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); \
70 #define mutex_lock_interruptible_nested(m, c) mutex_lock_interruptible(m)
73 * Reuse the interruptable method since the SX
74 * lock handles both signals and interrupts:
76 #define mutex_lock_killable(_m) ({ \
78 linux_mutex_lock_interruptible(_m); \
81 #define mutex_lock_killable_nested(_m, _sub) \
82 mutex_lock_killable(_m)
84 #define mutex_unlock(_m) do { \
87 sx_xunlock(&(_m)->sx); \
90 #define mutex_trylock(_m) ({ \
92 !!sx_try_xlock(&(_m)->sx); \
95 enum mutex_trylock_recursive_enum {
96 MUTEX_TRYLOCK_FAILED = 0,
97 MUTEX_TRYLOCK_SUCCESS = 1,
98 MUTEX_TRYLOCK_RECURSIVE = 2,
101 static inline __must_check enum mutex_trylock_recursive_enum
102 mutex_trylock_recursive(struct mutex *lock)
104 if (unlikely(sx_xholder(&lock->sx) == curthread))
105 return (MUTEX_TRYLOCK_RECURSIVE);
107 return (mutex_trylock(lock));
110 #define mutex_init(_m) \
111 linux_mutex_init(_m, mutex_name(#_m), SX_NOWITNESS)
113 #define __mutex_init(_m, _n, _l) \
114 linux_mutex_init(_m, _n, SX_NOWITNESS)
116 #define mutex_init_witness(_m) \
117 linux_mutex_init(_m, mutex_name(#_m), SX_DUPOK)
119 #define mutex_destroy(_m) \
120 linux_mutex_destroy(_m)
123 mutex_is_locked(mutex_t *m)
125 return ((struct thread *)SX_OWNER(m->sx.sx_lock) != NULL);
129 mutex_is_owned(mutex_t *m)
131 return (sx_xlocked(&m->sx));
134 static inline int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *m)
136 if (atomic_dec_and_test(cnt)) {
145 /* NOTE: the maximum WITNESS name is 64 chars */
146 #define __mutex_name(name, file, line) \
147 (((const char *){file ":" #line "-" name}) + \
148 (sizeof(file) > 16 ? sizeof(file) - 16 : 0))
150 #define __mutex_name(name, file, line) name
152 #define _mutex_name(...) __mutex_name(__VA_ARGS__)
153 #define mutex_name(name) _mutex_name(name, __FILE__, __LINE__)
155 #define DEFINE_MUTEX(lock) \
157 SX_SYSINIT_FLAGS(lock, &(lock).sx, mutex_name(#lock), SX_DUPOK)
160 linux_mutex_init(mutex_t *m, const char *name, int flags)
162 memset(m, 0, sizeof(*m));
163 sx_init_flags(&m->sx, name, flags);
167 linux_mutex_destroy(mutex_t *m)
169 if (mutex_is_owned(m))
174 extern int linux_mutex_lock_interruptible(mutex_t *m);
176 #endif /* _LINUX_MUTEX_H_ */