Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc

* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
  Remove DEBUG_SEMAPHORE from Kconfig
  Improve semaphore documentation
  Simplify semaphore implementation
  Add down_timeout and change ACPI to use it
  Introduce down_killable()
  Generic semaphore implementation
  Add semaphore.h to kernel_lock.c
  Fix quota.h includes

1 files changed, 51 insertions, 0 deletions

diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h
new file mode 100644
index 000000000000..9cae64b00d6b
--- /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 */