[linux-2.6-block.git] / drivers / cpufreq / cpufreq_governor.h

/*
 * drivers/cpufreq/cpufreq_governor.h
 *
 * Header file for CPUFreq governors common code
 *
 * Copyright	(C) 2001 Russell King
 *		(C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
 *		(C) 2003 Jun Nakajima <jun.nakajima@intel.com>
 *		(C) 2009 Alexander Clouter <alex@digriz.org.uk>
 *		(c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
 *
 * 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.
 */

#ifndef _CPUFREQ_GOVERNOR_H
#define _CPUFREQ_GOVERNOR_H

#include <linux/cpufreq.h>
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/mutex.h>

/*
 * The polling frequency depends on the capability of the processor. Default
 * polling frequency is 1000 times the transition latency of the processor. The
 * governor will work on any processor with transition latency <= 10ms, using
 * appropriate sampling rate.
 *
 * For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
 * this governor will not work. All times here are in us (micro seconds).
 */
#define MIN_SAMPLING_RATE_RATIO			(2)
#define LATENCY_MULTIPLIER			(1000)
#define MIN_LATENCY_MULTIPLIER			(20)
#define TRANSITION_LATENCY_LIMIT		(10 * 1000 * 1000)

/* Ondemand Sampling types */
enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};

/*
 * Macro for creating governors sysfs routines
 *
 * - gov_sys: One governor instance per whole system
 * - gov_pol: One governor instance per policy
 */

/* Create attributes */
#define gov_sys_attr_ro(_name)						\
static struct global_attr _name##_gov_sys =				\
__ATTR(_name, 0444, show_##_name##_gov_sys, NULL)

#define gov_sys_attr_rw(_name)						\
static struct global_attr _name##_gov_sys =				\
__ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)

#define gov_pol_attr_ro(_name)						\
static struct freq_attr _name##_gov_pol =				\
__ATTR(_name, 0444, show_##_name##_gov_pol, NULL)

#define gov_pol_attr_rw(_name)						\
static struct freq_attr _name##_gov_pol =				\
__ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)

#define gov_sys_pol_attr_rw(_name)					\
	gov_sys_attr_rw(_name);						\
	gov_pol_attr_rw(_name)

#define gov_sys_pol_attr_ro(_name)					\
	gov_sys_attr_ro(_name);						\
	gov_pol_attr_ro(_name)

/* Create show/store routines */
#define show_one(_gov, file_name)					\
static ssize_t show_##file_name##_gov_sys				\
(struct kobject *kobj, struct attribute *attr, char *buf)		\
{									\
	struct _gov##_dbs_tuners *tuners = _gov##_dbs_cdata.gdbs_data->tuners; \
	return sprintf(buf, "%u\n", tuners->file_name);			\
}									\
									\
static ssize_t show_##file_name##_gov_pol				\
(struct cpufreq_policy *policy, char *buf)				\
{									\
	struct dbs_data *dbs_data = policy->governor_data;		\
	struct _gov##_dbs_tuners *tuners = dbs_data->tuners;		\
	return sprintf(buf, "%u\n", tuners->file_name);			\
}

#define store_one(_gov, file_name)					\
static ssize_t store_##file_name##_gov_sys				\
(struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) \
{									\
	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data;		\
	return store_##file_name(dbs_data, buf, count);			\
}									\
									\
static ssize_t store_##file_name##_gov_pol				\
(struct cpufreq_policy *policy, const char *buf, size_t count)		\
{									\
	struct dbs_data *dbs_data = policy->governor_data;		\
	return store_##file_name(dbs_data, buf, count);			\
}

#define show_store_one(_gov, file_name)					\
show_one(_gov, file_name);						\
store_one(_gov, file_name)

/* create helper routines */
#define define_get_cpu_dbs_routines(_dbs_info)				\
static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu)		\
{									\
	return &per_cpu(_dbs_info, cpu).cdbs;				\
}									\
									\
static void *get_cpu_dbs_info_s(int cpu)				\
{									\
	return &per_cpu(_dbs_info, cpu);				\
}

/*
 * Abbreviations:
 * dbs: used as a shortform for demand based switching It helps to keep variable
 *	names smaller, simpler
 * cdbs: common dbs
 * od_*: On-demand governor
 * cs_*: Conservative governor
 */

/* Per cpu structures */
struct cpu_dbs_common_info {
	int cpu;
	u64 prev_cpu_idle;
	u64 prev_cpu_wall;
	u64 prev_cpu_nice;
	/*
	 * Used to keep track of load in the previous interval. However, when
	 * explicitly set to zero, it is used as a flag to ensure that we copy
	 * the previous load to the current interval only once, upon the first
	 * wake-up from idle.
	 */
	unsigned int prev_load;
	struct cpufreq_policy *cur_policy;
	struct delayed_work work;
	/*
	 * percpu mutex that serializes governor limit change with gov_dbs_timer
	 * invocation. We do not want gov_dbs_timer to run when user is changing
	 * the governor or limits.
	 */
	struct mutex timer_mutex;
	ktime_t time_stamp;
};

struct od_cpu_dbs_info_s {
	struct cpu_dbs_common_info cdbs;
	struct cpufreq_frequency_table *freq_table;
	unsigned int freq_lo;
	unsigned int freq_lo_jiffies;
	unsigned int freq_hi_jiffies;
	unsigned int rate_mult;
	unsigned int sample_type:1;
};

struct cs_cpu_dbs_info_s {
	struct cpu_dbs_common_info cdbs;
	unsigned int down_skip;
	unsigned int requested_freq;
	unsigned int enable:1;
};

/* Per policy Governors sysfs tunables */
struct od_dbs_tuners {
	unsigned int ignore_nice_load;
	unsigned int sampling_rate;
	unsigned int sampling_down_factor;
	unsigned int up_threshold;
	unsigned int powersave_bias;
	unsigned int io_is_busy;
};

struct cs_dbs_tuners {
	unsigned int ignore_nice_load;
	unsigned int sampling_rate;
	unsigned int sampling_down_factor;
	unsigned int up_threshold;
	unsigned int down_threshold;
	unsigned int freq_step;
};

/* Common Governor data across policies */
struct dbs_data;
struct common_dbs_data {
	/* Common across governors */
	#define GOV_ONDEMAND		0
	#define GOV_CONSERVATIVE	1
	int governor;
	struct attribute_group *attr_group_gov_sys; /* one governor - system */
	struct attribute_group *attr_group_gov_pol; /* one governor - policy */

	/*
	 * Common data for platforms that don't set
	 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
	 */
	struct dbs_data *gdbs_data;

	struct cpu_dbs_common_info *(*get_cpu_cdbs)(int cpu);
	void *(*get_cpu_dbs_info_s)(int cpu);
	void (*gov_dbs_timer)(struct work_struct *work);
	void (*gov_check_cpu)(int cpu, unsigned int load);
	int (*init)(struct dbs_data *dbs_data);
	void (*exit)(struct dbs_data *dbs_data);

	/* Governor specific ops, see below */
	void *gov_ops;
};

/* Governor Per policy data */
struct dbs_data {
	struct common_dbs_data *cdata;
	unsigned int min_sampling_rate;
	int usage_count;
	void *tuners;

	/* dbs_mutex protects dbs_enable in governor start/stop */
	struct mutex mutex;
};

/* Governor specific ops, will be passed to dbs_data->gov_ops */
struct od_ops {
	void (*powersave_bias_init_cpu)(int cpu);
	unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
			unsigned int freq_next, unsigned int relation);
	void (*freq_increase)(struct cpufreq_policy *policy, unsigned int freq);
};

struct cs_ops {
	struct notifier_block *notifier_block;
};

static inline int delay_for_sampling_rate(unsigned int sampling_rate)
{
	int delay = usecs_to_jiffies(sampling_rate);

	/* We want all CPUs to do sampling nearly on same jiffy */
	if (num_online_cpus() > 1)
		delay -= jiffies % delay;

	return delay;
}

#define declare_show_sampling_rate_min(_gov)				\
static ssize_t show_sampling_rate_min_gov_sys				\
(struct kobject *kobj, struct attribute *attr, char *buf)		\
{									\
	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data;		\
	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate);	\
}									\
									\
static ssize_t show_sampling_rate_min_gov_pol				\
(struct cpufreq_policy *policy, char *buf)				\
{									\
	struct dbs_data *dbs_data = policy->governor_data;		\
	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate);	\
}

extern struct mutex cpufreq_governor_lock;

void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
bool need_load_eval(struct cpu_dbs_common_info *cdbs,
		unsigned int sampling_rate);
int cpufreq_governor_dbs(struct cpufreq_policy *policy,
		struct common_dbs_data *cdata, unsigned int event);
void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,
		unsigned int delay, bool all_cpus);
void od_register_powersave_bias_handler(unsigned int (*f)
		(struct cpufreq_policy *, unsigned int, unsigned int),
		unsigned int powersave_bias);
void od_unregister_powersave_bias_handler(void);
#endif /* _CPUFREQ_GOVERNOR_H */
Commit	Line	Data
4471a34f VK	1	/*
	2	* drivers/cpufreq/cpufreq_governor.h
	3	*
	4	* Header file for CPUFreq governors common code
	5	*
	6	* Copyright (C) 2001 Russell King
	7	* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
	8	* (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
	9	* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
	10	* (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16
beb0ff39 BP	17	#ifndef _CPUFREQ_GOVERNOR_H
beb0ff39 BP	18	#define _CPUFREQ_GOVERNOR_H
4471a34f	19
4471a34f	20	#include <linux/cpufreq.h>
5ff0a268 VK	21	#include <linux/kernel_stat.h>
5ff0a268 VK	22	#include <linux/module.h>
4471a34f	23	#include <linux/mutex.h>
4471a34f VK	24
	25	/*
	26	* The polling frequency depends on the capability of the processor. Default
	27	* polling frequency is 1000 times the transition latency of the processor. The
c4afc410	28	* governor will work on any processor with transition latency <= 10ms, using
4471a34f VK	29	* appropriate sampling rate.
4471a34f VK	30	*
c4afc410 SK	31	* For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
c4afc410 SK	32	* this governor will not work. All times here are in us (micro seconds).
4471a34f VK	33	*/
	34	#define MIN_SAMPLING_RATE_RATIO (2)
	35	#define LATENCY_MULTIPLIER (1000)
98104ee2	36	#define MIN_LATENCY_MULTIPLIER (20)
4471a34f VK	37	#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
	38
	39	/* Ondemand Sampling types */
	40	enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
	41
4d5dcc42 VK	42	/*
	43	* Macro for creating governors sysfs routines
	44	*
	45	* - gov_sys: One governor instance per whole system
	46	* - gov_pol: One governor instance per policy
	47	*/
	48
	49	/* Create attributes */
	50	#define gov_sys_attr_ro(_name) \
	51	static struct global_attr _name##_gov_sys = \
	52	__ATTR(_name, 0444, show_##_name##_gov_sys, NULL)
	53
	54	#define gov_sys_attr_rw(_name) \
	55	static struct global_attr _name##_gov_sys = \
	56	__ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
	57
	58	#define gov_pol_attr_ro(_name) \
	59	static struct freq_attr _name##_gov_pol = \
	60	__ATTR(_name, 0444, show_##_name##_gov_pol, NULL)
	61
	62	#define gov_pol_attr_rw(_name) \
	63	static struct freq_attr _name##_gov_pol = \
	64	__ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
	65
	66	#define gov_sys_pol_attr_rw(_name) \
	67	gov_sys_attr_rw(_name); \
	68	gov_pol_attr_rw(_name)
	69
	70	#define gov_sys_pol_attr_ro(_name) \
	71	gov_sys_attr_ro(_name); \
	72	gov_pol_attr_ro(_name)
	73
	74	/* Create show/store routines */
	75	#define show_one(_gov, file_name) \
	76	static ssize_t show_##file_name##_gov_sys \
4471a34f VK	77	(struct kobject kobj, struct attribute attr, char *buf) \
4471a34f VK	78	{ \
4d5dcc42 VK	79	struct _gov##_dbs_tuners *tuners = _gov##_dbs_cdata.gdbs_data->tuners; \
	80	return sprintf(buf, "%u\n", tuners->file_name); \
	81	} \
	82	\
bb176f7d	83	static ssize_t show_##file_name##_gov_pol \
4d5dcc42 VK	84	(struct cpufreq_policy policy, char buf) \
	85	{ \
	86	struct dbs_data *dbs_data = policy->governor_data; \
	87	struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
	88	return sprintf(buf, "%u\n", tuners->file_name); \
	89	}
	90
	91	#define store_one(_gov, file_name) \
	92	static ssize_t store_##file_name##_gov_sys \
bb176f7d	93	(struct kobject kobj, struct attribute attr, const char *buf, size_t count) \
4d5dcc42 VK	94	{ \
	95	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \
	96	return store_##file_name(dbs_data, buf, count); \
	97	} \
	98	\
	99	static ssize_t store_##file_name##_gov_pol \
	100	(struct cpufreq_policy policy, const char buf, size_t count) \
	101	{ \
	102	struct dbs_data *dbs_data = policy->governor_data; \
	103	return store_##file_name(dbs_data, buf, count); \
4471a34f VK	104	}
4471a34f VK	105
4d5dcc42 VK	106	#define show_store_one(_gov, file_name) \
	107	show_one(_gov, file_name); \
	108	store_one(_gov, file_name)
	109
	110	/* create helper routines */
4471a34f VK	111	#define define_get_cpu_dbs_routines(_dbs_info) \
	112	static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu) \
	113	{ \
	114	return &per_cpu(_dbs_info, cpu).cdbs; \
	115	} \
	116	\
	117	static void *get_cpu_dbs_info_s(int cpu) \
	118	{ \
	119	return &per_cpu(_dbs_info, cpu); \
	120	}
	121
	122	/*
	123	* Abbreviations:
	124	* dbs: used as a shortform for demand based switching It helps to keep variable
	125	* names smaller, simpler
	126	* cdbs: common dbs
e5dde92c	127	* od_*: On-demand governor
4471a34f VK	128	* cs_*: Conservative governor
	129	*/
	130
	131	/* Per cpu structures */
	132	struct cpu_dbs_common_info {
	133	int cpu;
1e7586a1 VK	134	u64 prev_cpu_idle;
	135	u64 prev_cpu_wall;
	136	u64 prev_cpu_nice;
18b46abd	137	/*
c8ae481b VK	138	* Used to keep track of load in the previous interval. However, when
	139	* explicitly set to zero, it is used as a flag to ensure that we copy
	140	* the previous load to the current interval only once, upon the first
	141	* wake-up from idle.
18b46abd	142	*/
c8ae481b	143	unsigned int prev_load;
4471a34f VK	144	struct cpufreq_policy *cur_policy;
	145	struct delayed_work work;
	146	/*
	147	* percpu mutex that serializes governor limit change with gov_dbs_timer
	148	* invocation. We do not want gov_dbs_timer to run when user is changing
	149	* the governor or limits.
	150	*/
	151	struct mutex timer_mutex;
da53d61e	152	ktime_t time_stamp;
4471a34f VK	153	};
	154
	155	struct od_cpu_dbs_info_s {
	156	struct cpu_dbs_common_info cdbs;
4471a34f VK	157	struct cpufreq_frequency_table *freq_table;
	158	unsigned int freq_lo;
	159	unsigned int freq_lo_jiffies;
	160	unsigned int freq_hi_jiffies;
	161	unsigned int rate_mult;
	162	unsigned int sample_type:1;
	163	};
	164
	165	struct cs_cpu_dbs_info_s {
	166	struct cpu_dbs_common_info cdbs;
	167	unsigned int down_skip;
	168	unsigned int requested_freq;
	169	unsigned int enable:1;
	170	};
	171
c4afc410	172	/* Per policy Governors sysfs tunables */
4471a34f	173	struct od_dbs_tuners {
6c4640c3	174	unsigned int ignore_nice_load;
4471a34f VK	175	unsigned int sampling_rate;
	176	unsigned int sampling_down_factor;
	177	unsigned int up_threshold;
4471a34f VK	178	unsigned int powersave_bias;
	179	unsigned int io_is_busy;
	180	};
	181
	182	struct cs_dbs_tuners {
6c4640c3	183	unsigned int ignore_nice_load;
4471a34f VK	184	unsigned int sampling_rate;
	185	unsigned int sampling_down_factor;
	186	unsigned int up_threshold;
	187	unsigned int down_threshold;
	188	unsigned int freq_step;
	189	};
	190
c4afc410	191	/* Common Governor data across policies */
4d5dcc42 VK	192	struct dbs_data;
4d5dcc42 VK	193	struct common_dbs_data {
4471a34f VK	194	/* Common across governors */
	195	#define GOV_ONDEMAND 0
	196	#define GOV_CONSERVATIVE 1
	197	int governor;
4d5dcc42 VK	198	struct attribute_group attr_group_gov_sys; / one governor - system */
4d5dcc42 VK	199	struct attribute_group attr_group_gov_pol; / one governor - policy */
4471a34f	200
0b981e70 VK	201	/*
	202	* Common data for platforms that don't set
	203	* CPUFREQ_HAVE_GOVERNOR_PER_POLICY
	204	*/
4d5dcc42	205	struct dbs_data *gdbs_data;
4471a34f VK	206
	207	struct cpu_dbs_common_info (get_cpu_cdbs)(int cpu);
	208	void (get_cpu_dbs_info_s)(int cpu);
	209	void (gov_dbs_timer)(struct work_struct work);
	210	void (*gov_check_cpu)(int cpu, unsigned int load);
4d5dcc42 VK	211	int (init)(struct dbs_data dbs_data);
4d5dcc42 VK	212	void (exit)(struct dbs_data dbs_data);
4471a34f VK	213
	214	/* Governor specific ops, see below */
	215	void *gov_ops;
	216	};
	217
c4afc410	218	/* Governor Per policy data */
4d5dcc42 VK	219	struct dbs_data {
	220	struct common_dbs_data *cdata;
	221	unsigned int min_sampling_rate;
a97c98ad	222	int usage_count;
4d5dcc42 VK	223	void *tuners;
	224
	225	/* dbs_mutex protects dbs_enable in governor start/stop */
	226	struct mutex mutex;
	227	};
	228
4471a34f VK	229	/* Governor specific ops, will be passed to dbs_data->gov_ops */
4471a34f VK	230	struct od_ops {
4471a34f VK	231	void (*powersave_bias_init_cpu)(int cpu);
	232	unsigned int (powersave_bias_target)(struct cpufreq_policy policy,
	233	unsigned int freq_next, unsigned int relation);
3a3e9e06	234	void (freq_increase)(struct cpufreq_policy policy, unsigned int freq);
4471a34f VK	235	};
	236
	237	struct cs_ops {
	238	struct notifier_block *notifier_block;
	239	};
	240
	241	static inline int delay_for_sampling_rate(unsigned int sampling_rate)
	242	{
	243	int delay = usecs_to_jiffies(sampling_rate);
	244
	245	/* We want all CPUs to do sampling nearly on same jiffy */
	246	if (num_online_cpus() > 1)
	247	delay -= jiffies % delay;
	248
	249	return delay;
	250	}
	251
4d5dcc42 VK	252	#define declare_show_sampling_rate_min(_gov) \
	253	static ssize_t show_sampling_rate_min_gov_sys \
	254	(struct kobject kobj, struct attribute attr, char *buf) \
	255	{ \
	256	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \
	257	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
	258	} \
	259	\
	260	static ssize_t show_sampling_rate_min_gov_pol \
	261	(struct cpufreq_policy policy, char buf) \
	262	{ \
	263	struct dbs_data *dbs_data = policy->governor_data; \
	264	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
	265	}
	266
6f1e4efd JL	267	extern struct mutex cpufreq_governor_lock;
6f1e4efd JL	268
4471a34f	269	void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
4447266b VK	270	bool need_load_eval(struct cpu_dbs_common_info *cdbs,
4447266b VK	271	unsigned int sampling_rate);
4d5dcc42 VK	272	int cpufreq_governor_dbs(struct cpufreq_policy *policy,
4d5dcc42 VK	273	struct common_dbs_data *cdata, unsigned int event);
031299b3 VK	274	void gov_queue_work(struct dbs_data dbs_data, struct cpufreq_policy policy,
031299b3 VK	275	unsigned int delay, bool all_cpus);
fb30809e JS	276	void od_register_powersave_bias_handler(unsigned int (*f)
	277	(struct cpufreq_policy *, unsigned int, unsigned int),
	278	unsigned int powersave_bias);
	279	void od_unregister_powersave_bias_handler(void);
beb0ff39	280	#endif /* _CPUFREQ_GOVERNOR_H */