1/*
2 * Process-global memory barriers
3 *
4 * Copyright (c) 2018 Red Hat, Inc.
5 *
6 * Author: Paolo Bonzini <pbonzini@redhat.com>
7 */
8
9#ifndef QEMU_SYS_MEMBARRIER_H
10#define QEMU_SYS_MEMBARRIER_H
11
12#ifdef CONFIG_MEMBARRIER
13/* Only block reordering at the compiler level in the performance-critical
14 * side. The slow side forces processor-level ordering on all other cores
15 * through a system call.
16 */
17extern void smp_mb_global_init(void);
18extern void smp_mb_global(void);
19#define smp_mb_placeholder() barrier()
20#else
21/* Keep it simple, execute a real memory barrier on both sides. */
22static inline void smp_mb_global_init(void) {}
23#define smp_mb_global() smp_mb()
24#define smp_mb_placeholder() smp_mb()
25#endif
26
27#endif
28