xref: /linux-6.15/include/linux/workqueue.h (revision 7fcab099)
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>
11 #include <linux/lockdep.h>
12 #include <asm/atomic.h>
13 
14 struct workqueue_struct;
15 
16 struct work_struct;
17 typedef void (*work_func_t)(struct work_struct *work);
18 
19 /*
20  * The first word is the work queue pointer and the flags rolled into
21  * one
22  */
23 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
24 
25 struct work_struct {
26 	atomic_long_t data;
27 #define WORK_STRUCT_PENDING 0		/* T if work item pending execution */
28 #define WORK_STRUCT_FLAG_MASK (3UL)
29 #define WORK_STRUCT_WQ_DATA_MASK (~WORK_STRUCT_FLAG_MASK)
30 	struct list_head entry;
31 	work_func_t func;
32 #ifdef CONFIG_LOCKDEP
33 	struct lockdep_map lockdep_map;
34 #endif
35 };
36 
37 #define WORK_DATA_INIT()	ATOMIC_LONG_INIT(0)
38 
39 struct delayed_work {
40 	struct work_struct work;
41 	struct timer_list timer;
42 };
43 
44 static inline struct delayed_work *to_delayed_work(struct work_struct *work)
45 {
46 	return container_of(work, struct delayed_work, work);
47 }
48 
49 struct execute_work {
50 	struct work_struct work;
51 };
52 
53 #ifdef CONFIG_LOCKDEP
54 /*
55  * NB: because we have to copy the lockdep_map, setting _key
56  * here is required, otherwise it could get initialised to the
57  * copy of the lockdep_map!
58  */
59 #define __WORK_INIT_LOCKDEP_MAP(n, k) \
60 	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
61 #else
62 #define __WORK_INIT_LOCKDEP_MAP(n, k)
63 #endif
64 
65 #define __WORK_INITIALIZER(n, f) {				\
66 	.data = WORK_DATA_INIT(),				\
67 	.entry	= { &(n).entry, &(n).entry },			\
68 	.func = (f),						\
69 	__WORK_INIT_LOCKDEP_MAP(#n, &(n))			\
70 	}
71 
72 #define __DELAYED_WORK_INITIALIZER(n, f) {			\
73 	.work = __WORK_INITIALIZER((n).work, (f)),		\
74 	.timer = TIMER_INITIALIZER(NULL, 0, 0),			\
75 	}
76 
77 #define DECLARE_WORK(n, f)					\
78 	struct work_struct n = __WORK_INITIALIZER(n, f)
79 
80 #define DECLARE_DELAYED_WORK(n, f)				\
81 	struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
82 
83 /*
84  * initialize a work item's function pointer
85  */
86 #define PREPARE_WORK(_work, _func)				\
87 	do {							\
88 		(_work)->func = (_func);			\
89 	} while (0)
90 
91 #define PREPARE_DELAYED_WORK(_work, _func)			\
92 	PREPARE_WORK(&(_work)->work, (_func))
93 
94 /*
95  * initialize all of a work item in one go
96  *
97  * NOTE! No point in using "atomic_long_set()": useing a direct
98  * assignment of the work data initializer allows the compiler
99  * to generate better code.
100  */
101 #ifdef CONFIG_LOCKDEP
102 #define INIT_WORK(_work, _func)						\
103 	do {								\
104 		static struct lock_class_key __key;			\
105 									\
106 		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
107 		lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
108 		INIT_LIST_HEAD(&(_work)->entry);			\
109 		PREPARE_WORK((_work), (_func));				\
110 	} while (0)
111 #else
112 #define INIT_WORK(_work, _func)						\
113 	do {								\
114 		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
115 		INIT_LIST_HEAD(&(_work)->entry);			\
116 		PREPARE_WORK((_work), (_func));				\
117 	} while (0)
118 #endif
119 
120 #define INIT_DELAYED_WORK(_work, _func)				\
121 	do {							\
122 		INIT_WORK(&(_work)->work, (_func));		\
123 		init_timer(&(_work)->timer);			\
124 	} while (0)
125 
126 #define INIT_DELAYED_WORK_ON_STACK(_work, _func)		\
127 	do {							\
128 		INIT_WORK(&(_work)->work, (_func));		\
129 		init_timer_on_stack(&(_work)->timer);		\
130 	} while (0)
131 
132 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)			\
133 	do {							\
134 		INIT_WORK(&(_work)->work, (_func));		\
135 		init_timer_deferrable(&(_work)->timer);		\
136 	} while (0)
137 
138 #define INIT_DELAYED_WORK_ON_STACK(_work, _func)		\
139 	do {							\
140 		INIT_WORK(&(_work)->work, (_func));		\
141 		init_timer_on_stack(&(_work)->timer);		\
142 	} while (0)
143 
144 /**
145  * work_pending - Find out whether a work item is currently pending
146  * @work: The work item in question
147  */
148 #define work_pending(work) \
149 	test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
150 
151 /**
152  * delayed_work_pending - Find out whether a delayable work item is currently
153  * pending
154  * @work: The work item in question
155  */
156 #define delayed_work_pending(w) \
157 	work_pending(&(w)->work)
158 
159 /**
160  * work_clear_pending - for internal use only, mark a work item as not pending
161  * @work: The work item in question
162  */
163 #define work_clear_pending(work) \
164 	clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
165 
166 
167 extern struct workqueue_struct *
168 __create_workqueue_key(const char *name, int singlethread,
169 		       int freezeable, int rt, struct lock_class_key *key,
170 		       const char *lock_name);
171 
172 #ifdef CONFIG_LOCKDEP
173 #define __create_workqueue(name, singlethread, freezeable, rt)	\
174 ({								\
175 	static struct lock_class_key __key;			\
176 	const char *__lock_name;				\
177 								\
178 	if (__builtin_constant_p(name))				\
179 		__lock_name = (name);				\
180 	else							\
181 		__lock_name = #name;				\
182 								\
183 	__create_workqueue_key((name), (singlethread),		\
184 			       (freezeable), (rt), &__key,	\
185 			       __lock_name);			\
186 })
187 #else
188 #define __create_workqueue(name, singlethread, freezeable, rt)	\
189 	__create_workqueue_key((name), (singlethread), (freezeable), (rt), \
190 			       NULL, NULL)
191 #endif
192 
193 #define create_workqueue(name) __create_workqueue((name), 0, 0, 0)
194 #define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1)
195 #define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0)
196 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0)
197 
198 extern void destroy_workqueue(struct workqueue_struct *wq);
199 
200 extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
201 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
202 			struct work_struct *work);
203 extern int queue_delayed_work(struct workqueue_struct *wq,
204 			struct delayed_work *work, unsigned long delay);
205 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
206 			struct delayed_work *work, unsigned long delay);
207 
208 extern void flush_workqueue(struct workqueue_struct *wq);
209 extern void flush_scheduled_work(void);
210 
211 extern int schedule_work(struct work_struct *work);
212 extern int schedule_work_on(int cpu, struct work_struct *work);
213 extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
214 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
215 					unsigned long delay);
216 extern int schedule_on_each_cpu(work_func_t func);
217 extern int current_is_keventd(void);
218 extern int keventd_up(void);
219 
220 extern void init_workqueues(void);
221 int execute_in_process_context(work_func_t fn, struct execute_work *);
222 
223 extern int flush_work(struct work_struct *work);
224 
225 extern int cancel_work_sync(struct work_struct *work);
226 
227 /*
228  * Kill off a pending schedule_delayed_work().  Note that the work callback
229  * function may still be running on return from cancel_delayed_work(), unless
230  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
231  * cancel_work_sync() to wait on it.
232  */
233 static inline int cancel_delayed_work(struct delayed_work *work)
234 {
235 	int ret;
236 
237 	ret = del_timer_sync(&work->timer);
238 	if (ret)
239 		work_clear_pending(&work->work);
240 	return ret;
241 }
242 
243 extern int cancel_delayed_work_sync(struct delayed_work *work);
244 
245 /* Obsolete. use cancel_delayed_work_sync() */
246 static inline
247 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
248 					struct delayed_work *work)
249 {
250 	cancel_delayed_work_sync(work);
251 }
252 
253 /* Obsolete. use cancel_delayed_work_sync() */
254 static inline
255 void cancel_rearming_delayed_work(struct delayed_work *work)
256 {
257 	cancel_delayed_work_sync(work);
258 }
259 
260 #ifndef CONFIG_SMP
261 static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
262 {
263 	return fn(arg);
264 }
265 #else
266 long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
267 #endif /* CONFIG_SMP */
268 #endif
269