Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / include / linux / workqueue.h
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 /**
134  * work_pending - Find out whether a work item is currently pending
135  * @work: The work item in question
136  */
137 #define work_pending(work) \
138         test_bit(WORK_STRUCT_PENDING, work_data_bits(work))
139
140 /**
141  * delayed_work_pending - Find out whether a delayable work item is currently
142  * pending
143  * @work: The work item in question
144  */
145 #define delayed_work_pending(w) \
146         work_pending(&(w)->work)
147
148 /**
149  * work_clear_pending - for internal use only, mark a work item as not pending
150  * @work: The work item in question
151  */
152 #define work_clear_pending(work) \
153         clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
154
155
156 extern struct workqueue_struct *
157 __create_workqueue_key(const char *name, int singlethread,
158                        int freezeable, int rt, struct lock_class_key *key,
159                        const char *lock_name);
160
161 #ifdef CONFIG_LOCKDEP
162 #define __create_workqueue(name, singlethread, freezeable, rt)  \
163 ({                                                              \
164         static struct lock_class_key __key;                     \
165         const char *__lock_name;                                \
166                                                                 \
167         if (__builtin_constant_p(name))                         \
168                 __lock_name = (name);                           \
169         else                                                    \
170                 __lock_name = #name;                            \
171                                                                 \
172         __create_workqueue_key((name), (singlethread),          \
173                                (freezeable), (rt), &__key,      \
174                                __lock_name);                    \
175 })
176 #else
177 #define __create_workqueue(name, singlethread, freezeable, rt)  \
178         __create_workqueue_key((name), (singlethread), (freezeable), (rt), \
179                                NULL, NULL)
180 #endif
181
182 #define create_workqueue(name) __create_workqueue((name), 0, 0, 0)
183 #define create_rt_workqueue(name) __create_workqueue((name), 0, 0, 1)
184 #define create_freezeable_workqueue(name) __create_workqueue((name), 1, 1, 0)
185 #define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0, 0)
186
187 extern void destroy_workqueue(struct workqueue_struct *wq);
188
189 extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
190 extern int queue_work_on(int cpu, struct workqueue_struct *wq,
191                         struct work_struct *work);
192 extern int queue_delayed_work(struct workqueue_struct *wq,
193                         struct delayed_work *work, unsigned long delay);
194 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
195                         struct delayed_work *work, unsigned long delay);
196
197 extern void flush_workqueue(struct workqueue_struct *wq);
198 extern void flush_scheduled_work(void);
199
200 extern int schedule_work(struct work_struct *work);
201 extern int schedule_work_on(int cpu, struct work_struct *work);
202 extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
203 extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
204                                         unsigned long delay);
205 extern int schedule_on_each_cpu(work_func_t func);
206 extern int current_is_keventd(void);
207 extern int keventd_up(void);
208
209 extern void init_workqueues(void);
210 int execute_in_process_context(work_func_t fn, struct execute_work *);
211
212 extern int flush_work(struct work_struct *work);
213
214 extern int cancel_work_sync(struct work_struct *work);
215
216 /*
217  * Kill off a pending schedule_delayed_work().  Note that the work callback
218  * function may still be running on return from cancel_delayed_work(), unless
219  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
220  * cancel_work_sync() to wait on it.
221  */
222 static inline int cancel_delayed_work(struct delayed_work *work)
223 {
224         int ret;
225
226         ret = del_timer_sync(&work->timer);
227         if (ret)
228                 work_clear_pending(&work->work);
229         return ret;
230 }
231
232 extern int cancel_delayed_work_sync(struct delayed_work *work);
233
234 /* Obsolete. use cancel_delayed_work_sync() */
235 static inline
236 void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
237                                         struct delayed_work *work)
238 {
239         cancel_delayed_work_sync(work);
240 }
241
242 /* Obsolete. use cancel_delayed_work_sync() */
243 static inline
244 void cancel_rearming_delayed_work(struct delayed_work *work)
245 {
246         cancel_delayed_work_sync(work);
247 }
248
249 #ifndef CONFIG_SMP
250 static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
251 {
252         return fn(arg);
253 }
254 #else
255 long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
256 #endif /* CONFIG_SMP */
257 #endif