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  1/*
  2 * CPUFreq governor based on scheduler-provided CPU utilization data.
  3 *
  4 * Copyright (C) 2016, Intel Corporation
  5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 */
 11
 12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13
 14#include "sched.h"
 15
 16#include <trace/events/power.h>
 17
 18struct sugov_tunables {
 19	struct gov_attr_set	attr_set;
 20	unsigned int		rate_limit_us;
 21};
 22
 23struct sugov_policy {
 24	struct cpufreq_policy	*policy;
 25
 26	struct sugov_tunables	*tunables;
 27	struct list_head	tunables_hook;
 28
 29	raw_spinlock_t		update_lock;	/* For shared policies */
 30	u64			last_freq_update_time;
 31	s64			freq_update_delay_ns;
 32	unsigned int		next_freq;
 33	unsigned int		cached_raw_freq;
 34
 35	/* The next fields are only needed if fast switch cannot be used: */
 36	struct			irq_work irq_work;
 37	struct			kthread_work work;
 38	struct			mutex work_lock;
 39	struct			kthread_worker worker;
 40	struct task_struct	*thread;
 41	bool			work_in_progress;
 42
 43	bool			need_freq_update;
 44};
 45
 46struct sugov_cpu {
 47	struct update_util_data	update_util;
 48	struct sugov_policy	*sg_policy;
 49	unsigned int		cpu;
 50
 51	bool			iowait_boost_pending;
 52	unsigned int		iowait_boost;
 53	unsigned int		iowait_boost_max;
 54	u64 last_update;
 55
 56	/* The fields below are only needed when sharing a policy: */
 57	unsigned long		util_cfs;
 58	unsigned long		util_dl;
 59	unsigned long		max;
 60
 61	/* The field below is for single-CPU policies only: */
 62#ifdef CONFIG_NO_HZ_COMMON
 63	unsigned long		saved_idle_calls;
 64#endif
 65};
 66
 67static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu);
 68
 69/************************ Governor internals ***********************/
 70
 71static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
 72{
 73	s64 delta_ns;
 74
 75	/*
 76	 * Since cpufreq_update_util() is called with rq->lock held for
 77	 * the @target_cpu, our per-CPU data is fully serialized.
 78	 *
 79	 * However, drivers cannot in general deal with cross-CPU
 80	 * requests, so while get_next_freq() will work, our
 81	 * sugov_update_commit() call may not for the fast switching platforms.
 82	 *
 83	 * Hence stop here for remote requests if they aren't supported
 84	 * by the hardware, as calculating the frequency is pointless if
 85	 * we cannot in fact act on it.
 86	 *
 87	 * For the slow switching platforms, the kthread is always scheduled on
 88	 * the right set of CPUs and any CPU can find the next frequency and
 89	 * schedule the kthread.
 90	 */
 91	if (sg_policy->policy->fast_switch_enabled &&
 92	    !cpufreq_can_do_remote_dvfs(sg_policy->policy))
 93		return false;
 94
 95	if (sg_policy->work_in_progress)
 96		return false;
 97
 98	if (unlikely(sg_policy->need_freq_update)) {
 99		sg_policy->need_freq_update = false;
100		/*
101		 * This happens when limits change, so forget the previous
102		 * next_freq value and force an update.
103		 */
104		sg_policy->next_freq = UINT_MAX;
105		return true;
106	}
107
108	delta_ns = time - sg_policy->last_freq_update_time;
109
110	return delta_ns >= sg_policy->freq_update_delay_ns;
111}
112
113static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time,
114				unsigned int next_freq)
115{
116	struct cpufreq_policy *policy = sg_policy->policy;
117
118	if (sg_policy->next_freq == next_freq)
119		return;
120
121	sg_policy->next_freq = next_freq;
122	sg_policy->last_freq_update_time = time;
123
124	if (policy->fast_switch_enabled) {
125		next_freq = cpufreq_driver_fast_switch(policy, next_freq);
126		if (!next_freq)
127			return;
128
129		policy->cur = next_freq;
130		trace_cpu_frequency(next_freq, smp_processor_id());
131	} else {
132		sg_policy->work_in_progress = true;
133		irq_work_queue(&sg_policy->irq_work);
134	}
135}
136
137/**
138 * get_next_freq - Compute a new frequency for a given cpufreq policy.
139 * @sg_policy: schedutil policy object to compute the new frequency for.
140 * @util: Current CPU utilization.
141 * @max: CPU capacity.
142 *
143 * If the utilization is frequency-invariant, choose the new frequency to be
144 * proportional to it, that is
145 *
146 * next_freq = C * max_freq * util / max
147 *
148 * Otherwise, approximate the would-be frequency-invariant utilization by
149 * util_raw * (curr_freq / max_freq) which leads to
150 *
151 * next_freq = C * curr_freq * util_raw / max
152 *
153 * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8.
154 *
155 * The lowest driver-supported frequency which is equal or greater than the raw
156 * next_freq (as calculated above) is returned, subject to policy min/max and
157 * cpufreq driver limitations.
158 */
159static unsigned int get_next_freq(struct sugov_policy *sg_policy,
160				  unsigned long util, unsigned long max)
161{
162	struct cpufreq_policy *policy = sg_policy->policy;
163	unsigned int freq = arch_scale_freq_invariant() ?
164				policy->cpuinfo.max_freq : policy->cur;
165
166	freq = (freq + (freq >> 2)) * util / max;
167
168	if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_MAX)
169		return sg_policy->next_freq;
170	sg_policy->cached_raw_freq = freq;
171	return cpufreq_driver_resolve_freq(policy, freq);
172}
173
174static void sugov_get_util(struct sugov_cpu *sg_cpu)
175{
176	struct rq *rq = cpu_rq(sg_cpu->cpu);
177
178	sg_cpu->max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
179	sg_cpu->util_cfs = cpu_util_cfs(rq);
180	sg_cpu->util_dl  = cpu_util_dl(rq);
181}
182
183static unsigned long sugov_aggregate_util(struct sugov_cpu *sg_cpu)
184{
185	struct rq *rq = cpu_rq(sg_cpu->cpu);
186	unsigned long util;
187
188	if (rq->rt.rt_nr_running) {
189		util = sg_cpu->max;
190	} else {
191		util = sg_cpu->util_dl;
192		if (rq->cfs.h_nr_running)
193			util += sg_cpu->util_cfs;
194	}
195
196	/*
197	 * Ideally we would like to set util_dl as min/guaranteed freq and
198	 * util_cfs + util_dl as requested freq. However, cpufreq is not yet
199	 * ready for such an interface. So, we only do the latter for now.
200	 */
201	return min(util, sg_cpu->max);
202}
203
204static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, unsigned int flags)
205{
206	if (flags & SCHED_CPUFREQ_IOWAIT) {
207		if (sg_cpu->iowait_boost_pending)
208			return;
209
210		sg_cpu->iowait_boost_pending = true;
211
212		if (sg_cpu->iowait_boost) {
213			sg_cpu->iowait_boost <<= 1;
214			if (sg_cpu->iowait_boost > sg_cpu->iowait_boost_max)
215				sg_cpu->iowait_boost = sg_cpu->iowait_boost_max;
216		} else {
217			sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->min;
218		}
219	} else if (sg_cpu->iowait_boost) {
220		s64 delta_ns = time - sg_cpu->last_update;
221
222		/* Clear iowait_boost if the CPU apprears to have been idle. */
223		if (delta_ns > TICK_NSEC) {
224			sg_cpu->iowait_boost = 0;
225			sg_cpu->iowait_boost_pending = false;
226		}
227	}
228}
229
230static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util,
231			       unsigned long *max)
232{
233	unsigned int boost_util, boost_max;
234
235	if (!sg_cpu->iowait_boost)
236		return;
237
238	if (sg_cpu->iowait_boost_pending) {
239		sg_cpu->iowait_boost_pending = false;
240	} else {
241		sg_cpu->iowait_boost >>= 1;
242		if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) {
243			sg_cpu->iowait_boost = 0;
244			return;
245		}
246	}
247
248	boost_util = sg_cpu->iowait_boost;
249	boost_max = sg_cpu->iowait_boost_max;
250
251	if (*util * boost_max < *max * boost_util) {
252		*util = boost_util;
253		*max = boost_max;
254	}
255}
256
257#ifdef CONFIG_NO_HZ_COMMON
258static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
259{
260	unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);
261	bool ret = idle_calls == sg_cpu->saved_idle_calls;
262
263	sg_cpu->saved_idle_calls = idle_calls;
264	return ret;
265}
266#else
267static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
268#endif /* CONFIG_NO_HZ_COMMON */
269
270/*
271 * Make sugov_should_update_freq() ignore the rate limit when DL
272 * has increased the utilization.
273 */
274static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy)
275{
276	if (cpu_util_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->util_dl)
277		sg_policy->need_freq_update = true;
278}
279
280static void sugov_update_single(struct update_util_data *hook, u64 time,
281				unsigned int flags)
282{
283	struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
284	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
285	unsigned long util, max;
286	unsigned int next_f;
287	bool busy;
288
289	sugov_set_iowait_boost(sg_cpu, time, flags);
290	sg_cpu->last_update = time;
291
292	ignore_dl_rate_limit(sg_cpu, sg_policy);
293
294	if (!sugov_should_update_freq(sg_policy, time))
295		return;
296
297	busy = sugov_cpu_is_busy(sg_cpu);
298
299	sugov_get_util(sg_cpu);
300	max = sg_cpu->max;
301	util = sugov_aggregate_util(sg_cpu);
302	sugov_iowait_boost(sg_cpu, &util, &max);
303	next_f = get_next_freq(sg_policy, util, max);
304	/*
305	 * Do not reduce the frequency if the CPU has not been idle
306	 * recently, as the reduction is likely to be premature then.
307	 */
308	if (busy && next_f < sg_policy->next_freq &&
309	    sg_policy->next_freq != UINT_MAX) {
310		next_f = sg_policy->next_freq;
311
312		/* Reset cached freq as next_freq has changed */
313		sg_policy->cached_raw_freq = 0;
314	}
315
316	sugov_update_commit(sg_policy, time, next_f);
317}
318
319static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
320{
321	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
322	struct cpufreq_policy *policy = sg_policy->policy;
323	unsigned long util = 0, max = 1;
324	unsigned int j;
325
326	for_each_cpu(j, policy->cpus) {
327		struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j);
328		unsigned long j_util, j_max;
329		s64 delta_ns;
330
331		sugov_get_util(j_sg_cpu);
332
333		/*
334		 * If the CFS CPU utilization was last updated before the
335		 * previous frequency update and the time elapsed between the
336		 * last update of the CPU utilization and the last frequency
337		 * update is long enough, reset iowait_boost and util_cfs, as
338		 * they are now probably stale. However, still consider the
339		 * CPU contribution if it has some DEADLINE utilization
340		 * (util_dl).
341		 */
342		delta_ns = time - j_sg_cpu->last_update;
343		if (delta_ns > TICK_NSEC) {
344			j_sg_cpu->iowait_boost = 0;
345			j_sg_cpu->iowait_boost_pending = false;
346		}
347
348		j_max = j_sg_cpu->max;
349		j_util = sugov_aggregate_util(j_sg_cpu);
350		sugov_iowait_boost(j_sg_cpu, &j_util, &j_max);
351		if (j_util * max > j_max * util) {
352			util = j_util;
353			max = j_max;
354		}
355	}
356
357	return get_next_freq(sg_policy, util, max);
358}
359
360static void
361sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
362{
363	struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
364	struct sugov_policy *sg_policy = sg_cpu->sg_policy;
365	unsigned int next_f;
366
367	raw_spin_lock(&sg_policy->update_lock);
368
369	sugov_set_iowait_boost(sg_cpu, time, flags);
370	sg_cpu->last_update = time;
371
372	ignore_dl_rate_limit(sg_cpu, sg_policy);
373
374	if (sugov_should_update_freq(sg_policy, time)) {
375		next_f = sugov_next_freq_shared(sg_cpu, time);
376		sugov_update_commit(sg_policy, time, next_f);
377	}
378
379	raw_spin_unlock(&sg_policy->update_lock);
380}
381
382static void sugov_work(struct kthread_work *work)
383{
384	struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work);
385
386	mutex_lock(&sg_policy->work_lock);
387	__cpufreq_driver_target(sg_policy->policy, sg_policy->next_freq,
388				CPUFREQ_RELATION_L);
389	mutex_unlock(&sg_policy->work_lock);
390
391	sg_policy->work_in_progress = false;
392}
393
394static void sugov_irq_work(struct irq_work *irq_work)
395{
396	struct sugov_policy *sg_policy;
397
398	sg_policy = container_of(irq_work, struct sugov_policy, irq_work);
399
400	kthread_queue_work(&sg_policy->worker, &sg_policy->work);
401}
402
403/************************** sysfs interface ************************/
404
405static struct sugov_tunables *global_tunables;
406static DEFINE_MUTEX(global_tunables_lock);
407
408static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set)
409{
410	return container_of(attr_set, struct sugov_tunables, attr_set);
411}
412
413static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf)
414{
415	struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
416
417	return sprintf(buf, "%u\n", tunables->rate_limit_us);
418}
419
420static ssize_t
421rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count)
422{
423	struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
424	struct sugov_policy *sg_policy;
425	unsigned int rate_limit_us;
426
427	if (kstrtouint(buf, 10, &rate_limit_us))
428		return -EINVAL;
429
430	tunables->rate_limit_us = rate_limit_us;
431
432	list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook)
433		sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC;
434
435	return count;
436}
437
438static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
439
440static struct attribute *sugov_attributes[] = {
441	&rate_limit_us.attr,
442	NULL
443};
444
445static struct kobj_type sugov_tunables_ktype = {
446	.default_attrs = sugov_attributes,
447	.sysfs_ops = &governor_sysfs_ops,
448};
449
450/********************** cpufreq governor interface *********************/
451
452static struct cpufreq_governor schedutil_gov;
453
454static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
455{
456	struct sugov_policy *sg_policy;
457
458	sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL);
459	if (!sg_policy)
460		return NULL;
461
462	sg_policy->policy = policy;
463	raw_spin_lock_init(&sg_policy->update_lock);
464	return sg_policy;
465}
466
467static void sugov_policy_free(struct sugov_policy *sg_policy)
468{
469	kfree(sg_policy);
470}
471
472static int sugov_kthread_create(struct sugov_policy *sg_policy)
473{
474	struct task_struct *thread;
475	struct sched_attr attr = {
476		.size		= sizeof(struct sched_attr),
477		.sched_policy	= SCHED_DEADLINE,
478		.sched_flags	= SCHED_FLAG_SUGOV,
479		.sched_nice	= 0,
480		.sched_priority	= 0,
481		/*
482		 * Fake (unused) bandwidth; workaround to "fix"
483		 * priority inheritance.
484		 */
485		.sched_runtime	=  1000000,
486		.sched_deadline = 10000000,
487		.sched_period	= 10000000,
488	};
489	struct cpufreq_policy *policy = sg_policy->policy;
490	int ret;
491
492	/* kthread only required for slow path */
493	if (policy->fast_switch_enabled)
494		return 0;
495
496	kthread_init_work(&sg_policy->work, sugov_work);
497	kthread_init_worker(&sg_policy->worker);
498	thread = kthread_create(kthread_worker_fn, &sg_policy->worker,
499				"sugov:%d",
500				cpumask_first(policy->related_cpus));
501	if (IS_ERR(thread)) {
502		pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread));
503		return PTR_ERR(thread);
504	}
505
506	ret = sched_setattr_nocheck(thread, &attr);
507	if (ret) {
508		kthread_stop(thread);
509		pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__);
510		return ret;
511	}
512
513	sg_policy->thread = thread;
514
515	/* Kthread is bound to all CPUs by default */
516	if (!policy->dvfs_possible_from_any_cpu)
517		kthread_bind_mask(thread, policy->related_cpus);
518
519	init_irq_work(&sg_policy->irq_work, sugov_irq_work);
520	mutex_init(&sg_policy->work_lock);
521
522	wake_up_process(thread);
523
524	return 0;
525}
526
527static void sugov_kthread_stop(struct sugov_policy *sg_policy)
528{
529	/* kthread only required for slow path */
530	if (sg_policy->policy->fast_switch_enabled)
531		return;
532
533	kthread_flush_worker(&sg_policy->worker);
534	kthread_stop(sg_policy->thread);
535	mutex_destroy(&sg_policy->work_lock);
536}
537
538static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy)
539{
540	struct sugov_tunables *tunables;
541
542	tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
543	if (tunables) {
544		gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook);
545		if (!have_governor_per_policy())
546			global_tunables = tunables;
547	}
548	return tunables;
549}
550
551static void sugov_tunables_free(struct sugov_tunables *tunables)
552{
553	if (!have_governor_per_policy())
554		global_tunables = NULL;
555
556	kfree(tunables);
557}
558
559static int sugov_init(struct cpufreq_policy *policy)
560{
561	struct sugov_policy *sg_policy;
562	struct sugov_tunables *tunables;
563	int ret = 0;
564
565	/* State should be equivalent to EXIT */
566	if (policy->governor_data)
567		return -EBUSY;
568
569	cpufreq_enable_fast_switch(policy);
570
571	sg_policy = sugov_policy_alloc(policy);
572	if (!sg_policy) {
573		ret = -ENOMEM;
574		goto disable_fast_switch;
575	}
576
577	ret = sugov_kthread_create(sg_policy);
578	if (ret)
579		goto free_sg_policy;
580
581	mutex_lock(&global_tunables_lock);
582
583	if (global_tunables) {
584		if (WARN_ON(have_governor_per_policy())) {
585			ret = -EINVAL;
586			goto stop_kthread;
587		}
588		policy->governor_data = sg_policy;
589		sg_policy->tunables = global_tunables;
590
591		gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook);
592		goto out;
593	}
594
595	tunables = sugov_tunables_alloc(sg_policy);
596	if (!tunables) {
597		ret = -ENOMEM;
598		goto stop_kthread;
599	}
600
601	tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy);
602
603	policy->governor_data = sg_policy;
604	sg_policy->tunables = tunables;
605
606	ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype,
607				   get_governor_parent_kobj(policy), "%s",
608				   schedutil_gov.name);
609	if (ret)
610		goto fail;
611
612out:
613	mutex_unlock(&global_tunables_lock);
614	return 0;
615
616fail:
617	policy->governor_data = NULL;
618	sugov_tunables_free(tunables);
619
620stop_kthread:
621	sugov_kthread_stop(sg_policy);
622	mutex_unlock(&global_tunables_lock);
623
624free_sg_policy:
625	sugov_policy_free(sg_policy);
626
627disable_fast_switch:
628	cpufreq_disable_fast_switch(policy);
629
630	pr_err("initialization failed (error %d)\n", ret);
631	return ret;
632}
633
634static void sugov_exit(struct cpufreq_policy *policy)
635{
636	struct sugov_policy *sg_policy = policy->governor_data;
637	struct sugov_tunables *tunables = sg_policy->tunables;
638	unsigned int count;
639
640	mutex_lock(&global_tunables_lock);
641
642	count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
643	policy->governor_data = NULL;
644	if (!count)
645		sugov_tunables_free(tunables);
646
647	mutex_unlock(&global_tunables_lock);
648
649	sugov_kthread_stop(sg_policy);
650	sugov_policy_free(sg_policy);
651	cpufreq_disable_fast_switch(policy);
652}
653
654static int sugov_start(struct cpufreq_policy *policy)
655{
656	struct sugov_policy *sg_policy = policy->governor_data;
657	unsigned int cpu;
658
659	sg_policy->freq_update_delay_ns	= sg_policy->tunables->rate_limit_us * NSEC_PER_USEC;
660	sg_policy->last_freq_update_time	= 0;
661	sg_policy->next_freq			= UINT_MAX;
662	sg_policy->work_in_progress		= false;
663	sg_policy->need_freq_update		= false;
664	sg_policy->cached_raw_freq		= 0;
665
666	for_each_cpu(cpu, policy->cpus) {
667		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
668
669		memset(sg_cpu, 0, sizeof(*sg_cpu));
670		sg_cpu->cpu			= cpu;
671		sg_cpu->sg_policy		= sg_policy;
672		sg_cpu->iowait_boost_max	= policy->cpuinfo.max_freq;
673	}
674
675	for_each_cpu(cpu, policy->cpus) {
676		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
677
678		cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util,
679					     policy_is_shared(policy) ?
680							sugov_update_shared :
681							sugov_update_single);
682	}
683	return 0;
684}
685
686static void sugov_stop(struct cpufreq_policy *policy)
687{
688	struct sugov_policy *sg_policy = policy->governor_data;
689	unsigned int cpu;
690
691	for_each_cpu(cpu, policy->cpus)
692		cpufreq_remove_update_util_hook(cpu);
693
694	synchronize_sched();
695
696	if (!policy->fast_switch_enabled) {
697		irq_work_sync(&sg_policy->irq_work);
698		kthread_cancel_work_sync(&sg_policy->work);
699	}
700}
701
702static void sugov_limits(struct cpufreq_policy *policy)
703{
704	struct sugov_policy *sg_policy = policy->governor_data;
705
706	if (!policy->fast_switch_enabled) {
707		mutex_lock(&sg_policy->work_lock);
708		cpufreq_policy_apply_limits(policy);
709		mutex_unlock(&sg_policy->work_lock);
710	}
711
712	sg_policy->need_freq_update = true;
713}
714
715static struct cpufreq_governor schedutil_gov = {
716	.name			= "schedutil",
717	.owner			= THIS_MODULE,
718	.dynamic_switching	= true,
719	.init			= sugov_init,
720	.exit			= sugov_exit,
721	.start			= sugov_start,
722	.stop			= sugov_stop,
723	.limits			= sugov_limits,
724};
725
726#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
727struct cpufreq_governor *cpufreq_default_governor(void)
728{
729	return &schedutil_gov;
730}
731#endif
732
733static int __init sugov_register(void)
734{
735	return cpufreq_register_governor(&schedutil_gov);
736}
737fs_initcall(sugov_register);