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 struct cpu_defaults core_params = { 618 .pid_policy = { 619 .sample_rate_ms = 10, 620 .deadband = 0, 621 .setpoint = 97, 622 .p_gain_pct = 20, 623 .d_gain_pct = 0, 624 .i_gain_pct = 0, 625 }, 626 .funcs = { 627 .get_max = core_get_max_pstate, 628 .get_min = core_get_min_pstate, 629 .get_turbo = core_get_turbo_pstate, 630 .get_scaling = core_get_scaling, 631 .set = core_set_pstate, 632 }, 633 }; 634 635 static struct cpu_defaults byt_params = { 636 .pid_policy = { 637 .sample_rate_ms = 10, 638 .deadband = 0, 639 .setpoint = 97, 640 .p_gain_pct = 14, 641 .d_gain_pct = 0, 642 .i_gain_pct = 4, 643 }, 644 .funcs = { 645 .get_max = byt_get_max_pstate, 646 .get_min = byt_get_min_pstate, 647 .get_turbo = byt_get_turbo_pstate, 648 .set = byt_set_pstate, 649 .get_scaling = byt_get_scaling, 650 .get_vid = byt_get_vid, 651 }, 652 }; 653 654 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max) 655 { 656 int max_perf = cpu->pstate.turbo_pstate; 657 int max_perf_adj; 658 int min_perf; 659 660 if (limits.no_turbo || limits.turbo_disabled) 661 max_perf = cpu->pstate.max_pstate; 662 663 /* 664 * performance can be limited by user through sysfs, by cpufreq 665 * policy, or by cpu specific default values determined through 666 * experimentation. 667 */ 668 max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf)); 669 *max = clamp_t(int, max_perf_adj, 670 cpu->pstate.min_pstate, cpu->pstate.turbo_pstate); 671 672 min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits.min_perf)); 673 *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf); 674 } 675 676 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate) 677 { 678 int max_perf, min_perf; 679 680 update_turbo_state(); 681 682 intel_pstate_get_min_max(cpu, &min_perf, &max_perf); 683 684 pstate = clamp_t(int, pstate, min_perf, max_perf); 685 686 if (pstate == cpu->pstate.current_pstate) 687 return; 688 689 trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu); 690 691 cpu->pstate.current_pstate = pstate; 692 693 pstate_funcs.set(cpu, pstate); 694 } 695 696 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) 697 { 698 cpu->pstate.min_pstate = pstate_funcs.get_min(); 699 cpu->pstate.max_pstate = pstate_funcs.get_max(); 700 cpu->pstate.turbo_pstate = pstate_funcs.get_turbo(); 701 cpu->pstate.scaling = pstate_funcs.get_scaling(); 702 703 if (pstate_funcs.get_vid) 704 pstate_funcs.get_vid(cpu); 705 intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate); 706 } 707 708 static inline void intel_pstate_calc_busy(struct cpudata *cpu) 709 { 710 struct sample *sample = &cpu->sample; 711 int64_t core_pct; 712 713 core_pct = int_tofp(sample->aperf) * int_tofp(100); 714 core_pct = div64_u64(core_pct, int_tofp(sample->mperf)); 715 716 sample->freq = fp_toint( 717 mul_fp(int_tofp( 718 cpu->pstate.max_pstate * cpu->pstate.scaling / 100), 719 core_pct)); 720 721 sample->core_pct_busy = (int32_t)core_pct; 722 } 723 724 static inline void intel_pstate_sample(struct cpudata *cpu) 725 { 726 u64 aperf, mperf; 727 unsigned long flags; 728 729 local_irq_save(flags); 730 rdmsrl(MSR_IA32_APERF, aperf); 731 rdmsrl(MSR_IA32_MPERF, mperf); 732 local_irq_restore(flags); 733 734 cpu->last_sample_time = cpu->sample.time; 735 cpu->sample.time = ktime_get(); 736 cpu->sample.aperf = aperf; 737 cpu->sample.mperf = mperf; 738 cpu->sample.aperf -= cpu->prev_aperf; 739 cpu->sample.mperf -= cpu->prev_mperf; 740 741 intel_pstate_calc_busy(cpu); 742 743 cpu->prev_aperf = aperf; 744 cpu->prev_mperf = mperf; 745 } 746 747 static inline void intel_hwp_set_sample_time(struct cpudata *cpu) 748 { 749 int delay; 750 751 delay = msecs_to_jiffies(50); 752 mod_timer_pinned(&cpu->timer, jiffies + delay); 753 } 754 755 static inline void intel_pstate_set_sample_time(struct cpudata *cpu) 756 { 757 int delay; 758 759 delay = msecs_to_jiffies(pid_params.sample_rate_ms); 760 mod_timer_pinned(&cpu->timer, jiffies + delay); 761 } 762 763 static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu) 764 { 765 int32_t core_busy, max_pstate, current_pstate, sample_ratio; 766 u32 duration_us; 767 u32 sample_time; 768 769 /* 770 * core_busy is the ratio of actual performance to max 771 * max_pstate is the max non turbo pstate available 772 * current_pstate was the pstate that was requested during 773 * the last sample period. 774 * 775 * We normalize core_busy, which was our actual percent 776 * performance to what we requested during the last sample 777 * period. The result will be a percentage of busy at a 778 * specified pstate. 779 */ 780 core_busy = cpu->sample.core_pct_busy; 781 max_pstate = int_tofp(cpu->pstate.max_pstate); 782 current_pstate = int_tofp(cpu->pstate.current_pstate); 783 core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate)); 784 785 /* 786 * Since we have a deferred timer, it will not fire unless 787 * we are in C0. So, determine if the actual elapsed time 788 * is significantly greater (3x) than our sample interval. If it 789 * is, then we were idle for a long enough period of time 790 * to adjust our busyness. 791 */ 792 sample_time = pid_params.sample_rate_ms * USEC_PER_MSEC; 793 duration_us = (u32) ktime_us_delta(cpu->sample.time, 794 cpu->last_sample_time); 795 if (duration_us > sample_time * 3) { 796 sample_ratio = div_fp(int_tofp(sample_time), 797 int_tofp(duration_us)); 798 core_busy = mul_fp(core_busy, sample_ratio); 799 } 800 801 return core_busy; 802 } 803 804 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu) 805 { 806 int32_t busy_scaled; 807 struct _pid *pid; 808 signed int ctl; 809 810 pid = &cpu->pid; 811 busy_scaled = intel_pstate_get_scaled_busy(cpu); 812 813 ctl = pid_calc(pid, busy_scaled); 814 815 /* Negative values of ctl increase the pstate and vice versa */ 816 intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl); 817 } 818 819 static void intel_hwp_timer_func(unsigned long __data) 820 { 821 struct cpudata *cpu = (struct cpudata *) __data; 822 823 intel_pstate_sample(cpu); 824 intel_hwp_set_sample_time(cpu); 825 } 826 827 static void intel_pstate_timer_func(unsigned long __data) 828 { 829 struct cpudata *cpu = (struct cpudata *) __data; 830 struct sample *sample; 831 832 intel_pstate_sample(cpu); 833 834 sample = &cpu->sample; 835 836 intel_pstate_adjust_busy_pstate(cpu); 837 838 trace_pstate_sample(fp_toint(sample->core_pct_busy), 839 fp_toint(intel_pstate_get_scaled_busy(cpu)), 840 cpu->pstate.current_pstate, 841 sample->mperf, 842 sample->aperf, 843 sample->freq); 844 845 intel_pstate_set_sample_time(cpu); 846 } 847 848 #define ICPU(model, policy) \ 849 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\ 850 (unsigned long)&policy } 851 852 static const struct x86_cpu_id intel_pstate_cpu_ids[] = { 853 ICPU(0x2a, core_params), 854 ICPU(0x2d, core_params), 855 ICPU(0x37, byt_params), 856 ICPU(0x3a, core_params), 857 ICPU(0x3c, core_params), 858 ICPU(0x3d, core_params), 859 ICPU(0x3e, core_params), 860 ICPU(0x3f, core_params), 861 ICPU(0x45, core_params), 862 ICPU(0x46, core_params), 863 ICPU(0x47, core_params), 864 ICPU(0x4c, byt_params), 865 ICPU(0x4e, core_params), 866 ICPU(0x4f, core_params), 867 ICPU(0x56, core_params), 868 {} 869 }; 870 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids); 871 872 static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] = { 873 ICPU(0x56, core_params), 874 {} 875 }; 876 877 static int intel_pstate_init_cpu(unsigned int cpunum) 878 { 879 struct cpudata *cpu; 880 881 if (!all_cpu_data[cpunum]) 882 all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata), 883 GFP_KERNEL); 884 if (!all_cpu_data[cpunum]) 885 return -ENOMEM; 886 887 cpu = all_cpu_data[cpunum]; 888 889 cpu->cpu = cpunum; 890 intel_pstate_get_cpu_pstates(cpu); 891 892 init_timer_deferrable(&cpu->timer); 893 cpu->timer.data = (unsigned long)cpu; 894 cpu->timer.expires = jiffies + HZ/100; 895 896 if (!hwp_active) 897 cpu->timer.function = intel_pstate_timer_func; 898 else 899 cpu->timer.function = intel_hwp_timer_func; 900 901 intel_pstate_busy_pid_reset(cpu); 902 intel_pstate_sample(cpu); 903 904 add_timer_on(&cpu->timer, cpunum); 905 906 pr_debug("Intel pstate controlling: cpu %d\n", cpunum); 907 908 return 0; 909 } 910 911 static unsigned int intel_pstate_get(unsigned int cpu_num) 912 { 913 struct sample *sample; 914 struct cpudata *cpu; 915 916 cpu = all_cpu_data[cpu_num]; 917 if (!cpu) 918 return 0; 919 sample = &cpu->sample; 920 return sample->freq; 921 } 922 923 static int intel_pstate_set_policy(struct cpufreq_policy *policy) 924 { 925 if (!policy->cpuinfo.max_freq) 926 return -ENODEV; 927 928 if (policy->policy == CPUFREQ_POLICY_PERFORMANCE && 929 policy->max >= policy->cpuinfo.max_freq) { 930 limits.min_policy_pct = 100; 931 limits.min_perf_pct = 100; 932 limits.min_perf = int_tofp(1); 933 limits.max_policy_pct = 100; 934 limits.max_perf_pct = 100; 935 limits.max_perf = int_tofp(1); 936 limits.no_turbo = 0; 937 return 0; 938 } 939 940 limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq; 941 limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100); 942 limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); 943 limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); 944 945 limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq; 946 limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100); 947 limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); 948 limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); 949 950 if (hwp_active) 951 intel_pstate_hwp_set(); 952 953 return 0; 954 } 955 956 static int intel_pstate_verify_policy(struct cpufreq_policy *policy) 957 { 958 cpufreq_verify_within_cpu_limits(policy); 959 960 if (policy->policy != CPUFREQ_POLICY_POWERSAVE && 961 policy->policy != CPUFREQ_POLICY_PERFORMANCE) 962 return -EINVAL; 963 964 return 0; 965 } 966 967 static void intel_pstate_stop_cpu(struct cpufreq_policy *policy) 968 { 969 int cpu_num = policy->cpu; 970 struct cpudata *cpu = all_cpu_data[cpu_num]; 971 972 pr_info("intel_pstate CPU %d exiting\n", cpu_num); 973 974 del_timer_sync(&all_cpu_data[cpu_num]->timer); 975 if (hwp_active) 976 return; 977 978 intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate); 979 } 980 981 static int intel_pstate_cpu_init(struct cpufreq_policy *policy) 982 { 983 struct cpudata *cpu; 984 int rc; 985 986 rc = intel_pstate_init_cpu(policy->cpu); 987 if (rc) 988 return rc; 989 990 cpu = all_cpu_data[policy->cpu]; 991 992 if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100) 993 policy->policy = CPUFREQ_POLICY_PERFORMANCE; 994 else 995 policy->policy = CPUFREQ_POLICY_POWERSAVE; 996 997 policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling; 998 policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling; 999 1000 /* cpuinfo and default policy values */ 1001 policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling; 1002 policy->cpuinfo.max_freq = 1003 cpu->pstate.turbo_pstate * cpu->pstate.scaling; 1004 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; 1005 cpumask_set_cpu(policy->cpu, policy->cpus); 1006 1007 return 0; 1008 } 1009 1010 static struct cpufreq_driver intel_pstate_driver = { 1011 .flags = CPUFREQ_CONST_LOOPS, 1012 .verify = intel_pstate_verify_policy, 1013 .setpolicy = intel_pstate_set_policy, 1014 .get = intel_pstate_get, 1015 .init = intel_pstate_cpu_init, 1016 .stop_cpu = intel_pstate_stop_cpu, 1017 .name = "intel_pstate", 1018 }; 1019 1020 static int __initdata no_load; 1021 static int __initdata no_hwp; 1022 static int __initdata hwp_only; 1023 static unsigned int force_load; 1024 1025 static int intel_pstate_msrs_not_valid(void) 1026 { 1027 /* Check that all the msr's we are using are valid. */ 1028 u64 aperf, mperf, tmp; 1029 1030 rdmsrl(MSR_IA32_APERF, aperf); 1031 rdmsrl(MSR_IA32_MPERF, mperf); 1032 1033 if (!pstate_funcs.get_max() || 1034 !pstate_funcs.get_min() || 1035 !pstate_funcs.get_turbo()) 1036 return -ENODEV; 1037 1038 rdmsrl(MSR_IA32_APERF, tmp); 1039 if (!(tmp - aperf)) 1040 return -ENODEV; 1041 1042 rdmsrl(MSR_IA32_MPERF, tmp); 1043 if (!(tmp - mperf)) 1044 return -ENODEV; 1045 1046 return 0; 1047 } 1048 1049 static void copy_pid_params(struct pstate_adjust_policy *policy) 1050 { 1051 pid_params.sample_rate_ms = policy->sample_rate_ms; 1052 pid_params.p_gain_pct = policy->p_gain_pct; 1053 pid_params.i_gain_pct = policy->i_gain_pct; 1054 pid_params.d_gain_pct = policy->d_gain_pct; 1055 pid_params.deadband = policy->deadband; 1056 pid_params.setpoint = policy->setpoint; 1057 } 1058 1059 static void copy_cpu_funcs(struct pstate_funcs *funcs) 1060 { 1061 pstate_funcs.get_max = funcs->get_max; 1062 pstate_funcs.get_min = funcs->get_min; 1063 pstate_funcs.get_turbo = funcs->get_turbo; 1064 pstate_funcs.get_scaling = funcs->get_scaling; 1065 pstate_funcs.set = funcs->set; 1066 pstate_funcs.get_vid = funcs->get_vid; 1067 } 1068 1069 #if IS_ENABLED(CONFIG_ACPI) 1070 #include <acpi/processor.h> 1071 1072 static bool intel_pstate_no_acpi_pss(void) 1073 { 1074 int i; 1075 1076 for_each_possible_cpu(i) { 1077 acpi_status status; 1078 union acpi_object *pss; 1079 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 1080 struct acpi_processor *pr = per_cpu(processors, i); 1081 1082 if (!pr) 1083 continue; 1084 1085 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer); 1086 if (ACPI_FAILURE(status)) 1087 continue; 1088 1089 pss = buffer.pointer; 1090 if (pss && pss->type == ACPI_TYPE_PACKAGE) { 1091 kfree(pss); 1092 return false; 1093 } 1094 1095 kfree(pss); 1096 } 1097 1098 return true; 1099 } 1100 1101 static bool intel_pstate_has_acpi_ppc(void) 1102 { 1103 int i; 1104 1105 for_each_possible_cpu(i) { 1106 struct acpi_processor *pr = per_cpu(processors, i); 1107 1108 if (!pr) 1109 continue; 1110 if (acpi_has_method(pr->handle, "_PPC")) 1111 return true; 1112 } 1113 return false; 1114 } 1115 1116 enum { 1117 PSS, 1118 PPC, 1119 }; 1120 1121 struct hw_vendor_info { 1122 u16 valid; 1123 char oem_id[ACPI_OEM_ID_SIZE]; 1124 char oem_table_id[ACPI_OEM_TABLE_ID_SIZE]; 1125 int oem_pwr_table; 1126 }; 1127 1128 /* Hardware vendor-specific info that has its own power management modes */ 1129 static struct hw_vendor_info vendor_info[] = { 1130 {1, "HP ", "ProLiant", PSS}, 1131 {1, "ORACLE", "X4-2 ", PPC}, 1132 {1, "ORACLE", "X4-2L ", PPC}, 1133 {1, "ORACLE", "X4-2B ", PPC}, 1134 {1, "ORACLE", "X3-2 ", PPC}, 1135 {1, "ORACLE", "X3-2L ", PPC}, 1136 {1, "ORACLE", "X3-2B ", PPC}, 1137 {1, "ORACLE", "X4470M2 ", PPC}, 1138 {1, "ORACLE", "X4270M3 ", PPC}, 1139 {1, "ORACLE", "X4270M2 ", PPC}, 1140 {1, "ORACLE", "X4170M2 ", PPC}, 1141 {0, "", ""}, 1142 }; 1143 1144 static bool intel_pstate_platform_pwr_mgmt_exists(void) 1145 { 1146 struct acpi_table_header hdr; 1147 struct hw_vendor_info *v_info; 1148 const struct x86_cpu_id *id; 1149 u64 misc_pwr; 1150 1151 id = x86_match_cpu(intel_pstate_cpu_oob_ids); 1152 if (id) { 1153 rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr); 1154 if ( misc_pwr & (1 << 8)) 1155 return true; 1156 } 1157 1158 if (acpi_disabled || 1159 ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr))) 1160 return false; 1161 1162 for (v_info = vendor_info; v_info->valid; v_info++) { 1163 if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) && 1164 !strncmp(hdr.oem_table_id, v_info->oem_table_id, 1165 ACPI_OEM_TABLE_ID_SIZE)) 1166 switch (v_info->oem_pwr_table) { 1167 case PSS: 1168 return intel_pstate_no_acpi_pss(); 1169 case PPC: 1170 return intel_pstate_has_acpi_ppc() && 1171 (!force_load); 1172 } 1173 } 1174 1175 return false; 1176 } 1177 #else /* CONFIG_ACPI not enabled */ 1178 static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; } 1179 static inline bool intel_pstate_has_acpi_ppc(void) { return false; } 1180 #endif /* CONFIG_ACPI */ 1181 1182 static int __init intel_pstate_init(void) 1183 { 1184 int cpu, rc = 0; 1185 const struct x86_cpu_id *id; 1186 struct cpu_defaults *cpu_info; 1187 struct cpuinfo_x86 *c = &boot_cpu_data; 1188 1189 if (no_load) 1190 return -ENODEV; 1191 1192 id = x86_match_cpu(intel_pstate_cpu_ids); 1193 if (!id) 1194 return -ENODEV; 1195 1196 /* 1197 * The Intel pstate driver will be ignored if the platform 1198 * firmware has its own power management modes. 1199 */ 1200 if (intel_pstate_platform_pwr_mgmt_exists()) 1201 return -ENODEV; 1202 1203 cpu_info = (struct cpu_defaults *)id->driver_data; 1204 1205 copy_pid_params(&cpu_info->pid_policy); 1206 copy_cpu_funcs(&cpu_info->funcs); 1207 1208 if (intel_pstate_msrs_not_valid()) 1209 return -ENODEV; 1210 1211 pr_info("Intel P-state driver initializing.\n"); 1212 1213 all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus()); 1214 if (!all_cpu_data) 1215 return -ENOMEM; 1216 1217 if (cpu_has(c,X86_FEATURE_HWP) && !no_hwp) 1218 intel_pstate_hwp_enable(); 1219 1220 if (!hwp_active && hwp_only) 1221 goto out; 1222 1223 rc = cpufreq_register_driver(&intel_pstate_driver); 1224 if (rc) 1225 goto out; 1226 1227 intel_pstate_debug_expose_params(); 1228 intel_pstate_sysfs_expose_params(); 1229 1230 return rc; 1231 out: 1232 get_online_cpus(); 1233 for_each_online_cpu(cpu) { 1234 if (all_cpu_data[cpu]) { 1235 del_timer_sync(&all_cpu_data[cpu]->timer); 1236 kfree(all_cpu_data[cpu]); 1237 } 1238 } 1239 1240 put_online_cpus(); 1241 vfree(all_cpu_data); 1242 return -ENODEV; 1243 } 1244 device_initcall(intel_pstate_init); 1245 1246 static int __init intel_pstate_setup(char *str) 1247 { 1248 if (!str) 1249 return -EINVAL; 1250 1251 if (!strcmp(str, "disable")) 1252 no_load = 1; 1253 if (!strcmp(str, "no_hwp")) 1254 no_hwp = 1; 1255 if (!strcmp(str, "force")) 1256 force_load = 1; 1257 if (!strcmp(str, "hwp_only")) 1258 hwp_only = 1; 1259 return 0; 1260 } 1261 early_param("intel_pstate", intel_pstate_setup); 1262 1263 MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>"); 1264 MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors"); 1265 MODULE_LICENSE("GPL"); 1266