lock.h revision 1.14 
1/*	$NetBSD: lock.h,v 1.14 2008/04/28 20:23:26 martin Exp $	*/
2
3/*-
4 * Copyright (c) 2000 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.
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/*
33 * Machine-dependent spin lock operations.
34 */
35
36#ifndef _M68K_LOCK_H_
37#define	_M68K_LOCK_H_
38
39static __inline int
40__SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr)
41{
42	return *__ptr == __SIMPLELOCK_LOCKED;
43}
44
45static __inline int
46__SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr)
47{
48	return *__ptr == __SIMPLELOCK_UNLOCKED;
49}
50
51static __inline void
52__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
53{
54
55	*alp = __SIMPLELOCK_UNLOCKED;
56}
57
58
59static __inline void
60__cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr)
61{
62	*__ptr = __SIMPLELOCK_UNLOCKED;
63}
64
65static __inline void
66__cpu_simple_lock_set(__cpu_simple_lock_t *__ptr)
67{
68	*__ptr = __SIMPLELOCK_LOCKED;
69}
70
71static __inline void
72__cpu_simple_lock(__cpu_simple_lock_t *alp)
73{
74
75	__asm volatile(
76		"1:	tas	%0	\n"
77		"	jne	1b	\n"
78		: "=m" (*alp));
79}
80
81static __inline int
82__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
83{
84	int __rv;
85
86	__asm volatile(
87		"	moveq	#1, %1	\n"
88		"	tas	%0	\n"
89		"	jeq	1f	\n"
90		"	moveq	#0, %1	\n"
91		"1:			\n"
92		: "=m" (*alp), "=d" (__rv));
93
94	return (__rv);
95}
96
97static __inline void
98__cpu_simple_unlock(__cpu_simple_lock_t *alp)
99{
100
101	*alp = __SIMPLELOCK_UNLOCKED;
102}
103
104static __inline void
105mb_read(void)
106{
107	__asm volatile("" : : : "memory");
108}
109
110static __inline void
111mb_write(void)
112{
113	__asm volatile("" : : : "memory");
114}
115
116static __inline void
117mb_memory(void)
118{
119	__asm volatile("" : : : "memory");
120}
121
122#endif /* _M68K_LOCK_H_ */
123