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1da177e4 LT |
1 | #ifndef _LINUX_WAIT_H |
2 | #define _LINUX_WAIT_H | |
fb869b6e IM |
3 | /* |
4 | * Linux wait queue related types and methods | |
5 | */ | |
1da177e4 LT |
6 | #include <linux/list.h> |
7 | #include <linux/stddef.h> | |
8 | #include <linux/spinlock.h> | |
1da177e4 | 9 | #include <asm/current.h> |
607ca46e | 10 | #include <uapi/linux/wait.h> |
1da177e4 LT |
11 | |
12 | typedef struct __wait_queue wait_queue_t; | |
7d478721 PZ |
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); | |
1da177e4 | 15 | |
61ada528 PZ |
16 | /* __wait_queue::flags */ |
17 | #define WQ_FLAG_EXCLUSIVE 0x01 | |
18 | #define WQ_FLAG_WOKEN 0x02 | |
19 | ||
1da177e4 | 20 | struct __wait_queue { |
fb869b6e | 21 | unsigned int flags; |
fb869b6e IM |
22 | void *private; |
23 | wait_queue_func_t func; | |
24 | struct list_head task_list; | |
1da177e4 LT |
25 | }; |
26 | ||
27 | struct wait_bit_key { | |
fb869b6e IM |
28 | void *flags; |
29 | int bit_nr; | |
30 | #define WAIT_ATOMIC_T_BIT_NR -1 | |
cbbce822 | 31 | unsigned long timeout; |
1da177e4 LT |
32 | }; |
33 | ||
34 | struct wait_bit_queue { | |
fb869b6e IM |
35 | struct wait_bit_key key; |
36 | wait_queue_t wait; | |
1da177e4 LT |
37 | }; |
38 | ||
39 | struct __wait_queue_head { | |
fb869b6e IM |
40 | spinlock_t lock; |
41 | struct list_head task_list; | |
1da177e4 LT |
42 | }; |
43 | typedef struct __wait_queue_head wait_queue_head_t; | |
44 | ||
8c65b4a6 | 45 | struct task_struct; |
1da177e4 LT |
46 | |
47 | /* | |
48 | * Macros for declaration and initialisaton of the datatypes | |
49 | */ | |
50 | ||
51 | #define __WAITQUEUE_INITIALIZER(name, tsk) { \ | |
c43dc2fd | 52 | .private = tsk, \ |
1da177e4 LT |
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) { \ | |
e4d91918 | 60 | .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ |
1da177e4 LT |
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 | ||
cb65537e DH |
69 | #define __WAIT_ATOMIC_T_KEY_INITIALIZER(p) \ |
70 | { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, } | |
71 | ||
f07fdec5 | 72 | extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *); |
2fc39111 PZ |
73 | |
74 | #define init_waitqueue_head(q) \ | |
75 | do { \ | |
76 | static struct lock_class_key __key; \ | |
77 | \ | |
f07fdec5 | 78 | __init_waitqueue_head((q), #q, &__key); \ |
2fc39111 | 79 | } while (0) |
1da177e4 | 80 | |
7259f0d0 PZ |
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 | ||
1da177e4 LT |
90 | static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) |
91 | { | |
fb869b6e IM |
92 | q->flags = 0; |
93 | q->private = p; | |
94 | q->func = default_wake_function; | |
1da177e4 LT |
95 | } |
96 | ||
fb869b6e IM |
97 | static inline void |
98 | init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func) | |
1da177e4 | 99 | { |
fb869b6e IM |
100 | q->flags = 0; |
101 | q->private = NULL; | |
102 | q->func = func; | |
1da177e4 LT |
103 | } |
104 | ||
105 | static inline int waitqueue_active(wait_queue_head_t *q) | |
106 | { | |
107 | return !list_empty(&q->task_list); | |
108 | } | |
109 | ||
b3c97528 HH |
110 | extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); |
111 | extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait); | |
112 | extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); | |
1da177e4 LT |
113 | |
114 | static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) | |
115 | { | |
116 | list_add(&new->task_list, &head->task_list); | |
117 | } | |
118 | ||
119 | /* | |
120 | * Used for wake-one threads: | |
121 | */ | |
fb869b6e IM |
122 | static inline void |
123 | __add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait) | |
a93d2f17 CG |
124 | { |
125 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
126 | __add_wait_queue(q, wait); | |
127 | } | |
128 | ||
1da177e4 | 129 | static inline void __add_wait_queue_tail(wait_queue_head_t *head, |
a93d2f17 | 130 | wait_queue_t *new) |
1da177e4 LT |
131 | { |
132 | list_add_tail(&new->task_list, &head->task_list); | |
133 | } | |
134 | ||
fb869b6e IM |
135 | static inline void |
136 | __add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait) | |
a93d2f17 CG |
137 | { |
138 | wait->flags |= WQ_FLAG_EXCLUSIVE; | |
139 | __add_wait_queue_tail(q, wait); | |
140 | } | |
141 | ||
fb869b6e IM |
142 | static inline void |
143 | __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) | |
1da177e4 LT |
144 | { |
145 | list_del(&old->task_list); | |
146 | } | |
147 | ||
c1221321 | 148 | typedef int wait_bit_action_f(struct wait_bit_key *); |
b3c97528 | 149 | void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key); |
4ede816a | 150 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key); |
fb869b6e | 151 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key); |
63b20011 | 152 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr); |
4ede816a | 153 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr); |
b3c97528 | 154 | void __wake_up_bit(wait_queue_head_t *, void *, int); |
c1221321 N |
155 | int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); |
156 | int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); | |
b3c97528 | 157 | void wake_up_bit(void *, int); |
cb65537e | 158 | void wake_up_atomic_t(atomic_t *); |
c1221321 | 159 | int out_of_line_wait_on_bit(void *, int, wait_bit_action_f *, unsigned); |
cbbce822 | 160 | int out_of_line_wait_on_bit_timeout(void *, int, wait_bit_action_f *, unsigned, unsigned long); |
c1221321 | 161 | int out_of_line_wait_on_bit_lock(void *, int, wait_bit_action_f *, unsigned); |
cb65537e | 162 | int out_of_line_wait_on_atomic_t(atomic_t *, int (*)(atomic_t *), unsigned); |
b3c97528 | 163 | wait_queue_head_t *bit_waitqueue(void *, int); |
1da177e4 | 164 | |
e64d66c8 MW |
165 | #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) |
166 | #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) | |
167 | #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) | |
63b20011 TG |
168 | #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) |
169 | #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) | |
e64d66c8 | 170 | |
1da177e4 LT |
171 | #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) |
172 | #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) | |
173 | #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) | |
e64d66c8 | 174 | #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1) |
1da177e4 | 175 | |
0ccf831c | 176 | /* |
c0da3775 | 177 | * Wakeup macros to be used to report events to the targets. |
0ccf831c | 178 | */ |
fb869b6e | 179 | #define wake_up_poll(x, m) \ |
c0da3775 | 180 | __wake_up(x, TASK_NORMAL, 1, (void *) (m)) |
fb869b6e | 181 | #define wake_up_locked_poll(x, m) \ |
c0da3775 | 182 | __wake_up_locked_key((x), TASK_NORMAL, (void *) (m)) |
fb869b6e | 183 | #define wake_up_interruptible_poll(x, m) \ |
c0da3775 DL |
184 | __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m)) |
185 | #define wake_up_interruptible_sync_poll(x, m) \ | |
186 | __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m)) | |
0ccf831c | 187 | |
35a2af94 | 188 | #define ___wait_cond_timeout(condition) \ |
2953ef24 | 189 | ({ \ |
fb869b6e IM |
190 | bool __cond = (condition); \ |
191 | if (__cond && !__ret) \ | |
192 | __ret = 1; \ | |
193 | __cond || !__ret; \ | |
2953ef24 PZ |
194 | }) |
195 | ||
c2d81644 ON |
196 | #define ___wait_is_interruptible(state) \ |
197 | (!__builtin_constant_p(state) || \ | |
198 | state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ | |
41a1431b | 199 | |
8b32201d PZ |
200 | /* |
201 | * The below macro ___wait_event() has an explicit shadow of the __ret | |
202 | * variable when used from the wait_event_*() macros. | |
203 | * | |
204 | * This is so that both can use the ___wait_cond_timeout() construct | |
205 | * to wrap the condition. | |
206 | * | |
207 | * The type inconsistency of the wait_event_*() __ret variable is also | |
208 | * on purpose; we use long where we can return timeout values and int | |
209 | * otherwise. | |
210 | */ | |
211 | ||
41a1431b | 212 | #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ |
35a2af94 | 213 | ({ \ |
41a1431b | 214 | __label__ __out; \ |
c2d81644 | 215 | wait_queue_t __wait; \ |
8b32201d | 216 | long __ret = ret; /* explicit shadow */ \ |
41a1431b | 217 | \ |
c2d81644 ON |
218 | INIT_LIST_HEAD(&__wait.task_list); \ |
219 | if (exclusive) \ | |
220 | __wait.flags = WQ_FLAG_EXCLUSIVE; \ | |
221 | else \ | |
222 | __wait.flags = 0; \ | |
223 | \ | |
41a1431b | 224 | for (;;) { \ |
c2d81644 | 225 | long __int = prepare_to_wait_event(&wq, &__wait, state);\ |
41a1431b PZ |
226 | \ |
227 | if (condition) \ | |
228 | break; \ | |
229 | \ | |
c2d81644 ON |
230 | if (___wait_is_interruptible(state) && __int) { \ |
231 | __ret = __int; \ | |
41a1431b | 232 | if (exclusive) { \ |
fb869b6e IM |
233 | abort_exclusive_wait(&wq, &__wait, \ |
234 | state, NULL); \ | |
41a1431b PZ |
235 | goto __out; \ |
236 | } \ | |
237 | break; \ | |
238 | } \ | |
239 | \ | |
240 | cmd; \ | |
241 | } \ | |
242 | finish_wait(&wq, &__wait); \ | |
35a2af94 PZ |
243 | __out: __ret; \ |
244 | }) | |
41a1431b | 245 | |
fb869b6e | 246 | #define __wait_event(wq, condition) \ |
35a2af94 PZ |
247 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ |
248 | schedule()) | |
1da177e4 LT |
249 | |
250 | /** | |
251 | * wait_event - sleep until a condition gets true | |
252 | * @wq: the waitqueue to wait on | |
253 | * @condition: a C expression for the event to wait for | |
254 | * | |
255 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
256 | * @condition evaluates to true. The @condition is checked each time | |
257 | * the waitqueue @wq is woken up. | |
258 | * | |
259 | * wake_up() has to be called after changing any variable that could | |
260 | * change the result of the wait condition. | |
261 | */ | |
fb869b6e | 262 | #define wait_event(wq, condition) \ |
1da177e4 | 263 | do { \ |
fb869b6e | 264 | if (condition) \ |
1da177e4 LT |
265 | break; \ |
266 | __wait_event(wq, condition); \ | |
267 | } while (0) | |
268 | ||
35a2af94 PZ |
269 | #define __wait_event_timeout(wq, condition, timeout) \ |
270 | ___wait_event(wq, ___wait_cond_timeout(condition), \ | |
271 | TASK_UNINTERRUPTIBLE, 0, timeout, \ | |
272 | __ret = schedule_timeout(__ret)) | |
1da177e4 LT |
273 | |
274 | /** | |
275 | * wait_event_timeout - sleep until a condition gets true or a timeout elapses | |
276 | * @wq: the waitqueue to wait on | |
277 | * @condition: a C expression for the event to wait for | |
278 | * @timeout: timeout, in jiffies | |
279 | * | |
280 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
281 | * @condition evaluates to true. The @condition is checked each time | |
282 | * the waitqueue @wq is woken up. | |
283 | * | |
284 | * wake_up() has to be called after changing any variable that could | |
285 | * change the result of the wait condition. | |
286 | * | |
6b44f519 SD |
287 | * Returns: |
288 | * 0 if the @condition evaluated to %false after the @timeout elapsed, | |
289 | * 1 if the @condition evaluated to %true after the @timeout elapsed, | |
290 | * or the remaining jiffies (at least 1) if the @condition evaluated | |
291 | * to %true before the @timeout elapsed. | |
1da177e4 LT |
292 | */ |
293 | #define wait_event_timeout(wq, condition, timeout) \ | |
294 | ({ \ | |
295 | long __ret = timeout; \ | |
8922915b | 296 | if (!___wait_cond_timeout(condition)) \ |
35a2af94 | 297 | __ret = __wait_event_timeout(wq, condition, timeout); \ |
1da177e4 LT |
298 | __ret; \ |
299 | }) | |
300 | ||
82e06c81 SL |
301 | #define __wait_event_cmd(wq, condition, cmd1, cmd2) \ |
302 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ | |
303 | cmd1; schedule(); cmd2) | |
304 | ||
305 | /** | |
306 | * wait_event_cmd - sleep until a condition gets true | |
307 | * @wq: the waitqueue to wait on | |
308 | * @condition: a C expression for the event to wait for | |
f434f7af MI |
309 | * @cmd1: the command will be executed before sleep |
310 | * @cmd2: the command will be executed after sleep | |
82e06c81 SL |
311 | * |
312 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
313 | * @condition evaluates to true. The @condition is checked each time | |
314 | * the waitqueue @wq is woken up. | |
315 | * | |
316 | * wake_up() has to be called after changing any variable that could | |
317 | * change the result of the wait condition. | |
318 | */ | |
319 | #define wait_event_cmd(wq, condition, cmd1, cmd2) \ | |
320 | do { \ | |
321 | if (condition) \ | |
322 | break; \ | |
323 | __wait_event_cmd(wq, condition, cmd1, cmd2); \ | |
324 | } while (0) | |
325 | ||
35a2af94 PZ |
326 | #define __wait_event_interruptible(wq, condition) \ |
327 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ | |
f13f4c41 | 328 | schedule()) |
1da177e4 LT |
329 | |
330 | /** | |
331 | * wait_event_interruptible - sleep until a condition gets true | |
332 | * @wq: the waitqueue to wait on | |
333 | * @condition: a C expression for the event to wait for | |
334 | * | |
335 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
336 | * @condition evaluates to true or a signal is received. | |
337 | * The @condition is checked each time the waitqueue @wq is woken up. | |
338 | * | |
339 | * wake_up() has to be called after changing any variable that could | |
340 | * change the result of the wait condition. | |
341 | * | |
342 | * The function will return -ERESTARTSYS if it was interrupted by a | |
343 | * signal and 0 if @condition evaluated to true. | |
344 | */ | |
345 | #define wait_event_interruptible(wq, condition) \ | |
346 | ({ \ | |
347 | int __ret = 0; \ | |
348 | if (!(condition)) \ | |
35a2af94 | 349 | __ret = __wait_event_interruptible(wq, condition); \ |
1da177e4 LT |
350 | __ret; \ |
351 | }) | |
352 | ||
35a2af94 PZ |
353 | #define __wait_event_interruptible_timeout(wq, condition, timeout) \ |
354 | ___wait_event(wq, ___wait_cond_timeout(condition), \ | |
355 | TASK_INTERRUPTIBLE, 0, timeout, \ | |
356 | __ret = schedule_timeout(__ret)) | |
1da177e4 LT |
357 | |
358 | /** | |
359 | * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses | |
360 | * @wq: the waitqueue to wait on | |
361 | * @condition: a C expression for the event to wait for | |
362 | * @timeout: timeout, in jiffies | |
363 | * | |
364 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
365 | * @condition evaluates to true or a signal is received. | |
366 | * The @condition is checked each time the waitqueue @wq is woken up. | |
367 | * | |
368 | * wake_up() has to be called after changing any variable that could | |
369 | * change the result of the wait condition. | |
370 | * | |
4c663cfc | 371 | * Returns: |
6b44f519 SD |
372 | * 0 if the @condition evaluated to %false after the @timeout elapsed, |
373 | * 1 if the @condition evaluated to %true after the @timeout elapsed, | |
374 | * the remaining jiffies (at least 1) if the @condition evaluated | |
375 | * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was | |
376 | * interrupted by a signal. | |
1da177e4 LT |
377 | */ |
378 | #define wait_event_interruptible_timeout(wq, condition, timeout) \ | |
379 | ({ \ | |
380 | long __ret = timeout; \ | |
8922915b | 381 | if (!___wait_cond_timeout(condition)) \ |
fb869b6e | 382 | __ret = __wait_event_interruptible_timeout(wq, \ |
35a2af94 | 383 | condition, timeout); \ |
1da177e4 LT |
384 | __ret; \ |
385 | }) | |
386 | ||
774a08b3 KO |
387 | #define __wait_event_hrtimeout(wq, condition, timeout, state) \ |
388 | ({ \ | |
389 | int __ret = 0; \ | |
774a08b3 KO |
390 | struct hrtimer_sleeper __t; \ |
391 | \ | |
392 | hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \ | |
393 | HRTIMER_MODE_REL); \ | |
394 | hrtimer_init_sleeper(&__t, current); \ | |
395 | if ((timeout).tv64 != KTIME_MAX) \ | |
396 | hrtimer_start_range_ns(&__t.timer, timeout, \ | |
397 | current->timer_slack_ns, \ | |
398 | HRTIMER_MODE_REL); \ | |
399 | \ | |
35a2af94 | 400 | __ret = ___wait_event(wq, condition, state, 0, 0, \ |
774a08b3 KO |
401 | if (!__t.task) { \ |
402 | __ret = -ETIME; \ | |
403 | break; \ | |
404 | } \ | |
ebdc195f | 405 | schedule()); \ |
774a08b3 KO |
406 | \ |
407 | hrtimer_cancel(&__t.timer); \ | |
408 | destroy_hrtimer_on_stack(&__t.timer); \ | |
774a08b3 KO |
409 | __ret; \ |
410 | }) | |
411 | ||
412 | /** | |
413 | * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses | |
414 | * @wq: the waitqueue to wait on | |
415 | * @condition: a C expression for the event to wait for | |
416 | * @timeout: timeout, as a ktime_t | |
417 | * | |
418 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
419 | * @condition evaluates to true or a signal is received. | |
420 | * The @condition is checked each time the waitqueue @wq is woken up. | |
421 | * | |
422 | * wake_up() has to be called after changing any variable that could | |
423 | * change the result of the wait condition. | |
424 | * | |
425 | * The function returns 0 if @condition became true, or -ETIME if the timeout | |
426 | * elapsed. | |
427 | */ | |
428 | #define wait_event_hrtimeout(wq, condition, timeout) \ | |
429 | ({ \ | |
430 | int __ret = 0; \ | |
431 | if (!(condition)) \ | |
432 | __ret = __wait_event_hrtimeout(wq, condition, timeout, \ | |
433 | TASK_UNINTERRUPTIBLE); \ | |
434 | __ret; \ | |
435 | }) | |
436 | ||
437 | /** | |
438 | * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses | |
439 | * @wq: the waitqueue to wait on | |
440 | * @condition: a C expression for the event to wait for | |
441 | * @timeout: timeout, as a ktime_t | |
442 | * | |
443 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
444 | * @condition evaluates to true or a signal is received. | |
445 | * The @condition is checked each time the waitqueue @wq is woken up. | |
446 | * | |
447 | * wake_up() has to be called after changing any variable that could | |
448 | * change the result of the wait condition. | |
449 | * | |
450 | * The function returns 0 if @condition became true, -ERESTARTSYS if it was | |
451 | * interrupted by a signal, or -ETIME if the timeout elapsed. | |
452 | */ | |
453 | #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \ | |
454 | ({ \ | |
455 | long __ret = 0; \ | |
456 | if (!(condition)) \ | |
457 | __ret = __wait_event_hrtimeout(wq, condition, timeout, \ | |
458 | TASK_INTERRUPTIBLE); \ | |
459 | __ret; \ | |
460 | }) | |
461 | ||
35a2af94 PZ |
462 | #define __wait_event_interruptible_exclusive(wq, condition) \ |
463 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ | |
48c25217 | 464 | schedule()) |
1da177e4 LT |
465 | |
466 | #define wait_event_interruptible_exclusive(wq, condition) \ | |
467 | ({ \ | |
468 | int __ret = 0; \ | |
469 | if (!(condition)) \ | |
35a2af94 | 470 | __ret = __wait_event_interruptible_exclusive(wq, condition);\ |
1da177e4 LT |
471 | __ret; \ |
472 | }) | |
473 | ||
22c43c81 MN |
474 | |
475 | #define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \ | |
476 | ({ \ | |
477 | int __ret = 0; \ | |
478 | DEFINE_WAIT(__wait); \ | |
479 | if (exclusive) \ | |
480 | __wait.flags |= WQ_FLAG_EXCLUSIVE; \ | |
481 | do { \ | |
482 | if (likely(list_empty(&__wait.task_list))) \ | |
483 | __add_wait_queue_tail(&(wq), &__wait); \ | |
484 | set_current_state(TASK_INTERRUPTIBLE); \ | |
485 | if (signal_pending(current)) { \ | |
486 | __ret = -ERESTARTSYS; \ | |
487 | break; \ | |
488 | } \ | |
489 | if (irq) \ | |
490 | spin_unlock_irq(&(wq).lock); \ | |
491 | else \ | |
492 | spin_unlock(&(wq).lock); \ | |
493 | schedule(); \ | |
494 | if (irq) \ | |
495 | spin_lock_irq(&(wq).lock); \ | |
496 | else \ | |
497 | spin_lock(&(wq).lock); \ | |
498 | } while (!(condition)); \ | |
499 | __remove_wait_queue(&(wq), &__wait); \ | |
500 | __set_current_state(TASK_RUNNING); \ | |
501 | __ret; \ | |
502 | }) | |
503 | ||
504 | ||
505 | /** | |
506 | * wait_event_interruptible_locked - sleep until a condition gets true | |
507 | * @wq: the waitqueue to wait on | |
508 | * @condition: a C expression for the event to wait for | |
509 | * | |
510 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
511 | * @condition evaluates to true or a signal is received. | |
512 | * The @condition is checked each time the waitqueue @wq is woken up. | |
513 | * | |
514 | * It must be called with wq.lock being held. This spinlock is | |
515 | * unlocked while sleeping but @condition testing is done while lock | |
516 | * is held and when this macro exits the lock is held. | |
517 | * | |
518 | * The lock is locked/unlocked using spin_lock()/spin_unlock() | |
519 | * functions which must match the way they are locked/unlocked outside | |
520 | * of this macro. | |
521 | * | |
522 | * wake_up_locked() has to be called after changing any variable that could | |
523 | * change the result of the wait condition. | |
524 | * | |
525 | * The function will return -ERESTARTSYS if it was interrupted by a | |
526 | * signal and 0 if @condition evaluated to true. | |
527 | */ | |
528 | #define wait_event_interruptible_locked(wq, condition) \ | |
529 | ((condition) \ | |
530 | ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0)) | |
531 | ||
532 | /** | |
533 | * wait_event_interruptible_locked_irq - sleep until a condition gets true | |
534 | * @wq: the waitqueue to wait on | |
535 | * @condition: a C expression for the event to wait for | |
536 | * | |
537 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
538 | * @condition evaluates to true or a signal is received. | |
539 | * The @condition is checked each time the waitqueue @wq is woken up. | |
540 | * | |
541 | * It must be called with wq.lock being held. This spinlock is | |
542 | * unlocked while sleeping but @condition testing is done while lock | |
543 | * is held and when this macro exits the lock is held. | |
544 | * | |
545 | * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() | |
546 | * functions which must match the way they are locked/unlocked outside | |
547 | * of this macro. | |
548 | * | |
549 | * wake_up_locked() has to be called after changing any variable that could | |
550 | * change the result of the wait condition. | |
551 | * | |
552 | * The function will return -ERESTARTSYS if it was interrupted by a | |
553 | * signal and 0 if @condition evaluated to true. | |
554 | */ | |
555 | #define wait_event_interruptible_locked_irq(wq, condition) \ | |
556 | ((condition) \ | |
557 | ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1)) | |
558 | ||
559 | /** | |
560 | * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true | |
561 | * @wq: the waitqueue to wait on | |
562 | * @condition: a C expression for the event to wait for | |
563 | * | |
564 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
565 | * @condition evaluates to true or a signal is received. | |
566 | * The @condition is checked each time the waitqueue @wq is woken up. | |
567 | * | |
568 | * It must be called with wq.lock being held. This spinlock is | |
569 | * unlocked while sleeping but @condition testing is done while lock | |
570 | * is held and when this macro exits the lock is held. | |
571 | * | |
572 | * The lock is locked/unlocked using spin_lock()/spin_unlock() | |
573 | * functions which must match the way they are locked/unlocked outside | |
574 | * of this macro. | |
575 | * | |
576 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag | |
577 | * set thus when other process waits process on the list if this | |
578 | * process is awaken further processes are not considered. | |
579 | * | |
580 | * wake_up_locked() has to be called after changing any variable that could | |
581 | * change the result of the wait condition. | |
582 | * | |
583 | * The function will return -ERESTARTSYS if it was interrupted by a | |
584 | * signal and 0 if @condition evaluated to true. | |
585 | */ | |
586 | #define wait_event_interruptible_exclusive_locked(wq, condition) \ | |
587 | ((condition) \ | |
588 | ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0)) | |
589 | ||
590 | /** | |
591 | * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true | |
592 | * @wq: the waitqueue to wait on | |
593 | * @condition: a C expression for the event to wait for | |
594 | * | |
595 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
596 | * @condition evaluates to true or a signal is received. | |
597 | * The @condition is checked each time the waitqueue @wq is woken up. | |
598 | * | |
599 | * It must be called with wq.lock being held. This spinlock is | |
600 | * unlocked while sleeping but @condition testing is done while lock | |
601 | * is held and when this macro exits the lock is held. | |
602 | * | |
603 | * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() | |
604 | * functions which must match the way they are locked/unlocked outside | |
605 | * of this macro. | |
606 | * | |
607 | * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag | |
608 | * set thus when other process waits process on the list if this | |
609 | * process is awaken further processes are not considered. | |
610 | * | |
611 | * wake_up_locked() has to be called after changing any variable that could | |
612 | * change the result of the wait condition. | |
613 | * | |
614 | * The function will return -ERESTARTSYS if it was interrupted by a | |
615 | * signal and 0 if @condition evaluated to true. | |
616 | */ | |
617 | #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \ | |
618 | ((condition) \ | |
619 | ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1)) | |
620 | ||
621 | ||
35a2af94 PZ |
622 | #define __wait_event_killable(wq, condition) \ |
623 | ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) | |
1411d5a7 MW |
624 | |
625 | /** | |
626 | * wait_event_killable - sleep until a condition gets true | |
627 | * @wq: the waitqueue to wait on | |
628 | * @condition: a C expression for the event to wait for | |
629 | * | |
630 | * The process is put to sleep (TASK_KILLABLE) until the | |
631 | * @condition evaluates to true or a signal is received. | |
632 | * The @condition is checked each time the waitqueue @wq is woken up. | |
633 | * | |
634 | * wake_up() has to be called after changing any variable that could | |
635 | * change the result of the wait condition. | |
636 | * | |
637 | * The function will return -ERESTARTSYS if it was interrupted by a | |
638 | * signal and 0 if @condition evaluated to true. | |
639 | */ | |
640 | #define wait_event_killable(wq, condition) \ | |
641 | ({ \ | |
642 | int __ret = 0; \ | |
643 | if (!(condition)) \ | |
35a2af94 | 644 | __ret = __wait_event_killable(wq, condition); \ |
1411d5a7 MW |
645 | __ret; \ |
646 | }) | |
647 | ||
eed8c02e LC |
648 | |
649 | #define __wait_event_lock_irq(wq, condition, lock, cmd) \ | |
35a2af94 PZ |
650 | (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ |
651 | spin_unlock_irq(&lock); \ | |
652 | cmd; \ | |
653 | schedule(); \ | |
654 | spin_lock_irq(&lock)) | |
eed8c02e LC |
655 | |
656 | /** | |
657 | * wait_event_lock_irq_cmd - sleep until a condition gets true. The | |
658 | * condition is checked under the lock. This | |
659 | * is expected to be called with the lock | |
660 | * taken. | |
661 | * @wq: the waitqueue to wait on | |
662 | * @condition: a C expression for the event to wait for | |
663 | * @lock: a locked spinlock_t, which will be released before cmd | |
664 | * and schedule() and reacquired afterwards. | |
665 | * @cmd: a command which is invoked outside the critical section before | |
666 | * sleep | |
667 | * | |
668 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
669 | * @condition evaluates to true. The @condition is checked each time | |
670 | * the waitqueue @wq is woken up. | |
671 | * | |
672 | * wake_up() has to be called after changing any variable that could | |
673 | * change the result of the wait condition. | |
674 | * | |
675 | * This is supposed to be called while holding the lock. The lock is | |
676 | * dropped before invoking the cmd and going to sleep and is reacquired | |
677 | * afterwards. | |
678 | */ | |
679 | #define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \ | |
680 | do { \ | |
681 | if (condition) \ | |
682 | break; \ | |
683 | __wait_event_lock_irq(wq, condition, lock, cmd); \ | |
684 | } while (0) | |
685 | ||
686 | /** | |
687 | * wait_event_lock_irq - sleep until a condition gets true. The | |
688 | * condition is checked under the lock. This | |
689 | * is expected to be called with the lock | |
690 | * taken. | |
691 | * @wq: the waitqueue to wait on | |
692 | * @condition: a C expression for the event to wait for | |
693 | * @lock: a locked spinlock_t, which will be released before schedule() | |
694 | * and reacquired afterwards. | |
695 | * | |
696 | * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the | |
697 | * @condition evaluates to true. The @condition is checked each time | |
698 | * the waitqueue @wq is woken up. | |
699 | * | |
700 | * wake_up() has to be called after changing any variable that could | |
701 | * change the result of the wait condition. | |
702 | * | |
703 | * This is supposed to be called while holding the lock. The lock is | |
704 | * dropped before going to sleep and is reacquired afterwards. | |
705 | */ | |
706 | #define wait_event_lock_irq(wq, condition, lock) \ | |
707 | do { \ | |
708 | if (condition) \ | |
709 | break; \ | |
710 | __wait_event_lock_irq(wq, condition, lock, ); \ | |
711 | } while (0) | |
712 | ||
713 | ||
35a2af94 | 714 | #define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \ |
fb869b6e | 715 | ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ |
35a2af94 PZ |
716 | spin_unlock_irq(&lock); \ |
717 | cmd; \ | |
718 | schedule(); \ | |
8fbd88fa | 719 | spin_lock_irq(&lock)) |
eed8c02e LC |
720 | |
721 | /** | |
722 | * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. | |
723 | * The condition is checked under the lock. This is expected to | |
724 | * be called with the lock taken. | |
725 | * @wq: the waitqueue to wait on | |
726 | * @condition: a C expression for the event to wait for | |
727 | * @lock: a locked spinlock_t, which will be released before cmd and | |
728 | * schedule() and reacquired afterwards. | |
729 | * @cmd: a command which is invoked outside the critical section before | |
730 | * sleep | |
731 | * | |
732 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
733 | * @condition evaluates to true or a signal is received. The @condition is | |
734 | * checked each time the waitqueue @wq is woken up. | |
735 | * | |
736 | * wake_up() has to be called after changing any variable that could | |
737 | * change the result of the wait condition. | |
738 | * | |
739 | * This is supposed to be called while holding the lock. The lock is | |
740 | * dropped before invoking the cmd and going to sleep and is reacquired | |
741 | * afterwards. | |
742 | * | |
743 | * The macro will return -ERESTARTSYS if it was interrupted by a signal | |
744 | * and 0 if @condition evaluated to true. | |
745 | */ | |
746 | #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \ | |
747 | ({ \ | |
748 | int __ret = 0; \ | |
eed8c02e | 749 | if (!(condition)) \ |
fb869b6e | 750 | __ret = __wait_event_interruptible_lock_irq(wq, \ |
35a2af94 | 751 | condition, lock, cmd); \ |
eed8c02e LC |
752 | __ret; \ |
753 | }) | |
754 | ||
755 | /** | |
756 | * wait_event_interruptible_lock_irq - sleep until a condition gets true. | |
757 | * The condition is checked under the lock. This is expected | |
758 | * to be called with the lock taken. | |
759 | * @wq: the waitqueue to wait on | |
760 | * @condition: a C expression for the event to wait for | |
761 | * @lock: a locked spinlock_t, which will be released before schedule() | |
762 | * and reacquired afterwards. | |
763 | * | |
764 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
765 | * @condition evaluates to true or signal is received. The @condition is | |
766 | * checked each time the waitqueue @wq is woken up. | |
767 | * | |
768 | * wake_up() has to be called after changing any variable that could | |
769 | * change the result of the wait condition. | |
770 | * | |
771 | * This is supposed to be called while holding the lock. The lock is | |
772 | * dropped before going to sleep and is reacquired afterwards. | |
773 | * | |
774 | * The macro will return -ERESTARTSYS if it was interrupted by a signal | |
775 | * and 0 if @condition evaluated to true. | |
776 | */ | |
777 | #define wait_event_interruptible_lock_irq(wq, condition, lock) \ | |
778 | ({ \ | |
779 | int __ret = 0; \ | |
eed8c02e | 780 | if (!(condition)) \ |
35a2af94 | 781 | __ret = __wait_event_interruptible_lock_irq(wq, \ |
92ec1180 | 782 | condition, lock,); \ |
eed8c02e LC |
783 | __ret; \ |
784 | }) | |
785 | ||
fb869b6e IM |
786 | #define __wait_event_interruptible_lock_irq_timeout(wq, condition, \ |
787 | lock, timeout) \ | |
35a2af94 | 788 | ___wait_event(wq, ___wait_cond_timeout(condition), \ |
7d716456 | 789 | TASK_INTERRUPTIBLE, 0, timeout, \ |
35a2af94 PZ |
790 | spin_unlock_irq(&lock); \ |
791 | __ret = schedule_timeout(__ret); \ | |
a1dc6852 | 792 | spin_lock_irq(&lock)); |
d79ff142 MP |
793 | |
794 | /** | |
fb869b6e IM |
795 | * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets |
796 | * true or a timeout elapses. The condition is checked under | |
797 | * the lock. This is expected to be called with the lock taken. | |
d79ff142 MP |
798 | * @wq: the waitqueue to wait on |
799 | * @condition: a C expression for the event to wait for | |
800 | * @lock: a locked spinlock_t, which will be released before schedule() | |
801 | * and reacquired afterwards. | |
802 | * @timeout: timeout, in jiffies | |
803 | * | |
804 | * The process is put to sleep (TASK_INTERRUPTIBLE) until the | |
805 | * @condition evaluates to true or signal is received. The @condition is | |
806 | * checked each time the waitqueue @wq is woken up. | |
807 | * | |
808 | * wake_up() has to be called after changing any variable that could | |
809 | * change the result of the wait condition. | |
810 | * | |
811 | * This is supposed to be called while holding the lock. The lock is | |
812 | * dropped before going to sleep and is reacquired afterwards. | |
813 | * | |
814 | * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it | |
815 | * was interrupted by a signal, and the remaining jiffies otherwise | |
816 | * if the condition evaluated to true before the timeout elapsed. | |
817 | */ | |
818 | #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \ | |
819 | timeout) \ | |
820 | ({ \ | |
35a2af94 | 821 | long __ret = timeout; \ |
8922915b | 822 | if (!___wait_cond_timeout(condition)) \ |
35a2af94 PZ |
823 | __ret = __wait_event_interruptible_lock_irq_timeout( \ |
824 | wq, condition, lock, timeout); \ | |
d79ff142 MP |
825 | __ret; \ |
826 | }) | |
827 | ||
1da177e4 LT |
828 | /* |
829 | * Waitqueues which are removed from the waitqueue_head at wakeup time | |
830 | */ | |
b3c97528 HH |
831 | void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); |
832 | void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); | |
c2d81644 | 833 | long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); |
b3c97528 | 834 | void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); |
fb869b6e | 835 | void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); |
61ada528 PZ |
836 | long wait_woken(wait_queue_t *wait, unsigned mode, long timeout); |
837 | int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
1da177e4 LT |
838 | int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); |
839 | int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); | |
840 | ||
bf368e4e | 841 | #define DEFINE_WAIT_FUNC(name, function) \ |
1da177e4 | 842 | wait_queue_t name = { \ |
c43dc2fd | 843 | .private = current, \ |
bf368e4e | 844 | .func = function, \ |
7e43c84e | 845 | .task_list = LIST_HEAD_INIT((name).task_list), \ |
1da177e4 LT |
846 | } |
847 | ||
bf368e4e ED |
848 | #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) |
849 | ||
1da177e4 LT |
850 | #define DEFINE_WAIT_BIT(name, word, bit) \ |
851 | struct wait_bit_queue name = { \ | |
852 | .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ | |
853 | .wait = { \ | |
c43dc2fd | 854 | .private = current, \ |
1da177e4 LT |
855 | .func = wake_bit_function, \ |
856 | .task_list = \ | |
857 | LIST_HEAD_INIT((name).wait.task_list), \ | |
858 | }, \ | |
859 | } | |
860 | ||
861 | #define init_wait(wait) \ | |
862 | do { \ | |
c43dc2fd | 863 | (wait)->private = current; \ |
1da177e4 LT |
864 | (wait)->func = autoremove_wake_function; \ |
865 | INIT_LIST_HEAD(&(wait)->task_list); \ | |
231d0aef | 866 | (wait)->flags = 0; \ |
1da177e4 LT |
867 | } while (0) |
868 | ||
74316201 | 869 | |
c1221321 N |
870 | extern int bit_wait(struct wait_bit_key *); |
871 | extern int bit_wait_io(struct wait_bit_key *); | |
cbbce822 N |
872 | extern int bit_wait_timeout(struct wait_bit_key *); |
873 | extern int bit_wait_io_timeout(struct wait_bit_key *); | |
74316201 | 874 | |
1da177e4 LT |
875 | /** |
876 | * wait_on_bit - wait for a bit to be cleared | |
877 | * @word: the word being waited on, a kernel virtual address | |
878 | * @bit: the bit of the word being waited on | |
1da177e4 LT |
879 | * @mode: the task state to sleep in |
880 | * | |
881 | * There is a standard hashed waitqueue table for generic use. This | |
882 | * is the part of the hashtable's accessor API that waits on a bit. | |
883 | * For instance, if one were to have waiters on a bitflag, one would | |
884 | * call wait_on_bit() in threads waiting for the bit to clear. | |
885 | * One uses wait_on_bit() where one is waiting for the bit to clear, | |
886 | * but has no intention of setting it. | |
74316201 N |
887 | * Returned value will be zero if the bit was cleared, or non-zero |
888 | * if the process received a signal and the mode permitted wakeup | |
889 | * on that signal. | |
890 | */ | |
891 | static inline int | |
892 | wait_on_bit(void *word, int bit, unsigned mode) | |
893 | { | |
894 | if (!test_bit(bit, word)) | |
895 | return 0; | |
896 | return out_of_line_wait_on_bit(word, bit, | |
897 | bit_wait, | |
898 | mode); | |
899 | } | |
900 | ||
901 | /** | |
902 | * wait_on_bit_io - wait for a bit to be cleared | |
903 | * @word: the word being waited on, a kernel virtual address | |
904 | * @bit: the bit of the word being waited on | |
905 | * @mode: the task state to sleep in | |
906 | * | |
907 | * Use the standard hashed waitqueue table to wait for a bit | |
908 | * to be cleared. This is similar to wait_on_bit(), but calls | |
909 | * io_schedule() instead of schedule() for the actual waiting. | |
910 | * | |
911 | * Returned value will be zero if the bit was cleared, or non-zero | |
912 | * if the process received a signal and the mode permitted wakeup | |
913 | * on that signal. | |
914 | */ | |
915 | static inline int | |
916 | wait_on_bit_io(void *word, int bit, unsigned mode) | |
917 | { | |
918 | if (!test_bit(bit, word)) | |
919 | return 0; | |
920 | return out_of_line_wait_on_bit(word, bit, | |
921 | bit_wait_io, | |
922 | mode); | |
923 | } | |
924 | ||
925 | /** | |
926 | * wait_on_bit_action - wait for a bit to be cleared | |
927 | * @word: the word being waited on, a kernel virtual address | |
928 | * @bit: the bit of the word being waited on | |
929 | * @action: the function used to sleep, which may take special actions | |
930 | * @mode: the task state to sleep in | |
931 | * | |
932 | * Use the standard hashed waitqueue table to wait for a bit | |
933 | * to be cleared, and allow the waiting action to be specified. | |
934 | * This is like wait_on_bit() but allows fine control of how the waiting | |
935 | * is done. | |
936 | * | |
937 | * Returned value will be zero if the bit was cleared, or non-zero | |
938 | * if the process received a signal and the mode permitted wakeup | |
939 | * on that signal. | |
1da177e4 | 940 | */ |
fb869b6e | 941 | static inline int |
c1221321 | 942 | wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode) |
1da177e4 LT |
943 | { |
944 | if (!test_bit(bit, word)) | |
945 | return 0; | |
946 | return out_of_line_wait_on_bit(word, bit, action, mode); | |
947 | } | |
948 | ||
949 | /** | |
950 | * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it | |
951 | * @word: the word being waited on, a kernel virtual address | |
952 | * @bit: the bit of the word being waited on | |
1da177e4 LT |
953 | * @mode: the task state to sleep in |
954 | * | |
955 | * There is a standard hashed waitqueue table for generic use. This | |
956 | * is the part of the hashtable's accessor API that waits on a bit | |
957 | * when one intends to set it, for instance, trying to lock bitflags. | |
958 | * For instance, if one were to have waiters trying to set bitflag | |
959 | * and waiting for it to clear before setting it, one would call | |
960 | * wait_on_bit() in threads waiting to be able to set the bit. | |
961 | * One uses wait_on_bit_lock() where one is waiting for the bit to | |
962 | * clear with the intention of setting it, and when done, clearing it. | |
74316201 N |
963 | * |
964 | * Returns zero if the bit was (eventually) found to be clear and was | |
965 | * set. Returns non-zero if a signal was delivered to the process and | |
966 | * the @mode allows that signal to wake the process. | |
967 | */ | |
968 | static inline int | |
969 | wait_on_bit_lock(void *word, int bit, unsigned mode) | |
970 | { | |
971 | if (!test_and_set_bit(bit, word)) | |
972 | return 0; | |
973 | return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode); | |
974 | } | |
975 | ||
976 | /** | |
977 | * wait_on_bit_lock_io - wait for a bit to be cleared, when wanting to set it | |
978 | * @word: the word being waited on, a kernel virtual address | |
979 | * @bit: the bit of the word being waited on | |
980 | * @mode: the task state to sleep in | |
981 | * | |
982 | * Use the standard hashed waitqueue table to wait for a bit | |
983 | * to be cleared and then to atomically set it. This is similar | |
984 | * to wait_on_bit(), but calls io_schedule() instead of schedule() | |
985 | * for the actual waiting. | |
986 | * | |
987 | * Returns zero if the bit was (eventually) found to be clear and was | |
988 | * set. Returns non-zero if a signal was delivered to the process and | |
989 | * the @mode allows that signal to wake the process. | |
990 | */ | |
991 | static inline int | |
992 | wait_on_bit_lock_io(void *word, int bit, unsigned mode) | |
993 | { | |
994 | if (!test_and_set_bit(bit, word)) | |
995 | return 0; | |
996 | return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode); | |
997 | } | |
998 | ||
999 | /** | |
1000 | * wait_on_bit_lock_action - wait for a bit to be cleared, when wanting to set it | |
1001 | * @word: the word being waited on, a kernel virtual address | |
1002 | * @bit: the bit of the word being waited on | |
1003 | * @action: the function used to sleep, which may take special actions | |
1004 | * @mode: the task state to sleep in | |
1005 | * | |
1006 | * Use the standard hashed waitqueue table to wait for a bit | |
1007 | * to be cleared and then to set it, and allow the waiting action | |
1008 | * to be specified. | |
1009 | * This is like wait_on_bit() but allows fine control of how the waiting | |
1010 | * is done. | |
1011 | * | |
1012 | * Returns zero if the bit was (eventually) found to be clear and was | |
1013 | * set. Returns non-zero if a signal was delivered to the process and | |
1014 | * the @mode allows that signal to wake the process. | |
1da177e4 | 1015 | */ |
fb869b6e | 1016 | static inline int |
c1221321 | 1017 | wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode) |
1da177e4 LT |
1018 | { |
1019 | if (!test_and_set_bit(bit, word)) | |
1020 | return 0; | |
1021 | return out_of_line_wait_on_bit_lock(word, bit, action, mode); | |
1022 | } | |
cb65537e DH |
1023 | |
1024 | /** | |
1025 | * wait_on_atomic_t - Wait for an atomic_t to become 0 | |
1026 | * @val: The atomic value being waited on, a kernel virtual address | |
1027 | * @action: the function used to sleep, which may take special actions | |
1028 | * @mode: the task state to sleep in | |
1029 | * | |
1030 | * Wait for an atomic_t to become 0. We abuse the bit-wait waitqueue table for | |
1031 | * the purpose of getting a waitqueue, but we set the key to a bit number | |
1032 | * outside of the target 'word'. | |
1033 | */ | |
1034 | static inline | |
1035 | int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode) | |
1036 | { | |
1037 | if (atomic_read(val) == 0) | |
1038 | return 0; | |
1039 | return out_of_line_wait_on_atomic_t(val, action, mode); | |
1040 | } | |
fb869b6e IM |
1041 | |
1042 | #endif /* _LINUX_WAIT_H */ |