drivers/cpufreq/cpufreq_interactive.c

   1 /*
   2  * drivers/cpufreq/cpufreq_interactive.c
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * Author: Mike Chan (mike@android.com)
  16  *
  17  */
  18
  19 #include <linux/cpu.h>
  20 #include <linux/cpumask.h>
  21 #include <linux/cpufreq.h>
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/mutex.h>
  25 #include <linux/sched.h>
  26 #include <linux/sched/rt.h>
  27 #include <linux/tick.h>
  28 #include <linux/time.h>
  29 #include <linux/timer.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/kthread.h>
  32 #include <linux/mutex.h>
  33 #include <linux/slab.h>
  34 #include <asm/cputime.h>
  35
  36 #define CREATE_TRACE_POINTS
  37 #include <trace/events/cpufreq_interactive.h>
  38
  39 static atomic_t active_count = ATOMIC_INIT(0);
  40
  41 struct cpufreq_interactive_cpuinfo {
  42         struct timer_list cpu_timer;
  43         struct timer_list cpu_slack_timer;
  44         spinlock_t load_lock; /* protects the next 4 fields */
  45         u64 time_in_idle;
  46         u64 time_in_idle_timestamp;
  47         u64 cputime_speedadj;
  48         u64 cputime_speedadj_timestamp;
  49         struct cpufreq_policy *policy;
  50         struct cpufreq_frequency_table *freq_table;
  51         unsigned int target_freq;
  52         unsigned int floor_freq;
  53         u64 floor_validate_time;
  54         u64 hispeed_validate_time;
  55         int governor_enabled;
  56 };
  57
  58 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  59
  60 /* realtime thread handles frequency scaling */
  61 static struct task_struct *speedchange_task;
  62 static cpumask_t speedchange_cpumask;
  63 static spinlock_t speedchange_cpumask_lock;
  64
  65 /* Hi speed to bump to from lo speed when load burst (default max) */
  66 static unsigned int hispeed_freq;
  67
  68 /* Go to hi speed when CPU load at or above this value. */
  69 #define DEFAULT_GO_HISPEED_LOAD 85
  70 static unsigned long go_hispeed_load;
  71
  72 /* Target load.  Lower values result in higher CPU speeds. */
  73 #define DEFAULT_TARGET_LOAD 90
  74 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  75 static spinlock_t target_loads_lock;
  76 static unsigned int *target_loads = default_target_loads;
  77 static int ntarget_loads = ARRAY_SIZE(default_target_loads);
  78
  79 /*
  80  * The minimum amount of time to spend at a frequency before we can ramp down.
  81  */
  82 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  83 static unsigned long min_sample_time;
  84
  85 /*
  86  * The sample rate of the timer used to increase frequency
  87  */
  88 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  89 static unsigned long timer_rate;
  90
  91 /*
  92  * Wait this long before raising speed above hispeed, by default a single
  93  * timer interval.
  94  */
  95 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  96 static unsigned long above_hispeed_delay_val;
  97
  98 /* Non-zero means indefinite speed boost active */
  99 static int boost_val;
 100 /* Duration of a boot pulse in usecs */
 101 static int boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
 102 /* End time of boost pulse in ktime converted to usecs */
 103 static u64 boostpulse_endtime;
 104
 105 /*
 106  * Max additional time to wait in idle, beyond timer_rate, at speeds above
 107  * minimum before wakeup to reduce speed, or -1 if unnecessary.
 108  */
 109 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 110 static int timer_slack_val = DEFAULT_TIMER_SLACK;
 111
 112 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
 113                 unsigned int event);
 114
 115 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
 116 static
 117 #endif
 118 struct cpufreq_governor cpufreq_gov_interactive = {
 119         .name = "interactive",
 120         .governor = cpufreq_governor_interactive,
 121         .max_transition_latency = 10000000,
 122         .owner = THIS_MODULE,
 123 };
 124
 125 static void cpufreq_interactive_timer_resched(
 126         struct cpufreq_interactive_cpuinfo *pcpu)
 127 {
 128         unsigned long expires = jiffies + usecs_to_jiffies(timer_rate);
 129
 130         mod_timer_pinned(&pcpu->cpu_timer, expires);
 131         if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
 132                 expires += usecs_to_jiffies(timer_slack_val);
 133                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 134         }
 135
 136         spin_lock(&pcpu->load_lock);
 137         pcpu->time_in_idle =
 138                 get_cpu_idle_time_us(smp_processor_id(),
 139                                      &pcpu->time_in_idle_timestamp);
 140         pcpu->cputime_speedadj = 0;
 141         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 142         spin_unlock(&pcpu->load_lock);
 143 }
 144
 145 static unsigned int freq_to_targetload(unsigned int freq)
 146 {
 147         int i;
 148         unsigned int ret;
 149
 150         spin_lock(&target_loads_lock);
 151
 152         for (i = 0; i < ntarget_loads - 1 && freq >= target_loads[i+1]; i += 2)
 153                 ;
 154
 155         ret = target_loads[i];
 156         spin_unlock(&target_loads_lock);
 157         return ret;
 158 }
 159
 160 /*
 161  * If increasing frequencies never map to a lower target load then
 162  * choose_freq() will find the minimum frequency that does not exceed its
 163  * target load given the current load.
 164  */
 165
 166 static unsigned int choose_freq(
 167         struct cpufreq_interactive_cpuinfo *pcpu, unsigned int loadadjfreq)
 168 {
 169         unsigned int freq = pcpu->policy->cur;
 170         unsigned int prevfreq, freqmin, freqmax;
 171         unsigned int tl;
 172         int index;
 173
 174         freqmin = 0;
 175         freqmax = UINT_MAX;
 176
 177         do {
 178                 prevfreq = freq;
 179                 tl = freq_to_targetload(freq);
 180
 181                 /*
 182                  * Find the lowest frequency where the computed load is less
 183                  * than or equal to the target load.
 184                  */
 185
 186                 cpufreq_frequency_table_target(
 187                         pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 188                         CPUFREQ_RELATION_L, &index);
 189                 freq = pcpu->freq_table[index].frequency;
 190
 191                 if (freq > prevfreq) {
 192                         /* The previous frequency is too low. */
 193                         freqmin = prevfreq;
 194
 195                         if (freq >= freqmax) {
 196                                 /*
 197                                  * Find the highest frequency that is less
 198                                  * than freqmax.
 199                                  */
 200                                 cpufreq_frequency_table_target(
 201                                         pcpu->policy, pcpu->freq_table,
 202                                         freqmax - 1, CPUFREQ_RELATION_H,
 203                                         &index);
 204                                 freq = pcpu->freq_table[index].frequency;
 205
 206                                 if (freq == freqmin) {
 207                                         /*
 208                                          * The first frequency below freqmax
 209                                          * has already been found to be too
 210                                          * low.  freqmax is the lowest speed
 211                                          * we found that is fast enough.
 212                                          */
 213                                         freq = freqmax;
 214                                         break;
 215                                 }
 216                         }
 217                 } else if (freq < prevfreq) {
 218                         /* The previous frequency is high enough. */
 219                         freqmax = prevfreq;
 220
 221                         if (freq <= freqmin) {
 222                                 /*
 223                                  * Find the lowest frequency that is higher
 224                                  * than freqmin.
 225                                  */
 226                                 cpufreq_frequency_table_target(
 227                                         pcpu->policy, pcpu->freq_table,
 228                                         freqmin + 1, CPUFREQ_RELATION_L,
 229                                         &index);
 230                                 freq = pcpu->freq_table[index].frequency;
 231
 232                                 /*
 233                                  * If freqmax is the first frequency above
 234                                  * freqmin then we have already found that
 235                                  * this speed is fast enough.
 236                                  */
 237                                 if (freq == freqmax)
 238                                         break;
 239                         }
 240                 }
 241
 242                 /* If same frequency chosen as previous then done. */
 243         } while (freq != prevfreq);
 244
 245         return freq;
 246 }
 247
 248 static u64 update_load(int cpu)
 249 {
 250         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 251         u64 now;
 252         u64 now_idle;
 253         unsigned int delta_idle;
 254         unsigned int delta_time;
 255         u64 active_time;
 256
 257         now_idle = get_cpu_idle_time_us(cpu, &now);
 258         delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
 259         delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
 260         active_time = delta_time - delta_idle;
 261         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 262
 263         pcpu->time_in_idle = now_idle;
 264         pcpu->time_in_idle_timestamp = now;
 265         return now;
 266 }
 267
 268 static void cpufreq_interactive_timer(unsigned long data)
 269 {
 270         u64 now;
 271         unsigned int delta_time;
 272         u64 cputime_speedadj;
 273         int cpu_load;
 274         struct cpufreq_interactive_cpuinfo *pcpu =
 275                 &per_cpu(cpuinfo, data);
 276         unsigned int new_freq;
 277         unsigned int loadadjfreq;
 278         unsigned int index;
 279         unsigned long flags;
 280         bool boosted;
 281
 282         smp_rmb();
 283
 284         if (!pcpu->governor_enabled)
 285                 goto exit;
 286
 287         spin_lock(&pcpu->load_lock);
 288         now = update_load(data);
 289         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 290         cputime_speedadj = pcpu->cputime_speedadj;
 291         spin_unlock(&pcpu->load_lock);
 292
 293         if (WARN_ON_ONCE(!delta_time))
 294                 goto rearm;
 295
 296         do_div(cputime_speedadj, delta_time);
 297         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 298         cpu_load = loadadjfreq / pcpu->target_freq;
 299         boosted = boost_val || now < boostpulse_endtime;
 300
 301         if ((cpu_load >= go_hispeed_load || boosted) &&
 302             pcpu->target_freq < hispeed_freq)
 303                 new_freq = hispeed_freq;
 304         else
 305                 new_freq = choose_freq(pcpu, loadadjfreq);
 306
 307         if (pcpu->target_freq >= hispeed_freq &&
 308             new_freq > pcpu->target_freq &&
 309             now - pcpu->hispeed_validate_time < above_hispeed_delay_val) {
 310                 trace_cpufreq_interactive_notyet(
 311                         data, cpu_load, pcpu->target_freq,
 312                         pcpu->policy->cur, new_freq);
 313                 goto rearm;
 314         }
 315
 316         pcpu->hispeed_validate_time = now;
 317
 318         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 319                                            new_freq, CPUFREQ_RELATION_L,
 320                                            &index)) {
 321                 pr_warn_once("timer %d: cpufreq_frequency_table_target error\n",
 322                              (int) data);
 323                 goto rearm;
 324         }
 325
 326         new_freq = pcpu->freq_table[index].frequency;
 327
 328         /*
 329          * Do not scale below floor_freq unless we have been at or above the
 330          * floor frequency for the minimum sample time since last validated.
 331          */
 332         if (new_freq < pcpu->floor_freq) {
 333                 if (now - pcpu->floor_validate_time < min_sample_time) {
 334                         trace_cpufreq_interactive_notyet(
 335                                 data, cpu_load, pcpu->target_freq,
 336                                 pcpu->policy->cur, new_freq);
 337                         goto rearm;
 338                 }
 339         }
 340
 341         /*
 342          * Update the timestamp for checking whether speed has been held at
 343          * or above the selected frequency for a minimum of min_sample_time,
 344          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 345          * allow the speed to drop as soon as the boostpulse duration expires
 346          * (or the indefinite boost is turned off).
 347          */
 348
 349         if (!boosted || new_freq > hispeed_freq) {
 350                 pcpu->floor_freq = new_freq;
 351                 pcpu->floor_validate_time = now;
 352         }
 353
 354         if (pcpu->target_freq == new_freq) {
 355                 trace_cpufreq_interactive_already(
 356                         data, cpu_load, pcpu->target_freq,
 357                         pcpu->policy->cur, new_freq);
 358                 goto rearm_if_notmax;
 359         }
 360
 361         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 362                                          pcpu->policy->cur, new_freq);
 363
 364         pcpu->target_freq = new_freq;
 365         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 366         cpumask_set_cpu(data, &speedchange_cpumask);
 367         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 368         wake_up_process(speedchange_task);
 369
 370 rearm_if_notmax:
 371         /*
 372          * Already set max speed and don't see a need to change that,
 373          * wait until next idle to re-evaluate, don't need timer.
 374          */
 375         if (pcpu->target_freq == pcpu->policy->max)
 376                 goto exit;
 377
 378 rearm:
 379         if (!timer_pending(&pcpu->cpu_timer))
 380                 cpufreq_interactive_timer_resched(pcpu);
 381
 382 exit:
 383         return;
 384 }
 385
 386 static void cpufreq_interactive_idle_start(void)
 387 {
 388         struct cpufreq_interactive_cpuinfo *pcpu =
 389                 &per_cpu(cpuinfo, smp_processor_id());
 390         int pending;
 391
 392         if (!pcpu->governor_enabled)
 393                 return;
 394
 395         pending = timer_pending(&pcpu->cpu_timer);
 396
 397         if (pcpu->target_freq != pcpu->policy->min) {
 398                 /*
 399                  * Entering idle while not at lowest speed.  On some
 400                  * platforms this can hold the other CPU(s) at that speed
 401                  * even though the CPU is idle. Set a timer to re-evaluate
 402                  * speed so this idle CPU doesn't hold the other CPUs above
 403                  * min indefinitely.  This should probably be a quirk of
 404                  * the CPUFreq driver.
 405                  */
 406                 if (!pending)
 407                         cpufreq_interactive_timer_resched(pcpu);
 408         }
 409
 410 }
 411
 412 static void cpufreq_interactive_idle_end(void)
 413 {
 414         struct cpufreq_interactive_cpuinfo *pcpu =
 415                 &per_cpu(cpuinfo, smp_processor_id());
 416
 417         if (!pcpu->governor_enabled)
 418                 return;
 419
 420         /* Arm the timer for 1-2 ticks later if not already. */
 421         if (!timer_pending(&pcpu->cpu_timer)) {
 422                 cpufreq_interactive_timer_resched(pcpu);
 423         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 424                 del_timer(&pcpu->cpu_timer);
 425                 del_timer(&pcpu->cpu_slack_timer);
 426                 cpufreq_interactive_timer(smp_processor_id());
 427         }
 428 }
 429
 430 static int cpufreq_interactive_speedchange_task(void *data)
 431 {
 432         unsigned int cpu;
 433         cpumask_t tmp_mask;
 434         unsigned long flags;
 435         struct cpufreq_interactive_cpuinfo *pcpu;
 436
 437         while (1) {
 438                 set_current_state(TASK_INTERRUPTIBLE);
 439                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 440
 441                 if (cpumask_empty(&speedchange_cpumask)) {
 442                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 443                                                flags);
 444                         schedule();
 445
 446                         if (kthread_should_stop())
 447                                 break;
 448
 449                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 450                 }
 451
 452                 set_current_state(TASK_RUNNING);
 453                 tmp_mask = speedchange_cpumask;
 454                 cpumask_clear(&speedchange_cpumask);
 455                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 456
 457                 for_each_cpu(cpu, &tmp_mask) {
 458                         unsigned int j;
 459                         unsigned int max_freq = 0;
 460
 461                         pcpu = &per_cpu(cpuinfo, cpu);
 462                         smp_rmb();
 463
 464                         if (!pcpu->governor_enabled)
 465                                 continue;
 466
 467                         for_each_cpu(j, pcpu->policy->cpus) {
 468                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 469                                         &per_cpu(cpuinfo, j);
 470
 471                                 if (pjcpu->target_freq > max_freq)
 472                                         max_freq = pjcpu->target_freq;
 473                         }
 474
 475                         if (max_freq != pcpu->policy->cur)
 476                                 __cpufreq_driver_target(pcpu->policy,
 477                                                         max_freq,
 478                                                         CPUFREQ_RELATION_H);
 479                         trace_cpufreq_interactive_setspeed(cpu,
 480                                                      pcpu->target_freq,
 481                                                      pcpu->policy->cur);
 482                 }
 483         }
 484
 485         return 0;
 486 }
 487
 488 static void cpufreq_interactive_boost(void)
 489 {
 490         int i;
 491         int anyboost = 0;
 492         unsigned long flags;
 493         struct cpufreq_interactive_cpuinfo *pcpu;
 494
 495         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 496
 497         for_each_online_cpu(i) {
 498                 pcpu = &per_cpu(cpuinfo, i);
 499
 500                 if (pcpu->target_freq < hispeed_freq) {
 501                         pcpu->target_freq = hispeed_freq;
 502                         cpumask_set_cpu(i, &speedchange_cpumask);
 503                         pcpu->hispeed_validate_time =
 504                                 ktime_to_us(ktime_get());
 505                         anyboost = 1;
 506                 }
 507
 508                 /*
 509                  * Set floor freq and (re)start timer for when last
 510                  * validated.
 511                  */
 512
 513                 pcpu->floor_freq = hispeed_freq;
 514                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 515         }
 516
 517         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 518
 519         if (anyboost)
 520                 wake_up_process(speedchange_task);
 521 }
 522
 523 static int cpufreq_interactive_notifier(
 524         struct notifier_block *nb, unsigned long val, void *data)
 525 {
 526         struct cpufreq_freqs *freq = data;
 527         struct cpufreq_interactive_cpuinfo *pcpu;
 528         int cpu;
 529
 530         if (val == CPUFREQ_POSTCHANGE) {
 531                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 532
 533                 for_each_cpu(cpu, pcpu->policy->cpus) {
 534                         struct cpufreq_interactive_cpuinfo *pjcpu =
 535                                 &per_cpu(cpuinfo, cpu);
 536                         spin_lock(&pjcpu->load_lock);
 537                         update_load(cpu);
 538                         spin_unlock(&pjcpu->load_lock);
 539                 }
 540         }
 541
 542         return 0;
 543 }
 544
 545 static struct notifier_block cpufreq_notifier_block = {
 546         .notifier_call = cpufreq_interactive_notifier,
 547 };
 548
 549 static ssize_t show_target_loads(
 550         struct kobject *kobj, struct attribute *attr, char *buf)
 551 {
 552         int i;
 553         ssize_t ret = 0;
 554
 555         spin_lock(&target_loads_lock);
 556
 557         for (i = 0; i < ntarget_loads; i++)
 558                 ret += sprintf(buf + ret, "%u%s", target_loads[i],
 559                                i & 0x1 ? ":" : " ");
 560
 561         ret += sprintf(buf + ret, "\n");
 562         spin_unlock(&target_loads_lock);
 563         return ret;
 564 }
 565
 566 static ssize_t store_target_loads(
 567         struct kobject *kobj, struct attribute *attr, const char *buf,
 568         size_t count)
 569 {
 570         int ret;
 571         const char *cp;
 572         unsigned int *new_target_loads = NULL;
 573         int ntokens = 1;
 574         int i;
 575
 576         cp = buf;
 577         while ((cp = strpbrk(cp + 1, " :")))
 578                 ntokens++;
 579
 580         if (!(ntokens & 0x1))
 581                 goto err_inval;
 582
 583         new_target_loads = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 584         if (!new_target_loads) {
 585                 ret = -ENOMEM;
 586                 goto err;
 587         }
 588
 589         cp = buf;
 590         i = 0;
 591         while (i < ntokens) {
 592                 if (sscanf(cp, "%u", &new_target_loads[i++]) != 1)
 593                         goto err_inval;
 594
 595                 cp = strpbrk(cp, " :");
 596                 if (!cp)
 597                         break;
 598                 cp++;
 599         }
 600
 601         if (i != ntokens)
 602                 goto err_inval;
 603
 604         spin_lock(&target_loads_lock);
 605         if (target_loads != default_target_loads)
 606                 kfree(target_loads);
 607         target_loads = new_target_loads;
 608         ntarget_loads = ntokens;
 609         spin_unlock(&target_loads_lock);
 610         return count;
 611
 612 err_inval:
 613         ret = -EINVAL;
 614 err:
 615         kfree(new_target_loads);
 616         return ret;
 617 }
 618
 619 static struct global_attr target_loads_attr =
 620         __ATTR(target_loads, S_IRUGO | S_IWUSR,
 621                 show_target_loads, store_target_loads);
 622
 623 static ssize_t show_hispeed_freq(struct kobject *kobj,
 624                                  struct attribute *attr, char *buf)
 625 {
 626         return sprintf(buf, "%u\n", hispeed_freq);
 627 }
 628
 629 static ssize_t store_hispeed_freq(struct kobject *kobj,
 630                                   struct attribute *attr, const char *buf,
 631                                   size_t count)
 632 {
 633         int ret;
 634         long unsigned int val;
 635
 636         ret = strict_strtoul(buf, 0, &val);
 637         if (ret < 0)
 638                 return ret;
 639         hispeed_freq = val;
 640         return count;
 641 }
 642
 643 static struct global_attr hispeed_freq_attr = __ATTR(hispeed_freq, 0644,
 644                 show_hispeed_freq, store_hispeed_freq);
 645
 646
 647 static ssize_t show_go_hispeed_load(struct kobject *kobj,
 648                                      struct attribute *attr, char *buf)
 649 {
 650         return sprintf(buf, "%lu\n", go_hispeed_load);
 651 }
 652
 653 static ssize_t store_go_hispeed_load(struct kobject *kobj,
 654                         struct attribute *attr, const char *buf, size_t count)
 655 {
 656         int ret;
 657         unsigned long val;
 658
 659         ret = strict_strtoul(buf, 0, &val);
 660         if (ret < 0)
 661                 return ret;
 662         go_hispeed_load = val;
 663         return count;
 664 }
 665
 666 static struct global_attr go_hispeed_load_attr = __ATTR(go_hispeed_load, 0644,
 667                 show_go_hispeed_load, store_go_hispeed_load);
 668
 669 static ssize_t show_min_sample_time(struct kobject *kobj,
 670                                 struct attribute *attr, char *buf)
 671 {
 672         return sprintf(buf, "%lu\n", min_sample_time);
 673 }
 674
 675 static ssize_t store_min_sample_time(struct kobject *kobj,
 676                         struct attribute *attr, const char *buf, size_t count)
 677 {
 678         int ret;
 679         unsigned long val;
 680
 681         ret = strict_strtoul(buf, 0, &val);
 682         if (ret < 0)
 683                 return ret;
 684         min_sample_time = val;
 685         return count;
 686 }
 687
 688 static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,
 689                 show_min_sample_time, store_min_sample_time);
 690
 691 static ssize_t show_above_hispeed_delay(struct kobject *kobj,
 692                                         struct attribute *attr, char *buf)
 693 {
 694         return sprintf(buf, "%lu\n", above_hispeed_delay_val);
 695 }
 696
 697 static ssize_t store_above_hispeed_delay(struct kobject *kobj,
 698                                          struct attribute *attr,
 699                                          const char *buf, size_t count)
 700 {
 701         int ret;
 702         unsigned long val;
 703
 704         ret = strict_strtoul(buf, 0, &val);
 705         if (ret < 0)
 706                 return ret;
 707         above_hispeed_delay_val = val;
 708         return count;
 709 }
 710
 711 define_one_global_rw(above_hispeed_delay);
 712
 713 static ssize_t show_timer_rate(struct kobject *kobj,
 714                         struct attribute *attr, char *buf)
 715 {
 716         return sprintf(buf, "%lu\n", timer_rate);
 717 }
 718
 719 static ssize_t store_timer_rate(struct kobject *kobj,
 720                         struct attribute *attr, const char *buf, size_t count)
 721 {
 722         int ret;
 723         unsigned long val;
 724
 725         ret = strict_strtoul(buf, 0, &val);
 726         if (ret < 0)
 727                 return ret;
 728         timer_rate = val;
 729         return count;
 730 }
 731
 732 static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
 733                 show_timer_rate, store_timer_rate);
 734
 735 static ssize_t show_timer_slack(
 736         struct kobject *kobj, struct attribute *attr, char *buf)
 737 {
 738         return sprintf(buf, "%d\n", timer_slack_val);
 739 }
 740
 741 static ssize_t store_timer_slack(
 742         struct kobject *kobj, struct attribute *attr, const char *buf,
 743         size_t count)
 744 {
 745         int ret;
 746         unsigned long val;
 747
 748         ret = kstrtol(buf, 10, &val);
 749         if (ret < 0)
 750                 return ret;
 751
 752         timer_slack_val = val;
 753         return count;
 754 }
 755
 756 define_one_global_rw(timer_slack);
 757
 758 static ssize_t show_boost(struct kobject *kobj, struct attribute *attr,
 759                           char *buf)
 760 {
 761         return sprintf(buf, "%d\n", boost_val);
 762 }
 763
 764 static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
 765                            const char *buf, size_t count)
 766 {
 767         int ret;
 768         unsigned long val;
 769
 770         ret = kstrtoul(buf, 0, &val);
 771         if (ret < 0)
 772                 return ret;
 773
 774         boost_val = val;
 775
 776         if (boost_val) {
 777                 trace_cpufreq_interactive_boost("on");
 778                 cpufreq_interactive_boost();
 779         } else {
 780                 trace_cpufreq_interactive_unboost("off");
 781         }
 782
 783         return count;
 784 }
 785
 786 define_one_global_rw(boost);
 787
 788 static ssize_t store_boostpulse(struct kobject *kobj, struct attribute *attr,
 789                                 const char *buf, size_t count)
 790 {
 791         int ret;
 792         unsigned long val;
 793
 794         ret = kstrtoul(buf, 0, &val);
 795         if (ret < 0)
 796                 return ret;
 797
 798         boostpulse_endtime = ktime_to_us(ktime_get()) + boostpulse_duration_val;
 799         trace_cpufreq_interactive_boost("pulse");
 800         cpufreq_interactive_boost();
 801         return count;
 802 }
 803
 804 static struct global_attr boostpulse =
 805         __ATTR(boostpulse, 0200, NULL, store_boostpulse);
 806
 807 static ssize_t show_boostpulse_duration(
 808         struct kobject *kobj, struct attribute *attr, char *buf)
 809 {
 810         return sprintf(buf, "%d\n", boostpulse_duration_val);
 811 }
 812
 813 static ssize_t store_boostpulse_duration(
 814         struct kobject *kobj, struct attribute *attr, const char *buf,
 815         size_t count)
 816 {
 817         int ret;
 818         unsigned long val;
 819
 820         ret = kstrtoul(buf, 0, &val);
 821         if (ret < 0)
 822                 return ret;
 823
 824         boostpulse_duration_val = val;
 825         return count;
 826 }
 827
 828 define_one_global_rw(boostpulse_duration);
 829
 830 static struct attribute *interactive_attributes[] = {
 831         &target_loads_attr.attr,
 832         &hispeed_freq_attr.attr,
 833         &go_hispeed_load_attr.attr,
 834         &above_hispeed_delay.attr,
 835         &min_sample_time_attr.attr,
 836         &timer_rate_attr.attr,
 837         &timer_slack.attr,
 838         &boost.attr,
 839         &boostpulse.attr,
 840         &boostpulse_duration.attr,
 841         NULL,
 842 };
 843
 844 static struct attribute_group interactive_attr_group = {
 845         .attrs = interactive_attributes,
 846         .name = "interactive",
 847 };
 848
 849 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
 850                                              unsigned long val,
 851                                              void *data)
 852 {
 853         switch (val) {
 854         case IDLE_START:
 855                 cpufreq_interactive_idle_start();
 856                 break;
 857         case IDLE_END:
 858                 cpufreq_interactive_idle_end();
 859                 break;
 860         }
 861
 862         return 0;
 863 }
 864
 865 static struct notifier_block cpufreq_interactive_idle_nb = {
 866         .notifier_call = cpufreq_interactive_idle_notifier,
 867 };
 868
 869 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
 870                 unsigned int event)
 871 {
 872         int rc;
 873         unsigned int j;
 874         struct cpufreq_interactive_cpuinfo *pcpu;
 875         struct cpufreq_frequency_table *freq_table;
 876
 877         switch (event) {
 878         case CPUFREQ_GOV_START:
 879                 if (!cpu_online(policy->cpu))
 880                         return -EINVAL;
 881
 882                 freq_table =
 883                         cpufreq_frequency_get_table(policy->cpu);
 884                 if (!hispeed_freq)
 885                         hispeed_freq = policy->max;
 886
 887                 for_each_cpu(j, policy->cpus) {
 888                         unsigned long expires;
 889
 890                         pcpu = &per_cpu(cpuinfo, j);
 891                         pcpu->policy = policy;
 892                         pcpu->target_freq = policy->cur;
 893                         pcpu->freq_table = freq_table;
 894                         pcpu->floor_freq = pcpu->target_freq;
 895                         pcpu->floor_validate_time =
 896                                 ktime_to_us(ktime_get());
 897                         pcpu->hispeed_validate_time =
 898                                 pcpu->floor_validate_time;
 899                         pcpu->governor_enabled = 1;
 900                         smp_wmb();
 901                         expires = jiffies + usecs_to_jiffies(timer_rate);
 902                         pcpu->cpu_timer.expires = expires;
 903                         add_timer_on(&pcpu->cpu_timer, j);
 904
 905                         if (timer_slack_val >= 0) {
 906                                 expires += usecs_to_jiffies(timer_slack_val);
 907                                 pcpu->cpu_slack_timer.expires = expires;
 908                                 add_timer_on(&pcpu->cpu_slack_timer, j);
 909                         }
 910                 }
 911
 912                 /*
 913                  * Do not register the idle hook and create sysfs
 914                  * entries if we have already done so.
 915                  */
 916                 if (atomic_inc_return(&active_count) > 1)
 917                         return 0;
 918
 919                 rc = sysfs_create_group(cpufreq_global_kobject,
 920                                 &interactive_attr_group);
 921                 if (rc)
 922                         return rc;
 923
 924                 idle_notifier_register(&cpufreq_interactive_idle_nb);
 925                 cpufreq_register_notifier(
 926                         &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 927                 break;
 928
 929         case CPUFREQ_GOV_STOP:
 930                 for_each_cpu(j, policy->cpus) {
 931                         pcpu = &per_cpu(cpuinfo, j);
 932                         pcpu->governor_enabled = 0;
 933                         smp_wmb();
 934                         del_timer_sync(&pcpu->cpu_timer);
 935                         del_timer_sync(&pcpu->cpu_slack_timer);
 936                 }
 937
 938                 if (atomic_dec_return(&active_count) > 0)
 939                         return 0;
 940
 941                 cpufreq_unregister_notifier(
 942                         &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 943                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
 944                 sysfs_remove_group(cpufreq_global_kobject,
 945                                 &interactive_attr_group);
 946
 947                 break;
 948
 949         case CPUFREQ_GOV_LIMITS:
 950                 if (policy->max < policy->cur)
 951                         __cpufreq_driver_target(policy,
 952                                         policy->max, CPUFREQ_RELATION_H);
 953                 else if (policy->min > policy->cur)
 954                         __cpufreq_driver_target(policy,
 955                                         policy->min, CPUFREQ_RELATION_L);
 956                 break;
 957         }
 958         return 0;
 959 }
 960
 961 static void cpufreq_interactive_nop_timer(unsigned long data)
 962 {
 963 }
 964
 965 static int __init cpufreq_interactive_init(void)
 966 {
 967         unsigned int i;
 968         struct cpufreq_interactive_cpuinfo *pcpu;
 969         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 970
 971         go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
 972         min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
 973         above_hispeed_delay_val = DEFAULT_ABOVE_HISPEED_DELAY;
 974         timer_rate = DEFAULT_TIMER_RATE;
 975
 976         /* Initalize per-cpu timers */
 977         for_each_possible_cpu(i) {
 978                 pcpu = &per_cpu(cpuinfo, i);
 979                 init_timer_deferrable(&pcpu->cpu_timer);
 980                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
 981                 pcpu->cpu_timer.data = i;
 982                 init_timer(&pcpu->cpu_slack_timer);
 983                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
 984                 spin_lock_init(&pcpu->load_lock);
 985         }
 986
 987         spin_lock_init(&target_loads_lock);
 988         spin_lock_init(&speedchange_cpumask_lock);
 989         speedchange_task =
 990                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
 991                                "cfinteractive");
 992         if (IS_ERR(speedchange_task))
 993                 return PTR_ERR(speedchange_task);
 994
 995         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
 996         get_task_struct(speedchange_task);
 997
 998         /* NB: wake up so the thread does not look hung to the freezer */
 999         wake_up_process(speedchange_task);
1000
1001         return cpufreq_register_governor(&cpufreq_gov_interactive);
1002 }
1003
1004 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1005 fs_initcall(cpufreq_interactive_init);
1006 #else
1007 module_init(cpufreq_interactive_init);
1008 #endif
1009
1010 static void __exit cpufreq_interactive_exit(void)
1011 {
1012         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1013         kthread_stop(speedchange_task);
1014         put_task_struct(speedchange_task);
1015 }
1016
1017 module_exit(cpufreq_interactive_exit);
1018
1019 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1020 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1021         "Latency sensitive workloads");
1022 MODULE_LICENSE("GPL");