barrier.h 659 B

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  1. #if defined(__i386__) || defined(__x86_64__)
  2. #define barrier() asm volatile("" ::: "memory")
  3. #define virt_mb() __sync_synchronize()
  4. #define virt_rmb() barrier()
  5. #define virt_wmb() barrier()
  6. /* Atomic store should be enough, but gcc generates worse code in that case. */
  7. #define virt_store_mb(var, value) do { \
  8. typeof(var) virt_store_mb_value = (value); \
  9. __atomic_exchange(&(var), &virt_store_mb_value, &virt_store_mb_value, \
  10. __ATOMIC_SEQ_CST); \
  11. barrier(); \
  12. } while (0);
  13. /* Weak barriers should be used. If not - it's a bug */
  14. # define mb() abort()
  15. # define rmb() abort()
  16. # define wmb() abort()
  17. #else
  18. #error Please fill in barrier macros
  19. #endif