mutex.h revision 1.2 
1/*	$NetBSD: mutex.h,v 1.2 2007/02/09 21:55:14 ad Exp $	*/
2
3/*-
4 * Copyright (c) 2002, 2006 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe and Andrew Doran.
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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the NetBSD
21 *	Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#ifndef _X86_MUTEX_H_
40#define	_X86_MUTEX_H_
41
42struct kmutex {
43	union {
44		volatile uintptr_t	mtxa_owner;
45#ifdef __MUTEX_PRIVATE
46		struct {
47			volatile uint8_t	mtxs_dummy;
48			ipl_cookie_t		mtxs_ipl;
49                        __cpu_simple_lock_t	mtxs_lock;
50			volatile uint8_t	mtxs_unused;
51		} s;
52#endif
53	} u;
54	volatile uint32_t	mtx_id;
55};
56
57#ifdef __MUTEX_PRIVATE
58
59#define	mtx_owner 			u.mtxa_owner
60#define	mtx_ipl 			u.s.mtxs_ipl
61#define	mtx_lock			u.s.mtxs_lock
62
63#define __HAVE_MUTEX_STUBS		1
64#define __HAVE_SPIN_MUTEX_STUBS		1
65#define	__HAVE_SIMPLE_MUTEXES		1
66
67/*
68 * MUTEX_RECEIVE: no memory barrier required, as 'ret' implies a load fence.
69 */
70#define	MUTEX_RECEIVE(mtx)		/* nothing */
71
72/*
73 * MUTEX_GIVE: no memory barrier required, as _lock_cas() will take care of it.
74 */
75#define	MUTEX_GIVE(mtx)			/* nothing */
76
77#define	MUTEX_CAS(p, o, n)		_lock_cas((p), (o), (n))
78
79int	_lock_cas(volatile uintptr_t *, uintptr_t, uintptr_t);
80
81#endif	/* __MUTEX_PRIVATE */
82
83#endif /* _X86_MUTEX_H_ */
84