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-xtensa/semaphore.h b/include/asm-xtensa/semaphore.h
index 3e04167cd9dc..d9b2034ed1d2 100644
--- a/include/asm-xtensa/semaphore.h
+++ b/include/asm-xtensa/semaphore.h
@@ -1,99 +1 @@
-/*
- * linux/include/asm-xtensa/semaphore.h
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 2001 - 2005 Tensilica Inc.
- */
-
-#ifndef _XTENSA_SEMAPHORE_H
-#define _XTENSA_SEMAPHORE_H
-
-#include <asm/atomic.h>
-#include <asm/system.h>
-#include <linux/wait.h>
-#include <linux/rwsem.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)
-{
-        atomic_set(&sem->count, val);
-        sem->sleepers = 0;
-        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);
-}
-
-asmlinkage void __down(struct semaphore * sem);
-asmlinkage int  __down_interruptible(struct semaphore * sem);
-asmlinkage int  __down_trylock(struct semaphore * sem);
-asmlinkage void __up(struct semaphore * sem);
-
-extern spinlock_t semaphore_wake_lock;
-
-static inline void down(struct semaphore * sem)
-{
-        might_sleep();
-
-        if (atomic_sub_return(1, &sem->count) < 0)
-                __down(sem);
-}
-
-static inline int down_interruptible(struct semaphore * sem)
-{
-        int ret = 0;
-
-        might_sleep();
-
-        if (atomic_sub_return(1, &sem->count) < 0)
-                ret = __down_interruptible(sem);
-        return ret;
-}
-
-static inline int down_trylock(struct semaphore * sem)
-{
-        int ret = 0;
-
-        if (atomic_sub_return(1, &sem->count) < 0)
-                ret = __down_trylock(sem);
-        return ret;
-}
-
-/*
- * Note! This is subtle. We jump to wake people up only if
- * the semaphore was negative (== somebody was waiting on it).
- */
-static inline void up(struct semaphore * sem)
-{
-        if (atomic_add_return(1, &sem->count) <= 0)
-                __up(sem);
-}
-
-#endif /* _XTENSA_SEMAPHORE_H */
+#include <linux/semaphore.h>