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