1 /* $NetBSD: mutex.h,v 1.19 2023/07/13 07:46:43 mrg 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _HPPA_MUTEX_H_ 33 #define _HPPA_MUTEX_H_ 34 35 /* 36 * The HPPA mutex implementation is troublesome, because HPPA lacks 37 * a compare-and-set operation, yet there are many SMP HPPA machines 38 * in circulation. SMP for spin mutexes is easy - we don't need to 39 * know who owns the lock. For adaptive mutexes, we need an owner 40 * field and additional interlock 41 */ 42 43 #ifndef __ASSEMBLER__ 44 45 #include <sys/types.h> 46 47 #ifdef __MUTEX_PRIVATE 48 #include <machine/lock.h> 49 #include <machine/intr.h> 50 #endif 51 52 struct kmutex { 53 union { 54 /* 55 * Only the 16 bytes aligned word of __cpu_simple_lock_t will 56 * be used. It's 16 bytes to simplify the allocation. 57 * See hppa/lock.h 58 */ 59 #ifdef __MUTEX_PRIVATE 60 struct { 61 __cpu_simple_lock_t mtxu_lock; /* 0-15 */ 62 volatile uint32_t mtxs_owner; /* 16-19 */ 63 ipl_cookie_t mtxs_ipl; /* 20-23 */ 64 volatile uint8_t mtxs_waiters; /* 24 */ 65 66 /* For LOCKDEBUG */ 67 uint8_t mtxs_dodebug; /* 25 */ 68 } s; 69 #endif 70 uint8_t mtxu_pad[32]; /* 0 - 32 */ 71 } u; 72 } __aligned (16); 73 #endif 74 75 #ifdef __MUTEX_PRIVATE 76 77 #define __HAVE_MUTEX_STUBS 1 78 79 #define mtx_lock u.s.mtxu_lock 80 #define mtx_owner u.s.mtxs_owner 81 #define mtx_ipl u.s.mtxs_ipl 82 #define mtx_waiters u.s.mtxs_waiters 83 #define mtx_dodebug u.s.mtxs_dodebug 84 85 /* Magic constants for mtx_owner */ 86 #define MUTEX_ADAPTIVE_UNOWNED 0xffffff00 87 #define MUTEX_SPIN_FLAG 0xffffff10 88 #define MUTEX_UNOWNED_OR_SPIN(x) (((x) & 0xffffffef) == 0xffffff00) 89 90 #if !defined(__ASSEMBLER__) && defined(_KERNEL) 91 92 static inline uintptr_t 93 MUTEX_OWNER(uintptr_t owner) 94 { 95 return owner; 96 } 97 98 static inline int 99 MUTEX_OWNED(uintptr_t owner) 100 { 101 return owner != MUTEX_ADAPTIVE_UNOWNED; 102 } 103 104 static inline int 105 MUTEX_SET_WAITERS(struct kmutex *mtx, uintptr_t owner) 106 { 107 __sync(); /* formerly mb_read */ 108 mtx->mtx_waiters = 1; 109 __sync(); /* formerly mb_memory */ 110 return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED; 111 } 112 113 static inline int 114 MUTEX_HAS_WAITERS(const volatile struct kmutex *mtx) 115 { 116 return mtx->mtx_waiters != 0; 117 } 118 119 static inline void 120 MUTEX_INITIALIZE_SPIN(struct kmutex *mtx, bool dodebug, int ipl) 121 { 122 mtx->mtx_ipl = makeiplcookie(ipl); 123 mtx->mtx_dodebug = dodebug; 124 mtx->mtx_owner = MUTEX_SPIN_FLAG; 125 __cpu_simple_lock_init(&mtx->mtx_lock); 126 } 127 128 static inline void 129 MUTEX_INITIALIZE_ADAPTIVE(struct kmutex *mtx, bool dodebug) 130 { 131 mtx->mtx_dodebug = dodebug; 132 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 133 __cpu_simple_lock_init(&mtx->mtx_lock); 134 } 135 136 static inline void 137 MUTEX_DESTROY(struct kmutex *mtx) 138 { 139 mtx->mtx_owner = 0xffffffff; 140 } 141 142 static inline bool 143 MUTEX_DEBUG_P(const volatile struct kmutex *mtx) 144 { 145 return mtx->mtx_dodebug != 0; 146 } 147 148 static inline int 149 MUTEX_SPIN_P(const uintptr_t owner) 150 { 151 return owner == MUTEX_SPIN_FLAG; 152 } 153 154 static inline int 155 MUTEX_ADAPTIVE_P(const uintptr_t owner) 156 { 157 return owner != MUTEX_SPIN_FLAG; 158 } 159 160 /* Acquire an adaptive mutex */ 161 static inline int 162 MUTEX_ACQUIRE(struct kmutex *mtx, uintptr_t curthread) 163 { 164 if (!__cpu_simple_lock_try(&mtx->mtx_lock)) 165 return 0; 166 mtx->mtx_owner = curthread; 167 return 1; 168 } 169 170 /* Release an adaptive mutex */ 171 static inline void 172 MUTEX_RELEASE(struct kmutex *mtx) 173 { 174 mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; 175 __cpu_simple_unlock(&mtx->mtx_lock); 176 mtx->mtx_waiters = 0; 177 } 178 179 static inline void 180 MUTEX_CLEAR_WAITERS(struct kmutex *mtx) 181 { 182 mtx->mtx_waiters = 0; 183 } 184 185 #endif /* !__ASSEMBLER__ && _KERNEL */ 186 187 #endif /* __MUTEX_PRIVATE */ 188 189 #endif /* _HPPA_MUTEX_H_ */ 190
Indexes created Tue Sep 30 07:10:03 GMT 2025