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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_DELAYED_BIT = 1, /* work item is delayed */
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_DELAYED = 1 << WORK_STRUCT_DELAYED_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 : : /*
55 : : * The last color is no color used for works which don't
56 : : * participate in workqueue flushing.
57 : : */
58 : : WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
59 : : WORK_NO_COLOR = WORK_NR_COLORS,
60 : :
61 : : /* not bound to any CPU, prefer the local CPU */
62 : : WORK_CPU_UNBOUND = NR_CPUS,
63 : :
64 : : /*
65 : : * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
66 : : * This makes pwqs aligned to 256 bytes and allows 15 workqueue
67 : : * flush colors.
68 : : */
69 : : WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
70 : : WORK_STRUCT_COLOR_BITS,
71 : :
72 : : /* data contains off-queue information when !WORK_STRUCT_PWQ */
73 : : WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
74 : :
75 : : __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
76 : : WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING),
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 : : WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1,
88 : :
89 : : /* convenience constants */
90 : : WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
91 : : WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
92 : : WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT,
93 : :
94 : : /* bit mask for work_busy() return values */
95 : : WORK_BUSY_PENDING = 1 << 0,
96 : : WORK_BUSY_RUNNING = 1 << 1,
97 : :
98 : : /* maximum string length for set_worker_desc() */
99 : : WORKER_DESC_LEN = 24,
100 : : };
101 : :
102 : : struct work_struct {
103 : : atomic_long_t data;
104 : : struct list_head entry;
105 : : work_func_t func;
106 : : #ifdef CONFIG_LOCKDEP
107 : : struct lockdep_map lockdep_map;
108 : : #endif
109 : : };
110 : :
111 : : #define WORK_DATA_INIT() ATOMIC_LONG_INIT((unsigned long)WORK_STRUCT_NO_POOL)
112 : : #define WORK_DATA_STATIC_INIT() \
113 : : ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
114 : :
115 : : struct delayed_work {
116 : : struct work_struct work;
117 : : struct timer_list timer;
118 : :
119 : : /* target workqueue and CPU ->timer uses to queue ->work */
120 : : struct workqueue_struct *wq;
121 : : int cpu;
122 : : };
123 : :
124 : : struct rcu_work {
125 : : struct work_struct work;
126 : : struct rcu_head rcu;
127 : :
128 : : /* target workqueue ->rcu uses to queue ->work */
129 : : struct workqueue_struct *wq;
130 : : };
131 : :
132 : : /**
133 : : * struct workqueue_attrs - A struct for workqueue attributes.
134 : : *
135 : : * This can be used to change attributes of an unbound workqueue.
136 : : */
137 : : struct workqueue_attrs {
138 : : /**
139 : : * @nice: nice level
140 : : */
141 : : int nice;
142 : :
143 : : /**
144 : : * @cpumask: allowed CPUs
145 : : */
146 : : cpumask_var_t cpumask;
147 : :
148 : : /**
149 : : * @no_numa: disable NUMA affinity
150 : : *
151 : : * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It
152 : : * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus
153 : : * doesn't participate in pool hash calculations or equality comparisons.
154 : : */
155 : : bool no_numa;
156 : : };
157 : :
158 : 9240 : static inline struct delayed_work *to_delayed_work(struct work_struct *work)
159 : : {
160 [ # # ]: 9240 : return container_of(work, struct delayed_work, work);
161 : : }
162 : :
163 : 1479 : static inline struct rcu_work *to_rcu_work(struct work_struct *work)
164 : : {
165 : 1479 : return container_of(work, struct rcu_work, work);
166 : : }
167 : :
168 : : struct execute_work {
169 : : struct work_struct work;
170 : : };
171 : :
172 : : #ifdef CONFIG_LOCKDEP
173 : : /*
174 : : * NB: because we have to copy the lockdep_map, setting _key
175 : : * here is required, otherwise it could get initialised to the
176 : : * copy of the lockdep_map!
177 : : */
178 : : #define __WORK_INIT_LOCKDEP_MAP(n, k) \
179 : : .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
180 : : #else
181 : : #define __WORK_INIT_LOCKDEP_MAP(n, k)
182 : : #endif
183 : :
184 : : #define __WORK_INITIALIZER(n, f) { \
185 : : .data = WORK_DATA_STATIC_INIT(), \
186 : : .entry = { &(n).entry, &(n).entry }, \
187 : : .func = (f), \
188 : : __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
189 : : }
190 : :
191 : : #define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
192 : : .work = __WORK_INITIALIZER((n).work, (f)), \
193 : : .timer = __TIMER_INITIALIZER(delayed_work_timer_fn,\
194 : : (tflags) | TIMER_IRQSAFE), \
195 : : }
196 : :
197 : : #define DECLARE_WORK(n, f) \
198 : : struct work_struct n = __WORK_INITIALIZER(n, f)
199 : :
200 : : #define DECLARE_DELAYED_WORK(n, f) \
201 : : struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
202 : :
203 : : #define DECLARE_DEFERRABLE_WORK(n, f) \
204 : : struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
205 : :
206 : : #ifdef CONFIG_DEBUG_OBJECTS_WORK
207 : : extern void __init_work(struct work_struct *work, int onstack);
208 : : extern void destroy_work_on_stack(struct work_struct *work);
209 : : extern void destroy_delayed_work_on_stack(struct delayed_work *work);
210 : : static inline unsigned int work_static(struct work_struct *work)
211 : : {
212 : : return *work_data_bits(work) & WORK_STRUCT_STATIC;
213 : : }
214 : : #else
215 [ - + + - : 99560 : static inline void __init_work(struct work_struct *work, int onstack) { }
# # # # #
# # # ]
216 : 98 : static inline void destroy_work_on_stack(struct work_struct *work) { }
217 : 0 : static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { }
218 : 58102 : static inline unsigned int work_static(struct work_struct *work) { return 0; }
219 : : #endif
220 : :
221 : : /*
222 : : * initialize all of a work item in one go
223 : : *
224 : : * NOTE! No point in using "atomic_long_set()": using a direct
225 : : * assignment of the work data initializer allows the compiler
226 : : * to generate better code.
227 : : */
228 : : #ifdef CONFIG_LOCKDEP
229 : : #define __INIT_WORK(_work, _func, _onstack) \
230 : : do { \
231 : : static struct lock_class_key __key; \
232 : : \
233 : : __init_work((_work), _onstack); \
234 : : (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
235 : : lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \
236 : : INIT_LIST_HEAD(&(_work)->entry); \
237 : : (_work)->func = (_func); \
238 : : } while (0)
239 : : #else
240 : : #define __INIT_WORK(_work, _func, _onstack) \
241 : : do { \
242 : : __init_work((_work), _onstack); \
243 : : (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
244 : : INIT_LIST_HEAD(&(_work)->entry); \
245 : : (_work)->func = (_func); \
246 : : } while (0)
247 : : #endif
248 : :
249 : : #define INIT_WORK(_work, _func) \
250 : : __INIT_WORK((_work), (_func), 0)
251 : :
252 : : #define INIT_WORK_ONSTACK(_work, _func) \
253 : : __INIT_WORK((_work), (_func), 1)
254 : :
255 : : #define __INIT_DELAYED_WORK(_work, _func, _tflags) \
256 : : do { \
257 : : INIT_WORK(&(_work)->work, (_func)); \
258 : : __init_timer(&(_work)->timer, \
259 : : delayed_work_timer_fn, \
260 : : (_tflags) | TIMER_IRQSAFE); \
261 : : } while (0)
262 : :
263 : : #define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
264 : : do { \
265 : : INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
266 : : __init_timer_on_stack(&(_work)->timer, \
267 : : delayed_work_timer_fn, \
268 : : (_tflags) | TIMER_IRQSAFE); \
269 : : } while (0)
270 : :
271 : : #define INIT_DELAYED_WORK(_work, _func) \
272 : : __INIT_DELAYED_WORK(_work, _func, 0)
273 : :
274 : : #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
275 : : __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
276 : :
277 : : #define INIT_DEFERRABLE_WORK(_work, _func) \
278 : : __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
279 : :
280 : : #define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
281 : : __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
282 : :
283 : : #define INIT_RCU_WORK(_work, _func) \
284 : : INIT_WORK(&(_work)->work, (_func))
285 : :
286 : : #define INIT_RCU_WORK_ONSTACK(_work, _func) \
287 : : INIT_WORK_ONSTACK(&(_work)->work, (_func))
288 : :
289 : : /**
290 : : * work_pending - Find out whether a work item is currently pending
291 : : * @work: The work item in question
292 : : */
293 : : #define work_pending(work) \
294 : : test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
295 : :
296 : : /**
297 : : * delayed_work_pending - Find out whether a delayable work item is currently
298 : : * pending
299 : : * @w: The work item in question
300 : : */
301 : : #define delayed_work_pending(w) \
302 : : work_pending(&(w)->work)
303 : :
304 : : /*
305 : : * Workqueue flags and constants. For details, please refer to
306 : : * Documentation/core-api/workqueue.rst.
307 : : */
308 : : enum {
309 : : WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
310 : : WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
311 : : WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
312 : : WQ_HIGHPRI = 1 << 4, /* high priority */
313 : : WQ_CPU_INTENSIVE = 1 << 5, /* cpu intensive workqueue */
314 : : WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
315 : :
316 : : /*
317 : : * Per-cpu workqueues are generally preferred because they tend to
318 : : * show better performance thanks to cache locality. Per-cpu
319 : : * workqueues exclude the scheduler from choosing the CPU to
320 : : * execute the worker threads, which has an unfortunate side effect
321 : : * of increasing power consumption.
322 : : *
323 : : * The scheduler considers a CPU idle if it doesn't have any task
324 : : * to execute and tries to keep idle cores idle to conserve power;
325 : : * however, for example, a per-cpu work item scheduled from an
326 : : * interrupt handler on an idle CPU will force the scheduler to
327 : : * excute the work item on that CPU breaking the idleness, which in
328 : : * turn may lead to more scheduling choices which are sub-optimal
329 : : * in terms of power consumption.
330 : : *
331 : : * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
332 : : * but become unbound if workqueue.power_efficient kernel param is
333 : : * specified. Per-cpu workqueues which are identified to
334 : : * contribute significantly to power-consumption are identified and
335 : : * marked with this flag and enabling the power_efficient mode
336 : : * leads to noticeable power saving at the cost of small
337 : : * performance disadvantage.
338 : : *
339 : : * http://thread.gmane.org/gmane.linux.kernel/1480396
340 : : */
341 : : WQ_POWER_EFFICIENT = 1 << 7,
342 : :
343 : : __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
344 : : __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
345 : : __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
346 : : __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
347 : :
348 : : WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
349 : : WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
350 : : WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
351 : : };
352 : :
353 : : /* unbound wq's aren't per-cpu, scale max_active according to #cpus */
354 : : #define WQ_UNBOUND_MAX_ACTIVE \
355 : : max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
356 : :
357 : : /*
358 : : * System-wide workqueues which are always present.
359 : : *
360 : : * system_wq is the one used by schedule[_delayed]_work[_on]().
361 : : * Multi-CPU multi-threaded. There are users which expect relatively
362 : : * short queue flush time. Don't queue works which can run for too
363 : : * long.
364 : : *
365 : : * system_highpri_wq is similar to system_wq but for work items which
366 : : * require WQ_HIGHPRI.
367 : : *
368 : : * system_long_wq is similar to system_wq but may host long running
369 : : * works. Queue flushing might take relatively long.
370 : : *
371 : : * system_unbound_wq is unbound workqueue. Workers are not bound to
372 : : * any specific CPU, not concurrency managed, and all queued works are
373 : : * executed immediately as long as max_active limit is not reached and
374 : : * resources are available.
375 : : *
376 : : * system_freezable_wq is equivalent to system_wq except that it's
377 : : * freezable.
378 : : *
379 : : * *_power_efficient_wq are inclined towards saving power and converted
380 : : * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
381 : : * they are same as their non-power-efficient counterparts - e.g.
382 : : * system_power_efficient_wq is identical to system_wq if
383 : : * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
384 : : */
385 : : extern struct workqueue_struct *system_wq;
386 : : extern struct workqueue_struct *system_highpri_wq;
387 : : extern struct workqueue_struct *system_long_wq;
388 : : extern struct workqueue_struct *system_unbound_wq;
389 : : extern struct workqueue_struct *system_freezable_wq;
390 : : extern struct workqueue_struct *system_power_efficient_wq;
391 : : extern struct workqueue_struct *system_freezable_power_efficient_wq;
392 : :
393 : : /**
394 : : * alloc_workqueue - allocate a workqueue
395 : : * @fmt: printf format for the name of the workqueue
396 : : * @flags: WQ_* flags
397 : : * @max_active: max in-flight work items, 0 for default
398 : : * remaining args: args for @fmt
399 : : *
400 : : * Allocate a workqueue with the specified parameters. For detailed
401 : : * information on WQ_* flags, please refer to
402 : : * Documentation/core-api/workqueue.rst.
403 : : *
404 : : * RETURNS:
405 : : * Pointer to the allocated workqueue on success, %NULL on failure.
406 : : */
407 : : struct workqueue_struct *alloc_workqueue(const char *fmt,
408 : : unsigned int flags,
409 : : int max_active, ...);
410 : :
411 : : /**
412 : : * alloc_ordered_workqueue - allocate an ordered workqueue
413 : : * @fmt: printf format for the name of the workqueue
414 : : * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
415 : : * @args...: args for @fmt
416 : : *
417 : : * Allocate an ordered workqueue. An ordered workqueue executes at
418 : : * most one work item at any given time in the queued order. They are
419 : : * implemented as unbound workqueues with @max_active of one.
420 : : *
421 : : * RETURNS:
422 : : * Pointer to the allocated workqueue on success, %NULL on failure.
423 : : */
424 : : #define alloc_ordered_workqueue(fmt, flags, args...) \
425 : : alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | \
426 : : __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
427 : :
428 : : #define create_workqueue(name) \
429 : : alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
430 : : #define create_freezable_workqueue(name) \
431 : : alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
432 : : WQ_MEM_RECLAIM, 1, (name))
433 : : #define create_singlethread_workqueue(name) \
434 : : alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
435 : :
436 : : extern void destroy_workqueue(struct workqueue_struct *wq);
437 : :
438 : : struct workqueue_attrs *alloc_workqueue_attrs(void);
439 : : void free_workqueue_attrs(struct workqueue_attrs *attrs);
440 : : int apply_workqueue_attrs(struct workqueue_struct *wq,
441 : : const struct workqueue_attrs *attrs);
442 : : int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
443 : :
444 : : extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
445 : : struct work_struct *work);
446 : : extern bool queue_work_node(int node, 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 : : extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork);
453 : :
454 : : extern void flush_workqueue(struct workqueue_struct *wq);
455 : : extern void drain_workqueue(struct workqueue_struct *wq);
456 : :
457 : : extern int schedule_on_each_cpu(work_func_t func);
458 : :
459 : : int execute_in_process_context(work_func_t fn, struct execute_work *);
460 : :
461 : : extern bool flush_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 bool flush_rcu_work(struct rcu_work *rwork);
469 : :
470 : : extern void workqueue_set_max_active(struct workqueue_struct *wq,
471 : : int max_active);
472 : : extern struct work_struct *current_work(void);
473 : : extern bool current_is_workqueue_rescuer(void);
474 : : extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
475 : : extern unsigned int work_busy(struct work_struct *work);
476 : : extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
477 : : extern void print_worker_info(const char *log_lvl, struct task_struct *task);
478 : : extern void show_workqueue_state(void);
479 : : extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task);
480 : :
481 : : /**
482 : : * queue_work - queue work on a workqueue
483 : : * @wq: workqueue to use
484 : : * @work: work to queue
485 : : *
486 : : * Returns %false if @work was already on a queue, %true otherwise.
487 : : *
488 : : * We queue the work to the CPU on which it was submitted, but if the CPU dies
489 : : * it can be processed by another CPU.
490 : : *
491 : : * Memory-ordering properties: If it returns %true, guarantees that all stores
492 : : * preceding the call to queue_work() in the program order will be visible from
493 : : * the CPU which will execute @work by the time such work executes, e.g.,
494 : : *
495 : : * { x is initially 0 }
496 : : *
497 : : * CPU0 CPU1
498 : : *
499 : : * WRITE_ONCE(x, 1); [ @work is being executed ]
500 : : * r0 = queue_work(wq, work); r1 = READ_ONCE(x);
501 : : *
502 : : * Forbids: r0 == true && r1 == 0
503 : : */
504 : 9825 : static inline bool queue_work(struct workqueue_struct *wq,
505 : : struct work_struct *work)
506 : : {
507 : 9825 : return queue_work_on(WORK_CPU_UNBOUND, wq, work);
508 : : }
509 : :
510 : : /**
511 : : * queue_delayed_work - queue work on a workqueue after delay
512 : : * @wq: workqueue to use
513 : : * @dwork: delayable work to queue
514 : : * @delay: number of jiffies to wait before queueing
515 : : *
516 : : * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
517 : : */
518 : 6110 : static inline bool queue_delayed_work(struct workqueue_struct *wq,
519 : : struct delayed_work *dwork,
520 : : unsigned long delay)
521 : : {
522 : 6110 : return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
523 : : }
524 : :
525 : : /**
526 : : * mod_delayed_work - modify delay of or queue a delayed work
527 : : * @wq: workqueue to use
528 : : * @dwork: work to queue
529 : : * @delay: number of jiffies to wait before queueing
530 : : *
531 : : * mod_delayed_work_on() on local CPU.
532 : : */
533 : 330 : static inline bool mod_delayed_work(struct workqueue_struct *wq,
534 : : struct delayed_work *dwork,
535 : : unsigned long delay)
536 : : {
537 : 330 : return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
538 : : }
539 : :
540 : : /**
541 : : * schedule_work_on - put work task on a specific cpu
542 : : * @cpu: cpu to put the work task on
543 : : * @work: job to be done
544 : : *
545 : : * This puts a job on a specific cpu
546 : : */
547 : 0 : static inline bool schedule_work_on(int cpu, struct work_struct *work)
548 : : {
549 : 0 : return queue_work_on(cpu, system_wq, work);
550 : : }
551 : :
552 : : /**
553 : : * schedule_work - put work task in global workqueue
554 : : * @work: job to be done
555 : : *
556 : : * Returns %false if @work was already on the kernel-global workqueue and
557 : : * %true otherwise.
558 : : *
559 : : * This puts a job in the kernel-global workqueue if it was not already
560 : : * queued and leaves it in the same position on the kernel-global
561 : : * workqueue otherwise.
562 : : *
563 : : * Shares the same memory-ordering properties of queue_work(), cf. the
564 : : * DocBook header of queue_work().
565 : : */
566 : 7104 : static inline bool schedule_work(struct work_struct *work)
567 : : {
568 : 7104 : return queue_work(system_wq, work);
569 : : }
570 : :
571 : : /**
572 : : * flush_scheduled_work - ensure that any scheduled work has run to completion.
573 : : *
574 : : * Forces execution of the kernel-global workqueue and blocks until its
575 : : * completion.
576 : : *
577 : : * Think twice before calling this function! It's very easy to get into
578 : : * trouble if you don't take great care. Either of the following situations
579 : : * will lead to deadlock:
580 : : *
581 : : * One of the work items currently on the workqueue needs to acquire
582 : : * a lock held by your code or its caller.
583 : : *
584 : : * Your code is running in the context of a work routine.
585 : : *
586 : : * They will be detected by lockdep when they occur, but the first might not
587 : : * occur very often. It depends on what work items are on the workqueue and
588 : : * what locks they need, which you have no control over.
589 : : *
590 : : * In most situations flushing the entire workqueue is overkill; you merely
591 : : * need to know that a particular work item isn't queued and isn't running.
592 : : * In such cases you should use cancel_delayed_work_sync() or
593 : : * cancel_work_sync() instead.
594 : : */
595 : 0 : static inline void flush_scheduled_work(void)
596 : : {
597 : 0 : flush_workqueue(system_wq);
598 : : }
599 : :
600 : : /**
601 : : * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
602 : : * @cpu: cpu to use
603 : : * @dwork: job to be done
604 : : * @delay: number of jiffies to wait
605 : : *
606 : : * After waiting for a given time this puts a job in the kernel-global
607 : : * workqueue on the specified CPU.
608 : : */
609 : 0 : static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
610 : : unsigned long delay)
611 : : {
612 : 0 : return queue_delayed_work_on(cpu, system_wq, dwork, delay);
613 : : }
614 : :
615 : : /**
616 : : * schedule_delayed_work - put work task in global workqueue after delay
617 : : * @dwork: job to be done
618 : : * @delay: number of jiffies to wait or 0 for immediate execution
619 : : *
620 : : * After waiting for a given time this puts a job in the kernel-global
621 : : * workqueue.
622 : : */
623 : 1074 : static inline bool schedule_delayed_work(struct delayed_work *dwork,
624 : : unsigned long delay)
625 : : {
626 : 1074 : return queue_delayed_work(system_wq, dwork, delay);
627 : : }
628 : :
629 : : #ifndef CONFIG_SMP
630 : : static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
631 : : {
632 : : return fn(arg);
633 : : }
634 : : static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
635 : : {
636 : : return fn(arg);
637 : : }
638 : : #else
639 : : long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
640 : : long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg);
641 : : #endif /* CONFIG_SMP */
642 : :
643 : : #ifdef CONFIG_FREEZER
644 : : extern void freeze_workqueues_begin(void);
645 : : extern bool freeze_workqueues_busy(void);
646 : : extern void thaw_workqueues(void);
647 : : #endif /* CONFIG_FREEZER */
648 : :
649 : : #ifdef CONFIG_SYSFS
650 : : int workqueue_sysfs_register(struct workqueue_struct *wq);
651 : : #else /* CONFIG_SYSFS */
652 : : static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
653 : : { return 0; }
654 : : #endif /* CONFIG_SYSFS */
655 : :
656 : : #ifdef CONFIG_WQ_WATCHDOG
657 : : void wq_watchdog_touch(int cpu);
658 : : #else /* CONFIG_WQ_WATCHDOG */
659 : : static inline void wq_watchdog_touch(int cpu) { }
660 : : #endif /* CONFIG_WQ_WATCHDOG */
661 : :
662 : : #ifdef CONFIG_SMP
663 : : int workqueue_prepare_cpu(unsigned int cpu);
664 : : int workqueue_online_cpu(unsigned int cpu);
665 : : int workqueue_offline_cpu(unsigned int cpu);
666 : : #endif
667 : :
668 : : int __init workqueue_init_early(void);
669 : : int __init workqueue_init(void);
670 : :
671 : : #endif
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