LXR linux/drivers/cpufreq/cpufreq

   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_GOVERNOR_H
  18#define _CPUFREQ_GOVERNOR_H
  19
  20#include <linux/atomic.h>
  21#include <linux/irq_work.h>
  22#include <linux/cpufreq.h>
  23#include <linux/sched/cpufreq.h>
  24#include <linux/kernel_stat.h>
  25#include <linux/module.h>
  26#include <linux/mutex.h>
  27
  28/* Ondemand Sampling types */
  29enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
  30
  31/*
  32 * Abbreviations:
  33 * dbs: used as a shortform for demand based switching It helps to keep variable
  34 *      names smaller, simpler
  35 * cdbs: common dbs
  36 * od_*: On-demand governor
  37 * cs_*: Conservative governor
  38 */
  39
  40/* Governor demand based switching data (per-policy or global). */
  41struct dbs_data {
  42        struct gov_attr_set attr_set;
  43        void *tuners;
  44        unsigned int ignore_nice_load;
  45        unsigned int sampling_rate;
  46        unsigned int sampling_down_factor;
  47        unsigned int up_threshold;
  48        unsigned int io_is_busy;
  49};
  50
  51static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
  52{
  53        return container_of(attr_set, struct dbs_data, attr_set);
  54}
  55
  56#define gov_show_one(_gov, file_name)                                   \
  57static ssize_t show_##file_name                                         \
  58(struct gov_attr_set *attr_set, char *buf)                              \
  59{                                                                       \
  60        struct dbs_data *dbs_data = to_dbs_data(attr_set);              \
  61        struct _gov##_dbs_tuners *tuners = dbs_data->tuners;            \
  62        return sprintf(buf, "%u\n", tuners->file_name);                 \
  63}
  64
  65#define gov_show_one_common(file_name)                                  \
  66static ssize_t show_##file_name                                         \
  67(struct gov_attr_set *attr_set, char *buf)                              \
  68{                                                                       \
  69        struct dbs_data *dbs_data = to_dbs_data(attr_set);              \
  70        return sprintf(buf, "%u\n", dbs_data->file_name);               \
  71}
  72
  73#define gov_attr_ro(_name)                                              \
  74static struct governor_attr _name =                                     \
  75__ATTR(_name, 0444, show_##_name, NULL)
  76
  77#define gov_attr_rw(_name)                                              \
  78static struct governor_attr _name =                                     \
  79__ATTR(_name, 0644, show_##_name, store_##_name)
  80
  81/* Common to all CPUs of a policy */
  82struct policy_dbs_info {
  83        struct cpufreq_policy *policy;
  84        /*
  85         * Per policy mutex that serializes load evaluation from limit-change
  86         * and work-handler.
  87         */
  88        struct mutex update_mutex;
  89
  90        u64 last_sample_time;
  91        s64 sample_delay_ns;
  92        atomic_t work_count;
  93        struct irq_work irq_work;
  94        struct work_struct work;
  95        /* dbs_data may be shared between multiple policy objects */
  96        struct dbs_data *dbs_data;
  97        struct list_head list;
  98        /* Multiplier for increasing sample delay temporarily. */
  99        unsigned int rate_mult;
 100        unsigned int idle_periods;      /* For conservative */
 101        /* Status indicators */
 102        bool is_shared;         /* This object is used by multiple CPUs */
 103        bool work_in_progress;  /* Work is being queued up or in progress */
 104};
 105
 106static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
 107                                           unsigned int delay_us)
 108{
 109        policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
 110}
 111
 112/* Per cpu structures */
 113struct cpu_dbs_info {
 114        u64 prev_cpu_idle;
 115        u64 prev_update_time;
 116        u64 prev_cpu_nice;
 117        /*
 118         * Used to keep track of load in the previous interval. However, when
 119         * explicitly set to zero, it is used as a flag to ensure that we copy
 120         * the previous load to the current interval only once, upon the first
 121         * wake-up from idle.
 122         */
 123        unsigned int prev_load;
 124        struct update_util_data update_util;
 125        struct policy_dbs_info *policy_dbs;
 126};
 127
 128/* Common Governor data across policies */
 129struct dbs_governor {
 130        struct cpufreq_governor gov;
 131        struct kobj_type kobj_type;
 132
 133        /*
 134         * Common data for platforms that don't set
 135         * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
 136         */
 137        struct dbs_data *gdbs_data;
 138
 139        unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
 140        struct policy_dbs_info *(*alloc)(void);
 141        void (*free)(struct policy_dbs_info *policy_dbs);
 142        int (*init)(struct dbs_data *dbs_data);
 143        void (*exit)(struct dbs_data *dbs_data);
 144        void (*start)(struct cpufreq_policy *policy);
 145};
 146
 147static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
 148{
 149        return container_of(policy->governor, struct dbs_governor, gov);
 150}
 151
 152/* Governor callback routines */
 153int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
 154void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
 155int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
 156void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
 157void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
 158
 159#define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_)                        \
 160        {                                                               \
 161                .name = _name_,                                         \
 162                .dynamic_switching = true,                              \
 163                .owner = THIS_MODULE,                                   \
 164                .init = cpufreq_dbs_governor_init,                      \
 165                .exit = cpufreq_dbs_governor_exit,                      \
 166                .start = cpufreq_dbs_governor_start,                    \
 167                .stop = cpufreq_dbs_governor_stop,                      \
 168                .limits = cpufreq_dbs_governor_limits,                  \
 169        }
 170
 171/* Governor specific operations */
 172struct od_ops {
 173        unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
 174                        unsigned int freq_next, unsigned int relation);
 175};
 176
 177unsigned int dbs_update(struct cpufreq_policy *policy);
 178void od_register_powersave_bias_handler(unsigned int (*f)
 179                (struct cpufreq_policy *, unsigned int, unsigned int),
 180                unsigned int powersave_bias);
 181void od_unregister_powersave_bias_handler(void);
 182ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
 183                            size_t count);
 184void gov_update_cpu_data(struct dbs_data *dbs_data);
 185#endif /* _CPUFREQ_GOVERNOR_H */
 186