xref: /netbsd-src/sys/arch/acorn32/include/lock.h (revision cd22f25e6f6d1cc1f197fe8c5468a80f51d1c4e1)
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 
43 static __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 
52 static __inline void __attribute__((__unused__))
53 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
54 {
55 
56 	*alp = __SIMPLELOCK_UNLOCKED;
57 }
58 
59 static __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 
68 static __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 
79 static __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