1 files changed, 106 insertions, 0 deletions
diff --git a/include/asm-blackfin/semaphore.h b/include/asm-blackfin/semaphore.h
new file mode 100644
index 000000000000..94c04d7ab23e
--- /dev/null
+++ b/include/asm-blackfin/semaphore.h
@@ -0,0 +1,106 @@
+#ifndef _BFIN_SEMAPHORE_H
+#define _BFIN_SEMAPHORE_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/linkage.h>
+#include <linux/wait.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <asm/atomic.h>
+
+/*
+ * Interrupt-safe semaphores..
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ * BFIN version by akbar hussain Lineo Inc  April 2001
+ *
+ */
+
+struct semaphore {
+	atomic_t count;
+	int sleepers;
+	wait_queue_head_t wait;
+};
+
+#define __SEMAPHORE_INITIALIZER(name, n)				\
+{									\
+	.count		= ATOMIC_INIT(n),				\
+	.sleepers	= 0,						\
+	.wait		= __WAIT_QUEUE_HEAD_INITIALIZER((name).wait)	\
+}
+
+#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
+	struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
+
+#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
+#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
+
+static inline void sema_init(struct semaphore *sem, int val)
+{
+	*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
+}
+
+static inline void init_MUTEX(struct semaphore *sem)
+{
+	sema_init(sem, 1);
+}
+
+static inline void init_MUTEX_LOCKED(struct semaphore *sem)
+{
+	sema_init(sem, 0);
+}
+
+asmlinkage void __down(struct semaphore *sem);
+asmlinkage int __down_interruptible(struct semaphore *sem);
+asmlinkage int __down_trylock(struct semaphore *sem);
+asmlinkage void __up(struct semaphore *sem);
+
+extern spinlock_t semaphore_wake_lock;
+
+/*
+ * This is ugly, but we want the default case to fall through.
+ * "down_failed" is a special asm handler that calls the C
+ * routine that actually waits.
+ */
+static inline void down(struct semaphore *sem)
+{
+	might_sleep();
+	if (atomic_dec_return(&sem->count) < 0)
+		__down(sem);
+}
+
+static inline int down_interruptible(struct semaphore *sem)
+{
+	int ret = 0;
+
+	might_sleep();
+	if (atomic_dec_return(&sem->count) < 0)
+		ret = __down_interruptible(sem);
+	return (ret);
+}
+
+static inline int down_trylock(struct semaphore *sem)
+{
+	int ret = 0;
+
+	if (atomic_dec_return(&sem->count) < 0)
+		ret = __down_trylock(sem);
+	return ret;
+}
+
+/*
+ * Note! This is subtle. We jump to wake people up only if
+ * the semaphore was negative (== somebody was waiting on it).
+ * The default case (no contention) will result in NO
+ * jumps for both down() and up().
+ */
+static inline void up(struct semaphore *sem)
+{
+	if (atomic_inc_return(&sem->count) <= 0)
+		__up(sem);
+}
+
+#endif				/* __ASSEMBLY__ */
+#endif				/* _BFIN_SEMAPHORE_H */