xref: /netbsd-src/sys/arch/usermode/include/lock.h (revision 024d950bdcaa3e62a84d00564e8d8799125669be)
1 /* $NetBSD: lock.h,v 1.5 2017/10/23 06:43:00 msaitoh Exp $ */
2 
3 /*-
4  * Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
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  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef _ARCH_USERMODE_INCLUDE_LOCK_H
30 #define _ARCH_USERMODE_INCLUDE_LOCK_H
31 
32 __inline static void
__cpu_simple_lock_init(__cpu_simple_lock_t * lockp)33 __cpu_simple_lock_init(__cpu_simple_lock_t *lockp)
34 {
35 	*lockp = __SIMPLELOCK_UNLOCKED;
36 }
37 
38 __inline static int
__cpu_simple_lock_try(__cpu_simple_lock_t * lockp)39 __cpu_simple_lock_try(__cpu_simple_lock_t *lockp)
40 {
41 	if (*lockp == __SIMPLELOCK_LOCKED)
42 		return 0;
43 	*lockp = __SIMPLELOCK_LOCKED;
44 	return 1;
45 }
46 
47 __inline static void
__cpu_simple_lock(__cpu_simple_lock_t * lockp)48 __cpu_simple_lock(__cpu_simple_lock_t *lockp)
49 {
50 	while (!__cpu_simple_lock_try(lockp))
51 		;
52 }
53 
54 __inline static void
__cpu_simple_unlock(__cpu_simple_lock_t * lockp)55 __cpu_simple_unlock(__cpu_simple_lock_t *lockp)
56 {
57 	*lockp = __SIMPLELOCK_UNLOCKED;
58 }
59 
60 __inline static int
__SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t * lockp)61 __SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *lockp)
62 {
63 	return *lockp == __SIMPLELOCK_LOCKED;
64 }
65 
66 __inline static int
__SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t * lockp)67 __SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *lockp)
68 {
69 	return *lockp == __SIMPLELOCK_UNLOCKED;
70 }
71 
72 #endif /* !_ARCH_USERMODE_INCLUDE_LOCK_H */
73