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 d8393d11288d..d9b2034ed1d2 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>