2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #ifndef _LINUX_MUTEX_H_
32 #define _LINUX_MUTEX_H_
34 #include <sys/param.h>
39 #include <linux/spinlock.h>
40 #include <asm/atomic.h>
42 typedef struct mutex {
47 * By defining CONFIG_NO_MUTEX_SKIP LinuxKPI mutexes and asserts will
48 * not be skipped during panic().
50 #ifdef CONFIG_NO_MUTEX_SKIP
51 #define MUTEX_SKIP(void) 0
53 #define MUTEX_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active)
56 #define mutex_lock(_m) do { \
59 sx_xlock(&(_m)->sx); \
62 #define mutex_lock_nested(_m, _s) mutex_lock(_m)
63 #define mutex_lock_nest_lock(_m, _s) mutex_lock(_m)
65 #define mutex_lock_interruptible(_m) ({ \
67 linux_mutex_lock_interruptible(_m); \
71 * Reuse the interruptable method since the SX
72 * lock handles both signals and interrupts:
74 #define mutex_lock_killable(_m) ({ \
76 linux_mutex_lock_interruptible(_m); \
79 #define mutex_lock_killable_nested(_m, _sub) \
80 mutex_lock_killable(_m)
82 #define mutex_unlock(_m) do { \
85 sx_xunlock(&(_m)->sx); \
88 #define mutex_trylock(_m) ({ \
90 !!sx_try_xlock(&(_m)->sx); \
93 enum mutex_trylock_recursive_enum {
94 MUTEX_TRYLOCK_FAILED = 0,
95 MUTEX_TRYLOCK_SUCCESS = 1,
96 MUTEX_TRYLOCK_RECURSIVE = 2,
99 static inline __must_check enum mutex_trylock_recursive_enum
100 mutex_trylock_recursive(struct mutex *lock)
102 if (unlikely(sx_xholder(&lock->sx) == curthread))
103 return (MUTEX_TRYLOCK_RECURSIVE);
105 return (mutex_trylock(lock));
108 #define mutex_init(_m) \
109 linux_mutex_init(_m, mutex_name(#_m), SX_NOWITNESS)
111 #define __mutex_init(_m, _n, _l) \
112 linux_mutex_init(_m, _n, SX_NOWITNESS)
114 #define mutex_init_witness(_m) \
115 linux_mutex_init(_m, mutex_name(#_m), SX_DUPOK)
117 #define mutex_destroy(_m) \
118 linux_mutex_destroy(_m)
121 mutex_is_locked(mutex_t *m)
123 return ((struct thread *)SX_OWNER(m->sx.sx_lock) != NULL);
127 mutex_is_owned(mutex_t *m)
129 return (sx_xlocked(&m->sx));
132 static inline int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *m)
134 if (atomic_dec_and_test(cnt)) {
143 /* NOTE: the maximum WITNESS name is 64 chars */
144 #define __mutex_name(name, file, line) \
145 (((const char *){file ":" #line "-" name}) + \
146 (sizeof(file) > 16 ? sizeof(file) - 16 : 0))
148 #define __mutex_name(name, file, line) name
150 #define _mutex_name(...) __mutex_name(__VA_ARGS__)
151 #define mutex_name(name) _mutex_name(name, __FILE__, __LINE__)
153 #define DEFINE_MUTEX(lock) \
155 SX_SYSINIT_FLAGS(lock, &(lock).sx, mutex_name(#lock), SX_DUPOK)
158 linux_mutex_init(mutex_t *m, const char *name, int flags)
160 memset(m, 0, sizeof(*m));
161 sx_init_flags(&m->sx, name, flags);
165 linux_mutex_destroy(mutex_t *m)
167 if (mutex_is_owned(m))
172 extern int linux_mutex_lock_interruptible(mutex_t *m);
174 #endif /* _LINUX_MUTEX_H_ */