[linux-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.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 > 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 cpufreq_policy *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;

	dbs_check_cpu(policy);
	return delay_for_sampling_rate(cs_tuners->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)
{
	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);
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->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 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 */
4d5dcc42	63	if (load > cs_tuners->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 SK	80	/* if sampling_down_factor is active break out early */
	81	if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
	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;
4d5dcc42	110	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
43e0ee36	111
d10b5eb5	112	dbs_check_cpu(policy);
43e0ee36	113	return delay_for_sampling_rate(cs_tuners->sampling_rate);
66df2a01 FB	114	}
66df2a01 FB	115
4471a34f	116	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
af926185	117	void *data);
a8d7c3bc	118
8e0484d2 VK	119	static struct notifier_block cs_cpufreq_notifier_block = {
	120	.notifier_call = dbs_cpufreq_notifier,
	121	};
	122
b9170836	123	/************************ sysfs interface **********************/
7bdad34d	124	static struct dbs_governor cs_dbs_gov;
b9170836	125
4d5dcc42 VK	126	static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
4d5dcc42 VK	127	const char *buf, size_t count)
b9170836	128	{
4d5dcc42	129	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	130	unsigned int input;
b9170836 DJ	131	int ret;
9acef487	132	ret = sscanf(buf, "%u", &input);
8e677ce8	133
2c906b31	134	if (ret != 1 \|\| input > MAX_SAMPLING_DOWN_FACTOR \|\| input < 1)
b9170836 DJ	135	return -EINVAL;
b9170836 DJ	136
4d5dcc42	137	cs_tuners->sampling_down_factor = input;
b9170836 DJ	138	return count;
	139	}
	140
4d5dcc42 VK	141	static ssize_t store_sampling_rate(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	142	size_t count)
b9170836	143	{
4d5dcc42	144	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	145	unsigned int input;
b9170836 DJ	146	int ret;
9acef487	147	ret = sscanf(buf, "%u", &input);
b9170836	148
8e677ce8	149	if (ret != 1)
b9170836	150	return -EINVAL;
8e677ce8	151
4d5dcc42	152	cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
b9170836 DJ	153	return count;
	154	}
	155
4d5dcc42 VK	156	static ssize_t store_up_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	157	size_t count)
b9170836	158	{
4d5dcc42	159	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	160	unsigned int input;
b9170836 DJ	161	int ret;
9acef487	162	ret = sscanf(buf, "%u", &input);
b9170836	163
4d5dcc42	164	if (ret != 1 \|\| input > 100 \|\| input <= cs_tuners->down_threshold)
b9170836	165	return -EINVAL;
b9170836	166
4d5dcc42	167	cs_tuners->up_threshold = input;
b9170836 DJ	168	return count;
	169	}
	170
4d5dcc42 VK	171	static ssize_t store_down_threshold(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	172	size_t count)
b9170836	173	{
4d5dcc42	174	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	175	unsigned int input;
b9170836 DJ	176	int ret;
9acef487	177	ret = sscanf(buf, "%u", &input);
b9170836	178
8e677ce8 AC	179	/* cannot be lower than 11 otherwise freq will not fall */
8e677ce8 AC	180	if (ret != 1 \|\| input < 11 \|\| input > 100 \|\|
4d5dcc42	181	input >= cs_tuners->up_threshold)
b9170836	182	return -EINVAL;
b9170836	183
4d5dcc42	184	cs_tuners->down_threshold = input;
b9170836 DJ	185	return count;
	186	}
	187
6c4640c3 VK	188	static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
6c4640c3 VK	189	const char *buf, size_t count)
b9170836	190	{
4d5dcc42	191	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
4471a34f	192	unsigned int input, j;
b9170836 DJ	193	int ret;
b9170836 DJ	194
18a7247d DJ	195	ret = sscanf(buf, "%u", &input);
18a7247d DJ	196	if (ret != 1)
b9170836 DJ	197	return -EINVAL;
b9170836 DJ	198
18a7247d	199	if (input > 1)
b9170836	200	input = 1;
18a7247d	201
6c4640c3	202	if (input == cs_tuners->ignore_nice_load) /* nothing to do */
b9170836	203	return count;
326c86de	204
6c4640c3	205	cs_tuners->ignore_nice_load = input;
b9170836	206
8e677ce8	207	/* we need to re-evaluate prev_cpu_idle */
dac1c1a5	208	for_each_online_cpu(j) {
4471a34f	209	struct cs_cpu_dbs_info_s *dbs_info;
245b2e70	210	dbs_info = &per_cpu(cs_cpu_dbs_info, j);
4471a34f	211	dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
9366d840	212	&dbs_info->cdbs.prev_cpu_wall, 0);
6c4640c3	213	if (cs_tuners->ignore_nice_load)
4471a34f VK	214	dbs_info->cdbs.prev_cpu_nice =
4471a34f VK	215	kcpustat_cpu(j).cpustat[CPUTIME_NICE];
b9170836	216	}
b9170836 DJ	217	return count;
	218	}
	219
4d5dcc42 VK	220	static ssize_t store_freq_step(struct dbs_data dbs_data, const char buf,
4d5dcc42 VK	221	size_t count)
b9170836	222	{
4d5dcc42	223	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
b9170836 DJ	224	unsigned int input;
b9170836 DJ	225	int ret;
18a7247d	226	ret = sscanf(buf, "%u", &input);
b9170836	227
18a7247d	228	if (ret != 1)
b9170836 DJ	229	return -EINVAL;
b9170836 DJ	230
18a7247d	231	if (input > 100)
b9170836	232	input = 100;
18a7247d	233
4471a34f VK	234	/*
	235	* no need to test here if freq_step is zero as the user might actually
	236	* want this, they would be crazy though :)
	237	*/
4d5dcc42	238	cs_tuners->freq_step = input;
b9170836 DJ	239	return count;
	240	}
	241
4d5dcc42 VK	242	show_store_one(cs, sampling_rate);
	243	show_store_one(cs, sampling_down_factor);
	244	show_store_one(cs, up_threshold);
	245	show_store_one(cs, down_threshold);
6c4640c3	246	show_store_one(cs, ignore_nice_load);
4d5dcc42	247	show_store_one(cs, freq_step);
d0684d3b	248	show_one_common(cs, min_sampling_rate);
4d5dcc42 VK	249
	250	gov_sys_pol_attr_rw(sampling_rate);
	251	gov_sys_pol_attr_rw(sampling_down_factor);
	252	gov_sys_pol_attr_rw(up_threshold);
	253	gov_sys_pol_attr_rw(down_threshold);
6c4640c3	254	gov_sys_pol_attr_rw(ignore_nice_load);
4d5dcc42	255	gov_sys_pol_attr_rw(freq_step);
d0684d3b	256	gov_sys_pol_attr_ro(min_sampling_rate);
4d5dcc42 VK	257
4d5dcc42 VK	258	static struct attribute *dbs_attributes_gov_sys[] = {
d0684d3b	259	&min_sampling_rate_gov_sys.attr,
4d5dcc42 VK	260	&sampling_rate_gov_sys.attr,
	261	&sampling_down_factor_gov_sys.attr,
	262	&up_threshold_gov_sys.attr,
	263	&down_threshold_gov_sys.attr,
6c4640c3	264	&ignore_nice_load_gov_sys.attr,
4d5dcc42	265	&freq_step_gov_sys.attr,
b9170836 DJ	266	NULL
	267	};
	268
4d5dcc42 VK	269	static struct attribute_group cs_attr_group_gov_sys = {
	270	.attrs = dbs_attributes_gov_sys,
	271	.name = "conservative",
	272	};
	273
	274	static struct attribute *dbs_attributes_gov_pol[] = {
d0684d3b	275	&min_sampling_rate_gov_pol.attr,
4d5dcc42 VK	276	&sampling_rate_gov_pol.attr,
	277	&sampling_down_factor_gov_pol.attr,
	278	&up_threshold_gov_pol.attr,
	279	&down_threshold_gov_pol.attr,
6c4640c3	280	&ignore_nice_load_gov_pol.attr,
4d5dcc42 VK	281	&freq_step_gov_pol.attr,
	282	NULL
	283	};
	284
	285	static struct attribute_group cs_attr_group_gov_pol = {
	286	.attrs = dbs_attributes_gov_pol,
b9170836 DJ	287	.name = "conservative",
	288	};
	289
	290	/************************ sysfs end **********************/
	291
8e0484d2	292	static int cs_init(struct dbs_data *dbs_data, bool notify)
4d5dcc42 VK	293	{
	294	struct cs_dbs_tuners *tuners;
	295
d5b73cd8	296	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
4d5dcc42 VK	297	if (!tuners) {
	298	pr_err("%s: kzalloc failed\n", __func__);
	299	return -ENOMEM;
	300	}
	301
	302	tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
	303	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
	304	tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
6c4640c3	305	tuners->ignore_nice_load = 0;
98765847	306	tuners->freq_step = DEF_FREQUENCY_STEP;
4d5dcc42 VK	307
	308	dbs_data->tuners = tuners;
	309	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
	310	jiffies_to_usecs(10);
8e0484d2 VK	311
	312	if (notify)
	313	cpufreq_register_notifier(&cs_cpufreq_notifier_block,
	314	CPUFREQ_TRANSITION_NOTIFIER);
	315
4d5dcc42 VK	316	return 0;
	317	}
	318
8e0484d2	319	static void cs_exit(struct dbs_data *dbs_data, bool notify)
4d5dcc42	320	{
8e0484d2 VK	321	if (notify)
	322	cpufreq_unregister_notifier(&cs_cpufreq_notifier_block,
	323	CPUFREQ_TRANSITION_NOTIFIER);
	324
4d5dcc42 VK	325	kfree(dbs_data->tuners);
	326	}
	327
4471a34f	328	define_get_cpu_dbs_routines(cs_cpu_dbs_info);
8e677ce8	329
7bdad34d	330	static struct dbs_governor cs_dbs_gov = {
af926185 RW	331	.gov = {
af926185 RW	332	.name = "conservative",
906a6e5a	333	.governor = cpufreq_governor_dbs,
af926185 RW	334	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
	335	.owner = THIS_MODULE,
	336	},
4471a34f	337	.governor = GOV_CONSERVATIVE,
4d5dcc42 VK	338	.attr_group_gov_sys = &cs_attr_group_gov_sys,
4d5dcc42 VK	339	.attr_group_gov_pol = &cs_attr_group_gov_pol,
4471a34f VK	340	.get_cpu_cdbs = get_cpu_cdbs,
	341	.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
	342	.gov_dbs_timer = cs_dbs_timer,
	343	.gov_check_cpu = cs_check_cpu,
4d5dcc42 VK	344	.init = cs_init,
4d5dcc42 VK	345	.exit = cs_exit,
4471a34f	346	};
b9170836	347
7bdad34d	348	#define CPU_FREQ_GOV_CONSERVATIVE (&cs_dbs_gov.gov)
af926185	349
af926185 RW	350	static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
	351	void *data)
	352	{
	353	struct cpufreq_freqs *freq = data;
	354	struct cs_cpu_dbs_info_s *dbs_info =
	355	&per_cpu(cs_cpu_dbs_info, freq->cpu);
	356	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(freq->cpu);
	357
	358	if (!policy)
	359	return 0;
	360
	361	/* policy isn't governed by conservative governor */
	362	if (policy->governor != CPU_FREQ_GOV_CONSERVATIVE)
	363	return 0;
	364
	365	/*
	366	* we only care if our internally tracked freq moves outside the 'valid'
	367	* ranges of frequency available to us otherwise we do not change it
	368	*/
	369	if (dbs_info->requested_freq > policy->max
	370	\|\| dbs_info->requested_freq < policy->min)
	371	dbs_info->requested_freq = freq->new;
	372
	373	return 0;
	374	}
	375
b9170836 DJ	376	static int __init cpufreq_gov_dbs_init(void)
b9170836 DJ	377	{
af926185	378	return cpufreq_register_governor(CPU_FREQ_GOV_CONSERVATIVE);
b9170836 DJ	379	}
	380
	381	static void __exit cpufreq_gov_dbs_exit(void)
	382	{
af926185	383	cpufreq_unregister_governor(CPU_FREQ_GOV_CONSERVATIVE);
b9170836 DJ	384	}
b9170836 DJ	385
11a80a9c	386	MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
9acef487	387	MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
b9170836 DJ	388	"Low Latency Frequency Transition capable processors "
b9170836 DJ	389	"optimised for use in a battery environment");
9acef487	390	MODULE_LICENSE("GPL");
b9170836	391
6915719b	392	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
de1df26b RW	393	struct cpufreq_governor *cpufreq_default_governor(void)
de1df26b RW	394	{
af926185	395	return CPU_FREQ_GOV_CONSERVATIVE;
de1df26b RW	396	}
de1df26b RW	397
6915719b JW	398	fs_initcall(cpufreq_gov_dbs_init);
6915719b JW	399	#else
b9170836	400	module_init(cpufreq_gov_dbs_init);
6915719b	401	#endif
b9170836	402	module_exit(cpufreq_gov_dbs_exit);