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#include <uapi/linux/wait.h> 13 14typedef struct wait_queue_entry wait_queue_entry_t; 15 16typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); 17int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); 18 19/* wait_queue_entry::flags */ 20#define WQ_FLAG_EXCLUSIVE 0x01 21#define WQ_FLAG_WOKEN 0x02 22#define WQ_FLAG_BOOKMARK 0x04 23#define WQ_FLAG_CUSTOM 0x08 24#define WQ_FLAG_DONE 0x10 25#define WQ_FLAG_PRIORITY 0x20 26 27/* 28 * A single wait-queue entry structure: 29 */ 30struct wait_queue_entry { 31 unsigned int flags; 32 void *private; 33 wait_queue_func_t func; 34 struct list_head entry; 35}; 36 37struct wait_queue_head { 38 spinlock_t lock; 39 struct list_head head; 40}; 41typedef struct wait_queue_head wait_queue_head_t; 42 43struct task_struct; 44 45/* 46 * Macros for declaration and initialisaton of the datatypes 47 */ 48 49#define __WAITQUEUE_INITIALIZER(name, tsk) { \ 50 .private = tsk, \ 51 .func = default_wake_function, \ 52 .entry = { NULL, NULL } } 53 54#define DECLARE_WAITQUEUE(name, tsk) \ 55 struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk) 56 57#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ 58 .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ 59 .head = LIST_HEAD_INIT(name.head) } 60 61#define DECLARE_WAIT_QUEUE_HEAD(name) \ 62 struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name) 63 64extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *); 65 66#define init_waitqueue_head(wq_head) \ 67 do { \ 68 static struct lock_class_key __key; \ 69 \ 70 __init_waitqueue_head((wq_head), #wq_head, &__key); \ 71 } while (0) 72 73#ifdef CONFIG_LOCKDEP 74# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ 75 ({ init_waitqueue_head(&name); name; }) 76# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ 77 struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) 78#else 79# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name) 80#endif 81 82static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p) 83{ 84 wq_entry->flags = 0; 85 wq_entry->private = p; 86 wq_entry->func = default_wake_function; 87} 88 89static inline void 90init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func) 91{ 92 wq_entry->flags = 0; 93 wq_entry->private = NULL; 94 wq_entry->func = func; 95} 96 97/** 98 * waitqueue_active -- locklessly test for waiters on the queue 99 * @wq_head: the waitqueue to test for waiters 100 * 101 * returns true if the wait list is not empty 102 * 103 * NOTE: this function is lockless and requires care, incorrect usage _will_ 104 * lead to sporadic and non-obvious failure. 105 * 106 * Use either while holding wait_queue_head::lock or when used for wakeups 107 * with an extra smp_mb() like:: 108 * 109 * CPU0 - waker CPU1 - waiter 110 * 111 * for (;;) { 112 * @cond = true; prepare_to_wait(&wq_head, &wait, state); 113 * smp_mb(); // smp_mb() from set_current_state() 114 * if (waitqueue_active(wq_head)) if (@cond) 115 * wake_up(wq_head); break; 116 * schedule(); 117 * } 118 * finish_wait(&wq_head, &wait); 119 * 120 * Because without the explicit smp_mb() it's possible for the 121 * waitqueue_active() load to get hoisted over the @cond store such that we'll 122 * observe an empty wait list while the waiter might not observe @cond. 123 * 124 * Also note that this 'optimization' trades a spin_lock() for an smp_mb(), 125 * which (when the lock is uncontended) are of roughly equal cost. 126 */ 127static inline int waitqueue_active(struct wait_queue_head *wq_head) 128{ 129 return !list_empty(&wq_head->head); 130} 131 132/** 133 * wq_has_single_sleeper - check if there is only one sleeper 134 * @wq_head: wait queue head 135 * 136 * Returns true of wq_head has only one sleeper on the list. 137 * 138 * Please refer to the comment for waitqueue_active. 139 */ 140static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head) 141{ 142 return list_is_singular(&wq_head->head); 143} 144 145/** 146 * wq_has_sleeper - check if there are any waiting processes 147 * @wq_head: wait queue head 148 * 149 * Returns true if wq_head has waiting processes 150 * 151 * Please refer to the comment for waitqueue_active. 152 */ 153static inline bool wq_has_sleeper(struct wait_queue_head *wq_head) 154{ 155 /* 156 * We need to be sure we are in sync with the 157 * add_wait_queue modifications to the wait queue. 158 * 159 * This memory barrier should be paired with one on the 160 * waiting side. 161 */ 162 smp_mb(); 163 return waitqueue_active(wq_head); 164} 165 166extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 167extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 168extern void add_wait_queue_priority(struct wait_queue_head *wq_head, 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_locked_key_bookmark(struct wait_queue_head *wq_head, 216 unsigned int mode, void *key, wait_queue_entry_t *bookmark); 217void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); 218void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); 219void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr); 220void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode); 221void __wake_up_pollfree(struct wait_queue_head *wq_head); 222 223#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) 224#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) 225#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) 226#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) 227#define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) 228 229#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) 230#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) 231#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) 232#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE) 233 234/* 235 * Wakeup macros to be used to report events to the targets. 236 */ 237#define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m)) 238#define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m)) 239#define wake_up_poll(x, m) \ 240 __wake_up(x, TASK_NORMAL, 1, poll_to_key(m)) 241#define wake_up_poll_on_current_cpu(x, m) \ 242 __wake_up_on_current_cpu(x, TASK_NORMAL, poll_to_key(m)) 243#define wake_up_locked_poll(x, m) \ 244 __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m)) 245#define wake_up_interruptible_poll(x, m) \ 246 __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m)) 247#define wake_up_interruptible_sync_poll(x, m) \ 248 __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) 249#define wake_up_interruptible_sync_poll_locked(x, m) \ 250 __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) 251 252/** 253 * wake_up_pollfree - signal that a polled waitqueue is going away 254 * @wq_head: the wait queue head 255 * 256 * In the very rare cases where a ->poll() implementation uses a waitqueue whose 257 * lifetime is tied to a task rather than to the 'struct file' being polled, 258 * this function must be called before the waitqueue is freed so that 259 * non-blocking polls (e.g. epoll) are notified that the queue is going away. 260 * 261 * The caller must also RCU-delay the freeing of the wait_queue_head, e.g. via 262 * an explicit synchronize_rcu() or call_rcu(), or via SLAB_TYPESAFE_BY_RCU. 263 */ 264static inline void wake_up_pollfree(struct wait_queue_head *wq_head) 265{ 266 /* 267 * For performance reasons, we don't always take the queue lock here. 268 * Therefore, we might race with someone removing the last entry from 269 * the queue, and proceed while they still hold the queue lock. 270 * However, rcu_read_lock() is required to be held in such cases, so we 271 * can safely proceed with an RCU-delayed free. 272 */ 273 if (waitqueue_active(wq_head)) 274 __wake_up_pollfree(wq_head); 275} 276 277#define ___wait_cond_timeout(condition) \ 278({ \ 279 bool __cond = (condition); \ 280 if (__cond && !__ret) \ 281 __ret = 1; \ 282 __cond || !__ret; \ 283}) 284 285#define ___wait_is_interruptible(state) \ 286 (!__builtin_constant_p(state) || \ 287 (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) 288 289extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags); 290 291/* 292 * The below macro ___wait_event() has an explicit shadow of the __ret 293 * variable when used from the wait_event_*() macros. 294 * 295 * This is so that both can use the ___wait_cond_timeout() construct 296 * to wrap the condition. 297 * 298 * The type inconsistency of the wait_event_*() __ret variable is also 299 * on purpose; we use long where we can return timeout values and int 300 * otherwise. 301 */ 302 303#define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \ 304({ \ 305 __label__ __out; \ 306 struct wait_queue_entry __wq_entry; \ 307 long __ret = ret; /* explicit shadow */ \ 308 \ 309 init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \ 310 for (;;) { \ 311 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\ 312 \ 313 if (condition) \ 314 break; \ 315 \ 316 if (___wait_is_interruptible(state) && __int) { \ 317 __ret = __int; \ 318 goto __out; \ 319 } \ 320 \ 321 cmd; \ 322 } \ 323 finish_wait(&wq_head, &__wq_entry); \ 324__out: __ret; \ 325}) 326 327#define __wait_event(wq_head, condition) \ 328 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 329 schedule()) 330 331/** 332 * wait_event - sleep until a condition gets true 333 * @wq_head: the waitqueue to wait on 334 * @condition: a C expression for the event to wait for 335 * 336 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 337 * @condition evaluates to true. The @condition is checked each time 338 * the waitqueue @wq_head is woken up. 339 * 340 * wake_up() has to be called after changing any variable that could 341 * change the result of the wait condition. 342 */ 343#define wait_event(wq_head, condition) \ 344do { \ 345 might_sleep(); \ 346 if (condition) \ 347 break; \ 348 __wait_event(wq_head, condition); \ 349} while (0) 350 351#define __io_wait_event(wq_head, condition) \ 352 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 353 io_schedule()) 354 355/* 356 * io_wait_event() -- like wait_event() but with io_schedule() 357 */ 358#define io_wait_event(wq_head, condition) \ 359do { \ 360 might_sleep(); \ 361 if (condition) \ 362 break; \ 363 __io_wait_event(wq_head, condition); \ 364} while (0) 365 366#define __wait_event_freezable(wq_head, condition) \ 367 ___wait_event(wq_head, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), \ 368 0, 0, schedule()) 369 370/** 371 * wait_event_freezable - sleep (or freeze) until a condition gets true 372 * @wq_head: the waitqueue to wait on 373 * @condition: a C expression for the event to wait for 374 * 375 * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute 376 * to system load) until the @condition evaluates to true. The 377 * @condition is checked each time the waitqueue @wq_head is woken up. 378 * 379 * wake_up() has to be called after changing any variable that could 380 * change the result of the wait condition. 381 */ 382#define wait_event_freezable(wq_head, condition) \ 383({ \ 384 int __ret = 0; \ 385 might_sleep(); \ 386 if (!(condition)) \ 387 __ret = __wait_event_freezable(wq_head, condition); \ 388 __ret; \ 389}) 390 391#define __wait_event_timeout(wq_head, condition, timeout) \ 392 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 393 TASK_UNINTERRUPTIBLE, 0, timeout, \ 394 __ret = schedule_timeout(__ret)) 395 396/** 397 * wait_event_timeout - sleep until a condition gets true or a timeout elapses 398 * @wq_head: the waitqueue to wait on 399 * @condition: a C expression for the event to wait for 400 * @timeout: timeout, in jiffies 401 * 402 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 403 * @condition evaluates to true. The @condition is checked each time 404 * the waitqueue @wq_head is woken up. 405 * 406 * wake_up() has to be called after changing any variable that could 407 * change the result of the wait condition. 408 * 409 * Returns: 410 * 0 if the @condition evaluated to %false after the @timeout elapsed, 411 * 1 if the @condition evaluated to %true after the @timeout elapsed, 412 * or the remaining jiffies (at least 1) if the @condition evaluated 413 * to %true before the @timeout elapsed. 414 */ 415#define wait_event_timeout(wq_head, condition, timeout) \ 416({ \ 417 long __ret = timeout; \ 418 might_sleep(); \ 419 if (!___wait_cond_timeout(condition)) \ 420 __ret = __wait_event_timeout(wq_head, condition, timeout); \ 421 __ret; \ 422}) 423 424#define __wait_event_freezable_timeout(wq_head, condition, timeout) \ 425 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 426 (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 0, timeout, \ 427 __ret = schedule_timeout(__ret)) 428 429/* 430 * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid 431 * increasing load and is freezable. 432 */ 433#define wait_event_freezable_timeout(wq_head, condition, timeout) \ 434({ \ 435 long __ret = timeout; \ 436 might_sleep(); \ 437 if (!___wait_cond_timeout(condition)) \ 438 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \ 439 __ret; \ 440}) 441 442#define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \ 443 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0, \ 444 cmd1; schedule(); cmd2) 445/* 446 * Just like wait_event_cmd(), except it sets exclusive flag 447 */ 448#define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \ 449do { \ 450 if (condition) \ 451 break; \ 452 __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2); \ 453} while (0) 454 455#define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \ 456 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 457 cmd1; schedule(); cmd2) 458 459/** 460 * wait_event_cmd - sleep until a condition gets true 461 * @wq_head: the waitqueue to wait on 462 * @condition: a C expression for the event to wait for 463 * @cmd1: the command will be executed before sleep 464 * @cmd2: the command will be executed after sleep 465 * 466 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 467 * @condition evaluates to true. The @condition is checked each time 468 * the waitqueue @wq_head is woken up. 469 * 470 * wake_up() has to be called after changing any variable that could 471 * change the result of the wait condition. 472 */ 473#define wait_event_cmd(wq_head, condition, cmd1, cmd2) \ 474do { \ 475 if (condition) \ 476 break; \ 477 __wait_event_cmd(wq_head, condition, cmd1, cmd2); \ 478} while (0) 479 480#define __wait_event_interruptible(wq_head, condition) \ 481 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \ 482 schedule()) 483 484/** 485 * wait_event_interruptible - sleep until a condition gets true 486 * @wq_head: the waitqueue to wait on 487 * @condition: a C expression for the event to wait for 488 * 489 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 490 * @condition evaluates to true or a signal is received. 491 * The @condition is checked each time the waitqueue @wq_head is woken up. 492 * 493 * wake_up() has to be called after changing any variable that could 494 * change the result of the wait condition. 495 * 496 * The function will return -ERESTARTSYS if it was interrupted by a 497 * signal and 0 if @condition evaluated to true. 498 */ 499#define wait_event_interruptible(wq_head, condition) \ 500({ \ 501 int __ret = 0; \ 502 might_sleep(); \ 503 if (!(condition)) \ 504 __ret = __wait_event_interruptible(wq_head, condition); \ 505 __ret; \ 506}) 507 508#define __wait_event_interruptible_timeout(wq_head, condition, timeout) \ 509 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 510 TASK_INTERRUPTIBLE, 0, timeout, \ 511 __ret = schedule_timeout(__ret)) 512 513/** 514 * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses 515 * @wq_head: the waitqueue to wait on 516 * @condition: a C expression for the event to wait for 517 * @timeout: timeout, in jiffies 518 * 519 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 520 * @condition evaluates to true or a signal is received. 521 * The @condition is checked each time the waitqueue @wq_head is woken up. 522 * 523 * wake_up() has to be called after changing any variable that could 524 * change the result of the wait condition. 525 * 526 * Returns: 527 * 0 if the @condition evaluated to %false after the @timeout elapsed, 528 * 1 if the @condition evaluated to %true after the @timeout elapsed, 529 * the remaining jiffies (at least 1) if the @condition evaluated 530 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was 531 * interrupted by a signal. 532 */ 533#define wait_event_interruptible_timeout(wq_head, condition, timeout) \ 534({ \ 535 long __ret = timeout; \ 536 might_sleep(); \ 537 if (!___wait_cond_timeout(condition)) \ 538 __ret = __wait_event_interruptible_timeout(wq_head, \ 539 condition, timeout); \ 540 __ret; \ 541}) 542 543#define __wait_event_hrtimeout(wq_head, condition, timeout, state) \ 544({ \ 545 int __ret = 0; \ 546 struct hrtimer_sleeper __t; \ 547 \ 548 hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC, \ 549 HRTIMER_MODE_REL); \ 550 if ((timeout) != KTIME_MAX) { \ 551 hrtimer_set_expires_range_ns(&__t.timer, timeout, \ 552 current->timer_slack_ns); \ 553 hrtimer_sleeper_start_expires(&__t, HRTIMER_MODE_REL); \ 554 } \ 555 \ 556 __ret = ___wait_event(wq_head, condition, state, 0, 0, \ 557 if (!__t.task) { \ 558 __ret = -ETIME; \ 559 break; \ 560 } \ 561 schedule()); \ 562 \ 563 hrtimer_cancel(&__t.timer); \ 564 destroy_hrtimer_on_stack(&__t.timer); \ 565 __ret; \ 566}) 567 568/** 569 * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses 570 * @wq_head: the waitqueue to wait on 571 * @condition: a C expression for the event to wait for 572 * @timeout: timeout, as a ktime_t 573 * 574 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 575 * @condition evaluates to true or a signal is received. 576 * The @condition is checked each time the waitqueue @wq_head is woken up. 577 * 578 * wake_up() has to be called after changing any variable that could 579 * change the result of the wait condition. 580 * 581 * The function returns 0 if @condition became true, or -ETIME if the timeout 582 * elapsed. 583 */ 584#define wait_event_hrtimeout(wq_head, condition, timeout) \ 585({ \ 586 int __ret = 0; \ 587 might_sleep(); \ 588 if (!(condition)) \ 589 __ret = __wait_event_hrtimeout(wq_head, condition, timeout, \ 590 TASK_UNINTERRUPTIBLE); \ 591 __ret; \ 592}) 593 594/** 595 * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses 596 * @wq: the waitqueue to wait on 597 * @condition: a C expression for the event to wait for 598 * @timeout: timeout, as a ktime_t 599 * 600 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 601 * @condition evaluates to true or a signal is received. 602 * The @condition is checked each time the waitqueue @wq is woken up. 603 * 604 * wake_up() has to be called after changing any variable that could 605 * change the result of the wait condition. 606 * 607 * The function returns 0 if @condition became true, -ERESTARTSYS if it was 608 * interrupted by a signal, or -ETIME if the timeout elapsed. 609 */ 610#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \ 611({ \ 612 long __ret = 0; \ 613 might_sleep(); \ 614 if (!(condition)) \ 615 __ret = __wait_event_hrtimeout(wq, condition, timeout, \ 616 TASK_INTERRUPTIBLE); \ 617 __ret; \ 618}) 619 620#define __wait_event_interruptible_exclusive(wq, condition) \ 621 ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ 622 schedule()) 623 624#define wait_event_interruptible_exclusive(wq, condition) \ 625({ \ 626 int __ret = 0; \ 627 might_sleep(); \ 628 if (!(condition)) \ 629 __ret = __wait_event_interruptible_exclusive(wq, condition); \ 630 __ret; \ 631}) 632 633#define __wait_event_killable_exclusive(wq, condition) \ 634 ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \ 635 schedule()) 636 637#define wait_event_killable_exclusive(wq, condition) \ 638({ \ 639 int __ret = 0; \ 640 might_sleep(); \ 641 if (!(condition)) \ 642 __ret = __wait_event_killable_exclusive(wq, condition); \ 643 __ret; \ 644}) 645 646 647#define __wait_event_freezable_exclusive(wq, condition) \ 648 ___wait_event(wq, condition, (TASK_INTERRUPTIBLE|TASK_FREEZABLE), 1, 0,\ 649 schedule()) 650 651#define wait_event_freezable_exclusive(wq, condition) \ 652({ \ 653 int __ret = 0; \ 654 might_sleep(); \ 655 if (!(condition)) \ 656 __ret = __wait_event_freezable_exclusive(wq, condition); \ 657 __ret; \ 658}) 659 660/** 661 * wait_event_idle - wait for a condition without contributing to system load 662 * @wq_head: the waitqueue to wait on 663 * @condition: a C expression for the event to wait for 664 * 665 * The process is put to sleep (TASK_IDLE) until the 666 * @condition evaluates to true. 667 * The @condition is checked each time the waitqueue @wq_head is woken up. 668 * 669 * wake_up() has to be called after changing any variable that could 670 * change the result of the wait condition. 671 * 672 */ 673#define wait_event_idle(wq_head, condition) \ 674do { \ 675 might_sleep(); \ 676 if (!(condition)) \ 677 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \ 678} while (0) 679 680/** 681 * wait_event_idle_exclusive - wait for a condition with contributing to system load 682 * @wq_head: the waitqueue to wait on 683 * @condition: a C expression for the event to wait for 684 * 685 * The process is put to sleep (TASK_IDLE) until the 686 * @condition evaluates to true. 687 * The @condition is checked each time the waitqueue @wq_head is woken up. 688 * 689 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 690 * set thus if other processes wait on the same list, when this 691 * process is woken further processes are not considered. 692 * 693 * wake_up() has to be called after changing any variable that could 694 * change the result of the wait condition. 695 * 696 */ 697#define wait_event_idle_exclusive(wq_head, condition) \ 698do { \ 699 might_sleep(); \ 700 if (!(condition)) \ 701 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \ 702} while (0) 703 704#define __wait_event_idle_timeout(wq_head, condition, timeout) \ 705 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 706 TASK_IDLE, 0, timeout, \ 707 __ret = schedule_timeout(__ret)) 708 709/** 710 * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses 711 * @wq_head: the waitqueue to wait on 712 * @condition: a C expression for the event to wait for 713 * @timeout: timeout, in jiffies 714 * 715 * The process is put to sleep (TASK_IDLE) until the 716 * @condition evaluates to true. The @condition is checked each time 717 * the waitqueue @wq_head is woken up. 718 * 719 * wake_up() has to be called after changing any variable that could 720 * change the result of the wait condition. 721 * 722 * Returns: 723 * 0 if the @condition evaluated to %false after the @timeout elapsed, 724 * 1 if the @condition evaluated to %true after the @timeout elapsed, 725 * or the remaining jiffies (at least 1) if the @condition evaluated 726 * to %true before the @timeout elapsed. 727 */ 728#define wait_event_idle_timeout(wq_head, condition, timeout) \ 729({ \ 730 long __ret = timeout; \ 731 might_sleep(); \ 732 if (!___wait_cond_timeout(condition)) \ 733 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \ 734 __ret; \ 735}) 736 737#define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ 738 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 739 TASK_IDLE, 1, timeout, \ 740 __ret = schedule_timeout(__ret)) 741 742/** 743 * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses 744 * @wq_head: the waitqueue to wait on 745 * @condition: a C expression for the event to wait for 746 * @timeout: timeout, in jiffies 747 * 748 * The process is put to sleep (TASK_IDLE) until the 749 * @condition evaluates to true. The @condition is checked each time 750 * the waitqueue @wq_head is woken up. 751 * 752 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 753 * set thus if other processes wait on the same list, when this 754 * process is woken further processes are not considered. 755 * 756 * wake_up() has to be called after changing any variable that could 757 * change the result of the wait condition. 758 * 759 * Returns: 760 * 0 if the @condition evaluated to %false after the @timeout elapsed, 761 * 1 if the @condition evaluated to %true after the @timeout elapsed, 762 * or the remaining jiffies (at least 1) if the @condition evaluated 763 * to %true before the @timeout elapsed. 764 */ 765#define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ 766({ \ 767 long __ret = timeout; \ 768 might_sleep(); \ 769 if (!___wait_cond_timeout(condition)) \ 770 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\ 771 __ret; \ 772}) 773 774extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *); 775extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *); 776 777#define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \ 778({ \ 779 int __ret; \ 780 DEFINE_WAIT(__wait); \ 781 if (exclusive) \ 782 __wait.flags |= WQ_FLAG_EXCLUSIVE; \ 783 do { \ 784 __ret = fn(&(wq), &__wait); \ 785 if (__ret) \ 786 break; \ 787 } while (!(condition)); \ 788 __remove_wait_queue(&(wq), &__wait); \ 789 __set_current_state(TASK_RUNNING); \ 790 __ret; \ 791}) 792 793 794/** 795 * wait_event_interruptible_locked - sleep until a condition gets true 796 * @wq: the waitqueue to wait on 797 * @condition: a C expression for the event to wait for 798 * 799 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 800 * @condition evaluates to true or a signal is received. 801 * The @condition is checked each time the waitqueue @wq is woken up. 802 * 803 * It must be called with wq.lock being held. This spinlock is 804 * unlocked while sleeping but @condition testing is done while lock 805 * is held and when this macro exits the lock is held. 806 * 807 * The lock is locked/unlocked using spin_lock()/spin_unlock() 808 * functions which must match the way they are locked/unlocked outside 809 * of this macro. 810 * 811 * wake_up_locked() has to be called after changing any variable that could 812 * change the result of the wait condition. 813 * 814 * The function will return -ERESTARTSYS if it was interrupted by a 815 * signal and 0 if @condition evaluated to true. 816 */ 817#define wait_event_interruptible_locked(wq, condition) \ 818 ((condition) \ 819 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr)) 820 821/** 822 * wait_event_interruptible_locked_irq - sleep until a condition gets true 823 * @wq: the waitqueue to wait on 824 * @condition: a C expression for the event to wait for 825 * 826 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 827 * @condition evaluates to true or a signal is received. 828 * The @condition is checked each time the waitqueue @wq is woken up. 829 * 830 * It must be called with wq.lock being held. This spinlock is 831 * unlocked while sleeping but @condition testing is done while lock 832 * is held and when this macro exits the lock is held. 833 * 834 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() 835 * functions which must match the way they are locked/unlocked outside 836 * of this macro. 837 * 838 * wake_up_locked() has to be called after changing any variable that could 839 * change the result of the wait condition. 840 * 841 * The function will return -ERESTARTSYS if it was interrupted by a 842 * signal and 0 if @condition evaluated to true. 843 */ 844#define wait_event_interruptible_locked_irq(wq, condition) \ 845 ((condition) \ 846 ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq)) 847 848/** 849 * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true 850 * @wq: the waitqueue to wait on 851 * @condition: a C expression for the event to wait for 852 * 853 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 854 * @condition evaluates to true or a signal is received. 855 * The @condition is checked each time the waitqueue @wq is woken up. 856 * 857 * It must be called with wq.lock being held. This spinlock is 858 * unlocked while sleeping but @condition testing is done while lock 859 * is held and when this macro exits the lock is held. 860 * 861 * The lock is locked/unlocked using spin_lock()/spin_unlock() 862 * functions which must match the way they are locked/unlocked outside 863 * of this macro. 864 * 865 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 866 * set thus when other process waits process on the list if this 867 * process is awaken further processes are not considered. 868 * 869 * wake_up_locked() has to be called after changing any variable that could 870 * change the result of the wait condition. 871 * 872 * The function will return -ERESTARTSYS if it was interrupted by a 873 * signal and 0 if @condition evaluated to true. 874 */ 875#define wait_event_interruptible_exclusive_locked(wq, condition) \ 876 ((condition) \ 877 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr)) 878 879/** 880 * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true 881 * @wq: the waitqueue to wait on 882 * @condition: a C expression for the event to wait for 883 * 884 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 885 * @condition evaluates to true or a signal is received. 886 * The @condition is checked each time the waitqueue @wq is woken up. 887 * 888 * It must be called with wq.lock being held. This spinlock is 889 * unlocked while sleeping but @condition testing is done while lock 890 * is held and when this macro exits the lock is held. 891 * 892 * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() 893 * functions which must match the way they are locked/unlocked outside 894 * of this macro. 895 * 896 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag 897 * set thus when other process waits process on the list if this 898 * process is awaken further processes are not considered. 899 * 900 * wake_up_locked() has to be called after changing any variable that could 901 * change the result of the wait condition. 902 * 903 * The function will return -ERESTARTSYS if it was interrupted by a 904 * signal and 0 if @condition evaluated to true. 905 */ 906#define wait_event_interruptible_exclusive_locked_irq(wq, condition) \ 907 ((condition) \ 908 ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq)) 909 910 911#define __wait_event_killable(wq, condition) \ 912 ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) 913 914/** 915 * wait_event_killable - sleep until a condition gets true 916 * @wq_head: the waitqueue to wait on 917 * @condition: a C expression for the event to wait for 918 * 919 * The process is put to sleep (TASK_KILLABLE) until the 920 * @condition evaluates to true or a signal is received. 921 * The @condition is checked each time the waitqueue @wq_head is woken up. 922 * 923 * wake_up() has to be called after changing any variable that could 924 * change the result of the wait condition. 925 * 926 * The function will return -ERESTARTSYS if it was interrupted by a 927 * signal and 0 if @condition evaluated to true. 928 */ 929#define wait_event_killable(wq_head, condition) \ 930({ \ 931 int __ret = 0; \ 932 might_sleep(); \ 933 if (!(condition)) \ 934 __ret = __wait_event_killable(wq_head, condition); \ 935 __ret; \ 936}) 937 938#define __wait_event_state(wq, condition, state) \ 939 ___wait_event(wq, condition, state, 0, 0, schedule()) 940 941/** 942 * wait_event_state - sleep until a condition gets true 943 * @wq_head: the waitqueue to wait on 944 * @condition: a C expression for the event to wait for 945 * @state: state to sleep in 946 * 947 * The process is put to sleep (@state) until the @condition evaluates to true 948 * or a signal is received (when allowed by @state). The @condition is checked 949 * each time the waitqueue @wq_head is woken up. 950 * 951 * wake_up() has to be called after changing any variable that could 952 * change the result of the wait condition. 953 * 954 * The function will return -ERESTARTSYS if it was interrupted by a signal 955 * (when allowed by @state) and 0 if @condition evaluated to true. 956 */ 957#define wait_event_state(wq_head, condition, state) \ 958({ \ 959 int __ret = 0; \ 960 might_sleep(); \ 961 if (!(condition)) \ 962 __ret = __wait_event_state(wq_head, condition, state); \ 963 __ret; \ 964}) 965 966#define __wait_event_killable_timeout(wq_head, condition, timeout) \ 967 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 968 TASK_KILLABLE, 0, timeout, \ 969 __ret = schedule_timeout(__ret)) 970 971/** 972 * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses 973 * @wq_head: the waitqueue to wait on 974 * @condition: a C expression for the event to wait for 975 * @timeout: timeout, in jiffies 976 * 977 * The process is put to sleep (TASK_KILLABLE) until the 978 * @condition evaluates to true or a kill signal is received. 979 * The @condition is checked each time the waitqueue @wq_head is woken up. 980 * 981 * wake_up() has to be called after changing any variable that could 982 * change the result of the wait condition. 983 * 984 * Returns: 985 * 0 if the @condition evaluated to %false after the @timeout elapsed, 986 * 1 if the @condition evaluated to %true after the @timeout elapsed, 987 * the remaining jiffies (at least 1) if the @condition evaluated 988 * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was 989 * interrupted by a kill signal. 990 * 991 * Only kill signals interrupt this process. 992 */ 993#define wait_event_killable_timeout(wq_head, condition, timeout) \ 994({ \ 995 long __ret = timeout; \ 996 might_sleep(); \ 997 if (!___wait_cond_timeout(condition)) \ 998 __ret = __wait_event_killable_timeout(wq_head, \ 999 condition, timeout); \ 1000 __ret; \ 1001}) 1002 1003 1004#define __wait_event_lock_irq(wq_head, condition, lock, cmd) \ 1005 (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ 1006 spin_unlock_irq(&lock); \ 1007 cmd; \ 1008 schedule(); \ 1009 spin_lock_irq(&lock)) 1010 1011/** 1012 * wait_event_lock_irq_cmd - sleep until a condition gets true. The 1013 * condition is checked under the lock. This 1014 * is expected to be called with the lock 1015 * taken. 1016 * @wq_head: the waitqueue to wait on 1017 * @condition: a C expression for the event to wait for 1018 * @lock: a locked spinlock_t, which will be released before cmd 1019 * and schedule() and reacquired afterwards. 1020 * @cmd: a command which is invoked outside the critical section before 1021 * sleep 1022 * 1023 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 1024 * @condition evaluates to true. The @condition is checked each time 1025 * the waitqueue @wq_head is woken up. 1026 * 1027 * wake_up() has to be called after changing any variable that could 1028 * change the result of the wait condition. 1029 * 1030 * This is supposed to be called while holding the lock. The lock is 1031 * dropped before invoking the cmd and going to sleep and is reacquired 1032 * afterwards. 1033 */ 1034#define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd) \ 1035do { \ 1036 if (condition) \ 1037 break; \ 1038 __wait_event_lock_irq(wq_head, condition, lock, cmd); \ 1039} while (0) 1040 1041/** 1042 * wait_event_lock_irq - sleep until a condition gets true. The 1043 * condition is checked under the lock. This 1044 * is expected to be called with the lock 1045 * taken. 1046 * @wq_head: the waitqueue to wait on 1047 * @condition: a C expression for the event to wait for 1048 * @lock: a locked spinlock_t, which will be released before schedule() 1049 * and reacquired afterwards. 1050 * 1051 * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the 1052 * @condition evaluates to true. The @condition is checked each time 1053 * the waitqueue @wq_head is woken up. 1054 * 1055 * wake_up() has to be called after changing any variable that could 1056 * change the result of the wait condition. 1057 * 1058 * This is supposed to be called while holding the lock. The lock is 1059 * dropped before going to sleep and is reacquired afterwards. 1060 */ 1061#define wait_event_lock_irq(wq_head, condition, lock) \ 1062do { \ 1063 if (condition) \ 1064 break; \ 1065 __wait_event_lock_irq(wq_head, condition, lock, ); \ 1066} while (0) 1067 1068 1069#define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \ 1070 ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0, \ 1071 spin_unlock_irq(&lock); \ 1072 cmd; \ 1073 schedule(); \ 1074 spin_lock_irq(&lock)) 1075 1076/** 1077 * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. 1078 * The condition is checked under the lock. This is expected to 1079 * be called with the lock taken. 1080 * @wq_head: the waitqueue to wait on 1081 * @condition: a C expression for the event to wait for 1082 * @lock: a locked spinlock_t, which will be released before cmd and 1083 * schedule() and reacquired afterwards. 1084 * @cmd: a command which is invoked outside the critical section before 1085 * sleep 1086 * 1087 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 1088 * @condition evaluates to true or a signal is received. The @condition is 1089 * checked each time the waitqueue @wq_head is woken up. 1090 * 1091 * wake_up() has to be called after changing any variable that could 1092 * change the result of the wait condition. 1093 * 1094 * This is supposed to be called while holding the lock. The lock is 1095 * dropped before invoking the cmd and going to sleep and is reacquired 1096 * afterwards. 1097 * 1098 * The macro will return -ERESTARTSYS if it was interrupted by a signal 1099 * and 0 if @condition evaluated to true. 1100 */ 1101#define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd) \ 1102({ \ 1103 int __ret = 0; \ 1104 if (!(condition)) \ 1105 __ret = __wait_event_interruptible_lock_irq(wq_head, \ 1106 condition, lock, cmd); \ 1107 __ret; \ 1108}) 1109 1110/** 1111 * wait_event_interruptible_lock_irq - sleep until a condition gets true. 1112 * The condition is checked under the lock. This is expected 1113 * to be called with the lock taken. 1114 * @wq_head: the waitqueue to wait on 1115 * @condition: a C expression for the event to wait for 1116 * @lock: a locked spinlock_t, which will be released before schedule() 1117 * and reacquired afterwards. 1118 * 1119 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 1120 * @condition evaluates to true or signal is received. The @condition is 1121 * checked each time the waitqueue @wq_head is woken up. 1122 * 1123 * wake_up() has to be called after changing any variable that could 1124 * change the result of the wait condition. 1125 * 1126 * This is supposed to be called while holding the lock. The lock is 1127 * dropped before going to sleep and is reacquired afterwards. 1128 * 1129 * The macro will return -ERESTARTSYS if it was interrupted by a signal 1130 * and 0 if @condition evaluated to true. 1131 */ 1132#define wait_event_interruptible_lock_irq(wq_head, condition, lock) \ 1133({ \ 1134 int __ret = 0; \ 1135 if (!(condition)) \ 1136 __ret = __wait_event_interruptible_lock_irq(wq_head, \ 1137 condition, lock,); \ 1138 __ret; \ 1139}) 1140 1141#define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \ 1142 ___wait_event(wq_head, ___wait_cond_timeout(condition), \ 1143 state, 0, timeout, \ 1144 spin_unlock_irq(&lock); \ 1145 __ret = schedule_timeout(__ret); \ 1146 spin_lock_irq(&lock)); 1147 1148/** 1149 * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets 1150 * true or a timeout elapses. The condition is checked under 1151 * the lock. This is expected to be called with the lock taken. 1152 * @wq_head: the waitqueue to wait on 1153 * @condition: a C expression for the event to wait for 1154 * @lock: a locked spinlock_t, which will be released before schedule() 1155 * and reacquired afterwards. 1156 * @timeout: timeout, in jiffies 1157 * 1158 * The process is put to sleep (TASK_INTERRUPTIBLE) until the 1159 * @condition evaluates to true or signal is received. The @condition is 1160 * checked each time the waitqueue @wq_head is woken up. 1161 * 1162 * wake_up() has to be called after changing any variable that could 1163 * change the result of the wait condition. 1164 * 1165 * This is supposed to be called while holding the lock. The lock is 1166 * dropped before going to sleep and is reacquired afterwards. 1167 * 1168 * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it 1169 * was interrupted by a signal, and the remaining jiffies otherwise 1170 * if the condition evaluated to true before the timeout elapsed. 1171 */ 1172#define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock, \ 1173 timeout) \ 1174({ \ 1175 long __ret = timeout; \ 1176 if (!___wait_cond_timeout(condition)) \ 1177 __ret = __wait_event_lock_irq_timeout( \ 1178 wq_head, condition, lock, timeout, \ 1179 TASK_INTERRUPTIBLE); \ 1180 __ret; \ 1181}) 1182 1183#define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \ 1184({ \ 1185 long __ret = timeout; \ 1186 if (!___wait_cond_timeout(condition)) \ 1187 __ret = __wait_event_lock_irq_timeout( \ 1188 wq_head, condition, lock, timeout, \ 1189 TASK_UNINTERRUPTIBLE); \ 1190 __ret; \ 1191}) 1192 1193/* 1194 * Waitqueues which are removed from the waitqueue_head at wakeup time 1195 */ 1196void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); 1197bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); 1198long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); 1199void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); 1200long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout); 1201int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); 1202int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); 1203 1204#define DEFINE_WAIT_FUNC(name, function) \ 1205 struct wait_queue_entry name = { \ 1206 .private = current, \ 1207 .func = function, \ 1208 .entry = LIST_HEAD_INIT((name).entry), \ 1209 } 1210 1211#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) 1212 1213#define init_wait(wait) \ 1214 do { \ 1215 (wait)->private = current; \ 1216 (wait)->func = autoremove_wake_function; \ 1217 INIT_LIST_HEAD(&(wait)->entry); \ 1218 (wait)->flags = 0; \ 1219 } while (0) 1220 1221typedef int (*task_call_f)(struct task_struct *p, void *arg); 1222extern int task_call_func(struct task_struct *p, task_call_f func, void *arg); 1223 1224#endif /* _LINUX_WAIT_H */ 1225