workqueue: make work_busy() test WORK_STRUCT_PENDING first
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / workqueue.h
CommitLineData
1da177e4
LT
1/*
2 * workqueue.h --- work queue handling for Linux.
3 */
4
5#ifndef _LINUX_WORKQUEUE_H
6#define _LINUX_WORKQUEUE_H
7
8#include <linux/timer.h>
9#include <linux/linkage.h>
10#include <linux/bitops.h>
4e6045f1 11#include <linux/lockdep.h>
7a22ad75 12#include <linux/threads.h>
60063497 13#include <linux/atomic.h>
1da177e4
LT
14
15struct workqueue_struct;
16
65f27f38
DH
17struct work_struct;
18typedef void (*work_func_t)(struct work_struct *work);
d8e794df 19void delayed_work_timer_fn(unsigned long __data);
6bb49e59 20
a08727ba
LT
21/*
22 * The first word is the work queue pointer and the flags rolled into
23 * one
24 */
25#define work_data_bits(work) ((unsigned long *)(&(work)->data))
26
22df02bb
TH
27enum {
28 WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
8a2e8e5d
TH
29 WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */
30 WORK_STRUCT_CWQ_BIT = 2, /* data points to cwq */
31 WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */
22df02bb 32#ifdef CONFIG_DEBUG_OBJECTS_WORK
8a2e8e5d
TH
33 WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */
34 WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */
0f900049 35#else
8a2e8e5d 36 WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
22df02bb
TH
37#endif
38
73f53c4a
TH
39 WORK_STRUCT_COLOR_BITS = 4,
40
22df02bb 41 WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
8a2e8e5d 42 WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT,
e120153d 43 WORK_STRUCT_CWQ = 1 << WORK_STRUCT_CWQ_BIT,
affee4b2 44 WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
22df02bb
TH
45#ifdef CONFIG_DEBUG_OBJECTS_WORK
46 WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
47#else
48 WORK_STRUCT_STATIC = 0,
49#endif
50
73f53c4a
TH
51 /*
52 * The last color is no color used for works which don't
53 * participate in workqueue flushing.
54 */
55 WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
56 WORK_NO_COLOR = WORK_NR_COLORS,
57
bdbc5dd7 58 /* special cpu IDs */
f3421797 59 WORK_CPU_UNBOUND = NR_CPUS,
6be19588 60 WORK_CPU_END = NR_CPUS + 1,
bdbc5dd7 61
73f53c4a 62 /*
e120153d 63 * Reserve 7 bits off of cwq pointer w/ debugobjects turned
8a2e8e5d
TH
64 * off. This makes cwqs aligned to 256 bytes and allows 15
65 * workqueue flush colors.
73f53c4a
TH
66 */
67 WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
68 WORK_STRUCT_COLOR_BITS,
69
b5490077
TH
70 /* data contains off-queue information when !WORK_STRUCT_CWQ */
71 WORK_OFFQ_FLAG_BASE = WORK_STRUCT_FLAG_BITS,
bbb68dfa
TH
72
73 WORK_OFFQ_CANCELING = (1 << WORK_OFFQ_FLAG_BASE),
74
715b06b8
TH
75 /*
76 * When a work item is off queue, its high bits point to the last
7c3eed5c
TH
77 * pool it was on. Cap at 31 bits and use the highest number to
78 * indicate that no pool is associated.
715b06b8 79 */
bbb68dfa 80 WORK_OFFQ_FLAG_BITS = 1,
7c3eed5c
TH
81 WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
82 WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
83 WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
84 WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_BITS) - 1,
b5490077
TH
85
86 /* convenience constants */
0f900049 87 WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
22df02bb 88 WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
7c3eed5c 89 WORK_STRUCT_NO_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT,
dcd989cb
TH
90
91 /* bit mask for work_busy() return values */
92 WORK_BUSY_PENDING = 1 << 0,
93 WORK_BUSY_RUNNING = 1 << 1,
22df02bb
TH
94};
95
1da177e4 96struct work_struct {
a08727ba 97 atomic_long_t data;
1da177e4 98 struct list_head entry;
6bb49e59 99 work_func_t func;
4e6045f1
JB
100#ifdef CONFIG_LOCKDEP
101 struct lockdep_map lockdep_map;
102#endif
52bad64d
DH
103};
104
7c3eed5c 105#define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL)
7a22ad75 106#define WORK_DATA_STATIC_INIT() \
7c3eed5c 107 ATOMIC_LONG_INIT(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC)
a08727ba 108
52bad64d
DH
109struct delayed_work {
110 struct work_struct work;
1da177e4 111 struct timer_list timer;
1265057f 112 int cpu;
1da177e4
LT
113};
114
bf6aede7
JD
115static inline struct delayed_work *to_delayed_work(struct work_struct *work)
116{
117 return container_of(work, struct delayed_work, work);
118}
119
1fa44eca
JB
120struct execute_work {
121 struct work_struct work;
122};
123
4e6045f1
JB
124#ifdef CONFIG_LOCKDEP
125/*
126 * NB: because we have to copy the lockdep_map, setting _key
127 * here is required, otherwise it could get initialised to the
128 * copy of the lockdep_map!
129 */
130#define __WORK_INIT_LOCKDEP_MAP(n, k) \
131 .lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
132#else
133#define __WORK_INIT_LOCKDEP_MAP(n, k)
134#endif
135
ee64e7f6
TH
136#define __WORK_INITIALIZER(n, f) { \
137 .data = WORK_DATA_STATIC_INIT(), \
138 .entry = { &(n).entry, &(n).entry }, \
139 .func = (f), \
140 __WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
65f27f38
DH
141 }
142
f991b318 143#define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
ee64e7f6 144 .work = __WORK_INITIALIZER((n).work, (f)), \
f991b318 145 .timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
e0aecdd8
TH
146 0, (unsigned long)&(n), \
147 (tflags) | TIMER_IRQSAFE), \
dd6414b5
PC
148 }
149
ee64e7f6 150#define DECLARE_WORK(n, f) \
65f27f38
DH
151 struct work_struct n = __WORK_INITIALIZER(n, f)
152
ee64e7f6 153#define DECLARE_DELAYED_WORK(n, f) \
f991b318 154 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
65f27f38 155
203b42f7 156#define DECLARE_DEFERRABLE_WORK(n, f) \
f991b318 157 struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
dd6414b5 158
1da177e4 159/*
65f27f38 160 * initialize a work item's function pointer
1da177e4 161 */
ee64e7f6
TH
162#define PREPARE_WORK(_work, _func) \
163 do { \
164 (_work)->func = (_func); \
1da177e4
LT
165 } while (0)
166
ee64e7f6 167#define PREPARE_DELAYED_WORK(_work, _func) \
65f27f38 168 PREPARE_WORK(&(_work)->work, (_func))
52bad64d 169
dc186ad7
TG
170#ifdef CONFIG_DEBUG_OBJECTS_WORK
171extern void __init_work(struct work_struct *work, int onstack);
172extern void destroy_work_on_stack(struct work_struct *work);
4690c4ab
TH
173static inline unsigned int work_static(struct work_struct *work)
174{
22df02bb 175 return *work_data_bits(work) & WORK_STRUCT_STATIC;
4690c4ab 176}
dc186ad7
TG
177#else
178static inline void __init_work(struct work_struct *work, int onstack) { }
179static inline void destroy_work_on_stack(struct work_struct *work) { }
4690c4ab 180static inline unsigned int work_static(struct work_struct *work) { return 0; }
dc186ad7
TG
181#endif
182
1da177e4 183/*
52bad64d 184 * initialize all of a work item in one go
a08727ba 185 *
b9049df5 186 * NOTE! No point in using "atomic_long_set()": using a direct
a08727ba
LT
187 * assignment of the work data initializer allows the compiler
188 * to generate better code.
1da177e4 189 */
4e6045f1 190#ifdef CONFIG_LOCKDEP
dc186ad7 191#define __INIT_WORK(_work, _func, _onstack) \
65f27f38 192 do { \
4e6045f1
JB
193 static struct lock_class_key __key; \
194 \
dc186ad7 195 __init_work((_work), _onstack); \
23b2e599 196 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
ee64e7f6 197 lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
65f27f38
DH
198 INIT_LIST_HEAD(&(_work)->entry); \
199 PREPARE_WORK((_work), (_func)); \
200 } while (0)
4e6045f1 201#else
dc186ad7 202#define __INIT_WORK(_work, _func, _onstack) \
4e6045f1 203 do { \
dc186ad7 204 __init_work((_work), _onstack); \
4e6045f1
JB
205 (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
206 INIT_LIST_HEAD(&(_work)->entry); \
207 PREPARE_WORK((_work), (_func)); \
208 } while (0)
209#endif
65f27f38 210
ee64e7f6
TH
211#define INIT_WORK(_work, _func) \
212 do { \
213 __INIT_WORK((_work), (_func), 0); \
dc186ad7
TG
214 } while (0)
215
ee64e7f6
TH
216#define INIT_WORK_ONSTACK(_work, _func) \
217 do { \
218 __INIT_WORK((_work), (_func), 1); \
dc186ad7
TG
219 } while (0)
220
f991b318 221#define __INIT_DELAYED_WORK(_work, _func, _tflags) \
ee64e7f6
TH
222 do { \
223 INIT_WORK(&(_work)->work, (_func)); \
f991b318 224 __setup_timer(&(_work)->timer, delayed_work_timer_fn, \
e0aecdd8
TH
225 (unsigned long)(_work), \
226 (_tflags) | TIMER_IRQSAFE); \
52bad64d
DH
227 } while (0)
228
f991b318 229#define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
ee64e7f6
TH
230 do { \
231 INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
f991b318
TH
232 __setup_timer_on_stack(&(_work)->timer, \
233 delayed_work_timer_fn, \
234 (unsigned long)(_work), \
e0aecdd8 235 (_tflags) | TIMER_IRQSAFE); \
6d612b0f
PZ
236 } while (0)
237
f991b318
TH
238#define INIT_DELAYED_WORK(_work, _func) \
239 __INIT_DELAYED_WORK(_work, _func, 0)
240
241#define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
242 __INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
243
203b42f7 244#define INIT_DEFERRABLE_WORK(_work, _func) \
f991b318
TH
245 __INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
246
247#define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
248 __INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
28287033 249
365970a1
DH
250/**
251 * work_pending - Find out whether a work item is currently pending
252 * @work: The work item in question
253 */
254#define work_pending(work) \
22df02bb 255 test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
365970a1
DH
256
257/**
258 * delayed_work_pending - Find out whether a delayable work item is currently
259 * pending
260 * @work: The work item in question
261 */
0221872a
LT
262#define delayed_work_pending(w) \
263 work_pending(&(w)->work)
365970a1 264
65f27f38 265/**
23b2e599
ON
266 * work_clear_pending - for internal use only, mark a work item as not pending
267 * @work: The work item in question
65f27f38 268 */
23b2e599 269#define work_clear_pending(work) \
22df02bb 270 clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
65f27f38 271
c54fce6e
TH
272/*
273 * Workqueue flags and constants. For details, please refer to
274 * Documentation/workqueue.txt.
275 */
97e37d7b 276enum {
bdbc5dd7 277 WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */
c7fc77f7 278 WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
58a69cb4 279 WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
6370a6ad 280 WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
649027d7 281 WQ_HIGHPRI = 1 << 4, /* high priority */
fb0e7beb 282 WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */
b71ab8c2 283
9c5a2ba7 284 WQ_DRAINING = 1 << 6, /* internal: workqueue is draining */
6370a6ad 285 WQ_RESCUER = 1 << 7, /* internal: workqueue has rescuer */
e41e704b 286
b71ab8c2 287 WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
f3421797 288 WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
b71ab8c2 289 WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
97e37d7b 290};
52bad64d 291
f3421797
TH
292/* unbound wq's aren't per-cpu, scale max_active according to #cpus */
293#define WQ_UNBOUND_MAX_ACTIVE \
294 max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
65f27f38 295
d320c038
TH
296/*
297 * System-wide workqueues which are always present.
298 *
299 * system_wq is the one used by schedule[_delayed]_work[_on]().
300 * Multi-CPU multi-threaded. There are users which expect relatively
301 * short queue flush time. Don't queue works which can run for too
302 * long.
303 *
304 * system_long_wq is similar to system_wq but may host long running
305 * works. Queue flushing might take relatively long.
306 *
f3421797
TH
307 * system_unbound_wq is unbound workqueue. Workers are not bound to
308 * any specific CPU, not concurrency managed, and all queued works are
309 * executed immediately as long as max_active limit is not reached and
310 * resources are available.
4149efb2 311 *
24d51add
TH
312 * system_freezable_wq is equivalent to system_wq except that it's
313 * freezable.
d320c038
TH
314 */
315extern struct workqueue_struct *system_wq;
316extern struct workqueue_struct *system_long_wq;
f3421797 317extern struct workqueue_struct *system_unbound_wq;
24d51add 318extern struct workqueue_struct *system_freezable_wq;
ae930e0f 319
3b07e9ca 320static inline struct workqueue_struct * __deprecated __system_nrt_wq(void)
ae930e0f
TH
321{
322 return system_wq;
323}
324
3b07e9ca 325static inline struct workqueue_struct * __deprecated __system_nrt_freezable_wq(void)
ae930e0f
TH
326{
327 return system_freezable_wq;
328}
329
330/* equivlalent to system_wq and system_freezable_wq, deprecated */
331#define system_nrt_wq __system_nrt_wq()
332#define system_nrt_freezable_wq __system_nrt_freezable_wq()
52bad64d 333
4e6045f1 334extern struct workqueue_struct *
b196be89
TH
335__alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
336 struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);
4e6045f1 337
b196be89
TH
338/**
339 * alloc_workqueue - allocate a workqueue
340 * @fmt: printf format for the name of the workqueue
341 * @flags: WQ_* flags
342 * @max_active: max in-flight work items, 0 for default
343 * @args: args for @fmt
344 *
345 * Allocate a workqueue with the specified parameters. For detailed
346 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
347 *
348 * The __lock_name macro dance is to guarantee that single lock_class_key
349 * doesn't end up with different namesm, which isn't allowed by lockdep.
350 *
351 * RETURNS:
352 * Pointer to the allocated workqueue on success, %NULL on failure.
353 */
4e6045f1 354#ifdef CONFIG_LOCKDEP
ee64e7f6
TH
355#define alloc_workqueue(fmt, flags, max_active, args...) \
356({ \
357 static struct lock_class_key __key; \
358 const char *__lock_name; \
359 \
360 if (__builtin_constant_p(fmt)) \
361 __lock_name = (fmt); \
362 else \
363 __lock_name = #fmt; \
364 \
365 __alloc_workqueue_key((fmt), (flags), (max_active), \
366 &__key, __lock_name, ##args); \
4e6045f1
JB
367})
368#else
ee64e7f6
TH
369#define alloc_workqueue(fmt, flags, max_active, args...) \
370 __alloc_workqueue_key((fmt), (flags), (max_active), \
b196be89 371 NULL, NULL, ##args)
4e6045f1
JB
372#endif
373
81dcaf65
TH
374/**
375 * alloc_ordered_workqueue - allocate an ordered workqueue
b196be89 376 * @fmt: printf format for the name of the workqueue
58a69cb4 377 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
b196be89 378 * @args: args for @fmt
81dcaf65
TH
379 *
380 * Allocate an ordered workqueue. An ordered workqueue executes at
381 * most one work item at any given time in the queued order. They are
382 * implemented as unbound workqueues with @max_active of one.
383 *
384 * RETURNS:
385 * Pointer to the allocated workqueue on success, %NULL on failure.
386 */
ee64e7f6 387#define alloc_ordered_workqueue(fmt, flags, args...) \
b196be89 388 alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)
81dcaf65 389
ee64e7f6 390#define create_workqueue(name) \
6370a6ad 391 alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
ee64e7f6 392#define create_freezable_workqueue(name) \
58a69cb4 393 alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
ee64e7f6 394#define create_singlethread_workqueue(name) \
6370a6ad 395 alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
1da177e4
LT
396
397extern void destroy_workqueue(struct workqueue_struct *wq);
398
d4283e93 399extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
c1a220e7 400 struct work_struct *work);
d4283e93
TH
401extern bool queue_work(struct workqueue_struct *wq, struct work_struct *work);
402extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
28e53bdd 403 struct delayed_work *work, unsigned long delay);
d4283e93 404extern bool queue_delayed_work(struct workqueue_struct *wq,
0a13c00e 405 struct delayed_work *work, unsigned long delay);
8376fe22
TH
406extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
407 struct delayed_work *dwork, unsigned long delay);
408extern bool mod_delayed_work(struct workqueue_struct *wq,
409 struct delayed_work *dwork, unsigned long delay);
28e53bdd 410
b3c97528 411extern void flush_workqueue(struct workqueue_struct *wq);
9c5a2ba7 412extern void drain_workqueue(struct workqueue_struct *wq);
28e53bdd 413extern void flush_scheduled_work(void);
1da177e4 414
d4283e93
TH
415extern bool schedule_work_on(int cpu, struct work_struct *work);
416extern bool schedule_work(struct work_struct *work);
417extern bool schedule_delayed_work_on(int cpu, struct delayed_work *work,
418 unsigned long delay);
419extern bool schedule_delayed_work(struct delayed_work *work,
420 unsigned long delay);
65f27f38 421extern int schedule_on_each_cpu(work_func_t func);
1da177e4
LT
422extern int keventd_up(void);
423
65f27f38 424int execute_in_process_context(work_func_t fn, struct execute_work *);
1da177e4 425
401a8d04
TH
426extern bool flush_work(struct work_struct *work);
427extern bool cancel_work_sync(struct work_struct *work);
428
429extern bool flush_delayed_work(struct delayed_work *dwork);
57b30ae7 430extern bool cancel_delayed_work(struct delayed_work *dwork);
401a8d04 431extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
28e53bdd 432
dcd989cb
TH
433extern void workqueue_set_max_active(struct workqueue_struct *wq,
434 int max_active);
435extern bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq);
dcd989cb
TH
436extern unsigned int work_busy(struct work_struct *work);
437
4e49627b
ON
438/*
439 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
440 * if it returns 0 the timer function may be running and the queueing is in
441 * progress.
442 */
136b5721 443static inline bool __deprecated __cancel_delayed_work(struct delayed_work *work)
4e49627b 444{
401a8d04 445 bool ret;
4e49627b
ON
446
447 ret = del_timer(&work->timer);
448 if (ret)
449 work_clear_pending(&work->work);
450 return ret;
451}
452
606a5020 453/* used to be different but now identical to flush_work(), deprecated */
43829731 454static inline bool __deprecated flush_work_sync(struct work_struct *work)
606a5020
TH
455{
456 return flush_work(work);
457}
458
459/* used to be different but now identical to flush_delayed_work(), deprecated */
43829731 460static inline bool __deprecated flush_delayed_work_sync(struct delayed_work *dwork)
606a5020
TH
461{
462 return flush_delayed_work(dwork);
463}
464
2d3854a3
RR
465#ifndef CONFIG_SMP
466static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
467{
468 return fn(arg);
469}
470#else
471long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
472#endif /* CONFIG_SMP */
a25909a4 473
a0a1a5fd
TH
474#ifdef CONFIG_FREEZER
475extern void freeze_workqueues_begin(void);
476extern bool freeze_workqueues_busy(void);
477extern void thaw_workqueues(void);
478#endif /* CONFIG_FREEZER */
479
1da177e4 480#endif