1
0
Files
kernel-49/tools/virtio/asm/barrier.h
Andrey Zolotarev e72e9355e3 start the android-4.9 tree
git: https://android.googlesource.com/kernel/common
branch: android-4.9
commit: 03fcc2fe71308c2d164b4e6cbfc738c63e670444
2018-11-15 21:36:32 +03:00

21 lines
659 B
C

#if defined(__i386__) || defined(__x86_64__)
#define barrier() asm volatile("" ::: "memory")
#define virt_mb() __sync_synchronize()
#define virt_rmb() barrier()
#define virt_wmb() barrier()
/* Atomic store should be enough, but gcc generates worse code in that case. */
#define virt_store_mb(var, value) do { \
typeof(var) virt_store_mb_value = (value); \
__atomic_exchange(&(var), &virt_store_mb_value, &virt_store_mb_value, \
__ATOMIC_SEQ_CST); \
barrier(); \
} while (0);
/* Weak barriers should be used. If not - it's a bug */
# define mb() abort()
# define rmb() abort()
# define wmb() abort()
#else
#error Please fill in barrier macros
#endif