1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. 6 * Copyright (c) 2017 Mark Johnston <markj@FreeBSD.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice unmodified, this list of conditions, and the following 14 * 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #ifndef _LINUX_WAIT_H_ 34 #define _LINUX_WAIT_H_ 35 36 #include <linux/compiler.h> 37 #include <linux/list.h> 38 #include <linux/spinlock.h> 39 40 #include <asm/atomic.h> 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 45 #define SKIP_SLEEP() (SCHEDULER_STOPPED() || kdb_active) 46 47 #define might_sleep() \ 48 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()") 49 50 struct wait_queue; 51 struct wait_queue_head; 52 53 typedef struct wait_queue wait_queue_t; 54 typedef struct wait_queue_head wait_queue_head_t; 55 56 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *); 57 58 /* 59 * Many API consumers directly reference these fields and those of 60 * wait_queue_head. 61 */ 62 struct wait_queue { 63 unsigned int flags; /* always 0 */ 64 void *private; 65 wait_queue_func_t *func; 66 union { 67 struct list_head task_list; /* < v4.13 */ 68 struct list_head entry; /* >= v4.13 */ 69 }; 70 }; 71 72 struct wait_queue_head { 73 spinlock_t lock; 74 union { 75 struct list_head task_list; /* < v4.13 */ 76 struct list_head head; /* >= v4.13 */ 77 }; 78 }; 79 80 /* 81 * This function is referenced by at least one DRM driver, so it may not be 82 * renamed and furthermore must be the default wait queue callback. 83 */ 84 extern wait_queue_func_t autoremove_wake_function; 85 extern wait_queue_func_t default_wake_function; 86 87 #define DEFINE_WAIT_FUNC(name, function) \ 88 wait_queue_t name = { \ 89 .private = current, \ 90 .func = function, \ 91 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 92 } 93 94 #define DEFINE_WAIT(name) \ 95 DEFINE_WAIT_FUNC(name, autoremove_wake_function) 96 97 #define DECLARE_WAITQUEUE(name, task) \ 98 wait_queue_t name = { \ 99 .private = task, \ 100 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 101 } 102 103 #define DECLARE_WAIT_QUEUE_HEAD(name) \ 104 wait_queue_head_t name = { \ 105 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \ 106 }; \ 107 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF) 108 109 #define init_waitqueue_head(wqh) do { \ 110 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \ 111 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \ 112 INIT_LIST_HEAD(&(wqh)->task_list); \ 113 } while (0) 114 115 void linux_init_wait_entry(wait_queue_t *, int); 116 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool); 117 118 #define init_wait_entry(wq, flags) \ 119 linux_init_wait_entry(wq, flags) 120 #define wake_up(wqh) \ 121 linux_wake_up(wqh, TASK_NORMAL, 1, false) 122 #define wake_up_all(wqh) \ 123 linux_wake_up(wqh, TASK_NORMAL, 0, false) 124 #define wake_up_locked(wqh) \ 125 linux_wake_up(wqh, TASK_NORMAL, 1, true) 126 #define wake_up_all_locked(wqh) \ 127 linux_wake_up(wqh, TASK_NORMAL, 0, true) 128 #define wake_up_interruptible(wqh) \ 129 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false) 130 #define wake_up_interruptible_all(wqh) \ 131 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false) 132 133 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int, 134 unsigned int, spinlock_t *); 135 136 /* 137 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if 138 * cond is true after timeout, remaining jiffies (> 0) if cond is true before 139 * timeout. 140 */ 141 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \ 142 DEFINE_WAIT(__wq); \ 143 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \ 144 int __start = ticks; \ 145 int __ret = 0; \ 146 \ 147 for (;;) { \ 148 linux_prepare_to_wait(&(wqh), &__wq, state); \ 149 if (cond) \ 150 break; \ 151 __ret = linux_wait_event_common(&(wqh), &__wq, \ 152 __timeout, state, lock); \ 153 if (__ret != 0) \ 154 break; \ 155 } \ 156 linux_finish_wait(&(wqh), &__wq); \ 157 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \ 158 if (__ret == -EWOULDBLOCK) \ 159 __ret = !!(cond); \ 160 else if (__ret != -ERESTARTSYS) { \ 161 __ret = __timeout + __start - ticks; \ 162 /* range check return value */ \ 163 if (__ret < 1) \ 164 __ret = 1; \ 165 else if (__ret > __timeout) \ 166 __ret = __timeout; \ 167 } \ 168 } \ 169 __ret; \ 170 }) 171 172 #define wait_event(wqh, cond) do { \ 173 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 174 TASK_UNINTERRUPTIBLE, NULL); \ 175 } while (0) 176 177 #define wait_event_timeout(wqh, cond, timeout) ({ \ 178 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \ 179 NULL); \ 180 }) 181 182 #define wait_event_killable(wqh, cond) ({ \ 183 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 184 TASK_INTERRUPTIBLE, NULL); \ 185 }) 186 187 #define wait_event_interruptible(wqh, cond) ({ \ 188 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 189 TASK_INTERRUPTIBLE, NULL); \ 190 }) 191 192 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \ 193 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \ 194 NULL); \ 195 }) 196 197 /* 198 * Wait queue is already locked. 199 */ 200 #define wait_event_interruptible_locked(wqh, cond) ({ \ 201 int __ret; \ 202 \ 203 spin_unlock(&(wqh).lock); \ 204 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 205 TASK_INTERRUPTIBLE, NULL); \ 206 spin_lock(&(wqh).lock); \ 207 __ret; \ 208 }) 209 210 /* 211 * The passed spinlock is held when testing the condition. 212 */ 213 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \ 214 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 215 TASK_INTERRUPTIBLE, &(lock)); \ 216 }) 217 218 /* 219 * The passed spinlock is held when testing the condition. 220 */ 221 #define wait_event_lock_irq(wqh, cond, lock) ({ \ 222 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 223 TASK_UNINTERRUPTIBLE, &(lock)); \ 224 }) 225 226 static inline void 227 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 228 { 229 list_add(&wq->task_list, &wqh->task_list); 230 } 231 232 static inline void 233 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 234 { 235 236 spin_lock(&wqh->lock); 237 __add_wait_queue(wqh, wq); 238 spin_unlock(&wqh->lock); 239 } 240 241 static inline void 242 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq) 243 { 244 list_add_tail(&wq->task_list, &wqh->task_list); 245 } 246 247 static inline void 248 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 249 { 250 list_del(&wq->task_list); 251 } 252 253 static inline void 254 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 255 { 256 257 spin_lock(&wqh->lock); 258 __remove_wait_queue(wqh, wq); 259 spin_unlock(&wqh->lock); 260 } 261 262 bool linux_waitqueue_active(wait_queue_head_t *); 263 264 #define waitqueue_active(wqh) linux_waitqueue_active(wqh) 265 266 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int); 267 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *); 268 269 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state) 270 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq) 271 272 void linux_wake_up_bit(void *, int); 273 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int); 274 void linux_wake_up_atomic_t(atomic_t *); 275 int linux_wait_on_atomic_t(atomic_t *, unsigned int); 276 277 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit) 278 #define wait_on_bit(word, bit, state) \ 279 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT) 280 #define wait_on_bit_timeout(word, bit, state, timeout) \ 281 linux_wait_on_bit_timeout(word, bit, state, timeout) 282 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a) 283 /* 284 * All existing callers have a cb that just schedule()s. To avoid adding 285 * complexity, just emulate that internally. The prototype is different so that 286 * callers must be manually modified; a cb that does something other than call 287 * schedule() will require special treatment. 288 */ 289 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state) 290 291 struct task_struct; 292 bool linux_wake_up_state(struct task_struct *, unsigned int); 293 294 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL) 295 #define wake_up_state(task, state) linux_wake_up_state(task, state) 296 297 #endif /* _LINUX_WAIT_H_ */ 298