mutex.h revision 1.1.2.6
1 /* $NetBSD: mutex.h,v 1.1.2.6 2007/02/06 22:22:29 skrll 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 #ifndef __ASSEMBLER__ 50 struct kmutex { 51 union { 52 /* 53 * Only the low 4 bytes of the lock will be used by 54 * __cpu_simple_lock(), but it must be aligned on a 55 * 16-byte boundary. See hppa/lock.h 56 */ 57 #ifdef __MUTEX_PRIVATE 58 __cpu_simple_lock_t mtxu_lock; /* 0-15 */ 59 struct { 60 volatile uint32_t mtxs_lockword; /* 0-3 */ 61 volatile uint32_t mtxs_owner; /* 4-7 */ 62 ipl_cookie_t mtxs_ipl; /* 8-11 */ 63 volatile uint8_t mtxs_waiters; /* 12 */ 64 65 /* For LOCKDEBUG */ 66 uint8_t mtxs_id[3]; /* 13-15 */ 67 } s; 68 #endif 69 uint8_t mtxu_pad[16]; /* 0-15 */ 70 } u; 71 } __aligned (16); 72 #endif 73 74 #ifdef __MUTEX_PRIVATE 75 76 #define __HAVE_MUTEX_STUBS 1 77 78 #define mtx_lock u.mtxu_lock 79 #define mtx_owner u.s.mtxs_owner 80 #define mtx_ipl u.s.mtxs_ipl 81 #define mtx_waiters u.s.mtxs_waiters 82 #define mtx_id u.s.mtxs_id 83 84 /* Magic constants for mtx_owner */ 85 #define MUTEX_ADAPTIVE_UNOWNED 0xffffff00 86 #define MUTEX_SPIN_FLAG 0xffffff10 87 #define MUTEX_UNOWNED_OR_SPIN(x) (((x) & 0xffffffef) == 0xffffff00) 88 89 #ifndef __ASSEMBLER__ 90 91 static inline uintptr_t 92 MUTEX_OWNER(uintptr_t owner) 93 { 94 return owner; 95 } 96 97 static inline int 98 MUTEX_OWNED(uintptr_t owner) 99 { 100 return owner != MUTEX_ADAPTIVE_UNOWNED; 101 } 102 103 static inline int 104 MUTEX_SET_WAITERS(kmutex_t *mtx, uintptr_t owner) 105 { 106 mb_write(); 107 mtx->mtx_waiters = 1; 108 mb_memory(); 109 return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED; 110 } 111 112 static inline int 113 MUTEX_HAS_WAITERS(volatile kmutex_t *mtx) 114 { 115 return mtx->mtx_waiters != 0; 116 } 117 118 static inline void 119 MUTEX_INITIALIZE_SPIN(kmutex_t *mtx, u_int id, int ipl) 120 { 121 mtx->mtx_ipl = makeiplcookie(ipl); 122 mtx->mtx_id[0] = (uint8_t)id; 123 mtx->mtx_id[1] = (uint8_t)(id >> 8); 124 mtx->mtx_id[2] = (uint8_t)(id >> 16); 125 mtx->mtx_owner = MUTEX_SPIN_FLAG; 126 __cpu_simple_lock_init(&mtx->mtx_lock); 127 } 128 129 static inline void 130 MUTEX_INITIALIZE_ADAPTIVE(kmutex_t *mtx, u_int id) 131 { 132 mtx->mtx_id[0] = (uint8_t)id; 133 mtx->mtx_id[1] = (uint8_t)(id >> 8); 134 mtx->mtx_id[2] = (uint8_t)(id >> 16); 135 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 136 __cpu_simple_lock_init(&mtx->mtx_lock); 137 } 138 139 static inline void 140 MUTEX_DESTROY(kmutex_t *mtx) 141 { 142 mtx->mtx_waiters = 1; 143 mtx->mtx_id[0] = 0xff; 144 mtx->mtx_id[1] = 0xff; 145 mtx->mtx_id[2] = 0xff; 146 } 147 148 static inline u_int 149 MUTEX_GETID(kmutex_t *mtx) 150 { 151 return (u_int)mtx->mtx_id[0] | 152 ((u_int)mtx->mtx_id[1] << 8) | 153 ((u_int)mtx->mtx_id[2] << 16); 154 } 155 156 static inline int 157 MUTEX_SPIN_P(volatile kmutex_t *mtx) 158 { 159 return mtx->mtx_owner == MUTEX_SPIN_FLAG; 160 } 161 162 static inline int 163 MUTEX_ADAPTIVE_P(volatile kmutex_t *mtx) 164 { 165 return mtx->mtx_owner != MUTEX_SPIN_FLAG; 166 } 167 168 /* Acquire an adaptive mutex */ 169 static inline int 170 MUTEX_ACQUIRE(kmutex_t *mtx, uintptr_t curthread) 171 { 172 if (!__cpu_simple_lock_try(&mtx->mtx_lock)) 173 return 0; 174 mtx->mtx_owner = curthread; 175 return 1; 176 } 177 178 /* Release an adaptive mutex */ 179 static inline void 180 MUTEX_RELEASE(kmutex_t *mtx) 181 { 182 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 183 __cpu_simple_unlock(&mtx->mtx_lock); 184 mtx->mtx_waiters = 0; 185 } 186 187 #endif /* __ASSEMBLER__ */ 188 189 #endif /* __MUTEX_PRIVATE */ 190 191 #endif /* _HPPA_MUTEX_H_ */ 192
Indexes created Fri Oct 03 02:09:57 GMT 2025