xref: /netbsd/sys/arch/acorn32/include/lock.h (revision 6550d01e)
1 /*	$NetBSD: lock.h,v 1.9 2009/01/15 01:11:32 pooka 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 #include <sys/param.h>
36 
37 #ifdef _KERNEL_OPT
38 #include "opt_multiprocessor.h"
39 #endif
40 
41 #if defined(_HARDKERNEL) && defined(MULTIPROCESSOR)
42 
43 #include <arm/cpufunc.h>
44 
45 static __inline int
46 __swp(int __val, volatile unsigned char *__ptr)
47 {
48 
49 	__asm volatile("swpb %0, %1, [%2]"
50 	    : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");
51 	return __val;
52 }
53 
54 static __inline void __attribute__((__unused__))
55 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
56 {
57 
58 	*alp = __SIMPLELOCK_UNLOCKED;
59 }
60 
61 static __inline void __attribute__((__unused__))
62 __cpu_simple_lock(__cpu_simple_lock_t *alp)
63 {
64 
65 	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)
66 		continue;
67 	cpu_idcache_wbinv_all();
68 }
69 
70 static __inline int __attribute__((__unused__))
71 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
72 {
73 	int __result;
74 
75 	__result = __swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED;
76 	if (__result)
77 		cpu_idcache_wbinv_all();
78 	return __result;
79 }
80 
81 static __inline void __attribute__((__unused__))
82 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
83 {
84 
85 	*alp = __SIMPLELOCK_UNLOCKED;
86 }
87 
88 #else /* !(_HARDKERNEL && MULTIPROCESSOR) */
89 #include <arm/lock.h>
90 #endif /* !(_HARDKERNEL && MULTIPROCESSOR) */
91 #endif
92