xref: /minix3/sys/arch/x86/include/mutex.h (revision f6aac1c3b5ca21b829888677e8ee6bc9cda07e52)
1*f6aac1c3SLionel Sambuc /*	$NetBSD: mutex.h,v 1.6 2009/04/24 17:49:51 ad Exp $	*/
2*f6aac1c3SLionel Sambuc 
3*f6aac1c3SLionel Sambuc /*-
4*f6aac1c3SLionel Sambuc  * Copyright (c) 2002, 2006, 2009 The NetBSD Foundation, Inc.
5*f6aac1c3SLionel Sambuc  * All rights reserved.
6*f6aac1c3SLionel Sambuc  *
7*f6aac1c3SLionel Sambuc  * This code is derived from software contributed to The NetBSD Foundation
8*f6aac1c3SLionel Sambuc  * by Jason R. Thorpe and Andrew Doran.
9*f6aac1c3SLionel Sambuc  *
10*f6aac1c3SLionel Sambuc  * Redistribution and use in source and binary forms, with or without
11*f6aac1c3SLionel Sambuc  * modification, are permitted provided that the following conditions
12*f6aac1c3SLionel Sambuc  * are met:
13*f6aac1c3SLionel Sambuc  * 1. Redistributions of source code must retain the above copyright
14*f6aac1c3SLionel Sambuc  *    notice, this list of conditions and the following disclaimer.
15*f6aac1c3SLionel Sambuc  * 2. Redistributions in binary form must reproduce the above copyright
16*f6aac1c3SLionel Sambuc  *    notice, this list of conditions and the following disclaimer in the
17*f6aac1c3SLionel Sambuc  *    documentation and/or other materials provided with the distribution.
18*f6aac1c3SLionel Sambuc  *
19*f6aac1c3SLionel Sambuc  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20*f6aac1c3SLionel Sambuc  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21*f6aac1c3SLionel Sambuc  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22*f6aac1c3SLionel Sambuc  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23*f6aac1c3SLionel Sambuc  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24*f6aac1c3SLionel Sambuc  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25*f6aac1c3SLionel Sambuc  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26*f6aac1c3SLionel Sambuc  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27*f6aac1c3SLionel Sambuc  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28*f6aac1c3SLionel Sambuc  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29*f6aac1c3SLionel Sambuc  * POSSIBILITY OF SUCH DAMAGE.
30*f6aac1c3SLionel Sambuc  */
31*f6aac1c3SLionel Sambuc 
32*f6aac1c3SLionel Sambuc #ifndef _X86_MUTEX_H_
33*f6aac1c3SLionel Sambuc #define	_X86_MUTEX_H_
34*f6aac1c3SLionel Sambuc 
35*f6aac1c3SLionel Sambuc struct kmutex {
36*f6aac1c3SLionel Sambuc 	union {
37*f6aac1c3SLionel Sambuc 		volatile uintptr_t	mtxa_owner;
38*f6aac1c3SLionel Sambuc #ifdef __MUTEX_PRIVATE
39*f6aac1c3SLionel Sambuc 		struct {
40*f6aac1c3SLionel Sambuc 			volatile uint8_t	mtxs_dummy;
41*f6aac1c3SLionel Sambuc 			ipl_cookie_t		mtxs_ipl;
42*f6aac1c3SLionel Sambuc                         __cpu_simple_lock_t	mtxs_lock;
43*f6aac1c3SLionel Sambuc 			volatile uint8_t	mtxs_unused;
44*f6aac1c3SLionel Sambuc 		} s;
45*f6aac1c3SLionel Sambuc #endif
46*f6aac1c3SLionel Sambuc 	} u;
47*f6aac1c3SLionel Sambuc };
48*f6aac1c3SLionel Sambuc 
49*f6aac1c3SLionel Sambuc #ifdef __MUTEX_PRIVATE
50*f6aac1c3SLionel Sambuc 
51*f6aac1c3SLionel Sambuc #define	mtx_owner 			u.mtxa_owner
52*f6aac1c3SLionel Sambuc #define	mtx_ipl 			u.s.mtxs_ipl
53*f6aac1c3SLionel Sambuc #define	mtx_lock			u.s.mtxs_lock
54*f6aac1c3SLionel Sambuc 
55*f6aac1c3SLionel Sambuc #define __HAVE_MUTEX_STUBS		1
56*f6aac1c3SLionel Sambuc #define __HAVE_SPIN_MUTEX_STUBS		1
57*f6aac1c3SLionel Sambuc #define	__HAVE_SIMPLE_MUTEXES		1
58*f6aac1c3SLionel Sambuc 
59*f6aac1c3SLionel Sambuc /*
60*f6aac1c3SLionel Sambuc  * MUTEX_RECEIVE: technically, no memory barrier is required
61*f6aac1c3SLionel Sambuc  * as 'ret' implies a load fence.  However we need this to
62*f6aac1c3SLionel Sambuc  * handle a bug with some Opteron revisions.  See patch.c,
63*f6aac1c3SLionel Sambuc  * lock_stubs.S.
64*f6aac1c3SLionel Sambuc  */
65*f6aac1c3SLionel Sambuc #define	MUTEX_RECEIVE(mtx)		membar_consumer()
66*f6aac1c3SLionel Sambuc 
67*f6aac1c3SLionel Sambuc /*
68*f6aac1c3SLionel Sambuc  * MUTEX_GIVE: no memory barrier required, as _lock_cas() will take care of it.
69*f6aac1c3SLionel Sambuc  */
70*f6aac1c3SLionel Sambuc #define	MUTEX_GIVE(mtx)			/* nothing */
71*f6aac1c3SLionel Sambuc 
72*f6aac1c3SLionel Sambuc #define	MUTEX_CAS(p, o, n)		\
73*f6aac1c3SLionel Sambuc     (_atomic_cas_ulong((volatile unsigned long *)(p), (o), (n)) == (o))
74*f6aac1c3SLionel Sambuc 
75*f6aac1c3SLionel Sambuc unsigned long	_atomic_cas_ulong(volatile unsigned long *,
76*f6aac1c3SLionel Sambuc     unsigned long, unsigned long);
77*f6aac1c3SLionel Sambuc 
78*f6aac1c3SLionel Sambuc #endif	/* __MUTEX_PRIVATE */
79*f6aac1c3SLionel Sambuc 
80*f6aac1c3SLionel Sambuc #endif /* _X86_MUTEX_H_ */
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