LXR linux/drivers/cpufreq/cpufreq

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * drivers/cpufreq/cpufreq_governor.h
   4 *
   5 * Header file for CPUFreq governors common code
   6 *
   7 * Copyright    (C) 2001 Russell King
   8 *              (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
   9 *              (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
  10 *              (C) 2009 Alexander Clouter <alex@digriz.org.uk>
  11 *              (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
  12 */
  13
  14#ifndef _CPUFREQ_GOVERNOR_H
  15#define _CPUFREQ_GOVERNOR_H
  16
  17#include <linux/atomic.h>
  18#include <linux/irq_work.h>
  19#include <linux/cpufreq.h>
  20#include <linux/sched/cpufreq.h>
  21#include <linux/kernel_stat.h>
  22#include <linux/module.h>
  23#include <linux/mutex.h>
  24
  25/* Ondemand Sampling types */
  26enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
  27
  28/*
  29 * Abbreviations:
  30 * dbs: used as a shortform for demand based switching It helps to keep variable
  31 *      names smaller, simpler
  32 * cdbs: common dbs
  33 * od_*: On-demand governor
  34 * cs_*: Conservative governor
  35 */
  36
  37/* Governor demand based switching data (per-policy or global). */
  38struct dbs_data {
  39        struct gov_attr_set attr_set;
  40        void *tuners;
  41        unsigned int ignore_nice_load;
  42        unsigned int sampling_rate;
  43        unsigned int sampling_down_factor;
  44        unsigned int up_threshold;
  45        unsigned int io_is_busy;
  46};
  47
  48static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
  49{
  50        return container_of(attr_set, struct dbs_data, attr_set);
  51}
  52
  53#define gov_show_one(_gov, file_name)                                   \
  54static ssize_t show_##file_name                                         \
  55(struct gov_attr_set *attr_set, char *buf)                              \
  56{                                                                       \
  57        struct dbs_data *dbs_data = to_dbs_data(attr_set);              \
  58        struct _gov##_dbs_tuners *tuners = dbs_data->tuners;            \
  59        return sprintf(buf, "%u\n", tuners->file_name);                 \
  60}
  61
  62#define gov_show_one_common(file_name)                                  \
  63static ssize_t show_##file_name                                         \
  64(struct gov_attr_set *attr_set, char *buf)                              \
  65{                                                                       \
  66        struct dbs_data *dbs_data = to_dbs_data(attr_set);              \
  67        return sprintf(buf, "%u\n", dbs_data->file_name);               \
  68}
  69
  70#define gov_attr_ro(_name)                                              \
  71static struct governor_attr _name =                                     \
  72__ATTR(_name, 0444, show_##_name, NULL)
  73
  74#define gov_attr_rw(_name)                                              \
  75static struct governor_attr _name =                                     \
  76__ATTR(_name, 0644, show_##_name, store_##_name)
  77
  78/* Common to all CPUs of a policy */
  79struct policy_dbs_info {
  80        struct cpufreq_policy *policy;
  81        /*
  82         * Per policy mutex that serializes load evaluation from limit-change
  83         * and work-handler.
  84         */
  85        struct mutex update_mutex;
  86
  87        u64 last_sample_time;
  88        s64 sample_delay_ns;
  89        atomic_t work_count;
  90        struct irq_work irq_work;
  91        struct work_struct work;
  92        /* dbs_data may be shared between multiple policy objects */
  93        struct dbs_data *dbs_data;
  94        struct list_head list;
  95        /* Multiplier for increasing sample delay temporarily. */
  96        unsigned int rate_mult;
  97        unsigned int idle_periods;      /* For conservative */
  98        /* Status indicators */
  99        bool is_shared;         /* This object is used by multiple CPUs */
 100        bool work_in_progress;  /* Work is being queued up or in progress */
 101};
 102
 103static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
 104                                           unsigned int delay_us)
 105{
 106        policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
 107}
 108
 109/* Per cpu structures */
 110struct cpu_dbs_info {
 111        u64 prev_cpu_idle;
 112        u64 prev_update_time;
 113        u64 prev_cpu_nice;
 114        /*
 115         * Used to keep track of load in the previous interval. However, when
 116         * explicitly set to zero, it is used as a flag to ensure that we copy
 117         * the previous load to the current interval only once, upon the first
 118         * wake-up from idle.
 119         */
 120        unsigned int prev_load;
 121        struct update_util_data update_util;
 122        struct policy_dbs_info *policy_dbs;
 123};
 124
 125/* Common Governor data across policies */
 126struct dbs_governor {
 127        struct cpufreq_governor gov;
 128        struct kobj_type kobj_type;
 129
 130        /*
 131         * Common data for platforms that don't set
 132         * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
 133         */
 134        struct dbs_data *gdbs_data;
 135
 136        unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
 137        struct policy_dbs_info *(*alloc)(void);
 138        void (*free)(struct policy_dbs_info *policy_dbs);
 139        int (*init)(struct dbs_data *dbs_data);
 140        void (*exit)(struct dbs_data *dbs_data);
 141        void (*start)(struct cpufreq_policy *policy);
 142};
 143
 144static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
 145{
 146        return container_of(policy->governor, struct dbs_governor, gov);
 147}
 148
 149/* Governor callback routines */
 150int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
 151void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
 152int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
 153void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
 154void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
 155
 156#define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_)                        \
 157        {                                                               \
 158                .name = _name_,                                         \
 159                .dynamic_switching = true,                              \
 160                .owner = THIS_MODULE,                                   \
 161                .init = cpufreq_dbs_governor_init,                      \
 162                .exit = cpufreq_dbs_governor_exit,                      \
 163                .start = cpufreq_dbs_governor_start,                    \
 164                .stop = cpufreq_dbs_governor_stop,                      \
 165                .limits = cpufreq_dbs_governor_limits,                  \
 166        }
 167
 168/* Governor specific operations */
 169struct od_ops {
 170        unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
 171                        unsigned int freq_next, unsigned int relation);
 172};
 173
 174unsigned int dbs_update(struct cpufreq_policy *policy);
 175void od_register_powersave_bias_handler(unsigned int (*f)
 176                (struct cpufreq_policy *, unsigned int, unsigned int),
 177                unsigned int powersave_bias);
 178void od_unregister_powersave_bias_handler(void);
 179ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
 180                            size_t count);
 181void gov_update_cpu_data(struct dbs_data *dbs_data);
 182#endif /* _CPUFREQ_GOVERNOR_H */
 183