cpufreq_governor.h revision c4afc410942f9f0675a5431adbdb03cf5908d1df
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/kernel_stat.h> 22#include <linux/module.h> 23#include <linux/mutex.h> 24 25/* 26 * The polling frequency depends on the capability of the processor. Default 27 * polling frequency is 1000 times the transition latency of the processor. The 28 * governor will work on any processor with transition latency <= 10ms, using 29 * appropriate sampling rate. 30 * 31 * For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL) 32 * this governor will not work. All times here are in us (micro seconds). 33 */ 34#define MIN_SAMPLING_RATE_RATIO (2) 35#define LATENCY_MULTIPLIER (1000) 36#define MIN_LATENCY_MULTIPLIER (20) 37#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) 38 39/* Ondemand Sampling types */ 40enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE}; 41 42/* 43 * Macro for creating governors sysfs routines 44 * 45 * - gov_sys: One governor instance per whole system 46 * - gov_pol: One governor instance per policy 47 */ 48 49/* Create attributes */ 50#define gov_sys_attr_ro(_name) \ 51static struct global_attr _name##_gov_sys = \ 52__ATTR(_name, 0444, show_##_name##_gov_sys, NULL) 53 54#define gov_sys_attr_rw(_name) \ 55static struct global_attr _name##_gov_sys = \ 56__ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys) 57 58#define gov_pol_attr_ro(_name) \ 59static struct freq_attr _name##_gov_pol = \ 60__ATTR(_name, 0444, show_##_name##_gov_pol, NULL) 61 62#define gov_pol_attr_rw(_name) \ 63static struct freq_attr _name##_gov_pol = \ 64__ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol) 65 66#define gov_sys_pol_attr_rw(_name) \ 67 gov_sys_attr_rw(_name); \ 68 gov_pol_attr_rw(_name) 69 70#define gov_sys_pol_attr_ro(_name) \ 71 gov_sys_attr_ro(_name); \ 72 gov_pol_attr_ro(_name) 73 74/* Create show/store routines */ 75#define show_one(_gov, file_name) \ 76static ssize_t show_##file_name##_gov_sys \ 77(struct kobject *kobj, struct attribute *attr, char *buf) \ 78{ \ 79 struct _gov##_dbs_tuners *tuners = _gov##_dbs_cdata.gdbs_data->tuners; \ 80 return sprintf(buf, "%u\n", tuners->file_name); \ 81} \ 82 \ 83static ssize_t show_##file_name##_gov_pol \ 84(struct cpufreq_policy *policy, char *buf) \ 85{ \ 86 struct dbs_data *dbs_data = policy->governor_data; \ 87 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \ 88 return sprintf(buf, "%u\n", tuners->file_name); \ 89} 90 91#define store_one(_gov, file_name) \ 92static ssize_t store_##file_name##_gov_sys \ 93(struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) \ 94{ \ 95 struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \ 96 return store_##file_name(dbs_data, buf, count); \ 97} \ 98 \ 99static ssize_t store_##file_name##_gov_pol \ 100(struct cpufreq_policy *policy, const char *buf, size_t count) \ 101{ \ 102 struct dbs_data *dbs_data = policy->governor_data; \ 103 return store_##file_name(dbs_data, buf, count); \ 104} 105 106#define show_store_one(_gov, file_name) \ 107show_one(_gov, file_name); \ 108store_one(_gov, file_name) 109 110/* create helper routines */ 111#define define_get_cpu_dbs_routines(_dbs_info) \ 112static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu) \ 113{ \ 114 return &per_cpu(_dbs_info, cpu).cdbs; \ 115} \ 116 \ 117static void *get_cpu_dbs_info_s(int cpu) \ 118{ \ 119 return &per_cpu(_dbs_info, cpu); \ 120} 121 122/* 123 * Abbreviations: 124 * dbs: used as a shortform for demand based switching It helps to keep variable 125 * names smaller, simpler 126 * cdbs: common dbs 127 * od_*: On-demand governor 128 * cs_*: Conservative governor 129 */ 130 131/* Per cpu structures */ 132struct cpu_dbs_common_info { 133 int cpu; 134 u64 prev_cpu_idle; 135 u64 prev_cpu_wall; 136 u64 prev_cpu_nice; 137 struct cpufreq_policy *cur_policy; 138 struct delayed_work work; 139 /* 140 * percpu mutex that serializes governor limit change with gov_dbs_timer 141 * invocation. We do not want gov_dbs_timer to run when user is changing 142 * the governor or limits. 143 */ 144 struct mutex timer_mutex; 145 ktime_t time_stamp; 146}; 147 148struct od_cpu_dbs_info_s { 149 struct cpu_dbs_common_info cdbs; 150 struct cpufreq_frequency_table *freq_table; 151 unsigned int freq_lo; 152 unsigned int freq_lo_jiffies; 153 unsigned int freq_hi_jiffies; 154 unsigned int rate_mult; 155 unsigned int sample_type:1; 156}; 157 158struct cs_cpu_dbs_info_s { 159 struct cpu_dbs_common_info cdbs; 160 unsigned int down_skip; 161 unsigned int requested_freq; 162 unsigned int enable:1; 163}; 164 165/* Per policy Governors sysfs tunables */ 166struct od_dbs_tuners { 167 unsigned int ignore_nice_load; 168 unsigned int sampling_rate; 169 unsigned int sampling_down_factor; 170 unsigned int up_threshold; 171 unsigned int powersave_bias; 172 unsigned int io_is_busy; 173}; 174 175struct cs_dbs_tuners { 176 unsigned int ignore_nice_load; 177 unsigned int sampling_rate; 178 unsigned int sampling_down_factor; 179 unsigned int up_threshold; 180 unsigned int down_threshold; 181 unsigned int freq_step; 182}; 183 184/* Common Governor data across policies */ 185struct dbs_data; 186struct common_dbs_data { 187 /* Common across governors */ 188 #define GOV_ONDEMAND 0 189 #define GOV_CONSERVATIVE 1 190 int governor; 191 struct attribute_group *attr_group_gov_sys; /* one governor - system */ 192 struct attribute_group *attr_group_gov_pol; /* one governor - policy */ 193 194 /* Common data for platforms that don't set have_governor_per_policy */ 195 struct dbs_data *gdbs_data; 196 197 struct cpu_dbs_common_info *(*get_cpu_cdbs)(int cpu); 198 void *(*get_cpu_dbs_info_s)(int cpu); 199 void (*gov_dbs_timer)(struct work_struct *work); 200 void (*gov_check_cpu)(int cpu, unsigned int load); 201 int (*init)(struct dbs_data *dbs_data); 202 void (*exit)(struct dbs_data *dbs_data); 203 204 /* Governor specific ops, see below */ 205 void *gov_ops; 206}; 207 208/* Governor Per policy data */ 209struct dbs_data { 210 struct common_dbs_data *cdata; 211 unsigned int min_sampling_rate; 212 int usage_count; 213 void *tuners; 214 215 /* dbs_mutex protects dbs_enable in governor start/stop */ 216 struct mutex mutex; 217}; 218 219/* Governor specific ops, will be passed to dbs_data->gov_ops */ 220struct od_ops { 221 void (*powersave_bias_init_cpu)(int cpu); 222 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy, 223 unsigned int freq_next, unsigned int relation); 224 void (*freq_increase)(struct cpufreq_policy *policy, unsigned int freq); 225}; 226 227struct cs_ops { 228 struct notifier_block *notifier_block; 229}; 230 231static inline int delay_for_sampling_rate(unsigned int sampling_rate) 232{ 233 int delay = usecs_to_jiffies(sampling_rate); 234 235 /* We want all CPUs to do sampling nearly on same jiffy */ 236 if (num_online_cpus() > 1) 237 delay -= jiffies % delay; 238 239 return delay; 240} 241 242#define declare_show_sampling_rate_min(_gov) \ 243static ssize_t show_sampling_rate_min_gov_sys \ 244(struct kobject *kobj, struct attribute *attr, char *buf) \ 245{ \ 246 struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \ 247 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ 248} \ 249 \ 250static ssize_t show_sampling_rate_min_gov_pol \ 251(struct cpufreq_policy *policy, char *buf) \ 252{ \ 253 struct dbs_data *dbs_data = policy->governor_data; \ 254 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ 255} 256 257void dbs_check_cpu(struct dbs_data *dbs_data, int cpu); 258bool need_load_eval(struct cpu_dbs_common_info *cdbs, 259 unsigned int sampling_rate); 260int cpufreq_governor_dbs(struct cpufreq_policy *policy, 261 struct common_dbs_data *cdata, unsigned int event); 262void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy, 263 unsigned int delay, bool all_cpus); 264void od_register_powersave_bias_handler(unsigned int (*f) 265 (struct cpufreq_policy *, unsigned int, unsigned int), 266 unsigned int powersave_bias); 267void od_unregister_powersave_bias_handler(void); 268#endif /* _CPUFREQ_GOVERNOR_H */ 269