[mirror_ubuntu-bionic-kernel.git] / drivers / cpufreq / cpufreq_conservative.c

/*
 *  drivers/cpufreq/cpufreq_conservative.c
 *
 *  Copyright (C)  2001 Russell King
 *            (C)  2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
 *                      Jun Nakajima <jun.nakajima@intel.com>
 *            (C)  2009 Alexander Clouter <alex@digriz.org.uk>
 *
 * 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.
 */

#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/percpu-defs.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>

#include "cpufreq_governor.h"

/* Conservative governor macros */
#define DEF_FREQUENCY_UP_THRESHOLD		(80)
#define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
#define DEF_SAMPLING_DOWN_FACTOR		(1)
#define MAX_SAMPLING_DOWN_FACTOR		(10)

static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);

/*
 * Every sampling_rate, we check, if current idle time is less than 20%
 * (default), then we try to increase frequency. Every sampling_rate *
 * sampling_down_factor, we check, if current idle time is more than 80%
 * (default), then we try to decrease frequency
 *
 * Any frequency increase takes it to the maximum frequency. Frequency reduction
 * happens at minimum steps of 5% (default) of maximum frequency
 */
static void cs_check_cpu(int cpu, unsigned int load)
{
	struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
	struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
	struct dbs_data *dbs_data = policy->governor_data;
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int freq_target;

	/*
	 * break out if we 'cannot' reduce the speed as the user might
	 * want freq_step to be zero
	 */
	if (cs_tuners->freq_step == 0)
		return;

	/* Check for frequency increase */
	if (load > cs_tuners->up_threshold) {
		dbs_info->down_skip = 0;

		/* if we are already at full speed then break out early */
		if (dbs_info->requested_freq == policy->max)
			return;

		freq_target = (cs_tuners->freq_step * policy->max) / 100;

		/* max freq cannot be less than 100. But who knows.... */
		if (unlikely(freq_target == 0))
			freq_target = 5;

		dbs_info->requested_freq += freq_target;
		if (dbs_info->requested_freq > policy->max)
			dbs_info->requested_freq = policy->max;

		__cpufreq_driver_target(policy, dbs_info->requested_freq,
			CPUFREQ_RELATION_H);
		return;
	}

	/* if sampling_down_factor is active break out early */
	if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
		return;
	dbs_info->down_skip = 0;

	/* Check for frequency decrease */
	if (load < cs_tuners->down_threshold) {
		/*
		 * if we cannot reduce the frequency anymore, break out early
		 */
		if (policy->cur == policy->min)
			return;

		freq_target = (cs_tuners->freq_step * policy->max) / 100;

		dbs_info->requested_freq -= freq_target;
		if (dbs_info->requested_freq < policy->min)
			dbs_info->requested_freq = policy->min;

		__cpufreq_driver_target(policy, dbs_info->requested_freq,
				CPUFREQ_RELATION_L);
		return;
	}
}

static void cs_dbs_timer(struct work_struct *work)
{
	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
			struct cs_cpu_dbs_info_s, cdbs.work.work);
	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
			cpu);
	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
	bool modify_all = true;

	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
	if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
		modify_all = false;
	else
		dbs_check_cpu(dbs_data, cpu);

	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
}

static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
		void *data)
{
	struct cpufreq_freqs *freq = data;
	struct cs_cpu_dbs_info_s *dbs_info =
					&per_cpu(cs_cpu_dbs_info, freq->cpu);
	struct cpufreq_policy *policy;

	if (!dbs_info->enable)
		return 0;

	policy = dbs_info->cdbs.cur_policy;

	/*
	 * we only care if our internally tracked freq moves outside the 'valid'
	 * ranges of frequency available to us otherwise we do not change it
	*/
	if (dbs_info->requested_freq > policy->max
			|| dbs_info->requested_freq < policy->min)
		dbs_info->requested_freq = freq->new;

	return 0;
}

/************************** sysfs interface ************************/
static struct common_dbs_data cs_dbs_cdata;

static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
		const char *buf, size_t count)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int input;
	int ret;
	ret = sscanf(buf, "%u", &input);

	if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
		return -EINVAL;

	cs_tuners->sampling_down_factor = input;
	return count;
}

static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf,
		size_t count)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int input;
	int ret;
	ret = sscanf(buf, "%u", &input);

	if (ret != 1)
		return -EINVAL;

	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
	return count;
}

static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf,
		size_t count)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int input;
	int ret;
	ret = sscanf(buf, "%u", &input);

	if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
		return -EINVAL;

	cs_tuners->up_threshold = input;
	return count;
}

static ssize_t store_down_threshold(struct dbs_data *dbs_data, const char *buf,
		size_t count)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int input;
	int ret;
	ret = sscanf(buf, "%u", &input);

	/* cannot be lower than 11 otherwise freq will not fall */
	if (ret != 1 || input < 11 || input > 100 ||
			input >= cs_tuners->up_threshold)
		return -EINVAL;

	cs_tuners->down_threshold = input;
	return count;
}

static ssize_t store_ignore_nice(struct dbs_data *dbs_data, const char *buf,
		size_t count)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int input, j;
	int ret;

	ret = sscanf(buf, "%u", &input);
	if (ret != 1)
		return -EINVAL;

	if (input > 1)
		input = 1;

	if (input == cs_tuners->ignore_nice) /* nothing to do */
		return count;

	cs_tuners->ignore_nice = input;

	/* we need to re-evaluate prev_cpu_idle */
	for_each_online_cpu(j) {
		struct cs_cpu_dbs_info_s *dbs_info;
		dbs_info = &per_cpu(cs_cpu_dbs_info, j);
		dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
					&dbs_info->cdbs.prev_cpu_wall, 0);
		if (cs_tuners->ignore_nice)
			dbs_info->cdbs.prev_cpu_nice =
				kcpustat_cpu(j).cpustat[CPUTIME_NICE];
	}
	return count;
}

static ssize_t store_freq_step(struct dbs_data *dbs_data, const char *buf,
		size_t count)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	unsigned int input;
	int ret;
	ret = sscanf(buf, "%u", &input);

	if (ret != 1)
		return -EINVAL;

	if (input > 100)
		input = 100;

	/*
	 * no need to test here if freq_step is zero as the user might actually
	 * want this, they would be crazy though :)
	 */
	cs_tuners->freq_step = input;
	return count;
}

show_store_one(cs, sampling_rate);
show_store_one(cs, sampling_down_factor);
show_store_one(cs, up_threshold);
show_store_one(cs, down_threshold);
show_store_one(cs, ignore_nice);
show_store_one(cs, freq_step);
declare_show_sampling_rate_min(cs);

gov_sys_pol_attr_rw(sampling_rate);
gov_sys_pol_attr_rw(sampling_down_factor);
gov_sys_pol_attr_rw(up_threshold);
gov_sys_pol_attr_rw(down_threshold);
gov_sys_pol_attr_rw(ignore_nice);
gov_sys_pol_attr_rw(freq_step);
gov_sys_pol_attr_ro(sampling_rate_min);

static struct attribute *dbs_attributes_gov_sys[] = {
	&sampling_rate_min_gov_sys.attr,
	&sampling_rate_gov_sys.attr,
	&sampling_down_factor_gov_sys.attr,
	&up_threshold_gov_sys.attr,
	&down_threshold_gov_sys.attr,
	&ignore_nice_gov_sys.attr,
	&freq_step_gov_sys.attr,
	NULL
};

static struct attribute_group cs_attr_group_gov_sys = {
	.attrs = dbs_attributes_gov_sys,
	.name = "conservative",
};

static struct attribute *dbs_attributes_gov_pol[] = {
	&sampling_rate_min_gov_pol.attr,
	&sampling_rate_gov_pol.attr,
	&sampling_down_factor_gov_pol.attr,
	&up_threshold_gov_pol.attr,
	&down_threshold_gov_pol.attr,
	&ignore_nice_gov_pol.attr,
	&freq_step_gov_pol.attr,
	NULL
};

static struct attribute_group cs_attr_group_gov_pol = {
	.attrs = dbs_attributes_gov_pol,
	.name = "conservative",
};

/************************** sysfs end ************************/

static int cs_init(struct dbs_data *dbs_data)
{
	struct cs_dbs_tuners *tuners;

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

	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
	tuners->ignore_nice = 0;
	tuners->freq_step = 5;

	dbs_data->tuners = tuners;
	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
		jiffies_to_usecs(10);
	mutex_init(&dbs_data->mutex);
	return 0;
}

static void cs_exit(struct dbs_data *dbs_data)
{
	kfree(dbs_data->tuners);
}

define_get_cpu_dbs_routines(cs_cpu_dbs_info);

static struct notifier_block cs_cpufreq_notifier_block = {
	.notifier_call = dbs_cpufreq_notifier,
};

static struct cs_ops cs_ops = {
	.notifier_block = &cs_cpufreq_notifier_block,
};

static struct common_dbs_data cs_dbs_cdata = {
	.governor = GOV_CONSERVATIVE,
	.attr_group_gov_sys = &cs_attr_group_gov_sys,
	.attr_group_gov_pol = &cs_attr_group_gov_pol,
	.get_cpu_cdbs = get_cpu_cdbs,
	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	.gov_dbs_timer = cs_dbs_timer,
	.gov_check_cpu = cs_check_cpu,
	.gov_ops = &cs_ops,
	.init = cs_init,
	.exit = cs_exit,
};

static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
				   unsigned int event)
{
	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
}

#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
static
#endif
struct cpufreq_governor cpufreq_gov_conservative = {
	.name			= "conservative",
	.governor		= cs_cpufreq_governor_dbs,
	.max_transition_latency	= TRANSITION_LATENCY_LIMIT,
	.owner			= THIS_MODULE,
};

static int __init cpufreq_gov_dbs_init(void)
{
	return cpufreq_register_governor(&cpufreq_gov_conservative);
}

static void __exit cpufreq_gov_dbs_exit(void)
{
	cpufreq_unregister_governor(&cpufreq_gov_conservative);
}

MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
		"Low Latency Frequency Transition capable processors "
		"optimised for use in a battery environment");
MODULE_LICENSE("GPL");

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
fs_initcall(cpufreq_gov_dbs_init);
#else
module_init(cpufreq_gov_dbs_init);
#endif
module_exit(cpufreq_gov_dbs_exit);
Commit	Line	Data
b9170836 DJ	1	/*
	2	* drivers/cpufreq/cpufreq_conservative.c
	3	*
	4	* Copyright (C) 2001 Russell King
	5	* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
	6	* Jun Nakajima <jun.nakajima@intel.com>
11a80a9c	7	* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
b9170836 DJ	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
b9170836	14	#include <linux/cpufreq.h>
4471a34f VK	15	#include <linux/init.h>
4471a34f VK	16	#include <linux/kernel.h>
b9170836	17	#include <linux/kernel_stat.h>
4471a34f VK	18	#include <linux/kobject.h>
4471a34f VK	19	#include <linux/module.h>
3fc54d37	20	#include <linux/mutex.h>
4471a34f VK	21	#include <linux/notifier.h>
4471a34f VK	22	#include <linux/percpu-defs.h>
4d5dcc42	23	#include <linux/slab.h>
4471a34f VK	24	#include <linux/sysfs.h>
4471a34f VK	25	#include <linux/types.h>
8e677ce8	26
4471a34f	27	#include "cpufreq_governor.h"
b9170836	28
c88883cd	29	/* Conservative governor macros */
b9170836	30	#define DEF_FREQUENCY_UP_THRESHOLD (80)
b9170836	31	#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
2c906b31 AC	32	#define DEF_SAMPLING_DOWN_FACTOR (1)
2c906b31 AC	33	#define MAX_SAMPLING_DOWN_FACTOR (10)
b9170836	34
4471a34f	35	static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
b9170836	36
4471a34f VK	37	/*
4471a34f VK	38	* Every sampling_rate, we check, if current idle time is less than 20%
7af1c056 SK	39	* (default), then we try to increase frequency. Every sampling_rate *
	40	* sampling_down_factor, we check, if current idle time is more than 80%
	41	* (default), then we try to decrease frequency
4471a34f VK	42	*
	43	* Any frequency increase takes it to the maximum frequency. Frequency reduction
	44	* happens at minimum steps of 5% (default) of maximum frequency
	45	*/
	46	static void cs_check_cpu(int cpu, unsigned int load)
a8d7c3bc	47	{
4471a34f VK	48	struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
4471a34f VK	49	struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
4d5dcc42 VK	50	struct dbs_data *dbs_data = policy->governor_data;
4d5dcc42 VK	51	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f VK	52	unsigned int freq_target;
	53
	54	/*
	55	* break out if we 'cannot' reduce the speed as the user might
	56	* want freq_step to be zero
	57	*/
4d5dcc42	58	if (cs_tuners->freq_step == 0)
4471a34f VK	59	return;
	60
	61	/* Check for frequency increase */
4d5dcc42	62	if (load > cs_tuners->up_threshold) {
4471a34f VK	63	dbs_info->down_skip = 0;
	64
	65	/* if we are already at full speed then break out early */
	66	if (dbs_info->requested_freq == policy->max)
	67	return;
	68
4d5dcc42	69	freq_target = (cs_tuners->freq_step * policy->max) / 100;
4471a34f VK	70
	71	/* max freq cannot be less than 100. But who knows.... */
	72	if (unlikely(freq_target == 0))
	73	freq_target = 5;
	74
	75	dbs_info->requested_freq += freq_target;
	76	if (dbs_info->requested_freq > policy->max)
	77	dbs_info->requested_freq = policy->max;
a8d7c3bc	78
4471a34f VK	79	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	80	CPUFREQ_RELATION_H);
	81	return;
	82	}
	83
7af1c056 SK	84	/* if sampling_down_factor is active break out early */
	85	if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
	86	return;
	87	dbs_info->down_skip = 0;
	88
27ed3cd2 SK	89	/* Check for frequency decrease */
27ed3cd2 SK	90	if (load < cs_tuners->down_threshold) {
4471a34f VK	91	/*
	92	* if we cannot reduce the frequency anymore, break out early
	93	*/
	94	if (policy->cur == policy->min)
	95	return;
	96
ad529a9c NK	97	freq_target = (cs_tuners->freq_step * policy->max) / 100;
	98
	99	dbs_info->requested_freq -= freq_target;
	100	if (dbs_info->requested_freq < policy->min)
	101	dbs_info->requested_freq = policy->min;
	102
4471a34f	103	__cpufreq_driver_target(policy, dbs_info->requested_freq,
fed573d5	104	CPUFREQ_RELATION_L);
4471a34f VK	105	return;
	106	}
	107	}
	108
4447266b	109	static void cs_dbs_timer(struct work_struct *work)
4471a34f	110	{
4447266b VK	111	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
4447266b VK	112	struct cs_cpu_dbs_info_s, cdbs.work.work);
09dca5ae	113	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
4447266b VK	114	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
4447266b VK	115	cpu);
4d5dcc42 VK	116	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	117	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	118	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
031299b3	119	bool modify_all = true;
4471a34f	120
4447266b	121	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
031299b3 VK	122	if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
	123	modify_all = false;
	124	else
4d5dcc42	125	dbs_check_cpu(dbs_data, cpu);
66df2a01	126
031299b3	127	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
4447266b	128	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
66df2a01 FB	129	}
66df2a01 FB	130
4471a34f VK	131	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	132	void *data)
	133	{
	134	struct cpufreq_freqs *freq = data;
	135	struct cs_cpu_dbs_info_s *dbs_info =
	136	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	137	struct cpufreq_policy *policy;
f407a08b AC	138
4471a34f	139	if (!dbs_info->enable)
a8d7c3bc EO	140	return 0;
a8d7c3bc EO	141
4471a34f	142	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	143
f407a08b AC	144	/*
4471a34f	145	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	146	* ranges of frequency available to us otherwise we do not change it
f407a08b	147	*/
4471a34f VK	148	if (dbs_info->requested_freq > policy->max
	149	\|\| dbs_info->requested_freq < policy->min)
	150	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	151
	152	return 0;
	153	}
	154
b9170836	155	/************************ sysfs interface **********************/
4d5dcc42	156	static struct common_dbs_data cs_dbs_cdata;
b9170836	157
4d5dcc42 VK	158	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	159	const char *buf, size_t count)
b9170836	160	{
4d5dcc42	161	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	162	unsigned int input;
b9170836 DJ	163	int ret;
9acef487	164	ret = sscanf(buf, "%u", &input);
8e677ce8	165
2c906b31	166	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	167	return -EINVAL;
b9170836 DJ	168
4d5dcc42	169	cs_tuners->sampling_down_factor = input;
b9170836 DJ	170	return count;
	171	}
	172
4d5dcc42 VK	173	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	174	size_t count)
b9170836	175	{
4d5dcc42	176	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	177	unsigned int input;
b9170836 DJ	178	int ret;
9acef487	179	ret = sscanf(buf, "%u", &input);
b9170836	180
8e677ce8	181	if (ret != 1)
b9170836	182	return -EINVAL;
8e677ce8	183
4d5dcc42	184	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	185	return count;
	186	}
	187
4d5dcc42 VK	188	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	189	size_t count)
b9170836	190	{
4d5dcc42	191	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	192	unsigned int input;
b9170836 DJ	193	int ret;
9acef487	194	ret = sscanf(buf, "%u", &input);
b9170836	195
4d5dcc42	196	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	197	return -EINVAL;
b9170836	198
4d5dcc42	199	cs_tuners->up_threshold = input;
b9170836 DJ	200	return count;
	201	}
	202
4d5dcc42 VK	203	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	204	size_t count)
b9170836	205	{
4d5dcc42	206	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	207	unsigned int input;
b9170836 DJ	208	int ret;
9acef487	209	ret = sscanf(buf, "%u", &input);
b9170836	210
8e677ce8 AC	211	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	212	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	213	input >= cs_tuners->up_threshold)
b9170836	214	return -EINVAL;
b9170836	215
4d5dcc42	216	cs_tuners->down_threshold = input;
b9170836 DJ	217	return count;
	218	}
	219
4d5dcc42 VK	220	static ssize_t store_ignore_nice(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	221	size_t count)
b9170836	222	{
4d5dcc42	223	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	224	unsigned int input, j;
b9170836 DJ	225	int ret;
b9170836 DJ	226
18a7247d DJ	227	ret = sscanf(buf, "%u", &input);
18a7247d DJ	228	if (ret != 1)
b9170836 DJ	229	return -EINVAL;
b9170836 DJ	230
18a7247d	231	if (input > 1)
b9170836	232	input = 1;
18a7247d	233
4d5dcc42	234	if (input == cs_tuners->ignore_nice) /* nothing to do */
b9170836	235	return count;
326c86de	236
4d5dcc42	237	cs_tuners->ignore_nice = input;
b9170836	238
8e677ce8	239	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	240	for_each_online_cpu(j) {
4471a34f	241	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	242	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	243	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	244	&dbs_info->cdbs.prev_cpu_wall, 0);
4d5dcc42	245	if (cs_tuners->ignore_nice)
4471a34f VK	246	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	247	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	248	}
b9170836 DJ	249	return count;
	250	}
	251
4d5dcc42 VK	252	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	253	size_t count)
b9170836	254	{
4d5dcc42	255	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	256	unsigned int input;
b9170836 DJ	257	int ret;
18a7247d	258	ret = sscanf(buf, "%u", &input);
b9170836	259
18a7247d	260	if (ret != 1)
b9170836 DJ	261	return -EINVAL;
b9170836 DJ	262
18a7247d	263	if (input > 100)
b9170836	264	input = 100;
18a7247d	265
4471a34f VK	266	/*
	267	* no need to test here if freq_step is zero as the user might actually
	268	* want this, they would be crazy though :)
	269	*/
4d5dcc42	270	cs_tuners->freq_step = input;
b9170836 DJ	271	return count;
	272	}
	273
4d5dcc42 VK	274	show_store_one(cs, sampling_rate);
	275	show_store_one(cs, sampling_down_factor);
	276	show_store_one(cs, up_threshold);
	277	show_store_one(cs, down_threshold);
	278	show_store_one(cs, ignore_nice);
	279	show_store_one(cs, freq_step);
	280	declare_show_sampling_rate_min(cs);
	281
	282	gov_sys_pol_attr_rw(sampling_rate);
	283	gov_sys_pol_attr_rw(sampling_down_factor);
	284	gov_sys_pol_attr_rw(up_threshold);
	285	gov_sys_pol_attr_rw(down_threshold);
	286	gov_sys_pol_attr_rw(ignore_nice);
	287	gov_sys_pol_attr_rw(freq_step);
	288	gov_sys_pol_attr_ro(sampling_rate_min);
	289
	290	static struct attribute *dbs_attributes_gov_sys[] = {
	291	&sampling_rate_min_gov_sys.attr,
	292	&sampling_rate_gov_sys.attr,
	293	&sampling_down_factor_gov_sys.attr,
	294	&up_threshold_gov_sys.attr,
	295	&down_threshold_gov_sys.attr,
	296	&ignore_nice_gov_sys.attr,
	297	&freq_step_gov_sys.attr,
b9170836 DJ	298	NULL
	299	};
	300
4d5dcc42 VK	301	static struct attribute_group cs_attr_group_gov_sys = {
	302	.attrs = dbs_attributes_gov_sys,
	303	.name = "conservative",
	304	};
	305
	306	static struct attribute *dbs_attributes_gov_pol[] = {
	307	&sampling_rate_min_gov_pol.attr,
	308	&sampling_rate_gov_pol.attr,
	309	&sampling_down_factor_gov_pol.attr,
	310	&up_threshold_gov_pol.attr,
	311	&down_threshold_gov_pol.attr,
	312	&ignore_nice_gov_pol.attr,
	313	&freq_step_gov_pol.attr,
	314	NULL
	315	};
	316
	317	static struct attribute_group cs_attr_group_gov_pol = {
	318	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	319	.name = "conservative",
	320	};
	321
	322	/************************ sysfs end **********************/
	323
4d5dcc42 VK	324	static int cs_init(struct dbs_data *dbs_data)
	325	{
	326	struct cs_dbs_tuners *tuners;
	327
	328	tuners = kzalloc(sizeof(struct cs_dbs_tuners), GFP_KERNEL);
	329	if (!tuners) {
	330	pr_err("%s: kzalloc failed\n", __func__);
	331	return -ENOMEM;
	332	}
	333
	334	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	335	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	336	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
	337	tuners->ignore_nice = 0;
	338	tuners->freq_step = 5;
	339
	340	dbs_data->tuners = tuners;
	341	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	342	jiffies_to_usecs(10);
	343	mutex_init(&dbs_data->mutex);
	344	return 0;
	345	}
	346
	347	static void cs_exit(struct dbs_data *dbs_data)
	348	{
	349	kfree(dbs_data->tuners);
	350	}
	351
4471a34f	352	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	353
4471a34f VK	354	static struct notifier_block cs_cpufreq_notifier_block = {
	355	.notifier_call = dbs_cpufreq_notifier,
	356	};
8e677ce8	357
4471a34f VK	358	static struct cs_ops cs_ops = {
	359	.notifier_block = &cs_cpufreq_notifier_block,
	360	};
b9170836	361
4d5dcc42	362	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	363	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	364	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	365	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	366	.get_cpu_cdbs = get_cpu_cdbs,
	367	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	368	.gov_dbs_timer = cs_dbs_timer,
	369	.gov_check_cpu = cs_check_cpu,
	370	.gov_ops = &cs_ops,
4d5dcc42 VK	371	.init = cs_init,
4d5dcc42 VK	372	.exit = cs_exit,
4471a34f	373	};
b9170836	374
4471a34f	375	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	376	unsigned int event)
b9170836 DJ	377	{
4d5dcc42	378	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	379	}
b9170836 DJ	380
c4d14bc0 SW	381	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	382	static
	383	#endif
1c256245 TR	384	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	385	.name = "conservative",
4471a34f	386	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	387	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	388	.owner = THIS_MODULE,
b9170836 DJ	389	};
	390
	391	static int __init cpufreq_gov_dbs_init(void)
	392	{
57df5573	393	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	394	}
	395
	396	static void __exit cpufreq_gov_dbs_exit(void)
	397	{
1c256245	398	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	399	}
b9170836 DJ	400
11a80a9c	401	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	402	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	403	"Low Latency Frequency Transition capable processors "
b9170836 DJ	404	"optimised for use in a battery environment");
9acef487	405	MODULE_LICENSE("GPL");
b9170836	406
6915719b JW	407	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	408	fs_initcall(cpufreq_gov_dbs_init);
	409	#else
b9170836	410	module_init(cpufreq_gov_dbs_init);
6915719b	411	#endif
b9170836	412	module_exit(cpufreq_gov_dbs_exit);