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         unsigned int target_freq;
  49         unsigned int floor_freq;
  50         u64 floor_validate_time;
  51         u64 hispeed_validate_time;
  52         struct rw_semaphore enable_sem;
  53         int governor_enabled;
  54 };
  55
  56 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  57
  58 /* realtime thread handles frequency scaling */
  59 static struct task_struct *speedchange_task;
  60 static cpumask_t speedchange_cpumask;
  61 static spinlock_t speedchange_cpumask_lock;
  62 static struct mutex gov_lock;
  63
  64 /* Target load.  Lower values result in higher CPU speeds. */
  65 #define DEFAULT_TARGET_LOAD 90
  66 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  67
  68 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  69 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  70 static unsigned int default_above_hispeed_delay[] = {
  71         DEFAULT_ABOVE_HISPEED_DELAY };
  72
  73 struct cpufreq_interactive_tunables {
  74         int usage_count;
  75         /* Hi speed to bump to from lo speed when load burst (default max) */
  76         unsigned int hispeed_freq;
  77         /* Go to hi speed when CPU load at or above this value. */
  78 #define DEFAULT_GO_HISPEED_LOAD 99
  79         unsigned long go_hispeed_load;
  80         /* Target load. Lower values result in higher CPU speeds. */
  81         spinlock_t target_loads_lock;
  82         unsigned int *target_loads;
  83         int ntarget_loads;
  84         /*
  85          * The minimum amount of time to spend at a frequency before we can ramp
  86          * down.
  87          */
  88 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  89         unsigned long min_sample_time;
  90         /*
  91          * The sample rate of the timer used to increase frequency
  92          */
  93         unsigned long timer_rate;
  94         /*
  95          * Wait this long before raising speed above hispeed, by default a
  96          * single timer interval.
  97          */
  98         spinlock_t above_hispeed_delay_lock;
  99         unsigned int *above_hispeed_delay;
 100         int nabove_hispeed_delay;
 101         /* Non-zero means indefinite speed boost active */
 102         int boost_val;
 103         /* Duration of a boot pulse in usecs */
 104         int boostpulse_duration_val;
 105         /* End time of boost pulse in ktime converted to usecs */
 106         u64 boostpulse_endtime;
 107         /*
 108          * Max additional time to wait in idle, beyond timer_rate, at speeds
 109          * above minimum before wakeup to reduce speed, or -1 if unnecessary.
 110          */
 111 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 112         int timer_slack_val;
 113         bool io_is_busy;
 114 };
 115
 116 /* For cases where we have single governor instance for system */
 117 struct cpufreq_interactive_tunables *common_tunables;
 118
 119 static struct attribute_group *get_sysfs_attr(void);
 120
 121 static void cpufreq_interactive_timer_resched(
 122         struct cpufreq_interactive_cpuinfo *pcpu)
 123 {
 124         struct cpufreq_interactive_tunables *tunables =
 125                 pcpu->policy->governor_data;
 126         unsigned long expires;
 127         unsigned long flags;
 128
 129         spin_lock_irqsave(&pcpu->load_lock, flags);
 130         pcpu->time_in_idle =
 131                 get_cpu_idle_time(smp_processor_id(),
 132                                   &pcpu->time_in_idle_timestamp,
 133                                   tunables->io_is_busy);
 134         pcpu->cputime_speedadj = 0;
 135         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 136         expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 137         mod_timer_pinned(&pcpu->cpu_timer, expires);
 138
 139         if (tunables->timer_slack_val >= 0 &&
 140             pcpu->target_freq > pcpu->policy->min) {
 141                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 142                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 143         }
 144
 145         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 146 }
 147
 148 /* The caller shall take enable_sem write semaphore to avoid any timer race.
 149  * The cpu_timer and cpu_slack_timer must be deactivated when calling this
 150  * function.
 151  */
 152 static void cpufreq_interactive_timer_start(
 153         struct cpufreq_interactive_tunables *tunables, int cpu)
 154 {
 155         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 156         unsigned long expires = jiffies +
 157                 usecs_to_jiffies(tunables->timer_rate);
 158         unsigned long flags;
 159
 160         pcpu->cpu_timer.expires = expires;
 161         add_timer_on(&pcpu->cpu_timer, cpu);
 162         if (tunables->timer_slack_val >= 0 &&
 163             pcpu->target_freq > pcpu->policy->min) {
 164                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 165                 pcpu->cpu_slack_timer.expires = expires;
 166                 add_timer_on(&pcpu->cpu_slack_timer, cpu);
 167         }
 168
 169         spin_lock_irqsave(&pcpu->load_lock, flags);
 170         pcpu->time_in_idle =
 171                 get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp,
 172                                   tunables->io_is_busy);
 173         pcpu->cputime_speedadj = 0;
 174         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 175         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 176 }
 177
 178 static unsigned int freq_to_above_hispeed_delay(
 179         struct cpufreq_interactive_tunables *tunables,
 180         unsigned int freq)
 181 {
 182         int i;
 183         unsigned int ret;
 184         unsigned long flags;
 185
 186         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 187
 188         for (i = 0; i < tunables->nabove_hispeed_delay - 1 &&
 189                         freq >= tunables->above_hispeed_delay[i+1]; i += 2)
 190                 ;
 191
 192         ret = tunables->above_hispeed_delay[i];
 193         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 194         return ret;
 195 }
 196
 197 static unsigned int freq_to_targetload(
 198         struct cpufreq_interactive_tunables *tunables, unsigned int freq)
 199 {
 200         int i;
 201         unsigned int ret;
 202         unsigned long flags;
 203
 204         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 205
 206         for (i = 0; i < tunables->ntarget_loads - 1 &&
 207                     freq >= tunables->target_loads[i+1]; i += 2)
 208                 ;
 209
 210         ret = tunables->target_loads[i];
 211         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 212         return ret;
 213 }
 214
 215 /*
 216  * If increasing frequencies never map to a lower target load then
 217  * choose_freq() will find the minimum frequency that does not exceed its
 218  * target load given the current load.
 219  */
 220 static unsigned int choose_freq(struct cpufreq_interactive_cpuinfo *pcpu,
 221                 unsigned int loadadjfreq)
 222 {
 223         unsigned int freq = pcpu->policy->cur;
 224         unsigned int prevfreq, freqmin, freqmax;
 225         unsigned int tl;
 226         int index;
 227
 228         freqmin = 0;
 229         freqmax = UINT_MAX;
 230
 231         do {
 232                 prevfreq = freq;
 233                 tl = freq_to_targetload(pcpu->policy->governor_data, freq);
 234
 235                 /*
 236                  * Find the lowest frequency where the computed load is less
 237                  * than or equal to the target load.
 238                  */
 239
 240                 if (cpufreq_frequency_table_target(
 241                             pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 242                             CPUFREQ_RELATION_L, &index))
 243                         break;
 244                 freq = pcpu->freq_table[index].frequency;
 245
 246                 if (freq > prevfreq) {
 247                         /* The previous frequency is too low. */
 248                         freqmin = prevfreq;
 249
 250                         if (freq >= freqmax) {
 251                                 /*
 252                                  * Find the highest frequency that is less
 253                                  * than freqmax.
 254                                  */
 255                                 if (cpufreq_frequency_table_target(
 256                                             pcpu->policy, pcpu->freq_table,
 257                                             freqmax - 1, CPUFREQ_RELATION_H,
 258                                             &index))
 259                                         break;
 260                                 freq = pcpu->freq_table[index].frequency;
 261
 262                                 if (freq == freqmin) {
 263                                         /*
 264                                          * The first frequency below freqmax
 265                                          * has already been found to be too
 266                                          * low.  freqmax is the lowest speed
 267                                          * we found that is fast enough.
 268                                          */
 269                                         freq = freqmax;
 270                                         break;
 271                                 }
 272                         }
 273                 } else if (freq < prevfreq) {
 274                         /* The previous frequency is high enough. */
 275                         freqmax = prevfreq;
 276
 277                         if (freq <= freqmin) {
 278                                 /*
 279                                  * Find the lowest frequency that is higher
 280                                  * than freqmin.
 281                                  */
 282                                 if (cpufreq_frequency_table_target(
 283                                             pcpu->policy, pcpu->freq_table,
 284                                             freqmin + 1, CPUFREQ_RELATION_L,
 285                                             &index))
 286                                         break;
 287                                 freq = pcpu->freq_table[index].frequency;
 288
 289                                 /*
 290                                  * If freqmax is the first frequency above
 291                                  * freqmin then we have already found that
 292                                  * this speed is fast enough.
 293                                  */
 294                                 if (freq == freqmax)
 295                                         break;
 296                         }
 297                 }
 298
 299                 /* If same frequency chosen as previous then done. */
 300         } while (freq != prevfreq);
 301
 302         return freq;
 303 }
 304
 305 static u64 update_load(int cpu)
 306 {
 307         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 308         struct cpufreq_interactive_tunables *tunables =
 309                 pcpu->policy->governor_data;
 310         u64 now;
 311         u64 now_idle;
 312         u64 delta_idle;
 313         u64 delta_time;
 314         u64 active_time;
 315
 316         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 317         delta_idle = (now_idle - pcpu->time_in_idle);
 318         delta_time = (now - pcpu->time_in_idle_timestamp);
 319
 320         if (delta_time <= delta_idle)
 321                 active_time = 0;
 322         else
 323                 active_time = delta_time - delta_idle;
 324
 325         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 326
 327         pcpu->time_in_idle = now_idle;
 328         pcpu->time_in_idle_timestamp = now;
 329         return now;
 330 }
 331
 332 static void cpufreq_interactive_timer(unsigned long data)
 333 {
 334         u64 now;
 335         unsigned int delta_time;
 336         u64 cputime_speedadj;
 337         int cpu_load;
 338         struct cpufreq_interactive_cpuinfo *pcpu =
 339                 &per_cpu(cpuinfo, data);
 340         struct cpufreq_interactive_tunables *tunables =
 341                 pcpu->policy->governor_data;
 342         unsigned int new_freq;
 343         unsigned int loadadjfreq;
 344         unsigned int index;
 345         unsigned long flags;
 346         bool boosted;
 347
 348         if (!down_read_trylock(&pcpu->enable_sem))
 349                 return;
 350         if (!pcpu->governor_enabled)
 351                 goto exit;
 352
 353         spin_lock_irqsave(&pcpu->load_lock, flags);
 354         now = update_load(data);
 355         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 356         cputime_speedadj = pcpu->cputime_speedadj;
 357         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 358
 359         if (WARN_ON_ONCE(!delta_time))
 360                 goto rearm;
 361
 362         do_div(cputime_speedadj, delta_time);
 363         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 364         cpu_load = loadadjfreq / pcpu->target_freq;
 365         boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 366
 367 #ifdef CONFIG_ARCH_ROCKCHIP
 368         pcpu->target_freq = pcpu->policy->cur;
 369 #endif
 370
 371         if (cpu_load >= tunables->go_hispeed_load || boosted) {
 372                 if (pcpu->target_freq < 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         }
 383
 384         if (pcpu->target_freq >= tunables->hispeed_freq &&
 385             new_freq > pcpu->target_freq &&
 386             now - pcpu->hispeed_validate_time <
 387             freq_to_above_hispeed_delay(tunables, pcpu->target_freq)) {
 388                 trace_cpufreq_interactive_notyet(
 389                         data, cpu_load, pcpu->target_freq,
 390                         pcpu->policy->cur, new_freq);
 391                 goto rearm;
 392         }
 393
 394         pcpu->hispeed_validate_time = now;
 395
 396         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 397                                            new_freq, CPUFREQ_RELATION_L,
 398                                            &index))
 399                 goto rearm;
 400
 401         new_freq = pcpu->freq_table[index].frequency;
 402
 403         /*
 404          * Do not scale below floor_freq unless we have been at or above the
 405          * floor frequency for the minimum sample time since last validated.
 406          */
 407         if (new_freq < pcpu->floor_freq) {
 408                 if (now - pcpu->floor_validate_time <
 409                                 tunables->min_sample_time) {
 410                         trace_cpufreq_interactive_notyet(
 411                                 data, cpu_load, pcpu->target_freq,
 412                                 pcpu->policy->cur, new_freq);
 413                         goto rearm;
 414                 }
 415         }
 416
 417         /*
 418          * Update the timestamp for checking whether speed has been held at
 419          * or above the selected frequency for a minimum of min_sample_time,
 420          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 421          * allow the speed to drop as soon as the boostpulse duration expires
 422          * (or the indefinite boost is turned off).
 423          */
 424
 425         if (!boosted || new_freq > tunables->hispeed_freq) {
 426                 pcpu->floor_freq = new_freq;
 427                 pcpu->floor_validate_time = now;
 428         }
 429
 430         if (pcpu->target_freq == new_freq) {
 431                 trace_cpufreq_interactive_already(
 432                         data, cpu_load, pcpu->target_freq,
 433                         pcpu->policy->cur, new_freq);
 434                 goto rearm_if_notmax;
 435         }
 436
 437         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 438                                          pcpu->policy->cur, new_freq);
 439
 440         pcpu->target_freq = new_freq;
 441         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 442         cpumask_set_cpu(data, &speedchange_cpumask);
 443         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 444         wake_up_process(speedchange_task);
 445
 446 rearm_if_notmax:
 447         /*
 448          * Already set max speed and don't see a need to change that,
 449          * wait until next idle to re-evaluate, don't need timer.
 450          */
 451         if (pcpu->target_freq == pcpu->policy->max)
 452                 goto exit;
 453
 454 rearm:
 455         if (!timer_pending(&pcpu->cpu_timer))
 456                 cpufreq_interactive_timer_resched(pcpu);
 457
 458 exit:
 459         up_read(&pcpu->enable_sem);
 460         return;
 461 }
 462
 463 static void cpufreq_interactive_idle_start(void)
 464 {
 465         struct cpufreq_interactive_cpuinfo *pcpu =
 466                 &per_cpu(cpuinfo, smp_processor_id());
 467         int pending;
 468
 469         if (!down_read_trylock(&pcpu->enable_sem))
 470                 return;
 471         if (!pcpu->governor_enabled) {
 472                 up_read(&pcpu->enable_sem);
 473                 return;
 474         }
 475
 476         pending = timer_pending(&pcpu->cpu_timer);
 477
 478         if (pcpu->target_freq != pcpu->policy->min) {
 479                 /*
 480                  * Entering idle while not at lowest speed.  On some
 481                  * platforms this can hold the other CPU(s) at that speed
 482                  * even though the CPU is idle. Set a timer to re-evaluate
 483                  * speed so this idle CPU doesn't hold the other CPUs above
 484                  * min indefinitely.  This should probably be a quirk of
 485                  * the CPUFreq driver.
 486                  */
 487                 if (!pending)
 488                         cpufreq_interactive_timer_resched(pcpu);
 489         }
 490
 491         up_read(&pcpu->enable_sem);
 492 }
 493
 494 static void cpufreq_interactive_idle_end(void)
 495 {
 496         struct cpufreq_interactive_cpuinfo *pcpu =
 497                 &per_cpu(cpuinfo, smp_processor_id());
 498
 499         if (!down_read_trylock(&pcpu->enable_sem))
 500                 return;
 501         if (!pcpu->governor_enabled) {
 502                 up_read(&pcpu->enable_sem);
 503                 return;
 504         }
 505
 506         /* Arm the timer for 1-2 ticks later if not already. */
 507         if (!timer_pending(&pcpu->cpu_timer)) {
 508                 cpufreq_interactive_timer_resched(pcpu);
 509         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 510                 del_timer(&pcpu->cpu_timer);
 511                 del_timer(&pcpu->cpu_slack_timer);
 512                 cpufreq_interactive_timer(smp_processor_id());
 513         }
 514
 515         up_read(&pcpu->enable_sem);
 516 }
 517
 518 static int cpufreq_interactive_speedchange_task(void *data)
 519 {
 520         unsigned int cpu;
 521         cpumask_t tmp_mask;
 522         unsigned long flags;
 523         struct cpufreq_interactive_cpuinfo *pcpu;
 524
 525         while (1) {
 526                 set_current_state(TASK_INTERRUPTIBLE);
 527                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 528
 529                 if (cpumask_empty(&speedchange_cpumask)) {
 530                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 531                                                flags);
 532                         schedule();
 533
 534                         if (kthread_should_stop())
 535                                 break;
 536
 537                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 538                 }
 539
 540                 set_current_state(TASK_RUNNING);
 541                 tmp_mask = speedchange_cpumask;
 542                 cpumask_clear(&speedchange_cpumask);
 543                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 544
 545                 for_each_cpu(cpu, &tmp_mask) {
 546                         unsigned int j;
 547                         unsigned int max_freq = 0;
 548
 549                         pcpu = &per_cpu(cpuinfo, cpu);
 550                         if (!down_read_trylock(&pcpu->enable_sem))
 551                                 continue;
 552                         if (!pcpu->governor_enabled) {
 553                                 up_read(&pcpu->enable_sem);
 554                                 continue;
 555                         }
 556
 557                         for_each_cpu(j, pcpu->policy->cpus) {
 558                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 559                                         &per_cpu(cpuinfo, j);
 560
 561                                 if (pjcpu->target_freq > max_freq)
 562                                         max_freq = pjcpu->target_freq;
 563                         }
 564
 565                         if (max_freq != pcpu->policy->cur)
 566                                 __cpufreq_driver_target(pcpu->policy,
 567                                                         max_freq,
 568                                                         CPUFREQ_RELATION_H);
 569                         trace_cpufreq_interactive_setspeed(cpu,
 570                                                      pcpu->target_freq,
 571                                                      pcpu->policy->cur);
 572
 573                         up_read(&pcpu->enable_sem);
 574                 }
 575         }
 576
 577         return 0;
 578 }
 579
 580 static void cpufreq_interactive_boost(void)
 581 {
 582         int i;
 583         int anyboost = 0;
 584         unsigned long flags;
 585         struct cpufreq_interactive_cpuinfo *pcpu;
 586         struct cpufreq_interactive_tunables *tunables;
 587
 588         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 589
 590         for_each_online_cpu(i) {
 591                 pcpu = &per_cpu(cpuinfo, i);
 592                 tunables = pcpu->policy->governor_data;
 593
 594                 if (pcpu->target_freq < tunables->hispeed_freq) {
 595                         pcpu->target_freq = tunables->hispeed_freq;
 596                         cpumask_set_cpu(i, &speedchange_cpumask);
 597                         pcpu->hispeed_validate_time =
 598                                 ktime_to_us(ktime_get());
 599                         anyboost = 1;
 600                 }
 601
 602                 /*
 603                  * Set floor freq and (re)start timer for when last
 604                  * validated.
 605                  */
 606
 607                 pcpu->floor_freq = tunables->hispeed_freq;
 608                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 609         }
 610
 611         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 612
 613         if (anyboost)
 614                 wake_up_process(speedchange_task);
 615 }
 616
 617 static int cpufreq_interactive_notifier(
 618         struct notifier_block *nb, unsigned long val, void *data)
 619 {
 620         struct cpufreq_freqs *freq = data;
 621         struct cpufreq_interactive_cpuinfo *pcpu;
 622         int cpu;
 623         unsigned long flags;
 624
 625         if (val == CPUFREQ_POSTCHANGE) {
 626                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 627                 if (!down_read_trylock(&pcpu->enable_sem))
 628                         return 0;
 629                 if (!pcpu->governor_enabled) {
 630                         up_read(&pcpu->enable_sem);
 631                         return 0;
 632                 }
 633
 634                 for_each_cpu(cpu, pcpu->policy->cpus) {
 635                         struct cpufreq_interactive_cpuinfo *pjcpu =
 636                                 &per_cpu(cpuinfo, cpu);
 637                         if (cpu != freq->cpu) {
 638                                 if (!down_read_trylock(&pjcpu->enable_sem))
 639                                         continue;
 640                                 if (!pjcpu->governor_enabled) {
 641                                         up_read(&pjcpu->enable_sem);
 642                                         continue;
 643                                 }
 644                         }
 645                         spin_lock_irqsave(&pjcpu->load_lock, flags);
 646                         update_load(cpu);
 647                         spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 648                         if (cpu != freq->cpu)
 649                                 up_read(&pjcpu->enable_sem);
 650                 }
 651
 652                 up_read(&pcpu->enable_sem);
 653         }
 654         return 0;
 655 }
 656
 657 static struct notifier_block cpufreq_notifier_block = {
 658         .notifier_call = cpufreq_interactive_notifier,
 659 };
 660
 661 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 662 {
 663         const char *cp;
 664         int i;
 665         int ntokens = 1;
 666         unsigned int *tokenized_data;
 667         int err = -EINVAL;
 668
 669         cp = buf;
 670         while ((cp = strpbrk(cp + 1, " :")))
 671                 ntokens++;
 672
 673         if (!(ntokens & 0x1))
 674                 goto err;
 675
 676         tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 677         if (!tokenized_data) {
 678                 err = -ENOMEM;
 679                 goto err;
 680         }
 681
 682         cp = buf;
 683         i = 0;
 684         while (i < ntokens) {
 685                 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
 686                         goto err_kfree;
 687
 688                 cp = strpbrk(cp, " :");
 689                 if (!cp)
 690                         break;
 691                 cp++;
 692         }
 693
 694         if (i != ntokens)
 695                 goto err_kfree;
 696
 697         *num_tokens = ntokens;
 698         return tokenized_data;
 699
 700 err_kfree:
 701         kfree(tokenized_data);
 702 err:
 703         return ERR_PTR(err);
 704 }
 705
 706 static ssize_t show_target_loads(
 707         struct cpufreq_interactive_tunables *tunables,
 708         char *buf)
 709 {
 710         int i;
 711         ssize_t ret = 0;
 712         unsigned long flags;
 713
 714         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 715
 716         for (i = 0; i < tunables->ntarget_loads; i++)
 717                 ret += sprintf(buf + ret, "%u%s", tunables->target_loads[i],
 718                                i & 0x1 ? ":" : " ");
 719
 720         sprintf(buf + ret - 1, "\n");
 721         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 722         return ret;
 723 }
 724
 725 static ssize_t store_target_loads(
 726         struct cpufreq_interactive_tunables *tunables,
 727         const char *buf, size_t count)
 728 {
 729         int ntokens;
 730         unsigned int *new_target_loads = NULL;
 731         unsigned long flags;
 732
 733         new_target_loads = get_tokenized_data(buf, &ntokens);
 734         if (IS_ERR(new_target_loads))
 735                 return PTR_RET(new_target_loads);
 736
 737         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 738         if (tunables->target_loads != default_target_loads)
 739                 kfree(tunables->target_loads);
 740         tunables->target_loads = new_target_loads;
 741         tunables->ntarget_loads = ntokens;
 742         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 743         return count;
 744 }
 745
 746 static ssize_t show_above_hispeed_delay(
 747         struct cpufreq_interactive_tunables *tunables, char *buf)
 748 {
 749         int i;
 750         ssize_t ret = 0;
 751         unsigned long flags;
 752
 753         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 754
 755         for (i = 0; i < tunables->nabove_hispeed_delay; i++)
 756                 ret += sprintf(buf + ret, "%u%s",
 757                                tunables->above_hispeed_delay[i],
 758                                i & 0x1 ? ":" : " ");
 759
 760         sprintf(buf + ret - 1, "\n");
 761         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 762         return ret;
 763 }
 764
 765 static ssize_t store_above_hispeed_delay(
 766         struct cpufreq_interactive_tunables *tunables,
 767         const char *buf, size_t count)
 768 {
 769         int ntokens;
 770         unsigned int *new_above_hispeed_delay = NULL;
 771         unsigned long flags;
 772
 773         new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
 774         if (IS_ERR(new_above_hispeed_delay))
 775                 return PTR_RET(new_above_hispeed_delay);
 776
 777         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 778         if (tunables->above_hispeed_delay != default_above_hispeed_delay)
 779                 kfree(tunables->above_hispeed_delay);
 780         tunables->above_hispeed_delay = new_above_hispeed_delay;
 781         tunables->nabove_hispeed_delay = ntokens;
 782         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 783         return count;
 784
 785 }
 786
 787 static ssize_t show_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 788                 char *buf)
 789 {
 790         return sprintf(buf, "%u\n", tunables->hispeed_freq);
 791 }
 792
 793 static ssize_t store_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 794                 const char *buf, size_t count)
 795 {
 796         int ret;
 797         long unsigned int val;
 798
 799         ret = strict_strtoul(buf, 0, &val);
 800         if (ret < 0)
 801                 return ret;
 802         tunables->hispeed_freq = val;
 803         return count;
 804 }
 805
 806 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 807                 *tunables, char *buf)
 808 {
 809         return sprintf(buf, "%lu\n", tunables->go_hispeed_load);
 810 }
 811
 812 static ssize_t store_go_hispeed_load(struct cpufreq_interactive_tunables
 813                 *tunables, const char *buf, size_t count)
 814 {
 815         int ret;
 816         unsigned long val;
 817
 818         ret = strict_strtoul(buf, 0, &val);
 819         if (ret < 0)
 820                 return ret;
 821         tunables->go_hispeed_load = val;
 822         return count;
 823 }
 824
 825 static ssize_t show_min_sample_time(struct cpufreq_interactive_tunables
 826                 *tunables, char *buf)
 827 {
 828         return sprintf(buf, "%lu\n", tunables->min_sample_time);
 829 }
 830
 831 static ssize_t store_min_sample_time(struct cpufreq_interactive_tunables
 832                 *tunables, const char *buf, size_t count)
 833 {
 834         int ret;
 835         unsigned long val;
 836
 837         ret = strict_strtoul(buf, 0, &val);
 838         if (ret < 0)
 839                 return ret;
 840         tunables->min_sample_time = val;
 841         return count;
 842 }
 843
 844 static ssize_t show_timer_rate(struct cpufreq_interactive_tunables *tunables,
 845                 char *buf)
 846 {
 847         return sprintf(buf, "%lu\n", tunables->timer_rate);
 848 }
 849
 850 static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 851                 const char *buf, size_t count)
 852 {
 853         int ret;
 854         unsigned long val;
 855
 856         ret = strict_strtoul(buf, 0, &val);
 857         if (ret < 0)
 858                 return ret;
 859         tunables->timer_rate = val;
 860         return count;
 861 }
 862
 863 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 864                 char *buf)
 865 {
 866         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 867 }
 868
 869 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 870                 const char *buf, size_t count)
 871 {
 872         int ret;
 873         unsigned long val;
 874
 875         ret = kstrtol(buf, 10, &val);
 876         if (ret < 0)
 877                 return ret;
 878
 879         tunables->timer_slack_val = val;
 880         return count;
 881 }
 882
 883 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 884                           char *buf)
 885 {
 886         return sprintf(buf, "%d\n", tunables->boost_val);
 887 }
 888
 889 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 890                            const char *buf, size_t count)
 891 {
 892         int ret;
 893         unsigned long val;
 894
 895         ret = kstrtoul(buf, 0, &val);
 896         if (ret < 0)
 897                 return ret;
 898
 899         tunables->boost_val = val;
 900
 901         if (tunables->boost_val) {
 902                 trace_cpufreq_interactive_boost("on");
 903                 cpufreq_interactive_boost();
 904         } else {
 905                 trace_cpufreq_interactive_unboost("off");
 906         }
 907
 908         return count;
 909 }
 910
 911 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 912                                 const char *buf, size_t count)
 913 {
 914         int ret;
 915         unsigned long val;
 916
 917         ret = kstrtoul(buf, 0, &val);
 918         if (ret < 0)
 919                 return ret;
 920
 921         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 922                 tunables->boostpulse_duration_val;
 923         trace_cpufreq_interactive_boost("pulse");
 924         cpufreq_interactive_boost();
 925         return count;
 926 }
 927
 928 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 929                 *tunables, char *buf)
 930 {
 931         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 932 }
 933
 934 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 935                 *tunables, const char *buf, size_t count)
 936 {
 937         int ret;
 938         unsigned long val;
 939
 940         ret = kstrtoul(buf, 0, &val);
 941         if (ret < 0)
 942                 return ret;
 943
 944         tunables->boostpulse_duration_val = val;
 945         return count;
 946 }
 947
 948 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 949                 char *buf)
 950 {
 951         return sprintf(buf, "%u\n", tunables->io_is_busy);
 952 }
 953
 954 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 955                 const char *buf, size_t count)
 956 {
 957         int ret;
 958         unsigned long val;
 959
 960         ret = kstrtoul(buf, 0, &val);
 961         if (ret < 0)
 962                 return ret;
 963         tunables->io_is_busy = val;
 964         return count;
 965 }
 966
 967 /*
 968  * Create show/store routines
 969  * - sys: One governor instance for complete SYSTEM
 970  * - pol: One governor instance per struct cpufreq_policy
 971  */
 972 #define show_gov_pol_sys(file_name)                                     \
 973 static ssize_t show_##file_name##_gov_sys                               \
 974 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 975 {                                                                       \
 976         return show_##file_name(common_tunables, buf);                  \
 977 }                                                                       \
 978                                                                         \
 979 static ssize_t show_##file_name##_gov_pol                               \
 980 (struct cpufreq_policy *policy, char *buf)                              \
 981 {                                                                       \
 982         return show_##file_name(policy->governor_data, buf);            \
 983 }
 984
 985 #define store_gov_pol_sys(file_name)                                    \
 986 static ssize_t store_##file_name##_gov_sys                              \
 987 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
 988         size_t count)                                                   \
 989 {                                                                       \
 990         return store_##file_name(common_tunables, buf, count);          \
 991 }                                                                       \
 992                                                                         \
 993 static ssize_t store_##file_name##_gov_pol                              \
 994 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
 995 {                                                                       \
 996         return store_##file_name(policy->governor_data, buf, count);    \
 997 }
 998
 999 #define show_store_gov_pol_sys(file_name)                               \
1000 show_gov_pol_sys(file_name);                                            \
1001 store_gov_pol_sys(file_name)
1002
1003 show_store_gov_pol_sys(target_loads);
1004 show_store_gov_pol_sys(above_hispeed_delay);
1005 show_store_gov_pol_sys(hispeed_freq);
1006 show_store_gov_pol_sys(go_hispeed_load);
1007 show_store_gov_pol_sys(min_sample_time);
1008 show_store_gov_pol_sys(timer_rate);
1009 show_store_gov_pol_sys(timer_slack);
1010 show_store_gov_pol_sys(boost);
1011 store_gov_pol_sys(boostpulse);
1012 show_store_gov_pol_sys(boostpulse_duration);
1013 show_store_gov_pol_sys(io_is_busy);
1014
1015 #define gov_sys_attr_rw(_name)                                          \
1016 static struct global_attr _name##_gov_sys =                             \
1017 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
1018
1019 #define gov_pol_attr_rw(_name)                                          \
1020 static struct freq_attr _name##_gov_pol =                               \
1021 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
1022
1023 #define gov_sys_pol_attr_rw(_name)                                      \
1024         gov_sys_attr_rw(_name);                                         \
1025         gov_pol_attr_rw(_name)
1026
1027 gov_sys_pol_attr_rw(target_loads);
1028 gov_sys_pol_attr_rw(above_hispeed_delay);
1029 gov_sys_pol_attr_rw(hispeed_freq);
1030 gov_sys_pol_attr_rw(go_hispeed_load);
1031 gov_sys_pol_attr_rw(min_sample_time);
1032 gov_sys_pol_attr_rw(timer_rate);
1033 gov_sys_pol_attr_rw(timer_slack);
1034 gov_sys_pol_attr_rw(boost);
1035 gov_sys_pol_attr_rw(boostpulse_duration);
1036 gov_sys_pol_attr_rw(io_is_busy);
1037
1038 static struct global_attr boostpulse_gov_sys =
1039         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1040
1041 static struct freq_attr boostpulse_gov_pol =
1042         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1043
1044 /* One Governor instance for entire system */
1045 static struct attribute *interactive_attributes_gov_sys[] = {
1046         &target_loads_gov_sys.attr,
1047         &above_hispeed_delay_gov_sys.attr,
1048         &hispeed_freq_gov_sys.attr,
1049         &go_hispeed_load_gov_sys.attr,
1050         &min_sample_time_gov_sys.attr,
1051         &timer_rate_gov_sys.attr,
1052         &timer_slack_gov_sys.attr,
1053         &boost_gov_sys.attr,
1054         &boostpulse_gov_sys.attr,
1055         &boostpulse_duration_gov_sys.attr,
1056         &io_is_busy_gov_sys.attr,
1057         NULL,
1058 };
1059
1060 static struct attribute_group interactive_attr_group_gov_sys = {
1061         .attrs = interactive_attributes_gov_sys,
1062         .name = "interactive",
1063 };
1064
1065 /* Per policy governor instance */
1066 static struct attribute *interactive_attributes_gov_pol[] = {
1067         &target_loads_gov_pol.attr,
1068         &above_hispeed_delay_gov_pol.attr,
1069         &hispeed_freq_gov_pol.attr,
1070         &go_hispeed_load_gov_pol.attr,
1071         &min_sample_time_gov_pol.attr,
1072         &timer_rate_gov_pol.attr,
1073         &timer_slack_gov_pol.attr,
1074         &boost_gov_pol.attr,
1075         &boostpulse_gov_pol.attr,
1076         &boostpulse_duration_gov_pol.attr,
1077         &io_is_busy_gov_pol.attr,
1078         NULL,
1079 };
1080
1081 static struct attribute_group interactive_attr_group_gov_pol = {
1082         .attrs = interactive_attributes_gov_pol,
1083         .name = "interactive",
1084 };
1085
1086 static struct attribute_group *get_sysfs_attr(void)
1087 {
1088         if (have_governor_per_policy())
1089                 return &interactive_attr_group_gov_pol;
1090         else
1091                 return &interactive_attr_group_gov_sys;
1092 }
1093
1094 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1095                                              unsigned long val,
1096                                              void *data)
1097 {
1098         switch (val) {
1099         case IDLE_START:
1100                 cpufreq_interactive_idle_start();
1101                 break;
1102         case IDLE_END:
1103                 cpufreq_interactive_idle_end();
1104                 break;
1105         }
1106
1107         return 0;
1108 }
1109
1110 static struct notifier_block cpufreq_interactive_idle_nb = {
1111         .notifier_call = cpufreq_interactive_idle_notifier,
1112 };
1113
1114 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1115                 unsigned int event)
1116 {
1117         int rc;
1118         unsigned int j;
1119         struct cpufreq_interactive_cpuinfo *pcpu;
1120         struct cpufreq_frequency_table *freq_table;
1121         struct cpufreq_interactive_tunables *tunables;
1122
1123         if (have_governor_per_policy())
1124                 tunables = policy->governor_data;
1125         else
1126                 tunables = common_tunables;
1127
1128         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1129
1130         switch (event) {
1131         case CPUFREQ_GOV_POLICY_INIT:
1132                 if (have_governor_per_policy()) {
1133                         WARN_ON(tunables);
1134                 } else if (tunables) {
1135                         tunables->usage_count++;
1136                         policy->governor_data = tunables;
1137                         return 0;
1138                 }
1139
1140                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1141                 if (!tunables) {
1142                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1143                         return -ENOMEM;
1144                 }
1145
1146                 rc = sysfs_create_group(get_governor_parent_kobj(policy),
1147                                 get_sysfs_attr());
1148                 if (rc) {
1149                         kfree(tunables);
1150                         return rc;
1151                 }
1152
1153                 tunables->usage_count = 1;
1154                 tunables->above_hispeed_delay = default_above_hispeed_delay;
1155                 tunables->nabove_hispeed_delay =
1156                         ARRAY_SIZE(default_above_hispeed_delay);
1157                 tunables->go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
1158                 tunables->target_loads = default_target_loads;
1159                 tunables->ntarget_loads = ARRAY_SIZE(default_target_loads);
1160                 tunables->min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
1161                 tunables->timer_rate = DEFAULT_TIMER_RATE;
1162                 tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
1163                 tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
1164
1165 #ifdef CONFIG_ARCH_ROCKCHIP
1166                 {
1167                         unsigned int index;
1168                         freq_table = cpufreq_frequency_get_table(policy->cpu);
1169                         tunables->hispeed_freq = policy->max;
1170                         if (policy->min < 816000)
1171                                 tunables->hispeed_freq = 816000;
1172                         else if (cpufreq_frequency_table_target(policy, freq_table, policy->min + 1, CPUFREQ_RELATION_L, &index) == 0)
1173                                 tunables->hispeed_freq = freq_table[index].frequency;
1174                         if (policy->max > 1416000) {
1175                                 tunables->timer_slack_val = 20 * USEC_PER_MSEC;
1176                                 tunables->min_sample_time = 40 * USEC_PER_MSEC;
1177                                 tunables->above_hispeed_delay[0] = 80 * USEC_PER_MSEC;
1178                                 store_target_loads(tunables, "70 1200000:80 1416000:99", 0);
1179                         }
1180                         tunables->boostpulse_duration_val = 500 * USEC_PER_MSEC;
1181                 }
1182 #endif
1183
1184                 spin_lock_init(&tunables->target_loads_lock);
1185                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1186
1187                 if (!policy->governor->initialized) {
1188                         idle_notifier_register(&cpufreq_interactive_idle_nb);
1189                         cpufreq_register_notifier(&cpufreq_notifier_block,
1190                                         CPUFREQ_TRANSITION_NOTIFIER);
1191                 }
1192
1193                 policy->governor_data = tunables;
1194                 if (!have_governor_per_policy())
1195                         common_tunables = tunables;
1196
1197                 break;
1198
1199         case CPUFREQ_GOV_POLICY_EXIT:
1200                 if (!--tunables->usage_count) {
1201                         if (policy->governor->initialized == 1) {
1202                                 cpufreq_unregister_notifier(&cpufreq_notifier_block,
1203                                                 CPUFREQ_TRANSITION_NOTIFIER);
1204                                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1205                         }
1206
1207                         sysfs_remove_group(get_governor_parent_kobj(policy),
1208                                         get_sysfs_attr());
1209                         kfree(tunables);
1210                         common_tunables = NULL;
1211                 }
1212
1213                 policy->governor_data = NULL;
1214                 break;
1215
1216         case CPUFREQ_GOV_START:
1217                 mutex_lock(&gov_lock);
1218
1219                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1220                 if (!tunables->hispeed_freq)
1221                         tunables->hispeed_freq = policy->max;
1222
1223                 for_each_cpu(j, policy->cpus) {
1224                         pcpu = &per_cpu(cpuinfo, j);
1225                         pcpu->policy = policy;
1226                         pcpu->target_freq = policy->cur;
1227                         pcpu->freq_table = freq_table;
1228                         pcpu->floor_freq = pcpu->target_freq;
1229                         pcpu->floor_validate_time =
1230                                 ktime_to_us(ktime_get());
1231                         pcpu->hispeed_validate_time =
1232                                 pcpu->floor_validate_time;
1233                         down_write(&pcpu->enable_sem);
1234                         del_timer_sync(&pcpu->cpu_timer);
1235                         del_timer_sync(&pcpu->cpu_slack_timer);
1236                         cpufreq_interactive_timer_start(tunables, j);
1237                         pcpu->governor_enabled = 1;
1238                         up_write(&pcpu->enable_sem);
1239                 }
1240
1241                 mutex_unlock(&gov_lock);
1242                 break;
1243
1244         case CPUFREQ_GOV_STOP:
1245                 mutex_lock(&gov_lock);
1246                 for_each_cpu(j, policy->cpus) {
1247                         pcpu = &per_cpu(cpuinfo, j);
1248                         down_write(&pcpu->enable_sem);
1249                         pcpu->governor_enabled = 0;
1250                         del_timer_sync(&pcpu->cpu_timer);
1251                         del_timer_sync(&pcpu->cpu_slack_timer);
1252                         up_write(&pcpu->enable_sem);
1253                 }
1254
1255                 mutex_unlock(&gov_lock);
1256                 break;
1257
1258         case CPUFREQ_GOV_LIMITS:
1259                 if (policy->max < policy->cur)
1260                         __cpufreq_driver_target(policy,
1261                                         policy->max, CPUFREQ_RELATION_H);
1262                 else if (policy->min > policy->cur)
1263                         __cpufreq_driver_target(policy,
1264                                         policy->min, CPUFREQ_RELATION_L);
1265                 for_each_cpu(j, policy->cpus) {
1266                         pcpu = &per_cpu(cpuinfo, j);
1267
1268                         /* hold write semaphore to avoid race */
1269                         down_write(&pcpu->enable_sem);
1270                         if (pcpu->governor_enabled == 0) {
1271                                 up_write(&pcpu->enable_sem);
1272                                 continue;
1273                         }
1274
1275                         /* update target_freq firstly */
1276                         if (policy->max < pcpu->target_freq)
1277                                 pcpu->target_freq = policy->max;
1278                         else if (policy->min > pcpu->target_freq)
1279                                 pcpu->target_freq = policy->min;
1280
1281                         /* Reschedule timer.
1282                          * Delete the timers, else the timer callback may
1283                          * return without re-arm the timer when failed
1284                          * acquire the semaphore. This race may cause timer
1285                          * stopped unexpectedly.
1286                          */
1287                         del_timer_sync(&pcpu->cpu_timer);
1288                         del_timer_sync(&pcpu->cpu_slack_timer);
1289                         cpufreq_interactive_timer_start(tunables, j);
1290                         up_write(&pcpu->enable_sem);
1291                 }
1292                 break;
1293         }
1294         return 0;
1295 }
1296
1297 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1298 static
1299 #endif
1300 struct cpufreq_governor cpufreq_gov_interactive = {
1301         .name = "interactive",
1302         .governor = cpufreq_governor_interactive,
1303         .max_transition_latency = 10000000,
1304         .owner = THIS_MODULE,
1305 };
1306
1307 static void cpufreq_interactive_nop_timer(unsigned long data)
1308 {
1309 }
1310
1311 static int __init cpufreq_interactive_init(void)
1312 {
1313         unsigned int i;
1314         struct cpufreq_interactive_cpuinfo *pcpu;
1315         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1316
1317         /* Initalize per-cpu timers */
1318         for_each_possible_cpu(i) {
1319                 pcpu = &per_cpu(cpuinfo, i);
1320                 init_timer_deferrable(&pcpu->cpu_timer);
1321                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1322                 pcpu->cpu_timer.data = i;
1323                 init_timer(&pcpu->cpu_slack_timer);
1324                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1325                 spin_lock_init(&pcpu->load_lock);
1326                 init_rwsem(&pcpu->enable_sem);
1327         }
1328
1329         spin_lock_init(&speedchange_cpumask_lock);
1330         mutex_init(&gov_lock);
1331         speedchange_task =
1332                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1333                                "cfinteractive");
1334         if (IS_ERR(speedchange_task))
1335                 return PTR_ERR(speedchange_task);
1336
1337         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1338         get_task_struct(speedchange_task);
1339
1340         /* NB: wake up so the thread does not look hung to the freezer */
1341         wake_up_process(speedchange_task);
1342
1343         return cpufreq_register_governor(&cpufreq_gov_interactive);
1344 }
1345
1346 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1347 fs_initcall(cpufreq_interactive_init);
1348 #else
1349 module_init(cpufreq_interactive_init);
1350 #endif
1351
1352 static void __exit cpufreq_interactive_exit(void)
1353 {
1354         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1355         kthread_stop(speedchange_task);
1356         put_task_struct(speedchange_task);
1357 }
1358
1359 module_exit(cpufreq_interactive_exit);
1360
1361 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1362 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1363         "Latency sensitive workloads");
1364 MODULE_LICENSE("GPL");