1/* $NetBSD: barrier.h,v 1.2 2014/03/18 18:20:42 riastradh Exp $ */
2
3/*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _ASM_BARRIER_H_
33#define _ASM_BARRIER_H_
34
35#include <sys/atomic.h>
36
37#ifdef _KERNEL_OPT
38#include "opt_multiprocessor.h"
39#endif
40
41#define mb membar_sync
42#define wmb membar_producer
43#define rmb membar_consumer
44
45#ifdef __alpha__ /* XXX As if... */
46# define read_barrier_depends membar_sync
47#else
48# define read_barrier_depends() do {} while (0)
49#endif
50
51#ifdef MULTIPROCESSOR
52# define smp_mb mb
53# define smp_wmb wmb
54# define smp_rmb rmb
55# define smp_read_barrier_depends read_barrier_depends
56#else
57# define smp_mb() do {} while (0)
58# define smp_wmb() do {} while (0)
59# define smp_rmb() do {} while (0)
60# define smp_read_barrier_depends() do {} while (0)
61#endif
62
63#endif /* _ASM_BARRIER_H_ */
64