51 lines
1.2 KiB
C
51 lines
1.2 KiB
C
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/*
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* Process-global memory barriers
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*
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* Copyright (c) 2018 Red Hat, Inc.
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*
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* Author: Paolo Bonzini <pbonzini@redhat.com>
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*/
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#include "qemu/osdep.h"
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#include "qemu/sys_membarrier.h"
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#include "qemu/error-report.h"
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#ifdef CONFIG_LINUX
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#include <linux/membarrier.h>
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#include <sys/syscall.h>
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static int
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membarrier(int cmd, int flags)
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{
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return syscall(__NR_membarrier, cmd, flags);
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}
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#endif
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void smp_mb_global(void)
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{
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#if defined CONFIG_WIN32
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FlushProcessWriteBuffers();
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#elif defined CONFIG_LINUX
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membarrier(MEMBARRIER_CMD_SHARED, 0);
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#else
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#error --enable-membarrier is not supported on this operating system.
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#endif
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}
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void smp_mb_global_init(void)
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{
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#ifdef CONFIG_LINUX
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int ret = membarrier(MEMBARRIER_CMD_QUERY, 0);
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if (ret < 0) {
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error_report("This QEMU binary requires the membarrier system call.");
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error_report("Please upgrade your system to a newer version of Linux");
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exit(1);
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}
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if (!(ret & MEMBARRIER_CMD_SHARED)) {
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error_report("This QEMU binary requires MEMBARRIER_CMD_SHARED support.");
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error_report("Please upgrade your system to a newer version of Linux");
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exit(1);
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}
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#endif
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}
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