1 /* $NetBSD: lock.h,v 1.11 2007/10/17 19:56:41 garbled Exp $ */ 2 3 /*- 4 * Copyright (c) 2000, 2007 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 and Andrew Doran. 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 _POWERPC_LOCK_H_ 44 #define _POWERPC_LOCK_H_ 45 46 static __inline int 47 __SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr) 48 { 49 return *__ptr == __SIMPLELOCK_LOCKED; 50 } 51 52 static __inline int 53 __SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr) 54 { 55 return *__ptr == __SIMPLELOCK_UNLOCKED; 56 } 57 58 static __inline void 59 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr) 60 { 61 *__ptr = __SIMPLELOCK_UNLOCKED; 62 } 63 64 static __inline void 65 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr) 66 { 67 *__ptr = __SIMPLELOCK_LOCKED; 68 } 69 70 static __inline void 71 __cpu_simple_lock_init(__cpu_simple_lock_t *alp) 72 { 73 *alp = __SIMPLELOCK_UNLOCKED; 74 __asm volatile ("sync"); 75 } 76 77 static __inline void 78 __cpu_simple_lock(__cpu_simple_lock_t *alp) 79 { 80 int old; 81 82 __asm volatile (" \ 83 \n\ 84 1: lwarx %0,0,%1 \n\ 85 cmpwi %0,%2 \n\ 86 beq+ 3f \n\ 87 2: lwzx %0,0,%1 \n\ 88 cmpwi %0,%2 \n\ 89 beq+ 1b \n\ 90 b 2b \n\ 91 3: stwcx. %3,0,%1 \n\ 92 bne- 1b \n\ 93 isync \n\ 94 \n" 95 : "=&r"(old) 96 : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED) 97 : "memory"); 98 } 99 100 static __inline int 101 __cpu_simple_lock_try(__cpu_simple_lock_t *alp) 102 { 103 int old, dummy; 104 105 __asm volatile (" \ 106 \n\ 107 1: lwarx %0,0,%1 \n\ 108 cmpwi %0,%2 \n\ 109 bne 2f \n\ 110 stwcx. %3,0,%1 \n\ 111 bne- 1b \n\ 112 2: stwcx. %3,0,%4 \n\ 113 isync \n\ 114 \n" 115 : "=&r"(old) 116 : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED), 117 "r"(&dummy) 118 : "memory"); 119 120 return (old == __SIMPLELOCK_UNLOCKED); 121 } 122 123 static __inline void 124 __cpu_simple_unlock(__cpu_simple_lock_t *alp) 125 { 126 __asm volatile ("sync"); 127 *alp = __SIMPLELOCK_UNLOCKED; 128 } 129 130 static __inline void 131 mb_read(void) 132 { 133 __asm volatile ("isync" ::: "memory"); 134 } 135 136 static __inline void 137 mb_write(void) 138 { 139 __asm volatile ("sync" ::: "memory"); 140 } 141 142 static __inline void 143 mb_memory(void) 144 { 145 __asm volatile ("sync" ::: "memory"); 146 } 147 148 #endif /* _POWERPC_LOCK_H_ */ 149