lock.h revision 1.7 
1/*	$NetBSD: lock.h,v 1.7 2008/04/28 20:23:09 martin Exp $	*/
2
3/*-
4 * Copyright (c) 2000, 2001 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#ifndef _ACORN32_LOCK_H_
33#define _ACORN32_LOCK_H_
34
35#ifdef _KERNEL_OPT
36#include "opt_multiprocessor.h"
37#endif
38
39#if defined(_KERNEL) && defined(MULTIPROCESSOR)
40
41#include <arm/cpufunc.h>
42
43static __inline int
44__swp(int __val, volatile int *__ptr)
45{
46
47	__asm volatile("swp %0, %1, [%2]"
48	    : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");
49	return __val;
50}
51
52static __inline void __attribute__((__unused__))
53__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
54{
55
56	*alp = __SIMPLELOCK_UNLOCKED;
57}
58
59static __inline void __attribute__((__unused__))
60__cpu_simple_lock(__cpu_simple_lock_t *alp)
61{
62
63	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)
64		continue;
65	cpu_idcache_wbinv_all();
66}
67
68static __inline int __attribute__((__unused__))
69__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
70{
71	int __result;
72
73	__result = __swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED;
74	if (__result)
75		cpu_idcache_wbinv_all();
76	return __result;
77}
78
79static __inline void __attribute__((__unused__))
80__cpu_simple_unlock(__cpu_simple_lock_t *alp)
81{
82
83	*alp = __SIMPLELOCK_UNLOCKED;
84}
85
86#else /* !(_KERNEL && MULTIPROCESSOR) */
87#include <arm/lock.h>
88#endif /* !(_KERNEL && MULTIPROCESSOR) */
89#endif
90