tools/arch/s390/include/asm/barrier.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copied from the kernel sources:
   4  *
   5  * Copyright IBM Corp. 1999, 2009
   6  *
   7  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   8  */
   9
  10 #ifndef __TOOLS_LINUX_ASM_BARRIER_H
  11 #define __TOOLS_LINUX_ASM_BARRIER_H
  12
  13 /*
  14  * Force strict CPU ordering.
  15  * And yes, this is required on UP too when we're talking
  16  * to devices.
  17  */
  18
  19 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  20 /* Fast-BCR without checkpoint synchronization */
  21 #define __ASM_BARRIER "bcr 14,0\n"
  22 #else
  23 #define __ASM_BARRIER "bcr 15,0\n"
  24 #endif
  25
  26 #define mb() do {  asm volatile(__ASM_BARRIER : : : "memory"); } while (0)
  27
  28 #define rmb()                           mb()
  29 #define wmb()                           mb()
  30
  31 #define smp_store_release(p, v)                 \
  32 do {                                            \
  33         barrier();                              \
  34         WRITE_ONCE(*p, v);                      \
  35 } while (0)
  36
  37 #define smp_load_acquire(p)                     \
  38 ({                                              \
  39         typeof(*p) ___p1 = READ_ONCE(*p);       \
  40         barrier();                              \
  41         ___p1;                                  \
  42 })
  43
  44 #endif /* __TOOLS_LIB_ASM_BARRIER_H */