LXR qemu/include/qemu/sys

   1/*
   2 * Process-global memory barriers
   3 *
   4 * Copyright (c) 2018 Red Hat, Inc.
   5 *
   6 * Author: Paolo Bonzini <pbonzini@redhat.com>
   7 */
   8
   9#ifndef QEMU_SYS_MEMBARRIER_H
  10#define QEMU_SYS_MEMBARRIER_H
  11
  12#ifdef CONFIG_MEMBARRIER
  13/* Only block reordering at the compiler level in the performance-critical
  14 * side.  The slow side forces processor-level ordering on all other cores
  15 * through a system call.
  16 */
  17extern void smp_mb_global_init(void);
  18extern void smp_mb_global(void);
  19#define smp_mb_placeholder()       barrier()
  20#else
  21/* Keep it simple, execute a real memory barrier on both sides.  */
  22static inline void smp_mb_global_init(void) {}
  23#define smp_mb_global()            smp_mb()
  24#define smp_mb_placeholder()       smp_mb()
  25#endif
  26
  27#endif
  28