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Thomas Gleixner35728b82018-10-31 19:21:09 +01001// SPDX-License-Identifier: GPL-2.0
Thomas Gleixner906568c2007-02-16 01:28:01 -08002/*
Thomas Gleixner906568c2007-02-16 01:28:01 -08003 * This file contains the base functions to manage periodic tick
4 * related events.
5 *
6 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
8 * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
Thomas Gleixner906568c2007-02-16 01:28:01 -08009 */
10#include <linux/cpu.h>
11#include <linux/err.h>
12#include <linux/hrtimer.h>
Russell Kingd7b90682008-04-17 07:46:24 +020013#include <linux/interrupt.h>
Chunyan Zhang5167c502020-01-10 16:39:02 +080014#include <linux/nmi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080015#include <linux/percpu.h>
16#include <linux/profile.h>
17#include <linux/sched.h>
Thomas Gleixnerccf33d62013-04-25 20:31:49 +000018#include <linux/module.h>
Rafael J. Wysocki75e06782015-05-10 01:23:35 +020019#include <trace/events/power.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080020
Russell Kingd7b90682008-04-17 07:46:24 +020021#include <asm/irq_regs.h>
22
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -080023#include "tick-internal.h"
24
Thomas Gleixner906568c2007-02-16 01:28:01 -080025/*
26 * Tick devices
27 */
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -080028DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
Thomas Gleixner906568c2007-02-16 01:28:01 -080029/*
Thomas Gleixnerc3989602020-11-17 14:19:44 +010030 * Tick next event: keeps track of the tick time. It's updated by the
31 * CPU which handles the tick and protected by jiffies_lock. There is
32 * no requirement to write hold the jiffies seqcount for it.
Thomas Gleixner906568c2007-02-16 01:28:01 -080033 */
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -080034ktime_t tick_next_period;
Andrew Morton050ded12013-11-15 14:15:33 -080035
36/*
37 * tick_do_timer_cpu is a timer core internal variable which holds the CPU NR
38 * which is responsible for calling do_timer(), i.e. the timekeeping stuff. This
39 * variable has two functions:
40 *
41 * 1) Prevent a thundering herd issue of a gazillion of CPUs trying to grab the
42 * timekeeping lock all at once. Only the CPU which is assigned to do the
43 * update is handling it.
44 *
45 * 2) Hand off the duty in the NOHZ idle case by setting the value to
46 * TICK_DO_TIMER_NONE, i.e. a non existing CPU. So the next cpu which looks
47 * at it will take over and keep the time keeping alive. The handover
48 * procedure also covers cpu hotplug.
49 */
Thomas Gleixner64414022008-09-22 18:46:37 +020050int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
Nicholas Piggin08ae95f2019-04-11 13:34:48 +100051#ifdef CONFIG_NO_HZ_FULL
52/*
53 * tick_do_timer_boot_cpu indicates the boot CPU temporarily owns
54 * tick_do_timer_cpu and it should be taken over by an eligible secondary
55 * when one comes online.
56 */
57static int tick_do_timer_boot_cpu __read_mostly = -1;
58#endif
Thomas Gleixner906568c2007-02-16 01:28:01 -080059
Ingo Molnar289f4802007-02-16 01:28:15 -080060/*
61 * Debugging: see timer_list.c
62 */
63struct tick_device *tick_get_device(int cpu)
64{
65 return &per_cpu(tick_cpu_device, cpu);
66}
67
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080068/**
69 * tick_is_oneshot_available - check for a oneshot capable event device
70 */
71int tick_is_oneshot_available(void)
72{
Christoph Lameter909ea962010-12-08 16:22:55 +010073 struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080074
Thomas Gleixner3a142a02011-02-25 22:34:23 +010075 if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT))
76 return 0;
77 if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
78 return 1;
79 return tick_broadcast_oneshot_available();
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080080}
81
Thomas Gleixner906568c2007-02-16 01:28:01 -080082/*
83 * Periodic tick
84 */
85static void tick_periodic(int cpu)
86{
87 if (tick_do_timer_cpu == cpu) {
Thomas Gleixnere5d4d172020-03-21 12:25:58 +010088 raw_spin_lock(&jiffies_lock);
89 write_seqcount_begin(&jiffies_seq);
Thomas Gleixner906568c2007-02-16 01:28:01 -080090
91 /* Keep track of the next tick event */
Thomas Gleixnerb9965442020-11-17 14:19:49 +010092 tick_next_period = ktime_add_ns(tick_next_period, TICK_NSEC);
Thomas Gleixner906568c2007-02-16 01:28:01 -080093
94 do_timer(1);
Thomas Gleixnere5d4d172020-03-21 12:25:58 +010095 write_seqcount_end(&jiffies_seq);
96 raw_spin_unlock(&jiffies_lock);
John Stultz47a1b7962013-12-12 13:10:55 -080097 update_wall_time();
Thomas Gleixner906568c2007-02-16 01:28:01 -080098 }
99
100 update_process_times(user_mode(get_irq_regs()));
101 profile_tick(CPU_PROFILING);
102}
103
104/*
105 * Event handler for periodic ticks
106 */
107void tick_handle_periodic(struct clock_event_device *dev)
108{
109 int cpu = smp_processor_id();
Viresh Kumarb97f0292014-03-25 13:56:23 +0530110 ktime_t next = dev->next_event;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800111
112 tick_periodic(cpu);
113
Thomas Gleixnerc6eb3f72015-04-14 21:08:51 +0000114#if defined(CONFIG_HIGH_RES_TIMERS) || defined(CONFIG_NO_HZ_COMMON)
115 /*
116 * The cpu might have transitioned to HIGHRES or NOHZ mode via
117 * update_process_times() -> run_local_timers() ->
118 * hrtimer_run_queues().
119 */
120 if (dev->event_handler != tick_handle_periodic)
121 return;
122#endif
123
Viresh Kumar472c4a92015-05-21 13:33:46 +0530124 if (!clockevent_state_oneshot(dev))
Thomas Gleixner906568c2007-02-16 01:28:01 -0800125 return;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800126 for (;;) {
Viresh Kumarb97f0292014-03-25 13:56:23 +0530127 /*
128 * Setup the next period for devices, which do not have
129 * periodic mode:
130 */
Thomas Gleixnerb9965442020-11-17 14:19:49 +0100131 next = ktime_add_ns(next, TICK_NSEC);
Viresh Kumarb97f0292014-03-25 13:56:23 +0530132
Martin Schwidefskyd1748302011-08-23 15:29:42 +0200133 if (!clockevents_program_event(dev, next, false))
Thomas Gleixner906568c2007-02-16 01:28:01 -0800134 return;
john stultz74a03b62009-05-01 13:10:25 -0700135 /*
136 * Have to be careful here. If we're in oneshot mode,
137 * before we call tick_periodic() in a loop, we need
138 * to be sure we're using a real hardware clocksource.
139 * Otherwise we could get trapped in an infinite
140 * loop, as the tick_periodic() increments jiffies,
Viresh Kumarcacb3c72014-03-25 16:09:18 +0530141 * which then will increment time, possibly causing
john stultz74a03b62009-05-01 13:10:25 -0700142 * the loop to trigger again and again.
143 */
144 if (timekeeping_valid_for_hres())
145 tick_periodic(cpu);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800146 }
147}
148
149/*
150 * Setup the device for a periodic tick
151 */
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800152void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
Thomas Gleixner906568c2007-02-16 01:28:01 -0800153{
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800154 tick_set_periodic_handler(dev, broadcast);
155
156 /* Broadcast setup ? */
157 if (!tick_device_is_functional(dev))
158 return;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800159
Thomas Gleixner27ce4cb4a2008-09-22 19:04:02 +0200160 if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
161 !tick_broadcast_oneshot_active()) {
Thomas Gleixnerd7eb2312015-06-02 14:08:46 +0200162 clockevents_switch_state(dev, CLOCK_EVT_STATE_PERIODIC);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800163 } else {
Rasmus Villemoese1e41b62019-03-18 20:55:56 +0100164 unsigned int seq;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800165 ktime_t next;
166
167 do {
Thomas Gleixnere5d4d172020-03-21 12:25:58 +0100168 seq = read_seqcount_begin(&jiffies_seq);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800169 next = tick_next_period;
Thomas Gleixnere5d4d172020-03-21 12:25:58 +0100170 } while (read_seqcount_retry(&jiffies_seq, seq));
Thomas Gleixner906568c2007-02-16 01:28:01 -0800171
Thomas Gleixnerd7eb2312015-06-02 14:08:46 +0200172 clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800173
174 for (;;) {
Martin Schwidefskyd1748302011-08-23 15:29:42 +0200175 if (!clockevents_program_event(dev, next, false))
Thomas Gleixner906568c2007-02-16 01:28:01 -0800176 return;
Thomas Gleixnerb9965442020-11-17 14:19:49 +0100177 next = ktime_add_ns(next, TICK_NSEC);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800178 }
179 }
180}
181
Nicholas Piggin08ae95f2019-04-11 13:34:48 +1000182#ifdef CONFIG_NO_HZ_FULL
183static void giveup_do_timer(void *info)
184{
185 int cpu = *(unsigned int *)info;
186
187 WARN_ON(tick_do_timer_cpu != smp_processor_id());
188
189 tick_do_timer_cpu = cpu;
190}
191
192static void tick_take_do_timer_from_boot(void)
193{
194 int cpu = smp_processor_id();
195 int from = tick_do_timer_boot_cpu;
196
197 if (from >= 0 && from != cpu)
198 smp_call_function_single(from, giveup_do_timer, &cpu, 1);
199}
200#endif
201
Thomas Gleixner906568c2007-02-16 01:28:01 -0800202/*
203 * Setup the tick device
204 */
205static void tick_setup_device(struct tick_device *td,
206 struct clock_event_device *newdev, int cpu,
Rusty Russell0de26522008-12-13 21:20:26 +1030207 const struct cpumask *cpumask)
Thomas Gleixner906568c2007-02-16 01:28:01 -0800208{
Thomas Gleixner906568c2007-02-16 01:28:01 -0800209 void (*handler)(struct clock_event_device *) = NULL;
Thomas Gleixner8b0e1952016-12-25 12:30:41 +0100210 ktime_t next_event = 0;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800211
212 /*
213 * First device setup ?
214 */
215 if (!td->evtdev) {
216 /*
217 * If no cpu took the do_timer update, assign it to
218 * this cpu:
219 */
Thomas Gleixner64414022008-09-22 18:46:37 +0200220 if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
Nicholas Piggin08ae95f2019-04-11 13:34:48 +1000221 tick_do_timer_cpu = cpu;
222
Thomas Gleixner906568c2007-02-16 01:28:01 -0800223 tick_next_period = ktime_get();
Nicholas Piggin08ae95f2019-04-11 13:34:48 +1000224#ifdef CONFIG_NO_HZ_FULL
225 /*
226 * The boot CPU may be nohz_full, in which case set
227 * tick_do_timer_boot_cpu so the first housekeeping
228 * secondary that comes up will take do_timer from
229 * us.
230 */
231 if (tick_nohz_full_cpu(cpu))
232 tick_do_timer_boot_cpu = cpu;
233
234 } else if (tick_do_timer_boot_cpu != -1 &&
235 !tick_nohz_full_cpu(cpu)) {
236 tick_take_do_timer_from_boot();
237 tick_do_timer_boot_cpu = -1;
238 WARN_ON(tick_do_timer_cpu != cpu);
239#endif
Thomas Gleixner906568c2007-02-16 01:28:01 -0800240 }
241
242 /*
243 * Startup in periodic mode first.
244 */
245 td->mode = TICKDEV_MODE_PERIODIC;
246 } else {
247 handler = td->evtdev->event_handler;
248 next_event = td->evtdev->next_event;
Venkatesh Pallipadi7c1e7682008-09-03 21:36:50 +0000249 td->evtdev->event_handler = clockevents_handle_noop;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800250 }
251
252 td->evtdev = newdev;
253
254 /*
255 * When the device is not per cpu, pin the interrupt to the
256 * current cpu:
257 */
Rusty Russell320ab2b2008-12-13 21:20:26 +1030258 if (!cpumask_equal(newdev->cpumask, cpumask))
Rusty Russell0de26522008-12-13 21:20:26 +1030259 irq_set_affinity(newdev->irq, cpumask);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800260
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800261 /*
262 * When global broadcasting is active, check if the current
263 * device is registered as a placeholder for broadcast mode.
264 * This allows us to handle this x86 misfeature in a generic
Thomas Gleixner07bd1172013-07-01 22:14:10 +0200265 * way. This function also returns !=0 when we keep the
266 * current active broadcast state for this CPU.
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800267 */
268 if (tick_device_uses_broadcast(newdev, cpu))
269 return;
270
Thomas Gleixner906568c2007-02-16 01:28:01 -0800271 if (td->mode == TICKDEV_MODE_PERIODIC)
272 tick_setup_periodic(newdev, 0);
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800273 else
274 tick_setup_oneshot(newdev, handler, next_event);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800275}
276
Thomas Gleixner03e13cf2013-04-25 20:31:50 +0000277void tick_install_replacement(struct clock_event_device *newdev)
278{
Christoph Lameter22127e92014-08-17 12:30:25 -0500279 struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
Thomas Gleixner03e13cf2013-04-25 20:31:50 +0000280 int cpu = smp_processor_id();
281
282 clockevents_exchange_device(td->evtdev, newdev);
283 tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
284 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
285 tick_oneshot_notify();
286}
287
Thomas Gleixner45cb8e02013-04-25 20:31:50 +0000288static bool tick_check_percpu(struct clock_event_device *curdev,
289 struct clock_event_device *newdev, int cpu)
290{
291 if (!cpumask_test_cpu(cpu, newdev->cpumask))
292 return false;
293 if (cpumask_equal(newdev->cpumask, cpumask_of(cpu)))
294 return true;
295 /* Check if irq affinity can be set */
296 if (newdev->irq >= 0 && !irq_can_set_affinity(newdev->irq))
297 return false;
298 /* Prefer an existing cpu local device */
299 if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
300 return false;
301 return true;
302}
303
304static bool tick_check_preferred(struct clock_event_device *curdev,
305 struct clock_event_device *newdev)
306{
307 /* Prefer oneshot capable device */
308 if (!(newdev->features & CLOCK_EVT_FEAT_ONESHOT)) {
309 if (curdev && (curdev->features & CLOCK_EVT_FEAT_ONESHOT))
310 return false;
311 if (tick_oneshot_mode_active())
312 return false;
313 }
314
Stephen Boyd70e59752013-06-13 11:39:50 -0700315 /*
316 * Use the higher rated one, but prefer a CPU local device with a lower
317 * rating than a non-CPU local device
318 */
319 return !curdev ||
320 newdev->rating > curdev->rating ||
Sudeep Holla5b5ccbc2018-07-09 16:45:35 +0100321 !cpumask_equal(curdev->cpumask, newdev->cpumask);
Thomas Gleixner45cb8e02013-04-25 20:31:50 +0000322}
323
Thomas Gleixner906568c2007-02-16 01:28:01 -0800324/*
Thomas Gleixner03e13cf2013-04-25 20:31:50 +0000325 * Check whether the new device is a better fit than curdev. curdev
326 * can be NULL !
327 */
328bool tick_check_replacement(struct clock_event_device *curdev,
329 struct clock_event_device *newdev)
330{
Viresh Kumar521c4292014-04-15 10:54:37 +0530331 if (!tick_check_percpu(curdev, newdev, smp_processor_id()))
Thomas Gleixner03e13cf2013-04-25 20:31:50 +0000332 return false;
333
334 return tick_check_preferred(curdev, newdev);
335}
336
337/*
Thomas Gleixner7126cac2013-04-25 20:31:48 +0000338 * Check, if the new registered device should be used. Called with
339 * clockevents_lock held and interrupts disabled.
Thomas Gleixner906568c2007-02-16 01:28:01 -0800340 */
Thomas Gleixner7172a2862013-04-25 20:31:47 +0000341void tick_check_new_device(struct clock_event_device *newdev)
Thomas Gleixner906568c2007-02-16 01:28:01 -0800342{
343 struct clock_event_device *curdev;
344 struct tick_device *td;
Thomas Gleixner7172a2862013-04-25 20:31:47 +0000345 int cpu;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800346
347 cpu = smp_processor_id();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800348 td = &per_cpu(tick_cpu_device, cpu);
349 curdev = td->evtdev;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800350
Wang Wenshengd7840aa2021-03-26 02:23:28 +0000351 if (!tick_check_replacement(curdev, newdev))
Thomas Gleixner45cb8e02013-04-25 20:31:50 +0000352 goto out_bc;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800353
Thomas Gleixnerccf33d62013-04-25 20:31:49 +0000354 if (!try_module_get(newdev->owner))
355 return;
356
Thomas Gleixner906568c2007-02-16 01:28:01 -0800357 /*
358 * Replace the eventually existing device by the new
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800359 * device. If the current device is the broadcast device, do
360 * not give it back to the clockevents layer !
Thomas Gleixner906568c2007-02-16 01:28:01 -0800361 */
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800362 if (tick_is_broadcast_device(curdev)) {
Thomas Gleixner2344abb2008-09-16 11:32:50 -0700363 clockevents_shutdown(curdev);
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800364 curdev = NULL;
365 }
Thomas Gleixner906568c2007-02-16 01:28:01 -0800366 clockevents_exchange_device(curdev, newdev);
Rusty Russell6b954822009-01-01 10:12:25 +1030367 tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800368 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
369 tick_oneshot_notify();
Thomas Gleixner7172a2862013-04-25 20:31:47 +0000370 return;
Thomas Gleixnerf8381cb2007-02-16 01:28:02 -0800371
372out_bc:
373 /*
374 * Can the new device be used as a broadcast device ?
375 */
Will Deaconc94a8532021-05-24 23:18:16 +0100376 tick_install_broadcast_device(newdev, cpu);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800377}
378
Thomas Gleixnerf32dd112015-07-07 16:29:38 +0200379/**
380 * tick_broadcast_oneshot_control - Enter/exit broadcast oneshot mode
381 * @state: The target state (enter/exit)
382 *
383 * The system enters/leaves a state, where affected devices might stop
384 * Returns 0 on success, -EBUSY if the cpu is used to broadcast wakeups.
385 *
386 * Called with interrupts disabled, so clockevents_lock is not
387 * required here because the local clock event device cannot go away
388 * under us.
389 */
390int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
391{
392 struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
393
394 if (!(td->evtdev->features & CLOCK_EVT_FEAT_C3STOP))
395 return 0;
396
397 return __tick_broadcast_oneshot_control(state);
398}
Thomas Gleixner0f447052015-07-14 12:01:04 +0200399EXPORT_SYMBOL_GPL(tick_broadcast_oneshot_control);
Thomas Gleixnerf32dd112015-07-07 16:29:38 +0200400
Thomas Gleixner52c063d2015-04-03 02:37:24 +0200401#ifdef CONFIG_HOTPLUG_CPU
Thomas Gleixner906568c2007-02-16 01:28:01 -0800402/*
Sebastien Dugue94df7de2008-12-01 14:09:07 +0100403 * Transfer the do_timer job away from a dying cpu.
404 *
Thomas Gleixnerf12ad422020-12-06 22:12:54 +0100405 * Called with interrupts disabled. No locking required. If
Thomas Gleixner52c063d2015-04-03 02:37:24 +0200406 * tick_do_timer_cpu is owned by this cpu, nothing can change it.
Sebastien Dugue94df7de2008-12-01 14:09:07 +0100407 */
Thomas Gleixner52c063d2015-04-03 02:37:24 +0200408void tick_handover_do_timer(void)
Sebastien Dugue94df7de2008-12-01 14:09:07 +0100409{
Thomas Gleixnerf12ad422020-12-06 22:12:54 +0100410 if (tick_do_timer_cpu == smp_processor_id())
411 tick_do_timer_cpu = cpumask_first(cpu_online_mask);
Sebastien Dugue94df7de2008-12-01 14:09:07 +0100412}
413
414/*
Thomas Gleixner906568c2007-02-16 01:28:01 -0800415 * Shutdown an event device on a given cpu:
416 *
417 * This is called on a life CPU, when a CPU is dead. So we cannot
418 * access the hardware device itself.
419 * We just set the mode and remove it from the lists.
420 */
Thomas Gleixnera49b1162015-04-03 02:38:05 +0200421void tick_shutdown(unsigned int cpu)
Thomas Gleixner906568c2007-02-16 01:28:01 -0800422{
Thomas Gleixnera49b1162015-04-03 02:38:05 +0200423 struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800424 struct clock_event_device *dev = td->evtdev;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800425
Thomas Gleixner906568c2007-02-16 01:28:01 -0800426 td->mode = TICKDEV_MODE_PERIODIC;
427 if (dev) {
428 /*
429 * Prevent that the clock events layer tries to call
430 * the set mode function!
431 */
Thomas Gleixner051ebd12015-06-02 14:13:46 +0200432 clockevent_set_state(dev, CLOCK_EVT_STATE_DETACHED);
Thomas Gleixner906568c2007-02-16 01:28:01 -0800433 clockevents_exchange_device(dev, NULL);
Thomas Gleixner6f7a05d72013-04-25 11:45:53 +0200434 dev->event_handler = clockevents_handle_noop;
Thomas Gleixner906568c2007-02-16 01:28:01 -0800435 td->evtdev = NULL;
436 }
Thomas Gleixner906568c2007-02-16 01:28:01 -0800437}
Thomas Gleixnera49b1162015-04-03 02:38:05 +0200438#endif
Thomas Gleixner906568c2007-02-16 01:28:01 -0800439
Thomas Gleixner4ffee522015-03-25 13:09:16 +0100440/**
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100441 * tick_suspend_local - Suspend the local tick device
442 *
443 * Called from the local cpu for freeze with interrupts disabled.
444 *
445 * No locks required. Nothing can change the per cpu device.
446 */
Thomas Gleixner7270d112015-03-25 13:11:52 +0100447void tick_suspend_local(void)
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100448{
449 struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
450
451 clockevents_shutdown(td->evtdev);
452}
453
454/**
455 * tick_resume_local - Resume the local tick device
456 *
457 * Called from the local CPU for unfreeze or XEN resume magic.
458 *
459 * No locks required. Nothing can change the per cpu device.
460 */
461void tick_resume_local(void)
462{
463 struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
464 bool broadcast = tick_resume_check_broadcast();
465
466 clockevents_tick_resume(td->evtdev);
467 if (!broadcast) {
468 if (td->mode == TICKDEV_MODE_PERIODIC)
469 tick_setup_periodic(td->evtdev, 0);
470 else
471 tick_resume_oneshot();
472 }
Thomas Gleixnera761a672021-07-13 15:39:51 +0200473
474 /*
475 * Ensure that hrtimers are up to date and the clockevents device
476 * is reprogrammed correctly when high resolution timers are
477 * enabled.
478 */
479 hrtimers_resume_local();
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100480}
481
482/**
Thomas Gleixner4ffee522015-03-25 13:09:16 +0100483 * tick_suspend - Suspend the tick and the broadcast device
484 *
485 * Called from syscore_suspend() via timekeeping_suspend with only one
486 * CPU online and interrupts disabled or from tick_unfreeze() under
487 * tick_freeze_lock.
488 *
489 * No locks required. Nothing can change the per cpu device.
490 */
Thomas Gleixner8c53daf2013-04-25 20:31:48 +0000491void tick_suspend(void)
Thomas Gleixner6321dd62007-03-06 08:25:42 +0100492{
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100493 tick_suspend_local();
Thomas Gleixner4ffee522015-03-25 13:09:16 +0100494 tick_suspend_broadcast();
Thomas Gleixner6321dd62007-03-06 08:25:42 +0100495}
496
Thomas Gleixner4ffee522015-03-25 13:09:16 +0100497/**
498 * tick_resume - Resume the tick and the broadcast device
499 *
500 * Called from syscore_resume() via timekeeping_resume with only one
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100501 * CPU online and interrupts disabled.
Thomas Gleixner4ffee522015-03-25 13:09:16 +0100502 *
503 * No locks required. Nothing can change the per cpu device.
504 */
Thomas Gleixner8c53daf2013-04-25 20:31:48 +0000505void tick_resume(void)
Thomas Gleixner6321dd62007-03-06 08:25:42 +0100506{
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100507 tick_resume_broadcast();
508 tick_resume_local();
Thomas Gleixner6321dd62007-03-06 08:25:42 +0100509}
510
Rafael J. Wysocki87e9b9f2015-05-16 01:38:15 +0200511#ifdef CONFIG_SUSPEND
Rafael J. Wysocki124cf9112015-02-13 23:50:43 +0100512static DEFINE_RAW_SPINLOCK(tick_freeze_lock);
513static unsigned int tick_freeze_depth;
514
515/**
516 * tick_freeze - Suspend the local tick and (possibly) timekeeping.
517 *
518 * Check if this is the last online CPU executing the function and if so,
519 * suspend timekeeping. Otherwise suspend the local tick.
520 *
521 * Call with interrupts disabled. Must be balanced with %tick_unfreeze().
522 * Interrupts must not be enabled before the subsequent %tick_unfreeze().
523 */
524void tick_freeze(void)
525{
526 raw_spin_lock(&tick_freeze_lock);
527
528 tick_freeze_depth++;
Rafael J. Wysocki75e06782015-05-10 01:23:35 +0200529 if (tick_freeze_depth == num_online_cpus()) {
530 trace_suspend_resume(TPS("timekeeping_freeze"),
531 smp_processor_id(), true);
Thomas Gleixnerc1a957d2018-05-25 17:54:41 +0200532 system_state = SYSTEM_SUSPEND;
Chang-An Chen3f2552f2019-03-29 10:59:09 +0800533 sched_clock_suspend();
Rafael J. Wysocki124cf9112015-02-13 23:50:43 +0100534 timekeeping_suspend();
Rafael J. Wysocki75e06782015-05-10 01:23:35 +0200535 } else {
Thomas Gleixnerf46481d2015-03-25 13:11:04 +0100536 tick_suspend_local();
Rafael J. Wysocki75e06782015-05-10 01:23:35 +0200537 }
Rafael J. Wysocki124cf9112015-02-13 23:50:43 +0100538
539 raw_spin_unlock(&tick_freeze_lock);
540}
541
542/**
543 * tick_unfreeze - Resume the local tick and (possibly) timekeeping.
544 *
545 * Check if this is the first CPU executing the function and if so, resume
546 * timekeeping. Otherwise resume the local tick.
547 *
548 * Call with interrupts disabled. Must be balanced with %tick_freeze().
549 * Interrupts must not be enabled after the preceding %tick_freeze().
550 */
551void tick_unfreeze(void)
552{
553 raw_spin_lock(&tick_freeze_lock);
554
Rafael J. Wysocki75e06782015-05-10 01:23:35 +0200555 if (tick_freeze_depth == num_online_cpus()) {
Rafael J. Wysocki124cf9112015-02-13 23:50:43 +0100556 timekeeping_resume();
Chang-An Chen3f2552f2019-03-29 10:59:09 +0800557 sched_clock_resume();
Thomas Gleixnerc1a957d2018-05-25 17:54:41 +0200558 system_state = SYSTEM_RUNNING;
Rafael J. Wysocki75e06782015-05-10 01:23:35 +0200559 trace_suspend_resume(TPS("timekeeping_freeze"),
560 smp_processor_id(), false);
561 } else {
Chunyan Zhang5167c502020-01-10 16:39:02 +0800562 touch_softlockup_watchdog();
Rafael J. Wysocki422fe752015-04-03 15:21:51 +0200563 tick_resume_local();
Rafael J. Wysocki75e06782015-05-10 01:23:35 +0200564 }
Rafael J. Wysocki124cf9112015-02-13 23:50:43 +0100565
566 tick_freeze_depth--;
567
568 raw_spin_unlock(&tick_freeze_lock);
569}
Rafael J. Wysocki87e9b9f2015-05-16 01:38:15 +0200570#endif /* CONFIG_SUSPEND */
Rafael J. Wysocki124cf9112015-02-13 23:50:43 +0100571
Thomas Gleixner906568c2007-02-16 01:28:01 -0800572/**
573 * tick_init - initialize the tick control
Thomas Gleixner906568c2007-02-16 01:28:01 -0800574 */
575void __init tick_init(void)
576{
Thomas Gleixnerb352bc12013-03-05 14:25:32 +0100577 tick_broadcast_init();
Frederic Weisbeckera80e49e2014-08-16 17:47:18 +0200578 tick_nohz_init();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800579}