1 files changed, 106 insertions, 0 deletions

diff --git a/include/asm-arm/semaphore.h b/include/asm-arm/semaphore.h
new file mode 100644
index 000000000000..60f33e6eb800
--- /dev/null
+++ b/include/asm-arm/semaphore.h
@@ -0,0 +1,106 @@
+/*
+ * linux/include/asm-arm/semaphore.h
+ */
+#ifndef __ASM_ARM_SEMAPHORE_H
+#define __ASM_ARM_SEMAPHORE_H
+
+#include <linux/linkage.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/rwsem.h>
+
+#include <asm/atomic.h>
+#include <asm/locks.h>
+
+struct semaphore {
+        atomic_t count;
+        int sleepers;
+        wait_queue_head_t wait;
+};
+
+#define __SEMAPHORE_INIT(name, cnt)                             \
+{                                                               \
+        .count  = ATOMIC_INIT(cnt),                             \
+        .wait   = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait),   \
+}
+
+#define __MUTEX_INITIALIZER(name) __SEMAPHORE_INIT(name,1)
+
+#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
+        struct semaphore name = __SEMAPHORE_INIT(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)
+{
+        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);
+}
+
+static inline int sema_count(struct semaphore *sem)
+{
+        return atomic_read(&sem->count);
+}
+
+/*
+ * special register calling convention
+ */
+asmlinkage void __down_failed(void);
+asmlinkage int  __down_interruptible_failed(void);
+asmlinkage int  __down_trylock_failed(void);
+asmlinkage void __up_wakeup(void);
+
+extern void __down(struct semaphore * sem);
+extern int  __down_interruptible(struct semaphore * sem);
+extern int  __down_trylock(struct semaphore * sem);
+extern void __up(struct semaphore * sem);
+
+/*
+ * This is ugly, but we want the default case to fall through.
+ * "__down" is the actual routine that waits...
+ */
+static inline void down(struct semaphore * sem)
+{
+        might_sleep();
+        __down_op(sem, __down_failed);
+}
+
+/*
+ * This is ugly, but we want the default case to fall through.
+ * "__down_interruptible" is the actual routine that waits...
+ */
+static inline int down_interruptible (struct semaphore * sem)
+{
+        might_sleep();
+        return __down_op_ret(sem, __down_interruptible_failed);
+}
+
+static inline int down_trylock(struct semaphore *sem)
+{
+        return __down_op_ret(sem, __down_trylock_failed);
+}
+
+/*
+ * 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)
+{
+        __up_op(sem, __up_wakeup);
+}
+
+#endif