1 /* $NetBSD: lock.h,v 1.3 2000/05/02 05:17:45 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe. 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 _M68K_LOCK_H_ 44 #define _M68K_LOCK_H_ 45 46 typedef __volatile unsigned char __cpu_simple_lock_t; 47 48 #define __SIMPLELOCK_LOCKED 0x80 /* result of `tas' insn */ 49 #define __SIMPLELOCK_UNLOCKED 0 50 51 static __inline void __cpu_simple_lock_init __P((__cpu_simple_lock_t *)) 52 __attribute__((__unused__)); 53 static __inline void __cpu_simple_lock __P((__cpu_simple_lock_t *)) 54 __attribute__((__unused__)); 55 static __inline int __cpu_simple_lock_try __P((__cpu_simple_lock_t *)) 56 __attribute__((__unused__)); 57 static __inline void __cpu_simple_unlock __P((__cpu_simple_lock_t *)) 58 __attribute__((__unused__)); 59 60 static __inline void 61 __cpu_simple_lock_init(__cpu_simple_lock_t *alp) 62 { 63 64 *alp = __SIMPLELOCK_UNLOCKED; 65 } 66 67 static __inline void 68 __cpu_simple_lock(__cpu_simple_lock_t *alp) 69 { 70 71 __asm __volatile( 72 "1: tas %0 \n" 73 " jne 1b \n" 74 : "=m" (*alp)); 75 } 76 77 static __inline int 78 __cpu_simple_lock_try(__cpu_simple_lock_t *alp) 79 { 80 int __rv = 1; 81 82 __asm __volatile( 83 " tas %0 \n" 84 " jeq 1f \n" 85 " moveq #0, %1 \n" 86 "1: \n" 87 : "=m" (*alp), "=d" (__rv)); 88 89 return (__rv); 90 } 91 92 static __inline void 93 __cpu_simple_unlock(__cpu_simple_lock_t *alp) 94 { 95 96 *alp = __SIMPLELOCK_UNLOCKED; 97 } 98 99 #endif /* _M68K_LOCK_H_ */ 100