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/atomic.h> 21 #include <linux/cpufreq.h> 22 #include <linux/kernel_stat.h> 23 #include <linux/module.h> 24 #include <linux/mutex.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 (micro seconds). 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 return sprintf(buf, "%u\n", tuners->file_name); \ 82 } \ 83 \ 84 static ssize_t show_##file_name##_gov_pol \ 85 (struct cpufreq_policy *policy, char *buf) \ 86 { \ 87 struct dbs_data *dbs_data = policy->governor_data; \ 88 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \ 89 return sprintf(buf, "%u\n", tuners->file_name); \ 90 } 91 92 #define store_one(_gov, file_name) \ 93 static ssize_t store_##file_name##_gov_sys \ 94 (struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) \ 95 { \ 96 struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \ 97 return store_##file_name(dbs_data, buf, count); \ 98 } \ 99 \ 100 static ssize_t store_##file_name##_gov_pol \ 101 (struct cpufreq_policy *policy, const char *buf, size_t count) \ 102 { \ 103 struct dbs_data *dbs_data = policy->governor_data; \ 104 return store_##file_name(dbs_data, buf, count); \ 105 } 106 107 #define show_store_one(_gov, file_name) \ 108 show_one(_gov, file_name); \ 109 store_one(_gov, file_name) 110 111 /* create helper routines */ 112 #define define_get_cpu_dbs_routines(_dbs_info) \ 113 static struct cpu_dbs_info *get_cpu_cdbs(int cpu) \ 114 { \ 115 return &per_cpu(_dbs_info, cpu).cdbs; \ 116 } \ 117 \ 118 static void *get_cpu_dbs_info_s(int cpu) \ 119 { \ 120 return &per_cpu(_dbs_info, cpu); \ 121 } 122 123 /* 124 * Abbreviations: 125 * dbs: used as a shortform for demand based switching It helps to keep variable 126 * names smaller, simpler 127 * cdbs: common dbs 128 * od_*: On-demand governor 129 * cs_*: Conservative governor 130 */ 131 132 /* Common to all CPUs of a policy */ 133 struct cpu_common_dbs_info { 134 struct cpufreq_policy *policy; 135 /* 136 * Per policy mutex that serializes load evaluation from limit-change 137 * and work-handler. 138 */ 139 struct mutex timer_mutex; 140 141 ktime_t time_stamp; 142 atomic_t skip_work; 143 struct work_struct work; 144 }; 145 146 /* Per cpu structures */ 147 struct cpu_dbs_info { 148 u64 prev_cpu_idle; 149 u64 prev_cpu_wall; 150 u64 prev_cpu_nice; 151 /* 152 * Used to keep track of load in the previous interval. However, when 153 * explicitly set to zero, it is used as a flag to ensure that we copy 154 * the previous load to the current interval only once, upon the first 155 * wake-up from idle. 156 */ 157 unsigned int prev_load; 158 struct timer_list timer; 159 struct cpu_common_dbs_info *shared; 160 }; 161 162 struct od_cpu_dbs_info_s { 163 struct cpu_dbs_info cdbs; 164 struct cpufreq_frequency_table *freq_table; 165 unsigned int freq_lo; 166 unsigned int freq_lo_jiffies; 167 unsigned int freq_hi_jiffies; 168 unsigned int rate_mult; 169 unsigned int sample_type:1; 170 }; 171 172 struct cs_cpu_dbs_info_s { 173 struct cpu_dbs_info cdbs; 174 unsigned int down_skip; 175 unsigned int requested_freq; 176 }; 177 178 /* Per policy Governors sysfs tunables */ 179 struct od_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 powersave_bias; 185 unsigned int io_is_busy; 186 }; 187 188 struct cs_dbs_tuners { 189 unsigned int ignore_nice_load; 190 unsigned int sampling_rate; 191 unsigned int sampling_down_factor; 192 unsigned int up_threshold; 193 unsigned int down_threshold; 194 unsigned int freq_step; 195 }; 196 197 /* Common Governor data across policies */ 198 struct dbs_data; 199 struct common_dbs_data { 200 /* Common across governors */ 201 #define GOV_ONDEMAND 0 202 #define GOV_CONSERVATIVE 1 203 int governor; 204 struct attribute_group *attr_group_gov_sys; /* one governor - system */ 205 struct attribute_group *attr_group_gov_pol; /* one governor - policy */ 206 207 /* 208 * Common data for platforms that don't set 209 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY 210 */ 211 struct dbs_data *gdbs_data; 212 213 struct cpu_dbs_info *(*get_cpu_cdbs)(int cpu); 214 void *(*get_cpu_dbs_info_s)(int cpu); 215 unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy, 216 bool modify_all); 217 void (*gov_check_cpu)(int cpu, unsigned int load); 218 int (*init)(struct dbs_data *dbs_data, bool notify); 219 void (*exit)(struct dbs_data *dbs_data, bool notify); 220 221 /* Governor specific ops, see below */ 222 void *gov_ops; 223 224 /* 225 * Protects governor's data (struct dbs_data and struct common_dbs_data) 226 */ 227 struct mutex mutex; 228 }; 229 230 /* Governor Per policy data */ 231 struct dbs_data { 232 struct common_dbs_data *cdata; 233 unsigned int min_sampling_rate; 234 int usage_count; 235 void *tuners; 236 }; 237 238 /* Governor specific ops, will be passed to dbs_data->gov_ops */ 239 struct od_ops { 240 void (*powersave_bias_init_cpu)(int cpu); 241 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy, 242 unsigned int freq_next, unsigned int relation); 243 void (*freq_increase)(struct cpufreq_policy *policy, unsigned int freq); 244 }; 245 246 static inline int delay_for_sampling_rate(unsigned int sampling_rate) 247 { 248 int delay = usecs_to_jiffies(sampling_rate); 249 250 /* We want all CPUs to do sampling nearly on same jiffy */ 251 if (num_online_cpus() > 1) 252 delay -= jiffies % delay; 253 254 return delay; 255 } 256 257 #define declare_show_sampling_rate_min(_gov) \ 258 static ssize_t show_sampling_rate_min_gov_sys \ 259 (struct kobject *kobj, struct attribute *attr, char *buf) \ 260 { \ 261 struct dbs_data *dbs_data = _gov##_dbs_cdata.gdbs_data; \ 262 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ 263 } \ 264 \ 265 static ssize_t show_sampling_rate_min_gov_pol \ 266 (struct cpufreq_policy *policy, char *buf) \ 267 { \ 268 struct dbs_data *dbs_data = policy->governor_data; \ 269 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ 270 } 271 272 extern struct mutex cpufreq_governor_lock; 273 274 void gov_add_timers(struct cpufreq_policy *policy, unsigned int delay); 275 void gov_cancel_work(struct cpu_common_dbs_info *shared); 276 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu); 277 int cpufreq_governor_dbs(struct cpufreq_policy *policy, 278 struct common_dbs_data *cdata, unsigned int event); 279 void od_register_powersave_bias_handler(unsigned int (*f) 280 (struct cpufreq_policy *, unsigned int, unsigned int), 281 unsigned int powersave_bias); 282 void od_unregister_powersave_bias_handler(void); 283 #endif /* _CPUFREQ_GOVERNOR_H */ 284