diff options
Diffstat (limited to 'arch/parisc/include/asm/atomic.h')
| -rw-r--r-- | arch/parisc/include/asm/atomic.h | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index af9cf30ed47..0be2db2c7d4 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -7,6 +7,7 @@ #include <linux/types.h> #include <asm/cmpxchg.h> +#include <asm/barrier.h> /* * Atomic operations that C can't guarantee us. Useful for @@ -115,8 +116,8 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) } -#define atomic_add(i,v) ((void)(__atomic_add_return( (i),(v)))) -#define atomic_sub(i,v) ((void)(__atomic_add_return(-(i),(v)))) +#define atomic_add(i,v) ((void)(__atomic_add_return( (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)))) @@ -143,11 +144,6 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) #define ATOMIC_INIT(i) { (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 #define ATOMIC64_INIT(i) { (i) } @@ -229,6 +225,29 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) +/* + * atomic64_dec_if_positive - decrement by 1 if old value positive + * @v: pointer of type atomic_t + * + * The function returns the old value of *v minus 1, even if + * the atomic variable, v, was not decremented. + */ +static inline long atomic64_dec_if_positive(atomic64_t *v) +{ + long c, old, dec; + c = atomic64_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic64_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + return dec; +} + #endif /* !CONFIG_64BIT */ |