1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * workqueue.h --- work queue handling for Linux.
4 */
5
6 #ifndef _LINUX_WORKQUEUE_H
7 #define _LINUX_WORKQUEUE_H
8
9 #include <linux/timer.h>
10 #include <linux/linkage.h>
11 #include <linux/bitops.h>
12 #include <linux/lockdep.h>
13 #include <linux/threads.h>
14 #include <linux/atomic.h>
15 #include <linux/cpumask.h>
16
17 struct workqueue_struct;
18
19 struct work_struct;
20 typedef void (*work_func_t)(struct work_struct *work);
21 void delayed_work_timer_fn(unsigned long __data);
22
23 /*
24 * The first word is the work queue pointer and the flags rolled into
25 * one
26 */
27 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
28
29 enum {
30 WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
31 WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */
32 WORK_STRUCT_PWQ_BIT = 2, /* data points to pwq */
33 WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */
34 #ifdef CONFIG_DEBUG_OBJECTS_WORK
35 WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */
36 WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */
37 #else
38 WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
39 #endif
40
41 WORK_STRUCT_COLOR_BITS = 4,
42
43 WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
44 WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT,
45 WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT,
46 WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
47 #ifdef CONFIG_DEBUG_OBJECTS_WORK
48 WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
49 #else
50 WORK_STRUCT_STATIC = 0,
51 #endif
52
53 /*
54 * The last color is no color used for works which don't
55 * participate in workqueue flushing.
56 */
57 WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
58 WORK_NO_COLOR = WORK_NR_COLORS,
59
60 /* not bound to any CPU, prefer the local CPU */
61 WORK_CPU_UNBOUND = NR_CPUS,
62
63 /*
64 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
65 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
66 * flush colors.
67 */
68 WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
69 WORK_STRUCT_COLOR_BITS,
70
71 /* data contains off-queue information when !WORK_STRUCT_PWQ */
72 WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
73
74 __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
75 WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING),
76
77 /*
78 * When a work item is off queue, its high bits point to the last
79 * pool it was on. Cap at 31 bits and use the highest number to
80 * indicate that no pool is associated.
81 */
82 WORK_OFFQ_FLAG_BITS = 1,
83 WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
84 WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
85 WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
86 WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1,
87
88 /* convenience constants */
89 WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
90 WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
91 WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT,
92
93 /* bit mask for work_busy() return values */
94 WORK_BUSY_PENDING = 1 << 0,
95 WORK_BUSY_RUNNING = 1 << 1,
96
97 /* maximum string length for set_worker_desc() */
98 WORKER_DESC_LEN = 24,
99 };
100
101 struct work_struct {
102 atomic_long_t data;
103 struct list_head entry;
104 work_func_t func;
105 #ifdef CONFIG_LOCKDEP
106 struct lockdep_map lockdep_map;
107 #endif
108 };
109
110 #define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL)
111 #define WORK_DATA_STATIC_INIT() \
112 ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
113
114 struct delayed_work {
115 struct work_struct work;
116 struct timer_list timer;
117
118 /* target workqueue and CPU ->timer uses to queue ->work */
119 struct workqueue_struct *wq;
120 int cpu;
121 };
122
123 /**
124 * struct workqueue_attrs - A struct for workqueue attributes.
125 *
126 * This can be used to change attributes of an unbound workqueue.
127 */
128 struct workqueue_attrs {
129 /**
130 * @nice: nice level
131 */
132 int nice;
133
134 /**
135 * @cpumask: allowed CPUs
136 */
137 cpumask_var_t cpumask;
138
139 /**
140 * @no_numa: disable NUMA affinity
141 *
142 * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It
143 * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus
144 * doesn't participate in pool hash calculations or equality comparisons.
145 */
146 bool no_numa;
147 };
148
to_delayed_work(struct work_struct * work)149 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
150 {
151 return container_of(work, struct delayed_work, work);
152 }
153
154 struct execute_work {
155 struct work_struct work;
156 };
157
158 #ifdef CONFIG_LOCKDEP
159 /*
160 * NB: because we have to copy the lockdep_map, setting _key
161 * here is required, otherwise it could get initialised to the
162 * copy of the lockdep_map!
163 */
164 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
165 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
166 #else
167 #define __WORK_INIT_LOCKDEP_MAP(n, k)
168 #endif
169
170 #define __WORK_INITIALIZER(n, f) { \
171 .data = WORK_DATA_STATIC_INIT(), \
172 .entry = { &(n).entry, &(n).entry }, \
173 .func = (f), \
174 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
175 }
176
177 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
178 .work = __WORK_INITIALIZER((n).work, (f)), \
179 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
180 0, (unsigned long)&(n), \
181 (tflags) | TIMER_IRQSAFE), \
182 }
183
184 #define DECLARE_WORK(n, f) \
185 struct work_struct n = __WORK_INITIALIZER(n, f)
186
187 #define DECLARE_DELAYED_WORK(n, f) \
188 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
189
190 #define DECLARE_DEFERRABLE_WORK(n, f) \
191 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
192
193 #ifdef CONFIG_DEBUG_OBJECTS_WORK
194 extern void __init_work(struct work_struct *work, int onstack);
195 extern void destroy_work_on_stack(struct work_struct *work);
196 extern void destroy_delayed_work_on_stack(struct delayed_work *work);
work_static(struct work_struct * work)197 static inline unsigned int work_static(struct work_struct *work)
198 {
199 return *work_data_bits(work) & WORK_STRUCT_STATIC;
200 }
201 #else
__init_work(struct work_struct * work,int onstack)202 static inline void __init_work(struct work_struct *work, int onstack) { }
destroy_work_on_stack(struct work_struct * work)203 static inline void destroy_work_on_stack(struct work_struct *work) { }
destroy_delayed_work_on_stack(struct delayed_work * work)204 static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
work_static(struct work_struct * work)205 static inline unsigned int work_static(struct work_struct *work) { return 0; }
206 #endif
207
208 /*
209 * initialize all of a work item in one go
210 *
211 * NOTE! No point in using "atomic_long_set()": using a direct
212 * assignment of the work data initializer allows the compiler
213 * to generate better code.
214 */
215 #ifdef CONFIG_LOCKDEP
216 #define __INIT_WORK(_work, _func, _onstack) \
217 do { \
218 static struct lock_class_key __key; \
219 \
220 __init_work((_work), _onstack); \
221 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
222 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
223 INIT_LIST_HEAD(&(_work)->entry); \
224 (_work)->func = (_func); \
225 } while (0)
226 #else
227 #define __INIT_WORK(_work, _func, _onstack) \
228 do { \
229 __init_work((_work), _onstack); \
230 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
231 INIT_LIST_HEAD(&(_work)->entry); \
232 (_work)->func = (_func); \
233 } while (0)
234 #endif
235
236 #define INIT_WORK(_work, _func) \
237 __INIT_WORK((_work), (_func), 0)
238
239 #define INIT_WORK_ONSTACK(_work, _func) \
240 __INIT_WORK((_work), (_func), 1)
241
242 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
243 do { \
244 INIT_WORK(&(_work)->work, (_func)); \
245 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
246 (unsigned long)(_work), \
247 (_tflags) | TIMER_IRQSAFE); \
248 } while (0)
249
250 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
251 do { \
252 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
253 __setup_timer_on_stack(&(_work)->timer, \
254 delayed_work_timer_fn, \
255 (unsigned long)(_work), \
256 (_tflags) | TIMER_IRQSAFE); \
257 } while (0)
258
259 #define INIT_DELAYED_WORK(_work, _func) \
260 __INIT_DELAYED_WORK(_work, _func, 0)
261
262 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
263 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
264
265 #define INIT_DEFERRABLE_WORK(_work, _func) \
266 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
267
268 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
269 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
270
271 /**
272 * work_pending - Find out whether a work item is currently pending
273 * @work: The work item in question
274 */
275 #define work_pending(work) \
276 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
277
278 /**
279 * delayed_work_pending - Find out whether a delayable work item is currently
280 * pending
281 * @w: The work item in question
282 */
283 #define delayed_work_pending(w) \
284 work_pending(&(w)->work)
285
286 /*
287 * Workqueue flags and constants. For details, please refer to
288 * Documentation/core-api/workqueue.rst.
289 */
290 enum {
291 WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
292 WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
293 WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
294 WQ_HIGHPRI = 1 << 4, /* high priority */
295 WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
296 WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
297
298 /*
299 * Per-cpu workqueues are generally preferred because they tend to
300 * show better performance thanks to cache locality. Per-cpu
301 * workqueues exclude the scheduler from choosing the CPU to
302 * execute the worker threads, which has an unfortunate side effect
303 * of increasing power consumption.
304 *
305 * The scheduler considers a CPU idle if it doesn't have any task
306 * to execute and tries to keep idle cores idle to conserve power;
307 * however, for example, a per-cpu work item scheduled from an
308 * interrupt handler on an idle CPU will force the scheduler to
309 * excute the work item on that CPU breaking the idleness, which in
310 * turn may lead to more scheduling choices which are sub-optimal
311 * in terms of power consumption.
312 *
313 * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
314 * but become unbound if workqueue.power_efficient kernel param is
315 * specified. Per-cpu workqueues which are identified to
316 * contribute significantly to power-consumption are identified and
317 * marked with this flag and enabling the power_efficient mode
318 * leads to noticeable power saving at the cost of small
319 * performance disadvantage.
320 *
321 * http://thread.gmane.org/gmane.linux.kernel/1480396
322 */
323 WQ_POWER_EFFICIENT = 1 << 7,
324
325 __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
326 __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
327 __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
328 __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
329
330 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
331 WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
332 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
333 };
334
335 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
336 #define WQ_UNBOUND_MAX_ACTIVE \
337 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
338
339 /*
340 * System-wide workqueues which are always present.
341 *
342 * system_wq is the one used by schedule[_delayed]_work[_on]().
343 * Multi-CPU multi-threaded. There are users which expect relatively
344 * short queue flush time. Don't queue works which can run for too
345 * long.
346 *
347 * system_highpri_wq is similar to system_wq but for work items which
348 * require WQ_HIGHPRI.
349 *
350 * system_long_wq is similar to system_wq but may host long running
351 * works. Queue flushing might take relatively long.
352 *
353 * system_unbound_wq is unbound workqueue. Workers are not bound to
354 * any specific CPU, not concurrency managed, and all queued works are
355 * executed immediately as long as max_active limit is not reached and
356 * resources are available.
357 *
358 * system_freezable_wq is equivalent to system_wq except that it's
359 * freezable.
360 *
361 * *_power_efficient_wq are inclined towards saving power and converted
362 * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
363 * they are same as their non-power-efficient counterparts - e.g.
364 * system_power_efficient_wq is identical to system_wq if
365 * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
366 */
367 extern struct workqueue_struct *system_wq;
368 extern struct workqueue_struct *system_highpri_wq;
369 extern struct workqueue_struct *system_long_wq;
370 extern struct workqueue_struct *system_unbound_wq;
371 extern struct workqueue_struct *system_freezable_wq;
372 extern struct workqueue_struct *system_power_efficient_wq;
373 extern struct workqueue_struct *system_freezable_power_efficient_wq;
374
375 extern struct workqueue_struct *
376 __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
377 struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);
378
379 /**
380 * alloc_workqueue - allocate a workqueue
381 * @fmt: printf format for the name of the workqueue
382 * @flags: WQ_* flags
383 * @max_active: max in-flight work items, 0 for default
384 * @args...: args for @fmt
385 *
386 * Allocate a workqueue with the specified parameters. For detailed
387 * information on WQ_* flags, please refer to
388 * Documentation/core-api/workqueue.rst.
389 *
390 * The __lock_name macro dance is to guarantee that single lock_class_key
391 * doesn't end up with different namesm, which isn't allowed by lockdep.
392 *
393 * RETURNS:
394 * Pointer to the allocated workqueue on success, %NULL on failure.
395 */
396 #ifdef CONFIG_LOCKDEP
397 #define alloc_workqueue(fmt, flags, max_active, args...) \
398 ({ \
399 static struct lock_class_key __key; \
400 const char *__lock_name; \
401 \
402 __lock_name = #fmt#args; \
403 \
404 __alloc_workqueue_key((fmt), (flags), (max_active), \
405 &__key, __lock_name, ##args); \
406 })
407 #else
408 #define alloc_workqueue(fmt, flags, max_active, args...) \
409 __alloc_workqueue_key((fmt), (flags), (max_active), \
410 NULL, NULL, ##args)
411 #endif
412
413 /**
414 * alloc_ordered_workqueue - allocate an ordered workqueue
415 * @fmt: printf format for the name of the workqueue
416 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
417 * @args...: args for @fmt
418 *
419 * Allocate an ordered workqueue. An ordered workqueue executes at
420 * most one work item at any given time in the queued order. They are
421 * implemented as unbound workqueues with @max_active of one.
422 *
423 * RETURNS:
424 * Pointer to the allocated workqueue on success, %NULL on failure.
425 */
426 #define alloc_ordered_workqueue(fmt, flags, args...) \
427 alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \
428 __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
429
430 #define create_workqueue(name) \
431 alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
432 #define create_freezable_workqueue(name) \
433 alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
434 WQ_MEM_RECLAIM, 1, (name))
435 #define create_singlethread_workqueue(name) \
436 alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
437
438 extern void destroy_workqueue(struct workqueue_struct *wq);
439
440 struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask);
441 void free_workqueue_attrs(struct workqueue_attrs *attrs);
442 int apply_workqueue_attrs(struct workqueue_struct *wq,
443 const struct workqueue_attrs *attrs);
444 int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
445
446 extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
447 struct work_struct *work);
448 extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
449 struct delayed_work *work, unsigned long delay);
450 extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
451 struct delayed_work *dwork, unsigned long delay);
452
453 extern void flush_workqueue(struct workqueue_struct *wq);
454 extern void drain_workqueue(struct workqueue_struct *wq);
455
456 extern int schedule_on_each_cpu(work_func_t func);
457
458 int execute_in_process_context(work_func_t fn, struct execute_work *);
459
460 extern bool flush_work(struct work_struct *work);
461 extern bool cancel_work(struct work_struct *work);
462 extern bool cancel_work_sync(struct work_struct *work);
463
464 extern bool flush_delayed_work(struct delayed_work *dwork);
465 extern bool cancel_delayed_work(struct delayed_work *dwork);
466 extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
467
468 extern void workqueue_set_max_active(struct workqueue_struct *wq,
469 int max_active);
470 extern struct work_struct *current_work(void);
471 extern bool current_is_workqueue_rescuer(void);
472 extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
473 extern unsigned int work_busy(struct work_struct *work);
474 extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
475 extern void print_worker_info(const char *log_lvl, struct task_struct *task);
476 extern void show_workqueue_state(void);
477
478 /**
479 * queue_work - queue work on a workqueue
480 * @wq: workqueue to use
481 * @work: work to queue
482 *
483 * Returns %false if @work was already on a queue, %true otherwise.
484 *
485 * We queue the work to the CPU on which it was submitted, but if the CPU dies
486 * it can be processed by another CPU.
487 */
queue_work(struct workqueue_struct * wq,struct work_struct * work)488 static inline bool queue_work(struct workqueue_struct *wq,
489 struct work_struct *work)
490 {
491 return queue_work_on(WORK_CPU_UNBOUND, wq, work);
492 }
493
494 /**
495 * queue_delayed_work - queue work on a workqueue after delay
496 * @wq: workqueue to use
497 * @dwork: delayable work to queue
498 * @delay: number of jiffies to wait before queueing
499 *
500 * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
501 */
queue_delayed_work(struct workqueue_struct * wq,struct delayed_work * dwork,unsigned long delay)502 static inline bool queue_delayed_work(struct workqueue_struct *wq,
503 struct delayed_work *dwork,
504 unsigned long delay)
505 {
506 return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
507 }
508
509 /**
510 * mod_delayed_work - modify delay of or queue a delayed work
511 * @wq: workqueue to use
512 * @dwork: work to queue
513 * @delay: number of jiffies to wait before queueing
514 *
515 * mod_delayed_work_on() on local CPU.
516 */
mod_delayed_work(struct workqueue_struct * wq,struct delayed_work * dwork,unsigned long delay)517 static inline bool mod_delayed_work(struct workqueue_struct *wq,
518 struct delayed_work *dwork,
519 unsigned long delay)
520 {
521 return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
522 }
523
524 /**
525 * schedule_work_on - put work task on a specific cpu
526 * @cpu: cpu to put the work task on
527 * @work: job to be done
528 *
529 * This puts a job on a specific cpu
530 */
schedule_work_on(int cpu,struct work_struct * work)531 static inline bool schedule_work_on(int cpu, struct work_struct *work)
532 {
533 return queue_work_on(cpu, system_wq, work);
534 }
535
536 /**
537 * schedule_work - put work task in global workqueue
538 * @work: job to be done
539 *
540 * Returns %false if @work was already on the kernel-global workqueue and
541 * %true otherwise.
542 *
543 * This puts a job in the kernel-global workqueue if it was not already
544 * queued and leaves it in the same position on the kernel-global
545 * workqueue otherwise.
546 */
schedule_work(struct work_struct * work)547 static inline bool schedule_work(struct work_struct *work)
548 {
549 return queue_work(system_wq, work);
550 }
551
552 /**
553 * flush_scheduled_work - ensure that any scheduled work has run to completion.
554 *
555 * Forces execution of the kernel-global workqueue and blocks until its
556 * completion.
557 *
558 * Think twice before calling this function! It's very easy to get into
559 * trouble if you don't take great care. Either of the following situations
560 * will lead to deadlock:
561 *
562 * One of the work items currently on the workqueue needs to acquire
563 * a lock held by your code or its caller.
564 *
565 * Your code is running in the context of a work routine.
566 *
567 * They will be detected by lockdep when they occur, but the first might not
568 * occur very often. It depends on what work items are on the workqueue and
569 * what locks they need, which you have no control over.
570 *
571 * In most situations flushing the entire workqueue is overkill; you merely
572 * need to know that a particular work item isn't queued and isn't running.
573 * In such cases you should use cancel_delayed_work_sync() or
574 * cancel_work_sync() instead.
575 */
flush_scheduled_work(void)576 static inline void flush_scheduled_work(void)
577 {
578 flush_workqueue(system_wq);
579 }
580
581 /**
582 * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
583 * @cpu: cpu to use
584 * @dwork: job to be done
585 * @delay: number of jiffies to wait
586 *
587 * After waiting for a given time this puts a job in the kernel-global
588 * workqueue on the specified CPU.
589 */
schedule_delayed_work_on(int cpu,struct delayed_work * dwork,unsigned long delay)590 static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
591 unsigned long delay)
592 {
593 return queue_delayed_work_on(cpu, system_wq, dwork, delay);
594 }
595
596 /**
597 * schedule_delayed_work - put work task in global workqueue after delay
598 * @dwork: job to be done
599 * @delay: number of jiffies to wait or 0 for immediate execution
600 *
601 * After waiting for a given time this puts a job in the kernel-global
602 * workqueue.
603 */
schedule_delayed_work(struct delayed_work * dwork,unsigned long delay)604 static inline bool schedule_delayed_work(struct delayed_work *dwork,
605 unsigned long delay)
606 {
607 return queue_delayed_work(system_wq, dwork, delay);
608 }
609
610 #ifndef CONFIG_SMP
work_on_cpu(int cpu,long (* fn)(void *),void * arg)611 static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
612 {
613 return fn(arg);
614 }
work_on_cpu_safe(int cpu,long (* fn)(void *),void * arg)615 static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
616 {
617 return fn(arg);
618 }
619 #else
620 long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
621 long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);
622 #endif /* CONFIG_SMP */
623
624 #ifdef CONFIG_FREEZER
625 extern void freeze_workqueues_begin(void);
626 extern bool freeze_workqueues_busy(void);
627 extern void thaw_workqueues(void);
628 #endif /* CONFIG_FREEZER */
629
630 #ifdef CONFIG_SYSFS
631 int workqueue_sysfs_register(struct workqueue_struct *wq);
632 #else /* CONFIG_SYSFS */
workqueue_sysfs_register(struct workqueue_struct * wq)633 static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
634 { return 0; }
635 #endif /* CONFIG_SYSFS */
636
637 #ifdef CONFIG_WQ_WATCHDOG
638 void wq_watchdog_touch(int cpu);
639 #else /* CONFIG_WQ_WATCHDOG */
wq_watchdog_touch(int cpu)640 static inline void wq_watchdog_touch(int cpu) { }
641 #endif /* CONFIG_WQ_WATCHDOG */
642
643 #ifdef CONFIG_SMP
644 int workqueue_prepare_cpu(unsigned int cpu);
645 int workqueue_online_cpu(unsigned int cpu);
646 int workqueue_offline_cpu(unsigned int cpu);
647 #endif
648
649 int __init workqueue_init_early(void);
650 int __init workqueue_init(void);
651
652 #endif
653