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lock.h revision 1.4 
      1 /*	$NetBSD: lock.h,v 1.4 2000/05/02 04:41:11 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2000 Ludd, University of Lule}, Sweden.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *     This product includes software developed at Ludd, University of Lule}.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifndef _VAX_LOCK_H_
     34 #define _VAX_LOCK_H_
     35 
     36 typedef	__volatile int		__cpu_simple_lock_t;
     37 
     38 #define	__SIMPLELOCK_LOCKED	1
     39 #define	__SIMPLELOCK_UNLOCKED	0
     40 
     41 static __inline void
     42 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
     43 {
     44 	*alp = __SIMPLELOCK_UNLOCKED;
     45 }
     46 
     47 static __inline void
     48 __cpu_simple_lock(__cpu_simple_lock_t *alp)
     49 {
     50 	__asm__ __volatile ("1:;bbssi $0, (%0), 1b"
     51 		: /* No output */
     52 		: "r"(alp));
     53 }
     54 
     55 static __inline void
     56 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
     57 {
     58 	*alp = __SIMPLELOCK_UNLOCKED;
     59 }
     60 
     61 static __inline int
     62 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
     63 {
     64 	register int ret;
     65 
     66 	__asm__ __volatile ("movl $0,%0;bbssi $0,(%1),1f;incl %0;1:"
     67 		: "&=r"(ret)
     68 		: "r"(alp));
     69 
     70 	return ret;
     71 }
     72 
     73 #endif /* _VAX_LOCK_H_ */
     74