highres/dyntick: prevent xtime lock contention
[linux-2.6.git] / kernel / time / tick-internal.h
1 /*
2  * tick internal variable and functions used by low/high res code
3  */
4 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
5 extern spinlock_t tick_device_lock;
6 extern ktime_t tick_next_period;
7 extern ktime_t tick_period;
8 extern int tick_do_timer_cpu __read_mostly;
9
10 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
11 extern void tick_handle_periodic(struct clock_event_device *dev);
12
13 /*
14  * NO_HZ / high resolution timer shared code
15  */
16 #ifdef CONFIG_TICK_ONESHOT
17 extern void tick_setup_oneshot(struct clock_event_device *newdev,
18                                void (*handler)(struct clock_event_device *),
19                                ktime_t nextevt);
20 extern int tick_program_event(ktime_t expires, int force);
21 extern void tick_oneshot_notify(void);
22 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
23 extern void tick_resume_oneshot(void);
24 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
25 extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
26 extern void tick_broadcast_oneshot_control(unsigned long reason);
27 extern void tick_broadcast_switch_to_oneshot(void);
28 extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
29 extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
30 # else /* BROADCAST */
31 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
32 {
33         BUG();
34 }
35 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
36 static inline void tick_broadcast_switch_to_oneshot(void) { }
37 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
38 # endif /* !BROADCAST */
39
40 #else /* !ONESHOT */
41 static inline
42 void tick_setup_oneshot(struct clock_event_device *newdev,
43                         void (*handler)(struct clock_event_device *),
44                         ktime_t nextevt)
45 {
46         BUG();
47 }
48 static inline void tick_resume_oneshot(void)
49 {
50         BUG();
51 }
52 static inline int tick_program_event(ktime_t expires, int force)
53 {
54         return 0;
55 }
56 static inline void tick_oneshot_notify(void) { }
57 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
58 {
59         BUG();
60 }
61 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
62 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
63 static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
64 {
65         return 0;
66 }
67 #endif /* !TICK_ONESHOT */
68
69 /*
70  * Broadcasting support
71  */
72 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
73 extern int tick_do_broadcast(cpumask_t mask);
74
75 extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
76 extern int tick_check_broadcast_device(struct clock_event_device *dev);
77 extern int tick_is_broadcast_device(struct clock_event_device *dev);
78 extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);
79 extern void tick_shutdown_broadcast(unsigned int *cpup);
80 extern void tick_suspend_broadcast(void);
81 extern int tick_resume_broadcast(void);
82
83 extern void
84 tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
85
86 #else /* !BROADCAST */
87
88 static inline int tick_check_broadcast_device(struct clock_event_device *dev)
89 {
90         return 0;
91 }
92
93 static inline int tick_is_broadcast_device(struct clock_event_device *dev)
94 {
95         return 0;
96 }
97 static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
98                                              int cpu)
99 {
100         return 0;
101 }
102 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
103 static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
104 static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
105 static inline void tick_suspend_broadcast(void) { }
106 static inline int tick_resume_broadcast(void) { return 0; }
107
108 /*
109  * Set the periodic handler in non broadcast mode
110  */
111 static inline void tick_set_periodic_handler(struct clock_event_device *dev,
112                                              int broadcast)
113 {
114         dev->event_handler = tick_handle_periodic;
115 }
116 #endif /* !BROADCAST */
117
118 /*
119  * Check, if the device is functional or a dummy for broadcast
120  */
121 static inline int tick_device_is_functional(struct clock_event_device *dev)
122 {
123         return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
124 }