[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/irq_work.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};

/*
 * 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
 */

/* Governor demand based switching data (per-policy or global). */
struct dbs_data {
	struct gov_attr_set attr_set;
	void *tuners;
	unsigned int min_sampling_rate;
	unsigned int ignore_nice_load;
	unsigned int sampling_rate;
	unsigned int sampling_down_factor;
	unsigned int up_threshold;
	unsigned int io_is_busy;
};

static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
{
	return container_of(attr_set, struct dbs_data, attr_set);
}

#define gov_show_one(_gov, file_name)					\
static ssize_t show_##file_name						\
(struct gov_attr_set *attr_set, char *buf)				\
{									\
	struct dbs_data *dbs_data = to_dbs_data(attr_set);		\
	struct _gov##_dbs_tuners *tuners = dbs_data->tuners;		\
	return sprintf(buf, "%u\n", tuners->file_name);			\
}

#define gov_show_one_common(file_name)					\
static ssize_t show_##file_name						\
(struct gov_attr_set *attr_set, char *buf)				\
{									\
	struct dbs_data *dbs_data = to_dbs_data(attr_set);		\
	return sprintf(buf, "%u\n", dbs_data->file_name);		\
}

#define gov_attr_ro(_name)						\
static struct governor_attr _name =					\
__ATTR(_name, 0444, show_##_name, NULL)

#define gov_attr_rw(_name)						\
static struct governor_attr _name =					\
__ATTR(_name, 0644, show_##_name, store_##_name)

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

	u64 last_sample_time;
	s64 sample_delay_ns;
	atomic_t work_count;
	struct irq_work irq_work;
	struct work_struct work;
	/* dbs_data may be shared between multiple policy objects */
	struct dbs_data *dbs_data;
	struct list_head list;
	/* Multiplier for increasing sample delay temporarily. */
	unsigned int rate_mult;
	/* Status indicators */
	bool is_shared;		/* This object is used by multiple CPUs */
	bool work_in_progress;	/* Work is being queued up or in progress */
};

static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
					   unsigned int delay_us)
{
	policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
}

/* 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 update_util_data update_util;
	struct policy_dbs_info *policy_dbs;
};

/* Common Governor data across policies */
struct dbs_governor {
	struct cpufreq_governor gov;
	struct kobj_type kobj_type;

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

	unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy);
	struct policy_dbs_info *(*alloc)(void);
	void (*free)(struct policy_dbs_info *policy_dbs);
	int (*init)(struct dbs_data *dbs_data, bool notify);
	void (*exit)(struct dbs_data *dbs_data, bool notify);
	void (*start)(struct cpufreq_policy *policy);
};

static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
{
	return container_of(policy->governor, struct dbs_governor, gov);
}

/* Governor specific operations */
struct od_ops {
	unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
			unsigned int freq_next, unsigned int relation);
};

unsigned int dbs_update(struct cpufreq_policy *policy);
int cpufreq_governor_dbs(struct cpufreq_policy *policy, 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);
ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
			    size_t count);
void gov_update_cpu_data(struct dbs_data *dbs_data);
#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>
9be4fd2c	21	#include <linux/irq_work.h>
4471a34f	22	#include <linux/cpufreq.h>
5ff0a268 VK	23	#include <linux/kernel_stat.h>
5ff0a268 VK	24	#include <linux/module.h>
4471a34f	25	#include <linux/mutex.h>
4471a34f VK	26
	27	/*
	28	* The polling frequency depends on the capability of the processor. Default
	29	* polling frequency is 1000 times the transition latency of the processor. The
c4afc410	30	* governor will work on any processor with transition latency <= 10ms, using
4471a34f VK	31	* appropriate sampling rate.
4471a34f VK	32	*
c4afc410 SK	33	* For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
c4afc410 SK	34	* this governor will not work. All times here are in us (micro seconds).
4471a34f VK	35	*/
	36	#define MIN_SAMPLING_RATE_RATIO (2)
	37	#define LATENCY_MULTIPLIER (1000)
98104ee2	38	#define MIN_LATENCY_MULTIPLIER (20)
4471a34f VK	39	#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
	40
	41	/* Ondemand Sampling types */
	42	enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
	43
4471a34f VK	44	/*
	45	* Abbreviations:
	46	* dbs: used as a shortform for demand based switching It helps to keep variable
	47	* names smaller, simpler
	48	* cdbs: common dbs
e5dde92c	49	* od_*: On-demand governor
4471a34f VK	50	* cs_*: Conservative governor
	51	*/
	52
bc505475 RW	53	/* Governor demand based switching data (per-policy or global). */
bc505475 RW	54	struct dbs_data {
0dd3c1d6	55	struct gov_attr_set attr_set;
bc505475	56	void *tuners;
ff4b1789 VK	57	unsigned int min_sampling_rate;
	58	unsigned int ignore_nice_load;
	59	unsigned int sampling_rate;
	60	unsigned int sampling_down_factor;
	61	unsigned int up_threshold;
8847e038	62	unsigned int io_is_busy;
c4435630 VK	63	};
c4435630 VK	64
0dd3c1d6 RW	65	static inline struct dbs_data to_dbs_data(struct gov_attr_set attr_set)
	66	{
	67	return container_of(attr_set, struct dbs_data, attr_set);
	68	}
	69
c4435630 VK	70	#define gov_show_one(_gov, file_name) \
c4435630 VK	71	static ssize_t show_##file_name \
0dd3c1d6	72	(struct gov_attr_set attr_set, char buf) \
c4435630	73	{ \
0dd3c1d6	74	struct dbs_data *dbs_data = to_dbs_data(attr_set); \
c4435630 VK	75	struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
	76	return sprintf(buf, "%u\n", tuners->file_name); \
	77	}
	78
	79	#define gov_show_one_common(file_name) \
	80	static ssize_t show_##file_name \
0dd3c1d6	81	(struct gov_attr_set attr_set, char buf) \
c4435630	82	{ \
0dd3c1d6	83	struct dbs_data *dbs_data = to_dbs_data(attr_set); \
c4435630 VK	84	return sprintf(buf, "%u\n", dbs_data->file_name); \
	85	}
	86
	87	#define gov_attr_ro(_name) \
	88	static struct governor_attr _name = \
	89	__ATTR(_name, 0444, show_##_name, NULL)
	90
	91	#define gov_attr_rw(_name) \
	92	static struct governor_attr _name = \
	93	__ATTR(_name, 0644, show_##_name, store_##_name)
	94
44152cb8	95	/* Common to all CPUs of a policy */
e40e7b25	96	struct policy_dbs_info {
44152cb8 VK	97	struct cpufreq_policy *policy;
44152cb8 VK	98	/*
70f43e5e VK	99	* Per policy mutex that serializes load evaluation from limit-change
70f43e5e VK	100	* and work-handler.
44152cb8 VK	101	*/
44152cb8 VK	102	struct mutex timer_mutex;
70f43e5e	103
9be4fd2c RW	104	u64 last_sample_time;
9be4fd2c RW	105	s64 sample_delay_ns;
686cc637	106	atomic_t work_count;
9be4fd2c	107	struct irq_work irq_work;
70f43e5e	108	struct work_struct work;
bc505475 RW	109	/* dbs_data may be shared between multiple policy objects */
bc505475 RW	110	struct dbs_data *dbs_data;
c54df071	111	struct list_head list;
57dc3bcd RW	112	/* Multiplier for increasing sample delay temporarily. */
57dc3bcd RW	113	unsigned int rate_mult;
e4db2813 RW	114	/* Status indicators */
	115	bool is_shared; /* This object is used by multiple CPUs */
	116	bool work_in_progress; /* Work is being queued up or in progress */
44152cb8 VK	117	};
44152cb8 VK	118
e40e7b25	119	static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
9be4fd2c RW	120	unsigned int delay_us)
9be4fd2c RW	121	{
e40e7b25	122	policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
9be4fd2c RW	123	}
9be4fd2c RW	124
4471a34f	125	/* Per cpu structures */
875b8508	126	struct cpu_dbs_info {
1e7586a1 VK	127	u64 prev_cpu_idle;
	128	u64 prev_cpu_wall;
	129	u64 prev_cpu_nice;
18b46abd	130	/*
c8ae481b VK	131	* Used to keep track of load in the previous interval. However, when
	132	* explicitly set to zero, it is used as a flag to ensure that we copy
	133	* the previous load to the current interval only once, upon the first
	134	* wake-up from idle.
18b46abd	135	*/
c8ae481b	136	unsigned int prev_load;
9be4fd2c	137	struct update_util_data update_util;
e40e7b25	138	struct policy_dbs_info *policy_dbs;
4471a34f VK	139	};
4471a34f VK	140
c4afc410	141	/* Common Governor data across policies */
7bdad34d	142	struct dbs_governor {
af926185	143	struct cpufreq_governor gov;
c4435630	144	struct kobj_type kobj_type;
4471a34f	145
0b981e70 VK	146	/*
	147	* Common data for platforms that don't set
	148	* CPUFREQ_HAVE_GOVERNOR_PER_POLICY
	149	*/
4d5dcc42	150	struct dbs_data *gdbs_data;
4471a34f	151
9be4fd2c	152	unsigned int (gov_dbs_timer)(struct cpufreq_policy policy);
7d5a9956 RW	153	struct policy_dbs_info (alloc)(void);
7d5a9956 RW	154	void (free)(struct policy_dbs_info policy_dbs);
8e0484d2 VK	155	int (init)(struct dbs_data dbs_data, bool notify);
8e0484d2 VK	156	void (exit)(struct dbs_data dbs_data, bool notify);
702c9e54	157	void (start)(struct cpufreq_policy policy);
4471a34f VK	158	};
4471a34f VK	159
ea59ee0d RW	160	static inline struct dbs_governor dbs_governor_of(struct cpufreq_policy policy)
	161	{
	162	return container_of(policy->governor, struct dbs_governor, gov);
	163	}
	164
8434dadb	165	/* Governor specific operations */
4471a34f	166	struct od_ops {
4471a34f VK	167	unsigned int (powersave_bias_target)(struct cpufreq_policy policy,
4471a34f VK	168	unsigned int freq_next, unsigned int relation);
4471a34f VK	169	};
4471a34f VK	170
4cccf755	171	unsigned int dbs_update(struct cpufreq_policy *policy);
906a6e5a	172	int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event);
fb30809e JS	173	void od_register_powersave_bias_handler(unsigned int (*f)
	174	(struct cpufreq_policy *, unsigned int, unsigned int),
	175	unsigned int powersave_bias);
	176	void od_unregister_powersave_bias_handler(void);
0dd3c1d6	177	ssize_t store_sampling_rate(struct gov_attr_set attr_set, const char buf,
aded387b	178	size_t count);
8c8f77fd	179	void gov_update_cpu_data(struct dbs_data *dbs_data);
beb0ff39	180	#endif /* _CPUFREQ_GOVERNOR_H */