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Diffstat (limited to 'tools/arch/powerpc/include/asm')
| -rw-r--r-- | tools/arch/powerpc/include/asm/barrier.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/tools/arch/powerpc/include/asm/barrier.h b/tools/arch/powerpc/include/asm/barrier.h new file mode 100644 index 000000000..905a2c66d --- /dev/null +++ b/tools/arch/powerpc/include/asm/barrier.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * 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") + +#if defined(__powerpc64__) +#define smp_lwsync() __asm__ __volatile__ ("lwsync" : : : "memory") + +#define smp_store_release(p, v) \ +do { \ + smp_lwsync(); \ + WRITE_ONCE(*p, v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = READ_ONCE(*p); \ + smp_lwsync(); \ + ___p1; \ +}) +#endif /* defined(__powerpc64__) */ +#endif /* _TOOLS_LINUX_ASM_POWERPC_BARRIER_H */ |