mutex.h revision 1.4.8.1
1 /* $NetBSD: mutex.h,v 1.4.8.1 2007/05/27 12:27:25 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 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 #ifndef _HPPA_MUTEX_H_ 40 #define _HPPA_MUTEX_H_ 41 42 /* 43 * The HPPA mutex implementation is troublesome, because HPPA lacks 44 * a compare-and-set operation, yet there are many SMP HPPA machines 45 * in circulation. SMP for spin mutexes is easy - we don't need to 46 * know who owns the lock. For adaptive mutexes, we need an owner 47 * field and additional interlock 48 */ 49 50 #ifndef __ASSEMBLER__ 51 52 #include <machine/lock.h> 53 54 struct kmutex { 55 union { 56 /* 57 * Only the low 4 bytes of the lock will be used by 58 * __cpu_simple_lock(), but it must be aligned on a 59 * 16-byte boundary. See hppa/lock.h 60 */ 61 #ifdef __MUTEX_PRIVATE 62 __cpu_simple_lock_t mtxu_lock; /* 0-15 */ 63 struct { 64 volatile uint32_t mtxs_lockword; /* 0-3 */ 65 volatile uint32_t mtxs_owner; /* 4-7 */ 66 ipl_cookie_t mtxs_ipl; /* 8-11 */ 67 volatile uint8_t mtxs_waiters; /* 12 */ 68 69 /* For LOCKDEBUG */ 70 uint8_t mtxs_id[3]; /* 13-15 */ 71 } s; 72 #endif 73 uint8_t mtxu_pad[16]; /* 0-15 */ 74 } u; 75 } __aligned (16); 76 #endif 77 78 #ifdef __MUTEX_PRIVATE 79 80 #define __HAVE_MUTEX_STUBS 1 81 82 #define mtx_lock u.mtxu_lock 83 #define mtx_owner u.s.mtxs_owner 84 #define mtx_ipl u.s.mtxs_ipl 85 #define mtx_waiters u.s.mtxs_waiters 86 #define mtx_id u.s.mtxs_id 87 88 /* Magic constants for mtx_owner */ 89 #define MUTEX_ADAPTIVE_UNOWNED 0xffffff00 90 #define MUTEX_SPIN_FLAG 0xffffff10 91 #define MUTEX_UNOWNED_OR_SPIN(x) (((x) & 0xffffffef) == 0xffffff00) 92 93 #ifndef __ASSEMBLER__ 94 95 static inline uintptr_t 96 MUTEX_OWNER(uintptr_t owner) 97 { 98 return owner; 99 } 100 101 static inline int 102 MUTEX_OWNED(uintptr_t owner) 103 { 104 return owner != MUTEX_ADAPTIVE_UNOWNED; 105 } 106 107 static inline int 108 MUTEX_SET_WAITERS(kmutex_t *mtx, uintptr_t owner) 109 { 110 mb_write(); 111 mtx->mtx_waiters = 1; 112 mb_memory(); 113 return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED; 114 } 115 116 static inline int 117 MUTEX_HAS_WAITERS(volatile kmutex_t *mtx) 118 { 119 return mtx->mtx_waiters != 0; 120 } 121 122 static inline void 123 MUTEX_INITIALIZE_SPIN(kmutex_t *mtx, u_int id, int ipl) 124 { 125 mtx->mtx_ipl = makeiplcookie(ipl); 126 mtx->mtx_id[0] = (uint8_t)id; 127 mtx->mtx_id[1] = (uint8_t)(id >> 8); 128 mtx->mtx_id[2] = (uint8_t)(id >> 16); 129 mtx->mtx_owner = MUTEX_SPIN_FLAG; 130 __cpu_simple_lock_init(&mtx->mtx_lock); 131 } 132 133 static inline void 134 MUTEX_INITIALIZE_ADAPTIVE(kmutex_t *mtx, u_int id) 135 { 136 mtx->mtx_id[0] = (uint8_t)id; 137 mtx->mtx_id[1] = (uint8_t)(id >> 8); 138 mtx->mtx_id[2] = (uint8_t)(id >> 16); 139 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 140 __cpu_simple_lock_init(&mtx->mtx_lock); 141 } 142 143 static inline void 144 MUTEX_DESTROY(kmutex_t *mtx) 145 { 146 mtx->mtx_owner = 0xffffffff; 147 mtx->mtx_id[0] = 0xff; 148 mtx->mtx_id[1] = 0xff; 149 mtx->mtx_id[2] = 0xff; 150 } 151 152 static inline u_int 153 MUTEX_GETID(kmutex_t *mtx) 154 { 155 return (u_int)mtx->mtx_id[0] | 156 ((u_int)mtx->mtx_id[1] << 8) | 157 ((u_int)mtx->mtx_id[2] << 16); 158 } 159 160 static inline int 161 MUTEX_SPIN_P(volatile kmutex_t *mtx) 162 { 163 return mtx->mtx_owner == MUTEX_SPIN_FLAG; 164 } 165 166 static inline int 167 MUTEX_ADAPTIVE_P(volatile kmutex_t *mtx) 168 { 169 return mtx->mtx_owner != MUTEX_SPIN_FLAG; 170 } 171 172 /* Acquire an adaptive mutex */ 173 static inline int 174 MUTEX_ACQUIRE(kmutex_t *mtx, uintptr_t curthread) 175 { 176 if (!__cpu_simple_lock_try(&mtx->mtx_lock)) 177 return 0; 178 mtx->mtx_owner = curthread; 179 return 1; 180 } 181 182 /* Release an adaptive mutex */ 183 static inline void 184 MUTEX_RELEASE(kmutex_t *mtx) 185 { 186 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 187 __cpu_simple_unlock(&mtx->mtx_lock); 188 mtx->mtx_waiters = 0; 189 } 190 191 static inline void 192 MUTEX_CLEAR_WAITERS(kmutex_t *mtx) 193 { 194 mtx->mtx_waiters = 0; 195 } 196 197 #endif /* __ASSEMBLER__ */ 198 199 #endif /* __MUTEX_PRIVATE */ 200 201 #endif /* _HPPA_MUTEX_H_ */ 202
Indexes created Fri Oct 03 02:09:57 GMT 2025