[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/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.shared->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 unsigned int cs_dbs_timer(struct cpu_dbs_info *cdbs,
				 struct dbs_data *dbs_data, bool modify_all)
{
	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;

	if (modify_all)
		dbs_check_cpu(dbs_data, cdbs->shared->policy->cpu);

	return delay_for_sampling_rate(cs_tuners->sampling_rate);
}

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.shared->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;
}

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

/************************** 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, bool notify)
{
	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);

	if (notify)
		cpufreq_register_notifier(&cs_cpufreq_notifier_block,
					  CPUFREQ_TRANSITION_NOTIFIER);

	return 0;
}

static void cs_exit(struct dbs_data *dbs_data, bool notify)
{
	if (notify)
		cpufreq_unregister_notifier(&cs_cpufreq_notifier_block,
					    CPUFREQ_TRANSITION_NOTIFIER);

	kfree(dbs_data->tuners);
}

define_get_cpu_dbs_routines(cs_cpu_dbs_info);

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,
	.init = cs_init,
	.exit = cs_exit,
	.mutex = __MUTEX_INITIALIZER(cs_dbs_cdata.mutex),
};

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	49	struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
44152cb8	50	struct cpufreq_policy *policy = dbs_info->cdbs.shared->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
43e0ee36 VK	105	static unsigned int cs_dbs_timer(struct cpu_dbs_info *cdbs,
43e0ee36 VK	106	struct dbs_data *dbs_data, bool modify_all)
4471a34f	107	{
4d5dcc42	108	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
43e0ee36 VK	109
	110	if (modify_all)
	111	dbs_check_cpu(dbs_data, cdbs->shared->policy->cpu);
	112
	113	return delay_for_sampling_rate(cs_tuners->sampling_rate);
66df2a01 FB	114	}
66df2a01 FB	115
4471a34f VK	116	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	117	void *data)
	118	{
	119	struct cpufreq_freqs *freq = data;
	120	struct cs_cpu_dbs_info_s *dbs_info =
	121	&per_cpu(cs_cpu_dbs_info, freq->cpu);
f407a08b AC	122	struct cpufreq_policy *policy;
f407a08b AC	123
4471a34f	124	if (!dbs_info->enable)
a8d7c3bc EO	125	return 0;
a8d7c3bc EO	126
44152cb8	127	policy = dbs_info->cdbs.shared->policy;
f407a08b AC	128
f407a08b AC	129	/*
4471a34f	130	* we only care if our internally tracked freq moves outside the 'valid'
c88883cd	131	* ranges of frequency available to us otherwise we do not change it
f407a08b	132	*/
4471a34f VK	133	if (dbs_info->requested_freq > policy->max
	134	\|\| dbs_info->requested_freq < policy->min)
	135	dbs_info->requested_freq = freq->new;
a8d7c3bc EO	136
	137	return 0;
	138	}
	139
8e0484d2 VK	140	static struct notifier_block cs_cpufreq_notifier_block = {
	141	.notifier_call = dbs_cpufreq_notifier,
	142	};
	143
b9170836	144	/************************ sysfs interface **********************/
4d5dcc42	145	static struct common_dbs_data cs_dbs_cdata;
b9170836	146
4d5dcc42 VK	147	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	148	const char *buf, size_t count)
b9170836	149	{
4d5dcc42	150	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	151	unsigned int input;
b9170836 DJ	152	int ret;
9acef487	153	ret = sscanf(buf, "%u", &input);
8e677ce8	154
2c906b31	155	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	156	return -EINVAL;
b9170836 DJ	157
4d5dcc42	158	cs_tuners->sampling_down_factor = input;
b9170836 DJ	159	return count;
	160	}
	161
4d5dcc42 VK	162	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	163	size_t count)
b9170836	164	{
4d5dcc42	165	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	166	unsigned int input;
b9170836 DJ	167	int ret;
9acef487	168	ret = sscanf(buf, "%u", &input);
b9170836	169
8e677ce8	170	if (ret != 1)
b9170836	171	return -EINVAL;
8e677ce8	172
4d5dcc42	173	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	174	return count;
	175	}
	176
4d5dcc42 VK	177	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	178	size_t count)
b9170836	179	{
4d5dcc42	180	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	181	unsigned int input;
b9170836 DJ	182	int ret;
9acef487	183	ret = sscanf(buf, "%u", &input);
b9170836	184
4d5dcc42	185	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	186	return -EINVAL;
b9170836	187
4d5dcc42	188	cs_tuners->up_threshold = input;
b9170836 DJ	189	return count;
	190	}
	191
4d5dcc42 VK	192	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	193	size_t count)
b9170836	194	{
4d5dcc42	195	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	196	unsigned int input;
b9170836 DJ	197	int ret;
9acef487	198	ret = sscanf(buf, "%u", &input);
b9170836	199
8e677ce8 AC	200	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	201	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	202	input >= cs_tuners->up_threshold)
b9170836	203	return -EINVAL;
b9170836	204
4d5dcc42	205	cs_tuners->down_threshold = input;
b9170836 DJ	206	return count;
	207	}
	208
6c4640c3 VK	209	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
6c4640c3 VK	210	const char *buf, size_t count)
b9170836	211	{
4d5dcc42	212	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	213	unsigned int input, j;
b9170836 DJ	214	int ret;
b9170836 DJ	215
18a7247d DJ	216	ret = sscanf(buf, "%u", &input);
18a7247d DJ	217	if (ret != 1)
b9170836 DJ	218	return -EINVAL;
b9170836 DJ	219
18a7247d	220	if (input > 1)
b9170836	221	input = 1;
18a7247d	222
6c4640c3	223	if (input == cs_tuners->ignore_nice_load) /* nothing to do */
b9170836	224	return count;
326c86de	225
6c4640c3	226	cs_tuners->ignore_nice_load = input;
b9170836	227
8e677ce8	228	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	229	for_each_online_cpu(j) {
4471a34f	230	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	231	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	232	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	233	&dbs_info->cdbs.prev_cpu_wall, 0);
6c4640c3	234	if (cs_tuners->ignore_nice_load)
4471a34f VK	235	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	236	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	237	}
b9170836 DJ	238	return count;
	239	}
	240
4d5dcc42 VK	241	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	242	size_t count)
b9170836	243	{
4d5dcc42	244	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	245	unsigned int input;
b9170836 DJ	246	int ret;
18a7247d	247	ret = sscanf(buf, "%u", &input);
b9170836	248
18a7247d	249	if (ret != 1)
b9170836 DJ	250	return -EINVAL;
b9170836 DJ	251
18a7247d	252	if (input > 100)
b9170836	253	input = 100;
18a7247d	254
4471a34f VK	255	/*
	256	* no need to test here if freq_step is zero as the user might actually
	257	* want this, they would be crazy though :)
	258	*/
4d5dcc42	259	cs_tuners->freq_step = input;
b9170836 DJ	260	return count;
	261	}
	262
4d5dcc42 VK	263	show_store_one(cs, sampling_rate);
	264	show_store_one(cs, sampling_down_factor);
	265	show_store_one(cs, up_threshold);
	266	show_store_one(cs, down_threshold);
6c4640c3	267	show_store_one(cs, ignore_nice_load);
4d5dcc42 VK	268	show_store_one(cs, freq_step);
	269	declare_show_sampling_rate_min(cs);
	270
	271	gov_sys_pol_attr_rw(sampling_rate);
	272	gov_sys_pol_attr_rw(sampling_down_factor);
	273	gov_sys_pol_attr_rw(up_threshold);
	274	gov_sys_pol_attr_rw(down_threshold);
6c4640c3	275	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42 VK	276	gov_sys_pol_attr_rw(freq_step);
	277	gov_sys_pol_attr_ro(sampling_rate_min);
	278
	279	static struct attribute *dbs_attributes_gov_sys[] = {
	280	&sampling_rate_min_gov_sys.attr,
	281	&sampling_rate_gov_sys.attr,
	282	&sampling_down_factor_gov_sys.attr,
	283	&up_threshold_gov_sys.attr,
	284	&down_threshold_gov_sys.attr,
6c4640c3	285	&ignore_nice_load_gov_sys.attr,
4d5dcc42	286	&freq_step_gov_sys.attr,
b9170836 DJ	287	NULL
	288	};
	289
4d5dcc42 VK	290	static struct attribute_group cs_attr_group_gov_sys = {
	291	.attrs = dbs_attributes_gov_sys,
	292	.name = "conservative",
	293	};
	294
	295	static struct attribute *dbs_attributes_gov_pol[] = {
	296	&sampling_rate_min_gov_pol.attr,
	297	&sampling_rate_gov_pol.attr,
	298	&sampling_down_factor_gov_pol.attr,
	299	&up_threshold_gov_pol.attr,
	300	&down_threshold_gov_pol.attr,
6c4640c3	301	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	302	&freq_step_gov_pol.attr,
	303	NULL
	304	};
	305
	306	static struct attribute_group cs_attr_group_gov_pol = {
	307	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	308	.name = "conservative",
	309	};
	310
	311	/************************ sysfs end **********************/
	312
8e0484d2	313	static int cs_init(struct dbs_data *dbs_data, bool notify)
4d5dcc42 VK	314	{
	315	struct cs_dbs_tuners *tuners;
	316
d5b73cd8	317	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
4d5dcc42 VK	318	if (!tuners) {
	319	pr_err("%s: kzalloc failed\n", __func__);
	320	return -ENOMEM;
	321	}
	322
	323	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	324	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	325	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
6c4640c3	326	tuners->ignore_nice_load = 0;
98765847	327	tuners->freq_step = DEF_FREQUENCY_STEP;
4d5dcc42 VK	328
	329	dbs_data->tuners = tuners;
	330	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	331	jiffies_to_usecs(10);
8e0484d2 VK	332
	333	if (notify)
	334	cpufreq_register_notifier(&cs_cpufreq_notifier_block,
	335	CPUFREQ_TRANSITION_NOTIFIER);
	336
4d5dcc42 VK	337	return 0;
	338	}
	339
8e0484d2	340	static void cs_exit(struct dbs_data *dbs_data, bool notify)
4d5dcc42	341	{
8e0484d2 VK	342	if (notify)
	343	cpufreq_unregister_notifier(&cs_cpufreq_notifier_block,
	344	CPUFREQ_TRANSITION_NOTIFIER);
	345
4d5dcc42 VK	346	kfree(dbs_data->tuners);
	347	}
	348
4471a34f	349	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	350
4d5dcc42	351	static struct common_dbs_data cs_dbs_cdata = {
4471a34f	352	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	353	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	354	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	355	.get_cpu_cdbs = get_cpu_cdbs,
	356	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	357	.gov_dbs_timer = cs_dbs_timer,
	358	.gov_check_cpu = cs_check_cpu,
4d5dcc42 VK	359	.init = cs_init,
4d5dcc42 VK	360	.exit = cs_exit,
732b6d61	361	.mutex = __MUTEX_INITIALIZER(cs_dbs_cdata.mutex),
4471a34f	362	};
b9170836	363
4471a34f	364	static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
b9170836 DJ	365	unsigned int event)
b9170836 DJ	366	{
4d5dcc42	367	return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
b9170836 DJ	368	}
b9170836 DJ	369
c4d14bc0 SW	370	#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	371	static
	372	#endif
1c256245 TR	373	struct cpufreq_governor cpufreq_gov_conservative = {
1c256245 TR	374	.name = "conservative",
4471a34f	375	.governor = cs_cpufreq_governor_dbs,
1c256245 TR	376	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
1c256245 TR	377	.owner = THIS_MODULE,
b9170836 DJ	378	};
	379
	380	static int __init cpufreq_gov_dbs_init(void)
	381	{
57df5573	382	return cpufreq_register_governor(&cpufreq_gov_conservative);
b9170836 DJ	383	}
	384
	385	static void __exit cpufreq_gov_dbs_exit(void)
	386	{
1c256245	387	cpufreq_unregister_governor(&cpufreq_gov_conservative);
b9170836 DJ	388	}
b9170836 DJ	389
11a80a9c	390	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	391	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	392	"Low Latency Frequency Transition capable processors "
b9170836 DJ	393	"optimised for use in a battery environment");
9acef487	394	MODULE_LICENSE("GPL");
b9170836	395
6915719b JW	396	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
	397	fs_initcall(cpufreq_gov_dbs_init);
	398	#else
b9170836	399	module_init(cpufreq_gov_dbs_init);
6915719b	400	#endif
b9170836	401	module_exit(cpufreq_gov_dbs_exit);