sys/dev/drm/include/linux/mutex.h

   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_ */