| 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 8 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 | static inline struct delayed_work *to_delayed_work(struct work_struct *work) |
| 159 | { |
| 160 | return container_of(work, struct delayed_work, work); |
| 161 | } |
| 162 | |
| 163 | static inline struct rcu_work *to_rcu_work(struct work_struct *work) |
| 164 | { |
| 165 | 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 | static inline void __init_work(struct work_struct *work, int onstack) { } |
| 216 | static inline void destroy_work_on_stack(struct work_struct *work) { } |
| 217 | static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { } |
| 218 | 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 | static inline bool queue_work(struct workqueue_struct *wq, |
| 505 | struct work_struct *work) |
| 506 | { |
| 507 | 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 | static inline bool queue_delayed_work(struct workqueue_struct *wq, |
| 519 | struct delayed_work *dwork, |
| 520 | unsigned long delay) |
| 521 | { |
| 522 | 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 | static inline bool mod_delayed_work(struct workqueue_struct *wq, |
| 534 | struct delayed_work *dwork, |
| 535 | unsigned long delay) |
| 536 | { |
| 537 | 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 | static inline bool schedule_work_on(int cpu, struct work_struct *work) |
| 548 | { |
| 549 | 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 | static inline bool schedule_work(struct work_struct *work) |
| 567 | { |
| 568 | 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 | static inline void flush_scheduled_work(void) |
| 596 | { |
| 597 | 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 | static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork, |
| 610 | unsigned long delay) |
| 611 | { |
| 612 | 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 | static inline bool schedule_delayed_work(struct delayed_work *dwork, |
| 624 | unsigned long delay) |
| 625 | { |
| 626 | 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 | void __init workqueue_init_early(void); |
| 669 | void __init workqueue_init(void); |
| 670 | |
| 671 | #endif |