1 /* $NetBSD: mutex.h,v 1.17 2021/12/19 11:33:31 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
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 _LINUX_MUTEX_H_
33 #define _LINUX_MUTEX_H_
34
35 #include <sys/mutex.h>
36
37 #include <lib/libkern/libkern.h> /* KASSERT */
38
39 #include <asm/processor.h>
40
41 #include <linux/list.h>
42 #include <linux/spinlock.h>
43
44 struct mutex {
45 kmutex_t mtx_lock;
46 };
47
48 struct lock_class_key {
49 };
50
51 /* Name collision. Pooh. */
52 static inline void
linux_mutex_init(struct mutex * mutex)53 linux_mutex_init(struct mutex *mutex)
54 {
55 mutex_init(&mutex->mtx_lock, MUTEX_DEFAULT, IPL_NONE);
56 }
57
58 /* Lockdep stuff. */
59 static inline void
__mutex_init(struct mutex * mutex,const char * name __unused,struct lock_class_key * key __unused)60 __mutex_init(struct mutex *mutex, const char *name __unused,
61 struct lock_class_key *key __unused)
62 {
63 linux_mutex_init(mutex);
64 }
65
66 /* Another name collision. */
67 static inline void
linux_mutex_destroy(struct mutex * mutex)68 linux_mutex_destroy(struct mutex *mutex)
69 {
70 mutex_destroy(&mutex->mtx_lock);
71 }
72
73 static inline void
mutex_lock(struct mutex * mutex)74 mutex_lock(struct mutex *mutex)
75 {
76 mutex_enter(&mutex->mtx_lock);
77 }
78
79 static inline int
mutex_lock_interruptible(struct mutex * mutex)80 mutex_lock_interruptible(struct mutex *mutex)
81 {
82 mutex_enter(&mutex->mtx_lock); /* XXX */
83 return 0;
84 }
85
86 static inline int
mutex_trylock(struct mutex * mutex)87 mutex_trylock(struct mutex *mutex)
88 {
89 return mutex_tryenter(&mutex->mtx_lock);
90 }
91
92 static inline void
mutex_unlock(struct mutex * mutex)93 mutex_unlock(struct mutex *mutex)
94 {
95 mutex_exit(&mutex->mtx_lock);
96 }
97
98 static inline bool
mutex_is_locked(struct mutex * mutex)99 mutex_is_locked(struct mutex *mutex)
100 {
101 return mutex_owned(&mutex->mtx_lock);
102 }
103
104 static inline void
mutex_lock_nest_lock(struct mutex * mutex,struct mutex * already)105 mutex_lock_nest_lock(struct mutex *mutex, struct mutex *already)
106 {
107
108 KASSERT(mutex_is_locked(already));
109 mutex_lock(mutex);
110 }
111
112 static inline void
mutex_lock_nested(struct mutex * mutex,unsigned subclass __unused)113 mutex_lock_nested(struct mutex *mutex, unsigned subclass __unused)
114 {
115 mutex_lock(mutex);
116 }
117
118 static inline int
mutex_lock_interruptible_nested(struct mutex * mutex,unsigned subclass __unused)119 mutex_lock_interruptible_nested(struct mutex *mutex,
120 unsigned subclass __unused)
121 {
122 return mutex_lock_interruptible(mutex);
123 }
124
125 /*
126 * `recursive locking is bad, do not use this ever.'
127 * -- linux/scripts/checkpath.pl
128 */
129 static inline enum {
130 MUTEX_TRYLOCK_FAILED,
131 MUTEX_TRYLOCK_SUCCESS,
132 MUTEX_TRYLOCK_RECURSIVE,
133 }
mutex_trylock_recursive(struct mutex * mutex)134 mutex_trylock_recursive(struct mutex *mutex)
135 {
136 if (mutex_owned(&mutex->mtx_lock))
137 return MUTEX_TRYLOCK_RECURSIVE;
138 else if (mutex_tryenter(&mutex->mtx_lock))
139 return MUTEX_TRYLOCK_SUCCESS;
140 else
141 return MUTEX_TRYLOCK_FAILED;
142 }
143
144 #endif /* _LINUX_MUTEX_H_ */
145