1
0
Files
kernel-49/tools/arch/powerpc/include/asm/barrier.h
Andrey Zolotarev e72e9355e3 start the android-4.9 tree
git: https://android.googlesource.com/kernel/common
branch: android-4.9
commit: 03fcc2fe71308c2d164b4e6cbfc738c63e670444
2018-11-15 21:36:32 +03:00

30 lines
1.1 KiB
C

/*
* Copied from the kernel sources:
*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*/
#ifndef _TOOLS_LINUX_ASM_POWERPC_BARRIER_H
#define _TOOLS_LINUX_ASM_POWERPC_BARRIER_H
/*
* Memory barrier.
* The sync instruction guarantees that all memory accesses initiated
* by this processor have been performed (with respect to all other
* mechanisms that access memory). The eieio instruction is a barrier
* providing an ordering (separately) for (a) cacheable stores and (b)
* loads and stores to non-cacheable memory (e.g. I/O devices).
*
* mb() prevents loads and stores being reordered across this point.
* rmb() prevents loads being reordered across this point.
* wmb() prevents stores being reordered across this point.
*
* *mb() variants without smp_ prefix must order all types of memory
* operations with one another. sync is the only instruction sufficient
* to do this.
*/
#define mb() __asm__ __volatile__ ("sync" : : : "memory")
#define rmb() __asm__ __volatile__ ("sync" : : : "memory")
#define wmb() __asm__ __volatile__ ("sync" : : : "memory")
#endif /* _TOOLS_LINUX_ASM_POWERPC_BARRIER_H */