Generic semaphore implementation

Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility.  Thanks to Peter Zijlstra for fixing the lockdep
warning.  Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 99 deletions

diff --git a/include/asm-ia64/semaphore.h b/include/asm-ia64/semaphore.h
index d8393d11288..d9b2034ed1d 100644
--- a/include/asm-ia64/semaphore.h
+++ b/include/asm-ia64/semaphore.h
@@ -1,99 +1 @@
-#ifndef _ASM_IA64_SEMAPHORE_H
-#define _ASM_IA64_SEMAPHORE_H
-
-/*
- * Copyright (C) 1998-2000 Hewlett-Packard Co
- * Copyright (C) 1998-2000 David Mosberger-Tang <davidm@hpl.hp.com>
- */
-
-#include <linux/wait.h>
-#include <linux/rwsem.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 __DECLARE_SEMAPHORE_GENERIC(name,count)					\
-	struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
-
-#define DECLARE_MUTEX(name)		__DECLARE_SEMAPHORE_GENERIC(name, 1)
-
-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);
-}
-
-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);
-
-/*
- * Atomically decrement the semaphore's count.  If it goes negative,
- * block the calling thread in the TASK_UNINTERRUPTIBLE state.
- */
-static inline void
-down (struct semaphore *sem)
-{
-	might_sleep();
-	if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1)
-		__down(sem);
-}
-
-/*
- * Atomically decrement the semaphore's count.  If it goes negative,
- * block the calling thread in the TASK_INTERRUPTIBLE state.
- */
-static inline int
-down_interruptible (struct semaphore * sem)
-{
-	int ret = 0;
-
-	might_sleep();
-	if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1)
-		ret = __down_interruptible(sem);
-	return ret;
-}
-
-static inline int
-down_trylock (struct semaphore *sem)
-{
-	int ret = 0;
-
-	if (ia64_fetchadd(-1, &sem->count.counter, acq) < 1)
-		ret = __down_trylock(sem);
-	return ret;
-}
-
-static inline void
-up (struct semaphore * sem)
-{
-	if (ia64_fetchadd(1, &sem->count.counter, rel) <= -1)
-		__up(sem);
-}
-
-#endif /* _ASM_IA64_SEMAPHORE_H */
+#include <linux/semaphore.h>