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 | |
13 | typedef struct wait_queue_entry wait_queue_entry_t; |
14 | |
15 | typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key); |
16 | int 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 | */ |
28 | struct wait_queue_entry { |
29 | unsigned int flags; |
30 | void *private; |
31 | wait_queue_func_t func; |
32 | struct list_head entry; |
33 | }; |
34 | |
35 | struct wait_queue_head { |
36 | spinlock_t lock; |
37 | struct list_head head; |
38 | }; |
39 | typedef struct wait_queue_head wait_queue_head_t; |
40 | |
41 | struct 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 | |
62 | extern 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 | |
80 | static 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 | |
87 | static inline void |
88 | init_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 | */ |
125 | static inline int waitqueue_active(struct wait_queue_head *wq_head) |
126 | { |
127 | return !list_empty(head: &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 | */ |
138 | static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head) |
139 | { |
140 | return list_is_singular(head: &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 | */ |
151 | static 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 | |
164 | extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
165 | extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
166 | extern void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
167 | extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
168 | |
169 | static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
170 | { |
171 | struct list_head *head = &wq_head->head; |
172 | struct wait_queue_entry *wq; |
173 | |
174 | list_for_each_entry(wq, &wq_head->head, entry) { |
175 | if (!(wq->flags & WQ_FLAG_PRIORITY)) |
176 | break; |
177 | head = &wq->entry; |
178 | } |
179 | list_add(new: &wq_entry->entry, head); |
180 | } |
181 | |
182 | /* |
183 | * Used for wake-one threads: |
184 | */ |
185 | static inline void |
186 | __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
187 | { |
188 | wq_entry->flags |= WQ_FLAG_EXCLUSIVE; |
189 | __add_wait_queue(wq_head, wq_entry); |
190 | } |
191 | |
192 | static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
193 | { |
194 | list_add_tail(new: &wq_entry->entry, head: &wq_head->head); |
195 | } |
196 | |
197 | static inline void |
198 | __add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
199 | { |
200 | wq_entry->flags |= WQ_FLAG_EXCLUSIVE; |
201 | __add_wait_queue_entry_tail(wq_head, wq_entry); |
202 | } |
203 | |
204 | static inline void |
205 | __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) |
206 | { |
207 | list_del(entry: &wq_entry->entry); |
208 | } |
209 | |
210 | int __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key); |
211 | void __wake_up_on_current_cpu(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
212 | void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
213 | void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
214 | void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key); |
215 | void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr); |
216 | void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode); |
217 | void __wake_up_pollfree(struct wait_queue_head *wq_head); |
218 | |
219 | #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) |
220 | #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) |
221 | #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) |
222 | #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) |
223 | #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) |
224 | #define wake_up_sync(x) __wake_up_sync(x, TASK_NORMAL) |
225 | |
226 | #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) |
227 | #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) |
228 | #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) |
229 | #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE) |
230 | |
231 | /* |
232 | * Wakeup macros to be used to report events to the targets. |
233 | */ |
234 | #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m)) |
235 | #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m)) |
236 | #define wake_up_poll(x, m) \ |
237 | __wake_up(x, TASK_NORMAL, 1, poll_to_key(m)) |
238 | #define wake_up_poll_on_current_cpu(x, m) \ |
239 | __wake_up_on_current_cpu(x, TASK_NORMAL, poll_to_key(m)) |
240 | #define wake_up_locked_poll(x, m) \ |
241 | __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m)) |
242 | #define wake_up_interruptible_poll(x, m) \ |
243 | __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m)) |
244 | #define wake_up_interruptible_sync_poll(x, m) \ |
245 | __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) |
246 | #define wake_up_interruptible_sync_poll_locked(x, m) \ |
247 | __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m)) |
248 | |
249 | /** |
250 | * wake_up_pollfree - signal that a polled waitqueue is going away |
251 | * @wq_head: the wait queue head |
252 | * |
253 | * In the very rare cases where a ->poll() implementation uses a waitqueue whose |
254 | * lifetime is tied to a task rather than to the 'struct file' being polled, |
255 | * this function must be called before the waitqueue is freed so that |
256 | * non-blocking polls (e.g. epoll) are notified that the queue is going away. |
257 | * |
258 | * The caller must also RCU-delay the freeing of the wait_queue_head, e.g. via |
259 | * an explicit synchronize_rcu() or call_rcu(), or via SLAB_TYPESAFE_BY_RCU. |
260 | */ |
261 | static inline void wake_up_pollfree(struct wait_queue_head *wq_head) |
262 | { |
263 | /* |
264 | * For performance reasons, we don't always take the queue lock here. |
265 | * Therefore, we might race with someone removing the last entry from |
266 | * the queue, and proceed while they still hold the queue lock. |
267 | * However, rcu_read_lock() is required to be held in such cases, so we |
268 | * can safely proceed with an RCU-delayed free. |
269 | */ |
270 | if (waitqueue_active(wq_head)) |
271 | __wake_up_pollfree(wq_head); |
272 | } |
273 | |
274 | #define ___wait_cond_timeout(condition) \ |
275 | ({ \ |
276 | bool __cond = (condition); \ |
277 | if (__cond && !__ret) \ |
278 | __ret = 1; \ |
279 | __cond || !__ret; \ |
280 | }) |
281 | |
282 | #define ___wait_is_interruptible(state) \ |
283 | (!__builtin_constant_p(state) || \ |
284 | (state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL))) |
285 | |
286 | extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags); |
287 | |
288 | /* |
289 | * The below macro ___wait_event() has an explicit shadow of the __ret |
290 | * variable when used from the wait_event_*() macros. |
291 | * |
292 | * This is so that both can use the ___wait_cond_timeout() construct |
293 | * to wrap the condition. |
294 | * |
295 | * The type inconsistency of the wait_event_*() __ret variable is also |
296 | * on purpose; we use long where we can return timeout values and int |
297 | * otherwise. |
298 | */ |
299 | |
300 | #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \ |
301 | ({ \ |
302 | __label__ __out; \ |
303 | struct wait_queue_entry __wq_entry; \ |
304 | long __ret = ret; /* explicit shadow */ \ |
305 | \ |
306 | init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \ |
307 | for (;;) { \ |
308 | long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\ |
309 | \ |
310 | if (condition) \ |
311 | break; \ |
312 | \ |
313 | if (___wait_is_interruptible(state) && __int) { \ |
314 | __ret = __int; \ |
315 | goto __out; \ |
316 | } \ |
317 | \ |
318 | cmd; \ |
319 | \ |
320 | if (condition) \ |
321 | break; \ |
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) \ |
344 | do { \ |
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) \ |
359 | do { \ |
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) \ |
449 | do { \ |
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) \ |
474 | do { \ |
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_setup_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) \ |
674 | do { \ |
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) \ |
698 | do { \ |
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 | |
774 | extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *); |
775 | extern 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) \ |
1035 | do { \ |
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) \ |
1062 | do { \ |
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 | */ |
1196 | void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); |
1197 | bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); |
1198 | long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state); |
1199 | void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry); |
1200 | long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout); |
1201 | int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key); |
1202 | int 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_func(wait, function) \ |
1214 | do { \ |
1215 | (wait)->private = current; \ |
1216 | (wait)->func = function; \ |
1217 | INIT_LIST_HEAD(&(wait)->entry); \ |
1218 | (wait)->flags = 0; \ |
1219 | } while (0) |
1220 | |
1221 | #define init_wait(wait) init_wait_func(wait, autoremove_wake_function) |
1222 | |
1223 | typedef int (*task_call_f)(struct task_struct *p, void *arg); |
1224 | extern int task_call_func(struct task_struct *p, task_call_f func, void *arg); |
1225 | |
1226 | #endif /* _LINUX_WAIT_H */ |
1227 | |