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