[linux-2.6-block.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 delayed_work *dw = to_delayed_work(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);

	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
	if (need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
		dbs_check_cpu(dbs_data, cpu);

	schedule_delayed_work_on(smp_processor_id(), dw, delay);
	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 delayed_work *dw = to_delayed_work(work);
	111	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
	112	struct cs_cpu_dbs_info_s, cdbs.work.work);
09dca5ae	113	unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
4447266b VK	114	struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
4447266b VK	115	cpu);
4d5dcc42 VK	116	struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
	117	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
	118	int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
4471a34f	119
4447266b	120	mutex_lock(&core_dbs_info->cdbs.timer_mutex);
4d5dcc42 VK	121	if (need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
4d5dcc42 VK	122	dbs_check_cpu(dbs_data, cpu);
66df2a01 FB	123
66df2a01 FB	124	schedule_delayed_work_on(smp_processor_id(), dw, delay);
4447266b	125	mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
66df2a01 FB	126	}
66df2a01 FB	127
4471a34f VK	128	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	129	void *data)
	130	{
	131	struct cpufreq_freqs *freq = data;
	132	struct cs_cpu_dbs_info_s *dbs_info =
	133	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	134	struct cpufreq_policy *policy;
f407a08b AC	135
4471a34f	136	if (!dbs_info->enable)
a8d7c3bc EO	137	return 0;
a8d7c3bc EO	138
4471a34f	139	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	140
f407a08b AC	141	/*
4471a34f	142	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	143	* ranges of frequency available to us otherwise we do not change it
f407a08b	144	*/
4471a34f VK	145	if (dbs_info->requested_freq > policy->max
	146	\|\| dbs_info->requested_freq < policy->min)
	147	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	148
	149	return 0;
	150	}
	151
b9170836	152	/************************ sysfs interface **********************/
4d5dcc42	153	static struct common_dbs_data cs_dbs_cdata;
b9170836	154
4d5dcc42 VK	155	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	156	const char *buf, size_t count)
b9170836	157	{
4d5dcc42	158	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	159	unsigned int input;
b9170836 DJ	160	int ret;
9acef487	161	ret = sscanf(buf, "%u", &input);
8e677ce8	162
2c906b31	163	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	164	return -EINVAL;
b9170836 DJ	165
4d5dcc42	166	cs_tuners->sampling_down_factor = input;
b9170836 DJ	167	return count;
	168	}
	169
4d5dcc42 VK	170	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	171	size_t count)
b9170836	172	{
4d5dcc42	173	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	174	unsigned int input;
b9170836 DJ	175	int ret;
9acef487	176	ret = sscanf(buf, "%u", &input);
b9170836	177
8e677ce8	178	if (ret != 1)
b9170836	179	return -EINVAL;
8e677ce8	180
4d5dcc42	181	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	182	return count;
	183	}
	184
4d5dcc42 VK	185	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	186	size_t count)
b9170836	187	{
4d5dcc42	188	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	189	unsigned int input;
b9170836 DJ	190	int ret;
9acef487	191	ret = sscanf(buf, "%u", &input);
b9170836	192
4d5dcc42	193	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	194	return -EINVAL;
b9170836	195
4d5dcc42	196	cs_tuners->up_threshold = input;
b9170836 DJ	197	return count;
	198	}
	199
4d5dcc42 VK	200	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	201	size_t count)
b9170836	202	{
4d5dcc42	203	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	204	unsigned int input;
b9170836 DJ	205	int ret;
9acef487	206	ret = sscanf(buf, "%u", &input);
b9170836	207
8e677ce8 AC	208	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	209	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	210	input >= cs_tuners->up_threshold)
b9170836	211	return -EINVAL;
b9170836	212
4d5dcc42	213	cs_tuners->down_threshold = input;
b9170836 DJ	214	return count;
	215	}
	216
4d5dcc42 VK	217	static ssize_t store_ignore_nice(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	218	size_t count)
b9170836	219	{
4d5dcc42	220	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	221	unsigned int input, j;
b9170836 DJ	222	int ret;
b9170836 DJ	223
18a7247d DJ	224	ret = sscanf(buf, "%u", &input);
18a7247d DJ	225	if (ret != 1)
b9170836 DJ	226	return -EINVAL;
b9170836 DJ	227
18a7247d	228	if (input > 1)
b9170836	229	input = 1;
18a7247d	230
4d5dcc42	231	if (input == cs_tuners->ignore_nice) /* nothing to do */
b9170836	232	return count;
326c86de	233
4d5dcc42	234	cs_tuners->ignore_nice = input;
b9170836	235
8e677ce8	236	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	237	for_each_online_cpu(j) {
4471a34f	238	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	239	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f VK	240	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
4471a34f VK	241	&dbs_info->cdbs.prev_cpu_wall);
4d5dcc42	242	if (cs_tuners->ignore_nice)
4471a34f VK	243	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	244	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	245	}
b9170836 DJ	246	return count;
	247	}
	248
4d5dcc42 VK	249	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	250	size_t count)
b9170836	251	{
4d5dcc42	252	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	253	unsigned int input;
b9170836 DJ	254	int ret;
18a7247d	255	ret = sscanf(buf, "%u", &input);
b9170836	256
18a7247d	257	if (ret != 1)
b9170836 DJ	258	return -EINVAL;
b9170836 DJ	259
18a7247d	260	if (input > 100)
b9170836	261	input = 100;
18a7247d	262
4471a34f VK	263	/*
	264	* no need to test here if freq_step is zero as the user might actually
	265	* want this, they would be crazy though :)
	266	*/
4d5dcc42	267	cs_tuners->freq_step = input;
b9170836 DJ	268	return count;
	269	}
	270
4d5dcc42 VK	271	show_store_one(cs, sampling_rate);
	272	show_store_one(cs, sampling_down_factor);
	273	show_store_one(cs, up_threshold);
	274	show_store_one(cs, down_threshold);
	275	show_store_one(cs, ignore_nice);
	276	show_store_one(cs, freq_step);
	277	declare_show_sampling_rate_min(cs);
	278
	279	gov_sys_pol_attr_rw(sampling_rate);
	280	gov_sys_pol_attr_rw(sampling_down_factor);
	281	gov_sys_pol_attr_rw(up_threshold);
	282	gov_sys_pol_attr_rw(down_threshold);
	283	gov_sys_pol_attr_rw(ignore_nice);
	284	gov_sys_pol_attr_rw(freq_step);
	285	gov_sys_pol_attr_ro(sampling_rate_min);
	286
	287	static struct attribute *dbs_attributes_gov_sys[] = {
	288	&sampling_rate_min_gov_sys.attr,
	289	&sampling_rate_gov_sys.attr,
	290	&sampling_down_factor_gov_sys.attr,
	291	&up_threshold_gov_sys.attr,
	292	&down_threshold_gov_sys.attr,
	293	&ignore_nice_gov_sys.attr,
	294	&freq_step_gov_sys.attr,
b9170836 DJ	295	NULL
	296	};
	297
4d5dcc42 VK	298	static struct attribute_group cs_attr_group_gov_sys = {
	299	.attrs = dbs_attributes_gov_sys,
	300	.name = "conservative",
	301	};
	302
	303	static struct attribute *dbs_attributes_gov_pol[] = {
	304	&sampling_rate_min_gov_pol.attr,
	305	&sampling_rate_gov_pol.attr,
	306	&sampling_down_factor_gov_pol.attr,
	307	&up_threshold_gov_pol.attr,
	308	&down_threshold_gov_pol.attr,
	309	&ignore_nice_gov_pol.attr,
	310	&freq_step_gov_pol.attr,
	311	NULL
	312	};
	313
	314	static struct attribute_group cs_attr_group_gov_pol = {
	315	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	316	.name = "conservative",
	317	};
	318
	319	/************************ sysfs end **********************/
	320
4d5dcc42 VK	321	static int cs_init(struct dbs_data *dbs_data)
	322	{
	323	struct cs_dbs_tuners *tuners;
	324
	325	tuners = kzalloc(sizeof(struct cs_dbs_tuners), GFP_KERNEL);
	326	if (!tuners) {
	327	pr_err("%s: kzalloc failed\n", __func__);
	328	return -ENOMEM;
	329	}
	330
	331	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	332	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	333	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
	334	tuners->ignore_nice = 0;
	335	tuners->freq_step = 5;
	336
	337	dbs_data->tuners = tuners;
	338	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	339	jiffies_to_usecs(10);
	340	mutex_init(&dbs_data->mutex);
	341	return 0;
	342	}
	343
	344	static void cs_exit(struct dbs_data *dbs_data)
	345	{
	346	kfree(dbs_data->tuners);
	347	}
	348
4471a34f	349	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	350
4471a34f VK	351	static struct notifier_block cs_cpufreq_notifier_block = {
	352	.notifier_call = dbs_cpufreq_notifier,
	353	};
8e677ce8	354
4471a34f VK	355	static struct cs_ops cs_ops = {
	356	.notifier_block = &cs_cpufreq_notifier_block,
	357	};
b9170836	358
4d5dcc42	359	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	360	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	361	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	362	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	363	.get_cpu_cdbs = get_cpu_cdbs,
	364	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	365	.gov_dbs_timer = cs_dbs_timer,
	366	.gov_check_cpu = cs_check_cpu,
	367	.gov_ops = &cs_ops,
4d5dcc42 VK	368	.init = cs_init,
4d5dcc42 VK	369	.exit = cs_exit,
4471a34f	370	};
b9170836	371
4471a34f	372	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	373	unsigned int event)
b9170836 DJ	374	{
4d5dcc42	375	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	376	}
b9170836 DJ	377
c4d14bc0 SW	378	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	379	static
	380	#endif
1c256245 TR	381	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	382	.name = "conservative",
4471a34f	383	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	384	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	385	.owner = THIS_MODULE,
b9170836 DJ	386	};
	387
	388	static int __init cpufreq_gov_dbs_init(void)
	389	{
57df5573	390	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	391	}
	392
	393	static void __exit cpufreq_gov_dbs_exit(void)
	394	{
1c256245	395	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	396	}
b9170836 DJ	397
11a80a9c	398	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	399	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	400	"Low Latency Frequency Transition capable processors "
b9170836 DJ	401	"optimised for use in a battery environment");
9acef487	402	MODULE_LICENSE("GPL");
b9170836	403
6915719b JW	404	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	405	fs_initcall(cpufreq_gov_dbs_init);
	406	#else
b9170836	407	module_init(cpufreq_gov_dbs_init);
6915719b	408	#endif
b9170836	409	module_exit(cpufreq_gov_dbs_exit);