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