drivers/cpufreq/cpufreq_governor.h

   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/cpufreq.h>
  21 #include <linux/kobject.h>
  22 #include <linux/mutex.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/sysfs.h>
  25
  26 /*
  27  * The polling frequency depends on the capability of the processor. Default
  28  * polling frequency is 1000 times the transition latency of the processor. The
  29  * governor will work on any processor with transition latency <= 10mS, using
  30  * appropriate sampling rate.
  31  *
  32  * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
  33  * this governor will not work. All times here are in uS.
  34  */
  35 #define MIN_SAMPLING_RATE_RATIO                 (2)
  36 #define LATENCY_MULTIPLIER                      (1000)
  37 #define MIN_LATENCY_MULTIPLIER                  (20)
  38 #define TRANSITION_LATENCY_LIMIT                (10 * 1000 * 1000)
  39
  40 /* Ondemand Sampling types */
  41 enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
  42
  43 /*
  44  * Macro for creating governors sysfs routines
  45  *
  46  * - gov_sys: One governor instance per whole system
  47  * - gov_pol: One governor instance per policy
  48  */
  49
  50 /* Create attributes */
  51 #define gov_sys_attr_ro(_name)                                          \
  52 static struct global_attr _name##_gov_sys =                             \
  53 __ATTR(_name, 0444, show_##_name##_gov_sys, NULL)
  54
  55 #define gov_sys_attr_rw(_name)                                          \
  56 static struct global_attr _name##_gov_sys =                             \
  57 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
  58
  59 #define gov_pol_attr_ro(_name)                                          \
  60 static struct freq_attr _name##_gov_pol =                               \
  61 __ATTR(_name, 0444, show_##_name##_gov_pol, NULL)
  62
  63 #define gov_pol_attr_rw(_name)                                          \
  64 static struct freq_attr _name##_gov_pol =                               \
  65 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
  66
  67 #define gov_sys_pol_attr_rw(_name)                                      \
  68         gov_sys_attr_rw(_name);                                         \
  69         gov_pol_attr_rw(_name)
  70
  71 #define gov_sys_pol_attr_ro(_name)                                      \
  72         gov_sys_attr_ro(_name);                                         \
  73         gov_pol_attr_ro(_name)
  74
  75 /* Create show/store routines */
  76 #define show_one(_gov, file_name)                                       \
  77 static ssize_t show_##file_name##_gov_sys                               \
  78 (struct kobject *kobj, struct attribute *attr, char *buf)               \
  79 {                                                                       \
  80         struct _gov##_dbs_tuners *tuners = _gov##_dbs_cdata.gdbs_data->tuners; \
  81         if(tuners->file_name > 0)                                               \
  82                 return sprintf(buf, "%u\n", tuners->file_name);                 \
  83         else                                                                    \
  84                 return sprintf(buf, "%d\n", tuners->file_name);                 \
  85 }                                                                       \
  86                                                                         \
  87 static ssize_t show_##file_name##_gov_pol                                       \
  88 (struct cpufreq_policy *policy, char *buf)                              \
  89 {                                                                       \
  90         struct dbs_data *dbs_data = policy->governor_data;              \
  91         struct _gov##_dbs_tuners *tuners = dbs_data->tuners;            \
  92         return sprintf(buf, "%u\n", tuners->file_name);                 \
  93 }
  94
  95 #define store_one(_gov, file_name)                                      \
  96 static ssize_t store_##file_name##_gov_sys                              \
  97 (struct kobject *kobj, struct attribute *attr, const char *buf, size_t count)   \
  98 {                                                                       \
  99         struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data;         \
 100         return store_##file_name(dbs_data, buf, count);                 \
 101 }                                                                       \
 102                                                                         \
 103 static ssize_t store_##file_name##_gov_pol                              \
 104 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
 105 {                                                                       \
 106         struct dbs_data *dbs_data = policy->governor_data;              \
 107         return store_##file_name(dbs_data, buf, count);                 \
 108 }
 109
 110 #define show_store_one(_gov, file_name)                                 \
 111 show_one(_gov, file_name);                                              \
 112 store_one(_gov, file_name)
 113
 114 /* create helper routines */
 115 #define define_get_cpu_dbs_routines(_dbs_info)                          \
 116 static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu)                \
 117 {                                                                       \
 118         return &per_cpu(_dbs_info, cpu).cdbs;                           \
 119 }                                                                       \
 120                                                                         \
 121 static void *get_cpu_dbs_info_s(int cpu)                                \
 122 {                                                                       \
 123         return &per_cpu(_dbs_info, cpu);                                \
 124 }
 125
 126 /*
 127  * Abbreviations:
 128  * dbs: used as a shortform for demand based switching It helps to keep variable
 129  *      names smaller, simpler
 130  * cdbs: common dbs
 131  * od_*: On-demand governor
 132  * cs_*: Conservative governor
 133  */
 134
 135 /* Per cpu structures */
 136 struct cpu_dbs_common_info {
 137         int cpu;
 138         u64 prev_cpu_idle;
 139         u64 prev_cpu_wall;
 140         u64 prev_cpu_nice;
 141         struct cpufreq_policy *cur_policy;
 142         struct delayed_work work;
 143         /*
 144          * percpu mutex that serializes governor limit change with gov_dbs_timer
 145          * invocation. We do not want gov_dbs_timer to run when user is changing
 146          * the governor or limits.
 147          */
 148         struct mutex timer_mutex;
 149         ktime_t time_stamp;
 150 };
 151
 152 struct od_cpu_dbs_info_s {
 153         struct cpu_dbs_common_info cdbs;
 154         struct cpufreq_frequency_table *freq_table;
 155         unsigned int freq_lo;
 156         unsigned int freq_lo_jiffies;
 157         unsigned int freq_hi_jiffies;
 158         unsigned int rate_mult;
 159         unsigned int sample_type:1;
 160 };
 161
 162 struct cs_cpu_dbs_info_s {
 163         struct cpu_dbs_common_info cdbs;
 164         unsigned int down_skip;
 165         unsigned int requested_freq;
 166         unsigned int enable:1;
 167 };
 168
 169 /* Per policy Governers sysfs tunables */
 170 struct od_dbs_tuners {
 171         unsigned int ignore_nice_load;
 172         unsigned int sampling_rate;
 173         unsigned int sampling_down_factor;
 174         unsigned int up_threshold;
 175         unsigned int powersave_bias;
 176         unsigned int io_is_busy;
 177 };
 178
 179 struct cs_dbs_tuners {
 180         unsigned int ignore_nice_load;
 181         unsigned int sampling_rate;
 182         unsigned int sampling_down_factor;
 183         unsigned int up_threshold;
 184         unsigned int down_threshold;
 185         unsigned int freq_step;
 186 };
 187
 188 struct sd_dbs_tuners {
 189         unsigned int ignore_nice;
 190         unsigned int sampling_rate;
 191         unsigned int sampling_down_factor;
 192         unsigned int up_threshold;
 193         unsigned int adj_up_threshold;
 194         unsigned int powersave_bias;
 195         unsigned int io_is_busy;
 196
 197         unsigned int cpu_hotplug_disable;
 198         unsigned int is_suspend;
 199         unsigned int cpu_score_up_threshold;
 200         unsigned int load_critical;
 201         unsigned int load_hi;
 202         unsigned int load_mid;
 203         unsigned int load_light;
 204         unsigned int load_lo;
 205         int load_critical_score;
 206         int load_hi_score;
 207         int load_mid_score;
 208         int load_light_score;
 209         int load_lo_score;
 210         unsigned int cpu_down_threshold;
 211         unsigned int cpu_down_count;
 212         unsigned int cpu_num_limit;
 213         unsigned int cpu_up_mid_threshold;
 214         unsigned int cpu_up_high_threshold;
 215         unsigned int cpu_down_mid_threshold;
 216         unsigned int cpu_down_high_threshold;
 217         unsigned int window_size;
 218 };
 219
 220 /* Common Governer data across policies */
 221 struct dbs_data;
 222 struct common_dbs_data {
 223         /* Common across governors */
 224         #define GOV_ONDEMAND            0
 225         #define GOV_CONSERVATIVE        1
 226         int governor;
 227         struct attribute_group *attr_group_gov_sys; /* one governor - system */
 228         struct attribute_group *attr_group_gov_pol; /* one governor - policy */
 229
 230         /* Common data for platforms that don't set have_governor_per_policy */
 231         struct dbs_data *gdbs_data;
 232
 233         struct cpu_dbs_common_info *(*get_cpu_cdbs)(int cpu);
 234         void *(*get_cpu_dbs_info_s)(int cpu);
 235         void (*gov_dbs_timer)(struct work_struct *work);
 236         void (*gov_check_cpu)(int cpu, unsigned int load);
 237         int (*init)(struct dbs_data *dbs_data);
 238         void (*exit)(struct dbs_data *dbs_data);
 239
 240         /* Governor specific ops, see below */
 241         void *gov_ops;
 242 };
 243
 244 /* Governer Per policy data */
 245 struct dbs_data {
 246         struct common_dbs_data *cdata;
 247         unsigned int min_sampling_rate;
 248         int usage_count;
 249         void *tuners;
 250
 251         /* dbs_mutex protects dbs_enable in governor start/stop */
 252         struct mutex mutex;
 253 };
 254
 255 /* Governor specific ops, will be passed to dbs_data->gov_ops */
 256 struct od_ops {
 257         void (*powersave_bias_init_cpu)(int cpu);
 258         unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
 259                         unsigned int freq_next, unsigned int relation);
 260         void (*freq_increase)(struct cpufreq_policy *p, unsigned int freq);
 261 };
 262
 263 struct cs_ops {
 264         struct notifier_block *notifier_block;
 265 };
 266
 267 static inline int delay_for_sampling_rate(unsigned int sampling_rate)
 268 {
 269         int delay = usecs_to_jiffies(sampling_rate);
 270
 271         /* We want all CPUs to do sampling nearly on same jiffy */
 272         if (num_online_cpus() > 1)
 273                 delay -= jiffies % delay;
 274
 275         return delay;
 276 }
 277
 278 #define declare_show_sampling_rate_min(_gov)                            \
 279 static ssize_t show_sampling_rate_min_gov_sys                           \
 280 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 281 {                                                                       \
 282         struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data;         \
 283         return sprintf(buf, "%u\n", dbs_data->min_sampling_rate);       \
 284 }                                                                       \
 285                                                                         \
 286 static ssize_t show_sampling_rate_min_gov_pol                           \
 287 (struct cpufreq_policy *policy, char *buf)                              \
 288 {                                                                       \
 289         struct dbs_data *dbs_data = policy->governor_data;              \
 290         return sprintf(buf, "%u\n", dbs_data->min_sampling_rate);       \
 291 }
 292
 293 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
 294 bool need_load_eval(struct cpu_dbs_common_info *cdbs,
 295                 unsigned int sampling_rate);
 296 int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 297                 struct common_dbs_data *cdata, unsigned int event);
 298 void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,
 299                 unsigned int delay, bool all_cpus);
 300 void od_register_powersave_bias_handler(unsigned int (*f)
 301                 (struct cpufreq_policy *, unsigned int, unsigned int),
 302                 unsigned int powersave_bias);
 303 void od_unregister_powersave_bias_handler(void);
 304 #endif /* _CPUFREQ_GOVERNOR_H */