1 files changed, 119 insertions, 0 deletions
diff --git a/include/asm-sh/semaphore.h b/include/asm-sh/semaphore.h
new file mode 100644
index 000000000000..b923a77a8a7e
--- /dev/null
+++ b/include/asm-sh/semaphore.h
@@ -0,0 +1,119 @@
+#ifndef __ASM_SH_SEMAPHORE_H
+#define __ASM_SH_SEMAPHORE_H
+
+#include <linux/linkage.h>
+
+#ifdef __KERNEL__
+/*
+ * SMP- and interrupt-safe semaphores.
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ * SuperH verison by Niibe Yutaka
+ *  (Currently no asm implementation but generic C code...)
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/wait.h>
+
+#include <asm/system.h>
+#include <asm/atomic.h>
+
+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 __MUTEX_INITIALIZER(name) \
+	__SEMAPHORE_INITIALIZER(name,1)
+
+#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);
+ *
+ * i'd rather use the more flexible initialization above, but sadly
+ * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well.
+ */
+	atomic_set(&sem->count, val);
+	sem->sleepers = 0;
+	init_waitqueue_head(&sem->wait);
+}
+
+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);
+}
+
+#if 0
+asmlinkage void __down_failed(void /* special register calling convention */);
+asmlinkage int  __down_failed_interruptible(void  /* params in registers */);
+asmlinkage int  __down_failed_trylock(void  /* params in registers */);
+asmlinkage void __up_wakeup(void /* special register calling convention */);
+#endif
+
+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;
+
+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).
+ */
+static inline void up(struct semaphore * sem)
+{
+	if (atomic_inc_return(&sem->count) <= 0)
+		__up(sem);
+}
+
+#endif
+#endif /* __ASM_SH_SEMAPHORE_H */