xref: /netbsd-src/sys/arch/sh3/include/mutex.h (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
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 
44 struct kmutex {
45 	uintptr_t	mtx_pad1;
46 };
47 
48 #else	/* __MUTEX_PRIVATE */
49 
50 struct 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 
83 uintptr_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