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 <asm/cputime.h>
  34
  35 #define CREATE_TRACE_POINTS
  36 #include <trace/events/cpufreq_interactive.h>
  37
  38 static atomic_t active_count = ATOMIC_INIT(0);
  39
  40 struct cpufreq_interactive_cpuinfo {
  41         struct timer_list cpu_timer;
  42         struct timer_list cpu_slack_timer;
  43         spinlock_t load_lock; /* protects the next 4 fields */
  44         u64 time_in_idle;
  45         u64 time_in_idle_timestamp;
  46         u64 cputime_speedadj;
  47         u64 cputime_speedadj_timestamp;
  48         struct cpufreq_policy *policy;
  49         struct cpufreq_frequency_table *freq_table;
  50         unsigned int target_freq;
  51         unsigned int floor_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
  65 /* Hi speed to bump to from lo speed when load burst (default max) */
  66 static unsigned int hispeed_freq;
  67
  68 /* Go to hi speed when CPU load at or above this value. */
  69 #define DEFAULT_GO_HISPEED_LOAD 85
  70 static unsigned long go_hispeed_load;
  71
  72 /* Target load.  Lower values result in higher CPU speeds. */
  73 #define DEFAULT_TARGET_LOAD 90
  74 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  75 static spinlock_t target_loads_lock;
  76 static unsigned int *target_loads = default_target_loads;
  77 static int ntarget_loads = ARRAY_SIZE(default_target_loads);
  78
  79 /*
  80  * The minimum amount of time to spend at a frequency before we can ramp down.
  81  */
  82 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  83 static unsigned long min_sample_time;
  84
  85 /*
  86  * The sample rate of the timer used to increase frequency
  87  */
  88 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  89 static unsigned long timer_rate;
  90
  91 /*
  92  * Wait this long before raising speed above hispeed, by default a single
  93  * timer interval.
  94  */
  95 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  96 static unsigned long above_hispeed_delay_val;
  97
  98 /* Non-zero means indefinite speed boost active */
  99 static int boost_val;
 100 /* Duration of a boot pulse in usecs */
 101 static int boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
 102 /* End time of boost pulse in ktime converted to usecs */
 103 static u64 boostpulse_endtime;
 104
 105 /*
 106  * Max additional time to wait in idle, beyond timer_rate, at speeds above
 107  * minimum before wakeup to reduce speed, or -1 if unnecessary.
 108  */
 109 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 110 static int timer_slack_val = DEFAULT_TIMER_SLACK;
 111
 112 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
 113                 unsigned int event);
 114
 115 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
 116 static
 117 #endif
 118 struct cpufreq_governor cpufreq_gov_interactive = {
 119         .name = "interactive",
 120         .governor = cpufreq_governor_interactive,
 121         .max_transition_latency = 10000000,
 122         .owner = THIS_MODULE,
 123 };
 124
 125 static void cpufreq_interactive_timer_resched(
 126         struct cpufreq_interactive_cpuinfo *pcpu)
 127 {
 128         unsigned long expires = jiffies + usecs_to_jiffies(timer_rate);
 129
 130         mod_timer_pinned(&pcpu->cpu_timer, expires);
 131         if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
 132                 expires += usecs_to_jiffies(timer_slack_val);
 133                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 134         }
 135
 136         spin_lock(&pcpu->load_lock);
 137         pcpu->time_in_idle =
 138                 get_cpu_idle_time_us(smp_processor_id(),
 139                                      &pcpu->time_in_idle_timestamp);
 140         pcpu->cputime_speedadj = 0;
 141         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 142         spin_unlock(&pcpu->load_lock);
 143 }
 144
 145 static unsigned int freq_to_targetload(unsigned int freq)
 146 {
 147         int i;
 148         unsigned int ret;
 149
 150         spin_lock(&target_loads_lock);
 151
 152         for (i = 0; i < ntarget_loads - 1 && freq >= target_loads[i+1]; i += 2)
 153                 ;
 154
 155         ret = target_loads[i];
 156         spin_unlock(&target_loads_lock);
 157         return ret;
 158 }
 159
 160 /*
 161  * If increasing frequencies never map to a lower target load then
 162  * choose_freq() will find the minimum frequency that does not exceed its
 163  * target load given the current load.
 164  */
 165
 166 static unsigned int choose_freq(
 167         struct cpufreq_interactive_cpuinfo *pcpu, unsigned int loadadjfreq)
 168 {
 169         unsigned int freq = pcpu->policy->cur;
 170         unsigned int prevfreq, freqmin, freqmax;
 171         unsigned int tl;
 172         int index;
 173
 174         freqmin = 0;
 175         freqmax = UINT_MAX;
 176
 177         do {
 178                 prevfreq = freq;
 179                 tl = freq_to_targetload(freq);
 180
 181                 /*
 182                  * Find the lowest frequency where the computed load is less
 183                  * than or equal to the target load.
 184                  */
 185
 186                 cpufreq_frequency_table_target(
 187                         pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 188                         CPUFREQ_RELATION_L, &index);
 189                 freq = pcpu->freq_table[index].frequency;
 190
 191                 if (freq > prevfreq) {
 192                         /* The previous frequency is too low. */
 193                         freqmin = prevfreq;
 194
 195                         if (freq >= freqmax) {
 196                                 /*
 197                                  * Find the highest frequency that is less
 198                                  * than freqmax.
 199                                  */
 200                                 cpufreq_frequency_table_target(
 201                                         pcpu->policy, pcpu->freq_table,
 202                                         freqmax - 1, CPUFREQ_RELATION_H,
 203                                         &index);
 204                                 freq = pcpu->freq_table[index].frequency;
 205
 206                                 if (freq == freqmin) {
 207                                         /*
 208                                          * The first frequency below freqmax
 209                                          * has already been found to be too
 210                                          * low.  freqmax is the lowest speed
 211                                          * we found that is fast enough.
 212                                          */
 213                                         freq = freqmax;
 214                                         break;
 215                                 }
 216                         }
 217                 } else if (freq < prevfreq) {
 218                         /* The previous frequency is high enough. */
 219                         freqmax = prevfreq;
 220
 221                         if (freq <= freqmin) {
 222                                 /*
 223                                  * Find the lowest frequency that is higher
 224                                  * than freqmin.
 225                                  */
 226                                 cpufreq_frequency_table_target(
 227                                         pcpu->policy, pcpu->freq_table,
 228                                         freqmin + 1, CPUFREQ_RELATION_L,
 229                                         &index);
 230                                 freq = pcpu->freq_table[index].frequency;
 231
 232                                 /*
 233                                  * If freqmax is the first frequency above
 234                                  * freqmin then we have already found that
 235                                  * this speed is fast enough.
 236                                  */
 237                                 if (freq == freqmax)
 238                                         break;
 239                         }
 240                 }
 241
 242                 /* If same frequency chosen as previous then done. */
 243         } while (freq != prevfreq);
 244
 245         return freq;
 246 }
 247
 248 static u64 update_load(int cpu)
 249 {
 250         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 251         u64 now;
 252         u64 now_idle;
 253         unsigned int delta_idle;
 254         unsigned int delta_time;
 255         u64 active_time;
 256
 257         now_idle = get_cpu_idle_time_us(cpu, &now);
 258         delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
 259         delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
 260         active_time = delta_time - delta_idle;
 261         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 262
 263         pcpu->time_in_idle = now_idle;
 264         pcpu->time_in_idle_timestamp = now;
 265         return now;
 266 }
 267
 268 static void cpufreq_interactive_timer(unsigned long data)
 269 {
 270         u64 now;
 271         unsigned int delta_time;
 272         u64 cputime_speedadj;
 273         int cpu_load;
 274         struct cpufreq_interactive_cpuinfo *pcpu =
 275                 &per_cpu(cpuinfo, data);
 276         unsigned int new_freq;
 277         unsigned int loadadjfreq;
 278         unsigned int index;
 279         unsigned long flags;
 280         bool boosted;
 281
 282         if (!down_read_trylock(&pcpu->enable_sem))
 283                 return;
 284         if (!pcpu->governor_enabled)
 285                 goto exit;
 286
 287         spin_lock(&pcpu->load_lock);
 288         now = update_load(data);
 289         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 290         cputime_speedadj = pcpu->cputime_speedadj;
 291         spin_unlock(&pcpu->load_lock);
 292
 293         if (WARN_ON_ONCE(!delta_time))
 294                 goto rearm;
 295
 296         do_div(cputime_speedadj, delta_time);
 297         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 298         cpu_load = loadadjfreq / pcpu->target_freq;
 299         boosted = boost_val || now < boostpulse_endtime;
 300
 301         if (cpu_load >= go_hispeed_load || boosted) {
 302                 if (pcpu->target_freq < hispeed_freq) {
 303                         new_freq = hispeed_freq;
 304                 } else {
 305                         new_freq = choose_freq(pcpu, loadadjfreq);
 306
 307                         if (new_freq < hispeed_freq)
 308                                 new_freq = hispeed_freq;
 309                 }
 310         } else {
 311                 new_freq = choose_freq(pcpu, loadadjfreq);
 312         }
 313
 314         if (pcpu->target_freq >= hispeed_freq &&
 315             new_freq > pcpu->target_freq &&
 316             now - pcpu->hispeed_validate_time < above_hispeed_delay_val) {
 317                 trace_cpufreq_interactive_notyet(
 318                         data, cpu_load, pcpu->target_freq,
 319                         pcpu->policy->cur, new_freq);
 320                 goto rearm;
 321         }
 322
 323         pcpu->hispeed_validate_time = now;
 324
 325         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 326                                            new_freq, CPUFREQ_RELATION_L,
 327                                            &index)) {
 328                 pr_warn_once("timer %d: cpufreq_frequency_table_target error\n",
 329                              (int) data);
 330                 goto rearm;
 331         }
 332
 333         new_freq = pcpu->freq_table[index].frequency;
 334
 335         /*
 336          * Do not scale below floor_freq unless we have been at or above the
 337          * floor frequency for the minimum sample time since last validated.
 338          */
 339         if (new_freq < pcpu->floor_freq) {
 340                 if (now - pcpu->floor_validate_time < min_sample_time) {
 341                         trace_cpufreq_interactive_notyet(
 342                                 data, cpu_load, pcpu->target_freq,
 343                                 pcpu->policy->cur, new_freq);
 344                         goto rearm;
 345                 }
 346         }
 347
 348         /*
 349          * Update the timestamp for checking whether speed has been held at
 350          * or above the selected frequency for a minimum of min_sample_time,
 351          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 352          * allow the speed to drop as soon as the boostpulse duration expires
 353          * (or the indefinite boost is turned off).
 354          */
 355
 356         if (!boosted || new_freq > hispeed_freq) {
 357                 pcpu->floor_freq = new_freq;
 358                 pcpu->floor_validate_time = now;
 359         }
 360
 361         if (pcpu->target_freq == new_freq) {
 362                 trace_cpufreq_interactive_already(
 363                         data, cpu_load, pcpu->target_freq,
 364                         pcpu->policy->cur, new_freq);
 365                 goto rearm_if_notmax;
 366         }
 367
 368         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 369                                          pcpu->policy->cur, new_freq);
 370
 371         pcpu->target_freq = new_freq;
 372         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 373         cpumask_set_cpu(data, &speedchange_cpumask);
 374         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 375         wake_up_process(speedchange_task);
 376
 377 rearm_if_notmax:
 378         /*
 379          * Already set max speed and don't see a need to change that,
 380          * wait until next idle to re-evaluate, don't need timer.
 381          */
 382         if (pcpu->target_freq == pcpu->policy->max)
 383                 goto exit;
 384
 385 rearm:
 386         if (!timer_pending(&pcpu->cpu_timer))
 387                 cpufreq_interactive_timer_resched(pcpu);
 388
 389 exit:
 390         up_read(&pcpu->enable_sem);
 391         return;
 392 }
 393
 394 static void cpufreq_interactive_idle_start(void)
 395 {
 396         struct cpufreq_interactive_cpuinfo *pcpu =
 397                 &per_cpu(cpuinfo, smp_processor_id());
 398         int pending;
 399
 400         if (!down_read_trylock(&pcpu->enable_sem))
 401                 return;
 402         if (!pcpu->governor_enabled) {
 403                 up_read(&pcpu->enable_sem);
 404                 return;
 405         }
 406
 407         pending = timer_pending(&pcpu->cpu_timer);
 408
 409         if (pcpu->target_freq != pcpu->policy->min) {
 410                 /*
 411                  * Entering idle while not at lowest speed.  On some
 412                  * platforms this can hold the other CPU(s) at that speed
 413                  * even though the CPU is idle. Set a timer to re-evaluate
 414                  * speed so this idle CPU doesn't hold the other CPUs above
 415                  * min indefinitely.  This should probably be a quirk of
 416                  * the CPUFreq driver.
 417                  */
 418                 if (!pending)
 419                         cpufreq_interactive_timer_resched(pcpu);
 420         }
 421
 422         up_read(&pcpu->enable_sem);
 423 }
 424
 425 static void cpufreq_interactive_idle_end(void)
 426 {
 427         struct cpufreq_interactive_cpuinfo *pcpu =
 428                 &per_cpu(cpuinfo, smp_processor_id());
 429
 430         if (!down_read_trylock(&pcpu->enable_sem))
 431                 return;
 432         if (!pcpu->governor_enabled) {
 433                 up_read(&pcpu->enable_sem);
 434                 return;
 435         }
 436
 437         /* Arm the timer for 1-2 ticks later if not already. */
 438         if (!timer_pending(&pcpu->cpu_timer)) {
 439                 cpufreq_interactive_timer_resched(pcpu);
 440         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 441                 del_timer(&pcpu->cpu_timer);
 442                 del_timer(&pcpu->cpu_slack_timer);
 443                 cpufreq_interactive_timer(smp_processor_id());
 444         }
 445
 446         up_read(&pcpu->enable_sem);
 447 }
 448
 449 static int cpufreq_interactive_speedchange_task(void *data)
 450 {
 451         unsigned int cpu;
 452         cpumask_t tmp_mask;
 453         unsigned long flags;
 454         struct cpufreq_interactive_cpuinfo *pcpu;
 455
 456         while (1) {
 457                 set_current_state(TASK_INTERRUPTIBLE);
 458                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 459
 460                 if (cpumask_empty(&speedchange_cpumask)) {
 461                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 462                                                flags);
 463                         schedule();
 464
 465                         if (kthread_should_stop())
 466                                 break;
 467
 468                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 469                 }
 470
 471                 set_current_state(TASK_RUNNING);
 472                 tmp_mask = speedchange_cpumask;
 473                 cpumask_clear(&speedchange_cpumask);
 474                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 475
 476                 for_each_cpu(cpu, &tmp_mask) {
 477                         unsigned int j;
 478                         unsigned int max_freq = 0;
 479
 480                         pcpu = &per_cpu(cpuinfo, cpu);
 481                         if (!down_read_trylock(&pcpu->enable_sem))
 482                                 continue;
 483                         if (!pcpu->governor_enabled) {
 484                                 up_read(&pcpu->enable_sem);
 485                                 continue;
 486                         }
 487
 488                         for_each_cpu(j, pcpu->policy->cpus) {
 489                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 490                                         &per_cpu(cpuinfo, j);
 491
 492                                 if (pjcpu->target_freq > max_freq)
 493                                         max_freq = pjcpu->target_freq;
 494                         }
 495
 496                         if (max_freq != pcpu->policy->cur)
 497                                 __cpufreq_driver_target(pcpu->policy,
 498                                                         max_freq,
 499                                                         CPUFREQ_RELATION_H);
 500                         trace_cpufreq_interactive_setspeed(cpu,
 501                                                      pcpu->target_freq,
 502                                                      pcpu->policy->cur);
 503
 504                         up_read(&pcpu->enable_sem);
 505                 }
 506         }
 507
 508         return 0;
 509 }
 510
 511 static void cpufreq_interactive_boost(void)
 512 {
 513         int i;
 514         int anyboost = 0;
 515         unsigned long flags;
 516         struct cpufreq_interactive_cpuinfo *pcpu;
 517
 518         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 519
 520         for_each_online_cpu(i) {
 521                 pcpu = &per_cpu(cpuinfo, i);
 522
 523                 if (pcpu->target_freq < hispeed_freq) {
 524                         pcpu->target_freq = hispeed_freq;
 525                         cpumask_set_cpu(i, &speedchange_cpumask);
 526                         pcpu->hispeed_validate_time =
 527                                 ktime_to_us(ktime_get());
 528                         anyboost = 1;
 529                 }
 530
 531                 /*
 532                  * Set floor freq and (re)start timer for when last
 533                  * validated.
 534                  */
 535
 536                 pcpu->floor_freq = hispeed_freq;
 537                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 538         }
 539
 540         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 541
 542         if (anyboost)
 543                 wake_up_process(speedchange_task);
 544 }
 545
 546 static int cpufreq_interactive_notifier(
 547         struct notifier_block *nb, unsigned long val, void *data)
 548 {
 549         struct cpufreq_freqs *freq = data;
 550         struct cpufreq_interactive_cpuinfo *pcpu;
 551         int cpu;
 552
 553         if (val == CPUFREQ_POSTCHANGE) {
 554                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 555
 556                 for_each_cpu(cpu, pcpu->policy->cpus) {
 557                         struct cpufreq_interactive_cpuinfo *pjcpu =
 558                                 &per_cpu(cpuinfo, cpu);
 559                         spin_lock(&pjcpu->load_lock);
 560                         update_load(cpu);
 561                         spin_unlock(&pjcpu->load_lock);
 562                 }
 563         }
 564
 565         return 0;
 566 }
 567
 568 static struct notifier_block cpufreq_notifier_block = {
 569         .notifier_call = cpufreq_interactive_notifier,
 570 };
 571
 572 static ssize_t show_target_loads(
 573         struct kobject *kobj, struct attribute *attr, char *buf)
 574 {
 575         int i;
 576         ssize_t ret = 0;
 577
 578         spin_lock(&target_loads_lock);
 579
 580         for (i = 0; i < ntarget_loads; i++)
 581                 ret += sprintf(buf + ret, "%u%s", target_loads[i],
 582                                i & 0x1 ? ":" : " ");
 583
 584         ret += sprintf(buf + ret, "\n");
 585         spin_unlock(&target_loads_lock);
 586         return ret;
 587 }
 588
 589 static ssize_t store_target_loads(
 590         struct kobject *kobj, struct attribute *attr, const char *buf,
 591         size_t count)
 592 {
 593         int ret;
 594         const char *cp;
 595         unsigned int *new_target_loads = NULL;
 596         int ntokens = 1;
 597         int i;
 598
 599         cp = buf;
 600         while ((cp = strpbrk(cp + 1, " :")))
 601                 ntokens++;
 602
 603         if (!(ntokens & 0x1))
 604                 goto err_inval;
 605
 606         new_target_loads = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 607         if (!new_target_loads) {
 608                 ret = -ENOMEM;
 609                 goto err;
 610         }
 611
 612         cp = buf;
 613         i = 0;
 614         while (i < ntokens) {
 615                 if (sscanf(cp, "%u", &new_target_loads[i++]) != 1)
 616                         goto err_inval;
 617
 618                 cp = strpbrk(cp, " :");
 619                 if (!cp)
 620                         break;
 621                 cp++;
 622         }
 623
 624         if (i != ntokens)
 625                 goto err_inval;
 626
 627         spin_lock(&target_loads_lock);
 628         if (target_loads != default_target_loads)
 629                 kfree(target_loads);
 630         target_loads = new_target_loads;
 631         ntarget_loads = ntokens;
 632         spin_unlock(&target_loads_lock);
 633         return count;
 634
 635 err_inval:
 636         ret = -EINVAL;
 637 err:
 638         kfree(new_target_loads);
 639         return ret;
 640 }
 641
 642 static struct global_attr target_loads_attr =
 643         __ATTR(target_loads, S_IRUGO | S_IWUSR,
 644                 show_target_loads, store_target_loads);
 645
 646 static ssize_t show_hispeed_freq(struct kobject *kobj,
 647                                  struct attribute *attr, char *buf)
 648 {
 649         return sprintf(buf, "%u\n", hispeed_freq);
 650 }
 651
 652 static ssize_t store_hispeed_freq(struct kobject *kobj,
 653                                   struct attribute *attr, const char *buf,
 654                                   size_t count)
 655 {
 656         int ret;
 657         long unsigned int val;
 658
 659         ret = strict_strtoul(buf, 0, &val);
 660         if (ret < 0)
 661                 return ret;
 662         hispeed_freq = val;
 663         return count;
 664 }
 665
 666 static struct global_attr hispeed_freq_attr = __ATTR(hispeed_freq, 0644,
 667                 show_hispeed_freq, store_hispeed_freq);
 668
 669
 670 static ssize_t show_go_hispeed_load(struct kobject *kobj,
 671                                      struct attribute *attr, char *buf)
 672 {
 673         return sprintf(buf, "%lu\n", go_hispeed_load);
 674 }
 675
 676 static ssize_t store_go_hispeed_load(struct kobject *kobj,
 677                         struct attribute *attr, const char *buf, size_t count)
 678 {
 679         int ret;
 680         unsigned long val;
 681
 682         ret = strict_strtoul(buf, 0, &val);
 683         if (ret < 0)
 684                 return ret;
 685         go_hispeed_load = val;
 686         return count;
 687 }
 688
 689 static struct global_attr go_hispeed_load_attr = __ATTR(go_hispeed_load, 0644,
 690                 show_go_hispeed_load, store_go_hispeed_load);
 691
 692 static ssize_t show_min_sample_time(struct kobject *kobj,
 693                                 struct attribute *attr, char *buf)
 694 {
 695         return sprintf(buf, "%lu\n", min_sample_time);
 696 }
 697
 698 static ssize_t store_min_sample_time(struct kobject *kobj,
 699                         struct attribute *attr, const char *buf, size_t count)
 700 {
 701         int ret;
 702         unsigned long val;
 703
 704         ret = strict_strtoul(buf, 0, &val);
 705         if (ret < 0)
 706                 return ret;
 707         min_sample_time = val;
 708         return count;
 709 }
 710
 711 static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,
 712                 show_min_sample_time, store_min_sample_time);
 713
 714 static ssize_t show_above_hispeed_delay(struct kobject *kobj,
 715                                         struct attribute *attr, char *buf)
 716 {
 717         return sprintf(buf, "%lu\n", above_hispeed_delay_val);
 718 }
 719
 720 static ssize_t store_above_hispeed_delay(struct kobject *kobj,
 721                                          struct attribute *attr,
 722                                          const char *buf, size_t count)
 723 {
 724         int ret;
 725         unsigned long val;
 726
 727         ret = strict_strtoul(buf, 0, &val);
 728         if (ret < 0)
 729                 return ret;
 730         above_hispeed_delay_val = val;
 731         return count;
 732 }
 733
 734 define_one_global_rw(above_hispeed_delay);
 735
 736 static ssize_t show_timer_rate(struct kobject *kobj,
 737                         struct attribute *attr, char *buf)
 738 {
 739         return sprintf(buf, "%lu\n", timer_rate);
 740 }
 741
 742 static ssize_t store_timer_rate(struct kobject *kobj,
 743                         struct attribute *attr, const char *buf, size_t count)
 744 {
 745         int ret;
 746         unsigned long val;
 747
 748         ret = strict_strtoul(buf, 0, &val);
 749         if (ret < 0)
 750                 return ret;
 751         timer_rate = val;
 752         return count;
 753 }
 754
 755 static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
 756                 show_timer_rate, store_timer_rate);
 757
 758 static ssize_t show_timer_slack(
 759         struct kobject *kobj, struct attribute *attr, char *buf)
 760 {
 761         return sprintf(buf, "%d\n", timer_slack_val);
 762 }
 763
 764 static ssize_t store_timer_slack(
 765         struct kobject *kobj, struct attribute *attr, const char *buf,
 766         size_t count)
 767 {
 768         int ret;
 769         unsigned long val;
 770
 771         ret = kstrtol(buf, 10, &val);
 772         if (ret < 0)
 773                 return ret;
 774
 775         timer_slack_val = val;
 776         return count;
 777 }
 778
 779 define_one_global_rw(timer_slack);
 780
 781 static ssize_t show_boost(struct kobject *kobj, struct attribute *attr,
 782                           char *buf)
 783 {
 784         return sprintf(buf, "%d\n", boost_val);
 785 }
 786
 787 static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
 788                            const char *buf, size_t count)
 789 {
 790         int ret;
 791         unsigned long val;
 792
 793         ret = kstrtoul(buf, 0, &val);
 794         if (ret < 0)
 795                 return ret;
 796
 797         boost_val = val;
 798
 799         if (boost_val) {
 800                 trace_cpufreq_interactive_boost("on");
 801                 cpufreq_interactive_boost();
 802         } else {
 803                 trace_cpufreq_interactive_unboost("off");
 804         }
 805
 806         return count;
 807 }
 808
 809 define_one_global_rw(boost);
 810
 811 static ssize_t store_boostpulse(struct kobject *kobj, struct attribute *attr,
 812                                 const char *buf, size_t count)
 813 {
 814         int ret;
 815         unsigned long val;
 816
 817         ret = kstrtoul(buf, 0, &val);
 818         if (ret < 0)
 819                 return ret;
 820
 821         boostpulse_endtime = ktime_to_us(ktime_get()) + boostpulse_duration_val;
 822         trace_cpufreq_interactive_boost("pulse");
 823         cpufreq_interactive_boost();
 824         return count;
 825 }
 826
 827 static struct global_attr boostpulse =
 828         __ATTR(boostpulse, 0200, NULL, store_boostpulse);
 829
 830 static ssize_t show_boostpulse_duration(
 831         struct kobject *kobj, struct attribute *attr, char *buf)
 832 {
 833         return sprintf(buf, "%d\n", boostpulse_duration_val);
 834 }
 835
 836 static ssize_t store_boostpulse_duration(
 837         struct kobject *kobj, struct attribute *attr, const char *buf,
 838         size_t count)
 839 {
 840         int ret;
 841         unsigned long val;
 842
 843         ret = kstrtoul(buf, 0, &val);
 844         if (ret < 0)
 845                 return ret;
 846
 847         boostpulse_duration_val = val;
 848         return count;
 849 }
 850
 851 define_one_global_rw(boostpulse_duration);
 852
 853 static struct attribute *interactive_attributes[] = {
 854         &target_loads_attr.attr,
 855         &hispeed_freq_attr.attr,
 856         &go_hispeed_load_attr.attr,
 857         &above_hispeed_delay.attr,
 858         &min_sample_time_attr.attr,
 859         &timer_rate_attr.attr,
 860         &timer_slack.attr,
 861         &boost.attr,
 862         &boostpulse.attr,
 863         &boostpulse_duration.attr,
 864         NULL,
 865 };
 866
 867 static struct attribute_group interactive_attr_group = {
 868         .attrs = interactive_attributes,
 869         .name = "interactive",
 870 };
 871
 872 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
 873                                              unsigned long val,
 874                                              void *data)
 875 {
 876         switch (val) {
 877         case IDLE_START:
 878                 cpufreq_interactive_idle_start();
 879                 break;
 880         case IDLE_END:
 881                 cpufreq_interactive_idle_end();
 882                 break;
 883         }
 884
 885         return 0;
 886 }
 887
 888 static struct notifier_block cpufreq_interactive_idle_nb = {
 889         .notifier_call = cpufreq_interactive_idle_notifier,
 890 };
 891
 892 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
 893                 unsigned int event)
 894 {
 895         int rc;
 896         unsigned int j;
 897         struct cpufreq_interactive_cpuinfo *pcpu;
 898         struct cpufreq_frequency_table *freq_table;
 899
 900         switch (event) {
 901         case CPUFREQ_GOV_START:
 902                 if (!cpu_online(policy->cpu))
 903                         return -EINVAL;
 904
 905                 freq_table =
 906                         cpufreq_frequency_get_table(policy->cpu);
 907                 if (!hispeed_freq)
 908                         hispeed_freq = policy->max;
 909
 910                 for_each_cpu(j, policy->cpus) {
 911                         unsigned long expires;
 912
 913                         pcpu = &per_cpu(cpuinfo, j);
 914                         pcpu->policy = policy;
 915                         pcpu->target_freq = policy->cur;
 916                         pcpu->freq_table = freq_table;
 917                         pcpu->floor_freq = pcpu->target_freq;
 918                         pcpu->floor_validate_time =
 919                                 ktime_to_us(ktime_get());
 920                         pcpu->hispeed_validate_time =
 921                                 pcpu->floor_validate_time;
 922                         down_write(&pcpu->enable_sem);
 923                         expires = jiffies + usecs_to_jiffies(timer_rate);
 924                         pcpu->cpu_timer.expires = expires;
 925                         add_timer_on(&pcpu->cpu_timer, j);
 926                         if (timer_slack_val >= 0) {
 927                                 expires += usecs_to_jiffies(timer_slack_val);
 928                                 pcpu->cpu_slack_timer.expires = expires;
 929                                 add_timer_on(&pcpu->cpu_slack_timer, j);
 930                         }
 931                         pcpu->governor_enabled = 1;
 932                         up_write(&pcpu->enable_sem);
 933                 }
 934
 935                 /*
 936                  * Do not register the idle hook and create sysfs
 937                  * entries if we have already done so.
 938                  */
 939                 if (atomic_inc_return(&active_count) > 1)
 940                         return 0;
 941
 942                 rc = sysfs_create_group(cpufreq_global_kobject,
 943                                 &interactive_attr_group);
 944                 if (rc)
 945                         return rc;
 946
 947                 idle_notifier_register(&cpufreq_interactive_idle_nb);
 948                 cpufreq_register_notifier(
 949                         &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 950                 break;
 951
 952         case CPUFREQ_GOV_STOP:
 953                 for_each_cpu(j, policy->cpus) {
 954                         pcpu = &per_cpu(cpuinfo, j);
 955                         down_write(&pcpu->enable_sem);
 956                         pcpu->governor_enabled = 0;
 957                         del_timer_sync(&pcpu->cpu_timer);
 958                         del_timer_sync(&pcpu->cpu_slack_timer);
 959                         up_write(&pcpu->enable_sem);
 960                 }
 961
 962                 if (atomic_dec_return(&active_count) > 0)
 963                         return 0;
 964
 965                 cpufreq_unregister_notifier(
 966                         &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
 967                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
 968                 sysfs_remove_group(cpufreq_global_kobject,
 969                                 &interactive_attr_group);
 970
 971                 break;
 972
 973         case CPUFREQ_GOV_LIMITS:
 974                 if (policy->max < policy->cur)
 975                         __cpufreq_driver_target(policy,
 976                                         policy->max, CPUFREQ_RELATION_H);
 977                 else if (policy->min > policy->cur)
 978                         __cpufreq_driver_target(policy,
 979                                         policy->min, CPUFREQ_RELATION_L);
 980                 break;
 981         }
 982         return 0;
 983 }
 984
 985 static void cpufreq_interactive_nop_timer(unsigned long data)
 986 {
 987 }
 988
 989 static int __init cpufreq_interactive_init(void)
 990 {
 991         unsigned int i;
 992         struct cpufreq_interactive_cpuinfo *pcpu;
 993         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 994
 995         go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
 996         min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
 997         above_hispeed_delay_val = DEFAULT_ABOVE_HISPEED_DELAY;
 998         timer_rate = DEFAULT_TIMER_RATE;
 999
1000         /* Initalize per-cpu timers */
1001         for_each_possible_cpu(i) {
1002                 pcpu = &per_cpu(cpuinfo, i);
1003                 init_timer_deferrable(&pcpu->cpu_timer);
1004                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1005                 pcpu->cpu_timer.data = i;
1006                 init_timer(&pcpu->cpu_slack_timer);
1007                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1008                 spin_lock_init(&pcpu->load_lock);
1009                 init_rwsem(&pcpu->enable_sem);
1010         }
1011
1012         spin_lock_init(&target_loads_lock);
1013         spin_lock_init(&speedchange_cpumask_lock);
1014         speedchange_task =
1015                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1016                                "cfinteractive");
1017         if (IS_ERR(speedchange_task))
1018                 return PTR_ERR(speedchange_task);
1019
1020         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1021         get_task_struct(speedchange_task);
1022
1023         /* NB: wake up so the thread does not look hung to the freezer */
1024         wake_up_process(speedchange_task);
1025
1026         return cpufreq_register_governor(&cpufreq_gov_interactive);
1027 }
1028
1029 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1030 fs_initcall(cpufreq_interactive_init);
1031 #else
1032 module_init(cpufreq_interactive_init);
1033 #endif
1034
1035 static void __exit cpufreq_interactive_exit(void)
1036 {
1037         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1038         kthread_stop(speedchange_task);
1039         put_task_struct(speedchange_task);
1040 }
1041
1042 module_exit(cpufreq_interactive_exit);
1043
1044 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1045 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1046         "Latency sensitive workloads");
1047 MODULE_LICENSE("GPL");