Line data Source code
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 :
18 : struct workqueue_struct;
19 :
20 : struct work_struct;
21 : typedef void (*work_func_t)(struct work_struct *work);
22 : void delayed_work_timer_fn(struct timer_list *t);
23 :
24 : /*
25 : * The first word is the work queue pointer and the flags rolled into
26 : * one
27 : */
28 : #define work_data_bits(work) ((unsigned long *)(&(work)->data))
29 :
30 : enum {
31 : WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
32 : WORK_STRUCT_INACTIVE_BIT= 1, /* work item is inactive */
33 : WORK_STRUCT_PWQ_BIT = 2, /* data points to pwq */
34 : WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */
35 : #ifdef CONFIG_DEBUG_OBJECTS_WORK
36 : WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */
37 : WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */
38 : #else
39 : WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
40 : #endif
41 :
42 : WORK_STRUCT_COLOR_BITS = 4,
43 :
44 : WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
45 : WORK_STRUCT_INACTIVE = 1 << WORK_STRUCT_INACTIVE_BIT,
46 : WORK_STRUCT_PWQ = 1 << WORK_STRUCT_PWQ_BIT,
47 : WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
48 : #ifdef CONFIG_DEBUG_OBJECTS_WORK
49 : WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
50 : #else
51 : WORK_STRUCT_STATIC = 0,
52 : #endif
53 :
54 : WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS),
55 :
56 : /* not bound to any CPU, prefer the local CPU */
57 : WORK_CPU_UNBOUND = NR_CPUS,
58 :
59 : /*
60 : * Reserve 8 bits off of pwq pointer w/ debugobjects turned off.
61 : * This makes pwqs aligned to 256 bytes and allows 16 workqueue
62 : * flush colors.
63 : */
64 : WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
65 : WORK_STRUCT_COLOR_BITS,
66 :
67 : /* data contains off-queue information when !WORK_STRUCT_PWQ */
68 : WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
69 :
70 : __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
71 : WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING),
72 :
73 : /*
74 : * When a work item is off queue, its high bits point to the last
75 : * pool it was on. Cap at 31 bits and use the highest number to
76 : * indicate that no pool is associated.
77 : */
78 : WORK_OFFQ_FLAG_BITS = 1,
79 : WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
80 : WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
81 : WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
82 : WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1,
83 :
84 : /* convenience constants */
85 : WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
86 : WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
87 : WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT,
88 :
89 : /* bit mask for work_busy() return values */
90 : WORK_BUSY_PENDING = 1 << 0,
91 : WORK_BUSY_RUNNING = 1 << 1,
92 :
93 : /* maximum string length for set_worker_desc() */
94 : WORKER_DESC_LEN = 24,
95 : };
96 :
97 : struct work_struct {
98 : atomic_long_t data;
99 : struct list_head entry;
100 : work_func_t func;
101 : #ifdef CONFIG_LOCKDEP
102 : struct lockdep_map lockdep_map;
103 : #endif
104 : };
105 :
106 : #define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL)
107 : #define WORK_DATA_STATIC_INIT() \
108 : ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
109 :
110 : struct delayed_work {
111 : struct work_struct work;
112 : struct timer_list timer;
113 :
114 : /* target workqueue and CPU ->timer uses to queue ->work */
115 : struct workqueue_struct *wq;
116 : int cpu;
117 : };
118 :
119 : struct rcu_work {
120 : struct work_struct work;
121 : struct rcu_head rcu;
122 :
123 : /* target workqueue ->rcu uses to queue ->work */
124 : struct workqueue_struct *wq;
125 : };
126 :
127 : /**
128 : * struct workqueue_attrs - A struct for workqueue attributes.
129 : *
130 : * This can be used to change attributes of an unbound workqueue.
131 : */
132 : struct workqueue_attrs {
133 : /**
134 : * @nice: nice level
135 : */
136 : int nice;
137 :
138 : /**
139 : * @cpumask: allowed CPUs
140 : */
141 : cpumask_var_t cpumask;
142 :
143 : /**
144 : * @no_numa: disable NUMA affinity
145 : *
146 : * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It
147 : * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus
148 : * doesn't participate in pool hash calculations or equality comparisons.
149 : */
150 : bool no_numa;
151 : };
152 :
153 : static inline struct delayed_work *to_delayed_work(struct work_struct *work)
154 : {
155 0 : return container_of(work, struct delayed_work, work);
156 : }
157 :
158 : static inline struct rcu_work *to_rcu_work(struct work_struct *work)
159 : {
160 0 : return container_of(work, struct rcu_work, work);
161 : }
162 :
163 : struct execute_work {
164 : struct work_struct work;
165 : };
166 :
167 : #ifdef CONFIG_LOCKDEP
168 : /*
169 : * NB: because we have to copy the lockdep_map, setting _key
170 : * here is required, otherwise it could get initialised to the
171 : * copy of the lockdep_map!
172 : */
173 : #define __WORK_INIT_LOCKDEP_MAP(n, k) \
174 : .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
175 : #else
176 : #define __WORK_INIT_LOCKDEP_MAP(n, k)
177 : #endif
178 :
179 : #define __WORK_INITIALIZER(n, f) { \
180 : .data = WORK_DATA_STATIC_INIT(), \
181 : .entry = { &(n).entry, &(n).entry }, \
182 : .func = (f), \
183 : __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
184 : }
185 :
186 : #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
187 : .work = __WORK_INITIALIZER((n).work, (f)), \
188 : .timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\
189 : (tflags) | TIMER_IRQSAFE), \
190 : }
191 :
192 : #define DECLARE_WORK(n, f) \
193 : struct work_struct n = __WORK_INITIALIZER(n, f)
194 :
195 : #define DECLARE_DELAYED_WORK(n, f) \
196 : struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
197 :
198 : #define DECLARE_DEFERRABLE_WORK(n, f) \
199 : struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
200 :
201 : #ifdef CONFIG_DEBUG_OBJECTS_WORK
202 : extern void __init_work(struct work_struct *work, int onstack);
203 : extern void destroy_work_on_stack(struct work_struct *work);
204 : extern void destroy_delayed_work_on_stack(struct delayed_work *work);
205 : static inline unsigned int work_static(struct work_struct *work)
206 : {
207 : return *work_data_bits(work) & WORK_STRUCT_STATIC;
208 : }
209 : #else
210 : static inline void __init_work(struct work_struct *work, int onstack) { }
211 : static inline void destroy_work_on_stack(struct work_struct *work) { }
212 : static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
213 : static inline unsigned int work_static(struct work_struct *work) { return 0; }
214 : #endif
215 :
216 : /*
217 : * initialize all of a work item in one go
218 : *
219 : * NOTE! No point in using "atomic_long_set()": using a direct
220 : * assignment of the work data initializer allows the compiler
221 : * to generate better code.
222 : */
223 : #ifdef CONFIG_LOCKDEP
224 : #define __INIT_WORK(_work, _func, _onstack) \
225 : do { \
226 : static struct lock_class_key __key; \
227 : \
228 : __init_work((_work), _onstack); \
229 : (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
230 : lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \
231 : INIT_LIST_HEAD(&(_work)->entry); \
232 : (_work)->func = (_func); \
233 : } while (0)
234 : #else
235 : #define __INIT_WORK(_work, _func, _onstack) \
236 : do { \
237 : __init_work((_work), _onstack); \
238 : (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
239 : INIT_LIST_HEAD(&(_work)->entry); \
240 : (_work)->func = (_func); \
241 : } while (0)
242 : #endif
243 :
244 : #define INIT_WORK(_work, _func) \
245 : __INIT_WORK((_work), (_func), 0)
246 :
247 : #define INIT_WORK_ONSTACK(_work, _func) \
248 : __INIT_WORK((_work), (_func), 1)
249 :
250 : #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
251 : do { \
252 : INIT_WORK(&(_work)->work, (_func)); \
253 : __init_timer(&(_work)->timer, \
254 : delayed_work_timer_fn, \
255 : (_tflags) | TIMER_IRQSAFE); \
256 : } while (0)
257 :
258 : #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
259 : do { \
260 : INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
261 : __init_timer_on_stack(&(_work)->timer, \
262 : delayed_work_timer_fn, \
263 : (_tflags) | TIMER_IRQSAFE); \
264 : } while (0)
265 :
266 : #define INIT_DELAYED_WORK(_work, _func) \
267 : __INIT_DELAYED_WORK(_work, _func, 0)
268 :
269 : #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
270 : __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
271 :
272 : #define INIT_DEFERRABLE_WORK(_work, _func) \
273 : __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
274 :
275 : #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
276 : __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
277 :
278 : #define INIT_RCU_WORK(_work, _func) \
279 : INIT_WORK(&(_work)->work, (_func))
280 :
281 : #define INIT_RCU_WORK_ONSTACK(_work, _func) \
282 : INIT_WORK_ONSTACK(&(_work)->work, (_func))
283 :
284 : /**
285 : * work_pending - Find out whether a work item is currently pending
286 : * @work: The work item in question
287 : */
288 : #define work_pending(work) \
289 : test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
290 :
291 : /**
292 : * delayed_work_pending - Find out whether a delayable work item is currently
293 : * pending
294 : * @w: The work item in question
295 : */
296 : #define delayed_work_pending(w) \
297 : work_pending(&(w)->work)
298 :
299 : /*
300 : * Workqueue flags and constants. For details, please refer to
301 : * Documentation/core-api/workqueue.rst.
302 : */
303 : enum {
304 : WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
305 : WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
306 : WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
307 : WQ_HIGHPRI = 1 << 4, /* high priority */
308 : WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
309 : WQ_SYSFS = 1 << 6, /* visible in sysfs, see workqueue_sysfs_register() */
310 :
311 : /*
312 : * Per-cpu workqueues are generally preferred because they tend to
313 : * show better performance thanks to cache locality. Per-cpu
314 : * workqueues exclude the scheduler from choosing the CPU to
315 : * execute the worker threads, which has an unfortunate side effect
316 : * of increasing power consumption.
317 : *
318 : * The scheduler considers a CPU idle if it doesn't have any task
319 : * to execute and tries to keep idle cores idle to conserve power;
320 : * however, for example, a per-cpu work item scheduled from an
321 : * interrupt handler on an idle CPU will force the scheduler to
322 : * execute the work item on that CPU breaking the idleness, which in
323 : * turn may lead to more scheduling choices which are sub-optimal
324 : * in terms of power consumption.
325 : *
326 : * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
327 : * but become unbound if workqueue.power_efficient kernel param is
328 : * specified. Per-cpu workqueues which are identified to
329 : * contribute significantly to power-consumption are identified and
330 : * marked with this flag and enabling the power_efficient mode
331 : * leads to noticeable power saving at the cost of small
332 : * performance disadvantage.
333 : *
334 : * http://thread.gmane.org/gmane.linux.kernel/1480396
335 : */
336 : WQ_POWER_EFFICIENT = 1 << 7,
337 :
338 : __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
339 : __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
340 : __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
341 : __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
342 :
343 : WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
344 : WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
345 : WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
346 : };
347 :
348 : /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
349 : #define WQ_UNBOUND_MAX_ACTIVE \
350 : max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
351 :
352 : /*
353 : * System-wide workqueues which are always present.
354 : *
355 : * system_wq is the one used by schedule[_delayed]_work[_on]().
356 : * Multi-CPU multi-threaded. There are users which expect relatively
357 : * short queue flush time. Don't queue works which can run for too
358 : * long.
359 : *
360 : * system_highpri_wq is similar to system_wq but for work items which
361 : * require WQ_HIGHPRI.
362 : *
363 : * system_long_wq is similar to system_wq but may host long running
364 : * works. Queue flushing might take relatively long.
365 : *
366 : * system_unbound_wq is unbound workqueue. Workers are not bound to
367 : * any specific CPU, not concurrency managed, and all queued works are
368 : * executed immediately as long as max_active limit is not reached and
369 : * resources are available.
370 : *
371 : * system_freezable_wq is equivalent to system_wq except that it's
372 : * freezable.
373 : *
374 : * *_power_efficient_wq are inclined towards saving power and converted
375 : * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
376 : * they are same as their non-power-efficient counterparts - e.g.
377 : * system_power_efficient_wq is identical to system_wq if
378 : * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
379 : */
380 : extern struct workqueue_struct *system_wq;
381 : extern struct workqueue_struct *system_highpri_wq;
382 : extern struct workqueue_struct *system_long_wq;
383 : extern struct workqueue_struct *system_unbound_wq;
384 : extern struct workqueue_struct *system_freezable_wq;
385 : extern struct workqueue_struct *system_power_efficient_wq;
386 : extern struct workqueue_struct *system_freezable_power_efficient_wq;
387 :
388 : /**
389 : * alloc_workqueue - allocate a workqueue
390 : * @fmt: printf format for the name of the workqueue
391 : * @flags: WQ_* flags
392 : * @max_active: max in-flight work items, 0 for default
393 : * remaining args: args for @fmt
394 : *
395 : * Allocate a workqueue with the specified parameters. For detailed
396 : * information on WQ_* flags, please refer to
397 : * Documentation/core-api/workqueue.rst.
398 : *
399 : * RETURNS:
400 : * Pointer to the allocated workqueue on success, %NULL on failure.
401 : */
402 : __printf(1, 4) struct workqueue_struct *
403 : alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);
404 :
405 : /**
406 : * alloc_ordered_workqueue - allocate an ordered workqueue
407 : * @fmt: printf format for the name of the workqueue
408 : * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
409 : * @args...: args for @fmt
410 : *
411 : * Allocate an ordered workqueue. An ordered workqueue executes at
412 : * most one work item at any given time in the queued order. They are
413 : * implemented as unbound workqueues with @max_active of one.
414 : *
415 : * RETURNS:
416 : * Pointer to the allocated workqueue on success, %NULL on failure.
417 : */
418 : #define alloc_ordered_workqueue(fmt, flags, args...) \
419 : alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \
420 : __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
421 :
422 : #define create_workqueue(name) \
423 : alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
424 : #define create_freezable_workqueue(name) \
425 : alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
426 : WQ_MEM_RECLAIM, 1, (name))
427 : #define create_singlethread_workqueue(name) \
428 : alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
429 :
430 : extern void destroy_workqueue(struct workqueue_struct *wq);
431 :
432 : struct workqueue_attrs *alloc_workqueue_attrs(void);
433 : void free_workqueue_attrs(struct workqueue_attrs *attrs);
434 : int apply_workqueue_attrs(struct workqueue_struct *wq,
435 : const struct workqueue_attrs *attrs);
436 : int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
437 :
438 : extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
439 : struct work_struct *work);
440 : extern bool queue_work_node(int node, struct workqueue_struct *wq,
441 : struct work_struct *work);
442 : extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
443 : struct delayed_work *work, unsigned long delay);
444 : extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
445 : struct delayed_work *dwork, unsigned long delay);
446 : extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork);
447 :
448 : extern void flush_workqueue(struct workqueue_struct *wq);
449 : extern void drain_workqueue(struct workqueue_struct *wq);
450 :
451 : extern int schedule_on_each_cpu(work_func_t func);
452 :
453 : int execute_in_process_context(work_func_t fn, struct execute_work *);
454 :
455 : extern bool flush_work(struct work_struct *work);
456 : extern bool cancel_work(struct work_struct *work);
457 : extern bool cancel_work_sync(struct work_struct *work);
458 :
459 : extern bool flush_delayed_work(struct delayed_work *dwork);
460 : extern bool cancel_delayed_work(struct delayed_work *dwork);
461 : extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
462 :
463 : extern bool flush_rcu_work(struct rcu_work *rwork);
464 :
465 : extern void workqueue_set_max_active(struct workqueue_struct *wq,
466 : int max_active);
467 : extern struct work_struct *current_work(void);
468 : extern bool current_is_workqueue_rescuer(void);
469 : extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
470 : extern unsigned int work_busy(struct work_struct *work);
471 : extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
472 : extern void print_worker_info(const char *log_lvl, struct task_struct *task);
473 : extern void show_all_workqueues(void);
474 : extern void show_one_workqueue(struct workqueue_struct *wq);
475 : extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task);
476 :
477 : /**
478 : * queue_work - queue work on a workqueue
479 : * @wq: workqueue to use
480 : * @work: work to queue
481 : *
482 : * Returns %false if @work was already on a queue, %true otherwise.
483 : *
484 : * We queue the work to the CPU on which it was submitted, but if the CPU dies
485 : * it can be processed by another CPU.
486 : *
487 : * Memory-ordering properties: If it returns %true, guarantees that all stores
488 : * preceding the call to queue_work() in the program order will be visible from
489 : * the CPU which will execute @work by the time such work executes, e.g.,
490 : *
491 : * { x is initially 0 }
492 : *
493 : * CPU0 CPU1
494 : *
495 : * WRITE_ONCE(x, 1); [ @work is being executed ]
496 : * r0 = queue_work(wq, work); r1 = READ_ONCE(x);
497 : *
498 : * Forbids: r0 == true && r1 == 0
499 : */
500 : static inline bool queue_work(struct workqueue_struct *wq,
501 : struct work_struct *work)
502 : {
503 5 : return queue_work_on(WORK_CPU_UNBOUND, wq, work);
504 : }
505 :
506 : /**
507 : * queue_delayed_work - queue work on a workqueue after delay
508 : * @wq: workqueue to use
509 : * @dwork: delayable work to queue
510 : * @delay: number of jiffies to wait before queueing
511 : *
512 : * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
513 : */
514 : static inline bool queue_delayed_work(struct workqueue_struct *wq,
515 : struct delayed_work *dwork,
516 : unsigned long delay)
517 : {
518 1 : return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
519 : }
520 :
521 : /**
522 : * mod_delayed_work - modify delay of or queue a delayed work
523 : * @wq: workqueue to use
524 : * @dwork: work to queue
525 : * @delay: number of jiffies to wait before queueing
526 : *
527 : * mod_delayed_work_on() on local CPU.
528 : */
529 : static inline bool mod_delayed_work(struct workqueue_struct *wq,
530 : struct delayed_work *dwork,
531 : unsigned long delay)
532 : {
533 0 : return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
534 : }
535 :
536 : /**
537 : * schedule_work_on - put work task on a specific cpu
538 : * @cpu: cpu to put the work task on
539 : * @work: job to be done
540 : *
541 : * This puts a job on a specific cpu
542 : */
543 : static inline bool schedule_work_on(int cpu, struct work_struct *work)
544 : {
545 0 : return queue_work_on(cpu, system_wq, work);
546 : }
547 :
548 : /**
549 : * schedule_work - put work task in global workqueue
550 : * @work: job to be done
551 : *
552 : * Returns %false if @work was already on the kernel-global workqueue and
553 : * %true otherwise.
554 : *
555 : * This puts a job in the kernel-global workqueue if it was not already
556 : * queued and leaves it in the same position on the kernel-global
557 : * workqueue otherwise.
558 : *
559 : * Shares the same memory-ordering properties of queue_work(), cf. the
560 : * DocBook header of queue_work().
561 : */
562 : static inline bool schedule_work(struct work_struct *work)
563 : {
564 2 : return queue_work(system_wq, work);
565 : }
566 :
567 : /**
568 : * flush_scheduled_work - ensure that any scheduled work has run to completion.
569 : *
570 : * Forces execution of the kernel-global workqueue and blocks until its
571 : * completion.
572 : *
573 : * Think twice before calling this function! It's very easy to get into
574 : * trouble if you don't take great care. Either of the following situations
575 : * will lead to deadlock:
576 : *
577 : * One of the work items currently on the workqueue needs to acquire
578 : * a lock held by your code or its caller.
579 : *
580 : * Your code is running in the context of a work routine.
581 : *
582 : * They will be detected by lockdep when they occur, but the first might not
583 : * occur very often. It depends on what work items are on the workqueue and
584 : * what locks they need, which you have no control over.
585 : *
586 : * In most situations flushing the entire workqueue is overkill; you merely
587 : * need to know that a particular work item isn't queued and isn't running.
588 : * In such cases you should use cancel_delayed_work_sync() or
589 : * cancel_work_sync() instead.
590 : */
591 : static inline void flush_scheduled_work(void)
592 : {
593 0 : flush_workqueue(system_wq);
594 : }
595 :
596 : /**
597 : * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
598 : * @cpu: cpu to use
599 : * @dwork: job to be done
600 : * @delay: number of jiffies to wait
601 : *
602 : * After waiting for a given time this puts a job in the kernel-global
603 : * workqueue on the specified CPU.
604 : */
605 : static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
606 : unsigned long delay)
607 : {
608 : return queue_delayed_work_on(cpu, system_wq, dwork, delay);
609 : }
610 :
611 : /**
612 : * schedule_delayed_work - put work task in global workqueue after delay
613 : * @dwork: job to be done
614 : * @delay: number of jiffies to wait or 0 for immediate execution
615 : *
616 : * After waiting for a given time this puts a job in the kernel-global
617 : * workqueue.
618 : */
619 : static inline bool schedule_delayed_work(struct delayed_work *dwork,
620 : unsigned long delay)
621 : {
622 2 : return queue_delayed_work(system_wq, dwork, delay);
623 : }
624 :
625 : #ifndef CONFIG_SMP
626 : static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
627 : {
628 : return fn(arg);
629 : }
630 : static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
631 : {
632 : return fn(arg);
633 : }
634 : #else
635 : long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
636 : long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);
637 : #endif /* CONFIG_SMP */
638 :
639 : #ifdef CONFIG_FREEZER
640 : extern void freeze_workqueues_begin(void);
641 : extern bool freeze_workqueues_busy(void);
642 : extern void thaw_workqueues(void);
643 : #endif /* CONFIG_FREEZER */
644 :
645 : #ifdef CONFIG_SYSFS
646 : int workqueue_sysfs_register(struct workqueue_struct *wq);
647 : #else /* CONFIG_SYSFS */
648 : static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
649 : { return 0; }
650 : #endif /* CONFIG_SYSFS */
651 :
652 : #ifdef CONFIG_WQ_WATCHDOG
653 : void wq_watchdog_touch(int cpu);
654 : #else /* CONFIG_WQ_WATCHDOG */
655 : static inline void wq_watchdog_touch(int cpu) { }
656 : #endif /* CONFIG_WQ_WATCHDOG */
657 :
658 : #ifdef CONFIG_SMP
659 : int workqueue_prepare_cpu(unsigned int cpu);
660 : int workqueue_online_cpu(unsigned int cpu);
661 : int workqueue_offline_cpu(unsigned int cpu);
662 : #endif
663 :
664 : void __init workqueue_init_early(void);
665 : void __init workqueue_init(void);
666 :
667 : #endif
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