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/*
* 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
* on_*: 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 down_differential;
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 */
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