diff options
| author | Petri Savolainen <petri.savolainen@nokia.com> | 2015-10-23 10:00:19 +0300 |
|---|---|---|
| committer | Maxim Uvarov <maxim.uvarov@linaro.org> | 2016-02-08 20:45:24 +0300 |
| commit | 2145a338867f41b37acfb204807891d39002f2aa (patch) | |
| tree | 985d4d116eae842d3f7d39fff33b86eb240a2fc3 /platform | |
| parent | 2c4f0006c83a17ab910ff275f3fbe8a468be6e5c (diff) | |
api: atomic: added cas operations
Added cas operations for 32 and 64 bit atomic variables. These
use relaxed memory order (as all other operations).
Signed-off-by: Petri Savolainen <petri.savolainen@nokia.com>
Reviewed-by: Mike Holmes <mike.holmes@linaro.org>
Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
Diffstat (limited to 'platform')
| -rw-r--r-- | platform/linux-generic/include/odp/atomic.h | 24 | ||||
| -rw-r--r-- | platform/linux-generic/include/odp/plat/atomic_types.h | 21 |
2 files changed, 42 insertions, 3 deletions
diff --git a/platform/linux-generic/include/odp/atomic.h b/platform/linux-generic/include/odp/atomic.h index 10cf361b4..7d67bf54b 100644 --- a/platform/linux-generic/include/odp/atomic.h +++ b/platform/linux-generic/include/odp/atomic.h @@ -84,6 +84,15 @@ static inline void odp_atomic_dec_u32(odp_atomic_u32_t *atom) (void)__atomic_fetch_sub(&atom->v, 1, __ATOMIC_RELAXED); } +static inline int odp_atomic_cas_u32(odp_atomic_u32_t *atom, uint32_t *old_val, + uint32_t new_val) +{ + return __atomic_compare_exchange_n(&atom->v, old_val, new_val, + 0 /* strong */, + __ATOMIC_RELAXED, + __ATOMIC_RELAXED); +} + static inline void odp_atomic_init_u64(odp_atomic_u64_t *atom, uint64_t val) { atom->v = val; @@ -185,6 +194,21 @@ static inline void odp_atomic_dec_u64(odp_atomic_u64_t *atom) #endif } +static inline int odp_atomic_cas_u64(odp_atomic_u64_t *atom, uint64_t *old_val, + uint64_t new_val) +{ +#if __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + int ret; + *old_val = ATOMIC_OP(atom, ATOMIC_CAS_OP(&ret, *old_val, new_val)); + return ret; +#else + return __atomic_compare_exchange_n(&atom->v, old_val, new_val, + 0 /* strong */, + __ATOMIC_RELAXED, + __ATOMIC_RELAXED); +#endif +} + /** * @} */ diff --git a/platform/linux-generic/include/odp/plat/atomic_types.h b/platform/linux-generic/include/odp/plat/atomic_types.h index 0fe15ed13..bc0bd8bfe 100644 --- a/platform/linux-generic/include/odp/plat/atomic_types.h +++ b/platform/linux-generic/include/odp/plat/atomic_types.h @@ -43,6 +43,21 @@ struct odp_atomic_u32_s { } ODP_ALIGNED(sizeof(uint32_t)); /* Enforce alignement! */; #if __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + +/** + * @internal + * CAS operation expression for the ATOMIC_OP macro + */ +#define ATOMIC_CAS_OP(ret_ptr, old_val, new_val) \ +({ \ + if (atom->v == (old_val)) { \ + atom->v = (new_val); \ + *(ret_ptr) = 1; \ + } else { \ + *(ret_ptr) = 0; \ + } \ +}) + /** * @internal * Helper macro for lock-based atomic operations on 64-bit integers @@ -52,14 +67,14 @@ struct odp_atomic_u32_s { */ #define ATOMIC_OP(atom, expr) \ ({ \ - uint64_t old_val; \ + uint64_t _old_val; \ /* Loop while lock is already taken, stop when lock becomes clear */ \ while (__atomic_test_and_set(&(atom)->lock, __ATOMIC_ACQUIRE)) \ (void)0; \ - old_val = (atom)->v; \ + _old_val = (atom)->v; \ (expr); /* Perform whatever update is desired */ \ __atomic_clear(&(atom)->lock, __ATOMIC_RELEASE); \ - old_val; /* Return old value */ \ + _old_val; /* Return old value */ \ }) #endif |