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, 0 insertions, 89 deletions

diff --git a/include/asm-sh/semaphore-helper.h b/include/asm-sh/semaphore-helper.h
deleted file mode 100644
index bd8230c369ca..000000000000
--- a/include/asm-sh/semaphore-helper.h
+++ /dev/null
@@ -1,89 +0,0 @@
-#ifndef __ASM_SH_SEMAPHORE_HELPER_H
-#define __ASM_SH_SEMAPHORE_HELPER_H
-
-/*
- * SMP- and interrupt-safe semaphores helper functions.
- *
- * (C) Copyright 1996 Linus Torvalds
- * (C) Copyright 1999 Andrea Arcangeli
- */
-
-/*
- * These two _must_ execute atomically wrt each other.
- *
- * This is trivially done with load_locked/store_cond,
- * which we have.  Let the rest of the losers suck eggs.
- */
-static __inline__ void wake_one_more(struct semaphore * sem)
-{
-	atomic_inc((atomic_t *)&sem->sleepers);
-}
-
-static __inline__ int waking_non_zero(struct semaphore *sem)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	spin_lock_irqsave(&semaphore_wake_lock, flags);
-	if (sem->sleepers > 0) {
-		sem->sleepers--;
-		ret = 1;
-	}
-	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
-	return ret;
-}
-
-/*
- * waking_non_zero_interruptible:
- *	1	got the lock
- *	0	go to sleep
- *	-EINTR	interrupted
- *
- * We must undo the sem->count down_interruptible() increment while we are
- * protected by the spinlock in order to make atomic this atomic_inc() with the
- * atomic_read() in wake_one_more(), otherwise we can race. -arca
- */
-static __inline__ int waking_non_zero_interruptible(struct semaphore *sem,
-						struct task_struct *tsk)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	spin_lock_irqsave(&semaphore_wake_lock, flags);
-	if (sem->sleepers > 0) {
-		sem->sleepers--;
-		ret = 1;
-	} else if (signal_pending(tsk)) {
-		atomic_inc(&sem->count);
-		ret = -EINTR;
-	}
-	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
-	return ret;
-}
-
-/*
- * waking_non_zero_trylock:
- *	1	failed to lock
- *	0	got the lock
- *
- * We must undo the sem->count down_trylock() increment while we are
- * protected by the spinlock in order to make atomic this atomic_inc() with the
- * atomic_read() in wake_one_more(), otherwise we can race. -arca
- */
-static __inline__ int waking_non_zero_trylock(struct semaphore *sem)
-{
-	unsigned long flags;
-	int ret = 1;
-
-	spin_lock_irqsave(&semaphore_wake_lock, flags);
-	if (sem->sleepers <= 0)
-		atomic_inc(&sem->count);
-	else {
-		sem->sleepers--;
-		ret = 0;
-	}
-	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
-	return ret;
-}
-
-#endif /* __ASM_SH_SEMAPHORE_HELPER_H */