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 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  26 ACPI_MODULE_NAME("processor_throttling");
  27
  28 /* ignore_tpc:
  29  *  0 -> acpi processor driver doesn't ignore _TPC values
  30  *  1 -> acpi processor driver ignores _TPC values
  31  */
  32 static int ignore_tpc;
  33 module_param(ignore_tpc, int, 0644);
  34 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  35
  36 struct throttling_tstate {
  37         unsigned int cpu;               /* cpu nr */
  38         int target_state;               /* target T-state */
  39 };
  40
  41 struct acpi_processor_throttling_arg {
  42         struct acpi_processor *pr;
  43         int target_state;
  44         bool force;
  45 };
  46
  47 #define THROTTLING_PRECHANGE       (1)
  48 #define THROTTLING_POSTCHANGE      (2)
  49
  50 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  51 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
  52                                            int state, bool force, bool direct);
  53
  54 static int acpi_processor_update_tsd_coord(void)
  55 {
  56         int count, count_target;
  57         int retval = 0;
  58         unsigned int i, j;
  59         cpumask_var_t covered_cpus;
  60         struct acpi_processor *pr, *match_pr;
  61         struct acpi_tsd_package *pdomain, *match_pdomain;
  62         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  63
  64         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  65                 return -ENOMEM;
  66
  67         /*
  68          * Now that we have _TSD data from all CPUs, lets setup T-state
  69          * coordination between all CPUs.
  70          */
  71         for_each_possible_cpu(i) {
  72                 pr = per_cpu(processors, i);
  73                 if (!pr)
  74                         continue;
  75
  76                 /* Basic validity check for domain info */
  77                 pthrottling = &(pr->throttling);
  78
  79                 /*
  80                  * If tsd package for one cpu is invalid, the coordination
  81                  * among all CPUs is thought as invalid.
  82                  * Maybe it is ugly.
  83                  */
  84                 if (!pthrottling->tsd_valid_flag) {
  85                         retval = -EINVAL;
  86                         break;
  87                 }
  88         }
  89         if (retval)
  90                 goto err_ret;
  91
  92         for_each_possible_cpu(i) {
  93                 pr = per_cpu(processors, i);
  94                 if (!pr)
  95                         continue;
  96
  97                 if (cpumask_test_cpu(i, covered_cpus))
  98                         continue;
  99                 pthrottling = &pr->throttling;
 100
 101                 pdomain = &(pthrottling->domain_info);
 102                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 103                 cpumask_set_cpu(i, covered_cpus);
 104                 /*
 105                  * If the number of processor in the TSD domain is 1, it is
 106                  * unnecessary to parse the coordination for this CPU.
 107                  */
 108                 if (pdomain->num_processors <= 1)
 109                         continue;
 110
 111                 /* Validate the Domain info */
 112                 count_target = pdomain->num_processors;
 113                 count = 1;
 114
 115                 for_each_possible_cpu(j) {
 116                         if (i == j)
 117                                 continue;
 118
 119                         match_pr = per_cpu(processors, j);
 120                         if (!match_pr)
 121                                 continue;
 122
 123                         match_pthrottling = &(match_pr->throttling);
 124                         match_pdomain = &(match_pthrottling->domain_info);
 125                         if (match_pdomain->domain != pdomain->domain)
 126                                 continue;
 127
 128                         /* Here i and j are in the same domain.
 129                          * If two TSD packages have the same domain, they
 130                          * should have the same num_porcessors and
 131                          * coordination type. Otherwise it will be regarded
 132                          * as illegal.
 133                          */
 134                         if (match_pdomain->num_processors != count_target) {
 135                                 retval = -EINVAL;
 136                                 goto err_ret;
 137                         }
 138
 139                         if (pdomain->coord_type != match_pdomain->coord_type) {
 140                                 retval = -EINVAL;
 141                                 goto err_ret;
 142                         }
 143
 144                         cpumask_set_cpu(j, covered_cpus);
 145                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 146                         count++;
 147                 }
 148                 for_each_possible_cpu(j) {
 149                         if (i == j)
 150                                 continue;
 151
 152                         match_pr = per_cpu(processors, j);
 153                         if (!match_pr)
 154                                 continue;
 155
 156                         match_pthrottling = &(match_pr->throttling);
 157                         match_pdomain = &(match_pthrottling->domain_info);
 158                         if (match_pdomain->domain != pdomain->domain)
 159                                 continue;
 160
 161                         /*
 162                          * If some CPUS have the same domain, they
 163                          * will have the same shared_cpu_map.
 164                          */
 165                         cpumask_copy(match_pthrottling->shared_cpu_map,
 166                                      pthrottling->shared_cpu_map);
 167                 }
 168         }
 169
 170 err_ret:
 171         free_cpumask_var(covered_cpus);
 172
 173         for_each_possible_cpu(i) {
 174                 pr = per_cpu(processors, i);
 175                 if (!pr)
 176                         continue;
 177
 178                 /*
 179                  * Assume no coordination on any error parsing domain info.
 180                  * The coordination type will be forced as SW_ALL.
 181                  */
 182                 if (retval) {
 183                         pthrottling = &(pr->throttling);
 184                         cpumask_clear(pthrottling->shared_cpu_map);
 185                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 186                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 187                 }
 188         }
 189
 190         return retval;
 191 }
 192
 193 /*
 194  * Update the T-state coordination after the _TSD
 195  * data for all cpus is obtained.
 196  */
 197 void acpi_processor_throttling_init(void)
 198 {
 199         if (acpi_processor_update_tsd_coord()) {
 200                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 201                         "Assume no T-state coordination\n"));
 202         }
 203
 204         return;
 205 }
 206
 207 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 208 {
 209         struct throttling_tstate *p_tstate = data;
 210         struct acpi_processor *pr;
 211         unsigned int cpu ;
 212         int target_state;
 213         struct acpi_processor_limit *p_limit;
 214         struct acpi_processor_throttling *p_throttling;
 215
 216         cpu = p_tstate->cpu;
 217         pr = per_cpu(processors, cpu);
 218         if (!pr) {
 219                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 220                 return 0;
 221         }
 222         if (!pr->flags.throttling) {
 223                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 224                                 "unsupported on CPU %d\n", cpu));
 225                 return 0;
 226         }
 227         target_state = p_tstate->target_state;
 228         p_throttling = &(pr->throttling);
 229         switch (event) {
 230         case THROTTLING_PRECHANGE:
 231                 /*
 232                  * Prechange event is used to choose one proper t-state,
 233                  * which meets the limits of thermal, user and _TPC.
 234                  */
 235                 p_limit = &pr->limit;
 236                 if (p_limit->thermal.tx > target_state)
 237                         target_state = p_limit->thermal.tx;
 238                 if (p_limit->user.tx > target_state)
 239                         target_state = p_limit->user.tx;
 240                 if (pr->throttling_platform_limit > target_state)
 241                         target_state = pr->throttling_platform_limit;
 242                 if (target_state >= p_throttling->state_count) {
 243                         printk(KERN_WARNING
 244                                 "Exceed the limit of T-state \n");
 245                         target_state = p_throttling->state_count - 1;
 246                 }
 247                 p_tstate->target_state = target_state;
 248                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 249                                 "target T-state of CPU %d is T%d\n",
 250                                 cpu, target_state));
 251                 break;
 252         case THROTTLING_POSTCHANGE:
 253                 /*
 254                  * Postchange event is only used to update the
 255                  * T-state flag of acpi_processor_throttling.
 256                  */
 257                 p_throttling->state = target_state;
 258                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 259                                 "CPU %d is switched to T%d\n",
 260                                 cpu, target_state));
 261                 break;
 262         default:
 263                 printk(KERN_WARNING
 264                         "Unsupported Throttling notifier event\n");
 265                 break;
 266         }
 267
 268         return 0;
 269 }
 270
 271 /*
 272  * _TPC - Throttling Present Capabilities
 273  */
 274 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 275 {
 276         acpi_status status = 0;
 277         unsigned long long tpc = 0;
 278
 279         if (!pr)
 280                 return -EINVAL;
 281
 282         if (ignore_tpc)
 283                 goto end;
 284
 285         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 286         if (ACPI_FAILURE(status)) {
 287                 if (status != AE_NOT_FOUND) {
 288                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 289                 }
 290                 return -ENODEV;
 291         }
 292
 293 end:
 294         pr->throttling_platform_limit = (int)tpc;
 295         return 0;
 296 }
 297
 298 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 299 {
 300         int result = 0;
 301         int throttling_limit;
 302         int current_state;
 303         struct acpi_processor_limit *limit;
 304         int target_state;
 305
 306         if (ignore_tpc)
 307                 return 0;
 308
 309         result = acpi_processor_get_platform_limit(pr);
 310         if (result) {
 311                 /* Throttling Limit is unsupported */
 312                 return result;
 313         }
 314
 315         throttling_limit = pr->throttling_platform_limit;
 316         if (throttling_limit >= pr->throttling.state_count) {
 317                 /* Uncorrect Throttling Limit */
 318                 return -EINVAL;
 319         }
 320
 321         current_state = pr->throttling.state;
 322         if (current_state > throttling_limit) {
 323                 /*
 324                  * The current state can meet the requirement of
 325                  * _TPC limit. But it is reasonable that OSPM changes
 326                  * t-states from high to low for better performance.
 327                  * Of course the limit condition of thermal
 328                  * and user should be considered.
 329                  */
 330                 limit = &pr->limit;
 331                 target_state = throttling_limit;
 332                 if (limit->thermal.tx > target_state)
 333                         target_state = limit->thermal.tx;
 334                 if (limit->user.tx > target_state)
 335                         target_state = limit->user.tx;
 336         } else if (current_state == throttling_limit) {
 337                 /*
 338                  * Unnecessary to change the throttling state
 339                  */
 340                 return 0;
 341         } else {
 342                 /*
 343                  * If the current state is lower than the limit of _TPC, it
 344                  * will be forced to switch to the throttling state defined
 345                  * by throttling_platfor_limit.
 346                  * Because the previous state meets with the limit condition
 347                  * of thermal and user, it is unnecessary to check it again.
 348                  */
 349                 target_state = throttling_limit;
 350         }
 351         return acpi_processor_set_throttling(pr, target_state, false);
 352 }
 353
 354 /*
 355  * This function is used to reevaluate whether the T-state is valid
 356  * after one CPU is onlined/offlined.
 357  * It is noted that it won't reevaluate the following properties for
 358  * the T-state.
 359  *      1. Control method.
 360  *      2. the number of supported T-state
 361  *      3. TSD domain
 362  */
 363 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 364                                         bool is_dead)
 365 {
 366         int result = 0;
 367
 368         if (is_dead) {
 369                 /* When one CPU is offline, the T-state throttling
 370                  * will be invalidated.
 371                  */
 372                 pr->flags.throttling = 0;
 373                 return;
 374         }
 375         /* the following is to recheck whether the T-state is valid for
 376          * the online CPU
 377          */
 378         if (!pr->throttling.state_count) {
 379                 /* If the number of T-state is invalid, it is
 380                  * invalidated.
 381                  */
 382                 pr->flags.throttling = 0;
 383                 return;
 384         }
 385         pr->flags.throttling = 1;
 386
 387         /* Disable throttling (if enabled).  We'll let subsequent
 388          * policy (e.g.thermal) decide to lower performance if it
 389          * so chooses, but for now we'll crank up the speed.
 390          */
 391
 392         result = acpi_processor_get_throttling(pr);
 393         if (result)
 394                 goto end;
 395
 396         if (pr->throttling.state) {
 397                 result = acpi_processor_set_throttling(pr, 0, false);
 398                 if (result)
 399                         goto end;
 400         }
 401
 402 end:
 403         if (result)
 404                 pr->flags.throttling = 0;
 405 }
 406 /*
 407  * _PTC - Processor Throttling Control (and status) register location
 408  */
 409 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 410 {
 411         int result = 0;
 412         acpi_status status = 0;
 413         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 414         union acpi_object *ptc = NULL;
 415         union acpi_object obj = { 0 };
 416         struct acpi_processor_throttling *throttling;
 417
 418         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 419         if (ACPI_FAILURE(status)) {
 420                 if (status != AE_NOT_FOUND) {
 421                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 422                 }
 423                 return -ENODEV;
 424         }
 425
 426         ptc = (union acpi_object *)buffer.pointer;
 427         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 428             || (ptc->package.count != 2)) {
 429                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 430                 result = -EFAULT;
 431                 goto end;
 432         }
 433
 434         /*
 435          * control_register
 436          */
 437
 438         obj = ptc->package.elements[0];
 439
 440         if ((obj.type != ACPI_TYPE_BUFFER)
 441             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 442             || (obj.buffer.pointer == NULL)) {
 443                 printk(KERN_ERR PREFIX
 444                        "Invalid _PTC data (control_register)\n");
 445                 result = -EFAULT;
 446                 goto end;
 447         }
 448         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 449                sizeof(struct acpi_ptc_register));
 450
 451         /*
 452          * status_register
 453          */
 454
 455         obj = ptc->package.elements[1];
 456
 457         if ((obj.type != ACPI_TYPE_BUFFER)
 458             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 459             || (obj.buffer.pointer == NULL)) {
 460                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 461                 result = -EFAULT;
 462                 goto end;
 463         }
 464
 465         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 466                sizeof(struct acpi_ptc_register));
 467
 468         throttling = &pr->throttling;
 469
 470         if ((throttling->control_register.bit_width +
 471                 throttling->control_register.bit_offset) > 32) {
 472                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 473                 result = -EFAULT;
 474                 goto end;
 475         }
 476
 477         if ((throttling->status_register.bit_width +
 478                 throttling->status_register.bit_offset) > 32) {
 479                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 480                 result = -EFAULT;
 481                 goto end;
 482         }
 483
 484       end:
 485         kfree(buffer.pointer);
 486
 487         return result;
 488 }
 489
 490 /*
 491  * _TSS - Throttling Supported States
 492  */
 493 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 494 {
 495         int result = 0;
 496         acpi_status status = AE_OK;
 497         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 498         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 499         struct acpi_buffer state = { 0, NULL };
 500         union acpi_object *tss = NULL;
 501         int i;
 502
 503         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 504         if (ACPI_FAILURE(status)) {
 505                 if (status != AE_NOT_FOUND) {
 506                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 507                 }
 508                 return -ENODEV;
 509         }
 510
 511         tss = buffer.pointer;
 512         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 513                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 514                 result = -EFAULT;
 515                 goto end;
 516         }
 517
 518         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 519                           tss->package.count));
 520
 521         pr->throttling.state_count = tss->package.count;
 522         pr->throttling.states_tss =
 523             kmalloc_array(tss->package.count,
 524                           sizeof(struct acpi_processor_tx_tss),
 525                           GFP_KERNEL);
 526         if (!pr->throttling.states_tss) {
 527                 result = -ENOMEM;
 528                 goto end;
 529         }
 530
 531         for (i = 0; i < pr->throttling.state_count; i++) {
 532
 533                 struct acpi_processor_tx_tss *tx =
 534                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 535                                                       states_tss[i]);
 536
 537                 state.length = sizeof(struct acpi_processor_tx_tss);
 538                 state.pointer = tx;
 539
 540                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 541
 542                 status = acpi_extract_package(&(tss->package.elements[i]),
 543                                               &format, &state);
 544                 if (ACPI_FAILURE(status)) {
 545                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 546                         result = -EFAULT;
 547                         kfree(pr->throttling.states_tss);
 548                         goto end;
 549                 }
 550
 551                 if (!tx->freqpercentage) {
 552                         printk(KERN_ERR PREFIX
 553                                "Invalid _TSS data: freq is zero\n");
 554                         result = -EFAULT;
 555                         kfree(pr->throttling.states_tss);
 556                         goto end;
 557                 }
 558         }
 559
 560       end:
 561         kfree(buffer.pointer);
 562
 563         return result;
 564 }
 565
 566 /*
 567  * _TSD - T-State Dependencies
 568  */
 569 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 570 {
 571         int result = 0;
 572         acpi_status status = AE_OK;
 573         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 574         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 575         struct acpi_buffer state = { 0, NULL };
 576         union acpi_object *tsd = NULL;
 577         struct acpi_tsd_package *pdomain;
 578         struct acpi_processor_throttling *pthrottling;
 579
 580         pthrottling = &pr->throttling;
 581         pthrottling->tsd_valid_flag = 0;
 582
 583         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 584         if (ACPI_FAILURE(status)) {
 585                 if (status != AE_NOT_FOUND) {
 586                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 587                 }
 588                 return -ENODEV;
 589         }
 590
 591         tsd = buffer.pointer;
 592         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 593                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 594                 result = -EFAULT;
 595                 goto end;
 596         }
 597
 598         if (tsd->package.count != 1) {
 599                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 600                 result = -EFAULT;
 601                 goto end;
 602         }
 603
 604         pdomain = &(pr->throttling.domain_info);
 605
 606         state.length = sizeof(struct acpi_tsd_package);
 607         state.pointer = pdomain;
 608
 609         status = acpi_extract_package(&(tsd->package.elements[0]),
 610                                       &format, &state);
 611         if (ACPI_FAILURE(status)) {
 612                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 613                 result = -EFAULT;
 614                 goto end;
 615         }
 616
 617         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 618                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 619                 result = -EFAULT;
 620                 goto end;
 621         }
 622
 623         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 624                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 625                 result = -EFAULT;
 626                 goto end;
 627         }
 628
 629         pthrottling = &pr->throttling;
 630         pthrottling->tsd_valid_flag = 1;
 631         pthrottling->shared_type = pdomain->coord_type;
 632         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 633         /*
 634          * If the coordination type is not defined in ACPI spec,
 635          * the tsd_valid_flag will be clear and coordination type
 636          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 637          */
 638         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 639                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 640                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 641                 pthrottling->tsd_valid_flag = 0;
 642                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 643         }
 644
 645       end:
 646         kfree(buffer.pointer);
 647         return result;
 648 }
 649
 650 /* --------------------------------------------------------------------------
 651                               Throttling Control
 652    -------------------------------------------------------------------------- */
 653 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 654 {
 655         int state = 0;
 656         u32 value = 0;
 657         u32 duty_mask = 0;
 658         u32 duty_value = 0;
 659
 660         if (!pr)
 661                 return -EINVAL;
 662
 663         if (!pr->flags.throttling)
 664                 return -ENODEV;
 665
 666         /*
 667          * We don't care about error returns - we just try to mark
 668          * these reserved so that nobody else is confused into thinking
 669          * that this region might be unused..
 670          *
 671          * (In particular, allocating the IO range for Cardbus)
 672          */
 673         request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 674
 675         pr->throttling.state = 0;
 676
 677         duty_mask = pr->throttling.state_count - 1;
 678
 679         duty_mask <<= pr->throttling.duty_offset;
 680
 681         local_irq_disable();
 682
 683         value = inl(pr->throttling.address);
 684
 685         /*
 686          * Compute the current throttling state when throttling is enabled
 687          * (bit 4 is on).
 688          */
 689         if (value & 0x10) {
 690                 duty_value = value & duty_mask;
 691                 duty_value >>= pr->throttling.duty_offset;
 692
 693                 if (duty_value)
 694                         state = pr->throttling.state_count - duty_value;
 695         }
 696
 697         pr->throttling.state = state;
 698
 699         local_irq_enable();
 700
 701         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 702                           "Throttling state is T%d (%d%% throttling applied)\n",
 703                           state, pr->throttling.states[state].performance));
 704
 705         return 0;
 706 }
 707
 708 #ifdef CONFIG_X86
 709 static int acpi_throttling_rdmsr(u64 *value)
 710 {
 711         u64 msr_high, msr_low;
 712         u64 msr = 0;
 713         int ret = -1;
 714
 715         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 716                 !this_cpu_has(X86_FEATURE_ACPI)) {
 717                 printk(KERN_ERR PREFIX
 718                         "HARDWARE addr space,NOT supported yet\n");
 719         } else {
 720                 msr_low = 0;
 721                 msr_high = 0;
 722                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 723                         (u32 *)&msr_low , (u32 *) &msr_high);
 724                 msr = (msr_high << 32) | msr_low;
 725                 *value = (u64) msr;
 726                 ret = 0;
 727         }
 728         return ret;
 729 }
 730
 731 static int acpi_throttling_wrmsr(u64 value)
 732 {
 733         int ret = -1;
 734         u64 msr;
 735
 736         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 737                 !this_cpu_has(X86_FEATURE_ACPI)) {
 738                 printk(KERN_ERR PREFIX
 739                         "HARDWARE addr space,NOT supported yet\n");
 740         } else {
 741                 msr = value;
 742                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 743                         msr & 0xffffffff, msr >> 32);
 744                 ret = 0;
 745         }
 746         return ret;
 747 }
 748 #else
 749 static int acpi_throttling_rdmsr(u64 *value)
 750 {
 751         printk(KERN_ERR PREFIX
 752                 "HARDWARE addr space,NOT supported yet\n");
 753         return -1;
 754 }
 755
 756 static int acpi_throttling_wrmsr(u64 value)
 757 {
 758         printk(KERN_ERR PREFIX
 759                 "HARDWARE addr space,NOT supported yet\n");
 760         return -1;
 761 }
 762 #endif
 763
 764 static int acpi_read_throttling_status(struct acpi_processor *pr,
 765                                         u64 *value)
 766 {
 767         u32 bit_width, bit_offset;
 768         u32 ptc_value;
 769         u64 ptc_mask;
 770         struct acpi_processor_throttling *throttling;
 771         int ret = -1;
 772
 773         throttling = &pr->throttling;
 774         switch (throttling->status_register.space_id) {
 775         case ACPI_ADR_SPACE_SYSTEM_IO:
 776                 bit_width = throttling->status_register.bit_width;
 777                 bit_offset = throttling->status_register.bit_offset;
 778
 779                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 780                                   address, &ptc_value,
 781                                   (u32) (bit_width + bit_offset));
 782                 ptc_mask = (1 << bit_width) - 1;
 783                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 784                 ret = 0;
 785                 break;
 786         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 787                 ret = acpi_throttling_rdmsr(value);
 788                 break;
 789         default:
 790                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 791                        (u32) (throttling->status_register.space_id));
 792         }
 793         return ret;
 794 }
 795
 796 static int acpi_write_throttling_state(struct acpi_processor *pr,
 797                                 u64 value)
 798 {
 799         u32 bit_width, bit_offset;
 800         u64 ptc_value;
 801         u64 ptc_mask;
 802         struct acpi_processor_throttling *throttling;
 803         int ret = -1;
 804
 805         throttling = &pr->throttling;
 806         switch (throttling->control_register.space_id) {
 807         case ACPI_ADR_SPACE_SYSTEM_IO:
 808                 bit_width = throttling->control_register.bit_width;
 809                 bit_offset = throttling->control_register.bit_offset;
 810                 ptc_mask = (1 << bit_width) - 1;
 811                 ptc_value = value & ptc_mask;
 812
 813                 acpi_os_write_port((acpi_io_address) throttling->
 814                                         control_register.address,
 815                                         (u32) (ptc_value << bit_offset),
 816                                         (u32) (bit_width + bit_offset));
 817                 ret = 0;
 818                 break;
 819         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 820                 ret = acpi_throttling_wrmsr(value);
 821                 break;
 822         default:
 823                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 824                        (u32) (throttling->control_register.space_id));
 825         }
 826         return ret;
 827 }
 828
 829 static int acpi_get_throttling_state(struct acpi_processor *pr,
 830                                 u64 value)
 831 {
 832         int i;
 833
 834         for (i = 0; i < pr->throttling.state_count; i++) {
 835                 struct acpi_processor_tx_tss *tx =
 836                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 837                                                       states_tss[i]);
 838                 if (tx->control == value)
 839                         return i;
 840         }
 841         return -1;
 842 }
 843
 844 static int acpi_get_throttling_value(struct acpi_processor *pr,
 845                         int state, u64 *value)
 846 {
 847         int ret = -1;
 848
 849         if (state >= 0 && state <= pr->throttling.state_count) {
 850                 struct acpi_processor_tx_tss *tx =
 851                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 852                                                       states_tss[state]);
 853                 *value = tx->control;
 854                 ret = 0;
 855         }
 856         return ret;
 857 }
 858
 859 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 860 {
 861         int state = 0;
 862         int ret;
 863         u64 value;
 864
 865         if (!pr)
 866                 return -EINVAL;
 867
 868         if (!pr->flags.throttling)
 869                 return -ENODEV;
 870
 871         pr->throttling.state = 0;
 872
 873         value = 0;
 874         ret = acpi_read_throttling_status(pr, &value);
 875         if (ret >= 0) {
 876                 state = acpi_get_throttling_state(pr, value);
 877                 if (state == -1) {
 878                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 879                                 "Invalid throttling state, reset\n"));
 880                         state = 0;
 881                         ret = __acpi_processor_set_throttling(pr, state, true,
 882                                                               true);
 883                         if (ret)
 884                                 return ret;
 885                 }
 886                 pr->throttling.state = state;
 887         }
 888
 889         return 0;
 890 }
 891
 892 static long __acpi_processor_get_throttling(void *data)
 893 {
 894         struct acpi_processor *pr = data;
 895
 896         return pr->throttling.acpi_processor_get_throttling(pr);
 897 }
 898
 899 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 900 {
 901         if (!pr)
 902                 return -EINVAL;
 903
 904         if (!pr->flags.throttling)
 905                 return -ENODEV;
 906
 907         /*
 908          * This is either called from the CPU hotplug callback of
 909          * processor_driver or via the ACPI probe function. In the latter
 910          * case the CPU is not guaranteed to be online. Both call sites are
 911          * protected against CPU hotplug.
 912          */
 913         if (!cpu_online(pr->id))
 914                 return -ENODEV;
 915
 916         return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false);
 917 }
 918
 919 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 920 {
 921         int i, step;
 922
 923         if (!pr->throttling.address) {
 924                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 925                 return -EINVAL;
 926         } else if (!pr->throttling.duty_width) {
 927                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 928                 return -EINVAL;
 929         }
 930         /* TBD: Support duty_cycle values that span bit 4. */
 931         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 932                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 933                 return -EINVAL;
 934         }
 935
 936         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 937
 938         /*
 939          * Compute state values. Note that throttling displays a linear power
 940          * performance relationship (at 50% performance the CPU will consume
 941          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 942          */
 943
 944         step = (1000 / pr->throttling.state_count);
 945
 946         for (i = 0; i < pr->throttling.state_count; i++) {
 947                 pr->throttling.states[i].performance = 1000 - step * i;
 948                 pr->throttling.states[i].power = 1000 - step * i;
 949         }
 950         return 0;
 951 }
 952
 953 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 954                                               int state, bool force)
 955 {
 956         u32 value = 0;
 957         u32 duty_mask = 0;
 958         u32 duty_value = 0;
 959
 960         if (!pr)
 961                 return -EINVAL;
 962
 963         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 964                 return -EINVAL;
 965
 966         if (!pr->flags.throttling)
 967                 return -ENODEV;
 968
 969         if (!force && (state == pr->throttling.state))
 970                 return 0;
 971
 972         if (state < pr->throttling_platform_limit)
 973                 return -EPERM;
 974         /*
 975          * Calculate the duty_value and duty_mask.
 976          */
 977         if (state) {
 978                 duty_value = pr->throttling.state_count - state;
 979
 980                 duty_value <<= pr->throttling.duty_offset;
 981
 982                 /* Used to clear all duty_value bits */
 983                 duty_mask = pr->throttling.state_count - 1;
 984
 985                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 986                 duty_mask = ~duty_mask;
 987         }
 988
 989         local_irq_disable();
 990
 991         /*
 992          * Disable throttling by writing a 0 to bit 4.  Note that we must
 993          * turn it off before you can change the duty_value.
 994          */
 995         value = inl(pr->throttling.address);
 996         if (value & 0x10) {
 997                 value &= 0xFFFFFFEF;
 998                 outl(value, pr->throttling.address);
 999         }
1000
1001         /*
1002          * Write the new duty_value and then enable throttling.  Note
1003          * that a state value of 0 leaves throttling disabled.
1004          */
1005         if (state) {
1006                 value &= duty_mask;
1007                 value |= duty_value;
1008                 outl(value, pr->throttling.address);
1009
1010                 value |= 0x00000010;
1011                 outl(value, pr->throttling.address);
1012         }
1013
1014         pr->throttling.state = state;
1015
1016         local_irq_enable();
1017
1018         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1019                           "Throttling state set to T%d (%d%%)\n", state,
1020                           (pr->throttling.states[state].performance ? pr->
1021                            throttling.states[state].performance / 10 : 0)));
1022
1023         return 0;
1024 }
1025
1026 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1027                                              int state, bool force)
1028 {
1029         int ret;
1030         u64 value;
1031
1032         if (!pr)
1033                 return -EINVAL;
1034
1035         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1036                 return -EINVAL;
1037
1038         if (!pr->flags.throttling)
1039                 return -ENODEV;
1040
1041         if (!force && (state == pr->throttling.state))
1042                 return 0;
1043
1044         if (state < pr->throttling_platform_limit)
1045                 return -EPERM;
1046
1047         value = 0;
1048         ret = acpi_get_throttling_value(pr, state, &value);
1049         if (ret >= 0) {
1050                 acpi_write_throttling_state(pr, value);
1051                 pr->throttling.state = state;
1052         }
1053
1054         return 0;
1055 }
1056
1057 static long acpi_processor_throttling_fn(void *data)
1058 {
1059         struct acpi_processor_throttling_arg *arg = data;
1060         struct acpi_processor *pr = arg->pr;
1061
1062         return pr->throttling.acpi_processor_set_throttling(pr,
1063                         arg->target_state, arg->force);
1064 }
1065
1066 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
1067                                            int state, bool force, bool direct)
1068 {
1069         int ret = 0;
1070         unsigned int i;
1071         struct acpi_processor *match_pr;
1072         struct acpi_processor_throttling *p_throttling;
1073         struct acpi_processor_throttling_arg arg;
1074         struct throttling_tstate t_state;
1075
1076         if (!pr)
1077                 return -EINVAL;
1078
1079         if (!pr->flags.throttling)
1080                 return -ENODEV;
1081
1082         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1083                 return -EINVAL;
1084
1085         if (cpu_is_offline(pr->id)) {
1086                 /*
1087                  * the cpu pointed by pr->id is offline. Unnecessary to change
1088                  * the throttling state any more.
1089                  */
1090                 return -ENODEV;
1091         }
1092
1093         t_state.target_state = state;
1094         p_throttling = &(pr->throttling);
1095
1096         /*
1097          * The throttling notifier will be called for every
1098          * affected cpu in order to get one proper T-state.
1099          * The notifier event is THROTTLING_PRECHANGE.
1100          */
1101         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1102                 t_state.cpu = i;
1103                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1104                                                         &t_state);
1105         }
1106         /*
1107          * The function of acpi_processor_set_throttling will be called
1108          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1109          * it is necessary to call it for every affected cpu. Otherwise
1110          * it can be called only for the cpu pointed by pr.
1111          */
1112         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1113                 arg.pr = pr;
1114                 arg.target_state = state;
1115                 arg.force = force;
1116                 ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
1117                                   direct);
1118         } else {
1119                 /*
1120                  * When the T-state coordination is SW_ALL or HW_ALL,
1121                  * it is necessary to set T-state for every affected
1122                  * cpus.
1123                  */
1124                 for_each_cpu_and(i, cpu_online_mask,
1125                     p_throttling->shared_cpu_map) {
1126                         match_pr = per_cpu(processors, i);
1127                         /*
1128                          * If the pointer is invalid, we will report the
1129                          * error message and continue.
1130                          */
1131                         if (!match_pr) {
1132                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1133                                         "Invalid Pointer for CPU %d\n", i));
1134                                 continue;
1135                         }
1136                         /*
1137                          * If the throttling control is unsupported on CPU i,
1138                          * we will report the error message and continue.
1139                          */
1140                         if (!match_pr->flags.throttling) {
1141                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1142                                         "Throttling Control is unsupported "
1143                                         "on CPU %d\n", i));
1144                                 continue;
1145                         }
1146
1147                         arg.pr = match_pr;
1148                         arg.target_state = state;
1149                         arg.force = force;
1150                         ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
1151                                           &arg, direct);
1152                 }
1153         }
1154         /*
1155          * After the set_throttling is called, the
1156          * throttling notifier is called for every
1157          * affected cpu to update the T-states.
1158          * The notifier event is THROTTLING_POSTCHANGE
1159          */
1160         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1161                 t_state.cpu = i;
1162                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1163                                                         &t_state);
1164         }
1165
1166         return ret;
1167 }
1168
1169 int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
1170                                   bool force)
1171 {
1172         return __acpi_processor_set_throttling(pr, state, force, false);
1173 }
1174
1175 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1176 {
1177         int result = 0;
1178         struct acpi_processor_throttling *pthrottling;
1179
1180         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1181                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1182                           pr->throttling.address,
1183                           pr->throttling.duty_offset,
1184                           pr->throttling.duty_width));
1185
1186         /*
1187          * Evaluate _PTC, _TSS and _TPC
1188          * They must all be present or none of them can be used.
1189          */
1190         if (acpi_processor_get_throttling_control(pr) ||
1191                 acpi_processor_get_throttling_states(pr) ||
1192                 acpi_processor_get_platform_limit(pr))
1193         {
1194                 pr->throttling.acpi_processor_get_throttling =
1195                     &acpi_processor_get_throttling_fadt;
1196                 pr->throttling.acpi_processor_set_throttling =
1197                     &acpi_processor_set_throttling_fadt;
1198                 if (acpi_processor_get_fadt_info(pr))
1199                         return 0;
1200         } else {
1201                 pr->throttling.acpi_processor_get_throttling =
1202                     &acpi_processor_get_throttling_ptc;
1203                 pr->throttling.acpi_processor_set_throttling =
1204                     &acpi_processor_set_throttling_ptc;
1205         }
1206
1207         /*
1208          * If TSD package for one CPU can't be parsed successfully, it means
1209          * that this CPU will have no coordination with other CPUs.
1210          */
1211         if (acpi_processor_get_tsd(pr)) {
1212                 pthrottling = &pr->throttling;
1213                 pthrottling->tsd_valid_flag = 0;
1214                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1215                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1216         }
1217
1218         /*
1219          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1220          * This shouldn't be an issue as few (if any) mobile systems ever
1221          * used this part.
1222          */
1223         if (errata.piix4.throttle) {
1224                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1225                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1226                 return 0;
1227         }
1228
1229         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1230                           pr->throttling.state_count));
1231
1232         pr->flags.throttling = 1;
1233
1234         /*
1235          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1236          * thermal) decide to lower performance if it so chooses, but for now
1237          * we'll crank up the speed.
1238          */
1239
1240         result = acpi_processor_get_throttling(pr);
1241         if (result)
1242                 goto end;
1243
1244         if (pr->throttling.state) {
1245                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1246                                   "Disabling throttling (was T%d)\n",
1247                                   pr->throttling.state));
1248                 result = acpi_processor_set_throttling(pr, 0, false);
1249                 if (result)
1250                         goto end;
1251         }
1252
1253       end:
1254         if (result)
1255                 pr->flags.throttling = 0;
1256
1257         return result;
1258 }
1259