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 <linux/vmalloc.h>
  30 #include <trace/events/power.h>
  31
  32 #include <asm/div64.h>
  33 #include <asm/msr.h>
  34 #include <asm/cpu_device_id.h>
  35 #include <asm/cpufeature.h>
  36
  37 #define BYT_RATIOS              0x66a
  38 #define BYT_VIDS                0x66b
  39 #define BYT_TURBO_RATIOS        0x66c
  40 #define BYT_TURBO_VIDS          0x66d
  41
  42 #define FRAC_BITS 8
  43 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
  44 #define fp_toint(X) ((X) >> FRAC_BITS)
  45
  46
  47 static inline int32_t mul_fp(int32_t x, int32_t y)
  48 {
  49         return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
  50 }
  51
  52 static inline int32_t div_fp(s64 x, s64 y)
  53 {
  54         return div64_s64((int64_t)x << FRAC_BITS, y);
  55 }
  56
  57 static inline int ceiling_fp(int32_t x)
  58 {
  59         int mask, ret;
  60
  61         ret = fp_toint(x);
  62         mask = (1 << FRAC_BITS) - 1;
  63         if (x & mask)
  64                 ret += 1;
  65         return ret;
  66 }
  67
  68 struct sample {
  69         int32_t core_pct_busy;
  70         u64 aperf;
  71         u64 mperf;
  72         u64 tsc;
  73         int freq;
  74         ktime_t time;
  75 };
  76
  77 struct pstate_data {
  78         int     current_pstate;
  79         int     min_pstate;
  80         int     max_pstate;
  81         int     scaling;
  82         int     turbo_pstate;
  83 };
  84
  85 struct vid_data {
  86         int min;
  87         int max;
  88         int turbo;
  89         int32_t ratio;
  90 };
  91
  92 struct _pid {
  93         int setpoint;
  94         int32_t integral;
  95         int32_t p_gain;
  96         int32_t i_gain;
  97         int32_t d_gain;
  98         int deadband;
  99         int32_t last_err;
 100 };
 101
 102 struct cpudata {
 103         int cpu;
 104
 105         struct timer_list timer;
 106
 107         struct pstate_data pstate;
 108         struct vid_data vid;
 109         struct _pid pid;
 110
 111         ktime_t last_sample_time;
 112         u64     prev_aperf;
 113         u64     prev_mperf;
 114         u64     prev_tsc;
 115         struct sample sample;
 116 };
 117
 118 static struct cpudata **all_cpu_data;
 119 struct pstate_adjust_policy {
 120         int sample_rate_ms;
 121         int deadband;
 122         int setpoint;
 123         int p_gain_pct;
 124         int d_gain_pct;
 125         int i_gain_pct;
 126 };
 127
 128 struct pstate_funcs {
 129         int (*get_max)(void);
 130         int (*get_min)(void);
 131         int (*get_turbo)(void);
 132         int (*get_scaling)(void);
 133         void (*set)(struct cpudata*, int pstate);
 134         void (*get_vid)(struct cpudata *);
 135 };
 136
 137 struct cpu_defaults {
 138         struct pstate_adjust_policy pid_policy;
 139         struct pstate_funcs funcs;
 140 };
 141
 142 static struct pstate_adjust_policy pid_params;
 143 static struct pstate_funcs pstate_funcs;
 144 static int hwp_active;
 145
 146 struct perf_limits {
 147         int no_turbo;
 148         int turbo_disabled;
 149         int max_perf_pct;
 150         int min_perf_pct;
 151         int32_t max_perf;
 152         int32_t min_perf;
 153         int max_policy_pct;
 154         int max_sysfs_pct;
 155         int min_policy_pct;
 156         int min_sysfs_pct;
 157 };
 158
 159 static struct perf_limits limits = {
 160         .no_turbo = 0,
 161         .turbo_disabled = 0,
 162         .max_perf_pct = 100,
 163         .max_perf = int_tofp(1),
 164         .min_perf_pct = 0,
 165         .min_perf = 0,
 166         .max_policy_pct = 100,
 167         .max_sysfs_pct = 100,
 168         .min_policy_pct = 0,
 169         .min_sysfs_pct = 0,
 170 };
 171
 172 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
 173                              int deadband, int integral) {
 174         pid->setpoint = setpoint;
 175         pid->deadband  = deadband;
 176         pid->integral  = int_tofp(integral);
 177         pid->last_err  = int_tofp(setpoint) - int_tofp(busy);
 178 }
 179
 180 static inline void pid_p_gain_set(struct _pid *pid, int percent)
 181 {
 182         pid->p_gain = div_fp(int_tofp(percent), int_tofp(100));
 183 }
 184
 185 static inline void pid_i_gain_set(struct _pid *pid, int percent)
 186 {
 187         pid->i_gain = div_fp(int_tofp(percent), int_tofp(100));
 188 }
 189
 190 static inline void pid_d_gain_set(struct _pid *pid, int percent)
 191 {
 192         pid->d_gain = div_fp(int_tofp(percent), int_tofp(100));
 193 }
 194
 195 static signed int pid_calc(struct _pid *pid, int32_t busy)
 196 {
 197         signed int result;
 198         int32_t pterm, dterm, fp_error;
 199         int32_t integral_limit;
 200
 201         fp_error = int_tofp(pid->setpoint) - busy;
 202
 203         if (abs(fp_error) <= int_tofp(pid->deadband))
 204                 return 0;
 205
 206         pterm = mul_fp(pid->p_gain, fp_error);
 207
 208         pid->integral += fp_error;
 209
 210         /*
 211          * We limit the integral here so that it will never
 212          * get higher than 30.  This prevents it from becoming
 213          * too large an input over long periods of time and allows
 214          * it to get factored out sooner.
 215          *
 216          * The value of 30 was chosen through experimentation.
 217          */
 218         integral_limit = int_tofp(30);
 219         if (pid->integral > integral_limit)
 220                 pid->integral = integral_limit;
 221         if (pid->integral < -integral_limit)
 222                 pid->integral = -integral_limit;
 223
 224         dterm = mul_fp(pid->d_gain, fp_error - pid->last_err);
 225         pid->last_err = fp_error;
 226
 227         result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
 228         result = result + (1 << (FRAC_BITS-1));
 229         return (signed int)fp_toint(result);
 230 }
 231
 232 static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
 233 {
 234         pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
 235         pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
 236         pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
 237
 238         pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.deadband, 0);
 239 }
 240
 241 static inline void intel_pstate_reset_all_pid(void)
 242 {
 243         unsigned int cpu;
 244
 245         for_each_online_cpu(cpu) {
 246                 if (all_cpu_data[cpu])
 247                         intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
 248         }
 249 }
 250
 251 static inline void update_turbo_state(void)
 252 {
 253         u64 misc_en;
 254         struct cpudata *cpu;
 255
 256         cpu = all_cpu_data[0];
 257         rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
 258         limits.turbo_disabled =
 259                 (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
 260                  cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
 261 }
 262
 263 static void intel_pstate_hwp_set(void)
 264 {
 265         int min, hw_min, max, hw_max, cpu, range, adj_range;
 266         u64 value, cap;
 267
 268         rdmsrl(MSR_HWP_CAPABILITIES, cap);
 269         hw_min = HWP_LOWEST_PERF(cap);
 270         hw_max = HWP_HIGHEST_PERF(cap);
 271         range = hw_max - hw_min;
 272
 273         get_online_cpus();
 274
 275         for_each_online_cpu(cpu) {
 276                 rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
 277                 adj_range = limits.min_perf_pct * range / 100;
 278                 min = hw_min + adj_range;
 279                 value &= ~HWP_MIN_PERF(~0L);
 280                 value |= HWP_MIN_PERF(min);
 281
 282                 adj_range = limits.max_perf_pct * range / 100;
 283                 max = hw_min + adj_range;
 284                 if (limits.no_turbo) {
 285                         hw_max = HWP_GUARANTEED_PERF(cap);
 286                         if (hw_max < max)
 287                                 max = hw_max;
 288                 }
 289
 290                 value &= ~HWP_MAX_PERF(~0L);
 291                 value |= HWP_MAX_PERF(max);
 292                 wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
 293         }
 294
 295         put_online_cpus();
 296 }
 297
 298 /************************** debugfs begin ************************/
 299 static int pid_param_set(void *data, u64 val)
 300 {
 301         *(u32 *)data = val;
 302         intel_pstate_reset_all_pid();
 303         return 0;
 304 }
 305
 306 static int pid_param_get(void *data, u64 *val)
 307 {
 308         *val = *(u32 *)data;
 309         return 0;
 310 }
 311 DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get, pid_param_set, "%llu\n");
 312
 313 struct pid_param {
 314         char *name;
 315         void *value;
 316 };
 317
 318 static struct pid_param pid_files[] = {
 319         {"sample_rate_ms", &pid_params.sample_rate_ms},
 320         {"d_gain_pct", &pid_params.d_gain_pct},
 321         {"i_gain_pct", &pid_params.i_gain_pct},
 322         {"deadband", &pid_params.deadband},
 323         {"setpoint", &pid_params.setpoint},
 324         {"p_gain_pct", &pid_params.p_gain_pct},
 325         {NULL, NULL}
 326 };
 327
 328 static void __init intel_pstate_debug_expose_params(void)
 329 {
 330         struct dentry *debugfs_parent;
 331         int i = 0;
 332
 333         if (hwp_active)
 334                 return;
 335         debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
 336         if (IS_ERR_OR_NULL(debugfs_parent))
 337                 return;
 338         while (pid_files[i].name) {
 339                 debugfs_create_file(pid_files[i].name, 0660,
 340                                     debugfs_parent, pid_files[i].value,
 341                                     &fops_pid_param);
 342                 i++;
 343         }
 344 }
 345
 346 /************************** debugfs end ************************/
 347
 348 /************************** sysfs begin ************************/
 349 #define show_one(file_name, object)                                     \
 350         static ssize_t show_##file_name                                 \
 351         (struct kobject *kobj, struct attribute *attr, char *buf)       \
 352         {                                                               \
 353                 return sprintf(buf, "%u\n", limits.object);             \
 354         }
 355
 356 static ssize_t show_turbo_pct(struct kobject *kobj,
 357                                 struct attribute *attr, char *buf)
 358 {
 359         struct cpudata *cpu;
 360         int total, no_turbo, turbo_pct;
 361         uint32_t turbo_fp;
 362
 363         cpu = all_cpu_data[0];
 364
 365         total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
 366         no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
 367         turbo_fp = div_fp(int_tofp(no_turbo), int_tofp(total));
 368         turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
 369         return sprintf(buf, "%u\n", turbo_pct);
 370 }
 371
 372 static ssize_t show_num_pstates(struct kobject *kobj,
 373                                 struct attribute *attr, char *buf)
 374 {
 375         struct cpudata *cpu;
 376         int total;
 377
 378         cpu = all_cpu_data[0];
 379         total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
 380         return sprintf(buf, "%u\n", total);
 381 }
 382
 383 static ssize_t show_no_turbo(struct kobject *kobj,
 384                              struct attribute *attr, char *buf)
 385 {
 386         ssize_t ret;
 387
 388         update_turbo_state();
 389         if (limits.turbo_disabled)
 390                 ret = sprintf(buf, "%u\n", limits.turbo_disabled);
 391         else
 392                 ret = sprintf(buf, "%u\n", limits.no_turbo);
 393
 394         return ret;
 395 }
 396
 397 static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
 398                               const char *buf, size_t count)
 399 {
 400         unsigned int input;
 401         int ret;
 402
 403         ret = sscanf(buf, "%u", &input);
 404         if (ret != 1)
 405                 return -EINVAL;
 406
 407         update_turbo_state();
 408         if (limits.turbo_disabled) {
 409                 pr_warn("intel_pstate: Turbo disabled by BIOS or unavailable on processor\n");
 410                 return -EPERM;
 411         }
 412
 413         limits.no_turbo = clamp_t(int, input, 0, 1);
 414
 415         if (hwp_active)
 416                 intel_pstate_hwp_set();
 417
 418         return count;
 419 }
 420
 421 static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
 422                                   const char *buf, size_t count)
 423 {
 424         unsigned int input;
 425         int ret;
 426
 427         ret = sscanf(buf, "%u", &input);
 428         if (ret != 1)
 429                 return -EINVAL;
 430
 431         limits.max_sysfs_pct = clamp_t(int, input, 0 , 100);
 432         limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
 433         limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
 434         limits.max_perf_pct = max(limits.min_perf_pct, limits.max_perf_pct);
 435         limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
 436
 437         if (hwp_active)
 438                 intel_pstate_hwp_set();
 439         return count;
 440 }
 441
 442 static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
 443                                   const char *buf, size_t count)
 444 {
 445         unsigned int input;
 446         int ret;
 447
 448         ret = sscanf(buf, "%u", &input);
 449         if (ret != 1)
 450                 return -EINVAL;
 451
 452         limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
 453         limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
 454         limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
 455         limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
 456         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
 457
 458         if (hwp_active)
 459                 intel_pstate_hwp_set();
 460         return count;
 461 }
 462
 463 show_one(max_perf_pct, max_perf_pct);
 464 show_one(min_perf_pct, min_perf_pct);
 465
 466 define_one_global_rw(no_turbo);
 467 define_one_global_rw(max_perf_pct);
 468 define_one_global_rw(min_perf_pct);
 469 define_one_global_ro(turbo_pct);
 470 define_one_global_ro(num_pstates);
 471
 472 static struct attribute *intel_pstate_attributes[] = {
 473         &no_turbo.attr,
 474         &max_perf_pct.attr,
 475         &min_perf_pct.attr,
 476         &turbo_pct.attr,
 477         &num_pstates.attr,
 478         NULL
 479 };
 480
 481 static struct attribute_group intel_pstate_attr_group = {
 482         .attrs = intel_pstate_attributes,
 483 };
 484
 485 static void __init intel_pstate_sysfs_expose_params(void)
 486 {
 487         struct kobject *intel_pstate_kobject;
 488         int rc;
 489
 490         intel_pstate_kobject = kobject_create_and_add("intel_pstate",
 491                                                 &cpu_subsys.dev_root->kobj);
 492         BUG_ON(!intel_pstate_kobject);
 493         rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group);
 494         BUG_ON(rc);
 495 }
 496 /************************** sysfs end ************************/
 497
 498 static void intel_pstate_hwp_enable(struct cpudata *cpudata)
 499 {
 500         pr_info("intel_pstate: HWP enabled\n");
 501
 502         wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);
 503 }
 504
 505 static int byt_get_min_pstate(void)
 506 {
 507         u64 value;
 508
 509         rdmsrl(BYT_RATIOS, value);
 510         return (value >> 8) & 0x7F;
 511 }
 512
 513 static int byt_get_max_pstate(void)
 514 {
 515         u64 value;
 516
 517         rdmsrl(BYT_RATIOS, value);
 518         return (value >> 16) & 0x7F;
 519 }
 520
 521 static int byt_get_turbo_pstate(void)
 522 {
 523         u64 value;
 524
 525         rdmsrl(BYT_TURBO_RATIOS, value);
 526         return value & 0x7F;
 527 }
 528
 529 static void byt_set_pstate(struct cpudata *cpudata, int pstate)
 530 {
 531         u64 val;
 532         int32_t vid_fp;
 533         u32 vid;
 534
 535         val = (u64)pstate << 8;
 536         if (limits.no_turbo && !limits.turbo_disabled)
 537                 val |= (u64)1 << 32;
 538
 539         vid_fp = cpudata->vid.min + mul_fp(
 540                 int_tofp(pstate - cpudata->pstate.min_pstate),
 541                 cpudata->vid.ratio);
 542
 543         vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
 544         vid = ceiling_fp(vid_fp);
 545
 546         if (pstate > cpudata->pstate.max_pstate)
 547                 vid = cpudata->vid.turbo;
 548
 549         val |= vid;
 550
 551         wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
 552 }
 553
 554 #define BYT_BCLK_FREQS 5
 555 static int byt_freq_table[BYT_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
 556
 557 static int byt_get_scaling(void)
 558 {
 559         u64 value;
 560         int i;
 561
 562         rdmsrl(MSR_FSB_FREQ, value);
 563         i = value & 0x3;
 564
 565         BUG_ON(i > BYT_BCLK_FREQS);
 566
 567         return byt_freq_table[i] * 100;
 568 }
 569
 570 static void byt_get_vid(struct cpudata *cpudata)
 571 {
 572         u64 value;
 573
 574         rdmsrl(BYT_VIDS, value);
 575         cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
 576         cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
 577         cpudata->vid.ratio = div_fp(
 578                 cpudata->vid.max - cpudata->vid.min,
 579                 int_tofp(cpudata->pstate.max_pstate -
 580                         cpudata->pstate.min_pstate));
 581
 582         rdmsrl(BYT_TURBO_VIDS, value);
 583         cpudata->vid.turbo = value & 0x7f;
 584 }
 585
 586 static int core_get_min_pstate(void)
 587 {
 588         u64 value;
 589
 590         rdmsrl(MSR_PLATFORM_INFO, value);
 591         return (value >> 40) & 0xFF;
 592 }
 593
 594 static int core_get_max_pstate(void)
 595 {
 596         u64 value;
 597
 598         rdmsrl(MSR_PLATFORM_INFO, value);
 599         return (value >> 8) & 0xFF;
 600 }
 601
 602 static int core_get_turbo_pstate(void)
 603 {
 604         u64 value;
 605         int nont, ret;
 606
 607         rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 608         nont = core_get_max_pstate();
 609         ret = (value) & 255;
 610         if (ret <= nont)
 611                 ret = nont;
 612         return ret;
 613 }
 614
 615 static inline int core_get_scaling(void)
 616 {
 617         return 100000;
 618 }
 619
 620 static void core_set_pstate(struct cpudata *cpudata, int pstate)
 621 {
 622         u64 val;
 623
 624         val = (u64)pstate << 8;
 625         if (limits.no_turbo && !limits.turbo_disabled)
 626                 val |= (u64)1 << 32;
 627
 628         wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
 629 }
 630
 631 static int knl_get_turbo_pstate(void)
 632 {
 633         u64 value;
 634         int nont, ret;
 635
 636         rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
 637         nont = core_get_max_pstate();
 638         ret = (((value) >> 8) & 0xFF);
 639         if (ret <= nont)
 640                 ret = nont;
 641         return ret;
 642 }
 643
 644 static struct cpu_defaults core_params = {
 645         .pid_policy = {
 646                 .sample_rate_ms = 10,
 647                 .deadband = 0,
 648                 .setpoint = 97,
 649                 .p_gain_pct = 20,
 650                 .d_gain_pct = 0,
 651                 .i_gain_pct = 0,
 652         },
 653         .funcs = {
 654                 .get_max = core_get_max_pstate,
 655                 .get_min = core_get_min_pstate,
 656                 .get_turbo = core_get_turbo_pstate,
 657                 .get_scaling = core_get_scaling,
 658                 .set = core_set_pstate,
 659         },
 660 };
 661
 662 static struct cpu_defaults byt_params = {
 663         .pid_policy = {
 664                 .sample_rate_ms = 10,
 665                 .deadband = 0,
 666                 .setpoint = 60,
 667                 .p_gain_pct = 14,
 668                 .d_gain_pct = 0,
 669                 .i_gain_pct = 4,
 670         },
 671         .funcs = {
 672                 .get_max = byt_get_max_pstate,
 673                 .get_min = byt_get_min_pstate,
 674                 .get_turbo = byt_get_turbo_pstate,
 675                 .set = byt_set_pstate,
 676                 .get_scaling = byt_get_scaling,
 677                 .get_vid = byt_get_vid,
 678         },
 679 };
 680
 681 static struct cpu_defaults knl_params = {
 682         .pid_policy = {
 683                 .sample_rate_ms = 10,
 684                 .deadband = 0,
 685                 .setpoint = 97,
 686                 .p_gain_pct = 20,
 687                 .d_gain_pct = 0,
 688                 .i_gain_pct = 0,
 689         },
 690         .funcs = {
 691                 .get_max = core_get_max_pstate,
 692                 .get_min = core_get_min_pstate,
 693                 .get_turbo = knl_get_turbo_pstate,
 694                 .get_scaling = core_get_scaling,
 695                 .set = core_set_pstate,
 696         },
 697 };
 698
 699 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
 700 {
 701         int max_perf = cpu->pstate.turbo_pstate;
 702         int max_perf_adj;
 703         int min_perf;
 704
 705         if (limits.no_turbo || limits.turbo_disabled)
 706                 max_perf = cpu->pstate.max_pstate;
 707
 708         /*
 709          * performance can be limited by user through sysfs, by cpufreq
 710          * policy, or by cpu specific default values determined through
 711          * experimentation.
 712          */
 713         max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
 714         *max = clamp_t(int, max_perf_adj,
 715                         cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
 716
 717         min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.min_perf));
 718         *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
 719 }
 720
 721 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate, bool force)
 722 {
 723         int max_perf, min_perf;
 724
 725         if (force) {
 726                 update_turbo_state();
 727
 728                 intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
 729
 730                 pstate = clamp_t(int, pstate, min_perf, max_perf);
 731
 732                 if (pstate == cpu->pstate.current_pstate)
 733                         return;
 734         }
 735         trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
 736
 737         cpu->pstate.current_pstate = pstate;
 738
 739         pstate_funcs.set(cpu, pstate);
 740 }
 741
 742 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 743 {
 744         cpu->pstate.min_pstate = pstate_funcs.get_min();
 745         cpu->pstate.max_pstate = pstate_funcs.get_max();
 746         cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
 747         cpu->pstate.scaling = pstate_funcs.get_scaling();
 748
 749         if (pstate_funcs.get_vid)
 750                 pstate_funcs.get_vid(cpu);
 751         intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate, false);
 752 }
 753
 754 static inline void intel_pstate_calc_busy(struct cpudata *cpu)
 755 {
 756         struct sample *sample = &cpu->sample;
 757         int64_t core_pct;
 758
 759         core_pct = int_tofp(sample->aperf) * int_tofp(100);
 760         core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
 761
 762         sample->freq = fp_toint(
 763                 mul_fp(int_tofp(
 764                         cpu->pstate.max_pstate * cpu->pstate.scaling / 100),
 765                         core_pct));
 766
 767         sample->core_pct_busy = (int32_t)core_pct;
 768 }
 769
 770 static inline void intel_pstate_sample(struct cpudata *cpu)
 771 {
 772         u64 aperf, mperf;
 773         unsigned long flags;
 774         u64 tsc;
 775
 776         local_irq_save(flags);
 777         rdmsrl(MSR_IA32_APERF, aperf);
 778         rdmsrl(MSR_IA32_MPERF, mperf);
 779         tsc = rdtsc();
 780         local_irq_restore(flags);
 781
 782         cpu->last_sample_time = cpu->sample.time;
 783         cpu->sample.time = ktime_get();
 784         cpu->sample.aperf = aperf;
 785         cpu->sample.mperf = mperf;
 786         cpu->sample.tsc =  tsc;
 787         cpu->sample.aperf -= cpu->prev_aperf;
 788         cpu->sample.mperf -= cpu->prev_mperf;
 789         cpu->sample.tsc -= cpu->prev_tsc;
 790
 791         intel_pstate_calc_busy(cpu);
 792
 793         cpu->prev_aperf = aperf;
 794         cpu->prev_mperf = mperf;
 795         cpu->prev_tsc = tsc;
 796 }
 797
 798 static inline void intel_hwp_set_sample_time(struct cpudata *cpu)
 799 {
 800         int delay;
 801
 802         delay = msecs_to_jiffies(50);
 803         mod_timer_pinned(&cpu->timer, jiffies + delay);
 804 }
 805
 806 static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 807 {
 808         int delay;
 809
 810         delay = msecs_to_jiffies(pid_params.sample_rate_ms);
 811         mod_timer_pinned(&cpu->timer, jiffies + delay);
 812 }
 813
 814 static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
 815 {
 816         int32_t core_busy, max_pstate, current_pstate, sample_ratio;
 817         s64 duration_us;
 818         u32 sample_time;
 819
 820         /*
 821          * core_busy is the ratio of actual performance to max
 822          * max_pstate is the max non turbo pstate available
 823          * current_pstate was the pstate that was requested during
 824          *      the last sample period.
 825          *
 826          * We normalize core_busy, which was our actual percent
 827          * performance to what we requested during the last sample
 828          * period. The result will be a percentage of busy at a
 829          * specified pstate.
 830          */
 831         core_busy = cpu->sample.core_pct_busy;
 832         max_pstate = int_tofp(cpu->pstate.max_pstate);
 833         current_pstate = int_tofp(cpu->pstate.current_pstate);
 834         core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
 835
 836         /*
 837          * Since we have a deferred timer, it will not fire unless
 838          * we are in C0.  So, determine if the actual elapsed time
 839          * is significantly greater (3x) than our sample interval.  If it
 840          * is, then we were idle for a long enough period of time
 841          * to adjust our busyness.
 842          */
 843         sample_time = pid_params.sample_rate_ms  * USEC_PER_MSEC;
 844         duration_us = ktime_us_delta(cpu->sample.time,
 845                                      cpu->last_sample_time);
 846         if (duration_us > sample_time * 3) {
 847                 sample_ratio = div_fp(int_tofp(sample_time),
 848                                       int_tofp(duration_us));
 849                 core_busy = mul_fp(core_busy, sample_ratio);
 850         }
 851
 852         return core_busy;
 853 }
 854
 855 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
 856 {
 857         int32_t busy_scaled;
 858         struct _pid *pid;
 859         signed int ctl;
 860         int from;
 861         struct sample *sample;
 862
 863         from = cpu->pstate.current_pstate;
 864
 865         pid = &cpu->pid;
 866         busy_scaled = intel_pstate_get_scaled_busy(cpu);
 867
 868         ctl = pid_calc(pid, busy_scaled);
 869
 870         /* Negative values of ctl increase the pstate and vice versa */
 871         intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl, true);
 872
 873         sample = &cpu->sample;
 874         trace_pstate_sample(fp_toint(sample->core_pct_busy),
 875                 fp_toint(busy_scaled),
 876                 from,
 877                 cpu->pstate.current_pstate,
 878                 sample->mperf,
 879                 sample->aperf,
 880                 sample->tsc,
 881                 sample->freq);
 882 }
 883
 884 static void intel_hwp_timer_func(unsigned long __data)
 885 {
 886         struct cpudata *cpu = (struct cpudata *) __data;
 887
 888         intel_pstate_sample(cpu);
 889         intel_hwp_set_sample_time(cpu);
 890 }
 891
 892 static void intel_pstate_timer_func(unsigned long __data)
 893 {
 894         struct cpudata *cpu = (struct cpudata *) __data;
 895
 896         intel_pstate_sample(cpu);
 897
 898         intel_pstate_adjust_busy_pstate(cpu);
 899
 900         intel_pstate_set_sample_time(cpu);
 901 }
 902
 903 #define ICPU(model, policy) \
 904         { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\
 905                         (unsigned long)&policy }
 906
 907 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
 908         ICPU(0x2a, core_params),
 909         ICPU(0x2d, core_params),
 910         ICPU(0x37, byt_params),
 911         ICPU(0x3a, core_params),
 912         ICPU(0x3c, core_params),
 913         ICPU(0x3d, core_params),
 914         ICPU(0x3e, core_params),
 915         ICPU(0x3f, core_params),
 916         ICPU(0x45, core_params),
 917         ICPU(0x46, core_params),
 918         ICPU(0x47, core_params),
 919         ICPU(0x4c, byt_params),
 920         ICPU(0x4e, core_params),
 921         ICPU(0x4f, core_params),
 922         ICPU(0x5e, core_params),
 923         ICPU(0x56, core_params),
 924         ICPU(0x57, knl_params),
 925         {}
 926 };
 927 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
 928
 929 static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] = {
 930         ICPU(0x56, core_params),
 931         {}
 932 };
 933
 934 static int intel_pstate_init_cpu(unsigned int cpunum)
 935 {
 936         struct cpudata *cpu;
 937
 938         if (!all_cpu_data[cpunum])
 939                 all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata),
 940                                                GFP_KERNEL);
 941         if (!all_cpu_data[cpunum])
 942                 return -ENOMEM;
 943
 944         cpu = all_cpu_data[cpunum];
 945
 946         cpu->cpu = cpunum;
 947
 948         if (hwp_active)
 949                 intel_pstate_hwp_enable(cpu);
 950
 951         intel_pstate_get_cpu_pstates(cpu);
 952
 953         init_timer_deferrable(&cpu->timer);
 954         cpu->timer.data = (unsigned long)cpu;
 955         cpu->timer.expires = jiffies + HZ/100;
 956
 957         if (!hwp_active)
 958                 cpu->timer.function = intel_pstate_timer_func;
 959         else
 960                 cpu->timer.function = intel_hwp_timer_func;
 961
 962         intel_pstate_busy_pid_reset(cpu);
 963         intel_pstate_sample(cpu);
 964
 965         add_timer_on(&cpu->timer, cpunum);
 966
 967         pr_debug("intel_pstate: controlling: cpu %d\n", cpunum);
 968
 969         return 0;
 970 }
 971
 972 static unsigned int intel_pstate_get(unsigned int cpu_num)
 973 {
 974         struct sample *sample;
 975         struct cpudata *cpu;
 976
 977         cpu = all_cpu_data[cpu_num];
 978         if (!cpu)
 979                 return 0;
 980         sample = &cpu->sample;
 981         return sample->freq;
 982 }
 983
 984 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
 985 {
 986         if (!policy->cpuinfo.max_freq)
 987                 return -ENODEV;
 988
 989         if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
 990             policy->max >= policy->cpuinfo.max_freq) {
 991                 limits.min_policy_pct = 100;
 992                 limits.min_perf_pct = 100;
 993                 limits.min_perf = int_tofp(1);
 994                 limits.max_policy_pct = 100;
 995                 limits.max_perf_pct = 100;
 996                 limits.max_perf = int_tofp(1);
 997                 limits.no_turbo = 0;
 998                 return 0;
 999         }
1000
1001         limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
1002         limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100);
1003         limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
1004         limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100);
1005
1006         /* Normalize user input to [min_policy_pct, max_policy_pct] */
1007         limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
1008         limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
1009         limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
1010         limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
1011
1012         /* Make sure min_perf_pct <= max_perf_pct */
1013         limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
1014
1015         limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
1016         limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
1017
1018         if (hwp_active)
1019                 intel_pstate_hwp_set();
1020
1021         return 0;
1022 }
1023
1024 static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
1025 {
1026         cpufreq_verify_within_cpu_limits(policy);
1027
1028         if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
1029             policy->policy != CPUFREQ_POLICY_PERFORMANCE)
1030                 return -EINVAL;
1031
1032         return 0;
1033 }
1034
1035 static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
1036 {
1037         int cpu_num = policy->cpu;
1038         struct cpudata *cpu = all_cpu_data[cpu_num];
1039
1040         pr_debug("intel_pstate: CPU %d exiting\n", cpu_num);
1041
1042         del_timer_sync(&all_cpu_data[cpu_num]->timer);
1043         if (hwp_active)
1044                 return;
1045
1046         intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate, false);
1047 }
1048
1049 static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
1050 {
1051         struct cpudata *cpu;
1052         int rc;
1053
1054         rc = intel_pstate_init_cpu(policy->cpu);
1055         if (rc)
1056                 return rc;
1057
1058         cpu = all_cpu_data[policy->cpu];
1059
1060         if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100)
1061                 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
1062         else
1063                 policy->policy = CPUFREQ_POLICY_POWERSAVE;
1064
1065         policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
1066         policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1067
1068         /* cpuinfo and default policy values */
1069         policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
1070         policy->cpuinfo.max_freq =
1071                 cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1072         policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
1073         cpumask_set_cpu(policy->cpu, policy->cpus);
1074
1075         return 0;
1076 }
1077
1078 static struct cpufreq_driver intel_pstate_driver = {
1079         .flags          = CPUFREQ_CONST_LOOPS,
1080         .verify         = intel_pstate_verify_policy,
1081         .setpolicy      = intel_pstate_set_policy,
1082         .get            = intel_pstate_get,
1083         .init           = intel_pstate_cpu_init,
1084         .stop_cpu       = intel_pstate_stop_cpu,
1085         .name           = "intel_pstate",
1086 };
1087
1088 static int __initdata no_load;
1089 static int __initdata no_hwp;
1090 static int __initdata hwp_only;
1091 static unsigned int force_load;
1092
1093 static int intel_pstate_msrs_not_valid(void)
1094 {
1095         if (!pstate_funcs.get_max() ||
1096             !pstate_funcs.get_min() ||
1097             !pstate_funcs.get_turbo())
1098                 return -ENODEV;
1099
1100         return 0;
1101 }
1102
1103 static void copy_pid_params(struct pstate_adjust_policy *policy)
1104 {
1105         pid_params.sample_rate_ms = policy->sample_rate_ms;
1106         pid_params.p_gain_pct = policy->p_gain_pct;
1107         pid_params.i_gain_pct = policy->i_gain_pct;
1108         pid_params.d_gain_pct = policy->d_gain_pct;
1109         pid_params.deadband = policy->deadband;
1110         pid_params.setpoint = policy->setpoint;
1111 }
1112
1113 static void copy_cpu_funcs(struct pstate_funcs *funcs)
1114 {
1115         pstate_funcs.get_max   = funcs->get_max;
1116         pstate_funcs.get_min   = funcs->get_min;
1117         pstate_funcs.get_turbo = funcs->get_turbo;
1118         pstate_funcs.get_scaling = funcs->get_scaling;
1119         pstate_funcs.set       = funcs->set;
1120         pstate_funcs.get_vid   = funcs->get_vid;
1121 }
1122
1123 #if IS_ENABLED(CONFIG_ACPI)
1124 #include <acpi/processor.h>
1125
1126 static bool intel_pstate_no_acpi_pss(void)
1127 {
1128         int i;
1129
1130         for_each_possible_cpu(i) {
1131                 acpi_status status;
1132                 union acpi_object *pss;
1133                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1134                 struct acpi_processor *pr = per_cpu(processors, i);
1135
1136                 if (!pr)
1137                         continue;
1138
1139                 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
1140                 if (ACPI_FAILURE(status))
1141                         continue;
1142
1143                 pss = buffer.pointer;
1144                 if (pss && pss->type == ACPI_TYPE_PACKAGE) {
1145                         kfree(pss);
1146                         return false;
1147                 }
1148
1149                 kfree(pss);
1150         }
1151
1152         return true;
1153 }
1154
1155 static bool intel_pstate_has_acpi_ppc(void)
1156 {
1157         int i;
1158
1159         for_each_possible_cpu(i) {
1160                 struct acpi_processor *pr = per_cpu(processors, i);
1161
1162                 if (!pr)
1163                         continue;
1164                 if (acpi_has_method(pr->handle, "_PPC"))
1165                         return true;
1166         }
1167         return false;
1168 }
1169
1170 enum {
1171         PSS,
1172         PPC,
1173 };
1174
1175 struct hw_vendor_info {
1176         u16  valid;
1177         char oem_id[ACPI_OEM_ID_SIZE];
1178         char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
1179         int  oem_pwr_table;
1180 };
1181
1182 /* Hardware vendor-specific info that has its own power management modes */
1183 static struct hw_vendor_info vendor_info[] = {
1184         {1, "HP    ", "ProLiant", PSS},
1185         {1, "ORACLE", "X4-2    ", PPC},
1186         {1, "ORACLE", "X4-2L   ", PPC},
1187         {1, "ORACLE", "X4-2B   ", PPC},
1188         {1, "ORACLE", "X3-2    ", PPC},
1189         {1, "ORACLE", "X3-2L   ", PPC},
1190         {1, "ORACLE", "X3-2B   ", PPC},
1191         {1, "ORACLE", "X4470M2 ", PPC},
1192         {1, "ORACLE", "X4270M3 ", PPC},
1193         {1, "ORACLE", "X4270M2 ", PPC},
1194         {1, "ORACLE", "X4170M2 ", PPC},
1195         {1, "ORACLE", "X4170 M3", PPC},
1196         {1, "ORACLE", "X4275 M3", PPC},
1197         {1, "ORACLE", "X6-2    ", PPC},
1198         {1, "ORACLE", "Sudbury ", PPC},
1199         {0, "", ""},
1200 };
1201
1202 static bool intel_pstate_platform_pwr_mgmt_exists(void)
1203 {
1204         struct acpi_table_header hdr;
1205         struct hw_vendor_info *v_info;
1206         const struct x86_cpu_id *id;
1207         u64 misc_pwr;
1208
1209         id = x86_match_cpu(intel_pstate_cpu_oob_ids);
1210         if (id) {
1211                 rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
1212                 if ( misc_pwr & (1 << 8))
1213                         return true;
1214         }
1215
1216         if (acpi_disabled ||
1217             ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr)))
1218                 return false;
1219
1220         for (v_info = vendor_info; v_info->valid; v_info++) {
1221                 if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
1222                         !strncmp(hdr.oem_table_id, v_info->oem_table_id,
1223                                                 ACPI_OEM_TABLE_ID_SIZE))
1224                         switch (v_info->oem_pwr_table) {
1225                         case PSS:
1226                                 return intel_pstate_no_acpi_pss();
1227                         case PPC:
1228                                 return intel_pstate_has_acpi_ppc() &&
1229                                         (!force_load);
1230                         }
1231         }
1232
1233         return false;
1234 }
1235 #else /* CONFIG_ACPI not enabled */
1236 static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
1237 static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
1238 #endif /* CONFIG_ACPI */
1239
1240 static int __init intel_pstate_init(void)
1241 {
1242         int cpu, rc = 0;
1243         const struct x86_cpu_id *id;
1244         struct cpu_defaults *cpu_def;
1245
1246         if (no_load)
1247                 return -ENODEV;
1248
1249         id = x86_match_cpu(intel_pstate_cpu_ids);
1250         if (!id)
1251                 return -ENODEV;
1252
1253         /*
1254          * The Intel pstate driver will be ignored if the platform
1255          * firmware has its own power management modes.
1256          */
1257         if (intel_pstate_platform_pwr_mgmt_exists())
1258                 return -ENODEV;
1259
1260         cpu_def = (struct cpu_defaults *)id->driver_data;
1261
1262         copy_pid_params(&cpu_def->pid_policy);
1263         copy_cpu_funcs(&cpu_def->funcs);
1264
1265         if (intel_pstate_msrs_not_valid())
1266                 return -ENODEV;
1267
1268         pr_info("Intel P-state driver initializing.\n");
1269
1270         all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
1271         if (!all_cpu_data)
1272                 return -ENOMEM;
1273
1274         if (static_cpu_has_safe(X86_FEATURE_HWP) && !no_hwp)
1275                 hwp_active++;
1276
1277         if (!hwp_active && hwp_only)
1278                 goto out;
1279
1280         rc = cpufreq_register_driver(&intel_pstate_driver);
1281         if (rc)
1282                 goto out;
1283
1284         intel_pstate_debug_expose_params();
1285         intel_pstate_sysfs_expose_params();
1286
1287         return rc;
1288 out:
1289         get_online_cpus();
1290         for_each_online_cpu(cpu) {
1291                 if (all_cpu_data[cpu]) {
1292                         del_timer_sync(&all_cpu_data[cpu]->timer);
1293                         kfree(all_cpu_data[cpu]);
1294                 }
1295         }
1296
1297         put_online_cpus();
1298         vfree(all_cpu_data);
1299         return -ENODEV;
1300 }
1301 device_initcall(intel_pstate_init);
1302
1303 static int __init intel_pstate_setup(char *str)
1304 {
1305         if (!str)
1306                 return -EINVAL;
1307
1308         if (!strcmp(str, "disable"))
1309                 no_load = 1;
1310         if (!strcmp(str, "no_hwp"))
1311                 no_hwp = 1;
1312         if (!strcmp(str, "force"))
1313                 force_load = 1;
1314         if (!strcmp(str, "hwp_only"))
1315                 hwp_only = 1;
1316         return 0;
1317 }
1318 early_param("intel_pstate", intel_pstate_setup);
1319
1320 MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
1321 MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
1322 MODULE_LICENSE("GPL");