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1/*
2 * linux/kernel/time/tick-common.c
3 *
4 * This file contains the base functions to manage periodic tick
5 * related events.
6 *
7 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
8 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
9 * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
10 *
11 * This code is licenced under the GPL version 2. For details see
12 * kernel-base/COPYING.
13 */
14#include <linux/cpu.h>
15#include <linux/err.h>
16#include <linux/hrtimer.h>
17#include <linux/interrupt.h>
18#include <linux/percpu.h>
19#include <linux/profile.h>
20#include <linux/sched.h>
21#include <linux/module.h>
22
23#include <asm/irq_regs.h>
24
25#include "tick-internal.h"
26
27/*
28 * Tick devices
29 */
30DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
31/*
32 * Tick next event: keeps track of the tick time
33 */
34ktime_t tick_next_period;
35ktime_t tick_period;
36
37/*
38 * tick_do_timer_cpu is a timer core internal variable which holds the CPU NR
39 * which is responsible for calling do_timer(), i.e. the timekeeping stuff. This
40 * variable has two functions:
41 *
42 * 1) Prevent a thundering herd issue of a gazillion of CPUs trying to grab the
43 * timekeeping lock all at once. Only the CPU which is assigned to do the
44 * update is handling it.
45 *
46 * 2) Hand off the duty in the NOHZ idle case by setting the value to
47 * TICK_DO_TIMER_NONE, i.e. a non existing CPU. So the next cpu which looks
48 * at it will take over and keep the time keeping alive. The handover
49 * procedure also covers cpu hotplug.
50 */
51int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
52
53/*
54 * Debugging: see timer_list.c
55 */
56struct tick_device *tick_get_device(int cpu)
57{
58 return &per_cpu(tick_cpu_device, cpu);
59}
60
61/**
62 * tick_is_oneshot_available - check for a oneshot capable event device
63 */
64int tick_is_oneshot_available(void)
65{
66 struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
67
68 if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT))
69 return 0;
70 if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
71 return 1;
72 return tick_broadcast_oneshot_available();
73}
74
75/*
76 * Periodic tick
77 */
78static void tick_periodic(int cpu)
79{
80 if (tick_do_timer_cpu == cpu) {
81 write_seqlock(&jiffies_lock);
82
83 /* Keep track of the next tick event */
84 tick_next_period = ktime_add(tick_next_period, tick_period);
85
86 do_timer(1);
87 write_sequnlock(&jiffies_lock);
88 update_wall_time();
89 }
90
91 update_process_times(user_mode(get_irq_regs()));
92 profile_tick(CPU_PROFILING);
93}
94
95/*
96 * Event handler for periodic ticks
97 */
98void tick_handle_periodic(struct clock_event_device *dev)
99{
100 int cpu = smp_processor_id();
101 ktime_t next = dev->next_event;
102
103 tick_periodic(cpu);
104
105 if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
106 return;
107 for (;;) {
108 /*
109 * Setup the next period for devices, which do not have
110 * periodic mode:
111 */
112 next = ktime_add(next, tick_period);
113
114 if (!clockevents_program_event(dev, next, false))
115 return;
116 /*
117 * Have to be careful here. If we're in oneshot mode,
118 * before we call tick_periodic() in a loop, we need
119 * to be sure we're using a real hardware clocksource.
120 * Otherwise we could get trapped in an infinite
121 * loop, as the tick_periodic() increments jiffies,
122 * which then will increment time, possibly causing
123 * the loop to trigger again and again.
124 */
125 if (timekeeping_valid_for_hres())
126 tick_periodic(cpu);
127 }
128}
129
130/*
131 * Setup the device for a periodic tick
132 */
133void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
134{
135 tick_set_periodic_handler(dev, broadcast);
136
137 /* Broadcast setup ? */
138 if (!tick_device_is_functional(dev))
139 return;
140
141 if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
142 !tick_broadcast_oneshot_active()) {
143 clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
144 } else {
145 unsigned long seq;
146 ktime_t next;
147
148 do {
149 seq = read_seqbegin(&jiffies_lock);
150 next = tick_next_period;
151 } while (read_seqretry(&jiffies_lock, seq));
152
153 clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
154
155 for (;;) {
156 if (!clockevents_program_event(dev, next, false))
157 return;
158 next = ktime_add(next, tick_period);
159 }
160 }
161}
162
163/*
164 * Setup the tick device
165 */
166static void tick_setup_device(struct tick_device *td,
167 struct clock_event_device *newdev, int cpu,
168 const struct cpumask *cpumask)
169{
170 ktime_t next_event;
171 void (*handler)(struct clock_event_device *) = NULL;
172
173 /*
174 * First device setup ?
175 */
176 if (!td->evtdev) {
177 /*
178 * If no cpu took the do_timer update, assign it to
179 * this cpu:
180 */
181 if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
182 if (!tick_nohz_full_cpu(cpu))
183 tick_do_timer_cpu = cpu;
184 else
185 tick_do_timer_cpu = TICK_DO_TIMER_NONE;
186 tick_next_period = ktime_get();
187 tick_period = ktime_set(0, NSEC_PER_SEC / HZ);
188 }
189
190 /*
191 * Startup in periodic mode first.
192 */
193 td->mode = TICKDEV_MODE_PERIODIC;
194 } else {
195 handler = td->evtdev->event_handler;
196 next_event = td->evtdev->next_event;
197 td->evtdev->event_handler = clockevents_handle_noop;
198 }
199
200 td->evtdev = newdev;
201
202 /*
203 * When the device is not per cpu, pin the interrupt to the
204 * current cpu:
205 */
206 if (!cpumask_equal(newdev->cpumask, cpumask))
207 irq_set_affinity(newdev->irq, cpumask);
208
209 /*
210 * When global broadcasting is active, check if the current
211 * device is registered as a placeholder for broadcast mode.
212 * This allows us to handle this x86 misfeature in a generic
213 * way. This function also returns !=0 when we keep the
214 * current active broadcast state for this CPU.
215 */
216 if (tick_device_uses_broadcast(newdev, cpu))
217 return;
218
219 if (td->mode == TICKDEV_MODE_PERIODIC)
220 tick_setup_periodic(newdev, 0);
221 else
222 tick_setup_oneshot(newdev, handler, next_event);
223}
224
225void tick_install_replacement(struct clock_event_device *newdev)
226{
227 struct tick_device *td = &__get_cpu_var(tick_cpu_device);
228 int cpu = smp_processor_id();
229
230 clockevents_exchange_device(td->evtdev, newdev);
231 tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
232 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
233 tick_oneshot_notify();
234}
235
236static bool tick_check_percpu(struct clock_event_device *curdev,
237 struct clock_event_device *newdev, int cpu)
238{
239 if (!cpumask_test_cpu(cpu, newdev->cpumask))
240 return false;
241 if (cpumask_equal(newdev->cpumask, cpumask_of(cpu)))
242 return true;
243 /* Check if irq affinity can be set */
244 if (newdev->irq >= 0 && !irq_can_set_affinity(newdev->irq))
245 return false;
246 /* Prefer an existing cpu local device */
247 if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
248 return false;
249 return true;
250}
251
252static bool tick_check_preferred(struct clock_event_device *curdev,
253 struct clock_event_device *newdev)
254{
255 /* Prefer oneshot capable device */
256 if (!(newdev->features & CLOCK_EVT_FEAT_ONESHOT)) {
257 if (curdev && (curdev->features & CLOCK_EVT_FEAT_ONESHOT))
258 return false;
259 if (tick_oneshot_mode_active())
260 return false;
261 }
262
263 /*
264 * Use the higher rated one, but prefer a CPU local device with a lower
265 * rating than a non-CPU local device
266 */
267 return !curdev ||
268 newdev->rating > curdev->rating ||
269 !cpumask_equal(curdev->cpumask, newdev->cpumask);
270}
271
272/*
273 * Check whether the new device is a better fit than curdev. curdev
274 * can be NULL !
275 */
276bool tick_check_replacement(struct clock_event_device *curdev,
277 struct clock_event_device *newdev)
278{
279 if (!tick_check_percpu(curdev, newdev, smp_processor_id()))
280 return false;
281
282 return tick_check_preferred(curdev, newdev);
283}
284
285/*
286 * Check, if the new registered device should be used. Called with
287 * clockevents_lock held and interrupts disabled.
288 */
289void tick_check_new_device(struct clock_event_device *newdev)
290{
291 struct clock_event_device *curdev;
292 struct tick_device *td;
293 int cpu;
294
295 cpu = smp_processor_id();
296 if (!cpumask_test_cpu(cpu, newdev->cpumask))
297 goto out_bc;
298
299 td = &per_cpu(tick_cpu_device, cpu);
300 curdev = td->evtdev;
301
302 /* cpu local device ? */
303 if (!tick_check_percpu(curdev, newdev, cpu))
304 goto out_bc;
305
306 /* Preference decision */
307 if (!tick_check_preferred(curdev, newdev))
308 goto out_bc;
309
310 if (!try_module_get(newdev->owner))
311 return;
312
313 /*
314 * Replace the eventually existing device by the new
315 * device. If the current device is the broadcast device, do
316 * not give it back to the clockevents layer !
317 */
318 if (tick_is_broadcast_device(curdev)) {
319 clockevents_shutdown(curdev);
320 curdev = NULL;
321 }
322 clockevents_exchange_device(curdev, newdev);
323 tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
324 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
325 tick_oneshot_notify();
326 return;
327
328out_bc:
329 /*
330 * Can the new device be used as a broadcast device ?
331 */
332 tick_install_broadcast_device(newdev);
333}
334
335/*
336 * Transfer the do_timer job away from a dying cpu.
337 *
338 * Called with interrupts disabled.
339 */
340void tick_handover_do_timer(int *cpup)
341{
342 if (*cpup == tick_do_timer_cpu) {
343 int cpu = cpumask_first(cpu_online_mask);
344
345 tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
346 TICK_DO_TIMER_NONE;
347 }
348}
349
350/*
351 * Shutdown an event device on a given cpu:
352 *
353 * This is called on a life CPU, when a CPU is dead. So we cannot
354 * access the hardware device itself.
355 * We just set the mode and remove it from the lists.
356 */
357void tick_shutdown(unsigned int *cpup)
358{
359 struct tick_device *td = &per_cpu(tick_cpu_device, *cpup);
360 struct clock_event_device *dev = td->evtdev;
361
362 td->mode = TICKDEV_MODE_PERIODIC;
363 if (dev) {
364 /*
365 * Prevent that the clock events layer tries to call
366 * the set mode function!
367 */
368 dev->mode = CLOCK_EVT_MODE_UNUSED;
369 clockevents_exchange_device(dev, NULL);
370 dev->event_handler = clockevents_handle_noop;
371 td->evtdev = NULL;
372 }
373}
374
375void tick_suspend(void)
376{
377 struct tick_device *td = &__get_cpu_var(tick_cpu_device);
378
379 clockevents_shutdown(td->evtdev);
380}
381
382void tick_resume(void)
383{
384 struct tick_device *td = &__get_cpu_var(tick_cpu_device);
385 int broadcast = tick_resume_broadcast();
386
387 clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
388
389 if (!broadcast) {
390 if (td->mode == TICKDEV_MODE_PERIODIC)
391 tick_setup_periodic(td->evtdev, 0);
392 else
393 tick_resume_oneshot();
394 }
395}
396
397/**
398 * tick_init - initialize the tick control
399 */
400void __init tick_init(void)
401{
402 tick_broadcast_init();
403}
1/*
2 * linux/kernel/time/tick-common.c
3 *
4 * This file contains the base functions to manage periodic tick
5 * related events.
6 *
7 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
8 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
9 * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
10 *
11 * This code is licenced under the GPL version 2. For details see
12 * kernel-base/COPYING.
13 */
14#include <linux/cpu.h>
15#include <linux/err.h>
16#include <linux/hrtimer.h>
17#include <linux/interrupt.h>
18#include <linux/percpu.h>
19#include <linux/profile.h>
20#include <linux/sched.h>
21
22#include <asm/irq_regs.h>
23
24#include "tick-internal.h"
25
26/*
27 * Tick devices
28 */
29DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
30/*
31 * Tick next event: keeps track of the tick time
32 */
33ktime_t tick_next_period;
34ktime_t tick_period;
35int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
36static DEFINE_RAW_SPINLOCK(tick_device_lock);
37
38/*
39 * Debugging: see timer_list.c
40 */
41struct tick_device *tick_get_device(int cpu)
42{
43 return &per_cpu(tick_cpu_device, cpu);
44}
45
46/**
47 * tick_is_oneshot_available - check for a oneshot capable event device
48 */
49int tick_is_oneshot_available(void)
50{
51 struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
52
53 if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT))
54 return 0;
55 if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
56 return 1;
57 return tick_broadcast_oneshot_available();
58}
59
60/*
61 * Periodic tick
62 */
63static void tick_periodic(int cpu)
64{
65 if (tick_do_timer_cpu == cpu) {
66 write_seqlock(&xtime_lock);
67
68 /* Keep track of the next tick event */
69 tick_next_period = ktime_add(tick_next_period, tick_period);
70
71 do_timer(1);
72 write_sequnlock(&xtime_lock);
73 }
74
75 update_process_times(user_mode(get_irq_regs()));
76 profile_tick(CPU_PROFILING);
77}
78
79/*
80 * Event handler for periodic ticks
81 */
82void tick_handle_periodic(struct clock_event_device *dev)
83{
84 int cpu = smp_processor_id();
85 ktime_t next;
86
87 tick_periodic(cpu);
88
89 if (dev->mode != CLOCK_EVT_MODE_ONESHOT)
90 return;
91 /*
92 * Setup the next period for devices, which do not have
93 * periodic mode:
94 */
95 next = ktime_add(dev->next_event, tick_period);
96 for (;;) {
97 if (!clockevents_program_event(dev, next, ktime_get()))
98 return;
99 /*
100 * Have to be careful here. If we're in oneshot mode,
101 * before we call tick_periodic() in a loop, we need
102 * to be sure we're using a real hardware clocksource.
103 * Otherwise we could get trapped in an infinite
104 * loop, as the tick_periodic() increments jiffies,
105 * when then will increment time, posibly causing
106 * the loop to trigger again and again.
107 */
108 if (timekeeping_valid_for_hres())
109 tick_periodic(cpu);
110 next = ktime_add(next, tick_period);
111 }
112}
113
114/*
115 * Setup the device for a periodic tick
116 */
117void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
118{
119 tick_set_periodic_handler(dev, broadcast);
120
121 /* Broadcast setup ? */
122 if (!tick_device_is_functional(dev))
123 return;
124
125 if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
126 !tick_broadcast_oneshot_active()) {
127 clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
128 } else {
129 unsigned long seq;
130 ktime_t next;
131
132 do {
133 seq = read_seqbegin(&xtime_lock);
134 next = tick_next_period;
135 } while (read_seqretry(&xtime_lock, seq));
136
137 clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
138
139 for (;;) {
140 if (!clockevents_program_event(dev, next, ktime_get()))
141 return;
142 next = ktime_add(next, tick_period);
143 }
144 }
145}
146
147/*
148 * Setup the tick device
149 */
150static void tick_setup_device(struct tick_device *td,
151 struct clock_event_device *newdev, int cpu,
152 const struct cpumask *cpumask)
153{
154 ktime_t next_event;
155 void (*handler)(struct clock_event_device *) = NULL;
156
157 /*
158 * First device setup ?
159 */
160 if (!td->evtdev) {
161 /*
162 * If no cpu took the do_timer update, assign it to
163 * this cpu:
164 */
165 if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
166 tick_do_timer_cpu = cpu;
167 tick_next_period = ktime_get();
168 tick_period = ktime_set(0, NSEC_PER_SEC / HZ);
169 }
170
171 /*
172 * Startup in periodic mode first.
173 */
174 td->mode = TICKDEV_MODE_PERIODIC;
175 } else {
176 handler = td->evtdev->event_handler;
177 next_event = td->evtdev->next_event;
178 td->evtdev->event_handler = clockevents_handle_noop;
179 }
180
181 td->evtdev = newdev;
182
183 /*
184 * When the device is not per cpu, pin the interrupt to the
185 * current cpu:
186 */
187 if (!cpumask_equal(newdev->cpumask, cpumask))
188 irq_set_affinity(newdev->irq, cpumask);
189
190 /*
191 * When global broadcasting is active, check if the current
192 * device is registered as a placeholder for broadcast mode.
193 * This allows us to handle this x86 misfeature in a generic
194 * way.
195 */
196 if (tick_device_uses_broadcast(newdev, cpu))
197 return;
198
199 if (td->mode == TICKDEV_MODE_PERIODIC)
200 tick_setup_periodic(newdev, 0);
201 else
202 tick_setup_oneshot(newdev, handler, next_event);
203}
204
205/*
206 * Check, if the new registered device should be used.
207 */
208static int tick_check_new_device(struct clock_event_device *newdev)
209{
210 struct clock_event_device *curdev;
211 struct tick_device *td;
212 int cpu, ret = NOTIFY_OK;
213 unsigned long flags;
214
215 raw_spin_lock_irqsave(&tick_device_lock, flags);
216
217 cpu = smp_processor_id();
218 if (!cpumask_test_cpu(cpu, newdev->cpumask))
219 goto out_bc;
220
221 td = &per_cpu(tick_cpu_device, cpu);
222 curdev = td->evtdev;
223
224 /* cpu local device ? */
225 if (!cpumask_equal(newdev->cpumask, cpumask_of(cpu))) {
226
227 /*
228 * If the cpu affinity of the device interrupt can not
229 * be set, ignore it.
230 */
231 if (!irq_can_set_affinity(newdev->irq))
232 goto out_bc;
233
234 /*
235 * If we have a cpu local device already, do not replace it
236 * by a non cpu local device
237 */
238 if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
239 goto out_bc;
240 }
241
242 /*
243 * If we have an active device, then check the rating and the oneshot
244 * feature.
245 */
246 if (curdev) {
247 /*
248 * Prefer one shot capable devices !
249 */
250 if ((curdev->features & CLOCK_EVT_FEAT_ONESHOT) &&
251 !(newdev->features & CLOCK_EVT_FEAT_ONESHOT))
252 goto out_bc;
253 /*
254 * Check the rating
255 */
256 if (curdev->rating >= newdev->rating)
257 goto out_bc;
258 }
259
260 /*
261 * Replace the eventually existing device by the new
262 * device. If the current device is the broadcast device, do
263 * not give it back to the clockevents layer !
264 */
265 if (tick_is_broadcast_device(curdev)) {
266 clockevents_shutdown(curdev);
267 curdev = NULL;
268 }
269 clockevents_exchange_device(curdev, newdev);
270 tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
271 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
272 tick_oneshot_notify();
273
274 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
275 return NOTIFY_STOP;
276
277out_bc:
278 /*
279 * Can the new device be used as a broadcast device ?
280 */
281 if (tick_check_broadcast_device(newdev))
282 ret = NOTIFY_STOP;
283
284 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
285
286 return ret;
287}
288
289/*
290 * Transfer the do_timer job away from a dying cpu.
291 *
292 * Called with interrupts disabled.
293 */
294static void tick_handover_do_timer(int *cpup)
295{
296 if (*cpup == tick_do_timer_cpu) {
297 int cpu = cpumask_first(cpu_online_mask);
298
299 tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
300 TICK_DO_TIMER_NONE;
301 }
302}
303
304/*
305 * Shutdown an event device on a given cpu:
306 *
307 * This is called on a life CPU, when a CPU is dead. So we cannot
308 * access the hardware device itself.
309 * We just set the mode and remove it from the lists.
310 */
311static void tick_shutdown(unsigned int *cpup)
312{
313 struct tick_device *td = &per_cpu(tick_cpu_device, *cpup);
314 struct clock_event_device *dev = td->evtdev;
315 unsigned long flags;
316
317 raw_spin_lock_irqsave(&tick_device_lock, flags);
318 td->mode = TICKDEV_MODE_PERIODIC;
319 if (dev) {
320 /*
321 * Prevent that the clock events layer tries to call
322 * the set mode function!
323 */
324 dev->mode = CLOCK_EVT_MODE_UNUSED;
325 clockevents_exchange_device(dev, NULL);
326 td->evtdev = NULL;
327 }
328 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
329}
330
331static void tick_suspend(void)
332{
333 struct tick_device *td = &__get_cpu_var(tick_cpu_device);
334 unsigned long flags;
335
336 raw_spin_lock_irqsave(&tick_device_lock, flags);
337 clockevents_shutdown(td->evtdev);
338 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
339}
340
341static void tick_resume(void)
342{
343 struct tick_device *td = &__get_cpu_var(tick_cpu_device);
344 unsigned long flags;
345 int broadcast = tick_resume_broadcast();
346
347 raw_spin_lock_irqsave(&tick_device_lock, flags);
348 clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
349
350 if (!broadcast) {
351 if (td->mode == TICKDEV_MODE_PERIODIC)
352 tick_setup_periodic(td->evtdev, 0);
353 else
354 tick_resume_oneshot();
355 }
356 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
357}
358
359/*
360 * Notification about clock event devices
361 */
362static int tick_notify(struct notifier_block *nb, unsigned long reason,
363 void *dev)
364{
365 switch (reason) {
366
367 case CLOCK_EVT_NOTIFY_ADD:
368 return tick_check_new_device(dev);
369
370 case CLOCK_EVT_NOTIFY_BROADCAST_ON:
371 case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
372 case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
373 tick_broadcast_on_off(reason, dev);
374 break;
375
376 case CLOCK_EVT_NOTIFY_BROADCAST_ENTER:
377 case CLOCK_EVT_NOTIFY_BROADCAST_EXIT:
378 tick_broadcast_oneshot_control(reason);
379 break;
380
381 case CLOCK_EVT_NOTIFY_CPU_DYING:
382 tick_handover_do_timer(dev);
383 break;
384
385 case CLOCK_EVT_NOTIFY_CPU_DEAD:
386 tick_shutdown_broadcast_oneshot(dev);
387 tick_shutdown_broadcast(dev);
388 tick_shutdown(dev);
389 break;
390
391 case CLOCK_EVT_NOTIFY_SUSPEND:
392 tick_suspend();
393 tick_suspend_broadcast();
394 break;
395
396 case CLOCK_EVT_NOTIFY_RESUME:
397 tick_resume();
398 break;
399
400 default:
401 break;
402 }
403
404 return NOTIFY_OK;
405}
406
407static struct notifier_block tick_notifier = {
408 .notifier_call = tick_notify,
409};
410
411/**
412 * tick_init - initialize the tick control
413 *
414 * Register the notifier with the clockevents framework
415 */
416void __init tick_init(void)
417{
418 clockevents_register_notifier(&tick_notifier);
419}