[PATCH] powerpc: merge semaphore.h

powerpc: Merge semaphore.h

Adopted the ppc64 version of semaphore.h.  The 32-bit version used
smp_wmb(), but recent updates to atomic.h mean this is no longer required.
The 64-bit version made use of unlikely(), which has been retained in the
combined version.

This patch requires the recent atomic.h patch.
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-ppc64/semaphore.h → include/asm-powerpc/semaphore.h

-#ifndef _PPC64_SEMAPHORE_H
-#define _PPC64_SEMAPHORE_H
+#ifndef _ASM_POWERPC_SEMAPHORE_H
+#define _ASM_POWERPC_SEMAPHORE_H
 
 /*
  * Remove spinlock-based RW semaphores; RW semaphore definitions are
@@ -95,4 +95,4 @@ static inline void up(struct semaphore * sem)
 
 #endif /* __KERNEL__ */
 
-#endif /* !(_PPC64_SEMAPHORE_H) */
+#endif /* _ASM_POWERPC_SEMAPHORE_H */

include/asm-ppc/semaphore.h

-#ifndef _PPC_SEMAPHORE_H
-#define _PPC_SEMAPHORE_H
-
-/*
- * Swiped from asm-sparc/semaphore.h and modified
- * -- Cort (cort@cs.nmt.edu)
- *
- * Stole some rw spinlock-based semaphore stuff from asm-alpha/semaphore.h
- * -- Ani Joshi (ajoshi@unixbox.com)
- *
- * Remove spinlock-based RW semaphores; RW semaphore definitions are
- * now in rwsem.h and we use the generic lib/rwsem.c implementation.
- * Rework semaphores to use atomic_dec_if_positive.
- * -- Paul Mackerras (paulus@samba.org)
- */
-
-#ifdef __KERNEL__
-
-#include <asm/atomic.h>
-#include <asm/system.h>
-#include <linux/wait.h>
-#include <linux/rwsem.h>
-
-struct semaphore {
-	/*
-	 * Note that any negative value of count is equivalent to 0,
-	 * but additionally indicates that some process(es) might be
-	 * sleeping on `wait'.
-	 */
-	atomic_t count;
-	wait_queue_head_t wait;
-};
-
-#define __SEMAPHORE_INITIALIZER(name, n)				\
-{									\
-	.count		= ATOMIC_INIT(n),				\
-	.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)
-{
-	atomic_set(&sem->count, val);
-	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);
-}
-
-extern void __down(struct semaphore * sem);
-extern int  __down_interruptible(struct semaphore * sem);
-extern void __up(struct semaphore * sem);
-
-extern inline void down(struct semaphore * sem)
-{
-	might_sleep();
-
-	/*
-	 * Try to get the semaphore, take the slow path if we fail.
-	 */
-	if (atomic_dec_return(&sem->count) < 0)
-		__down(sem);
-	smp_wmb();
-}
-
-extern inline int down_interruptible(struct semaphore * sem)
-{
-	int ret = 0;
-
-	might_sleep();
-
-	if (atomic_dec_return(&sem->count) < 0)
-		ret = __down_interruptible(sem);
-	smp_wmb();
-	return ret;
-}
-
-extern inline int down_trylock(struct semaphore * sem)
-{
-	int ret;
-
-	ret = atomic_dec_if_positive(&sem->count) < 0;
-	smp_wmb();
-	return ret;
-}
-
-extern inline void up(struct semaphore * sem)
-{
-	smp_wmb();
-	if (atomic_inc_return(&sem->count) <= 0)
-		__up(sem);
-}
-
-#endif /* __KERNEL__ */
-
-#endif /* !(_PPC_SEMAPHORE_H) */