xref: /dragonfly/sys/dev/drm/include/linux/mutex.h (revision 31524921)
1 /*
2  * Copyright (c) 2014-2015 François Tigeot
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef _LINUX_MUTEX_H_
28 #define _LINUX_MUTEX_H_
29 
30 #include <sys/lock.h>
31 #include <linux/lockdep.h>
32 
33 #define mutex_is_locked(lock)	(lockcount(lock) != 0)
34 
35 #define mutex_lock(lock)	lockmgr(lock, LK_EXCLUSIVE)
36 #define mutex_unlock(lock)	lockmgr(lock, LK_RELEASE)
37 
38 /* NOTE: mutex_trylock() returns non-zero on success */
39 #define mutex_trylock(lock)	(!lockmgr(lock, LK_EXCLUSIVE|LK_NOWAIT))
40 
41 static inline int
42 mutex_lock_interruptible(struct lock *lock)
43 {
44 	if (lockmgr(lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_PCATCH))
45 		return -EINTR;
46 
47 	return 0;
48 }
49 
50 #define DEFINE_MUTEX(mutex)	\
51 	struct lock mutex;	\
52 	LOCK_SYSINIT(mutex, &mutex, "lmutex", LK_CANRECURSE)
53 
54 #endif	/* _LINUX_MUTEX_H_ */
55