diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/qemu/atomic.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 5bc4d6c..96db6e9 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -36,7 +36,18 @@ #define smp_wmb() ({ barrier(); __atomic_thread_fence(__ATOMIC_RELEASE); barrier(); }) #define smp_rmb() ({ barrier(); __atomic_thread_fence(__ATOMIC_ACQUIRE); barrier(); }) +/* Most compilers currently treat consume and acquire the same, but really + * no processors except Alpha need a barrier here. Leave it in if + * using Thread Sanitizer to avoid warnings, otherwise optimize it away. + */ +#if defined(__SANITIZE_THREAD__) #define smp_read_barrier_depends() ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); barrier(); }) +#elsif defined(__alpha__) +#define smp_read_barrier_depends() asm volatile("mb":::"memory") +#else +#define smp_read_barrier_depends() barrier() +#endif + /* Weak atomic operations prevent the compiler moving other * loads/stores past the atomic operation load/store. However there is |