diff options
Diffstat (limited to 'include/linux/atomic.h')
| -rw-r--r-- | include/linux/atomic.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h index 5313f850..73024023 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -41,6 +41,17 @@ typedef struct { #define cmpxchg_acquire(p, old, new) uatomic_cmpxchg(p, old, new) #define cmpxchg_release(p, old, new) uatomic_cmpxchg(p, old, new) +#define try_cmpxchg(p, _old, _new) \ +({ \ + typeof(*(_old)) _v = cmpxchg(p, *(_old), _new); \ + bool _ret = _v == *(_old); \ + *(_old) = _v; \ + _ret; \ +}) + +#define try_cmpxchg_acquire(p, _old, _new) \ + try_cmpxchg(p, _old, _new) + #define smp_mb__before_atomic() cmm_smp_mb__before_uatomic_add() #define smp_mb__after_atomic() cmm_smp_mb__after_uatomic_add() #define smp_wmb() cmm_smp_wmb() @@ -65,6 +76,11 @@ typedef struct { #define xchg(p, v) __atomic_exchange_n(p, v, __ATOMIC_SEQ_CST) #define xchg_acquire(p, v) __atomic_exchange_n(p, v, __ATOMIC_ACQUIRE) +#define try_cmpxchg(p, old, new) \ + __atomic_compare_exchange_n((p), __old, new, false, \ + __ATOMIC_SEQ_CST, \ + __ATOMIC_SEQ_CST) + #define cmpxchg(p, old, new) \ ({ \ typeof(*(p)) __old = (old); \ @@ -281,6 +297,11 @@ static inline i_type a_type##_cmpxchg(a_type##_t *v, i_type old, i_type new)\ return cmpxchg(&v->counter, old, new); \ } \ \ +static inline bool a_type##_try_cmpxchg(a_type##_t *v, i_type *old, i_type new)\ +{ \ + return try_cmpxchg(&v->counter, old, new); \ +} \ + \ static inline i_type a_type##_cmpxchg_acquire(a_type##_t *v, i_type old, i_type new)\ { \ return cmpxchg_acquire(&v->counter, old, new); \ |