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>
diff --git a/include/asm-ia64/semaphore.h b/include/asm-ia64/semaphore.h
index d8393d1..d9b2034 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>