[deliverable/linux.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/slab.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);

		__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);

		__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_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(*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
4d5dcc42	14	#include <linux/slab.h>
4471a34f	15	#include "cpufreq_governor.h"
b9170836	16
c88883cd	17	/* Conservative governor macros */
b9170836	18	#define DEF_FREQUENCY_UP_THRESHOLD (80)
b9170836	19	#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
98765847	20	#define DEF_FREQUENCY_STEP (5)
2c906b31 AC	21	#define DEF_SAMPLING_DOWN_FACTOR (1)
2c906b31 AC	22	#define MAX_SAMPLING_DOWN_FACTOR (10)
b9170836	23
4471a34f	24	static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
b9170836	25
98765847 SK	26	static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
	27	struct cpufreq_policy *policy)
	28	{
	29	unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100;
	30
	31	/* max freq cannot be less than 100. But who knows... */
	32	if (unlikely(freq_target == 0))
	33	freq_target = DEF_FREQUENCY_STEP;
	34
	35	return freq_target;
	36	}
	37
4471a34f VK	38	/*
4471a34f VK	39	* Every sampling_rate, we check, if current idle time is less than 20%
7af1c056 SK	40	* (default), then we try to increase frequency. Every sampling_rate *
	41	* sampling_down_factor, we check, if current idle time is more than 80%
	42	* (default), then we try to decrease frequency
4471a34f VK	43	*
	44	* Any frequency increase takes it to the maximum frequency. Frequency reduction
	45	* happens at minimum steps of 5% (default) of maximum frequency
	46	*/
	47	static void cs_check_cpu(int cpu, unsigned int load)
a8d7c3bc	48	{
4471a34f VK	49	struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
4471a34f VK	50	struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
4d5dcc42 VK	51	struct dbs_data *dbs_data = policy->governor_data;
4d5dcc42 VK	52	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f VK	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
98765847	69	dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
a8d7c3bc	70
4471a34f VK	71	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	72	CPUFREQ_RELATION_H);
	73	return;
	74	}
	75
7af1c056 SK	76	/* if sampling_down_factor is active break out early */
	77	if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
	78	return;
	79	dbs_info->down_skip = 0;
	80
27ed3cd2 SK	81	/* Check for frequency decrease */
27ed3cd2 SK	82	if (load < cs_tuners->down_threshold) {
4471a34f VK	83	/*
	84	* if we cannot reduce the frequency anymore, break out early
	85	*/
	86	if (policy->cur == policy->min)
	87	return;
	88
98765847	89	dbs_info->requested_freq -= get_freq_target(cs_tuners, policy);
ad529a9c	90
4471a34f	91	__cpufreq_driver_target(policy, dbs_info->requested_freq,
fed573d5	92	CPUFREQ_RELATION_L);
4471a34f VK	93	return;
	94	}
	95	}
	96
4447266b	97	static void cs_dbs_timer(struct work_struct *work)
4471a34f	98	{
4447266b VK	99	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
4447266b VK	100	struct cs_cpu_dbs_info_s, cdbs.work.work);
09dca5ae	101	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
4447266b VK	102	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
4447266b VK	103	cpu);
4d5dcc42 VK	104	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	105	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	106	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
031299b3	107	bool modify_all = true;
4471a34f	108
4447266b	109	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
031299b3 VK	110	if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
	111	modify_all = false;
	112	else
4d5dcc42	113	dbs_check_cpu(dbs_data, cpu);
66df2a01	114
031299b3	115	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
4447266b	116	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
66df2a01 FB	117	}
66df2a01 FB	118
4471a34f VK	119	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	120	void *data)
	121	{
	122	struct cpufreq_freqs *freq = data;
	123	struct cs_cpu_dbs_info_s *dbs_info =
	124	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	125	struct cpufreq_policy *policy;
f407a08b AC	126
4471a34f	127	if (!dbs_info->enable)
a8d7c3bc EO	128	return 0;
a8d7c3bc EO	129
4471a34f	130	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	131
f407a08b AC	132	/*
4471a34f	133	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	134	* ranges of frequency available to us otherwise we do not change it
f407a08b	135	*/
4471a34f VK	136	if (dbs_info->requested_freq > policy->max
	137	\|\| dbs_info->requested_freq < policy->min)
	138	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	139
	140	return 0;
	141	}
	142
b9170836	143	/************************ sysfs interface **********************/
4d5dcc42	144	static struct common_dbs_data cs_dbs_cdata;
b9170836	145
4d5dcc42 VK	146	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	147	const char *buf, size_t count)
b9170836	148	{
4d5dcc42	149	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	150	unsigned int input;
b9170836 DJ	151	int ret;
9acef487	152	ret = sscanf(buf, "%u", &input);
8e677ce8	153
2c906b31	154	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	155	return -EINVAL;
b9170836 DJ	156
4d5dcc42	157	cs_tuners->sampling_down_factor = input;
b9170836 DJ	158	return count;
	159	}
	160
4d5dcc42 VK	161	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	162	size_t count)
b9170836	163	{
4d5dcc42	164	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	165	unsigned int input;
b9170836 DJ	166	int ret;
9acef487	167	ret = sscanf(buf, "%u", &input);
b9170836	168
8e677ce8	169	if (ret != 1)
b9170836	170	return -EINVAL;
8e677ce8	171
4d5dcc42	172	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	173	return count;
	174	}
	175
4d5dcc42 VK	176	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	177	size_t count)
b9170836	178	{
4d5dcc42	179	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	180	unsigned int input;
b9170836 DJ	181	int ret;
9acef487	182	ret = sscanf(buf, "%u", &input);
b9170836	183
4d5dcc42	184	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	185	return -EINVAL;
b9170836	186
4d5dcc42	187	cs_tuners->up_threshold = input;
b9170836 DJ	188	return count;
	189	}
	190
4d5dcc42 VK	191	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	192	size_t count)
b9170836	193	{
4d5dcc42	194	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	195	unsigned int input;
b9170836 DJ	196	int ret;
9acef487	197	ret = sscanf(buf, "%u", &input);
b9170836	198
8e677ce8 AC	199	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	200	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	201	input >= cs_tuners->up_threshold)
b9170836	202	return -EINVAL;
b9170836	203
4d5dcc42	204	cs_tuners->down_threshold = input;
b9170836 DJ	205	return count;
	206	}
	207
6c4640c3 VK	208	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
6c4640c3 VK	209	const char *buf, size_t count)
b9170836	210	{
4d5dcc42	211	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	212	unsigned int input, j;
b9170836 DJ	213	int ret;
b9170836 DJ	214
18a7247d DJ	215	ret = sscanf(buf, "%u", &input);
18a7247d DJ	216	if (ret != 1)
b9170836 DJ	217	return -EINVAL;
b9170836 DJ	218
18a7247d	219	if (input > 1)
b9170836	220	input = 1;
18a7247d	221
6c4640c3	222	if (input == cs_tuners->ignore_nice_load) /* nothing to do */
b9170836	223	return count;
326c86de	224
6c4640c3	225	cs_tuners->ignore_nice_load = input;
b9170836	226
8e677ce8	227	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	228	for_each_online_cpu(j) {
4471a34f	229	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	230	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	231	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	232	&dbs_info->cdbs.prev_cpu_wall, 0);
6c4640c3	233	if (cs_tuners->ignore_nice_load)
4471a34f VK	234	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	235	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	236	}
b9170836 DJ	237	return count;
	238	}
	239
4d5dcc42 VK	240	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	241	size_t count)
b9170836	242	{
4d5dcc42	243	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	244	unsigned int input;
b9170836 DJ	245	int ret;
18a7247d	246	ret = sscanf(buf, "%u", &input);
b9170836	247
18a7247d	248	if (ret != 1)
b9170836 DJ	249	return -EINVAL;
b9170836 DJ	250
18a7247d	251	if (input > 100)
b9170836	252	input = 100;
18a7247d	253
4471a34f VK	254	/*
	255	* no need to test here if freq_step is zero as the user might actually
	256	* want this, they would be crazy though :)
	257	*/
4d5dcc42	258	cs_tuners->freq_step = input;
b9170836 DJ	259	return count;
	260	}
	261
4d5dcc42 VK	262	show_store_one(cs, sampling_rate);
	263	show_store_one(cs, sampling_down_factor);
	264	show_store_one(cs, up_threshold);
	265	show_store_one(cs, down_threshold);
6c4640c3	266	show_store_one(cs, ignore_nice_load);
4d5dcc42 VK	267	show_store_one(cs, freq_step);
	268	declare_show_sampling_rate_min(cs);
	269
	270	gov_sys_pol_attr_rw(sampling_rate);
	271	gov_sys_pol_attr_rw(sampling_down_factor);
	272	gov_sys_pol_attr_rw(up_threshold);
	273	gov_sys_pol_attr_rw(down_threshold);
6c4640c3	274	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42 VK	275	gov_sys_pol_attr_rw(freq_step);
	276	gov_sys_pol_attr_ro(sampling_rate_min);
	277
	278	static struct attribute *dbs_attributes_gov_sys[] = {
	279	&sampling_rate_min_gov_sys.attr,
	280	&sampling_rate_gov_sys.attr,
	281	&sampling_down_factor_gov_sys.attr,
	282	&up_threshold_gov_sys.attr,
	283	&down_threshold_gov_sys.attr,
6c4640c3	284	&ignore_nice_load_gov_sys.attr,
4d5dcc42	285	&freq_step_gov_sys.attr,
b9170836 DJ	286	NULL
	287	};
	288
4d5dcc42 VK	289	static struct attribute_group cs_attr_group_gov_sys = {
	290	.attrs = dbs_attributes_gov_sys,
	291	.name = "conservative",
	292	};
	293
	294	static struct attribute *dbs_attributes_gov_pol[] = {
	295	&sampling_rate_min_gov_pol.attr,
	296	&sampling_rate_gov_pol.attr,
	297	&sampling_down_factor_gov_pol.attr,
	298	&up_threshold_gov_pol.attr,
	299	&down_threshold_gov_pol.attr,
6c4640c3	300	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	301	&freq_step_gov_pol.attr,
	302	NULL
	303	};
	304
	305	static struct attribute_group cs_attr_group_gov_pol = {
	306	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	307	.name = "conservative",
	308	};
	309
	310	/************************ sysfs end **********************/
	311
4d5dcc42 VK	312	static int cs_init(struct dbs_data *dbs_data)
	313	{
	314	struct cs_dbs_tuners *tuners;
	315
d5b73cd8	316	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
4d5dcc42 VK	317	if (!tuners) {
	318	pr_err("%s: kzalloc failed\n", __func__);
	319	return -ENOMEM;
	320	}
	321
	322	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	323	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	324	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
6c4640c3	325	tuners->ignore_nice_load = 0;
98765847	326	tuners->freq_step = DEF_FREQUENCY_STEP;
4d5dcc42 VK	327
	328	dbs_data->tuners = tuners;
	329	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	330	jiffies_to_usecs(10);
	331	mutex_init(&dbs_data->mutex);
	332	return 0;
	333	}
	334
	335	static void cs_exit(struct dbs_data *dbs_data)
	336	{
	337	kfree(dbs_data->tuners);
	338	}
	339
4471a34f	340	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	341
4471a34f VK	342	static struct notifier_block cs_cpufreq_notifier_block = {
	343	.notifier_call = dbs_cpufreq_notifier,
	344	};
8e677ce8	345
4471a34f VK	346	static struct cs_ops cs_ops = {
	347	.notifier_block = &cs_cpufreq_notifier_block,
	348	};
b9170836	349
4d5dcc42	350	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	351	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	352	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	353	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	354	.get_cpu_cdbs = get_cpu_cdbs,
	355	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	356	.gov_dbs_timer = cs_dbs_timer,
	357	.gov_check_cpu = cs_check_cpu,
	358	.gov_ops = &cs_ops,
4d5dcc42 VK	359	.init = cs_init,
4d5dcc42 VK	360	.exit = cs_exit,
4471a34f	361	};
b9170836	362
4471a34f	363	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	364	unsigned int event)
b9170836 DJ	365	{
4d5dcc42	366	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	367	}
b9170836 DJ	368
c4d14bc0 SW	369	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	370	static
	371	#endif
1c256245 TR	372	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	373	.name = "conservative",
4471a34f	374	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	375	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	376	.owner = THIS_MODULE,
b9170836 DJ	377	};
	378
	379	static int __init cpufreq_gov_dbs_init(void)
	380	{
57df5573	381	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	382	}
	383
	384	static void __exit cpufreq_gov_dbs_exit(void)
	385	{
1c256245	386	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	387	}
b9170836 DJ	388
11a80a9c	389	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	390	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	391	"Low Latency Frequency Transition capable processors "
b9170836 DJ	392	"optimised for use in a battery environment");
9acef487	393	MODULE_LICENSE("GPL");
b9170836	394
6915719b JW	395	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	396	fs_initcall(cpufreq_gov_dbs_init);
	397	#else
b9170836	398	module_init(cpufreq_gov_dbs_init);
6915719b	399	#endif
b9170836	400	module_exit(cpufreq_gov_dbs_exit);