drivers/cpufreq/intel_pstate.c

   1 /*
   2  * intel_pstate.c: Native P state management for Intel processors
   3  *
   4  * (C) Copyright 2012 Intel Corporation
   5  * Author: Dirk Brandewie <dirk.j.brandewie@intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; version 2
  10  * of the License.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/kernel_stat.h>
  15 #include <linux/module.h>
  16 #include <linux/ktime.h>
  17 #include <linux/hrtimer.h>
  18 #include <linux/tick.h>
  19 #include <linux/slab.h>
  20 #include <linux/sched.h>
  21 #include <linux/list.h>
  22 #include <linux/cpu.h>
  23 #include <linux/cpufreq.h>
  24 #include <linux/sysfs.h>
  25 #include <linux/types.h>
  26 #include <linux/fs.h>
  27 #include <linux/debugfs.h>
  28 #include <trace/events/power.h>
  29
  30 #include <asm/div64.h>
  31 #include <asm/msr.h>
  32 #include <asm/cpu_device_id.h>
  33
  34 #define SAMPLE_COUNT            3
  35
  36 #define FRAC_BITS 8
  37 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
  38 #define fp_toint(X) ((X) >> FRAC_BITS)
  39
  40 static inline int32_t mul_fp(int32_t x, int32_t y)
  41 {
  42         return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
  43 }
  44
  45 static inline int32_t div_fp(int32_t x, int32_t y)
  46 {
  47         return div_s64((int64_t)x << FRAC_BITS, (int64_t)y);
  48 }
  49
  50 struct sample {
  51         ktime_t start_time;
  52         ktime_t end_time;
  53         int core_pct_busy;
  54         int pstate_pct_busy;
  55         u64 duration_us;
  56         u64 idletime_us;
  57         u64 aperf;
  58         u64 mperf;
  59         int freq;
  60 };
  61
  62 struct pstate_data {
  63         int     current_pstate;
  64         int     min_pstate;
  65         int     max_pstate;
  66         int     turbo_pstate;
  67 };
  68
  69 struct _pid {
  70         int setpoint;
  71         int32_t integral;
  72         int32_t p_gain;
  73         int32_t i_gain;
  74         int32_t d_gain;
  75         int deadband;
  76         int last_err;
  77 };
  78
  79 struct cpudata {
  80         int cpu;
  81
  82         char name[64];
  83
  84         struct timer_list timer;
  85
  86         struct pstate_adjust_policy *pstate_policy;
  87         struct pstate_data pstate;
  88         struct _pid pid;
  89         struct _pid idle_pid;
  90
  91         int min_pstate_count;
  92         int idle_mode;
  93
  94         ktime_t prev_sample;
  95         u64     prev_idle_time_us;
  96         u64     prev_aperf;
  97         u64     prev_mperf;
  98         int     sample_ptr;
  99         struct sample samples[SAMPLE_COUNT];
 100 };
 101
 102 static struct cpudata **all_cpu_data;
 103 struct pstate_adjust_policy {
 104         int sample_rate_ms;
 105         int deadband;
 106         int setpoint;
 107         int p_gain_pct;
 108         int d_gain_pct;
 109         int i_gain_pct;
 110 };
 111
 112 static struct pstate_adjust_policy default_policy = {
 113         .sample_rate_ms = 10,
 114         .deadband = 0,
 115         .setpoint = 109,
 116         .p_gain_pct = 17,
 117         .d_gain_pct = 0,
 118         .i_gain_pct = 4,
 119 };
 120
 121 struct perf_limits {
 122         int no_turbo;
 123         int max_perf_pct;
 124         int min_perf_pct;
 125         int32_t max_perf;
 126         int32_t min_perf;
 127 };
 128
 129 static struct perf_limits limits = {
 130         .no_turbo = 0,
 131         .max_perf_pct = 100,
 132         .max_perf = int_tofp(1),
 133         .min_perf_pct = 0,
 134         .min_perf = 0,
 135 };
 136
 137 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
 138                         int deadband, int integral) {
 139         pid->setpoint = setpoint;
 140         pid->deadband  = deadband;
 141         pid->integral  = int_tofp(integral);
 142         pid->last_err  = setpoint - busy;
 143 }
 144
 145 static inline void pid_p_gain_set(struct _pid *pid, int percent)
 146 {
 147         pid->p_gain = div_fp(int_tofp(percent), int_tofp(100));
 148 }
 149
 150 static inline void pid_i_gain_set(struct _pid *pid, int percent)
 151 {
 152         pid->i_gain = div_fp(int_tofp(percent), int_tofp(100));
 153 }
 154
 155 static inline void pid_d_gain_set(struct _pid *pid, int percent)
 156 {
 157
 158         pid->d_gain = div_fp(int_tofp(percent), int_tofp(100));
 159 }
 160
 161 static signed int pid_calc(struct _pid *pid, int busy)
 162 {
 163         signed int err, result;
 164         int32_t pterm, dterm, fp_error;
 165         int32_t integral_limit;
 166
 167         err = pid->setpoint - busy;
 168         fp_error = int_tofp(err);
 169
 170         if (abs(err) <= pid->deadband)
 171                 return 0;
 172
 173         pterm = mul_fp(pid->p_gain, fp_error);
 174
 175         pid->integral += fp_error;
 176
 177         /* limit the integral term */
 178         integral_limit = int_tofp(30);
 179         if (pid->integral > integral_limit)
 180                 pid->integral = integral_limit;
 181         if (pid->integral < -integral_limit)
 182                 pid->integral = -integral_limit;
 183
 184         dterm = mul_fp(pid->d_gain, (err - pid->last_err));
 185         pid->last_err = err;
 186
 187         result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
 188
 189         return (signed int)fp_toint(result);
 190 }
 191
 192 static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
 193 {
 194         pid_p_gain_set(&cpu->pid, cpu->pstate_policy->p_gain_pct);
 195         pid_d_gain_set(&cpu->pid, cpu->pstate_policy->d_gain_pct);
 196         pid_i_gain_set(&cpu->pid, cpu->pstate_policy->i_gain_pct);
 197
 198         pid_reset(&cpu->pid,
 199                 cpu->pstate_policy->setpoint,
 200                 100,
 201                 cpu->pstate_policy->deadband,
 202                 0);
 203 }
 204
 205 static inline void intel_pstate_idle_pid_reset(struct cpudata *cpu)
 206 {
 207         pid_p_gain_set(&cpu->idle_pid, cpu->pstate_policy->p_gain_pct);
 208         pid_d_gain_set(&cpu->idle_pid, cpu->pstate_policy->d_gain_pct);
 209         pid_i_gain_set(&cpu->idle_pid, cpu->pstate_policy->i_gain_pct);
 210
 211         pid_reset(&cpu->idle_pid,
 212                 75,
 213                 50,
 214                 cpu->pstate_policy->deadband,
 215                 0);
 216 }
 217
 218 static inline void intel_pstate_reset_all_pid(void)
 219 {
 220         unsigned int cpu;
 221         for_each_online_cpu(cpu) {
 222                 if (all_cpu_data[cpu])
 223                         intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
 224         }
 225 }
 226
 227 /************************** debugfs begin ************************/
 228 static int pid_param_set(void *data, u64 val)
 229 {
 230         *(u32 *)data = val;
 231         intel_pstate_reset_all_pid();
 232         return 0;
 233 }
 234 static int pid_param_get(void *data, u64 *val)
 235 {
 236         *val = *(u32 *)data;
 237         return 0;
 238 }
 239 DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get,
 240                         pid_param_set, "%llu\n");
 241
 242 struct pid_param {
 243         char *name;
 244         void *value;
 245 };
 246
 247 static struct pid_param pid_files[] = {
 248         {"sample_rate_ms", &default_policy.sample_rate_ms},
 249         {"d_gain_pct", &default_policy.d_gain_pct},
 250         {"i_gain_pct", &default_policy.i_gain_pct},
 251         {"deadband", &default_policy.deadband},
 252         {"setpoint", &default_policy.setpoint},
 253         {"p_gain_pct", &default_policy.p_gain_pct},
 254         {NULL, NULL}
 255 };
 256
 257 static struct dentry *debugfs_parent;
 258 static void intel_pstate_debug_expose_params(void)
 259 {
 260         int i = 0;
 261
 262         debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
 263         if (IS_ERR_OR_NULL(debugfs_parent))
 264                 return;
 265         while (pid_files[i].name) {
 266                 debugfs_create_file(pid_files[i].name, 0660,
 267                                 debugfs_parent, pid_files[i].value,
 268                                 &fops_pid_param);
 269                 i++;
 270         }
 271 }
 272
 273 /************************** debugfs end ************************/
 274
 275 /************************** sysfs begin ************************/
 276 #define show_one(file_name, object)                                     \
 277         static ssize_t show_##file_name                                 \
 278         (struct kobject *kobj, struct attribute *attr, char *buf)       \
 279         {                                                               \
 280                 return sprintf(buf, "%u\n", limits.object);             \
 281         }
 282
 283 static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
 284                                 const char *buf, size_t count)
 285 {
 286         unsigned int input;
 287         int ret;
 288         ret = sscanf(buf, "%u", &input);
 289         if (ret != 1)
 290                 return -EINVAL;
 291         limits.no_turbo = clamp_t(int, input, 0 , 1);
 292
 293         return count;
 294 }
 295
 296 static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
 297                                 const char *buf, size_t count)
 298 {
 299         unsigned int input;
 300         int ret;
 301         ret = sscanf(buf, "%u", &input);
 302         if (ret != 1)
 303                 return -EINVAL;
 304
 305         limits.max_perf_pct = clamp_t(int, input, 0 , 100);
 306         limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 307         return count;
 308 }
 309
 310 static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
 311                                 const char *buf, size_t count)
 312 {
 313         unsigned int input;
 314         int ret;
 315         ret = sscanf(buf, "%u", &input);
 316         if (ret != 1)
 317                 return -EINVAL;
 318         limits.min_perf_pct = clamp_t(int, input, 0 , 100);
 319         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 320
 321         return count;
 322 }
 323
 324 show_one(no_turbo, no_turbo);
 325 show_one(max_perf_pct, max_perf_pct);
 326 show_one(min_perf_pct, min_perf_pct);
 327
 328 define_one_global_rw(no_turbo);
 329 define_one_global_rw(max_perf_pct);
 330 define_one_global_rw(min_perf_pct);
 331
 332 static struct attribute *intel_pstate_attributes[] = {
 333         &no_turbo.attr,
 334         &max_perf_pct.attr,
 335         &min_perf_pct.attr,
 336         NULL
 337 };
 338
 339 static struct attribute_group intel_pstate_attr_group = {
 340         .attrs = intel_pstate_attributes,
 341 };
 342 static struct kobject *intel_pstate_kobject;
 343
 344 static void intel_pstate_sysfs_expose_params(void)
 345 {
 346         int rc;
 347
 348         intel_pstate_kobject = kobject_create_and_add("intel_pstate",
 349                                                 &cpu_subsys.dev_root->kobj);
 350         BUG_ON(!intel_pstate_kobject);
 351         rc = sysfs_create_group(intel_pstate_kobject,
 352                                 &intel_pstate_attr_group);
 353         BUG_ON(rc);
 354 }
 355
 356 /************************** sysfs end ************************/
 357
 358 static int intel_pstate_min_pstate(void)
 359 {
 360         u64 value;
 361         rdmsrl(MSR_PLATFORM_INFO, value);
 362         return (value >> 40) & 0xFF;
 363 }
 364
 365 static int intel_pstate_max_pstate(void)
 366 {
 367         u64 value;
 368         rdmsrl(MSR_PLATFORM_INFO, value);
 369         return (value >> 8) & 0xFF;
 370 }
 371
 372 static int intel_pstate_turbo_pstate(void)
 373 {
 374         u64 value;
 375         int nont, ret;
 376         rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 377         nont = intel_pstate_max_pstate();
 378         ret = ((value) & 255);
 379         if (ret <= nont)
 380                 ret = nont;
 381         return ret;
 382 }
 383
 384 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 385 {
 386         int max_perf = cpu->pstate.turbo_pstate;
 387         int min_perf;
 388         if (limits.no_turbo)
 389                 max_perf = cpu->pstate.max_pstate;
 390
 391         max_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
 392         *max = clamp_t(int, max_perf,
 393                         cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
 394
 395         min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.min_perf));
 396         *min = clamp_t(int, min_perf,
 397                         cpu->pstate.min_pstate, max_perf);
 398 }
 399
 400 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
 401 {
 402         int max_perf, min_perf;
 403
 404         intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
 405
 406         pstate = clamp_t(int, pstate, min_perf, max_perf);
 407
 408         if (pstate == cpu->pstate.current_pstate)
 409                 return;
 410
 411 #ifndef MODULE
 412         trace_cpu_frequency(pstate * 100000, cpu->cpu);
 413 #endif
 414         cpu->pstate.current_pstate = pstate;
 415         wrmsrl(MSR_IA32_PERF_CTL, pstate << 8);
 416
 417 }
 418
 419 static inline void intel_pstate_pstate_increase(struct cpudata *cpu, int steps)
 420 {
 421         int target;
 422         target = cpu->pstate.current_pstate + steps;
 423
 424         intel_pstate_set_pstate(cpu, target);
 425 }
 426
 427 static inline void intel_pstate_pstate_decrease(struct cpudata *cpu, int steps)
 428 {
 429         int target;
 430         target = cpu->pstate.current_pstate - steps;
 431         intel_pstate_set_pstate(cpu, target);
 432 }
 433
 434 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 435 {
 436         sprintf(cpu->name, "Intel 2nd generation core");
 437
 438         cpu->pstate.min_pstate = intel_pstate_min_pstate();
 439         cpu->pstate.max_pstate = intel_pstate_max_pstate();
 440         cpu->pstate.turbo_pstate = intel_pstate_turbo_pstate();
 441
 442         /*
 443          * goto max pstate so we don't slow up boot if we are built-in if we are
 444          * a module we will take care of it during normal operation
 445          */
 446         intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
 447 }
 448
 449 static inline void intel_pstate_calc_busy(struct cpudata *cpu,
 450                                         struct sample *sample)
 451 {
 452         u64 core_pct;
 453         sample->pstate_pct_busy = 100 - div64_u64(
 454                                         sample->idletime_us * 100,
 455                                         sample->duration_us);
 456         core_pct = div64_u64(sample->aperf * 100, sample->mperf);
 457         sample->freq = cpu->pstate.max_pstate * core_pct * 1000;
 458
 459         sample->core_pct_busy = div_s64((sample->pstate_pct_busy * core_pct),
 460                                         100);
 461 }
 462
 463 static inline void intel_pstate_sample(struct cpudata *cpu)
 464 {
 465         ktime_t now;
 466         u64 idle_time_us;
 467         u64 aperf, mperf;
 468
 469         now = ktime_get();
 470         idle_time_us = get_cpu_idle_time_us(cpu->cpu, NULL);
 471
 472         rdmsrl(MSR_IA32_APERF, aperf);
 473         rdmsrl(MSR_IA32_MPERF, mperf);
 474         /* for the first sample, don't actually record a sample, just
 475          * set the baseline */
 476         if (cpu->prev_idle_time_us > 0) {
 477                 cpu->sample_ptr = (cpu->sample_ptr + 1) % SAMPLE_COUNT;
 478                 cpu->samples[cpu->sample_ptr].start_time = cpu->prev_sample;
 479                 cpu->samples[cpu->sample_ptr].end_time = now;
 480                 cpu->samples[cpu->sample_ptr].duration_us =
 481                         ktime_us_delta(now, cpu->prev_sample);
 482                 cpu->samples[cpu->sample_ptr].idletime_us =
 483                         idle_time_us - cpu->prev_idle_time_us;
 484
 485                 cpu->samples[cpu->sample_ptr].aperf = aperf;
 486                 cpu->samples[cpu->sample_ptr].mperf = mperf;
 487                 cpu->samples[cpu->sample_ptr].aperf -= cpu->prev_aperf;
 488                 cpu->samples[cpu->sample_ptr].mperf -= cpu->prev_mperf;
 489
 490                 intel_pstate_calc_busy(cpu, &cpu->samples[cpu->sample_ptr]);
 491         }
 492
 493         cpu->prev_sample = now;
 494         cpu->prev_idle_time_us = idle_time_us;
 495         cpu->prev_aperf = aperf;
 496         cpu->prev_mperf = mperf;
 497 }
 498
 499 static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 500 {
 501         int sample_time, delay;
 502
 503         sample_time = cpu->pstate_policy->sample_rate_ms;
 504         delay = msecs_to_jiffies(sample_time);
 505         mod_timer_pinned(&cpu->timer, jiffies + delay);
 506 }
 507
 508 static inline void intel_pstate_idle_mode(struct cpudata *cpu)
 509 {
 510         cpu->idle_mode = 1;
 511 }
 512
 513 static inline void intel_pstate_normal_mode(struct cpudata *cpu)
 514 {
 515         cpu->idle_mode = 0;
 516 }
 517
 518 static inline int intel_pstate_get_scaled_busy(struct cpudata *cpu)
 519 {
 520         int32_t busy_scaled;
 521         int32_t core_busy, turbo_pstate, current_pstate;
 522
 523         core_busy = int_tofp(cpu->samples[cpu->sample_ptr].core_pct_busy);
 524         turbo_pstate = int_tofp(cpu->pstate.turbo_pstate);
 525         current_pstate = int_tofp(cpu->pstate.current_pstate);
 526         busy_scaled = mul_fp(core_busy, div_fp(turbo_pstate, current_pstate));
 527
 528         return fp_toint(busy_scaled);
 529 }
 530
 531 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 532 {
 533         int busy_scaled;
 534         struct _pid *pid;
 535         signed int ctl = 0;
 536         int steps;
 537
 538         pid = &cpu->pid;
 539         busy_scaled = intel_pstate_get_scaled_busy(cpu);
 540
 541         ctl = pid_calc(pid, busy_scaled);
 542
 543         steps = abs(ctl);
 544         if (ctl < 0)
 545                 intel_pstate_pstate_increase(cpu, steps);
 546         else
 547                 intel_pstate_pstate_decrease(cpu, steps);
 548 }
 549
 550 static inline void intel_pstate_adjust_idle_pstate(struct cpudata *cpu)
 551 {
 552         int busy_scaled;
 553         struct _pid *pid;
 554         int ctl = 0;
 555         int steps;
 556
 557         pid = &cpu->idle_pid;
 558
 559         busy_scaled = intel_pstate_get_scaled_busy(cpu);
 560
 561         ctl = pid_calc(pid, 100 - busy_scaled);
 562
 563         steps = abs(ctl);
 564         if (ctl < 0)
 565                 intel_pstate_pstate_decrease(cpu, steps);
 566         else
 567                 intel_pstate_pstate_increase(cpu, steps);
 568
 569         if (cpu->pstate.current_pstate == cpu->pstate.min_pstate)
 570                 intel_pstate_normal_mode(cpu);
 571 }
 572
 573 static void intel_pstate_timer_func(unsigned long __data)
 574 {
 575         struct cpudata *cpu = (struct cpudata *) __data;
 576
 577         intel_pstate_sample(cpu);
 578
 579         if (!cpu->idle_mode)
 580                 intel_pstate_adjust_busy_pstate(cpu);
 581         else
 582                 intel_pstate_adjust_idle_pstate(cpu);
 583
 584 #if defined(XPERF_FIX)
 585         if (cpu->pstate.current_pstate == cpu->pstate.min_pstate) {
 586                 cpu->min_pstate_count++;
 587                 if (!(cpu->min_pstate_count % 5)) {
 588                         intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
 589                         intel_pstate_idle_mode(cpu);
 590                 }
 591         } else
 592                 cpu->min_pstate_count = 0;
 593 #endif
 594         intel_pstate_set_sample_time(cpu);
 595 }
 596
 597 #define ICPU(model, policy) \
 598         { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&policy }
 599
 600 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
 601         ICPU(0x2a, default_policy),
 602         ICPU(0x2d, default_policy),
 603         {}
 604 };
 605 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
 606
 607 static int intel_pstate_init_cpu(unsigned int cpunum)
 608 {
 609
 610         const struct x86_cpu_id *id;
 611         struct cpudata *cpu;
 612
 613         id = x86_match_cpu(intel_pstate_cpu_ids);
 614         if (!id)
 615                 return -ENODEV;
 616
 617         all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
 618         if (!all_cpu_data[cpunum])
 619                 return -ENOMEM;
 620
 621         cpu = all_cpu_data[cpunum];
 622
 623         intel_pstate_get_cpu_pstates(cpu);
 624
 625         cpu->cpu = cpunum;
 626         cpu->pstate_policy =
 627                 (struct pstate_adjust_policy *)id->driver_data;
 628         init_timer_deferrable(&cpu->timer);
 629         cpu->timer.function = intel_pstate_timer_func;
 630         cpu->timer.data =
 631                 (unsigned long)cpu;
 632         cpu->timer.expires = jiffies + HZ/100;
 633         intel_pstate_busy_pid_reset(cpu);
 634         intel_pstate_idle_pid_reset(cpu);
 635         intel_pstate_sample(cpu);
 636         intel_pstate_set_pstate(cpu, cpu->pstate.max_pstate);
 637
 638         add_timer_on(&cpu->timer, cpunum);
 639
 640         pr_info("Intel pstate controlling: cpu %d\n", cpunum);
 641
 642         return 0;
 643 }
 644
 645 static unsigned int intel_pstate_get(unsigned int cpu_num)
 646 {
 647         struct sample *sample;
 648         struct cpudata *cpu;
 649
 650         cpu = all_cpu_data[cpu_num];
 651         if (!cpu)
 652                 return 0;
 653         sample = &cpu->samples[cpu->sample_ptr];
 654         return sample->freq;
 655 }
 656
 657 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 658 {
 659         struct cpudata *cpu;
 660
 661         cpu = all_cpu_data[policy->cpu];
 662
 663         if (!policy->cpuinfo.max_freq)
 664                 return -ENODEV;
 665
 666         if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
 667                 limits.min_perf_pct = 100;
 668                 limits.min_perf = int_tofp(1);
 669                 limits.max_perf_pct = 100;
 670                 limits.max_perf = int_tofp(1);
 671                 limits.no_turbo = 0;
 672                 return 0;
 673         }
 674         limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
 675         limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
 676         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 677
 678         limits.max_perf_pct = policy->max * 100 / policy->cpuinfo.max_freq;
 679         limits.max_perf_pct = clamp_t(int, limits.max_perf_pct, 0 , 100);
 680         limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 681
 682         return 0;
 683 }
 684
 685 static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
 686 {
 687         cpufreq_verify_within_limits(policy,
 688                                 policy->cpuinfo.min_freq,
 689                                 policy->cpuinfo.max_freq);
 690
 691         if ((policy->policy != CPUFREQ_POLICY_POWERSAVE) &&
 692                 (policy->policy != CPUFREQ_POLICY_PERFORMANCE))
 693                 return -EINVAL;
 694
 695         return 0;
 696 }
 697
 698 static int __cpuinit intel_pstate_cpu_exit(struct cpufreq_policy *policy)
 699 {
 700         int cpu = policy->cpu;
 701
 702         del_timer(&all_cpu_data[cpu]->timer);
 703         kfree(all_cpu_data[cpu]);
 704         all_cpu_data[cpu] = NULL;
 705         return 0;
 706 }
 707
 708 static int __cpuinit intel_pstate_cpu_init(struct cpufreq_policy *policy)
 709 {
 710         int rc, min_pstate, max_pstate;
 711         struct cpudata *cpu;
 712
 713         rc = intel_pstate_init_cpu(policy->cpu);
 714         if (rc)
 715                 return rc;
 716
 717         cpu = all_cpu_data[policy->cpu];
 718
 719         if (!limits.no_turbo &&
 720                 limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
 721                 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
 722         else
 723                 policy->policy = CPUFREQ_POLICY_POWERSAVE;
 724
 725         intel_pstate_get_min_max(cpu, &min_pstate, &max_pstate);
 726         policy->min = min_pstate * 100000;
 727         policy->max = max_pstate * 100000;
 728
 729         /* cpuinfo and default policy values */
 730         policy->cpuinfo.min_freq = cpu->pstate.min_pstate * 100000;
 731         policy->cpuinfo.max_freq = cpu->pstate.turbo_pstate * 100000;
 732         policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
 733         cpumask_set_cpu(policy->cpu, policy->cpus);
 734
 735         return 0;
 736 }
 737
 738 static struct cpufreq_driver intel_pstate_driver = {
 739         .flags          = CPUFREQ_CONST_LOOPS,
 740         .verify         = intel_pstate_verify_policy,
 741         .setpolicy      = intel_pstate_set_policy,
 742         .get            = intel_pstate_get,
 743         .init           = intel_pstate_cpu_init,
 744         .exit           = intel_pstate_cpu_exit,
 745         .name           = "intel_pstate",
 746         .owner          = THIS_MODULE,
 747 };
 748
 749 static int __initdata no_load;
 750
 751 static int intel_pstate_msrs_not_valid(void)
 752 {
 753         /* Check that all the msr's we are using are valid. */
 754         u64 aperf, mperf, tmp;
 755
 756         rdmsrl(MSR_IA32_APERF, aperf);
 757         rdmsrl(MSR_IA32_MPERF, mperf);
 758
 759         if (!intel_pstate_min_pstate() ||
 760                 !intel_pstate_max_pstate() ||
 761                 !intel_pstate_turbo_pstate())
 762                 return -ENODEV;
 763
 764         rdmsrl(MSR_IA32_APERF, tmp);
 765         if (!(tmp - aperf))
 766                 return -ENODEV;
 767
 768         rdmsrl(MSR_IA32_MPERF, tmp);
 769         if (!(tmp - mperf))
 770                 return -ENODEV;
 771
 772         return 0;
 773 }
 774 static int __init intel_pstate_init(void)
 775 {
 776         int cpu, rc = 0;
 777         const struct x86_cpu_id *id;
 778
 779         if (no_load)
 780                 return -ENODEV;
 781
 782         id = x86_match_cpu(intel_pstate_cpu_ids);
 783         if (!id)
 784                 return -ENODEV;
 785
 786         if (intel_pstate_msrs_not_valid())
 787                 return -ENODEV;
 788
 789         pr_info("Intel P-state driver initializing.\n");
 790
 791         all_cpu_data = vmalloc(sizeof(void *) * num_possible_cpus());
 792         if (!all_cpu_data)
 793                 return -ENOMEM;
 794         memset(all_cpu_data, 0, sizeof(void *) * num_possible_cpus());
 795
 796         rc = cpufreq_register_driver(&intel_pstate_driver);
 797         if (rc)
 798                 goto out;
 799
 800         intel_pstate_debug_expose_params();
 801         intel_pstate_sysfs_expose_params();
 802         return rc;
 803 out:
 804         get_online_cpus();
 805         for_each_online_cpu(cpu) {
 806                 if (all_cpu_data[cpu]) {
 807                         del_timer_sync(&all_cpu_data[cpu]->timer);
 808                         kfree(all_cpu_data[cpu]);
 809                 }
 810         }
 811
 812         put_online_cpus();
 813         vfree(all_cpu_data);
 814         return -ENODEV;
 815 }
 816 device_initcall(intel_pstate_init);
 817
 818 static int __init intel_pstate_setup(char *str)
 819 {
 820         if (!str)
 821                 return -EINVAL;
 822
 823         if (!strcmp(str, "disable"))
 824                 no_load = 1;
 825         return 0;
 826 }
 827 early_param("intel_pstate", intel_pstate_setup);
 828
 829 MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
 830 MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
 831 MODULE_LICENSE("GPL");