LXR linux/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)                 \
  32do {                                            \
  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 */
  45