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spinlock.h revision 1.1.2.5 
      1 /*	$NetBSD: spinlock.h,v 1.1.2.5 2013/07/24 02:24:58 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _LINUX_SPINLOCK_H_
     33 #define _LINUX_SPINLOCK_H_
     34 
     35 #include <sys/cdefs.h>
     36 #include <sys/mutex.h>
     37 
     38 typedef struct {
     39 	kmutex_t sl_lock;
     40 } spinlock_t;
     41 
     42 static inline int
     43 spin_is_locked(spinlock_t *spinlock)
     44 {
     45 	return mutex_owned(&spinlock->sl_lock);
     46 }
     47 
     48 static inline void
     49 spin_lock(spinlock_t *spinlock)
     50 {
     51 	mutex_enter(&spinlock->sl_lock);
     52 }
     53 
     54 static inline void
     55 spin_unlock(spinlock_t *spinlock)
     56 {
     57 	mutex_exit(&spinlock->sl_lock);
     58 }
     59 
     60 /* Must be a macro because the second argument is to be assigned.  */
     61 #define	spin_lock_irqsave(SPINLOCK, FLAGS)				\
     62 	do {								\
     63 		(FLAGS) = 0;						\
     64 		mutex_enter(&((spinlock_t *)(SPINLOCK))->sl_lock);	\
     65 	} while (0)
     66 
     67 static inline void
     68 spin_unlock_irqrestore(spinlock_t *spinlock, unsigned long __unused flags)
     69 {
     70 	mutex_exit(&spinlock->sl_lock);
     71 }
     72 
     73 static inline void
     74 spin_lock_init(spinlock_t *spinlock)
     75 {
     76 	/* XXX Need to identify which need to block intrs.  */
     77 	mutex_init(&spinlock->sl_lock, MUTEX_DEFAULT, IPL_NONE);
     78 }
     79 
     80 /*
     81  * XXX Linux doesn't ever destroy spin locks, it seems.  We'll have to
     82  * kludge it up.
     83  */
     84 
     85 static inline void
     86 spin_lock_destroy(spinlock_t *spinlock)
     87 {
     88 	mutex_destroy(&spinlock->sl_lock);
     89 }
     90 
     91 #endif  /* _LINUX_SPINLOCK_H_ */
     92