drivers/cpufreq/cpufreq_interactive.c

   1 /*
   2  * drivers/cpufreq/cpufreq_interactive.c
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * Author: Mike Chan (mike@android.com)
  16  *
  17  */
  18
  19 #include <linux/cpu.h>
  20 #include <linux/cpumask.h>
  21 #include <linux/cpufreq.h>
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/sched.h>
  26 #include <linux/sched/rt.h>
  27 #include <linux/tick.h>
  28 #include <linux/time.h>
  29 #include <linux/timer.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/kthread.h>
  32 #include <linux/slab.h>
  33
  34 #define CREATE_TRACE_POINTS
  35 #include <trace/events/cpufreq_interactive.h>
  36
  37 struct cpufreq_interactive_cpuinfo {
  38         struct timer_list cpu_timer;
  39         struct timer_list cpu_slack_timer;
  40         spinlock_t load_lock; /* protects the next 4 fields */
  41         u64 time_in_idle;
  42         u64 time_in_idle_timestamp;
  43         u64 cputime_speedadj;
  44         u64 cputime_speedadj_timestamp;
  45         struct cpufreq_policy *policy;
  46         struct cpufreq_frequency_table *freq_table;
  47         spinlock_t target_freq_lock; /*protects target freq */
  48         unsigned int target_freq;
  49         unsigned int floor_freq;
  50         u64 pol_floor_val_time; /* policy floor_validate_time */
  51         u64 loc_floor_val_time; /* per-cpu floor_validate_time */
  52         u64 pol_hispeed_val_time; /* policy hispeed_validate_time */
  53         u64 loc_hispeed_val_time; /* per-cpu hispeed_validate_time */
  54         struct rw_semaphore enable_sem;
  55         int governor_enabled;
  56 };
  57
  58 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  59
  60 /* realtime thread handles frequency scaling */
  61 static struct task_struct *speedchange_task;
  62 static cpumask_t speedchange_cpumask;
  63 static spinlock_t speedchange_cpumask_lock;
  64 static struct mutex gov_lock;
  65
  66 /* Target load.  Lower values result in higher CPU speeds. */
  67 #define DEFAULT_TARGET_LOAD 90
  68 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  69
  70 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  71 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  72 static unsigned int default_above_hispeed_delay[] = {
  73         DEFAULT_ABOVE_HISPEED_DELAY };
  74
  75 struct cpufreq_interactive_tunables {
  76         int usage_count;
  77         /* Hi speed to bump to from lo speed when load burst (default max) */
  78         unsigned int hispeed_freq;
  79         /* Go to hi speed when CPU load at or above this value. */
  80 #define DEFAULT_GO_HISPEED_LOAD 99
  81         unsigned long go_hispeed_load;
  82         /* Target load. Lower values result in higher CPU speeds. */
  83         spinlock_t target_loads_lock;
  84         unsigned int *target_loads;
  85         int ntarget_loads;
  86         /*
  87          * The minimum amount of time to spend at a frequency before we can ramp
  88          * down.
  89          */
  90 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  91         unsigned long min_sample_time;
  92         /*
  93          * The sample rate of the timer used to increase frequency
  94          */
  95         unsigned long timer_rate;
  96         /*
  97          * Wait this long before raising speed above hispeed, by default a
  98          * single timer interval.
  99          */
 100         spinlock_t above_hispeed_delay_lock;
 101         unsigned int *above_hispeed_delay;
 102         int nabove_hispeed_delay;
 103         /* Non-zero means indefinite speed boost active */
 104         int boost_val;
 105         /* Duration of a boot pulse in usecs */
 106         int boostpulse_duration_val;
 107         /* End time of boost pulse in ktime converted to usecs */
 108         u64 boostpulse_endtime;
 109         bool boosted;
 110         /*
 111          * Max additional time to wait in idle, beyond timer_rate, at speeds
 112          * above minimum before wakeup to reduce speed, or -1 if unnecessary.
 113          */
 114 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 115         int timer_slack_val;
 116         bool io_is_busy;
 117 };
 118
 119 /*
 120  * HACK: FIXME: Bring back cpufreq_{get,put}_global_kobject()
 121  * definition removed by upstream commit 8eec1020f0c0 "cpufreq:
 122  * create cpu/cpufreq at boot time" to fix build failures.
 123  */
 124 static int cpufreq_global_kobject_usage;
 125
 126 int cpufreq_get_global_kobject(void)
 127 {
 128         if (!cpufreq_global_kobject_usage++)
 129                 return kobject_add(cpufreq_global_kobject,
 130                                 &cpu_subsys.dev_root->kobj, "%s", "cpufreq");
 131
 132         return 0;
 133 }
 134
 135 void cpufreq_put_global_kobject(void)
 136 {
 137         if (!--cpufreq_global_kobject_usage)
 138                 kobject_del(cpufreq_global_kobject);
 139 }
 140
 141 /* For cases where we have single governor instance for system */
 142 static struct cpufreq_interactive_tunables *common_tunables;
 143
 144 static struct attribute_group *get_sysfs_attr(void);
 145
 146 static void cpufreq_interactive_timer_resched(
 147         struct cpufreq_interactive_cpuinfo *pcpu)
 148 {
 149         struct cpufreq_interactive_tunables *tunables =
 150                 pcpu->policy->governor_data;
 151         unsigned long expires;
 152         unsigned long flags;
 153
 154         spin_lock_irqsave(&pcpu->load_lock, flags);
 155         pcpu->time_in_idle =
 156                 get_cpu_idle_time(smp_processor_id(),
 157                                   &pcpu->time_in_idle_timestamp,
 158                                   tunables->io_is_busy);
 159         pcpu->cputime_speedadj = 0;
 160         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 161         expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 162         mod_timer_pinned(&pcpu->cpu_timer, expires);
 163
 164         if (tunables->timer_slack_val >= 0 &&
 165             pcpu->target_freq > pcpu->policy->min) {
 166                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 167                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 168         }
 169
 170         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 171 }
 172
 173 /* The caller shall take enable_sem write semaphore to avoid any timer race.
 174  * The cpu_timer and cpu_slack_timer must be deactivated when calling this
 175  * function.
 176  */
 177 static void cpufreq_interactive_timer_start(
 178         struct cpufreq_interactive_tunables *tunables, int cpu)
 179 {
 180         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 181         unsigned long expires = jiffies +
 182                 usecs_to_jiffies(tunables->timer_rate);
 183         unsigned long flags;
 184
 185         pcpu->cpu_timer.expires = expires;
 186         add_timer_on(&pcpu->cpu_timer, cpu);
 187         if (tunables->timer_slack_val >= 0 &&
 188             pcpu->target_freq > pcpu->policy->min) {
 189                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 190                 pcpu->cpu_slack_timer.expires = expires;
 191                 add_timer_on(&pcpu->cpu_slack_timer, cpu);
 192         }
 193
 194         spin_lock_irqsave(&pcpu->load_lock, flags);
 195         pcpu->time_in_idle =
 196                 get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp,
 197                                   tunables->io_is_busy);
 198         pcpu->cputime_speedadj = 0;
 199         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 200         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 201 }
 202
 203 static unsigned int freq_to_above_hispeed_delay(
 204         struct cpufreq_interactive_tunables *tunables,
 205         unsigned int freq)
 206 {
 207         int i;
 208         unsigned int ret;
 209         unsigned long flags;
 210
 211         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 212
 213         for (i = 0; i < tunables->nabove_hispeed_delay - 1 &&
 214                         freq >= tunables->above_hispeed_delay[i+1]; i += 2)
 215                 ;
 216
 217         ret = tunables->above_hispeed_delay[i];
 218         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 219         return ret;
 220 }
 221
 222 static unsigned int freq_to_targetload(
 223         struct cpufreq_interactive_tunables *tunables, unsigned int freq)
 224 {
 225         int i;
 226         unsigned int ret;
 227         unsigned long flags;
 228
 229         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 230
 231         for (i = 0; i < tunables->ntarget_loads - 1 &&
 232                     freq >= tunables->target_loads[i+1]; i += 2)
 233                 ;
 234
 235         ret = tunables->target_loads[i];
 236         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 237         return ret;
 238 }
 239
 240 /*
 241  * If increasing frequencies never map to a lower target load then
 242  * choose_freq() will find the minimum frequency that does not exceed its
 243  * target load given the current load.
 244  */
 245 static unsigned int choose_freq(struct cpufreq_interactive_cpuinfo *pcpu,
 246                 unsigned int loadadjfreq)
 247 {
 248         unsigned int freq = pcpu->policy->cur;
 249         unsigned int prevfreq, freqmin, freqmax;
 250         unsigned int tl;
 251         int index;
 252
 253         freqmin = 0;
 254         freqmax = UINT_MAX;
 255
 256         do {
 257                 prevfreq = freq;
 258                 tl = freq_to_targetload(pcpu->policy->governor_data, freq);
 259
 260                 /*
 261                  * Find the lowest frequency where the computed load is less
 262                  * than or equal to the target load.
 263                  */
 264
 265                 if (cpufreq_frequency_table_target(
 266                             pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 267                             CPUFREQ_RELATION_L, &index))
 268                         break;
 269                 freq = pcpu->freq_table[index].frequency;
 270
 271                 if (freq > prevfreq) {
 272                         /* The previous frequency is too low. */
 273                         freqmin = prevfreq;
 274
 275                         if (freq >= freqmax) {
 276                                 /*
 277                                  * Find the highest frequency that is less
 278                                  * than freqmax.
 279                                  */
 280                                 if (cpufreq_frequency_table_target(
 281                                             pcpu->policy, pcpu->freq_table,
 282                                             freqmax - 1, CPUFREQ_RELATION_H,
 283                                             &index))
 284                                         break;
 285                                 freq = pcpu->freq_table[index].frequency;
 286
 287                                 if (freq == freqmin) {
 288                                         /*
 289                                          * The first frequency below freqmax
 290                                          * has already been found to be too
 291                                          * low.  freqmax is the lowest speed
 292                                          * we found that is fast enough.
 293                                          */
 294                                         freq = freqmax;
 295                                         break;
 296                                 }
 297                         }
 298                 } else if (freq < prevfreq) {
 299                         /* The previous frequency is high enough. */
 300                         freqmax = prevfreq;
 301
 302                         if (freq <= freqmin) {
 303                                 /*
 304                                  * Find the lowest frequency that is higher
 305                                  * than freqmin.
 306                                  */
 307                                 if (cpufreq_frequency_table_target(
 308                                             pcpu->policy, pcpu->freq_table,
 309                                             freqmin + 1, CPUFREQ_RELATION_L,
 310                                             &index))
 311                                         break;
 312                                 freq = pcpu->freq_table[index].frequency;
 313
 314                                 /*
 315                                  * If freqmax is the first frequency above
 316                                  * freqmin then we have already found that
 317                                  * this speed is fast enough.
 318                                  */
 319                                 if (freq == freqmax)
 320                                         break;
 321                         }
 322                 }
 323
 324                 /* If same frequency chosen as previous then done. */
 325         } while (freq != prevfreq);
 326
 327         return freq;
 328 }
 329
 330 static u64 update_load(int cpu)
 331 {
 332         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 333         struct cpufreq_interactive_tunables *tunables =
 334                 pcpu->policy->governor_data;
 335         u64 now;
 336         u64 now_idle;
 337         unsigned int delta_idle;
 338         unsigned int delta_time;
 339         u64 active_time;
 340
 341         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 342         delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
 343         delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
 344
 345         if (delta_time <= delta_idle)
 346                 active_time = 0;
 347         else
 348                 active_time = delta_time - delta_idle;
 349
 350         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 351
 352         pcpu->time_in_idle = now_idle;
 353         pcpu->time_in_idle_timestamp = now;
 354         return now;
 355 }
 356
 357 static void cpufreq_interactive_timer(unsigned long data)
 358 {
 359         u64 now;
 360         unsigned int delta_time;
 361         u64 cputime_speedadj;
 362         int cpu_load;
 363         struct cpufreq_interactive_cpuinfo *pcpu =
 364                 &per_cpu(cpuinfo, data);
 365         struct cpufreq_interactive_tunables *tunables =
 366                 pcpu->policy->governor_data;
 367         unsigned int new_freq;
 368         unsigned int loadadjfreq;
 369         unsigned int index;
 370         unsigned long flags;
 371         u64 max_fvtime;
 372
 373         if (!down_read_trylock(&pcpu->enable_sem))
 374                 return;
 375         if (!pcpu->governor_enabled)
 376                 goto exit;
 377
 378         spin_lock_irqsave(&pcpu->load_lock, flags);
 379         now = update_load(data);
 380         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 381         cputime_speedadj = pcpu->cputime_speedadj;
 382         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 383
 384         if (WARN_ON_ONCE(!delta_time))
 385                 goto rearm;
 386
 387         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
 388         do_div(cputime_speedadj, delta_time);
 389         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 390         cpu_load = loadadjfreq / pcpu->policy->cur;
 391         tunables->boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 392
 393         if (cpu_load >= tunables->go_hispeed_load || tunables->boosted) {
 394                 if (pcpu->policy->cur < tunables->hispeed_freq) {
 395                         new_freq = tunables->hispeed_freq;
 396                 } else {
 397                         new_freq = choose_freq(pcpu, loadadjfreq);
 398
 399                         if (new_freq < tunables->hispeed_freq)
 400                                 new_freq = tunables->hispeed_freq;
 401                 }
 402         } else {
 403                 new_freq = choose_freq(pcpu, loadadjfreq);
 404                 if (new_freq > tunables->hispeed_freq &&
 405                                 pcpu->policy->cur < tunables->hispeed_freq)
 406                         new_freq = tunables->hispeed_freq;
 407         }
 408
 409         if (pcpu->policy->cur >= tunables->hispeed_freq &&
 410             new_freq > pcpu->policy->cur &&
 411             now - pcpu->pol_hispeed_val_time <
 412             freq_to_above_hispeed_delay(tunables, pcpu->policy->cur)) {
 413                 trace_cpufreq_interactive_notyet(
 414                         data, cpu_load, pcpu->target_freq,
 415                         pcpu->policy->cur, new_freq);
 416                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 417                 goto rearm;
 418         }
 419
 420         pcpu->loc_hispeed_val_time = now;
 421
 422         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 423                                            new_freq, CPUFREQ_RELATION_L,
 424                                            &index)) {
 425                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 426                 goto rearm;
 427         }
 428
 429         new_freq = pcpu->freq_table[index].frequency;
 430
 431         /*
 432          * Do not scale below floor_freq unless we have been at or above the
 433          * floor frequency for the minimum sample time since last validated.
 434          */
 435         max_fvtime = max(pcpu->pol_floor_val_time, pcpu->loc_floor_val_time);
 436         if (new_freq < pcpu->floor_freq &&
 437             pcpu->target_freq >= pcpu->policy->cur) {
 438                 if (now - max_fvtime < tunables->min_sample_time) {
 439                         trace_cpufreq_interactive_notyet(
 440                                 data, cpu_load, pcpu->target_freq,
 441                                 pcpu->policy->cur, new_freq);
 442                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 443                         goto rearm;
 444                 }
 445         }
 446
 447         /*
 448          * Update the timestamp for checking whether speed has been held at
 449          * or above the selected frequency for a minimum of min_sample_time,
 450          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 451          * allow the speed to drop as soon as the boostpulse duration expires
 452          * (or the indefinite boost is turned off).
 453          */
 454
 455         if (!tunables->boosted || new_freq > tunables->hispeed_freq) {
 456                 pcpu->floor_freq = new_freq;
 457                 if (pcpu->target_freq >= pcpu->policy->cur ||
 458                     new_freq >= pcpu->policy->cur)
 459                         pcpu->loc_floor_val_time = now;
 460         }
 461
 462         if (pcpu->target_freq == new_freq &&
 463                         pcpu->target_freq <= pcpu->policy->cur) {
 464                 trace_cpufreq_interactive_already(
 465                         data, cpu_load, pcpu->target_freq,
 466                         pcpu->policy->cur, new_freq);
 467                 spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 468                 goto rearm;
 469         }
 470
 471         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 472                                          pcpu->policy->cur, new_freq);
 473
 474         pcpu->target_freq = new_freq;
 475         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
 476         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 477         cpumask_set_cpu(data, &speedchange_cpumask);
 478         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 479         wake_up_process(speedchange_task);
 480
 481 rearm:
 482         if (!timer_pending(&pcpu->cpu_timer))
 483                 cpufreq_interactive_timer_resched(pcpu);
 484
 485 exit:
 486         up_read(&pcpu->enable_sem);
 487         return;
 488 }
 489
 490 static void cpufreq_interactive_idle_end(void)
 491 {
 492         struct cpufreq_interactive_cpuinfo *pcpu =
 493                 &per_cpu(cpuinfo, smp_processor_id());
 494
 495         if (!down_read_trylock(&pcpu->enable_sem))
 496                 return;
 497         if (!pcpu->governor_enabled) {
 498                 up_read(&pcpu->enable_sem);
 499                 return;
 500         }
 501
 502         /* Arm the timer for 1-2 ticks later if not already. */
 503         if (!timer_pending(&pcpu->cpu_timer)) {
 504                 cpufreq_interactive_timer_resched(pcpu);
 505         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 506                 del_timer(&pcpu->cpu_timer);
 507                 del_timer(&pcpu->cpu_slack_timer);
 508                 cpufreq_interactive_timer(smp_processor_id());
 509         }
 510
 511         up_read(&pcpu->enable_sem);
 512 }
 513
 514 static int cpufreq_interactive_speedchange_task(void *data)
 515 {
 516         unsigned int cpu;
 517         cpumask_t tmp_mask;
 518         unsigned long flags;
 519         struct cpufreq_interactive_cpuinfo *pcpu;
 520
 521         while (1) {
 522                 set_current_state(TASK_INTERRUPTIBLE);
 523                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 524
 525                 if (cpumask_empty(&speedchange_cpumask)) {
 526                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 527                                                flags);
 528                         schedule();
 529
 530                         if (kthread_should_stop())
 531                                 break;
 532
 533                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 534                 }
 535
 536                 set_current_state(TASK_RUNNING);
 537                 tmp_mask = speedchange_cpumask;
 538                 cpumask_clear(&speedchange_cpumask);
 539                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 540
 541                 for_each_cpu(cpu, &tmp_mask) {
 542                         unsigned int j;
 543                         unsigned int max_freq = 0;
 544                         struct cpufreq_interactive_cpuinfo *pjcpu;
 545                         u64 hvt = ~0ULL, fvt = 0;
 546
 547                         pcpu = &per_cpu(cpuinfo, cpu);
 548                         if (!down_read_trylock(&pcpu->enable_sem))
 549                                 continue;
 550                         if (!pcpu->governor_enabled) {
 551                                 up_read(&pcpu->enable_sem);
 552                                 continue;
 553                         }
 554
 555                         for_each_cpu(j, pcpu->policy->cpus) {
 556                                 pjcpu = &per_cpu(cpuinfo, j);
 557
 558                                 fvt = max(fvt, pjcpu->loc_floor_val_time);
 559                                 if (pjcpu->target_freq > max_freq) {
 560                                         max_freq = pjcpu->target_freq;
 561                                         hvt = pjcpu->loc_hispeed_val_time;
 562                                 } else if (pjcpu->target_freq == max_freq) {
 563                                         hvt = min(hvt, pjcpu->loc_hispeed_val_time);
 564                                 }
 565                         }
 566                         for_each_cpu(j, pcpu->policy->cpus) {
 567                                 pjcpu = &per_cpu(cpuinfo, j);
 568                                 pjcpu->pol_floor_val_time = fvt;
 569                         }
 570
 571                         if (max_freq != pcpu->policy->cur) {
 572                                 __cpufreq_driver_target(pcpu->policy,
 573                                                         max_freq,
 574                                                         CPUFREQ_RELATION_H);
 575                                 for_each_cpu(j, pcpu->policy->cpus) {
 576                                         pjcpu = &per_cpu(cpuinfo, j);
 577                                         pjcpu->pol_hispeed_val_time = hvt;
 578                                 }
 579                         }
 580                         trace_cpufreq_interactive_setspeed(cpu,
 581                                                      pcpu->target_freq,
 582                                                      pcpu->policy->cur);
 583
 584                         up_read(&pcpu->enable_sem);
 585                 }
 586         }
 587
 588         return 0;
 589 }
 590
 591 static void cpufreq_interactive_boost(struct cpufreq_interactive_tunables *tunables)
 592 {
 593         int i;
 594         int anyboost = 0;
 595         unsigned long flags[2];
 596         struct cpufreq_interactive_cpuinfo *pcpu;
 597
 598         tunables->boosted = true;
 599
 600         spin_lock_irqsave(&speedchange_cpumask_lock, flags[0]);
 601
 602         for_each_online_cpu(i) {
 603                 pcpu = &per_cpu(cpuinfo, i);
 604                 if (tunables != pcpu->policy->governor_data)
 605                         continue;
 606
 607                 spin_lock_irqsave(&pcpu->target_freq_lock, flags[1]);
 608                 if (pcpu->target_freq < tunables->hispeed_freq) {
 609                         pcpu->target_freq = tunables->hispeed_freq;
 610                         cpumask_set_cpu(i, &speedchange_cpumask);
 611                         pcpu->pol_hispeed_val_time =
 612                                 ktime_to_us(ktime_get());
 613                         anyboost = 1;
 614                 }
 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 = kstrtoul(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 = kstrtoul(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 = kstrtoul(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, val_round;
 862
 863         ret = kstrtoul(buf, 0, &val);
 864         if (ret < 0)
 865                 return ret;
 866
 867         val_round = jiffies_to_usecs(usecs_to_jiffies(val));
 868         if (val != val_round)
 869                 pr_warn("timer_rate not aligned to jiffy. Rounded up to %lu\n",
 870                         val_round);
 871
 872         tunables->timer_rate = val_round;
 873         return count;
 874 }
 875
 876 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 877                 char *buf)
 878 {
 879         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 880 }
 881
 882 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 883                 const char *buf, size_t count)
 884 {
 885         int ret;
 886         unsigned long val;
 887
 888         ret = kstrtol(buf, 10, &val);
 889         if (ret < 0)
 890                 return ret;
 891
 892         tunables->timer_slack_val = val;
 893         return count;
 894 }
 895
 896 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 897                           char *buf)
 898 {
 899         return sprintf(buf, "%d\n", tunables->boost_val);
 900 }
 901
 902 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 903                            const char *buf, size_t count)
 904 {
 905         int ret;
 906         unsigned long val;
 907
 908         ret = kstrtoul(buf, 0, &val);
 909         if (ret < 0)
 910                 return ret;
 911
 912         tunables->boost_val = val;
 913
 914         if (tunables->boost_val) {
 915                 trace_cpufreq_interactive_boost("on");
 916                 if (!tunables->boosted)
 917                         cpufreq_interactive_boost(tunables);
 918         } else {
 919                 tunables->boostpulse_endtime = ktime_to_us(ktime_get());
 920                 trace_cpufreq_interactive_unboost("off");
 921         }
 922
 923         return count;
 924 }
 925
 926 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 927                                 const char *buf, size_t count)
 928 {
 929         int ret;
 930         unsigned long val;
 931
 932         ret = kstrtoul(buf, 0, &val);
 933         if (ret < 0)
 934                 return ret;
 935
 936         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 937                 tunables->boostpulse_duration_val;
 938         trace_cpufreq_interactive_boost("pulse");
 939         if (!tunables->boosted)
 940                 cpufreq_interactive_boost(tunables);
 941         return count;
 942 }
 943
 944 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 945                 *tunables, char *buf)
 946 {
 947         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 948 }
 949
 950 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 951                 *tunables, const char *buf, size_t count)
 952 {
 953         int ret;
 954         unsigned long val;
 955
 956         ret = kstrtoul(buf, 0, &val);
 957         if (ret < 0)
 958                 return ret;
 959
 960         tunables->boostpulse_duration_val = val;
 961         return count;
 962 }
 963
 964 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 965                 char *buf)
 966 {
 967         return sprintf(buf, "%u\n", tunables->io_is_busy);
 968 }
 969
 970 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 971                 const char *buf, size_t count)
 972 {
 973         int ret;
 974         unsigned long val;
 975
 976         ret = kstrtoul(buf, 0, &val);
 977         if (ret < 0)
 978                 return ret;
 979         tunables->io_is_busy = val;
 980         return count;
 981 }
 982
 983 /*
 984  * Create show/store routines
 985  * - sys: One governor instance for complete SYSTEM
 986  * - pol: One governor instance per struct cpufreq_policy
 987  */
 988 #define show_gov_pol_sys(file_name)                                     \
 989 static ssize_t show_##file_name##_gov_sys                               \
 990 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 991 {                                                                       \
 992         return show_##file_name(common_tunables, buf);                  \
 993 }                                                                       \
 994                                                                         \
 995 static ssize_t show_##file_name##_gov_pol                               \
 996 (struct cpufreq_policy *policy, char *buf)                              \
 997 {                                                                       \
 998         return show_##file_name(policy->governor_data, buf);            \
 999 }
1000
1001 #define store_gov_pol_sys(file_name)                                    \
1002 static ssize_t store_##file_name##_gov_sys                              \
1003 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
1004         size_t count)                                                   \
1005 {                                                                       \
1006         return store_##file_name(common_tunables, buf, count);          \
1007 }                                                                       \
1008                                                                         \
1009 static ssize_t store_##file_name##_gov_pol                              \
1010 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
1011 {                                                                       \
1012         return store_##file_name(policy->governor_data, buf, count);    \
1013 }
1014
1015 #define show_store_gov_pol_sys(file_name)                               \
1016 show_gov_pol_sys(file_name);                                            \
1017 store_gov_pol_sys(file_name)
1018
1019 show_store_gov_pol_sys(target_loads);
1020 show_store_gov_pol_sys(above_hispeed_delay);
1021 show_store_gov_pol_sys(hispeed_freq);
1022 show_store_gov_pol_sys(go_hispeed_load);
1023 show_store_gov_pol_sys(min_sample_time);
1024 show_store_gov_pol_sys(timer_rate);
1025 show_store_gov_pol_sys(timer_slack);
1026 show_store_gov_pol_sys(boost);
1027 store_gov_pol_sys(boostpulse);
1028 show_store_gov_pol_sys(boostpulse_duration);
1029 show_store_gov_pol_sys(io_is_busy);
1030
1031 #define gov_sys_attr_rw(_name)                                          \
1032 static struct global_attr _name##_gov_sys =                             \
1033 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
1034
1035 #define gov_pol_attr_rw(_name)                                          \
1036 static struct freq_attr _name##_gov_pol =                               \
1037 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
1038
1039 #define gov_sys_pol_attr_rw(_name)                                      \
1040         gov_sys_attr_rw(_name);                                         \
1041         gov_pol_attr_rw(_name)
1042
1043 gov_sys_pol_attr_rw(target_loads);
1044 gov_sys_pol_attr_rw(above_hispeed_delay);
1045 gov_sys_pol_attr_rw(hispeed_freq);
1046 gov_sys_pol_attr_rw(go_hispeed_load);
1047 gov_sys_pol_attr_rw(min_sample_time);
1048 gov_sys_pol_attr_rw(timer_rate);
1049 gov_sys_pol_attr_rw(timer_slack);
1050 gov_sys_pol_attr_rw(boost);
1051 gov_sys_pol_attr_rw(boostpulse_duration);
1052 gov_sys_pol_attr_rw(io_is_busy);
1053
1054 static struct global_attr boostpulse_gov_sys =
1055         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1056
1057 static struct freq_attr boostpulse_gov_pol =
1058         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1059
1060 /* One Governor instance for entire system */
1061 static struct attribute *interactive_attributes_gov_sys[] = {
1062         &target_loads_gov_sys.attr,
1063         &above_hispeed_delay_gov_sys.attr,
1064         &hispeed_freq_gov_sys.attr,
1065         &go_hispeed_load_gov_sys.attr,
1066         &min_sample_time_gov_sys.attr,
1067         &timer_rate_gov_sys.attr,
1068         &timer_slack_gov_sys.attr,
1069         &boost_gov_sys.attr,
1070         &boostpulse_gov_sys.attr,
1071         &boostpulse_duration_gov_sys.attr,
1072         &io_is_busy_gov_sys.attr,
1073         NULL,
1074 };
1075
1076 static struct attribute_group interactive_attr_group_gov_sys = {
1077         .attrs = interactive_attributes_gov_sys,
1078         .name = "interactive",
1079 };
1080
1081 /* Per policy governor instance */
1082 static struct attribute *interactive_attributes_gov_pol[] = {
1083         &target_loads_gov_pol.attr,
1084         &above_hispeed_delay_gov_pol.attr,
1085         &hispeed_freq_gov_pol.attr,
1086         &go_hispeed_load_gov_pol.attr,
1087         &min_sample_time_gov_pol.attr,
1088         &timer_rate_gov_pol.attr,
1089         &timer_slack_gov_pol.attr,
1090         &boost_gov_pol.attr,
1091         &boostpulse_gov_pol.attr,
1092         &boostpulse_duration_gov_pol.attr,
1093         &io_is_busy_gov_pol.attr,
1094         NULL,
1095 };
1096
1097 static struct attribute_group interactive_attr_group_gov_pol = {
1098         .attrs = interactive_attributes_gov_pol,
1099         .name = "interactive",
1100 };
1101
1102 static struct attribute_group *get_sysfs_attr(void)
1103 {
1104         if (have_governor_per_policy())
1105                 return &interactive_attr_group_gov_pol;
1106         else
1107                 return &interactive_attr_group_gov_sys;
1108 }
1109
1110 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1111                                              unsigned long val,
1112                                              void *data)
1113 {
1114         if (val == IDLE_END)
1115                 cpufreq_interactive_idle_end();
1116
1117         return 0;
1118 }
1119
1120 static struct notifier_block cpufreq_interactive_idle_nb = {
1121         .notifier_call = cpufreq_interactive_idle_notifier,
1122 };
1123
1124 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1125                 unsigned int event)
1126 {
1127         int rc;
1128         unsigned int j;
1129         struct cpufreq_interactive_cpuinfo *pcpu;
1130         struct cpufreq_frequency_table *freq_table;
1131         struct cpufreq_interactive_tunables *tunables;
1132         unsigned long flags;
1133
1134         if (have_governor_per_policy())
1135                 tunables = policy->governor_data;
1136         else
1137                 tunables = common_tunables;
1138
1139         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1140
1141         switch (event) {
1142         case CPUFREQ_GOV_POLICY_INIT:
1143                 if (have_governor_per_policy()) {
1144                         WARN_ON(tunables);
1145                 } else if (tunables) {
1146                         tunables->usage_count++;
1147                         policy->governor_data = tunables;
1148                         return 0;
1149                 }
1150
1151                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1152                 if (!tunables) {
1153                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1154                         return -ENOMEM;
1155                 }
1156
1157                 tunables->usage_count = 1;
1158                 tunables->above_hispeed_delay = default_above_hispeed_delay;
1159                 tunables->nabove_hispeed_delay =
1160                         ARRAY_SIZE(default_above_hispeed_delay);
1161                 tunables->go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
1162                 tunables->target_loads = default_target_loads;
1163                 tunables->ntarget_loads = ARRAY_SIZE(default_target_loads);
1164                 tunables->min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
1165                 tunables->timer_rate = DEFAULT_TIMER_RATE;
1166                 tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
1167                 tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
1168
1169                 spin_lock_init(&tunables->target_loads_lock);
1170                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1171
1172                 policy->governor_data = tunables;
1173                 if (!have_governor_per_policy()) {
1174                         common_tunables = tunables;
1175                         WARN_ON(cpufreq_get_global_kobject());
1176                 }
1177
1178                 rc = sysfs_create_group(get_governor_parent_kobj(policy),
1179                                 get_sysfs_attr());
1180                 if (rc) {
1181                         kfree(tunables);
1182                         policy->governor_data = NULL;
1183                         if (!have_governor_per_policy()) {
1184                                 common_tunables = NULL;
1185                                 cpufreq_put_global_kobject();
1186                         }
1187                         return rc;
1188                 }
1189
1190                 if (!policy->governor->initialized) {
1191                         idle_notifier_register(&cpufreq_interactive_idle_nb);
1192                         cpufreq_register_notifier(&cpufreq_notifier_block,
1193                                         CPUFREQ_TRANSITION_NOTIFIER);
1194                 }
1195
1196                 break;
1197
1198         case CPUFREQ_GOV_POLICY_EXIT:
1199                 if (!--tunables->usage_count) {
1200                         if (policy->governor->initialized == 1) {
1201                                 cpufreq_unregister_notifier(&cpufreq_notifier_block,
1202                                                 CPUFREQ_TRANSITION_NOTIFIER);
1203                                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1204                         }
1205
1206                         sysfs_remove_group(get_governor_parent_kobj(policy),
1207                                         get_sysfs_attr());
1208
1209                         if (!have_governor_per_policy())
1210                                 cpufreq_put_global_kobject();
1211
1212                         kfree(tunables);
1213                         common_tunables = NULL;
1214                 }
1215
1216                 policy->governor_data = NULL;
1217                 break;
1218
1219         case CPUFREQ_GOV_START:
1220                 mutex_lock(&gov_lock);
1221
1222                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1223                 if (!tunables->hispeed_freq)
1224                         tunables->hispeed_freq = policy->max;
1225
1226                 for_each_cpu(j, policy->cpus) {
1227                         pcpu = &per_cpu(cpuinfo, j);
1228                         pcpu->policy = policy;
1229                         pcpu->target_freq = policy->cur;
1230                         pcpu->freq_table = freq_table;
1231                         pcpu->floor_freq = pcpu->target_freq;
1232                         pcpu->pol_floor_val_time =
1233                                 ktime_to_us(ktime_get());
1234                         pcpu->loc_floor_val_time = pcpu->pol_floor_val_time;
1235                         pcpu->pol_hispeed_val_time = pcpu->pol_floor_val_time;
1236                         pcpu->loc_hispeed_val_time = pcpu->pol_floor_val_time;
1237                         down_write(&pcpu->enable_sem);
1238                         del_timer_sync(&pcpu->cpu_timer);
1239                         del_timer_sync(&pcpu->cpu_slack_timer);
1240                         cpufreq_interactive_timer_start(tunables, j);
1241                         pcpu->governor_enabled = 1;
1242                         up_write(&pcpu->enable_sem);
1243                 }
1244
1245                 mutex_unlock(&gov_lock);
1246                 break;
1247
1248         case CPUFREQ_GOV_STOP:
1249                 mutex_lock(&gov_lock);
1250                 for_each_cpu(j, policy->cpus) {
1251                         pcpu = &per_cpu(cpuinfo, j);
1252                         down_write(&pcpu->enable_sem);
1253                         pcpu->governor_enabled = 0;
1254                         del_timer_sync(&pcpu->cpu_timer);
1255                         del_timer_sync(&pcpu->cpu_slack_timer);
1256                         up_write(&pcpu->enable_sem);
1257                 }
1258
1259                 mutex_unlock(&gov_lock);
1260                 break;
1261
1262         case CPUFREQ_GOV_LIMITS:
1263                 if (policy->max < policy->cur)
1264                         __cpufreq_driver_target(policy,
1265                                         policy->max, CPUFREQ_RELATION_H);
1266                 else if (policy->min > policy->cur)
1267                         __cpufreq_driver_target(policy,
1268                                         policy->min, CPUFREQ_RELATION_L);
1269                 for_each_cpu(j, policy->cpus) {
1270                         pcpu = &per_cpu(cpuinfo, j);
1271
1272                         down_read(&pcpu->enable_sem);
1273                         if (pcpu->governor_enabled == 0) {
1274                                 up_read(&pcpu->enable_sem);
1275                                 continue;
1276                         }
1277
1278                         spin_lock_irqsave(&pcpu->target_freq_lock, flags);
1279                         if (policy->max < pcpu->target_freq)
1280                                 pcpu->target_freq = policy->max;
1281                         else if (policy->min > pcpu->target_freq)
1282                                 pcpu->target_freq = policy->min;
1283
1284                         spin_unlock_irqrestore(&pcpu->target_freq_lock, flags);
1285                         up_read(&pcpu->enable_sem);
1286                 }
1287                 break;
1288         }
1289         return 0;
1290 }
1291
1292 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1293 static
1294 #endif
1295 struct cpufreq_governor cpufreq_gov_interactive = {
1296         .name = "interactive",
1297         .governor = cpufreq_governor_interactive,
1298         .max_transition_latency = 10000000,
1299         .owner = THIS_MODULE,
1300 };
1301
1302 static void cpufreq_interactive_nop_timer(unsigned long data)
1303 {
1304 }
1305
1306 static int __init cpufreq_interactive_init(void)
1307 {
1308         unsigned int i;
1309         struct cpufreq_interactive_cpuinfo *pcpu;
1310         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1311
1312         /* Initalize per-cpu timers */
1313         for_each_possible_cpu(i) {
1314                 pcpu = &per_cpu(cpuinfo, i);
1315                 init_timer_deferrable(&pcpu->cpu_timer);
1316                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1317                 pcpu->cpu_timer.data = i;
1318                 init_timer(&pcpu->cpu_slack_timer);
1319                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1320                 spin_lock_init(&pcpu->load_lock);
1321                 spin_lock_init(&pcpu->target_freq_lock);
1322                 init_rwsem(&pcpu->enable_sem);
1323         }
1324
1325         spin_lock_init(&speedchange_cpumask_lock);
1326         mutex_init(&gov_lock);
1327         speedchange_task =
1328                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1329                                "cfinteractive");
1330         if (IS_ERR(speedchange_task))
1331                 return PTR_ERR(speedchange_task);
1332
1333         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1334         get_task_struct(speedchange_task);
1335
1336         /* NB: wake up so the thread does not look hung to the freezer */
1337         wake_up_process(speedchange_task);
1338
1339         return cpufreq_register_governor(&cpufreq_gov_interactive);
1340 }
1341
1342 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1343 fs_initcall(cpufreq_interactive_init);
1344 #else
1345 module_init(cpufreq_interactive_init);
1346 #endif
1347
1348 static void __exit cpufreq_interactive_exit(void)
1349 {
1350         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1351         kthread_stop(speedchange_task);
1352         put_task_struct(speedchange_task);
1353 }
1354
1355 module_exit(cpufreq_interactive_exit);
1356
1357 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1358 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1359         "Latency sensitive workloads");
1360 MODULE_LICENSE("GPL");