mutex.h revision 1.4.8.3
1 /* $NetBSD: mutex.h,v 1.4.8.3 2007/12/03 18:36:19 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 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_dodebug; /* 25 */ 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_dodebug u.s.mtxs_dodebug 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, bool dodebug, int ipl) 123 { 124 mtx->mtx_ipl = makeiplcookie(ipl); 125 mtx->mtx_dodebug = dodebug; 126 mtx->mtx_owner = MUTEX_SPIN_FLAG; 127 __cpu_simple_lock_init(&mtx->mtx_lock); 128 } 129 130 static inline void 131 MUTEX_INITIALIZE_ADAPTIVE(kmutex_t *mtx, bool dodebug) 132 { 133 mtx->mtx_dodebug = dodebug; 134 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 135 __cpu_simple_lock_init(&mtx->mtx_lock); 136 } 137 138 static inline void 139 MUTEX_DESTROY(kmutex_t *mtx) 140 { 141 mtx->mtx_owner = 0xffffffff; 142 } 143 144 static inline bool 145 MUTEX_DEBUG_P(kmutex_t *mtx) 146 { 147 return mtx->mtx_dodebug != 0; 148 } 149 150 static inline int 151 MUTEX_SPIN_P(volatile kmutex_t *mtx) 152 { 153 return mtx->mtx_owner == MUTEX_SPIN_FLAG; 154 } 155 156 static inline int 157 MUTEX_ADAPTIVE_P(volatile kmutex_t *mtx) 158 { 159 return mtx->mtx_owner != MUTEX_SPIN_FLAG; 160 } 161 162 /* Acquire an adaptive mutex */ 163 static inline int 164 MUTEX_ACQUIRE(kmutex_t *mtx, uintptr_t curthread) 165 { 166 if (!__cpu_simple_lock_try(&mtx->mtx_lock)) 167 return 0; 168 mtx->mtx_owner = curthread; 169 return 1; 170 } 171 172 /* Release an adaptive mutex */ 173 static inline void 174 MUTEX_RELEASE(kmutex_t *mtx) 175 { 176 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 177 __cpu_simple_unlock(&mtx->mtx_lock); 178 mtx->mtx_waiters = 0; 179 } 180 181 static inline void 182 MUTEX_CLEAR_WAITERS(kmutex_t *mtx) 183 { 184 mtx->mtx_waiters = 0; 185 } 186 187 #endif /* __ASSEMBLER__ */ 188 189 #endif /* __MUTEX_PRIVATE */ 190 191 #endif /* _HPPA_MUTEX_H_ */ 192
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