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