[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};

/* 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
 */

/* Governor demand based switching data (per-policy or global). */
struct dbs_data {
	int usage_count;
	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;

	struct kobject kobj;
	struct list_head policy_dbs_list;
	/*
	 * Protect concurrent updates to governor tunables from sysfs,
	 * policy_dbs_list and usage_count.
	 */
	struct mutex mutex;
};

/* Governor's specific attributes */
struct dbs_data;
struct governor_attr {
	struct attribute attr;
	ssize_t (*show)(struct dbs_data *dbs_data, char *buf);
	ssize_t (*store)(struct dbs_data *dbs_data, const char *buf,
			 size_t count);
};

#define gov_show_one(_gov, file_name)					\
static ssize_t show_##file_name						\
(struct dbs_data *dbs_data, char *buf)					\
{									\
	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 dbs_data *dbs_data, char *buf)					\
{									\
	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;
};

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;
};

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 powersave_bias;
	unsigned int io_is_busy;
};

struct cs_dbs_tuners {
	unsigned int down_threshold;
	unsigned int freq_step;
};

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

	#define GOV_ONDEMAND		0
	#define GOV_CONSERVATIVE	1
	int governor;
	struct kobj_type kobj_type;

	/*
	 * 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);
	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;
};

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

/* 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;
}

extern struct mutex dbs_data_mutex;
void dbs_check_cpu(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);
#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
4d5dcc42	44	/* create helper routines */
4471a34f	45	#define define_get_cpu_dbs_routines(_dbs_info) \
875b8508	46	static struct cpu_dbs_info *get_cpu_cdbs(int cpu) \
4471a34f VK	47	{ \
	48	return &per_cpu(_dbs_info, cpu).cdbs; \
	49	} \
	50	\
	51	static void *get_cpu_dbs_info_s(int cpu) \
	52	{ \
	53	return &per_cpu(_dbs_info, cpu); \
	54	}
	55
	56	/*
	57	* Abbreviations:
	58	* dbs: used as a shortform for demand based switching It helps to keep variable
	59	* names smaller, simpler
	60	* cdbs: common dbs
e5dde92c	61	* od_*: On-demand governor
4471a34f VK	62	* cs_*: Conservative governor
	63	*/
	64
bc505475 RW	65	/* Governor demand based switching data (per-policy or global). */
bc505475 RW	66	struct dbs_data {
bc505475 RW	67	int usage_count;
bc505475 RW	68	void *tuners;
ff4b1789 VK	69	unsigned int min_sampling_rate;
	70	unsigned int ignore_nice_load;
	71	unsigned int sampling_rate;
	72	unsigned int sampling_down_factor;
	73	unsigned int up_threshold;
c4435630 VK	74
c4435630 VK	75	struct kobject kobj;
c54df071 VK	76	struct list_head policy_dbs_list;
	77	/*
	78	* Protect concurrent updates to governor tunables from sysfs,
	79	* policy_dbs_list and usage_count.
	80	*/
c4435630 VK	81	struct mutex mutex;
	82	};
	83
	84	/* Governor's specific attributes */
	85	struct dbs_data;
	86	struct governor_attr {
	87	struct attribute attr;
	88	ssize_t (show)(struct dbs_data dbs_data, char *buf);
	89	ssize_t (store)(struct dbs_data dbs_data, const char *buf,
	90	size_t count);
bc505475 RW	91	};
bc505475 RW	92
c4435630 VK	93	#define gov_show_one(_gov, file_name) \
	94	static ssize_t show_##file_name \
	95	(struct dbs_data dbs_data, char buf) \
	96	{ \
	97	struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
	98	return sprintf(buf, "%u\n", tuners->file_name); \
	99	}
	100
	101	#define gov_show_one_common(file_name) \
	102	static ssize_t show_##file_name \
	103	(struct dbs_data dbs_data, char buf) \
	104	{ \
	105	return sprintf(buf, "%u\n", dbs_data->file_name); \
	106	}
	107
	108	#define gov_attr_ro(_name) \
	109	static struct governor_attr _name = \
	110	__ATTR(_name, 0444, show_##_name, NULL)
	111
	112	#define gov_attr_rw(_name) \
	113	static struct governor_attr _name = \
	114	__ATTR(_name, 0644, show_##_name, store_##_name)
	115
44152cb8	116	/* Common to all CPUs of a policy */
e40e7b25	117	struct policy_dbs_info {
44152cb8 VK	118	struct cpufreq_policy *policy;
44152cb8 VK	119	/*
70f43e5e VK	120	* Per policy mutex that serializes load evaluation from limit-change
70f43e5e VK	121	* and work-handler.
44152cb8 VK	122	*/
44152cb8 VK	123	struct mutex timer_mutex;
70f43e5e	124
9be4fd2c RW	125	u64 last_sample_time;
9be4fd2c RW	126	s64 sample_delay_ns;
686cc637	127	atomic_t work_count;
9be4fd2c	128	struct irq_work irq_work;
70f43e5e	129	struct work_struct work;
bc505475 RW	130	/* dbs_data may be shared between multiple policy objects */
bc505475 RW	131	struct dbs_data *dbs_data;
c54df071	132	struct list_head list;
44152cb8 VK	133	};
44152cb8 VK	134
e40e7b25	135	static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
9be4fd2c RW	136	unsigned int delay_us)
9be4fd2c RW	137	{
e40e7b25	138	policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
9be4fd2c RW	139	}
9be4fd2c RW	140
4471a34f	141	/* Per cpu structures */
875b8508	142	struct cpu_dbs_info {
1e7586a1 VK	143	u64 prev_cpu_idle;
	144	u64 prev_cpu_wall;
	145	u64 prev_cpu_nice;
18b46abd	146	/*
c8ae481b VK	147	* Used to keep track of load in the previous interval. However, when
	148	* explicitly set to zero, it is used as a flag to ensure that we copy
	149	* the previous load to the current interval only once, upon the first
	150	* wake-up from idle.
18b46abd	151	*/
c8ae481b	152	unsigned int prev_load;
9be4fd2c	153	struct update_util_data update_util;
e40e7b25	154	struct policy_dbs_info *policy_dbs;
4471a34f VK	155	};
	156
	157	struct od_cpu_dbs_info_s {
875b8508	158	struct cpu_dbs_info cdbs;
4471a34f VK	159	struct cpufreq_frequency_table *freq_table;
	160	unsigned int freq_lo;
	161	unsigned int freq_lo_jiffies;
	162	unsigned int freq_hi_jiffies;
	163	unsigned int rate_mult;
	164	unsigned int sample_type:1;
	165	};
	166
	167	struct cs_cpu_dbs_info_s {
875b8508	168	struct cpu_dbs_info cdbs;
4471a34f VK	169	unsigned int down_skip;
4471a34f VK	170	unsigned int requested_freq;
4471a34f VK	171	};
4471a34f VK	172
c4afc410	173	/* Per policy Governors sysfs tunables */
4471a34f	174	struct od_dbs_tuners {
4471a34f VK	175	unsigned int powersave_bias;
	176	unsigned int io_is_busy;
	177	};
	178
	179	struct cs_dbs_tuners {
4471a34f VK	180	unsigned int down_threshold;
	181	unsigned int freq_step;
	182	};
	183
c4afc410	184	/* Common Governor data across policies */
7bdad34d	185	struct dbs_governor {
af926185 RW	186	struct cpufreq_governor gov;
af926185 RW	187
4471a34f VK	188	#define GOV_ONDEMAND 0
	189	#define GOV_CONSERVATIVE 1
	190	int governor;
c4435630	191	struct kobj_type kobj_type;
4471a34f	192
0b981e70 VK	193	/*
	194	* Common data for platforms that don't set
	195	* CPUFREQ_HAVE_GOVERNOR_PER_POLICY
	196	*/
4d5dcc42	197	struct dbs_data *gdbs_data;
4471a34f	198
875b8508	199	struct cpu_dbs_info (get_cpu_cdbs)(int cpu);
4471a34f	200	void (get_cpu_dbs_info_s)(int cpu);
9be4fd2c	201	unsigned int (gov_dbs_timer)(struct cpufreq_policy policy);
4471a34f	202	void (*gov_check_cpu)(int cpu, unsigned int load);
8e0484d2 VK	203	int (init)(struct dbs_data dbs_data, bool notify);
8e0484d2 VK	204	void (exit)(struct dbs_data dbs_data, bool notify);
4471a34f VK	205
	206	/* Governor specific ops, see below */
	207	void *gov_ops;
	208	};
	209
ea59ee0d RW	210	static inline struct dbs_governor dbs_governor_of(struct cpufreq_policy policy)
	211	{
	212	return container_of(policy->governor, struct dbs_governor, gov);
	213	}
	214
4471a34f VK	215	/* Governor specific ops, will be passed to dbs_data->gov_ops */
4471a34f VK	216	struct od_ops {
4471a34f VK	217	void (*powersave_bias_init_cpu)(int cpu);
	218	unsigned int (powersave_bias_target)(struct cpufreq_policy policy,
	219	unsigned int freq_next, unsigned int relation);
3a3e9e06	220	void (freq_increase)(struct cpufreq_policy policy, unsigned int freq);
4471a34f VK	221	};
4471a34f VK	222
4471a34f VK	223	static inline int delay_for_sampling_rate(unsigned int sampling_rate)
	224	{
	225	int delay = usecs_to_jiffies(sampling_rate);
	226
	227	/* We want all CPUs to do sampling nearly on same jiffy */
	228	if (num_online_cpus() > 1)
	229	delay -= jiffies % delay;
	230
	231	return delay;
	232	}
	233
2bb8d94f	234	extern struct mutex dbs_data_mutex;
d10b5eb5	235	void dbs_check_cpu(struct cpufreq_policy *policy);
906a6e5a	236	int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event);
fb30809e JS	237	void od_register_powersave_bias_handler(unsigned int (*f)
	238	(struct cpufreq_policy *, unsigned int, unsigned int),
	239	unsigned int powersave_bias);
	240	void od_unregister_powersave_bias_handler(void);
beb0ff39	241	#endif /* _CPUFREQ_GOVERNOR_H */