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 31 #ifndef _LINUXKPI_LINUX_WAIT_H_ 32 #define _LINUXKPI_LINUX_WAIT_H_ 33 34 #include <linux/compiler.h> 35 #include <linux/list.h> 36 #include <linux/spinlock.h> 37 #include <linux/sched.h> 38 39 #include <asm/atomic.h> 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 44 #define SKIP_SLEEP() (SCHEDULER_STOPPED() || kdb_active) 45 46 #define might_sleep() \ 47 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()") 48 49 #define might_sleep_if(cond) do { \ 50 if (cond) { might_sleep(); } \ 51 } while (0) 52 53 struct wait_queue; 54 struct wait_queue_head; 55 56 #define wait_queue_entry wait_queue 57 58 typedef struct wait_queue wait_queue_t; 59 typedef struct wait_queue_entry wait_queue_entry_t; 60 typedef struct wait_queue_head wait_queue_head_t; 61 62 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *); 63 64 /* 65 * Many API consumers directly reference these fields and those of 66 * wait_queue_head. 67 */ 68 struct wait_queue { 69 unsigned int flags; /* always 0 */ 70 void *private; 71 wait_queue_func_t *func; 72 union { 73 struct list_head task_list; /* < v4.13 */ 74 struct list_head entry; /* >= v4.13 */ 75 }; 76 }; 77 78 struct wait_queue_head { 79 spinlock_t lock; 80 union { 81 struct list_head task_list; /* < v4.13 */ 82 struct list_head head; /* >= v4.13 */ 83 }; 84 }; 85 86 /* 87 * This function is referenced by at least one DRM driver, so it may not be 88 * renamed and furthermore must be the default wait queue callback. 89 */ 90 extern wait_queue_func_t autoremove_wake_function; 91 extern wait_queue_func_t default_wake_function; 92 93 #define DEFINE_WAIT_FUNC(name, function) \ 94 wait_queue_t name = { \ 95 .private = current, \ 96 .func = function, \ 97 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 98 } 99 100 #define DEFINE_WAIT(name) \ 101 DEFINE_WAIT_FUNC(name, autoremove_wake_function) 102 103 #define DECLARE_WAITQUEUE(name, task) \ 104 wait_queue_t name = { \ 105 .private = task, \ 106 .task_list = LINUX_LIST_HEAD_INIT(name.task_list) \ 107 } 108 109 #define DECLARE_WAIT_QUEUE_HEAD(name) \ 110 wait_queue_head_t name = { \ 111 .task_list = LINUX_LIST_HEAD_INIT(name.task_list), \ 112 }; \ 113 MTX_SYSINIT(name, &(name).lock.m, spin_lock_name("wqhead"), MTX_DEF) 114 115 #define init_waitqueue_head(wqh) do { \ 116 mtx_init(&(wqh)->lock.m, spin_lock_name("wqhead"), \ 117 NULL, MTX_DEF | MTX_NEW | MTX_NOWITNESS); \ 118 INIT_LIST_HEAD(&(wqh)->task_list); \ 119 } while (0) 120 121 #define __init_waitqueue_head(wqh, name, lk) init_waitqueue_head(wqh) 122 123 void linux_init_wait_entry(wait_queue_t *, int); 124 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool); 125 126 #define init_wait_entry(wq, flags) \ 127 linux_init_wait_entry(wq, flags) 128 #define wake_up(wqh) \ 129 linux_wake_up(wqh, TASK_NORMAL, 1, false) 130 #define wake_up_all(wqh) \ 131 linux_wake_up(wqh, TASK_NORMAL, 0, false) 132 #define wake_up_locked(wqh) \ 133 linux_wake_up(wqh, TASK_NORMAL, 1, true) 134 #define wake_up_all_locked(wqh) \ 135 linux_wake_up(wqh, TASK_NORMAL, 0, true) 136 #define wake_up_interruptible(wqh) \ 137 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 1, false) 138 #define wake_up_interruptible_all(wqh) \ 139 linux_wake_up(wqh, TASK_INTERRUPTIBLE, 0, false) 140 141 int linux_wait_event_common(wait_queue_head_t *, wait_queue_t *, int, 142 unsigned int, spinlock_t *); 143 144 /* 145 * Returns -ERESTARTSYS for a signal, 0 if cond is false after timeout, 1 if 146 * cond is true after timeout, remaining jiffies (> 0) if cond is true before 147 * timeout. 148 */ 149 #define __wait_event_common(wqh, cond, timeout, state, lock) ({ \ 150 DEFINE_WAIT(__wq); \ 151 const int __timeout = ((int)(timeout)) < 1 ? 1 : (timeout); \ 152 int __start = ticks; \ 153 int __ret = 0; \ 154 \ 155 for (;;) { \ 156 linux_prepare_to_wait(&(wqh), &__wq, state); \ 157 if (cond) \ 158 break; \ 159 __ret = linux_wait_event_common(&(wqh), &__wq, \ 160 __timeout, state, lock); \ 161 if (__ret != 0) \ 162 break; \ 163 } \ 164 linux_finish_wait(&(wqh), &__wq); \ 165 if (__timeout != MAX_SCHEDULE_TIMEOUT) { \ 166 if (__ret == -EWOULDBLOCK) \ 167 __ret = !!(cond); \ 168 else if (__ret != -ERESTARTSYS) { \ 169 __ret = __timeout + __start - ticks; \ 170 /* range check return value */ \ 171 if (__ret < 1) \ 172 __ret = 1; \ 173 else if (__ret > __timeout) \ 174 __ret = __timeout; \ 175 } \ 176 } \ 177 __ret; \ 178 }) 179 180 #define wait_event(wqh, cond) do { \ 181 (void) __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 182 TASK_UNINTERRUPTIBLE, NULL); \ 183 } while (0) 184 185 #define wait_event_timeout(wqh, cond, timeout) ({ \ 186 __wait_event_common(wqh, cond, timeout, TASK_UNINTERRUPTIBLE, \ 187 NULL); \ 188 }) 189 190 #define wait_event_killable(wqh, cond) ({ \ 191 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 192 TASK_INTERRUPTIBLE, NULL); \ 193 }) 194 195 #define wait_event_interruptible(wqh, cond) ({ \ 196 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 197 TASK_INTERRUPTIBLE, NULL); \ 198 }) 199 200 #define wait_event_interruptible_timeout(wqh, cond, timeout) ({ \ 201 __wait_event_common(wqh, cond, timeout, TASK_INTERRUPTIBLE, \ 202 NULL); \ 203 }) 204 205 /* 206 * Wait queue is already locked. 207 */ 208 #define wait_event_interruptible_locked(wqh, cond) ({ \ 209 int __ret; \ 210 \ 211 spin_unlock(&(wqh).lock); \ 212 __ret = __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 213 TASK_INTERRUPTIBLE, NULL); \ 214 spin_lock(&(wqh).lock); \ 215 __ret; \ 216 }) 217 218 /* 219 * The passed spinlock is held when testing the condition. 220 */ 221 #define wait_event_interruptible_lock_irq(wqh, cond, lock) ({ \ 222 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 223 TASK_INTERRUPTIBLE, &(lock)); \ 224 }) 225 226 /* 227 * The passed spinlock is held when testing the condition. 228 */ 229 #define wait_event_lock_irq(wqh, cond, lock) ({ \ 230 __wait_event_common(wqh, cond, MAX_SCHEDULE_TIMEOUT, \ 231 TASK_UNINTERRUPTIBLE, &(lock)); \ 232 }) 233 234 static inline void 235 __add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 236 { 237 list_add(&wq->task_list, &wqh->task_list); 238 } 239 240 static inline void 241 add_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 242 { 243 244 spin_lock(&wqh->lock); 245 __add_wait_queue(wqh, wq); 246 spin_unlock(&wqh->lock); 247 } 248 249 static inline void 250 __add_wait_queue_tail(wait_queue_head_t *wqh, wait_queue_t *wq) 251 { 252 list_add_tail(&wq->task_list, &wqh->task_list); 253 } 254 255 static inline void 256 __add_wait_queue_entry_tail(wait_queue_head_t *wqh, wait_queue_entry_t *wq) 257 { 258 list_add_tail(&wq->entry, &wqh->head); 259 } 260 261 static inline void 262 __remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 263 { 264 list_del(&wq->task_list); 265 } 266 267 static inline void 268 remove_wait_queue(wait_queue_head_t *wqh, wait_queue_t *wq) 269 { 270 271 spin_lock(&wqh->lock); 272 __remove_wait_queue(wqh, wq); 273 spin_unlock(&wqh->lock); 274 } 275 276 bool linux_waitqueue_active(wait_queue_head_t *); 277 278 #define waitqueue_active(wqh) linux_waitqueue_active(wqh) 279 280 void linux_prepare_to_wait(wait_queue_head_t *, wait_queue_t *, int); 281 void linux_finish_wait(wait_queue_head_t *, wait_queue_t *); 282 283 #define prepare_to_wait(wqh, wq, state) linux_prepare_to_wait(wqh, wq, state) 284 #define finish_wait(wqh, wq) linux_finish_wait(wqh, wq) 285 286 void linux_wake_up_bit(void *, int); 287 int linux_wait_on_bit_timeout(unsigned long *, int, unsigned int, int); 288 void linux_wake_up_atomic_t(atomic_t *); 289 int linux_wait_on_atomic_t(atomic_t *, unsigned int); 290 291 #define wake_up_bit(word, bit) linux_wake_up_bit(word, bit) 292 #define wait_on_bit(word, bit, state) \ 293 linux_wait_on_bit_timeout(word, bit, state, MAX_SCHEDULE_TIMEOUT) 294 #define wait_on_bit_timeout(word, bit, state, timeout) \ 295 linux_wait_on_bit_timeout(word, bit, state, timeout) 296 #define wake_up_atomic_t(a) linux_wake_up_atomic_t(a) 297 /* 298 * All existing callers have a cb that just schedule()s. To avoid adding 299 * complexity, just emulate that internally. The prototype is different so that 300 * callers must be manually modified; a cb that does something other than call 301 * schedule() will require special treatment. 302 */ 303 #define wait_on_atomic_t(a, state) linux_wait_on_atomic_t(a, state) 304 305 struct task_struct; 306 bool linux_wake_up_state(struct task_struct *, unsigned int); 307 308 #define wake_up_process(task) linux_wake_up_state(task, TASK_NORMAL) 309 #define wake_up_state(task, state) linux_wake_up_state(task, state) 310 311 #endif /* _LINUXKPI_LINUX_WAIT_H_ */ 312