mutex.h revision 1.8 
1/*	$NetBSD: mutex.h,v 1.8 2007/11/29 17:33:09 ad Exp $	*/
2
3/*-
4 * Copyright (c) 2002, 2007 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 _SH3_MUTEX_H_
40#define	_SH3_MUTEX_H_
41
42#ifndef __MUTEX_PRIVATE
43
44struct kmutex {
45	uintptr_t	mtx_pad1;
46};
47
48#else	/* __MUTEX_PRIVATE */
49
50struct kmutex {
51	union {
52		/* Adaptive mutex */
53		volatile uintptr_t	mtxa_owner;	/* 0-3 */
54
55		/* Spin mutex */
56		struct {
57			volatile uint8_t	mtxs_dummy;
58			ipl_cookie_t		mtxs_ipl;
59			__cpu_simple_lock_t	mtxs_lock;
60			volatile uint8_t	mtxs_unused;
61		} s;
62	} u;
63};
64
65#define	mtx_owner		u.mtxa_owner
66#define	mtx_ipl			u.s.mtxs_ipl
67#define	mtx_lock		u.s.mtxs_lock
68
69#define	__HAVE_SIMPLE_MUTEXES		1
70#define	__HAVE_MUTEX_STUBS		1
71
72/*
73 * MUTEX_RECEIVE: no memory barrier required; we're synchronizing against
74 * interrupts, not multiple processors.
75 */
76#define	MUTEX_RECEIVE(mtx)		/* nothing */
77
78/*
79 * MUTEX_GIVE: no memory barrier required; same reason.
80 */
81#define	MUTEX_GIVE(mtx)			/* nothing */
82
83uintptr_t	_lock_cas(volatile uintptr_t *, uintptr_t, uintptr_t);
84
85#define	MUTEX_CAS(p, o, n)		(_lock_cas((p), (o), (n)) == (o))
86
87#endif	/* __MUTEX_PRIVATE */
88
89#endif /* _SH3_MUTEX_H_ */
90