Merge tag 'xtensa-20190307' of git://github.com/jcmvbkbc/linux-xtensa

Pull xtensa updates from Max Filippov:

 - use generic spinlock/rwlock implementations

 - clean up IPI processing

 - document boot parameters passing to the kernel

 - fix get_wchan

 - various cleanups in time.c, process.c, traps.c and thread_info.h

* tag 'xtensa-20190307' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: simplify trap_init
  xtensa: drop unused definitions
  xtensa: fix get_wchan
  xtensa: use generic spinlock/rwlock implementation
  xtensa: provide xchg for sizes 1 and 2
  xtensa: clean up arch/xtensa/kernel/time.c
  xtensa: SMP: rework IPI processing
  xtensa: document boot parameter passing

5 files changed, 40 insertions, 207 deletions

diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
index 809f39ce08c0..d939e13e8d84 100644
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -23,6 +23,8 @@ generic-y += mm-arch-hooks.h
 generic-y += param.h
 generic-y += percpu.h
 generic-y += preempt.h
+generic-y += qrwlock.h
+generic-y += qspinlock.h
 generic-y += rwsem.h
 generic-y += sections.h
 generic-y += socket.h
diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 201e9009efd8..22a10c715c1f 100644
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h
@@ -13,6 +13,7 @@
 
 #ifndef __ASSEMBLY__
 
+#include <linux/bits.h>
 #include <linux/stringify.h>
 
 /*
@@ -138,6 +139,28 @@ static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
 #define xchg(ptr,x) \
 	((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 
+static inline u32 xchg_small(volatile void *ptr, u32 x, int size)
+{
+	int off = (unsigned long)ptr % sizeof(u32);
+	volatile u32 *p = ptr - off;
+#ifdef __BIG_ENDIAN
+	int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
+#else
+	int bitoff = off * BITS_PER_BYTE;
+#endif
+	u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
+	u32 oldv, newv;
+	u32 ret;
+
+	do {
+		oldv = READ_ONCE(*p);
+		ret = (oldv & bitmask) >> bitoff;
+		newv = (oldv & ~bitmask) | (x << bitoff);
+	} while (__cmpxchg_u32(p, oldv, newv) != oldv);
+
+	return ret;
+}
+
 /*
  * This only works if the compiler isn't horribly bad at optimizing.
  * gcc-2.5.8 reportedly can't handle this, but I define that one to
@@ -150,11 +173,16 @@ static __inline__ unsigned long
 __xchg(unsigned long x, volatile void * ptr, int size)
 {
 	switch (size) {
-		case 4:
-			return xchg_u32(ptr, x);
+	case 1:
+		return xchg_small(ptr, x, 1);
+	case 2:
+		return xchg_small(ptr, x, 2);
+	case 4:
+		return xchg_u32(ptr, x);
+	default:
+		__xchg_called_with_bad_pointer();
+		return x;
 	}
-	__xchg_called_with_bad_pointer();
-	return x;
 }
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/xtensa/include/asm/spinlock.h b/arch/xtensa/include/asm/spinlock.h
index c6e1290dcbb7..584b0de6f2ca 100644
--- a/arch/xtensa/include/asm/spinlock.h
+++ b/arch/xtensa/include/asm/spinlock.h
@@ -12,188 +12,9 @@
 #define _XTENSA_SPINLOCK_H
 
 #include <asm/barrier.h>
-#include <asm/processor.h>
+#include <asm/qrwlock.h>
+#include <asm/qspinlock.h>
 
-/*
- * spinlock
- *
- * There is at most one owner of a spinlock.  There are not different
- * types of spinlock owners like there are for rwlocks (see below).
- *
- * When trying to obtain a spinlock, the function "spins" forever, or busy-
- * waits, until the lock is obtained.  When spinning, presumably some other
- * owner will soon give up the spinlock making it available to others.  Use
- * the trylock functions to avoid spinning forever.
- *
- * possible values:
- *
- *    0         nobody owns the spinlock
- *    1         somebody owns the spinlock
- */
-
-#define arch_spin_is_locked(x) ((x)->slock != 0)
-
-static inline void arch_spin_lock(arch_spinlock_t *lock)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       movi    %0, 0\n"
-			"       wsr     %0, scompare1\n"
-			"1:     movi    %0, 1\n"
-			"       s32c1i  %0, %1, 0\n"
-			"       bnez    %0, 1b\n"
-			: "=&a" (tmp)
-			: "a" (&lock->slock)
-			: "memory");
-}
-
-/* Returns 1 if the lock is obtained, 0 otherwise. */
-
-static inline int arch_spin_trylock(arch_spinlock_t *lock)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       movi    %0, 0\n"
-			"       wsr     %0, scompare1\n"
-			"       movi    %0, 1\n"
-			"       s32c1i  %0, %1, 0\n"
-			: "=&a" (tmp)
-			: "a" (&lock->slock)
-			: "memory");
-
-	return tmp == 0 ? 1 : 0;
-}
-
-static inline void arch_spin_unlock(arch_spinlock_t *lock)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       movi    %0, 0\n"
-			"       s32ri   %0, %1, 0\n"
-			: "=&a" (tmp)
-			: "a" (&lock->slock)
-			: "memory");
-}
-
-/*
- * rwlock
- *
- * Read-write locks are really a more flexible spinlock.  They allow
- * multiple readers but only one writer.  Write ownership is exclusive
- * (i.e., all other readers and writers are blocked from ownership while
- * there is a write owner).  These rwlocks are unfair to writers.  Writers
- * can be starved for an indefinite time by readers.
- *
- * possible values:
- *
- *   0          nobody owns the rwlock
- *  >0          one or more readers own the rwlock
- *                (the positive value is the actual number of readers)
- *  0x80000000  one writer owns the rwlock, no other writers, no readers
- */
-
-static inline void arch_write_lock(arch_rwlock_t *rw)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       movi    %0, 0\n"
-			"       wsr     %0, scompare1\n"
-			"1:     movi    %0, 1\n"
-			"       slli    %0, %0, 31\n"
-			"       s32c1i  %0, %1, 0\n"
-			"       bnez    %0, 1b\n"
-			: "=&a" (tmp)
-			: "a" (&rw->lock)
-			: "memory");
-}
-
-/* Returns 1 if the lock is obtained, 0 otherwise. */
-
-static inline int arch_write_trylock(arch_rwlock_t *rw)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       movi    %0, 0\n"
-			"       wsr     %0, scompare1\n"
-			"       movi    %0, 1\n"
-			"       slli    %0, %0, 31\n"
-			"       s32c1i  %0, %1, 0\n"
-			: "=&a" (tmp)
-			: "a" (&rw->lock)
-			: "memory");
-
-	return tmp == 0 ? 1 : 0;
-}
-
-static inline void arch_write_unlock(arch_rwlock_t *rw)
-{
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       movi    %0, 0\n"
-			"       s32ri   %0, %1, 0\n"
-			: "=&a" (tmp)
-			: "a" (&rw->lock)
-			: "memory");
-}
-
-static inline void arch_read_lock(arch_rwlock_t *rw)
-{
-	unsigned long tmp;
-	unsigned long result;
-
-	__asm__ __volatile__(
-			"1:     l32i    %1, %2, 0\n"
-			"       bltz    %1, 1b\n"
-			"       wsr     %1, scompare1\n"
-			"       addi    %0, %1, 1\n"
-			"       s32c1i  %0, %2, 0\n"
-			"       bne     %0, %1, 1b\n"
-			: "=&a" (result), "=&a" (tmp)
-			: "a" (&rw->lock)
-			: "memory");
-}
-
-/* Returns 1 if the lock is obtained, 0 otherwise. */
-
-static inline int arch_read_trylock(arch_rwlock_t *rw)
-{
-	unsigned long result;
-	unsigned long tmp;
-
-	__asm__ __volatile__(
-			"       l32i    %1, %2, 0\n"
-			"       addi    %0, %1, 1\n"
-			"       bltz    %0, 1f\n"
-			"       wsr     %1, scompare1\n"
-			"       s32c1i  %0, %2, 0\n"
-			"       sub     %0, %0, %1\n"
-			"1:\n"
-			: "=&a" (result), "=&a" (tmp)
-			: "a" (&rw->lock)
-			: "memory");
-
-	return result == 0;
-}
-
-static inline void arch_read_unlock(arch_rwlock_t *rw)
-{
-	unsigned long tmp1, tmp2;
-
-	__asm__ __volatile__(
-			"1:     l32i    %1, %2, 0\n"
-			"       addi    %0, %1, -1\n"
-			"       wsr     %1, scompare1\n"
-			"       s32c1i  %0, %2, 0\n"
-			"       bne     %0, %1, 1b\n"
-			: "=&a" (tmp1), "=&a" (tmp2)
-			: "a" (&rw->lock)
-			: "memory");
-}
+#define smp_mb__after_spinlock()	smp_mb()
 
 #endif	/* _XTENSA_SPINLOCK_H */
diff --git a/arch/xtensa/include/asm/spinlock_types.h b/arch/xtensa/include/asm/spinlock_types.h
index bb1fe6c1816e..64c9389254f1 100644
--- a/arch/xtensa/include/asm/spinlock_types.h
+++ b/arch/xtensa/include/asm/spinlock_types.h
@@ -2,20 +2,11 @@
 #ifndef __ASM_SPINLOCK_TYPES_H
 #define __ASM_SPINLOCK_TYPES_H
 
-#ifndef __LINUX_SPINLOCK_TYPES_H
+#if !defined(__LINUX_SPINLOCK_TYPES_H) && !defined(__ASM_SPINLOCK_H)
 # error "please don't include this file directly"
 #endif
 
-typedef struct {
-	volatile unsigned int slock;
-} arch_spinlock_t;
-
-#define __ARCH_SPIN_LOCK_UNLOCKED	{ 0 }
-
-typedef struct {
-	volatile unsigned int lock;
-} arch_rwlock_t;
-
-#define __ARCH_RW_LOCK_UNLOCKED		{ 0 }
+#include <asm-generic/qspinlock_types.h>
+#include <asm-generic/qrwlock_types.h>
 
 #endif
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index f333f10a7650..f092cc3f4e66 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -121,15 +121,6 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_WORK_MASK		(_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
 				 _TIF_SYSCALL_TRACEPOINT)
 
-/*
- * Thread-synchronous status.
- *
- * This is different from the flags in that nobody else
- * ever touches our thread-synchronous status, so we don't
- * have to worry about atomic accesses.
- */
-#define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */
-
 #define THREAD_SIZE KERNEL_STACK_SIZE
 #define THREAD_SIZE_ORDER (KERNEL_STACK_SHIFT - PAGE_SHIFT)