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1 | #ifndef _LINUX_WAIT_H | |
2 | #define _LINUX_WAIT_H | |
3 | /* | |
4 | * Linux wait queue related types and methods | |
5 | */ | |
6 | #include <linux/list.h> | |
7 | #include <linux/stddef.h> | |
8 | #include <linux/spinlock.h> | |
9 | #include <asm/current.h> | |
10 | #include <uapi/linux/wait.h> | |
11 | ||
12 | typedef struct __wait_queue wait_queue_t; | |
13 | typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key); | |
14 | int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key); | |
15 | ||
16 | /* __wait_queue::flags */ | |
17 | #define WQ_FLAG_EXCLUSIVE 0x01 | |
18 | #define WQ_FLAG_WOKEN 0x02 | |
19 | ||
20 | struct __wait_queue { | |
21 | unsigned int flags; | |
22 | void *private; | |
23 | wait_queue_func_t func; | |
24 | struct list_head task_list; | |
25 | }; | |
26 | ||
27 | struct wait_bit_key { | |
28 | void *flags; | |
29 | int bit_nr; | |
30 | #define WAIT_ATOMIC_T_BIT_NR -1 | |
31 | unsigned long timeout; | |
32 | }; | |
33 | ||
34 | struct wait_bit_queue { | |
35 | struct wait_bit_key key; | |
36 | wait_queue_t wait; | |
37 | }; | |
38 | ||
39 | struct __wait_queue_head { | |
40 | spinlock_t lock; | |
41 | struct list_head task_list; | |
42 | }; | |
43 | typedef struct __wait_queue_head wait_queue_head_t; | |
44 | ||
45 | struct task_struct; | |
46 | ||
47 | /* | |
48 | * Macros for declaration and initialisaton of the datatypes | |
49 | */ | |
50 | ||
51 | #define __WAITQUEUE_INITIALIZER(name, tsk) { \ | |
52 | .private = tsk, \ | |
53 | .func = default_wake_function, \ | |
54 | .task_list = { NULL, NULL } } | |
55 | ||
56 | #define DECLARE_WAITQUEUE(name, tsk) \ | |
57 | wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk) | |
58 | ||
59 | #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ | |
60 | .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ | |
61 | .task_list = { &(name).task_list, &(name).task_list } } | |
62 | ||
63 | #define DECLARE_WAIT_QUEUE_HEAD(name) \ | |
64 | wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name) | |
65 | ||
66 | #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \ | |
67 | { .flags = word, .bit_nr = bit, } | |
68 | ||
69 | #define __WAIT_ATOMIC_T_KEY_INITIALIZER(p) \ | |
70 | { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, } | |
71 | ||
72 | extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *); | |
73 | ||
74 | #define init_waitqueue_head(q) \ | |
75 | do { \ | |
76 | static struct lock_class_key __key; \ | |
77 | \ | |
78 | __init_waitqueue_head((q), #q, &__key); \ | |
79 | } while (0) | |
80 | ||
81 | #ifdef CONFIG_LOCKDEP | |
82 | # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ | |
83 | ({ init_waitqueue_head(&name); name; }) | |
84 | # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ | |
85 | wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) | |
86 | #else | |
87 | # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name) | |
88 | #endif | |
89 | ||
90 | static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) | |
91 | { | |
92 | q->flags = 0; | |
93 | q->private = p; | |
94 | q->func = default_wake_function; | |
95 | } | |
96 | ||
97 | static inline void | |
98 | init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func) | |
99 | { | |
100 | q->flags = 0; | |
101 | q->private = NULL; | |
102 | q->func = func; | |
103 | } | |
104 | ||
105 | /** | |
106 | * waitqueue_active -- locklessly test for waiters on the queue | |
107 | * @q: the waitqueue to test for waiters | |
108 | * | |
109 | * returns true if the wait list is not empty | |
110 | * | |
111 | * NOTE: this function is lockless and requires care, incorrect usage _will_ | |
112 | * lead to sporadic and non-obvious failure. | |
113 | * | |
114 | * Use either while holding wait_queue_head_t::lock or when used for wakeups | |
115 | * with an extra smp_mb() like: | |
116 | * | |
117 | * CPU0 - waker CPU1 - waiter | |
118 | * | |
119 | * for (;;) { | |
120 | * @cond = true; prepare_to_wait(&wq, &wait, state); | |
121 | * smp_mb(); // smp_mb() from set_current_state() | |
122 | * if (waitqueue_active(wq)) if (@cond) | |
123 | * wake_up(wq); break; | |
124 | * schedule(); | |
125 | * } | |
126 | * finish_wait(&wq, &wait); | |
127 | * | |
128 | * Because without the explicit smp_mb() it's possible for the | |
129 | * waitqueue_active() load to get hoisted over the @cond store such that we'll | |
130 | * observe an empty wait list while the waiter might not observe @cond. | |
131 | * | |
132 | * Also note that this 'optimization' trades a spin_lock() for an smp_mb(), | |
133 | * which (when the lock is uncontended) are of roughly equal cost. | |
134 | */ | |
135 | static inline int waitqueue_active(wait_queue_head_t *q) | |
136 | { | |
137 | return !list_empty(&q->task_list); | |
138 | } | |
139 | ||
140 | /** | |
141 | * wq_has_sleeper - check if there are any waiting processes | |
142 | * @wq: wait queue head | |
143 | * | |
144 | * Returns true if wq has waiting processes | |
145 | * | |
146 | * Please refer to the comment for waitqueue_active. | |
147 | */ | |
148 | static inline bool wq_has_sleeper(wait_queue_head_t *wq) | |
149 | { | |
150 | /* | |
151 | * We need to be sure we are in sync with the | |
152 | * add_wait_queue modifications to the wait queue. | |
153 | * | |
154 | * This memory barrier should be paired with one on the | |
155 | * waiting side. | |
156 | */ | |
157 | smp_mb(); | |
158 | return waitqueue_active(wq); | |
159 | } | |
160 | ||
161 | extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); | |
162 | extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait); | |
163 | extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); | |
164 | ||
165 | static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) | |
166 | { | |
167 | list_add(&new->task_list, &head->task_list); | |
168 | } | |
169 | ||
170 | /* | |
171 | * Used for wake-one threads: | |
172 | */ | |
173 | static inline void | |
174 | __add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait) | |
175 | { | |
176 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
177 | __add_wait_queue(q, wait); | |
178 | } | |
179 | ||
180 | static inline void __add_wait_queue_tail(wait_queue_head_t *head, | |
181 | wait_queue_t *new) | |
182 | { | |
183 | list_add_tail(&new->task_list, &head->task_list); | |
184 | } | |
185 | ||
186 | static inline void | |
187 | __add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait) | |
188 | { | |
189 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
190 | __add_wait_queue_tail(q, wait); | |
191 | } | |
192 | ||
193 | static inline void | |
194 | __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) | |
195 | { | |
196 | list_del(&old->task_list); | |
197 | } | |
198 | ||
199 | typedef int wait_bit_action_f(struct wait_bit_key *, int mode); | |
200 | void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key); | |
201 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key); | |
202 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key); | |
203 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr); | |
204 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr); | |
205 | void __wake_up_bit(wait_queue_head_t *, void *, int); | |
206 | int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); | |
207 | int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); | |
208 | void wake_up_bit(void *, int); | |
209 | void wake_up_atomic_t(atomic_t *); | |
210 | int out_of_line_wait_on_bit(void *, int, wait_bit_action_f *, unsigned); | |
211 | int out_of_line_wait_on_bit_timeout(void *, int, wait_bit_action_f *, unsigned, unsigned long); | |
212 | int out_of_line_wait_on_bit_lock(void *, int, wait_bit_action_f *, unsigned); | |
213 | int out_of_line_wait_on_atomic_t(atomic_t *, int (*)(atomic_t *), unsigned); | |
214 | wait_queue_head_t *bit_waitqueue(void *, int); | |
215 | ||
216 | #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) | |
217 | #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) | |
218 | #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) | |
219 | #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) | |
220 | #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) | |
221 | ||
222 | #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) | |
223 | #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) | |
224 | #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) | |
225 | #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1) | |
226 | ||
227 | /* | |
228 | * Wakeup macros to be used to report events to the targets. | |
229 | */ | |
230 | #define wake_up_poll(x, m) \ | |
231 | __wake_up(x, TASK_NORMAL, 1, (void *) (m)) | |
232 | #define wake_up_locked_poll(x, m) \ | |
233 | __wake_up_locked_key((x), TASK_NORMAL, (void *) (m)) | |
234 | #define wake_up_interruptible_poll(x, m) \ | |
235 | __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m)) | |
236 | #define wake_up_interruptible_sync_poll(x, m) \ | |
237 | __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m)) | |
238 | ||
239 | #define ___wait_cond_timeout(condition) \ | |
240 | ({ \ | |
241 | bool __cond = (condition); \ | |
242 | if (__cond && !__ret) \ | |
243 | __ret = 1; \ | |
244 | __cond || !__ret; \ | |
245 | }) | |
246 | ||
247 | #define ___wait_is_interruptible(state) \ | |
248 | (!__builtin_constant_p(state) || \ | |
249 | state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ | |
250 | ||
251 | /* | |
252 | * The below macro ___wait_event() has an explicit shadow of the __ret | |
253 | * variable when used from the wait_event_*() macros. | |
254 | * | |
255 | * This is so that both can use the ___wait_cond_timeout() construct | |
256 | * to wrap the condition. | |
257 | * | |
258 | * The type inconsistency of the wait_event_*() __ret variable is also | |
259 | * on purpose; we use long where we can return timeout values and int | |
260 | * otherwise. | |
261 | */ | |
262 | ||
263 | #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ | |
264 | ({ \ | |
265 | __label__ __out; \ | |
266 | wait_queue_t __wait; \ | |
267 | long __ret = ret; /* explicit shadow */ \ | |
268 | \ | |
269 | INIT_LIST_HEAD(&__wait.task_list); \ | |
270 | if (exclusive) \ | |
271 | __wait.flags = WQ_FLAG_EXCLUSIVE; \ | |
272 | else \ | |
273 | __wait.flags = 0; \ | |
274 | \ | |
275 | for (;;) { \ | |
276 | long __int = prepare_to_wait_event(&wq, &__wait, state);\ | |
277 | \ | |
278 | if (condition) \ | |
279 | break; \ | |
280 | \ | |
281 | if (___wait_is_interruptible(state) && __int) { \ | |
282 | __ret = __int; \ | |
283 | if (exclusive) { \ | |
284 | abort_exclusive_wait(&wq, &__wait, \ | |
285 | state, NULL); \ | |
286 | goto __out; \ | |
287 | } \ | |
288 | break; \ | |
289 | } \ | |
290 | \ | |
291 | cmd; \ | |
292 | } \ | |
293 | finish_wait(&wq, &__wait); \ | |
294 | __out: __ret; \ | |
295 | }) | |
296 | ||
297 | #define __wait_event(wq, condition) \ | |
298 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ | |
299 | schedule()) | |
300 | ||
301 | /** | |
302 | * wait_event - sleep until a condition gets true | |
303 | * @wq: the waitqueue to wait on | |
304 | * @condition: a C expression for the event to wait for | |
305 | * | |
306 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
307 | * @condition evaluates to true. The @condition is checked each time | |
308 | * the waitqueue @wq is woken up. | |
309 | * | |
310 | * wake_up() has to be called after changing any variable that could | |
311 | * change the result of the wait condition. | |
312 | */ | |
313 | #define wait_event(wq, condition) \ | |
314 | do { \ | |
315 | might_sleep(); \ | |
316 | if (condition) \ | |
317 | break; \ | |
318 | __wait_event(wq, condition); \ | |
319 | } while (0) | |
320 | ||
321 | #define __io_wait_event(wq, condition) \ | |
322 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ | |
323 | io_schedule()) | |
324 | ||
325 | /* | |
326 | * io_wait_event() -- like wait_event() but with io_schedule() | |
327 | */ | |
328 | #define io_wait_event(wq, condition) \ | |
329 | do { \ | |
330 | might_sleep(); \ | |
331 | if (condition) \ | |
332 | break; \ | |
333 | __io_wait_event(wq, condition); \ | |
334 | } while (0) | |
335 | ||
336 | #define __wait_event_freezable(wq, condition) \ | |
337 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ | |
338 | schedule(); try_to_freeze()) | |
339 | ||
340 | /** | |
341 | * wait_event_freezable - sleep (or freeze) until a condition gets true | |
342 | * @wq: the waitqueue to wait on | |
343 | * @condition: a C expression for the event to wait for | |
344 | * | |
345 | * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute | |
346 | * to system load) until the @condition evaluates to true. The | |
347 | * @condition is checked each time the waitqueue @wq is woken up. | |
348 | * | |
349 | * wake_up() has to be called after changing any variable that could | |
350 | * change the result of the wait condition. | |
351 | */ | |
352 | #define wait_event_freezable(wq, condition) \ | |
353 | ({ \ | |
354 | int __ret = 0; \ | |
355 | might_sleep(); \ | |
356 | if (!(condition)) \ | |
357 | __ret = __wait_event_freezable(wq, condition); \ | |
358 | __ret; \ | |
359 | }) | |
360 | ||
361 | #define __wait_event_timeout(wq, condition, timeout) \ | |
362 | ___wait_event(wq, ___wait_cond_timeout(condition), \ | |
363 | TASK_UNINTERRUPTIBLE, 0, timeout, \ | |
364 | __ret = schedule_timeout(__ret)) | |
365 | ||
366 | /** | |
367 | * wait_event_timeout - sleep until a condition gets true or a timeout elapses | |
368 | * @wq: the waitqueue to wait on | |
369 | * @condition: a C expression for the event to wait for | |
370 | * @timeout: timeout, in jiffies | |
371 | * | |
372 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
373 | * @condition evaluates to true. The @condition is checked each time | |
374 | * the waitqueue @wq is woken up. | |
375 | * | |
376 | * wake_up() has to be called after changing any variable that could | |
377 | * change the result of the wait condition. | |
378 | * | |
379 | * Returns: | |
380 | * 0 if the @condition evaluated to %false after the @timeout elapsed, | |
381 | * 1 if the @condition evaluated to %true after the @timeout elapsed, | |
382 | * or the remaining jiffies (at least 1) if the @condition evaluated | |
383 | * to %true before the @timeout elapsed. | |
384 | */ | |
385 | #define wait_event_timeout(wq, condition, timeout) \ | |
386 | ({ \ | |
387 | long __ret = timeout; \ | |
388 | might_sleep(); \ | |
389 | if (!___wait_cond_timeout(condition)) \ | |
390 | __ret = __wait_event_timeout(wq, condition, timeout); \ | |
391 | __ret; \ | |
392 | }) | |
393 | ||
394 | #define __wait_event_freezable_timeout(wq, condition, timeout) \ | |
395 | ___wait_event(wq, ___wait_cond_timeout(condition), \ | |
396 | TASK_INTERRUPTIBLE, 0, timeout, \ | |
397 | __ret = schedule_timeout(__ret); try_to_freeze()) | |
398 | ||
399 | /* | |
400 | * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid | |
401 | * increasing load and is freezable. | |
402 | */ | |
403 | #define wait_event_freezable_timeout(wq, condition, timeout) \ | |
404 | ({ \ | |
405 | long __ret = timeout; \ | |
406 | might_sleep(); \ | |
407 | if (!___wait_cond_timeout(condition)) \ | |
408 | __ret = __wait_event_freezable_timeout(wq, condition, timeout); \ | |
409 | __ret; \ | |
410 | }) | |
411 | ||
412 | #define __wait_event_exclusive_cmd(wq, condition, cmd1, cmd2) \ | |
413 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 1, 0, \ | |
414 | cmd1; schedule(); cmd2) | |
415 | /* | |
416 | * Just like wait_event_cmd(), except it sets exclusive flag | |
417 | */ | |
418 | #define wait_event_exclusive_cmd(wq, condition, cmd1, cmd2) \ | |
419 | do { \ | |
420 | if (condition) \ | |
421 | break; \ | |
422 | __wait_event_exclusive_cmd(wq, condition, cmd1, cmd2); \ | |
423 | } while (0) | |
424 | ||
425 | #define __wait_event_cmd(wq, condition, cmd1, cmd2) \ | |
426 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ | |
427 | cmd1; schedule(); cmd2) | |
428 | ||
429 | /** | |
430 | * wait_event_cmd - sleep until a condition gets true | |
431 | * @wq: the waitqueue to wait on | |
432 | * @condition: a C expression for the event to wait for | |
433 | * @cmd1: the command will be executed before sleep | |
434 | * @cmd2: the command will be executed after sleep | |
435 | * | |
436 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
437 | * @condition evaluates to true. The @condition is checked each time | |
438 | * the waitqueue @wq is woken up. | |
439 | * | |
440 | * wake_up() has to be called after changing any variable that could | |
441 | * change the result of the wait condition. | |
442 | */ | |
443 | #define wait_event_cmd(wq, condition, cmd1, cmd2) \ | |
444 | do { \ | |
445 | if (condition) \ | |
446 | break; \ | |
447 | __wait_event_cmd(wq, condition, cmd1, cmd2); \ | |
448 | } while (0) | |
449 | ||
450 | #define __wait_event_interruptible(wq, condition) \ | |
451 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ | |
452 | schedule()) | |
453 | ||
454 | /** | |
455 | * wait_event_interruptible - sleep until a condition gets true | |
456 | * @wq: the waitqueue to wait on | |
457 | * @condition: a C expression for the event to wait for | |
458 | * | |
459 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
460 | * @condition evaluates to true or a signal is received. | |
461 | * The @condition is checked each time the waitqueue @wq is woken up. | |
462 | * | |
463 | * wake_up() has to be called after changing any variable that could | |
464 | * change the result of the wait condition. | |
465 | * | |
466 | * The function will return -ERESTARTSYS if it was interrupted by a | |
467 | * signal and 0 if @condition evaluated to true. | |
468 | */ | |
469 | #define wait_event_interruptible(wq, condition) \ | |
470 | ({ \ | |
471 | int __ret = 0; \ | |
472 | might_sleep(); \ | |
473 | if (!(condition)) \ | |
474 | __ret = __wait_event_interruptible(wq, condition); \ | |
475 | __ret; \ | |
476 | }) | |
477 | ||
478 | #define __wait_event_interruptible_timeout(wq, condition, timeout) \ | |
479 | ___wait_event(wq, ___wait_cond_timeout(condition), \ | |
480 | TASK_INTERRUPTIBLE, 0, timeout, \ | |
481 | __ret = schedule_timeout(__ret)) | |
482 | ||
483 | /** | |
484 | * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses | |
485 | * @wq: the waitqueue to wait on | |
486 | * @condition: a C expression for the event to wait for | |
487 | * @timeout: timeout, in jiffies | |
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 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 | * Returns: | |
497 | * 0 if the @condition evaluated to %false after the @timeout elapsed, | |
498 | * 1 if the @condition evaluated to %true after the @timeout elapsed, | |
499 | * the remaining jiffies (at least 1) if the @condition evaluated | |
500 | * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was | |
501 | * interrupted by a signal. | |
502 | */ | |
503 | #define wait_event_interruptible_timeout(wq, condition, timeout) \ | |
504 | ({ \ | |
505 | long __ret = timeout; \ | |
506 | might_sleep(); \ | |
507 | if (!___wait_cond_timeout(condition)) \ | |
508 | __ret = __wait_event_interruptible_timeout(wq, \ | |
509 | condition, timeout); \ | |
510 | __ret; \ | |
511 | }) | |
512 | ||
513 | #define __wait_event_hrtimeout(wq, condition, timeout, state) \ | |
514 | ({ \ | |
515 | int __ret = 0; \ | |
516 | struct hrtimer_sleeper __t; \ | |
517 | \ | |
518 | hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \ | |
519 | HRTIMER_MODE_REL); \ | |
520 | hrtimer_init_sleeper(&__t, current); \ | |
521 | if ((timeout).tv64 != KTIME_MAX) \ | |
522 | hrtimer_start_range_ns(&__t.timer, timeout, \ | |
523 | current->timer_slack_ns, \ | |
524 | HRTIMER_MODE_REL); \ | |
525 | \ | |
526 | __ret = ___wait_event(wq, condition, state, 0, 0, \ | |
527 | if (!__t.task) { \ | |
528 | __ret = -ETIME; \ | |
529 | break; \ | |
530 | } \ | |
531 | schedule()); \ | |
532 | \ | |
533 | hrtimer_cancel(&__t.timer); \ | |
534 | destroy_hrtimer_on_stack(&__t.timer); \ | |
535 | __ret; \ | |
536 | }) | |
537 | ||
538 | /** | |
539 | * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses | |
540 | * @wq: the waitqueue to wait on | |
541 | * @condition: a C expression for the event to wait for | |
542 | * @timeout: timeout, as a ktime_t | |
543 | * | |
544 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
545 | * @condition evaluates to true or a signal is received. | |
546 | * The @condition is checked each time the waitqueue @wq is woken up. | |
547 | * | |
548 | * wake_up() has to be called after changing any variable that could | |
549 | * change the result of the wait condition. | |
550 | * | |
551 | * The function returns 0 if @condition became true, or -ETIME if the timeout | |
552 | * elapsed. | |
553 | */ | |
554 | #define wait_event_hrtimeout(wq, condition, timeout) \ | |
555 | ({ \ | |
556 | int __ret = 0; \ | |
557 | might_sleep(); \ | |
558 | if (!(condition)) \ | |
559 | __ret = __wait_event_hrtimeout(wq, condition, timeout, \ | |
560 | TASK_UNINTERRUPTIBLE); \ | |
561 | __ret; \ | |
562 | }) | |
563 | ||
564 | /** | |
565 | * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses | |
566 | * @wq: the waitqueue to wait on | |
567 | * @condition: a C expression for the event to wait for | |
568 | * @timeout: timeout, as a ktime_t | |
569 | * | |
570 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
571 | * @condition evaluates to true or a signal is received. | |
572 | * The @condition is checked each time the waitqueue @wq is woken up. | |
573 | * | |
574 | * wake_up() has to be called after changing any variable that could | |
575 | * change the result of the wait condition. | |
576 | * | |
577 | * The function returns 0 if @condition became true, -ERESTARTSYS if it was | |
578 | * interrupted by a signal, or -ETIME if the timeout elapsed. | |
579 | */ | |
580 | #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \ | |
581 | ({ \ | |
582 | long __ret = 0; \ | |
583 | might_sleep(); \ | |
584 | if (!(condition)) \ | |
585 | __ret = __wait_event_hrtimeout(wq, condition, timeout, \ | |
586 | TASK_INTERRUPTIBLE); \ | |
587 | __ret; \ | |
588 | }) | |
589 | ||
590 | #define __wait_event_interruptible_exclusive(wq, condition) \ | |
591 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ | |
592 | schedule()) | |
593 | ||
594 | #define wait_event_interruptible_exclusive(wq, condition) \ | |
595 | ({ \ | |
596 | int __ret = 0; \ | |
597 | might_sleep(); \ | |
598 | if (!(condition)) \ | |
599 | __ret = __wait_event_interruptible_exclusive(wq, condition);\ | |
600 | __ret; \ | |
601 | }) | |
602 | ||
603 | ||
604 | #define __wait_event_freezable_exclusive(wq, condition) \ | |
605 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ | |
606 | schedule(); try_to_freeze()) | |
607 | ||
608 | #define wait_event_freezable_exclusive(wq, condition) \ | |
609 | ({ \ | |
610 | int __ret = 0; \ | |
611 | might_sleep(); \ | |
612 | if (!(condition)) \ | |
613 | __ret = __wait_event_freezable_exclusive(wq, condition);\ | |
614 | __ret; \ | |
615 | }) | |
616 | ||
617 | ||
618 | #define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \ | |
619 | ({ \ | |
620 | int __ret = 0; \ | |
621 | DEFINE_WAIT(__wait); \ | |
622 | if (exclusive) \ | |
623 | __wait.flags |= WQ_FLAG_EXCLUSIVE; \ | |
624 | do { \ | |
625 | if (likely(list_empty(&__wait.task_list))) \ | |
626 | __add_wait_queue_tail(&(wq), &__wait); \ | |
627 | set_current_state(TASK_INTERRUPTIBLE); \ | |
628 | if (signal_pending(current)) { \ | |
629 | __ret = -ERESTARTSYS; \ | |
630 | break; \ | |
631 | } \ | |
632 | if (irq) \ | |
633 | spin_unlock_irq(&(wq).lock); \ | |
634 | else \ | |
635 | spin_unlock(&(wq).lock); \ | |
636 | schedule(); \ | |
637 | if (irq) \ | |
638 | spin_lock_irq(&(wq).lock); \ | |
639 | else \ | |
640 | spin_lock(&(wq).lock); \ | |
641 | } while (!(condition)); \ | |
642 | __remove_wait_queue(&(wq), &__wait); \ | |
643 | __set_current_state(TASK_RUNNING); \ | |
644 | __ret; \ | |
645 | }) | |
646 | ||
647 | ||
648 | /** | |
649 | * wait_event_interruptible_locked - sleep until a condition gets true | |
650 | * @wq: the waitqueue to wait on | |
651 | * @condition: a C expression for the event to wait for | |
652 | * | |
653 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
654 | * @condition evaluates to true or a signal is received. | |
655 | * The @condition is checked each time the waitqueue @wq is woken up. | |
656 | * | |
657 | * It must be called with wq.lock being held. This spinlock is | |
658 | * unlocked while sleeping but @condition testing is done while lock | |
659 | * is held and when this macro exits the lock is held. | |
660 | * | |
661 | * The lock is locked/unlocked using spin_lock()/spin_unlock() | |
662 | * functions which must match the way they are locked/unlocked outside | |
663 | * of this macro. | |
664 | * | |
665 | * wake_up_locked() has to be called after changing any variable that could | |
666 | * change the result of the wait condition. | |
667 | * | |
668 | * The function will return -ERESTARTSYS if it was interrupted by a | |
669 | * signal and 0 if @condition evaluated to true. | |
670 | */ | |
671 | #define wait_event_interruptible_locked(wq, condition) \ | |
672 | ((condition) \ | |
673 | ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0)) | |
674 | ||
675 | /** | |
676 | * wait_event_interruptible_locked_irq - sleep until a condition gets true | |
677 | * @wq: the waitqueue to wait on | |
678 | * @condition: a C expression for the event to wait for | |
679 | * | |
680 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
681 | * @condition evaluates to true or a signal is received. | |
682 | * The @condition is checked each time the waitqueue @wq is woken up. | |
683 | * | |
684 | * It must be called with wq.lock being held. This spinlock is | |
685 | * unlocked while sleeping but @condition testing is done while lock | |
686 | * is held and when this macro exits the lock is held. | |
687 | * | |
688 | * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() | |
689 | * functions which must match the way they are locked/unlocked outside | |
690 | * of this macro. | |
691 | * | |
692 | * wake_up_locked() has to be called after changing any variable that could | |
693 | * change the result of the wait condition. | |
694 | * | |
695 | * The function will return -ERESTARTSYS if it was interrupted by a | |
696 | * signal and 0 if @condition evaluated to true. | |
697 | */ | |
698 | #define wait_event_interruptible_locked_irq(wq, condition) \ | |
699 | ((condition) \ | |
700 | ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1)) | |
701 | ||
702 | /** | |
703 | * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true | |
704 | * @wq: the waitqueue to wait on | |
705 | * @condition: a C expression for the event to wait for | |
706 | * | |
707 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
708 | * @condition evaluates to true or a signal is received. | |
709 | * The @condition is checked each time the waitqueue @wq is woken up. | |
710 | * | |
711 | * It must be called with wq.lock being held. This spinlock is | |
712 | * unlocked while sleeping but @condition testing is done while lock | |
713 | * is held and when this macro exits the lock is held. | |
714 | * | |
715 | * The lock is locked/unlocked using spin_lock()/spin_unlock() | |
716 | * functions which must match the way they are locked/unlocked outside | |
717 | * of this macro. | |
718 | * | |
719 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag | |
720 | * set thus when other process waits process on the list if this | |
721 | * process is awaken further processes are not considered. | |
722 | * | |
723 | * wake_up_locked() has to be called after changing any variable that could | |
724 | * change the result of the wait condition. | |
725 | * | |
726 | * The function will return -ERESTARTSYS if it was interrupted by a | |
727 | * signal and 0 if @condition evaluated to true. | |
728 | */ | |
729 | #define wait_event_interruptible_exclusive_locked(wq, condition) \ | |
730 | ((condition) \ | |
731 | ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0)) | |
732 | ||
733 | /** | |
734 | * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true | |
735 | * @wq: the waitqueue to wait on | |
736 | * @condition: a C expression for the event to wait for | |
737 | * | |
738 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
739 | * @condition evaluates to true or a signal is received. | |
740 | * The @condition is checked each time the waitqueue @wq is woken up. | |
741 | * | |
742 | * It must be called with wq.lock being held. This spinlock is | |
743 | * unlocked while sleeping but @condition testing is done while lock | |
744 | * is held and when this macro exits the lock is held. | |
745 | * | |
746 | * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() | |
747 | * functions which must match the way they are locked/unlocked outside | |
748 | * of this macro. | |
749 | * | |
750 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag | |
751 | * set thus when other process waits process on the list if this | |
752 | * process is awaken further processes are not considered. | |
753 | * | |
754 | * wake_up_locked() has to be called after changing any variable that could | |
755 | * change the result of the wait condition. | |
756 | * | |
757 | * The function will return -ERESTARTSYS if it was interrupted by a | |
758 | * signal and 0 if @condition evaluated to true. | |
759 | */ | |
760 | #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \ | |
761 | ((condition) \ | |
762 | ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1)) | |
763 | ||
764 | ||
765 | #define __wait_event_killable(wq, condition) \ | |
766 | ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) | |
767 | ||
768 | /** | |
769 | * wait_event_killable - sleep until a condition gets true | |
770 | * @wq: the waitqueue to wait on | |
771 | * @condition: a C expression for the event to wait for | |
772 | * | |
773 | * The process is put to sleep (TASK_KILLABLE) until the | |
774 | * @condition evaluates to true or a signal is received. | |
775 | * The @condition is checked each time the waitqueue @wq is woken up. | |
776 | * | |
777 | * wake_up() has to be called after changing any variable that could | |
778 | * change the result of the wait condition. | |
779 | * | |
780 | * The function will return -ERESTARTSYS if it was interrupted by a | |
781 | * signal and 0 if @condition evaluated to true. | |
782 | */ | |
783 | #define wait_event_killable(wq, condition) \ | |
784 | ({ \ | |
785 | int __ret = 0; \ | |
786 | might_sleep(); \ | |
787 | if (!(condition)) \ | |
788 | __ret = __wait_event_killable(wq, condition); \ | |
789 | __ret; \ | |
790 | }) | |
791 | ||
792 | ||
793 | #define __wait_event_lock_irq(wq, condition, lock, cmd) \ | |
794 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ | |
795 | spin_unlock_irq(&lock); \ | |
796 | cmd; \ | |
797 | schedule(); \ | |
798 | spin_lock_irq(&lock)) | |
799 | ||
800 | /** | |
801 | * wait_event_lock_irq_cmd - sleep until a condition gets true. The | |
802 | * condition is checked under the lock. This | |
803 | * is expected to be called with the lock | |
804 | * taken. | |
805 | * @wq: the waitqueue to wait on | |
806 | * @condition: a C expression for the event to wait for | |
807 | * @lock: a locked spinlock_t, which will be released before cmd | |
808 | * and schedule() and reacquired afterwards. | |
809 | * @cmd: a command which is invoked outside the critical section before | |
810 | * sleep | |
811 | * | |
812 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
813 | * @condition evaluates to true. The @condition is checked each time | |
814 | * the waitqueue @wq is woken up. | |
815 | * | |
816 | * wake_up() has to be called after changing any variable that could | |
817 | * change the result of the wait condition. | |
818 | * | |
819 | * This is supposed to be called while holding the lock. The lock is | |
820 | * dropped before invoking the cmd and going to sleep and is reacquired | |
821 | * afterwards. | |
822 | */ | |
823 | #define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \ | |
824 | do { \ | |
825 | if (condition) \ | |
826 | break; \ | |
827 | __wait_event_lock_irq(wq, condition, lock, cmd); \ | |
828 | } while (0) | |
829 | ||
830 | /** | |
831 | * wait_event_lock_irq - sleep until a condition gets true. The | |
832 | * condition is checked under the lock. This | |
833 | * is expected to be called with the lock | |
834 | * taken. | |
835 | * @wq: the waitqueue to wait on | |
836 | * @condition: a C expression for the event to wait for | |
837 | * @lock: a locked spinlock_t, which will be released before schedule() | |
838 | * and reacquired afterwards. | |
839 | * | |
840 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
841 | * @condition evaluates to true. The @condition is checked each time | |
842 | * the waitqueue @wq is woken up. | |
843 | * | |
844 | * wake_up() has to be called after changing any variable that could | |
845 | * change the result of the wait condition. | |
846 | * | |
847 | * This is supposed to be called while holding the lock. The lock is | |
848 | * dropped before going to sleep and is reacquired afterwards. | |
849 | */ | |
850 | #define wait_event_lock_irq(wq, condition, lock) \ | |
851 | do { \ | |
852 | if (condition) \ | |
853 | break; \ | |
854 | __wait_event_lock_irq(wq, condition, lock, ); \ | |
855 | } while (0) | |
856 | ||
857 | ||
858 | #define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \ | |
859 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ | |
860 | spin_unlock_irq(&lock); \ | |
861 | cmd; \ | |
862 | schedule(); \ | |
863 | spin_lock_irq(&lock)) | |
864 | ||
865 | /** | |
866 | * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. | |
867 | * The condition is checked under the lock. This is expected to | |
868 | * be called with the lock taken. | |
869 | * @wq: the waitqueue to wait on | |
870 | * @condition: a C expression for the event to wait for | |
871 | * @lock: a locked spinlock_t, which will be released before cmd and | |
872 | * schedule() and reacquired afterwards. | |
873 | * @cmd: a command which is invoked outside the critical section before | |
874 | * sleep | |
875 | * | |
876 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
877 | * @condition evaluates to true or a signal is received. The @condition is | |
878 | * checked each time the waitqueue @wq is woken up. | |
879 | * | |
880 | * wake_up() has to be called after changing any variable that could | |
881 | * change the result of the wait condition. | |
882 | * | |
883 | * This is supposed to be called while holding the lock. The lock is | |
884 | * dropped before invoking the cmd and going to sleep and is reacquired | |
885 | * afterwards. | |
886 | * | |
887 | * The macro will return -ERESTARTSYS if it was interrupted by a signal | |
888 | * and 0 if @condition evaluated to true. | |
889 | */ | |
890 | #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \ | |
891 | ({ \ | |
892 | int __ret = 0; \ | |
893 | if (!(condition)) \ | |
894 | __ret = __wait_event_interruptible_lock_irq(wq, \ | |
895 | condition, lock, cmd); \ | |
896 | __ret; \ | |
897 | }) | |
898 | ||
899 | /** | |
900 | * wait_event_interruptible_lock_irq - sleep until a condition gets true. | |
901 | * The condition is checked under the lock. This is expected | |
902 | * to be called with the lock taken. | |
903 | * @wq: the waitqueue to wait on | |
904 | * @condition: a C expression for the event to wait for | |
905 | * @lock: a locked spinlock_t, which will be released before schedule() | |
906 | * and reacquired afterwards. | |
907 | * | |
908 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
909 | * @condition evaluates to true or signal is received. The @condition is | |
910 | * checked each time the waitqueue @wq is woken up. | |
911 | * | |
912 | * wake_up() has to be called after changing any variable that could | |
913 | * change the result of the wait condition. | |
914 | * | |
915 | * This is supposed to be called while holding the lock. The lock is | |
916 | * dropped before going to sleep and is reacquired afterwards. | |
917 | * | |
918 | * The macro will return -ERESTARTSYS if it was interrupted by a signal | |
919 | * and 0 if @condition evaluated to true. | |
920 | */ | |
921 | #define wait_event_interruptible_lock_irq(wq, condition, lock) \ | |
922 | ({ \ | |
923 | int __ret = 0; \ | |
924 | if (!(condition)) \ | |
925 | __ret = __wait_event_interruptible_lock_irq(wq, \ | |
926 | condition, lock,); \ | |
927 | __ret; \ | |
928 | }) | |
929 | ||
930 | #define __wait_event_interruptible_lock_irq_timeout(wq, condition, \ | |
931 | lock, timeout) \ | |
932 | ___wait_event(wq, ___wait_cond_timeout(condition), \ | |
933 | TASK_INTERRUPTIBLE, 0, timeout, \ | |
934 | spin_unlock_irq(&lock); \ | |
935 | __ret = schedule_timeout(__ret); \ | |
936 | spin_lock_irq(&lock)); | |
937 | ||
938 | /** | |
939 | * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets | |
940 | * true or a timeout elapses. The condition is checked under | |
941 | * the lock. This is expected to be called with the lock taken. | |
942 | * @wq: the waitqueue to wait on | |
943 | * @condition: a C expression for the event to wait for | |
944 | * @lock: a locked spinlock_t, which will be released before schedule() | |
945 | * and reacquired afterwards. | |
946 | * @timeout: timeout, in jiffies | |
947 | * | |
948 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
949 | * @condition evaluates to true or signal is received. The @condition is | |
950 | * checked each time the waitqueue @wq is woken up. | |
951 | * | |
952 | * wake_up() has to be called after changing any variable that could | |
953 | * change the result of the wait condition. | |
954 | * | |
955 | * This is supposed to be called while holding the lock. The lock is | |
956 | * dropped before going to sleep and is reacquired afterwards. | |
957 | * | |
958 | * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it | |
959 | * was interrupted by a signal, and the remaining jiffies otherwise | |
960 | * if the condition evaluated to true before the timeout elapsed. | |
961 | */ | |
962 | #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \ | |
963 | timeout) \ | |
964 | ({ \ | |
965 | long __ret = timeout; \ | |
966 | if (!___wait_cond_timeout(condition)) \ | |
967 | __ret = __wait_event_interruptible_lock_irq_timeout( \ | |
968 | wq, condition, lock, timeout); \ | |
969 | __ret; \ | |
970 | }) | |
971 | ||
972 | /* | |
973 | * Waitqueues which are removed from the waitqueue_head at wakeup time | |
974 | */ | |
975 | void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); | |
976 | void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); | |
977 | long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); | |
978 | void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); | |
979 | void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); | |
980 | long wait_woken(wait_queue_t *wait, unsigned mode, long timeout); | |
981 | int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
982 | int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
983 | int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
984 | ||
985 | #define DEFINE_WAIT_FUNC(name, function) \ | |
986 | wait_queue_t name = { \ | |
987 | .private = current, \ | |
988 | .func = function, \ | |
989 | .task_list = LIST_HEAD_INIT((name).task_list), \ | |
990 | } | |
991 | ||
992 | #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) | |
993 | ||
994 | #define DEFINE_WAIT_BIT(name, word, bit) \ | |
995 | struct wait_bit_queue name = { \ | |
996 | .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ | |
997 | .wait = { \ | |
998 | .private = current, \ | |
999 | .func = wake_bit_function, \ | |
1000 | .task_list = \ | |
1001 | LIST_HEAD_INIT((name).wait.task_list), \ | |
1002 | }, \ | |
1003 | } | |
1004 | ||
1005 | #define init_wait(wait) \ | |
1006 | do { \ | |
1007 | (wait)->private = current; \ | |
1008 | (wait)->func = autoremove_wake_function; \ | |
1009 | INIT_LIST_HEAD(&(wait)->task_list); \ | |
1010 | (wait)->flags = 0; \ | |
1011 | } while (0) | |
1012 | ||
1013 | ||
1014 | extern int bit_wait(struct wait_bit_key *, int); | |
1015 | extern int bit_wait_io(struct wait_bit_key *, int); | |
1016 | extern int bit_wait_timeout(struct wait_bit_key *, int); | |
1017 | extern int bit_wait_io_timeout(struct wait_bit_key *, int); | |
1018 | ||
1019 | /** | |
1020 | * wait_on_bit - wait for a bit to be cleared | |
1021 | * @word: the word being waited on, a kernel virtual address | |
1022 | * @bit: the bit of the word being waited on | |
1023 | * @mode: the task state to sleep in | |
1024 | * | |
1025 | * There is a standard hashed waitqueue table for generic use. This | |
1026 | * is the part of the hashtable's accessor API that waits on a bit. | |
1027 | * For instance, if one were to have waiters on a bitflag, one would | |
1028 | * call wait_on_bit() in threads waiting for the bit to clear. | |
1029 | * One uses wait_on_bit() where one is waiting for the bit to clear, | |
1030 | * but has no intention of setting it. | |
1031 | * Returned value will be zero if the bit was cleared, or non-zero | |
1032 | * if the process received a signal and the mode permitted wakeup | |
1033 | * on that signal. | |
1034 | */ | |
1035 | static inline int | |
1036 | wait_on_bit(unsigned long *word, int bit, unsigned mode) | |
1037 | { | |
1038 | might_sleep(); | |
1039 | if (!test_bit(bit, word)) | |
1040 | return 0; | |
1041 | return out_of_line_wait_on_bit(word, bit, | |
1042 | bit_wait, | |
1043 | mode); | |
1044 | } | |
1045 | ||
1046 | /** | |
1047 | * wait_on_bit_io - wait for a bit to be cleared | |
1048 | * @word: the word being waited on, a kernel virtual address | |
1049 | * @bit: the bit of the word being waited on | |
1050 | * @mode: the task state to sleep in | |
1051 | * | |
1052 | * Use the standard hashed waitqueue table to wait for a bit | |
1053 | * to be cleared. This is similar to wait_on_bit(), but calls | |
1054 | * io_schedule() instead of schedule() for the actual waiting. | |
1055 | * | |
1056 | * Returned value will be zero if the bit was cleared, or non-zero | |
1057 | * if the process received a signal and the mode permitted wakeup | |
1058 | * on that signal. | |
1059 | */ | |
1060 | static inline int | |
1061 | wait_on_bit_io(unsigned long *word, int bit, unsigned mode) | |
1062 | { | |
1063 | might_sleep(); | |
1064 | if (!test_bit(bit, word)) | |
1065 | return 0; | |
1066 | return out_of_line_wait_on_bit(word, bit, | |
1067 | bit_wait_io, | |
1068 | mode); | |
1069 | } | |
1070 | ||
1071 | /** | |
1072 | * wait_on_bit_timeout - wait for a bit to be cleared or a timeout elapses | |
1073 | * @word: the word being waited on, a kernel virtual address | |
1074 | * @bit: the bit of the word being waited on | |
1075 | * @mode: the task state to sleep in | |
1076 | * @timeout: timeout, in jiffies | |
1077 | * | |
1078 | * Use the standard hashed waitqueue table to wait for a bit | |
1079 | * to be cleared. This is similar to wait_on_bit(), except also takes a | |
1080 | * timeout parameter. | |
1081 | * | |
1082 | * Returned value will be zero if the bit was cleared before the | |
1083 | * @timeout elapsed, or non-zero if the @timeout elapsed or process | |
1084 | * received a signal and the mode permitted wakeup on that signal. | |
1085 | */ | |
1086 | static inline int | |
1087 | wait_on_bit_timeout(unsigned long *word, int bit, unsigned mode, | |
1088 | unsigned long timeout) | |
1089 | { | |
1090 | might_sleep(); | |
1091 | if (!test_bit(bit, word)) | |
1092 | return 0; | |
1093 | return out_of_line_wait_on_bit_timeout(word, bit, | |
1094 | bit_wait_timeout, | |
1095 | mode, timeout); | |
1096 | } | |
1097 | ||
1098 | /** | |
1099 | * wait_on_bit_action - wait for a bit to be cleared | |
1100 | * @word: the word being waited on, a kernel virtual address | |
1101 | * @bit: the bit of the word being waited on | |
1102 | * @action: the function used to sleep, which may take special actions | |
1103 | * @mode: the task state to sleep in | |
1104 | * | |
1105 | * Use the standard hashed waitqueue table to wait for a bit | |
1106 | * to be cleared, and allow the waiting action to be specified. | |
1107 | * This is like wait_on_bit() but allows fine control of how the waiting | |
1108 | * is done. | |
1109 | * | |
1110 | * Returned value will be zero if the bit was cleared, or non-zero | |
1111 | * if the process received a signal and the mode permitted wakeup | |
1112 | * on that signal. | |
1113 | */ | |
1114 | static inline int | |
1115 | wait_on_bit_action(unsigned long *word, int bit, wait_bit_action_f *action, | |
1116 | unsigned mode) | |
1117 | { | |
1118 | might_sleep(); | |
1119 | if (!test_bit(bit, word)) | |
1120 | return 0; | |
1121 | return out_of_line_wait_on_bit(word, bit, action, mode); | |
1122 | } | |
1123 | ||
1124 | /** | |
1125 | * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it | |
1126 | * @word: the word being waited on, a kernel virtual address | |
1127 | * @bit: the bit of the word being waited on | |
1128 | * @mode: the task state to sleep in | |
1129 | * | |
1130 | * There is a standard hashed waitqueue table for generic use. This | |
1131 | * is the part of the hashtable's accessor API that waits on a bit | |
1132 | * when one intends to set it, for instance, trying to lock bitflags. | |
1133 | * For instance, if one were to have waiters trying to set bitflag | |
1134 | * and waiting for it to clear before setting it, one would call | |
1135 | * wait_on_bit() in threads waiting to be able to set the bit. | |
1136 | * One uses wait_on_bit_lock() where one is waiting for the bit to | |
1137 | * clear with the intention of setting it, and when done, clearing it. | |
1138 | * | |
1139 | * Returns zero if the bit was (eventually) found to be clear and was | |
1140 | * set. Returns non-zero if a signal was delivered to the process and | |
1141 | * the @mode allows that signal to wake the process. | |
1142 | */ | |
1143 | static inline int | |
1144 | wait_on_bit_lock(unsigned long *word, int bit, unsigned mode) | |
1145 | { | |
1146 | might_sleep(); | |
1147 | if (!test_and_set_bit(bit, word)) | |
1148 | return 0; | |
1149 | return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode); | |
1150 | } | |
1151 | ||
1152 | /** | |
1153 | * wait_on_bit_lock_io - wait for a bit to be cleared, when wanting to set it | |
1154 | * @word: the word being waited on, a kernel virtual address | |
1155 | * @bit: the bit of the word being waited on | |
1156 | * @mode: the task state to sleep in | |
1157 | * | |
1158 | * Use the standard hashed waitqueue table to wait for a bit | |
1159 | * to be cleared and then to atomically set it. This is similar | |
1160 | * to wait_on_bit(), but calls io_schedule() instead of schedule() | |
1161 | * for the actual waiting. | |
1162 | * | |
1163 | * Returns zero if the bit was (eventually) found to be clear and was | |
1164 | * set. Returns non-zero if a signal was delivered to the process and | |
1165 | * the @mode allows that signal to wake the process. | |
1166 | */ | |
1167 | static inline int | |
1168 | wait_on_bit_lock_io(unsigned long *word, int bit, unsigned mode) | |
1169 | { | |
1170 | might_sleep(); | |
1171 | if (!test_and_set_bit(bit, word)) | |
1172 | return 0; | |
1173 | return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode); | |
1174 | } | |
1175 | ||
1176 | /** | |
1177 | * wait_on_bit_lock_action - wait for a bit to be cleared, when wanting to set it | |
1178 | * @word: the word being waited on, a kernel virtual address | |
1179 | * @bit: the bit of the word being waited on | |
1180 | * @action: the function used to sleep, which may take special actions | |
1181 | * @mode: the task state to sleep in | |
1182 | * | |
1183 | * Use the standard hashed waitqueue table to wait for a bit | |
1184 | * to be cleared and then to set it, and allow the waiting action | |
1185 | * to be specified. | |
1186 | * This is like wait_on_bit() but allows fine control of how the waiting | |
1187 | * is done. | |
1188 | * | |
1189 | * Returns zero if the bit was (eventually) found to be clear and was | |
1190 | * set. Returns non-zero if a signal was delivered to the process and | |
1191 | * the @mode allows that signal to wake the process. | |
1192 | */ | |
1193 | static inline int | |
1194 | wait_on_bit_lock_action(unsigned long *word, int bit, wait_bit_action_f *action, | |
1195 | unsigned mode) | |
1196 | { | |
1197 | might_sleep(); | |
1198 | if (!test_and_set_bit(bit, word)) | |
1199 | return 0; | |
1200 | return out_of_line_wait_on_bit_lock(word, bit, action, mode); | |
1201 | } | |
1202 | ||
1203 | /** | |
1204 | * wait_on_atomic_t - Wait for an atomic_t to become 0 | |
1205 | * @val: The atomic value being waited on, a kernel virtual address | |
1206 | * @action: the function used to sleep, which may take special actions | |
1207 | * @mode: the task state to sleep in | |
1208 | * | |
1209 | * Wait for an atomic_t to become 0. We abuse the bit-wait waitqueue table for | |
1210 | * the purpose of getting a waitqueue, but we set the key to a bit number | |
1211 | * outside of the target 'word'. | |
1212 | */ | |
1213 | static inline | |
1214 | int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode) | |
1215 | { | |
1216 | might_sleep(); | |
1217 | if (atomic_read(val) == 0) | |
1218 | return 0; | |
1219 | return out_of_line_wait_on_atomic_t(val, action, mode); | |
1220 | } | |
1221 | ||
1222 | #endif /* _LINUX_WAIT_H */ |