patch-2.4.25 linux-2.4.25/include/asm-mips64/semaphore-helper.h

• Lines: 183
• Date: 1969-12-31 16:00:00.000000000 -0800
• Orig file: linux-2.4.24/include/asm-mips64/semaphore-helper.h
• Orig date: 2003-08-25 04:44:44.000000000 -0700

diff -urN linux-2.4.24/include/asm-mips64/semaphore-helper.h linux-2.4.25/include/asm-mips64/semaphore-helper.h
@@ -1,182 +0,0 @@
-/*
- * SMP- and interrupt-safe semaphores helper functions.
- *
- * Copyright (C) 1996 Linus Torvalds
- * Copyright (C) 1999 Andrea Arcangeli
- * Copyright (C) 1999, 2001, 2002 Ralf Baechle
- * Copyright (C) 1999, 2001 Silicon Graphics, Inc.
- * Copyright (C) 2000 MIPS Technologies, Inc.
- */
-#ifndef _ASM_SEMAPHORE_HELPER_H
-#define _ASM_SEMAPHORE_HELPER_H
-
-#include <linux/config.h>
-#include <linux/errno.h>
-
-#define sem_read(a) ((a)->counter)
-#define sem_inc(a) (((a)->counter)++)
-#define sem_dec(a) (((a)->counter)--)
-/*
- * These two _must_ execute atomically wrt each other.
- */
-static inline void wake_one_more(struct semaphore * sem)
-{
-	atomic_inc(&sem->waking);
-}
-
-#ifdef CONFIG_CPU_HAS_LLSC
-
-static inline int waking_non_zero(struct semaphore *sem)
-{
-	int ret, tmp;
-
-	__asm__ __volatile__(
-	"1:\tll\t%1, %2\t\t\t# waking_non_zero\n\t"
-	"blez\t%1, 2f\n\t"
-	"subu\t%0, %1, 1\n\t"
-	"sc\t%0, %2\n\t"
-	"beqz\t%0, 1b\n"
-	"2:"
-	: "=r" (ret), "=r" (tmp), "+m" (sem->waking)
-	: "0" (0));
-
-	return ret;
-}
-
-#else /* !CONFIG_CPU_HAS_LLSC */
-
-/*
- * It doesn't make sense, IMHO, to endlessly turn interrupts off and on again.
- * Do it once and that's it. ll/sc *has* it's advantages. HK
- */
-
-static inline int waking_non_zero(struct semaphore *sem)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	local_irq_save(flags);
-	if (sem_read(&sem->waking) > 0) {
-		sem_dec(&sem->waking);
-		ret = 1;
-	}
-	local_irq_restore(flags);
-	return ret;
-}
-#endif /* !CONFIG_CPU_HAS_LLSC */
-
-#ifdef CONFIG_CPU_HAS_LLDSCD
-
-/*
- * waking_non_zero_interruptible:
- *	1	got the lock
- *	0	go to sleep
- *	-EINTR	interrupted
- *
- * We must undo the sem->count down_interruptible decrement
- * simultaneously and atomically with the sem->waking adjustment,
- * otherwise we can race with wake_one_more.
- *
- * This is accomplished by doing a 64-bit lld/scd on the 2 32-bit words.
- *
- * This is crazy.  Normally it's strictly forbidden to use 64-bit operations
- * in the 32-bit MIPS kernel.  In this case it's however ok because if an
- * interrupt has destroyed the upper half of registers sc will fail.
- * Note also that this will not work for MIPS32 CPUs!
- *
- * Pseudocode:
- *
- * If(sem->waking > 0) {
- *	Decrement(sem->waking)
- *	Return(SUCCESS)
- * } else If(signal_pending(tsk)) {
- *	Increment(sem->count)
- *	Return(-EINTR)
- * } else {
- *	Return(SLEEP)
- * }
- */
-
-static inline int
-waking_non_zero_interruptible(struct semaphore *sem, struct task_struct *tsk)
-{
-	long ret, tmp;
-
-	__asm__ __volatile__(
-	".set\tpush\t\t\t# waking_non_zero_interruptible\n\t"
-	".set\tmips3\n\t"
-	".set\tnoat\n"
-	"0:\tlld\t%1, %2\n\t"
-	"li\t%0, 0\n\t"
-	"sll\t$1, %1, 0\n\t"
-	"blez\t$1, 1f\n\t"
-	"daddiu\t%1, %1, -1\n\t"
-	"li\t%0, 1\n\t"
-	"b\t2f\n"
-	"1:\tbeqz\t%3, 2f\n\t"
-	"li\t%0, %4\n\t"
-	"dli\t$1, 0x0000000100000000\n\t"
-	"daddu\t%1, %1, $1\n"
-	"2:\tscd\t%1, %2\n\t"
-	"beqz\t%1, 0b\n\t"
-	".set\tpop"
-	: "=&r" (ret), "=&r" (tmp), "=m" (*sem)
-	: "r" (signal_pending(tsk)), "i" (-EINTR));
-
-	return ret;
-}
-
-/*
- * waking_non_zero_trylock is unused.  we do everything in
- * down_trylock and let non-ll/sc hosts bounce around.
- */
-
-static inline int waking_non_zero_trylock(struct semaphore *sem)
-{
-#if WAITQUEUE_DEBUG
-	CHECK_MAGIC(sem->__magic);
-#endif
-
-	return 0;
-}
-
-#else /* !CONFIG_CPU_HAS_LLDSCD */
-
-static inline int waking_non_zero_interruptible(struct semaphore *sem,
-						struct task_struct *tsk)
-{
-	int ret = 0;
-	unsigned long flags;
-
-	local_irq_save(flags);
-	if (sem_read(&sem->waking) > 0) {
-		sem_dec(&sem->waking);
-		ret = 1;
-	} else if (signal_pending(tsk)) {
-		sem_inc(&sem->count);
-		ret = -EINTR;
-	}
-	local_irq_restore(flags);
-	return ret;
-}
-
-static inline int waking_non_zero_trylock(struct semaphore *sem)
-{
-        int ret = 1;
-	unsigned long flags;
-
-	local_irq_save(flags);
-	if (sem_read(&sem->waking) <= 0)
-		sem_inc(&sem->count);
-	else {
-		sem_dec(&sem->waking);
-		ret = 0;
-	}
-	local_irq_restore(flags);
-
-	return ret;
-}
-
-#endif /* !CONFIG_CPU_HAS_LLDSCD */
-
-#endif /* _ASM_SEMAPHORE_HELPER_H */