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 #include <linux/rcupdate.h>
17 #include <linux/android_kabi.h>
18
19 struct workqueue_struct;
20
21 struct work_struct;
22 typedef void (*work_func_t)(struct work_struct *work);
23 void delayed_work_timer_fn(struct timer_list *t);
24
25 /*
26 * The first word is the work queue pointer and the flags rolled into
27 * one
28 */
29 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
30
31 enum {
32 WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
33 WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */
34 WORK_STRUCT_PWQ_BIT = 2, /* data points to pwq */
35 WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */
36 #ifdef CONFIG_DEBUG_OBJECTS_WORK
37 WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */
38 WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */
39 #else
40 WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
41 #endif
42
43 WORK_STRUCT_COLOR_BITS = 4,
44
45 WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
46 WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT,
47 WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT,
48 WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
49 #ifdef CONFIG_DEBUG_OBJECTS_WORK
50 WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
51 #else
52 WORK_STRUCT_STATIC = 0,
53 #endif
54
55 /*
56 * The last color is no color used for works which don't
57 * participate in workqueue flushing.
58 */
59 WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
60 WORK_NO_COLOR = WORK_NR_COLORS,
61
62 /* not bound to any CPU, prefer the local CPU */
63 WORK_CPU_UNBOUND = NR_CPUS,
64
65 /*
66 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
67 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
68 * flush colors.
69 */
70 WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
71 WORK_STRUCT_COLOR_BITS,
72
73 /* data contains off-queue information when !WORK_STRUCT_PWQ */
74 WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
75
76 __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
77
78 /*
79 * When a work item is off queue, its high bits point to the last
80 * pool it was on. Cap at 31 bits and use the highest number to
81 * indicate that no pool is associated.
82 */
83 WORK_OFFQ_FLAG_BITS = 1,
84 WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
85 WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
86 WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
87
88 /* bit mask for work_busy() return values */
89 WORK_BUSY_PENDING = 1 << 0,
90 WORK_BUSY_RUNNING = 1 << 1,
91
92 /* maximum string length for set_worker_desc() */
93 WORKER_DESC_LEN = 24,
94 };
95
96 /* Convenience constants - of type 'unsigned long', not 'enum'! */
97 #define WORK_OFFQ_CANCELING (1ul << __WORK_OFFQ_CANCELING)
98 #define WORK_OFFQ_POOL_NONE ((1ul << WORK_OFFQ_POOL_BITS) - 1)
99 #define WORK_STRUCT_NO_POOL (WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT)
100
101 #define WORK_STRUCT_FLAG_MASK ((1ul << WORK_STRUCT_FLAG_BITS) - 1)
102 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
103
104 struct work_struct {
105 atomic_long_t data;
106 struct list_head entry;
107 work_func_t func;
108 #ifdef CONFIG_LOCKDEP
109 struct lockdep_map lockdep_map;
110 #endif
111 ANDROID_KABI_RESERVE(1);
112 ANDROID_KABI_RESERVE(2);
113 };
114
115 #define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL)
116 #define WORK_DATA_STATIC_INIT() \
117 ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
118
119 struct delayed_work {
120 struct work_struct work;
121 struct timer_list timer;
122
123 /* target workqueue and CPU ->timer uses to queue ->work */
124 struct workqueue_struct *wq;
125 int cpu;
126
127 ANDROID_KABI_RESERVE(1);
128 ANDROID_KABI_RESERVE(2);
129 };
130
131 struct rcu_work {
132 struct work_struct work;
133 struct rcu_head rcu;
134
135 /* target workqueue ->rcu uses to queue ->work */
136 struct workqueue_struct *wq;
137 };
138
139 /**
140 * struct workqueue_attrs - A struct for workqueue attributes.
141 *
142 * This can be used to change attributes of an unbound workqueue.
143 */
144 struct workqueue_attrs {
145 /**
146 * @nice: nice level
147 */
148 int nice;
149
150 /**
151 * @cpumask: allowed CPUs
152 */
153 cpumask_var_t cpumask;
154
155 /**
156 * @no_numa: disable NUMA affinity
157 *
158 * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It
159 * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus
160 * doesn't participate in pool hash calculations or equality comparisons.
161 */
162 bool no_numa;
163 };
164
to_delayed_work(struct work_struct * work)165 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
166 {
167 return container_of(work, struct delayed_work, work);
168 }
169
to_rcu_work(struct work_struct * work)170 static inline struct rcu_work *to_rcu_work(struct work_struct *work)
171 {
172 return container_of(work, struct rcu_work, work);
173 }
174
175 struct execute_work {
176 struct work_struct work;
177 };
178
179 #ifdef CONFIG_LOCKDEP
180 /*
181 * NB: because we have to copy the lockdep_map, setting _key
182 * here is required, otherwise it could get initialised to the
183 * copy of the lockdep_map!
184 */
185 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
186 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
187 #else
188 #define __WORK_INIT_LOCKDEP_MAP(n, k)
189 #endif
190
191 #define __WORK_INITIALIZER(n, f) { \
192 .data = WORK_DATA_STATIC_INIT(), \
193 .entry = { &(n).entry, &(n).entry }, \
194 .func = (f), \
195 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
196 }
197
198 #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
199 .work = __WORK_INITIALIZER((n).work, (f)), \
200 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\
201 (tflags) | TIMER_IRQSAFE), \
202 }
203
204 #define DECLARE_WORK(n, f) \
205 struct work_struct n = __WORK_INITIALIZER(n, f)
206
207 #define DECLARE_DELAYED_WORK(n, f) \
208 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
209
210 #define DECLARE_DEFERRABLE_WORK(n, f) \
211 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
212
213 #ifdef CONFIG_DEBUG_OBJECTS_WORK
214 extern void __init_work(struct work_struct *work, int onstack);
215 extern void destroy_work_on_stack(struct work_struct *work);
216 extern void destroy_delayed_work_on_stack(struct delayed_work *work);
work_static(struct work_struct * work)217 static inline unsigned int work_static(struct work_struct *work)
218 {
219 return *work_data_bits(work) & WORK_STRUCT_STATIC;
220 }
221 #else
__init_work(struct work_struct * work,int onstack)222 static inline void __init_work(struct work_struct *work, int onstack) { }
destroy_work_on_stack(struct work_struct * work)223 static inline void destroy_work_on_stack(struct work_struct *work) { }
destroy_delayed_work_on_stack(struct delayed_work * work)224 static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
work_static(struct work_struct * work)225 static inline unsigned int work_static(struct work_struct *work) { return 0; }
226 #endif
227
228 /*
229 * initialize all of a work item in one go
230 *
231 * NOTE! No point in using "atomic_long_set()": using a direct
232 * assignment of the work data initializer allows the compiler
233 * to generate better code.
234 */
235 #ifdef CONFIG_LOCKDEP
236 #define __INIT_WORK(_work, _func, _onstack) \
237 do { \
238 static struct lock_class_key __key; \
239 \
240 __init_work((_work), _onstack); \
241 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
242 lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \
243 INIT_LIST_HEAD(&(_work)->entry); \
244 (_work)->func = (_func); \
245 } while (0)
246 #else
247 #define __INIT_WORK(_work, _func, _onstack) \
248 do { \
249 __init_work((_work), _onstack); \
250 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
251 INIT_LIST_HEAD(&(_work)->entry); \
252 (_work)->func = (_func); \
253 } while (0)
254 #endif
255
256 #define INIT_WORK(_work, _func) \
257 __INIT_WORK((_work), (_func), 0)
258
259 #define INIT_WORK_ONSTACK(_work, _func) \
260 __INIT_WORK((_work), (_func), 1)
261
262 #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
263 do { \
264 INIT_WORK(&(_work)->work, (_func)); \
265 __init_timer(&(_work)->timer, \
266 delayed_work_timer_fn, \
267 (_tflags) | TIMER_IRQSAFE); \
268 } while (0)
269
270 #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
271 do { \
272 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
273 __init_timer_on_stack(&(_work)->timer, \
274 delayed_work_timer_fn, \
275 (_tflags) | TIMER_IRQSAFE); \
276 } while (0)
277
278 #define INIT_DELAYED_WORK(_work, _func) \
279 __INIT_DELAYED_WORK(_work, _func, 0)
280
281 #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
282 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
283
284 #define INIT_DEFERRABLE_WORK(_work, _func) \
285 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
286
287 #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
288 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
289
290 #define INIT_RCU_WORK(_work, _func) \
291 INIT_WORK(&(_work)->work, (_func))
292
293 #define INIT_RCU_WORK_ONSTACK(_work, _func) \
294 INIT_WORK_ONSTACK(&(_work)->work, (_func))
295
296 /**
297 * work_pending - Find out whether a work item is currently pending
298 * @work: The work item in question
299 */
300 #define work_pending(work) \
301 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
302
303 /**
304 * delayed_work_pending - Find out whether a delayable work item is currently
305 * pending
306 * @w: The work item in question
307 */
308 #define delayed_work_pending(w) \
309 work_pending(&(w)->work)
310
311 /*
312 * Workqueue flags and constants. For details, please refer to
313 * Documentation/core-api/workqueue.rst.
314 */
315 enum {
316 WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
317 WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
318 WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
319 WQ_HIGHPRI = 1 << 4, /* high priority */
320 WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
321 WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
322
323 /*
324 * Per-cpu workqueues are generally preferred because they tend to
325 * show better performance thanks to cache locality. Per-cpu
326 * workqueues exclude the scheduler from choosing the CPU to
327 * execute the worker threads, which has an unfortunate side effect
328 * of increasing power consumption.
329 *
330 * The scheduler considers a CPU idle if it doesn't have any task
331 * to execute and tries to keep idle cores idle to conserve power;
332 * however, for example, a per-cpu work item scheduled from an
333 * interrupt handler on an idle CPU will force the scheduler to
334 * excute the work item on that CPU breaking the idleness, which in
335 * turn may lead to more scheduling choices which are sub-optimal
336 * in terms of power consumption.
337 *
338 * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
339 * but become unbound if workqueue.power_efficient kernel param is
340 * specified. Per-cpu workqueues which are identified to
341 * contribute significantly to power-consumption are identified and
342 * marked with this flag and enabling the power_efficient mode
343 * leads to noticeable power saving at the cost of small
344 * performance disadvantage.
345 *
346 * http://thread.gmane.org/gmane.linux.kernel/1480396
347 */
348 WQ_POWER_EFFICIENT = 1 << 7,
349
350 __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
351 __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
352 __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
353 __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
354
355 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
356 WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
357 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
358 };
359
360 /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
361 #define WQ_UNBOUND_MAX_ACTIVE \
362 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
363
364 /*
365 * System-wide workqueues which are always present.
366 *
367 * system_wq is the one used by schedule[_delayed]_work[_on]().
368 * Multi-CPU multi-threaded. There are users which expect relatively
369 * short queue flush time. Don't queue works which can run for too
370 * long.
371 *
372 * system_highpri_wq is similar to system_wq but for work items which
373 * require WQ_HIGHPRI.
374 *
375 * system_long_wq is similar to system_wq but may host long running
376 * works. Queue flushing might take relatively long.
377 *
378 * system_unbound_wq is unbound workqueue. Workers are not bound to
379 * any specific CPU, not concurrency managed, and all queued works are
380 * executed immediately as long as max_active limit is not reached and
381 * resources are available.
382 *
383 * system_freezable_wq is equivalent to system_wq except that it's
384 * freezable.
385 *
386 * *_power_efficient_wq are inclined towards saving power and converted
387 * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
388 * they are same as their non-power-efficient counterparts - e.g.
389 * system_power_efficient_wq is identical to system_wq if
390 * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
391 */
392 extern struct workqueue_struct *system_wq;
393 extern struct workqueue_struct *system_highpri_wq;
394 extern struct workqueue_struct *system_long_wq;
395 extern struct workqueue_struct *system_unbound_wq;
396 extern struct workqueue_struct *system_freezable_wq;
397 extern struct workqueue_struct *system_power_efficient_wq;
398 extern struct workqueue_struct *system_freezable_power_efficient_wq;
399
400 /**
401 * alloc_workqueue - allocate a workqueue
402 * @fmt: printf format for the name of the workqueue
403 * @flags: WQ_* flags
404 * @max_active: max in-flight work items, 0 for default
405 * remaining args: args for @fmt
406 *
407 * Allocate a workqueue with the specified parameters. For detailed
408 * information on WQ_* flags, please refer to
409 * Documentation/core-api/workqueue.rst.
410 *
411 * RETURNS:
412 * Pointer to the allocated workqueue on success, %NULL on failure.
413 */
414 struct workqueue_struct *alloc_workqueue(const char *fmt,
415 unsigned int flags,
416 int max_active, ...);
417
418 /**
419 * alloc_ordered_workqueue - allocate an ordered workqueue
420 * @fmt: printf format for the name of the workqueue
421 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
422 * @args...: args for @fmt
423 *
424 * Allocate an ordered workqueue. An ordered workqueue executes at
425 * most one work item at any given time in the queued order. They are
426 * implemented as unbound workqueues with @max_active of one.
427 *
428 * RETURNS:
429 * Pointer to the allocated workqueue on success, %NULL on failure.
430 */
431 #define alloc_ordered_workqueue(fmt, flags, args...) \
432 alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \
433 __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
434
435 #define create_workqueue(name) \
436 alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
437 #define create_freezable_workqueue(name) \
438 alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
439 WQ_MEM_RECLAIM, 1, (name))
440 #define create_singlethread_workqueue(name) \
441 alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
442
443 extern void destroy_workqueue(struct workqueue_struct *wq);
444
445 struct workqueue_attrs *alloc_workqueue_attrs(void);
446 void free_workqueue_attrs(struct workqueue_attrs *attrs);
447 int apply_workqueue_attrs(struct workqueue_struct *wq,
448 const struct workqueue_attrs *attrs);
449 int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
450
451 extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
452 struct work_struct *work);
453 extern bool queue_work_node(int node, struct workqueue_struct *wq,
454 struct work_struct *work);
455 extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
456 struct delayed_work *work, unsigned long delay);
457 extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
458 struct delayed_work *dwork, unsigned long delay);
459 extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork);
460
461 extern void flush_workqueue(struct workqueue_struct *wq);
462 extern void drain_workqueue(struct workqueue_struct *wq);
463
464 extern int schedule_on_each_cpu(work_func_t func);
465
466 int execute_in_process_context(work_func_t fn, struct execute_work *);
467
468 extern bool flush_work(struct work_struct *work);
469 extern bool cancel_work_sync(struct work_struct *work);
470
471 extern bool flush_delayed_work(struct delayed_work *dwork);
472 extern bool cancel_delayed_work(struct delayed_work *dwork);
473 extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
474
475 extern bool flush_rcu_work(struct rcu_work *rwork);
476
477 extern void workqueue_set_max_active(struct workqueue_struct *wq,
478 int max_active);
479 extern struct work_struct *current_work(void);
480 extern bool current_is_workqueue_rescuer(void);
481 extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
482 extern unsigned int work_busy(struct work_struct *work);
483 extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
484 extern void print_worker_info(const char *log_lvl, struct task_struct *task);
485 extern void show_workqueue_state(void);
486 extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task);
487
488 /**
489 * queue_work - queue work on a workqueue
490 * @wq: workqueue to use
491 * @work: work to queue
492 *
493 * Returns %false if @work was already on a queue, %true otherwise.
494 *
495 * We queue the work to the CPU on which it was submitted, but if the CPU dies
496 * it can be processed by another CPU.
497 */
queue_work(struct workqueue_struct * wq,struct work_struct * work)498 static inline bool queue_work(struct workqueue_struct *wq,
499 struct work_struct *work)
500 {
501 return queue_work_on(WORK_CPU_UNBOUND, wq, work);
502 }
503
504 /**
505 * queue_delayed_work - queue work on a workqueue after delay
506 * @wq: workqueue to use
507 * @dwork: delayable work to queue
508 * @delay: number of jiffies to wait before queueing
509 *
510 * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
511 */
queue_delayed_work(struct workqueue_struct * wq,struct delayed_work * dwork,unsigned long delay)512 static inline bool queue_delayed_work(struct workqueue_struct *wq,
513 struct delayed_work *dwork,
514 unsigned long delay)
515 {
516 return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
517 }
518
519 /**
520 * mod_delayed_work - modify delay of or queue a delayed work
521 * @wq: workqueue to use
522 * @dwork: work to queue
523 * @delay: number of jiffies to wait before queueing
524 *
525 * mod_delayed_work_on() on local CPU.
526 */
mod_delayed_work(struct workqueue_struct * wq,struct delayed_work * dwork,unsigned long delay)527 static inline bool mod_delayed_work(struct workqueue_struct *wq,
528 struct delayed_work *dwork,
529 unsigned long delay)
530 {
531 return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
532 }
533
534 /**
535 * schedule_work_on - put work task on a specific cpu
536 * @cpu: cpu to put the work task on
537 * @work: job to be done
538 *
539 * This puts a job on a specific cpu
540 */
schedule_work_on(int cpu,struct work_struct * work)541 static inline bool schedule_work_on(int cpu, struct work_struct *work)
542 {
543 return queue_work_on(cpu, system_wq, work);
544 }
545
546 /**
547 * schedule_work - put work task in global workqueue
548 * @work: job to be done
549 *
550 * Returns %false if @work was already on the kernel-global workqueue and
551 * %true otherwise.
552 *
553 * This puts a job in the kernel-global workqueue if it was not already
554 * queued and leaves it in the same position on the kernel-global
555 * workqueue otherwise.
556 */
schedule_work(struct work_struct * work)557 static inline bool schedule_work(struct work_struct *work)
558 {
559 return queue_work(system_wq, work);
560 }
561
562 /**
563 * flush_scheduled_work - ensure that any scheduled work has run to completion.
564 *
565 * Forces execution of the kernel-global workqueue and blocks until its
566 * completion.
567 *
568 * Think twice before calling this function! It's very easy to get into
569 * trouble if you don't take great care. Either of the following situations
570 * will lead to deadlock:
571 *
572 * One of the work items currently on the workqueue needs to acquire
573 * a lock held by your code or its caller.
574 *
575 * Your code is running in the context of a work routine.
576 *
577 * They will be detected by lockdep when they occur, but the first might not
578 * occur very often. It depends on what work items are on the workqueue and
579 * what locks they need, which you have no control over.
580 *
581 * In most situations flushing the entire workqueue is overkill; you merely
582 * need to know that a particular work item isn't queued and isn't running.
583 * In such cases you should use cancel_delayed_work_sync() or
584 * cancel_work_sync() instead.
585 */
flush_scheduled_work(void)586 static inline void flush_scheduled_work(void)
587 {
588 flush_workqueue(system_wq);
589 }
590
591 /**
592 * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
593 * @cpu: cpu to use
594 * @dwork: job to be done
595 * @delay: number of jiffies to wait
596 *
597 * After waiting for a given time this puts a job in the kernel-global
598 * workqueue on the specified CPU.
599 */
schedule_delayed_work_on(int cpu,struct delayed_work * dwork,unsigned long delay)600 static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
601 unsigned long delay)
602 {
603 return queue_delayed_work_on(cpu, system_wq, dwork, delay);
604 }
605
606 /**
607 * schedule_delayed_work - put work task in global workqueue after delay
608 * @dwork: job to be done
609 * @delay: number of jiffies to wait or 0 for immediate execution
610 *
611 * After waiting for a given time this puts a job in the kernel-global
612 * workqueue.
613 */
schedule_delayed_work(struct delayed_work * dwork,unsigned long delay)614 static inline bool schedule_delayed_work(struct delayed_work *dwork,
615 unsigned long delay)
616 {
617 return queue_delayed_work(system_wq, dwork, delay);
618 }
619
620 #ifndef CONFIG_SMP
work_on_cpu(int cpu,long (* fn)(void *),void * arg)621 static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
622 {
623 return fn(arg);
624 }
work_on_cpu_safe(int cpu,long (* fn)(void *),void * arg)625 static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
626 {
627 return fn(arg);
628 }
629 #else
630 long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
631 long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);
632 #endif /* CONFIG_SMP */
633
634 #ifdef CONFIG_FREEZER
635 extern void freeze_workqueues_begin(void);
636 extern bool freeze_workqueues_busy(void);
637 extern void thaw_workqueues(void);
638 #endif /* CONFIG_FREEZER */
639
640 #ifdef CONFIG_SYSFS
641 int workqueue_sysfs_register(struct workqueue_struct *wq);
642 #else /* CONFIG_SYSFS */
workqueue_sysfs_register(struct workqueue_struct * wq)643 static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
644 { return 0; }
645 #endif /* CONFIG_SYSFS */
646
647 #ifdef CONFIG_WQ_WATCHDOG
648 void wq_watchdog_touch(int cpu);
649 #else /* CONFIG_WQ_WATCHDOG */
wq_watchdog_touch(int cpu)650 static inline void wq_watchdog_touch(int cpu) { }
651 #endif /* CONFIG_WQ_WATCHDOG */
652
653 #ifdef CONFIG_SMP
654 int workqueue_prepare_cpu(unsigned int cpu);
655 int workqueue_online_cpu(unsigned int cpu);
656 int workqueue_offline_cpu(unsigned int cpu);
657 #endif
658
659 int __init workqueue_init_early(void);
660 int __init workqueue_init(void);
661
662 #endif
663