lock.h revision 1.4 
1/*	$NetBSD: lock.h,v 1.4 2000/05/02 04:41:11 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 2000 Ludd, University of Lule}, Sweden.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *     This product includes software developed at Ludd, University of Lule}.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#ifndef _VAX_LOCK_H_
34#define _VAX_LOCK_H_
35
36typedef	__volatile int		__cpu_simple_lock_t;
37
38#define	__SIMPLELOCK_LOCKED	1
39#define	__SIMPLELOCK_UNLOCKED	0
40
41static __inline void
42__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
43{
44	*alp = __SIMPLELOCK_UNLOCKED;
45}
46
47static __inline void
48__cpu_simple_lock(__cpu_simple_lock_t *alp)
49{
50	__asm__ __volatile ("1:;bbssi $0, (%0), 1b"
51		: /* No output */
52		: "r"(alp));
53}
54
55static __inline void
56__cpu_simple_unlock(__cpu_simple_lock_t *alp)
57{
58	*alp = __SIMPLELOCK_UNLOCKED;
59}
60
61static __inline int
62__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
63{
64	register int ret;
65
66	__asm__ __volatile ("movl $0,%0;bbssi $0,(%1),1f;incl %0;1:"
67		: "&=r"(ret)
68		: "r"(alp));
69
70	return ret;
71}
72
73#endif /* _VAX_LOCK_H_ */
74