbacks/set_release +++ b/scripts/atomic/fallbacks/set_release @@ -1,6 +1,6 @@ cat <<EOF static __always_inline void -${arch}${atomic}_set_release(${atomic}_t *v, ${int} i) +arch_${atomic}_set_release(${atomic}_t *v, ${int} i) { smp_store_release(&(v)->counter, i); } diff --git a/scripts/atomic/fallbacks/sub_and_test b/scripts/atomic/fallbacks/sub_and_test index c580f4c2136e..260f37341c88 100755 --- a/scripts/atomic/fallbacks/sub_and_test +++ b/scripts/atomic/fallbacks/sub_and_test @@ -1,6 +1,6 @@ cat <<EOF /** - * ${arch}${atomic}_sub_and_test - subtract value from variable and test result + * arch_${atomic}_sub_and_test - subtract value from variable and test result * @i: integer value to subtract * @v: pointer of type ${atomic}_t * @@ -9,8 +9,8 @@ cat <<EOF * other cases. */ static __always_inline bool -${arch}${atomic}_sub_and_test(${int} i, ${atomic}_t *v) +arch_${atomic}_sub_and_test(${int} i, ${atomic}_t *v) { - return ${arch}${atomic}_sub_return(i, v) == 0; + return arch_${atomic}_sub_return(i, v) == 0; } EOF diff --git a/scripts/atomic/fallbacks/try_cmpxchg b/scripts/atomic/fallbacks/try_cmpxchg index 06db0f738e45..890f850ede37 100755 --- a/scripts/atomic/fallbacks/try_cmpxchg +++ b/scripts/atomic/fallbacks/try_cmpxchg @@ -1,9 +1,9 @@ cat <<EOF static __always_inline bool -${arch}${atomic}_try_cmpxchg${order}(${atomic}_t *v, ${int} *old, ${int} new) +arch_${atomic}_try_cmpxchg${order}(${atomic}_t *v, ${int} *old, ${int} new) { ${int} r, o = *old; - r = ${arch}${atomic}_cmpxchg${order}(v, o, new); + r = arch_${atomic}_cmpxchg${order}(v, o, new); if (unlikely(r != o)) *old = r; return likely(r == o); diff --git a/scripts/atomic/gen-atomic-fallback.sh b/scripts/atomic/gen-atomic-fallback.sh index 317a6cec76e1..8e2da71f1d5f 100755 --- a/scripts/atomic/gen-atomic-fallback.sh +++ b/scripts/atomic/gen-atomic-fallback.sh @@ -2,11 +2,10 @@ # SPDX-License-Identifier: GPL-2.0 ATOMICDIR=$(dirname $0) -ARCH=$2 . ${ATOMICDIR}/atomic-tbl.sh -#gen_template_fallback(template, meta, pfx, name, sfx, order, arch, atomic, int, args...) +#gen_template_fallback(template, meta, pfx, name, sfx, order, atomic, int, args...) gen_template_fallback() { local template="$1"; shift @@ -15,11 +14,10 @@ gen_template_fallback() local name="$1"; shift local sfx="$1"; shift local order="$1"; shift - local arch="$1"; shift local atomic="$1"; shift local int="$1"; shift - local atomicname="${arch}${atomic}_${pfx}${name}${sfx}${order}" + local atomicname="arch_${atomic}_${pfx}${name}${sfx}${order}" local ret="$(gen_ret_type "${meta}" "${int}")" local retstmt="$(gen_ret_stmt "${meta}")" @@ -34,7 +32,7 @@ gen_template_fallback() fi } -#gen_proto_fallback(meta, pfx, name, sfx, order, arch, atomic, int, args...) +#gen_proto_fallback(meta, pfx, name, sfx, order, atomic, int, args...) gen_proto_fallback() { local meta="$1"; shift @@ -65,44 +63,26 @@ gen_proto_order_variant() local name="$1"; shift local sfx="$1"; shift local order="$1"; shift - local arch="$1" - local atomic="$2" + local atomic="$1" - local basename="${arch}${atomic}_${pfx}${name}${sfx}" + local basename="arch_${atomic}_${pfx}${name}${sfx}" - printf "#define arch_${basename}${order} ${basename}${order}\n" + printf "#define ${basename}${order} ${basename}${order}\n" } -#gen_proto_order_variants(meta, pfx, name, sfx, arch, atomic, int, args...) +#gen_proto_order_variants(meta, pfx, name, sfx, atomic, int, args...) gen_proto_order_variants() { local meta="$1"; shift local pfx="$1"; shift local name="$1"; shift local sfx="$1"; shift - local arch="$1" - local atomic="$2" + local atomic="$1" - local basename="${arch}${atomic}_${pfx}${name}${sfx}" + local basename="arch_${atomic}_${pfx}${name}${sfx}" local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")" - if [ -z "$arch" ]; then - gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@" - - if meta_has_acquire "${meta}"; then - gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@" - fi - if meta_has_release "${meta}"; then - gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@" - fi - if meta_has_relaxed "${meta}"; then - gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_relaxed" "$@" - fi - - echo "" - fi - # If we don't have relaxed atomics, then we don't bother with ordering fallbacks # read_acquire and set_release need to be templated, though if ! meta_has_relaxed "${meta}"; then @@ -128,7 +108,7 @@ gen_proto_order_variants() gen_basic_fallbacks "${basename}" if [ ! -z "${template}" ]; then - printf "#endif /* ${arch}${atomic}_${pfx}${name}${sfx} */\n\n" + printf "#endif /* ${basename} */\n\n" gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@" gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@" gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@" @@ -187,38 +167,38 @@ gen_try_cmpxchg_fallback() local order="$1"; shift; cat <<EOF -#ifndef ${ARCH}try_cmpxchg${order} -#define ${ARCH}try_cmpxchg${order}(_ptr, _oldp, _new) \\ +#ifndef arch_try_cmpxchg${order} +#define arch_try_cmpxchg${order}(_ptr, _oldp, _new) \\ ({ \\ typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \\ - ___r = ${ARCH}cmpxchg${order}((_ptr), ___o, (_new)); \\ + ___r = arch_cmpxchg${order}((_ptr), ___o, (_new)); \\ if (unlikely(___r != ___o)) \\ *___op = ___r; \\ likely(___r == ___o); \\ }) -#endif /* ${ARCH}try_cmpxchg${order} */ +#endif /* arch_try_cmpxchg${order} */ EOF } gen_try_cmpxchg_fallbacks() { - printf "#ifndef ${ARCH}try_cmpxchg_relaxed\n" - printf "#ifdef ${ARCH}try_cmpxchg\n" + printf "#ifndef arch_try_cmpxchg_relaxed\n" + printf "#ifdef arch_try_cmpxchg\n" - gen_basic_fallbacks "${ARCH}try_cmpxchg" + gen_basic_fallbacks "arch_try_cmpxchg" - printf "#endif /* ${ARCH}try_cmpxchg */\n\n" + printf "#endif /* arch_try_cmpxchg */\n\n" for order in "" "_acquire" "_release" "_relaxed"; do gen_try_cmpxchg_fallback "${order}" done - printf "#else /* ${ARCH}try_cmpxchg_relaxed */\n" + printf "#else /* arch_try_cmpxchg_relaxed */\n" - gen_order_fallbacks "${ARCH}try_cmpxchg" + gen_order_fallbacks "arch_try_cmpxchg" - printf "#endif /* ${ARCH}try_cmpxchg_relaxed */\n\n" + printf "#endif /* arch_try_cmpxchg_relaxed */\n\n" } cat << EOF @@ -234,14 +214,14 @@ cat << EOF EOF -for xchg in "${ARCH}xchg" "${ARCH}cmpxchg" "${ARCH}cmpxchg64"; do +for xchg in "arch_xchg" "arch_cmpxchg" "arch_cmpxchg64"; do gen_xchg_fallbacks "${xchg}" done gen_try_cmpxchg_fallbacks grep '^[a-z]' "$1" | while read name meta args; do - gen_proto "${meta}" "${name}" "${ARCH}" "atomic" "int" ${args} + gen_proto "${meta}" "${name}" "atomic" "int" ${args} done cat <<EOF @@ -252,7 +232,7 @@ cat <<EOF EOF grep '^[a-z]' "$1" | while read name meta args; do - gen_proto "${meta}" "${name}" "${ARCH}" "atomic64" "s64" ${args} + gen_proto "${meta}" "${name}" "atomic64" "s64" ${args} done cat <<EOF diff --git a/scripts/atomic/gen-atomic-instrumented.sh b/scripts/atomic/gen-atomic-instrumented.sh index b0c45aee19d7..035ceb4ee85c 100755 --- a/scripts/atomic/gen-atomic-instrumented.sh +++ b/scripts/atomic/gen-atomic-instrumented.sh @@ -121,8 +121,8 @@ cat << EOF * arch_ variants (i.e. arch_atomic_read()/arch_atomic_cmpxchg()) to avoid * double instrumentation. */ -#ifndef _ASM_GENERIC_ATOMIC_INSTRUMENTED_H -#define _ASM_GENERIC_ATOMIC_INSTRUMENTED_H +#ifndef _LINUX_ATOMIC_INSTRUMENTED_H +#define _LINUX_ATOMIC_INSTRUMENTED_H #include <linux/build_bug.h> #include <linux/compiler.h> @@ -138,6 +138,11 @@ grep '^[a-z]' "$1" | while read name meta args; do gen_proto "${meta}" "${name}" "atomic64" "s64" ${args} done +grep '^[a-z]' "$1" | while read name meta args; do + gen_proto "${meta}" "${name}" "atomic_long" "long" ${args} +done + + for xchg in "xchg" "cmpxchg" "cmpxchg64" "try_cmpxchg"; do for order in "" "_acquire" "_release" "_relaxed"; do gen_xchg "${xchg}${order}" "" @@ -158,5 +163,5 @@ gen_xchg "cmpxchg_double_local" "2 * " cat <<EOF -#endif /* _ASM_GENERIC_ATOMIC_INSTRUMENTED_H */ +#endif /* _LINUX_ATOMIC_INSTRUMENTED_H */ EOF diff --git a/scripts/atomic/gen-atomic-long.sh b/scripts/atomic/gen-atomic-long.sh index e318d3f92e53..eda89cea6e1d 100755 --- a/scripts/atomic/gen-atomic-long.sh +++ b/scripts/atomic/gen-atomic-long.sh @@ -47,9 +47,9 @@ gen_proto_order_variant() cat <<EOF static __always_inline ${ret} -atomic_long_${name}(${params}) +arch_atomic_long_${name}(${params}) { - ${retstmt}${atomic}_${name}(${argscast}); + ${retstmt}arch_${atomic}_${name}(${argscast}); } EOF @@ -61,8 +61,8 @@ cat << EOF // Generated by $0 // DO NOT MODIFY THIS FILE DIRECTLY -#ifndef _ASM_GENERIC_ATOMIC_LONG_H -#define _ASM_GENERIC_ATOMIC_LONG_H +#ifndef _LINUX_ATOMIC_LONG_H +#define _LINUX_ATOMIC_LONG_H #include <linux/compiler.h> #include <asm/types.h> @@ -98,5 +98,5 @@ done cat <<EOF #endif /* CONFIG_64BIT */ -#endif /* _ASM_GENERIC_ATOMIC_LONG_H */ +#endif /* _LINUX_ATOMIC_LONG_H */ EOF diff --git a/scripts/atomic/gen-atomics.sh b/scripts/atomic/gen-atomics.sh index f776a574224d..5b98a8307693 100755 --- a/scripts/atomic/gen-atomics.sh +++ b/scripts/atomic/gen-atomics.sh @@ -8,9 +8,9 @@ ATOMICTBL=${ATOMICDIR}/atomics.tbl LINUXDIR=${ATOMICDIR}/../.. cat <<EOF | -gen-atomic-instrumented.sh asm-generic/atomic-instrumented.h -gen-atomic-long.sh asm-generic/atomic-long.h -gen-atomic-fallback.sh linux/atomic-arch-fallback.h arch_ +gen-atomic-instrumented.sh linux/atomic/atomic-instrumented.h +gen-atomic-long.sh linux/atomic/atomic-long.h +gen-atomic-fallback.sh linux/atomic/atomic-arch-fallback.h EOF while read script header args; do /bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} ${args} > ${LINUXDIR}/include/${header} |