arch/s390/include/asm/barrier.h

   1 /*
   2  * Copyright IBM Corp. 1999, 2009
   3  *
   4  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   5  */
   6
   7 #ifndef __ASM_BARRIER_H
   8 #define __ASM_BARRIER_H
   9
  10 /*
  11  * Force strict CPU ordering.
  12  * And yes, this is required on UP too when we're talking
  13  * to devices.
  14  */
  15
  16 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  17 /* Fast-BCR without checkpoint synchronization */
  18 #define __ASM_BARRIER "bcr 14,0\n"
  19 #else
  20 #define __ASM_BARRIER "bcr 15,0\n"
  21 #endif
  22
  23 #define mb() do {  asm volatile(__ASM_BARRIER : : : "memory"); } while (0)
  24
  25 #define rmb()                           mb()
  26 #define wmb()                           mb()
  27 #define smp_mb()                        mb()
  28 #define smp_rmb()                       rmb()
  29 #define smp_wmb()                       wmb()
  30
  31 #define read_barrier_depends()          do { } while (0)
  32 #define smp_read_barrier_depends()      do { } while (0)
  33
  34 #define smp_mb__before_atomic()         smp_mb()
  35 #define smp_mb__after_atomic()          smp_mb()
  36
  37 #define set_mb(var, value)              do { var = value; mb(); } while (0)
  38
  39 #define smp_store_release(p, v)                                         \
  40 do {                                                                    \
  41         compiletime_assert_atomic_type(*p);                             \
  42         barrier();                                                      \
  43         ACCESS_ONCE(*p) = (v);                                          \
  44 } while (0)
  45
  46 #define smp_load_acquire(p)                                             \
  47 ({                                                                      \
  48         typeof(*p) ___p1 = ACCESS_ONCE(*p);                             \
  49         compiletime_assert_atomic_type(*p);                             \
  50         barrier();                                                      \
  51         ___p1;                                                          \
  52 })
  53
  54 #endif /* __ASM_BARRIER_H */