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 #ifndef _LINUXKPI_LINUX_WW_MUTEX_H_ 27 #define _LINUXKPI_LINUX_WW_MUTEX_H_ 28 29 #include <sys/param.h> 30 #include <sys/proc.h> 31 #include <sys/condvar.h> 32 #include <sys/kernel.h> 33 34 #include <linux/mutex.h> 35 36 struct ww_class { 37 const char *mutex_name; 38 }; 39 40 struct ww_acquire_ctx { 41 }; 42 43 struct ww_mutex { 44 struct mutex base; 45 struct cv condvar; 46 struct ww_acquire_ctx *ctx; 47 }; 48 49 #define DEFINE_WW_CLASS(name) \ 50 struct ww_class name = { \ 51 .mutex_name = mutex_name(#name "_mutex") \ 52 } 53 54 #define DEFINE_WW_MUTEX(name, ww_class) \ 55 struct ww_mutex name; \ 56 static void name##_init(void *arg) \ 57 { \ 58 ww_mutex_init(&name, &ww_class); \ 59 } \ 60 SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL) 61 62 #define DEFINE_WD_CLASS(name) DEFINE_WW_CLASS(name) 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 #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51600 74 static inline int __must_check 75 ww_mutex_trylock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx __unused) 76 #else 77 static inline int __must_check 78 ww_mutex_trylock(struct ww_mutex *lock) 79 #endif 80 { 81 return (mutex_trylock(&lock->base)); 82 } 83 84 extern int linux_ww_mutex_lock_sub(struct ww_mutex *, 85 struct ww_acquire_ctx *, int catch_signal); 86 87 static inline int 88 ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) 89 { 90 if (MUTEX_SKIP()) 91 return (0); 92 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) 93 return (-EALREADY); 94 else 95 return (linux_ww_mutex_lock_sub(lock, ctx, 0)); 96 } 97 98 static inline int 99 ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) 100 { 101 if (MUTEX_SKIP()) 102 return (0); 103 else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) 104 return (-EALREADY); 105 else 106 return (linux_ww_mutex_lock_sub(lock, ctx, 1)); 107 } 108 109 extern void linux_ww_mutex_unlock_sub(struct ww_mutex *); 110 111 static inline void 112 ww_mutex_unlock(struct ww_mutex *lock) 113 { 114 if (MUTEX_SKIP()) 115 return; 116 else 117 linux_ww_mutex_unlock_sub(lock); 118 } 119 120 static inline void 121 ww_mutex_destroy(struct ww_mutex *lock) 122 { 123 cv_destroy(&lock->condvar); 124 mutex_destroy(&lock->base); 125 } 126 127 static inline void 128 ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class) 129 { 130 } 131 132 static inline void 133 ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class) 134 { 135 linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS); 136 cv_init(&lock->condvar, "lkpi-ww"); 137 } 138 139 static inline void 140 ww_acquire_fini(struct ww_acquire_ctx *ctx) 141 { 142 } 143 144 static inline void 145 ww_acquire_done(struct ww_acquire_ctx *ctx) 146 { 147 } 148 149 #endif /* _LINUXKPI_LINUX_WW_MUTEX_H_ */ 150