[deliverable/linux.git] / drivers / cpufreq / cpufreq_conservative.c

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

#include <linux/slab.h>
#include "cpufreq_governor.h"

/* Conservative governor macros */
#define DEF_FREQUENCY_UP_THRESHOLD		(80)
#define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
#define DEF_FREQUENCY_STEP			(5)
#define DEF_SAMPLING_DOWN_FACTOR		(1)
#define MAX_SAMPLING_DOWN_FACTOR		(10)

static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);

static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
					   struct cpufreq_policy *policy)
{
	unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100;

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

	return freq_target;
}

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

	dbs_check_cpu(policy);
	return delay_for_sampling_rate(dbs_data->sampling_rate);
}

static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
				void *data);

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

/************************** sysfs interface ************************/
static struct dbs_governor cs_dbs_gov;

static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
		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;

	dbs_data->sampling_down_factor = input;
	return count;
}

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

	if (ret != 1)
		return -EINVAL;

	dbs_data->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;

	dbs_data->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 >= dbs_data->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)
{
	unsigned int input, j;
	int ret;

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

	if (input > 1)
		input = 1;

	if (input == dbs_data->ignore_nice_load) /* nothing to do */
		return count;

	dbs_data->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 (dbs_data->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, down_threshold);
show_store_one(cs, freq_step);
show_store_one_common(cs, sampling_rate);
show_store_one_common(cs, sampling_down_factor);
show_store_one_common(cs, up_threshold);
show_store_one_common(cs, ignore_nice_load);
show_one_common(cs, min_sampling_rate);

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(min_sampling_rate);

static struct attribute *dbs_attributes_gov_sys[] = {
	&min_sampling_rate_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[] = {
	&min_sampling_rate_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->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	tuners->freq_step = DEF_FREQUENCY_STEP;
	dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
	dbs_data->ignore_nice_load = 0;

	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 dbs_governor cs_dbs_gov = {
	.gov = {
		.name = "conservative",
		.governor = cpufreq_governor_dbs,
		.max_transition_latency = TRANSITION_LATENCY_LIMIT,
		.owner = THIS_MODULE,
	},
	.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,
};

#define CPU_FREQ_GOV_CONSERVATIVE	(&cs_dbs_gov.gov)

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 = cpufreq_cpu_get_raw(freq->cpu);

	if (!policy)
		return 0;

	/* policy isn't governed by conservative governor */
	if (policy->governor != CPU_FREQ_GOV_CONSERVATIVE)
		return 0;

	/*
	 * 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 int __init cpufreq_gov_dbs_init(void)
{
	return cpufreq_register_governor(CPU_FREQ_GOV_CONSERVATIVE);
}

static void __exit cpufreq_gov_dbs_exit(void)
{
	cpufreq_unregister_governor(CPU_FREQ_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
struct cpufreq_governor *cpufreq_default_governor(void)
{
	return CPU_FREQ_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);
e40e7b25	50	struct cpufreq_policy *policy = dbs_info->cdbs.policy_dbs->policy;
bc505475 RW	51	struct policy_dbs_info *policy_dbs = policy->governor_data;
bc505475 RW	52	struct dbs_data *dbs_data = policy_dbs->dbs_data;
4d5dcc42	53	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f VK	54
	55	/*
	56	* break out if we 'cannot' reduce the speed as the user might
	57	* want freq_step to be zero
	58	*/
4d5dcc42	59	if (cs_tuners->freq_step == 0)
4471a34f VK	60	return;
	61
	62	/* Check for frequency increase */
ff4b1789	63	if (load > dbs_data->up_threshold) {
4471a34f VK	64	dbs_info->down_skip = 0;
	65
	66	/* if we are already at full speed then break out early */
	67	if (dbs_info->requested_freq == policy->max)
	68	return;
	69
98765847	70	dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
a8d7c3bc	71
6d7bcb14 XC	72	if (dbs_info->requested_freq > policy->max)
	73	dbs_info->requested_freq = policy->max;
	74
4471a34f VK	75	__cpufreq_driver_target(policy, dbs_info->requested_freq,
	76	CPUFREQ_RELATION_H);
	77	return;
	78	}
	79
7af1c056	80	/* if sampling_down_factor is active break out early */
ff4b1789	81	if (++dbs_info->down_skip < dbs_data->sampling_down_factor)
7af1c056 SK	82	return;
	83	dbs_info->down_skip = 0;
	84
27ed3cd2 SK	85	/* Check for frequency decrease */
27ed3cd2 SK	86	if (load < cs_tuners->down_threshold) {
3baa976a	87	unsigned int freq_target;
4471a34f VK	88	/*
	89	* if we cannot reduce the frequency anymore, break out early
	90	*/
	91	if (policy->cur == policy->min)
	92	return;
	93
3baa976a XC	94	freq_target = get_freq_target(cs_tuners, policy);
	95	if (dbs_info->requested_freq > freq_target)
	96	dbs_info->requested_freq -= freq_target;
	97	else
	98	dbs_info->requested_freq = policy->min;
ad529a9c	99
4471a34f	100	__cpufreq_driver_target(policy, dbs_info->requested_freq,
fed573d5	101	CPUFREQ_RELATION_L);
4471a34f VK	102	return;
	103	}
	104	}
	105
9be4fd2c	106	static unsigned int cs_dbs_timer(struct cpufreq_policy *policy)
4471a34f	107	{
bc505475 RW	108	struct policy_dbs_info *policy_dbs = policy->governor_data;
bc505475 RW	109	struct dbs_data *dbs_data = policy_dbs->dbs_data;
43e0ee36	110
d10b5eb5	111	dbs_check_cpu(policy);
ff4b1789	112	return delay_for_sampling_rate(dbs_data->sampling_rate);
66df2a01 FB	113	}
66df2a01 FB	114
4471a34f	115	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
af926185	116	void *data);
a8d7c3bc	117
8e0484d2 VK	118	static struct notifier_block cs_cpufreq_notifier_block = {
	119	.notifier_call = dbs_cpufreq_notifier,
	120	};
	121
b9170836	122	/************************ sysfs interface **********************/
7bdad34d	123	static struct dbs_governor cs_dbs_gov;
b9170836	124
4d5dcc42 VK	125	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	126	const char *buf, size_t count)
b9170836 DJ	127	{
	128	unsigned int input;
	129	int ret;
9acef487	130	ret = sscanf(buf, "%u", &input);
8e677ce8	131
2c906b31	132	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	133	return -EINVAL;
b9170836 DJ	134
ff4b1789	135	dbs_data->sampling_down_factor = input;
b9170836 DJ	136	return count;
	137	}
	138
4d5dcc42 VK	139	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	140	size_t count)
b9170836 DJ	141	{
	142	unsigned int input;
	143	int ret;
9acef487	144	ret = sscanf(buf, "%u", &input);
b9170836	145
8e677ce8	146	if (ret != 1)
b9170836	147	return -EINVAL;
8e677ce8	148
ff4b1789	149	dbs_data->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	150	return count;
	151	}
	152
4d5dcc42 VK	153	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	154	size_t count)
b9170836	155	{
4d5dcc42	156	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	157	unsigned int input;
b9170836 DJ	158	int ret;
9acef487	159	ret = sscanf(buf, "%u", &input);
b9170836	160
4d5dcc42	161	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	162	return -EINVAL;
b9170836	163
ff4b1789	164	dbs_data->up_threshold = input;
b9170836 DJ	165	return count;
	166	}
	167
4d5dcc42 VK	168	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	169	size_t count)
b9170836	170	{
4d5dcc42	171	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	172	unsigned int input;
b9170836 DJ	173	int ret;
9acef487	174	ret = sscanf(buf, "%u", &input);
b9170836	175
8e677ce8 AC	176	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	177	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
ff4b1789	178	input >= dbs_data->up_threshold)
b9170836	179	return -EINVAL;
b9170836	180
4d5dcc42	181	cs_tuners->down_threshold = input;
b9170836 DJ	182	return count;
	183	}
	184
6c4640c3 VK	185	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
6c4640c3 VK	186	const char *buf, size_t count)
b9170836	187	{
4471a34f	188	unsigned int input, j;
b9170836 DJ	189	int ret;
b9170836 DJ	190
18a7247d DJ	191	ret = sscanf(buf, "%u", &input);
18a7247d DJ	192	if (ret != 1)
b9170836 DJ	193	return -EINVAL;
b9170836 DJ	194
18a7247d	195	if (input > 1)
b9170836	196	input = 1;
18a7247d	197
ff4b1789	198	if (input == dbs_data->ignore_nice_load) /* nothing to do */
b9170836	199	return count;
326c86de	200
ff4b1789	201	dbs_data->ignore_nice_load = input;
b9170836	202
8e677ce8	203	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	204	for_each_online_cpu(j) {
4471a34f	205	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	206	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	207	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	208	&dbs_info->cdbs.prev_cpu_wall, 0);
ff4b1789	209	if (dbs_data->ignore_nice_load)
4471a34f VK	210	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	211	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	212	}
b9170836 DJ	213	return count;
	214	}
	215
4d5dcc42 VK	216	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	217	size_t count)
b9170836	218	{
4d5dcc42	219	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	220	unsigned int input;
b9170836 DJ	221	int ret;
18a7247d	222	ret = sscanf(buf, "%u", &input);
b9170836	223
18a7247d	224	if (ret != 1)
b9170836 DJ	225	return -EINVAL;
b9170836 DJ	226
18a7247d	227	if (input > 100)
b9170836	228	input = 100;
18a7247d	229
4471a34f VK	230	/*
	231	* no need to test here if freq_step is zero as the user might actually
	232	* want this, they would be crazy though :)
	233	*/
4d5dcc42	234	cs_tuners->freq_step = input;
b9170836 DJ	235	return count;
	236	}
	237
4d5dcc42	238	show_store_one(cs, down_threshold);
4d5dcc42	239	show_store_one(cs, freq_step);
ff4b1789 VK	240	show_store_one_common(cs, sampling_rate);
	241	show_store_one_common(cs, sampling_down_factor);
	242	show_store_one_common(cs, up_threshold);
	243	show_store_one_common(cs, ignore_nice_load);
d0684d3b	244	show_one_common(cs, min_sampling_rate);
4d5dcc42 VK	245
	246	gov_sys_pol_attr_rw(sampling_rate);
	247	gov_sys_pol_attr_rw(sampling_down_factor);
	248	gov_sys_pol_attr_rw(up_threshold);
	249	gov_sys_pol_attr_rw(down_threshold);
6c4640c3	250	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42	251	gov_sys_pol_attr_rw(freq_step);
d0684d3b	252	gov_sys_pol_attr_ro(min_sampling_rate);
4d5dcc42 VK	253
4d5dcc42 VK	254	static struct attribute *dbs_attributes_gov_sys[] = {
d0684d3b	255	&min_sampling_rate_gov_sys.attr,
4d5dcc42 VK	256	&sampling_rate_gov_sys.attr,
	257	&sampling_down_factor_gov_sys.attr,
	258	&up_threshold_gov_sys.attr,
	259	&down_threshold_gov_sys.attr,
6c4640c3	260	&ignore_nice_load_gov_sys.attr,
4d5dcc42	261	&freq_step_gov_sys.attr,
b9170836 DJ	262	NULL
	263	};
	264
4d5dcc42 VK	265	static struct attribute_group cs_attr_group_gov_sys = {
	266	.attrs = dbs_attributes_gov_sys,
	267	.name = "conservative",
	268	};
	269
	270	static struct attribute *dbs_attributes_gov_pol[] = {
d0684d3b	271	&min_sampling_rate_gov_pol.attr,
4d5dcc42 VK	272	&sampling_rate_gov_pol.attr,
	273	&sampling_down_factor_gov_pol.attr,
	274	&up_threshold_gov_pol.attr,
	275	&down_threshold_gov_pol.attr,
6c4640c3	276	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	277	&freq_step_gov_pol.attr,
	278	NULL
	279	};
	280
	281	static struct attribute_group cs_attr_group_gov_pol = {
	282	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	283	.name = "conservative",
	284	};
	285
	286	/************************ sysfs end **********************/
	287
8e0484d2	288	static int cs_init(struct dbs_data *dbs_data, bool notify)
4d5dcc42 VK	289	{
	290	struct cs_dbs_tuners *tuners;
	291
d5b73cd8	292	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
4d5dcc42 VK	293	if (!tuners) {
	294	pr_err("%s: kzalloc failed\n", __func__);
	295	return -ENOMEM;
	296	}
	297
4d5dcc42	298	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
98765847	299	tuners->freq_step = DEF_FREQUENCY_STEP;
ff4b1789 VK	300	dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	301	dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
	302	dbs_data->ignore_nice_load = 0;
4d5dcc42 VK	303
	304	dbs_data->tuners = tuners;
	305	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	306	jiffies_to_usecs(10);
8e0484d2 VK	307
	308	if (notify)
	309	cpufreq_register_notifier(&cs_cpufreq_notifier_block,
	310	CPUFREQ_TRANSITION_NOTIFIER);
	311
4d5dcc42 VK	312	return 0;
	313	}
	314
8e0484d2	315	static void cs_exit(struct dbs_data *dbs_data, bool notify)
4d5dcc42	316	{
8e0484d2 VK	317	if (notify)
	318	cpufreq_unregister_notifier(&cs_cpufreq_notifier_block,
	319	CPUFREQ_TRANSITION_NOTIFIER);
	320
4d5dcc42 VK	321	kfree(dbs_data->tuners);
	322	}
	323
4471a34f	324	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	325
7bdad34d	326	static struct dbs_governor cs_dbs_gov = {
af926185 RW	327	.gov = {
af926185 RW	328	.name = "conservative",
906a6e5a	329	.governor = cpufreq_governor_dbs,
af926185 RW	330	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
	331	.owner = THIS_MODULE,
	332	},
4471a34f	333	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	334	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	335	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	336	.get_cpu_cdbs = get_cpu_cdbs,
	337	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	338	.gov_dbs_timer = cs_dbs_timer,
	339	.gov_check_cpu = cs_check_cpu,
4d5dcc42 VK	340	.init = cs_init,
4d5dcc42 VK	341	.exit = cs_exit,
4471a34f	342	};
b9170836	343
7bdad34d	344	#define CPU_FREQ_GOV_CONSERVATIVE (&cs_dbs_gov.gov)
af926185	345
af926185 RW	346	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	347	void *data)
	348	{
	349	struct cpufreq_freqs *freq = data;
	350	struct cs_cpu_dbs_info_s *dbs_info =
	351	&per_cpu(cs_cpu_dbs_info, freq->cpu);
	352	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(freq->cpu);
	353
	354	if (!policy)
	355	return 0;
	356
	357	/* policy isn't governed by conservative governor */
	358	if (policy->governor != CPU_FREQ_GOV_CONSERVATIVE)
	359	return 0;
	360
	361	/*
	362	* we only care if our internally tracked freq moves outside the 'valid'
	363	* ranges of frequency available to us otherwise we do not change it
	364	*/
	365	if (dbs_info->requested_freq > policy->max
	366	\|\| dbs_info->requested_freq < policy->min)
	367	dbs_info->requested_freq = freq->new;
	368
	369	return 0;
	370	}
	371
b9170836 DJ	372	static int __init cpufreq_gov_dbs_init(void)
b9170836 DJ	373	{
af926185	374	return cpufreq_register_governor(CPU_FREQ_GOV_CONSERVATIVE);
b9170836 DJ	375	}
	376
	377	static void __exit cpufreq_gov_dbs_exit(void)
	378	{
af926185	379	cpufreq_unregister_governor(CPU_FREQ_GOV_CONSERVATIVE);
b9170836 DJ	380	}
b9170836 DJ	381
11a80a9c	382	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	383	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	384	"Low Latency Frequency Transition capable processors "
b9170836 DJ	385	"optimised for use in a battery environment");
9acef487	386	MODULE_LICENSE("GPL");
b9170836	387
6915719b	388	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
de1df26b RW	389	struct cpufreq_governor *cpufreq_default_governor(void)
de1df26b RW	390	{
af926185	391	return CPU_FREQ_GOV_CONSERVATIVE;
de1df26b RW	392	}
de1df26b RW	393
6915719b JW	394	fs_initcall(cpufreq_gov_dbs_init);
6915719b JW	395	#else
b9170836	396	module_init(cpufreq_gov_dbs_init);
6915719b	397	#endif
b9170836	398	module_exit(cpufreq_gov_dbs_exit);