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

/*
 *  drivers/cpufreq/cpufreq_conservative.c
 *
 *  Copyright (C)  2001 Russell King
 *            (C)  2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
 *                      Jun Nakajima <jun.nakajima@intel.com>
 *            (C)  2009 Alexander Clouter <alex@digriz.org.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

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

#include "cpufreq_governor.h"

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

static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);

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

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

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

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

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

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

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

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

	/*
	 * The optimal frequency is the frequency that is the lowest that can
	 * support the current CPU usage without triggering the up policy. To be
	 * safe, we focus 10 points under the threshold.
	 */
	if (load < (cs_tuners->down_threshold - 10)) {
		freq_target = (cs_tuners->freq_step * policy->max) / 100;

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

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

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

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

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

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

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

	if (!dbs_info->enable)
		return 0;

	policy = dbs_info->cdbs.cur_policy;

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

	return 0;
}

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

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

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

	cs_tuners->sampling_down_factor = input;
	return count;
}

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

	if (ret != 1)
		return -EINVAL;

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

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

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

	cs_tuners->up_threshold = input;
	return count;
}

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

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

	cs_tuners->down_threshold = input;
	return count;
}

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

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

	if (input > 1)
		input = 1;

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

	cs_tuners->ignore_nice = input;

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

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

	if (ret != 1)
		return -EINVAL;

	if (input > 100)
		input = 100;

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

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

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

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

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

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

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

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

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

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

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

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

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

define_get_cpu_dbs_routines(cs_cpu_dbs_info);

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

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

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

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

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

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

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

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

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