1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LIBCFS_LINUX_WAIT_BIT_H
3 #define __LIBCFS_LINUX_WAIT_BIT_H
5 /* Make sure we can see if we have TASK_NOLOAD */
6 #include <linux/sched.h>
8 * Linux wait-bit related types and methods:
10 #ifdef HAVE_WAIT_BIT_HEADER_H
11 #include <linux/wait_bit.h>
13 #include <linux/wait.h>
15 #ifndef HAVE_WAIT_QUEUE_ENTRY
16 #define wait_queue_entry_t wait_queue_t
19 #ifndef HAVE_WAIT_BIT_HEADER_H
20 struct wait_bit_queue_entry {
21 struct wait_bit_key key;
22 wait_queue_entry_t wq_entry;
25 #define ___wait_is_interruptible(state) \
26 (!__builtin_constant_p(state) || \
27 state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \
29 #endif /* ! HAVE_WAIT_BIT_HEADER_H */
31 #ifndef HAVE_PREPARE_TO_WAIT_EVENT
32 extern long prepare_to_wait_event(wait_queue_head_t *wq_head,
33 wait_queue_entry_t *wq_entry, int state);
36 /* ___wait_cond_timeout changed number of args in v3.12-rc1-78-g35a2af94c7ce
37 * so let's define our own ___wait_cond_timeout1
40 #define ___wait_cond_timeout1(condition) \
42 bool __cond = (condition); \
43 if (__cond && !__ret) \
48 #ifndef HAVE_CLEAR_AND_WAKE_UP_BIT
50 * clear_and_wake_up_bit - clear a bit and wake up anyone waiting on that bit
52 * @bit: the bit of the word being waited on
53 * @word: the word being waited on, a kernel virtual address
55 * You can use this helper if bitflags are manipulated atomically rather than
56 * non-atomically under a lock.
58 static inline void clear_and_wake_up_bit(int bit, void *word)
60 clear_bit_unlock(bit, word);
61 /* See wake_up_bit() for which memory barrier you need to use. */
62 smp_mb__after_atomic();
63 wake_up_bit(word, bit);
65 #endif /* ! HAVE_CLEAR_AND_WAKE_UP_BIT */
67 #ifndef HAVE_WAIT_VAR_EVENT
68 extern void __init wait_bit_init(void);
69 extern void init_wait_var_entry(struct wait_bit_queue_entry *wbq_entry,
70 void *var, int flags);
71 extern void wake_up_var(void *var);
72 extern wait_queue_head_t *__var_waitqueue(void *p);
74 #define ___wait_var_event(var, condition, state, exclusive, ret, cmd) \
77 wait_queue_head_t *__wq_head = __var_waitqueue(var); \
78 struct wait_bit_queue_entry __wbq_entry; \
79 long __ret = ret; /* explicit shadow */ \
81 init_wait_var_entry(&__wbq_entry, var, \
82 exclusive ? WQ_FLAG_EXCLUSIVE : 0); \
84 long __int = prepare_to_wait_event(__wq_head, \
85 &__wbq_entry.wq_entry, \
90 if (___wait_is_interruptible(state) && __int) { \
97 finish_wait(__wq_head, &__wbq_entry.wq_entry); \
101 #define __wait_var_event(var, condition) \
102 ___wait_var_event(var, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
105 #define wait_var_event(var, condition) \
110 __wait_var_event(var, condition); \
113 #define __wait_var_event_killable(var, condition) \
114 ___wait_var_event(var, condition, TASK_KILLABLE, 0, 0, \
117 #define wait_var_event_killable(var, condition) \
122 __ret = __wait_var_event_killable(var, condition); \
126 #define __wait_var_event_timeout(var, condition, timeout) \
127 ___wait_var_event(var, ___wait_cond_timeout1(condition), \
128 TASK_UNINTERRUPTIBLE, 0, timeout, \
129 __ret = schedule_timeout(__ret))
131 #define wait_var_event_timeout(var, condition, timeout) \
133 long __ret = timeout; \
135 if (!___wait_cond_timeout1(condition)) \
136 __ret = __wait_var_event_timeout(var, condition, timeout); \
139 #endif /* ! HAVE_WAIT_VAR_EVENT */
142 * prepare_to_wait_event() does not support an exclusive
144 * However it will not relink the wait_queue_entry if
145 * it is already linked. So we link to the head of the
146 * queue here, and it will stay there.
148 static inline void prepare_to_wait_exclusive_head(
149 wait_queue_head_t *waitq, wait_queue_entry_t *link)
153 spin_lock_irqsave(&(waitq->lock), flags);
154 #ifdef HAVE_WAIT_QUEUE_ENTRY_LIST
155 if (list_empty(&link->entry))
157 if (list_empty(&link->task_list))
159 __add_wait_queue_exclusive(waitq, link);
160 spin_unlock_irqrestore(&((waitq)->lock), flags);
163 #ifndef ___wait_event
165 * The below macro ___wait_event() has an explicit shadow of the __ret
166 * variable when used from the wait_event_*() macros.
168 * This is so that both can use the ___wait_cond_timeout1() construct
169 * to wrap the condition.
171 * The type inconsistency of the wait_event_*() __ret variable is also
172 * on purpose; we use long where we can return timeout values and int
176 #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \
179 wait_queue_entry_ __wq_entry; \
180 long __ret = ret; /* explicit shadow */ \
182 init_wait(&__wq_entry); \
184 __wq_entry.flags = WQ_FLAG_EXCLUSIVE \
186 long __int = prepare_to_wait_event(&wq_head, \
187 &__wq_entry, state); \
192 if (___wait_is_interruptible(state) && __int) { \
199 finish_wait(&wq_head, &__wq_entry); \
206 #define ___wait_event_idle(wq_head, condition, exclusive, ret, cmd) \
208 wait_queue_entry_t __wq_entry; \
209 long __ret = ret; /* explicit shadow */ \
210 sigset_t __blocked; \
212 __blocked = cfs_block_sigsinv(0); \
213 init_wait(&__wq_entry); \
215 __wq_entry.flags = WQ_FLAG_EXCLUSIVE; \
217 prepare_to_wait_event(&wq_head, \
219 TASK_INTERRUPTIBLE); \
223 /* See justification in __l_wait_event */ \
224 if (signal_pending(current)) \
225 cfs_clear_sigpending(); \
229 finish_wait(&wq_head, &__wq_entry); \
230 cfs_restore_sigs(__blocked); \
234 #define wait_event_idle(wq_head, condition) \
238 ___wait_event_idle(wq_head, condition, 0, 0, schedule());\
241 #define wait_event_idle_exclusive(wq_head, condition) \
245 ___wait_event_idle(wq_head, condition, 1, 0, schedule());\
248 #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout)\
249 ___wait_event_idle(wq_head, ___wait_cond_timeout1(condition), \
251 __ret = schedule_timeout(__ret))
253 #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
255 long __ret = timeout; \
257 if (!___wait_cond_timeout1(condition)) \
258 __ret = __wait_event_idle_exclusive_timeout( \
259 wq_head, condition, timeout); \
263 #define __wait_event_idle_exclusive_timeout_cmd(wq_head, condition, \
264 timeout, cmd1, cmd2) \
265 ___wait_event_idle(wq_head, ___wait_cond_timeout1(condition), \
267 cmd1; __ret = schedule_timeout(__ret); cmd2)
269 #define wait_event_idle_exclusive_timeout_cmd(wq_head, condition, timeout,\
272 long __ret = timeout; \
274 if (!___wait_cond_timeout1(condition)) \
275 __ret = __wait_event_idle_exclusive_timeout_cmd( \
276 wq_head, condition, timeout, cmd1, cmd2); \
280 #define __wait_event_idle_timeout(wq_head, condition, timeout) \
281 ___wait_event_idle(wq_head, ___wait_cond_timeout1(condition), \
283 __ret = schedule_timeout(__ret))
285 #define wait_event_idle_timeout(wq_head, condition, timeout) \
287 long __ret = timeout; \
289 if (!___wait_cond_timeout1(condition)) \
290 __ret = __wait_event_idle_timeout(wq_head, condition, \
295 #else /* TASK_IDLE */
296 #ifndef wait_event_idle
298 * wait_event_idle - wait for a condition without contributing to system load
299 * @wq_head: the waitqueue to wait on
300 * @condition: a C expression for the event to wait for
302 * The process is put to sleep (TASK_IDLE) until the
303 * @condition evaluates to true.
304 * The @condition is checked each time the waitqueue @wq_head is woken up.
306 * wake_up() has to be called after changing any variable that could
307 * change the result of the wait condition.
310 #define wait_event_idle(wq_head, condition) \
314 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, \
318 #ifndef wait_event_idle_exclusive
320 * wait_event_idle_exclusive - wait for a condition without contributing to
322 * @wq_head: the waitqueue to wait on
323 * @condition: a C expression for the event to wait for
325 * The process is put to sleep (TASK_IDLE) until the
326 * @condition evaluates to true.
327 * The @condition is checked each time the waitqueue @wq_head is woken up.
329 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
330 * set thus if other processes wait on the same list, when this
331 * process is woken further processes are not considered.
333 * wake_up() has to be called after changing any variable that could
334 * change the result of the wait condition.
337 #define wait_event_idle_exclusive(wq_head, condition) \
341 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, \
345 #ifndef wait_event_idle_exclusive_timeout
347 * wait_event_idle_exclusive_timeout - sleep without load until a condition
348 * becomes true or a timeout elapses
349 * @wq_head: the waitqueue to wait on
350 * @condition: a C expression for the event to wait for
351 * @timeout: timeout, in jiffies
353 * The process is put to sleep (TASK_IDLE) until the
354 * @condition evaluates to true. The @condition is checked each time
355 * the waitqueue @wq_head is woken up.
357 * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
358 * set thus if other processes wait on the same list, when this
359 * process is woken further processes are not considered.
361 * wake_up() has to be called after changing any variable that could
362 * change the result of the wait condition.
365 * 0 if the @condition evaluated to %false after the @timeout elapsed,
366 * 1 if the @condition evaluated to %true after the @timeout elapsed,
367 * or the remaining jiffies (at least 1) if the @condition evaluated
368 * to %true before the @timeout elapsed.
370 #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \
372 long __ret = timeout; \
374 if (!___wait_cond_timeout1(condition)) \
375 __ret = __wait_event_idle_exclusive_timeout(wq_head, \
381 #ifndef wait_event_idle_exclusive_timeout_cmd
382 #define __wait_event_idle_exclusive_timeout_cmd(wq_head, condition, \
383 timeout, cmd1, cmd2) \
384 ___wait_event(wq_head, ___wait_cond_timeout1(condition), \
385 TASK_IDLE, 1, timeout, \
386 cmd1; __ret = schedule_timeout(__ret); cmd2)
388 #define wait_event_idle_exclusive_timeout_cmd(wq_head, condition, timeout,\
391 long __ret = timeout; \
393 if (!___wait_cond_timeout1(condition)) \
394 __ret = __wait_event_idle_exclusive_timeout_cmd( \
395 wq_head, condition, timeout, cmd1, cmd2); \
400 #ifndef wait_event_idle_timeout
402 #define __wait_event_idle_timeout(wq_head, condition, timeout) \
403 ___wait_event(wq_head, ___wait_cond_timeout1(condition), \
404 TASK_IDLE, 0, timeout, \
405 __ret = schedule_timeout(__ret))
408 * wait_event_idle_timeout - sleep without load until a condition becomes
409 * true or a timeout elapses
410 * @wq_head: the waitqueue to wait on
411 * @condition: a C expression for the event to wait for
412 * @timeout: timeout, in jiffies
414 * The process is put to sleep (TASK_IDLE) until the
415 * @condition evaluates to true. The @condition is checked each time
416 * the waitqueue @wq_head is woken up.
418 * wake_up() has to be called after changing any variable that could
419 * change the result of the wait condition.
422 * 0 if the @condition evaluated to %false after the @timeout elapsed,
423 * 1 if the @condition evaluated to %true after the @timeout elapsed,
424 * or the remaining jiffies (at least 1) if the @condition evaluated
425 * to %true before the @timeout elapsed.
427 #define wait_event_idle_timeout(wq_head, condition, timeout) \
429 long __ret = timeout; \
431 if (!___wait_cond_timeout1(condition)) \
432 __ret = __wait_event_idle_timeout(wq_head, condition, \
437 #endif /* TASK_IDLE */
439 /* ___wait_event_lifo is used for lifo exclusive 'idle' waits */
442 #define ___wait_event_lifo(wq_head, condition, ret, cmd) \
444 wait_queue_entry_t __wq_entry; \
445 long __ret = ret; /* explicit shadow */ \
447 init_wait(&__wq_entry); \
448 __wq_entry.flags = WQ_FLAG_EXCLUSIVE; \
450 prepare_to_wait_exclusive_head(&wq_head, &__wq_entry); \
451 prepare_to_wait_event(&wq_head, &__wq_entry, TASK_IDLE);\
458 finish_wait(&wq_head, &__wq_entry); \
462 #define ___wait_event_lifo(wq_head, condition, ret, cmd) \
464 wait_queue_entry_t __wq_entry; \
465 long __ret = ret; /* explicit shadow */ \
466 sigset_t __blocked; \
468 __blocked = cfs_block_sigsinv(0); \
469 init_wait(&__wq_entry); \
470 __wq_entry.flags = WQ_FLAG_EXCLUSIVE; \
472 prepare_to_wait_exclusive_head(&wq_head, &__wq_entry); \
473 prepare_to_wait_event(&wq_head, &__wq_entry, \
474 TASK_INTERRUPTIBLE); \
478 /* See justification in __l_wait_event */ \
479 if (signal_pending(current)) \
480 cfs_clear_sigpending(); \
484 cfs_restore_sigs(__blocked); \
485 finish_wait(&wq_head, &__wq_entry); \
490 #define wait_event_idle_exclusive_lifo(wq_head, condition) \
494 ___wait_event_lifo(wq_head, condition, 0, schedule()); \
497 #define __wait_event_idle_lifo_timeout(wq_head, condition, timeout) \
498 ___wait_event_lifo(wq_head, ___wait_cond_timeout1(condition), \
500 __ret = schedule_timeout(__ret))
502 #define wait_event_idle_exclusive_lifo_timeout(wq_head, condition, timeout)\
504 long __ret = timeout; \
506 if (!___wait_cond_timeout1(condition)) \
507 __ret = __wait_event_idle_lifo_timeout(wq_head, \
513 /* l_wait_event_abortable() is a bit like wait_event_killable()
514 * except there is a fixed set of signals which will abort:
517 #define LUSTRE_FATAL_SIGS \
518 (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGTERM) | \
519 sigmask(SIGQUIT) | sigmask(SIGALRM))
521 #define l_wait_event_abortable(wq, condition) \
523 sigset_t __new_blocked, __old_blocked; \
525 siginitsetinv(&__new_blocked, LUSTRE_FATAL_SIGS); \
526 sigprocmask(SIG_BLOCK, &__new_blocked, &__old_blocked); \
527 __ret = wait_event_interruptible(wq, condition); \
528 sigprocmask(SIG_SETMASK, &__old_blocked, NULL); \
532 #define l_wait_event_abortable_timeout(wq, condition, timeout) \
534 sigset_t __new_blocked, __old_blocked; \
536 siginitsetinv(&__new_blocked, LUSTRE_FATAL_SIGS); \
537 sigprocmask(SIG_BLOCK, &__new_blocked, &__old_blocked); \
538 __ret = wait_event_interruptible_timeout(wq, condition, timeout);\
539 sigprocmask(SIG_SETMASK, &__old_blocked, NULL); \
543 #define l_wait_event_abortable_exclusive(wq, condition) \
545 sigset_t __new_blocked, __old_blocked; \
547 siginitsetinv(&__new_blocked, LUSTRE_FATAL_SIGS); \
548 sigprocmask(SIG_BLOCK, &__new_blocked, &__old_blocked); \
549 __ret = wait_event_interruptible_exclusive(wq, condition); \
550 sigprocmask(SIG_SETMASK, &__old_blocked, NULL); \
554 #endif /* __LICBFS_LINUX_WAIT_BIT_H */