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author | Kyle McMartin <kyle@mcmartin.ca> | 2008-07-29 05:02:13 +0200 |
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committer | Kyle McMartin <kyle@hera.kernel.org> | 2008-10-10 18:32:29 +0200 |
commit | deae26bf6a10e47983606f5df080b91e97650ead (patch) | |
tree | 84a8a68145d0f713d7c5a1f9e6b3b03be9b3a4c8 /arch/parisc/include/asm/atomic.h | |
parent | parisc: move pdc_result to real2.S (diff) | |
download | linux-deae26bf6a10e47983606f5df080b91e97650ead.tar.xz linux-deae26bf6a10e47983606f5df080b91e97650ead.zip |
parisc: move include/asm-parisc to arch/parisc/include/asm
Diffstat (limited to 'arch/parisc/include/asm/atomic.h')
-rw-r--r-- | arch/parisc/include/asm/atomic.h | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h new file mode 100644 index 000000000000..57fcc4a5ebb4 --- /dev/null +++ b/arch/parisc/include/asm/atomic.h @@ -0,0 +1,348 @@ +/* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> + * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org> + */ + +#ifndef _ASM_PARISC_ATOMIC_H_ +#define _ASM_PARISC_ATOMIC_H_ + +#include <linux/types.h> +#include <asm/system.h> + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + * + * And probably incredibly slow on parisc. OTOH, we don't + * have to write any serious assembly. prumpf + */ + +#ifdef CONFIG_SMP +#include <asm/spinlock.h> +#include <asm/cache.h> /* we use L1_CACHE_BYTES */ + +/* Use an array of spinlocks for our atomic_ts. + * Hash function to index into a different SPINLOCK. + * Since "a" is usually an address, use one spinlock per cacheline. + */ +# define ATOMIC_HASH_SIZE 4 +# define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) a)/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ])) + +extern raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned; + +/* Can't use raw_spin_lock_irq because of #include problems, so + * this is the substitute */ +#define _atomic_spin_lock_irqsave(l,f) do { \ + raw_spinlock_t *s = ATOMIC_HASH(l); \ + local_irq_save(f); \ + __raw_spin_lock(s); \ +} while(0) + +#define _atomic_spin_unlock_irqrestore(l,f) do { \ + raw_spinlock_t *s = ATOMIC_HASH(l); \ + __raw_spin_unlock(s); \ + local_irq_restore(f); \ +} while(0) + + +#else +# define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0) +# define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0) +#endif + +/* This should get optimized out since it's never called. +** Or get a link error if xchg is used "wrong". +*/ +extern void __xchg_called_with_bad_pointer(void); + + +/* __xchg32/64 defined in arch/parisc/lib/bitops.c */ +extern unsigned long __xchg8(char, char *); +extern unsigned long __xchg32(int, int *); +#ifdef CONFIG_64BIT +extern unsigned long __xchg64(unsigned long, unsigned long *); +#endif + +/* optimizer better get rid of switch since size is a constant */ +static __inline__ unsigned long +__xchg(unsigned long x, __volatile__ void * ptr, int size) +{ + switch(size) { +#ifdef CONFIG_64BIT + case 8: return __xchg64(x,(unsigned long *) ptr); +#endif + case 4: return __xchg32((int) x, (int *) ptr); + case 1: return __xchg8((char) x, (char *) ptr); + } + __xchg_called_with_bad_pointer(); + return x; +} + + +/* +** REVISIT - Abandoned use of LDCW in xchg() for now: +** o need to test sizeof(*ptr) to avoid clearing adjacent bytes +** o and while we are at it, could CONFIG_64BIT code use LDCD too? +** +** if (__builtin_constant_p(x) && (x == NULL)) +** if (((unsigned long)p & 0xf) == 0) +** return __ldcw(p); +*/ +#define xchg(ptr,x) \ + ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) + + +#define __HAVE_ARCH_CMPXCHG 1 + +/* bug catcher for when unsupported size is used - won't link */ +extern void __cmpxchg_called_with_bad_pointer(void); + +/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */ +extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old, unsigned int new_); +extern unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new_); + +/* don't worry...optimizer will get rid of most of this */ +static __inline__ unsigned long +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) +{ + switch(size) { +#ifdef CONFIG_64BIT + case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_); +#endif + case 4: return __cmpxchg_u32((unsigned int *)ptr, (unsigned int) old, (unsigned int) new_); + } + __cmpxchg_called_with_bad_pointer(); + return old; +} + +#define cmpxchg(ptr,o,n) \ + ({ \ + __typeof__(*(ptr)) _o_ = (o); \ + __typeof__(*(ptr)) _n_ = (n); \ + (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ + (unsigned long)_n_, sizeof(*(ptr))); \ + }) + +#include <asm-generic/cmpxchg-local.h> + +static inline unsigned long __cmpxchg_local(volatile void *ptr, + unsigned long old, + unsigned long new_, int size) +{ + switch (size) { +#ifdef CONFIG_64BIT + case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_); +#endif + case 4: return __cmpxchg_u32(ptr, old, new_); + default: + return __cmpxchg_local_generic(ptr, old, new_, size); + } +} + +/* + * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make + * them available. + */ +#define cmpxchg_local(ptr, o, n) \ + ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))) +#ifdef CONFIG_64BIT +#define cmpxchg64_local(ptr, o, n) \ + ({ \ + BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ + cmpxchg_local((ptr), (o), (n)); \ + }) +#else +#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#endif + +/* Note that we need not lock read accesses - aligned word writes/reads + * are atomic, so a reader never sees unconsistent values. + * + * Cache-line alignment would conflict with, for example, linux/module.h + */ + +typedef struct { volatile int counter; } atomic_t; + +/* It's possible to reduce all atomic operations to either + * __atomic_add_return, atomic_set and atomic_read (the latter + * is there only for consistency). + */ + +static __inline__ int __atomic_add_return(int i, atomic_t *v) +{ + int ret; + unsigned long flags; + _atomic_spin_lock_irqsave(v, flags); + + ret = (v->counter += i); + + _atomic_spin_unlock_irqrestore(v, flags); + return ret; +} + +static __inline__ void atomic_set(atomic_t *v, int i) +{ + unsigned long flags; + _atomic_spin_lock_irqsave(v, flags); + + v->counter = i; + + _atomic_spin_unlock_irqrestore(v, flags); +} + +static __inline__ int atomic_read(const atomic_t *v) +{ + return v->counter; +} + +/* exported interface */ +#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) +#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) + +/** + * atomic_add_unless - add unless the number is a given value + * @v: pointer of type atomic_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as it was not @u. + * Returns non-zero if @v was not @u, and zero otherwise. + */ +static __inline__ int atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, old; + c = atomic_read(v); + for (;;) { + if (unlikely(c == (u))) + break; + old = atomic_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c != (u); +} + +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + +#define atomic_add(i,v) ((void)(__atomic_add_return( ((int)i),(v)))) +#define atomic_sub(i,v) ((void)(__atomic_add_return(-((int)i),(v)))) +#define atomic_inc(v) ((void)(__atomic_add_return( 1,(v)))) +#define atomic_dec(v) ((void)(__atomic_add_return( -1,(v)))) + +#define atomic_add_return(i,v) (__atomic_add_return( ((int)i),(v))) +#define atomic_sub_return(i,v) (__atomic_add_return(-((int)i),(v))) +#define atomic_inc_return(v) (__atomic_add_return( 1,(v))) +#define atomic_dec_return(v) (__atomic_add_return( -1,(v))) + +#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) + +/* + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) + +#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) + +#define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0) + +#define ATOMIC_INIT(i) ((atomic_t) { (i) }) + +#define smp_mb__before_atomic_dec() smp_mb() +#define smp_mb__after_atomic_dec() smp_mb() +#define smp_mb__before_atomic_inc() smp_mb() +#define smp_mb__after_atomic_inc() smp_mb() + +#ifdef CONFIG_64BIT + +typedef struct { volatile s64 counter; } atomic64_t; + +#define ATOMIC64_INIT(i) ((atomic64_t) { (i) }) + +static __inline__ int +__atomic64_add_return(s64 i, atomic64_t *v) +{ + int ret; + unsigned long flags; + _atomic_spin_lock_irqsave(v, flags); + + ret = (v->counter += i); + + _atomic_spin_unlock_irqrestore(v, flags); + return ret; +} + +static __inline__ void +atomic64_set(atomic64_t *v, s64 i) +{ + unsigned long flags; + _atomic_spin_lock_irqsave(v, flags); + + v->counter = i; + + _atomic_spin_unlock_irqrestore(v, flags); +} + +static __inline__ s64 +atomic64_read(const atomic64_t *v) +{ + return v->counter; +} + +#define atomic64_add(i,v) ((void)(__atomic64_add_return( ((s64)i),(v)))) +#define atomic64_sub(i,v) ((void)(__atomic64_add_return(-((s64)i),(v)))) +#define atomic64_inc(v) ((void)(__atomic64_add_return( 1,(v)))) +#define atomic64_dec(v) ((void)(__atomic64_add_return( -1,(v)))) + +#define atomic64_add_return(i,v) (__atomic64_add_return( ((s64)i),(v))) +#define atomic64_sub_return(i,v) (__atomic64_add_return(-((s64)i),(v))) +#define atomic64_inc_return(v) (__atomic64_add_return( 1,(v))) +#define atomic64_dec_return(v) (__atomic64_add_return( -1,(v))) + +#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) + +#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) +#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0) +#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i),(v)) == 0) + +/* exported interface */ +#define atomic64_cmpxchg(v, o, n) \ + ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n))) +#define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) + +/** + * atomic64_add_unless - add unless the number is a given value + * @v: pointer of type atomic64_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as it was not @u. + * Returns non-zero if @v was not @u, and zero otherwise. + */ +static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) +{ + long c, old; + c = atomic64_read(v); + for (;;) { + if (unlikely(c == (u))) + break; + old = atomic64_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c != (u); +} + +#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) + +#endif /* CONFIG_64BIT */ + +#include <asm-generic/atomic.h> + +#endif /* _ASM_PARISC_ATOMIC_H_ */ |