diff options
Diffstat (limited to 'arch/sh/include/asm/atomic.h')
-rw-r--r-- | arch/sh/include/asm/atomic.h | 73 |
1 files changed, 29 insertions, 44 deletions
diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h index b16388d7195..275a448ae8c 100644 --- a/arch/sh/include/asm/atomic.h +++ b/arch/sh/include/asm/atomic.h @@ -25,58 +25,43 @@ #endif #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) +#define atomic_dec_return(v) atomic_sub_return(1, (v)) +#define atomic_inc_return(v) atomic_add_return(1, (v)) +#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) +#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) +#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) -#define atomic_dec_return(v) atomic_sub_return(1,(v)) -#define atomic_inc_return(v) atomic_add_return(1,(v)) +#define atomic_inc(v) atomic_add(1, (v)) +#define atomic_dec(v) atomic_sub(1, (v)) -/* - * atomic_inc_and_test - increment and test +#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) +#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) + +/** + * 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 increments @v by 1 - * and returns true if the result is zero, or false for all - * other cases. + * Atomically adds @a to @v, so long as it was not @u. + * Returns non-zero if @v was not @u, and zero otherwise. */ -#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) - -#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) -#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) - -#define atomic_inc(v) atomic_add(1,(v)) -#define atomic_dec(v) atomic_sub(1,(v)) - -#if !defined(CONFIG_GUSA_RB) && !defined(CONFIG_CPU_SH4A) -static inline int atomic_cmpxchg(atomic_t *v, int old, int new) -{ - int ret; - unsigned long flags; - - local_irq_save(flags); - ret = v->counter; - if (likely(ret == old)) - v->counter = new; - local_irq_restore(flags); - - return ret; -} - static inline int atomic_add_unless(atomic_t *v, int a, int u) { - int ret; - unsigned long flags; - - local_irq_save(flags); - ret = v->counter; - if (ret != u) - v->counter += a; - local_irq_restore(flags); - - return ret != 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); } -#endif /* !CONFIG_GUSA_RB && !CONFIG_CPU_SH4A */ - -#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) -#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) #define smp_mb__before_atomic_dec() smp_mb() #define smp_mb__after_atomic_dec() smp_mb() |