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/rwsem.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/slab.h>
  33
  34 #define CREATE_TRACE_POINTS
  35 #include <trace/events/cpufreq_interactive.h>
  36
  37 struct cpufreq_interactive_cpuinfo {
  38         struct timer_list cpu_timer;
  39         struct timer_list cpu_slack_timer;
  40         spinlock_t load_lock; /* protects the next 4 fields */
  41         u64 time_in_idle;
  42         u64 time_in_idle_timestamp;
  43         u64 cputime_speedadj;
  44         u64 cputime_speedadj_timestamp;
  45         struct cpufreq_policy *policy;
  46         struct cpufreq_frequency_table *freq_table;
  47         spinlock_t target_freq_lock; /*protects target freq */
  48         unsigned int target_freq;
  49         unsigned int floor_freq;
  50         unsigned int max_freq;
  51         u64 floor_validate_time;
  52         u64 hispeed_validate_time;
  53         struct rw_semaphore enable_sem;
  54         int governor_enabled;
  55 };
  56
  57 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  58
  59 /* realtime thread handles frequency scaling */
  60 static struct task_struct *speedchange_task;
  61 static cpumask_t speedchange_cpumask;
  62 static spinlock_t speedchange_cpumask_lock;
  63 static struct mutex gov_lock;
  64
  65 /* Target load.  Lower values result in higher CPU speeds. */
  66 #define DEFAULT_TARGET_LOAD 90
  67 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  68
  69 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  70 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  71 static unsigned int default_above_hispeed_delay[] = {
  72         DEFAULT_ABOVE_HISPEED_DELAY };
  73
  74 struct cpufreq_interactive_tunables {
  75         int usage_count;
  76         /* Hi speed to bump to from lo speed when load burst (default max) */
  77         unsigned int hispeed_freq;
  78         /* Go to hi speed when CPU load at or above this value. */
  79 #define DEFAULT_GO_HISPEED_LOAD 99
  80         unsigned long go_hispeed_load;
  81         /* Target load. Lower values result in higher CPU speeds. */
  82         spinlock_t target_loads_lock;
  83         unsigned int *target_loads;
  84         int ntarget_loads;
  85         /*
  86          * The minimum amount of time to spend at a frequency before we can ramp
  87          * down.
  88          */
  89 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  90         unsigned long min_sample_time;
  91         /*
  92          * The sample rate of the timer used to increase frequency
  93          */
  94         unsigned long timer_rate;
  95         /*
  96          * Wait this long before raising speed above hispeed, by default a
  97          * single timer interval.
  98          */
  99         spinlock_t above_hispeed_delay_lock;
 100         unsigned int *above_hispeed_delay;
 101         int nabove_hispeed_delay;
 102         /* Non-zero means indefinite speed boost active */
 103         int boost_val;
 104         /* Duration of a boot pulse in usecs */
 105         int boostpulse_duration_val;
 106         /* End time of boost pulse in ktime converted to usecs */
 107         u64 boostpulse_endtime;
 108         /*
 109          * Max additional time to wait in idle, beyond timer_rate, at speeds
 110          * above minimum before wakeup to reduce speed, or -1 if unnecessary.
 111          */
 112 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 113         int timer_slack_val;
 114         bool io_is_busy;
 115 };
 116
 117 /* For cases where we have single governor instance for system */
 118 static struct cpufreq_interactive_tunables *common_tunables;
 119
 120 static struct attribute_group *get_sysfs_attr(void);
 121
 122 static void cpufreq_interactive_timer_resched(
 123         struct cpufreq_interactive_cpuinfo *pcpu)
 124 {
 125         struct cpufreq_interactive_tunables *tunables =
 126                 pcpu->policy->governor_data;
 127         unsigned long expires;
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&pcpu->load_lock, flags);
 131         pcpu->time_in_idle =
 132                 get_cpu_idle_time(smp_processor_id(),
 133                                   &pcpu->time_in_idle_timestamp,
 134                                   tunables->io_is_busy);
 135         pcpu->cputime_speedadj = 0;
 136         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 137         expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 138         mod_timer_pinned(&pcpu->cpu_timer, expires);
 139
 140         if (tunables->timer_slack_val >= 0 &&
 141             pcpu->target_freq > pcpu->policy->min) {
 142                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 143                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 144         }
 145
 146         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 147 }
 148
 149 /* The caller shall take enable_sem write semaphore to avoid any timer race.
 150  * The cpu_timer and cpu_slack_timer must be deactivated when calling this
 151  * function.
 152  */
 153 static void cpufreq_interactive_timer_start(
 154         struct cpufreq_interactive_tunables *tunables, int cpu)
 155 {
 156         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 157         unsigned long expires = jiffies +
 158                 usecs_to_jiffies(tunables->timer_rate);
 159         unsigned long flags;
 160
 161         pcpu->cpu_timer.expires = expires;
 162         add_timer_on(&pcpu->cpu_timer, cpu);
 163         if (tunables->timer_slack_val >= 0 &&
 164             pcpu->target_freq > pcpu->policy->min) {
 165                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 166                 pcpu->cpu_slack_timer.expires = expires;
 167                 add_timer_on(&pcpu->cpu_slack_timer, cpu);
 168         }
 169
 170         spin_lock_irqsave(&pcpu->load_lock, flags);
 171         pcpu->time_in_idle =
 172                 get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp,
 173                                   tunables->io_is_busy);
 174         pcpu->cputime_speedadj = 0;
 175         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 176         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 177 }
 178
 179 static unsigned int freq_to_above_hispeed_delay(
 180         struct cpufreq_interactive_tunables *tunables,
 181         unsigned int freq)
 182 {
 183         int i;
 184         unsigned int ret;
 185         unsigned long flags;
 186
 187         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 188
 189         for (i = 0; i < tunables->nabove_hispeed_delay - 1 &&
 190                         freq >= tunables->above_hispeed_delay[i+1]; i += 2)
 191                 ;
 192
 193         ret = tunables->above_hispeed_delay[i];
 194         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 195         return ret;
 196 }
 197
 198 static unsigned int freq_to_targetload(
 199         struct cpufreq_interactive_tunables *tunables, unsigned int freq)
 200 {
 201         int i;
 202         unsigned int ret;
 203         unsigned long flags;
 204
 205         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 206
 207         for (i = 0; i < tunables->ntarget_loads - 1 &&
 208                     freq >= tunables->target_loads[i+1]; i += 2)
 209                 ;
 210
 211         ret = tunables->target_loads[i];
 212         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 213         return ret;
 214 }
 215
 216 /*
 217  * If increasing frequencies never map to a lower target load then
 218  * choose_freq() will find the minimum frequency that does not exceed its
 219  * target load given the current load.
 220  */
 221 static unsigned int choose_freq(struct cpufreq_interactive_cpuinfo *pcpu,
 222                 unsigned int loadadjfreq)
 223 {
 224         unsigned int freq = pcpu->policy->cur;
 225         unsigned int prevfreq, freqmin, freqmax;
 226         unsigned int tl;
 227         int index;
 228
 229         freqmin = 0;
 230         freqmax = UINT_MAX;
 231
 232         do {
 233                 prevfreq = freq;
 234                 tl = freq_to_targetload(pcpu->policy->governor_data, freq);
 235
 236                 /*
 237                  * Find the lowest frequency where the computed load is less
 238                  * than or equal to the target load.
 239                  */
 240
 241                 if (cpufreq_frequency_table_target(
 242                             pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 243                             CPUFREQ_RELATION_L, &index))
 244                         break;
 245                 freq = pcpu->freq_table[index].frequency;
 246
 247                 if (freq > prevfreq) {
 248                         /* The previous frequency is too low. */
 249                         freqmin = prevfreq;
 250
 251                         if (freq >= freqmax) {
 252                                 /*
 253                                  * Find the highest frequency that is less
 254                                  * than freqmax.
 255                                  */
 256                                 if (cpufreq_frequency_table_target(
 257                                             pcpu->policy, pcpu->freq_table,
 258                                             freqmax - 1, CPUFREQ_RELATION_H,
 259                                             &index))
 260                                         break;
 261                                 freq = pcpu->freq_table[index].frequency;
 262
 263                                 if (freq == freqmin) {
 264                                         /*
 265                                          * The first frequency below freqmax
 266                                          * has already been found to be too
 267                                          * low.  freqmax is the lowest speed
 268                                          * we found that is fast enough.
 269                                          */
 270                                         freq = freqmax;
 271                                         break;
 272                                 }
 273                         }
 274                 } else if (freq < prevfreq) {
 275                         /* The previous frequency is high enough. */
 276                         freqmax = prevfreq;
 277
 278                         if (freq <= freqmin) {
 279                                 /*
 280                                  * Find the lowest frequency that is higher
 281                                  * than freqmin.
 282                                  */
 283                                 if (cpufreq_frequency_table_target(
 284                                             pcpu->policy, pcpu->freq_table,
 285                                             freqmin + 1, CPUFREQ_RELATION_L,
 286                                             &index))
 287                                         break;
 288                                 freq = pcpu->freq_table[index].frequency;
 289
 290                                 /*
 291                                  * If freqmax is the first frequency above
 292                                  * freqmin then we have already found that
 293                                  * this speed is fast enough.
 294                                  */
 295                                 if (freq == freqmax)
 296                                         break;
 297                         }
 298                 }
 299
 300                 /* If same frequency chosen as previous then done. */
 301         } while (freq != prevfreq);
 302
 303         return freq;
 304 }
 305
 306 static u64 update_load(int cpu)
 307 {
 308         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 309         struct cpufreq_interactive_tunables *tunables =
 310                 pcpu->policy->governor_data;
 311         u64 now;
 312         u64 now_idle;
 313         unsigned int delta_idle;
 314         unsigned int delta_time;
 315         u64 active_time;
 316
 317         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 318         delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
 319         delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
 320
 321         if (delta_time <= delta_idle)
 322                 active_time = 0;
 323         else
 324                 active_time = delta_time - delta_idle;
 325
 326         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 327
 328         pcpu->time_in_idle = now_idle;
 329         pcpu->time_in_idle_timestamp = now;
 330         return now;
 331 }
 332
 333 static void cpufreq_interactive_timer(unsigned long data)
 334 {
 335         u64 now;
 336         unsigned int delta_time;
 337         u64 cputime_speedadj;
 338         int cpu_load;
 339         struct cpufreq_interactive_cpuinfo *pcpu =
 340                 &per_cpu(cpuinfo, data);
 341         struct cpufreq_interactive_tunables *tunables =
 342                 pcpu->policy->governor_data;
 343         unsigned int new_freq;
 344         unsigned int loadadjfreq;
 345         unsigned int index;
 346         unsigned long flags;
 347         bool boosted;
 348
 349         if (!down_read_trylock(&pcpu->enable_sem))
 350                 return;
 351         if (!pcpu->governor_enabled)
 352                 goto exit;
 353
 354         spin_lock_irqsave(&pcpu->load_lock, flags);
 355         now = update_load(data);
 356         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 357         cputime_speedadj = pcpu->cputime_speedadj;
 358         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 359
 360         if (WARN_ON_ONCE(!delta_time))
 361                 goto rearm;
 362
 363         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
 364         do_div(cputime_speedadj, delta_time);
 365         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 366         cpu_load = loadadjfreq / pcpu->target_freq;
 367         boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 368
 369         if (cpu_load >= tunables->go_hispeed_load || boosted) {
 370                 if (pcpu->target_freq < tunables->hispeed_freq) {
 371                         new_freq = tunables->hispeed_freq;
 372                 } else {
 373                         new_freq = choose_freq(pcpu, loadadjfreq);
 374
 375                         if (new_freq < tunables->hispeed_freq)
 376                                 new_freq = tunables->hispeed_freq;
 377                 }
 378         } else {
 379                 new_freq = choose_freq(pcpu, loadadjfreq);
 380                 if (new_freq > tunables->hispeed_freq &&
 381                                 pcpu->target_freq < tunables->hispeed_freq)
 382                         new_freq = tunables->hispeed_freq;
 383         }
 384
 385         if (pcpu->target_freq >= tunables->hispeed_freq &&
 386             new_freq > pcpu->target_freq &&
 387             now - pcpu->hispeed_validate_time <
 388             freq_to_above_hispeed_delay(tunables, pcpu->target_freq)) {
 389                 trace_cpufreq_interactive_notyet(
 390                         data, cpu_load, pcpu->target_freq,
 391                         pcpu->policy->cur, new_freq);
 392                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 393                 goto rearm;
 394         }
 395
 396         pcpu->hispeed_validate_time = now;
 397
 398         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 399                                            new_freq, CPUFREQ_RELATION_L,
 400                                            &index)) {
 401                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 402                 goto rearm;
 403         }
 404
 405         new_freq = pcpu->freq_table[index].frequency;
 406
 407         /*
 408          * Do not scale below floor_freq unless we have been at or above the
 409          * floor frequency for the minimum sample time since last validated.
 410          */
 411         if (new_freq < pcpu->floor_freq) {
 412                 if (now - pcpu->floor_validate_time <
 413                                 tunables->min_sample_time) {
 414                         trace_cpufreq_interactive_notyet(
 415                                 data, cpu_load, pcpu->target_freq,
 416                                 pcpu->policy->cur, new_freq);
 417                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 418                         goto rearm;
 419                 }
 420         }
 421
 422         /*
 423          * Update the timestamp for checking whether speed has been held at
 424          * or above the selected frequency for a minimum of min_sample_time,
 425          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 426          * allow the speed to drop as soon as the boostpulse duration expires
 427          * (or the indefinite boost is turned off).
 428          */
 429
 430         if (!boosted || new_freq > tunables->hispeed_freq) {
 431                 pcpu->floor_freq = new_freq;
 432                 pcpu->floor_validate_time = now;
 433         }
 434
 435         if (pcpu->target_freq == new_freq &&
 436                         pcpu->target_freq <= pcpu->policy->cur) {
 437                 trace_cpufreq_interactive_already(
 438                         data, cpu_load, pcpu->target_freq,
 439                         pcpu->policy->cur, new_freq);
 440                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 441                 goto rearm_if_notmax;
 442         }
 443
 444         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 445                                          pcpu->policy->cur, new_freq);
 446
 447         pcpu->target_freq = new_freq;
 448         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 449         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 450         cpumask_set_cpu(data, &speedchange_cpumask);
 451         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 452         wake_up_process(speedchange_task);
 453
 454 rearm_if_notmax:
 455         /*
 456          * Already set max speed and don't see a need to change that,
 457          * wait until next idle to re-evaluate, don't need timer.
 458          */
 459         if (pcpu->target_freq == pcpu->policy->max)
 460                 goto exit;
 461
 462 rearm:
 463         if (!timer_pending(&pcpu->cpu_timer))
 464                 cpufreq_interactive_timer_resched(pcpu);
 465
 466 exit:
 467         up_read(&pcpu->enable_sem);
 468         return;
 469 }
 470
 471 static void cpufreq_interactive_idle_start(void)
 472 {
 473         struct cpufreq_interactive_cpuinfo *pcpu =
 474                 &per_cpu(cpuinfo, smp_processor_id());
 475         int pending;
 476
 477         if (!down_read_trylock(&pcpu->enable_sem))
 478                 return;
 479         if (!pcpu->governor_enabled) {
 480                 up_read(&pcpu->enable_sem);
 481                 return;
 482         }
 483
 484         pending = timer_pending(&pcpu->cpu_timer);
 485
 486         if (pcpu->target_freq != pcpu->policy->min) {
 487                 /*
 488                  * Entering idle while not at lowest speed.  On some
 489                  * platforms this can hold the other CPU(s) at that speed
 490                  * even though the CPU is idle. Set a timer to re-evaluate
 491                  * speed so this idle CPU doesn't hold the other CPUs above
 492                  * min indefinitely.  This should probably be a quirk of
 493                  * the CPUFreq driver.
 494                  */
 495                 if (!pending)
 496                         cpufreq_interactive_timer_resched(pcpu);
 497         }
 498
 499         up_read(&pcpu->enable_sem);
 500 }
 501
 502 static void cpufreq_interactive_idle_end(void)
 503 {
 504         struct cpufreq_interactive_cpuinfo *pcpu =
 505                 &per_cpu(cpuinfo, smp_processor_id());
 506
 507         if (!down_read_trylock(&pcpu->enable_sem))
 508                 return;
 509         if (!pcpu->governor_enabled) {
 510                 up_read(&pcpu->enable_sem);
 511                 return;
 512         }
 513
 514         /* Arm the timer for 1-2 ticks later if not already. */
 515         if (!timer_pending(&pcpu->cpu_timer)) {
 516                 cpufreq_interactive_timer_resched(pcpu);
 517         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 518                 del_timer(&pcpu->cpu_timer);
 519                 del_timer(&pcpu->cpu_slack_timer);
 520                 cpufreq_interactive_timer(smp_processor_id());
 521         }
 522
 523         up_read(&pcpu->enable_sem);
 524 }
 525
 526 static int cpufreq_interactive_speedchange_task(void *data)
 527 {
 528         unsigned int cpu;
 529         cpumask_t tmp_mask;
 530         unsigned long flags;
 531         struct cpufreq_interactive_cpuinfo *pcpu;
 532
 533         while (1) {
 534                 set_current_state(TASK_INTERRUPTIBLE);
 535                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 536
 537                 if (cpumask_empty(&speedchange_cpumask)) {
 538                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 539                                                flags);
 540                         schedule();
 541
 542                         if (kthread_should_stop())
 543                                 break;
 544
 545                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 546                 }
 547
 548                 set_current_state(TASK_RUNNING);
 549                 tmp_mask = speedchange_cpumask;
 550                 cpumask_clear(&speedchange_cpumask);
 551                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 552
 553                 for_each_cpu(cpu, &tmp_mask) {
 554                         unsigned int j;
 555                         unsigned int max_freq = 0;
 556
 557                         pcpu = &per_cpu(cpuinfo, cpu);
 558                         if (!down_read_trylock(&pcpu->enable_sem))
 559                                 continue;
 560                         if (!pcpu->governor_enabled) {
 561                                 up_read(&pcpu->enable_sem);
 562                                 continue;
 563                         }
 564
 565                         for_each_cpu(j, pcpu->policy->cpus) {
 566                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 567                                         &per_cpu(cpuinfo, j);
 568
 569                                 if (pjcpu->target_freq > max_freq)
 570                                         max_freq = pjcpu->target_freq;
 571                         }
 572
 573                         if (max_freq != pcpu->policy->cur)
 574                                 __cpufreq_driver_target(pcpu->policy,
 575                                                         max_freq,
 576                                                         CPUFREQ_RELATION_H);
 577                         trace_cpufreq_interactive_setspeed(cpu,
 578                                                      pcpu->target_freq,
 579                                                      pcpu->policy->cur);
 580
 581                         up_read(&pcpu->enable_sem);
 582                 }
 583         }
 584
 585         return 0;
 586 }
 587
 588 static void cpufreq_interactive_boost(void)
 589 {
 590         int i;
 591         int anyboost = 0;
 592         unsigned long flags[2];
 593         struct cpufreq_interactive_cpuinfo *pcpu;
 594         struct cpufreq_interactive_tunables *tunables;
 595
 596         spin_lock_irqsave(&speedchange_cpumask_lock, flags[0]);
 597
 598         for_each_online_cpu(i) {
 599                 pcpu = &per_cpu(cpuinfo, i);
 600                 tunables = pcpu->policy->governor_data;
 601
 602                 spin_lock_irqsave(&pcpu->target_freq_lock, flags[1]);
 603                 if (pcpu->target_freq < tunables->hispeed_freq) {
 604                         pcpu->target_freq = tunables->hispeed_freq;
 605                         cpumask_set_cpu(i, &speedchange_cpumask);
 606                         pcpu->hispeed_validate_time =
 607                                 ktime_to_us(ktime_get());
 608                         anyboost = 1;
 609                 }
 610
 611                 /*
 612                  * Set floor freq and (re)start timer for when last
 613                  * validated.
 614                  */
 615
 616                 pcpu->floor_freq = tunables->hispeed_freq;
 617                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 618                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags[1]);
 619         }
 620
 621         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags[0]);
 622
 623         if (anyboost)
 624                 wake_up_process(speedchange_task);
 625 }
 626
 627 static int cpufreq_interactive_notifier(
 628         struct notifier_block *nb, unsigned long val, void *data)
 629 {
 630         struct cpufreq_freqs *freq = data;
 631         struct cpufreq_interactive_cpuinfo *pcpu;
 632         int cpu;
 633         unsigned long flags;
 634
 635         if (val == CPUFREQ_POSTCHANGE) {
 636                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 637                 if (!down_read_trylock(&pcpu->enable_sem))
 638                         return 0;
 639                 if (!pcpu->governor_enabled) {
 640                         up_read(&pcpu->enable_sem);
 641                         return 0;
 642                 }
 643
 644                 for_each_cpu(cpu, pcpu->policy->cpus) {
 645                         struct cpufreq_interactive_cpuinfo *pjcpu =
 646                                 &per_cpu(cpuinfo, cpu);
 647                         if (cpu != freq->cpu) {
 648                                 if (!down_read_trylock(&pjcpu->enable_sem))
 649                                         continue;
 650                                 if (!pjcpu->governor_enabled) {
 651                                         up_read(&pjcpu->enable_sem);
 652                                         continue;
 653                                 }
 654                         }
 655                         spin_lock_irqsave(&pjcpu->load_lock, flags);
 656                         update_load(cpu);
 657                         spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 658                         if (cpu != freq->cpu)
 659                                 up_read(&pjcpu->enable_sem);
 660                 }
 661
 662                 up_read(&pcpu->enable_sem);
 663         }
 664         return 0;
 665 }
 666
 667 static struct notifier_block cpufreq_notifier_block = {
 668         .notifier_call = cpufreq_interactive_notifier,
 669 };
 670
 671 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 672 {
 673         const char *cp;
 674         int i;
 675         int ntokens = 1;
 676         unsigned int *tokenized_data;
 677         int err = -EINVAL;
 678
 679         cp = buf;
 680         while ((cp = strpbrk(cp + 1, " :")))
 681                 ntokens++;
 682
 683         if (!(ntokens & 0x1))
 684                 goto err;
 685
 686         tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 687         if (!tokenized_data) {
 688                 err = -ENOMEM;
 689                 goto err;
 690         }
 691
 692         cp = buf;
 693         i = 0;
 694         while (i < ntokens) {
 695                 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
 696                         goto err_kfree;
 697
 698                 cp = strpbrk(cp, " :");
 699                 if (!cp)
 700                         break;
 701                 cp++;
 702         }
 703
 704         if (i != ntokens)
 705                 goto err_kfree;
 706
 707         *num_tokens = ntokens;
 708         return tokenized_data;
 709
 710 err_kfree:
 711         kfree(tokenized_data);
 712 err:
 713         return ERR_PTR(err);
 714 }
 715
 716 static ssize_t show_target_loads(
 717         struct cpufreq_interactive_tunables *tunables,
 718         char *buf)
 719 {
 720         int i;
 721         ssize_t ret = 0;
 722         unsigned long flags;
 723
 724         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 725
 726         for (i = 0; i < tunables->ntarget_loads; i++)
 727                 ret += sprintf(buf + ret, "%u%s", tunables->target_loads[i],
 728                                i & 0x1 ? ":" : " ");
 729
 730         sprintf(buf + ret - 1, "\n");
 731         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 732         return ret;
 733 }
 734
 735 static ssize_t store_target_loads(
 736         struct cpufreq_interactive_tunables *tunables,
 737         const char *buf, size_t count)
 738 {
 739         int ntokens;
 740         unsigned int *new_target_loads = NULL;
 741         unsigned long flags;
 742
 743         new_target_loads = get_tokenized_data(buf, &ntokens);
 744         if (IS_ERR(new_target_loads))
 745                 return PTR_RET(new_target_loads);
 746
 747         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 748         if (tunables->target_loads != default_target_loads)
 749                 kfree(tunables->target_loads);
 750         tunables->target_loads = new_target_loads;
 751         tunables->ntarget_loads = ntokens;
 752         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 753         return count;
 754 }
 755
 756 static ssize_t show_above_hispeed_delay(
 757         struct cpufreq_interactive_tunables *tunables, char *buf)
 758 {
 759         int i;
 760         ssize_t ret = 0;
 761         unsigned long flags;
 762
 763         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 764
 765         for (i = 0; i < tunables->nabove_hispeed_delay; i++)
 766                 ret += sprintf(buf + ret, "%u%s",
 767                                tunables->above_hispeed_delay[i],
 768                                i & 0x1 ? ":" : " ");
 769
 770         sprintf(buf + ret - 1, "\n");
 771         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 772         return ret;
 773 }
 774
 775 static ssize_t store_above_hispeed_delay(
 776         struct cpufreq_interactive_tunables *tunables,
 777         const char *buf, size_t count)
 778 {
 779         int ntokens;
 780         unsigned int *new_above_hispeed_delay = NULL;
 781         unsigned long flags;
 782
 783         new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
 784         if (IS_ERR(new_above_hispeed_delay))
 785                 return PTR_RET(new_above_hispeed_delay);
 786
 787         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 788         if (tunables->above_hispeed_delay != default_above_hispeed_delay)
 789                 kfree(tunables->above_hispeed_delay);
 790         tunables->above_hispeed_delay = new_above_hispeed_delay;
 791         tunables->nabove_hispeed_delay = ntokens;
 792         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 793         return count;
 794
 795 }
 796
 797 static ssize_t show_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 798                 char *buf)
 799 {
 800         return sprintf(buf, "%u\n", tunables->hispeed_freq);
 801 }
 802
 803 static ssize_t store_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 804                 const char *buf, size_t count)
 805 {
 806         int ret;
 807         long unsigned int val;
 808
 809         ret = strict_strtoul(buf, 0, &val);
 810         if (ret < 0)
 811                 return ret;
 812         tunables->hispeed_freq = val;
 813         return count;
 814 }
 815
 816 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 817                 *tunables, char *buf)
 818 {
 819         return sprintf(buf, "%lu\n", tunables->go_hispeed_load);
 820 }
 821
 822 static ssize_t store_go_hispeed_load(struct cpufreq_interactive_tunables
 823                 *tunables, const char *buf, size_t count)
 824 {
 825         int ret;
 826         unsigned long val;
 827
 828         ret = strict_strtoul(buf, 0, &val);
 829         if (ret < 0)
 830                 return ret;
 831         tunables->go_hispeed_load = val;
 832         return count;
 833 }
 834
 835 static ssize_t show_min_sample_time(struct cpufreq_interactive_tunables
 836                 *tunables, char *buf)
 837 {
 838         return sprintf(buf, "%lu\n", tunables->min_sample_time);
 839 }
 840
 841 static ssize_t store_min_sample_time(struct cpufreq_interactive_tunables
 842                 *tunables, const char *buf, size_t count)
 843 {
 844         int ret;
 845         unsigned long val;
 846
 847         ret = strict_strtoul(buf, 0, &val);
 848         if (ret < 0)
 849                 return ret;
 850         tunables->min_sample_time = val;
 851         return count;
 852 }
 853
 854 static ssize_t show_timer_rate(struct cpufreq_interactive_tunables *tunables,
 855                 char *buf)
 856 {
 857         return sprintf(buf, "%lu\n", tunables->timer_rate);
 858 }
 859
 860 static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 861                 const char *buf, size_t count)
 862 {
 863         int ret;
 864         unsigned long val;
 865
 866         ret = strict_strtoul(buf, 0, &val);
 867         if (ret < 0)
 868                 return ret;
 869         tunables->timer_rate = val;
 870         return count;
 871 }
 872
 873 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 874                 char *buf)
 875 {
 876         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 877 }
 878
 879 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 880                 const char *buf, size_t count)
 881 {
 882         int ret;
 883         unsigned long val;
 884
 885         ret = kstrtol(buf, 10, &val);
 886         if (ret < 0)
 887                 return ret;
 888
 889         tunables->timer_slack_val = val;
 890         return count;
 891 }
 892
 893 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 894                           char *buf)
 895 {
 896         return sprintf(buf, "%d\n", tunables->boost_val);
 897 }
 898
 899 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 900                            const char *buf, size_t count)
 901 {
 902         int ret;
 903         unsigned long val;
 904
 905         ret = kstrtoul(buf, 0, &val);
 906         if (ret < 0)
 907                 return ret;
 908
 909         tunables->boost_val = val;
 910
 911         if (tunables->boost_val) {
 912                 trace_cpufreq_interactive_boost("on");
 913                 cpufreq_interactive_boost();
 914         } else {
 915                 tunables->boostpulse_endtime = ktime_to_us(ktime_get());
 916                 trace_cpufreq_interactive_unboost("off");
 917         }
 918
 919         return count;
 920 }
 921
 922 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 923                                 const char *buf, size_t count)
 924 {
 925         int ret;
 926         unsigned long val;
 927
 928         ret = kstrtoul(buf, 0, &val);
 929         if (ret < 0)
 930                 return ret;
 931
 932         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 933                 tunables->boostpulse_duration_val;
 934         trace_cpufreq_interactive_boost("pulse");
 935         cpufreq_interactive_boost();
 936         return count;
 937 }
 938
 939 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 940                 *tunables, char *buf)
 941 {
 942         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 943 }
 944
 945 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 946                 *tunables, const char *buf, size_t count)
 947 {
 948         int ret;
 949         unsigned long val;
 950
 951         ret = kstrtoul(buf, 0, &val);
 952         if (ret < 0)
 953                 return ret;
 954
 955         tunables->boostpulse_duration_val = val;
 956         return count;
 957 }
 958
 959 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 960                 char *buf)
 961 {
 962         return sprintf(buf, "%u\n", tunables->io_is_busy);
 963 }
 964
 965 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 966                 const char *buf, size_t count)
 967 {
 968         int ret;
 969         unsigned long val;
 970
 971         ret = kstrtoul(buf, 0, &val);
 972         if (ret < 0)
 973                 return ret;
 974         tunables->io_is_busy = val;
 975         return count;
 976 }
 977
 978 /*
 979  * Create show/store routines
 980  * - sys: One governor instance for complete SYSTEM
 981  * - pol: One governor instance per struct cpufreq_policy
 982  */
 983 #define show_gov_pol_sys(file_name)                                     \
 984 static ssize_t show_##file_name##_gov_sys                               \
 985 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 986 {                                                                       \
 987         return show_##file_name(common_tunables, buf);                  \
 988 }                                                                       \
 989                                                                         \
 990 static ssize_t show_##file_name##_gov_pol                               \
 991 (struct cpufreq_policy *policy, char *buf)                              \
 992 {                                                                       \
 993         return show_##file_name(policy->governor_data, buf);            \
 994 }
 995
 996 #define store_gov_pol_sys(file_name)                                    \
 997 static ssize_t store_##file_name##_gov_sys                              \
 998 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
 999         size_t count)                                                   \
1000 {                                                                       \
1001         return store_##file_name(common_tunables, buf, count);          \
1002 }                                                                       \
1003                                                                         \
1004 static ssize_t store_##file_name##_gov_pol                              \
1005 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
1006 {                                                                       \
1007         return store_##file_name(policy->governor_data, buf, count);    \
1008 }
1009
1010 #define show_store_gov_pol_sys(file_name)                               \
1011 show_gov_pol_sys(file_name);                                            \
1012 store_gov_pol_sys(file_name)
1013
1014 show_store_gov_pol_sys(target_loads);
1015 show_store_gov_pol_sys(above_hispeed_delay);
1016 show_store_gov_pol_sys(hispeed_freq);
1017 show_store_gov_pol_sys(go_hispeed_load);
1018 show_store_gov_pol_sys(min_sample_time);
1019 show_store_gov_pol_sys(timer_rate);
1020 show_store_gov_pol_sys(timer_slack);
1021 show_store_gov_pol_sys(boost);
1022 store_gov_pol_sys(boostpulse);
1023 show_store_gov_pol_sys(boostpulse_duration);
1024 show_store_gov_pol_sys(io_is_busy);
1025
1026 #define gov_sys_attr_rw(_name)                                          \
1027 static struct global_attr _name##_gov_sys =                             \
1028 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
1029
1030 #define gov_pol_attr_rw(_name)                                          \
1031 static struct freq_attr _name##_gov_pol =                               \
1032 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
1033
1034 #define gov_sys_pol_attr_rw(_name)                                      \
1035         gov_sys_attr_rw(_name);                                         \
1036         gov_pol_attr_rw(_name)
1037
1038 gov_sys_pol_attr_rw(target_loads);
1039 gov_sys_pol_attr_rw(above_hispeed_delay);
1040 gov_sys_pol_attr_rw(hispeed_freq);
1041 gov_sys_pol_attr_rw(go_hispeed_load);
1042 gov_sys_pol_attr_rw(min_sample_time);
1043 gov_sys_pol_attr_rw(timer_rate);
1044 gov_sys_pol_attr_rw(timer_slack);
1045 gov_sys_pol_attr_rw(boost);
1046 gov_sys_pol_attr_rw(boostpulse_duration);
1047 gov_sys_pol_attr_rw(io_is_busy);
1048
1049 static struct global_attr boostpulse_gov_sys =
1050         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1051
1052 static struct freq_attr boostpulse_gov_pol =
1053         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1054
1055 /* One Governor instance for entire system */
1056 static struct attribute *interactive_attributes_gov_sys[] = {
1057         &target_loads_gov_sys.attr,
1058         &above_hispeed_delay_gov_sys.attr,
1059         &hispeed_freq_gov_sys.attr,
1060         &go_hispeed_load_gov_sys.attr,
1061         &min_sample_time_gov_sys.attr,
1062         &timer_rate_gov_sys.attr,
1063         &timer_slack_gov_sys.attr,
1064         &boost_gov_sys.attr,
1065         &boostpulse_gov_sys.attr,
1066         &boostpulse_duration_gov_sys.attr,
1067         &io_is_busy_gov_sys.attr,
1068         NULL,
1069 };
1070
1071 static struct attribute_group interactive_attr_group_gov_sys = {
1072         .attrs = interactive_attributes_gov_sys,
1073         .name = "interactive",
1074 };
1075
1076 /* Per policy governor instance */
1077 static struct attribute *interactive_attributes_gov_pol[] = {
1078         &target_loads_gov_pol.attr,
1079         &above_hispeed_delay_gov_pol.attr,
1080         &hispeed_freq_gov_pol.attr,
1081         &go_hispeed_load_gov_pol.attr,
1082         &min_sample_time_gov_pol.attr,
1083         &timer_rate_gov_pol.attr,
1084         &timer_slack_gov_pol.attr,
1085         &boost_gov_pol.attr,
1086         &boostpulse_gov_pol.attr,
1087         &boostpulse_duration_gov_pol.attr,
1088         &io_is_busy_gov_pol.attr,
1089         NULL,
1090 };
1091
1092 static struct attribute_group interactive_attr_group_gov_pol = {
1093         .attrs = interactive_attributes_gov_pol,
1094         .name = "interactive",
1095 };
1096
1097 static struct attribute_group *get_sysfs_attr(void)
1098 {
1099         if (have_governor_per_policy())
1100                 return &interactive_attr_group_gov_pol;
1101         else
1102                 return &interactive_attr_group_gov_sys;
1103 }
1104
1105 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1106                                              unsigned long val,
1107                                              void *data)
1108 {
1109         switch (val) {
1110         case IDLE_START:
1111                 cpufreq_interactive_idle_start();
1112                 break;
1113         case IDLE_END:
1114                 cpufreq_interactive_idle_end();
1115                 break;
1116         }
1117
1118         return 0;
1119 }
1120
1121 static struct notifier_block cpufreq_interactive_idle_nb = {
1122         .notifier_call = cpufreq_interactive_idle_notifier,
1123 };
1124
1125 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1126                 unsigned int event)
1127 {
1128         int rc;
1129         unsigned int j;
1130         struct cpufreq_interactive_cpuinfo *pcpu;
1131         struct cpufreq_frequency_table *freq_table;
1132         struct cpufreq_interactive_tunables *tunables;
1133         unsigned long flags;
1134
1135         if (have_governor_per_policy())
1136                 tunables = policy->governor_data;
1137         else
1138                 tunables = common_tunables;
1139
1140         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1141
1142         switch (event) {
1143         case CPUFREQ_GOV_POLICY_INIT:
1144                 if (have_governor_per_policy()) {
1145                         WARN_ON(tunables);
1146                 } else if (tunables) {
1147                         tunables->usage_count++;
1148                         policy->governor_data = tunables;
1149                         return 0;
1150                 }
1151
1152                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1153                 if (!tunables) {
1154                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1155                         return -ENOMEM;
1156                 }
1157
1158                 tunables->usage_count = 1;
1159                 tunables->above_hispeed_delay = default_above_hispeed_delay;
1160                 tunables->nabove_hispeed_delay =
1161                         ARRAY_SIZE(default_above_hispeed_delay);
1162                 tunables->go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
1163                 tunables->target_loads = default_target_loads;
1164                 tunables->ntarget_loads = ARRAY_SIZE(default_target_loads);
1165                 tunables->min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
1166                 tunables->timer_rate = DEFAULT_TIMER_RATE;
1167                 tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
1168                 tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
1169
1170                 spin_lock_init(&tunables->target_loads_lock);
1171                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1172
1173                 policy->governor_data = tunables;
1174                 if (!have_governor_per_policy()) {
1175                         common_tunables = tunables;
1176                         WARN_ON(cpufreq_get_global_kobject());
1177                 }
1178
1179                 rc = sysfs_create_group(get_governor_parent_kobj(policy),
1180                                 get_sysfs_attr());
1181                 if (rc) {
1182                         kfree(tunables);
1183                         policy->governor_data = NULL;
1184                         if (!have_governor_per_policy())
1185                                 common_tunables = NULL;
1186                         return rc;
1187                 }
1188
1189                 if (!policy->governor->initialized) {
1190                         idle_notifier_register(&cpufreq_interactive_idle_nb);
1191                         cpufreq_register_notifier(&cpufreq_notifier_block,
1192                                         CPUFREQ_TRANSITION_NOTIFIER);
1193                 }
1194
1195                 break;
1196
1197         case CPUFREQ_GOV_POLICY_EXIT:
1198                 if (!--tunables->usage_count) {
1199                         if (policy->governor->initialized == 1) {
1200                                 cpufreq_unregister_notifier(&cpufreq_notifier_block,
1201                                                 CPUFREQ_TRANSITION_NOTIFIER);
1202                                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1203                         }
1204
1205                         sysfs_remove_group(get_governor_parent_kobj(policy),
1206                                         get_sysfs_attr());
1207
1208                         if (!have_governor_per_policy())
1209                                 cpufreq_put_global_kobject();
1210
1211                         kfree(tunables);
1212                         common_tunables = NULL;
1213                 }
1214
1215                 policy->governor_data = NULL;
1216                 break;
1217
1218         case CPUFREQ_GOV_START:
1219                 mutex_lock(&gov_lock);
1220
1221                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1222                 if (!tunables->hispeed_freq)
1223                         tunables->hispeed_freq = policy->max;
1224
1225                 for_each_cpu(j, policy->cpus) {
1226                         pcpu = &per_cpu(cpuinfo, j);
1227                         pcpu->policy = policy;
1228                         pcpu->target_freq = policy->cur;
1229                         pcpu->freq_table = freq_table;
1230                         pcpu->floor_freq = pcpu->target_freq;
1231                         pcpu->floor_validate_time =
1232                                 ktime_to_us(ktime_get());
1233                         pcpu->hispeed_validate_time =
1234                                 pcpu->floor_validate_time;
1235                         pcpu->max_freq = policy->max;
1236                         down_write(&pcpu->enable_sem);
1237                         del_timer_sync(&pcpu->cpu_timer);
1238                         del_timer_sync(&pcpu->cpu_slack_timer);
1239                         cpufreq_interactive_timer_start(tunables, j);
1240                         pcpu->governor_enabled = 1;
1241                         up_write(&pcpu->enable_sem);
1242                 }
1243
1244                 mutex_unlock(&gov_lock);
1245                 break;
1246
1247         case CPUFREQ_GOV_STOP:
1248                 mutex_lock(&gov_lock);
1249                 for_each_cpu(j, policy->cpus) {
1250                         pcpu = &per_cpu(cpuinfo, j);
1251                         down_write(&pcpu->enable_sem);
1252                         pcpu->governor_enabled = 0;
1253                         del_timer_sync(&pcpu->cpu_timer);
1254                         del_timer_sync(&pcpu->cpu_slack_timer);
1255                         up_write(&pcpu->enable_sem);
1256                 }
1257
1258                 mutex_unlock(&gov_lock);
1259                 break;
1260
1261         case CPUFREQ_GOV_LIMITS:
1262                 if (policy->max < policy->cur)
1263                         __cpufreq_driver_target(policy,
1264                                         policy->max, CPUFREQ_RELATION_H);
1265                 else if (policy->min > policy->cur)
1266                         __cpufreq_driver_target(policy,
1267                                         policy->min, CPUFREQ_RELATION_L);
1268                 for_each_cpu(j, policy->cpus) {
1269                         pcpu = &per_cpu(cpuinfo, j);
1270
1271                         down_read(&pcpu->enable_sem);
1272                         if (pcpu->governor_enabled == 0) {
1273                                 up_read(&pcpu->enable_sem);
1274                                 continue;
1275                         }
1276
1277                         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
1278                         if (policy->max < pcpu->target_freq)
1279                                 pcpu->target_freq = policy->max;
1280                         else if (policy->min > pcpu->target_freq)
1281                                 pcpu->target_freq = policy->min;
1282
1283                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
1284                         up_read(&pcpu->enable_sem);
1285
1286                         /* Reschedule timer only if policy->max is raised.
1287                          * Delete the timers, else the timer callback may
1288                          * return without re-arm the timer when failed
1289                          * acquire the semaphore. This race may cause timer
1290                          * stopped unexpectedly.
1291                          */
1292
1293                         if (policy->max > pcpu->max_freq) {
1294                                 down_write(&pcpu->enable_sem);
1295                                 del_timer_sync(&pcpu->cpu_timer);
1296                                 del_timer_sync(&pcpu->cpu_slack_timer);
1297                                 cpufreq_interactive_timer_start(tunables, j);
1298                                 up_write(&pcpu->enable_sem);
1299                         }
1300
1301                         pcpu->max_freq = policy->max;
1302                 }
1303                 break;
1304         }
1305         return 0;
1306 }
1307
1308 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1309 static
1310 #endif
1311 struct cpufreq_governor cpufreq_gov_interactive = {
1312         .name = "interactive",
1313         .governor = cpufreq_governor_interactive,
1314         .max_transition_latency = 10000000,
1315         .owner = THIS_MODULE,
1316 };
1317
1318 static void cpufreq_interactive_nop_timer(unsigned long data)
1319 {
1320 }
1321
1322 static int __init cpufreq_interactive_init(void)
1323 {
1324         unsigned int i;
1325         struct cpufreq_interactive_cpuinfo *pcpu;
1326         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1327
1328         /* Initalize per-cpu timers */
1329         for_each_possible_cpu(i) {
1330                 pcpu = &per_cpu(cpuinfo, i);
1331                 init_timer_deferrable(&pcpu->cpu_timer);
1332                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1333                 pcpu->cpu_timer.data = i;
1334                 init_timer(&pcpu->cpu_slack_timer);
1335                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1336                 spin_lock_init(&pcpu->load_lock);
1337                 spin_lock_init(&pcpu->target_freq_lock);
1338                 init_rwsem(&pcpu->enable_sem);
1339         }
1340
1341         spin_lock_init(&speedchange_cpumask_lock);
1342         mutex_init(&gov_lock);
1343         speedchange_task =
1344                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1345                                "cfinteractive");
1346         if (IS_ERR(speedchange_task))
1347                 return PTR_ERR(speedchange_task);
1348
1349         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1350         get_task_struct(speedchange_task);
1351
1352         /* NB: wake up so the thread does not look hung to the freezer */
1353         wake_up_process(speedchange_task);
1354
1355         return cpufreq_register_governor(&cpufreq_gov_interactive);
1356 }
1357
1358 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1359 fs_initcall(cpufreq_interactive_init);
1360 #else
1361 module_init(cpufreq_interactive_init);
1362 #endif
1363
1364 static void __exit cpufreq_interactive_exit(void)
1365 {
1366         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1367         kthread_stop(speedchange_task);
1368         put_task_struct(speedchange_task);
1369 }
1370
1371 module_exit(cpufreq_interactive_exit);
1372
1373 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1374 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1375         "Latency sensitive workloads");
1376 MODULE_LICENSE("GPL");