1 /* $NetBSD: mutex.h,v 1.17 2021/12/19 11:33:31 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 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 _LINUX_MUTEX_H_ 33 #define _LINUX_MUTEX_H_ 34 35 #include <sys/mutex.h> 36 37 #include <lib/libkern/libkern.h> /* KASSERT */ 38 39 #include <asm/processor.h> 40 41 #include <linux/list.h> 42 #include <linux/spinlock.h> 43 44 struct mutex { 45 kmutex_t mtx_lock; 46 }; 47 48 struct lock_class_key { 49 }; 50 51 /* Name collision. Pooh. */ 52 static inline void 53 linux_mutex_init(struct mutex *mutex) 54 { 55 mutex_init(&mutex->mtx_lock, MUTEX_DEFAULT, IPL_NONE); 56 } 57 58 /* Lockdep stuff. */ 59 static inline void 60 __mutex_init(struct mutex *mutex, const char *name __unused, 61 struct lock_class_key *key __unused) 62 { 63 linux_mutex_init(mutex); 64 } 65 66 /* Another name collision. */ 67 static inline void 68 linux_mutex_destroy(struct mutex *mutex) 69 { 70 mutex_destroy(&mutex->mtx_lock); 71 } 72 73 static inline void 74 mutex_lock(struct mutex *mutex) 75 { 76 mutex_enter(&mutex->mtx_lock); 77 } 78 79 static inline int 80 mutex_lock_interruptible(struct mutex *mutex) 81 { 82 mutex_enter(&mutex->mtx_lock); /* XXX */ 83 return 0; 84 } 85 86 static inline int 87 mutex_trylock(struct mutex *mutex) 88 { 89 return mutex_tryenter(&mutex->mtx_lock); 90 } 91 92 static inline void 93 mutex_unlock(struct mutex *mutex) 94 { 95 mutex_exit(&mutex->mtx_lock); 96 } 97 98 static inline bool 99 mutex_is_locked(struct mutex *mutex) 100 { 101 return mutex_owned(&mutex->mtx_lock); 102 } 103 104 static inline void 105 mutex_lock_nest_lock(struct mutex *mutex, struct mutex *already) 106 { 107 108 KASSERT(mutex_is_locked(already)); 109 mutex_lock(mutex); 110 } 111 112 static inline void 113 mutex_lock_nested(struct mutex *mutex, unsigned subclass __unused) 114 { 115 mutex_lock(mutex); 116 } 117 118 static inline int 119 mutex_lock_interruptible_nested(struct mutex *mutex, 120 unsigned subclass __unused) 121 { 122 return mutex_lock_interruptible(mutex); 123 } 124 125 /* 126 * `recursive locking is bad, do not use this ever.' 127 * -- linux/scripts/checkpath.pl 128 */ 129 static inline enum { 130 MUTEX_TRYLOCK_FAILED, 131 MUTEX_TRYLOCK_SUCCESS, 132 MUTEX_TRYLOCK_RECURSIVE, 133 } 134 mutex_trylock_recursive(struct mutex *mutex) 135 { 136 if (mutex_owned(&mutex->mtx_lock)) 137 return MUTEX_TRYLOCK_RECURSIVE; 138 else if (mutex_tryenter(&mutex->mtx_lock)) 139 return MUTEX_TRYLOCK_SUCCESS; 140 else 141 return MUTEX_TRYLOCK_FAILED; 142 } 143 144 #endif /* _LINUX_MUTEX_H_ */ 145