spinlock.h revision 1.3.4.3
1 1.3.4.2 tls /* $NetBSD: spinlock.h,v 1.3.4.3 2017/12/03 11:37:59 jdolecek Exp $ */ 2 1.3.4.2 tls 3 1.3.4.2 tls /*- 4 1.3.4.2 tls * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 1.3.4.2 tls * All rights reserved. 6 1.3.4.2 tls * 7 1.3.4.2 tls * This code is derived from software contributed to The NetBSD Foundation 8 1.3.4.2 tls * by Taylor R. Campbell. 9 1.3.4.2 tls * 10 1.3.4.2 tls * Redistribution and use in source and binary forms, with or without 11 1.3.4.2 tls * modification, are permitted provided that the following conditions 12 1.3.4.2 tls * are met: 13 1.3.4.2 tls * 1. Redistributions of source code must retain the above copyright 14 1.3.4.2 tls * notice, this list of conditions and the following disclaimer. 15 1.3.4.2 tls * 2. Redistributions in binary form must reproduce the above copyright 16 1.3.4.2 tls * notice, this list of conditions and the following disclaimer in the 17 1.3.4.2 tls * documentation and/or other materials provided with the distribution. 18 1.3.4.2 tls * 19 1.3.4.2 tls * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.3.4.2 tls * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.3.4.2 tls * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.3.4.2 tls * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.3.4.2 tls * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.3.4.2 tls * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.3.4.2 tls * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.3.4.2 tls * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.3.4.2 tls * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.3.4.2 tls * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.3.4.2 tls * POSSIBILITY OF SUCH DAMAGE. 30 1.3.4.2 tls */ 31 1.3.4.2 tls 32 1.3.4.2 tls #ifndef _LINUX_SPINLOCK_H_ 33 1.3.4.2 tls #define _LINUX_SPINLOCK_H_ 34 1.3.4.2 tls 35 1.3.4.2 tls #include <sys/cdefs.h> 36 1.3.4.2 tls #include <sys/mutex.h> 37 1.3.4.2 tls 38 1.3.4.3 jdolecek #include <machine/limits.h> 39 1.3.4.3 jdolecek 40 1.3.4.3 jdolecek #define __acquires(lock) /* XXX lockdep stuff */ 41 1.3.4.3 jdolecek #define __releases(lock) /* XXX lockdep stuff */ 42 1.3.4.3 jdolecek 43 1.3.4.2 tls typedef struct spinlock { 44 1.3.4.2 tls kmutex_t sl_lock; 45 1.3.4.2 tls } spinlock_t; 46 1.3.4.2 tls 47 1.3.4.2 tls static inline int 48 1.3.4.2 tls spin_is_locked(spinlock_t *spinlock) 49 1.3.4.2 tls { 50 1.3.4.2 tls return mutex_owned(&spinlock->sl_lock); 51 1.3.4.2 tls } 52 1.3.4.2 tls 53 1.3.4.2 tls static inline void 54 1.3.4.2 tls spin_lock(spinlock_t *spinlock) 55 1.3.4.2 tls { 56 1.3.4.2 tls mutex_enter(&spinlock->sl_lock); 57 1.3.4.2 tls } 58 1.3.4.2 tls 59 1.3.4.2 tls static inline void 60 1.3.4.2 tls spin_unlock(spinlock_t *spinlock) 61 1.3.4.2 tls { 62 1.3.4.2 tls mutex_exit(&spinlock->sl_lock); 63 1.3.4.2 tls } 64 1.3.4.2 tls 65 1.3.4.2 tls static inline void 66 1.3.4.2 tls spin_lock_irq(spinlock_t *spinlock) 67 1.3.4.2 tls { 68 1.3.4.2 tls spin_lock(spinlock); 69 1.3.4.2 tls } 70 1.3.4.2 tls 71 1.3.4.2 tls static inline void 72 1.3.4.2 tls spin_unlock_irq(spinlock_t *spinlock) 73 1.3.4.2 tls { 74 1.3.4.2 tls spin_unlock(spinlock); 75 1.3.4.2 tls } 76 1.3.4.2 tls 77 1.3.4.2 tls /* Must be a macro because the second argument is to be assigned. */ 78 1.3.4.2 tls #define spin_lock_irqsave(SPINLOCK, FLAGS) \ 79 1.3.4.2 tls do { \ 80 1.3.4.2 tls (FLAGS) = 0; \ 81 1.3.4.2 tls mutex_enter(&((spinlock_t *)(SPINLOCK))->sl_lock); \ 82 1.3.4.2 tls } while (0) 83 1.3.4.2 tls 84 1.3.4.2 tls static inline void 85 1.3.4.2 tls spin_unlock_irqrestore(spinlock_t *spinlock, unsigned long __unused flags) 86 1.3.4.2 tls { 87 1.3.4.2 tls mutex_exit(&spinlock->sl_lock); 88 1.3.4.2 tls } 89 1.3.4.2 tls 90 1.3.4.2 tls static inline void 91 1.3.4.2 tls spin_lock_init(spinlock_t *spinlock) 92 1.3.4.2 tls { 93 1.3.4.2 tls /* XXX What's the right IPL? IPL_DRM...? */ 94 1.3.4.2 tls mutex_init(&spinlock->sl_lock, MUTEX_DEFAULT, IPL_VM); 95 1.3.4.2 tls } 96 1.3.4.2 tls 97 1.3.4.2 tls /* 98 1.3.4.2 tls * XXX Linux doesn't ever destroy spin locks, it seems. We'll have to 99 1.3.4.2 tls * kludge it up. 100 1.3.4.2 tls */ 101 1.3.4.2 tls 102 1.3.4.2 tls static inline void 103 1.3.4.2 tls spin_lock_destroy(spinlock_t *spinlock) 104 1.3.4.2 tls { 105 1.3.4.2 tls mutex_destroy(&spinlock->sl_lock); 106 1.3.4.2 tls } 107 1.3.4.2 tls 108 1.3.4.2 tls /* This is a macro to make the panic message clearer. */ 109 1.3.4.2 tls #define assert_spin_locked(spinlock) \ 110 1.3.4.2 tls KASSERT(mutex_owned(&(spinlock)->sl_lock)) 111 1.3.4.2 tls 112 1.3.4.2 tls /* 113 1.3.4.3 jdolecek * Stupid reader/writer spin locks. No attempt to avoid writer 114 1.3.4.3 jdolecek * starvation. Must allow recursive readers. We use mutex and state 115 1.3.4.3 jdolecek * instead of compare-and-swap for expedience and LOCKDEBUG support. 116 1.3.4.2 tls */ 117 1.3.4.2 tls 118 1.3.4.3 jdolecek typedef struct linux_rwlock { 119 1.3.4.3 jdolecek kmutex_t rw_lock; 120 1.3.4.3 jdolecek unsigned rw_nreaders; 121 1.3.4.3 jdolecek } rwlock_t; 122 1.3.4.3 jdolecek 123 1.3.4.3 jdolecek static inline void 124 1.3.4.3 jdolecek rwlock_init(rwlock_t *rw) 125 1.3.4.3 jdolecek { 126 1.3.4.3 jdolecek 127 1.3.4.3 jdolecek mutex_init(&rw->rw_lock, MUTEX_DEFAULT, IPL_VM); 128 1.3.4.3 jdolecek rw->rw_nreaders = 0; 129 1.3.4.3 jdolecek } 130 1.3.4.3 jdolecek 131 1.3.4.3 jdolecek static inline void 132 1.3.4.3 jdolecek rwlock_destroy(rwlock_t *rw) 133 1.3.4.3 jdolecek { 134 1.3.4.3 jdolecek 135 1.3.4.3 jdolecek KASSERTMSG(rw->rw_nreaders == 0, 136 1.3.4.3 jdolecek "rwlock still held by %u readers", rw->rw_nreaders); 137 1.3.4.3 jdolecek mutex_destroy(&rw->rw_lock); 138 1.3.4.3 jdolecek } 139 1.3.4.3 jdolecek 140 1.3.4.3 jdolecek static inline void 141 1.3.4.3 jdolecek write_lock_irq(rwlock_t *rw) 142 1.3.4.3 jdolecek { 143 1.3.4.3 jdolecek 144 1.3.4.3 jdolecek for (;;) { 145 1.3.4.3 jdolecek mutex_spin_enter(&rw->rw_lock); 146 1.3.4.3 jdolecek if (rw->rw_nreaders == 0) 147 1.3.4.3 jdolecek break; 148 1.3.4.3 jdolecek mutex_spin_exit(&rw->rw_lock); 149 1.3.4.3 jdolecek } 150 1.3.4.3 jdolecek } 151 1.3.4.3 jdolecek 152 1.3.4.3 jdolecek static inline void 153 1.3.4.3 jdolecek write_unlock_irq(rwlock_t *rw) 154 1.3.4.3 jdolecek { 155 1.3.4.3 jdolecek 156 1.3.4.3 jdolecek KASSERT(rw->rw_nreaders == 0); 157 1.3.4.3 jdolecek mutex_spin_exit(&rw->rw_lock); 158 1.3.4.3 jdolecek } 159 1.3.4.3 jdolecek 160 1.3.4.3 jdolecek static inline void 161 1.3.4.3 jdolecek read_lock(rwlock_t *rw) 162 1.3.4.3 jdolecek { 163 1.3.4.3 jdolecek 164 1.3.4.3 jdolecek mutex_spin_enter(&rw->rw_lock); 165 1.3.4.3 jdolecek KASSERT(rw->rw_nreaders < UINT_MAX); 166 1.3.4.3 jdolecek rw->rw_nreaders++; 167 1.3.4.3 jdolecek mutex_spin_exit(&rw->rw_lock); 168 1.3.4.3 jdolecek } 169 1.3.4.3 jdolecek 170 1.3.4.3 jdolecek static inline void 171 1.3.4.3 jdolecek read_unlock(rwlock_t *rw) 172 1.3.4.3 jdolecek { 173 1.3.4.3 jdolecek 174 1.3.4.3 jdolecek mutex_spin_enter(&rw->rw_lock); 175 1.3.4.3 jdolecek KASSERT(0 < rw->rw_nreaders); 176 1.3.4.3 jdolecek rw->rw_nreaders--; 177 1.3.4.3 jdolecek mutex_spin_exit(&rw->rw_lock); 178 1.3.4.3 jdolecek } 179 1.3.4.2 tls 180 1.3.4.2 tls #endif /* _LINUX_SPINLOCK_H_ */ 181
Indexes created Thu Oct 02 14:10:14 GMT 2025