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 #define might_sleep_if(cond) do { \ 51 if (cond) { might_sleep(); } \ 52 } while (0) 53 54 struct wait_queue; 55 struct wait_queue_head; 56 57 typedef struct wait_queue wait_queue_t; 58 typedef struct wait_queue_head wait_queue_head_t; 59 60 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *); 61 62 /* 63 * Many API consumers directly reference these fields and those of 64 * wait_queue_head. 65 */ 66 struct wait_queue { 67 unsigned int flags; /* always 0 */ 68 void *private; 69 wait_queue_func_t *func; 70 union { 71 struct list_head task_list; /* < v4.13 */ 72 struct list_head entry; /* >= v4.13 */ 73 }; 74 }; 75 76 struct wait_queue_head { 77 spinlock_t lock; 78 union { 79 struct list_head task_list; /* < v4.13 */ 80 struct list_head head; /* >= v4.13 */ 81 }; 82 }; 83 84 /* 85 * This function is referenced by at least one DRM driver, so it may not be 86 * renamed and furthermore must be the default wait queue callback. 87 */ 88 extern wait_queue_func_t autoremove_wake_function; 89 extern wait_queue_func_t default_wake_function; 90 91 #define DEFINE_WAIT_FUNC(name, function) \ 92 wait_queue_t name = { \ 93 .private = current, \ 94 .func = function, \ 95 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 96 } 97 98 #define DEFINE_WAIT(name) \ 99 DEFINE_WAIT_FUNC(name, autoremove_wake_function) 100 101 #define DECLARE_WAITQUEUE(name, task) \ 102 wait_queue_t name = { \ 103 .private = task, \ 104 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 105 } 106 107 #define DECLARE_WAIT_QUEUE_HEAD(name) \ 108 wait_queue_head_t name = { \ 109 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \ 110 }; \ 111 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF) 112 113 #define init_waitqueue_head(wqh) do { \ 114 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \ 115 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \ 116 INIT_LIST_HEAD(&(wqh)->task_list); \ 117 } while (0) 118 119 void linux_init_wait_entry(wait_queue_t *, int); 120 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool); 121 122 #define init_wait_entry(wq, flags) \ 123 linux_init_wait_entry(wq, flags) 124 #define wake_up(wqh) \ 125 linux_wake_up(wqh, TASK_NORMAL, 1, false) 126 #define wake_up_all(wqh) \ 127 linux_wake_up(wqh, TASK_NORMAL, 0, false) 128 #define wake_up_locked(wqh) \ 129 linux_wake_up(wqh, TASK_NORMAL, 1, true) 130 #define wake_up_all_locked(wqh) \ 131 linux_wake_up(wqh, TASK_NORMAL, 0, true) 132 #define wake_up_interruptible(wqh) \ 133 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false) 134 #define wake_up_interruptible_all(wqh) \ 135 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false) 136 137 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int, 138 unsigned int, spinlock_t *); 139 140 /* 141 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if 142 * cond is true after timeout, remaining jiffies (> 0) if cond is true before 143 * timeout. 144 */ 145 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \ 146 DEFINE_WAIT(__wq); \ 147 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \ 148 int __start = ticks; \ 149 int __ret = 0; \ 150 \ 151 for (;;) { \ 152 linux_prepare_to_wait(&(wqh), &__wq, state); \ 153 if (cond) \ 154 break; \ 155 __ret = linux_wait_event_common(&(wqh), &__wq, \ 156 __timeout, state, lock); \ 157 if (__ret != 0) \ 158 break; \ 159 } \ 160 linux_finish_wait(&(wqh), &__wq); \ 161 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \ 162 if (__ret == -EWOULDBLOCK) \ 163 __ret = !!(cond); \ 164 else if (__ret != -ERESTARTSYS) { \ 165 __ret = __timeout + __start - ticks; \ 166 /* range check return value */ \ 167 if (__ret < 1) \ 168 __ret = 1; \ 169 else if (__ret > __timeout) \ 170 __ret = __timeout; \ 171 } \ 172 } \ 173 __ret; \ 174 }) 175 176 #define wait_event(wqh, cond) do { \ 177 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 178 TASK_UNINTERRUPTIBLE, NULL); \ 179 } while (0) 180 181 #define wait_event_timeout(wqh, cond, timeout) ({ \ 182 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \ 183 NULL); \ 184 }) 185 186 #define wait_event_killable(wqh, cond) ({ \ 187 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 188 TASK_INTERRUPTIBLE, NULL); \ 189 }) 190 191 #define wait_event_interruptible(wqh, cond) ({ \ 192 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 193 TASK_INTERRUPTIBLE, NULL); \ 194 }) 195 196 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \ 197 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \ 198 NULL); \ 199 }) 200 201 /* 202 * Wait queue is already locked. 203 */ 204 #define wait_event_interruptible_locked(wqh, cond) ({ \ 205 int __ret; \ 206 \ 207 spin_unlock(&(wqh).lock); \ 208 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 209 TASK_INTERRUPTIBLE, NULL); \ 210 spin_lock(&(wqh).lock); \ 211 __ret; \ 212 }) 213 214 /* 215 * The passed spinlock is held when testing the condition. 216 */ 217 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \ 218 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 219 TASK_INTERRUPTIBLE, &(lock)); \ 220 }) 221 222 /* 223 * The passed spinlock is held when testing the condition. 224 */ 225 #define wait_event_lock_irq(wqh, cond, lock) ({ \ 226 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 227 TASK_UNINTERRUPTIBLE, &(lock)); \ 228 }) 229 230 static inline void 231 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 232 { 233 list_add(&wq->task_list, &wqh->task_list); 234 } 235 236 static inline void 237 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 238 { 239 240 spin_lock(&wqh->lock); 241 __add_wait_queue(wqh, wq); 242 spin_unlock(&wqh->lock); 243 } 244 245 static inline void 246 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq) 247 { 248 list_add_tail(&wq->task_list, &wqh->task_list); 249 } 250 251 static inline void 252 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 253 { 254 list_del(&wq->task_list); 255 } 256 257 static inline void 258 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 259 { 260 261 spin_lock(&wqh->lock); 262 __remove_wait_queue(wqh, wq); 263 spin_unlock(&wqh->lock); 264 } 265 266 bool linux_waitqueue_active(wait_queue_head_t *); 267 268 #define waitqueue_active(wqh) linux_waitqueue_active(wqh) 269 270 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int); 271 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *); 272 273 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state) 274 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq) 275 276 void linux_wake_up_bit(void *, int); 277 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int); 278 void linux_wake_up_atomic_t(atomic_t *); 279 int linux_wait_on_atomic_t(atomic_t *, unsigned int); 280 281 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit) 282 #define wait_on_bit(word, bit, state) \ 283 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT) 284 #define wait_on_bit_timeout(word, bit, state, timeout) \ 285 linux_wait_on_bit_timeout(word, bit, state, timeout) 286 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a) 287 /* 288 * All existing callers have a cb that just schedule()s. To avoid adding 289 * complexity, just emulate that internally. The prototype is different so that 290 * callers must be manually modified; a cb that does something other than call 291 * schedule() will require special treatment. 292 */ 293 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state) 294 295 struct task_struct; 296 bool linux_wake_up_state(struct task_struct *, unsigned int); 297 298 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL) 299 #define wake_up_state(task, state) linux_wake_up_state(task, state) 300 301 #endif /* _LINUX_WAIT_H_ */ 302