[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);

		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) {
		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
6d7bcb14 XC	71	if (dbs_info->requested_freq > policy->max)
	72	dbs_info->requested_freq = policy->max;
	73
4471a34f VK	74	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	75	CPUFREQ_RELATION_H);
	76	return;
	77	}
	78
7af1c056 SK	79	/* if sampling_down_factor is active break out early */
	80	if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
	81	return;
	82	dbs_info->down_skip = 0;
	83
27ed3cd2 SK	84	/* Check for frequency decrease */
27ed3cd2 SK	85	if (load < cs_tuners->down_threshold) {
3baa976a	86	unsigned int freq_target;
4471a34f VK	87	/*
	88	* if we cannot reduce the frequency anymore, break out early
	89	*/
	90	if (policy->cur == policy->min)
	91	return;
	92
3baa976a XC	93	freq_target = get_freq_target(cs_tuners, policy);
	94	if (dbs_info->requested_freq > freq_target)
	95	dbs_info->requested_freq -= freq_target;
	96	else
	97	dbs_info->requested_freq = policy->min;
ad529a9c	98
4471a34f	99	__cpufreq_driver_target(policy, dbs_info->requested_freq,
fed573d5	100	CPUFREQ_RELATION_L);
4471a34f VK	101	return;
	102	}
	103	}
	104
4447266b	105	static void cs_dbs_timer(struct work_struct *work)
4471a34f	106	{
4447266b VK	107	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
4447266b VK	108	struct cs_cpu_dbs_info_s, cdbs.work.work);
09dca5ae	109	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
4447266b VK	110	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
4447266b VK	111	cpu);
4d5dcc42 VK	112	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	113	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	114	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
031299b3	115	bool modify_all = true;
4471a34f	116
4447266b	117	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
031299b3 VK	118	if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
	119	modify_all = false;
	120	else
4d5dcc42	121	dbs_check_cpu(dbs_data, cpu);
66df2a01	122
031299b3	123	gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
4447266b	124	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
66df2a01 FB	125	}
66df2a01 FB	126
4471a34f VK	127	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	128	void *data)
	129	{
	130	struct cpufreq_freqs *freq = data;
	131	struct cs_cpu_dbs_info_s *dbs_info =
	132	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	133	struct cpufreq_policy *policy;
f407a08b AC	134
4471a34f	135	if (!dbs_info->enable)
a8d7c3bc EO	136	return 0;
a8d7c3bc EO	137
4471a34f	138	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	139
f407a08b AC	140	/*
4471a34f	141	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	142	* ranges of frequency available to us otherwise we do not change it
f407a08b	143	*/
4471a34f VK	144	if (dbs_info->requested_freq > policy->max
	145	\|\| dbs_info->requested_freq < policy->min)
	146	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	147
	148	return 0;
	149	}
	150
b9170836	151	/************************ sysfs interface **********************/
4d5dcc42	152	static struct common_dbs_data cs_dbs_cdata;
b9170836	153
4d5dcc42 VK	154	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	155	const char *buf, size_t count)
b9170836	156	{
4d5dcc42	157	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	158	unsigned int input;
b9170836 DJ	159	int ret;
9acef487	160	ret = sscanf(buf, "%u", &input);
8e677ce8	161
2c906b31	162	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	163	return -EINVAL;
b9170836 DJ	164
4d5dcc42	165	cs_tuners->sampling_down_factor = input;
b9170836 DJ	166	return count;
	167	}
	168
4d5dcc42 VK	169	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	170	size_t count)
b9170836	171	{
4d5dcc42	172	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	173	unsigned int input;
b9170836 DJ	174	int ret;
9acef487	175	ret = sscanf(buf, "%u", &input);
b9170836	176
8e677ce8	177	if (ret != 1)
b9170836	178	return -EINVAL;
8e677ce8	179
4d5dcc42	180	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	181	return count;
	182	}
	183
4d5dcc42 VK	184	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	185	size_t count)
b9170836	186	{
4d5dcc42	187	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	188	unsigned int input;
b9170836 DJ	189	int ret;
9acef487	190	ret = sscanf(buf, "%u", &input);
b9170836	191
4d5dcc42	192	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	193	return -EINVAL;
b9170836	194
4d5dcc42	195	cs_tuners->up_threshold = input;
b9170836 DJ	196	return count;
	197	}
	198
4d5dcc42 VK	199	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	200	size_t count)
b9170836	201	{
4d5dcc42	202	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	203	unsigned int input;
b9170836 DJ	204	int ret;
9acef487	205	ret = sscanf(buf, "%u", &input);
b9170836	206
8e677ce8 AC	207	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	208	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	209	input >= cs_tuners->up_threshold)
b9170836	210	return -EINVAL;
b9170836	211
4d5dcc42	212	cs_tuners->down_threshold = input;
b9170836 DJ	213	return count;
	214	}
	215
6c4640c3 VK	216	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
6c4640c3 VK	217	const char *buf, size_t count)
b9170836	218	{
4d5dcc42	219	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	220	unsigned int input, j;
b9170836 DJ	221	int ret;
b9170836 DJ	222
18a7247d DJ	223	ret = sscanf(buf, "%u", &input);
18a7247d DJ	224	if (ret != 1)
b9170836 DJ	225	return -EINVAL;
b9170836 DJ	226
18a7247d	227	if (input > 1)
b9170836	228	input = 1;
18a7247d	229
6c4640c3	230	if (input == cs_tuners->ignore_nice_load) /* nothing to do */
b9170836	231	return count;
326c86de	232
6c4640c3	233	cs_tuners->ignore_nice_load = input;
b9170836	234
8e677ce8	235	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	236	for_each_online_cpu(j) {
4471a34f	237	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	238	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	239	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	240	&dbs_info->cdbs.prev_cpu_wall, 0);
6c4640c3	241	if (cs_tuners->ignore_nice_load)
4471a34f VK	242	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	243	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	244	}
b9170836 DJ	245	return count;
	246	}
	247
4d5dcc42 VK	248	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	249	size_t count)
b9170836	250	{
4d5dcc42	251	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	252	unsigned int input;
b9170836 DJ	253	int ret;
18a7247d	254	ret = sscanf(buf, "%u", &input);
b9170836	255
18a7247d	256	if (ret != 1)
b9170836 DJ	257	return -EINVAL;
b9170836 DJ	258
18a7247d	259	if (input > 100)
b9170836	260	input = 100;
18a7247d	261
4471a34f VK	262	/*
	263	* no need to test here if freq_step is zero as the user might actually
	264	* want this, they would be crazy though :)
	265	*/
4d5dcc42	266	cs_tuners->freq_step = input;
b9170836 DJ	267	return count;
	268	}
	269
4d5dcc42 VK	270	show_store_one(cs, sampling_rate);
	271	show_store_one(cs, sampling_down_factor);
	272	show_store_one(cs, up_threshold);
	273	show_store_one(cs, down_threshold);
6c4640c3	274	show_store_one(cs, ignore_nice_load);
4d5dcc42 VK	275	show_store_one(cs, freq_step);
	276	declare_show_sampling_rate_min(cs);
	277
	278	gov_sys_pol_attr_rw(sampling_rate);
	279	gov_sys_pol_attr_rw(sampling_down_factor);
	280	gov_sys_pol_attr_rw(up_threshold);
	281	gov_sys_pol_attr_rw(down_threshold);
6c4640c3	282	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42 VK	283	gov_sys_pol_attr_rw(freq_step);
	284	gov_sys_pol_attr_ro(sampling_rate_min);
	285
	286	static struct attribute *dbs_attributes_gov_sys[] = {
	287	&sampling_rate_min_gov_sys.attr,
	288	&sampling_rate_gov_sys.attr,
	289	&sampling_down_factor_gov_sys.attr,
	290	&up_threshold_gov_sys.attr,
	291	&down_threshold_gov_sys.attr,
6c4640c3	292	&ignore_nice_load_gov_sys.attr,
4d5dcc42	293	&freq_step_gov_sys.attr,
b9170836 DJ	294	NULL
	295	};
	296
4d5dcc42 VK	297	static struct attribute_group cs_attr_group_gov_sys = {
	298	.attrs = dbs_attributes_gov_sys,
	299	.name = "conservative",
	300	};
	301
	302	static struct attribute *dbs_attributes_gov_pol[] = {
	303	&sampling_rate_min_gov_pol.attr,
	304	&sampling_rate_gov_pol.attr,
	305	&sampling_down_factor_gov_pol.attr,
	306	&up_threshold_gov_pol.attr,
	307	&down_threshold_gov_pol.attr,
6c4640c3	308	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	309	&freq_step_gov_pol.attr,
	310	NULL
	311	};
	312
	313	static struct attribute_group cs_attr_group_gov_pol = {
	314	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	315	.name = "conservative",
	316	};
	317
	318	/************************ sysfs end **********************/
	319
4d5dcc42 VK	320	static int cs_init(struct dbs_data *dbs_data)
	321	{
	322	struct cs_dbs_tuners *tuners;
	323
d5b73cd8	324	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
4d5dcc42 VK	325	if (!tuners) {
	326	pr_err("%s: kzalloc failed\n", __func__);
	327	return -ENOMEM;
	328	}
	329
	330	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	331	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	332	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
6c4640c3	333	tuners->ignore_nice_load = 0;
98765847	334	tuners->freq_step = DEF_FREQUENCY_STEP;
4d5dcc42 VK	335
	336	dbs_data->tuners = tuners;
	337	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	338	jiffies_to_usecs(10);
	339	mutex_init(&dbs_data->mutex);
	340	return 0;
	341	}
	342
	343	static void cs_exit(struct dbs_data *dbs_data)
	344	{
	345	kfree(dbs_data->tuners);
	346	}
	347
4471a34f	348	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	349
4471a34f VK	350	static struct notifier_block cs_cpufreq_notifier_block = {
	351	.notifier_call = dbs_cpufreq_notifier,
	352	};
8e677ce8	353
4471a34f VK	354	static struct cs_ops cs_ops = {
	355	.notifier_block = &cs_cpufreq_notifier_block,
	356	};
b9170836	357
4d5dcc42	358	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	359	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	360	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	361	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	362	.get_cpu_cdbs = get_cpu_cdbs,
	363	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	364	.gov_dbs_timer = cs_dbs_timer,
	365	.gov_check_cpu = cs_check_cpu,
	366	.gov_ops = &cs_ops,
4d5dcc42 VK	367	.init = cs_init,
4d5dcc42 VK	368	.exit = cs_exit,
4471a34f	369	};
b9170836	370
4471a34f	371	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	372	unsigned int event)
b9170836 DJ	373	{
4d5dcc42	374	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	375	}
b9170836 DJ	376
c4d14bc0 SW	377	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	378	static
	379	#endif
1c256245 TR	380	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	381	.name = "conservative",
4471a34f	382	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	383	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	384	.owner = THIS_MODULE,
b9170836 DJ	385	};
	386
	387	static int __init cpufreq_gov_dbs_init(void)
	388	{
57df5573	389	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	390	}
	391
	392	static void __exit cpufreq_gov_dbs_exit(void)
	393	{
1c256245	394	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	395	}
b9170836 DJ	396
11a80a9c	397	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	398	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	399	"Low Latency Frequency Transition capable processors "
b9170836 DJ	400	"optimised for use in a battery environment");
9acef487	401	MODULE_LICENSE("GPL");
b9170836	402
6915719b JW	403	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	404	fs_initcall(cpufreq_gov_dbs_init);
	405	#else
b9170836	406	module_init(cpufreq_gov_dbs_init);
6915719b	407	#endif
b9170836	408	module_exit(cpufreq_gov_dbs_exit);