1 /*- 2 * Copyright (c) 2017 Mellanox Technologies, Ltd. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 #ifndef _LINUX_WW_MUTEX_H_ 29 #define _LINUX_WW_MUTEX_H_ 30 31 #include <sys/param.h> 32 #include <sys/proc.h> 33 #include <sys/condvar.h> 34 #include <sys/kernel.h> 35 36 #include <linux/mutex.h> 37 38 struct ww_class { 39 const char *mutex_name; 40 }; 41 42 struct ww_acquire_ctx { 43 }; 44 45 struct ww_mutex { 46 struct mutex base; 47 struct cv condvar; 48 }; 49 50 #define DEFINE_WW_CLASS(name) \ 51 struct ww_class name = { \ 52 .mutex_name = mutex_name(#name "_mutex") \ 53 } 54 55 #define DEFINE_WW_MUTEX(name, ww_class) \ 56 struct ww_mutex name; \ 57 static void name##_init(void *arg) \ 58 { \ 59 ww_mutex_init(&name, &ww_class); \ 60 } \ 61 SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL) 62 63 #define ww_mutex_is_locked(_m) \ 64 sx_xlocked(&(_m)->base.sx) 65 66 #define ww_mutex_lock_slow(_m, _x) \ 67 ww_mutex_lock(_m, _x) 68 69 #define ww_mutex_lock_slow_interruptible(_m, _x) \ 70 ww_mutex_lock_interruptible(_m, _x) 71 72 static inline int __must_check 73 ww_mutex_trylock(struct ww_mutex *lock) 74 { 75 return (mutex_trylock(&lock->base)); 76 } 77 78 extern int linux_ww_mutex_lock_sub(struct ww_mutex *, int catch_signal); 79 80 static inline int 81 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) 82 { 83 if (MUTEX_SKIP()) 84 return (0); 85 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) 86 return (-EALREADY); 87 else 88 return (linux_ww_mutex_lock_sub(lock, 0)); 89 } 90 91 static inline int 92 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) 93 { 94 if (MUTEX_SKIP()) 95 return (0); 96 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) 97 return (-EALREADY); 98 else 99 return (linux_ww_mutex_lock_sub(lock, 1)); 100 } 101 102 extern void linux_ww_mutex_unlock_sub(struct ww_mutex *); 103 104 static inline void 105 ww_mutex_unlock(struct ww_mutex *lock) 106 { 107 if (MUTEX_SKIP()) 108 return; 109 else 110 linux_ww_mutex_unlock_sub(lock); 111 } 112 113 static inline void 114 ww_mutex_destroy(struct ww_mutex *lock) 115 { 116 cv_destroy(&lock->condvar); 117 mutex_destroy(&lock->base); 118 } 119 120 static inline void 121 ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class) 122 { 123 } 124 125 static inline void 126 ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class) 127 { 128 linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS); 129 cv_init(&lock->condvar, "lkpi-ww"); 130 } 131 132 static inline void 133 ww_acquire_fini(struct ww_acquire_ctx *ctx) 134 { 135 } 136 137 static inline void 138 ww_acquire_done(struct ww_acquire_ctx *ctx) 139 { 140 } 141 142 #endif /* _LINUX_WW_MUTEX_H_ */ 143