| 1 | /* |
| 2 | * drivers/cpufreq/cpufreq_ondemand.c |
| 3 | * |
| 4 | * Copyright (C) 2001 Russell King |
| 5 | * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. |
| 6 | * Jun Nakajima <jun.nakajima@intel.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 14 | |
| 15 | #include <linux/cpu.h> |
| 16 | #include <linux/percpu-defs.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/tick.h> |
| 19 | #include "cpufreq_governor.h" |
| 20 | |
| 21 | /* On-demand governor macros */ |
| 22 | #define DEF_FREQUENCY_UP_THRESHOLD (80) |
| 23 | #define DEF_SAMPLING_DOWN_FACTOR (1) |
| 24 | #define MAX_SAMPLING_DOWN_FACTOR (100000) |
| 25 | #define MICRO_FREQUENCY_UP_THRESHOLD (95) |
| 26 | #define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) |
| 27 | #define MIN_FREQUENCY_UP_THRESHOLD (11) |
| 28 | #define MAX_FREQUENCY_UP_THRESHOLD (100) |
| 29 | |
| 30 | static DEFINE_PER_CPU(struct od_cpu_dbs_info_s, od_cpu_dbs_info); |
| 31 | |
| 32 | static struct od_ops od_ops; |
| 33 | |
| 34 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
| 35 | static struct cpufreq_governor cpufreq_gov_ondemand; |
| 36 | #endif |
| 37 | |
| 38 | static unsigned int default_powersave_bias; |
| 39 | |
| 40 | static void ondemand_powersave_bias_init_cpu(int cpu) |
| 41 | { |
| 42 | struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| 43 | |
| 44 | dbs_info->freq_table = cpufreq_frequency_get_table(cpu); |
| 45 | dbs_info->freq_lo = 0; |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Not all CPUs want IO time to be accounted as busy; this depends on how |
| 50 | * efficient idling at a higher frequency/voltage is. |
| 51 | * Pavel Machek says this is not so for various generations of AMD and old |
| 52 | * Intel systems. |
| 53 | * Mike Chan (android.com) claims this is also not true for ARM. |
| 54 | * Because of this, whitelist specific known (series) of CPUs by default, and |
| 55 | * leave all others up to the user. |
| 56 | */ |
| 57 | static int should_io_be_busy(void) |
| 58 | { |
| 59 | #if defined(CONFIG_X86) |
| 60 | /* |
| 61 | * For Intel, Core 2 (model 15) and later have an efficient idle. |
| 62 | */ |
| 63 | if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && |
| 64 | boot_cpu_data.x86 == 6 && |
| 65 | boot_cpu_data.x86_model >= 15) |
| 66 | return 1; |
| 67 | #endif |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * Find right freq to be set now with powersave_bias on. |
| 73 | * Returns the freq_hi to be used right now and will set freq_hi_jiffies, |
| 74 | * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. |
| 75 | */ |
| 76 | static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy, |
| 77 | unsigned int freq_next, unsigned int relation) |
| 78 | { |
| 79 | unsigned int freq_req, freq_reduc, freq_avg; |
| 80 | unsigned int freq_hi, freq_lo; |
| 81 | unsigned int index = 0; |
| 82 | unsigned int jiffies_total, jiffies_hi, jiffies_lo; |
| 83 | struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, |
| 84 | policy->cpu); |
| 85 | struct dbs_data *dbs_data = policy->governor_data; |
| 86 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 87 | |
| 88 | if (!dbs_info->freq_table) { |
| 89 | dbs_info->freq_lo = 0; |
| 90 | dbs_info->freq_lo_jiffies = 0; |
| 91 | return freq_next; |
| 92 | } |
| 93 | |
| 94 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, |
| 95 | relation, &index); |
| 96 | freq_req = dbs_info->freq_table[index].frequency; |
| 97 | freq_reduc = freq_req * od_tuners->powersave_bias / 1000; |
| 98 | freq_avg = freq_req - freq_reduc; |
| 99 | |
| 100 | /* Find freq bounds for freq_avg in freq_table */ |
| 101 | index = 0; |
| 102 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, |
| 103 | CPUFREQ_RELATION_H, &index); |
| 104 | freq_lo = dbs_info->freq_table[index].frequency; |
| 105 | index = 0; |
| 106 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, |
| 107 | CPUFREQ_RELATION_L, &index); |
| 108 | freq_hi = dbs_info->freq_table[index].frequency; |
| 109 | |
| 110 | /* Find out how long we have to be in hi and lo freqs */ |
| 111 | if (freq_hi == freq_lo) { |
| 112 | dbs_info->freq_lo = 0; |
| 113 | dbs_info->freq_lo_jiffies = 0; |
| 114 | return freq_lo; |
| 115 | } |
| 116 | jiffies_total = usecs_to_jiffies(od_tuners->sampling_rate); |
| 117 | jiffies_hi = (freq_avg - freq_lo) * jiffies_total; |
| 118 | jiffies_hi += ((freq_hi - freq_lo) / 2); |
| 119 | jiffies_hi /= (freq_hi - freq_lo); |
| 120 | jiffies_lo = jiffies_total - jiffies_hi; |
| 121 | dbs_info->freq_lo = freq_lo; |
| 122 | dbs_info->freq_lo_jiffies = jiffies_lo; |
| 123 | dbs_info->freq_hi_jiffies = jiffies_hi; |
| 124 | return freq_hi; |
| 125 | } |
| 126 | |
| 127 | static void ondemand_powersave_bias_init(void) |
| 128 | { |
| 129 | int i; |
| 130 | for_each_online_cpu(i) { |
| 131 | ondemand_powersave_bias_init_cpu(i); |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq) |
| 136 | { |
| 137 | struct dbs_data *dbs_data = policy->governor_data; |
| 138 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 139 | |
| 140 | if (od_tuners->powersave_bias) |
| 141 | freq = od_ops.powersave_bias_target(policy, freq, |
| 142 | CPUFREQ_RELATION_H); |
| 143 | else if (policy->cur == policy->max) |
| 144 | return; |
| 145 | |
| 146 | __cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ? |
| 147 | CPUFREQ_RELATION_L : CPUFREQ_RELATION_H); |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * Every sampling_rate, we check, if current idle time is less than 20% |
| 152 | * (default), then we try to increase frequency. Else, we adjust the frequency |
| 153 | * proportional to load. |
| 154 | */ |
| 155 | static void od_check_cpu(int cpu, unsigned int load) |
| 156 | { |
| 157 | struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| 158 | struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy; |
| 159 | struct dbs_data *dbs_data = policy->governor_data; |
| 160 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 161 | |
| 162 | dbs_info->freq_lo = 0; |
| 163 | |
| 164 | /* Check for frequency increase */ |
| 165 | if (load > od_tuners->up_threshold) { |
| 166 | /* If switching to max speed, apply sampling_down_factor */ |
| 167 | if (policy->cur < policy->max) |
| 168 | dbs_info->rate_mult = |
| 169 | od_tuners->sampling_down_factor; |
| 170 | dbs_freq_increase(policy, policy->max); |
| 171 | } else { |
| 172 | /* Calculate the next frequency proportional to load */ |
| 173 | unsigned int freq_next, min_f, max_f; |
| 174 | |
| 175 | min_f = policy->cpuinfo.min_freq; |
| 176 | max_f = policy->cpuinfo.max_freq; |
| 177 | freq_next = min_f + load * (max_f - min_f) / 100; |
| 178 | |
| 179 | /* No longer fully busy, reset rate_mult */ |
| 180 | dbs_info->rate_mult = 1; |
| 181 | |
| 182 | if (!od_tuners->powersave_bias) { |
| 183 | __cpufreq_driver_target(policy, freq_next, |
| 184 | CPUFREQ_RELATION_C); |
| 185 | return; |
| 186 | } |
| 187 | |
| 188 | freq_next = od_ops.powersave_bias_target(policy, freq_next, |
| 189 | CPUFREQ_RELATION_L); |
| 190 | __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_C); |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | static void od_dbs_timer(struct work_struct *work) |
| 195 | { |
| 196 | struct od_cpu_dbs_info_s *dbs_info = |
| 197 | container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work); |
| 198 | unsigned int cpu = dbs_info->cdbs.cur_policy->cpu; |
| 199 | struct od_cpu_dbs_info_s *core_dbs_info = &per_cpu(od_cpu_dbs_info, |
| 200 | cpu); |
| 201 | struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data; |
| 202 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 203 | int delay = 0, sample_type = core_dbs_info->sample_type; |
| 204 | bool modify_all = true; |
| 205 | |
| 206 | mutex_lock(&core_dbs_info->cdbs.timer_mutex); |
| 207 | if (!need_load_eval(&core_dbs_info->cdbs, od_tuners->sampling_rate)) { |
| 208 | modify_all = false; |
| 209 | goto max_delay; |
| 210 | } |
| 211 | |
| 212 | /* Common NORMAL_SAMPLE setup */ |
| 213 | core_dbs_info->sample_type = OD_NORMAL_SAMPLE; |
| 214 | if (sample_type == OD_SUB_SAMPLE) { |
| 215 | delay = core_dbs_info->freq_lo_jiffies; |
| 216 | __cpufreq_driver_target(core_dbs_info->cdbs.cur_policy, |
| 217 | core_dbs_info->freq_lo, CPUFREQ_RELATION_H); |
| 218 | } else { |
| 219 | dbs_check_cpu(dbs_data, cpu); |
| 220 | if (core_dbs_info->freq_lo) { |
| 221 | /* Setup timer for SUB_SAMPLE */ |
| 222 | core_dbs_info->sample_type = OD_SUB_SAMPLE; |
| 223 | delay = core_dbs_info->freq_hi_jiffies; |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | max_delay: |
| 228 | if (!delay) |
| 229 | delay = delay_for_sampling_rate(od_tuners->sampling_rate |
| 230 | * core_dbs_info->rate_mult); |
| 231 | |
| 232 | gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all); |
| 233 | mutex_unlock(&core_dbs_info->cdbs.timer_mutex); |
| 234 | } |
| 235 | |
| 236 | /************************** sysfs interface ************************/ |
| 237 | static struct common_dbs_data od_dbs_cdata; |
| 238 | |
| 239 | /** |
| 240 | * update_sampling_rate - update sampling rate effective immediately if needed. |
| 241 | * @new_rate: new sampling rate |
| 242 | * |
| 243 | * If new rate is smaller than the old, simply updating |
| 244 | * dbs_tuners_int.sampling_rate might not be appropriate. For example, if the |
| 245 | * original sampling_rate was 1 second and the requested new sampling rate is 10 |
| 246 | * ms because the user needs immediate reaction from ondemand governor, but not |
| 247 | * sure if higher frequency will be required or not, then, the governor may |
| 248 | * change the sampling rate too late; up to 1 second later. Thus, if we are |
| 249 | * reducing the sampling rate, we need to make the new value effective |
| 250 | * immediately. |
| 251 | */ |
| 252 | static void update_sampling_rate(struct dbs_data *dbs_data, |
| 253 | unsigned int new_rate) |
| 254 | { |
| 255 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 256 | int cpu; |
| 257 | |
| 258 | od_tuners->sampling_rate = new_rate = max(new_rate, |
| 259 | dbs_data->min_sampling_rate); |
| 260 | |
| 261 | for_each_online_cpu(cpu) { |
| 262 | struct cpufreq_policy *policy; |
| 263 | struct od_cpu_dbs_info_s *dbs_info; |
| 264 | unsigned long next_sampling, appointed_at; |
| 265 | |
| 266 | policy = cpufreq_cpu_get(cpu); |
| 267 | if (!policy) |
| 268 | continue; |
| 269 | if (policy->governor != &cpufreq_gov_ondemand) { |
| 270 | cpufreq_cpu_put(policy); |
| 271 | continue; |
| 272 | } |
| 273 | dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| 274 | cpufreq_cpu_put(policy); |
| 275 | |
| 276 | mutex_lock(&dbs_info->cdbs.timer_mutex); |
| 277 | |
| 278 | if (!delayed_work_pending(&dbs_info->cdbs.work)) { |
| 279 | mutex_unlock(&dbs_info->cdbs.timer_mutex); |
| 280 | continue; |
| 281 | } |
| 282 | |
| 283 | next_sampling = jiffies + usecs_to_jiffies(new_rate); |
| 284 | appointed_at = dbs_info->cdbs.work.timer.expires; |
| 285 | |
| 286 | if (time_before(next_sampling, appointed_at)) { |
| 287 | |
| 288 | mutex_unlock(&dbs_info->cdbs.timer_mutex); |
| 289 | cancel_delayed_work_sync(&dbs_info->cdbs.work); |
| 290 | mutex_lock(&dbs_info->cdbs.timer_mutex); |
| 291 | |
| 292 | gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, |
| 293 | usecs_to_jiffies(new_rate), true); |
| 294 | |
| 295 | } |
| 296 | mutex_unlock(&dbs_info->cdbs.timer_mutex); |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf, |
| 301 | size_t count) |
| 302 | { |
| 303 | unsigned int input; |
| 304 | int ret; |
| 305 | ret = sscanf(buf, "%u", &input); |
| 306 | if (ret != 1) |
| 307 | return -EINVAL; |
| 308 | |
| 309 | update_sampling_rate(dbs_data, input); |
| 310 | return count; |
| 311 | } |
| 312 | |
| 313 | static ssize_t store_io_is_busy(struct dbs_data *dbs_data, const char *buf, |
| 314 | size_t count) |
| 315 | { |
| 316 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 317 | unsigned int input; |
| 318 | int ret; |
| 319 | unsigned int j; |
| 320 | |
| 321 | ret = sscanf(buf, "%u", &input); |
| 322 | if (ret != 1) |
| 323 | return -EINVAL; |
| 324 | od_tuners->io_is_busy = !!input; |
| 325 | |
| 326 | /* we need to re-evaluate prev_cpu_idle */ |
| 327 | for_each_online_cpu(j) { |
| 328 | struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, |
| 329 | j); |
| 330 | dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, |
| 331 | &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy); |
| 332 | } |
| 333 | return count; |
| 334 | } |
| 335 | |
| 336 | static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf, |
| 337 | size_t count) |
| 338 | { |
| 339 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 340 | unsigned int input; |
| 341 | int ret; |
| 342 | ret = sscanf(buf, "%u", &input); |
| 343 | |
| 344 | if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || |
| 345 | input < MIN_FREQUENCY_UP_THRESHOLD) { |
| 346 | return -EINVAL; |
| 347 | } |
| 348 | |
| 349 | od_tuners->up_threshold = input; |
| 350 | return count; |
| 351 | } |
| 352 | |
| 353 | static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data, |
| 354 | const char *buf, size_t count) |
| 355 | { |
| 356 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 357 | unsigned int input, j; |
| 358 | int ret; |
| 359 | ret = sscanf(buf, "%u", &input); |
| 360 | |
| 361 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
| 362 | return -EINVAL; |
| 363 | od_tuners->sampling_down_factor = input; |
| 364 | |
| 365 | /* Reset down sampling multiplier in case it was active */ |
| 366 | for_each_online_cpu(j) { |
| 367 | struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, |
| 368 | j); |
| 369 | dbs_info->rate_mult = 1; |
| 370 | } |
| 371 | return count; |
| 372 | } |
| 373 | |
| 374 | static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data, |
| 375 | const char *buf, size_t count) |
| 376 | { |
| 377 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 378 | unsigned int input; |
| 379 | int ret; |
| 380 | |
| 381 | unsigned int j; |
| 382 | |
| 383 | ret = sscanf(buf, "%u", &input); |
| 384 | if (ret != 1) |
| 385 | return -EINVAL; |
| 386 | |
| 387 | if (input > 1) |
| 388 | input = 1; |
| 389 | |
| 390 | if (input == od_tuners->ignore_nice_load) { /* nothing to do */ |
| 391 | return count; |
| 392 | } |
| 393 | od_tuners->ignore_nice_load = input; |
| 394 | |
| 395 | /* we need to re-evaluate prev_cpu_idle */ |
| 396 | for_each_online_cpu(j) { |
| 397 | struct od_cpu_dbs_info_s *dbs_info; |
| 398 | dbs_info = &per_cpu(od_cpu_dbs_info, j); |
| 399 | dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, |
| 400 | &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy); |
| 401 | if (od_tuners->ignore_nice_load) |
| 402 | dbs_info->cdbs.prev_cpu_nice = |
| 403 | kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| 404 | |
| 405 | } |
| 406 | return count; |
| 407 | } |
| 408 | |
| 409 | static ssize_t store_powersave_bias(struct dbs_data *dbs_data, const char *buf, |
| 410 | size_t count) |
| 411 | { |
| 412 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 413 | unsigned int input; |
| 414 | int ret; |
| 415 | ret = sscanf(buf, "%u", &input); |
| 416 | |
| 417 | if (ret != 1) |
| 418 | return -EINVAL; |
| 419 | |
| 420 | if (input > 1000) |
| 421 | input = 1000; |
| 422 | |
| 423 | od_tuners->powersave_bias = input; |
| 424 | ondemand_powersave_bias_init(); |
| 425 | return count; |
| 426 | } |
| 427 | |
| 428 | show_store_one(od, sampling_rate); |
| 429 | show_store_one(od, io_is_busy); |
| 430 | show_store_one(od, up_threshold); |
| 431 | show_store_one(od, sampling_down_factor); |
| 432 | show_store_one(od, ignore_nice_load); |
| 433 | show_store_one(od, powersave_bias); |
| 434 | declare_show_sampling_rate_min(od); |
| 435 | |
| 436 | gov_sys_pol_attr_rw(sampling_rate); |
| 437 | gov_sys_pol_attr_rw(io_is_busy); |
| 438 | gov_sys_pol_attr_rw(up_threshold); |
| 439 | gov_sys_pol_attr_rw(sampling_down_factor); |
| 440 | gov_sys_pol_attr_rw(ignore_nice_load); |
| 441 | gov_sys_pol_attr_rw(powersave_bias); |
| 442 | gov_sys_pol_attr_ro(sampling_rate_min); |
| 443 | |
| 444 | static struct attribute *dbs_attributes_gov_sys[] = { |
| 445 | &sampling_rate_min_gov_sys.attr, |
| 446 | &sampling_rate_gov_sys.attr, |
| 447 | &up_threshold_gov_sys.attr, |
| 448 | &sampling_down_factor_gov_sys.attr, |
| 449 | &ignore_nice_load_gov_sys.attr, |
| 450 | &powersave_bias_gov_sys.attr, |
| 451 | &io_is_busy_gov_sys.attr, |
| 452 | NULL |
| 453 | }; |
| 454 | |
| 455 | static struct attribute_group od_attr_group_gov_sys = { |
| 456 | .attrs = dbs_attributes_gov_sys, |
| 457 | .name = "ondemand", |
| 458 | }; |
| 459 | |
| 460 | static struct attribute *dbs_attributes_gov_pol[] = { |
| 461 | &sampling_rate_min_gov_pol.attr, |
| 462 | &sampling_rate_gov_pol.attr, |
| 463 | &up_threshold_gov_pol.attr, |
| 464 | &sampling_down_factor_gov_pol.attr, |
| 465 | &ignore_nice_load_gov_pol.attr, |
| 466 | &powersave_bias_gov_pol.attr, |
| 467 | &io_is_busy_gov_pol.attr, |
| 468 | NULL |
| 469 | }; |
| 470 | |
| 471 | static struct attribute_group od_attr_group_gov_pol = { |
| 472 | .attrs = dbs_attributes_gov_pol, |
| 473 | .name = "ondemand", |
| 474 | }; |
| 475 | |
| 476 | /************************** sysfs end ************************/ |
| 477 | |
| 478 | static int od_init(struct dbs_data *dbs_data) |
| 479 | { |
| 480 | struct od_dbs_tuners *tuners; |
| 481 | u64 idle_time; |
| 482 | int cpu; |
| 483 | |
| 484 | tuners = kzalloc(sizeof(*tuners), GFP_KERNEL); |
| 485 | if (!tuners) { |
| 486 | pr_err("%s: kzalloc failed\n", __func__); |
| 487 | return -ENOMEM; |
| 488 | } |
| 489 | |
| 490 | cpu = get_cpu(); |
| 491 | idle_time = get_cpu_idle_time_us(cpu, NULL); |
| 492 | put_cpu(); |
| 493 | if (idle_time != -1ULL) { |
| 494 | /* Idle micro accounting is supported. Use finer thresholds */ |
| 495 | tuners->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; |
| 496 | /* |
| 497 | * In nohz/micro accounting case we set the minimum frequency |
| 498 | * not depending on HZ, but fixed (very low). The deferred |
| 499 | * timer might skip some samples if idle/sleeping as needed. |
| 500 | */ |
| 501 | dbs_data->min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; |
| 502 | } else { |
| 503 | tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD; |
| 504 | |
| 505 | /* For correct statistics, we need 10 ticks for each measure */ |
| 506 | dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO * |
| 507 | jiffies_to_usecs(10); |
| 508 | } |
| 509 | |
| 510 | tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; |
| 511 | tuners->ignore_nice_load = 0; |
| 512 | tuners->powersave_bias = default_powersave_bias; |
| 513 | tuners->io_is_busy = should_io_be_busy(); |
| 514 | |
| 515 | dbs_data->tuners = tuners; |
| 516 | mutex_init(&dbs_data->mutex); |
| 517 | return 0; |
| 518 | } |
| 519 | |
| 520 | static void od_exit(struct dbs_data *dbs_data) |
| 521 | { |
| 522 | kfree(dbs_data->tuners); |
| 523 | } |
| 524 | |
| 525 | define_get_cpu_dbs_routines(od_cpu_dbs_info); |
| 526 | |
| 527 | static struct od_ops od_ops = { |
| 528 | .powersave_bias_init_cpu = ondemand_powersave_bias_init_cpu, |
| 529 | .powersave_bias_target = generic_powersave_bias_target, |
| 530 | .freq_increase = dbs_freq_increase, |
| 531 | }; |
| 532 | |
| 533 | static struct common_dbs_data od_dbs_cdata = { |
| 534 | .governor = GOV_ONDEMAND, |
| 535 | .attr_group_gov_sys = &od_attr_group_gov_sys, |
| 536 | .attr_group_gov_pol = &od_attr_group_gov_pol, |
| 537 | .get_cpu_cdbs = get_cpu_cdbs, |
| 538 | .get_cpu_dbs_info_s = get_cpu_dbs_info_s, |
| 539 | .gov_dbs_timer = od_dbs_timer, |
| 540 | .gov_check_cpu = od_check_cpu, |
| 541 | .gov_ops = &od_ops, |
| 542 | .init = od_init, |
| 543 | .exit = od_exit, |
| 544 | }; |
| 545 | |
| 546 | static void od_set_powersave_bias(unsigned int powersave_bias) |
| 547 | { |
| 548 | struct cpufreq_policy *policy; |
| 549 | struct dbs_data *dbs_data; |
| 550 | struct od_dbs_tuners *od_tuners; |
| 551 | unsigned int cpu; |
| 552 | cpumask_t done; |
| 553 | |
| 554 | default_powersave_bias = powersave_bias; |
| 555 | cpumask_clear(&done); |
| 556 | |
| 557 | get_online_cpus(); |
| 558 | for_each_online_cpu(cpu) { |
| 559 | if (cpumask_test_cpu(cpu, &done)) |
| 560 | continue; |
| 561 | |
| 562 | policy = per_cpu(od_cpu_dbs_info, cpu).cdbs.cur_policy; |
| 563 | if (!policy) |
| 564 | continue; |
| 565 | |
| 566 | cpumask_or(&done, &done, policy->cpus); |
| 567 | |
| 568 | if (policy->governor != &cpufreq_gov_ondemand) |
| 569 | continue; |
| 570 | |
| 571 | dbs_data = policy->governor_data; |
| 572 | od_tuners = dbs_data->tuners; |
| 573 | od_tuners->powersave_bias = default_powersave_bias; |
| 574 | } |
| 575 | put_online_cpus(); |
| 576 | } |
| 577 | |
| 578 | void od_register_powersave_bias_handler(unsigned int (*f) |
| 579 | (struct cpufreq_policy *, unsigned int, unsigned int), |
| 580 | unsigned int powersave_bias) |
| 581 | { |
| 582 | od_ops.powersave_bias_target = f; |
| 583 | od_set_powersave_bias(powersave_bias); |
| 584 | } |
| 585 | EXPORT_SYMBOL_GPL(od_register_powersave_bias_handler); |
| 586 | |
| 587 | void od_unregister_powersave_bias_handler(void) |
| 588 | { |
| 589 | od_ops.powersave_bias_target = generic_powersave_bias_target; |
| 590 | od_set_powersave_bias(0); |
| 591 | } |
| 592 | EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler); |
| 593 | |
| 594 | static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy, |
| 595 | unsigned int event) |
| 596 | { |
| 597 | return cpufreq_governor_dbs(policy, &od_dbs_cdata, event); |
| 598 | } |
| 599 | |
| 600 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
| 601 | static |
| 602 | #endif |
| 603 | struct cpufreq_governor cpufreq_gov_ondemand = { |
| 604 | .name = "ondemand", |
| 605 | .governor = od_cpufreq_governor_dbs, |
| 606 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, |
| 607 | .owner = THIS_MODULE, |
| 608 | }; |
| 609 | |
| 610 | static int __init cpufreq_gov_dbs_init(void) |
| 611 | { |
| 612 | return cpufreq_register_governor(&cpufreq_gov_ondemand); |
| 613 | } |
| 614 | |
| 615 | static void __exit cpufreq_gov_dbs_exit(void) |
| 616 | { |
| 617 | cpufreq_unregister_governor(&cpufreq_gov_ondemand); |
| 618 | } |
| 619 | |
| 620 | MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); |
| 621 | MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); |
| 622 | MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " |
| 623 | "Low Latency Frequency Transition capable processors"); |
| 624 | MODULE_LICENSE("GPL"); |
| 625 | |
| 626 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
| 627 | fs_initcall(cpufreq_gov_dbs_init); |
| 628 | #else |
| 629 | module_init(cpufreq_gov_dbs_init); |
| 630 | #endif |
| 631 | module_exit(cpufreq_gov_dbs_exit); |