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spinlock.h revision 1.3.4.2
      1  1.3.4.2  tls /*	$NetBSD: spinlock.h,v 1.3.4.2 2014/08/20 00:04:21 tls Exp $	*/
      2  1.3.4.2  tls 
      3  1.3.4.2  tls /*-
      4  1.3.4.2  tls  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  1.3.4.2  tls  * All rights reserved.
      6  1.3.4.2  tls  *
      7  1.3.4.2  tls  * This code is derived from software contributed to The NetBSD Foundation
      8  1.3.4.2  tls  * by Taylor R. Campbell.
      9  1.3.4.2  tls  *
     10  1.3.4.2  tls  * Redistribution and use in source and binary forms, with or without
     11  1.3.4.2  tls  * modification, are permitted provided that the following conditions
     12  1.3.4.2  tls  * are met:
     13  1.3.4.2  tls  * 1. Redistributions of source code must retain the above copyright
     14  1.3.4.2  tls  *    notice, this list of conditions and the following disclaimer.
     15  1.3.4.2  tls  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.3.4.2  tls  *    notice, this list of conditions and the following disclaimer in the
     17  1.3.4.2  tls  *    documentation and/or other materials provided with the distribution.
     18  1.3.4.2  tls  *
     19  1.3.4.2  tls  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  1.3.4.2  tls  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  1.3.4.2  tls  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  1.3.4.2  tls  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  1.3.4.2  tls  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  1.3.4.2  tls  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  1.3.4.2  tls  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  1.3.4.2  tls  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  1.3.4.2  tls  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  1.3.4.2  tls  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  1.3.4.2  tls  * POSSIBILITY OF SUCH DAMAGE.
     30  1.3.4.2  tls  */
     31  1.3.4.2  tls 
     32  1.3.4.2  tls #ifndef _LINUX_SPINLOCK_H_
     33  1.3.4.2  tls #define _LINUX_SPINLOCK_H_
     34  1.3.4.2  tls 
     35  1.3.4.2  tls #include <sys/cdefs.h>
     36  1.3.4.2  tls #include <sys/mutex.h>
     37  1.3.4.2  tls 
     38  1.3.4.2  tls typedef struct spinlock {
     39  1.3.4.2  tls 	kmutex_t sl_lock;
     40  1.3.4.2  tls } spinlock_t;
     41  1.3.4.2  tls 
     42  1.3.4.2  tls static inline int
     43  1.3.4.2  tls spin_is_locked(spinlock_t *spinlock)
     44  1.3.4.2  tls {
     45  1.3.4.2  tls 	return mutex_owned(&spinlock->sl_lock);
     46  1.3.4.2  tls }
     47  1.3.4.2  tls 
     48  1.3.4.2  tls static inline void
     49  1.3.4.2  tls spin_lock(spinlock_t *spinlock)
     50  1.3.4.2  tls {
     51  1.3.4.2  tls 	mutex_enter(&spinlock->sl_lock);
     52  1.3.4.2  tls }
     53  1.3.4.2  tls 
     54  1.3.4.2  tls static inline void
     55  1.3.4.2  tls spin_unlock(spinlock_t *spinlock)
     56  1.3.4.2  tls {
     57  1.3.4.2  tls 	mutex_exit(&spinlock->sl_lock);
     58  1.3.4.2  tls }
     59  1.3.4.2  tls 
     60  1.3.4.2  tls static inline void
     61  1.3.4.2  tls spin_lock_irq(spinlock_t *spinlock)
     62  1.3.4.2  tls {
     63  1.3.4.2  tls 	spin_lock(spinlock);
     64  1.3.4.2  tls }
     65  1.3.4.2  tls 
     66  1.3.4.2  tls static inline void
     67  1.3.4.2  tls spin_unlock_irq(spinlock_t *spinlock)
     68  1.3.4.2  tls {
     69  1.3.4.2  tls 	spin_unlock(spinlock);
     70  1.3.4.2  tls }
     71  1.3.4.2  tls 
     72  1.3.4.2  tls /* Must be a macro because the second argument is to be assigned.  */
     73  1.3.4.2  tls #define	spin_lock_irqsave(SPINLOCK, FLAGS)				\
     74  1.3.4.2  tls 	do {								\
     75  1.3.4.2  tls 		(FLAGS) = 0;						\
     76  1.3.4.2  tls 		mutex_enter(&((spinlock_t *)(SPINLOCK))->sl_lock);	\
     77  1.3.4.2  tls 	} while (0)
     78  1.3.4.2  tls 
     79  1.3.4.2  tls static inline void
     80  1.3.4.2  tls spin_unlock_irqrestore(spinlock_t *spinlock, unsigned long __unused flags)
     81  1.3.4.2  tls {
     82  1.3.4.2  tls 	mutex_exit(&spinlock->sl_lock);
     83  1.3.4.2  tls }
     84  1.3.4.2  tls 
     85  1.3.4.2  tls static inline void
     86  1.3.4.2  tls spin_lock_init(spinlock_t *spinlock)
     87  1.3.4.2  tls {
     88  1.3.4.2  tls 	/* XXX What's the right IPL?  IPL_DRM...?  */
     89  1.3.4.2  tls 	mutex_init(&spinlock->sl_lock, MUTEX_DEFAULT, IPL_VM);
     90  1.3.4.2  tls }
     91  1.3.4.2  tls 
     92  1.3.4.2  tls /*
     93  1.3.4.2  tls  * XXX Linux doesn't ever destroy spin locks, it seems.  We'll have to
     94  1.3.4.2  tls  * kludge it up.
     95  1.3.4.2  tls  */
     96  1.3.4.2  tls 
     97  1.3.4.2  tls static inline void
     98  1.3.4.2  tls spin_lock_destroy(spinlock_t *spinlock)
     99  1.3.4.2  tls {
    100  1.3.4.2  tls 	mutex_destroy(&spinlock->sl_lock);
    101  1.3.4.2  tls }
    102  1.3.4.2  tls 
    103  1.3.4.2  tls /* This is a macro to make the panic message clearer.  */
    104  1.3.4.2  tls #define	assert_spin_locked(spinlock)	\
    105  1.3.4.2  tls 	KASSERT(mutex_owned(&(spinlock)->sl_lock))
    106  1.3.4.2  tls 
    107  1.3.4.2  tls /*
    108  1.3.4.2  tls  * Linux rwlocks are reader/writer spin locks.  We implement them as
    109  1.3.4.2  tls  * normal spin locks without reader/writer semantics for expedience.
    110  1.3.4.2  tls  * If that turns out to not work, adapting to reader/writer semantics
    111  1.3.4.2  tls  * shouldn't be too hard.
    112  1.3.4.2  tls  */
    113  1.3.4.2  tls 
    114  1.3.4.2  tls #define	rwlock_t		spinlock_t
    115  1.3.4.2  tls #define	rwlock_init		spin_lock_init
    116  1.3.4.2  tls #define	rwlock_destroy		spin_lock_destroy
    117  1.3.4.2  tls #define	write_lock_irq		spin_lock_irq
    118  1.3.4.2  tls #define	write_unlock_irq	spin_unlock_irq
    119  1.3.4.2  tls #define	read_lock		spin_lock
    120  1.3.4.2  tls #define	read_unlock		spin_unlock
    121  1.3.4.2  tls 
    122  1.3.4.2  tls #endif  /* _LINUX_SPINLOCK_H_ */
    123