mutex.h revision 1.5.10.1
1 /* $NetBSD: mutex.h,v 1.5.10.1 2007/11/06 23:17:07 matt 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 16 bytes aligned word of __cpu_simple_lock_t will 58 * be used. It's 16 bytes to simplify the allocation. 59 * See hppa/lock.h 60 */ 61 #ifdef __MUTEX_PRIVATE 62 struct { 63 __cpu_simple_lock_t mtxu_lock; /* 0-15 */ 64 volatile uint32_t mtxs_owner; /* 16-19 */ 65 ipl_cookie_t mtxs_ipl; /* 20-23 */ 66 volatile uint8_t mtxs_waiters; /* 24 */ 67 68 /* For LOCKDEBUG */ 69 uint8_t mtxs_id[3]; /* 25-27 */ 70 } s; 71 #endif 72 uint8_t mtxu_pad[32]; /* 0 - 32 */ 73 } u; 74 } __aligned (16); 75 #endif 76 77 #ifdef __MUTEX_PRIVATE 78 79 #define __HAVE_MUTEX_STUBS 1 80 81 #define mtx_lock u.s.mtxu_lock 82 #define mtx_owner u.s.mtxs_owner 83 #define mtx_ipl u.s.mtxs_ipl 84 #define mtx_waiters u.s.mtxs_waiters 85 #define mtx_id u.s.mtxs_id 86 87 /* Magic constants for mtx_owner */ 88 #define MUTEX_ADAPTIVE_UNOWNED 0xffffff00 89 #define MUTEX_SPIN_FLAG 0xffffff10 90 #define MUTEX_UNOWNED_OR_SPIN(x) (((x) & 0xffffffef) == 0xffffff00) 91 92 #ifndef __ASSEMBLER__ 93 94 static inline uintptr_t 95 MUTEX_OWNER(uintptr_t owner) 96 { 97 return owner; 98 } 99 100 static inline int 101 MUTEX_OWNED(uintptr_t owner) 102 { 103 return owner != MUTEX_ADAPTIVE_UNOWNED; 104 } 105 106 static inline int 107 MUTEX_SET_WAITERS(kmutex_t *mtx, uintptr_t owner) 108 { 109 mb_write(); 110 mtx->mtx_waiters = 1; 111 mb_memory(); 112 return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED; 113 } 114 115 static inline int 116 MUTEX_HAS_WAITERS(volatile kmutex_t *mtx) 117 { 118 return mtx->mtx_waiters != 0; 119 } 120 121 static inline void 122 MUTEX_INITIALIZE_SPIN(kmutex_t *mtx, u_int id, int ipl) 123 { 124 mtx->mtx_ipl = makeiplcookie(ipl); 125 mtx->mtx_id[0] = (uint8_t)id; 126 mtx->mtx_id[1] = (uint8_t)(id >> 8); 127 mtx->mtx_id[2] = (uint8_t)(id >> 16); 128 mtx->mtx_owner = MUTEX_SPIN_FLAG; 129 __cpu_simple_lock_init(&mtx->mtx_lock); 130 } 131 132 static inline void 133 MUTEX_INITIALIZE_ADAPTIVE(kmutex_t *mtx, u_int id) 134 { 135 mtx->mtx_id[0] = (uint8_t)id; 136 mtx->mtx_id[1] = (uint8_t)(id >> 8); 137 mtx->mtx_id[2] = (uint8_t)(id >> 16); 138 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 139 __cpu_simple_lock_init(&mtx->mtx_lock); 140 } 141 142 static inline void 143 MUTEX_DESTROY(kmutex_t *mtx) 144 { 145 mtx->mtx_owner = 0xffffffff; 146 mtx->mtx_id[0] = 0xff; 147 mtx->mtx_id[1] = 0xff; 148 mtx->mtx_id[2] = 0xff; 149 } 150 151 static inline u_int 152 MUTEX_GETID(kmutex_t *mtx) 153 { 154 return (u_int)mtx->mtx_id[0] | 155 ((u_int)mtx->mtx_id[1] << 8) | 156 ((u_int)mtx->mtx_id[2] << 16); 157 } 158 159 static inline int 160 MUTEX_SPIN_P(volatile kmutex_t *mtx) 161 { 162 return mtx->mtx_owner == MUTEX_SPIN_FLAG; 163 } 164 165 static inline int 166 MUTEX_ADAPTIVE_P(volatile kmutex_t *mtx) 167 { 168 return mtx->mtx_owner != MUTEX_SPIN_FLAG; 169 } 170 171 /* Acquire an adaptive mutex */ 172 static inline int 173 MUTEX_ACQUIRE(kmutex_t *mtx, uintptr_t curthread) 174 { 175 if (!__cpu_simple_lock_try(&mtx->mtx_lock)) 176 return 0; 177 mtx->mtx_owner = curthread; 178 return 1; 179 } 180 181 /* Release an adaptive mutex */ 182 static inline void 183 MUTEX_RELEASE(kmutex_t *mtx) 184 { 185 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 186 __cpu_simple_unlock(&mtx->mtx_lock); 187 mtx->mtx_waiters = 0; 188 } 189 190 static inline void 191 MUTEX_CLEAR_WAITERS(kmutex_t *mtx) 192 { 193 mtx->mtx_waiters = 0; 194 } 195 196 #endif /* __ASSEMBLER__ */ 197 198 #endif /* __MUTEX_PRIVATE */ 199 200 #endif /* _HPPA_MUTEX_H_ */ 201
Indexes created Fri Oct 03 02:09:57 GMT 2025