drivers/cpufreq/cpufreq_governor.h

   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 */
  26 enum {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). */
  38 struct 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
  48 static 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)                                   \
  54 static 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)                                  \
  63 static 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)                                              \
  71 static struct governor_attr _name =                                     \
  72 __ATTR(_name, 0444, show_##_name, NULL)
  73
  74 #define gov_attr_rw(_name)                                              \
  75 static struct governor_attr _name =                                     \
  76 __ATTR(_name, 0644, show_##_name, store_##_name)
  77
  78 /* Common to all CPUs of a policy */
  79 struct 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
 103 static 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 */
 110 struct 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 */
 126 struct 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
 144 static 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 */
 150 int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
 151 void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
 152 int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
 153 void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
 154 void 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 */
 169 struct od_ops {
 170         unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
 171                         unsigned int freq_next, unsigned int relation);
 172 };
 173
 174 unsigned int dbs_update(struct cpufreq_policy *policy);
 175 void od_register_powersave_bias_handler(unsigned int (*f)
 176                 (struct cpufreq_policy *, unsigned int, unsigned int),
 177                 unsigned int powersave_bias);
 178 void od_unregister_powersave_bias_handler(void);
 179 ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
 180                             size_t count);
 181 void gov_update_cpu_data(struct dbs_data *dbs_data);
 182 #endif /* _CPUFREQ_GOVERNOR_H */