semaphore: Add DEFINE_SEMAPHORE, semaphore_init, semaphore_init_locked

The full cleanup of init_MUTEX[_LOCKED] and DECLARE_MUTEX has not been
done. Some of the users are real semaphores and we should name them as
such instead of confusing everyone with "MUTEX".

Provide the infrastructure to get finally rid of init_MUTEX[_LOCKED]
and DECLARE_MUTEX.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/semaphore.h

@@ -26,6 +26,9 @@ struct semaphore {
 	.wait_list	= LIST_HEAD_INIT((name).wait_list),		\
 }
 
+#define DEFINE_SEMAPHORE(name)	\
+	struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
+
 #define DECLARE_MUTEX(name)	\
 	struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
 
@@ -36,6 +39,20 @@ static inline void sema_init(struct semaphore *sem, int val)
 	lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0);
 }
 
+static inline void semaphore_init(struct semaphore *sem)
+{
+	sema_init(sem, 1);
+}
+
+/*
+ * semaphore_init_locked() is mostly a sign for a mutex which is
+ * abused as completion.
+ */
+static inline void __deprecated semaphore_init_locked(struct semaphore *sem)
+{
+	sema_init(sem, 0);
+}
+
 #define init_MUTEX(sem)		sema_init(sem, 1)
 #define init_MUTEX_LOCKED(sem)	sema_init(sem, 0)