1 /* $NetBSD: lock.h,v 1.14 2007/10/17 19:54:40 garbled Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 1999, 2000, 2001 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 of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center, and Matthew Fredette. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Machine-dependent spin lock operations. 42 */ 43 44 #ifndef _HPPA_LOCK_H_ 45 #define _HPPA_LOCK_H_ 46 47 #include <sys/stdint.h> 48 49 #define HPPA_LDCW_ALIGN 16 50 51 #define __SIMPLELOCK_ALIGN(p) \ 52 (volatile unsigned long *)(((uintptr_t)(p) + HPPA_LDCW_ALIGN - 1) & \ 53 ~(HPPA_LDCW_ALIGN - 1)) 54 55 #define __SIMPLELOCK_RAW_LOCKED 0 56 #define __SIMPLELOCK_RAW_UNLOCKED 1 57 58 static __inline int 59 __SIMPLELOCK_LOCKED_P(__cpu_simple_lock_t *__ptr) 60 { 61 return *__SIMPLELOCK_ALIGN(__ptr) == __SIMPLELOCK_RAW_LOCKED; 62 } 63 64 static __inline int 65 __SIMPLELOCK_UNLOCKED_P(__cpu_simple_lock_t *__ptr) 66 { 67 return *__SIMPLELOCK_ALIGN(__ptr) == __SIMPLELOCK_RAW_UNLOCKED; 68 } 69 70 static __inline int 71 __ldcw(volatile unsigned long *__ptr) 72 { 73 int __val; 74 75 __asm volatile("ldcw 0(%1), %0" 76 : "=r" (__val) : "r" (__ptr) 77 : "memory"); 78 79 return __val; 80 } 81 82 static __inline void 83 __sync(void) 84 { 85 86 __asm volatile("sync\n" 87 : /* no outputs */ 88 : /* no inputs */ 89 : "memory"); 90 } 91 92 static __inline void 93 __cpu_simple_lock_init(__cpu_simple_lock_t *alp) 94 { 95 __cpu_simple_lock_t ul = __SIMPLELOCK_UNLOCKED; 96 97 *alp = ul; 98 __sync(); 99 } 100 101 static __inline void 102 __cpu_simple_lock(__cpu_simple_lock_t *alp) 103 { 104 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 105 106 /* 107 * Note, if we detect that the lock is held when 108 * we do the initial load-clear-word, we spin using 109 * a non-locked load to save the coherency logic 110 * some work. 111 */ 112 113 while (__ldcw(__aptr) == __SIMPLELOCK_RAW_LOCKED) 114 while (*__aptr == __SIMPLELOCK_RAW_LOCKED) 115 ; 116 } 117 118 static __inline int 119 __cpu_simple_lock_try(__cpu_simple_lock_t *alp) 120 { 121 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 122 123 return (__ldcw(__aptr) != __SIMPLELOCK_RAW_LOCKED); 124 } 125 126 static __inline void 127 __cpu_simple_unlock(__cpu_simple_lock_t *alp) 128 { 129 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 130 131 __sync(); 132 *__aptr = __SIMPLELOCK_RAW_UNLOCKED; 133 } 134 135 static __inline void 136 __cpu_simple_lock_set(__cpu_simple_lock_t *alp) 137 { 138 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 139 140 *__aptr = __SIMPLELOCK_RAW_LOCKED; 141 } 142 143 static __inline void 144 __cpu_simple_lock_clear(__cpu_simple_lock_t *alp) 145 { 146 volatile unsigned long *__aptr = __SIMPLELOCK_ALIGN(alp); 147 148 *__aptr = __SIMPLELOCK_RAW_UNLOCKED; 149 } 150 151 static __inline void 152 mb_read(void) 153 { 154 __sync(); 155 } 156 157 static __inline void 158 mb_write(void) 159 { 160 __sync(); 161 } 162 163 static __inline void 164 mb_memory(void) 165 { 166 __sync(); 167 } 168 169 #endif /* _HPPA_LOCK_H_ */ 170