patch-2.4.0-test11 linux/include/asm-alpha/semaphore-helper.h
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- Lines: 129
- Date:
Wed Dec 31 16:00:00 1969
- Orig file:
v2.4.0-test10/linux/include/asm-alpha/semaphore-helper.h
- Orig date:
Sun Oct 8 10:50:33 2000
diff -u --recursive --new-file v2.4.0-test10/linux/include/asm-alpha/semaphore-helper.h linux/include/asm-alpha/semaphore-helper.h
@@ -1,128 +0,0 @@
-#ifndef _ALPHA_SEMAPHORE_HELPER_H
-#define _ALPHA_SEMAPHORE_HELPER_H
-
-/*
- * SMP- and interrupt-safe semaphores helper functions.
- *
- * (C) Copyright 1996 Linus Torvalds
- * (C) Copyright 1999 Richard Henderson
- */
-
-/*
- * 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(&sem->waking);
-}
-
-static inline int
-waking_non_zero(struct semaphore *sem)
-{
- long ret, tmp;
-
- /* An atomic conditional decrement. */
- __asm__ __volatile__(
- "1: ldl_l %1,%2\n"
- " blt %1,2f\n"
- " subl %1,1,%0\n"
- " stl_c %0,%2\n"
- " beq %0,3f\n"
- "2:\n"
- ".subsection 2\n"
- "3: br 1b\n"
- ".previous"
- : "=r"(ret), "=r"(tmp), "=m"(sem->waking.counter)
- : "0"(0));
-
- return ret > 0;
-}
-
-
-/*
- * 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 atomicly with the sem->waking adjustment,
- * otherwise we can race with wake_one_more.
- *
- * This is accomplished by doing a 64-bit ll/sc on the 2 32-bit words.
- */
-
-static inline int
-waking_non_zero_interruptible(struct semaphore *sem, struct task_struct *tsk)
-{
- long ret, tmp, tmp2, tmp3;
-
- /* "Equivalent" C. Note that we have to do this all without
- (taken) branches in order to be a valid ll/sc sequence.
-
- do {
- tmp = ldq_l;
- ret = 0;
- if (tmp >= 0) {
- tmp += 0xffffffff00000000;
- ret = 1;
- }
- else if (pending) {
- // Since -1 + 1 carries into the high word, we have
- // to be more careful adding 1 here.
- tmp = (tmp & 0xffffffff00000000)
- | ((tmp + 1) & 0x00000000ffffffff;
- ret = -EINTR;
- }
- else {
- break; // ideally. we don't actually break
- // since this is a predicate we don't
- // have, and is more trouble to build
- // than to elide the noop stq_c.
- }
- tmp = stq_c = tmp;
- } while (tmp == 0);
- */
-
- __asm__ __volatile__(
- "1: ldq_l %1,%4\n"
- " lda %0,0\n"
- " cmovne %5,%6,%0\n"
- " addq %1,1,%2\n"
- " and %1,%7,%3\n"
- " andnot %2,%7,%2\n"
- " cmovge %1,1,%0\n"
- " or %3,%2,%2\n"
- " addq %1,%7,%3\n"
- " cmovne %5,%2,%1\n"
- " cmovge %2,%3,%1\n"
- " stq_c %1,%4\n"
- " beq %1,3f\n"
- "2:\n"
- ".subsection 2\n"
- "3: br 1b\n"
- ".previous"
- : "=&r"(ret), "=&r"(tmp), "=&r"(tmp2), "=&r"(tmp3), "=m"(*sem)
- : "r"(signal_pending(tsk)), "r"(-EINTR),
- "r"(0xffffffff00000000));
-
- 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)
-{
- return 0;
-}
-
-#endif
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