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 <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   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         return;
 200 }
 201
 202 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 203 {
 204         struct throttling_tstate *p_tstate = data;
 205         struct acpi_processor *pr;
 206         unsigned int cpu ;
 207         int target_state;
 208         struct acpi_processor_limit *p_limit;
 209         struct acpi_processor_throttling *p_throttling;
 210
 211         cpu = p_tstate->cpu;
 212         pr = per_cpu(processors, cpu);
 213         if (!pr) {
 214                 pr_debug("Invalid pr pointer\n");
 215                 return 0;
 216         }
 217         if (!pr->flags.throttling) {
 218                 acpi_handle_debug(pr->handle,
 219                                   "Throttling control unsupported on CPU %d\n",
 220                                   cpu);
 221                 return 0;
 222         }
 223         target_state = p_tstate->target_state;
 224         p_throttling = &(pr->throttling);
 225         switch (event) {
 226         case THROTTLING_PRECHANGE:
 227                 /*
 228                  * Prechange event is used to choose one proper t-state,
 229                  * which meets the limits of thermal, user and _TPC.
 230                  */
 231                 p_limit = &pr->limit;
 232                 if (p_limit->thermal.tx > target_state)
 233                         target_state = p_limit->thermal.tx;
 234                 if (p_limit->user.tx > target_state)
 235                         target_state = p_limit->user.tx;
 236                 if (pr->throttling_platform_limit > target_state)
 237                         target_state = pr->throttling_platform_limit;
 238                 if (target_state >= p_throttling->state_count) {
 239                         printk(KERN_WARNING
 240                                 "Exceed the limit of T-state \n");
 241                         target_state = p_throttling->state_count - 1;
 242                 }
 243                 p_tstate->target_state = target_state;
 244                 acpi_handle_debug(pr->handle,
 245                                   "PreChange Event: target T-state of CPU %d is T%d\n",
 246                                   cpu, target_state);
 247                 break;
 248         case THROTTLING_POSTCHANGE:
 249                 /*
 250                  * Postchange event is only used to update the
 251                  * T-state flag of acpi_processor_throttling.
 252                  */
 253                 p_throttling->state = target_state;
 254                 acpi_handle_debug(pr->handle,
 255                                   "PostChange Event: CPU %d is switched to T%d\n",
 256                                   cpu, target_state);
 257                 break;
 258         default:
 259                 printk(KERN_WARNING
 260                         "Unsupported Throttling notifier event\n");
 261                 break;
 262         }
 263
 264         return 0;
 265 }
 266
 267 /*
 268  * _TPC - Throttling Present Capabilities
 269  */
 270 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 271 {
 272         acpi_status status = 0;
 273         unsigned long long tpc = 0;
 274
 275         if (!pr)
 276                 return -EINVAL;
 277
 278         if (ignore_tpc)
 279                 goto end;
 280
 281         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 282         if (ACPI_FAILURE(status)) {
 283                 if (status != AE_NOT_FOUND)
 284                         acpi_evaluation_failure_warn(pr->handle, "_TPC", status);
 285
 286                 return -ENODEV;
 287         }
 288
 289 end:
 290         pr->throttling_platform_limit = (int)tpc;
 291         return 0;
 292 }
 293
 294 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 295 {
 296         int result = 0;
 297         int throttling_limit;
 298         int current_state;
 299         struct acpi_processor_limit *limit;
 300         int target_state;
 301
 302         if (ignore_tpc)
 303                 return 0;
 304
 305         result = acpi_processor_get_platform_limit(pr);
 306         if (result) {
 307                 /* Throttling Limit is unsupported */
 308                 return result;
 309         }
 310
 311         throttling_limit = pr->throttling_platform_limit;
 312         if (throttling_limit >= pr->throttling.state_count) {
 313                 /* Uncorrect Throttling Limit */
 314                 return -EINVAL;
 315         }
 316
 317         current_state = pr->throttling.state;
 318         if (current_state > throttling_limit) {
 319                 /*
 320                  * The current state can meet the requirement of
 321                  * _TPC limit. But it is reasonable that OSPM changes
 322                  * t-states from high to low for better performance.
 323                  * Of course the limit condition of thermal
 324                  * and user should be considered.
 325                  */
 326                 limit = &pr->limit;
 327                 target_state = throttling_limit;
 328                 if (limit->thermal.tx > target_state)
 329                         target_state = limit->thermal.tx;
 330                 if (limit->user.tx > target_state)
 331                         target_state = limit->user.tx;
 332         } else if (current_state == throttling_limit) {
 333                 /*
 334                  * Unnecessary to change the throttling state
 335                  */
 336                 return 0;
 337         } else {
 338                 /*
 339                  * If the current state is lower than the limit of _TPC, it
 340                  * will be forced to switch to the throttling state defined
 341                  * by throttling_platfor_limit.
 342                  * Because the previous state meets with the limit condition
 343                  * of thermal and user, it is unnecessary to check it again.
 344                  */
 345                 target_state = throttling_limit;
 346         }
 347         return acpi_processor_set_throttling(pr, target_state, false);
 348 }
 349
 350 /*
 351  * This function is used to reevaluate whether the T-state is valid
 352  * after one CPU is onlined/offlined.
 353  * It is noted that it won't reevaluate the following properties for
 354  * the T-state.
 355  *      1. Control method.
 356  *      2. the number of supported T-state
 357  *      3. TSD domain
 358  */
 359 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 360                                         bool is_dead)
 361 {
 362         int result = 0;
 363
 364         if (is_dead) {
 365                 /* When one CPU is offline, the T-state throttling
 366                  * will be invalidated.
 367                  */
 368                 pr->flags.throttling = 0;
 369                 return;
 370         }
 371         /* the following is to recheck whether the T-state is valid for
 372          * the online CPU
 373          */
 374         if (!pr->throttling.state_count) {
 375                 /* If the number of T-state is invalid, it is
 376                  * invalidated.
 377                  */
 378                 pr->flags.throttling = 0;
 379                 return;
 380         }
 381         pr->flags.throttling = 1;
 382
 383         /* Disable throttling (if enabled).  We'll let subsequent
 384          * policy (e.g.thermal) decide to lower performance if it
 385          * so chooses, but for now we'll crank up the speed.
 386          */
 387
 388         result = acpi_processor_get_throttling(pr);
 389         if (result)
 390                 goto end;
 391
 392         if (pr->throttling.state) {
 393                 result = acpi_processor_set_throttling(pr, 0, false);
 394                 if (result)
 395                         goto end;
 396         }
 397
 398 end:
 399         if (result)
 400                 pr->flags.throttling = 0;
 401 }
 402 /*
 403  * _PTC - Processor Throttling Control (and status) register location
 404  */
 405 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 406 {
 407         int result = 0;
 408         acpi_status status = 0;
 409         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 410         union acpi_object *ptc = NULL;
 411         union acpi_object obj = { 0 };
 412         struct acpi_processor_throttling *throttling;
 413
 414         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 415         if (ACPI_FAILURE(status)) {
 416                 if (status != AE_NOT_FOUND)
 417                         acpi_evaluation_failure_warn(pr->handle, "_PTC", status);
 418
 419                 return -ENODEV;
 420         }
 421
 422         ptc = (union acpi_object *)buffer.pointer;
 423         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 424             || (ptc->package.count != 2)) {
 425                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 426                 result = -EFAULT;
 427                 goto end;
 428         }
 429
 430         /*
 431          * control_register
 432          */
 433
 434         obj = ptc->package.elements[0];
 435
 436         if ((obj.type != ACPI_TYPE_BUFFER)
 437             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 438             || (obj.buffer.pointer == NULL)) {
 439                 printk(KERN_ERR PREFIX
 440                        "Invalid _PTC data (control_register)\n");
 441                 result = -EFAULT;
 442                 goto end;
 443         }
 444         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 445                sizeof(struct acpi_ptc_register));
 446
 447         /*
 448          * status_register
 449          */
 450
 451         obj = ptc->package.elements[1];
 452
 453         if ((obj.type != ACPI_TYPE_BUFFER)
 454             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 455             || (obj.buffer.pointer == NULL)) {
 456                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 457                 result = -EFAULT;
 458                 goto end;
 459         }
 460
 461         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 462                sizeof(struct acpi_ptc_register));
 463
 464         throttling = &pr->throttling;
 465
 466         if ((throttling->control_register.bit_width +
 467                 throttling->control_register.bit_offset) > 32) {
 468                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 469                 result = -EFAULT;
 470                 goto end;
 471         }
 472
 473         if ((throttling->status_register.bit_width +
 474                 throttling->status_register.bit_offset) > 32) {
 475                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 476                 result = -EFAULT;
 477                 goto end;
 478         }
 479
 480       end:
 481         kfree(buffer.pointer);
 482
 483         return result;
 484 }
 485
 486 /*
 487  * _TSS - Throttling Supported States
 488  */
 489 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 490 {
 491         int result = 0;
 492         acpi_status status = AE_OK;
 493         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 494         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 495         struct acpi_buffer state = { 0, NULL };
 496         union acpi_object *tss = NULL;
 497         int i;
 498
 499         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 500         if (ACPI_FAILURE(status)) {
 501                 if (status != AE_NOT_FOUND)
 502                         acpi_evaluation_failure_warn(pr->handle, "_TSS", status);
 503
 504                 return -ENODEV;
 505         }
 506
 507         tss = buffer.pointer;
 508         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 509                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 510                 result = -EFAULT;
 511                 goto end;
 512         }
 513
 514         acpi_handle_debug(pr->handle, "Found %d throttling states\n",
 515                           tss->package.count);
 516
 517         pr->throttling.state_count = tss->package.count;
 518         pr->throttling.states_tss =
 519             kmalloc_array(tss->package.count,
 520                           sizeof(struct acpi_processor_tx_tss),
 521                           GFP_KERNEL);
 522         if (!pr->throttling.states_tss) {
 523                 result = -ENOMEM;
 524                 goto end;
 525         }
 526
 527         for (i = 0; i < pr->throttling.state_count; i++) {
 528
 529                 struct acpi_processor_tx_tss *tx =
 530                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 531                                                       states_tss[i]);
 532
 533                 state.length = sizeof(struct acpi_processor_tx_tss);
 534                 state.pointer = tx;
 535
 536                 acpi_handle_debug(pr->handle, "Extracting state %d\n", i);
 537
 538                 status = acpi_extract_package(&(tss->package.elements[i]),
 539                                               &format, &state);
 540                 if (ACPI_FAILURE(status)) {
 541                         acpi_handle_warn(pr->handle, "Invalid _TSS data: %s\n",
 542                                          acpi_format_exception(status));
 543                         result = -EFAULT;
 544                         kfree(pr->throttling.states_tss);
 545                         goto end;
 546                 }
 547
 548                 if (!tx->freqpercentage) {
 549                         printk(KERN_ERR PREFIX
 550                                "Invalid _TSS data: freq is zero\n");
 551                         result = -EFAULT;
 552                         kfree(pr->throttling.states_tss);
 553                         goto end;
 554                 }
 555         }
 556
 557       end:
 558         kfree(buffer.pointer);
 559
 560         return result;
 561 }
 562
 563 /*
 564  * _TSD - T-State Dependencies
 565  */
 566 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 567 {
 568         int result = 0;
 569         acpi_status status = AE_OK;
 570         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 571         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 572         struct acpi_buffer state = { 0, NULL };
 573         union acpi_object *tsd = NULL;
 574         struct acpi_tsd_package *pdomain;
 575         struct acpi_processor_throttling *pthrottling;
 576
 577         pthrottling = &pr->throttling;
 578         pthrottling->tsd_valid_flag = 0;
 579
 580         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 581         if (ACPI_FAILURE(status)) {
 582                 if (status != AE_NOT_FOUND)
 583                         acpi_evaluation_failure_warn(pr->handle, "_TSD", status);
 584
 585                 return -ENODEV;
 586         }
 587
 588         tsd = buffer.pointer;
 589         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 590                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 591                 result = -EFAULT;
 592                 goto end;
 593         }
 594
 595         if (tsd->package.count != 1) {
 596                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 597                 result = -EFAULT;
 598                 goto end;
 599         }
 600
 601         pdomain = &(pr->throttling.domain_info);
 602
 603         state.length = sizeof(struct acpi_tsd_package);
 604         state.pointer = pdomain;
 605
 606         status = acpi_extract_package(&(tsd->package.elements[0]),
 607                                       &format, &state);
 608         if (ACPI_FAILURE(status)) {
 609                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 610                 result = -EFAULT;
 611                 goto end;
 612         }
 613
 614         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 615                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 616                 result = -EFAULT;
 617                 goto end;
 618         }
 619
 620         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 621                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 622                 result = -EFAULT;
 623                 goto end;
 624         }
 625
 626         pthrottling = &pr->throttling;
 627         pthrottling->tsd_valid_flag = 1;
 628         pthrottling->shared_type = pdomain->coord_type;
 629         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 630         /*
 631          * If the coordination type is not defined in ACPI spec,
 632          * the tsd_valid_flag will be clear and coordination type
 633          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 634          */
 635         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 636                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 637                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 638                 pthrottling->tsd_valid_flag = 0;
 639                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 640         }
 641
 642       end:
 643         kfree(buffer.pointer);
 644         return result;
 645 }
 646
 647 /* --------------------------------------------------------------------------
 648                               Throttling Control
 649    -------------------------------------------------------------------------- */
 650 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 651 {
 652         int state = 0;
 653         u32 value = 0;
 654         u32 duty_mask = 0;
 655         u32 duty_value = 0;
 656
 657         if (!pr)
 658                 return -EINVAL;
 659
 660         if (!pr->flags.throttling)
 661                 return -ENODEV;
 662
 663         /*
 664          * We don't care about error returns - we just try to mark
 665          * these reserved so that nobody else is confused into thinking
 666          * that this region might be unused..
 667          *
 668          * (In particular, allocating the IO range for Cardbus)
 669          */
 670         request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 671
 672         pr->throttling.state = 0;
 673
 674         duty_mask = pr->throttling.state_count - 1;
 675
 676         duty_mask <<= pr->throttling.duty_offset;
 677
 678         local_irq_disable();
 679
 680         value = inl(pr->throttling.address);
 681
 682         /*
 683          * Compute the current throttling state when throttling is enabled
 684          * (bit 4 is on).
 685          */
 686         if (value & 0x10) {
 687                 duty_value = value & duty_mask;
 688                 duty_value >>= pr->throttling.duty_offset;
 689
 690                 if (duty_value)
 691                         state = pr->throttling.state_count - duty_value;
 692         }
 693
 694         pr->throttling.state = state;
 695
 696         local_irq_enable();
 697
 698         acpi_handle_debug(pr->handle,
 699                           "Throttling state is T%d (%d%% throttling applied)\n",
 700                           state, pr->throttling.states[state].performance);
 701
 702         return 0;
 703 }
 704
 705 #ifdef CONFIG_X86
 706 static int acpi_throttling_rdmsr(u64 *value)
 707 {
 708         u64 msr_high, msr_low;
 709         u64 msr = 0;
 710         int ret = -1;
 711
 712         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 713                 !this_cpu_has(X86_FEATURE_ACPI)) {
 714                 printk(KERN_ERR PREFIX
 715                         "HARDWARE addr space,NOT supported yet\n");
 716         } else {
 717                 msr_low = 0;
 718                 msr_high = 0;
 719                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 720                         (u32 *)&msr_low , (u32 *) &msr_high);
 721                 msr = (msr_high << 32) | msr_low;
 722                 *value = (u64) msr;
 723                 ret = 0;
 724         }
 725         return ret;
 726 }
 727
 728 static int acpi_throttling_wrmsr(u64 value)
 729 {
 730         int ret = -1;
 731         u64 msr;
 732
 733         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 734                 !this_cpu_has(X86_FEATURE_ACPI)) {
 735                 printk(KERN_ERR PREFIX
 736                         "HARDWARE addr space,NOT supported yet\n");
 737         } else {
 738                 msr = value;
 739                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 740                         msr & 0xffffffff, msr >> 32);
 741                 ret = 0;
 742         }
 743         return ret;
 744 }
 745 #else
 746 static int acpi_throttling_rdmsr(u64 *value)
 747 {
 748         printk(KERN_ERR PREFIX
 749                 "HARDWARE addr space,NOT supported yet\n");
 750         return -1;
 751 }
 752
 753 static int acpi_throttling_wrmsr(u64 value)
 754 {
 755         printk(KERN_ERR PREFIX
 756                 "HARDWARE addr space,NOT supported yet\n");
 757         return -1;
 758 }
 759 #endif
 760
 761 static int acpi_read_throttling_status(struct acpi_processor *pr,
 762                                         u64 *value)
 763 {
 764         u32 bit_width, bit_offset;
 765         u32 ptc_value;
 766         u64 ptc_mask;
 767         struct acpi_processor_throttling *throttling;
 768         int ret = -1;
 769
 770         throttling = &pr->throttling;
 771         switch (throttling->status_register.space_id) {
 772         case ACPI_ADR_SPACE_SYSTEM_IO:
 773                 bit_width = throttling->status_register.bit_width;
 774                 bit_offset = throttling->status_register.bit_offset;
 775
 776                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 777                                   address, &ptc_value,
 778                                   (u32) (bit_width + bit_offset));
 779                 ptc_mask = (1 << bit_width) - 1;
 780                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 781                 ret = 0;
 782                 break;
 783         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 784                 ret = acpi_throttling_rdmsr(value);
 785                 break;
 786         default:
 787                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 788                        (u32) (throttling->status_register.space_id));
 789         }
 790         return ret;
 791 }
 792
 793 static int acpi_write_throttling_state(struct acpi_processor *pr,
 794                                 u64 value)
 795 {
 796         u32 bit_width, bit_offset;
 797         u64 ptc_value;
 798         u64 ptc_mask;
 799         struct acpi_processor_throttling *throttling;
 800         int ret = -1;
 801
 802         throttling = &pr->throttling;
 803         switch (throttling->control_register.space_id) {
 804         case ACPI_ADR_SPACE_SYSTEM_IO:
 805                 bit_width = throttling->control_register.bit_width;
 806                 bit_offset = throttling->control_register.bit_offset;
 807                 ptc_mask = (1 << bit_width) - 1;
 808                 ptc_value = value & ptc_mask;
 809
 810                 acpi_os_write_port((acpi_io_address) throttling->
 811                                         control_register.address,
 812                                         (u32) (ptc_value << bit_offset),
 813                                         (u32) (bit_width + bit_offset));
 814                 ret = 0;
 815                 break;
 816         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 817                 ret = acpi_throttling_wrmsr(value);
 818                 break;
 819         default:
 820                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 821                        (u32) (throttling->control_register.space_id));
 822         }
 823         return ret;
 824 }
 825
 826 static int acpi_get_throttling_state(struct acpi_processor *pr,
 827                                 u64 value)
 828 {
 829         int i;
 830
 831         for (i = 0; i < pr->throttling.state_count; i++) {
 832                 struct acpi_processor_tx_tss *tx =
 833                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 834                                                       states_tss[i]);
 835                 if (tx->control == value)
 836                         return i;
 837         }
 838         return -1;
 839 }
 840
 841 static int acpi_get_throttling_value(struct acpi_processor *pr,
 842                         int state, u64 *value)
 843 {
 844         int ret = -1;
 845
 846         if (state >= 0 && state <= pr->throttling.state_count) {
 847                 struct acpi_processor_tx_tss *tx =
 848                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 849                                                       states_tss[state]);
 850                 *value = tx->control;
 851                 ret = 0;
 852         }
 853         return ret;
 854 }
 855
 856 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 857 {
 858         int state = 0;
 859         int ret;
 860         u64 value;
 861
 862         if (!pr)
 863                 return -EINVAL;
 864
 865         if (!pr->flags.throttling)
 866                 return -ENODEV;
 867
 868         pr->throttling.state = 0;
 869
 870         value = 0;
 871         ret = acpi_read_throttling_status(pr, &value);
 872         if (ret >= 0) {
 873                 state = acpi_get_throttling_state(pr, value);
 874                 if (state == -1) {
 875                         acpi_handle_debug(pr->handle,
 876                                           "Invalid throttling state, reset\n");
 877                         state = 0;
 878                         ret = __acpi_processor_set_throttling(pr, state, true,
 879                                                               true);
 880                         if (ret)
 881                                 return ret;
 882                 }
 883                 pr->throttling.state = state;
 884         }
 885
 886         return 0;
 887 }
 888
 889 static long __acpi_processor_get_throttling(void *data)
 890 {
 891         struct acpi_processor *pr = data;
 892
 893         return pr->throttling.acpi_processor_get_throttling(pr);
 894 }
 895
 896 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 897 {
 898         if (!pr)
 899                 return -EINVAL;
 900
 901         if (!pr->flags.throttling)
 902                 return -ENODEV;
 903
 904         /*
 905          * This is either called from the CPU hotplug callback of
 906          * processor_driver or via the ACPI probe function. In the latter
 907          * case the CPU is not guaranteed to be online. Both call sites are
 908          * protected against CPU hotplug.
 909          */
 910         if (!cpu_online(pr->id))
 911                 return -ENODEV;
 912
 913         return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false);
 914 }
 915
 916 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 917 {
 918         int i, step;
 919
 920         if (!pr->throttling.address) {
 921                 acpi_handle_debug(pr->handle, "No throttling register\n");
 922                 return -EINVAL;
 923         } else if (!pr->throttling.duty_width) {
 924                 acpi_handle_debug(pr->handle, "No throttling states\n");
 925                 return -EINVAL;
 926         }
 927         /* TBD: Support duty_cycle values that span bit 4. */
 928         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 929                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 930                 return -EINVAL;
 931         }
 932
 933         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 934
 935         /*
 936          * Compute state values. Note that throttling displays a linear power
 937          * performance relationship (at 50% performance the CPU will consume
 938          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 939          */
 940
 941         step = (1000 / pr->throttling.state_count);
 942
 943         for (i = 0; i < pr->throttling.state_count; i++) {
 944                 pr->throttling.states[i].performance = 1000 - step * i;
 945                 pr->throttling.states[i].power = 1000 - step * i;
 946         }
 947         return 0;
 948 }
 949
 950 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 951                                               int state, bool force)
 952 {
 953         u32 value = 0;
 954         u32 duty_mask = 0;
 955         u32 duty_value = 0;
 956
 957         if (!pr)
 958                 return -EINVAL;
 959
 960         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 961                 return -EINVAL;
 962
 963         if (!pr->flags.throttling)
 964                 return -ENODEV;
 965
 966         if (!force && (state == pr->throttling.state))
 967                 return 0;
 968
 969         if (state < pr->throttling_platform_limit)
 970                 return -EPERM;
 971         /*
 972          * Calculate the duty_value and duty_mask.
 973          */
 974         if (state) {
 975                 duty_value = pr->throttling.state_count - state;
 976
 977                 duty_value <<= pr->throttling.duty_offset;
 978
 979                 /* Used to clear all duty_value bits */
 980                 duty_mask = pr->throttling.state_count - 1;
 981
 982                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 983                 duty_mask = ~duty_mask;
 984         }
 985
 986         local_irq_disable();
 987
 988         /*
 989          * Disable throttling by writing a 0 to bit 4.  Note that we must
 990          * turn it off before you can change the duty_value.
 991          */
 992         value = inl(pr->throttling.address);
 993         if (value & 0x10) {
 994                 value &= 0xFFFFFFEF;
 995                 outl(value, pr->throttling.address);
 996         }
 997
 998         /*
 999          * Write the new duty_value and then enable throttling.  Note
1000          * that a state value of 0 leaves throttling disabled.
1001          */
1002         if (state) {
1003                 value &= duty_mask;
1004                 value |= duty_value;
1005                 outl(value, pr->throttling.address);
1006
1007                 value |= 0x00000010;
1008                 outl(value, pr->throttling.address);
1009         }
1010
1011         pr->throttling.state = state;
1012
1013         local_irq_enable();
1014
1015         acpi_handle_debug(pr->handle,
1016                           "Throttling state set to T%d (%d%%)\n", state,
1017                           (pr->throttling.states[state].performance ? pr->
1018                            throttling.states[state].performance / 10 : 0));
1019
1020         return 0;
1021 }
1022
1023 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1024                                              int state, bool force)
1025 {
1026         int ret;
1027         u64 value;
1028
1029         if (!pr)
1030                 return -EINVAL;
1031
1032         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1033                 return -EINVAL;
1034
1035         if (!pr->flags.throttling)
1036                 return -ENODEV;
1037
1038         if (!force && (state == pr->throttling.state))
1039                 return 0;
1040
1041         if (state < pr->throttling_platform_limit)
1042                 return -EPERM;
1043
1044         value = 0;
1045         ret = acpi_get_throttling_value(pr, state, &value);
1046         if (ret >= 0) {
1047                 acpi_write_throttling_state(pr, value);
1048                 pr->throttling.state = state;
1049         }
1050
1051         return 0;
1052 }
1053
1054 static long acpi_processor_throttling_fn(void *data)
1055 {
1056         struct acpi_processor_throttling_arg *arg = data;
1057         struct acpi_processor *pr = arg->pr;
1058
1059         return pr->throttling.acpi_processor_set_throttling(pr,
1060                         arg->target_state, arg->force);
1061 }
1062
1063 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
1064                                            int state, bool force, bool direct)
1065 {
1066         int ret = 0;
1067         unsigned int i;
1068         struct acpi_processor *match_pr;
1069         struct acpi_processor_throttling *p_throttling;
1070         struct acpi_processor_throttling_arg arg;
1071         struct throttling_tstate t_state;
1072
1073         if (!pr)
1074                 return -EINVAL;
1075
1076         if (!pr->flags.throttling)
1077                 return -ENODEV;
1078
1079         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1080                 return -EINVAL;
1081
1082         if (cpu_is_offline(pr->id)) {
1083                 /*
1084                  * the cpu pointed by pr->id is offline. Unnecessary to change
1085                  * the throttling state any more.
1086                  */
1087                 return -ENODEV;
1088         }
1089
1090         t_state.target_state = state;
1091         p_throttling = &(pr->throttling);
1092
1093         /*
1094          * The throttling notifier will be called for every
1095          * affected cpu in order to get one proper T-state.
1096          * The notifier event is THROTTLING_PRECHANGE.
1097          */
1098         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1099                 t_state.cpu = i;
1100                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1101                                                         &t_state);
1102         }
1103         /*
1104          * The function of acpi_processor_set_throttling will be called
1105          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1106          * it is necessary to call it for every affected cpu. Otherwise
1107          * it can be called only for the cpu pointed by pr.
1108          */
1109         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1110                 arg.pr = pr;
1111                 arg.target_state = state;
1112                 arg.force = force;
1113                 ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
1114                                   direct);
1115         } else {
1116                 /*
1117                  * When the T-state coordination is SW_ALL or HW_ALL,
1118                  * it is necessary to set T-state for every affected
1119                  * cpus.
1120                  */
1121                 for_each_cpu_and(i, cpu_online_mask,
1122                     p_throttling->shared_cpu_map) {
1123                         match_pr = per_cpu(processors, i);
1124                         /*
1125                          * If the pointer is invalid, we will report the
1126                          * error message and continue.
1127                          */
1128                         if (!match_pr) {
1129                                 acpi_handle_debug(pr->handle,
1130                                         "Invalid Pointer for CPU %d\n", i);
1131                                 continue;
1132                         }
1133                         /*
1134                          * If the throttling control is unsupported on CPU i,
1135                          * we will report the error message and continue.
1136                          */
1137                         if (!match_pr->flags.throttling) {
1138                                 acpi_handle_debug(pr->handle,
1139                                         "Throttling Control unsupported on CPU %d\n", i);
1140                                 continue;
1141                         }
1142
1143                         arg.pr = match_pr;
1144                         arg.target_state = state;
1145                         arg.force = force;
1146                         ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
1147                                           &arg, direct);
1148                 }
1149         }
1150         /*
1151          * After the set_throttling is called, the
1152          * throttling notifier is called for every
1153          * affected cpu to update the T-states.
1154          * The notifier event is THROTTLING_POSTCHANGE
1155          */
1156         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1157                 t_state.cpu = i;
1158                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1159                                                         &t_state);
1160         }
1161
1162         return ret;
1163 }
1164
1165 int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
1166                                   bool force)
1167 {
1168         return __acpi_processor_set_throttling(pr, state, force, false);
1169 }
1170
1171 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1172 {
1173         int result = 0;
1174         struct acpi_processor_throttling *pthrottling;
1175
1176         acpi_handle_debug(pr->handle,
1177                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1178                           pr->throttling.address,
1179                           pr->throttling.duty_offset,
1180                           pr->throttling.duty_width);
1181
1182         /*
1183          * Evaluate _PTC, _TSS and _TPC
1184          * They must all be present or none of them can be used.
1185          */
1186         if (acpi_processor_get_throttling_control(pr) ||
1187                 acpi_processor_get_throttling_states(pr) ||
1188                 acpi_processor_get_platform_limit(pr))
1189         {
1190                 pr->throttling.acpi_processor_get_throttling =
1191                     &acpi_processor_get_throttling_fadt;
1192                 pr->throttling.acpi_processor_set_throttling =
1193                     &acpi_processor_set_throttling_fadt;
1194                 if (acpi_processor_get_fadt_info(pr))
1195                         return 0;
1196         } else {
1197                 pr->throttling.acpi_processor_get_throttling =
1198                     &acpi_processor_get_throttling_ptc;
1199                 pr->throttling.acpi_processor_set_throttling =
1200                     &acpi_processor_set_throttling_ptc;
1201         }
1202
1203         /*
1204          * If TSD package for one CPU can't be parsed successfully, it means
1205          * that this CPU will have no coordination with other CPUs.
1206          */
1207         if (acpi_processor_get_tsd(pr)) {
1208                 pthrottling = &pr->throttling;
1209                 pthrottling->tsd_valid_flag = 0;
1210                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1211                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1212         }
1213
1214         /*
1215          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1216          * This shouldn't be an issue as few (if any) mobile systems ever
1217          * used this part.
1218          */
1219         if (errata.piix4.throttle) {
1220                 acpi_handle_debug(pr->handle,
1221                                   "Throttling not supported on PIIX4 A- or B-step\n");
1222                 return 0;
1223         }
1224
1225         acpi_handle_debug(pr->handle, "Found %d throttling states\n",
1226                           pr->throttling.state_count);
1227
1228         pr->flags.throttling = 1;
1229
1230         /*
1231          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1232          * thermal) decide to lower performance if it so chooses, but for now
1233          * we'll crank up the speed.
1234          */
1235
1236         result = acpi_processor_get_throttling(pr);
1237         if (result)
1238                 goto end;
1239
1240         if (pr->throttling.state) {
1241                 acpi_handle_debug(pr->handle,
1242                                   "Disabling throttling (was T%d)\n",
1243                                   pr->throttling.state);
1244                 result = acpi_processor_set_throttling(pr, 0, false);
1245                 if (result)
1246                         goto end;
1247         }
1248
1249       end:
1250         if (result)
1251                 pr->flags.throttling = 0;
1252
1253         return result;
1254 }
1255