[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_GOVERNER_H
#define _CPUFREQ_GOVERNER_H

#include <linux/cpufreq.h>
#include <linux/kobject.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/sysfs.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.
 */
#define MIN_SAMPLING_RATE_RATIO			(2)
#define LATENCY_MULTIPLIER			(1000)
#define MIN_LATENCY_MULTIPLIER			(100)
#define TRANSITION_LATENCY_LIMIT		(10 * 1000 * 1000)

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

/* Macro creating sysfs show routines */
#define show_one(_gov, file_name, object)				\
static ssize_t show_##file_name						\
(struct kobject *kobj, struct attribute *attr, char *buf)		\
{									\
	return sprintf(buf, "%u\n", _gov##_tuners.object);		\
}

#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;
	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;
	u64 prev_cpu_iowait;
	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;
};

/* Governers sysfs tunables */
struct od_dbs_tuners {
	unsigned int ignore_nice;
	unsigned int sampling_rate;
	unsigned int sampling_down_factor;
	unsigned int up_threshold;
	unsigned int adj_up_threshold;
	unsigned int powersave_bias;
	unsigned int io_is_busy;
};

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

/* Per Governer data */
struct dbs_data {
	/* Common across governors */
	#define GOV_ONDEMAND		0
	#define GOV_CONSERVATIVE	1
	int governor;
	unsigned int min_sampling_rate;
	struct attribute_group *attr_group;
	void *tuners;

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

	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);

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

/* Governor specific ops, will be passed to dbs_data->gov_ops */
struct od_ops {
	int (*io_busy)(void);
	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 *p, 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;
}

u64 get_cpu_idle_time(unsigned int cpu, u64 *wall);
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 dbs_data *dbs_data,
		struct cpufreq_policy *policy, unsigned int event);
#endif /* _CPUFREQ_GOVERNER_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
	17	#ifndef _CPUFREQ_GOVERNER_H
	18	#define _CPUFREQ_GOVERNER_H
	19
4471a34f VK	20	#include <linux/cpufreq.h>
	21	#include <linux/kobject.h>
	22	#include <linux/mutex.h>
	23	#include <linux/workqueue.h>
	24	#include <linux/sysfs.h>
	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
	29	* governor will work on any processor with transition latency <= 10mS, using
	30	* appropriate sampling rate.
	31	*
	32	* For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
	33	* this governor will not work. All times here are in uS.
	34	*/
	35	#define MIN_SAMPLING_RATE_RATIO (2)
	36	#define LATENCY_MULTIPLIER (1000)
	37	#define MIN_LATENCY_MULTIPLIER (100)
	38	#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
	39
	40	/* Ondemand Sampling types */
	41	enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
	42
	43	/* Macro creating sysfs show routines */
	44	#define show_one(_gov, file_name, object) \
	45	static ssize_t show_##file_name \
	46	(struct kobject kobj, struct attribute attr, char *buf) \
	47	{ \
	48	return sprintf(buf, "%u\n", _gov##_tuners.object); \
	49	}
	50
	51	#define define_get_cpu_dbs_routines(_dbs_info) \
	52	static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu) \
	53	{ \
	54	return &per_cpu(_dbs_info, cpu).cdbs; \
	55	} \
	56	\
	57	static void *get_cpu_dbs_info_s(int cpu) \
	58	{ \
	59	return &per_cpu(_dbs_info, cpu); \
	60	}
	61
	62	/*
	63	* Abbreviations:
	64	* dbs: used as a shortform for demand based switching It helps to keep variable
	65	* names smaller, simpler
	66	* cdbs: common dbs
e5dde92c	67	* od_*: On-demand governor
4471a34f VK	68	* cs_*: Conservative governor
	69	*/
	70
	71	/* Per cpu structures */
	72	struct cpu_dbs_common_info {
	73	int cpu;
1e7586a1 VK	74	u64 prev_cpu_idle;
	75	u64 prev_cpu_wall;
	76	u64 prev_cpu_nice;
4471a34f VK	77	struct cpufreq_policy *cur_policy;
	78	struct delayed_work work;
	79	/*
	80	* percpu mutex that serializes governor limit change with gov_dbs_timer
	81	* invocation. We do not want gov_dbs_timer to run when user is changing
	82	* the governor or limits.
	83	*/
	84	struct mutex timer_mutex;
da53d61e	85	ktime_t time_stamp;
4471a34f VK	86	};
	87
	88	struct od_cpu_dbs_info_s {
	89	struct cpu_dbs_common_info cdbs;
1e7586a1	90	u64 prev_cpu_iowait;
4471a34f VK	91	struct cpufreq_frequency_table *freq_table;
	92	unsigned int freq_lo;
	93	unsigned int freq_lo_jiffies;
	94	unsigned int freq_hi_jiffies;
	95	unsigned int rate_mult;
	96	unsigned int sample_type:1;
	97	};
	98
	99	struct cs_cpu_dbs_info_s {
	100	struct cpu_dbs_common_info cdbs;
	101	unsigned int down_skip;
	102	unsigned int requested_freq;
	103	unsigned int enable:1;
	104	};
	105
	106	/* Governers sysfs tunables */
	107	struct od_dbs_tuners {
	108	unsigned int ignore_nice;
	109	unsigned int sampling_rate;
	110	unsigned int sampling_down_factor;
	111	unsigned int up_threshold;
4bd4e428	112	unsigned int adj_up_threshold;
4471a34f VK	113	unsigned int powersave_bias;
	114	unsigned int io_is_busy;
	115	};
	116
	117	struct cs_dbs_tuners {
	118	unsigned int ignore_nice;
	119	unsigned int sampling_rate;
	120	unsigned int sampling_down_factor;
	121	unsigned int up_threshold;
	122	unsigned int down_threshold;
	123	unsigned int freq_step;
	124	};
	125
	126	/* Per Governer data */
	127	struct dbs_data {
	128	/* Common across governors */
	129	#define GOV_ONDEMAND 0
	130	#define GOV_CONSERVATIVE 1
	131	int governor;
	132	unsigned int min_sampling_rate;
4471a34f VK	133	struct attribute_group *attr_group;
	134	void *tuners;
	135
	136	/* dbs_mutex protects dbs_enable in governor start/stop */
	137	struct mutex mutex;
	138
	139	struct cpu_dbs_common_info (get_cpu_cdbs)(int cpu);
	140	void (get_cpu_dbs_info_s)(int cpu);
	141	void (gov_dbs_timer)(struct work_struct work);
	142	void (*gov_check_cpu)(int cpu, unsigned int load);
	143
	144	/* Governor specific ops, see below */
	145	void *gov_ops;
	146	};
	147
	148	/* Governor specific ops, will be passed to dbs_data->gov_ops */
	149	struct od_ops {
	150	int (*io_busy)(void);
	151	void (*powersave_bias_init_cpu)(int cpu);
	152	unsigned int (powersave_bias_target)(struct cpufreq_policy policy,
	153	unsigned int freq_next, unsigned int relation);
	154	void (freq_increase)(struct cpufreq_policy p, unsigned int freq);
	155	};
	156
	157	struct cs_ops {
	158	struct notifier_block *notifier_block;
	159	};
	160
	161	static inline int delay_for_sampling_rate(unsigned int sampling_rate)
	162	{
	163	int delay = usecs_to_jiffies(sampling_rate);
	164
	165	/* We want all CPUs to do sampling nearly on same jiffy */
	166	if (num_online_cpus() > 1)
	167	delay -= jiffies % delay;
	168
	169	return delay;
	170	}
	171
1e7586a1	172	u64 get_cpu_idle_time(unsigned int cpu, u64 *wall);
4471a34f	173	void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
4447266b VK	174	bool need_load_eval(struct cpu_dbs_common_info *cdbs,
4447266b VK	175	unsigned int sampling_rate);
4471a34f VK	176	int cpufreq_governor_dbs(struct dbs_data *dbs_data,
	177	struct cpufreq_policy *policy, unsigned int event);
	178	#endif /* _CPUFREQ_GOVERNER_H */