spinlock.h revision 1.3.4.2 1 1.3.4.2 tls /* $NetBSD: spinlock.h,v 1.3.4.2 2014/08/20 00:04:21 tls Exp $ */
2 1.3.4.2 tls
3 1.3.4.2 tls /*-
4 1.3.4.2 tls * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 1.3.4.2 tls * All rights reserved.
6 1.3.4.2 tls *
7 1.3.4.2 tls * This code is derived from software contributed to The NetBSD Foundation
8 1.3.4.2 tls * by Taylor R. Campbell.
9 1.3.4.2 tls *
10 1.3.4.2 tls * Redistribution and use in source and binary forms, with or without
11 1.3.4.2 tls * modification, are permitted provided that the following conditions
12 1.3.4.2 tls * are met:
13 1.3.4.2 tls * 1. Redistributions of source code must retain the above copyright
14 1.3.4.2 tls * notice, this list of conditions and the following disclaimer.
15 1.3.4.2 tls * 2. Redistributions in binary form must reproduce the above copyright
16 1.3.4.2 tls * notice, this list of conditions and the following disclaimer in the
17 1.3.4.2 tls * documentation and/or other materials provided with the distribution.
18 1.3.4.2 tls *
19 1.3.4.2 tls * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.3.4.2 tls * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.3.4.2 tls * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.3.4.2 tls * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.3.4.2 tls * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.3.4.2 tls * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.3.4.2 tls * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.3.4.2 tls * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.3.4.2 tls * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.3.4.2 tls * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.3.4.2 tls * POSSIBILITY OF SUCH DAMAGE.
30 1.3.4.2 tls */
31 1.3.4.2 tls
32 1.3.4.2 tls #ifndef _LINUX_SPINLOCK_H_
33 1.3.4.2 tls #define _LINUX_SPINLOCK_H_
34 1.3.4.2 tls
35 1.3.4.2 tls #include <sys/cdefs.h>
36 1.3.4.2 tls #include <sys/mutex.h>
37 1.3.4.2 tls
38 1.3.4.2 tls typedef struct spinlock {
39 1.3.4.2 tls kmutex_t sl_lock;
40 1.3.4.2 tls } spinlock_t;
41 1.3.4.2 tls
42 1.3.4.2 tls static inline int
43 1.3.4.2 tls spin_is_locked(spinlock_t *spinlock)
44 1.3.4.2 tls {
45 1.3.4.2 tls return mutex_owned(&spinlock->sl_lock);
46 1.3.4.2 tls }
47 1.3.4.2 tls
48 1.3.4.2 tls static inline void
49 1.3.4.2 tls spin_lock(spinlock_t *spinlock)
50 1.3.4.2 tls {
51 1.3.4.2 tls mutex_enter(&spinlock->sl_lock);
52 1.3.4.2 tls }
53 1.3.4.2 tls
54 1.3.4.2 tls static inline void
55 1.3.4.2 tls spin_unlock(spinlock_t *spinlock)
56 1.3.4.2 tls {
57 1.3.4.2 tls mutex_exit(&spinlock->sl_lock);
58 1.3.4.2 tls }
59 1.3.4.2 tls
60 1.3.4.2 tls static inline void
61 1.3.4.2 tls spin_lock_irq(spinlock_t *spinlock)
62 1.3.4.2 tls {
63 1.3.4.2 tls spin_lock(spinlock);
64 1.3.4.2 tls }
65 1.3.4.2 tls
66 1.3.4.2 tls static inline void
67 1.3.4.2 tls spin_unlock_irq(spinlock_t *spinlock)
68 1.3.4.2 tls {
69 1.3.4.2 tls spin_unlock(spinlock);
70 1.3.4.2 tls }
71 1.3.4.2 tls
72 1.3.4.2 tls /* Must be a macro because the second argument is to be assigned. */
73 1.3.4.2 tls #define spin_lock_irqsave(SPINLOCK, FLAGS) \
74 1.3.4.2 tls do { \
75 1.3.4.2 tls (FLAGS) = 0; \
76 1.3.4.2 tls mutex_enter(&((spinlock_t *)(SPINLOCK))->sl_lock); \
77 1.3.4.2 tls } while (0)
78 1.3.4.2 tls
79 1.3.4.2 tls static inline void
80 1.3.4.2 tls spin_unlock_irqrestore(spinlock_t *spinlock, unsigned long __unused flags)
81 1.3.4.2 tls {
82 1.3.4.2 tls mutex_exit(&spinlock->sl_lock);
83 1.3.4.2 tls }
84 1.3.4.2 tls
85 1.3.4.2 tls static inline void
86 1.3.4.2 tls spin_lock_init(spinlock_t *spinlock)
87 1.3.4.2 tls {
88 1.3.4.2 tls /* XXX What's the right IPL? IPL_DRM...? */
89 1.3.4.2 tls mutex_init(&spinlock->sl_lock, MUTEX_DEFAULT, IPL_VM);
90 1.3.4.2 tls }
91 1.3.4.2 tls
92 1.3.4.2 tls /*
93 1.3.4.2 tls * XXX Linux doesn't ever destroy spin locks, it seems. We'll have to
94 1.3.4.2 tls * kludge it up.
95 1.3.4.2 tls */
96 1.3.4.2 tls
97 1.3.4.2 tls static inline void
98 1.3.4.2 tls spin_lock_destroy(spinlock_t *spinlock)
99 1.3.4.2 tls {
100 1.3.4.2 tls mutex_destroy(&spinlock->sl_lock);
101 1.3.4.2 tls }
102 1.3.4.2 tls
103 1.3.4.2 tls /* This is a macro to make the panic message clearer. */
104 1.3.4.2 tls #define assert_spin_locked(spinlock) \
105 1.3.4.2 tls KASSERT(mutex_owned(&(spinlock)->sl_lock))
106 1.3.4.2 tls
107 1.3.4.2 tls /*
108 1.3.4.2 tls * Linux rwlocks are reader/writer spin locks. We implement them as
109 1.3.4.2 tls * normal spin locks without reader/writer semantics for expedience.
110 1.3.4.2 tls * If that turns out to not work, adapting to reader/writer semantics
111 1.3.4.2 tls * shouldn't be too hard.
112 1.3.4.2 tls */
113 1.3.4.2 tls
114 1.3.4.2 tls #define rwlock_t spinlock_t
115 1.3.4.2 tls #define rwlock_init spin_lock_init
116 1.3.4.2 tls #define rwlock_destroy spin_lock_destroy
117 1.3.4.2 tls #define write_lock_irq spin_lock_irq
118 1.3.4.2 tls #define write_unlock_irq spin_unlock_irq
119 1.3.4.2 tls #define read_lock spin_lock
120 1.3.4.2 tls #define read_unlock spin_unlock
121 1.3.4.2 tls
122 1.3.4.2 tls #endif /* _LINUX_SPINLOCK_H_ */
123