drivers/cpufreq/cpufreq_governor.c - kernel/msm-4.19 - Gitiles

 /*
  * drivers/cpufreq/cpufreq_governor.c
  *
  * CPUFREQ governors common code
  *
  * Copyright	(C) 2001 Russell King
  *		(C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
  *		(C) 2003 Jun Nakajima <jun.nakajima@intel.com>
  *		(C) 2009 Alexander Clouter <alex@digriz.org.uk>
  *		(c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <asm/cputime.h>
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
 #include <linux/export.h>
 #include <linux/kernel_stat.h>
 #include <linux/mutex.h>
 #include <linux/tick.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>

 #include "cpufreq_governor.h"

 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
 {
 	u64 idle_time;
 	u64 cur_wall_time;
 	u64 busy_time;

 	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());

 	busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
 	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
 	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
 	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
 	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
 	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];

 	idle_time = cur_wall_time - busy_time;
 	if (wall)
 		*wall = cputime_to_usecs(cur_wall_time);

 	return cputime_to_usecs(idle_time);
 }

 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
 {
 	u64 idle_time = get_cpu_idle_time_us(cpu, NULL);

 	if (idle_time == -1ULL)
 		return get_cpu_idle_time_jiffy(cpu, wall);
 	else
 		idle_time += get_cpu_iowait_time_us(cpu, wall);

 	return idle_time;
 }
 EXPORT_SYMBOL_GPL(get_cpu_idle_time);

 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
 {
 	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);
 	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
 	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
 	struct cpufreq_policy *policy;
 	unsigned int max_load = 0;
 	unsigned int ignore_nice;
 	unsigned int j;

 	if (dbs_data->governor == GOV_ONDEMAND)
 		ignore_nice = od_tuners->ignore_nice;
 	else
 		ignore_nice = cs_tuners->ignore_nice;

 	policy = cdbs->cur_policy;

 	/* Get Absolute Load (in terms of freq for ondemand gov) */
 	for_each_cpu(j, policy->cpus) {
 		struct cpu_dbs_common_info *j_cdbs;
 		u64 cur_wall_time, cur_idle_time, cur_iowait_time;
 		unsigned int idle_time, wall_time, iowait_time;
 		unsigned int load;

 		j_cdbs = dbs_data->get_cpu_cdbs(j);

 		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);

 		wall_time = (unsigned int)
 			(cur_wall_time - j_cdbs->prev_cpu_wall);
 		j_cdbs->prev_cpu_wall = cur_wall_time;

 		idle_time = (unsigned int)
 			(cur_idle_time - j_cdbs->prev_cpu_idle);
 		j_cdbs->prev_cpu_idle = cur_idle_time;

 		if (ignore_nice) {
 			u64 cur_nice;
 			unsigned long cur_nice_jiffies;

 			cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
 					 cdbs->prev_cpu_nice;
 			/*
 			 * Assumption: nice time between sampling periods will
 			 * be less than 2^32 jiffies for 32 bit sys
 			 */
 			cur_nice_jiffies = (unsigned long)
 					cputime64_to_jiffies64(cur_nice);

 			cdbs->prev_cpu_nice =
 				kcpustat_cpu(j).cpustat[CPUTIME_NICE];
 			idle_time += jiffies_to_usecs(cur_nice_jiffies);
 		}

 		if (dbs_data->governor == GOV_ONDEMAND) {
 			struct od_cpu_dbs_info_s *od_j_dbs_info =
 				dbs_data->get_cpu_dbs_info_s(cpu);

 			cur_iowait_time = get_cpu_iowait_time_us(j,
 					&cur_wall_time);
 			if (cur_iowait_time == -1ULL)
 				cur_iowait_time = 0;

 			iowait_time = (unsigned int) (cur_iowait_time -
 					od_j_dbs_info->prev_cpu_iowait);
 			od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;

 			/*
 			 * For the purpose of ondemand, waiting for disk IO is
 			 * an indication that you're performance critical, and
 			 * not that the system is actually idle. So subtract the
 			 * iowait time from the cpu idle time.
 			 */
 			if (od_tuners->io_is_busy && idle_time >= iowait_time)
 				idle_time -= iowait_time;
 		}

 		if (unlikely(!wall_time || wall_time < idle_time))
 			continue;

 		load = 100 * (wall_time - idle_time) / wall_time;

 		if (dbs_data->governor == GOV_ONDEMAND) {
 			int freq_avg = __cpufreq_driver_getavg(policy, j);
 			if (freq_avg <= 0)
 				freq_avg = policy->cur;

 			load *= freq_avg;
 		}

 		if (load > max_load)
 			max_load = load;
 	}

 	dbs_data->gov_check_cpu(cpu, max_load);
 }
 EXPORT_SYMBOL_GPL(dbs_check_cpu);

 static inline void dbs_timer_init(struct dbs_data *dbs_data, int cpu,
 				  unsigned int sampling_rate)
 {
 	int delay = delay_for_sampling_rate(sampling_rate);
 	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);

 	schedule_delayed_work_on(cpu, &cdbs->work, delay);
 }

 static inline void dbs_timer_exit(struct dbs_data *dbs_data, int cpu)
 {
 	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);

 	cancel_delayed_work_sync(&cdbs->work);
 }

 int cpufreq_governor_dbs(struct dbs_data *dbs_data,
 		struct cpufreq_policy *policy, unsigned int event)
 {
 	struct od_cpu_dbs_info_s *od_dbs_info = NULL;
 	struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
 	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
 	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
 	struct cpu_dbs_common_info *cpu_cdbs;
 	unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
 	int rc;

 	cpu_cdbs = dbs_data->get_cpu_cdbs(cpu);

 	if (dbs_data->governor == GOV_CONSERVATIVE) {
 		cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
 		sampling_rate = &cs_tuners->sampling_rate;
 		ignore_nice = cs_tuners->ignore_nice;
 	} else {
 		od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
 		sampling_rate = &od_tuners->sampling_rate;
 		ignore_nice = od_tuners->ignore_nice;
 	}

 	switch (event) {
 	case CPUFREQ_GOV_START:
 		if ((!cpu_online(cpu)) || (!policy->cur))
 			return -EINVAL;

 		mutex_lock(&dbs_data->mutex);

 		dbs_data->enable++;
 		for_each_cpu(j, policy->cpus) {
 			struct cpu_dbs_common_info *j_cdbs;
 			j_cdbs = dbs_data->get_cpu_cdbs(j);

 			j_cdbs->cpu = j;
 			j_cdbs->cur_policy = policy;
 			j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
 					&j_cdbs->prev_cpu_wall);
 			if (ignore_nice)
 				j_cdbs->prev_cpu_nice =
 					kcpustat_cpu(j).cpustat[CPUTIME_NICE];

 			mutex_init(&j_cdbs->timer_mutex);
 			INIT_DEFERRABLE_WORK(&j_cdbs->work,
 					     dbs_data->gov_dbs_timer);
 		}

 		/*
 		 * Start the timerschedule work, when this governor is used for
 		 * first time
 		 */
 		if (dbs_data->enable != 1)
 			goto second_time;

 		rc = sysfs_create_group(cpufreq_global_kobject,
 				dbs_data->attr_group);
 		if (rc) {
 			mutex_unlock(&dbs_data->mutex);
 			return rc;
 		}

 		/* policy latency is in nS. Convert it to uS first */
 		latency = policy->cpuinfo.transition_latency / 1000;
 		if (latency == 0)
 			latency = 1;

 		/*
 		 * conservative does not implement micro like ondemand
 		 * governor, thus we are bound to jiffes/HZ
 		 */
 		if (dbs_data->governor == GOV_CONSERVATIVE) {
 			struct cs_ops *ops = dbs_data->gov_ops;

 			cpufreq_register_notifier(ops->notifier_block,
 					CPUFREQ_TRANSITION_NOTIFIER);

 			dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
 				jiffies_to_usecs(10);
 		} else {
 			struct od_ops *ops = dbs_data->gov_ops;

 			od_tuners->io_is_busy = ops->io_busy();
 		}

 		/* Bring kernel and HW constraints together */
 		dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
 				MIN_LATENCY_MULTIPLIER * latency);
 		*sampling_rate = max(dbs_data->min_sampling_rate, latency *
 				LATENCY_MULTIPLIER);

 second_time:
 		if (dbs_data->governor == GOV_CONSERVATIVE) {
 			cs_dbs_info->down_skip = 0;
 			cs_dbs_info->enable = 1;
 			cs_dbs_info->requested_freq = policy->cur;
 		} else {
 			struct od_ops *ops = dbs_data->gov_ops;
 			od_dbs_info->rate_mult = 1;
 			od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
 			ops->powersave_bias_init_cpu(cpu);
 		}
 		mutex_unlock(&dbs_data->mutex);

 		/* Initiate timer time stamp */
 		cpu_cdbs->time_stamp = ktime_get();

 		for_each_cpu(j, policy->cpus)
 			dbs_timer_init(dbs_data, j, *sampling_rate);
 		break;

 	case CPUFREQ_GOV_STOP:
 		if (dbs_data->governor == GOV_CONSERVATIVE)
 			cs_dbs_info->enable = 0;

 		for_each_cpu(j, policy->cpus)
 			dbs_timer_exit(dbs_data, j);

 		mutex_lock(&dbs_data->mutex);
 		mutex_destroy(&cpu_cdbs->timer_mutex);
 		dbs_data->enable--;
 		if (!dbs_data->enable) {
 			struct cs_ops *ops = dbs_data->gov_ops;

 			sysfs_remove_group(cpufreq_global_kobject,
 					dbs_data->attr_group);
 			if (dbs_data->governor == GOV_CONSERVATIVE)
 				cpufreq_unregister_notifier(ops->notifier_block,
 						CPUFREQ_TRANSITION_NOTIFIER);
 		}
 		mutex_unlock(&dbs_data->mutex);

 		break;

 	case CPUFREQ_GOV_LIMITS:
 		mutex_lock(&cpu_cdbs->timer_mutex);
 		if (policy->max < cpu_cdbs->cur_policy->cur)
 			__cpufreq_driver_target(cpu_cdbs->cur_policy,
 					policy->max, CPUFREQ_RELATION_H);
 		else if (policy->min > cpu_cdbs->cur_policy->cur)
 			__cpufreq_driver_target(cpu_cdbs->cur_policy,
 					policy->min, CPUFREQ_RELATION_L);
 		dbs_check_cpu(dbs_data, cpu);
 		mutex_unlock(&cpu_cdbs->timer_mutex);
 		break;
 	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);
	/*
	* drivers/cpufreq/cpufreq_governor.c
	*
	* CPUFREQ governors common code
	*
	* Copyright (C) 2001 Russell King
	* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
	* (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
	* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
	* (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <asm/cputime.h>
	#include <linux/cpufreq.h>
	#include <linux/cpumask.h>
	#include <linux/export.h>
	#include <linux/kernel_stat.h>
	#include <linux/mutex.h>
	#include <linux/tick.h>
	#include <linux/types.h>
	#include <linux/workqueue.h>

	#include "cpufreq_governor.h"

	static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
	{
	u64 idle_time;
	u64 cur_wall_time;
	u64 busy_time;

	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());

	busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];

	idle_time = cur_wall_time - busy_time;
	if (wall)
	*wall = cputime_to_usecs(cur_wall_time);

	return cputime_to_usecs(idle_time);
	}

	u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
	{
	u64 idle_time = get_cpu_idle_time_us(cpu, NULL);

	if (idle_time == -1ULL)
	return get_cpu_idle_time_jiffy(cpu, wall);
	else
	idle_time += get_cpu_iowait_time_us(cpu, wall);

	return idle_time;
	}
	EXPORT_SYMBOL_GPL(get_cpu_idle_time);

	void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
	{
	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);
	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	struct cpufreq_policy *policy;
	unsigned int max_load = 0;
	unsigned int ignore_nice;
	unsigned int j;

	if (dbs_data->governor == GOV_ONDEMAND)
	ignore_nice = od_tuners->ignore_nice;
	else
	ignore_nice = cs_tuners->ignore_nice;

	policy = cdbs->cur_policy;

	/* Get Absolute Load (in terms of freq for ondemand gov) */
	for_each_cpu(j, policy->cpus) {
	struct cpu_dbs_common_info *j_cdbs;
	u64 cur_wall_time, cur_idle_time, cur_iowait_time;
	unsigned int idle_time, wall_time, iowait_time;
	unsigned int load;

	j_cdbs = dbs_data->get_cpu_cdbs(j);

	cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);

	wall_time = (unsigned int)
	(cur_wall_time - j_cdbs->prev_cpu_wall);
	j_cdbs->prev_cpu_wall = cur_wall_time;

	idle_time = (unsigned int)
	(cur_idle_time - j_cdbs->prev_cpu_idle);
	j_cdbs->prev_cpu_idle = cur_idle_time;

	if (ignore_nice) {
	u64 cur_nice;
	unsigned long cur_nice_jiffies;

	cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
	cdbs->prev_cpu_nice;
	/*
	* Assumption: nice time between sampling periods will
	* be less than 2^32 jiffies for 32 bit sys
	*/
	cur_nice_jiffies = (unsigned long)
	cputime64_to_jiffies64(cur_nice);

	cdbs->prev_cpu_nice =
	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
	idle_time += jiffies_to_usecs(cur_nice_jiffies);
	}

	if (dbs_data->governor == GOV_ONDEMAND) {
	struct od_cpu_dbs_info_s *od_j_dbs_info =
	dbs_data->get_cpu_dbs_info_s(cpu);

	cur_iowait_time = get_cpu_iowait_time_us(j,
	&cur_wall_time);
	if (cur_iowait_time == -1ULL)
	cur_iowait_time = 0;

	iowait_time = (unsigned int) (cur_iowait_time -
	od_j_dbs_info->prev_cpu_iowait);
	od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;

	/*
	* For the purpose of ondemand, waiting for disk IO is
	* an indication that you're performance critical, and
	* not that the system is actually idle. So subtract the
	* iowait time from the cpu idle time.
	*/
	if (od_tuners->io_is_busy && idle_time >= iowait_time)
	idle_time -= iowait_time;
	}

	if (unlikely(!wall_time \|\| wall_time < idle_time))
	continue;

	load = 100 * (wall_time - idle_time) / wall_time;

	if (dbs_data->governor == GOV_ONDEMAND) {
	int freq_avg = __cpufreq_driver_getavg(policy, j);
	if (freq_avg <= 0)
	freq_avg = policy->cur;

	load *= freq_avg;
	}

	if (load > max_load)
	max_load = load;
	}

	dbs_data->gov_check_cpu(cpu, max_load);
	}
	EXPORT_SYMBOL_GPL(dbs_check_cpu);

	static inline void dbs_timer_init(struct dbs_data *dbs_data, int cpu,
	unsigned int sampling_rate)
	{
	int delay = delay_for_sampling_rate(sampling_rate);
	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);

	schedule_delayed_work_on(cpu, &cdbs->work, delay);
	}

	static inline void dbs_timer_exit(struct dbs_data *dbs_data, int cpu)
	{
	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);

	cancel_delayed_work_sync(&cdbs->work);
	}

	int cpufreq_governor_dbs(struct dbs_data *dbs_data,
	struct cpufreq_policy *policy, unsigned int event)
	{
	struct od_cpu_dbs_info_s *od_dbs_info = NULL;
	struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	struct cpu_dbs_common_info *cpu_cdbs;
	unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
	int rc;

	cpu_cdbs = dbs_data->get_cpu_cdbs(cpu);

	if (dbs_data->governor == GOV_CONSERVATIVE) {
	cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
	sampling_rate = &cs_tuners->sampling_rate;
	ignore_nice = cs_tuners->ignore_nice;
	} else {
	od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
	sampling_rate = &od_tuners->sampling_rate;
	ignore_nice = od_tuners->ignore_nice;
	}

	switch (event) {
	case CPUFREQ_GOV_START:
	if ((!cpu_online(cpu)) \|\| (!policy->cur))
	return -EINVAL;

	mutex_lock(&dbs_data->mutex);

	dbs_data->enable++;
	for_each_cpu(j, policy->cpus) {
	struct cpu_dbs_common_info *j_cdbs;
	j_cdbs = dbs_data->get_cpu_cdbs(j);

	j_cdbs->cpu = j;
	j_cdbs->cur_policy = policy;
	j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
	&j_cdbs->prev_cpu_wall);
	if (ignore_nice)
	j_cdbs->prev_cpu_nice =
	kcpustat_cpu(j).cpustat[CPUTIME_NICE];

	mutex_init(&j_cdbs->timer_mutex);
	INIT_DEFERRABLE_WORK(&j_cdbs->work,
	dbs_data->gov_dbs_timer);
	}

	/*
	* Start the timerschedule work, when this governor is used for
	* first time
	*/
	if (dbs_data->enable != 1)
	goto second_time;

	rc = sysfs_create_group(cpufreq_global_kobject,
	dbs_data->attr_group);
	if (rc) {
	mutex_unlock(&dbs_data->mutex);
	return rc;
	}

	/* policy latency is in nS. Convert it to uS first */
	latency = policy->cpuinfo.transition_latency / 1000;
	if (latency == 0)
	latency = 1;

	/*
	* conservative does not implement micro like ondemand
	* governor, thus we are bound to jiffes/HZ
	*/
	if (dbs_data->governor == GOV_CONSERVATIVE) {
	struct cs_ops *ops = dbs_data->gov_ops;

	cpufreq_register_notifier(ops->notifier_block,
	CPUFREQ_TRANSITION_NOTIFIER);

	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	jiffies_to_usecs(10);
	} else {
	struct od_ops *ops = dbs_data->gov_ops;

	od_tuners->io_is_busy = ops->io_busy();
	}

	/* Bring kernel and HW constraints together */
	dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
	MIN_LATENCY_MULTIPLIER * latency);
	sampling_rate = max(dbs_data->min_sampling_rate, latency
	LATENCY_MULTIPLIER);

	second_time:
	if (dbs_data->governor == GOV_CONSERVATIVE) {
	cs_dbs_info->down_skip = 0;
	cs_dbs_info->enable = 1;
	cs_dbs_info->requested_freq = policy->cur;
	} else {
	struct od_ops *ops = dbs_data->gov_ops;
	od_dbs_info->rate_mult = 1;
	od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
	ops->powersave_bias_init_cpu(cpu);
	}
	mutex_unlock(&dbs_data->mutex);

	/* Initiate timer time stamp */
	cpu_cdbs->time_stamp = ktime_get();

	for_each_cpu(j, policy->cpus)
	dbs_timer_init(dbs_data, j, *sampling_rate);
	break;

	case CPUFREQ_GOV_STOP:
	if (dbs_data->governor == GOV_CONSERVATIVE)
	cs_dbs_info->enable = 0;

	for_each_cpu(j, policy->cpus)
	dbs_timer_exit(dbs_data, j);

	mutex_lock(&dbs_data->mutex);
	mutex_destroy(&cpu_cdbs->timer_mutex);
	dbs_data->enable--;
	if (!dbs_data->enable) {
	struct cs_ops *ops = dbs_data->gov_ops;

	sysfs_remove_group(cpufreq_global_kobject,
	dbs_data->attr_group);
	if (dbs_data->governor == GOV_CONSERVATIVE)
	cpufreq_unregister_notifier(ops->notifier_block,
	CPUFREQ_TRANSITION_NOTIFIER);
	}
	mutex_unlock(&dbs_data->mutex);

	break;

	case CPUFREQ_GOV_LIMITS:
	mutex_lock(&cpu_cdbs->timer_mutex);
	if (policy->max < cpu_cdbs->cur_policy->cur)
	__cpufreq_driver_target(cpu_cdbs->cur_policy,
	policy->max, CPUFREQ_RELATION_H);
	else if (policy->min > cpu_cdbs->cur_policy->cur)
	__cpufreq_driver_target(cpu_cdbs->cur_policy,
	policy->min, CPUFREQ_RELATION_L);
	dbs_check_cpu(dbs_data, cpu);
	mutex_unlock(&cpu_cdbs->timer_mutex);
	break;
	}
	return 0;
	}
	EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);