tools/include/asm-generic/barrier.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Copied from the kernel sources to tools/perf/:
   4  *
   5  * Generic barrier definitions.
   6  *
   7  * It should be possible to use these on really simple architectures,
   8  * but it serves more as a starting point for new ports.
   9  *
  10  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  11  * Written by David Howells (dhowells@redhat.com)
  12  */
  13 #ifndef __TOOLS_LINUX_ASM_GENERIC_BARRIER_H
  14 #define __TOOLS_LINUX_ASM_GENERIC_BARRIER_H
  15
  16 #ifndef __ASSEMBLY__
  17
  18 #include <linux/compiler.h>
  19
  20 /*
  21  * Force strict CPU ordering. And yes, this is required on UP too when we're
  22  * talking to devices.
  23  *
  24  * Fall back to compiler barriers if nothing better is provided.
  25  */
  26
  27 #ifndef mb
  28 #define mb()    barrier()
  29 #endif
  30
  31 #ifndef rmb
  32 #define rmb()   mb()
  33 #endif
  34
  35 #ifndef wmb
  36 #define wmb()   mb()
  37 #endif
  38
  39 #endif /* !__ASSEMBLY__ */
  40 #endif /* __TOOLS_LINUX_ASM_GENERIC_BARRIER_H */