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 struct ww_acquire_ctx *ctx; 49 }; 50 51 #define DEFINE_WW_CLASS(name) \ 52 struct ww_class name = { \ 53 .mutex_name = mutex_name(#name "_mutex") \ 54 } 55 56 #define DEFINE_WW_MUTEX(name, ww_class) \ 57 struct ww_mutex name; \ 58 static void name##_init(void *arg) \ 59 { \ 60 ww_mutex_init(&name, &ww_class); \ 61 } \ 62 SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL) 63 64 #define ww_mutex_is_locked(_m) \ 65 sx_xlocked(&(_m)->base.sx) 66 67 #define ww_mutex_lock_slow(_m, _x) \ 68 ww_mutex_lock(_m, _x) 69 70 #define ww_mutex_lock_slow_interruptible(_m, _x) \ 71 ww_mutex_lock_interruptible(_m, _x) 72 73 static inline int __must_check 74 ww_mutex_trylock(struct ww_mutex *lock) 75 { 76 return (mutex_trylock(&lock->base)); 77 } 78 79 extern int linux_ww_mutex_lock_sub(struct ww_mutex *, int catch_signal); 80 81 static inline int 82 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) 83 { 84 if (MUTEX_SKIP()) 85 return (0); 86 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) 87 return (-EALREADY); 88 else 89 return (linux_ww_mutex_lock_sub(lock, 0)); 90 } 91 92 static inline int 93 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) 94 { 95 if (MUTEX_SKIP()) 96 return (0); 97 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) 98 return (-EALREADY); 99 else 100 return (linux_ww_mutex_lock_sub(lock, 1)); 101 } 102 103 extern void linux_ww_mutex_unlock_sub(struct ww_mutex *); 104 105 static inline void 106 ww_mutex_unlock(struct ww_mutex *lock) 107 { 108 if (MUTEX_SKIP()) 109 return; 110 else 111 linux_ww_mutex_unlock_sub(lock); 112 } 113 114 static inline void 115 ww_mutex_destroy(struct ww_mutex *lock) 116 { 117 cv_destroy(&lock->condvar); 118 mutex_destroy(&lock->base); 119 } 120 121 static inline void 122 ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class) 123 { 124 } 125 126 static inline void 127 ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class) 128 { 129 linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS); 130 cv_init(&lock->condvar, "lkpi-ww"); 131 } 132 133 static inline void 134 ww_acquire_fini(struct ww_acquire_ctx *ctx) 135 { 136 } 137 138 static inline void 139 ww_acquire_done(struct ww_acquire_ctx *ctx) 140 { 141 } 142 143 #endif /* _LINUX_WW_MUTEX_H_ */ 144