diff options
| author | Richard Henderson <rth@twiddle.net> | 2016-10-24 10:29:32 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2016-10-26 08:28:57 -0700 |
| commit | 84bca3927b36fb1d9a2ca85cbbdf9023d2b84678 (patch) | |
| tree | a6abbc1f644b374178c1517051df1a68e2141769 /include | |
| parent | 83d0c719f837724d9e3963b078211b2242bdd2a5 (diff) | |
| download | qemu-84bca3927b36fb1d9a2ca85cbbdf9023d2b84678.tar.gz | |
atomics: Add __nocheck atomic operations
While the check against sizeof(void *) is appropriate for
normal usage within qemu, there are places in which we want
wider operaions and have checked for their existance.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/qemu/atomic.h | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index a26a36bb49..878fa0700d 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -99,15 +99,21 @@ * no effect on the generated code but not using the atomic primitives * will get flagged by sanitizers as a violation. */ +#define atomic_read__nocheck(ptr) \ + __atomic_load_n(ptr, __ATOMIC_RELAXED) + #define atomic_read(ptr) \ ({ \ QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \ - __atomic_load_n(ptr, __ATOMIC_RELAXED); \ + atomic_read__nocheck(ptr); \ }) +#define atomic_set__nocheck(ptr, i) \ + __atomic_store_n(ptr, i, __ATOMIC_RELAXED) + #define atomic_set(ptr, i) do { \ QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \ - __atomic_store_n(ptr, i, __ATOMIC_RELAXED); \ + atomic_set__nocheck(ptr, i); \ } while(0) /* See above: most compilers currently treat consume and acquire the @@ -151,20 +157,27 @@ /* All the remaining operations are fully sequentially consistent */ +#define atomic_xchg__nocheck(ptr, i) ({ \ + __atomic_exchange_n(ptr, (i), __ATOMIC_SEQ_CST); \ +}) + #define atomic_xchg(ptr, i) ({ \ QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \ - __atomic_exchange_n(ptr, i, __ATOMIC_SEQ_CST); \ + atomic_xchg__nocheck(ptr, i); \ }) /* Returns the eventual value, failed or not */ -#define atomic_cmpxchg(ptr, old, new) \ - ({ \ - QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \ +#define atomic_cmpxchg__nocheck(ptr, old, new) ({ \ typeof_strip_qual(*ptr) _old = (old); \ __atomic_compare_exchange_n(ptr, &_old, new, false, \ __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); \ _old; \ - }) +}) + +#define atomic_cmpxchg(ptr, old, new) ({ \ + QEMU_BUILD_BUG_ON(sizeof(*ptr) > sizeof(void *)); \ + atomic_cmpxchg__nocheck(ptr, old, new); \ +}) /* Provide shorter names for GCC atomic builtins, return old value */ #define atomic_fetch_inc(ptr) __atomic_fetch_add(ptr, 1, __ATOMIC_SEQ_CST) @@ -279,8 +292,11 @@ /* These will only be atomic if the processor does the fetch or store * in a single issue memory operation */ -#define atomic_read(ptr) (*(__typeof__(*ptr) volatile*) (ptr)) -#define atomic_set(ptr, i) ((*(__typeof__(*ptr) volatile*) (ptr)) = (i)) +#define atomic_read__nocheck(p) (*(__typeof__(*(p)) volatile*) (p)) +#define atomic_set__nocheck(p, i) ((*(__typeof__(*(p)) volatile*) (p)) = (i)) + +#define atomic_read(ptr) atomic_read__nocheck(ptr) +#define atomic_set(ptr, i) atomic_set__nocheck(ptr,i) /** * atomic_rcu_read - reads a RCU-protected pointer to a local variable @@ -341,6 +357,7 @@ #define atomic_xchg(ptr, i) (smp_mb(), __sync_lock_test_and_set(ptr, i)) #endif #endif +#define atomic_xchg__nocheck atomic_xchg /* Provide shorter names for GCC atomic builtins. */ #define atomic_fetch_inc(ptr) __sync_fetch_and_add(ptr, 1) @@ -360,6 +377,7 @@ #define atomic_xor_fetch(ptr, n) __sync_xor_and_fetch(ptr, n) #define atomic_cmpxchg(ptr, old, new) __sync_val_compare_and_swap(ptr, old, new) +#define atomic_cmpxchg__nocheck(ptr, old, new) atomic_cmpxchg(ptr, old, new) /* And even shorter names that return void. */ #define atomic_inc(ptr) ((void) __sync_fetch_and_add(ptr, 1)) |