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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/tick.h>
22
23#include "tick-internal.h"
24
25
26
27
28
29
30static struct tick_device tick_broadcast_device;
31
32static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS);
33static DECLARE_BITMAP(tmpmask, NR_CPUS);
34static DEFINE_SPINLOCK(tick_broadcast_lock);
35static int tick_broadcast_force;
36
37#ifdef CONFIG_TICK_ONESHOT
38static void tick_broadcast_clear_oneshot(int cpu);
39#else
40static inline void tick_broadcast_clear_oneshot(int cpu) { }
41#endif
42
43
44
45
46struct tick_device *tick_get_broadcast_device(void)
47{
48 return &tick_broadcast_device;
49}
50
51struct cpumask *tick_get_broadcast_mask(void)
52{
53 return to_cpumask(tick_broadcast_mask);
54}
55
56
57
58
59static void tick_broadcast_start_periodic(struct clock_event_device *bc)
60{
61 if (bc)
62 tick_setup_periodic(bc, 1);
63}
64
65
66
67
68int tick_check_broadcast_device(struct clock_event_device *dev)
69{
70 if ((tick_broadcast_device.evtdev &&
71 tick_broadcast_device.evtdev->rating >= dev->rating) ||
72 (dev->features & CLOCK_EVT_FEAT_C3STOP))
73 return 0;
74
75 clockevents_exchange_device(NULL, dev);
76 tick_broadcast_device.evtdev = dev;
77 if (!cpumask_empty(tick_get_broadcast_mask()))
78 tick_broadcast_start_periodic(dev);
79 return 1;
80}
81
82
83
84
85int tick_is_broadcast_device(struct clock_event_device *dev)
86{
87 return (dev && tick_broadcast_device.evtdev == dev);
88}
89
90
91
92
93
94int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
95{
96 unsigned long flags;
97 int ret = 0;
98
99 spin_lock_irqsave(&tick_broadcast_lock, flags);
100
101
102
103
104
105
106
107 if (!tick_device_is_functional(dev)) {
108 dev->event_handler = tick_handle_periodic;
109 cpumask_set_cpu(cpu, tick_get_broadcast_mask());
110 tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
111 ret = 1;
112 } else {
113
114
115
116
117
118 if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
119 int cpu = smp_processor_id();
120
121 cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
122 tick_broadcast_clear_oneshot(cpu);
123 }
124 }
125 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
126 return ret;
127}
128
129
130
131
132static void tick_do_broadcast(struct cpumask *mask)
133{
134 int cpu = smp_processor_id();
135 struct tick_device *td;
136
137
138
139
140 if (cpumask_test_cpu(cpu, mask)) {
141 cpumask_clear_cpu(cpu, mask);
142 td = &per_cpu(tick_cpu_device, cpu);
143 td->evtdev->event_handler(td->evtdev);
144 }
145
146 if (!cpumask_empty(mask)) {
147
148
149
150
151
152
153 td = &per_cpu(tick_cpu_device, cpumask_first(mask));
154 td->evtdev->broadcast(mask);
155 }
156}
157
158
159
160
161
162static void tick_do_periodic_broadcast(void)
163{
164 spin_lock(&tick_broadcast_lock);
165
166 cpumask_and(to_cpumask(tmpmask),
167 cpu_online_mask, tick_get_broadcast_mask());
168 tick_do_broadcast(to_cpumask(tmpmask));
169
170 spin_unlock(&tick_broadcast_lock);
171}
172
173
174
175
176static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
177{
178 ktime_t next;
179
180 tick_do_periodic_broadcast();
181
182
183
184
185 if (dev->mode == CLOCK_EVT_MODE_PERIODIC)
186 return;
187
188
189
190
191
192
193
194
195 for (next = dev->next_event; ;) {
196 next = ktime_add(next, tick_period);
197
198 if (!clockevents_program_event(dev, next, ktime_get()))
199 return;
200 tick_do_periodic_broadcast();
201 }
202}
203
204
205
206
207
208static void tick_do_broadcast_on_off(unsigned long *reason)
209{
210 struct clock_event_device *bc, *dev;
211 struct tick_device *td;
212 unsigned long flags;
213 int cpu, bc_stopped;
214
215 spin_lock_irqsave(&tick_broadcast_lock, flags);
216
217 cpu = smp_processor_id();
218 td = &per_cpu(tick_cpu_device, cpu);
219 dev = td->evtdev;
220 bc = tick_broadcast_device.evtdev;
221
222
223
224
225 if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP))
226 goto out;
227
228 if (!tick_device_is_functional(dev))
229 goto out;
230
231 bc_stopped = cpumask_empty(tick_get_broadcast_mask());
232
233 switch (*reason) {
234 case CLOCK_EVT_NOTIFY_BROADCAST_ON:
235 case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
236 if (!cpumask_test_cpu(cpu, tick_get_broadcast_mask())) {
237 cpumask_set_cpu(cpu, tick_get_broadcast_mask());
238 if (tick_broadcast_device.mode ==
239 TICKDEV_MODE_PERIODIC)
240 clockevents_shutdown(dev);
241 }
242 if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
243 tick_broadcast_force = 1;
244 break;
245 case CLOCK_EVT_NOTIFY_BROADCAST_OFF:
246 if (!tick_broadcast_force &&
247 cpumask_test_cpu(cpu, tick_get_broadcast_mask())) {
248 cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
249 if (tick_broadcast_device.mode ==
250 TICKDEV_MODE_PERIODIC)
251 tick_setup_periodic(dev, 0);
252 }
253 break;
254 }
255
256 if (cpumask_empty(tick_get_broadcast_mask())) {
257 if (!bc_stopped)
258 clockevents_shutdown(bc);
259 } else if (bc_stopped) {
260 if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
261 tick_broadcast_start_periodic(bc);
262 else
263 tick_broadcast_setup_oneshot(bc);
264 }
265out:
266 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
267}
268
269
270
271
272
273void tick_broadcast_on_off(unsigned long reason, int *oncpu)
274{
275 if (!cpumask_test_cpu(*oncpu, cpu_online_mask))
276 printk(KERN_ERR "tick-broadcast: ignoring broadcast for "
277 "offline CPU #%d\n", *oncpu);
278 else
279 tick_do_broadcast_on_off(&reason);
280}
281
282
283
284
285void tick_set_periodic_handler(struct clock_event_device *dev, int broadcast)
286{
287 if (!broadcast)
288 dev->event_handler = tick_handle_periodic;
289 else
290 dev->event_handler = tick_handle_periodic_broadcast;
291}
292
293
294
295
296void tick_shutdown_broadcast(unsigned int *cpup)
297{
298 struct clock_event_device *bc;
299 unsigned long flags;
300 unsigned int cpu = *cpup;
301
302 spin_lock_irqsave(&tick_broadcast_lock, flags);
303
304 bc = tick_broadcast_device.evtdev;
305 cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
306
307 if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
308 if (bc && cpumask_empty(tick_get_broadcast_mask()))
309 clockevents_shutdown(bc);
310 }
311
312 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
313}
314
315void tick_suspend_broadcast(void)
316{
317 struct clock_event_device *bc;
318 unsigned long flags;
319
320 spin_lock_irqsave(&tick_broadcast_lock, flags);
321
322 bc = tick_broadcast_device.evtdev;
323 if (bc)
324 clockevents_shutdown(bc);
325
326 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
327}
328
329int tick_resume_broadcast(void)
330{
331 struct clock_event_device *bc;
332 unsigned long flags;
333 int broadcast = 0;
334
335 spin_lock_irqsave(&tick_broadcast_lock, flags);
336
337 bc = tick_broadcast_device.evtdev;
338
339 if (bc) {
340 clockevents_set_mode(bc, CLOCK_EVT_MODE_RESUME);
341
342 switch (tick_broadcast_device.mode) {
343 case TICKDEV_MODE_PERIODIC:
344 if (!cpumask_empty(tick_get_broadcast_mask()))
345 tick_broadcast_start_periodic(bc);
346 broadcast = cpumask_test_cpu(smp_processor_id(),
347 tick_get_broadcast_mask());
348 break;
349 case TICKDEV_MODE_ONESHOT:
350 broadcast = tick_resume_broadcast_oneshot(bc);
351 break;
352 }
353 }
354 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
355
356 return broadcast;
357}
358
359
360#ifdef CONFIG_TICK_ONESHOT
361
362
363static DECLARE_BITMAP(tick_broadcast_oneshot_mask, NR_CPUS);
364
365
366
367
368struct cpumask *tick_get_broadcast_oneshot_mask(void)
369{
370 return to_cpumask(tick_broadcast_oneshot_mask);
371}
372
373static int tick_broadcast_set_event(ktime_t expires, int force)
374{
375 struct clock_event_device *bc = tick_broadcast_device.evtdev;
376
377 return tick_dev_program_event(bc, expires, force);
378}
379
380int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
381{
382 clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
383 return 0;
384}
385
386
387
388
389
390void tick_check_oneshot_broadcast(int cpu)
391{
392 if (cpumask_test_cpu(cpu, to_cpumask(tick_broadcast_oneshot_mask))) {
393 struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
394
395 clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
396 }
397}
398
399
400
401
402static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
403{
404 struct tick_device *td;
405 ktime_t now, next_event;
406 int cpu;
407
408 spin_lock(&tick_broadcast_lock);
409again:
410 dev->next_event.tv64 = KTIME_MAX;
411 next_event.tv64 = KTIME_MAX;
412 cpumask_clear(to_cpumask(tmpmask));
413 now = ktime_get();
414
415 for_each_cpu(cpu, tick_get_broadcast_oneshot_mask()) {
416 td = &per_cpu(tick_cpu_device, cpu);
417 if (td->evtdev->next_event.tv64 <= now.tv64)
418 cpumask_set_cpu(cpu, to_cpumask(tmpmask));
419 else if (td->evtdev->next_event.tv64 < next_event.tv64)
420 next_event.tv64 = td->evtdev->next_event.tv64;
421 }
422
423
424
425
426 tick_do_broadcast(to_cpumask(tmpmask));
427
428
429
430
431
432
433
434
435
436
437
438 if (next_event.tv64 != KTIME_MAX) {
439
440
441
442
443 if (tick_broadcast_set_event(next_event, 0))
444 goto again;
445 }
446 spin_unlock(&tick_broadcast_lock);
447}
448
449
450
451
452
453void tick_broadcast_oneshot_control(unsigned long reason)
454{
455 struct clock_event_device *bc, *dev;
456 struct tick_device *td;
457 unsigned long flags;
458 int cpu;
459
460 spin_lock_irqsave(&tick_broadcast_lock, flags);
461
462
463
464
465
466 if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
467 goto out;
468
469 bc = tick_broadcast_device.evtdev;
470 cpu = smp_processor_id();
471 td = &per_cpu(tick_cpu_device, cpu);
472 dev = td->evtdev;
473
474 if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
475 goto out;
476
477 if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
478 if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
479 cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask());
480 clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
481 if (dev->next_event.tv64 < bc->next_event.tv64)
482 tick_broadcast_set_event(dev->next_event, 1);
483 }
484 } else {
485 if (cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
486 cpumask_clear_cpu(cpu,
487 tick_get_broadcast_oneshot_mask());
488 clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
489 if (dev->next_event.tv64 != KTIME_MAX)
490 tick_program_event(dev->next_event, 1);
491 }
492 }
493
494out:
495 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
496}
497
498
499
500
501
502
503static void tick_broadcast_clear_oneshot(int cpu)
504{
505 cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());
506}
507
508static void tick_broadcast_init_next_event(struct cpumask *mask,
509 ktime_t expires)
510{
511 struct tick_device *td;
512 int cpu;
513
514 for_each_cpu(cpu, mask) {
515 td = &per_cpu(tick_cpu_device, cpu);
516 if (td->evtdev)
517 td->evtdev->next_event = expires;
518 }
519}
520
521
522
523
524void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
525{
526
527 if (bc->event_handler != tick_handle_oneshot_broadcast) {
528 int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC;
529 int cpu = smp_processor_id();
530
531 bc->event_handler = tick_handle_oneshot_broadcast;
532 clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
533
534
535 tick_do_timer_cpu = cpu;
536
537
538
539
540
541
542
543 cpumask_copy(to_cpumask(tmpmask), tick_get_broadcast_mask());
544 cpumask_clear_cpu(cpu, to_cpumask(tmpmask));
545 cpumask_or(tick_get_broadcast_oneshot_mask(),
546 tick_get_broadcast_oneshot_mask(),
547 to_cpumask(tmpmask));
548
549 if (was_periodic && !cpumask_empty(to_cpumask(tmpmask))) {
550 tick_broadcast_init_next_event(to_cpumask(tmpmask),
551 tick_next_period);
552 tick_broadcast_set_event(tick_next_period, 1);
553 } else
554 bc->next_event.tv64 = KTIME_MAX;
555 }
556}
557
558
559
560
561void tick_broadcast_switch_to_oneshot(void)
562{
563 struct clock_event_device *bc;
564 unsigned long flags;
565
566 spin_lock_irqsave(&tick_broadcast_lock, flags);
567
568 tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
569 bc = tick_broadcast_device.evtdev;
570 if (bc)
571 tick_broadcast_setup_oneshot(bc);
572 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
573}
574
575
576
577
578
579void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
580{
581 unsigned long flags;
582 unsigned int cpu = *cpup;
583
584 spin_lock_irqsave(&tick_broadcast_lock, flags);
585
586
587
588
589
590 cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());
591
592 spin_unlock_irqrestore(&tick_broadcast_lock, flags);
593}
594
595
596
597
598int tick_broadcast_oneshot_active(void)
599{
600 return tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT;
601}
602
603#endif
604