drivers/acpi/processor_throttling.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * processor_throttling.c - Throttling submodule of the ACPI processor driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
   7  *  Copyright (C) 2004       Dominik Brodowski <[email protected]>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <[email protected]>
   9  *                      - Added processor hotplug support
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/init.h>
  16 #include <linux/sched.h>
  17 #include <linux/cpufreq.h>
  18 #include <linux/acpi.h>
  19 #include <acpi/processor.h>
  20 #include <asm/io.h>
  21 #include <linux/uaccess.h>
  22
  23 #define PREFIX "ACPI: "
  24
  25 /* ignore_tpc:
  26  *  0 -> acpi processor driver doesn't ignore _TPC values
  27  *  1 -> acpi processor driver ignores _TPC values
  28  */
  29 static int ignore_tpc;
  30 module_param(ignore_tpc, int, 0644);
  31 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  32
  33 struct throttling_tstate {
  34         unsigned int cpu;               /* cpu nr */
  35         int target_state;               /* target T-state */
  36 };
  37
  38 struct acpi_processor_throttling_arg {
  39         struct acpi_processor *pr;
  40         int target_state;
  41         bool force;
  42 };
  43
  44 #define THROTTLING_PRECHANGE       (1)
  45 #define THROTTLING_POSTCHANGE      (2)
  46
  47 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  48 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
  49                                            int state, bool force, bool direct);
  50
  51 static int acpi_processor_update_tsd_coord(void)
  52 {
  53         int count, count_target;
  54         int retval = 0;
  55         unsigned int i, j;
  56         cpumask_var_t covered_cpus;
  57         struct acpi_processor *pr, *match_pr;
  58         struct acpi_tsd_package *pdomain, *match_pdomain;
  59         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  60
  61         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  62                 return -ENOMEM;
  63
  64         /*
  65          * Now that we have _TSD data from all CPUs, lets setup T-state
  66          * coordination between all CPUs.
  67          */
  68         for_each_possible_cpu(i) {
  69                 pr = per_cpu(processors, i);
  70                 if (!pr)
  71                         continue;
  72
  73                 /* Basic validity check for domain info */
  74                 pthrottling = &(pr->throttling);
  75
  76                 /*
  77                  * If tsd package for one cpu is invalid, the coordination
  78                  * among all CPUs is thought as invalid.
  79                  * Maybe it is ugly.
  80                  */
  81                 if (!pthrottling->tsd_valid_flag) {
  82                         retval = -EINVAL;
  83                         break;
  84                 }
  85         }
  86         if (retval)
  87                 goto err_ret;
  88
  89         for_each_possible_cpu(i) {
  90                 pr = per_cpu(processors, i);
  91                 if (!pr)
  92                         continue;
  93
  94                 if (cpumask_test_cpu(i, covered_cpus))
  95                         continue;
  96                 pthrottling = &pr->throttling;
  97
  98                 pdomain = &(pthrottling->domain_info);
  99                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 100                 cpumask_set_cpu(i, covered_cpus);
 101                 /*
 102                  * If the number of processor in the TSD domain is 1, it is
 103                  * unnecessary to parse the coordination for this CPU.
 104                  */
 105                 if (pdomain->num_processors <= 1)
 106                         continue;
 107
 108                 /* Validate the Domain info */
 109                 count_target = pdomain->num_processors;
 110                 count = 1;
 111
 112                 for_each_possible_cpu(j) {
 113                         if (i == j)
 114                                 continue;
 115
 116                         match_pr = per_cpu(processors, j);
 117                         if (!match_pr)
 118                                 continue;
 119
 120                         match_pthrottling = &(match_pr->throttling);
 121                         match_pdomain = &(match_pthrottling->domain_info);
 122                         if (match_pdomain->domain != pdomain->domain)
 123                                 continue;
 124
 125                         /* Here i and j are in the same domain.
 126                          * If two TSD packages have the same domain, they
 127                          * should have the same num_porcessors and
 128                          * coordination type. Otherwise it will be regarded
 129                          * as illegal.
 130                          */
 131                         if (match_pdomain->num_processors != count_target) {
 132                                 retval = -EINVAL;
 133                                 goto err_ret;
 134                         }
 135
 136                         if (pdomain->coord_type != match_pdomain->coord_type) {
 137                                 retval = -EINVAL;
 138                                 goto err_ret;
 139                         }
 140
 141                         cpumask_set_cpu(j, covered_cpus);
 142                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 143                         count++;
 144                 }
 145                 for_each_possible_cpu(j) {
 146                         if (i == j)
 147                                 continue;
 148
 149                         match_pr = per_cpu(processors, j);
 150                         if (!match_pr)
 151                                 continue;
 152
 153                         match_pthrottling = &(match_pr->throttling);
 154                         match_pdomain = &(match_pthrottling->domain_info);
 155                         if (match_pdomain->domain != pdomain->domain)
 156                                 continue;
 157
 158                         /*
 159                          * If some CPUS have the same domain, they
 160                          * will have the same shared_cpu_map.
 161                          */
 162                         cpumask_copy(match_pthrottling->shared_cpu_map,
 163                                      pthrottling->shared_cpu_map);
 164                 }
 165         }
 166
 167 err_ret:
 168         free_cpumask_var(covered_cpus);
 169
 170         for_each_possible_cpu(i) {
 171                 pr = per_cpu(processors, i);
 172                 if (!pr)
 173                         continue;
 174
 175                 /*
 176                  * Assume no coordination on any error parsing domain info.
 177                  * The coordination type will be forced as SW_ALL.
 178                  */
 179                 if (retval) {
 180                         pthrottling = &(pr->throttling);
 181                         cpumask_clear(pthrottling->shared_cpu_map);
 182                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 183                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 184                 }
 185         }
 186
 187         return retval;
 188 }
 189
 190 /*
 191  * Update the T-state coordination after the _TSD
 192  * data for all cpus is obtained.
 193  */
 194 void acpi_processor_throttling_init(void)
 195 {
 196         if (acpi_processor_update_tsd_coord())
 197                 pr_debug("Assume no T-state coordination\n");
 198 }
 199
 200 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 201 {
 202         struct throttling_tstate *p_tstate = data;
 203         struct acpi_processor *pr;
 204         unsigned int cpu;
 205         int target_state;
 206         struct acpi_processor_limit *p_limit;
 207         struct acpi_processor_throttling *p_throttling;
 208
 209         cpu = p_tstate->cpu;
 210         pr = per_cpu(processors, cpu);
 211         if (!pr) {
 212                 pr_debug("Invalid pr pointer\n");
 213                 return 0;
 214         }
 215         if (!pr->flags.throttling) {
 216                 acpi_handle_debug(pr->handle,
 217                                   "Throttling control unsupported on CPU %d\n",
 218                                   cpu);
 219                 return 0;
 220         }
 221         target_state = p_tstate->target_state;
 222         p_throttling = &(pr->throttling);
 223         switch (event) {
 224         case THROTTLING_PRECHANGE:
 225                 /*
 226                  * Prechange event is used to choose one proper t-state,
 227                  * which meets the limits of thermal, user and _TPC.
 228                  */
 229                 p_limit = &pr->limit;
 230                 if (p_limit->thermal.tx > target_state)
 231                         target_state = p_limit->thermal.tx;
 232                 if (p_limit->user.tx > target_state)
 233                         target_state = p_limit->user.tx;
 234                 if (pr->throttling_platform_limit > target_state)
 235                         target_state = pr->throttling_platform_limit;
 236                 if (target_state >= p_throttling->state_count) {
 237                         printk(KERN_WARNING
 238                                 "Exceed the limit of T-state \n");
 239                         target_state = p_throttling->state_count - 1;
 240                 }
 241                 p_tstate->target_state = target_state;
 242                 acpi_handle_debug(pr->handle,
 243                                   "PreChange Event: target T-state of CPU %d is T%d\n",
 244                                   cpu, target_state);
 245                 break;
 246         case THROTTLING_POSTCHANGE:
 247                 /*
 248                  * Postchange event is only used to update the
 249                  * T-state flag of acpi_processor_throttling.
 250                  */
 251                 p_throttling->state = target_state;
 252                 acpi_handle_debug(pr->handle,
 253                                   "PostChange Event: CPU %d is switched to T%d\n",
 254                                   cpu, target_state);
 255                 break;
 256         default:
 257                 printk(KERN_WARNING
 258                         "Unsupported Throttling notifier event\n");
 259                 break;
 260         }
 261
 262         return 0;
 263 }
 264
 265 /*
 266  * _TPC - Throttling Present Capabilities
 267  */
 268 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 269 {
 270         acpi_status status = 0;
 271         unsigned long long tpc = 0;
 272
 273         if (!pr)
 274                 return -EINVAL;
 275
 276         if (ignore_tpc)
 277                 goto end;
 278
 279         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 280         if (ACPI_FAILURE(status)) {
 281                 if (status != AE_NOT_FOUND)
 282                         acpi_evaluation_failure_warn(pr->handle, "_TPC", status);
 283
 284                 return -ENODEV;
 285         }
 286
 287 end:
 288         pr->throttling_platform_limit = (int)tpc;
 289         return 0;
 290 }
 291
 292 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 293 {
 294         int result = 0;
 295         int throttling_limit;
 296         int current_state;
 297         struct acpi_processor_limit *limit;
 298         int target_state;
 299
 300         if (ignore_tpc)
 301                 return 0;
 302
 303         result = acpi_processor_get_platform_limit(pr);
 304         if (result) {
 305                 /* Throttling Limit is unsupported */
 306                 return result;
 307         }
 308
 309         throttling_limit = pr->throttling_platform_limit;
 310         if (throttling_limit >= pr->throttling.state_count) {
 311                 /* Uncorrect Throttling Limit */
 312                 return -EINVAL;
 313         }
 314
 315         current_state = pr->throttling.state;
 316         if (current_state > throttling_limit) {
 317                 /*
 318                  * The current state can meet the requirement of
 319                  * _TPC limit. But it is reasonable that OSPM changes
 320                  * t-states from high to low for better performance.
 321                  * Of course the limit condition of thermal
 322                  * and user should be considered.
 323                  */
 324                 limit = &pr->limit;
 325                 target_state = throttling_limit;
 326                 if (limit->thermal.tx > target_state)
 327                         target_state = limit->thermal.tx;
 328                 if (limit->user.tx > target_state)
 329                         target_state = limit->user.tx;
 330         } else if (current_state == throttling_limit) {
 331                 /*
 332                  * Unnecessary to change the throttling state
 333                  */
 334                 return 0;
 335         } else {
 336                 /*
 337                  * If the current state is lower than the limit of _TPC, it
 338                  * will be forced to switch to the throttling state defined
 339                  * by throttling_platfor_limit.
 340                  * Because the previous state meets with the limit condition
 341                  * of thermal and user, it is unnecessary to check it again.
 342                  */
 343                 target_state = throttling_limit;
 344         }
 345         return acpi_processor_set_throttling(pr, target_state, false);
 346 }
 347
 348 /*
 349  * This function is used to reevaluate whether the T-state is valid
 350  * after one CPU is onlined/offlined.
 351  * It is noted that it won't reevaluate the following properties for
 352  * the T-state.
 353  *      1. Control method.
 354  *      2. the number of supported T-state
 355  *      3. TSD domain
 356  */
 357 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 358                                         bool is_dead)
 359 {
 360         int result = 0;
 361
 362         if (is_dead) {
 363                 /* When one CPU is offline, the T-state throttling
 364                  * will be invalidated.
 365                  */
 366                 pr->flags.throttling = 0;
 367                 return;
 368         }
 369         /* the following is to recheck whether the T-state is valid for
 370          * the online CPU
 371          */
 372         if (!pr->throttling.state_count) {
 373                 /* If the number of T-state is invalid, it is
 374                  * invalidated.
 375                  */
 376                 pr->flags.throttling = 0;
 377                 return;
 378         }
 379         pr->flags.throttling = 1;
 380
 381         /* Disable throttling (if enabled).  We'll let subsequent
 382          * policy (e.g.thermal) decide to lower performance if it
 383          * so chooses, but for now we'll crank up the speed.
 384          */
 385
 386         result = acpi_processor_get_throttling(pr);
 387         if (result)
 388                 goto end;
 389
 390         if (pr->throttling.state) {
 391                 result = acpi_processor_set_throttling(pr, 0, false);
 392                 if (result)
 393                         goto end;
 394         }
 395
 396 end:
 397         if (result)
 398                 pr->flags.throttling = 0;
 399 }
 400 /*
 401  * _PTC - Processor Throttling Control (and status) register location
 402  */
 403 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 404 {
 405         int result = 0;
 406         acpi_status status = 0;
 407         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 408         union acpi_object *ptc = NULL;
 409         union acpi_object obj;
 410         struct acpi_processor_throttling *throttling;
 411
 412         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 413         if (ACPI_FAILURE(status)) {
 414                 if (status != AE_NOT_FOUND)
 415                         acpi_evaluation_failure_warn(pr->handle, "_PTC", status);
 416
 417                 return -ENODEV;
 418         }
 419
 420         ptc = (union acpi_object *)buffer.pointer;
 421         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 422             || (ptc->package.count != 2)) {
 423                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 424                 result = -EFAULT;
 425                 goto end;
 426         }
 427
 428         /*
 429          * control_register
 430          */
 431
 432         obj = ptc->package.elements[0];
 433
 434         if ((obj.type != ACPI_TYPE_BUFFER)
 435             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 436             || (obj.buffer.pointer == NULL)) {
 437                 printk(KERN_ERR PREFIX
 438                        "Invalid _PTC data (control_register)\n");
 439                 result = -EFAULT;
 440                 goto end;
 441         }
 442         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 443                sizeof(struct acpi_ptc_register));
 444
 445         /*
 446          * status_register
 447          */
 448
 449         obj = ptc->package.elements[1];
 450
 451         if ((obj.type != ACPI_TYPE_BUFFER)
 452             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 453             || (obj.buffer.pointer == NULL)) {
 454                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 455                 result = -EFAULT;
 456                 goto end;
 457         }
 458
 459         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 460                sizeof(struct acpi_ptc_register));
 461
 462         throttling = &pr->throttling;
 463
 464         if ((throttling->control_register.bit_width +
 465                 throttling->control_register.bit_offset) > 32) {
 466                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 467                 result = -EFAULT;
 468                 goto end;
 469         }
 470
 471         if ((throttling->status_register.bit_width +
 472                 throttling->status_register.bit_offset) > 32) {
 473                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 474                 result = -EFAULT;
 475                 goto end;
 476         }
 477
 478 end:
 479         kfree(buffer.pointer);
 480
 481         return result;
 482 }
 483
 484 /*
 485  * _TSS - Throttling Supported States
 486  */
 487 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 488 {
 489         int result = 0;
 490         acpi_status status = AE_OK;
 491         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 492         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 493         struct acpi_buffer state = { 0, NULL };
 494         union acpi_object *tss = NULL;
 495         int i;
 496
 497         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 498         if (ACPI_FAILURE(status)) {
 499                 if (status != AE_NOT_FOUND)
 500                         acpi_evaluation_failure_warn(pr->handle, "_TSS", status);
 501
 502                 return -ENODEV;
 503         }
 504
 505         tss = buffer.pointer;
 506         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 507                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 508                 result = -EFAULT;
 509                 goto end;
 510         }
 511
 512         acpi_handle_debug(pr->handle, "Found %d throttling states\n",
 513                           tss->package.count);
 514
 515         pr->throttling.state_count = tss->package.count;
 516         pr->throttling.states_tss =
 517             kmalloc_array(tss->package.count,
 518                           sizeof(struct acpi_processor_tx_tss),
 519                           GFP_KERNEL);
 520         if (!pr->throttling.states_tss) {
 521                 result = -ENOMEM;
 522                 goto end;
 523         }
 524
 525         for (i = 0; i < pr->throttling.state_count; i++) {
 526
 527                 struct acpi_processor_tx_tss *tx =
 528                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 529                                                       states_tss[i]);
 530
 531                 state.length = sizeof(struct acpi_processor_tx_tss);
 532                 state.pointer = tx;
 533
 534                 acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
 535
 536                 status = acpi_extract_package(&(tss->package.elements[i]),
 537                                               &format, &state);
 538                 if (ACPI_FAILURE(status)) {
 539                         acpi_handle_warn(pr->handle, "Invalid _TSS data: %s\n",
 540                                          acpi_format_exception(status));
 541                         result = -EFAULT;
 542                         kfree(pr->throttling.states_tss);
 543                         goto end;
 544                 }
 545
 546                 if (!tx->freqpercentage) {
 547                         printk(KERN_ERR PREFIX
 548                                "Invalid _TSS data: freq is zero\n");
 549                         result = -EFAULT;
 550                         kfree(pr->throttling.states_tss);
 551                         goto end;
 552                 }
 553         }
 554
 555 end:
 556         kfree(buffer.pointer);
 557
 558         return result;
 559 }
 560
 561 /*
 562  * _TSD - T-State Dependencies
 563  */
 564 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 565 {
 566         int result = 0;
 567         acpi_status status = AE_OK;
 568         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 569         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 570         struct acpi_buffer state = { 0, NULL };
 571         union acpi_object *tsd = NULL;
 572         struct acpi_tsd_package *pdomain;
 573         struct acpi_processor_throttling *pthrottling;
 574
 575         pthrottling = &pr->throttling;
 576         pthrottling->tsd_valid_flag = 0;
 577
 578         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 579         if (ACPI_FAILURE(status)) {
 580                 if (status != AE_NOT_FOUND)
 581                         acpi_evaluation_failure_warn(pr->handle, "_TSD", status);
 582
 583                 return -ENODEV;
 584         }
 585
 586         tsd = buffer.pointer;
 587         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 588                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 589                 result = -EFAULT;
 590                 goto end;
 591         }
 592
 593         if (tsd->package.count != 1) {
 594                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 595                 result = -EFAULT;
 596                 goto end;
 597         }
 598
 599         pdomain = &(pr->throttling.domain_info);
 600
 601         state.length = sizeof(struct acpi_tsd_package);
 602         state.pointer = pdomain;
 603
 604         status = acpi_extract_package(&(tsd->package.elements[0]),
 605                                       &format, &state);
 606         if (ACPI_FAILURE(status)) {
 607                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 608                 result = -EFAULT;
 609                 goto end;
 610         }
 611
 612         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 613                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 614                 result = -EFAULT;
 615                 goto end;
 616         }
 617
 618         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 619                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 620                 result = -EFAULT;
 621                 goto end;
 622         }
 623
 624         pthrottling = &pr->throttling;
 625         pthrottling->tsd_valid_flag = 1;
 626         pthrottling->shared_type = pdomain->coord_type;
 627         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 628         /*
 629          * If the coordination type is not defined in ACPI spec,
 630          * the tsd_valid_flag will be clear and coordination type
 631          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 632          */
 633         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 634                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 635                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 636                 pthrottling->tsd_valid_flag = 0;
 637                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 638         }
 639
 640 end:
 641         kfree(buffer.pointer);
 642         return result;
 643 }
 644
 645 /* --------------------------------------------------------------------------
 646                               Throttling Control
 647    -------------------------------------------------------------------------- */
 648 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 649 {
 650         int state = 0;
 651         u32 value = 0;
 652         u32 duty_mask = 0;
 653         u32 duty_value = 0;
 654
 655         if (!pr)
 656                 return -EINVAL;
 657
 658         if (!pr->flags.throttling)
 659                 return -ENODEV;
 660
 661         /*
 662          * We don't care about error returns - we just try to mark
 663          * these reserved so that nobody else is confused into thinking
 664          * that this region might be unused..
 665          *
 666          * (In particular, allocating the IO range for Cardbus)
 667          */
 668         request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 669
 670         pr->throttling.state = 0;
 671
 672         duty_mask = pr->throttling.state_count - 1;
 673
 674         duty_mask <<= pr->throttling.duty_offset;
 675
 676         local_irq_disable();
 677
 678         value = inl(pr->throttling.address);
 679
 680         /*
 681          * Compute the current throttling state when throttling is enabled
 682          * (bit 4 is on).
 683          */
 684         if (value & 0x10) {
 685                 duty_value = value & duty_mask;
 686                 duty_value >>= pr->throttling.duty_offset;
 687
 688                 if (duty_value)
 689                         state = pr->throttling.state_count - duty_value;
 690         }
 691
 692         pr->throttling.state = state;
 693
 694         local_irq_enable();
 695
 696         acpi_handle_debug(pr->handle,
 697                           "Throttling state is T%d (%d%% throttling applied)\n",
 698                           state, pr->throttling.states[state].performance);
 699
 700         return 0;
 701 }
 702
 703 #ifdef CONFIG_X86
 704 static int acpi_throttling_rdmsr(u64 *value)
 705 {
 706         u64 msr_high, msr_low;
 707         u64 msr = 0;
 708         int ret = -1;
 709
 710         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 711                 !this_cpu_has(X86_FEATURE_ACPI)) {
 712                 printk(KERN_ERR PREFIX
 713                         "HARDWARE addr space,NOT supported yet\n");
 714         } else {
 715                 msr_low = 0;
 716                 msr_high = 0;
 717                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 718                         (u32 *)&msr_low, (u32 *) &msr_high);
 719                 msr = (msr_high << 32) | msr_low;
 720                 *value = (u64) msr;
 721                 ret = 0;
 722         }
 723         return ret;
 724 }
 725
 726 static int acpi_throttling_wrmsr(u64 value)
 727 {
 728         int ret = -1;
 729         u64 msr;
 730
 731         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 732                 !this_cpu_has(X86_FEATURE_ACPI)) {
 733                 printk(KERN_ERR PREFIX
 734                         "HARDWARE addr space,NOT supported yet\n");
 735         } else {
 736                 msr = value;
 737                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 738                         msr & 0xffffffff, msr >> 32);
 739                 ret = 0;
 740         }
 741         return ret;
 742 }
 743 #else
 744 static int acpi_throttling_rdmsr(u64 *value)
 745 {
 746         printk(KERN_ERR PREFIX
 747                 "HARDWARE addr space,NOT supported yet\n");
 748         return -1;
 749 }
 750
 751 static int acpi_throttling_wrmsr(u64 value)
 752 {
 753         printk(KERN_ERR PREFIX
 754                 "HARDWARE addr space,NOT supported yet\n");
 755         return -1;
 756 }
 757 #endif
 758
 759 static int acpi_read_throttling_status(struct acpi_processor *pr,
 760                                         u64 *value)
 761 {
 762         u32 bit_width, bit_offset;
 763         u32 ptc_value;
 764         u64 ptc_mask;
 765         struct acpi_processor_throttling *throttling;
 766         int ret = -1;
 767
 768         throttling = &pr->throttling;
 769         switch (throttling->status_register.space_id) {
 770         case ACPI_ADR_SPACE_SYSTEM_IO:
 771                 bit_width = throttling->status_register.bit_width;
 772                 bit_offset = throttling->status_register.bit_offset;
 773
 774                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 775                                   address, &ptc_value,
 776                                   (u32) (bit_width + bit_offset));
 777                 ptc_mask = (1 << bit_width) - 1;
 778                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 779                 ret = 0;
 780                 break;
 781         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 782                 ret = acpi_throttling_rdmsr(value);
 783                 break;
 784         default:
 785                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 786                        (u32) (throttling->status_register.space_id));
 787         }
 788         return ret;
 789 }
 790
 791 static int acpi_write_throttling_state(struct acpi_processor *pr,
 792                                 u64 value)
 793 {
 794         u32 bit_width, bit_offset;
 795         u64 ptc_value;
 796         u64 ptc_mask;
 797         struct acpi_processor_throttling *throttling;
 798         int ret = -1;
 799
 800         throttling = &pr->throttling;
 801         switch (throttling->control_register.space_id) {
 802         case ACPI_ADR_SPACE_SYSTEM_IO:
 803                 bit_width = throttling->control_register.bit_width;
 804                 bit_offset = throttling->control_register.bit_offset;
 805                 ptc_mask = (1 << bit_width) - 1;
 806                 ptc_value = value & ptc_mask;
 807
 808                 acpi_os_write_port((acpi_io_address) throttling->
 809                                         control_register.address,
 810                                         (u32) (ptc_value << bit_offset),
 811                                         (u32) (bit_width + bit_offset));
 812                 ret = 0;
 813                 break;
 814         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 815                 ret = acpi_throttling_wrmsr(value);
 816                 break;
 817         default:
 818                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 819                        (u32) (throttling->control_register.space_id));
 820         }
 821         return ret;
 822 }
 823
 824 static int acpi_get_throttling_state(struct acpi_processor *pr,
 825                                 u64 value)
 826 {
 827         int i;
 828
 829         for (i = 0; i < pr->throttling.state_count; i++) {
 830                 struct acpi_processor_tx_tss *tx =
 831                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 832                                                       states_tss[i]);
 833                 if (tx->control == value)
 834                         return i;
 835         }
 836         return -1;
 837 }
 838
 839 static int acpi_get_throttling_value(struct acpi_processor *pr,
 840                         int state, u64 *value)
 841 {
 842         int ret = -1;
 843
 844         if (state >= 0 && state <= pr->throttling.state_count) {
 845                 struct acpi_processor_tx_tss *tx =
 846                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 847                                                       states_tss[state]);
 848                 *value = tx->control;
 849                 ret = 0;
 850         }
 851         return ret;
 852 }
 853
 854 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 855 {
 856         int state = 0;
 857         int ret;
 858         u64 value;
 859
 860         if (!pr)
 861                 return -EINVAL;
 862
 863         if (!pr->flags.throttling)
 864                 return -ENODEV;
 865
 866         pr->throttling.state = 0;
 867
 868         value = 0;
 869         ret = acpi_read_throttling_status(pr, &value);
 870         if (ret >= 0) {
 871                 state = acpi_get_throttling_state(pr, value);
 872                 if (state == -1) {
 873                         acpi_handle_debug(pr->handle,
 874                                           "Invalid throttling state, reset\n");
 875                         state = 0;
 876                         ret = __acpi_processor_set_throttling(pr, state, true,
 877                                                               true);
 878                         if (ret)
 879                                 return ret;
 880                 }
 881                 pr->throttling.state = state;
 882         }
 883
 884         return 0;
 885 }
 886
 887 static long __acpi_processor_get_throttling(void *data)
 888 {
 889         struct acpi_processor *pr = data;
 890
 891         return pr->throttling.acpi_processor_get_throttling(pr);
 892 }
 893
 894 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 895 {
 896         if (!pr)
 897                 return -EINVAL;
 898
 899         if (!pr->flags.throttling)
 900                 return -ENODEV;
 901
 902         /*
 903          * This is either called from the CPU hotplug callback of
 904          * processor_driver or via the ACPI probe function. In the latter
 905          * case the CPU is not guaranteed to be online. Both call sites are
 906          * protected against CPU hotplug.
 907          */
 908         if (!cpu_online(pr->id))
 909                 return -ENODEV;
 910
 911         return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false);
 912 }
 913
 914 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 915 {
 916         int i, step;
 917
 918         if (!pr->throttling.address) {
 919                 acpi_handle_debug(pr->handle, "No throttling register\n");
 920                 return -EINVAL;
 921         } else if (!pr->throttling.duty_width) {
 922                 acpi_handle_debug(pr->handle, "No throttling states\n");
 923                 return -EINVAL;
 924         }
 925         /* TBD: Support duty_cycle values that span bit 4. */
 926         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 927                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 928                 return -EINVAL;
 929         }
 930
 931         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 932
 933         /*
 934          * Compute state values. Note that throttling displays a linear power
 935          * performance relationship (at 50% performance the CPU will consume
 936          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 937          */
 938
 939         step = (1000 / pr->throttling.state_count);
 940
 941         for (i = 0; i < pr->throttling.state_count; i++) {
 942                 pr->throttling.states[i].performance = 1000 - step * i;
 943                 pr->throttling.states[i].power = 1000 - step * i;
 944         }
 945         return 0;
 946 }
 947
 948 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 949                                               int state, bool force)
 950 {
 951         u32 value = 0;
 952         u32 duty_mask = 0;
 953         u32 duty_value = 0;
 954
 955         if (!pr)
 956                 return -EINVAL;
 957
 958         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 959                 return -EINVAL;
 960
 961         if (!pr->flags.throttling)
 962                 return -ENODEV;
 963
 964         if (!force && (state == pr->throttling.state))
 965                 return 0;
 966
 967         if (state < pr->throttling_platform_limit)
 968                 return -EPERM;
 969         /*
 970          * Calculate the duty_value and duty_mask.
 971          */
 972         if (state) {
 973                 duty_value = pr->throttling.state_count - state;
 974
 975                 duty_value <<= pr->throttling.duty_offset;
 976
 977                 /* Used to clear all duty_value bits */
 978                 duty_mask = pr->throttling.state_count - 1;
 979
 980                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 981                 duty_mask = ~duty_mask;
 982         }
 983
 984         local_irq_disable();
 985
 986         /*
 987          * Disable throttling by writing a 0 to bit 4.  Note that we must
 988          * turn it off before you can change the duty_value.
 989          */
 990         value = inl(pr->throttling.address);
 991         if (value & 0x10) {
 992                 value &= 0xFFFFFFEF;
 993                 outl(value, pr->throttling.address);
 994         }
 995
 996         /*
 997          * Write the new duty_value and then enable throttling.  Note
 998          * that a state value of 0 leaves throttling disabled.
 999          */
1000         if (state) {
1001                 value &= duty_mask;
1002                 value |= duty_value;
1003                 outl(value, pr->throttling.address);
1004
1005                 value |= 0x00000010;
1006                 outl(value, pr->throttling.address);
1007         }
1008
1009         pr->throttling.state = state;
1010
1011         local_irq_enable();
1012
1013         acpi_handle_debug(pr->handle,
1014                           "Throttling state set to T%d (%d%%)\n", state,
1015                           (pr->throttling.states[state].performance ? pr->
1016                            throttling.states[state].performance / 10 : 0));
1017
1018         return 0;
1019 }
1020
1021 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1022                                              int state, bool force)
1023 {
1024         int ret;
1025         u64 value;
1026
1027         if (!pr)
1028                 return -EINVAL;
1029
1030         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1031                 return -EINVAL;
1032
1033         if (!pr->flags.throttling)
1034                 return -ENODEV;
1035
1036         if (!force && (state == pr->throttling.state))
1037                 return 0;
1038
1039         if (state < pr->throttling_platform_limit)
1040                 return -EPERM;
1041
1042         value = 0;
1043         ret = acpi_get_throttling_value(pr, state, &value);
1044         if (ret >= 0) {
1045                 acpi_write_throttling_state(pr, value);
1046                 pr->throttling.state = state;
1047         }
1048
1049         return 0;
1050 }
1051
1052 static long acpi_processor_throttling_fn(void *data)
1053 {
1054         struct acpi_processor_throttling_arg *arg = data;
1055         struct acpi_processor *pr = arg->pr;
1056
1057         return pr->throttling.acpi_processor_set_throttling(pr,
1058                         arg->target_state, arg->force);
1059 }
1060
1061 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
1062                                            int state, bool force, bool direct)
1063 {
1064         int ret = 0;
1065         unsigned int i;
1066         struct acpi_processor *match_pr;
1067         struct acpi_processor_throttling *p_throttling;
1068         struct acpi_processor_throttling_arg arg;
1069         struct throttling_tstate t_state;
1070
1071         if (!pr)
1072                 return -EINVAL;
1073
1074         if (!pr->flags.throttling)
1075                 return -ENODEV;
1076
1077         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1078                 return -EINVAL;
1079
1080         if (cpu_is_offline(pr->id)) {
1081                 /*
1082                  * the cpu pointed by pr->id is offline. Unnecessary to change
1083                  * the throttling state any more.
1084                  */
1085                 return -ENODEV;
1086         }
1087
1088         t_state.target_state = state;
1089         p_throttling = &(pr->throttling);
1090
1091         /*
1092          * The throttling notifier will be called for every
1093          * affected cpu in order to get one proper T-state.
1094          * The notifier event is THROTTLING_PRECHANGE.
1095          */
1096         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1097                 t_state.cpu = i;
1098                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1099                                                         &t_state);
1100         }
1101         /*
1102          * The function of acpi_processor_set_throttling will be called
1103          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1104          * it is necessary to call it for every affected cpu. Otherwise
1105          * it can be called only for the cpu pointed by pr.
1106          */
1107         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1108                 arg.pr = pr;
1109                 arg.target_state = state;
1110                 arg.force = force;
1111                 ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
1112                                   direct);
1113         } else {
1114                 /*
1115                  * When the T-state coordination is SW_ALL or HW_ALL,
1116                  * it is necessary to set T-state for every affected
1117                  * cpus.
1118                  */
1119                 for_each_cpu_and(i, cpu_online_mask,
1120                     p_throttling->shared_cpu_map) {
1121                         match_pr = per_cpu(processors, i);
1122                         /*
1123                          * If the pointer is invalid, we will report the
1124                          * error message and continue.
1125                          */
1126                         if (!match_pr) {
1127                                 acpi_handle_debug(pr->handle,
1128                                         "Invalid Pointer for CPU %d\n", i);
1129                                 continue;
1130                         }
1131                         /*
1132                          * If the throttling control is unsupported on CPU i,
1133                          * we will report the error message and continue.
1134                          */
1135                         if (!match_pr->flags.throttling) {
1136                                 acpi_handle_debug(pr->handle,
1137                                         "Throttling Control unsupported on CPU %d\n", i);
1138                                 continue;
1139                         }
1140
1141                         arg.pr = match_pr;
1142                         arg.target_state = state;
1143                         arg.force = force;
1144                         ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
1145                                           &arg, direct);
1146                 }
1147         }
1148         /*
1149          * After the set_throttling is called, the
1150          * throttling notifier is called for every
1151          * affected cpu to update the T-states.
1152          * The notifier event is THROTTLING_POSTCHANGE
1153          */
1154         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1155                 t_state.cpu = i;
1156                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1157                                                         &t_state);
1158         }
1159
1160         return ret;
1161 }
1162
1163 int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
1164                                   bool force)
1165 {
1166         return __acpi_processor_set_throttling(pr, state, force, false);
1167 }
1168
1169 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1170 {
1171         int result = 0;
1172         struct acpi_processor_throttling *pthrottling;
1173
1174         acpi_handle_debug(pr->handle,
1175                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1176                           pr->throttling.address,
1177                           pr->throttling.duty_offset,
1178                           pr->throttling.duty_width);
1179
1180         /*
1181          * Evaluate _PTC, _TSS and _TPC
1182          * They must all be present or none of them can be used.
1183          */
1184         if (acpi_processor_get_throttling_control(pr) ||
1185                 acpi_processor_get_throttling_states(pr) ||
1186                 acpi_processor_get_platform_limit(pr)) {
1187                 pr->throttling.acpi_processor_get_throttling =
1188                     &acpi_processor_get_throttling_fadt;
1189                 pr->throttling.acpi_processor_set_throttling =
1190                     &acpi_processor_set_throttling_fadt;
1191                 if (acpi_processor_get_fadt_info(pr))
1192                         return 0;
1193         } else {
1194                 pr->throttling.acpi_processor_get_throttling =
1195                     &acpi_processor_get_throttling_ptc;
1196                 pr->throttling.acpi_processor_set_throttling =
1197                     &acpi_processor_set_throttling_ptc;
1198         }
1199
1200         /*
1201          * If TSD package for one CPU can't be parsed successfully, it means
1202          * that this CPU will have no coordination with other CPUs.
1203          */
1204         if (acpi_processor_get_tsd(pr)) {
1205                 pthrottling = &pr->throttling;
1206                 pthrottling->tsd_valid_flag = 0;
1207                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1208                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1209         }
1210
1211         /*
1212          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1213          * This shouldn't be an issue as few (if any) mobile systems ever
1214          * used this part.
1215          */
1216         if (errata.piix4.throttle) {
1217                 acpi_handle_debug(pr->handle,
1218                                   "Throttling not supported on PIIX4 A- or B-step\n");
1219                 return 0;
1220         }
1221
1222         acpi_handle_debug(pr->handle, "Found %d throttling states\n",
1223                           pr->throttling.state_count);
1224
1225         pr->flags.throttling = 1;
1226
1227         /*
1228          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1229          * thermal) decide to lower performance if it so chooses, but for now
1230          * we'll crank up the speed.
1231          */
1232
1233         result = acpi_processor_get_throttling(pr);
1234         if (result)
1235                 goto end;
1236
1237         if (pr->throttling.state) {
1238                 acpi_handle_debug(pr->handle,
1239                                   "Disabling throttling (was T%d)\n",
1240                                   pr->throttling.state);
1241                 result = acpi_processor_set_throttling(pr, 0, false);
1242                 if (result)
1243                         goto end;
1244         }
1245
1246 end:
1247         if (result)
1248                 pr->flags.throttling = 0;
1249
1250         return result;
1251 }
1252