[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/sysfs.h>
#include <linux/types.h>

#include "cpufreq_governor.h"

/* Conservative governor macors */
#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 struct dbs_data cs_dbs_data;
static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);

static struct cs_dbs_tuners cs_tuners = {
	.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
	.down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
	.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
	.ignore_nice = 0,
	.freq_step = 5,
};

/*
 * 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;
	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_timer_update(struct cs_cpu_dbs_info_s *dbs_info, bool sample,
			    struct delayed_work *dw)
{
	unsigned int cpu = dbs_info->cdbs.cpu;
	int delay = delay_for_sampling_rate(cs_tuners.sampling_rate);

	if (sample)
		dbs_check_cpu(&cs_dbs_data, cpu);

	schedule_delayed_work_on(smp_processor_id(), dw, delay);
}

static void cs_timer_coordinated(struct cs_cpu_dbs_info_s *dbs_info_local,
				 struct delayed_work *dw)
{
	struct cs_cpu_dbs_info_s *dbs_info;
	ktime_t time_now;
	s64 delta_us;
	bool sample = true;

	/* use leader CPU's dbs_info */
	dbs_info = &per_cpu(cs_cpu_dbs_info, dbs_info_local->cdbs.cpu);
	mutex_lock(&dbs_info->cdbs.timer_mutex);

	time_now = ktime_get();
	delta_us = ktime_us_delta(time_now, dbs_info->cdbs.time_stamp);

	/* Do nothing if we recently have sampled */
	if (delta_us < (s64)(cs_tuners.sampling_rate / 2))
		sample = false;
	else
		dbs_info->cdbs.time_stamp = time_now;

	cs_timer_update(dbs_info, sample, dw);
	mutex_unlock(&dbs_info->cdbs.timer_mutex);
}

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);

	if (policy_is_shared(dbs_info->cdbs.cur_policy)) {
		cs_timer_coordinated(dbs_info, dw);
	} else {
		mutex_lock(&dbs_info->cdbs.timer_mutex);
		cs_timer_update(dbs_info, true, dw);
		mutex_unlock(&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 freqency 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 ssize_t show_sampling_rate_min(struct kobject *kobj,
				      struct attribute *attr, char *buf)
{
	return sprintf(buf, "%u\n", cs_dbs_data.min_sampling_rate);
}

static ssize_t store_sampling_down_factor(struct kobject *a,
					  struct attribute *b,
					  const char *buf, size_t count)
{
	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 kobject *a, struct attribute *b,
				   const char *buf, size_t count)
{
	unsigned int input;
	int ret;
	ret = sscanf(buf, "%u", &input);

	if (ret != 1)
		return -EINVAL;

	cs_tuners.sampling_rate = max(input, cs_dbs_data.min_sampling_rate);
	return count;
}

static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
				  const char *buf, size_t count)
{
	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 kobject *a, struct attribute *b,
				    const char *buf, size_t count)
{
	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 kobject *a, struct attribute *b,
				      const char *buf, size_t count)
{
	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 kobject *a, struct attribute *b,
			       const char *buf, size_t count)
{
	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_one(cs, sampling_rate, sampling_rate);
show_one(cs, sampling_down_factor, sampling_down_factor);
show_one(cs, up_threshold, up_threshold);
show_one(cs, down_threshold, down_threshold);
show_one(cs, ignore_nice_load, ignore_nice);
show_one(cs, freq_step, freq_step);

define_one_global_rw(sampling_rate);
define_one_global_rw(sampling_down_factor);
define_one_global_rw(up_threshold);
define_one_global_rw(down_threshold);
define_one_global_rw(ignore_nice_load);
define_one_global_rw(freq_step);
define_one_global_ro(sampling_rate_min);

static struct attribute *dbs_attributes[] = {
	&sampling_rate_min.attr,
	&sampling_rate.attr,
	&sampling_down_factor.attr,
	&up_threshold.attr,
	&down_threshold.attr,
	&ignore_nice_load.attr,
	&freq_step.attr,
	NULL
};

static struct attribute_group cs_attr_group = {
	.attrs = dbs_attributes,
	.name = "conservative",
};

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

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 dbs_data cs_dbs_data = {
	.governor = GOV_CONSERVATIVE,
	.attr_group = &cs_attr_group,
	.tuners = &cs_tuners,
	.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,
};

static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
				   unsigned int event)
{
	return cpufreq_governor_dbs(&cs_dbs_data, policy, 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)
{
	mutex_init(&cs_dbs_data.mutex);
	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>
	22	#include <linux/percpu-defs.h>
	23	#include <linux/sysfs.h>
	24	#include <linux/types.h>
8e677ce8	25
4471a34f	26	#include "cpufreq_governor.h"
b9170836	27
4471a34f	28	/* Conservative governor macors */
b9170836	29	#define DEF_FREQUENCY_UP_THRESHOLD (80)
b9170836	30	#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
2c906b31 AC	31	#define DEF_SAMPLING_DOWN_FACTOR (1)
2c906b31 AC	32	#define MAX_SAMPLING_DOWN_FACTOR (10)
b9170836	33
4471a34f VK	34	static struct dbs_data cs_dbs_data;
4471a34f VK	35	static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
b9170836	36
4471a34f	37	static struct cs_dbs_tuners cs_tuners = {
18a7247d DJ	38	.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
	39	.down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
	40	.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
	41	.ignore_nice = 0,
	42	.freq_step = 5,
b9170836 DJ	43	};
b9170836 DJ	44
4471a34f VK	45	/*
	46	* Every sampling_rate, we check, if current idle time is less than 20%
	47	* (default), then we try to increase frequency Every sampling_rate *
	48	* sampling_down_factor, we check, if current idle time is more than 80%, then
	49	* we try to decrease frequency
	50	*
	51	* Any frequency increase takes it to the maximum frequency. Frequency reduction
	52	* happens at minimum steps of 5% (default) of maximum frequency
	53	*/
	54	static void cs_check_cpu(int cpu, unsigned int load)
a8d7c3bc	55	{
4471a34f VK	56	struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
	57	struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
	58	unsigned int freq_target;
	59
	60	/*
	61	* break out if we 'cannot' reduce the speed as the user might
	62	* want freq_step to be zero
	63	*/
	64	if (cs_tuners.freq_step == 0)
	65	return;
	66
	67	/* Check for frequency increase */
	68	if (load > cs_tuners.up_threshold) {
	69	dbs_info->down_skip = 0;
	70
	71	/* if we are already at full speed then break out early */
	72	if (dbs_info->requested_freq == policy->max)
	73	return;
	74
	75	freq_target = (cs_tuners.freq_step * policy->max) / 100;
	76
	77	/* max freq cannot be less than 100. But who knows.... */
	78	if (unlikely(freq_target == 0))
	79	freq_target = 5;
	80
	81	dbs_info->requested_freq += freq_target;
	82	if (dbs_info->requested_freq > policy->max)
	83	dbs_info->requested_freq = policy->max;
a8d7c3bc	84
4471a34f VK	85	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	86	CPUFREQ_RELATION_H);
	87	return;
	88	}
	89
	90	/*
	91	* The optimal frequency is the frequency that is the lowest that can
	92	* support the current CPU usage without triggering the up policy. To be
	93	* safe, we focus 10 points under the threshold.
	94	*/
	95	if (load < (cs_tuners.down_threshold - 10)) {
	96	freq_target = (cs_tuners.freq_step * policy->max) / 100;
	97
	98	dbs_info->requested_freq -= freq_target;
	99	if (dbs_info->requested_freq < policy->min)
	100	dbs_info->requested_freq = policy->min;
	101
	102	/*
	103	* if we cannot reduce the frequency anymore, break out early
	104	*/
	105	if (policy->cur == policy->min)
	106	return;
	107
	108	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	109	CPUFREQ_RELATION_H);
	110	return;
	111	}
	112	}
	113
66df2a01 FB	114	static void cs_timer_update(struct cs_cpu_dbs_info_s *dbs_info, bool sample,
66df2a01 FB	115	struct delayed_work *dw)
4471a34f	116	{
4471a34f VK	117	unsigned int cpu = dbs_info->cdbs.cpu;
	118	int delay = delay_for_sampling_rate(cs_tuners.sampling_rate);
	119
66df2a01 FB	120	if (sample)
	121	dbs_check_cpu(&cs_dbs_data, cpu);
	122
	123	schedule_delayed_work_on(smp_processor_id(), dw, delay);
	124	}
	125
	126	static void cs_timer_coordinated(struct cs_cpu_dbs_info_s *dbs_info_local,
	127	struct delayed_work *dw)
	128	{
	129	struct cs_cpu_dbs_info_s *dbs_info;
	130	ktime_t time_now;
	131	s64 delta_us;
	132	bool sample = true;
	133
	134	/* use leader CPU's dbs_info */
	135	dbs_info = &per_cpu(cs_cpu_dbs_info, dbs_info_local->cdbs.cpu);
4471a34f VK	136	mutex_lock(&dbs_info->cdbs.timer_mutex);
4471a34f VK	137
66df2a01 FB	138	time_now = ktime_get();
66df2a01 FB	139	delta_us = ktime_us_delta(time_now, dbs_info->cdbs.time_stamp);
4471a34f	140
66df2a01 FB	141	/* Do nothing if we recently have sampled */
	142	if (delta_us < (s64)(cs_tuners.sampling_rate / 2))
	143	sample = false;
	144	else
	145	dbs_info->cdbs.time_stamp = time_now;
	146
	147	cs_timer_update(dbs_info, sample, dw);
4471a34f VK	148	mutex_unlock(&dbs_info->cdbs.timer_mutex);
	149	}
	150
66df2a01 FB	151	static void cs_dbs_timer(struct work_struct *work)
	152	{
	153	struct delayed_work *dw = to_delayed_work(work);
	154	struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
	155	struct cs_cpu_dbs_info_s, cdbs.work.work);
	156
2624f90c	157	if (policy_is_shared(dbs_info->cdbs.cur_policy)) {
66df2a01 FB	158	cs_timer_coordinated(dbs_info, dw);
	159	} else {
	160	mutex_lock(&dbs_info->cdbs.timer_mutex);
	161	cs_timer_update(dbs_info, true, dw);
	162	mutex_unlock(&dbs_info->cdbs.timer_mutex);
	163	}
	164	}
4471a34f VK	165	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	166	void *data)
	167	{
	168	struct cpufreq_freqs *freq = data;
	169	struct cs_cpu_dbs_info_s *dbs_info =
	170	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	171	struct cpufreq_policy *policy;
f407a08b AC	172
4471a34f	173	if (!dbs_info->enable)
a8d7c3bc EO	174	return 0;
a8d7c3bc EO	175
4471a34f	176	policy = dbs_info->cdbs.cur_policy;
f407a08b AC	177
f407a08b AC	178	/*
4471a34f VK	179	* we only care if our internally tracked freq moves outside the 'valid'
4471a34f VK	180	* ranges of freqency available to us otherwise we do not change it
f407a08b	181	*/
4471a34f VK	182	if (dbs_info->requested_freq > policy->max
	183	\|\| dbs_info->requested_freq < policy->min)
	184	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	185
	186	return 0;
	187	}
	188
b9170836	189	/************************ sysfs interface **********************/
49b015ce TR	190	static ssize_t show_sampling_rate_min(struct kobject *kobj,
49b015ce TR	191	struct attribute attr, char buf)
b9170836	192	{
4471a34f	193	return sprintf(buf, "%u\n", cs_dbs_data.min_sampling_rate);
b9170836 DJ	194	}
b9170836 DJ	195
49b015ce TR	196	static ssize_t store_sampling_down_factor(struct kobject *a,
	197	struct attribute *b,
	198	const char *buf, size_t count)
b9170836 DJ	199	{
	200	unsigned int input;
	201	int ret;
9acef487	202	ret = sscanf(buf, "%u", &input);
8e677ce8	203
2c906b31	204	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	205	return -EINVAL;
b9170836 DJ	206
4471a34f	207	cs_tuners.sampling_down_factor = input;
b9170836 DJ	208	return count;
	209	}
	210
49b015ce TR	211	static ssize_t store_sampling_rate(struct kobject a, struct attribute b,
49b015ce TR	212	const char *buf, size_t count)
b9170836 DJ	213	{
	214	unsigned int input;
	215	int ret;
9acef487	216	ret = sscanf(buf, "%u", &input);
b9170836	217
8e677ce8	218	if (ret != 1)
b9170836	219	return -EINVAL;
8e677ce8	220
4471a34f	221	cs_tuners.sampling_rate = max(input, cs_dbs_data.min_sampling_rate);
b9170836 DJ	222	return count;
	223	}
	224
49b015ce TR	225	static ssize_t store_up_threshold(struct kobject a, struct attribute b,
49b015ce TR	226	const char *buf, size_t count)
b9170836 DJ	227	{
	228	unsigned int input;
	229	int ret;
9acef487	230	ret = sscanf(buf, "%u", &input);
b9170836	231
4471a34f	232	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners.down_threshold)
b9170836	233	return -EINVAL;
b9170836	234
4471a34f	235	cs_tuners.up_threshold = input;
b9170836 DJ	236	return count;
	237	}
	238
49b015ce TR	239	static ssize_t store_down_threshold(struct kobject a, struct attribute b,
49b015ce TR	240	const char *buf, size_t count)
b9170836 DJ	241	{
	242	unsigned int input;
	243	int ret;
9acef487	244	ret = sscanf(buf, "%u", &input);
b9170836	245
8e677ce8 AC	246	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	247	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4471a34f	248	input >= cs_tuners.up_threshold)
b9170836	249	return -EINVAL;
b9170836	250
4471a34f	251	cs_tuners.down_threshold = input;
b9170836 DJ	252	return count;
	253	}
	254
49b015ce TR	255	static ssize_t store_ignore_nice_load(struct kobject a, struct attribute b,
49b015ce TR	256	const char *buf, size_t count)
b9170836	257	{
4471a34f	258	unsigned int input, j;
b9170836 DJ	259	int ret;
b9170836 DJ	260
18a7247d DJ	261	ret = sscanf(buf, "%u", &input);
18a7247d DJ	262	if (ret != 1)
b9170836 DJ	263	return -EINVAL;
b9170836 DJ	264
18a7247d	265	if (input > 1)
b9170836	266	input = 1;
18a7247d	267
4471a34f	268	if (input == cs_tuners.ignore_nice) /* nothing to do */
b9170836	269	return count;
326c86de	270
4471a34f	271	cs_tuners.ignore_nice = input;
b9170836	272
8e677ce8	273	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	274	for_each_online_cpu(j) {
4471a34f	275	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	276	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f VK	277	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
	278	&dbs_info->cdbs.prev_cpu_wall);
	279	if (cs_tuners.ignore_nice)
	280	dbs_info->cdbs.prev_cpu_nice =
	281	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	282	}
b9170836 DJ	283	return count;
	284	}
	285
49b015ce TR	286	static ssize_t store_freq_step(struct kobject a, struct attribute b,
49b015ce TR	287	const char *buf, size_t count)
b9170836 DJ	288	{
	289	unsigned int input;
	290	int ret;
18a7247d	291	ret = sscanf(buf, "%u", &input);
b9170836	292
18a7247d	293	if (ret != 1)
b9170836 DJ	294	return -EINVAL;
b9170836 DJ	295
18a7247d	296	if (input > 100)
b9170836	297	input = 100;
18a7247d	298
4471a34f VK	299	/*
	300	* no need to test here if freq_step is zero as the user might actually
	301	* want this, they would be crazy though :)
	302	*/
	303	cs_tuners.freq_step = input;
b9170836 DJ	304	return count;
	305	}
	306
4471a34f VK	307	show_one(cs, sampling_rate, sampling_rate);
	308	show_one(cs, sampling_down_factor, sampling_down_factor);
	309	show_one(cs, up_threshold, up_threshold);
	310	show_one(cs, down_threshold, down_threshold);
	311	show_one(cs, ignore_nice_load, ignore_nice);
	312	show_one(cs, freq_step, freq_step);
	313
6dad2a29 BP	314	define_one_global_rw(sampling_rate);
	315	define_one_global_rw(sampling_down_factor);
	316	define_one_global_rw(up_threshold);
	317	define_one_global_rw(down_threshold);
	318	define_one_global_rw(ignore_nice_load);
	319	define_one_global_rw(freq_step);
4471a34f	320	define_one_global_ro(sampling_rate_min);
b9170836	321
9acef487	322	static struct attribute *dbs_attributes[] = {
b9170836 DJ	323	&sampling_rate_min.attr,
	324	&sampling_rate.attr,
	325	&sampling_down_factor.attr,
	326	&up_threshold.attr,
	327	&down_threshold.attr,
001893cd	328	&ignore_nice_load.attr,
b9170836 DJ	329	&freq_step.attr,
	330	NULL
	331	};
	332
4471a34f	333	static struct attribute_group cs_attr_group = {
b9170836 DJ	334	.attrs = dbs_attributes,
	335	.name = "conservative",
	336	};
	337
	338	/************************ sysfs end **********************/
	339
4471a34f	340	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	341
4471a34f VK	342	static struct notifier_block cs_cpufreq_notifier_block = {
	343	.notifier_call = dbs_cpufreq_notifier,
	344	};
8e677ce8	345
4471a34f VK	346	static struct cs_ops cs_ops = {
	347	.notifier_block = &cs_cpufreq_notifier_block,
	348	};
b9170836	349
4471a34f VK	350	static struct dbs_data cs_dbs_data = {
	351	.governor = GOV_CONSERVATIVE,
	352	.attr_group = &cs_attr_group,
	353	.tuners = &cs_tuners,
	354	.get_cpu_cdbs = get_cpu_cdbs,
	355	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	356	.gov_dbs_timer = cs_dbs_timer,
	357	.gov_check_cpu = cs_check_cpu,
	358	.gov_ops = &cs_ops,
	359	};
b9170836	360
4471a34f	361	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	362	unsigned int event)
b9170836 DJ	363	{
4471a34f	364	return cpufreq_governor_dbs(&cs_dbs_data, policy, event);
b9170836 DJ	365	}
b9170836 DJ	366
c4d14bc0 SW	367	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	368	static
	369	#endif
1c256245 TR	370	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	371	.name = "conservative",
4471a34f	372	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	373	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	374	.owner = THIS_MODULE,
b9170836 DJ	375	};
	376
	377	static int __init cpufreq_gov_dbs_init(void)
	378	{
4471a34f	379	mutex_init(&cs_dbs_data.mutex);
57df5573	380	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	381	}
	382
	383	static void __exit cpufreq_gov_dbs_exit(void)
	384	{
1c256245	385	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	386	}
b9170836 DJ	387
11a80a9c	388	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	389	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	390	"Low Latency Frequency Transition capable processors "
b9170836 DJ	391	"optimised for use in a battery environment");
9acef487	392	MODULE_LICENSE("GPL");
b9170836	393
6915719b JW	394	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	395	fs_initcall(cpufreq_gov_dbs_init);
	396	#else
b9170836	397	module_init(cpufreq_gov_dbs_init);
6915719b	398	#endif
b9170836	399	module_exit(cpufreq_gov_dbs_exit);