[deliverable/linux.git] / drivers / cpufreq / cpufreq_governor.c

/*
 * 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,
		struct cpu_dbs_common_info *cdbs, unsigned int sampling_rate)
{
	int delay = delay_for_sampling_rate(sampling_rate);

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

static inline void dbs_timer_exit(struct cpu_dbs_common_info *cdbs)
{
	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++;
		cpu_cdbs->cpu = cpu;
		for_each_cpu(j, policy->cpus) {
			struct cpu_dbs_common_info *j_cdbs;
			j_cdbs = dbs_data->get_cpu_cdbs(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];
		}

		/*
		 * 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);

		mutex_init(&cpu_cdbs->timer_mutex);
		dbs_timer_init(dbs_data, cpu_cdbs, *sampling_rate);
		break;

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

		dbs_timer_exit(cpu_cdbs);

		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);
Commit	Line	Data
2aacdfff	1	/*
	2	* drivers/cpufreq/cpufreq_governor.c
	3	*
	4	* CPUFREQ governors common code
	5	*
4471a34f VK	6	* Copyright (C) 2001 Russell King
	7	* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
	8	* (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
	9	* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
	10	* (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
	11	*
2aacdfff	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16
4471a34f VK	17	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
4471a34f VK	18
2aacdfff	19	#include <asm/cputime.h>
4471a34f VK	20	#include <linux/cpufreq.h>
4471a34f VK	21	#include <linux/cpumask.h>
2aacdfff	22	#include <linux/export.h>
2aacdfff	23	#include <linux/kernel_stat.h>
4471a34f	24	#include <linux/mutex.h>
2aacdfff	25	#include <linux/tick.h>
2aacdfff	26	#include <linux/types.h>
4471a34f VK	27	#include <linux/workqueue.h>
	28
	29	#include "cpufreq_governor.h"
	30
2aacdfff	31	static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
	32	{
	33	u64 idle_time;
	34	u64 cur_wall_time;
	35	u64 busy_time;
	36
	37	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
	38
	39	busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
	40	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
	41	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
	42	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
	43	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
	44	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
	45
	46	idle_time = cur_wall_time - busy_time;
	47	if (wall)
a0e5af3c	48	*wall = cputime_to_usecs(cur_wall_time);
2aacdfff	49
a0e5af3c	50	return cputime_to_usecs(idle_time);
2aacdfff	51	}
2aacdfff	52
1e7586a1	53	u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
2aacdfff	54	{
	55	u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
	56
	57	if (idle_time == -1ULL)
	58	return get_cpu_idle_time_jiffy(cpu, wall);
	59	else
	60	idle_time += get_cpu_iowait_time_us(cpu, wall);
	61
	62	return idle_time;
	63	}
	64	EXPORT_SYMBOL_GPL(get_cpu_idle_time);
4471a34f VK	65
	66	void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
	67	{
	68	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);
	69	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
	70	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	71	struct cpufreq_policy *policy;
	72	unsigned int max_load = 0;
	73	unsigned int ignore_nice;
	74	unsigned int j;
	75
	76	if (dbs_data->governor == GOV_ONDEMAND)
	77	ignore_nice = od_tuners->ignore_nice;
	78	else
	79	ignore_nice = cs_tuners->ignore_nice;
	80
	81	policy = cdbs->cur_policy;
	82
	83	/* Get Absolute Load (in terms of freq for ondemand gov) */
	84	for_each_cpu(j, policy->cpus) {
	85	struct cpu_dbs_common_info *j_cdbs;
1e7586a1	86	u64 cur_wall_time, cur_idle_time, cur_iowait_time;
4471a34f VK	87	unsigned int idle_time, wall_time, iowait_time;
	88	unsigned int load;
	89
	90	j_cdbs = dbs_data->get_cpu_cdbs(j);
	91
	92	cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
	93
	94	wall_time = (unsigned int)
	95	(cur_wall_time - j_cdbs->prev_cpu_wall);
	96	j_cdbs->prev_cpu_wall = cur_wall_time;
	97
	98	idle_time = (unsigned int)
	99	(cur_idle_time - j_cdbs->prev_cpu_idle);
	100	j_cdbs->prev_cpu_idle = cur_idle_time;
	101
	102	if (ignore_nice) {
	103	u64 cur_nice;
	104	unsigned long cur_nice_jiffies;
	105
	106	cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
	107	cdbs->prev_cpu_nice;
	108	/*
	109	* Assumption: nice time between sampling periods will
	110	* be less than 2^32 jiffies for 32 bit sys
	111	*/
	112	cur_nice_jiffies = (unsigned long)
	113	cputime64_to_jiffies64(cur_nice);
	114
	115	cdbs->prev_cpu_nice =
	116	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
	117	idle_time += jiffies_to_usecs(cur_nice_jiffies);
	118	}
	119
	120	if (dbs_data->governor == GOV_ONDEMAND) {
	121	struct od_cpu_dbs_info_s *od_j_dbs_info =
	122	dbs_data->get_cpu_dbs_info_s(cpu);
	123
	124	cur_iowait_time = get_cpu_iowait_time_us(j,
	125	&cur_wall_time);
	126	if (cur_iowait_time == -1ULL)
	127	cur_iowait_time = 0;
	128
	129	iowait_time = (unsigned int) (cur_iowait_time -
	130	od_j_dbs_info->prev_cpu_iowait);
	131	od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;
	132
	133	/*
	134	* For the purpose of ondemand, waiting for disk IO is
	135	* an indication that you're performance critical, and
	136	* not that the system is actually idle. So subtract the
	137	* iowait time from the cpu idle time.
	138	*/
	139	if (od_tuners->io_is_busy && idle_time >= iowait_time)
	140	idle_time -= iowait_time;
	141	}
	142
	143	if (unlikely(!wall_time \|\| wall_time < idle_time))
	144	continue;
	145
	146	load = 100 * (wall_time - idle_time) / wall_time;
	147
	148	if (dbs_data->governor == GOV_ONDEMAND) {
	149	int freq_avg = __cpufreq_driver_getavg(policy, j);
	150	if (freq_avg <= 0)
151	freq_avg = policy->cur;
152
153	load *= freq_avg;
154	}
155
156	if (load > max_load)
157	max_load = load;
158	}
159
160	dbs_data->gov_check_cpu(cpu, max_load);
161	}
162	EXPORT_SYMBOL_GPL(dbs_check_cpu);
163
164	static inline void dbs_timer_init(struct dbs_data *dbs_data,
165	struct cpu_dbs_common_info *cdbs, unsigned int sampling_rate)
166	{
167	int delay = delay_for_sampling_rate(sampling_rate);
168
169	INIT_DEFERRABLE_WORK(&cdbs->work, dbs_data->gov_dbs_timer);
170	schedule_delayed_work_on(cdbs->cpu, &cdbs->work, delay);
171	}
172
173	static inline void dbs_timer_exit(struct cpu_dbs_common_info *cdbs)
174	{
175	cancel_delayed_work_sync(&cdbs->work);
176	}
177
178	int cpufreq_governor_dbs(struct dbs_data *dbs_data,
179	struct cpufreq_policy *policy, unsigned int event)
180	{
181	struct od_cpu_dbs_info_s *od_dbs_info = NULL;
182	struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
183	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
184	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
185	struct cpu_dbs_common_info *cpu_cdbs;
186	unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
187	int rc;
188
189	cpu_cdbs = dbs_data->get_cpu_cdbs(cpu);
190
191	if (dbs_data->governor == GOV_CONSERVATIVE) {
192	cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
193	sampling_rate = &cs_tuners->sampling_rate;
194	ignore_nice = cs_tuners->ignore_nice;
195	} else {
196	od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
197	sampling_rate = &od_tuners->sampling_rate;
198	ignore_nice = od_tuners->ignore_nice;
199	}
200
201	switch (event) {
202	case CPUFREQ_GOV_START:
203	if ((!cpu_online(cpu)) \|\| (!policy->cur))
204	return -EINVAL;
205
206	mutex_lock(&dbs_data->mutex);
207
208	dbs_data->enable++;
209	cpu_cdbs->cpu = cpu;
210	for_each_cpu(j, policy->cpus) {
211	struct cpu_dbs_common_info *j_cdbs;
212	j_cdbs = dbs_data->get_cpu_cdbs(j);
213
214	j_cdbs->cur_policy = policy;
215	j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
216	&j_cdbs->prev_cpu_wall);
217	if (ignore_nice)
218	j_cdbs->prev_cpu_nice =
219	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
220	}
221
222	/*
223	* Start the timerschedule work, when this governor is used for
224	* first time
225	*/
226	if (dbs_data->enable != 1)
227	goto second_time;
228
229	rc = sysfs_create_group(cpufreq_global_kobject,
230	dbs_data->attr_group);
231	if (rc) {
232	mutex_unlock(&dbs_data->mutex);
233	return rc;
234	}
235
236	/* policy latency is in nS. Convert it to uS first */
237	latency = policy->cpuinfo.transition_latency / 1000;
238	if (latency == 0)
239	latency = 1;
240
241	/*
242	* conservative does not implement micro like ondemand
243	* governor, thus we are bound to jiffes/HZ
244	*/
245	if (dbs_data->governor == GOV_CONSERVATIVE) {
246	struct cs_ops *ops = dbs_data->gov_ops;
247
248	cpufreq_register_notifier(ops->notifier_block,
249	CPUFREQ_TRANSITION_NOTIFIER);
250
251	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
252	jiffies_to_usecs(10);
253	} else {
254	struct od_ops *ops = dbs_data->gov_ops;
255
256	od_tuners->io_is_busy = ops->io_busy();
257	}
258
259	/* Bring kernel and HW constraints together */
260	dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
261	MIN_LATENCY_MULTIPLIER * latency);
262	sampling_rate = max(dbs_data->min_sampling_rate, latency
263	LATENCY_MULTIPLIER);
264
265	second_time:
266	if (dbs_data->governor == GOV_CONSERVATIVE) {
267	cs_dbs_info->down_skip = 0;
268	cs_dbs_info->enable = 1;
269	cs_dbs_info->requested_freq = policy->cur;
270	} else {
271	struct od_ops *ops = dbs_data->gov_ops;
272	od_dbs_info->rate_mult = 1;
273	od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
274	ops->powersave_bias_init_cpu(cpu);
275	}
276	mutex_unlock(&dbs_data->mutex);
277
278	mutex_init(&cpu_cdbs->timer_mutex);
279	dbs_timer_init(dbs_data, cpu_cdbs, *sampling_rate);
280	break;
281
282	case CPUFREQ_GOV_STOP:
283	if (dbs_data->governor == GOV_CONSERVATIVE)
284	cs_dbs_info->enable = 0;
285
286	dbs_timer_exit(cpu_cdbs);
287
288	mutex_lock(&dbs_data->mutex);
289	mutex_destroy(&cpu_cdbs->timer_mutex);
290	dbs_data->enable--;
291	if (!dbs_data->enable) {
292	struct cs_ops *ops = dbs_data->gov_ops;
293
294	sysfs_remove_group(cpufreq_global_kobject,
295	dbs_data->attr_group);
296	if (dbs_data->governor == GOV_CONSERVATIVE)
297	cpufreq_unregister_notifier(ops->notifier_block,
298	CPUFREQ_TRANSITION_NOTIFIER);
299	}
300	mutex_unlock(&dbs_data->mutex);
301
302	break;
303
304	case CPUFREQ_GOV_LIMITS:
305	mutex_lock(&cpu_cdbs->timer_mutex);
306	if (policy->max < cpu_cdbs->cur_policy->cur)
307	__cpufreq_driver_target(cpu_cdbs->cur_policy,
308	policy->max, CPUFREQ_RELATION_H);
309	else if (policy->min > cpu_cdbs->cur_policy->cur)
310	__cpufreq_driver_target(cpu_cdbs->cur_policy,
311	policy->min, CPUFREQ_RELATION_L);
312	dbs_check_cpu(dbs_data, cpu);
313	mutex_unlock(&cpu_cdbs->timer_mutex);
314	break;
315	}
316	return 0;
317	}
318	EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);