wait.h 30 KB

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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. typedef struct __wait_queue wait_queue_t;
  12. typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
  13. int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
  14. struct __wait_queue {
  15. unsigned int flags;
  16. #define WQ_FLAG_EXCLUSIVE 0x01
  17. void *private;
  18. wait_queue_func_t func;
  19. struct list_head task_list;
  20. };
  21. struct wait_bit_key {
  22. void *flags;
  23. int bit_nr;
  24. #define WAIT_ATOMIC_T_BIT_NR -1
  25. };
  26. struct wait_bit_queue {
  27. struct wait_bit_key key;
  28. wait_queue_t wait;
  29. };
  30. struct __wait_queue_head {
  31. spinlock_t lock;
  32. struct list_head task_list;
  33. };
  34. typedef struct __wait_queue_head wait_queue_head_t;
  35. struct task_struct;
  36. /*
  37. * Macros for declaration and initialisaton of the datatypes
  38. */
  39. #define __WAITQUEUE_INITIALIZER(name, tsk) { \
  40. .private = tsk, \
  41. .func = default_wake_function, \
  42. .task_list = { NULL, NULL } }
  43. #define DECLARE_WAITQUEUE(name, tsk) \
  44. wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
  45. #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
  46. .lock = __SPIN_LOCK_UNLOCKED(name.lock), \
  47. .task_list = { &(name).task_list, &(name).task_list } }
  48. #define DECLARE_WAIT_QUEUE_HEAD(name) \
  49. wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
  50. #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
  51. { .flags = word, .bit_nr = bit, }
  52. #define __WAIT_ATOMIC_T_KEY_INITIALIZER(p) \
  53. { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, }
  54. extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *);
  55. #define init_waitqueue_head(q) \
  56. do { \
  57. static struct lock_class_key __key; \
  58. \
  59. __init_waitqueue_head((q), #q, &__key); \
  60. } while (0)
  61. #ifdef CONFIG_LOCKDEP
  62. # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
  63. ({ init_waitqueue_head(&name); name; })
  64. # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
  65. wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
  66. #else
  67. # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
  68. #endif
  69. static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
  70. {
  71. q->flags = 0;
  72. q->private = p;
  73. q->func = default_wake_function;
  74. }
  75. static inline void
  76. init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func)
  77. {
  78. q->flags = 0;
  79. q->private = NULL;
  80. q->func = func;
  81. }
  82. static inline int waitqueue_active(wait_queue_head_t *q)
  83. {
  84. return !list_empty(&q->task_list);
  85. }
  86. extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
  87. extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
  88. extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
  89. static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
  90. {
  91. list_add(&new->task_list, &head->task_list);
  92. }
  93. /*
  94. * Used for wake-one threads:
  95. */
  96. static inline void
  97. __add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
  98. {
  99. wait->flags |= WQ_FLAG_EXCLUSIVE;
  100. __add_wait_queue(q, wait);
  101. }
  102. static inline void __add_wait_queue_tail(wait_queue_head_t *head,
  103. wait_queue_t *new)
  104. {
  105. list_add_tail(&new->task_list, &head->task_list);
  106. }
  107. static inline void
  108. __add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait)
  109. {
  110. wait->flags |= WQ_FLAG_EXCLUSIVE;
  111. __add_wait_queue_tail(q, wait);
  112. }
  113. static inline void
  114. __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old)
  115. {
  116. list_del(&old->task_list);
  117. }
  118. void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
  119. void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
  120. void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
  121. void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
  122. void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
  123. void __wake_up_bit(wait_queue_head_t *, void *, int);
  124. int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
  125. int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
  126. void wake_up_bit(void *, int);
  127. void wake_up_atomic_t(atomic_t *);
  128. int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
  129. int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
  130. int out_of_line_wait_on_atomic_t(atomic_t *, int (*)(atomic_t *), unsigned);
  131. wait_queue_head_t *bit_waitqueue(void *, int);
  132. #define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
  133. #define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
  134. #define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
  135. #define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
  136. #define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
  137. #define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
  138. #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
  139. #define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
  140. #define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
  141. /*
  142. * Wakeup macros to be used to report events to the targets.
  143. */
  144. #define wake_up_poll(x, m) \
  145. __wake_up(x, TASK_NORMAL, 1, (void *) (m))
  146. #define wake_up_locked_poll(x, m) \
  147. __wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
  148. #define wake_up_interruptible_poll(x, m) \
  149. __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
  150. #define wake_up_interruptible_sync_poll(x, m) \
  151. __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
  152. #define ___wait_cond_timeout(condition) \
  153. ({ \
  154. bool __cond = (condition); \
  155. if (__cond && !__ret) \
  156. __ret = 1; \
  157. __cond || !__ret; \
  158. })
  159. #define ___wait_is_interruptible(state) \
  160. (!__builtin_constant_p(state) || \
  161. state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
  162. #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \
  163. ({ \
  164. __label__ __out; \
  165. wait_queue_t __wait; \
  166. long __ret = ret; \
  167. \
  168. INIT_LIST_HEAD(&__wait.task_list); \
  169. if (exclusive) \
  170. __wait.flags = WQ_FLAG_EXCLUSIVE; \
  171. else \
  172. __wait.flags = 0; \
  173. \
  174. for (;;) { \
  175. long __int = prepare_to_wait_event(&wq, &__wait, state);\
  176. \
  177. if (condition) \
  178. break; \
  179. \
  180. if (___wait_is_interruptible(state) && __int) { \
  181. __ret = __int; \
  182. if (exclusive) { \
  183. abort_exclusive_wait(&wq, &__wait, \
  184. state, NULL); \
  185. goto __out; \
  186. } \
  187. break; \
  188. } \
  189. \
  190. cmd; \
  191. } \
  192. finish_wait(&wq, &__wait); \
  193. __out: __ret; \
  194. })
  195. #define __wait_event(wq, condition) \
  196. (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
  197. schedule())
  198. /**
  199. * wait_event - sleep until a condition gets true
  200. * @wq: the waitqueue to wait on
  201. * @condition: a C expression for the event to wait for
  202. *
  203. * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
  204. * @condition evaluates to true. The @condition is checked each time
  205. * the waitqueue @wq is woken up.
  206. *
  207. * wake_up() has to be called after changing any variable that could
  208. * change the result of the wait condition.
  209. */
  210. #define wait_event(wq, condition) \
  211. do { \
  212. if (condition) \
  213. break; \
  214. __wait_event(wq, condition); \
  215. } while (0)
  216. #define __wait_event_timeout(wq, condition, timeout) \
  217. ___wait_event(wq, ___wait_cond_timeout(condition), \
  218. TASK_UNINTERRUPTIBLE, 0, timeout, \
  219. __ret = schedule_timeout(__ret))
  220. /**
  221. * wait_event_timeout - sleep until a condition gets true or a timeout elapses
  222. * @wq: the waitqueue to wait on
  223. * @condition: a C expression for the event to wait for
  224. * @timeout: timeout, in jiffies
  225. *
  226. * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
  227. * @condition evaluates to true. The @condition is checked each time
  228. * the waitqueue @wq is woken up.
  229. *
  230. * wake_up() has to be called after changing any variable that could
  231. * change the result of the wait condition.
  232. *
  233. * The function returns 0 if the @timeout elapsed, or the remaining
  234. * jiffies (at least 1) if the @condition evaluated to %true before
  235. * the @timeout elapsed.
  236. */
  237. #define wait_event_timeout(wq, condition, timeout) \
  238. ({ \
  239. long __ret = timeout; \
  240. if (!___wait_cond_timeout(condition)) \
  241. __ret = __wait_event_timeout(wq, condition, timeout); \
  242. __ret; \
  243. })
  244. #define __wait_event_interruptible(wq, condition) \
  245. ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
  246. schedule())
  247. /**
  248. * wait_event_interruptible - sleep until a condition gets true
  249. * @wq: the waitqueue to wait on
  250. * @condition: a C expression for the event to wait for
  251. *
  252. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  253. * @condition evaluates to true or a signal is received.
  254. * The @condition is checked each time the waitqueue @wq is woken up.
  255. *
  256. * wake_up() has to be called after changing any variable that could
  257. * change the result of the wait condition.
  258. *
  259. * The function will return -ERESTARTSYS if it was interrupted by a
  260. * signal and 0 if @condition evaluated to true.
  261. */
  262. #define wait_event_interruptible(wq, condition) \
  263. ({ \
  264. int __ret = 0; \
  265. if (!(condition)) \
  266. __ret = __wait_event_interruptible(wq, condition); \
  267. __ret; \
  268. })
  269. #define __wait_event_interruptible_timeout(wq, condition, timeout) \
  270. ___wait_event(wq, ___wait_cond_timeout(condition), \
  271. TASK_INTERRUPTIBLE, 0, timeout, \
  272. __ret = schedule_timeout(__ret))
  273. /**
  274. * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
  275. * @wq: the waitqueue to wait on
  276. * @condition: a C expression for the event to wait for
  277. * @timeout: timeout, in jiffies
  278. *
  279. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  280. * @condition evaluates to true or a signal is received.
  281. * The @condition is checked each time the waitqueue @wq is woken up.
  282. *
  283. * wake_up() has to be called after changing any variable that could
  284. * change the result of the wait condition.
  285. *
  286. * Returns:
  287. * 0 if the @timeout elapsed, -%ERESTARTSYS if it was interrupted by
  288. * a signal, or the remaining jiffies (at least 1) if the @condition
  289. * evaluated to %true before the @timeout elapsed.
  290. */
  291. #define wait_event_interruptible_timeout(wq, condition, timeout) \
  292. ({ \
  293. long __ret = timeout; \
  294. if (!___wait_cond_timeout(condition)) \
  295. __ret = __wait_event_interruptible_timeout(wq, \
  296. condition, timeout); \
  297. __ret; \
  298. })
  299. #define __wait_event_hrtimeout(wq, condition, timeout, state) \
  300. ({ \
  301. int __ret = 0; \
  302. struct hrtimer_sleeper __t; \
  303. \
  304. hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \
  305. HRTIMER_MODE_REL); \
  306. hrtimer_init_sleeper(&__t, current); \
  307. if ((timeout).tv64 != KTIME_MAX) \
  308. hrtimer_start_range_ns(&__t.timer, timeout, \
  309. current->timer_slack_ns, \
  310. HRTIMER_MODE_REL); \
  311. \
  312. __ret = ___wait_event(wq, condition, state, 0, 0, \
  313. if (!__t.task) { \
  314. __ret = -ETIME; \
  315. break; \
  316. } \
  317. schedule()); \
  318. \
  319. hrtimer_cancel(&__t.timer); \
  320. destroy_hrtimer_on_stack(&__t.timer); \
  321. __ret; \
  322. })
  323. /**
  324. * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
  325. * @wq: the waitqueue to wait on
  326. * @condition: a C expression for the event to wait for
  327. * @timeout: timeout, as a ktime_t
  328. *
  329. * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
  330. * @condition evaluates to true or a signal is received.
  331. * The @condition is checked each time the waitqueue @wq is woken up.
  332. *
  333. * wake_up() has to be called after changing any variable that could
  334. * change the result of the wait condition.
  335. *
  336. * The function returns 0 if @condition became true, or -ETIME if the timeout
  337. * elapsed.
  338. */
  339. #define wait_event_hrtimeout(wq, condition, timeout) \
  340. ({ \
  341. int __ret = 0; \
  342. if (!(condition)) \
  343. __ret = __wait_event_hrtimeout(wq, condition, timeout, \
  344. TASK_UNINTERRUPTIBLE); \
  345. __ret; \
  346. })
  347. /**
  348. * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
  349. * @wq: the waitqueue to wait on
  350. * @condition: a C expression for the event to wait for
  351. * @timeout: timeout, as a ktime_t
  352. *
  353. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  354. * @condition evaluates to true or a signal is received.
  355. * The @condition is checked each time the waitqueue @wq is woken up.
  356. *
  357. * wake_up() has to be called after changing any variable that could
  358. * change the result of the wait condition.
  359. *
  360. * The function returns 0 if @condition became true, -ERESTARTSYS if it was
  361. * interrupted by a signal, or -ETIME if the timeout elapsed.
  362. */
  363. #define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
  364. ({ \
  365. long __ret = 0; \
  366. if (!(condition)) \
  367. __ret = __wait_event_hrtimeout(wq, condition, timeout, \
  368. TASK_INTERRUPTIBLE); \
  369. __ret; \
  370. })
  371. #define __wait_event_interruptible_exclusive(wq, condition) \
  372. ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
  373. schedule())
  374. #define wait_event_interruptible_exclusive(wq, condition) \
  375. ({ \
  376. int __ret = 0; \
  377. if (!(condition)) \
  378. __ret = __wait_event_interruptible_exclusive(wq, condition);\
  379. __ret; \
  380. })
  381. #define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
  382. ({ \
  383. int __ret = 0; \
  384. DEFINE_WAIT(__wait); \
  385. if (exclusive) \
  386. __wait.flags |= WQ_FLAG_EXCLUSIVE; \
  387. do { \
  388. if (likely(list_empty(&__wait.task_list))) \
  389. __add_wait_queue_tail(&(wq), &__wait); \
  390. set_current_state(TASK_INTERRUPTIBLE); \
  391. if (signal_pending(current)) { \
  392. __ret = -ERESTARTSYS; \
  393. break; \
  394. } \
  395. if (irq) \
  396. spin_unlock_irq(&(wq).lock); \
  397. else \
  398. spin_unlock(&(wq).lock); \
  399. schedule(); \
  400. if (irq) \
  401. spin_lock_irq(&(wq).lock); \
  402. else \
  403. spin_lock(&(wq).lock); \
  404. } while (!(condition)); \
  405. __remove_wait_queue(&(wq), &__wait); \
  406. __set_current_state(TASK_RUNNING); \
  407. __ret; \
  408. })
  409. /**
  410. * wait_event_interruptible_locked - sleep until a condition gets true
  411. * @wq: the waitqueue to wait on
  412. * @condition: a C expression for the event to wait for
  413. *
  414. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  415. * @condition evaluates to true or a signal is received.
  416. * The @condition is checked each time the waitqueue @wq is woken up.
  417. *
  418. * It must be called with wq.lock being held. This spinlock is
  419. * unlocked while sleeping but @condition testing is done while lock
  420. * is held and when this macro exits the lock is held.
  421. *
  422. * The lock is locked/unlocked using spin_lock()/spin_unlock()
  423. * functions which must match the way they are locked/unlocked outside
  424. * of this macro.
  425. *
  426. * wake_up_locked() has to be called after changing any variable that could
  427. * change the result of the wait condition.
  428. *
  429. * The function will return -ERESTARTSYS if it was interrupted by a
  430. * signal and 0 if @condition evaluated to true.
  431. */
  432. #define wait_event_interruptible_locked(wq, condition) \
  433. ((condition) \
  434. ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
  435. /**
  436. * wait_event_interruptible_locked_irq - sleep until a condition gets true
  437. * @wq: the waitqueue to wait on
  438. * @condition: a C expression for the event to wait for
  439. *
  440. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  441. * @condition evaluates to true or a signal is received.
  442. * The @condition is checked each time the waitqueue @wq is woken up.
  443. *
  444. * It must be called with wq.lock being held. This spinlock is
  445. * unlocked while sleeping but @condition testing is done while lock
  446. * is held and when this macro exits the lock is held.
  447. *
  448. * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
  449. * functions which must match the way they are locked/unlocked outside
  450. * of this macro.
  451. *
  452. * wake_up_locked() has to be called after changing any variable that could
  453. * change the result of the wait condition.
  454. *
  455. * The function will return -ERESTARTSYS if it was interrupted by a
  456. * signal and 0 if @condition evaluated to true.
  457. */
  458. #define wait_event_interruptible_locked_irq(wq, condition) \
  459. ((condition) \
  460. ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))
  461. /**
  462. * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
  463. * @wq: the waitqueue to wait on
  464. * @condition: a C expression for the event to wait for
  465. *
  466. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  467. * @condition evaluates to true or a signal is received.
  468. * The @condition is checked each time the waitqueue @wq is woken up.
  469. *
  470. * It must be called with wq.lock being held. This spinlock is
  471. * unlocked while sleeping but @condition testing is done while lock
  472. * is held and when this macro exits the lock is held.
  473. *
  474. * The lock is locked/unlocked using spin_lock()/spin_unlock()
  475. * functions which must match the way they are locked/unlocked outside
  476. * of this macro.
  477. *
  478. * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
  479. * set thus when other process waits process on the list if this
  480. * process is awaken further processes are not considered.
  481. *
  482. * wake_up_locked() has to be called after changing any variable that could
  483. * change the result of the wait condition.
  484. *
  485. * The function will return -ERESTARTSYS if it was interrupted by a
  486. * signal and 0 if @condition evaluated to true.
  487. */
  488. #define wait_event_interruptible_exclusive_locked(wq, condition) \
  489. ((condition) \
  490. ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))
  491. /**
  492. * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
  493. * @wq: the waitqueue to wait on
  494. * @condition: a C expression for the event to wait for
  495. *
  496. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  497. * @condition evaluates to true or a signal is received.
  498. * The @condition is checked each time the waitqueue @wq is woken up.
  499. *
  500. * It must be called with wq.lock being held. This spinlock is
  501. * unlocked while sleeping but @condition testing is done while lock
  502. * is held and when this macro exits the lock is held.
  503. *
  504. * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
  505. * functions which must match the way they are locked/unlocked outside
  506. * of this macro.
  507. *
  508. * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
  509. * set thus when other process waits process on the list if this
  510. * process is awaken further processes are not considered.
  511. *
  512. * wake_up_locked() has to be called after changing any variable that could
  513. * change the result of the wait condition.
  514. *
  515. * The function will return -ERESTARTSYS if it was interrupted by a
  516. * signal and 0 if @condition evaluated to true.
  517. */
  518. #define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
  519. ((condition) \
  520. ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
  521. #define __wait_event_killable(wq, condition) \
  522. ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
  523. /**
  524. * wait_event_killable - sleep until a condition gets true
  525. * @wq: the waitqueue to wait on
  526. * @condition: a C expression for the event to wait for
  527. *
  528. * The process is put to sleep (TASK_KILLABLE) until the
  529. * @condition evaluates to true or a signal is received.
  530. * The @condition is checked each time the waitqueue @wq is woken up.
  531. *
  532. * wake_up() has to be called after changing any variable that could
  533. * change the result of the wait condition.
  534. *
  535. * The function will return -ERESTARTSYS if it was interrupted by a
  536. * signal and 0 if @condition evaluated to true.
  537. */
  538. #define wait_event_killable(wq, condition) \
  539. ({ \
  540. int __ret = 0; \
  541. if (!(condition)) \
  542. __ret = __wait_event_killable(wq, condition); \
  543. __ret; \
  544. })
  545. #define __wait_event_lock_irq(wq, condition, lock, cmd) \
  546. (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
  547. spin_unlock_irq(&lock); \
  548. cmd; \
  549. schedule(); \
  550. spin_lock_irq(&lock))
  551. /**
  552. * wait_event_lock_irq_cmd - sleep until a condition gets true. The
  553. * condition is checked under the lock. This
  554. * is expected to be called with the lock
  555. * taken.
  556. * @wq: the waitqueue to wait on
  557. * @condition: a C expression for the event to wait for
  558. * @lock: a locked spinlock_t, which will be released before cmd
  559. * and schedule() and reacquired afterwards.
  560. * @cmd: a command which is invoked outside the critical section before
  561. * sleep
  562. *
  563. * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
  564. * @condition evaluates to true. The @condition is checked each time
  565. * the waitqueue @wq is woken up.
  566. *
  567. * wake_up() has to be called after changing any variable that could
  568. * change the result of the wait condition.
  569. *
  570. * This is supposed to be called while holding the lock. The lock is
  571. * dropped before invoking the cmd and going to sleep and is reacquired
  572. * afterwards.
  573. */
  574. #define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \
  575. do { \
  576. if (condition) \
  577. break; \
  578. __wait_event_lock_irq(wq, condition, lock, cmd); \
  579. } while (0)
  580. /**
  581. * wait_event_lock_irq - sleep until a condition gets true. The
  582. * condition is checked under the lock. This
  583. * is expected to be called with the lock
  584. * taken.
  585. * @wq: the waitqueue to wait on
  586. * @condition: a C expression for the event to wait for
  587. * @lock: a locked spinlock_t, which will be released before schedule()
  588. * and reacquired afterwards.
  589. *
  590. * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
  591. * @condition evaluates to true. The @condition is checked each time
  592. * the waitqueue @wq is woken up.
  593. *
  594. * wake_up() has to be called after changing any variable that could
  595. * change the result of the wait condition.
  596. *
  597. * This is supposed to be called while holding the lock. The lock is
  598. * dropped before going to sleep and is reacquired afterwards.
  599. */
  600. #define wait_event_lock_irq(wq, condition, lock) \
  601. do { \
  602. if (condition) \
  603. break; \
  604. __wait_event_lock_irq(wq, condition, lock, ); \
  605. } while (0)
  606. #define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \
  607. ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
  608. spin_unlock_irq(&lock); \
  609. cmd; \
  610. schedule(); \
  611. spin_lock_irq(&lock))
  612. /**
  613. * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
  614. * The condition is checked under the lock. This is expected to
  615. * be called with the lock taken.
  616. * @wq: the waitqueue to wait on
  617. * @condition: a C expression for the event to wait for
  618. * @lock: a locked spinlock_t, which will be released before cmd and
  619. * schedule() and reacquired afterwards.
  620. * @cmd: a command which is invoked outside the critical section before
  621. * sleep
  622. *
  623. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  624. * @condition evaluates to true or a signal is received. The @condition is
  625. * checked each time the waitqueue @wq is woken up.
  626. *
  627. * wake_up() has to be called after changing any variable that could
  628. * change the result of the wait condition.
  629. *
  630. * This is supposed to be called while holding the lock. The lock is
  631. * dropped before invoking the cmd and going to sleep and is reacquired
  632. * afterwards.
  633. *
  634. * The macro will return -ERESTARTSYS if it was interrupted by a signal
  635. * and 0 if @condition evaluated to true.
  636. */
  637. #define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \
  638. ({ \
  639. int __ret = 0; \
  640. if (!(condition)) \
  641. __ret = __wait_event_interruptible_lock_irq(wq, \
  642. condition, lock, cmd); \
  643. __ret; \
  644. })
  645. /**
  646. * wait_event_interruptible_lock_irq - sleep until a condition gets true.
  647. * The condition is checked under the lock. This is expected
  648. * to be called with the lock taken.
  649. * @wq: the waitqueue to wait on
  650. * @condition: a C expression for the event to wait for
  651. * @lock: a locked spinlock_t, which will be released before schedule()
  652. * and reacquired afterwards.
  653. *
  654. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  655. * @condition evaluates to true or signal is received. The @condition is
  656. * checked each time the waitqueue @wq is woken up.
  657. *
  658. * wake_up() has to be called after changing any variable that could
  659. * change the result of the wait condition.
  660. *
  661. * This is supposed to be called while holding the lock. The lock is
  662. * dropped before going to sleep and is reacquired afterwards.
  663. *
  664. * The macro will return -ERESTARTSYS if it was interrupted by a signal
  665. * and 0 if @condition evaluated to true.
  666. */
  667. #define wait_event_interruptible_lock_irq(wq, condition, lock) \
  668. ({ \
  669. int __ret = 0; \
  670. if (!(condition)) \
  671. __ret = __wait_event_interruptible_lock_irq(wq, \
  672. condition, lock,); \
  673. __ret; \
  674. })
  675. #define __wait_event_interruptible_lock_irq_timeout(wq, condition, \
  676. lock, timeout) \
  677. ___wait_event(wq, ___wait_cond_timeout(condition), \
  678. TASK_INTERRUPTIBLE, 0, ret, \
  679. spin_unlock_irq(&lock); \
  680. __ret = schedule_timeout(__ret); \
  681. spin_lock_irq(&lock));
  682. /**
  683. * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
  684. * true or a timeout elapses. The condition is checked under
  685. * the lock. This is expected to be called with the lock taken.
  686. * @wq: the waitqueue to wait on
  687. * @condition: a C expression for the event to wait for
  688. * @lock: a locked spinlock_t, which will be released before schedule()
  689. * and reacquired afterwards.
  690. * @timeout: timeout, in jiffies
  691. *
  692. * The process is put to sleep (TASK_INTERRUPTIBLE) until the
  693. * @condition evaluates to true or signal is received. The @condition is
  694. * checked each time the waitqueue @wq is woken up.
  695. *
  696. * wake_up() has to be called after changing any variable that could
  697. * change the result of the wait condition.
  698. *
  699. * This is supposed to be called while holding the lock. The lock is
  700. * dropped before going to sleep and is reacquired afterwards.
  701. *
  702. * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
  703. * was interrupted by a signal, and the remaining jiffies otherwise
  704. * if the condition evaluated to true before the timeout elapsed.
  705. */
  706. #define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \
  707. timeout) \
  708. ({ \
  709. long __ret = timeout; \
  710. if (!___wait_cond_timeout(condition)) \
  711. __ret = __wait_event_interruptible_lock_irq_timeout( \
  712. wq, condition, lock, timeout); \
  713. __ret; \
  714. })
  715. /*
  716. * These are the old interfaces to sleep waiting for an event.
  717. * They are racy. DO NOT use them, use the wait_event* interfaces above.
  718. * We plan to remove these interfaces.
  719. */
  720. extern void sleep_on(wait_queue_head_t *q);
  721. extern long sleep_on_timeout(wait_queue_head_t *q, signed long timeout);
  722. extern void interruptible_sleep_on(wait_queue_head_t *q);
  723. extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long timeout);
  724. /*
  725. * Waitqueues which are removed from the waitqueue_head at wakeup time
  726. */
  727. void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state);
  728. void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state);
  729. long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state);
  730. void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
  731. void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key);
  732. int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
  733. int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
  734. #define DEFINE_WAIT_FUNC(name, function) \
  735. wait_queue_t name = { \
  736. .private = current, \
  737. .func = function, \
  738. .task_list = LIST_HEAD_INIT((name).task_list), \
  739. }
  740. #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
  741. #define DEFINE_WAIT_BIT(name, word, bit) \
  742. struct wait_bit_queue name = { \
  743. .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \
  744. .wait = { \
  745. .private = current, \
  746. .func = wake_bit_function, \
  747. .task_list = \
  748. LIST_HEAD_INIT((name).wait.task_list), \
  749. }, \
  750. }
  751. #define init_wait(wait) \
  752. do { \
  753. (wait)->private = current; \
  754. (wait)->func = autoremove_wake_function; \
  755. INIT_LIST_HEAD(&(wait)->task_list); \
  756. (wait)->flags = 0; \
  757. } while (0)
  758. /**
  759. * wait_on_bit - wait for a bit to be cleared
  760. * @word: the word being waited on, a kernel virtual address
  761. * @bit: the bit of the word being waited on
  762. * @action: the function used to sleep, which may take special actions
  763. * @mode: the task state to sleep in
  764. *
  765. * There is a standard hashed waitqueue table for generic use. This
  766. * is the part of the hashtable's accessor API that waits on a bit.
  767. * For instance, if one were to have waiters on a bitflag, one would
  768. * call wait_on_bit() in threads waiting for the bit to clear.
  769. * One uses wait_on_bit() where one is waiting for the bit to clear,
  770. * but has no intention of setting it.
  771. */
  772. static inline int
  773. wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode)
  774. {
  775. if (!test_bit(bit, word))
  776. return 0;
  777. return out_of_line_wait_on_bit(word, bit, action, mode);
  778. }
  779. /**
  780. * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
  781. * @word: the word being waited on, a kernel virtual address
  782. * @bit: the bit of the word being waited on
  783. * @action: the function used to sleep, which may take special actions
  784. * @mode: the task state to sleep in
  785. *
  786. * There is a standard hashed waitqueue table for generic use. This
  787. * is the part of the hashtable's accessor API that waits on a bit
  788. * when one intends to set it, for instance, trying to lock bitflags.
  789. * For instance, if one were to have waiters trying to set bitflag
  790. * and waiting for it to clear before setting it, one would call
  791. * wait_on_bit() in threads waiting to be able to set the bit.
  792. * One uses wait_on_bit_lock() where one is waiting for the bit to
  793. * clear with the intention of setting it, and when done, clearing it.
  794. */
  795. static inline int
  796. wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode)
  797. {
  798. if (!test_and_set_bit(bit, word))
  799. return 0;
  800. return out_of_line_wait_on_bit_lock(word, bit, action, mode);
  801. }
  802. /**
  803. * wait_on_atomic_t - Wait for an atomic_t to become 0
  804. * @val: The atomic value being waited on, a kernel virtual address
  805. * @action: the function used to sleep, which may take special actions
  806. * @mode: the task state to sleep in
  807. *
  808. * Wait for an atomic_t to become 0. We abuse the bit-wait waitqueue table for
  809. * the purpose of getting a waitqueue, but we set the key to a bit number
  810. * outside of the target 'word'.
  811. */
  812. static inline
  813. int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
  814. {
  815. if (atomic_read(val) == 0)
  816. return 0;
  817. return out_of_line_wait_on_atomic_t(val, action, mode);
  818. }
  819. #endif /* _LINUX_WAIT_H */