drivers/cpufreq/cpufreq_interactive.c

   1 /*
   2  * drivers/cpufreq/cpufreq_interactive.c
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * Author: Mike Chan (mike@android.com)
  16  *
  17  */
  18
  19 #include <linux/cpu.h>
  20 #include <linux/cpumask.h>
  21 #include <linux/cpufreq.h>
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/sched.h>
  26 #include <linux/sched/rt.h>
  27 #include <linux/tick.h>
  28 #include <linux/time.h>
  29 #include <linux/timer.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/kthread.h>
  32 #include <linux/slab.h>
  33 #include "cpufreq_governor.h"
  34
  35 #define CREATE_TRACE_POINTS
  36 #include <trace/events/cpufreq_interactive.h>
  37
  38 struct cpufreq_interactive_cpuinfo {
  39         struct timer_list cpu_timer;
  40         struct timer_list cpu_slack_timer;
  41         spinlock_t load_lock; /* protects the next 4 fields */
  42         u64 time_in_idle;
  43         u64 time_in_idle_timestamp;
  44         u64 cputime_speedadj;
  45         u64 cputime_speedadj_timestamp;
  46         struct cpufreq_policy *policy;
  47         struct cpufreq_frequency_table *freq_table;
  48         spinlock_t target_freq_lock; /*protects target freq */
  49         unsigned int target_freq;
  50         unsigned int floor_freq;
  51         unsigned int max_freq;
  52         u64 floor_validate_time;
  53         u64 hispeed_validate_time;
  54         struct rw_semaphore enable_sem;
  55         int governor_enabled;
  56 };
  57
  58 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  59
  60 /* realtime thread handles frequency scaling */
  61 static struct task_struct *speedchange_task;
  62 static cpumask_t speedchange_cpumask;
  63 static spinlock_t speedchange_cpumask_lock;
  64 static struct mutex gov_lock;
  65
  66 /* Target load.  Lower values result in higher CPU speeds. */
  67 #define DEFAULT_TARGET_LOAD 90
  68 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  69
  70 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  71 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  72 static unsigned int default_above_hispeed_delay[] = {
  73         DEFAULT_ABOVE_HISPEED_DELAY };
  74
  75 struct cpufreq_interactive_tunables {
  76         int usage_count;
  77         /* Hi speed to bump to from lo speed when load burst (default max) */
  78         unsigned int hispeed_freq;
  79         /* Go to hi speed when CPU load at or above this value. */
  80 #define DEFAULT_GO_HISPEED_LOAD 99
  81         unsigned long go_hispeed_load;
  82         /* Target load. Lower values result in higher CPU speeds. */
  83         spinlock_t target_loads_lock;
  84         unsigned int *target_loads;
  85         int ntarget_loads;
  86         /*
  87          * The minimum amount of time to spend at a frequency before we can ramp
  88          * down.
  89          */
  90 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  91         unsigned long min_sample_time;
  92         /*
  93          * The sample rate of the timer used to increase frequency
  94          */
  95         unsigned long timer_rate;
  96         /*
  97          * Wait this long before raising speed above hispeed, by default a
  98          * single timer interval.
  99          */
 100         spinlock_t above_hispeed_delay_lock;
 101         unsigned int *above_hispeed_delay;
 102         int nabove_hispeed_delay;
 103         /* Non-zero means indefinite speed boost active */
 104         int boost_val;
 105         /* Duration of a boot pulse in usecs */
 106         int boostpulse_duration_val;
 107         /* End time of boost pulse in ktime converted to usecs */
 108         u64 boostpulse_endtime;
 109         /*
 110          * Max additional time to wait in idle, beyond timer_rate, at speeds
 111          * above minimum before wakeup to reduce speed, or -1 if unnecessary.
 112          */
 113 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 114         int timer_slack_val;
 115         bool io_is_busy;
 116 };
 117
 118 /* For cases where we have single governor instance for system */
 119 struct cpufreq_interactive_tunables *common_tunables;
 120
 121 static struct attribute_group *get_sysfs_attr(void);
 122
 123 static void cpufreq_interactive_timer_resched(
 124         struct cpufreq_interactive_cpuinfo *pcpu)
 125 {
 126         struct cpufreq_interactive_tunables *tunables =
 127                 pcpu->policy->governor_data;
 128         unsigned long expires;
 129         unsigned long flags;
 130
 131         spin_lock_irqsave(&pcpu->load_lock, flags);
 132         pcpu->time_in_idle =
 133                 get_cpu_idle_time(smp_processor_id(),
 134                                   &pcpu->time_in_idle_timestamp,
 135                                   tunables->io_is_busy);
 136         pcpu->cputime_speedadj = 0;
 137         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 138         expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 139         mod_timer_pinned(&pcpu->cpu_timer, expires);
 140
 141         if (tunables->timer_slack_val >= 0 &&
 142             pcpu->target_freq > pcpu->policy->min) {
 143                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 144                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 145         }
 146
 147         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 148 }
 149
 150 /* The caller shall take enable_sem write semaphore to avoid any timer race.
 151  * The cpu_timer and cpu_slack_timer must be deactivated when calling this
 152  * function.
 153  */
 154 static void cpufreq_interactive_timer_start(
 155         struct cpufreq_interactive_tunables *tunables, int cpu)
 156 {
 157         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 158         unsigned long expires = jiffies +
 159                 usecs_to_jiffies(tunables->timer_rate);
 160         unsigned long flags;
 161
 162         pcpu->cpu_timer.expires = expires;
 163         add_timer_on(&pcpu->cpu_timer, cpu);
 164         if (tunables->timer_slack_val >= 0 &&
 165             pcpu->target_freq > pcpu->policy->min) {
 166                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 167                 pcpu->cpu_slack_timer.expires = expires;
 168                 add_timer_on(&pcpu->cpu_slack_timer, cpu);
 169         }
 170
 171         spin_lock_irqsave(&pcpu->load_lock, flags);
 172         pcpu->time_in_idle =
 173                 get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp,
 174                                   tunables->io_is_busy);
 175         pcpu->cputime_speedadj = 0;
 176         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 177         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 178 }
 179
 180 static unsigned int freq_to_above_hispeed_delay(
 181         struct cpufreq_interactive_tunables *tunables,
 182         unsigned int freq)
 183 {
 184         int i;
 185         unsigned int ret;
 186         unsigned long flags;
 187
 188         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 189
 190         for (i = 0; i < tunables->nabove_hispeed_delay - 1 &&
 191                         freq >= tunables->above_hispeed_delay[i+1]; i += 2)
 192                 ;
 193
 194         ret = tunables->above_hispeed_delay[i];
 195         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 196         return ret;
 197 }
 198
 199 static unsigned int freq_to_targetload(
 200         struct cpufreq_interactive_tunables *tunables, unsigned int freq)
 201 {
 202         int i;
 203         unsigned int ret;
 204         unsigned long flags;
 205
 206         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 207
 208         for (i = 0; i < tunables->ntarget_loads - 1 &&
 209                     freq >= tunables->target_loads[i+1]; i += 2)
 210                 ;
 211
 212         ret = tunables->target_loads[i];
 213         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 214         return ret;
 215 }
 216
 217 /*
 218  * If increasing frequencies never map to a lower target load then
 219  * choose_freq() will find the minimum frequency that does not exceed its
 220  * target load given the current load.
 221  */
 222 static unsigned int choose_freq(struct cpufreq_interactive_cpuinfo *pcpu,
 223                 unsigned int loadadjfreq)
 224 {
 225         unsigned int freq = pcpu->policy->cur;
 226         unsigned int prevfreq, freqmin, freqmax;
 227         unsigned int tl;
 228         int index;
 229
 230         freqmin = 0;
 231         freqmax = UINT_MAX;
 232
 233         do {
 234                 prevfreq = freq;
 235                 tl = freq_to_targetload(pcpu->policy->governor_data, freq);
 236
 237                 /*
 238                  * Find the lowest frequency where the computed load is less
 239                  * than or equal to the target load.
 240                  */
 241
 242                 if (cpufreq_frequency_table_target(
 243                             pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 244                             CPUFREQ_RELATION_L, &index))
 245                         break;
 246                 freq = pcpu->freq_table[index].frequency;
 247
 248                 if (freq > prevfreq) {
 249                         /* The previous frequency is too low. */
 250                         freqmin = prevfreq;
 251
 252                         if (freq >= freqmax) {
 253                                 /*
 254                                  * Find the highest frequency that is less
 255                                  * than freqmax.
 256                                  */
 257                                 if (cpufreq_frequency_table_target(
 258                                             pcpu->policy, pcpu->freq_table,
 259                                             freqmax - 1, CPUFREQ_RELATION_H,
 260                                             &index))
 261                                         break;
 262                                 freq = pcpu->freq_table[index].frequency;
 263
 264                                 if (freq == freqmin) {
 265                                         /*
 266                                          * The first frequency below freqmax
 267                                          * has already been found to be too
 268                                          * low.  freqmax is the lowest speed
 269                                          * we found that is fast enough.
 270                                          */
 271                                         freq = freqmax;
 272                                         break;
 273                                 }
 274                         }
 275                 } else if (freq < prevfreq) {
 276                         /* The previous frequency is high enough. */
 277                         freqmax = prevfreq;
 278
 279                         if (freq <= freqmin) {
 280                                 /*
 281                                  * Find the lowest frequency that is higher
 282                                  * than freqmin.
 283                                  */
 284                                 if (cpufreq_frequency_table_target(
 285                                             pcpu->policy, pcpu->freq_table,
 286                                             freqmin + 1, CPUFREQ_RELATION_L,
 287                                             &index))
 288                                         break;
 289                                 freq = pcpu->freq_table[index].frequency;
 290
 291                                 /*
 292                                  * If freqmax is the first frequency above
 293                                  * freqmin then we have already found that
 294                                  * this speed is fast enough.
 295                                  */
 296                                 if (freq == freqmax)
 297                                         break;
 298                         }
 299                 }
 300
 301                 /* If same frequency chosen as previous then done. */
 302         } while (freq != prevfreq);
 303
 304         return freq;
 305 }
 306
 307 static u64 update_load(int cpu)
 308 {
 309         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 310         struct cpufreq_interactive_tunables *tunables =
 311                 pcpu->policy->governor_data;
 312         u64 now;
 313         u64 now_idle;
 314         u64 delta_idle;
 315         u64 delta_time;
 316         u64 active_time;
 317
 318         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 319         delta_idle = (now_idle - pcpu->time_in_idle);
 320         delta_time = (now - pcpu->time_in_idle_timestamp);
 321
 322         if (delta_time <= delta_idle)
 323                 active_time = 0;
 324         else
 325                 active_time = delta_time - delta_idle;
 326
 327         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 328
 329         pcpu->time_in_idle = now_idle;
 330         pcpu->time_in_idle_timestamp = now;
 331         return now;
 332 }
 333
 334 static void cpufreq_interactive_timer(unsigned long data)
 335 {
 336         u64 now;
 337         unsigned int delta_time;
 338         u64 cputime_speedadj;
 339         int cpu_load;
 340         struct cpufreq_interactive_cpuinfo *pcpu =
 341                 &per_cpu(cpuinfo, data);
 342         struct cpufreq_interactive_tunables *tunables =
 343                 pcpu->policy->governor_data;
 344         unsigned int new_freq;
 345         unsigned int loadadjfreq;
 346         unsigned int index;
 347         unsigned long flags;
 348         bool boosted;
 349
 350         if (!down_read_trylock(&pcpu->enable_sem))
 351                 return;
 352         if (!pcpu->governor_enabled)
 353                 goto exit;
 354
 355         spin_lock_irqsave(&pcpu->load_lock, flags);
 356         now = update_load(data);
 357         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 358         cputime_speedadj = pcpu->cputime_speedadj;
 359         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 360
 361         if (WARN_ON_ONCE(!delta_time))
 362                 goto rearm;
 363
 364         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
 365         do_div(cputime_speedadj, delta_time);
 366         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 367         cpu_load = loadadjfreq / pcpu->target_freq;
 368         boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 369
 370         if (cpu_load >= tunables->go_hispeed_load || boosted) {
 371                 if (pcpu->target_freq < tunables->hispeed_freq) {
 372                         new_freq = tunables->hispeed_freq;
 373                 } else {
 374                         new_freq = choose_freq(pcpu, loadadjfreq);
 375
 376                         if (new_freq < tunables->hispeed_freq)
 377                                 new_freq = tunables->hispeed_freq;
 378                 }
 379         } else {
 380                 new_freq = choose_freq(pcpu, loadadjfreq);
 381         }
 382
 383         if (pcpu->target_freq >= tunables->hispeed_freq &&
 384             new_freq > pcpu->target_freq &&
 385             now - pcpu->hispeed_validate_time <
 386             freq_to_above_hispeed_delay(tunables, pcpu->target_freq)) {
 387                 trace_cpufreq_interactive_notyet(
 388                         data, cpu_load, pcpu->target_freq,
 389                         pcpu->policy->cur, new_freq);
 390                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 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                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 400                 goto rearm;
 401         }
 402
 403         new_freq = pcpu->freq_table[index].frequency;
 404
 405         /*
 406          * Do not scale below floor_freq unless we have been at or above the
 407          * floor frequency for the minimum sample time since last validated.
 408          */
 409         if (new_freq < pcpu->floor_freq) {
 410                 if (now - pcpu->floor_validate_time <
 411                                 tunables->min_sample_time) {
 412                         trace_cpufreq_interactive_notyet(
 413                                 data, cpu_load, pcpu->target_freq,
 414                                 pcpu->policy->cur, new_freq);
 415                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 416                         goto rearm;
 417                 }
 418         }
 419
 420         /*
 421          * Update the timestamp for checking whether speed has been held at
 422          * or above the selected frequency for a minimum of min_sample_time,
 423          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 424          * allow the speed to drop as soon as the boostpulse duration expires
 425          * (or the indefinite boost is turned off).
 426          */
 427
 428         if (!boosted || new_freq > tunables->hispeed_freq) {
 429                 pcpu->floor_freq = new_freq;
 430                 pcpu->floor_validate_time = now;
 431         }
 432
 433         if (pcpu->target_freq == new_freq) {
 434                 trace_cpufreq_interactive_already(
 435                         data, cpu_load, pcpu->target_freq,
 436                         pcpu->policy->cur, new_freq);
 437                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 438                 goto rearm_if_notmax;
 439         }
 440
 441         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 442                                          pcpu->policy->cur, new_freq);
 443
 444         pcpu->target_freq = new_freq;
 445         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 446         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 447         cpumask_set_cpu(data, &speedchange_cpumask);
 448         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 449         wake_up_process(speedchange_task);
 450
 451 rearm_if_notmax:
 452         /*
 453          * Already set max speed and don't see a need to change that,
 454          * wait until next idle to re-evaluate, don't need timer.
 455          */
 456         if (pcpu->target_freq == pcpu->policy->max)
 457                 goto exit;
 458
 459 rearm:
 460         if (!timer_pending(&pcpu->cpu_timer))
 461                 cpufreq_interactive_timer_resched(pcpu);
 462
 463 exit:
 464         up_read(&pcpu->enable_sem);
 465         return;
 466 }
 467
 468 static void cpufreq_interactive_idle_start(void)
 469 {
 470         struct cpufreq_interactive_cpuinfo *pcpu =
 471                 &per_cpu(cpuinfo, smp_processor_id());
 472         int pending;
 473
 474         if (!down_read_trylock(&pcpu->enable_sem))
 475                 return;
 476         if (!pcpu->governor_enabled) {
 477                 up_read(&pcpu->enable_sem);
 478                 return;
 479         }
 480
 481         pending = timer_pending(&pcpu->cpu_timer);
 482
 483         if (pcpu->target_freq != pcpu->policy->min) {
 484                 /*
 485                  * Entering idle while not at lowest speed.  On some
 486                  * platforms this can hold the other CPU(s) at that speed
 487                  * even though the CPU is idle. Set a timer to re-evaluate
 488                  * speed so this idle CPU doesn't hold the other CPUs above
 489                  * min indefinitely.  This should probably be a quirk of
 490                  * the CPUFreq driver.
 491                  */
 492                 if (!pending)
 493                         cpufreq_interactive_timer_resched(pcpu);
 494         }
 495
 496         up_read(&pcpu->enable_sem);
 497 }
 498
 499 static void cpufreq_interactive_idle_end(void)
 500 {
 501         struct cpufreq_interactive_cpuinfo *pcpu =
 502                 &per_cpu(cpuinfo, smp_processor_id());
 503
 504         if (!down_read_trylock(&pcpu->enable_sem))
 505                 return;
 506         if (!pcpu->governor_enabled) {
 507                 up_read(&pcpu->enable_sem);
 508                 return;
 509         }
 510
 511         /* Arm the timer for 1-2 ticks later if not already. */
 512         if (!timer_pending(&pcpu->cpu_timer)) {
 513                 cpufreq_interactive_timer_resched(pcpu);
 514         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 515                 del_timer(&pcpu->cpu_timer);
 516                 del_timer(&pcpu->cpu_slack_timer);
 517                 cpufreq_interactive_timer(smp_processor_id());
 518         }
 519
 520         up_read(&pcpu->enable_sem);
 521 }
 522
 523 static int cpufreq_interactive_speedchange_task(void *data)
 524 {
 525         unsigned int cpu;
 526         cpumask_t tmp_mask;
 527         unsigned long flags;
 528         struct cpufreq_interactive_cpuinfo *pcpu;
 529
 530         while (1) {
 531                 set_current_state(TASK_INTERRUPTIBLE);
 532                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 533
 534                 if (cpumask_empty(&speedchange_cpumask)) {
 535                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 536                                                flags);
 537                         schedule();
 538
 539                         if (kthread_should_stop())
 540                                 break;
 541
 542                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 543                 }
 544
 545                 set_current_state(TASK_RUNNING);
 546                 tmp_mask = speedchange_cpumask;
 547                 cpumask_clear(&speedchange_cpumask);
 548                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 549
 550                 for_each_cpu(cpu, &tmp_mask) {
 551                         unsigned int j;
 552                         unsigned int max_freq = 0;
 553
 554                         pcpu = &per_cpu(cpuinfo, cpu);
 555                         if (!down_read_trylock(&pcpu->enable_sem))
 556                                 continue;
 557                         if (!pcpu->governor_enabled) {
 558                                 up_read(&pcpu->enable_sem);
 559                                 continue;
 560                         }
 561
 562                         for_each_cpu(j, pcpu->policy->cpus) {
 563                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 564                                         &per_cpu(cpuinfo, j);
 565
 566                                 if (pjcpu->target_freq > max_freq)
 567                                         max_freq = pjcpu->target_freq;
 568                         }
 569
 570                         if (max_freq != pcpu->policy->cur)
 571                                 __cpufreq_driver_target(pcpu->policy,
 572                                                         max_freq,
 573                                                         CPUFREQ_RELATION_H);
 574                         trace_cpufreq_interactive_setspeed(cpu,
 575                                                      pcpu->target_freq,
 576                                                      pcpu->policy->cur);
 577
 578                         up_read(&pcpu->enable_sem);
 579                 }
 580         }
 581
 582         return 0;
 583 }
 584
 585 static void cpufreq_interactive_boost(void)
 586 {
 587         int i;
 588         int anyboost = 0;
 589         unsigned long flags[2];
 590         struct cpufreq_interactive_cpuinfo *pcpu;
 591         struct cpufreq_interactive_tunables *tunables;
 592
 593         spin_lock_irqsave(&speedchange_cpumask_lock, flags[0]);
 594
 595         for_each_online_cpu(i) {
 596                 pcpu = &per_cpu(cpuinfo, i);
 597                 tunables = pcpu->policy->governor_data;
 598
 599                 spin_lock_irqsave(&pcpu->target_freq_lock, flags[1]);
 600                 if (pcpu->target_freq < tunables->hispeed_freq) {
 601                         pcpu->target_freq = tunables->hispeed_freq;
 602                         cpumask_set_cpu(i, &speedchange_cpumask);
 603                         pcpu->hispeed_validate_time =
 604                                 ktime_to_us(ktime_get());
 605                         anyboost = 1;
 606                 }
 607
 608                 /*
 609                  * Set floor freq and (re)start timer for when last
 610                  * validated.
 611                  */
 612
 613                 pcpu->floor_freq = tunables->hispeed_freq;
 614                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 615                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags[1]);
 616         }
 617
 618         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags[0]);
 619
 620         if (anyboost)
 621                 wake_up_process(speedchange_task);
 622 }
 623
 624 static int cpufreq_interactive_notifier(
 625         struct notifier_block *nb, unsigned long val, void *data)
 626 {
 627         struct cpufreq_freqs *freq = data;
 628         struct cpufreq_interactive_cpuinfo *pcpu;
 629         int cpu;
 630         unsigned long flags;
 631
 632         if (val == CPUFREQ_POSTCHANGE) {
 633                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 634                 if (!down_read_trylock(&pcpu->enable_sem))
 635                         return 0;
 636                 if (!pcpu->governor_enabled) {
 637                         up_read(&pcpu->enable_sem);
 638                         return 0;
 639                 }
 640
 641                 for_each_cpu(cpu, pcpu->policy->cpus) {
 642                         struct cpufreq_interactive_cpuinfo *pjcpu =
 643                                 &per_cpu(cpuinfo, cpu);
 644                         if (cpu != freq->cpu) {
 645                                 if (!down_read_trylock(&pjcpu->enable_sem))
 646                                         continue;
 647                                 if (!pjcpu->governor_enabled) {
 648                                         up_read(&pjcpu->enable_sem);
 649                                         continue;
 650                                 }
 651                         }
 652                         spin_lock_irqsave(&pjcpu->load_lock, flags);
 653                         update_load(cpu);
 654                         spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 655                         if (cpu != freq->cpu)
 656                                 up_read(&pjcpu->enable_sem);
 657                 }
 658
 659                 up_read(&pcpu->enable_sem);
 660         }
 661         return 0;
 662 }
 663
 664 static struct notifier_block cpufreq_notifier_block = {
 665         .notifier_call = cpufreq_interactive_notifier,
 666 };
 667
 668 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 669 {
 670         const char *cp;
 671         int i;
 672         int ntokens = 1;
 673         unsigned int *tokenized_data;
 674         int err = -EINVAL;
 675
 676         cp = buf;
 677         while ((cp = strpbrk(cp + 1, " :")))
 678                 ntokens++;
 679
 680         if (!(ntokens & 0x1))
 681                 goto err;
 682
 683         tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 684         if (!tokenized_data) {
 685                 err = -ENOMEM;
 686                 goto err;
 687         }
 688
 689         cp = buf;
 690         i = 0;
 691         while (i < ntokens) {
 692                 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
 693                         goto err_kfree;
 694
 695                 cp = strpbrk(cp, " :");
 696                 if (!cp)
 697                         break;
 698                 cp++;
 699         }
 700
 701         if (i != ntokens)
 702                 goto err_kfree;
 703
 704         *num_tokens = ntokens;
 705         return tokenized_data;
 706
 707 err_kfree:
 708         kfree(tokenized_data);
 709 err:
 710         return ERR_PTR(err);
 711 }
 712
 713 static ssize_t show_target_loads(
 714         struct cpufreq_interactive_tunables *tunables,
 715         char *buf)
 716 {
 717         int i;
 718         ssize_t ret = 0;
 719         unsigned long flags;
 720
 721         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 722
 723         for (i = 0; i < tunables->ntarget_loads; i++)
 724                 ret += sprintf(buf + ret, "%u%s", tunables->target_loads[i],
 725                                i & 0x1 ? ":" : " ");
 726
 727         sprintf(buf + ret - 1, "\n");
 728         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 729         return ret;
 730 }
 731
 732 static ssize_t store_target_loads(
 733         struct cpufreq_interactive_tunables *tunables,
 734         const char *buf, size_t count)
 735 {
 736         int ntokens;
 737         unsigned int *new_target_loads = NULL;
 738         unsigned long flags;
 739
 740         new_target_loads = get_tokenized_data(buf, &ntokens);
 741         if (IS_ERR(new_target_loads))
 742                 return PTR_RET(new_target_loads);
 743
 744         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 745         if (tunables->target_loads != default_target_loads)
 746                 kfree(tunables->target_loads);
 747         tunables->target_loads = new_target_loads;
 748         tunables->ntarget_loads = ntokens;
 749         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 750         return count;
 751 }
 752
 753 static ssize_t show_above_hispeed_delay(
 754         struct cpufreq_interactive_tunables *tunables, char *buf)
 755 {
 756         int i;
 757         ssize_t ret = 0;
 758         unsigned long flags;
 759
 760         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 761
 762         for (i = 0; i < tunables->nabove_hispeed_delay; i++)
 763                 ret += sprintf(buf + ret, "%u%s",
 764                                tunables->above_hispeed_delay[i],
 765                                i & 0x1 ? ":" : " ");
 766
 767         sprintf(buf + ret - 1, "\n");
 768         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 769         return ret;
 770 }
 771
 772 static ssize_t store_above_hispeed_delay(
 773         struct cpufreq_interactive_tunables *tunables,
 774         const char *buf, size_t count)
 775 {
 776         int ntokens;
 777         unsigned int *new_above_hispeed_delay = NULL;
 778         unsigned long flags;
 779
 780         new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
 781         if (IS_ERR(new_above_hispeed_delay))
 782                 return PTR_RET(new_above_hispeed_delay);
 783
 784         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 785         if (tunables->above_hispeed_delay != default_above_hispeed_delay)
 786                 kfree(tunables->above_hispeed_delay);
 787         tunables->above_hispeed_delay = new_above_hispeed_delay;
 788         tunables->nabove_hispeed_delay = ntokens;
 789         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 790         return count;
 791
 792 }
 793
 794 static ssize_t show_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 795                 char *buf)
 796 {
 797         return sprintf(buf, "%u\n", tunables->hispeed_freq);
 798 }
 799
 800 static ssize_t store_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 801                 const char *buf, size_t count)
 802 {
 803         int ret;
 804         long unsigned int val;
 805
 806         ret = strict_strtoul(buf, 0, &val);
 807         if (ret < 0)
 808                 return ret;
 809         tunables->hispeed_freq = val;
 810         return count;
 811 }
 812
 813 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 814                 *tunables, char *buf)
 815 {
 816         return sprintf(buf, "%lu\n", tunables->go_hispeed_load);
 817 }
 818
 819 static ssize_t store_go_hispeed_load(struct cpufreq_interactive_tunables
 820                 *tunables, const char *buf, size_t count)
 821 {
 822         int ret;
 823         unsigned long val;
 824
 825         ret = strict_strtoul(buf, 0, &val);
 826         if (ret < 0)
 827                 return ret;
 828         tunables->go_hispeed_load = val;
 829         return count;
 830 }
 831
 832 static ssize_t show_min_sample_time(struct cpufreq_interactive_tunables
 833                 *tunables, char *buf)
 834 {
 835         return sprintf(buf, "%lu\n", tunables->min_sample_time);
 836 }
 837
 838 static ssize_t store_min_sample_time(struct cpufreq_interactive_tunables
 839                 *tunables, const char *buf, size_t count)
 840 {
 841         int ret;
 842         unsigned long val;
 843
 844         ret = strict_strtoul(buf, 0, &val);
 845         if (ret < 0)
 846                 return ret;
 847         tunables->min_sample_time = val;
 848         return count;
 849 }
 850
 851 static ssize_t show_timer_rate(struct cpufreq_interactive_tunables *tunables,
 852                 char *buf)
 853 {
 854         return sprintf(buf, "%lu\n", tunables->timer_rate);
 855 }
 856
 857 static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 858                 const char *buf, size_t count)
 859 {
 860         int ret;
 861         unsigned long val;
 862
 863         ret = strict_strtoul(buf, 0, &val);
 864         if (ret < 0)
 865                 return ret;
 866         tunables->timer_rate = val;
 867         return count;
 868 }
 869
 870 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 871                 char *buf)
 872 {
 873         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 874 }
 875
 876 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 877                 const char *buf, size_t count)
 878 {
 879         int ret;
 880         unsigned long val;
 881
 882         ret = kstrtol(buf, 10, &val);
 883         if (ret < 0)
 884                 return ret;
 885
 886         tunables->timer_slack_val = val;
 887         return count;
 888 }
 889
 890 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 891                           char *buf)
 892 {
 893         return sprintf(buf, "%d\n", tunables->boost_val);
 894 }
 895
 896 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 897                            const char *buf, size_t count)
 898 {
 899         int ret;
 900         unsigned long val;
 901
 902         ret = kstrtoul(buf, 0, &val);
 903         if (ret < 0)
 904                 return ret;
 905
 906         tunables->boost_val = val;
 907
 908         if (tunables->boost_val) {
 909                 trace_cpufreq_interactive_boost("on");
 910                 cpufreq_interactive_boost();
 911         } else {
 912                 tunables->boostpulse_endtime = ktime_to_us(ktime_get());
 913                 trace_cpufreq_interactive_unboost("off");
 914         }
 915
 916         return count;
 917 }
 918
 919 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 920                                 const char *buf, size_t count)
 921 {
 922         int ret;
 923         unsigned long val;
 924
 925         ret = kstrtoul(buf, 0, &val);
 926         if (ret < 0)
 927                 return ret;
 928
 929         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 930                 tunables->boostpulse_duration_val;
 931         trace_cpufreq_interactive_boost("pulse");
 932         cpufreq_interactive_boost();
 933         return count;
 934 }
 935
 936 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 937                 *tunables, char *buf)
 938 {
 939         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 940 }
 941
 942 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 943                 *tunables, const char *buf, size_t count)
 944 {
 945         int ret;
 946         unsigned long val;
 947
 948         ret = kstrtoul(buf, 0, &val);
 949         if (ret < 0)
 950                 return ret;
 951
 952         tunables->boostpulse_duration_val = val;
 953         return count;
 954 }
 955
 956 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 957                 char *buf)
 958 {
 959         return sprintf(buf, "%u\n", tunables->io_is_busy);
 960 }
 961
 962 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 963                 const char *buf, size_t count)
 964 {
 965         int ret;
 966         unsigned long val;
 967
 968         ret = kstrtoul(buf, 0, &val);
 969         if (ret < 0)
 970                 return ret;
 971         tunables->io_is_busy = val;
 972         return count;
 973 }
 974
 975 /*
 976  * Create show/store routines
 977  * - sys: One governor instance for complete SYSTEM
 978  * - pol: One governor instance per struct cpufreq_policy
 979  */
 980 #define show_gov_pol_sys(file_name)                                     \
 981 static ssize_t show_##file_name##_gov_sys                               \
 982 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 983 {                                                                       \
 984         return show_##file_name(common_tunables, buf);                  \
 985 }                                                                       \
 986                                                                         \
 987 static ssize_t show_##file_name##_gov_pol                               \
 988 (struct cpufreq_policy *policy, char *buf)                              \
 989 {                                                                       \
 990         return show_##file_name(policy->governor_data, buf);            \
 991 }
 992
 993 #define store_gov_pol_sys(file_name)                                    \
 994 static ssize_t store_##file_name##_gov_sys                              \
 995 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
 996         size_t count)                                                   \
 997 {                                                                       \
 998         return store_##file_name(common_tunables, buf, count);          \
 999 }                                                                       \
1000                                                                         \
1001 static ssize_t store_##file_name##_gov_pol                              \
1002 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
1003 {                                                                       \
1004         return store_##file_name(policy->governor_data, buf, count);    \
1005 }
1006
1007 #define show_store_gov_pol_sys(file_name)                               \
1008 show_gov_pol_sys(file_name);                                            \
1009 store_gov_pol_sys(file_name)
1010
1011 show_store_gov_pol_sys(target_loads);
1012 show_store_gov_pol_sys(above_hispeed_delay);
1013 show_store_gov_pol_sys(hispeed_freq);
1014 show_store_gov_pol_sys(go_hispeed_load);
1015 show_store_gov_pol_sys(min_sample_time);
1016 show_store_gov_pol_sys(timer_rate);
1017 show_store_gov_pol_sys(timer_slack);
1018 show_store_gov_pol_sys(boost);
1019 store_gov_pol_sys(boostpulse);
1020 show_store_gov_pol_sys(boostpulse_duration);
1021 show_store_gov_pol_sys(io_is_busy);
1022
1023 #define gov_sys_attr_rw(_name)                                          \
1024 static struct global_attr _name##_gov_sys =                             \
1025 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
1026
1027 #define gov_pol_attr_rw(_name)                                          \
1028 static struct freq_attr _name##_gov_pol =                               \
1029 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
1030
1031 #define gov_sys_pol_attr_rw(_name)                                      \
1032         gov_sys_attr_rw(_name);                                         \
1033         gov_pol_attr_rw(_name)
1034
1035 gov_sys_pol_attr_rw(target_loads);
1036 gov_sys_pol_attr_rw(above_hispeed_delay);
1037 gov_sys_pol_attr_rw(hispeed_freq);
1038 gov_sys_pol_attr_rw(go_hispeed_load);
1039 gov_sys_pol_attr_rw(min_sample_time);
1040 gov_sys_pol_attr_rw(timer_rate);
1041 gov_sys_pol_attr_rw(timer_slack);
1042 gov_sys_pol_attr_rw(boost);
1043 gov_sys_pol_attr_rw(boostpulse_duration);
1044 gov_sys_pol_attr_rw(io_is_busy);
1045
1046 static struct global_attr boostpulse_gov_sys =
1047         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1048
1049 static struct freq_attr boostpulse_gov_pol =
1050         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1051
1052 /* One Governor instance for entire system */
1053 static struct attribute *interactive_attributes_gov_sys[] = {
1054         &target_loads_gov_sys.attr,
1055         &above_hispeed_delay_gov_sys.attr,
1056         &hispeed_freq_gov_sys.attr,
1057         &go_hispeed_load_gov_sys.attr,
1058         &min_sample_time_gov_sys.attr,
1059         &timer_rate_gov_sys.attr,
1060         &timer_slack_gov_sys.attr,
1061         &boost_gov_sys.attr,
1062         &boostpulse_gov_sys.attr,
1063         &boostpulse_duration_gov_sys.attr,
1064         &io_is_busy_gov_sys.attr,
1065         NULL,
1066 };
1067
1068 static struct attribute_group interactive_attr_group_gov_sys = {
1069         .attrs = interactive_attributes_gov_sys,
1070         .name = "interactive",
1071 };
1072
1073 /* Per policy governor instance */
1074 static struct attribute *interactive_attributes_gov_pol[] = {
1075         &target_loads_gov_pol.attr,
1076         &above_hispeed_delay_gov_pol.attr,
1077         &hispeed_freq_gov_pol.attr,
1078         &go_hispeed_load_gov_pol.attr,
1079         &min_sample_time_gov_pol.attr,
1080         &timer_rate_gov_pol.attr,
1081         &timer_slack_gov_pol.attr,
1082         &boost_gov_pol.attr,
1083         &boostpulse_gov_pol.attr,
1084         &boostpulse_duration_gov_pol.attr,
1085         &io_is_busy_gov_pol.attr,
1086         NULL,
1087 };
1088
1089 static struct attribute_group interactive_attr_group_gov_pol = {
1090         .attrs = interactive_attributes_gov_pol,
1091         .name = "interactive",
1092 };
1093
1094 static struct attribute_group *get_sysfs_attr(void)
1095 {
1096         if (have_governor_per_policy())
1097                 return &interactive_attr_group_gov_pol;
1098         else
1099                 return &interactive_attr_group_gov_sys;
1100 }
1101
1102 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1103                                              unsigned long val,
1104                                              void *data)
1105 {
1106         switch (val) {
1107         case IDLE_START:
1108                 cpufreq_interactive_idle_start();
1109                 break;
1110         case IDLE_END:
1111                 cpufreq_interactive_idle_end();
1112                 break;
1113         }
1114
1115         return 0;
1116 }
1117
1118 static struct notifier_block cpufreq_interactive_idle_nb = {
1119         .notifier_call = cpufreq_interactive_idle_notifier,
1120 };
1121
1122 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1123                 unsigned int event)
1124 {
1125         int rc;
1126         unsigned int j;
1127         struct cpufreq_interactive_cpuinfo *pcpu;
1128         struct cpufreq_frequency_table *freq_table;
1129         struct cpufreq_interactive_tunables *tunables;
1130         unsigned long flags;
1131
1132         if (have_governor_per_policy())
1133                 tunables = policy->governor_data;
1134         else
1135                 tunables = common_tunables;
1136
1137         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1138
1139         switch (event) {
1140         case CPUFREQ_GOV_POLICY_INIT:
1141                 if (have_governor_per_policy()) {
1142                         WARN_ON(tunables);
1143                 } else if (tunables) {
1144                         tunables->usage_count++;
1145                         policy->governor_data = tunables;
1146                         return 0;
1147                 }
1148
1149                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1150                 if (!tunables) {
1151                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1152                         return -ENOMEM;
1153                 }
1154
1155                 tunables->usage_count = 1;
1156                 tunables->above_hispeed_delay = default_above_hispeed_delay;
1157                 tunables->nabove_hispeed_delay =
1158                         ARRAY_SIZE(default_above_hispeed_delay);
1159                 tunables->go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
1160                 tunables->target_loads = default_target_loads;
1161                 tunables->ntarget_loads = ARRAY_SIZE(default_target_loads);
1162                 tunables->min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
1163                 tunables->timer_rate = DEFAULT_TIMER_RATE;
1164                 tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
1165                 tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
1166
1167                 spin_lock_init(&tunables->target_loads_lock);
1168                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1169
1170                 policy->governor_data = tunables;
1171                 if (!have_governor_per_policy())
1172                         common_tunables = tunables;
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                         kfree(tunables);
1203                         common_tunables = NULL;
1204                 }
1205
1206                 policy->governor_data = NULL;
1207                 break;
1208
1209         case CPUFREQ_GOV_START:
1210                 mutex_lock(&gov_lock);
1211
1212                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1213                 if (!tunables->hispeed_freq)
1214                         tunables->hispeed_freq = policy->max;
1215
1216                 for_each_cpu(j, policy->cpus) {
1217                         pcpu = &per_cpu(cpuinfo, j);
1218                         pcpu->policy = policy;
1219                         pcpu->target_freq = policy->cur;
1220                         pcpu->freq_table = freq_table;
1221                         pcpu->floor_freq = pcpu->target_freq;
1222                         pcpu->floor_validate_time =
1223                                 ktime_to_us(ktime_get());
1224                         pcpu->hispeed_validate_time =
1225                                 pcpu->floor_validate_time;
1226                         pcpu->max_freq = policy->max;
1227                         down_write(&pcpu->enable_sem);
1228                         del_timer_sync(&pcpu->cpu_timer);
1229                         del_timer_sync(&pcpu->cpu_slack_timer);
1230                         cpufreq_interactive_timer_start(tunables, j);
1231                         pcpu->governor_enabled = 1;
1232                         up_write(&pcpu->enable_sem);
1233                 }
1234
1235                 mutex_unlock(&gov_lock);
1236                 break;
1237
1238         case CPUFREQ_GOV_STOP:
1239                 mutex_lock(&gov_lock);
1240                 for_each_cpu(j, policy->cpus) {
1241                         pcpu = &per_cpu(cpuinfo, j);
1242                         down_write(&pcpu->enable_sem);
1243                         pcpu->governor_enabled = 0;
1244                         del_timer_sync(&pcpu->cpu_timer);
1245                         del_timer_sync(&pcpu->cpu_slack_timer);
1246                         up_write(&pcpu->enable_sem);
1247                 }
1248
1249                 mutex_unlock(&gov_lock);
1250                 break;
1251
1252         case CPUFREQ_GOV_LIMITS:
1253                 if (policy->max < policy->cur)
1254                         __cpufreq_driver_target(policy,
1255                                         policy->max, CPUFREQ_RELATION_H);
1256                 else if (policy->min > policy->cur)
1257                         __cpufreq_driver_target(policy,
1258                                         policy->min, CPUFREQ_RELATION_L);
1259                 for_each_cpu(j, policy->cpus) {
1260                         pcpu = &per_cpu(cpuinfo, j);
1261
1262                         down_read(&pcpu->enable_sem);
1263                         if (pcpu->governor_enabled == 0) {
1264                                 up_read(&pcpu->enable_sem);
1265                                 continue;
1266                         }
1267
1268                         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
1269                         if (policy->max < pcpu->target_freq)
1270                                 pcpu->target_freq = policy->max;
1271                         else if (policy->min > pcpu->target_freq)
1272                                 pcpu->target_freq = policy->min;
1273
1274                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
1275                         up_read(&pcpu->enable_sem);
1276
1277                         /* Reschedule timer only if policy->max is raised.
1278                          * Delete the timers, else the timer callback may
1279                          * return without re-arm the timer when failed
1280                          * acquire the semaphore. This race may cause timer
1281                          * stopped unexpectedly.
1282                          */
1283
1284                         if (policy->max > pcpu->max_freq) {
1285                                 down_write(&pcpu->enable_sem);
1286                                 del_timer_sync(&pcpu->cpu_timer);
1287                                 del_timer_sync(&pcpu->cpu_slack_timer);
1288                                 cpufreq_interactive_timer_start(tunables, j);
1289                                 up_write(&pcpu->enable_sem);
1290                         }
1291
1292                         pcpu->max_freq = policy->max;
1293                 }
1294                 break;
1295         }
1296         return 0;
1297 }
1298
1299 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1300 static
1301 #endif
1302 struct cpufreq_governor cpufreq_gov_interactive = {
1303         .name = "interactive",
1304         .governor = cpufreq_governor_interactive,
1305         .max_transition_latency = 10000000,
1306         .owner = THIS_MODULE,
1307 };
1308
1309 static void cpufreq_interactive_nop_timer(unsigned long data)
1310 {
1311 }
1312
1313 static int __init cpufreq_interactive_init(void)
1314 {
1315         unsigned int i;
1316         struct cpufreq_interactive_cpuinfo *pcpu;
1317         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1318
1319         /* Initalize per-cpu timers */
1320         for_each_possible_cpu(i) {
1321                 pcpu = &per_cpu(cpuinfo, i);
1322                 init_timer_deferrable(&pcpu->cpu_timer);
1323                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1324                 pcpu->cpu_timer.data = i;
1325                 init_timer(&pcpu->cpu_slack_timer);
1326                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1327                 spin_lock_init(&pcpu->load_lock);
1328                 spin_lock_init(&pcpu->target_freq_lock);
1329                 init_rwsem(&pcpu->enable_sem);
1330         }
1331
1332         spin_lock_init(&speedchange_cpumask_lock);
1333         mutex_init(&gov_lock);
1334         speedchange_task =
1335                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1336                                "cfinteractive");
1337         if (IS_ERR(speedchange_task))
1338                 return PTR_ERR(speedchange_task);
1339
1340         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1341         get_task_struct(speedchange_task);
1342
1343         /* NB: wake up so the thread does not look hung to the freezer */
1344         wake_up_process(speedchange_task);
1345
1346         return cpufreq_register_governor(&cpufreq_gov_interactive);
1347 }
1348
1349 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1350 fs_initcall(cpufreq_interactive_init);
1351 #else
1352 module_init(cpufreq_interactive_init);
1353 #endif
1354
1355 static void __exit cpufreq_interactive_exit(void)
1356 {
1357         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1358         kthread_stop(speedchange_task);
1359         put_task_struct(speedchange_task);
1360 }
1361
1362 module_exit(cpufreq_interactive_exit);
1363
1364 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1365 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1366         "Latency sensitive workloads");
1367 MODULE_LICENSE("GPL");