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 <linux/acpi.h>
  29 #include <trace/events/power.h>
  30
  31 #include <asm/div64.h>
  32 #include <asm/msr.h>
  33 #include <asm/cpu_device_id.h>
  34
  35 #define BYT_RATIOS              0x66a
  36 #define BYT_VIDS                0x66b
  37 #define BYT_TURBO_RATIOS        0x66c
  38 #define BYT_TURBO_VIDS          0x66d
  39
  40 #define FRAC_BITS 8
  41 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
  42 #define fp_toint(X) ((X) >> FRAC_BITS)
  43
  44
  45 static inline int32_t mul_fp(int32_t x, int32_t y)
  46 {
  47         return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
  48 }
  49
  50 static inline int32_t div_fp(int32_t x, int32_t y)
  51 {
  52         return div_s64((int64_t)x << FRAC_BITS, y);
  53 }
  54
  55 static inline int ceiling_fp(int32_t x)
  56 {
  57         int mask, ret;
  58
  59         ret = fp_toint(x);
  60         mask = (1 << FRAC_BITS) - 1;
  61         if (x & mask)
  62                 ret += 1;
  63         return ret;
  64 }
  65
  66 struct sample {
  67         int32_t core_pct_busy;
  68         u64 aperf;
  69         u64 mperf;
  70         int freq;
  71         ktime_t time;
  72 };
  73
  74 struct pstate_data {
  75         int     current_pstate;
  76         int     min_pstate;
  77         int     max_pstate;
  78         int     scaling;
  79         int     turbo_pstate;
  80 };
  81
  82 struct vid_data {
  83         int min;
  84         int max;
  85         int turbo;
  86         int32_t ratio;
  87 };
  88
  89 struct _pid {
  90         int setpoint;
  91         int32_t integral;
  92         int32_t p_gain;
  93         int32_t i_gain;
  94         int32_t d_gain;
  95         int deadband;
  96         int32_t last_err;
  97 };
  98
  99 struct cpudata {
 100         int cpu;
 101
 102         struct timer_list timer;
 103
 104         struct pstate_data pstate;
 105         struct vid_data vid;
 106         struct _pid pid;
 107
 108         ktime_t last_sample_time;
 109         u64     prev_aperf;
 110         u64     prev_mperf;
 111         struct sample sample;
 112 };
 113
 114 static struct cpudata **all_cpu_data;
 115 struct pstate_adjust_policy {
 116         int sample_rate_ms;
 117         int deadband;
 118         int setpoint;
 119         int p_gain_pct;
 120         int d_gain_pct;
 121         int i_gain_pct;
 122 };
 123
 124 struct pstate_funcs {
 125         int (*get_max)(void);
 126         int (*get_min)(void);
 127         int (*get_turbo)(void);
 128         int (*get_scaling)(void);
 129         void (*set)(struct cpudata*, int pstate);
 130         void (*get_vid)(struct cpudata *);
 131 };
 132
 133 struct cpu_defaults {
 134         struct pstate_adjust_policy pid_policy;
 135         struct pstate_funcs funcs;
 136 };
 137
 138 static struct pstate_adjust_policy pid_params;
 139 static struct pstate_funcs pstate_funcs;
 140 static int hwp_active;
 141
 142 struct perf_limits {
 143         int no_turbo;
 144         int turbo_disabled;
 145         int max_perf_pct;
 146         int min_perf_pct;
 147         int32_t max_perf;
 148         int32_t min_perf;
 149         int max_policy_pct;
 150         int max_sysfs_pct;
 151         int min_policy_pct;
 152         int min_sysfs_pct;
 153 };
 154
 155 static struct perf_limits limits = {
 156         .no_turbo = 0,
 157         .turbo_disabled = 0,
 158         .max_perf_pct = 100,
 159         .max_perf = int_tofp(1),
 160         .min_perf_pct = 0,
 161         .min_perf = 0,
 162         .max_policy_pct = 100,
 163         .max_sysfs_pct = 100,
 164         .min_policy_pct = 0,
 165         .min_sysfs_pct = 0,
 166 };
 167
 168 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
 169                              int deadband, int integral) {
 170         pid->setpoint = setpoint;
 171         pid->deadband  = deadband;
 172         pid->integral  = int_tofp(integral);
 173         pid->last_err  = int_tofp(setpoint) - int_tofp(busy);
 174 }
 175
 176 static inline void pid_p_gain_set(struct _pid *pid, int percent)
 177 {
 178         pid->p_gain = div_fp(int_tofp(percent), int_tofp(100));
 179 }
 180
 181 static inline void pid_i_gain_set(struct _pid *pid, int percent)
 182 {
 183         pid->i_gain = div_fp(int_tofp(percent), int_tofp(100));
 184 }
 185
 186 static inline void pid_d_gain_set(struct _pid *pid, int percent)
 187 {
 188         pid->d_gain = div_fp(int_tofp(percent), int_tofp(100));
 189 }
 190
 191 static signed int pid_calc(struct _pid *pid, int32_t busy)
 192 {
 193         signed int result;
 194         int32_t pterm, dterm, fp_error;
 195         int32_t integral_limit;
 196
 197         fp_error = int_tofp(pid->setpoint) - busy;
 198
 199         if (abs(fp_error) <= int_tofp(pid->deadband))
 200                 return 0;
 201
 202         pterm = mul_fp(pid->p_gain, fp_error);
 203
 204         pid->integral += fp_error;
 205
 206         /*
 207          * We limit the integral here so that it will never
 208          * get higher than 30.  This prevents it from becoming
 209          * too large an input over long periods of time and allows
 210          * it to get factored out sooner.
 211          *
 212          * The value of 30 was chosen through experimentation.
 213          */
 214         integral_limit = int_tofp(30);
 215         if (pid->integral > integral_limit)
 216                 pid->integral = integral_limit;
 217         if (pid->integral < -integral_limit)
 218                 pid->integral = -integral_limit;
 219
 220         dterm = mul_fp(pid->d_gain, fp_error - pid->last_err);
 221         pid->last_err = fp_error;
 222
 223         result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
 224         result = result + (1 << (FRAC_BITS-1));
 225         return (signed int)fp_toint(result);
 226 }
 227
 228 static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
 229 {
 230         pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
 231         pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
 232         pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
 233
 234         pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.deadband, 0);
 235 }
 236
 237 static inline void intel_pstate_reset_all_pid(void)
 238 {
 239         unsigned int cpu;
 240
 241         for_each_online_cpu(cpu) {
 242                 if (all_cpu_data[cpu])
 243                         intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
 244         }
 245 }
 246
 247 static inline void update_turbo_state(void)
 248 {
 249         u64 misc_en;
 250         struct cpudata *cpu;
 251
 252         cpu = all_cpu_data[0];
 253         rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
 254         limits.turbo_disabled =
 255                 (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
 256                  cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
 257 }
 258
 259 #define PCT_TO_HWP(x) (x * 255 / 100)
 260 static void intel_pstate_hwp_set(void)
 261 {
 262         int min, max, cpu;
 263         u64 value, freq;
 264
 265         get_online_cpus();
 266
 267         for_each_online_cpu(cpu) {
 268                 rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
 269                 min = PCT_TO_HWP(limits.min_perf_pct);
 270                 value &= ~HWP_MIN_PERF(~0L);
 271                 value |= HWP_MIN_PERF(min);
 272
 273                 max = PCT_TO_HWP(limits.max_perf_pct);
 274                 if (limits.no_turbo) {
 275                         rdmsrl( MSR_HWP_CAPABILITIES, freq);
 276                         max = HWP_GUARANTEED_PERF(freq);
 277                 }
 278
 279                 value &= ~HWP_MAX_PERF(~0L);
 280                 value |= HWP_MAX_PERF(max);
 281                 wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
 282         }
 283
 284         put_online_cpus();
 285 }
 286
 287 /************************** debugfs begin ************************/
 288 static int pid_param_set(void *data, u64 val)
 289 {
 290         *(u32 *)data = val;
 291         intel_pstate_reset_all_pid();
 292         return 0;
 293 }
 294
 295 static int pid_param_get(void *data, u64 *val)
 296 {
 297         *val = *(u32 *)data;
 298         return 0;
 299 }
 300 DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get, pid_param_set, "%llu\n");
 301
 302 struct pid_param {
 303         char *name;
 304         void *value;
 305 };
 306
 307 static struct pid_param pid_files[] = {
 308         {"sample_rate_ms", &pid_params.sample_rate_ms},
 309         {"d_gain_pct", &pid_params.d_gain_pct},
 310         {"i_gain_pct", &pid_params.i_gain_pct},
 311         {"deadband", &pid_params.deadband},
 312         {"setpoint", &pid_params.setpoint},
 313         {"p_gain_pct", &pid_params.p_gain_pct},
 314         {NULL, NULL}
 315 };
 316
 317 static void __init intel_pstate_debug_expose_params(void)
 318 {
 319         struct dentry *debugfs_parent;
 320         int i = 0;
 321
 322         if (hwp_active)
 323                 return;
 324         debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
 325         if (IS_ERR_OR_NULL(debugfs_parent))
 326                 return;
 327         while (pid_files[i].name) {
 328                 debugfs_create_file(pid_files[i].name, 0660,
 329                                     debugfs_parent, pid_files[i].value,
 330                                     &fops_pid_param);
 331                 i++;
 332         }
 333 }
 334
 335 /************************** debugfs end ************************/
 336
 337 /************************** sysfs begin ************************/
 338 #define show_one(file_name, object)                                     \
 339         static ssize_t show_##file_name                                 \
 340         (struct kobject *kobj, struct attribute *attr, char *buf)       \
 341         {                                                               \
 342                 return sprintf(buf, "%u\n", limits.object);             \
 343         }
 344
 345 static ssize_t show_turbo_pct(struct kobject *kobj,
 346                                 struct attribute *attr, char *buf)
 347 {
 348         struct cpudata *cpu;
 349         int total, no_turbo, turbo_pct;
 350         uint32_t turbo_fp;
 351
 352         cpu = all_cpu_data[0];
 353
 354         total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
 355         no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
 356         turbo_fp = div_fp(int_tofp(no_turbo), int_tofp(total));
 357         turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
 358         return sprintf(buf, "%u\n", turbo_pct);
 359 }
 360
 361 static ssize_t show_num_pstates(struct kobject *kobj,
 362                                 struct attribute *attr, char *buf)
 363 {
 364         struct cpudata *cpu;
 365         int total;
 366
 367         cpu = all_cpu_data[0];
 368         total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
 369         return sprintf(buf, "%u\n", total);
 370 }
 371
 372 static ssize_t show_no_turbo(struct kobject *kobj,
 373                              struct attribute *attr, char *buf)
 374 {
 375         ssize_t ret;
 376
 377         update_turbo_state();
 378         if (limits.turbo_disabled)
 379                 ret = sprintf(buf, "%u\n", limits.turbo_disabled);
 380         else
 381                 ret = sprintf(buf, "%u\n", limits.no_turbo);
 382
 383         return ret;
 384 }
 385
 386 static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
 387                               const char *buf, size_t count)
 388 {
 389         unsigned int input;
 390         int ret;
 391
 392         ret = sscanf(buf, "%u", &input);
 393         if (ret != 1)
 394                 return -EINVAL;
 395
 396         update_turbo_state();
 397         if (limits.turbo_disabled) {
 398                 pr_warn("Turbo disabled by BIOS or unavailable on processor\n");
 399                 return -EPERM;
 400         }
 401
 402         limits.no_turbo = clamp_t(int, input, 0, 1);
 403
 404         if (hwp_active)
 405                 intel_pstate_hwp_set();
 406
 407         return count;
 408 }
 409
 410 static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
 411                                   const char *buf, size_t count)
 412 {
 413         unsigned int input;
 414         int ret;
 415
 416         ret = sscanf(buf, "%u", &input);
 417         if (ret != 1)
 418                 return -EINVAL;
 419
 420         limits.max_sysfs_pct = clamp_t(int, input, 0 , 100);
 421         limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
 422         limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 423
 424         if (hwp_active)
 425                 intel_pstate_hwp_set();
 426         return count;
 427 }
 428
 429 static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
 430                                   const char *buf, size_t count)
 431 {
 432         unsigned int input;
 433         int ret;
 434
 435         ret = sscanf(buf, "%u", &input);
 436         if (ret != 1)
 437                 return -EINVAL;
 438
 439         limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
 440         limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
 441         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 442
 443         if (hwp_active)
 444                 intel_pstate_hwp_set();
 445         return count;
 446 }
 447
 448 show_one(max_perf_pct, max_perf_pct);
 449 show_one(min_perf_pct, min_perf_pct);
 450
 451 define_one_global_rw(no_turbo);
 452 define_one_global_rw(max_perf_pct);
 453 define_one_global_rw(min_perf_pct);
 454 define_one_global_ro(turbo_pct);
 455 define_one_global_ro(num_pstates);
 456
 457 static struct attribute *intel_pstate_attributes[] = {
 458         &no_turbo.attr,
 459         &max_perf_pct.attr,
 460         &min_perf_pct.attr,
 461         &turbo_pct.attr,
 462         &num_pstates.attr,
 463         NULL
 464 };
 465
 466 static struct attribute_group intel_pstate_attr_group = {
 467         .attrs = intel_pstate_attributes,
 468 };
 469
 470 static void __init intel_pstate_sysfs_expose_params(void)
 471 {
 472         struct kobject *intel_pstate_kobject;
 473         int rc;
 474
 475         intel_pstate_kobject = kobject_create_and_add("intel_pstate",
 476                                                 &cpu_subsys.dev_root->kobj);
 477         BUG_ON(!intel_pstate_kobject);
 478         rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group);
 479         BUG_ON(rc);
 480 }
 481 /************************** sysfs end ************************/
 482
 483 static void intel_pstate_hwp_enable(void)
 484 {
 485         hwp_active++;
 486         pr_info("intel_pstate HWP enabled\n");
 487
 488         wrmsrl( MSR_PM_ENABLE, 0x1);
 489 }
 490
 491 static int byt_get_min_pstate(void)
 492 {
 493         u64 value;
 494
 495         rdmsrl(BYT_RATIOS, value);
 496         return (value >> 8) & 0x7F;
 497 }
 498
 499 static int byt_get_max_pstate(void)
 500 {
 501         u64 value;
 502
 503         rdmsrl(BYT_RATIOS, value);
 504         return (value >> 16) & 0x7F;
 505 }
 506
 507 static int byt_get_turbo_pstate(void)
 508 {
 509         u64 value;
 510
 511         rdmsrl(BYT_TURBO_RATIOS, value);
 512         return value & 0x7F;
 513 }
 514
 515 static void byt_set_pstate(struct cpudata *cpudata, int pstate)
 516 {
 517         u64 val;
 518         int32_t vid_fp;
 519         u32 vid;
 520
 521         val = pstate << 8;
 522         if (limits.no_turbo && !limits.turbo_disabled)
 523                 val |= (u64)1 << 32;
 524
 525         vid_fp = cpudata->vid.min + mul_fp(
 526                 int_tofp(pstate - cpudata->pstate.min_pstate),
 527                 cpudata->vid.ratio);
 528
 529         vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
 530         vid = ceiling_fp(vid_fp);
 531
 532         if (pstate > cpudata->pstate.max_pstate)
 533                 vid = cpudata->vid.turbo;
 534
 535         val |= vid;
 536
 537         wrmsrl(MSR_IA32_PERF_CTL, val);
 538 }
 539
 540 #define BYT_BCLK_FREQS 5
 541 static int byt_freq_table[BYT_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
 542
 543 static int byt_get_scaling(void)
 544 {
 545         u64 value;
 546         int i;
 547
 548         rdmsrl(MSR_FSB_FREQ, value);
 549         i = value & 0x3;
 550
 551         BUG_ON(i > BYT_BCLK_FREQS);
 552
 553         return byt_freq_table[i] * 100;
 554 }
 555
 556 static void byt_get_vid(struct cpudata *cpudata)
 557 {
 558         u64 value;
 559
 560         rdmsrl(BYT_VIDS, value);
 561         cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
 562         cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
 563         cpudata->vid.ratio = div_fp(
 564                 cpudata->vid.max - cpudata->vid.min,
 565                 int_tofp(cpudata->pstate.max_pstate -
 566                         cpudata->pstate.min_pstate));
 567
 568         rdmsrl(BYT_TURBO_VIDS, value);
 569         cpudata->vid.turbo = value & 0x7f;
 570 }
 571
 572 static int core_get_min_pstate(void)
 573 {
 574         u64 value;
 575
 576         rdmsrl(MSR_PLATFORM_INFO, value);
 577         return (value >> 40) & 0xFF;
 578 }
 579
 580 static int core_get_max_pstate(void)
 581 {
 582         u64 value;
 583
 584         rdmsrl(MSR_PLATFORM_INFO, value);
 585         return (value >> 8) & 0xFF;
 586 }
 587
 588 static int core_get_turbo_pstate(void)
 589 {
 590         u64 value;
 591         int nont, ret;
 592
 593         rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 594         nont = core_get_max_pstate();
 595         ret = (value) & 255;
 596         if (ret <= nont)
 597                 ret = nont;
 598         return ret;
 599 }
 600
 601 static inline int core_get_scaling(void)
 602 {
 603         return 100000;
 604 }
 605
 606 static void core_set_pstate(struct cpudata *cpudata, int pstate)
 607 {
 608         u64 val;
 609
 610         val = pstate << 8;
 611         if (limits.no_turbo && !limits.turbo_disabled)
 612                 val |= (u64)1 << 32;
 613
 614         wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
 615 }
 616
 617 static int knl_get_turbo_pstate(void)
 618 {
 619         u64 value;
 620         int nont, ret;
 621
 622         rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 623         nont = core_get_max_pstate();
 624         ret = (((value) >> 8) & 0xFF);
 625         if (ret <= nont)
 626                 ret = nont;
 627         return ret;
 628 }
 629
 630 static struct cpu_defaults core_params = {
 631         .pid_policy = {
 632                 .sample_rate_ms = 10,
 633                 .deadband = 0,
 634                 .setpoint = 97,
 635                 .p_gain_pct = 20,
 636                 .d_gain_pct = 0,
 637                 .i_gain_pct = 0,
 638         },
 639         .funcs = {
 640                 .get_max = core_get_max_pstate,
 641                 .get_min = core_get_min_pstate,
 642                 .get_turbo = core_get_turbo_pstate,
 643                 .get_scaling = core_get_scaling,
 644                 .set = core_set_pstate,
 645         },
 646 };
 647
 648 static struct cpu_defaults byt_params = {
 649         .pid_policy = {
 650                 .sample_rate_ms = 10,
 651                 .deadband = 0,
 652                 .setpoint = 97,
 653                 .p_gain_pct = 14,
 654                 .d_gain_pct = 0,
 655                 .i_gain_pct = 4,
 656         },
 657         .funcs = {
 658                 .get_max = byt_get_max_pstate,
 659                 .get_min = byt_get_min_pstate,
 660                 .get_turbo = byt_get_turbo_pstate,
 661                 .set = byt_set_pstate,
 662                 .get_scaling = byt_get_scaling,
 663                 .get_vid = byt_get_vid,
 664         },
 665 };
 666
 667 static struct cpu_defaults knl_params = {
 668         .pid_policy = {
 669                 .sample_rate_ms = 10,
 670                 .deadband = 0,
 671                 .setpoint = 97,
 672                 .p_gain_pct = 20,
 673                 .d_gain_pct = 0,
 674                 .i_gain_pct = 0,
 675         },
 676         .funcs = {
 677                 .get_max = core_get_max_pstate,
 678                 .get_min = core_get_min_pstate,
 679                 .get_turbo = knl_get_turbo_pstate,
 680                 .set = core_set_pstate,
 681         },
 682 };
 683
 684 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 685 {
 686         int max_perf = cpu->pstate.turbo_pstate;
 687         int max_perf_adj;
 688         int min_perf;
 689
 690         if (limits.no_turbo || limits.turbo_disabled)
 691                 max_perf = cpu->pstate.max_pstate;
 692
 693         /*
 694          * performance can be limited by user through sysfs, by cpufreq
 695          * policy, or by cpu specific default values determined through
 696          * experimentation.
 697          */
 698         max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
 699         *max = clamp_t(int, max_perf_adj,
 700                         cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
 701
 702         min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.min_perf));
 703         *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
 704 }
 705
 706 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
 707 {
 708         int max_perf, min_perf;
 709
 710         update_turbo_state();
 711
 712         intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
 713
 714         pstate = clamp_t(int, pstate, min_perf, max_perf);
 715
 716         if (pstate == cpu->pstate.current_pstate)
 717                 return;
 718
 719         trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
 720
 721         cpu->pstate.current_pstate = pstate;
 722
 723         pstate_funcs.set(cpu, pstate);
 724 }
 725
 726 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 727 {
 728         cpu->pstate.min_pstate = pstate_funcs.get_min();
 729         cpu->pstate.max_pstate = pstate_funcs.get_max();
 730         cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
 731         cpu->pstate.scaling = pstate_funcs.get_scaling();
 732
 733         if (pstate_funcs.get_vid)
 734                 pstate_funcs.get_vid(cpu);
 735         intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
 736 }
 737
 738 static inline void intel_pstate_calc_busy(struct cpudata *cpu)
 739 {
 740         struct sample *sample = &cpu->sample;
 741         int64_t core_pct;
 742
 743         core_pct = int_tofp(sample->aperf) * int_tofp(100);
 744         core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
 745
 746         sample->freq = fp_toint(
 747                 mul_fp(int_tofp(
 748                         cpu->pstate.max_pstate * cpu->pstate.scaling / 100),
 749                         core_pct));
 750
 751         sample->core_pct_busy = (int32_t)core_pct;
 752 }
 753
 754 static inline void intel_pstate_sample(struct cpudata *cpu)
 755 {
 756         u64 aperf, mperf;
 757         unsigned long flags;
 758
 759         local_irq_save(flags);
 760         rdmsrl(MSR_IA32_APERF, aperf);
 761         rdmsrl(MSR_IA32_MPERF, mperf);
 762         local_irq_restore(flags);
 763
 764         cpu->last_sample_time = cpu->sample.time;
 765         cpu->sample.time = ktime_get();
 766         cpu->sample.aperf = aperf;
 767         cpu->sample.mperf = mperf;
 768         cpu->sample.aperf -= cpu->prev_aperf;
 769         cpu->sample.mperf -= cpu->prev_mperf;
 770
 771         intel_pstate_calc_busy(cpu);
 772
 773         cpu->prev_aperf = aperf;
 774         cpu->prev_mperf = mperf;
 775 }
 776
 777 static inline void intel_hwp_set_sample_time(struct cpudata *cpu)
 778 {
 779         int delay;
 780
 781         delay = msecs_to_jiffies(50);
 782         mod_timer_pinned(&cpu->timer, jiffies + delay);
 783 }
 784
 785 static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 786 {
 787         int delay;
 788
 789         delay = msecs_to_jiffies(pid_params.sample_rate_ms);
 790         mod_timer_pinned(&cpu->timer, jiffies + delay);
 791 }
 792
 793 static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
 794 {
 795         int32_t core_busy, max_pstate, current_pstate, sample_ratio;
 796         u32 duration_us;
 797         u32 sample_time;
 798
 799         /*
 800          * core_busy is the ratio of actual performance to max
 801          * max_pstate is the max non turbo pstate available
 802          * current_pstate was the pstate that was requested during
 803          *      the last sample period.
 804          *
 805          * We normalize core_busy, which was our actual percent
 806          * performance to what we requested during the last sample
 807          * period. The result will be a percentage of busy at a
 808          * specified pstate.
 809          */
 810         core_busy = cpu->sample.core_pct_busy;
 811         max_pstate = int_tofp(cpu->pstate.max_pstate);
 812         current_pstate = int_tofp(cpu->pstate.current_pstate);
 813         core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
 814
 815         /*
 816          * Since we have a deferred timer, it will not fire unless
 817          * we are in C0.  So, determine if the actual elapsed time
 818          * is significantly greater (3x) than our sample interval.  If it
 819          * is, then we were idle for a long enough period of time
 820          * to adjust our busyness.
 821          */
 822         sample_time = pid_params.sample_rate_ms  * USEC_PER_MSEC;
 823         duration_us = (u32) ktime_us_delta(cpu->sample.time,
 824                                            cpu->last_sample_time);
 825         if (duration_us > sample_time * 3) {
 826                 sample_ratio = div_fp(int_tofp(sample_time),
 827                                       int_tofp(duration_us));
 828                 core_busy = mul_fp(core_busy, sample_ratio);
 829         }
 830
 831         return core_busy;
 832 }
 833
 834 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 835 {
 836         int32_t busy_scaled;
 837         struct _pid *pid;
 838         signed int ctl;
 839
 840         pid = &cpu->pid;
 841         busy_scaled = intel_pstate_get_scaled_busy(cpu);
 842
 843         ctl = pid_calc(pid, busy_scaled);
 844
 845         /* Negative values of ctl increase the pstate and vice versa */
 846         intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
 847 }
 848
 849 static void intel_hwp_timer_func(unsigned long __data)
 850 {
 851         struct cpudata *cpu = (struct cpudata *) __data;
 852
 853         intel_pstate_sample(cpu);
 854         intel_hwp_set_sample_time(cpu);
 855 }
 856
 857 static void intel_pstate_timer_func(unsigned long __data)
 858 {
 859         struct cpudata *cpu = (struct cpudata *) __data;
 860         struct sample *sample;
 861
 862         intel_pstate_sample(cpu);
 863
 864         sample = &cpu->sample;
 865
 866         intel_pstate_adjust_busy_pstate(cpu);
 867
 868         trace_pstate_sample(fp_toint(sample->core_pct_busy),
 869                         fp_toint(intel_pstate_get_scaled_busy(cpu)),
 870                         cpu->pstate.current_pstate,
 871                         sample->mperf,
 872                         sample->aperf,
 873                         sample->freq);
 874
 875         intel_pstate_set_sample_time(cpu);
 876 }
 877
 878 #define ICPU(model, policy) \
 879         { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\
 880                         (unsigned long)&policy }
 881
 882 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
 883         ICPU(0x2a, core_params),
 884         ICPU(0x2d, core_params),
 885         ICPU(0x37, byt_params),
 886         ICPU(0x3a, core_params),
 887         ICPU(0x3c, core_params),
 888         ICPU(0x3d, core_params),
 889         ICPU(0x3e, core_params),
 890         ICPU(0x3f, core_params),
 891         ICPU(0x45, core_params),
 892         ICPU(0x46, core_params),
 893         ICPU(0x47, core_params),
 894         ICPU(0x4c, byt_params),
 895         ICPU(0x4e, core_params),
 896         ICPU(0x4f, core_params),
 897         ICPU(0x56, core_params),
 898         ICPU(0x57, knl_params),
 899         {}
 900 };
 901 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
 902
 903 static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] = {
 904         ICPU(0x56, core_params),
 905         {}
 906 };
 907
 908 static int intel_pstate_init_cpu(unsigned int cpunum)
 909 {
 910         struct cpudata *cpu;
 911
 912         if (!all_cpu_data[cpunum])
 913                 all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata),
 914                                                GFP_KERNEL);
 915         if (!all_cpu_data[cpunum])
 916                 return -ENOMEM;
 917
 918         cpu = all_cpu_data[cpunum];
 919
 920         cpu->cpu = cpunum;
 921         intel_pstate_get_cpu_pstates(cpu);
 922
 923         init_timer_deferrable(&cpu->timer);
 924         cpu->timer.data = (unsigned long)cpu;
 925         cpu->timer.expires = jiffies + HZ/100;
 926
 927         if (!hwp_active)
 928                 cpu->timer.function = intel_pstate_timer_func;
 929         else
 930                 cpu->timer.function = intel_hwp_timer_func;
 931
 932         intel_pstate_busy_pid_reset(cpu);
 933         intel_pstate_sample(cpu);
 934
 935         add_timer_on(&cpu->timer, cpunum);
 936
 937         pr_debug("Intel pstate controlling: cpu %d\n", cpunum);
 938
 939         return 0;
 940 }
 941
 942 static unsigned int intel_pstate_get(unsigned int cpu_num)
 943 {
 944         struct sample *sample;
 945         struct cpudata *cpu;
 946
 947         cpu = all_cpu_data[cpu_num];
 948         if (!cpu)
 949                 return 0;
 950         sample = &cpu->sample;
 951         return sample->freq;
 952 }
 953
 954 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 955 {
 956         if (!policy->cpuinfo.max_freq)
 957                 return -ENODEV;
 958
 959         if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
 960             policy->max >= policy->cpuinfo.max_freq) {
 961                 limits.min_policy_pct = 100;
 962                 limits.min_perf_pct = 100;
 963                 limits.min_perf = int_tofp(1);
 964                 limits.max_policy_pct = 100;
 965                 limits.max_perf_pct = 100;
 966                 limits.max_perf = int_tofp(1);
 967                 limits.no_turbo = 0;
 968                 return 0;
 969         }
 970
 971         limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
 972         limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100);
 973         limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
 974         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 975
 976         limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
 977         limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100);
 978         limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
 979         limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 980
 981         if (hwp_active)
 982                 intel_pstate_hwp_set();
 983
 984         return 0;
 985 }
 986
 987 static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
 988 {
 989         cpufreq_verify_within_cpu_limits(policy);
 990
 991         if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
 992             policy->policy != CPUFREQ_POLICY_PERFORMANCE)
 993                 return -EINVAL;
 994
 995         return 0;
 996 }
 997
 998 static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
 999 {
1000         int cpu_num = policy->cpu;
1001         struct cpudata *cpu = all_cpu_data[cpu_num];
1002
1003         pr_info("intel_pstate CPU %d exiting\n", cpu_num);
1004
1005         del_timer_sync(&all_cpu_data[cpu_num]->timer);
1006         if (hwp_active)
1007                 return;
1008
1009         intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
1010 }
1011
1012 static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
1013 {
1014         struct cpudata *cpu;
1015         int rc;
1016
1017         rc = intel_pstate_init_cpu(policy->cpu);
1018         if (rc)
1019                 return rc;
1020
1021         cpu = all_cpu_data[policy->cpu];
1022
1023         if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
1024                 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
1025         else
1026                 policy->policy = CPUFREQ_POLICY_POWERSAVE;
1027
1028         policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
1029         policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1030
1031         /* cpuinfo and default policy values */
1032         policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
1033         policy->cpuinfo.max_freq =
1034                 cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1035         policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
1036         cpumask_set_cpu(policy->cpu, policy->cpus);
1037
1038         return 0;
1039 }
1040
1041 static struct cpufreq_driver intel_pstate_driver = {
1042         .flags          = CPUFREQ_CONST_LOOPS,
1043         .verify         = intel_pstate_verify_policy,
1044         .setpolicy      = intel_pstate_set_policy,
1045         .get            = intel_pstate_get,
1046         .init           = intel_pstate_cpu_init,
1047         .stop_cpu       = intel_pstate_stop_cpu,
1048         .name           = "intel_pstate",
1049 };
1050
1051 static int __initdata no_load;
1052 static int __initdata no_hwp;
1053 static int __initdata hwp_only;
1054 static unsigned int force_load;
1055
1056 static int intel_pstate_msrs_not_valid(void)
1057 {
1058         if (!pstate_funcs.get_max() ||
1059             !pstate_funcs.get_min() ||
1060             !pstate_funcs.get_turbo())
1061                 return -ENODEV;
1062
1063         return 0;
1064 }
1065
1066 static void copy_pid_params(struct pstate_adjust_policy *policy)
1067 {
1068         pid_params.sample_rate_ms = policy->sample_rate_ms;
1069         pid_params.p_gain_pct = policy->p_gain_pct;
1070         pid_params.i_gain_pct = policy->i_gain_pct;
1071         pid_params.d_gain_pct = policy->d_gain_pct;
1072         pid_params.deadband = policy->deadband;
1073         pid_params.setpoint = policy->setpoint;
1074 }
1075
1076 static void copy_cpu_funcs(struct pstate_funcs *funcs)
1077 {
1078         pstate_funcs.get_max   = funcs->get_max;
1079         pstate_funcs.get_min   = funcs->get_min;
1080         pstate_funcs.get_turbo = funcs->get_turbo;
1081         pstate_funcs.get_scaling = funcs->get_scaling;
1082         pstate_funcs.set       = funcs->set;
1083         pstate_funcs.get_vid   = funcs->get_vid;
1084 }
1085
1086 #if IS_ENABLED(CONFIG_ACPI)
1087 #include <acpi/processor.h>
1088
1089 static bool intel_pstate_no_acpi_pss(void)
1090 {
1091         int i;
1092
1093         for_each_possible_cpu(i) {
1094                 acpi_status status;
1095                 union acpi_object *pss;
1096                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1097                 struct acpi_processor *pr = per_cpu(processors, i);
1098
1099                 if (!pr)
1100                         continue;
1101
1102                 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
1103                 if (ACPI_FAILURE(status))
1104                         continue;
1105
1106                 pss = buffer.pointer;
1107                 if (pss && pss->type == ACPI_TYPE_PACKAGE) {
1108                         kfree(pss);
1109                         return false;
1110                 }
1111
1112                 kfree(pss);
1113         }
1114
1115         return true;
1116 }
1117
1118 static bool intel_pstate_has_acpi_ppc(void)
1119 {
1120         int i;
1121
1122         for_each_possible_cpu(i) {
1123                 struct acpi_processor *pr = per_cpu(processors, i);
1124
1125                 if (!pr)
1126                         continue;
1127                 if (acpi_has_method(pr->handle, "_PPC"))
1128                         return true;
1129         }
1130         return false;
1131 }
1132
1133 enum {
1134         PSS,
1135         PPC,
1136 };
1137
1138 struct hw_vendor_info {
1139         u16  valid;
1140         char oem_id[ACPI_OEM_ID_SIZE];
1141         char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
1142         int  oem_pwr_table;
1143 };
1144
1145 /* Hardware vendor-specific info that has its own power management modes */
1146 static struct hw_vendor_info vendor_info[] = {
1147         {1, "HP    ", "ProLiant", PSS},
1148         {1, "ORACLE", "X4-2    ", PPC},
1149         {1, "ORACLE", "X4-2L   ", PPC},
1150         {1, "ORACLE", "X4-2B   ", PPC},
1151         {1, "ORACLE", "X3-2    ", PPC},
1152         {1, "ORACLE", "X3-2L   ", PPC},
1153         {1, "ORACLE", "X3-2B   ", PPC},
1154         {1, "ORACLE", "X4470M2 ", PPC},
1155         {1, "ORACLE", "X4270M3 ", PPC},
1156         {1, "ORACLE", "X4270M2 ", PPC},
1157         {1, "ORACLE", "X4170M2 ", PPC},
1158         {0, "", ""},
1159 };
1160
1161 static bool intel_pstate_platform_pwr_mgmt_exists(void)
1162 {
1163         struct acpi_table_header hdr;
1164         struct hw_vendor_info *v_info;
1165         const struct x86_cpu_id *id;
1166         u64 misc_pwr;
1167
1168         id = x86_match_cpu(intel_pstate_cpu_oob_ids);
1169         if (id) {
1170                 rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
1171                 if ( misc_pwr & (1 << 8))
1172                         return true;
1173         }
1174
1175         if (acpi_disabled ||
1176             ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr)))
1177                 return false;
1178
1179         for (v_info = vendor_info; v_info->valid; v_info++) {
1180                 if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
1181                         !strncmp(hdr.oem_table_id, v_info->oem_table_id,
1182                                                 ACPI_OEM_TABLE_ID_SIZE))
1183                         switch (v_info->oem_pwr_table) {
1184                         case PSS:
1185                                 return intel_pstate_no_acpi_pss();
1186                         case PPC:
1187                                 return intel_pstate_has_acpi_ppc() &&
1188                                         (!force_load);
1189                         }
1190         }
1191
1192         return false;
1193 }
1194 #else /* CONFIG_ACPI not enabled */
1195 static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
1196 static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
1197 #endif /* CONFIG_ACPI */
1198
1199 static int __init intel_pstate_init(void)
1200 {
1201         int cpu, rc = 0;
1202         const struct x86_cpu_id *id;
1203         struct cpu_defaults *cpu_info;
1204         struct cpuinfo_x86 *c = &boot_cpu_data;
1205
1206         if (no_load)
1207                 return -ENODEV;
1208
1209         id = x86_match_cpu(intel_pstate_cpu_ids);
1210         if (!id)
1211                 return -ENODEV;
1212
1213         /*
1214          * The Intel pstate driver will be ignored if the platform
1215          * firmware has its own power management modes.
1216          */
1217         if (intel_pstate_platform_pwr_mgmt_exists())
1218                 return -ENODEV;
1219
1220         cpu_info = (struct cpu_defaults *)id->driver_data;
1221
1222         copy_pid_params(&cpu_info->pid_policy);
1223         copy_cpu_funcs(&cpu_info->funcs);
1224
1225         if (intel_pstate_msrs_not_valid())
1226                 return -ENODEV;
1227
1228         pr_info("Intel P-state driver initializing.\n");
1229
1230         all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
1231         if (!all_cpu_data)
1232                 return -ENOMEM;
1233
1234         if (cpu_has(c,X86_FEATURE_HWP) && !no_hwp)
1235                 intel_pstate_hwp_enable();
1236
1237         if (!hwp_active && hwp_only)
1238                 goto out;
1239
1240         rc = cpufreq_register_driver(&intel_pstate_driver);
1241         if (rc)
1242                 goto out;
1243
1244         intel_pstate_debug_expose_params();
1245         intel_pstate_sysfs_expose_params();
1246
1247         return rc;
1248 out:
1249         get_online_cpus();
1250         for_each_online_cpu(cpu) {
1251                 if (all_cpu_data[cpu]) {
1252                         del_timer_sync(&all_cpu_data[cpu]->timer);
1253                         kfree(all_cpu_data[cpu]);
1254                 }
1255         }
1256
1257         put_online_cpus();
1258         vfree(all_cpu_data);
1259         return -ENODEV;
1260 }
1261 device_initcall(intel_pstate_init);
1262
1263 static int __init intel_pstate_setup(char *str)
1264 {
1265         if (!str)
1266                 return -EINVAL;
1267
1268         if (!strcmp(str, "disable"))
1269                 no_load = 1;
1270         if (!strcmp(str, "no_hwp"))
1271                 no_hwp = 1;
1272         if (!strcmp(str, "force"))
1273                 force_load = 1;
1274         if (!strcmp(str, "hwp_only"))
1275                 hwp_only = 1;
1276         return 0;
1277 }
1278 early_param("intel_pstate", intel_pstate_setup);
1279
1280 MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
1281 MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
1282 MODULE_LICENSE("GPL");