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 */ 40 enum {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) \ 51 static struct global_attr _name##_gov_sys = \ 52 __ATTR(_name, 0444, show_##_name##_gov_sys, NULL) 53 54 #define gov_sys_attr_rw(_name) \ 55 static 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) \ 59 static struct freq_attr _name##_gov_pol = \ 60 __ATTR(_name, 0444, show_##_name##_gov_pol, NULL) 61 62 #define gov_pol_attr_rw(_name) \ 63 static 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) \ 76 static 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 \ 83 static 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) \ 92 static 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 \ 99 static 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) \ 107 show_one(_gov, file_name); \ 108 store_one(_gov, file_name) 109 110 /* create helper routines */ 111 #define define_get_cpu_dbs_routines(_dbs_info) \ 112 static struct cpu_dbs_info *get_cpu_cdbs(int cpu) \ 113 { \ 114 return &per_cpu(_dbs_info, cpu).cdbs; \ 115 } \ 116 \ 117 static 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 /* Common to all CPUs of a policy */ 132 struct cpu_common_dbs_info { 133 struct cpufreq_policy *policy; 134 /* 135 * percpu mutex that serializes governor limit change with dbs_timer 136 * invocation. We do not want dbs_timer to run when user is changing 137 * the governor or limits. 138 */ 139 struct mutex timer_mutex; 140 ktime_t time_stamp; 141 }; 142 143 /* Per cpu structures */ 144 struct cpu_dbs_info { 145 u64 prev_cpu_idle; 146 u64 prev_cpu_wall; 147 u64 prev_cpu_nice; 148 /* 149 * Used to keep track of load in the previous interval. However, when 150 * explicitly set to zero, it is used as a flag to ensure that we copy 151 * the previous load to the current interval only once, upon the first 152 * wake-up from idle. 153 */ 154 unsigned int prev_load; 155 struct delayed_work dwork; 156 struct cpu_common_dbs_info *shared; 157 }; 158 159 struct od_cpu_dbs_info_s { 160 struct cpu_dbs_info cdbs; 161 struct cpufreq_frequency_table *freq_table; 162 unsigned int freq_lo; 163 unsigned int freq_lo_jiffies; 164 unsigned int freq_hi_jiffies; 165 unsigned int rate_mult; 166 unsigned int sample_type:1; 167 }; 168 169 struct cs_cpu_dbs_info_s { 170 struct cpu_dbs_info cdbs; 171 unsigned int down_skip; 172 unsigned int requested_freq; 173 unsigned int enable:1; 174 }; 175 176 /* Per policy Governors sysfs tunables */ 177 struct od_dbs_tuners { 178 unsigned int ignore_nice_load; 179 unsigned int sampling_rate; 180 unsigned int sampling_down_factor; 181 unsigned int up_threshold; 182 unsigned int powersave_bias; 183 unsigned int io_is_busy; 184 }; 185 186 struct cs_dbs_tuners { 187 unsigned int ignore_nice_load; 188 unsigned int sampling_rate; 189 unsigned int sampling_down_factor; 190 unsigned int up_threshold; 191 unsigned int down_threshold; 192 unsigned int freq_step; 193 }; 194 195 /* Common Governor data across policies */ 196 struct dbs_data; 197 struct common_dbs_data { 198 /* Common across governors */ 199 #define GOV_ONDEMAND 0 200 #define GOV_CONSERVATIVE 1 201 int governor; 202 struct attribute_group *attr_group_gov_sys; /* one governor - system */ 203 struct attribute_group *attr_group_gov_pol; /* one governor - policy */ 204 205 /* 206 * Common data for platforms that don't set 207 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY 208 */ 209 struct dbs_data *gdbs_data; 210 211 struct cpu_dbs_info *(*get_cpu_cdbs)(int cpu); 212 void *(*get_cpu_dbs_info_s)(int cpu); 213 unsigned int (*gov_dbs_timer)(struct cpu_dbs_info *cdbs, 214 struct dbs_data *dbs_data, 215 bool modify_all); 216 void (*gov_check_cpu)(int cpu, unsigned int load); 217 int (*init)(struct dbs_data *dbs_data, bool notify); 218 void (*exit)(struct dbs_data *dbs_data, bool notify); 219 220 /* Governor specific ops, see below */ 221 void *gov_ops; 222 223 /* 224 * Protects governor's data (struct dbs_data and struct common_dbs_data) 225 */ 226 struct mutex mutex; 227 }; 228 229 /* Governor Per policy data */ 230 struct dbs_data { 231 struct common_dbs_data *cdata; 232 unsigned int min_sampling_rate; 233 int usage_count; 234 void *tuners; 235 }; 236 237 /* Governor specific ops, will be passed to dbs_data->gov_ops */ 238 struct od_ops { 239 void (*powersave_bias_init_cpu)(int cpu); 240 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy, 241 unsigned int freq_next, unsigned int relation); 242 void (*freq_increase)(struct cpufreq_policy *policy, unsigned int freq); 243 }; 244 245 static inline int delay_for_sampling_rate(unsigned int sampling_rate) 246 { 247 int delay = usecs_to_jiffies(sampling_rate); 248 249 /* We want all CPUs to do sampling nearly on same jiffy */ 250 if (num_online_cpus() > 1) 251 delay -= jiffies % delay; 252 253 return delay; 254 } 255 256 #define declare_show_sampling_rate_min(_gov) \ 257 static ssize_t show_sampling_rate_min_gov_sys \ 258 (struct kobject *kobj, struct attribute *attr, char *buf) \ 259 { \ 260 struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \ 261 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ 262 } \ 263 \ 264 static ssize_t show_sampling_rate_min_gov_pol \ 265 (struct cpufreq_policy *policy, char *buf) \ 266 { \ 267 struct dbs_data *dbs_data = policy->governor_data; \ 268 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ 269 } 270 271 extern struct mutex cpufreq_governor_lock; 272 273 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu); 274 int cpufreq_governor_dbs(struct cpufreq_policy *policy, 275 struct common_dbs_data *cdata, unsigned int event); 276 void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy, 277 unsigned int delay, bool all_cpus); 278 void od_register_powersave_bias_handler(unsigned int (*f) 279 (struct cpufreq_policy *, unsigned int, unsigned int), 280 unsigned int powersave_bias); 281 void od_unregister_powersave_bias_handler(void); 282 #endif /* _CPUFREQ_GOVERNOR_H */ 283