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wait.h
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linux-6.19.14/include/linux/wait.h
1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _LINUX_WAIT_H 3#define _LINUX_WAIT_H 4/* 5 * Linux wait queue related types and methods 6 */ 7#include <linux/list.h> 8#include <linux/stddef.h> 9#include <linux/spinlock.h> 10 11#include <asm/current.h> 12 13typedef struct wait_queue_entry wait_queue_entry_t; 14 15typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); 16int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); 17 18/* wait_queue_entry::flags */ 19#define WQ_FLAG_EXCLUSIVE 0x01 20#define WQ_FLAG_WOKEN 0x02 21#define WQ_FLAG_CUSTOM 0x04 22#define WQ_FLAG_DONE 0x08 23#define WQ_FLAG_PRIORITY 0x10 24 25/* 26 * A single wait-queue entry structure: 27 */ 28struct wait_queue_entry { 29 unsigned int flags; 30 void *private; 31 wait_queue_func_t func; 32 struct list_head entry; 33}; 34 35struct wait_queue_head { 36 spinlock_t lock; 37 struct list_head head; 38}; 39typedef struct wait_queue_head wait_queue_head_t; 40 41struct task_struct; 42 43/* 44 * Macros for declaration and initialisaton of the datatypes 45 */ 46 47#define __WAITQUEUE_INITIALIZER(name, tsk) { \ 48 .private = tsk, \ 49 .func = default_wake_function, \ 50 .entry = { NULL, NULL } } 51 52#define DECLARE_WAITQUEUE(name, tsk) \ 53 struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk) 54 55#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ 56 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ 57 .head = LIST_HEAD_INIT(name.head) } 58 59#define DECLARE_WAIT_QUEUE_HEAD(name) \ 60 struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name) 61 62extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *); 63 64#define init_waitqueue_head(wq_head) \ 65 do { \ 66 static struct lock_class_key __key; \ 67 \ 68 __init_waitqueue_head((wq_head), #wq_head, &__key); \ 69 } while (0) 70 71#ifdef CONFIG_LOCKDEP 72# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ 73 ({ init_waitqueue_head(&name); name; }) 74# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ 75 struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) 76#else 77# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name) 78#endif 79 80static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p) 81{ 82 wq_entry->flags = 0; 83 wq_entry->private = p; 84 wq_entry->func = default_wake_function; 85} 86 87static inline void 88init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func) 89{ 90 wq_entry->flags = 0; 91 wq_entry->private = NULL; 92 wq_entry->func = func; 93} 94 95/** 96 * waitqueue_active -- locklessly test for waiters on the queue 97 * @wq_head: the waitqueue to test for waiters 98 * 99 * returns true if the wait list is not empty 100 * 101 * NOTE: this function is lockless and requires care, incorrect usage _will_ 102 * lead to sporadic and non-obvious failure. 103 * 104 * Use either while holding wait_queue_head::lock or when used for wakeups 105 * with an extra smp_mb() like:: 106 * 107 * CPU0 - waker CPU1 - waiter 108 * 109 * for (;;) { 110 * @cond = true; prepare_to_wait(&wq_head, &wait, state); 111 * smp_mb(); // smp_mb() from set_current_state() 112 * if (waitqueue_active(wq_head)) if (@cond) 113 * wake_up(wq_head); break; 114 * schedule(); 115 * } 116 * finish_wait(&wq_head, &wait); 117 * 118 * Because without the explicit smp_mb() it's possible for the 119 * waitqueue_active() load to get hoisted over the @cond store such that we'll 120 * observe an empty wait list while the waiter might not observe @cond. 121 * 122 * Also note that this 'optimization' trades a spin_lock() for an smp_mb(), 123 * which (when the lock is uncontended) are of roughly equal cost. 124 */ 125static inline int waitqueue_active(struct wait_queue_head *wq_head) 126{ 127 return !list_empty(&wq_head->head); 128} 129 130/** 131 * wq_has_single_sleeper - check if there is only one sleeper 132 * @wq_head: wait queue head 133 * 134 * Returns true of wq_head has only one sleeper on the list. 135 * 136 * Please refer to the comment for waitqueue_active. 137 */ 138static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head) 139{ 140 return list_is_singular(&wq_head->head); 141} 142 143/** 144 * wq_has_sleeper - check if there are any waiting processes 145 * @wq_head: wait queue head 146 * 147 * Returns true if wq_head has waiting processes 148 * 149 * Please refer to the comment for waitqueue_active. 150 */ 151static inline bool wq_has_sleeper(struct wait_queue_head *wq_head) 152{ 153 /* 154 * We need to be sure we are in sync with the 155 * add_wait_queue modifications to the wait queue. 156 * 157 * This memory barrier should be paired with one on the 158 * waiting side. 159 */ 160 smp_mb(); 161 return waitqueue_active(wq_head); 162} 163 164extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 165extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 166extern void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 167extern int add_wait_queue_priority_exclusive(struct wait_queue_head *wq_head, 168 struct wait_queue_entry *wq_entry); 169extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 170 171static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) 172{ 173 struct list_head *head = &wq_head->head; 174 struct wait_queue_entry *wq; 175 176 list_for_each_entry(wq, &wq_head->head, entry) { 177 if (!(wq->flags & WQ_FLAG_PRIORITY)) 178 break; 179 head = &wq->entry; 180 } 181 list_add(&wq_entry->entry, head); 182} 183 184/* 185 * Used for wake-one threads: 186 */ 187static inline void 188__add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) 189{ 190 wq_entry->flags |= WQ_FLAG_EXCLUSIVE; 191 __add_wait_queue(wq_head, wq_entry); 192} 193 194static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) 195{ 196 list_add_tail(&wq_entry->entry, &wq_head->head); 197} 198 199static inline void 200__add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) 201{ 202 wq_entry->flags |= WQ_FLAG_EXCLUSIVE; 203 __add_wait_queue_entry_tail(wq_head, wq_entry); 204} 205 206static inline void 207__remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) 208{ 209 list_del(&wq_entry->entry); 210} 211 212int __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key); 213void __wake_up_on_current_cpu(struct wait_queue_head *wq_head, unsigned int mode, void *key); 214void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); 215void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); 216void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); 217void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr); 218void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode); 219void __wake_up_pollfree(struct wait_queue_head *wq_head); 220 221#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) 222#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) 223#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) 224#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) 225#define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) 226#define wake_up_sync(x) __wake_up_sync(x, TASK_NORMAL) 227 228#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) 229#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) 230#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) 231#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE) 232 233/* 234 * Wakeup macros to be used to report events to the targets. 235 */ 236#define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m)) 237#define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m)) 238#define wake_up_poll(x, m) \ 239 __wake_up(x, TASK_NORMAL, 1, poll_to_key(m)) 240#define wake_up_poll_on_current_cpu(x, m) \ 241 __wake_up_on_current_cpu(x, TASK_NORMAL, poll_to_key(m)) 242#define wake_up_locked_poll(x, m) \ 243 __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m)) 244#define wake_up_interruptible_poll(x, m) \ 245 __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m)) 246#define wake_up_interruptible_sync_poll(x, m) \ 247 __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) 248#define wake_up_interruptible_sync_poll_locked(x, m) \ 249 __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) 250 251/** 252 * wake_up_pollfree - signal that a polled waitqueue is going away 253 * @wq_head: the wait queue head 254 * 255 * In the very rare cases where a ->poll() implementation uses a waitqueue whose 256 * lifetime is tied to a task rather than to the 'struct file' being polled, 257 * this function must be called before the waitqueue is freed so that 258 * non-blocking polls (e.g. epoll) are notified that the queue is going away. 259 * 260 * The caller must also RCU-delay the freeing of the wait_queue_head, e.g. via 261 * an explicit synchronize_rcu() or call_rcu(), or via SLAB_TYPESAFE_BY_RCU. 262 */ 263static inline void wake_up_pollfree(struct wait_queue_head *wq_head) 264{ 265 /* 266 * For performance reasons, we don't always take the queue lock here. 267 * Therefore, we might race with someone removing the last entry from 268 * the queue, and proceed while they still hold the queue lock. 269 * However, rcu_read_lock() is required to be held in such cases, so we 270 * can safely proceed with an RCU-delayed free. 271 */ 272 if (waitqueue_active(wq_head)) 273 __wake_up_pollfree(wq_head); 274} 275 276#define ___wait_cond_timeout(condition) \ 277({ \ 278 bool __cond = (condition); \ 279 if (__cond && !__ret) \ 280 __ret = 1; \ 281 __cond || !__ret; \ 282}) 283 284#define ___wait_is_interruptible(state) \ 285 (!__builtin_constant_p(state) || \ 286 (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) 287 288extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags); 289 290/* 291 * The below macro ___wait_event() has an explicit shadow of the __ret 292 * variable when used from the wait_event_*() macros. 293 * 294 * This is so that both can use the ___wait_cond_timeout() construct 295 * to wrap the condition. 296 * 297 * The type inconsistency of the wait_event_*() __ret variable is also 298 * on purpose; we use long where we can return timeout values and int 299 * otherwise. 300 */ 301 302#define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \ 303({ \ 304 __label__ __out; \ 305 struct wait_queue_entry __wq_entry; \ 306 long __ret = ret; /* explicit shadow */ \ 307 \ 308 init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \ 309 for (;;) { \ 310 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\ 311 \ 312 if (condition) \ 313 break; \ 314 \ 315 if (___wait_is_interruptible(state) && __int) { \ 316 __ret = __int; \ 317 goto __out; \ 318 } \ 319 \ 320 cmd; \ 321 \ 322 if (condition) \ 323 break; \ 324 } \ 325 finish_wait(&wq_head, &__wq_entry); \ 326__out: __ret; \ 327}) 328 329#define __wait_event(wq_head, condition) \ 330 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 331 schedule()) 332 333/** 334 * wait_event - sleep until a condition gets true 335 * @wq_head: the waitqueue to wait on 336 * @condition: a C expression for the event to wait for 337 * 338 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 339 * @condition evaluates to true. The @condition is checked each time 340 * the waitqueue @wq_head is woken up. 341 * 342 * wake_up() has to be called after changing any variable that could 343 * change the result of the wait condition. 344 */ 345#define wait_event(wq_head, condition) \ 346do { \ 347 might_sleep(); \ 348 if (condition) \ 349 break; \ 350 __wait_event(wq_head, condition); \ 351} while (0) 352 353#define __io_wait_event(wq_head, condition) \ 354 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 355 io_schedule()) 356 357/* 358 * io_wait_event() -- like wait_event() but with io_schedule() 359 */ 360#define io_wait_event(wq_head, condition) \ 361do { \ 362 might_sleep(); \ 363 if (condition) \ 364 break; \ 365 __io_wait_event(wq_head, condition); \ 366} while (0) 367 368#define __wait_event_freezable(wq_head, condition) \ 369 ___wait_event(wq_head, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), \ 370 0, 0, schedule()) 371 372/** 373 * wait_event_freezable - sleep (or freeze) until a condition gets true 374 * @wq_head: the waitqueue to wait on 375 * @condition: a C expression for the event to wait for 376 * 377 * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute 378 * to system load) until the @condition evaluates to true. The 379 * @condition is checked each time the waitqueue @wq_head is woken up. 380 * 381 * wake_up() has to be called after changing any variable that could 382 * change the result of the wait condition. 383 */ 384#define wait_event_freezable(wq_head, condition) \ 385({ \ 386 int __ret = 0; \ 387 might_sleep(); \ 388 if (!(condition)) \ 389 __ret = __wait_event_freezable(wq_head, condition); \ 390 __ret; \ 391}) 392 393#define __wait_event_timeout(wq_head, condition, timeout) \ 394 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 395 TASK_UNINTERRUPTIBLE, 0, timeout, \ 396 __ret = schedule_timeout(__ret)) 397 398/** 399 * wait_event_timeout - sleep until a condition gets true or a timeout elapses 400 * @wq_head: the waitqueue to wait on 401 * @condition: a C expression for the event to wait for 402 * @timeout: timeout, in jiffies 403 * 404 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 405 * @condition evaluates to true. The @condition is checked each time 406 * the waitqueue @wq_head is woken up. 407 * 408 * wake_up() has to be called after changing any variable that could 409 * change the result of the wait condition. 410 * 411 * Returns: 412 * 0 if the @condition evaluated to %false after the @timeout elapsed, 413 * 1 if the @condition evaluated to %true after the @timeout elapsed, 414 * or the remaining jiffies (at least 1) if the @condition evaluated 415 * to %true before the @timeout elapsed. 416 */ 417#define wait_event_timeout(wq_head, condition, timeout) \ 418({ \ 419 long __ret = timeout; \ 420 might_sleep(); \ 421 if (!___wait_cond_timeout(condition)) \ 422 __ret = __wait_event_timeout(wq_head, condition, timeout); \ 423 __ret; \ 424}) 425 426#define __wait_event_freezable_timeout(wq_head, condition, timeout) \ 427 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 428 (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 0, timeout, \ 429 __ret = schedule_timeout(__ret)) 430 431/* 432 * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid 433 * increasing load and is freezable. 434 */ 435#define wait_event_freezable_timeout(wq_head, condition, timeout) \ 436({ \ 437 long __ret = timeout; \ 438 might_sleep(); \ 439 if (!___wait_cond_timeout(condition)) \ 440 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \ 441 __ret; \ 442}) 443 444#define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \ 445 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0, \ 446 cmd1; schedule(); cmd2) 447/* 448 * Just like wait_event_cmd(), except it sets exclusive flag 449 */ 450#define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \ 451do { \ 452 if (condition) \ 453 break; \ 454 __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2); \ 455} while (0) 456 457#define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \ 458 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 459 cmd1; schedule(); cmd2) 460 461/** 462 * wait_event_cmd - sleep until a condition gets true 463 * @wq_head: the waitqueue to wait on 464 * @condition: a C expression for the event to wait for 465 * @cmd1: the command will be executed before sleep 466 * @cmd2: the command will be executed after sleep 467 * 468 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 469 * @condition evaluates to true. The @condition is checked each time 470 * the waitqueue @wq_head is woken up. 471 * 472 * wake_up() has to be called after changing any variable that could 473 * change the result of the wait condition. 474 */ 475#define wait_event_cmd(wq_head, condition, cmd1, cmd2) \ 476do { \ 477 if (condition) \ 478 break; \ 479 __wait_event_cmd(wq_head, condition, cmd1, cmd2); \ 480} while (0) 481 482#define __wait_event_interruptible(wq_head, condition) \ 483 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \ 484 schedule()) 485 486/** 487 * wait_event_interruptible - sleep until a condition gets true 488 * @wq_head: the waitqueue to wait on 489 * @condition: a C expression for the event to wait for 490 * 491 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 492 * @condition evaluates to true or a signal is received. 493 * The @condition is checked each time the waitqueue @wq_head is woken up. 494 * 495 * wake_up() has to be called after changing any variable that could 496 * change the result of the wait condition. 497 * 498 * The function will return -ERESTARTSYS if it was interrupted by a 499 * signal and 0 if @condition evaluated to true. 500 */ 501#define wait_event_interruptible(wq_head, condition) \ 502({ \ 503 int __ret = 0; \ 504 might_sleep(); \ 505 if (!(condition)) \ 506 __ret = __wait_event_interruptible(wq_head, condition); \ 507 __ret; \ 508}) 509 510#define __wait_event_interruptible_timeout(wq_head, condition, timeout) \ 511 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 512 TASK_INTERRUPTIBLE, 0, timeout, \ 513 __ret = schedule_timeout(__ret)) 514 515/** 516 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses 517 * @wq_head: the waitqueue to wait on 518 * @condition: a C expression for the event to wait for 519 * @timeout: timeout, in jiffies 520 * 521 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 522 * @condition evaluates to true or a signal is received. 523 * The @condition is checked each time the waitqueue @wq_head is woken up. 524 * 525 * wake_up() has to be called after changing any variable that could 526 * change the result of the wait condition. 527 * 528 * Returns: 529 * 0 if the @condition evaluated to %false after the @timeout elapsed, 530 * 1 if the @condition evaluated to %true after the @timeout elapsed, 531 * the remaining jiffies (at least 1) if the @condition evaluated 532 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was 533 * interrupted by a signal. 534 */ 535#define wait_event_interruptible_timeout(wq_head, condition, timeout) \ 536({ \ 537 long __ret = timeout; \ 538 might_sleep(); \ 539 if (!___wait_cond_timeout(condition)) \ 540 __ret = __wait_event_interruptible_timeout(wq_head, \ 541 condition, timeout); \ 542 __ret; \ 543}) 544 545#define __wait_event_hrtimeout(wq_head, condition, timeout, state) \ 546({ \ 547 int __ret = 0; \ 548 struct hrtimer_sleeper __t; \ 549 \ 550 hrtimer_setup_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \ 551 HRTIMER_MODE_REL); \ 552 if ((timeout) != KTIME_MAX) { \ 553 hrtimer_set_expires_range_ns(&__t.timer, timeout, \ 554 current->timer_slack_ns); \ 555 hrtimer_sleeper_start_expires(&__t, HRTIMER_MODE_REL); \ 556 } \ 557 \ 558 __ret = ___wait_event(wq_head, condition, state, 0, 0, \ 559 if (!__t.task) { \ 560 __ret = -ETIME; \ 561 break; \ 562 } \ 563 schedule()); \ 564 \ 565 hrtimer_cancel(&__t.timer); \ 566 destroy_hrtimer_on_stack(&__t.timer); \ 567 __ret; \ 568}) 569 570/** 571 * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses 572 * @wq_head: the waitqueue to wait on 573 * @condition: a C expression for the event to wait for 574 * @timeout: timeout, as a ktime_t 575 * 576 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 577 * @condition evaluates to true or a signal is received. 578 * The @condition is checked each time the waitqueue @wq_head is woken up. 579 * 580 * wake_up() has to be called after changing any variable that could 581 * change the result of the wait condition. 582 * 583 * The function returns 0 if @condition became true, or -ETIME if the timeout 584 * elapsed. 585 */ 586#define wait_event_hrtimeout(wq_head, condition, timeout) \ 587({ \ 588 int __ret = 0; \ 589 might_sleep(); \ 590 if (!(condition)) \ 591 __ret = __wait_event_hrtimeout(wq_head, condition, timeout, \ 592 TASK_UNINTERRUPTIBLE); \ 593 __ret; \ 594}) 595 596/** 597 * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses 598 * @wq: the waitqueue to wait on 599 * @condition: a C expression for the event to wait for 600 * @timeout: timeout, as a ktime_t 601 * 602 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 603 * @condition evaluates to true or a signal is received. 604 * The @condition is checked each time the waitqueue @wq is woken up. 605 * 606 * wake_up() has to be called after changing any variable that could 607 * change the result of the wait condition. 608 * 609 * The function returns 0 if @condition became true, -ERESTARTSYS if it was 610 * interrupted by a signal, or -ETIME if the timeout elapsed. 611 */ 612#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \ 613({ \ 614 long __ret = 0; \ 615 might_sleep(); \ 616 if (!(condition)) \ 617 __ret = __wait_event_hrtimeout(wq, condition, timeout, \ 618 TASK_INTERRUPTIBLE); \ 619 __ret; \ 620}) 621 622#define __wait_event_interruptible_exclusive(wq, condition) \ 623 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ 624 schedule()) 625 626#define wait_event_interruptible_exclusive(wq, condition) \ 627({ \ 628 int __ret = 0; \ 629 might_sleep(); \ 630 if (!(condition)) \ 631 __ret = __wait_event_interruptible_exclusive(wq, condition); \ 632 __ret; \ 633}) 634 635#define __wait_event_killable_exclusive(wq, condition) \ 636 ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \ 637 schedule()) 638 639#define wait_event_killable_exclusive(wq, condition) \ 640({ \ 641 int __ret = 0; \ 642 might_sleep(); \ 643 if (!(condition)) \ 644 __ret = __wait_event_killable_exclusive(wq, condition); \ 645 __ret; \ 646}) 647 648 649#define __wait_event_freezable_exclusive(wq, condition) \ 650 ___wait_event(wq, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 1, 0,\ 651 schedule()) 652 653#define wait_event_freezable_exclusive(wq, condition) \ 654({ \ 655 int __ret = 0; \ 656 might_sleep(); \ 657 if (!(condition)) \ 658 __ret = __wait_event_freezable_exclusive(wq, condition); \ 659 __ret; \ 660}) 661 662/** 663 * wait_event_idle - wait for a condition without contributing to system load 664 * @wq_head: the waitqueue to wait on 665 * @condition: a C expression for the event to wait for 666 * 667 * The process is put to sleep (TASK_IDLE) until the 668 * @condition evaluates to true. 669 * The @condition is checked each time the waitqueue @wq_head is woken up. 670 * 671 * wake_up() has to be called after changing any variable that could 672 * change the result of the wait condition. 673 * 674 */ 675#define wait_event_idle(wq_head, condition) \ 676do { \ 677 might_sleep(); \ 678 if (!(condition)) \ 679 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \ 680} while (0) 681 682/** 683 * wait_event_idle_exclusive - wait for a condition with contributing to system load 684 * @wq_head: the waitqueue to wait on 685 * @condition: a C expression for the event to wait for 686 * 687 * The process is put to sleep (TASK_IDLE) until the 688 * @condition evaluates to true. 689 * The @condition is checked each time the waitqueue @wq_head is woken up. 690 * 691 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 692 * set thus if other processes wait on the same list, when this 693 * process is woken further processes are not considered. 694 * 695 * wake_up() has to be called after changing any variable that could 696 * change the result of the wait condition. 697 * 698 */ 699#define wait_event_idle_exclusive(wq_head, condition) \ 700do { \ 701 might_sleep(); \ 702 if (!(condition)) \ 703 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \ 704} while (0) 705 706#define __wait_event_idle_timeout(wq_head, condition, timeout) \ 707 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 708 TASK_IDLE, 0, timeout, \ 709 __ret = schedule_timeout(__ret)) 710 711/** 712 * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses 713 * @wq_head: the waitqueue to wait on 714 * @condition: a C expression for the event to wait for 715 * @timeout: timeout, in jiffies 716 * 717 * The process is put to sleep (TASK_IDLE) until the 718 * @condition evaluates to true. The @condition is checked each time 719 * the waitqueue @wq_head is woken up. 720 * 721 * wake_up() has to be called after changing any variable that could 722 * change the result of the wait condition. 723 * 724 * Returns: 725 * 0 if the @condition evaluated to %false after the @timeout elapsed, 726 * 1 if the @condition evaluated to %true after the @timeout elapsed, 727 * or the remaining jiffies (at least 1) if the @condition evaluated 728 * to %true before the @timeout elapsed. 729 */ 730#define wait_event_idle_timeout(wq_head, condition, timeout) \ 731({ \ 732 long __ret = timeout; \ 733 might_sleep(); \ 734 if (!___wait_cond_timeout(condition)) \ 735 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \ 736 __ret; \ 737}) 738 739#define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ 740 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 741 TASK_IDLE, 1, timeout, \ 742 __ret = schedule_timeout(__ret)) 743 744/** 745 * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses 746 * @wq_head: the waitqueue to wait on 747 * @condition: a C expression for the event to wait for 748 * @timeout: timeout, in jiffies 749 * 750 * The process is put to sleep (TASK_IDLE) until the 751 * @condition evaluates to true. The @condition is checked each time 752 * the waitqueue @wq_head is woken up. 753 * 754 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 755 * set thus if other processes wait on the same list, when this 756 * process is woken further processes are not considered. 757 * 758 * wake_up() has to be called after changing any variable that could 759 * change the result of the wait condition. 760 * 761 * Returns: 762 * 0 if the @condition evaluated to %false after the @timeout elapsed, 763 * 1 if the @condition evaluated to %true after the @timeout elapsed, 764 * or the remaining jiffies (at least 1) if the @condition evaluated 765 * to %true before the @timeout elapsed. 766 */ 767#define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ 768({ \ 769 long __ret = timeout; \ 770 might_sleep(); \ 771 if (!___wait_cond_timeout(condition)) \ 772 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\ 773 __ret; \ 774}) 775 776extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *); 777extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *); 778 779#define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \ 780({ \ 781 int __ret; \ 782 DEFINE_WAIT(__wait); \ 783 if (exclusive) \ 784 __wait.flags |= WQ_FLAG_EXCLUSIVE; \ 785 do { \ 786 __ret = fn(&(wq), &__wait); \ 787 if (__ret) \ 788 break; \ 789 } while (!(condition)); \ 790 __remove_wait_queue(&(wq), &__wait); \ 791 __set_current_state(TASK_RUNNING); \ 792 __ret; \ 793}) 794 795 796/** 797 * wait_event_interruptible_locked - sleep until a condition gets true 798 * @wq: the waitqueue to wait on 799 * @condition: a C expression for the event to wait for 800 * 801 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 802 * @condition evaluates to true or a signal is received. 803 * The @condition is checked each time the waitqueue @wq is woken up. 804 * 805 * It must be called with wq.lock being held. This spinlock is 806 * unlocked while sleeping but @condition testing is done while lock 807 * is held and when this macro exits the lock is held. 808 * 809 * The lock is locked/unlocked using spin_lock()/spin_unlock() 810 * functions which must match the way they are locked/unlocked outside 811 * of this macro. 812 * 813 * wake_up_locked() has to be called after changing any variable that could 814 * change the result of the wait condition. 815 * 816 * The function will return -ERESTARTSYS if it was interrupted by a 817 * signal and 0 if @condition evaluated to true. 818 */ 819#define wait_event_interruptible_locked(wq, condition) \ 820 ((condition) \ 821 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr)) 822 823/** 824 * wait_event_interruptible_locked_irq - sleep until a condition gets true 825 * @wq: the waitqueue to wait on 826 * @condition: a C expression for the event to wait for 827 * 828 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 829 * @condition evaluates to true or a signal is received. 830 * The @condition is checked each time the waitqueue @wq is woken up. 831 * 832 * It must be called with wq.lock being held. This spinlock is 833 * unlocked while sleeping but @condition testing is done while lock 834 * is held and when this macro exits the lock is held. 835 * 836 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() 837 * functions which must match the way they are locked/unlocked outside 838 * of this macro. 839 * 840 * wake_up_locked() has to be called after changing any variable that could 841 * change the result of the wait condition. 842 * 843 * The function will return -ERESTARTSYS if it was interrupted by a 844 * signal and 0 if @condition evaluated to true. 845 */ 846#define wait_event_interruptible_locked_irq(wq, condition) \ 847 ((condition) \ 848 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq)) 849 850/** 851 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true 852 * @wq: the waitqueue to wait on 853 * @condition: a C expression for the event to wait for 854 * 855 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 856 * @condition evaluates to true or a signal is received. 857 * The @condition is checked each time the waitqueue @wq is woken up. 858 * 859 * It must be called with wq.lock being held. This spinlock is 860 * unlocked while sleeping but @condition testing is done while lock 861 * is held and when this macro exits the lock is held. 862 * 863 * The lock is locked/unlocked using spin_lock()/spin_unlock() 864 * functions which must match the way they are locked/unlocked outside 865 * of this macro. 866 * 867 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 868 * set thus when other process waits process on the list if this 869 * process is awaken further processes are not considered. 870 * 871 * wake_up_locked() has to be called after changing any variable that could 872 * change the result of the wait condition. 873 * 874 * The function will return -ERESTARTSYS if it was interrupted by a 875 * signal and 0 if @condition evaluated to true. 876 */ 877#define wait_event_interruptible_exclusive_locked(wq, condition) \ 878 ((condition) \ 879 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr)) 880 881/** 882 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true 883 * @wq: the waitqueue to wait on 884 * @condition: a C expression for the event to wait for 885 * 886 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 887 * @condition evaluates to true or a signal is received. 888 * The @condition is checked each time the waitqueue @wq is woken up. 889 * 890 * It must be called with wq.lock being held. This spinlock is 891 * unlocked while sleeping but @condition testing is done while lock 892 * is held and when this macro exits the lock is held. 893 * 894 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() 895 * functions which must match the way they are locked/unlocked outside 896 * of this macro. 897 * 898 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 899 * set thus when other process waits process on the list if this 900 * process is awaken further processes are not considered. 901 * 902 * wake_up_locked() has to be called after changing any variable that could 903 * change the result of the wait condition. 904 * 905 * The function will return -ERESTARTSYS if it was interrupted by a 906 * signal and 0 if @condition evaluated to true. 907 */ 908#define wait_event_interruptible_exclusive_locked_irq(wq, condition) \ 909 ((condition) \ 910 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq)) 911 912 913#define __wait_event_killable(wq, condition) \ 914 ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) 915 916/** 917 * wait_event_killable - sleep until a condition gets true 918 * @wq_head: the waitqueue to wait on 919 * @condition: a C expression for the event to wait for 920 * 921 * The process is put to sleep (TASK_KILLABLE) until the 922 * @condition evaluates to true or a signal is received. 923 * The @condition is checked each time the waitqueue @wq_head is woken up. 924 * 925 * wake_up() has to be called after changing any variable that could 926 * change the result of the wait condition. 927 * 928 * The function will return -ERESTARTSYS if it was interrupted by a 929 * signal and 0 if @condition evaluated to true. 930 */ 931#define wait_event_killable(wq_head, condition) \ 932({ \ 933 int __ret = 0; \ 934 might_sleep(); \ 935 if (!(condition)) \ 936 __ret = __wait_event_killable(wq_head, condition); \ 937 __ret; \ 938}) 939 940#define __wait_event_state(wq, condition, state) \ 941 ___wait_event(wq, condition, state, 0, 0, schedule()) 942 943/** 944 * wait_event_state - sleep until a condition gets true 945 * @wq_head: the waitqueue to wait on 946 * @condition: a C expression for the event to wait for 947 * @state: state to sleep in 948 * 949 * The process is put to sleep (@state) until the @condition evaluates to true 950 * or a signal is received (when allowed by @state). The @condition is checked 951 * each time the waitqueue @wq_head is woken up. 952 * 953 * wake_up() has to be called after changing any variable that could 954 * change the result of the wait condition. 955 * 956 * The function will return -ERESTARTSYS if it was interrupted by a signal 957 * (when allowed by @state) and 0 if @condition evaluated to true. 958 */ 959#define wait_event_state(wq_head, condition, state) \ 960({ \ 961 int __ret = 0; \ 962 might_sleep(); \ 963 if (!(condition)) \ 964 __ret = __wait_event_state(wq_head, condition, state); \ 965 __ret; \ 966}) 967 968#define __wait_event_state_exclusive(wq, condition, state) \ 969 ___wait_event(wq, condition, state, 1, 0, schedule()) 970 971#define wait_event_state_exclusive(wq, condition, state) \ 972({ \ 973 int __ret = 0; \ 974 might_sleep(); \ 975 if (!(condition)) \ 976 __ret = __wait_event_state_exclusive(wq, condition, state); \ 977 __ret; \ 978}) 979 980#define __wait_event_killable_timeout(wq_head, condition, timeout) \ 981 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 982 TASK_KILLABLE, 0, timeout, \ 983 __ret = schedule_timeout(__ret)) 984 985/** 986 * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses 987 * @wq_head: the waitqueue to wait on 988 * @condition: a C expression for the event to wait for 989 * @timeout: timeout, in jiffies 990 * 991 * The process is put to sleep (TASK_KILLABLE) until the 992 * @condition evaluates to true or a kill signal is received. 993 * The @condition is checked each time the waitqueue @wq_head is woken up. 994 * 995 * wake_up() has to be called after changing any variable that could 996 * change the result of the wait condition. 997 * 998 * Returns: 999 * 0 if the @condition evaluated to %false after the @timeout elapsed, 1000 * 1 if the @condition evaluated to %true after the @timeout elapsed, 1001 * the remaining jiffies (at least 1) if the @condition evaluated 1002 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was 1003 * interrupted by a kill signal. 1004 * 1005 * Only kill signals interrupt this process. 1006 */ 1007#define wait_event_killable_timeout(wq_head, condition, timeout) \ 1008({ \ 1009 long __ret = timeout; \ 1010 might_sleep(); \ 1011 if (!___wait_cond_timeout(condition)) \ 1012 __ret = __wait_event_killable_timeout(wq_head, \ 1013 condition, timeout); \ 1014 __ret; \ 1015}) 1016 1017 1018#define __wait_event_lock_irq(wq_head, condition, lock, cmd) \ 1019 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 1020 spin_unlock_irq(&lock); \ 1021 cmd; \ 1022 schedule(); \ 1023 spin_lock_irq(&lock)) 1024 1025/** 1026 * wait_event_lock_irq_cmd - sleep until a condition gets true. The 1027 * condition is checked under the lock. This 1028 * is expected to be called with the lock 1029 * taken. 1030 * @wq_head: the waitqueue to wait on 1031 * @condition: a C expression for the event to wait for 1032 * @lock: a locked spinlock_t, which will be released before cmd 1033 * and schedule() and reacquired afterwards. 1034 * @cmd: a command which is invoked outside the critical section before 1035 * sleep 1036 * 1037 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 1038 * @condition evaluates to true. The @condition is checked each time 1039 * the waitqueue @wq_head is woken up. 1040 * 1041 * wake_up() has to be called after changing any variable that could 1042 * change the result of the wait condition. 1043 * 1044 * This is supposed to be called while holding the lock. The lock is 1045 * dropped before invoking the cmd and going to sleep and is reacquired 1046 * afterwards. 1047 */ 1048#define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \ 1049do { \ 1050 if (condition) \ 1051 break; \ 1052 __wait_event_lock_irq(wq_head, condition, lock, cmd); \ 1053} while (0) 1054 1055/** 1056 * wait_event_lock_irq - sleep until a condition gets true. The 1057 * condition is checked under the lock. This 1058 * is expected to be called with the lock 1059 * taken. 1060 * @wq_head: the waitqueue to wait on 1061 * @condition: a C expression for the event to wait for 1062 * @lock: a locked spinlock_t, which will be released before schedule() 1063 * and reacquired afterwards. 1064 * 1065 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 1066 * @condition evaluates to true. The @condition is checked each time 1067 * the waitqueue @wq_head is woken up. 1068 * 1069 * wake_up() has to be called after changing any variable that could 1070 * change the result of the wait condition. 1071 * 1072 * This is supposed to be called while holding the lock. The lock is 1073 * dropped before going to sleep and is reacquired afterwards. 1074 */ 1075#define wait_event_lock_irq(wq_head, condition, lock) \ 1076do { \ 1077 if (condition) \ 1078 break; \ 1079 __wait_event_lock_irq(wq_head, condition, lock, ); \ 1080} while (0) 1081 1082 1083#define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \ 1084 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \ 1085 spin_unlock_irq(&lock); \ 1086 cmd; \ 1087 schedule(); \ 1088 spin_lock_irq(&lock)) 1089 1090/** 1091 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. 1092 * The condition is checked under the lock. This is expected to 1093 * be called with the lock taken. 1094 * @wq_head: the waitqueue to wait on 1095 * @condition: a C expression for the event to wait for 1096 * @lock: a locked spinlock_t, which will be released before cmd and 1097 * schedule() and reacquired afterwards. 1098 * @cmd: a command which is invoked outside the critical section before 1099 * sleep 1100 * 1101 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 1102 * @condition evaluates to true or a signal is received. The @condition is 1103 * checked each time the waitqueue @wq_head is woken up. 1104 * 1105 * wake_up() has to be called after changing any variable that could 1106 * change the result of the wait condition. 1107 * 1108 * This is supposed to be called while holding the lock. The lock is 1109 * dropped before invoking the cmd and going to sleep and is reacquired 1110 * afterwards. 1111 * 1112 * The macro will return -ERESTARTSYS if it was interrupted by a signal 1113 * and 0 if @condition evaluated to true. 1114 */ 1115#define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \ 1116({ \ 1117 int __ret = 0; \ 1118 if (!(condition)) \ 1119 __ret = __wait_event_interruptible_lock_irq(wq_head, \ 1120 condition, lock, cmd); \ 1121 __ret; \ 1122}) 1123 1124/** 1125 * wait_event_interruptible_lock_irq - sleep until a condition gets true. 1126 * The condition is checked under the lock. This is expected 1127 * to be called with the lock taken. 1128 * @wq_head: the waitqueue to wait on 1129 * @condition: a C expression for the event to wait for 1130 * @lock: a locked spinlock_t, which will be released before schedule() 1131 * and reacquired afterwards. 1132 * 1133 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 1134 * @condition evaluates to true or signal is received. The @condition is 1135 * checked each time the waitqueue @wq_head is woken up. 1136 * 1137 * wake_up() has to be called after changing any variable that could 1138 * change the result of the wait condition. 1139 * 1140 * This is supposed to be called while holding the lock. The lock is 1141 * dropped before going to sleep and is reacquired afterwards. 1142 * 1143 * The macro will return -ERESTARTSYS if it was interrupted by a signal 1144 * and 0 if @condition evaluated to true. 1145 */ 1146#define wait_event_interruptible_lock_irq(wq_head, condition, lock) \ 1147({ \ 1148 int __ret = 0; \ 1149 if (!(condition)) \ 1150 __ret = __wait_event_interruptible_lock_irq(wq_head, \ 1151 condition, lock,); \ 1152 __ret; \ 1153}) 1154 1155#define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \ 1156 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 1157 state, 0, timeout, \ 1158 spin_unlock_irq(&lock); \ 1159 __ret = schedule_timeout(__ret); \ 1160 spin_lock_irq(&lock)); 1161 1162/** 1163 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets 1164 * true or a timeout elapses. The condition is checked under 1165 * the lock. This is expected to be called with the lock taken. 1166 * @wq_head: the waitqueue to wait on 1167 * @condition: a C expression for the event to wait for 1168 * @lock: a locked spinlock_t, which will be released before schedule() 1169 * and reacquired afterwards. 1170 * @timeout: timeout, in jiffies 1171 * 1172 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 1173 * @condition evaluates to true or signal is received. The @condition is 1174 * checked each time the waitqueue @wq_head is woken up. 1175 * 1176 * wake_up() has to be called after changing any variable that could 1177 * change the result of the wait condition. 1178 * 1179 * This is supposed to be called while holding the lock. The lock is 1180 * dropped before going to sleep and is reacquired afterwards. 1181 * 1182 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it 1183 * was interrupted by a signal, and the remaining jiffies otherwise 1184 * if the condition evaluated to true before the timeout elapsed. 1185 */ 1186#define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \ 1187 timeout) \ 1188({ \ 1189 long __ret = timeout; \ 1190 if (!___wait_cond_timeout(condition)) \ 1191 __ret = __wait_event_lock_irq_timeout( \ 1192 wq_head, condition, lock, timeout, \ 1193 TASK_INTERRUPTIBLE); \ 1194 __ret; \ 1195}) 1196 1197#define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \ 1198({ \ 1199 long __ret = timeout; \ 1200 if (!___wait_cond_timeout(condition)) \ 1201 __ret = __wait_event_lock_irq_timeout( \ 1202 wq_head, condition, lock, timeout, \ 1203 TASK_UNINTERRUPTIBLE); \ 1204 __ret; \ 1205}) 1206 1207/* 1208 * Waitqueues which are removed from the waitqueue_head at wakeup time 1209 */ 1210void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); 1211bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); 1212long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); 1213void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 1214long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout); 1215int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); 1216int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); 1217 1218#define DEFINE_WAIT_FUNC(name, function) \ 1219 struct wait_queue_entry name = { \ 1220 .private = current, \ 1221 .func = function, \ 1222 .entry = LIST_HEAD_INIT((name).entry), \ 1223 } 1224 1225#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) 1226 1227#define init_wait_func(wait, function) \ 1228 do { \ 1229 (wait)->private = current; \ 1230 (wait)->func = function; \ 1231 INIT_LIST_HEAD(&(wait)->entry); \ 1232 (wait)->flags = 0; \ 1233 } while (0) 1234 1235#define init_wait(wait) init_wait_func(wait, autoremove_wake_function) 1236 1237typedef int (*task_call_f)(struct task_struct *p, void *arg); 1238extern int task_call_func(struct task_struct *p, task_call_f func, void *arg); 1239 1240#endif /* _LINUX_WAIT_H */
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