[deliverable/linux.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/atomic.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_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
 */

/* Common to all CPUs of a policy */
struct cpu_common_dbs_info {
	struct cpufreq_policy *policy;
	/*
	 * Per policy mutex that serializes load evaluation from limit-change
	 * and work-handler.
	 */
	struct mutex timer_mutex;

	ktime_t time_stamp;
	atomic_t skip_work;
	struct work_struct work;
};

/* Per cpu structures */
struct cpu_dbs_info {
	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 timer_list timer;
	struct cpu_common_dbs_info *shared;
};

struct od_cpu_dbs_info_s {
	struct cpu_dbs_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_info cdbs;
	unsigned int down_skip;
	unsigned int requested_freq;
};

/* 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_info *(*get_cpu_cdbs)(int cpu);
	void *(*get_cpu_dbs_info_s)(int cpu);
	unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy,
				      bool modify_all);
	void (*gov_check_cpu)(int cpu, unsigned int load);
	int (*init)(struct dbs_data *dbs_data, bool notify);
	void (*exit)(struct dbs_data *dbs_data, bool notify);

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

	/*
	 * Protects governor's data (struct dbs_data and struct common_dbs_data)
	 */
	struct mutex mutex;
};

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

/* 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);
};

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 gov_add_timers(struct cpufreq_policy *policy, unsigned int delay);
void gov_cancel_work(struct cpu_common_dbs_info *shared);
void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
int cpufreq_governor_dbs(struct cpufreq_policy *policy,
		struct common_dbs_data *cdata, unsigned int event);
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
2dd3e724	20	#include <linux/atomic.h>
4471a34f	21	#include <linux/cpufreq.h>
5ff0a268 VK	22	#include <linux/kernel_stat.h>
5ff0a268 VK	23	#include <linux/module.h>
4471a34f	24	#include <linux/mutex.h>
4471a34f VK	25
	26	/*
	27	* The polling frequency depends on the capability of the processor. Default
	28	* polling frequency is 1000 times the transition latency of the processor. The
c4afc410	29	* governor will work on any processor with transition latency <= 10ms, using
4471a34f VK	30	* appropriate sampling rate.
4471a34f VK	31	*
c4afc410 SK	32	* For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
c4afc410 SK	33	* this governor will not work. All times here are in us (micro seconds).
4471a34f VK	34	*/
	35	#define MIN_SAMPLING_RATE_RATIO (2)
	36	#define LATENCY_MULTIPLIER (1000)
98104ee2	37	#define MIN_LATENCY_MULTIPLIER (20)
4471a34f VK	38	#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
	39
	40	/* Ondemand Sampling types */
	41	enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
	42
4d5dcc42 VK	43	/*
	44	* Macro for creating governors sysfs routines
	45	*
	46	* - gov_sys: One governor instance per whole system
	47	* - gov_pol: One governor instance per policy
	48	*/
	49
	50	/* Create attributes */
	51	#define gov_sys_attr_ro(_name) \
	52	static struct global_attr _name##_gov_sys = \
	53	__ATTR(_name, 0444, show_##_name##_gov_sys, NULL)
	54
	55	#define gov_sys_attr_rw(_name) \
	56	static struct global_attr _name##_gov_sys = \
	57	__ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
	58
	59	#define gov_pol_attr_ro(_name) \
	60	static struct freq_attr _name##_gov_pol = \
	61	__ATTR(_name, 0444, show_##_name##_gov_pol, NULL)
	62
	63	#define gov_pol_attr_rw(_name) \
	64	static struct freq_attr _name##_gov_pol = \
	65	__ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
	66
	67	#define gov_sys_pol_attr_rw(_name) \
	68	gov_sys_attr_rw(_name); \
	69	gov_pol_attr_rw(_name)
	70
	71	#define gov_sys_pol_attr_ro(_name) \
	72	gov_sys_attr_ro(_name); \
	73	gov_pol_attr_ro(_name)
	74
	75	/* Create show/store routines */
	76	#define show_one(_gov, file_name) \
	77	static ssize_t show_##file_name##_gov_sys \
4471a34f VK	78	(struct kobject kobj, struct attribute attr, char *buf) \
4471a34f VK	79	{ \
4d5dcc42 VK	80	struct _gov##_dbs_tuners *tuners = _gov##_dbs_cdata.gdbs_data->tuners; \
	81	return sprintf(buf, "%u\n", tuners->file_name); \
	82	} \
	83	\
bb176f7d	84	static ssize_t show_##file_name##_gov_pol \
4d5dcc42 VK	85	(struct cpufreq_policy policy, char buf) \
	86	{ \
	87	struct dbs_data *dbs_data = policy->governor_data; \
	88	struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
	89	return sprintf(buf, "%u\n", tuners->file_name); \
	90	}
	91
	92	#define store_one(_gov, file_name) \
	93	static ssize_t store_##file_name##_gov_sys \
bb176f7d	94	(struct kobject kobj, struct attribute attr, const char *buf, size_t count) \
4d5dcc42 VK	95	{ \
	96	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \
	97	return store_##file_name(dbs_data, buf, count); \
	98	} \
	99	\
	100	static ssize_t store_##file_name##_gov_pol \
	101	(struct cpufreq_policy policy, const char buf, size_t count) \
	102	{ \
	103	struct dbs_data *dbs_data = policy->governor_data; \
	104	return store_##file_name(dbs_data, buf, count); \
4471a34f VK	105	}
4471a34f VK	106
4d5dcc42 VK	107	#define show_store_one(_gov, file_name) \
	108	show_one(_gov, file_name); \
	109	store_one(_gov, file_name)
	110
	111	/* create helper routines */
4471a34f	112	#define define_get_cpu_dbs_routines(_dbs_info) \
875b8508	113	static struct cpu_dbs_info *get_cpu_cdbs(int cpu) \
4471a34f VK	114	{ \
	115	return &per_cpu(_dbs_info, cpu).cdbs; \
	116	} \
	117	\
	118	static void *get_cpu_dbs_info_s(int cpu) \
	119	{ \
	120	return &per_cpu(_dbs_info, cpu); \
	121	}
	122
	123	/*
	124	* Abbreviations:
	125	* dbs: used as a shortform for demand based switching It helps to keep variable
	126	* names smaller, simpler
	127	* cdbs: common dbs
e5dde92c	128	* od_*: On-demand governor
4471a34f VK	129	* cs_*: Conservative governor
	130	*/
	131
44152cb8 VK	132	/* Common to all CPUs of a policy */
	133	struct cpu_common_dbs_info {
	134	struct cpufreq_policy *policy;
	135	/*
70f43e5e VK	136	* Per policy mutex that serializes load evaluation from limit-change
70f43e5e VK	137	* and work-handler.
44152cb8 VK	138	*/
44152cb8 VK	139	struct mutex timer_mutex;
70f43e5e	140
44152cb8	141	ktime_t time_stamp;
2dd3e724	142	atomic_t skip_work;
70f43e5e	143	struct work_struct work;
44152cb8 VK	144	};
44152cb8 VK	145
4471a34f	146	/* Per cpu structures */
875b8508	147	struct cpu_dbs_info {
1e7586a1 VK	148	u64 prev_cpu_idle;
	149	u64 prev_cpu_wall;
	150	u64 prev_cpu_nice;
18b46abd	151	/*
c8ae481b VK	152	* Used to keep track of load in the previous interval. However, when
	153	* explicitly set to zero, it is used as a flag to ensure that we copy
	154	* the previous load to the current interval only once, upon the first
	155	* wake-up from idle.
18b46abd	156	*/
c8ae481b	157	unsigned int prev_load;
70f43e5e	158	struct timer_list timer;
44152cb8	159	struct cpu_common_dbs_info *shared;
4471a34f VK	160	};
	161
	162	struct od_cpu_dbs_info_s {
875b8508	163	struct cpu_dbs_info cdbs;
4471a34f VK	164	struct cpufreq_frequency_table *freq_table;
	165	unsigned int freq_lo;
	166	unsigned int freq_lo_jiffies;
	167	unsigned int freq_hi_jiffies;
	168	unsigned int rate_mult;
	169	unsigned int sample_type:1;
	170	};
	171
	172	struct cs_cpu_dbs_info_s {
875b8508	173	struct cpu_dbs_info cdbs;
4471a34f VK	174	unsigned int down_skip;
4471a34f VK	175	unsigned int requested_freq;
4471a34f VK	176	};
4471a34f VK	177
c4afc410	178	/* Per policy Governors sysfs tunables */
4471a34f	179	struct od_dbs_tuners {
6c4640c3	180	unsigned int ignore_nice_load;
4471a34f VK	181	unsigned int sampling_rate;
	182	unsigned int sampling_down_factor;
	183	unsigned int up_threshold;
4471a34f VK	184	unsigned int powersave_bias;
	185	unsigned int io_is_busy;
	186	};
	187
	188	struct cs_dbs_tuners {
6c4640c3	189	unsigned int ignore_nice_load;
4471a34f VK	190	unsigned int sampling_rate;
	191	unsigned int sampling_down_factor;
	192	unsigned int up_threshold;
	193	unsigned int down_threshold;
	194	unsigned int freq_step;
	195	};
	196
c4afc410	197	/* Common Governor data across policies */
4d5dcc42 VK	198	struct dbs_data;
4d5dcc42 VK	199	struct common_dbs_data {
4471a34f VK	200	/* Common across governors */
	201	#define GOV_ONDEMAND 0
	202	#define GOV_CONSERVATIVE 1
	203	int governor;
4d5dcc42 VK	204	struct attribute_group attr_group_gov_sys; / one governor - system */
4d5dcc42 VK	205	struct attribute_group attr_group_gov_pol; / one governor - policy */
4471a34f	206
0b981e70 VK	207	/*
	208	* Common data for platforms that don't set
	209	* CPUFREQ_HAVE_GOVERNOR_PER_POLICY
	210	*/
4d5dcc42	211	struct dbs_data *gdbs_data;
4471a34f	212
875b8508	213	struct cpu_dbs_info (get_cpu_cdbs)(int cpu);
4471a34f	214	void (get_cpu_dbs_info_s)(int cpu);
affde5d0	215	unsigned int (gov_dbs_timer)(struct cpufreq_policy policy,
43e0ee36	216	bool modify_all);
4471a34f	217	void (*gov_check_cpu)(int cpu, unsigned int load);
8e0484d2 VK	218	int (init)(struct dbs_data dbs_data, bool notify);
8e0484d2 VK	219	void (exit)(struct dbs_data dbs_data, bool notify);
4471a34f VK	220
	221	/* Governor specific ops, see below */
	222	void *gov_ops;
732b6d61 VK	223
	224	/*
	225	* Protects governor's data (struct dbs_data and struct common_dbs_data)
	226	*/
	227	struct mutex mutex;
4471a34f VK	228	};
4471a34f VK	229
c4afc410	230	/* Governor Per policy data */
4d5dcc42 VK	231	struct dbs_data {
	232	struct common_dbs_data *cdata;
	233	unsigned int min_sampling_rate;
a97c98ad	234	int usage_count;
4d5dcc42	235	void *tuners;
4d5dcc42 VK	236	};
4d5dcc42 VK	237
4471a34f VK	238	/* Governor specific ops, will be passed to dbs_data->gov_ops */
4471a34f VK	239	struct od_ops {
4471a34f VK	240	void (*powersave_bias_init_cpu)(int cpu);
	241	unsigned int (powersave_bias_target)(struct cpufreq_policy policy,
	242	unsigned int freq_next, unsigned int relation);
3a3e9e06	243	void (freq_increase)(struct cpufreq_policy policy, unsigned int freq);
4471a34f VK	244	};
4471a34f VK	245
4471a34f VK	246	static inline int delay_for_sampling_rate(unsigned int sampling_rate)
	247	{
	248	int delay = usecs_to_jiffies(sampling_rate);
	249
	250	/* We want all CPUs to do sampling nearly on same jiffy */
	251	if (num_online_cpus() > 1)
	252	delay -= jiffies % delay;
	253
	254	return delay;
	255	}
	256
4d5dcc42 VK	257	#define declare_show_sampling_rate_min(_gov) \
	258	static ssize_t show_sampling_rate_min_gov_sys \
	259	(struct kobject kobj, struct attribute attr, char *buf) \
	260	{ \
	261	struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \
	262	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
	263	} \
	264	\
	265	static ssize_t show_sampling_rate_min_gov_pol \
	266	(struct cpufreq_policy policy, char buf) \
	267	{ \
	268	struct dbs_data *dbs_data = policy->governor_data; \
	269	return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
	270	}
	271
6f1e4efd JL	272	extern struct mutex cpufreq_governor_lock;
6f1e4efd JL	273
70f43e5e VK	274	void gov_add_timers(struct cpufreq_policy *policy, unsigned int delay);
70f43e5e VK	275	void gov_cancel_work(struct cpu_common_dbs_info *shared);
4471a34f	276	void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
4d5dcc42 VK	277	int cpufreq_governor_dbs(struct cpufreq_policy *policy,
4d5dcc42 VK	278	struct common_dbs_data *cdata, unsigned int event);
fb30809e JS	279	void od_register_powersave_bias_handler(unsigned int (*f)
	280	(struct cpufreq_policy *, unsigned int, unsigned int),
	281	unsigned int powersave_bias);
	282	void od_unregister_powersave_bias_handler(void);
beb0ff39	283	#endif /* _CPUFREQ_GOVERNOR_H */