drivers/cpufreq/cpufreq_interactive.c

   1 /*
   2  * drivers/cpufreq/cpufreq_interactive.c
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * Author: Mike Chan (mike@android.com)
  16  *
  17  */
  18
  19 #include <linux/cpu.h>
  20 #include <linux/cpumask.h>
  21 #include <linux/cpufreq.h>
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/sched.h>
  26 #include <linux/sched/rt.h>
  27 #include <linux/tick.h>
  28 #include <linux/time.h>
  29 #include <linux/timer.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/kthread.h>
  32 #include <linux/slab.h>
  33
  34 #define CREATE_TRACE_POINTS
  35 #include <trace/events/cpufreq_interactive.h>
  36
  37 struct cpufreq_interactive_cpuinfo {
  38         struct timer_list cpu_timer;
  39         struct timer_list cpu_slack_timer;
  40         spinlock_t load_lock; /* protects the next 4 fields */
  41         u64 time_in_idle;
  42         u64 time_in_idle_timestamp;
  43         u64 cputime_speedadj;
  44         u64 cputime_speedadj_timestamp;
  45         struct cpufreq_policy *policy;
  46         struct cpufreq_frequency_table *freq_table;
  47         spinlock_t target_freq_lock; /*protects target freq */
  48         unsigned int target_freq;
  49         unsigned int floor_freq;
  50         unsigned int max_freq;
  51         u64 floor_validate_time;
  52         u64 hispeed_validate_time;
  53         struct rw_semaphore enable_sem;
  54         int governor_enabled;
  55 };
  56
  57 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  58
  59 /* realtime thread handles frequency scaling */
  60 static struct task_struct *speedchange_task;
  61 static cpumask_t speedchange_cpumask;
  62 static spinlock_t speedchange_cpumask_lock;
  63 static struct mutex gov_lock;
  64
  65 /* Target load.  Lower values result in higher CPU speeds. */
  66 #define DEFAULT_TARGET_LOAD 90
  67 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  68
  69 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  70 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  71 static unsigned int default_above_hispeed_delay[] = {
  72         DEFAULT_ABOVE_HISPEED_DELAY };
  73
  74 struct cpufreq_interactive_tunables {
  75         int usage_count;
  76         /* Hi speed to bump to from lo speed when load burst (default max) */
  77         unsigned int hispeed_freq;
  78         /* Go to hi speed when CPU load at or above this value. */
  79 #define DEFAULT_GO_HISPEED_LOAD 99
  80         unsigned long go_hispeed_load;
  81         /* Target load. Lower values result in higher CPU speeds. */
  82         spinlock_t target_loads_lock;
  83         unsigned int *target_loads;
  84         int ntarget_loads;
  85         /*
  86          * The minimum amount of time to spend at a frequency before we can ramp
  87          * down.
  88          */
  89 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  90         unsigned long min_sample_time;
  91         /*
  92          * The sample rate of the timer used to increase frequency
  93          */
  94         unsigned long timer_rate;
  95         /*
  96          * Wait this long before raising speed above hispeed, by default a
  97          * single timer interval.
  98          */
  99         spinlock_t above_hispeed_delay_lock;
 100         unsigned int *above_hispeed_delay;
 101         int nabove_hispeed_delay;
 102         /* Non-zero means indefinite speed boost active */
 103         int boost_val;
 104         /* Duration of a boot pulse in usecs */
 105         int boostpulse_duration_val;
 106         /* End time of boost pulse in ktime converted to usecs */
 107         u64 boostpulse_endtime;
 108         /*
 109          * Max additional time to wait in idle, beyond timer_rate, at speeds
 110          * above minimum before wakeup to reduce speed, or -1 if unnecessary.
 111          */
 112 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 113         int timer_slack_val;
 114         bool io_is_busy;
 115 };
 116
 117 /* For cases where we have single governor instance for system */
 118 struct cpufreq_interactive_tunables *common_tunables;
 119
 120 static struct attribute_group *get_sysfs_attr(void);
 121
 122 static void cpufreq_interactive_timer_resched(
 123         struct cpufreq_interactive_cpuinfo *pcpu)
 124 {
 125         struct cpufreq_interactive_tunables *tunables =
 126                 pcpu->policy->governor_data;
 127         unsigned long expires;
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&pcpu->load_lock, flags);
 131         pcpu->time_in_idle =
 132                 get_cpu_idle_time(smp_processor_id(),
 133                                   &pcpu->time_in_idle_timestamp,
 134                                   tunables->io_is_busy);
 135         pcpu->cputime_speedadj = 0;
 136         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 137         expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 138         mod_timer_pinned(&pcpu->cpu_timer, expires);
 139
 140         if (tunables->timer_slack_val >= 0 &&
 141             pcpu->target_freq > pcpu->policy->min) {
 142                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 143                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 144         }
 145
 146         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 147 }
 148
 149 /* The caller shall take enable_sem write semaphore to avoid any timer race.
 150  * The cpu_timer and cpu_slack_timer must be deactivated when calling this
 151  * function.
 152  */
 153 static void cpufreq_interactive_timer_start(
 154         struct cpufreq_interactive_tunables *tunables, int cpu)
 155 {
 156         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 157         unsigned long expires = jiffies +
 158                 usecs_to_jiffies(tunables->timer_rate);
 159         unsigned long flags;
 160
 161         pcpu->cpu_timer.expires = expires;
 162         add_timer_on(&pcpu->cpu_timer, cpu);
 163         if (tunables->timer_slack_val >= 0 &&
 164             pcpu->target_freq > pcpu->policy->min) {
 165                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 166                 pcpu->cpu_slack_timer.expires = expires;
 167                 add_timer_on(&pcpu->cpu_slack_timer, cpu);
 168         }
 169
 170         spin_lock_irqsave(&pcpu->load_lock, flags);
 171         pcpu->time_in_idle =
 172                 get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp,
 173                                   tunables->io_is_busy);
 174         pcpu->cputime_speedadj = 0;
 175         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 176         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 177 }
 178
 179 static unsigned int freq_to_above_hispeed_delay(
 180         struct cpufreq_interactive_tunables *tunables,
 181         unsigned int freq)
 182 {
 183         int i;
 184         unsigned int ret;
 185         unsigned long flags;
 186
 187         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 188
 189         for (i = 0; i < tunables->nabove_hispeed_delay - 1 &&
 190                         freq >= tunables->above_hispeed_delay[i+1]; i += 2)
 191                 ;
 192
 193         ret = tunables->above_hispeed_delay[i];
 194         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 195         return ret;
 196 }
 197
 198 static unsigned int freq_to_targetload(
 199         struct cpufreq_interactive_tunables *tunables, unsigned int freq)
 200 {
 201         int i;
 202         unsigned int ret;
 203         unsigned long flags;
 204
 205         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 206
 207         for (i = 0; i < tunables->ntarget_loads - 1 &&
 208                     freq >= tunables->target_loads[i+1]; i += 2)
 209                 ;
 210
 211         ret = tunables->target_loads[i];
 212         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 213         return ret;
 214 }
 215
 216 /*
 217  * If increasing frequencies never map to a lower target load then
 218  * choose_freq() will find the minimum frequency that does not exceed its
 219  * target load given the current load.
 220  */
 221 static unsigned int choose_freq(struct cpufreq_interactive_cpuinfo *pcpu,
 222                 unsigned int loadadjfreq)
 223 {
 224         unsigned int freq = pcpu->policy->cur;
 225         unsigned int prevfreq, freqmin, freqmax;
 226         unsigned int tl;
 227         int index;
 228
 229         freqmin = 0;
 230         freqmax = UINT_MAX;
 231
 232         do {
 233                 prevfreq = freq;
 234                 tl = freq_to_targetload(pcpu->policy->governor_data, freq);
 235
 236                 /*
 237                  * Find the lowest frequency where the computed load is less
 238                  * than or equal to the target load.
 239                  */
 240
 241                 if (cpufreq_frequency_table_target(
 242                             pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 243                             CPUFREQ_RELATION_L, &index))
 244                         break;
 245                 freq = pcpu->freq_table[index].frequency;
 246
 247                 if (freq > prevfreq) {
 248                         /* The previous frequency is too low. */
 249                         freqmin = prevfreq;
 250
 251                         if (freq >= freqmax) {
 252                                 /*
 253                                  * Find the highest frequency that is less
 254                                  * than freqmax.
 255                                  */
 256                                 if (cpufreq_frequency_table_target(
 257                                             pcpu->policy, pcpu->freq_table,
 258                                             freqmax - 1, CPUFREQ_RELATION_H,
 259                                             &index))
 260                                         break;
 261                                 freq = pcpu->freq_table[index].frequency;
 262
 263                                 if (freq == freqmin) {
 264                                         /*
 265                                          * The first frequency below freqmax
 266                                          * has already been found to be too
 267                                          * low.  freqmax is the lowest speed
 268                                          * we found that is fast enough.
 269                                          */
 270                                         freq = freqmax;
 271                                         break;
 272                                 }
 273                         }
 274                 } else if (freq < prevfreq) {
 275                         /* The previous frequency is high enough. */
 276                         freqmax = prevfreq;
 277
 278                         if (freq <= freqmin) {
 279                                 /*
 280                                  * Find the lowest frequency that is higher
 281                                  * than freqmin.
 282                                  */
 283                                 if (cpufreq_frequency_table_target(
 284                                             pcpu->policy, pcpu->freq_table,
 285                                             freqmin + 1, CPUFREQ_RELATION_L,
 286                                             &index))
 287                                         break;
 288                                 freq = pcpu->freq_table[index].frequency;
 289
 290                                 /*
 291                                  * If freqmax is the first frequency above
 292                                  * freqmin then we have already found that
 293                                  * this speed is fast enough.
 294                                  */
 295                                 if (freq == freqmax)
 296                                         break;
 297                         }
 298                 }
 299
 300                 /* If same frequency chosen as previous then done. */
 301         } while (freq != prevfreq);
 302
 303         return freq;
 304 }
 305
 306 static u64 update_load(int cpu)
 307 {
 308         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 309         struct cpufreq_interactive_tunables *tunables =
 310                 pcpu->policy->governor_data;
 311         u64 now;
 312         u64 now_idle;
 313         unsigned int delta_idle;
 314         unsigned int delta_time;
 315         u64 active_time;
 316
 317         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 318         delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
 319         delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
 320
 321         if (delta_time <= delta_idle)
 322                 active_time = 0;
 323         else
 324                 active_time = delta_time - delta_idle;
 325
 326         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 327
 328         pcpu->time_in_idle = now_idle;
 329         pcpu->time_in_idle_timestamp = now;
 330         return now;
 331 }
 332
 333 static void cpufreq_interactive_timer(unsigned long data)
 334 {
 335         u64 now;
 336         unsigned int delta_time;
 337         u64 cputime_speedadj;
 338         int cpu_load;
 339         struct cpufreq_interactive_cpuinfo *pcpu =
 340                 &per_cpu(cpuinfo, data);
 341         struct cpufreq_interactive_tunables *tunables =
 342                 pcpu->policy->governor_data;
 343         unsigned int new_freq;
 344         unsigned int loadadjfreq;
 345         unsigned int index;
 346         unsigned long flags;
 347         bool boosted;
 348
 349         if (!down_read_trylock(&pcpu->enable_sem))
 350                 return;
 351         if (!pcpu->governor_enabled)
 352                 goto exit;
 353
 354         spin_lock_irqsave(&pcpu->load_lock, flags);
 355         now = update_load(data);
 356         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 357         cputime_speedadj = pcpu->cputime_speedadj;
 358         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 359
 360         if (WARN_ON_ONCE(!delta_time))
 361                 goto rearm;
 362
 363         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
 364         do_div(cputime_speedadj, delta_time);
 365         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 366         cpu_load = loadadjfreq / pcpu->target_freq;
 367         boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 368
 369         if (cpu_load >= tunables->go_hispeed_load || boosted) {
 370                 if (pcpu->target_freq < tunables->hispeed_freq) {
 371                         new_freq = tunables->hispeed_freq;
 372                 } else {
 373                         new_freq = choose_freq(pcpu, loadadjfreq);
 374
 375                         if (new_freq < tunables->hispeed_freq)
 376                                 new_freq = tunables->hispeed_freq;
 377                 }
 378         } else {
 379                 new_freq = choose_freq(pcpu, loadadjfreq);
 380         }
 381
 382         if (pcpu->target_freq >= tunables->hispeed_freq &&
 383             new_freq > pcpu->target_freq &&
 384             now - pcpu->hispeed_validate_time <
 385             freq_to_above_hispeed_delay(tunables, pcpu->target_freq)) {
 386                 trace_cpufreq_interactive_notyet(
 387                         data, cpu_load, pcpu->target_freq,
 388                         pcpu->policy->cur, new_freq);
 389                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 390                 goto rearm;
 391         }
 392
 393         pcpu->hispeed_validate_time = now;
 394
 395         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 396                                            new_freq, CPUFREQ_RELATION_L,
 397                                            &index)) {
 398                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 399                 goto rearm;
 400         }
 401
 402         new_freq = pcpu->freq_table[index].frequency;
 403
 404         /*
 405          * Do not scale below floor_freq unless we have been at or above the
 406          * floor frequency for the minimum sample time since last validated.
 407          */
 408         if (new_freq < pcpu->floor_freq) {
 409                 if (now - pcpu->floor_validate_time <
 410                                 tunables->min_sample_time) {
 411                         trace_cpufreq_interactive_notyet(
 412                                 data, cpu_load, pcpu->target_freq,
 413                                 pcpu->policy->cur, new_freq);
 414                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 415                         goto rearm;
 416                 }
 417         }
 418
 419         /*
 420          * Update the timestamp for checking whether speed has been held at
 421          * or above the selected frequency for a minimum of min_sample_time,
 422          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 423          * allow the speed to drop as soon as the boostpulse duration expires
 424          * (or the indefinite boost is turned off).
 425          */
 426
 427         if (!boosted || new_freq > tunables->hispeed_freq) {
 428                 pcpu->floor_freq = new_freq;
 429                 pcpu->floor_validate_time = now;
 430         }
 431
 432         if (pcpu->target_freq == new_freq) {
 433                 trace_cpufreq_interactive_already(
 434                         data, cpu_load, pcpu->target_freq,
 435                         pcpu->policy->cur, new_freq);
 436                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 437                 goto rearm_if_notmax;
 438         }
 439
 440         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 441                                          pcpu->policy->cur, new_freq);
 442
 443         pcpu->target_freq = new_freq;
 444         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 445         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 446         cpumask_set_cpu(data, &speedchange_cpumask);
 447         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 448         wake_up_process(speedchange_task);
 449
 450 rearm_if_notmax:
 451         /*
 452          * Already set max speed and don't see a need to change that,
 453          * wait until next idle to re-evaluate, don't need timer.
 454          */
 455         if (pcpu->target_freq == pcpu->policy->max)
 456                 goto exit;
 457
 458 rearm:
 459         if (!timer_pending(&pcpu->cpu_timer))
 460                 cpufreq_interactive_timer_resched(pcpu);
 461
 462 exit:
 463         up_read(&pcpu->enable_sem);
 464         return;
 465 }
 466
 467 static void cpufreq_interactive_idle_start(void)
 468 {
 469         struct cpufreq_interactive_cpuinfo *pcpu =
 470                 &per_cpu(cpuinfo, smp_processor_id());
 471         int pending;
 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         pending = timer_pending(&pcpu->cpu_timer);
 481
 482         if (pcpu->target_freq != pcpu->policy->min) {
 483                 /*
 484                  * Entering idle while not at lowest speed.  On some
 485                  * platforms this can hold the other CPU(s) at that speed
 486                  * even though the CPU is idle. Set a timer to re-evaluate
 487                  * speed so this idle CPU doesn't hold the other CPUs above
 488                  * min indefinitely.  This should probably be a quirk of
 489                  * the CPUFreq driver.
 490                  */
 491                 if (!pending)
 492                         cpufreq_interactive_timer_resched(pcpu);
 493         }
 494
 495         up_read(&pcpu->enable_sem);
 496 }
 497
 498 static void cpufreq_interactive_idle_end(void)
 499 {
 500         struct cpufreq_interactive_cpuinfo *pcpu =
 501                 &per_cpu(cpuinfo, smp_processor_id());
 502
 503         if (!down_read_trylock(&pcpu->enable_sem))
 504                 return;
 505         if (!pcpu->governor_enabled) {
 506                 up_read(&pcpu->enable_sem);
 507                 return;
 508         }
 509
 510         /* Arm the timer for 1-2 ticks later if not already. */
 511         if (!timer_pending(&pcpu->cpu_timer)) {
 512                 cpufreq_interactive_timer_resched(pcpu);
 513         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 514                 del_timer(&pcpu->cpu_timer);
 515                 del_timer(&pcpu->cpu_slack_timer);
 516                 cpufreq_interactive_timer(smp_processor_id());
 517         }
 518
 519         up_read(&pcpu->enable_sem);
 520 }
 521
 522 static int cpufreq_interactive_speedchange_task(void *data)
 523 {
 524         unsigned int cpu;
 525         cpumask_t tmp_mask;
 526         unsigned long flags;
 527         struct cpufreq_interactive_cpuinfo *pcpu;
 528
 529         while (1) {
 530                 set_current_state(TASK_INTERRUPTIBLE);
 531                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 532
 533                 if (cpumask_empty(&speedchange_cpumask)) {
 534                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 535                                                flags);
 536                         schedule();
 537
 538                         if (kthread_should_stop())
 539                                 break;
 540
 541                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 542                 }
 543
 544                 set_current_state(TASK_RUNNING);
 545                 tmp_mask = speedchange_cpumask;
 546                 cpumask_clear(&speedchange_cpumask);
 547                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 548
 549                 for_each_cpu(cpu, &tmp_mask) {
 550                         unsigned int j;
 551                         unsigned int max_freq = 0;
 552
 553                         pcpu = &per_cpu(cpuinfo, cpu);
 554                         if (!down_read_trylock(&pcpu->enable_sem))
 555                                 continue;
 556                         if (!pcpu->governor_enabled) {
 557                                 up_read(&pcpu->enable_sem);
 558                                 continue;
 559                         }
 560
 561                         for_each_cpu(j, pcpu->policy->cpus) {
 562                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 563                                         &per_cpu(cpuinfo, j);
 564
 565                                 if (pjcpu->target_freq > max_freq)
 566                                         max_freq = pjcpu->target_freq;
 567                         }
 568
 569                         if (max_freq != pcpu->policy->cur)
 570                                 __cpufreq_driver_target(pcpu->policy,
 571                                                         max_freq,
 572                                                         CPUFREQ_RELATION_H);
 573                         trace_cpufreq_interactive_setspeed(cpu,
 574                                                      pcpu->target_freq,
 575                                                      pcpu->policy->cur);
 576
 577                         up_read(&pcpu->enable_sem);
 578                 }
 579         }
 580
 581         return 0;
 582 }
 583
 584 static void cpufreq_interactive_boost(void)
 585 {
 586         int i;
 587         int anyboost = 0;
 588         unsigned long flags[2];
 589         struct cpufreq_interactive_cpuinfo *pcpu;
 590         struct cpufreq_interactive_tunables *tunables;
 591
 592         spin_lock_irqsave(&speedchange_cpumask_lock, flags[0]);
 593
 594         for_each_online_cpu(i) {
 595                 pcpu = &per_cpu(cpuinfo, i);
 596                 tunables = pcpu->policy->governor_data;
 597
 598                 spin_lock_irqsave(&pcpu->target_freq_lock, flags[1]);
 599                 if (pcpu->target_freq < tunables->hispeed_freq) {
 600                         pcpu->target_freq = tunables->hispeed_freq;
 601                         cpumask_set_cpu(i, &speedchange_cpumask);
 602                         pcpu->hispeed_validate_time =
 603                                 ktime_to_us(ktime_get());
 604                         anyboost = 1;
 605                 }
 606
 607                 /*
 608                  * Set floor freq and (re)start timer for when last
 609                  * validated.
 610                  */
 611
 612                 pcpu->floor_freq = tunables->hispeed_freq;
 613                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 614                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags[1]);
 615         }
 616
 617         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags[0]);
 618
 619         if (anyboost)
 620                 wake_up_process(speedchange_task);
 621 }
 622
 623 static int cpufreq_interactive_notifier(
 624         struct notifier_block *nb, unsigned long val, void *data)
 625 {
 626         struct cpufreq_freqs *freq = data;
 627         struct cpufreq_interactive_cpuinfo *pcpu;
 628         int cpu;
 629         unsigned long flags;
 630
 631         if (val == CPUFREQ_POSTCHANGE) {
 632                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 633                 if (!down_read_trylock(&pcpu->enable_sem))
 634                         return 0;
 635                 if (!pcpu->governor_enabled) {
 636                         up_read(&pcpu->enable_sem);
 637                         return 0;
 638                 }
 639
 640                 for_each_cpu(cpu, pcpu->policy->cpus) {
 641                         struct cpufreq_interactive_cpuinfo *pjcpu =
 642                                 &per_cpu(cpuinfo, cpu);
 643                         if (cpu != freq->cpu) {
 644                                 if (!down_read_trylock(&pjcpu->enable_sem))
 645                                         continue;
 646                                 if (!pjcpu->governor_enabled) {
 647                                         up_read(&pjcpu->enable_sem);
 648                                         continue;
 649                                 }
 650                         }
 651                         spin_lock_irqsave(&pjcpu->load_lock, flags);
 652                         update_load(cpu);
 653                         spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 654                         if (cpu != freq->cpu)
 655                                 up_read(&pjcpu->enable_sem);
 656                 }
 657
 658                 up_read(&pcpu->enable_sem);
 659         }
 660         return 0;
 661 }
 662
 663 static struct notifier_block cpufreq_notifier_block = {
 664         .notifier_call = cpufreq_interactive_notifier,
 665 };
 666
 667 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 668 {
 669         const char *cp;
 670         int i;
 671         int ntokens = 1;
 672         unsigned int *tokenized_data;
 673         int err = -EINVAL;
 674
 675         cp = buf;
 676         while ((cp = strpbrk(cp + 1, " :")))
 677                 ntokens++;
 678
 679         if (!(ntokens & 0x1))
 680                 goto err;
 681
 682         tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 683         if (!tokenized_data) {
 684                 err = -ENOMEM;
 685                 goto err;
 686         }
 687
 688         cp = buf;
 689         i = 0;
 690         while (i < ntokens) {
 691                 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
 692                         goto err_kfree;
 693
 694                 cp = strpbrk(cp, " :");
 695                 if (!cp)
 696                         break;
 697                 cp++;
 698         }
 699
 700         if (i != ntokens)
 701                 goto err_kfree;
 702
 703         *num_tokens = ntokens;
 704         return tokenized_data;
 705
 706 err_kfree:
 707         kfree(tokenized_data);
 708 err:
 709         return ERR_PTR(err);
 710 }
 711
 712 static ssize_t show_target_loads(
 713         struct cpufreq_interactive_tunables *tunables,
 714         char *buf)
 715 {
 716         int i;
 717         ssize_t ret = 0;
 718         unsigned long flags;
 719
 720         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 721
 722         for (i = 0; i < tunables->ntarget_loads; i++)
 723                 ret += sprintf(buf + ret, "%u%s", tunables->target_loads[i],
 724                                i & 0x1 ? ":" : " ");
 725
 726         sprintf(buf + ret - 1, "\n");
 727         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 728         return ret;
 729 }
 730
 731 static ssize_t store_target_loads(
 732         struct cpufreq_interactive_tunables *tunables,
 733         const char *buf, size_t count)
 734 {
 735         int ntokens;
 736         unsigned int *new_target_loads = NULL;
 737         unsigned long flags;
 738
 739         new_target_loads = get_tokenized_data(buf, &ntokens);
 740         if (IS_ERR(new_target_loads))
 741                 return PTR_RET(new_target_loads);
 742
 743         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 744         if (tunables->target_loads != default_target_loads)
 745                 kfree(tunables->target_loads);
 746         tunables->target_loads = new_target_loads;
 747         tunables->ntarget_loads = ntokens;
 748         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 749         return count;
 750 }
 751
 752 static ssize_t show_above_hispeed_delay(
 753         struct cpufreq_interactive_tunables *tunables, char *buf)
 754 {
 755         int i;
 756         ssize_t ret = 0;
 757         unsigned long flags;
 758
 759         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 760
 761         for (i = 0; i < tunables->nabove_hispeed_delay; i++)
 762                 ret += sprintf(buf + ret, "%u%s",
 763                                tunables->above_hispeed_delay[i],
 764                                i & 0x1 ? ":" : " ");
 765
 766         sprintf(buf + ret - 1, "\n");
 767         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 768         return ret;
 769 }
 770
 771 static ssize_t store_above_hispeed_delay(
 772         struct cpufreq_interactive_tunables *tunables,
 773         const char *buf, size_t count)
 774 {
 775         int ntokens;
 776         unsigned int *new_above_hispeed_delay = NULL;
 777         unsigned long flags;
 778
 779         new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
 780         if (IS_ERR(new_above_hispeed_delay))
 781                 return PTR_RET(new_above_hispeed_delay);
 782
 783         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 784         if (tunables->above_hispeed_delay != default_above_hispeed_delay)
 785                 kfree(tunables->above_hispeed_delay);
 786         tunables->above_hispeed_delay = new_above_hispeed_delay;
 787         tunables->nabove_hispeed_delay = ntokens;
 788         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 789         return count;
 790
 791 }
 792
 793 static ssize_t show_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 794                 char *buf)
 795 {
 796         return sprintf(buf, "%u\n", tunables->hispeed_freq);
 797 }
 798
 799 static ssize_t store_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 800                 const char *buf, size_t count)
 801 {
 802         int ret;
 803         long unsigned int val;
 804
 805         ret = strict_strtoul(buf, 0, &val);
 806         if (ret < 0)
 807                 return ret;
 808         tunables->hispeed_freq = val;
 809         return count;
 810 }
 811
 812 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 813                 *tunables, char *buf)
 814 {
 815         return sprintf(buf, "%lu\n", tunables->go_hispeed_load);
 816 }
 817
 818 static ssize_t store_go_hispeed_load(struct cpufreq_interactive_tunables
 819                 *tunables, const char *buf, size_t count)
 820 {
 821         int ret;
 822         unsigned long val;
 823
 824         ret = strict_strtoul(buf, 0, &val);
 825         if (ret < 0)
 826                 return ret;
 827         tunables->go_hispeed_load = val;
 828         return count;
 829 }
 830
 831 static ssize_t show_min_sample_time(struct cpufreq_interactive_tunables
 832                 *tunables, char *buf)
 833 {
 834         return sprintf(buf, "%lu\n", tunables->min_sample_time);
 835 }
 836
 837 static ssize_t store_min_sample_time(struct cpufreq_interactive_tunables
 838                 *tunables, const char *buf, size_t count)
 839 {
 840         int ret;
 841         unsigned long val;
 842
 843         ret = strict_strtoul(buf, 0, &val);
 844         if (ret < 0)
 845                 return ret;
 846         tunables->min_sample_time = val;
 847         return count;
 848 }
 849
 850 static ssize_t show_timer_rate(struct cpufreq_interactive_tunables *tunables,
 851                 char *buf)
 852 {
 853         return sprintf(buf, "%lu\n", tunables->timer_rate);
 854 }
 855
 856 static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 857                 const char *buf, size_t count)
 858 {
 859         int ret;
 860         unsigned long val;
 861
 862         ret = strict_strtoul(buf, 0, &val);
 863         if (ret < 0)
 864                 return ret;
 865         tunables->timer_rate = val;
 866         return count;
 867 }
 868
 869 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 870                 char *buf)
 871 {
 872         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 873 }
 874
 875 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 876                 const char *buf, size_t count)
 877 {
 878         int ret;
 879         unsigned long val;
 880
 881         ret = kstrtol(buf, 10, &val);
 882         if (ret < 0)
 883                 return ret;
 884
 885         tunables->timer_slack_val = val;
 886         return count;
 887 }
 888
 889 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 890                           char *buf)
 891 {
 892         return sprintf(buf, "%d\n", tunables->boost_val);
 893 }
 894
 895 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 896                            const char *buf, size_t count)
 897 {
 898         int ret;
 899         unsigned long val;
 900
 901         ret = kstrtoul(buf, 0, &val);
 902         if (ret < 0)
 903                 return ret;
 904
 905         tunables->boost_val = val;
 906
 907         if (tunables->boost_val) {
 908                 trace_cpufreq_interactive_boost("on");
 909                 cpufreq_interactive_boost();
 910         } else {
 911                 trace_cpufreq_interactive_unboost("off");
 912         }
 913
 914         return count;
 915 }
 916
 917 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 918                                 const char *buf, size_t count)
 919 {
 920         int ret;
 921         unsigned long val;
 922
 923         ret = kstrtoul(buf, 0, &val);
 924         if (ret < 0)
 925                 return ret;
 926
 927         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 928                 tunables->boostpulse_duration_val;
 929         trace_cpufreq_interactive_boost("pulse");
 930         cpufreq_interactive_boost();
 931         return count;
 932 }
 933
 934 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 935                 *tunables, char *buf)
 936 {
 937         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 938 }
 939
 940 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 941                 *tunables, const char *buf, size_t count)
 942 {
 943         int ret;
 944         unsigned long val;
 945
 946         ret = kstrtoul(buf, 0, &val);
 947         if (ret < 0)
 948                 return ret;
 949
 950         tunables->boostpulse_duration_val = val;
 951         return count;
 952 }
 953
 954 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 955                 char *buf)
 956 {
 957         return sprintf(buf, "%u\n", tunables->io_is_busy);
 958 }
 959
 960 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 961                 const char *buf, size_t count)
 962 {
 963         int ret;
 964         unsigned long val;
 965
 966         ret = kstrtoul(buf, 0, &val);
 967         if (ret < 0)
 968                 return ret;
 969         tunables->io_is_busy = val;
 970         return count;
 971 }
 972
 973 /*
 974  * Create show/store routines
 975  * - sys: One governor instance for complete SYSTEM
 976  * - pol: One governor instance per struct cpufreq_policy
 977  */
 978 #define show_gov_pol_sys(file_name)                                     \
 979 static ssize_t show_##file_name##_gov_sys                               \
 980 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 981 {                                                                       \
 982         return show_##file_name(common_tunables, buf);                  \
 983 }                                                                       \
 984                                                                         \
 985 static ssize_t show_##file_name##_gov_pol                               \
 986 (struct cpufreq_policy *policy, char *buf)                              \
 987 {                                                                       \
 988         return show_##file_name(policy->governor_data, buf);            \
 989 }
 990
 991 #define store_gov_pol_sys(file_name)                                    \
 992 static ssize_t store_##file_name##_gov_sys                              \
 993 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
 994         size_t count)                                                   \
 995 {                                                                       \
 996         return store_##file_name(common_tunables, buf, count);          \
 997 }                                                                       \
 998                                                                         \
 999 static ssize_t store_##file_name##_gov_pol                              \
1000 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
1001 {                                                                       \
1002         return store_##file_name(policy->governor_data, buf, count);    \
1003 }
1004
1005 #define show_store_gov_pol_sys(file_name)                               \
1006 show_gov_pol_sys(file_name);                                            \
1007 store_gov_pol_sys(file_name)
1008
1009 show_store_gov_pol_sys(target_loads);
1010 show_store_gov_pol_sys(above_hispeed_delay);
1011 show_store_gov_pol_sys(hispeed_freq);
1012 show_store_gov_pol_sys(go_hispeed_load);
1013 show_store_gov_pol_sys(min_sample_time);
1014 show_store_gov_pol_sys(timer_rate);
1015 show_store_gov_pol_sys(timer_slack);
1016 show_store_gov_pol_sys(boost);
1017 store_gov_pol_sys(boostpulse);
1018 show_store_gov_pol_sys(boostpulse_duration);
1019 show_store_gov_pol_sys(io_is_busy);
1020
1021 #define gov_sys_attr_rw(_name)                                          \
1022 static struct global_attr _name##_gov_sys =                             \
1023 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
1024
1025 #define gov_pol_attr_rw(_name)                                          \
1026 static struct freq_attr _name##_gov_pol =                               \
1027 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
1028
1029 #define gov_sys_pol_attr_rw(_name)                                      \
1030         gov_sys_attr_rw(_name);                                         \
1031         gov_pol_attr_rw(_name)
1032
1033 gov_sys_pol_attr_rw(target_loads);
1034 gov_sys_pol_attr_rw(above_hispeed_delay);
1035 gov_sys_pol_attr_rw(hispeed_freq);
1036 gov_sys_pol_attr_rw(go_hispeed_load);
1037 gov_sys_pol_attr_rw(min_sample_time);
1038 gov_sys_pol_attr_rw(timer_rate);
1039 gov_sys_pol_attr_rw(timer_slack);
1040 gov_sys_pol_attr_rw(boost);
1041 gov_sys_pol_attr_rw(boostpulse_duration);
1042 gov_sys_pol_attr_rw(io_is_busy);
1043
1044 static struct global_attr boostpulse_gov_sys =
1045         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1046
1047 static struct freq_attr boostpulse_gov_pol =
1048         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1049
1050 /* One Governor instance for entire system */
1051 static struct attribute *interactive_attributes_gov_sys[] = {
1052         &target_loads_gov_sys.attr,
1053         &above_hispeed_delay_gov_sys.attr,
1054         &hispeed_freq_gov_sys.attr,
1055         &go_hispeed_load_gov_sys.attr,
1056         &min_sample_time_gov_sys.attr,
1057         &timer_rate_gov_sys.attr,
1058         &timer_slack_gov_sys.attr,
1059         &boost_gov_sys.attr,
1060         &boostpulse_gov_sys.attr,
1061         &boostpulse_duration_gov_sys.attr,
1062         &io_is_busy_gov_sys.attr,
1063         NULL,
1064 };
1065
1066 static struct attribute_group interactive_attr_group_gov_sys = {
1067         .attrs = interactive_attributes_gov_sys,
1068         .name = "interactive",
1069 };
1070
1071 /* Per policy governor instance */
1072 static struct attribute *interactive_attributes_gov_pol[] = {
1073         &target_loads_gov_pol.attr,
1074         &above_hispeed_delay_gov_pol.attr,
1075         &hispeed_freq_gov_pol.attr,
1076         &go_hispeed_load_gov_pol.attr,
1077         &min_sample_time_gov_pol.attr,
1078         &timer_rate_gov_pol.attr,
1079         &timer_slack_gov_pol.attr,
1080         &boost_gov_pol.attr,
1081         &boostpulse_gov_pol.attr,
1082         &boostpulse_duration_gov_pol.attr,
1083         &io_is_busy_gov_pol.attr,
1084         NULL,
1085 };
1086
1087 static struct attribute_group interactive_attr_group_gov_pol = {
1088         .attrs = interactive_attributes_gov_pol,
1089         .name = "interactive",
1090 };
1091
1092 static struct attribute_group *get_sysfs_attr(void)
1093 {
1094         if (have_governor_per_policy())
1095                 return &interactive_attr_group_gov_pol;
1096         else
1097                 return &interactive_attr_group_gov_sys;
1098 }
1099
1100 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1101                                              unsigned long val,
1102                                              void *data)
1103 {
1104         switch (val) {
1105         case IDLE_START:
1106                 cpufreq_interactive_idle_start();
1107                 break;
1108         case IDLE_END:
1109                 cpufreq_interactive_idle_end();
1110                 break;
1111         }
1112
1113         return 0;
1114 }
1115
1116 static struct notifier_block cpufreq_interactive_idle_nb = {
1117         .notifier_call = cpufreq_interactive_idle_notifier,
1118 };
1119
1120 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1121                 unsigned int event)
1122 {
1123         int rc;
1124         unsigned int j;
1125         struct cpufreq_interactive_cpuinfo *pcpu;
1126         struct cpufreq_frequency_table *freq_table;
1127         struct cpufreq_interactive_tunables *tunables;
1128         unsigned long flags;
1129
1130         if (have_governor_per_policy())
1131                 tunables = policy->governor_data;
1132         else
1133                 tunables = common_tunables;
1134
1135         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1136
1137         switch (event) {
1138         case CPUFREQ_GOV_POLICY_INIT:
1139                 if (have_governor_per_policy()) {
1140                         WARN_ON(tunables);
1141                 } else if (tunables) {
1142                         tunables->usage_count++;
1143                         policy->governor_data = tunables;
1144                         return 0;
1145                 }
1146
1147                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1148                 if (!tunables) {
1149                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1150                         return -ENOMEM;
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                 spin_lock_init(&tunables->target_loads_lock);
1166                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1167
1168                 policy->governor_data = tunables;
1169                 if (!have_governor_per_policy()) {
1170                         common_tunables = tunables;
1171                         WARN_ON(cpufreq_get_global_kobject());
1172                 }
1173
1174                 rc = sysfs_create_group(get_governor_parent_kobj(policy),
1175                                 get_sysfs_attr());
1176                 if (rc) {
1177                         kfree(tunables);
1178                         policy->governor_data = NULL;
1179                         if (!have_governor_per_policy())
1180                                 common_tunables = NULL;
1181                         return rc;
1182                 }
1183
1184                 if (!policy->governor->initialized) {
1185                         idle_notifier_register(&cpufreq_interactive_idle_nb);
1186                         cpufreq_register_notifier(&cpufreq_notifier_block,
1187                                         CPUFREQ_TRANSITION_NOTIFIER);
1188                 }
1189
1190                 break;
1191
1192         case CPUFREQ_GOV_POLICY_EXIT:
1193                 if (!--tunables->usage_count) {
1194                         if (policy->governor->initialized == 1) {
1195                                 cpufreq_unregister_notifier(&cpufreq_notifier_block,
1196                                                 CPUFREQ_TRANSITION_NOTIFIER);
1197                                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1198                         }
1199
1200                         sysfs_remove_group(get_governor_parent_kobj(policy),
1201                                         get_sysfs_attr());
1202
1203                         if (!have_governor_per_policy())
1204                                 cpufreq_put_global_kobject();
1205
1206                         kfree(tunables);
1207                         common_tunables = NULL;
1208                 }
1209
1210                 policy->governor_data = NULL;
1211                 break;
1212
1213         case CPUFREQ_GOV_START:
1214                 mutex_lock(&gov_lock);
1215
1216                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1217                 if (!tunables->hispeed_freq)
1218                         tunables->hispeed_freq = policy->max;
1219
1220                 for_each_cpu(j, policy->cpus) {
1221                         pcpu = &per_cpu(cpuinfo, j);
1222                         pcpu->policy = policy;
1223                         pcpu->target_freq = policy->cur;
1224                         pcpu->freq_table = freq_table;
1225                         pcpu->floor_freq = pcpu->target_freq;
1226                         pcpu->floor_validate_time =
1227                                 ktime_to_us(ktime_get());
1228                         pcpu->hispeed_validate_time =
1229                                 pcpu->floor_validate_time;
1230                         pcpu->max_freq = policy->max;
1231                         down_write(&pcpu->enable_sem);
1232                         del_timer_sync(&pcpu->cpu_timer);
1233                         del_timer_sync(&pcpu->cpu_slack_timer);
1234                         cpufreq_interactive_timer_start(tunables, j);
1235                         pcpu->governor_enabled = 1;
1236                         up_write(&pcpu->enable_sem);
1237                 }
1238
1239                 mutex_unlock(&gov_lock);
1240                 break;
1241
1242         case CPUFREQ_GOV_STOP:
1243                 mutex_lock(&gov_lock);
1244                 for_each_cpu(j, policy->cpus) {
1245                         pcpu = &per_cpu(cpuinfo, j);
1246                         down_write(&pcpu->enable_sem);
1247                         pcpu->governor_enabled = 0;
1248                         del_timer_sync(&pcpu->cpu_timer);
1249                         del_timer_sync(&pcpu->cpu_slack_timer);
1250                         up_write(&pcpu->enable_sem);
1251                 }
1252
1253                 mutex_unlock(&gov_lock);
1254                 break;
1255
1256         case CPUFREQ_GOV_LIMITS:
1257                 if (policy->max < policy->cur)
1258                         __cpufreq_driver_target(policy,
1259                                         policy->max, CPUFREQ_RELATION_H);
1260                 else if (policy->min > policy->cur)
1261                         __cpufreq_driver_target(policy,
1262                                         policy->min, CPUFREQ_RELATION_L);
1263                 for_each_cpu(j, policy->cpus) {
1264                         pcpu = &per_cpu(cpuinfo, j);
1265
1266                         down_read(&pcpu->enable_sem);
1267                         if (pcpu->governor_enabled == 0) {
1268                                 up_read(&pcpu->enable_sem);
1269                                 continue;
1270                         }
1271
1272                         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
1273                         if (policy->max < pcpu->target_freq)
1274                                 pcpu->target_freq = policy->max;
1275                         else if (policy->min > pcpu->target_freq)
1276                                 pcpu->target_freq = policy->min;
1277
1278                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
1279                         up_read(&pcpu->enable_sem);
1280
1281                         /* Reschedule timer only if policy->max is raised.
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
1288                         if (policy->max > pcpu->max_freq) {
1289                                 down_write(&pcpu->enable_sem);
1290                                 del_timer_sync(&pcpu->cpu_timer);
1291                                 del_timer_sync(&pcpu->cpu_slack_timer);
1292                                 cpufreq_interactive_timer_start(tunables, j);
1293                                 up_write(&pcpu->enable_sem);
1294                         }
1295
1296                         pcpu->max_freq = policy->max;
1297                 }
1298                 break;
1299         }
1300         return 0;
1301 }
1302
1303 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1304 static
1305 #endif
1306 struct cpufreq_governor cpufreq_gov_interactive = {
1307         .name = "interactive",
1308         .governor = cpufreq_governor_interactive,
1309         .max_transition_latency = 10000000,
1310         .owner = THIS_MODULE,
1311 };
1312
1313 static void cpufreq_interactive_nop_timer(unsigned long data)
1314 {
1315 }
1316
1317 static int __init cpufreq_interactive_init(void)
1318 {
1319         unsigned int i;
1320         struct cpufreq_interactive_cpuinfo *pcpu;
1321         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1322
1323         /* Initalize per-cpu timers */
1324         for_each_possible_cpu(i) {
1325                 pcpu = &per_cpu(cpuinfo, i);
1326                 init_timer_deferrable(&pcpu->cpu_timer);
1327                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1328                 pcpu->cpu_timer.data = i;
1329                 init_timer(&pcpu->cpu_slack_timer);
1330                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1331                 spin_lock_init(&pcpu->load_lock);
1332                 spin_lock_init(&pcpu->target_freq_lock);
1333                 init_rwsem(&pcpu->enable_sem);
1334         }
1335
1336         spin_lock_init(&speedchange_cpumask_lock);
1337         mutex_init(&gov_lock);
1338         speedchange_task =
1339                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1340                                "cfinteractive");
1341         if (IS_ERR(speedchange_task))
1342                 return PTR_ERR(speedchange_task);
1343
1344         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1345         get_task_struct(speedchange_task);
1346
1347         /* NB: wake up so the thread does not look hung to the freezer */
1348         wake_up_process(speedchange_task);
1349
1350         return cpufreq_register_governor(&cpufreq_gov_interactive);
1351 }
1352
1353 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1354 fs_initcall(cpufreq_interactive_init);
1355 #else
1356 module_init(cpufreq_interactive_init);
1357 #endif
1358
1359 static void __exit cpufreq_interactive_exit(void)
1360 {
1361         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1362         kthread_stop(speedchange_task);
1363         put_task_struct(speedchange_task);
1364 }
1365
1366 module_exit(cpufreq_interactive_exit);
1367
1368 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1369 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1370         "Latency sensitive workloads");
1371 MODULE_LICENSE("GPL");