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lock.h revision 1.7 
      1 /*	$NetBSD: lock.h,v 1.7 2005/12/11 12:18:58 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Gregory McGarry.
      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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Machine-dependent spin lock operations.
     41  */
     42 
     43 #ifndef _SH3_LOCK_H_
     44 #define	_SH3_LOCK_H_
     45 
     46 static __inline void __cpu_simple_lock_init __P((__cpu_simple_lock_t *))
     47 	__attribute__((__unused__));
     48 static __inline void __cpu_simple_lock __P((__cpu_simple_lock_t *))
     49 	__attribute__((__unused__));
     50 static __inline int __cpu_simple_lock_try __P((__cpu_simple_lock_t *))
     51 	__attribute__((__unused__));
     52 static __inline void __cpu_simple_unlock __P((__cpu_simple_lock_t *))
     53 	__attribute__((__unused__));
     54 
     55 static __inline void
     56 __cpu_simple_lock_init(__cpu_simple_lock_t *alp)
     57 {
     58 
     59 	*alp = __SIMPLELOCK_UNLOCKED;
     60 }
     61 
     62 static __inline void
     63 __cpu_simple_lock(__cpu_simple_lock_t *alp)
     64 {
     65 
     66 	 __asm __volatile(
     67 		"1:	tas.b	%0	\n"
     68 		"	bf	1b	\n"
     69 		: "=m" (*alp));
     70 }
     71 
     72 static __inline int
     73 __cpu_simple_lock_try(__cpu_simple_lock_t *alp)
     74 {
     75 	int __rv;
     76 
     77 	__asm __volatile(
     78 		"	tas.b	%0	\n"
     79 		"	mov	#0, %1	\n"
     80 		"	rotcl	%1	\n"
     81 		: "=m" (*alp), "=r" (__rv));
     82 
     83 	return (__rv);
     84 }
     85 
     86 static __inline void
     87 __cpu_simple_unlock(__cpu_simple_lock_t *alp)
     88 {
     89 
     90 	*alp = __SIMPLELOCK_UNLOCKED;
     91 }
     92 
     93 #endif /* !_SH3_LOCK_H_ */
     94