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