1 /* $NetBSD: lock.h,v 1.16 2021/09/13 11:54:42 rin 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 * 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 /* 33 * Machine-dependent spin lock operations. 34 */ 35 36 #ifndef _POWERPC_LOCK_H_ 37 #define _POWERPC_LOCK_H_ 38 39 static __inline int 40 __SIMPLELOCK_LOCKED_P(const __cpu_simple_lock_t *__ptr) 41 { 42 return *__ptr == __SIMPLELOCK_LOCKED; 43 } 44 45 static __inline int 46 __SIMPLELOCK_UNLOCKED_P(const __cpu_simple_lock_t *__ptr) 47 { 48 return *__ptr == __SIMPLELOCK_UNLOCKED; 49 } 50 51 static __inline void 52 __cpu_simple_lock_clear(__cpu_simple_lock_t *__ptr) 53 { 54 *__ptr = __SIMPLELOCK_UNLOCKED; 55 } 56 57 static __inline void 58 __cpu_simple_lock_set(__cpu_simple_lock_t *__ptr) 59 { 60 *__ptr = __SIMPLELOCK_LOCKED; 61 } 62 63 static __inline void 64 __cpu_simple_lock_init(__cpu_simple_lock_t *alp) 65 { 66 *alp = __SIMPLELOCK_UNLOCKED; 67 __asm volatile ("sync"); 68 } 69 70 static __inline void 71 __cpu_simple_lock(__cpu_simple_lock_t *alp) 72 { 73 int old; 74 75 __asm volatile (" \ 76 \n\ 77 1: lwarx %0,0,%1 \n\ 78 cmpwi %0,%2 \n\ 79 beq+ 3f \n\ 80 2: lwzx %0,0,%1 \n\ 81 cmpwi %0,%2 \n\ 82 beq+ 1b \n\ 83 b 2b \n\ 84 3: \n" 85 #ifdef IBM405_ERRATA77 86 "dcbt 0,%1 \n" 87 #endif 88 "stwcx. %3,0,%1 \n\ 89 bne- 1b \n\ 90 isync \n\ 91 \n" 92 : "=&r"(old) 93 : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED) 94 : "memory"); 95 } 96 97 static __inline int 98 __cpu_simple_lock_try(__cpu_simple_lock_t *alp) 99 { 100 int old, dummy; 101 102 __asm volatile (" \ 103 \n\ 104 1: lwarx %0,0,%1 \n\ 105 cmpwi %0,%2 \n\ 106 bne 2f \n" 107 #ifdef IBM405_ERRATA77 108 "dcbt 0,%1 \n" 109 #endif 110 "stwcx. %3,0,%1 \n\ 111 bne- 1b \n\ 112 2: \n" 113 #ifdef IBM405_ERRATA77 114 "dcbt 0,%4 \n" 115 #endif 116 "stwcx. %3,0,%4 \n\ 117 isync \n\ 118 \n" 119 : "=&r"(old) 120 : "r"(alp), "I"(__SIMPLELOCK_UNLOCKED), "r"(__SIMPLELOCK_LOCKED), 121 "r"(&dummy) 122 : "memory"); 123 124 return (old == __SIMPLELOCK_UNLOCKED); 125 } 126 127 static __inline void 128 __cpu_simple_unlock(__cpu_simple_lock_t *alp) 129 { 130 __asm volatile ("sync"); 131 *alp = __SIMPLELOCK_UNLOCKED; 132 } 133 134 #endif /* _POWERPC_LOCK_H_ */ 135