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         u64 pol_floor_val_time; /* policy floor_validate_time */
  51         u64 loc_floor_val_time; /* per-cpu floor_validate_time */
  52         u64 pol_hispeed_val_time; /* policy hispeed_validate_time */
  53         u64 loc_hispeed_val_time; /* per-cpu 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         unsigned int delta_idle;
 316         unsigned int delta_time;
 317         u64 active_time;
 318
 319         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 320         delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
 321         delta_time = (unsigned int)(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         u64 max_fvtime;
 350
 351         if (!down_read_trylock(&pcpu->enable_sem))
 352                 return;
 353         if (!pcpu->governor_enabled)
 354                 goto exit;
 355
 356         spin_lock_irqsave(&pcpu->load_lock, flags);
 357         now = update_load(data);
 358         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 359         cputime_speedadj = pcpu->cputime_speedadj;
 360         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 361
 362         if (WARN_ON_ONCE(!delta_time))
 363                 goto rearm;
 364
 365         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
 366         do_div(cputime_speedadj, delta_time);
 367         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 368         cpu_load = loadadjfreq / pcpu->policy->cur;
 369         tunables->boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 370
 371         if (cpu_load >= tunables->go_hispeed_load || tunables->boosted) {
 372                 if (pcpu->policy->cur < tunables->hispeed_freq) {
 373                         new_freq = tunables->hispeed_freq;
 374                 } else {
 375                         new_freq = choose_freq(pcpu, loadadjfreq);
 376
 377                         if (new_freq < tunables->hispeed_freq)
 378                                 new_freq = tunables->hispeed_freq;
 379                 }
 380         } else {
 381                 new_freq = choose_freq(pcpu, loadadjfreq);
 382                 if (new_freq > tunables->hispeed_freq &&
 383                                 pcpu->policy->cur < tunables->hispeed_freq)
 384                         new_freq = tunables->hispeed_freq;
 385         }
 386
 387         if (pcpu->policy->cur >= tunables->hispeed_freq &&
 388             new_freq > pcpu->policy->cur &&
 389             now - pcpu->pol_hispeed_val_time <
 390             freq_to_above_hispeed_delay(tunables, pcpu->policy->cur)) {
 391                 trace_cpufreq_interactive_notyet(
 392                         data, cpu_load, pcpu->target_freq,
 393                         pcpu->policy->cur, new_freq);
 394                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 395                 goto rearm;
 396         }
 397
 398         pcpu->loc_hispeed_val_time = now;
 399
 400         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 401                                            new_freq, CPUFREQ_RELATION_L,
 402                                            &index)) {
 403                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 404                 goto rearm;
 405         }
 406
 407         new_freq = pcpu->freq_table[index].frequency;
 408
 409         /*
 410          * Do not scale below floor_freq unless we have been at or above the
 411          * floor frequency for the minimum sample time since last validated.
 412          */
 413         max_fvtime = max(pcpu->pol_floor_val_time, pcpu->loc_floor_val_time);
 414         if (new_freq < pcpu->floor_freq &&
 415             pcpu->target_freq >= pcpu->policy->cur) {
 416                 if (now - max_fvtime < tunables->min_sample_time) {
 417                         trace_cpufreq_interactive_notyet(
 418                                 data, cpu_load, pcpu->target_freq,
 419                                 pcpu->policy->cur, new_freq);
 420                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 421                         goto rearm;
 422                 }
 423         }
 424
 425         /*
 426          * Update the timestamp for checking whether speed has been held at
 427          * or above the selected frequency for a minimum of min_sample_time,
 428          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 429          * allow the speed to drop as soon as the boostpulse duration expires
 430          * (or the indefinite boost is turned off).
 431          */
 432
 433         if (!tunables->boosted || new_freq > tunables->hispeed_freq) {
 434                 pcpu->floor_freq = new_freq;
 435                 if (pcpu->target_freq >= pcpu->policy->cur ||
 436                     new_freq >= pcpu->policy->cur)
 437                         pcpu->loc_floor_val_time = now;
 438         }
 439
 440         if (pcpu->target_freq == new_freq &&
 441                         pcpu->target_freq <= pcpu->policy->cur) {
 442                 trace_cpufreq_interactive_already(
 443                         data, cpu_load, pcpu->target_freq,
 444                         pcpu->policy->cur, new_freq);
 445                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 446                 goto rearm;
 447         }
 448
 449         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 450                                          pcpu->policy->cur, new_freq);
 451
 452         pcpu->target_freq = new_freq;
 453         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 454         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 455         cpumask_set_cpu(data, &speedchange_cpumask);
 456         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 457         wake_up_process(speedchange_task);
 458
 459 rearm:
 460         if (!timer_pending(&pcpu->cpu_timer))
 461                 cpufreq_interactive_timer_resched(pcpu);
 462
 463 exit:
 464         up_read(&pcpu->enable_sem);
 465         return;
 466 }
 467
 468 static void cpufreq_interactive_idle_end(void)
 469 {
 470         struct cpufreq_interactive_cpuinfo *pcpu =
 471                 &per_cpu(cpuinfo, smp_processor_id());
 472
 473         if (!down_read_trylock(&pcpu->enable_sem))
 474                 return;
 475         if (!pcpu->governor_enabled) {
 476                 up_read(&pcpu->enable_sem);
 477                 return;
 478         }
 479
 480         /* Arm the timer for 1-2 ticks later if not already. */
 481         if (!timer_pending(&pcpu->cpu_timer)) {
 482                 cpufreq_interactive_timer_resched(pcpu);
 483         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 484                 del_timer(&pcpu->cpu_timer);
 485                 del_timer(&pcpu->cpu_slack_timer);
 486                 cpufreq_interactive_timer(smp_processor_id());
 487         }
 488
 489         up_read(&pcpu->enable_sem);
 490 }
 491
 492 static int cpufreq_interactive_speedchange_task(void *data)
 493 {
 494         unsigned int cpu;
 495         cpumask_t tmp_mask;
 496         unsigned long flags;
 497         struct cpufreq_interactive_cpuinfo *pcpu;
 498
 499         while (1) {
 500                 set_current_state(TASK_INTERRUPTIBLE);
 501                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 502
 503                 if (cpumask_empty(&speedchange_cpumask)) {
 504                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 505                                                flags);
 506                         schedule();
 507
 508                         if (kthread_should_stop())
 509                                 break;
 510
 511                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 512                 }
 513
 514                 set_current_state(TASK_RUNNING);
 515                 tmp_mask = speedchange_cpumask;
 516                 cpumask_clear(&speedchange_cpumask);
 517                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 518
 519                 for_each_cpu(cpu, &tmp_mask) {
 520                         unsigned int j;
 521                         unsigned int max_freq = 0;
 522                         struct cpufreq_interactive_cpuinfo *pjcpu;
 523                         u64 hvt = ~0ULL, fvt = 0;
 524
 525                         pcpu = &per_cpu(cpuinfo, cpu);
 526                         if (!down_read_trylock(&pcpu->enable_sem))
 527                                 continue;
 528                         if (!pcpu->governor_enabled) {
 529                                 up_read(&pcpu->enable_sem);
 530                                 continue;
 531                         }
 532
 533                         for_each_cpu(j, pcpu->policy->cpus) {
 534                                 pjcpu = &per_cpu(cpuinfo, j);
 535
 536                                 fvt = max(fvt, pjcpu->loc_floor_val_time);
 537                                 if (pjcpu->target_freq > max_freq) {
 538                                         max_freq = pjcpu->target_freq;
 539                                         hvt = pjcpu->loc_hispeed_val_time;
 540                                 } else if (pjcpu->target_freq == max_freq) {
 541                                         hvt = min(hvt, pjcpu->loc_hispeed_val_time);
 542                                 }
 543                         }
 544                         for_each_cpu(j, pcpu->policy->cpus) {
 545                                 pjcpu = &per_cpu(cpuinfo, j);
 546                                 pjcpu->pol_floor_val_time = fvt;
 547                         }
 548
 549                         if (max_freq != pcpu->policy->cur) {
 550                                 __cpufreq_driver_target(pcpu->policy,
 551                                                         max_freq,
 552                                                         CPUFREQ_RELATION_H);
 553                                 for_each_cpu(j, pcpu->policy->cpus) {
 554                                         pjcpu = &per_cpu(cpuinfo, j);
 555                                         pjcpu->pol_hispeed_val_time = hvt;
 556                                 }
 557                         }
 558                         trace_cpufreq_interactive_setspeed(cpu,
 559                                                      pcpu->target_freq,
 560                                                      pcpu->policy->cur);
 561
 562                         up_read(&pcpu->enable_sem);
 563                 }
 564         }
 565
 566         return 0;
 567 }
 568
 569 static void cpufreq_interactive_boost(struct cpufreq_interactive_tunables *tunables)
 570 {
 571         int i;
 572         int anyboost = 0;
 573         unsigned long flags[2];
 574         struct cpufreq_interactive_cpuinfo *pcpu;
 575
 576         tunables->boosted = true;
 577
 578         spin_lock_irqsave(&speedchange_cpumask_lock, flags[0]);
 579
 580         for_each_online_cpu(i) {
 581                 pcpu = &per_cpu(cpuinfo, i);
 582                 if (tunables != pcpu->policy->governor_data)
 583                         continue;
 584
 585                 spin_lock_irqsave(&pcpu->target_freq_lock, flags[1]);
 586                 if (pcpu->target_freq < tunables->hispeed_freq) {
 587                         pcpu->target_freq = tunables->hispeed_freq;
 588                         cpumask_set_cpu(i, &speedchange_cpumask);
 589                         pcpu->pol_hispeed_val_time =
 590                                 ktime_to_us(ktime_get());
 591                         anyboost = 1;
 592                 }
 593                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags[1]);
 594         }
 595
 596         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags[0]);
 597
 598         if (anyboost)
 599                 wake_up_process(speedchange_task);
 600 }
 601
 602 static int cpufreq_interactive_notifier(
 603         struct notifier_block *nb, unsigned long val, void *data)
 604 {
 605         struct cpufreq_freqs *freq = data;
 606         struct cpufreq_interactive_cpuinfo *pcpu;
 607         int cpu;
 608         unsigned long flags;
 609
 610         if (val == CPUFREQ_POSTCHANGE) {
 611                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 612                 if (!down_read_trylock(&pcpu->enable_sem))
 613                         return 0;
 614                 if (!pcpu->governor_enabled) {
 615                         up_read(&pcpu->enable_sem);
 616                         return 0;
 617                 }
 618
 619                 for_each_cpu(cpu, pcpu->policy->cpus) {
 620                         struct cpufreq_interactive_cpuinfo *pjcpu =
 621                                 &per_cpu(cpuinfo, cpu);
 622                         if (cpu != freq->cpu) {
 623                                 if (!down_read_trylock(&pjcpu->enable_sem))
 624                                         continue;
 625                                 if (!pjcpu->governor_enabled) {
 626                                         up_read(&pjcpu->enable_sem);
 627                                         continue;
 628                                 }
 629                         }
 630                         spin_lock_irqsave(&pjcpu->load_lock, flags);
 631                         update_load(cpu);
 632                         spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 633                         if (cpu != freq->cpu)
 634                                 up_read(&pjcpu->enable_sem);
 635                 }
 636
 637                 up_read(&pcpu->enable_sem);
 638         }
 639         return 0;
 640 }
 641
 642 static struct notifier_block cpufreq_notifier_block = {
 643         .notifier_call = cpufreq_interactive_notifier,
 644 };
 645
 646 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 647 {
 648         const char *cp;
 649         int i;
 650         int ntokens = 1;
 651         unsigned int *tokenized_data;
 652         int err = -EINVAL;
 653
 654         cp = buf;
 655         while ((cp = strpbrk(cp + 1, " :")))
 656                 ntokens++;
 657
 658         if (!(ntokens & 0x1))
 659                 goto err;
 660
 661         tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 662         if (!tokenized_data) {
 663                 err = -ENOMEM;
 664                 goto err;
 665         }
 666
 667         cp = buf;
 668         i = 0;
 669         while (i < ntokens) {
 670                 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
 671                         goto err_kfree;
 672
 673                 cp = strpbrk(cp, " :");
 674                 if (!cp)
 675                         break;
 676                 cp++;
 677         }
 678
 679         if (i != ntokens)
 680                 goto err_kfree;
 681
 682         *num_tokens = ntokens;
 683         return tokenized_data;
 684
 685 err_kfree:
 686         kfree(tokenized_data);
 687 err:
 688         return ERR_PTR(err);
 689 }
 690
 691 static ssize_t show_target_loads(
 692         struct cpufreq_interactive_tunables *tunables,
 693         char *buf)
 694 {
 695         int i;
 696         ssize_t ret = 0;
 697         unsigned long flags;
 698
 699         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 700
 701         for (i = 0; i < tunables->ntarget_loads; i++)
 702                 ret += sprintf(buf + ret, "%u%s", tunables->target_loads[i],
 703                                i & 0x1 ? ":" : " ");
 704
 705         sprintf(buf + ret - 1, "\n");
 706         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 707         return ret;
 708 }
 709
 710 static ssize_t store_target_loads(
 711         struct cpufreq_interactive_tunables *tunables,
 712         const char *buf, size_t count)
 713 {
 714         int ntokens;
 715         unsigned int *new_target_loads = NULL;
 716         unsigned long flags;
 717
 718         new_target_loads = get_tokenized_data(buf, &ntokens);
 719         if (IS_ERR(new_target_loads))
 720                 return PTR_RET(new_target_loads);
 721
 722         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 723         if (tunables->target_loads != default_target_loads)
 724                 kfree(tunables->target_loads);
 725         tunables->target_loads = new_target_loads;
 726         tunables->ntarget_loads = ntokens;
 727         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 728         return count;
 729 }
 730
 731 static ssize_t show_above_hispeed_delay(
 732         struct cpufreq_interactive_tunables *tunables, char *buf)
 733 {
 734         int i;
 735         ssize_t ret = 0;
 736         unsigned long flags;
 737
 738         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 739
 740         for (i = 0; i < tunables->nabove_hispeed_delay; i++)
 741                 ret += sprintf(buf + ret, "%u%s",
 742                                tunables->above_hispeed_delay[i],
 743                                i & 0x1 ? ":" : " ");
 744
 745         sprintf(buf + ret - 1, "\n");
 746         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 747         return ret;
 748 }
 749
 750 static ssize_t store_above_hispeed_delay(
 751         struct cpufreq_interactive_tunables *tunables,
 752         const char *buf, size_t count)
 753 {
 754         int ntokens;
 755         unsigned int *new_above_hispeed_delay = NULL;
 756         unsigned long flags;
 757
 758         new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
 759         if (IS_ERR(new_above_hispeed_delay))
 760                 return PTR_RET(new_above_hispeed_delay);
 761
 762         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 763         if (tunables->above_hispeed_delay != default_above_hispeed_delay)
 764                 kfree(tunables->above_hispeed_delay);
 765         tunables->above_hispeed_delay = new_above_hispeed_delay;
 766         tunables->nabove_hispeed_delay = ntokens;
 767         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 768         return count;
 769
 770 }
 771
 772 static ssize_t show_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 773                 char *buf)
 774 {
 775         return sprintf(buf, "%u\n", tunables->hispeed_freq);
 776 }
 777
 778 static ssize_t store_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 779                 const char *buf, size_t count)
 780 {
 781         int ret;
 782         long unsigned int val;
 783
 784         ret = kstrtoul(buf, 0, &val);
 785         if (ret < 0)
 786                 return ret;
 787         tunables->hispeed_freq = val;
 788         return count;
 789 }
 790
 791 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 792                 *tunables, char *buf)
 793 {
 794         return sprintf(buf, "%lu\n", tunables->go_hispeed_load);
 795 }
 796
 797 static ssize_t store_go_hispeed_load(struct cpufreq_interactive_tunables
 798                 *tunables, const char *buf, size_t count)
 799 {
 800         int ret;
 801         unsigned long val;
 802
 803         ret = kstrtoul(buf, 0, &val);
 804         if (ret < 0)
 805                 return ret;
 806         tunables->go_hispeed_load = val;
 807         return count;
 808 }
 809
 810 static ssize_t show_min_sample_time(struct cpufreq_interactive_tunables
 811                 *tunables, char *buf)
 812 {
 813         return sprintf(buf, "%lu\n", tunables->min_sample_time);
 814 }
 815
 816 static ssize_t store_min_sample_time(struct cpufreq_interactive_tunables
 817                 *tunables, const char *buf, size_t count)
 818 {
 819         int ret;
 820         unsigned long val;
 821
 822         ret = kstrtoul(buf, 0, &val);
 823         if (ret < 0)
 824                 return ret;
 825         tunables->min_sample_time = val;
 826         return count;
 827 }
 828
 829 static ssize_t show_timer_rate(struct cpufreq_interactive_tunables *tunables,
 830                 char *buf)
 831 {
 832         return sprintf(buf, "%lu\n", tunables->timer_rate);
 833 }
 834
 835 static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 836                 const char *buf, size_t count)
 837 {
 838         int ret;
 839         unsigned long val, val_round;
 840
 841         ret = kstrtoul(buf, 0, &val);
 842         if (ret < 0)
 843                 return ret;
 844
 845         val_round = jiffies_to_usecs(usecs_to_jiffies(val));
 846         if (val != val_round)
 847                 pr_warn("timer_rate not aligned to jiffy. Rounded up to %lu\n",
 848                         val_round);
 849
 850         tunables->timer_rate = val_round;
 851         return count;
 852 }
 853
 854 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 855                 char *buf)
 856 {
 857         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 858 }
 859
 860 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 861                 const char *buf, size_t count)
 862 {
 863         int ret;
 864         unsigned long val;
 865
 866         ret = kstrtol(buf, 10, &val);
 867         if (ret < 0)
 868                 return ret;
 869
 870         tunables->timer_slack_val = val;
 871         return count;
 872 }
 873
 874 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 875                           char *buf)
 876 {
 877         return sprintf(buf, "%d\n", tunables->boost_val);
 878 }
 879
 880 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 881                            const char *buf, size_t count)
 882 {
 883         int ret;
 884         unsigned long val;
 885
 886         ret = kstrtoul(buf, 0, &val);
 887         if (ret < 0)
 888                 return ret;
 889
 890         tunables->boost_val = val;
 891
 892         if (tunables->boost_val) {
 893                 trace_cpufreq_interactive_boost("on");
 894                 if (!tunables->boosted)
 895                         cpufreq_interactive_boost(tunables);
 896         } else {
 897                 tunables->boostpulse_endtime = ktime_to_us(ktime_get());
 898                 trace_cpufreq_interactive_unboost("off");
 899         }
 900
 901         return count;
 902 }
 903
 904 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 905                                 const char *buf, size_t count)
 906 {
 907         int ret;
 908         unsigned long val;
 909
 910         ret = kstrtoul(buf, 0, &val);
 911         if (ret < 0)
 912                 return ret;
 913
 914         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 915                 tunables->boostpulse_duration_val;
 916         trace_cpufreq_interactive_boost("pulse");
 917         if (!tunables->boosted)
 918                 cpufreq_interactive_boost(tunables);
 919         return count;
 920 }
 921
 922 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 923                 *tunables, char *buf)
 924 {
 925         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 926 }
 927
 928 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 929                 *tunables, const char *buf, size_t count)
 930 {
 931         int ret;
 932         unsigned long val;
 933
 934         ret = kstrtoul(buf, 0, &val);
 935         if (ret < 0)
 936                 return ret;
 937
 938         tunables->boostpulse_duration_val = val;
 939         return count;
 940 }
 941
 942 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 943                 char *buf)
 944 {
 945         return sprintf(buf, "%u\n", tunables->io_is_busy);
 946 }
 947
 948 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 949                 const char *buf, size_t count)
 950 {
 951         int ret;
 952         unsigned long val;
 953
 954         ret = kstrtoul(buf, 0, &val);
 955         if (ret < 0)
 956                 return ret;
 957         tunables->io_is_busy = val;
 958         return count;
 959 }
 960
 961 /*
 962  * Create show/store routines
 963  * - sys: One governor instance for complete SYSTEM
 964  * - pol: One governor instance per struct cpufreq_policy
 965  */
 966 #define show_gov_pol_sys(file_name)                                     \
 967 static ssize_t show_##file_name##_gov_sys                               \
 968 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 969 {                                                                       \
 970         return show_##file_name(common_tunables, buf);                  \
 971 }                                                                       \
 972                                                                         \
 973 static ssize_t show_##file_name##_gov_pol                               \
 974 (struct cpufreq_policy *policy, char *buf)                              \
 975 {                                                                       \
 976         return show_##file_name(policy->governor_data, buf);            \
 977 }
 978
 979 #define store_gov_pol_sys(file_name)                                    \
 980 static ssize_t store_##file_name##_gov_sys                              \
 981 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
 982         size_t count)                                                   \
 983 {                                                                       \
 984         return store_##file_name(common_tunables, buf, count);          \
 985 }                                                                       \
 986                                                                         \
 987 static ssize_t store_##file_name##_gov_pol                              \
 988 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
 989 {                                                                       \
 990         return store_##file_name(policy->governor_data, buf, count);    \
 991 }
 992
 993 #define show_store_gov_pol_sys(file_name)                               \
 994 show_gov_pol_sys(file_name);                                            \
 995 store_gov_pol_sys(file_name)
 996
 997 show_store_gov_pol_sys(target_loads);
 998 show_store_gov_pol_sys(above_hispeed_delay);
 999 show_store_gov_pol_sys(hispeed_freq);
1000 show_store_gov_pol_sys(go_hispeed_load);
1001 show_store_gov_pol_sys(min_sample_time);
1002 show_store_gov_pol_sys(timer_rate);
1003 show_store_gov_pol_sys(timer_slack);
1004 show_store_gov_pol_sys(boost);
1005 store_gov_pol_sys(boostpulse);
1006 show_store_gov_pol_sys(boostpulse_duration);
1007 show_store_gov_pol_sys(io_is_busy);
1008
1009 #define gov_sys_attr_rw(_name)                                          \
1010 static struct global_attr _name##_gov_sys =                             \
1011 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
1012
1013 #define gov_pol_attr_rw(_name)                                          \
1014 static struct freq_attr _name##_gov_pol =                               \
1015 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
1016
1017 #define gov_sys_pol_attr_rw(_name)                                      \
1018         gov_sys_attr_rw(_name);                                         \
1019         gov_pol_attr_rw(_name)
1020
1021 gov_sys_pol_attr_rw(target_loads);
1022 gov_sys_pol_attr_rw(above_hispeed_delay);
1023 gov_sys_pol_attr_rw(hispeed_freq);
1024 gov_sys_pol_attr_rw(go_hispeed_load);
1025 gov_sys_pol_attr_rw(min_sample_time);
1026 gov_sys_pol_attr_rw(timer_rate);
1027 gov_sys_pol_attr_rw(timer_slack);
1028 gov_sys_pol_attr_rw(boost);
1029 gov_sys_pol_attr_rw(boostpulse_duration);
1030 gov_sys_pol_attr_rw(io_is_busy);
1031
1032 static struct global_attr boostpulse_gov_sys =
1033         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1034
1035 static struct freq_attr boostpulse_gov_pol =
1036         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1037
1038 /* One Governor instance for entire system */
1039 static struct attribute *interactive_attributes_gov_sys[] = {
1040         &target_loads_gov_sys.attr,
1041         &above_hispeed_delay_gov_sys.attr,
1042         &hispeed_freq_gov_sys.attr,
1043         &go_hispeed_load_gov_sys.attr,
1044         &min_sample_time_gov_sys.attr,
1045         &timer_rate_gov_sys.attr,
1046         &timer_slack_gov_sys.attr,
1047         &boost_gov_sys.attr,
1048         &boostpulse_gov_sys.attr,
1049         &boostpulse_duration_gov_sys.attr,
1050         &io_is_busy_gov_sys.attr,
1051         NULL,
1052 };
1053
1054 static struct attribute_group interactive_attr_group_gov_sys = {
1055         .attrs = interactive_attributes_gov_sys,
1056         .name = "interactive",
1057 };
1058
1059 /* Per policy governor instance */
1060 static struct attribute *interactive_attributes_gov_pol[] = {
1061         &target_loads_gov_pol.attr,
1062         &above_hispeed_delay_gov_pol.attr,
1063         &hispeed_freq_gov_pol.attr,
1064         &go_hispeed_load_gov_pol.attr,
1065         &min_sample_time_gov_pol.attr,
1066         &timer_rate_gov_pol.attr,
1067         &timer_slack_gov_pol.attr,
1068         &boost_gov_pol.attr,
1069         &boostpulse_gov_pol.attr,
1070         &boostpulse_duration_gov_pol.attr,
1071         &io_is_busy_gov_pol.attr,
1072         NULL,
1073 };
1074
1075 static struct attribute_group interactive_attr_group_gov_pol = {
1076         .attrs = interactive_attributes_gov_pol,
1077         .name = "interactive",
1078 };
1079
1080 static struct attribute_group *get_sysfs_attr(void)
1081 {
1082         if (have_governor_per_policy())
1083                 return &interactive_attr_group_gov_pol;
1084         else
1085                 return &interactive_attr_group_gov_sys;
1086 }
1087
1088 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1089                                              unsigned long val,
1090                                              void *data)
1091 {
1092         if (val == IDLE_END)
1093                 cpufreq_interactive_idle_end();
1094
1095         return 0;
1096 }
1097
1098 static struct notifier_block cpufreq_interactive_idle_nb = {
1099         .notifier_call = cpufreq_interactive_idle_notifier,
1100 };
1101
1102 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1103                 unsigned int event)
1104 {
1105         int rc;
1106         unsigned int j;
1107         struct cpufreq_interactive_cpuinfo *pcpu;
1108         struct cpufreq_frequency_table *freq_table;
1109         struct cpufreq_interactive_tunables *tunables;
1110         unsigned long flags;
1111
1112         if (have_governor_per_policy())
1113                 tunables = policy->governor_data;
1114         else
1115                 tunables = common_tunables;
1116
1117         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1118
1119         switch (event) {
1120         case CPUFREQ_GOV_POLICY_INIT:
1121                 if (have_governor_per_policy()) {
1122                         WARN_ON(tunables);
1123                 } else if (tunables) {
1124                         tunables->usage_count++;
1125                         policy->governor_data = tunables;
1126                         return 0;
1127                 }
1128
1129                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1130                 if (!tunables) {
1131                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1132                         return -ENOMEM;
1133                 }
1134
1135                 tunables->usage_count = 1;
1136                 tunables->above_hispeed_delay = default_above_hispeed_delay;
1137                 tunables->nabove_hispeed_delay =
1138                         ARRAY_SIZE(default_above_hispeed_delay);
1139                 tunables->go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
1140                 tunables->target_loads = default_target_loads;
1141                 tunables->ntarget_loads = ARRAY_SIZE(default_target_loads);
1142                 tunables->min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
1143                 tunables->timer_rate = DEFAULT_TIMER_RATE;
1144                 tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
1145                 tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
1146
1147                 spin_lock_init(&tunables->target_loads_lock);
1148                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1149
1150                 policy->governor_data = tunables;
1151                 if (!have_governor_per_policy()) {
1152                         common_tunables = tunables;
1153                 }
1154
1155                 rc = sysfs_create_group(get_governor_parent_kobj(policy),
1156                                 get_sysfs_attr());
1157                 if (rc) {
1158                         kfree(tunables);
1159                         policy->governor_data = NULL;
1160                         if (!have_governor_per_policy()) {
1161                                 common_tunables = NULL;
1162                         }
1163                         return rc;
1164                 }
1165
1166                 if (!policy->governor->initialized) {
1167                         idle_notifier_register(&cpufreq_interactive_idle_nb);
1168                         cpufreq_register_notifier(&cpufreq_notifier_block,
1169                                         CPUFREQ_TRANSITION_NOTIFIER);
1170                 }
1171
1172                 break;
1173
1174         case CPUFREQ_GOV_POLICY_EXIT:
1175                 if (!--tunables->usage_count) {
1176                         if (policy->governor->initialized == 1) {
1177                                 cpufreq_unregister_notifier(&cpufreq_notifier_block,
1178                                                 CPUFREQ_TRANSITION_NOTIFIER);
1179                                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1180                         }
1181
1182                         sysfs_remove_group(get_governor_parent_kobj(policy),
1183                                         get_sysfs_attr());
1184
1185
1186                         kfree(tunables);
1187                         common_tunables = NULL;
1188                 }
1189
1190                 policy->governor_data = NULL;
1191                 break;
1192
1193         case CPUFREQ_GOV_START:
1194                 mutex_lock(&gov_lock);
1195
1196                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1197                 if (!tunables->hispeed_freq)
1198                         tunables->hispeed_freq = policy->max;
1199
1200                 for_each_cpu(j, policy->cpus) {
1201                         pcpu = &per_cpu(cpuinfo, j);
1202                         pcpu->policy = policy;
1203                         pcpu->target_freq = policy->cur;
1204                         pcpu->freq_table = freq_table;
1205                         pcpu->floor_freq = pcpu->target_freq;
1206                         pcpu->pol_floor_val_time =
1207                                 ktime_to_us(ktime_get());
1208                         pcpu->loc_floor_val_time = pcpu->pol_floor_val_time;
1209                         pcpu->pol_hispeed_val_time = pcpu->pol_floor_val_time;
1210                         pcpu->loc_hispeed_val_time = pcpu->pol_floor_val_time;
1211                         down_write(&pcpu->enable_sem);
1212                         del_timer_sync(&pcpu->cpu_timer);
1213                         del_timer_sync(&pcpu->cpu_slack_timer);
1214                         cpufreq_interactive_timer_start(tunables, j);
1215                         pcpu->governor_enabled = 1;
1216                         up_write(&pcpu->enable_sem);
1217                 }
1218
1219                 mutex_unlock(&gov_lock);
1220                 break;
1221
1222         case CPUFREQ_GOV_STOP:
1223                 mutex_lock(&gov_lock);
1224                 for_each_cpu(j, policy->cpus) {
1225                         pcpu = &per_cpu(cpuinfo, j);
1226                         down_write(&pcpu->enable_sem);
1227                         pcpu->governor_enabled = 0;
1228                         del_timer_sync(&pcpu->cpu_timer);
1229                         del_timer_sync(&pcpu->cpu_slack_timer);
1230                         up_write(&pcpu->enable_sem);
1231                 }
1232
1233                 mutex_unlock(&gov_lock);
1234                 break;
1235
1236         case CPUFREQ_GOV_LIMITS:
1237                 if (policy->max < policy->cur)
1238                         __cpufreq_driver_target(policy,
1239                                         policy->max, CPUFREQ_RELATION_H);
1240                 else if (policy->min > policy->cur)
1241                         __cpufreq_driver_target(policy,
1242                                         policy->min, CPUFREQ_RELATION_L);
1243                 for_each_cpu(j, policy->cpus) {
1244                         pcpu = &per_cpu(cpuinfo, j);
1245
1246                         down_read(&pcpu->enable_sem);
1247                         if (pcpu->governor_enabled == 0) {
1248                                 up_read(&pcpu->enable_sem);
1249                                 continue;
1250                         }
1251
1252                         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
1253                         if (policy->max < pcpu->target_freq)
1254                                 pcpu->target_freq = policy->max;
1255                         else if (policy->min > pcpu->target_freq)
1256                                 pcpu->target_freq = policy->min;
1257
1258                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
1259                         up_read(&pcpu->enable_sem);
1260                 }
1261                 break;
1262         }
1263         return 0;
1264 }
1265
1266 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1267 static
1268 #endif
1269 struct cpufreq_governor cpufreq_gov_interactive = {
1270         .name = "interactive",
1271         .governor = cpufreq_governor_interactive,
1272         .max_transition_latency = 10000000,
1273         .owner = THIS_MODULE,
1274 };
1275
1276 static void cpufreq_interactive_nop_timer(unsigned long data)
1277 {
1278 }
1279
1280 static int __init cpufreq_interactive_init(void)
1281 {
1282         unsigned int i;
1283         struct cpufreq_interactive_cpuinfo *pcpu;
1284         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1285
1286         /* Initalize per-cpu timers */
1287         for_each_possible_cpu(i) {
1288                 pcpu = &per_cpu(cpuinfo, i);
1289                 init_timer_deferrable(&pcpu->cpu_timer);
1290                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1291                 pcpu->cpu_timer.data = i;
1292                 init_timer(&pcpu->cpu_slack_timer);
1293                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1294                 spin_lock_init(&pcpu->load_lock);
1295                 spin_lock_init(&pcpu->target_freq_lock);
1296                 init_rwsem(&pcpu->enable_sem);
1297         }
1298
1299         spin_lock_init(&speedchange_cpumask_lock);
1300         mutex_init(&gov_lock);
1301         speedchange_task =
1302                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1303                                "cfinteractive");
1304         if (IS_ERR(speedchange_task))
1305                 return PTR_ERR(speedchange_task);
1306
1307         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1308         get_task_struct(speedchange_task);
1309
1310         /* NB: wake up so the thread does not look hung to the freezer */
1311         wake_up_process(speedchange_task);
1312
1313         return cpufreq_register_governor(&cpufreq_gov_interactive);
1314 }
1315
1316 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1317 fs_initcall(cpufreq_interactive_init);
1318 #else
1319 module_init(cpufreq_interactive_init);
1320 #endif
1321
1322 static void __exit cpufreq_interactive_exit(void)
1323 {
1324         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1325         kthread_stop(speedchange_task);
1326         put_task_struct(speedchange_task);
1327 }
1328
1329 module_exit(cpufreq_interactive_exit);
1330
1331 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1332 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1333         "Latency sensitive workloads");
1334 MODULE_LICENSE("GPL");