| 1 | /*
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| 2 | * Copyright (C) 2001-2004 Jakub Jermar
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | #ifndef __SPINLOCK_H__
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| 30 | #define __SPINLOCK_H__
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| 31 |
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| 32 | #include <arch/types.h>
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| 33 | #include <typedefs.h>
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| 34 | #include <preemption.h>
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| 35 | #include <arch/atomic.h>
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| 36 |
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| 37 | #ifdef CONFIG_SMP
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| 38 | struct spinlock {
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| 39 | #ifdef CONFIG_DEBUG_SPINLOCK
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| 40 | char *name;
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| 41 | #endif
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| 42 | atomic_t val;
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| 43 | };
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| 44 |
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| 45 | /*
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| 46 | * SPINLOCK_DECLARE is to be used for dynamically allocated spinlocks,
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| 47 | * where the lock gets initialized in run time.
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| 48 | */
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| 49 | #define SPINLOCK_DECLARE(slname) spinlock_t slname
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| 50 |
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| 51 | /*
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| 52 | * SPINLOCK_INITIALIZE is to be used for statically allocated spinlocks.
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| 53 | * It declares and initializes the lock.
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| 54 | */
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| 55 | #ifdef CONFIG_DEBUG_SPINLOCK
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| 56 | #define SPINLOCK_INITIALIZE(slname) \
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| 57 | spinlock_t slname = { \
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| 58 | .name = #slname, \
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| 59 | .val = { 0 } \
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| 60 | }
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| 61 | #else
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| 62 | #define SPINLOCK_INITIALIZE(slname) \
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| 63 | spinlock_t slname = { \
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| 64 | .val = { 0 } \
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| 65 | }
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| 66 | #endif
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| 67 |
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| 68 | extern void spinlock_initialize(spinlock_t *sl, char *name);
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| 69 | extern void spinlock_lock(spinlock_t *sl);
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| 70 | extern int spinlock_trylock(spinlock_t *sl);
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| 71 | extern void spinlock_unlock(spinlock_t *sl);
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| 72 |
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| 73 | #else
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| 74 |
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| 75 | /* On UP systems, spinlocks are effectively left out. */
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| 76 | #define SPINLOCK_DECLARE(name)
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| 77 | #define SPINLOCK_INITIALIZE(name)
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| 78 |
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| 79 | #define spinlock_initialize(x,name)
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| 80 | #define spinlock_lock(x) preemption_disable()
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| 81 | #define spinlock_trylock(x) (preemption_disable(), 1)
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| 82 | #define spinlock_unlock(x) preemption_enable()
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| 83 |
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| 84 | #endif
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| 85 |
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| 86 | #endif
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