diff options
Diffstat (limited to 'include/linux/semaphore.h')
| -rw-r--r-- | include/linux/semaphore.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h new file mode 100644 index 00000000000..9cae64b00d6 --- /dev/null +++ b/include/linux/semaphore.h @@ -0,0 +1,51 @@ +/* + * Copyright (c) 2008 Intel Corporation + * Author: Matthew Wilcox <willy@linux.intel.com> + * + * Distributed under the terms of the GNU GPL, version 2 + * + * Please see kernel/semaphore.c for documentation of these functions + */ +#ifndef __LINUX_SEMAPHORE_H +#define __LINUX_SEMAPHORE_H + +#include <linux/list.h> +#include <linux/spinlock.h> + +/* Please don't access any members of this structure directly */ +struct semaphore { + spinlock_t lock; + unsigned int count; + struct list_head wait_list; +}; + +#define __SEMAPHORE_INITIALIZER(name, n) \ +{ \ + .lock = __SPIN_LOCK_UNLOCKED((name).lock), \ + .count = n, \ + .wait_list = LIST_HEAD_INIT((name).wait_list), \ +} + +#define __DECLARE_SEMAPHORE_GENERIC(name, count) \ + struct semaphore name = __SEMAPHORE_INITIALIZER(name, count) + +#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1) + +static inline void sema_init(struct semaphore *sem, int val) +{ + static struct lock_class_key __key; + *sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val); + lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0); +} + +#define init_MUTEX(sem) sema_init(sem, 1) +#define init_MUTEX_LOCKED(sem) sema_init(sem, 0) + +extern void down(struct semaphore *sem); +extern int __must_check down_interruptible(struct semaphore *sem); +extern int __must_check down_killable(struct semaphore *sem); +extern int __must_check down_trylock(struct semaphore *sem); +extern int __must_check down_timeout(struct semaphore *sem, long jiffies); +extern void up(struct semaphore *sem); + +#endif /* __LINUX_SEMAPHORE_H */ |