spinlock.h revision 1.3.2.2
1 1.3.2.2 snj /* $NetBSD: spinlock.h,v 1.3.2.2 2016/04/15 08:46:42 snj Exp $ */ 2 1.2 riastrad 3 1.2 riastrad /*- 4 1.2 riastrad * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 1.2 riastrad * All rights reserved. 6 1.2 riastrad * 7 1.2 riastrad * This code is derived from software contributed to The NetBSD Foundation 8 1.2 riastrad * by Taylor R. Campbell. 9 1.2 riastrad * 10 1.2 riastrad * Redistribution and use in source and binary forms, with or without 11 1.2 riastrad * modification, are permitted provided that the following conditions 12 1.2 riastrad * are met: 13 1.2 riastrad * 1. Redistributions of source code must retain the above copyright 14 1.2 riastrad * notice, this list of conditions and the following disclaimer. 15 1.2 riastrad * 2. Redistributions in binary form must reproduce the above copyright 16 1.2 riastrad * notice, this list of conditions and the following disclaimer in the 17 1.2 riastrad * documentation and/or other materials provided with the distribution. 18 1.2 riastrad * 19 1.2 riastrad * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.2 riastrad * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2 riastrad * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2 riastrad * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.2 riastrad * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.2 riastrad * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.2 riastrad * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.2 riastrad * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.2 riastrad * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.2 riastrad * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.2 riastrad * POSSIBILITY OF SUCH DAMAGE. 30 1.2 riastrad */ 31 1.2 riastrad 32 1.2 riastrad #ifndef _LINUX_SPINLOCK_H_ 33 1.2 riastrad #define _LINUX_SPINLOCK_H_ 34 1.2 riastrad 35 1.2 riastrad #include <sys/cdefs.h> 36 1.2 riastrad #include <sys/mutex.h> 37 1.2 riastrad 38 1.3.2.2 snj #include <machine/limits.h> 39 1.3.2.2 snj 40 1.3.2.1 snj #define __acquires(lock) /* XXX lockdep stuff */ 41 1.3.2.1 snj #define __releases(lock) /* XXX lockdep stuff */ 42 1.3.2.1 snj 43 1.2 riastrad typedef struct spinlock { 44 1.2 riastrad kmutex_t sl_lock; 45 1.2 riastrad } spinlock_t; 46 1.2 riastrad 47 1.2 riastrad static inline int 48 1.2 riastrad spin_is_locked(spinlock_t *spinlock) 49 1.2 riastrad { 50 1.2 riastrad return mutex_owned(&spinlock->sl_lock); 51 1.2 riastrad } 52 1.2 riastrad 53 1.2 riastrad static inline void 54 1.2 riastrad spin_lock(spinlock_t *spinlock) 55 1.2 riastrad { 56 1.2 riastrad mutex_enter(&spinlock->sl_lock); 57 1.2 riastrad } 58 1.2 riastrad 59 1.2 riastrad static inline void 60 1.2 riastrad spin_unlock(spinlock_t *spinlock) 61 1.2 riastrad { 62 1.2 riastrad mutex_exit(&spinlock->sl_lock); 63 1.2 riastrad } 64 1.2 riastrad 65 1.2 riastrad static inline void 66 1.2 riastrad spin_lock_irq(spinlock_t *spinlock) 67 1.2 riastrad { 68 1.2 riastrad spin_lock(spinlock); 69 1.2 riastrad } 70 1.2 riastrad 71 1.2 riastrad static inline void 72 1.2 riastrad spin_unlock_irq(spinlock_t *spinlock) 73 1.2 riastrad { 74 1.2 riastrad spin_unlock(spinlock); 75 1.2 riastrad } 76 1.2 riastrad 77 1.2 riastrad /* Must be a macro because the second argument is to be assigned. */ 78 1.2 riastrad #define spin_lock_irqsave(SPINLOCK, FLAGS) \ 79 1.2 riastrad do { \ 80 1.2 riastrad (FLAGS) = 0; \ 81 1.2 riastrad mutex_enter(&((spinlock_t *)(SPINLOCK))->sl_lock); \ 82 1.2 riastrad } while (0) 83 1.2 riastrad 84 1.2 riastrad static inline void 85 1.2 riastrad spin_unlock_irqrestore(spinlock_t *spinlock, unsigned long __unused flags) 86 1.2 riastrad { 87 1.2 riastrad mutex_exit(&spinlock->sl_lock); 88 1.2 riastrad } 89 1.2 riastrad 90 1.2 riastrad static inline void 91 1.2 riastrad spin_lock_init(spinlock_t *spinlock) 92 1.2 riastrad { 93 1.2 riastrad /* XXX What's the right IPL? IPL_DRM...? */ 94 1.2 riastrad mutex_init(&spinlock->sl_lock, MUTEX_DEFAULT, IPL_VM); 95 1.2 riastrad } 96 1.2 riastrad 97 1.2 riastrad /* 98 1.2 riastrad * XXX Linux doesn't ever destroy spin locks, it seems. We'll have to 99 1.2 riastrad * kludge it up. 100 1.2 riastrad */ 101 1.2 riastrad 102 1.2 riastrad static inline void 103 1.2 riastrad spin_lock_destroy(spinlock_t *spinlock) 104 1.2 riastrad { 105 1.2 riastrad mutex_destroy(&spinlock->sl_lock); 106 1.2 riastrad } 107 1.2 riastrad 108 1.2 riastrad /* This is a macro to make the panic message clearer. */ 109 1.2 riastrad #define assert_spin_locked(spinlock) \ 110 1.2 riastrad KASSERT(mutex_owned(&(spinlock)->sl_lock)) 111 1.2 riastrad 112 1.3 riastrad /* 113 1.3.2.2 snj * Stupid reader/writer spin locks. No attempt to avoid writer 114 1.3.2.2 snj * starvation. Must allow recursive readers. We use mutex and state 115 1.3.2.2 snj * instead of compare-and-swap for expedience and LOCKDEBUG support. 116 1.3 riastrad */ 117 1.3 riastrad 118 1.3.2.2 snj typedef struct linux_rwlock { 119 1.3.2.2 snj kmutex_t rw_lock; 120 1.3.2.2 snj unsigned rw_nreaders; 121 1.3.2.2 snj } rwlock_t; 122 1.3.2.2 snj 123 1.3.2.2 snj static inline void 124 1.3.2.2 snj rwlock_init(rwlock_t *rw) 125 1.3.2.2 snj { 126 1.3.2.2 snj 127 1.3.2.2 snj mutex_init(&rw->rw_lock, MUTEX_DEFAULT, IPL_VM); 128 1.3.2.2 snj rw->rw_nreaders = 0; 129 1.3.2.2 snj } 130 1.3.2.2 snj 131 1.3.2.2 snj static inline void 132 1.3.2.2 snj rwlock_destroy(rwlock_t *rw) 133 1.3.2.2 snj { 134 1.3.2.2 snj 135 1.3.2.2 snj KASSERTMSG(rw->rw_nreaders == 0, 136 1.3.2.2 snj "rwlock still held by %u readers", rw->rw_nreaders); 137 1.3.2.2 snj mutex_destroy(&rw->rw_lock); 138 1.3.2.2 snj } 139 1.3.2.2 snj 140 1.3.2.2 snj static inline void 141 1.3.2.2 snj write_lock_irq(rwlock_t *rw) 142 1.3.2.2 snj { 143 1.3.2.2 snj 144 1.3.2.2 snj for (;;) { 145 1.3.2.2 snj mutex_spin_enter(&rw->rw_lock); 146 1.3.2.2 snj if (rw->rw_nreaders == 0) 147 1.3.2.2 snj break; 148 1.3.2.2 snj mutex_spin_exit(&rw->rw_lock); 149 1.3.2.2 snj } 150 1.3.2.2 snj } 151 1.3.2.2 snj 152 1.3.2.2 snj static inline void 153 1.3.2.2 snj write_unlock_irq(rwlock_t *rw) 154 1.3.2.2 snj { 155 1.3.2.2 snj 156 1.3.2.2 snj KASSERT(rw->rw_nreaders == 0); 157 1.3.2.2 snj mutex_spin_exit(&rw->rw_lock); 158 1.3.2.2 snj } 159 1.3.2.2 snj 160 1.3.2.2 snj static inline void 161 1.3.2.2 snj read_lock(rwlock_t *rw) 162 1.3.2.2 snj { 163 1.3.2.2 snj 164 1.3.2.2 snj mutex_spin_enter(&rw->rw_lock); 165 1.3.2.2 snj KASSERT(rw->rw_nreaders < UINT_MAX); 166 1.3.2.2 snj rw->rw_nreaders++; 167 1.3.2.2 snj mutex_spin_exit(&rw->rw_lock); 168 1.3.2.2 snj } 169 1.3.2.2 snj 170 1.3.2.2 snj static inline void 171 1.3.2.2 snj read_unlock(rwlock_t *rw) 172 1.3.2.2 snj { 173 1.3.2.2 snj 174 1.3.2.2 snj mutex_spin_enter(&rw->rw_lock); 175 1.3.2.2 snj KASSERT(0 < rw->rw_nreaders); 176 1.3.2.2 snj rw->rw_nreaders--; 177 1.3.2.2 snj mutex_spin_exit(&rw->rw_lock); 178 1.3.2.2 snj } 179 1.3 riastrad 180 1.2 riastrad #endif /* _LINUX_SPINLOCK_H_ */ 181
Indexes created Thu Oct 02 14:10:14 GMT 2025