clockevents: prevent cpu online to interfere with nohz
[linux-2.6.git] / kernel / time / tick-internal.h
1 /*
2  * tick internal variable and functions used by low/high res code
3  */
4
5 #define TICK_DO_TIMER_NONE      -1
6 #define TICK_DO_TIMER_BOOT      -2
7
8 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
9 extern spinlock_t tick_device_lock;
10 extern ktime_t tick_next_period;
11 extern ktime_t tick_period;
12 extern int tick_do_timer_cpu __read_mostly;
13
14 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
15 extern void tick_handle_periodic(struct clock_event_device *dev);
16
17 extern void clockevents_shutdown(struct clock_event_device *dev);
18
19 /*
20  * NO_HZ / high resolution timer shared code
21  */
22 #ifdef CONFIG_TICK_ONESHOT
23 extern void tick_setup_oneshot(struct clock_event_device *newdev,
24                                void (*handler)(struct clock_event_device *),
25                                ktime_t nextevt);
26 extern int tick_dev_program_event(struct clock_event_device *dev,
27                                   ktime_t expires, int force);
28 extern int tick_program_event(ktime_t expires, int force);
29 extern void tick_oneshot_notify(void);
30 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
31 extern void tick_resume_oneshot(void);
32 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
33 extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
34 extern void tick_broadcast_oneshot_control(unsigned long reason);
35 extern void tick_broadcast_switch_to_oneshot(void);
36 extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
37 extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
38 # else /* BROADCAST */
39 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
40 {
41         BUG();
42 }
43 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
44 static inline void tick_broadcast_switch_to_oneshot(void) { }
45 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
46 # endif /* !BROADCAST */
47
48 #else /* !ONESHOT */
49 static inline
50 void tick_setup_oneshot(struct clock_event_device *newdev,
51                         void (*handler)(struct clock_event_device *),
52                         ktime_t nextevt)
53 {
54         BUG();
55 }
56 static inline void tick_resume_oneshot(void)
57 {
58         BUG();
59 }
60 static inline int tick_program_event(ktime_t expires, int force)
61 {
62         return 0;
63 }
64 static inline void tick_oneshot_notify(void) { }
65 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
66 {
67         BUG();
68 }
69 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
70 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
71 static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
72 {
73         return 0;
74 }
75 #endif /* !TICK_ONESHOT */
76
77 /*
78  * Broadcasting support
79  */
80 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
81 extern int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu);
82 extern int tick_check_broadcast_device(struct clock_event_device *dev);
83 extern int tick_is_broadcast_device(struct clock_event_device *dev);
84 extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);
85 extern void tick_shutdown_broadcast(unsigned int *cpup);
86 extern void tick_suspend_broadcast(void);
87 extern int tick_resume_broadcast(void);
88
89 extern void
90 tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
91
92 #else /* !BROADCAST */
93
94 static inline int tick_check_broadcast_device(struct clock_event_device *dev)
95 {
96         return 0;
97 }
98
99 static inline int tick_is_broadcast_device(struct clock_event_device *dev)
100 {
101         return 0;
102 }
103 static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
104                                              int cpu)
105 {
106         return 0;
107 }
108 static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
109 static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
110 static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
111 static inline void tick_suspend_broadcast(void) { }
112 static inline int tick_resume_broadcast(void) { return 0; }
113
114 /*
115  * Set the periodic handler in non broadcast mode
116  */
117 static inline void tick_set_periodic_handler(struct clock_event_device *dev,
118                                              int broadcast)
119 {
120         dev->event_handler = tick_handle_periodic;
121 }
122 #endif /* !BROADCAST */
123
124 /*
125  * Check, if the device is functional or a dummy for broadcast
126  */
127 static inline int tick_device_is_functional(struct clock_event_device *dev)
128 {
129         return !(dev->features & CLOCK_EVT_FEAT_DUMMY);
130 }