[GitHub/mt8127/android_kernel_alcatel_ttab.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_FREQUENCY_STEP			(5)
#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);

static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
					   struct cpufreq_policy *policy)
{
	unsigned int 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 = DEF_FREQUENCY_STEP;

	return freq_target;
}

/*
 * 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;

	/*
	 * 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;

		dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
		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;

		dbs_info->requested_freq -= get_freq_target(cs_tuners, policy);
		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 1 otherwise freq will not fall */
	if (ret != 1 || input < 1 || input > 100 ||
			input >= cs_tuners->up_threshold)
		return -EINVAL;

	cs_tuners->down_threshold = input;
	return count;
}

static ssize_t store_ignore_nice_load(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_load) /* nothing to do */
		return count;

	cs_tuners->ignore_nice_load = 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_load)
			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_load);
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_load);
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_load_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_load_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_load = 0;
	tuners->freq_step = DEF_FREQUENCY_STEP;

	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)
98765847	32	#define DEF_FREQUENCY_STEP (5)
2c906b31 AC	33	#define DEF_SAMPLING_DOWN_FACTOR (1)
2c906b31 AC	34	#define MAX_SAMPLING_DOWN_FACTOR (10)
b9170836	35
4471a34f	36	static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
b9170836	37
98765847 SK	38	static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
	39	struct cpufreq_policy *policy)
	40	{
	41	unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100;
	42
	43	/* max freq cannot be less than 100. But who knows... */
	44	if (unlikely(freq_target == 0))
	45	freq_target = DEF_FREQUENCY_STEP;
	46
	47	return freq_target;
	48	}
	49
4471a34f VK	50	/*
4471a34f VK	51	* Every sampling_rate, we check, if current idle time is less than 20%
7af1c056 SK	52	* (default), then we try to increase frequency. Every sampling_rate *
	53	* sampling_down_factor, we check, if current idle time is more than 80%
	54	* (default), then we try to decrease frequency
4471a34f VK	55	*
	56	* Any frequency increase takes it to the maximum frequency. Frequency reduction
	57	* happens at minimum steps of 5% (default) of maximum frequency
	58	*/
	59	static void cs_check_cpu(int cpu, unsigned int load)
a8d7c3bc	60	{
4471a34f VK	61	struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
4471a34f VK	62	struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
4d5dcc42 VK	63	struct dbs_data *dbs_data = policy->governor_data;
4d5dcc42 VK	64	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f VK	65
	66	/*
	67	* break out if we 'cannot' reduce the speed as the user might
	68	* want freq_step to be zero
	69	*/
4d5dcc42	70	if (cs_tuners->freq_step == 0)
4471a34f VK	71	return;
	72
	73	/* Check for frequency increase */
4d5dcc42	74	if (load > cs_tuners->up_threshold) {
4471a34f VK	75	dbs_info->down_skip = 0;
	76
	77	/* if we are already at full speed then break out early */
	78	if (dbs_info->requested_freq == policy->max)
	79	return;
	80
98765847	81	dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
4471a34f VK	82	if (dbs_info->requested_freq > policy->max)
4471a34f VK	83	dbs_info->requested_freq = policy->max;
a8d7c3bc	84
4471a34f VK	85	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	86	CPUFREQ_RELATION_H);
	87	return;
	88	}
	89
7af1c056 SK	90	/* if sampling_down_factor is active break out early */
	91	if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
	92	return;
	93	dbs_info->down_skip = 0;
	94
27ed3cd2 SK	95	/* Check for frequency decrease */
27ed3cd2 SK	96	if (load < cs_tuners->down_threshold) {
4471a34f VK	97	/*
	98	* if we cannot reduce the frequency anymore, break out early
	99	*/
	100	if (policy->cur == policy->min)
	101	return;
	102
98765847	103	dbs_info->requested_freq -= get_freq_target(cs_tuners, policy);
ad529a9c NK	104	if (dbs_info->requested_freq < policy->min)
	105	dbs_info->requested_freq = policy->min;
	106
4471a34f	107	__cpufreq_driver_target(policy, dbs_info->requested_freq,
fed573d5	108	CPUFREQ_RELATION_L);
4471a34f VK	109	return;
	110	}
	111	}
	112
4447266b	113	static void cs_dbs_timer(struct work_struct *work)
4471a34f	114	{
4447266b VK	115	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
4447266b VK	116	struct cs_cpu_dbs_info_s, cdbs.work.work);
09dca5ae	117	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
4447266b VK	118	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
4447266b VK	119	cpu);
4d5dcc42 VK	120	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	121	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	122	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
031299b3	123	bool modify_all = true;
4471a34f	124
4447266b	125	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
031299b3 VK	126	if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
	127	modify_all = false;
	128	else
4d5dcc42	129	dbs_check_cpu(dbs_data, cpu);
66df2a01	130
031299b3	131	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
4447266b	132	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
66df2a01 FB	133	}
66df2a01 FB	134
4471a34f VK	135	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	136	void *data)
	137	{
	138	struct cpufreq_freqs *freq = data;
	139	struct cs_cpu_dbs_info_s *dbs_info =
	140	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	141	struct cpufreq_policy *policy;
f407a08b AC	142
4471a34f	143	if (!dbs_info->enable)
a8d7c3bc EO	144	return 0;
a8d7c3bc EO	145
4471a34f	146	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	147
f407a08b AC	148	/*
4471a34f	149	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	150	* ranges of frequency available to us otherwise we do not change it
f407a08b	151	*/
4471a34f VK	152	if (dbs_info->requested_freq > policy->max
	153	\|\| dbs_info->requested_freq < policy->min)
	154	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	155
	156	return 0;
	157	}
	158
b9170836	159	/************************ sysfs interface **********************/
4d5dcc42	160	static struct common_dbs_data cs_dbs_cdata;
b9170836	161
4d5dcc42 VK	162	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	163	const char *buf, size_t count)
b9170836	164	{
4d5dcc42	165	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	166	unsigned int input;
b9170836 DJ	167	int ret;
9acef487	168	ret = sscanf(buf, "%u", &input);
8e677ce8	169
2c906b31	170	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	171	return -EINVAL;
b9170836 DJ	172
4d5dcc42	173	cs_tuners->sampling_down_factor = input;
b9170836 DJ	174	return count;
	175	}
	176
4d5dcc42 VK	177	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	178	size_t count)
b9170836	179	{
4d5dcc42	180	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	181	unsigned int input;
b9170836 DJ	182	int ret;
9acef487	183	ret = sscanf(buf, "%u", &input);
b9170836	184
8e677ce8	185	if (ret != 1)
b9170836	186	return -EINVAL;
8e677ce8	187
4d5dcc42	188	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	189	return count;
	190	}
	191
4d5dcc42 VK	192	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	193	size_t count)
b9170836	194	{
4d5dcc42	195	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	196	unsigned int input;
b9170836 DJ	197	int ret;
9acef487	198	ret = sscanf(buf, "%u", &input);
b9170836	199
4d5dcc42	200	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	201	return -EINVAL;
b9170836	202
4d5dcc42	203	cs_tuners->up_threshold = input;
b9170836 DJ	204	return count;
	205	}
	206
4d5dcc42 VK	207	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	208	size_t count)
b9170836	209	{
4d5dcc42	210	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	211	unsigned int input;
b9170836 DJ	212	int ret;
9acef487	213	ret = sscanf(buf, "%u", &input);
b9170836	214
69e0576f TW	215	/* cannot be lower than 1 otherwise freq will not fall */
69e0576f TW	216	if (ret != 1 \|\| input < 1 \|\| input > 100 \|\|
4d5dcc42	217	input >= cs_tuners->up_threshold)
b9170836	218	return -EINVAL;
b9170836	219
4d5dcc42	220	cs_tuners->down_threshold = input;
b9170836 DJ	221	return count;
	222	}
	223
da712f3a VK	224	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
da712f3a VK	225	const char *buf, size_t count)
b9170836	226	{
4d5dcc42	227	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	228	unsigned int input, j;
b9170836 DJ	229	int ret;
b9170836 DJ	230
18a7247d DJ	231	ret = sscanf(buf, "%u", &input);
18a7247d DJ	232	if (ret != 1)
b9170836 DJ	233	return -EINVAL;
b9170836 DJ	234
18a7247d	235	if (input > 1)
b9170836	236	input = 1;
18a7247d	237
da712f3a	238	if (input == cs_tuners->ignore_nice_load) /* nothing to do */
b9170836	239	return count;
326c86de	240
da712f3a	241	cs_tuners->ignore_nice_load = input;
b9170836	242
8e677ce8	243	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	244	for_each_online_cpu(j) {
4471a34f	245	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	246	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	247	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	248	&dbs_info->cdbs.prev_cpu_wall, 0);
da712f3a	249	if (cs_tuners->ignore_nice_load)
4471a34f VK	250	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	251	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	252	}
b9170836 DJ	253	return count;
	254	}
	255
4d5dcc42 VK	256	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	257	size_t count)
b9170836	258	{
4d5dcc42	259	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	260	unsigned int input;
b9170836 DJ	261	int ret;
18a7247d	262	ret = sscanf(buf, "%u", &input);
b9170836	263
18a7247d	264	if (ret != 1)
b9170836 DJ	265	return -EINVAL;
b9170836 DJ	266
18a7247d	267	if (input > 100)
b9170836	268	input = 100;
18a7247d	269
4471a34f VK	270	/*
	271	* no need to test here if freq_step is zero as the user might actually
	272	* want this, they would be crazy though :)
	273	*/
4d5dcc42	274	cs_tuners->freq_step = input;
b9170836 DJ	275	return count;
	276	}
	277
4d5dcc42 VK	278	show_store_one(cs, sampling_rate);
	279	show_store_one(cs, sampling_down_factor);
	280	show_store_one(cs, up_threshold);
	281	show_store_one(cs, down_threshold);
da712f3a	282	show_store_one(cs, ignore_nice_load);
4d5dcc42 VK	283	show_store_one(cs, freq_step);
	284	declare_show_sampling_rate_min(cs);
	285
	286	gov_sys_pol_attr_rw(sampling_rate);
	287	gov_sys_pol_attr_rw(sampling_down_factor);
	288	gov_sys_pol_attr_rw(up_threshold);
	289	gov_sys_pol_attr_rw(down_threshold);
da712f3a	290	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42 VK	291	gov_sys_pol_attr_rw(freq_step);
	292	gov_sys_pol_attr_ro(sampling_rate_min);
	293
	294	static struct attribute *dbs_attributes_gov_sys[] = {
	295	&sampling_rate_min_gov_sys.attr,
	296	&sampling_rate_gov_sys.attr,
	297	&sampling_down_factor_gov_sys.attr,
	298	&up_threshold_gov_sys.attr,
	299	&down_threshold_gov_sys.attr,
da712f3a	300	&ignore_nice_load_gov_sys.attr,
4d5dcc42	301	&freq_step_gov_sys.attr,
b9170836 DJ	302	NULL
	303	};
	304
4d5dcc42 VK	305	static struct attribute_group cs_attr_group_gov_sys = {
	306	.attrs = dbs_attributes_gov_sys,
	307	.name = "conservative",
	308	};
	309
	310	static struct attribute *dbs_attributes_gov_pol[] = {
	311	&sampling_rate_min_gov_pol.attr,
	312	&sampling_rate_gov_pol.attr,
	313	&sampling_down_factor_gov_pol.attr,
	314	&up_threshold_gov_pol.attr,
	315	&down_threshold_gov_pol.attr,
da712f3a	316	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	317	&freq_step_gov_pol.attr,
	318	NULL
	319	};
	320
	321	static struct attribute_group cs_attr_group_gov_pol = {
	322	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	323	.name = "conservative",
	324	};
	325
	326	/************************ sysfs end **********************/
	327
4d5dcc42 VK	328	static int cs_init(struct dbs_data *dbs_data)
	329	{
	330	struct cs_dbs_tuners *tuners;
	331
	332	tuners = kzalloc(sizeof(struct cs_dbs_tuners), GFP_KERNEL);
	333	if (!tuners) {
	334	pr_err("%s: kzalloc failed\n", __func__);
	335	return -ENOMEM;
	336	}
	337
	338	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	339	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	340	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
da712f3a	341	tuners->ignore_nice_load = 0;
98765847	342	tuners->freq_step = DEF_FREQUENCY_STEP;
4d5dcc42 VK	343
	344	dbs_data->tuners = tuners;
	345	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	346	jiffies_to_usecs(10);
	347	mutex_init(&dbs_data->mutex);
	348	return 0;
	349	}
	350
	351	static void cs_exit(struct dbs_data *dbs_data)
	352	{
	353	kfree(dbs_data->tuners);
	354	}
	355
4471a34f	356	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	357
4471a34f VK	358	static struct notifier_block cs_cpufreq_notifier_block = {
	359	.notifier_call = dbs_cpufreq_notifier,
	360	};
8e677ce8	361
4471a34f VK	362	static struct cs_ops cs_ops = {
	363	.notifier_block = &cs_cpufreq_notifier_block,
	364	};
b9170836	365
4d5dcc42	366	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	367	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	368	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	369	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	370	.get_cpu_cdbs = get_cpu_cdbs,
	371	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	372	.gov_dbs_timer = cs_dbs_timer,
	373	.gov_check_cpu = cs_check_cpu,
	374	.gov_ops = &cs_ops,
4d5dcc42 VK	375	.init = cs_init,
4d5dcc42 VK	376	.exit = cs_exit,
4471a34f	377	};
b9170836	378
4471a34f	379	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	380	unsigned int event)
b9170836 DJ	381	{
4d5dcc42	382	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	383	}
b9170836 DJ	384
c4d14bc0 SW	385	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	386	static
	387	#endif
1c256245 TR	388	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	389	.name = "conservative",
4471a34f	390	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	391	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	392	.owner = THIS_MODULE,
b9170836 DJ	393	};
	394
	395	static int __init cpufreq_gov_dbs_init(void)
	396	{
57df5573	397	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	398	}
	399
	400	static void __exit cpufreq_gov_dbs_exit(void)
	401	{
1c256245	402	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	403	}
b9170836 DJ	404
11a80a9c	405	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	406	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	407	"Low Latency Frequency Transition capable processors "
b9170836 DJ	408	"optimised for use in a battery environment");
9acef487	409	MODULE_LICENSE("GPL");
b9170836	410
6915719b JW	411	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	412	fs_initcall(cpufreq_gov_dbs_init);
	413	#else
b9170836	414	module_init(cpufreq_gov_dbs_init);
6915719b	415	#endif
b9170836	416	module_exit(cpufreq_gov_dbs_exit);