clockevents: prevent endless loop lockup
[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_dev_program_event(struct clock_event_device *dev,
21                                   ktime_t expires, int force);
22 extern int tick_program_event(ktime_t expires, int force);
23 extern void tick_oneshot_notify(void);
24 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
25 extern void tick_resume_oneshot(void);
26 # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
27 extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
28 extern void tick_broadcast_oneshot_control(unsigned long reason);
29 extern void tick_broadcast_switch_to_oneshot(void);
30 extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
31 extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
32 # else /* BROADCAST */
33 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
34 {
35         BUG();
36 }
37 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
38 static inline void tick_broadcast_switch_to_oneshot(void) { }
39 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
40 # endif /* !BROADCAST */
41
42 #else /* !ONESHOT */
43 static inline
44 void tick_setup_oneshot(struct clock_event_device *newdev,
45                         void (*handler)(struct clock_event_device *),
46                         ktime_t nextevt)
47 {
48         BUG();
49 }
50 static inline void tick_resume_oneshot(void)
51 {
52         BUG();
53 }
54 static inline int tick_program_event(ktime_t expires, int force)
55 {
56         return 0;
57 }
58 static inline void tick_oneshot_notify(void) { }
59 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
60 {
61         BUG();
62 }
63 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
64 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
65 static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
66 {
67         return 0;
68 }
69 #endif /* !TICK_ONESHOT */
70
71 /*
72  * Broadcasting support
73  */
74 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
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 }