[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) {
		unsigned int freq_target;
		/*
		 * if we cannot reduce the frequency anymore, break out early
		 */
		if (policy->cur == policy->min)
			return;

		freq_target = get_freq_target(cs_tuners, policy);
		if (dbs_info->requested_freq > freq_target)
			dbs_info->requested_freq -= freq_target;
		else
			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_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) {
3baa976a	83	unsigned int freq_target;
4471a34f VK	84	/*
	85	* if we cannot reduce the frequency anymore, break out early
	86	*/
	87	if (policy->cur == policy->min)
	88	return;
	89
3baa976a XC	90	freq_target = get_freq_target(cs_tuners, policy);
	91	if (dbs_info->requested_freq > freq_target)
	92	dbs_info->requested_freq -= freq_target;
	93	else
	94	dbs_info->requested_freq = policy->min;
ad529a9c	95
4471a34f	96	__cpufreq_driver_target(policy, dbs_info->requested_freq,
fed573d5	97	CPUFREQ_RELATION_L);
4471a34f VK	98	return;
	99	}
	100	}
	101
4447266b	102	static void cs_dbs_timer(struct work_struct *work)
4471a34f	103	{
4447266b VK	104	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
4447266b VK	105	struct cs_cpu_dbs_info_s, cdbs.work.work);
09dca5ae	106	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
4447266b VK	107	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
4447266b VK	108	cpu);
4d5dcc42 VK	109	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	110	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	111	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
031299b3	112	bool modify_all = true;
4471a34f	113
4447266b	114	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
031299b3 VK	115	if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
	116	modify_all = false;
	117	else
4d5dcc42	118	dbs_check_cpu(dbs_data, cpu);
66df2a01	119
031299b3	120	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
4447266b	121	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
66df2a01 FB	122	}
66df2a01 FB	123
4471a34f VK	124	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	125	void *data)
	126	{
	127	struct cpufreq_freqs *freq = data;
	128	struct cs_cpu_dbs_info_s *dbs_info =
	129	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	130	struct cpufreq_policy *policy;
f407a08b AC	131
4471a34f	132	if (!dbs_info->enable)
a8d7c3bc EO	133	return 0;
a8d7c3bc EO	134
4471a34f	135	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	136
f407a08b AC	137	/*
4471a34f	138	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	139	* ranges of frequency available to us otherwise we do not change it
f407a08b	140	*/
4471a34f VK	141	if (dbs_info->requested_freq > policy->max
	142	\|\| dbs_info->requested_freq < policy->min)
	143	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	144
	145	return 0;
	146	}
	147
b9170836	148	/************************ sysfs interface **********************/
4d5dcc42	149	static struct common_dbs_data cs_dbs_cdata;
b9170836	150
4d5dcc42 VK	151	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	152	const char *buf, size_t count)
b9170836	153	{
4d5dcc42	154	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	155	unsigned int input;
b9170836 DJ	156	int ret;
9acef487	157	ret = sscanf(buf, "%u", &input);
8e677ce8	158
2c906b31	159	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	160	return -EINVAL;
b9170836 DJ	161
4d5dcc42	162	cs_tuners->sampling_down_factor = input;
b9170836 DJ	163	return count;
	164	}
	165
4d5dcc42 VK	166	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	167	size_t count)
b9170836	168	{
4d5dcc42	169	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	170	unsigned int input;
b9170836 DJ	171	int ret;
9acef487	172	ret = sscanf(buf, "%u", &input);
b9170836	173
8e677ce8	174	if (ret != 1)
b9170836	175	return -EINVAL;
8e677ce8	176
4d5dcc42	177	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	178	return count;
	179	}
	180
4d5dcc42 VK	181	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	182	size_t count)
b9170836	183	{
4d5dcc42	184	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	185	unsigned int input;
b9170836 DJ	186	int ret;
9acef487	187	ret = sscanf(buf, "%u", &input);
b9170836	188
4d5dcc42	189	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	190	return -EINVAL;
b9170836	191
4d5dcc42	192	cs_tuners->up_threshold = input;
b9170836 DJ	193	return count;
	194	}
	195
4d5dcc42 VK	196	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	197	size_t count)
b9170836	198	{
4d5dcc42	199	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	200	unsigned int input;
b9170836 DJ	201	int ret;
9acef487	202	ret = sscanf(buf, "%u", &input);
b9170836	203
8e677ce8 AC	204	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	205	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	206	input >= cs_tuners->up_threshold)
b9170836	207	return -EINVAL;
b9170836	208
4d5dcc42	209	cs_tuners->down_threshold = input;
b9170836 DJ	210	return count;
	211	}
	212
6c4640c3 VK	213	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
6c4640c3 VK	214	const char *buf, size_t count)
b9170836	215	{
4d5dcc42	216	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	217	unsigned int input, j;
b9170836 DJ	218	int ret;
b9170836 DJ	219
18a7247d DJ	220	ret = sscanf(buf, "%u", &input);
18a7247d DJ	221	if (ret != 1)
b9170836 DJ	222	return -EINVAL;
b9170836 DJ	223
18a7247d	224	if (input > 1)
b9170836	225	input = 1;
18a7247d	226
6c4640c3	227	if (input == cs_tuners->ignore_nice_load) /* nothing to do */
b9170836	228	return count;
326c86de	229
6c4640c3	230	cs_tuners->ignore_nice_load = input;
b9170836	231
8e677ce8	232	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	233	for_each_online_cpu(j) {
4471a34f	234	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	235	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	236	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	237	&dbs_info->cdbs.prev_cpu_wall, 0);
6c4640c3	238	if (cs_tuners->ignore_nice_load)
4471a34f VK	239	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	240	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	241	}
b9170836 DJ	242	return count;
	243	}
	244
4d5dcc42 VK	245	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	246	size_t count)
b9170836	247	{
4d5dcc42	248	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	249	unsigned int input;
b9170836 DJ	250	int ret;
18a7247d	251	ret = sscanf(buf, "%u", &input);
b9170836	252
18a7247d	253	if (ret != 1)
b9170836 DJ	254	return -EINVAL;
b9170836 DJ	255
18a7247d	256	if (input > 100)
b9170836	257	input = 100;
18a7247d	258
4471a34f VK	259	/*
	260	* no need to test here if freq_step is zero as the user might actually
	261	* want this, they would be crazy though :)
	262	*/
4d5dcc42	263	cs_tuners->freq_step = input;
b9170836 DJ	264	return count;
	265	}
	266
4d5dcc42 VK	267	show_store_one(cs, sampling_rate);
	268	show_store_one(cs, sampling_down_factor);
	269	show_store_one(cs, up_threshold);
	270	show_store_one(cs, down_threshold);
6c4640c3	271	show_store_one(cs, ignore_nice_load);
4d5dcc42 VK	272	show_store_one(cs, freq_step);
	273	declare_show_sampling_rate_min(cs);
	274
	275	gov_sys_pol_attr_rw(sampling_rate);
	276	gov_sys_pol_attr_rw(sampling_down_factor);
	277	gov_sys_pol_attr_rw(up_threshold);
	278	gov_sys_pol_attr_rw(down_threshold);
6c4640c3	279	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42 VK	280	gov_sys_pol_attr_rw(freq_step);
	281	gov_sys_pol_attr_ro(sampling_rate_min);
	282
	283	static struct attribute *dbs_attributes_gov_sys[] = {
	284	&sampling_rate_min_gov_sys.attr,
	285	&sampling_rate_gov_sys.attr,
	286	&sampling_down_factor_gov_sys.attr,
	287	&up_threshold_gov_sys.attr,
	288	&down_threshold_gov_sys.attr,
6c4640c3	289	&ignore_nice_load_gov_sys.attr,
4d5dcc42	290	&freq_step_gov_sys.attr,
b9170836 DJ	291	NULL
	292	};
	293
4d5dcc42 VK	294	static struct attribute_group cs_attr_group_gov_sys = {
	295	.attrs = dbs_attributes_gov_sys,
	296	.name = "conservative",
	297	};
	298
	299	static struct attribute *dbs_attributes_gov_pol[] = {
	300	&sampling_rate_min_gov_pol.attr,
	301	&sampling_rate_gov_pol.attr,
	302	&sampling_down_factor_gov_pol.attr,
	303	&up_threshold_gov_pol.attr,
	304	&down_threshold_gov_pol.attr,
6c4640c3	305	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	306	&freq_step_gov_pol.attr,
	307	NULL
	308	};
	309
	310	static struct attribute_group cs_attr_group_gov_pol = {
	311	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	312	.name = "conservative",
	313	};
	314
	315	/************************ sysfs end **********************/
	316
4d5dcc42 VK	317	static int cs_init(struct dbs_data *dbs_data)
	318	{
	319	struct cs_dbs_tuners *tuners;
	320
d5b73cd8	321	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
4d5dcc42 VK	322	if (!tuners) {
	323	pr_err("%s: kzalloc failed\n", __func__);
	324	return -ENOMEM;
	325	}
	326
	327	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	328	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	329	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
6c4640c3	330	tuners->ignore_nice_load = 0;
98765847	331	tuners->freq_step = DEF_FREQUENCY_STEP;
4d5dcc42 VK	332
	333	dbs_data->tuners = tuners;
	334	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	335	jiffies_to_usecs(10);
	336	mutex_init(&dbs_data->mutex);
	337	return 0;
	338	}
	339
	340	static void cs_exit(struct dbs_data *dbs_data)
	341	{
	342	kfree(dbs_data->tuners);
	343	}
	344
4471a34f	345	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	346
4471a34f VK	347	static struct notifier_block cs_cpufreq_notifier_block = {
	348	.notifier_call = dbs_cpufreq_notifier,
	349	};
8e677ce8	350
4471a34f VK	351	static struct cs_ops cs_ops = {
	352	.notifier_block = &cs_cpufreq_notifier_block,
	353	};
b9170836	354
4d5dcc42	355	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	356	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	357	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	358	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	359	.get_cpu_cdbs = get_cpu_cdbs,
	360	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	361	.gov_dbs_timer = cs_dbs_timer,
	362	.gov_check_cpu = cs_check_cpu,
	363	.gov_ops = &cs_ops,
4d5dcc42 VK	364	.init = cs_init,
4d5dcc42 VK	365	.exit = cs_exit,
4471a34f	366	};
b9170836	367
4471a34f	368	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	369	unsigned int event)
b9170836 DJ	370	{
4d5dcc42	371	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	372	}
b9170836 DJ	373
c4d14bc0 SW	374	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	375	static
	376	#endif
1c256245 TR	377	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	378	.name = "conservative",
4471a34f	379	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	380	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	381	.owner = THIS_MODULE,
b9170836 DJ	382	};
	383
	384	static int __init cpufreq_gov_dbs_init(void)
	385	{
57df5573	386	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	387	}
	388
	389	static void __exit cpufreq_gov_dbs_exit(void)
	390	{
1c256245	391	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	392	}
b9170836 DJ	393
11a80a9c	394	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	395	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	396	"Low Latency Frequency Transition capable processors "
b9170836 DJ	397	"optimised for use in a battery environment");
9acef487	398	MODULE_LICENSE("GPL");
b9170836	399
6915719b JW	400	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	401	fs_initcall(cpufreq_gov_dbs_init);
	402	#else
b9170836	403	module_init(cpufreq_gov_dbs_init);
6915719b	404	#endif
b9170836	405	module_exit(cpufreq_gov_dbs_exit);