[GitHub/mt8127/android_kernel_alcatel_ttab.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/slab.h>
#include <linux/tick.h>
#include <linux/types.h>
#include <linux/workqueue.h>

#include "cpufreq_governor.h"

static struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
{
	if (have_governor_per_policy())
		return &policy->kobj;
	else
		return cpufreq_global_kobject;
}

static struct attribute_group *get_sysfs_attr(struct dbs_data *dbs_data)
{
	if (have_governor_per_policy())
		return dbs_data->cdata->attr_group_gov_pol;
	else
		return dbs_data->cdata->attr_group_gov_sys;
}

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, int io_busy)
{
	u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);

	if (idle_time == -1ULL)
		return get_cpu_idle_time_jiffy(cpu, wall);
	else if (!io_busy)
		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->cdata->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->cdata->governor == GOV_ONDEMAND)
		ignore_nice = od_tuners->ignore_nice_load;
	else
		ignore_nice = cs_tuners->ignore_nice_load;

	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;
		unsigned int idle_time, wall_time;
		unsigned int load;
		int io_busy = 0;

		j_cdbs = dbs_data->cdata->get_cpu_cdbs(j);

		/*
		 * 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 do not add
		 * the iowait time to the cpu idle time.
		 */
		if (dbs_data->cdata->governor == GOV_ONDEMAND)
			io_busy = od_tuners->io_is_busy;
		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time, io_busy);

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

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

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

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

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

void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,
		unsigned int delay, bool all_cpus)
{
	int i;

	if (!all_cpus) {
		__gov_queue_work(smp_processor_id(), dbs_data, delay);
	} else {
		for_each_cpu(i, policy->cpus)
			__gov_queue_work(i, dbs_data, delay);
	}
}
EXPORT_SYMBOL_GPL(gov_queue_work);

static inline void gov_cancel_work(struct dbs_data *dbs_data,
		struct cpufreq_policy *policy)
{
	struct cpu_dbs_common_info *cdbs;
	int i;

	for_each_cpu(i, policy->cpus) {
		cdbs = dbs_data->cdata->get_cpu_cdbs(i);
		cancel_delayed_work_sync(&cdbs->work);
	}
}

/* Will return if we need to evaluate cpu load again or not */
bool need_load_eval(struct cpu_dbs_common_info *cdbs,
		unsigned int sampling_rate)
{
	if (policy_is_shared(cdbs->cur_policy)) {
		ktime_t time_now = ktime_get();
		s64 delta_us = ktime_us_delta(time_now, cdbs->time_stamp);

		/* Do nothing if we recently have sampled */
		if (delta_us < (s64)(sampling_rate / 2))
			return false;
		else
			cdbs->time_stamp = time_now;
	}

	return true;
}
EXPORT_SYMBOL_GPL(need_load_eval);

static void set_sampling_rate(struct dbs_data *dbs_data,
		unsigned int sampling_rate)
{
	if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
		struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
		cs_tuners->sampling_rate = sampling_rate;
	} else {
		struct od_dbs_tuners *od_tuners = dbs_data->tuners;
		od_tuners->sampling_rate = sampling_rate;
	}
}

int cpufreq_governor_dbs(struct cpufreq_policy *policy,
		struct common_dbs_data *cdata, unsigned int event)
{
	struct dbs_data *dbs_data;
	struct od_cpu_dbs_info_s *od_dbs_info = NULL;
	struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
	struct od_ops *od_ops = NULL;
	struct od_dbs_tuners *od_tuners = NULL;
	struct cs_dbs_tuners *cs_tuners = NULL;
	struct cpu_dbs_common_info *cpu_cdbs;
	unsigned int sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
	int io_busy = 0;
	int rc;

	if (have_governor_per_policy())
		dbs_data = policy->governor_data;
	else
		dbs_data = cdata->gdbs_data;

	WARN_ON(!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT));

	switch (event) {
	case CPUFREQ_GOV_POLICY_INIT:
		if (have_governor_per_policy()) {
			WARN_ON(dbs_data);
		} else if (dbs_data) {
			dbs_data->usage_count++;
			policy->governor_data = dbs_data;
			return 0;
		}

		dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL);
		if (!dbs_data) {
			pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
			return -ENOMEM;
		}

		dbs_data->cdata = cdata;
		dbs_data->usage_count = 1;
		rc = cdata->init(dbs_data);
		if (rc) {
			pr_err("%s: POLICY_INIT: init() failed\n", __func__);
			kfree(dbs_data);
			return rc;
		}

		rc = sysfs_create_group(get_governor_parent_kobj(policy),
				get_sysfs_attr(dbs_data));
		if (rc) {
			cdata->exit(dbs_data);
			kfree(dbs_data);
			return rc;
		}

		policy->governor_data = dbs_data;

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

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

		if ((cdata->governor == GOV_CONSERVATIVE) &&
				(!policy->governor->initialized)) {
			struct cs_ops *cs_ops = dbs_data->cdata->gov_ops;

			cpufreq_register_notifier(cs_ops->notifier_block,
					CPUFREQ_TRANSITION_NOTIFIER);
		}

		if (!have_governor_per_policy())
			cdata->gdbs_data = dbs_data;

		return 0;
	case CPUFREQ_GOV_POLICY_EXIT:
		if (!--dbs_data->usage_count) {
			sysfs_remove_group(get_governor_parent_kobj(policy),
					get_sysfs_attr(dbs_data));

			if ((dbs_data->cdata->governor == GOV_CONSERVATIVE) &&
				(policy->governor->initialized == 1)) {
				struct cs_ops *cs_ops = dbs_data->cdata->gov_ops;

				cpufreq_unregister_notifier(cs_ops->notifier_block,
						CPUFREQ_TRANSITION_NOTIFIER);
			}

			cdata->exit(dbs_data);
			kfree(dbs_data);
			cdata->gdbs_data = NULL;
		}

		policy->governor_data = NULL;
		return 0;
	}

	cpu_cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);

	if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
		cs_tuners = dbs_data->tuners;
		cs_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu);
		sampling_rate = cs_tuners->sampling_rate;
		ignore_nice = cs_tuners->ignore_nice_load;
	} else {
		od_tuners = dbs_data->tuners;
		od_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu);
		sampling_rate = od_tuners->sampling_rate;
		ignore_nice = od_tuners->ignore_nice_load;
		od_ops = dbs_data->cdata->gov_ops;
		io_busy = od_tuners->io_is_busy;
	}

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

		mutex_lock(&dbs_data->mutex);

		for_each_cpu(j, policy->cpus) {
			struct cpu_dbs_common_info *j_cdbs =
				dbs_data->cdata->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, io_busy);
			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->cdata->gov_dbs_timer);
		}

		/*
		 * conservative does not implement micro like ondemand
		 * governor, thus we are bound to jiffes/HZ
		 */
		if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
			cs_dbs_info->down_skip = 0;
			cs_dbs_info->enable = 1;
			cs_dbs_info->requested_freq = policy->cur;
		} else {
			od_dbs_info->rate_mult = 1;
			od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
			od_ops->powersave_bias_init_cpu(cpu);
		}

		mutex_unlock(&dbs_data->mutex);

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

		gov_queue_work(dbs_data, policy,
				delay_for_sampling_rate(sampling_rate), true);
		break;

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

		gov_cancel_work(dbs_data, policy);

		mutex_lock(&dbs_data->mutex);
		mutex_destroy(&cpu_cdbs->timer_mutex);

		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>
4d5dcc42	25	#include <linux/slab.h>
2aacdfff	26	#include <linux/tick.h>
2aacdfff	27	#include <linux/types.h>
4471a34f VK	28	#include <linux/workqueue.h>
	29
	30	#include "cpufreq_governor.h"
	31
4d5dcc42 VK	32	static struct kobject get_governor_parent_kobj(struct cpufreq_policy policy)
	33	{
	34	if (have_governor_per_policy())
	35	return &policy->kobj;
	36	else
	37	return cpufreq_global_kobject;
	38	}
	39
	40	static struct attribute_group get_sysfs_attr(struct dbs_data dbs_data)
	41	{
	42	if (have_governor_per_policy())
	43	return dbs_data->cdata->attr_group_gov_pol;
	44	else
	45	return dbs_data->cdata->attr_group_gov_sys;
	46	}
	47
2aacdfff	48	static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
	49	{
	50	u64 idle_time;
	51	u64 cur_wall_time;
	52	u64 busy_time;
	53
	54	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
	55
	56	busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
	57	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
	58	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
	59	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
	60	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
	61	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
	62
	63	idle_time = cur_wall_time - busy_time;
	64	if (wall)
a0e5af3c	65	*wall = cputime_to_usecs(cur_wall_time);
2aacdfff	66
a0e5af3c	67	return cputime_to_usecs(idle_time);
2aacdfff	68	}
2aacdfff	69
9366d840	70	u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
2aacdfff	71	{
9366d840	72	u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
2aacdfff	73
	74	if (idle_time == -1ULL)
	75	return get_cpu_idle_time_jiffy(cpu, wall);
9366d840	76	else if (!io_busy)
2aacdfff	77	idle_time += get_cpu_iowait_time_us(cpu, wall);
	78
	79	return idle_time;
	80	}
	81	EXPORT_SYMBOL_GPL(get_cpu_idle_time);
4471a34f VK	82
	83	void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
	84	{
4d5dcc42	85	struct cpu_dbs_common_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
4471a34f VK	86	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
	87	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	88	struct cpufreq_policy *policy;
	89	unsigned int max_load = 0;
	90	unsigned int ignore_nice;
	91	unsigned int j;
	92
4d5dcc42	93	if (dbs_data->cdata->governor == GOV_ONDEMAND)
da712f3a	94	ignore_nice = od_tuners->ignore_nice_load;
4471a34f	95	else
da712f3a	96	ignore_nice = cs_tuners->ignore_nice_load;
4471a34f VK	97
	98	policy = cdbs->cur_policy;
	99
	100	/* Get Absolute Load (in terms of freq for ondemand gov) */
	101	for_each_cpu(j, policy->cpus) {
	102	struct cpu_dbs_common_info *j_cdbs;
9366d840 SK	103	u64 cur_wall_time, cur_idle_time;
9366d840 SK	104	unsigned int idle_time, wall_time;
4471a34f	105	unsigned int load;
9366d840	106	int io_busy = 0;
4471a34f	107
4d5dcc42	108	j_cdbs = dbs_data->cdata->get_cpu_cdbs(j);
4471a34f	109
9366d840 SK	110	/*
	111	* For the purpose of ondemand, waiting for disk IO is
	112	* an indication that you're performance critical, and
	113	* not that the system is actually idle. So do not add
	114	* the iowait time to the cpu idle time.
	115	*/
	116	if (dbs_data->cdata->governor == GOV_ONDEMAND)
	117	io_busy = od_tuners->io_is_busy;
	118	cur_idle_time = get_cpu_idle_time(j, &cur_wall_time, io_busy);
4471a34f VK	119
	120	wall_time = (unsigned int)
	121	(cur_wall_time - j_cdbs->prev_cpu_wall);
	122	j_cdbs->prev_cpu_wall = cur_wall_time;
	123
	124	idle_time = (unsigned int)
	125	(cur_idle_time - j_cdbs->prev_cpu_idle);
	126	j_cdbs->prev_cpu_idle = cur_idle_time;
	127
	128	if (ignore_nice) {
	129	u64 cur_nice;
	130	unsigned long cur_nice_jiffies;
	131
	132	cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
	133	cdbs->prev_cpu_nice;
	134	/*
	135	* Assumption: nice time between sampling periods will
	136	* be less than 2^32 jiffies for 32 bit sys
	137	*/
	138	cur_nice_jiffies = (unsigned long)
	139	cputime64_to_jiffies64(cur_nice);
	140
	141	cdbs->prev_cpu_nice =
	142	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
	143	idle_time += jiffies_to_usecs(cur_nice_jiffies);
	144	}
	145
4471a34f VK	146	if (unlikely(!wall_time \|\| wall_time < idle_time))
	147	continue;
	148
	149	load = 100 * (wall_time - idle_time) / wall_time;
	150
4d5dcc42	151	if (dbs_data->cdata->governor == GOV_ONDEMAND) {
4471a34f VK	152	int freq_avg = __cpufreq_driver_getavg(policy, j);
	153	if (freq_avg <= 0)
	154	freq_avg = policy->cur;
	155
	156	load *= freq_avg;
	157	}
	158
	159	if (load > max_load)
	160	max_load = load;
	161	}
	162
4d5dcc42	163	dbs_data->cdata->gov_check_cpu(cpu, max_load);
4471a34f VK	164	}
	165	EXPORT_SYMBOL_GPL(dbs_check_cpu);
	166
031299b3 VK	167	static inline void __gov_queue_work(int cpu, struct dbs_data *dbs_data,
031299b3 VK	168	unsigned int delay)
4471a34f	169	{
4d5dcc42	170	struct cpu_dbs_common_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
4471a34f	171
031299b3	172	mod_delayed_work_on(cpu, system_wq, &cdbs->work, delay);
4471a34f VK	173	}
4471a34f VK	174
031299b3 VK	175	void gov_queue_work(struct dbs_data dbs_data, struct cpufreq_policy policy,
031299b3 VK	176	unsigned int delay, bool all_cpus)
4471a34f	177	{
031299b3 VK	178	int i;
	179
	180	if (!all_cpus) {
	181	__gov_queue_work(smp_processor_id(), dbs_data, delay);
	182	} else {
	183	for_each_cpu(i, policy->cpus)
	184	__gov_queue_work(i, dbs_data, delay);
	185	}
	186	}
	187	EXPORT_SYMBOL_GPL(gov_queue_work);
	188
	189	static inline void gov_cancel_work(struct dbs_data *dbs_data,
	190	struct cpufreq_policy *policy)
	191	{
	192	struct cpu_dbs_common_info *cdbs;
	193	int i;
58ddcead	194
031299b3 VK	195	for_each_cpu(i, policy->cpus) {
	196	cdbs = dbs_data->cdata->get_cpu_cdbs(i);
	197	cancel_delayed_work_sync(&cdbs->work);
	198	}
4471a34f VK	199	}
4471a34f VK	200
4447266b VK	201	/* Will return if we need to evaluate cpu load again or not */
	202	bool need_load_eval(struct cpu_dbs_common_info *cdbs,
	203	unsigned int sampling_rate)
	204	{
	205	if (policy_is_shared(cdbs->cur_policy)) {
	206	ktime_t time_now = ktime_get();
	207	s64 delta_us = ktime_us_delta(time_now, cdbs->time_stamp);
	208
	209	/* Do nothing if we recently have sampled */
	210	if (delta_us < (s64)(sampling_rate / 2))
	211	return false;
	212	else
	213	cdbs->time_stamp = time_now;
	214	}
	215
	216	return true;
	217	}
	218	EXPORT_SYMBOL_GPL(need_load_eval);
	219
4d5dcc42 VK	220	static void set_sampling_rate(struct dbs_data *dbs_data,
	221	unsigned int sampling_rate)
	222	{
	223	if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
	224	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	225	cs_tuners->sampling_rate = sampling_rate;
	226	} else {
	227	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
	228	od_tuners->sampling_rate = sampling_rate;
	229	}
	230	}
	231
	232	int cpufreq_governor_dbs(struct cpufreq_policy *policy,
	233	struct common_dbs_data *cdata, unsigned int event)
4471a34f	234	{
4d5dcc42	235	struct dbs_data *dbs_data;
4471a34f VK	236	struct od_cpu_dbs_info_s *od_dbs_info = NULL;
4471a34f VK	237	struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
8eeed095	238	struct od_ops *od_ops = NULL;
4d5dcc42 VK	239	struct od_dbs_tuners *od_tuners = NULL;
4d5dcc42 VK	240	struct cs_dbs_tuners *cs_tuners = NULL;
4471a34f	241	struct cpu_dbs_common_info *cpu_cdbs;
4d5dcc42	242	unsigned int sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
9366d840	243	int io_busy = 0;
4471a34f VK	244	int rc;
4471a34f VK	245
4d5dcc42 VK	246	if (have_governor_per_policy())
	247	dbs_data = policy->governor_data;
	248	else
	249	dbs_data = cdata->gdbs_data;
	250
	251	WARN_ON(!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT));
	252
	253	switch (event) {
	254	case CPUFREQ_GOV_POLICY_INIT:
	255	if (have_governor_per_policy()) {
	256	WARN_ON(dbs_data);
	257	} else if (dbs_data) {
a97c98ad	258	dbs_data->usage_count++;
4d5dcc42 VK	259	policy->governor_data = dbs_data;
	260	return 0;
	261	}
	262
	263	dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL);
	264	if (!dbs_data) {
	265	pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
	266	return -ENOMEM;
	267	}
	268
	269	dbs_data->cdata = cdata;
a97c98ad	270	dbs_data->usage_count = 1;
4d5dcc42 VK	271	rc = cdata->init(dbs_data);
	272	if (rc) {
	273	pr_err("%s: POLICY_INIT: init() failed\n", __func__);
	274	kfree(dbs_data);
	275	return rc;
	276	}
	277
	278	rc = sysfs_create_group(get_governor_parent_kobj(policy),
	279	get_sysfs_attr(dbs_data));
	280	if (rc) {
	281	cdata->exit(dbs_data);
	282	kfree(dbs_data);
	283	return rc;
	284	}
	285
	286	policy->governor_data = dbs_data;
	287
	288	/* policy latency is in nS. Convert it to uS first */
	289	latency = policy->cpuinfo.transition_latency / 1000;
	290	if (latency == 0)
	291	latency = 1;
	292
	293	/* Bring kernel and HW constraints together */
	294	dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
	295	MIN_LATENCY_MULTIPLIER * latency);
	296	set_sampling_rate(dbs_data, max(dbs_data->min_sampling_rate,
	297	latency * LATENCY_MULTIPLIER));
	298
a97c98ad VK	299	if ((cdata->governor == GOV_CONSERVATIVE) &&
a97c98ad VK	300	(!policy->governor->initialized)) {
4d5dcc42 VK	301	struct cs_ops *cs_ops = dbs_data->cdata->gov_ops;
	302
	303	cpufreq_register_notifier(cs_ops->notifier_block,
	304	CPUFREQ_TRANSITION_NOTIFIER);
	305	}
	306
	307	if (!have_governor_per_policy())
	308	cdata->gdbs_data = dbs_data;
	309
	310	return 0;
	311	case CPUFREQ_GOV_POLICY_EXIT:
a97c98ad	312	if (!--dbs_data->usage_count) {
4d5dcc42 VK	313	sysfs_remove_group(get_governor_parent_kobj(policy),
	314	get_sysfs_attr(dbs_data));
	315
a97c98ad VK	316	if ((dbs_data->cdata->governor == GOV_CONSERVATIVE) &&
a97c98ad VK	317	(policy->governor->initialized == 1)) {
4d5dcc42 VK	318	struct cs_ops *cs_ops = dbs_data->cdata->gov_ops;
	319
	320	cpufreq_unregister_notifier(cs_ops->notifier_block,
	321	CPUFREQ_TRANSITION_NOTIFIER);
	322	}
	323
	324	cdata->exit(dbs_data);
	325	kfree(dbs_data);
	326	cdata->gdbs_data = NULL;
	327	}
4471a34f	328
4d5dcc42 VK	329	policy->governor_data = NULL;
	330	return 0;
	331	}
	332
	333	cpu_cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
	334
	335	if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
	336	cs_tuners = dbs_data->tuners;
	337	cs_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu);
	338	sampling_rate = cs_tuners->sampling_rate;
da712f3a	339	ignore_nice = cs_tuners->ignore_nice_load;
4471a34f	340	} else {
4d5dcc42 VK	341	od_tuners = dbs_data->tuners;
	342	od_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu);
	343	sampling_rate = od_tuners->sampling_rate;
da712f3a	344	ignore_nice = od_tuners->ignore_nice_load;
4d5dcc42	345	od_ops = dbs_data->cdata->gov_ops;
9366d840	346	io_busy = od_tuners->io_is_busy;
4471a34f VK	347	}
	348
	349	switch (event) {
	350	case CPUFREQ_GOV_START:
3361b7b1	351	if (!policy->cur)
4471a34f VK	352	return -EINVAL;
	353
	354	mutex_lock(&dbs_data->mutex);
	355
4471a34f	356	for_each_cpu(j, policy->cpus) {
8eeed095	357	struct cpu_dbs_common_info *j_cdbs =
4d5dcc42	358	dbs_data->cdata->get_cpu_cdbs(j);
4471a34f	359
09dca5ae	360	j_cdbs->cpu = j;
4471a34f VK	361	j_cdbs->cur_policy = policy;
4471a34f VK	362	j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
9366d840	363	&j_cdbs->prev_cpu_wall, io_busy);
4471a34f VK	364	if (ignore_nice)
	365	j_cdbs->prev_cpu_nice =
	366	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
2abfa876 RA	367
	368	mutex_init(&j_cdbs->timer_mutex);
	369	INIT_DEFERRABLE_WORK(&j_cdbs->work,
4d5dcc42	370	dbs_data->cdata->gov_dbs_timer);
4471a34f VK	371	}
4471a34f VK	372
4471a34f VK	373	/*
	374	* conservative does not implement micro like ondemand
	375	* governor, thus we are bound to jiffes/HZ
	376	*/
4d5dcc42	377	if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
8eeed095 VK	378	cs_dbs_info->down_skip = 0;
	379	cs_dbs_info->enable = 1;
	380	cs_dbs_info->requested_freq = policy->cur;
4471a34f	381	} else {
8eeed095 VK	382	od_dbs_info->rate_mult = 1;
	383	od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
	384	od_ops->powersave_bias_init_cpu(cpu);
4471a34f VK	385	}
4471a34f VK	386
4471a34f VK	387	mutex_unlock(&dbs_data->mutex);
4471a34f VK	388
58ddcead FB	389	/* Initiate timer time stamp */
58ddcead FB	390	cpu_cdbs->time_stamp = ktime_get();
da53d61e	391
031299b3 VK	392	gov_queue_work(dbs_data, policy,
031299b3 VK	393	delay_for_sampling_rate(sampling_rate), true);
4471a34f VK	394	break;
	395
	396	case CPUFREQ_GOV_STOP:
4d5dcc42	397	if (dbs_data->cdata->governor == GOV_CONSERVATIVE)
4471a34f VK	398	cs_dbs_info->enable = 0;
4471a34f VK	399
031299b3	400	gov_cancel_work(dbs_data, policy);
4471a34f VK	401
	402	mutex_lock(&dbs_data->mutex);
	403	mutex_destroy(&cpu_cdbs->timer_mutex);
8eeed095	404
4471a34f VK	405	mutex_unlock(&dbs_data->mutex);
	406
	407	break;
	408
	409	case CPUFREQ_GOV_LIMITS:
	410	mutex_lock(&cpu_cdbs->timer_mutex);
	411	if (policy->max < cpu_cdbs->cur_policy->cur)
	412	__cpufreq_driver_target(cpu_cdbs->cur_policy,
	413	policy->max, CPUFREQ_RELATION_H);
	414	else if (policy->min > cpu_cdbs->cur_policy->cur)
	415	__cpufreq_driver_target(cpu_cdbs->cur_policy,
	416	policy->min, CPUFREQ_RELATION_L);
	417	dbs_check_cpu(dbs_data, cpu);
	418	mutex_unlock(&cpu_cdbs->timer_mutex);
	419	break;
	420	}
	421	return 0;
	422	}
	423	EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);