/* Atomic operations usable in machine independent code */ #ifndef _LINUX_ATOMIC_H #define _LINUX_ATOMIC_H #include /* * BluesMan: Porting from 3.10.61 kernel to 3.10.73 * Without this, compilation fails when we build * Queue spinlocks */ #ifdef CONFIG_OSQ_MUTEX_AND_QUEUE_SPINLOCK #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() #endif /* * Provide __deprecated wrappers for the new interface, avoid flag day changes. * We need the ugly external functions to break header recursion hell. */ #ifndef smp_mb__before_atomic_inc static inline void __deprecated smp_mb__before_atomic_inc(void) { extern void __smp_mb__before_atomic(void); __smp_mb__before_atomic(); } #endif #ifndef smp_mb__after_atomic_inc static inline void __deprecated smp_mb__after_atomic_inc(void) { extern void __smp_mb__after_atomic(void); __smp_mb__after_atomic(); } #endif #ifndef smp_mb__before_atomic_dec static inline void __deprecated smp_mb__before_atomic_dec(void) { extern void __smp_mb__before_atomic(void); __smp_mb__before_atomic(); } #endif #ifndef smp_mb__after_atomic_dec static inline void __deprecated smp_mb__after_atomic_dec(void) { extern void __smp_mb__after_atomic(void); __smp_mb__after_atomic(); } #endif /** * 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. */ #ifndef atomic_inc_not_zero #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) #endif /** * atomic_inc_not_zero_hint - increment if not null * @v: pointer of type atomic_t * @hint: probable value of the atomic before the increment * * This version of atomic_inc_not_zero() gives a hint of probable * value of the atomic. This helps processor to not read the memory * before doing the atomic read/modify/write cycle, lowering * number of bus transactions on some arches. * * Returns: 0 if increment was not done, 1 otherwise. */ #ifndef atomic_inc_not_zero_hint static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint) { int val, c = hint; /* sanity test, should be removed by compiler if hint is a constant */ if (!hint) return atomic_inc_not_zero(v); do { val = atomic_cmpxchg(v, c, c + 1); if (val == c) return 1; c = val; } while (c); return 0; } #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 /* * atomic_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. */ #ifndef atomic_dec_if_positive static inline int atomic_dec_if_positive(atomic_t *v) { int c, old, dec; c = atomic_read(v); for (;;) { dec = c - 1; if (unlikely(dec < 0)) break; old = atomic_cmpxchg((v), c, dec); if (likely(old == c)) break; c = old; } return dec; } #endif #ifndef CONFIG_ARCH_HAS_ATOMIC_OR static inline void atomic_or(int i, atomic_t *v) { int old; int new; do { old = atomic_read(v); new = old | i; } while (atomic_cmpxchg(v, old, new) != old); } #endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */ #include #ifdef CONFIG_GENERIC_ATOMIC64 #include #endif #endif /* _LINUX_ATOMIC_H */