diff options
Diffstat (limited to 'include/linux/atomic.h')
| -rw-r--r-- | include/linux/atomic.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h index ee456c79b0e6..42b77b5446d2 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -1,8 +1,32 @@ +/* Atomic operations usable in machine independent code */ #ifndef _LINUX_ATOMIC_H #define _LINUX_ATOMIC_H #include <asm/atomic.h> /** + * 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. + * + * Atomically adds @a to @v, so long as @v was not already @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) +{ + return __atomic_add_unless(v, a, u) != u; +} + +/** + * atomic_inc_not_zero - increment unless the number is zero + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1, so long as @v is non-zero. + * Returns non-zero if @v was non-zero, and zero otherwise. + */ +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + +/** * atomic_inc_not_zero_hint - increment if not null * @v: pointer of type atomic_t * @hint: probable value of the atomic before the increment @@ -34,6 +58,32 @@ static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint) } #endif +#ifndef atomic_inc_unless_negative +static inline int atomic_inc_unless_negative(atomic_t *p) +{ + int v, v1; + for (v = 0; v >= 0; v = v1) { + v1 = atomic_cmpxchg(p, v, v + 1); + if (likely(v1 == v)) + return 1; + } + return 0; +} +#endif + +#ifndef atomic_dec_unless_positive +static inline int atomic_dec_unless_positive(atomic_t *p) +{ + int v, v1; + for (v = 0; v <= 0; v = v1) { + v1 = atomic_cmpxchg(p, v, v - 1); + if (likely(v1 == v)) + return 1; + } + return 0; +} +#endif + #ifndef CONFIG_ARCH_HAS_ATOMIC_OR static inline void atomic_or(int i, atomic_t *v) { @@ -47,4 +97,8 @@ static inline void atomic_or(int i, atomic_t *v) } #endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */ +#include <asm-generic/atomic-long.h> +#ifdef CONFIG_GENERIC_ATOMIC64 +#include <asm-generic/atomic64.h> +#endif #endif /* _LINUX_ATOMIC_H */ |