barrier.h 1.3 KB

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  1. /*
  2. * Copyright IBM Corp. 1999, 2009
  3. *
  4. * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  5. */
  6. #ifndef __ASM_BARRIER_H
  7. #define __ASM_BARRIER_H
  8. /*
  9. * Force strict CPU ordering.
  10. * And yes, this is required on UP too when we're talking
  11. * to devices.
  12. *
  13. * This is very similar to the ppc eieio/sync instruction in that is
  14. * does a checkpoint syncronisation & makes sure that
  15. * all memory ops have completed wrt other CPU's ( see 7-15 POP DJB ).
  16. */
  17. #define eieio() asm volatile("bcr 15,0" : : : "memory")
  18. #define SYNC_OTHER_CORES(x) eieio()
  19. #define mb() eieio()
  20. #define rmb() eieio()
  21. #define wmb() eieio()
  22. #define read_barrier_depends() do { } while(0)
  23. #define smp_mb() mb()
  24. #define smp_rmb() rmb()
  25. #define smp_wmb() wmb()
  26. #define smp_read_barrier_depends() read_barrier_depends()
  27. #define smp_mb__before_clear_bit() smp_mb()
  28. #define smp_mb__after_clear_bit() smp_mb()
  29. #define set_mb(var, value) do { var = value; mb(); } while (0)
  30. #define smp_store_release(p, v) \
  31. do { \
  32. compiletime_assert_atomic_type(*p); \
  33. barrier(); \
  34. ACCESS_ONCE(*p) = (v); \
  35. } while (0)
  36. #define smp_load_acquire(p) \
  37. ({ \
  38. typeof(*p) ___p1 = ACCESS_ONCE(*p); \
  39. compiletime_assert_atomic_type(*p); \
  40. barrier(); \
  41. ___p1; \
  42. })
  43. #endif /* __ASM_BARRIER_H */