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Diffstat (limited to 'tools/arch/x86/include/asm/barrier.h')
| -rw-r--r-- | tools/arch/x86/include/asm/barrier.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/tools/arch/x86/include/asm/barrier.h b/tools/arch/x86/include/asm/barrier.h new file mode 100644 index 000000000..0adf295dd --- /dev/null +++ b/tools/arch/x86/include/asm/barrier.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _TOOLS_LINUX_ASM_X86_BARRIER_H +#define _TOOLS_LINUX_ASM_X86_BARRIER_H + +/* + * Copied from the Linux kernel sources, and also moving code + * out from tools/perf/perf-sys.h so as to make it be located + * in a place similar as in the kernel sources. + * + * Force strict CPU ordering. + * And yes, this is required on UP too when we're talking + * to devices. + */ + +#if defined(__i386__) +/* + * Some non-Intel clones support out of order store. wmb() ceases to be a + * nop for these. + */ +#define mb() asm volatile("lock; addl $0,0(%%esp)" ::: "memory") +#define rmb() asm volatile("lock; addl $0,0(%%esp)" ::: "memory") +#define wmb() asm volatile("lock; addl $0,0(%%esp)" ::: "memory") +#elif defined(__x86_64__) +#define mb() asm volatile("mfence" ::: "memory") +#define rmb() asm volatile("lfence" ::: "memory") +#define wmb() asm volatile("sfence" ::: "memory") +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#define smp_mb() asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc") +#endif + +#if defined(__x86_64__) +#define smp_store_release(p, v) \ +do { \ + barrier(); \ + WRITE_ONCE(*p, v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = READ_ONCE(*p); \ + barrier(); \ + ___p1; \ +}) +#endif /* defined(__x86_64__) */ +#endif /* _TOOLS_LINUX_ASM_X86_BARRIER_H */ |