aboutsummaryrefslogtreecommitdiff
path: root/include/linux/semaphore.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/semaphore.h')
-rw-r--r--include/linux/semaphore.h51
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 */