drivers/acpi/processor_throttling.c

   1 /*
   2  * processor_throttling.c - Throttling submodule of the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/slab.h>
  32 #include <linux/init.h>
  33 #include <linux/sched.h>
  34 #include <linux/cpufreq.h>
  35
  36 #include <asm/io.h>
  37 #include <asm/uaccess.h>
  38
  39 #include <acpi/acpi_bus.h>
  40 #include <acpi/acpi_drivers.h>
  41 #include <acpi/processor.h>
  42
  43 #define PREFIX "ACPI: "
  44
  45 #define ACPI_PROCESSOR_CLASS            "processor"
  46 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  47 ACPI_MODULE_NAME("processor_throttling");
  48
  49 /* ignore_tpc:
  50  *  0 -> acpi processor driver doesn't ignore _TPC values
  51  *  1 -> acpi processor driver ignores _TPC values
  52  */
  53 static int ignore_tpc;
  54 module_param(ignore_tpc, int, 0644);
  55 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  56
  57 struct throttling_tstate {
  58         unsigned int cpu;               /* cpu nr */
  59         int target_state;               /* target T-state */
  60 };
  61
  62 struct acpi_processor_throttling_arg {
  63         struct acpi_processor *pr;
  64         int target_state;
  65         bool force;
  66 };
  67
  68 #define THROTTLING_PRECHANGE       (1)
  69 #define THROTTLING_POSTCHANGE      (2)
  70
  71 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  72 int acpi_processor_set_throttling(struct acpi_processor *pr,
  73                                                 int state, bool force);
  74
  75 static int acpi_processor_update_tsd_coord(void)
  76 {
  77         int count, count_target;
  78         int retval = 0;
  79         unsigned int i, j;
  80         cpumask_var_t covered_cpus;
  81         struct acpi_processor *pr, *match_pr;
  82         struct acpi_tsd_package *pdomain, *match_pdomain;
  83         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  84
  85         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  86                 return -ENOMEM;
  87
  88         /*
  89          * Now that we have _TSD data from all CPUs, lets setup T-state
  90          * coordination between all CPUs.
  91          */
  92         for_each_possible_cpu(i) {
  93                 pr = per_cpu(processors, i);
  94                 if (!pr)
  95                         continue;
  96
  97                 /* Basic validity check for domain info */
  98                 pthrottling = &(pr->throttling);
  99
 100                 /*
 101                  * If tsd package for one cpu is invalid, the coordination
 102                  * among all CPUs is thought as invalid.
 103                  * Maybe it is ugly.
 104                  */
 105                 if (!pthrottling->tsd_valid_flag) {
 106                         retval = -EINVAL;
 107                         break;
 108                 }
 109         }
 110         if (retval)
 111                 goto err_ret;
 112
 113         for_each_possible_cpu(i) {
 114                 pr = per_cpu(processors, i);
 115                 if (!pr)
 116                         continue;
 117
 118                 if (cpumask_test_cpu(i, covered_cpus))
 119                         continue;
 120                 pthrottling = &pr->throttling;
 121
 122                 pdomain = &(pthrottling->domain_info);
 123                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 124                 cpumask_set_cpu(i, covered_cpus);
 125                 /*
 126                  * If the number of processor in the TSD domain is 1, it is
 127                  * unnecessary to parse the coordination for this CPU.
 128                  */
 129                 if (pdomain->num_processors <= 1)
 130                         continue;
 131
 132                 /* Validate the Domain info */
 133                 count_target = pdomain->num_processors;
 134                 count = 1;
 135
 136                 for_each_possible_cpu(j) {
 137                         if (i == j)
 138                                 continue;
 139
 140                         match_pr = per_cpu(processors, j);
 141                         if (!match_pr)
 142                                 continue;
 143
 144                         match_pthrottling = &(match_pr->throttling);
 145                         match_pdomain = &(match_pthrottling->domain_info);
 146                         if (match_pdomain->domain != pdomain->domain)
 147                                 continue;
 148
 149                         /* Here i and j are in the same domain.
 150                          * If two TSD packages have the same domain, they
 151                          * should have the same num_porcessors and
 152                          * coordination type. Otherwise it will be regarded
 153                          * as illegal.
 154                          */
 155                         if (match_pdomain->num_processors != count_target) {
 156                                 retval = -EINVAL;
 157                                 goto err_ret;
 158                         }
 159
 160                         if (pdomain->coord_type != match_pdomain->coord_type) {
 161                                 retval = -EINVAL;
 162                                 goto err_ret;
 163                         }
 164
 165                         cpumask_set_cpu(j, covered_cpus);
 166                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 167                         count++;
 168                 }
 169                 for_each_possible_cpu(j) {
 170                         if (i == j)
 171                                 continue;
 172
 173                         match_pr = per_cpu(processors, j);
 174                         if (!match_pr)
 175                                 continue;
 176
 177                         match_pthrottling = &(match_pr->throttling);
 178                         match_pdomain = &(match_pthrottling->domain_info);
 179                         if (match_pdomain->domain != pdomain->domain)
 180                                 continue;
 181
 182                         /*
 183                          * If some CPUS have the same domain, they
 184                          * will have the same shared_cpu_map.
 185                          */
 186                         cpumask_copy(match_pthrottling->shared_cpu_map,
 187                                      pthrottling->shared_cpu_map);
 188                 }
 189         }
 190
 191 err_ret:
 192         free_cpumask_var(covered_cpus);
 193
 194         for_each_possible_cpu(i) {
 195                 pr = per_cpu(processors, i);
 196                 if (!pr)
 197                         continue;
 198
 199                 /*
 200                  * Assume no coordination on any error parsing domain info.
 201                  * The coordination type will be forced as SW_ALL.
 202                  */
 203                 if (retval) {
 204                         pthrottling = &(pr->throttling);
 205                         cpumask_clear(pthrottling->shared_cpu_map);
 206                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 207                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 208                 }
 209         }
 210
 211         return retval;
 212 }
 213
 214 /*
 215  * Update the T-state coordination after the _TSD
 216  * data for all cpus is obtained.
 217  */
 218 void acpi_processor_throttling_init(void)
 219 {
 220         if (acpi_processor_update_tsd_coord()) {
 221                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 222                         "Assume no T-state coordination\n"));
 223         }
 224
 225         return;
 226 }
 227
 228 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 229 {
 230         struct throttling_tstate *p_tstate = data;
 231         struct acpi_processor *pr;
 232         unsigned int cpu ;
 233         int target_state;
 234         struct acpi_processor_limit *p_limit;
 235         struct acpi_processor_throttling *p_throttling;
 236
 237         cpu = p_tstate->cpu;
 238         pr = per_cpu(processors, cpu);
 239         if (!pr) {
 240                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 241                 return 0;
 242         }
 243         if (!pr->flags.throttling) {
 244                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 245                                 "unsupported on CPU %d\n", cpu));
 246                 return 0;
 247         }
 248         target_state = p_tstate->target_state;
 249         p_throttling = &(pr->throttling);
 250         switch (event) {
 251         case THROTTLING_PRECHANGE:
 252                 /*
 253                  * Prechange event is used to choose one proper t-state,
 254                  * which meets the limits of thermal, user and _TPC.
 255                  */
 256                 p_limit = &pr->limit;
 257                 if (p_limit->thermal.tx > target_state)
 258                         target_state = p_limit->thermal.tx;
 259                 if (p_limit->user.tx > target_state)
 260                         target_state = p_limit->user.tx;
 261                 if (pr->throttling_platform_limit > target_state)
 262                         target_state = pr->throttling_platform_limit;
 263                 if (target_state >= p_throttling->state_count) {
 264                         printk(KERN_WARNING
 265                                 "Exceed the limit of T-state \n");
 266                         target_state = p_throttling->state_count - 1;
 267                 }
 268                 p_tstate->target_state = target_state;
 269                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 270                                 "target T-state of CPU %d is T%d\n",
 271                                 cpu, target_state));
 272                 break;
 273         case THROTTLING_POSTCHANGE:
 274                 /*
 275                  * Postchange event is only used to update the
 276                  * T-state flag of acpi_processor_throttling.
 277                  */
 278                 p_throttling->state = target_state;
 279                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 280                                 "CPU %d is switched to T%d\n",
 281                                 cpu, target_state));
 282                 break;
 283         default:
 284                 printk(KERN_WARNING
 285                         "Unsupported Throttling notifier event\n");
 286                 break;
 287         }
 288
 289         return 0;
 290 }
 291
 292 /*
 293  * _TPC - Throttling Present Capabilities
 294  */
 295 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 296 {
 297         acpi_status status = 0;
 298         unsigned long long tpc = 0;
 299
 300         if (!pr)
 301                 return -EINVAL;
 302
 303         if (ignore_tpc)
 304                 goto end;
 305
 306         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 307         if (ACPI_FAILURE(status)) {
 308                 if (status != AE_NOT_FOUND) {
 309                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 310                 }
 311                 return -ENODEV;
 312         }
 313
 314 end:
 315         pr->throttling_platform_limit = (int)tpc;
 316         return 0;
 317 }
 318
 319 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 320 {
 321         int result = 0;
 322         int throttling_limit;
 323         int current_state;
 324         struct acpi_processor_limit *limit;
 325         int target_state;
 326
 327         if (ignore_tpc)
 328                 return 0;
 329
 330         result = acpi_processor_get_platform_limit(pr);
 331         if (result) {
 332                 /* Throttling Limit is unsupported */
 333                 return result;
 334         }
 335
 336         throttling_limit = pr->throttling_platform_limit;
 337         if (throttling_limit >= pr->throttling.state_count) {
 338                 /* Uncorrect Throttling Limit */
 339                 return -EINVAL;
 340         }
 341
 342         current_state = pr->throttling.state;
 343         if (current_state > throttling_limit) {
 344                 /*
 345                  * The current state can meet the requirement of
 346                  * _TPC limit. But it is reasonable that OSPM changes
 347                  * t-states from high to low for better performance.
 348                  * Of course the limit condition of thermal
 349                  * and user should be considered.
 350                  */
 351                 limit = &pr->limit;
 352                 target_state = throttling_limit;
 353                 if (limit->thermal.tx > target_state)
 354                         target_state = limit->thermal.tx;
 355                 if (limit->user.tx > target_state)
 356                         target_state = limit->user.tx;
 357         } else if (current_state == throttling_limit) {
 358                 /*
 359                  * Unnecessary to change the throttling state
 360                  */
 361                 return 0;
 362         } else {
 363                 /*
 364                  * If the current state is lower than the limit of _TPC, it
 365                  * will be forced to switch to the throttling state defined
 366                  * by throttling_platfor_limit.
 367                  * Because the previous state meets with the limit condition
 368                  * of thermal and user, it is unnecessary to check it again.
 369                  */
 370                 target_state = throttling_limit;
 371         }
 372         return acpi_processor_set_throttling(pr, target_state, false);
 373 }
 374
 375 /*
 376  * This function is used to reevaluate whether the T-state is valid
 377  * after one CPU is onlined/offlined.
 378  * It is noted that it won't reevaluate the following properties for
 379  * the T-state.
 380  *      1. Control method.
 381  *      2. the number of supported T-state
 382  *      3. TSD domain
 383  */
 384 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 385                                         unsigned long action)
 386 {
 387         int result = 0;
 388
 389         if (action == CPU_DEAD) {
 390                 /* When one CPU is offline, the T-state throttling
 391                  * will be invalidated.
 392                  */
 393                 pr->flags.throttling = 0;
 394                 return;
 395         }
 396         /* the following is to recheck whether the T-state is valid for
 397          * the online CPU
 398          */
 399         if (!pr->throttling.state_count) {
 400                 /* If the number of T-state is invalid, it is
 401                  * invalidated.
 402                  */
 403                 pr->flags.throttling = 0;
 404                 return;
 405         }
 406         pr->flags.throttling = 1;
 407
 408         /* Disable throttling (if enabled).  We'll let subsequent
 409          * policy (e.g.thermal) decide to lower performance if it
 410          * so chooses, but for now we'll crank up the speed.
 411          */
 412
 413         result = acpi_processor_get_throttling(pr);
 414         if (result)
 415                 goto end;
 416
 417         if (pr->throttling.state) {
 418                 result = acpi_processor_set_throttling(pr, 0, false);
 419                 if (result)
 420                         goto end;
 421         }
 422
 423 end:
 424         if (result)
 425                 pr->flags.throttling = 0;
 426 }
 427 /*
 428  * _PTC - Processor Throttling Control (and status) register location
 429  */
 430 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 431 {
 432         int result = 0;
 433         acpi_status status = 0;
 434         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 435         union acpi_object *ptc = NULL;
 436         union acpi_object obj = { 0 };
 437         struct acpi_processor_throttling *throttling;
 438
 439         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 440         if (ACPI_FAILURE(status)) {
 441                 if (status != AE_NOT_FOUND) {
 442                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 443                 }
 444                 return -ENODEV;
 445         }
 446
 447         ptc = (union acpi_object *)buffer.pointer;
 448         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 449             || (ptc->package.count != 2)) {
 450                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 451                 result = -EFAULT;
 452                 goto end;
 453         }
 454
 455         /*
 456          * control_register
 457          */
 458
 459         obj = ptc->package.elements[0];
 460
 461         if ((obj.type != ACPI_TYPE_BUFFER)
 462             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 463             || (obj.buffer.pointer == NULL)) {
 464                 printk(KERN_ERR PREFIX
 465                        "Invalid _PTC data (control_register)\n");
 466                 result = -EFAULT;
 467                 goto end;
 468         }
 469         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 470                sizeof(struct acpi_ptc_register));
 471
 472         /*
 473          * status_register
 474          */
 475
 476         obj = ptc->package.elements[1];
 477
 478         if ((obj.type != ACPI_TYPE_BUFFER)
 479             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 480             || (obj.buffer.pointer == NULL)) {
 481                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 482                 result = -EFAULT;
 483                 goto end;
 484         }
 485
 486         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 487                sizeof(struct acpi_ptc_register));
 488
 489         throttling = &pr->throttling;
 490
 491         if ((throttling->control_register.bit_width +
 492                 throttling->control_register.bit_offset) > 32) {
 493                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 494                 result = -EFAULT;
 495                 goto end;
 496         }
 497
 498         if ((throttling->status_register.bit_width +
 499                 throttling->status_register.bit_offset) > 32) {
 500                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 501                 result = -EFAULT;
 502                 goto end;
 503         }
 504
 505       end:
 506         kfree(buffer.pointer);
 507
 508         return result;
 509 }
 510
 511 /*
 512  * _TSS - Throttling Supported States
 513  */
 514 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 515 {
 516         int result = 0;
 517         acpi_status status = AE_OK;
 518         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 519         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 520         struct acpi_buffer state = { 0, NULL };
 521         union acpi_object *tss = NULL;
 522         int i;
 523
 524         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 525         if (ACPI_FAILURE(status)) {
 526                 if (status != AE_NOT_FOUND) {
 527                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 528                 }
 529                 return -ENODEV;
 530         }
 531
 532         tss = buffer.pointer;
 533         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 534                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 535                 result = -EFAULT;
 536                 goto end;
 537         }
 538
 539         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 540                           tss->package.count));
 541
 542         pr->throttling.state_count = tss->package.count;
 543         pr->throttling.states_tss =
 544             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 545                     GFP_KERNEL);
 546         if (!pr->throttling.states_tss) {
 547                 result = -ENOMEM;
 548                 goto end;
 549         }
 550
 551         for (i = 0; i < pr->throttling.state_count; i++) {
 552
 553                 struct acpi_processor_tx_tss *tx =
 554                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 555                                                       states_tss[i]);
 556
 557                 state.length = sizeof(struct acpi_processor_tx_tss);
 558                 state.pointer = tx;
 559
 560                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 561
 562                 status = acpi_extract_package(&(tss->package.elements[i]),
 563                                               &format, &state);
 564                 if (ACPI_FAILURE(status)) {
 565                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 566                         result = -EFAULT;
 567                         kfree(pr->throttling.states_tss);
 568                         goto end;
 569                 }
 570
 571                 if (!tx->freqpercentage) {
 572                         printk(KERN_ERR PREFIX
 573                                "Invalid _TSS data: freq is zero\n");
 574                         result = -EFAULT;
 575                         kfree(pr->throttling.states_tss);
 576                         goto end;
 577                 }
 578         }
 579
 580       end:
 581         kfree(buffer.pointer);
 582
 583         return result;
 584 }
 585
 586 /*
 587  * _TSD - T-State Dependencies
 588  */
 589 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 590 {
 591         int result = 0;
 592         acpi_status status = AE_OK;
 593         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 594         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 595         struct acpi_buffer state = { 0, NULL };
 596         union acpi_object *tsd = NULL;
 597         struct acpi_tsd_package *pdomain;
 598         struct acpi_processor_throttling *pthrottling;
 599
 600         pthrottling = &pr->throttling;
 601         pthrottling->tsd_valid_flag = 0;
 602
 603         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 604         if (ACPI_FAILURE(status)) {
 605                 if (status != AE_NOT_FOUND) {
 606                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 607                 }
 608                 return -ENODEV;
 609         }
 610
 611         tsd = buffer.pointer;
 612         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 613                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 614                 result = -EFAULT;
 615                 goto end;
 616         }
 617
 618         if (tsd->package.count != 1) {
 619                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 620                 result = -EFAULT;
 621                 goto end;
 622         }
 623
 624         pdomain = &(pr->throttling.domain_info);
 625
 626         state.length = sizeof(struct acpi_tsd_package);
 627         state.pointer = pdomain;
 628
 629         status = acpi_extract_package(&(tsd->package.elements[0]),
 630                                       &format, &state);
 631         if (ACPI_FAILURE(status)) {
 632                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 633                 result = -EFAULT;
 634                 goto end;
 635         }
 636
 637         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 638                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 639                 result = -EFAULT;
 640                 goto end;
 641         }
 642
 643         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 644                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 645                 result = -EFAULT;
 646                 goto end;
 647         }
 648
 649         pthrottling = &pr->throttling;
 650         pthrottling->tsd_valid_flag = 1;
 651         pthrottling->shared_type = pdomain->coord_type;
 652         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 653         /*
 654          * If the coordination type is not defined in ACPI spec,
 655          * the tsd_valid_flag will be clear and coordination type
 656          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 657          */
 658         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 659                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 660                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 661                 pthrottling->tsd_valid_flag = 0;
 662                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 663         }
 664
 665       end:
 666         kfree(buffer.pointer);
 667         return result;
 668 }
 669
 670 /* --------------------------------------------------------------------------
 671                               Throttling Control
 672    -------------------------------------------------------------------------- */
 673 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 674 {
 675         int state = 0;
 676         u32 value = 0;
 677         u32 duty_mask = 0;
 678         u32 duty_value = 0;
 679
 680         if (!pr)
 681                 return -EINVAL;
 682
 683         if (!pr->flags.throttling)
 684                 return -ENODEV;
 685
 686         pr->throttling.state = 0;
 687
 688         duty_mask = pr->throttling.state_count - 1;
 689
 690         duty_mask <<= pr->throttling.duty_offset;
 691
 692         local_irq_disable();
 693
 694         value = inl(pr->throttling.address);
 695
 696         /*
 697          * Compute the current throttling state when throttling is enabled
 698          * (bit 4 is on).
 699          */
 700         if (value & 0x10) {
 701                 duty_value = value & duty_mask;
 702                 duty_value >>= pr->throttling.duty_offset;
 703
 704                 if (duty_value)
 705                         state = pr->throttling.state_count - duty_value;
 706         }
 707
 708         pr->throttling.state = state;
 709
 710         local_irq_enable();
 711
 712         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 713                           "Throttling state is T%d (%d%% throttling applied)\n",
 714                           state, pr->throttling.states[state].performance));
 715
 716         return 0;
 717 }
 718
 719 #ifdef CONFIG_X86
 720 static int acpi_throttling_rdmsr(u64 *value)
 721 {
 722         u64 msr_high, msr_low;
 723         u64 msr = 0;
 724         int ret = -1;
 725
 726         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 727                 !this_cpu_has(X86_FEATURE_ACPI)) {
 728                 printk(KERN_ERR PREFIX
 729                         "HARDWARE addr space,NOT supported yet\n");
 730         } else {
 731                 msr_low = 0;
 732                 msr_high = 0;
 733                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 734                         (u32 *)&msr_low , (u32 *) &msr_high);
 735                 msr = (msr_high << 32) | msr_low;
 736                 *value = (u64) msr;
 737                 ret = 0;
 738         }
 739         return ret;
 740 }
 741
 742 static int acpi_throttling_wrmsr(u64 value)
 743 {
 744         int ret = -1;
 745         u64 msr;
 746
 747         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 748                 !this_cpu_has(X86_FEATURE_ACPI)) {
 749                 printk(KERN_ERR PREFIX
 750                         "HARDWARE addr space,NOT supported yet\n");
 751         } else {
 752                 msr = value;
 753                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 754                         msr & 0xffffffff, msr >> 32);
 755                 ret = 0;
 756         }
 757         return ret;
 758 }
 759 #else
 760 static int acpi_throttling_rdmsr(u64 *value)
 761 {
 762         printk(KERN_ERR PREFIX
 763                 "HARDWARE addr space,NOT supported yet\n");
 764         return -1;
 765 }
 766
 767 static int acpi_throttling_wrmsr(u64 value)
 768 {
 769         printk(KERN_ERR PREFIX
 770                 "HARDWARE addr space,NOT supported yet\n");
 771         return -1;
 772 }
 773 #endif
 774
 775 static int acpi_read_throttling_status(struct acpi_processor *pr,
 776                                         u64 *value)
 777 {
 778         u32 bit_width, bit_offset;
 779         u32 ptc_value;
 780         u64 ptc_mask;
 781         struct acpi_processor_throttling *throttling;
 782         int ret = -1;
 783
 784         throttling = &pr->throttling;
 785         switch (throttling->status_register.space_id) {
 786         case ACPI_ADR_SPACE_SYSTEM_IO:
 787                 bit_width = throttling->status_register.bit_width;
 788                 bit_offset = throttling->status_register.bit_offset;
 789
 790                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 791                                   address, &ptc_value,
 792                                   (u32) (bit_width + bit_offset));
 793                 ptc_mask = (1 << bit_width) - 1;
 794                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 795                 ret = 0;
 796                 break;
 797         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 798                 ret = acpi_throttling_rdmsr(value);
 799                 break;
 800         default:
 801                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 802                        (u32) (throttling->status_register.space_id));
 803         }
 804         return ret;
 805 }
 806
 807 static int acpi_write_throttling_state(struct acpi_processor *pr,
 808                                 u64 value)
 809 {
 810         u32 bit_width, bit_offset;
 811         u64 ptc_value;
 812         u64 ptc_mask;
 813         struct acpi_processor_throttling *throttling;
 814         int ret = -1;
 815
 816         throttling = &pr->throttling;
 817         switch (throttling->control_register.space_id) {
 818         case ACPI_ADR_SPACE_SYSTEM_IO:
 819                 bit_width = throttling->control_register.bit_width;
 820                 bit_offset = throttling->control_register.bit_offset;
 821                 ptc_mask = (1 << bit_width) - 1;
 822                 ptc_value = value & ptc_mask;
 823
 824                 acpi_os_write_port((acpi_io_address) throttling->
 825                                         control_register.address,
 826                                         (u32) (ptc_value << bit_offset),
 827                                         (u32) (bit_width + bit_offset));
 828                 ret = 0;
 829                 break;
 830         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 831                 ret = acpi_throttling_wrmsr(value);
 832                 break;
 833         default:
 834                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 835                        (u32) (throttling->control_register.space_id));
 836         }
 837         return ret;
 838 }
 839
 840 static int acpi_get_throttling_state(struct acpi_processor *pr,
 841                                 u64 value)
 842 {
 843         int i;
 844
 845         for (i = 0; i < pr->throttling.state_count; i++) {
 846                 struct acpi_processor_tx_tss *tx =
 847                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 848                                                       states_tss[i]);
 849                 if (tx->control == value)
 850                         return i;
 851         }
 852         return -1;
 853 }
 854
 855 static int acpi_get_throttling_value(struct acpi_processor *pr,
 856                         int state, u64 *value)
 857 {
 858         int ret = -1;
 859
 860         if (state >= 0 && state <= pr->throttling.state_count) {
 861                 struct acpi_processor_tx_tss *tx =
 862                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 863                                                       states_tss[state]);
 864                 *value = tx->control;
 865                 ret = 0;
 866         }
 867         return ret;
 868 }
 869
 870 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 871 {
 872         int state = 0;
 873         int ret;
 874         u64 value;
 875
 876         if (!pr)
 877                 return -EINVAL;
 878
 879         if (!pr->flags.throttling)
 880                 return -ENODEV;
 881
 882         pr->throttling.state = 0;
 883
 884         value = 0;
 885         ret = acpi_read_throttling_status(pr, &value);
 886         if (ret >= 0) {
 887                 state = acpi_get_throttling_state(pr, value);
 888                 if (state == -1) {
 889                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 890                                 "Invalid throttling state, reset\n"));
 891                         state = 0;
 892                         ret = acpi_processor_set_throttling(pr, state, true);
 893                         if (ret)
 894                                 return ret;
 895                 }
 896                 pr->throttling.state = state;
 897         }
 898
 899         return 0;
 900 }
 901
 902 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 903 {
 904         cpumask_var_t saved_mask;
 905         int ret;
 906
 907         if (!pr)
 908                 return -EINVAL;
 909
 910         if (!pr->flags.throttling)
 911                 return -ENODEV;
 912
 913         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 914                 return -ENOMEM;
 915
 916         /*
 917          * Migrate task to the cpu pointed by pr.
 918          */
 919         cpumask_copy(saved_mask, &current->cpus_allowed);
 920         /* FIXME: use work_on_cpu() */
 921         if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
 922                 /* Can't migrate to the target pr->id CPU. Exit */
 923                 free_cpumask_var(saved_mask);
 924                 return -ENODEV;
 925         }
 926         ret = pr->throttling.acpi_processor_get_throttling(pr);
 927         /* restore the previous state */
 928         set_cpus_allowed_ptr(current, saved_mask);
 929         free_cpumask_var(saved_mask);
 930
 931         return ret;
 932 }
 933
 934 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 935 {
 936         int i, step;
 937
 938         if (!pr->throttling.address) {
 939                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 940                 return -EINVAL;
 941         } else if (!pr->throttling.duty_width) {
 942                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 943                 return -EINVAL;
 944         }
 945         /* TBD: Support duty_cycle values that span bit 4. */
 946         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 947                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 948                 return -EINVAL;
 949         }
 950
 951         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 952
 953         /*
 954          * Compute state values. Note that throttling displays a linear power
 955          * performance relationship (at 50% performance the CPU will consume
 956          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 957          */
 958
 959         step = (1000 / pr->throttling.state_count);
 960
 961         for (i = 0; i < pr->throttling.state_count; i++) {
 962                 pr->throttling.states[i].performance = 1000 - step * i;
 963                 pr->throttling.states[i].power = 1000 - step * i;
 964         }
 965         return 0;
 966 }
 967
 968 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 969                                               int state, bool force)
 970 {
 971         u32 value = 0;
 972         u32 duty_mask = 0;
 973         u32 duty_value = 0;
 974
 975         if (!pr)
 976                 return -EINVAL;
 977
 978         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 979                 return -EINVAL;
 980
 981         if (!pr->flags.throttling)
 982                 return -ENODEV;
 983
 984         if (!force && (state == pr->throttling.state))
 985                 return 0;
 986
 987         if (state < pr->throttling_platform_limit)
 988                 return -EPERM;
 989         /*
 990          * Calculate the duty_value and duty_mask.
 991          */
 992         if (state) {
 993                 duty_value = pr->throttling.state_count - state;
 994
 995                 duty_value <<= pr->throttling.duty_offset;
 996
 997                 /* Used to clear all duty_value bits */
 998                 duty_mask = pr->throttling.state_count - 1;
 999
1000                 duty_mask <<= acpi_gbl_FADT.duty_offset;
1001                 duty_mask = ~duty_mask;
1002         }
1003
1004         local_irq_disable();
1005
1006         /*
1007          * Disable throttling by writing a 0 to bit 4.  Note that we must
1008          * turn it off before you can change the duty_value.
1009          */
1010         value = inl(pr->throttling.address);
1011         if (value & 0x10) {
1012                 value &= 0xFFFFFFEF;
1013                 outl(value, pr->throttling.address);
1014         }
1015
1016         /*
1017          * Write the new duty_value and then enable throttling.  Note
1018          * that a state value of 0 leaves throttling disabled.
1019          */
1020         if (state) {
1021                 value &= duty_mask;
1022                 value |= duty_value;
1023                 outl(value, pr->throttling.address);
1024
1025                 value |= 0x00000010;
1026                 outl(value, pr->throttling.address);
1027         }
1028
1029         pr->throttling.state = state;
1030
1031         local_irq_enable();
1032
1033         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1034                           "Throttling state set to T%d (%d%%)\n", state,
1035                           (pr->throttling.states[state].performance ? pr->
1036                            throttling.states[state].performance / 10 : 0)));
1037
1038         return 0;
1039 }
1040
1041 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1042                                              int state, bool force)
1043 {
1044         int ret;
1045         u64 value;
1046
1047         if (!pr)
1048                 return -EINVAL;
1049
1050         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1051                 return -EINVAL;
1052
1053         if (!pr->flags.throttling)
1054                 return -ENODEV;
1055
1056         if (!force && (state == pr->throttling.state))
1057                 return 0;
1058
1059         if (state < pr->throttling_platform_limit)
1060                 return -EPERM;
1061
1062         value = 0;
1063         ret = acpi_get_throttling_value(pr, state, &value);
1064         if (ret >= 0) {
1065                 acpi_write_throttling_state(pr, value);
1066                 pr->throttling.state = state;
1067         }
1068
1069         return 0;
1070 }
1071
1072 static long acpi_processor_throttling_fn(void *data)
1073 {
1074         struct acpi_processor_throttling_arg *arg = data;
1075         struct acpi_processor *pr = arg->pr;
1076
1077         return pr->throttling.acpi_processor_set_throttling(pr,
1078                         arg->target_state, arg->force);
1079 }
1080
1081 int acpi_processor_set_throttling(struct acpi_processor *pr,
1082                                                 int state, bool force)
1083 {
1084         int ret = 0;
1085         unsigned int i;
1086         struct acpi_processor *match_pr;
1087         struct acpi_processor_throttling *p_throttling;
1088         struct acpi_processor_throttling_arg arg;
1089         struct throttling_tstate t_state;
1090
1091         if (!pr)
1092                 return -EINVAL;
1093
1094         if (!pr->flags.throttling)
1095                 return -ENODEV;
1096
1097         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1098                 return -EINVAL;
1099
1100         if (cpu_is_offline(pr->id)) {
1101                 /*
1102                  * the cpu pointed by pr->id is offline. Unnecessary to change
1103                  * the throttling state any more.
1104                  */
1105                 return -ENODEV;
1106         }
1107
1108         t_state.target_state = state;
1109         p_throttling = &(pr->throttling);
1110
1111         /*
1112          * The throttling notifier will be called for every
1113          * affected cpu in order to get one proper T-state.
1114          * The notifier event is THROTTLING_PRECHANGE.
1115          */
1116         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1117                 t_state.cpu = i;
1118                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1119                                                         &t_state);
1120         }
1121         /*
1122          * The function of acpi_processor_set_throttling will be called
1123          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1124          * it is necessary to call it for every affected cpu. Otherwise
1125          * it can be called only for the cpu pointed by pr.
1126          */
1127         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1128                 arg.pr = pr;
1129                 arg.target_state = state;
1130                 arg.force = force;
1131                 ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
1132         } else {
1133                 /*
1134                  * When the T-state coordination is SW_ALL or HW_ALL,
1135                  * it is necessary to set T-state for every affected
1136                  * cpus.
1137                  */
1138                 for_each_cpu_and(i, cpu_online_mask,
1139                     p_throttling->shared_cpu_map) {
1140                         match_pr = per_cpu(processors, i);
1141                         /*
1142                          * If the pointer is invalid, we will report the
1143                          * error message and continue.
1144                          */
1145                         if (!match_pr) {
1146                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1147                                         "Invalid Pointer for CPU %d\n", i));
1148                                 continue;
1149                         }
1150                         /*
1151                          * If the throttling control is unsupported on CPU i,
1152                          * we will report the error message and continue.
1153                          */
1154                         if (!match_pr->flags.throttling) {
1155                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1156                                         "Throttling Control is unsupported "
1157                                         "on CPU %d\n", i));
1158                                 continue;
1159                         }
1160
1161                         arg.pr = match_pr;
1162                         arg.target_state = state;
1163                         arg.force = force;
1164                         ret = work_on_cpu(pr->id, acpi_processor_throttling_fn,
1165                                 &arg);
1166                 }
1167         }
1168         /*
1169          * After the set_throttling is called, the
1170          * throttling notifier is called for every
1171          * affected cpu to update the T-states.
1172          * The notifier event is THROTTLING_POSTCHANGE
1173          */
1174         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1175                 t_state.cpu = i;
1176                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1177                                                         &t_state);
1178         }
1179
1180         return ret;
1181 }
1182
1183 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1184 {
1185         int result = 0;
1186         struct acpi_processor_throttling *pthrottling;
1187
1188         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1189                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1190                           pr->throttling.address,
1191                           pr->throttling.duty_offset,
1192                           pr->throttling.duty_width));
1193
1194         /*
1195          * Evaluate _PTC, _TSS and _TPC
1196          * They must all be present or none of them can be used.
1197          */
1198         if (acpi_processor_get_throttling_control(pr) ||
1199                 acpi_processor_get_throttling_states(pr) ||
1200                 acpi_processor_get_platform_limit(pr))
1201         {
1202                 pr->throttling.acpi_processor_get_throttling =
1203                     &acpi_processor_get_throttling_fadt;
1204                 pr->throttling.acpi_processor_set_throttling =
1205                     &acpi_processor_set_throttling_fadt;
1206                 if (acpi_processor_get_fadt_info(pr))
1207                         return 0;
1208         } else {
1209                 pr->throttling.acpi_processor_get_throttling =
1210                     &acpi_processor_get_throttling_ptc;
1211                 pr->throttling.acpi_processor_set_throttling =
1212                     &acpi_processor_set_throttling_ptc;
1213         }
1214
1215         /*
1216          * If TSD package for one CPU can't be parsed successfully, it means
1217          * that this CPU will have no coordination with other CPUs.
1218          */
1219         if (acpi_processor_get_tsd(pr)) {
1220                 pthrottling = &pr->throttling;
1221                 pthrottling->tsd_valid_flag = 0;
1222                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1223                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1224         }
1225
1226         /*
1227          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1228          * This shouldn't be an issue as few (if any) mobile systems ever
1229          * used this part.
1230          */
1231         if (errata.piix4.throttle) {
1232                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1233                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1234                 return 0;
1235         }
1236
1237         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1238                           pr->throttling.state_count));
1239
1240         pr->flags.throttling = 1;
1241
1242         /*
1243          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1244          * thermal) decide to lower performance if it so chooses, but for now
1245          * we'll crank up the speed.
1246          */
1247
1248         result = acpi_processor_get_throttling(pr);
1249         if (result)
1250                 goto end;
1251
1252         if (pr->throttling.state) {
1253                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1254                                   "Disabling throttling (was T%d)\n",
1255                                   pr->throttling.state));
1256                 result = acpi_processor_set_throttling(pr, 0, false);
1257                 if (result)
1258                         goto end;
1259         }
1260
1261       end:
1262         if (result)
1263                 pr->flags.throttling = 0;
1264
1265         return result;
1266 }
1267