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/init.h>
  32 #include <linux/sched.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/seq_file.h>
  36
  37 #include <asm/io.h>
  38 #include <asm/uaccess.h>
  39
  40 #include <acpi/acpi_bus.h>
  41 #include <acpi/processor.h>
  42
  43 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  44 #define ACPI_PROCESSOR_CLASS            "processor"
  45 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  46 ACPI_MODULE_NAME("processor_throttling");
  47
  48 struct throttling_tstate {
  49         unsigned int cpu;               /* cpu nr */
  50         int target_state;               /* target T-state */
  51 };
  52
  53 #define THROTTLING_PRECHANGE       (1)
  54 #define THROTTLING_POSTCHANGE      (2)
  55
  56 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  57 int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
  58
  59 static int acpi_processor_update_tsd_coord(void)
  60 {
  61         int count, count_target;
  62         int retval = 0;
  63         unsigned int i, j;
  64         cpumask_t covered_cpus;
  65         struct acpi_processor *pr, *match_pr;
  66         struct acpi_tsd_package *pdomain, *match_pdomain;
  67         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  68
  69         /*
  70          * Now that we have _TSD data from all CPUs, lets setup T-state
  71          * coordination between all CPUs.
  72          */
  73         for_each_possible_cpu(i) {
  74                 pr = processors[i];
  75                 if (!pr)
  76                         continue;
  77
  78                 /* Basic validity check for domain info */
  79                 pthrottling = &(pr->throttling);
  80
  81                 /*
  82                  * If tsd package for one cpu is invalid, the coordination
  83                  * among all CPUs is thought as invalid.
  84                  * Maybe it is ugly.
  85                  */
  86                 if (!pthrottling->tsd_valid_flag) {
  87                         retval = -EINVAL;
  88                         break;
  89                 }
  90         }
  91         if (retval)
  92                 goto err_ret;
  93
  94         cpus_clear(covered_cpus);
  95         for_each_possible_cpu(i) {
  96                 pr = processors[i];
  97                 if (!pr)
  98                         continue;
  99
 100                 if (cpu_isset(i, covered_cpus))
 101                         continue;
 102                 pthrottling = &pr->throttling;
 103
 104                 pdomain = &(pthrottling->domain_info);
 105                 cpu_set(i, pthrottling->shared_cpu_map);
 106                 cpu_set(i, covered_cpus);
 107                 /*
 108                  * If the number of processor in the TSD domain is 1, it is
 109                  * unnecessary to parse the coordination for this CPU.
 110                  */
 111                 if (pdomain->num_processors <= 1)
 112                         continue;
 113
 114                 /* Validate the Domain info */
 115                 count_target = pdomain->num_processors;
 116                 count = 1;
 117
 118                 for_each_possible_cpu(j) {
 119                         if (i == j)
 120                                 continue;
 121
 122                         match_pr = processors[j];
 123                         if (!match_pr)
 124                                 continue;
 125
 126                         match_pthrottling = &(match_pr->throttling);
 127                         match_pdomain = &(match_pthrottling->domain_info);
 128                         if (match_pdomain->domain != pdomain->domain)
 129                                 continue;
 130
 131                         /* Here i and j are in the same domain.
 132                          * If two TSD packages have the same domain, they
 133                          * should have the same num_porcessors and
 134                          * coordination type. Otherwise it will be regarded
 135                          * as illegal.
 136                          */
 137                         if (match_pdomain->num_processors != count_target) {
 138                                 retval = -EINVAL;
 139                                 goto err_ret;
 140                         }
 141
 142                         if (pdomain->coord_type != match_pdomain->coord_type) {
 143                                 retval = -EINVAL;
 144                                 goto err_ret;
 145                         }
 146
 147                         cpu_set(j, covered_cpus);
 148                         cpu_set(j, pthrottling->shared_cpu_map);
 149                         count++;
 150                 }
 151                 for_each_possible_cpu(j) {
 152                         if (i == j)
 153                                 continue;
 154
 155                         match_pr = processors[j];
 156                         if (!match_pr)
 157                                 continue;
 158
 159                         match_pthrottling = &(match_pr->throttling);
 160                         match_pdomain = &(match_pthrottling->domain_info);
 161                         if (match_pdomain->domain != pdomain->domain)
 162                                 continue;
 163
 164                         /*
 165                          * If some CPUS have the same domain, they
 166                          * will have the same shared_cpu_map.
 167                          */
 168                         match_pthrottling->shared_cpu_map =
 169                                 pthrottling->shared_cpu_map;
 170                 }
 171         }
 172
 173 err_ret:
 174         for_each_possible_cpu(i) {
 175                 pr = processors[i];
 176                 if (!pr)
 177                         continue;
 178
 179                 /*
 180                  * Assume no coordination on any error parsing domain info.
 181                  * The coordination type will be forced as SW_ALL.
 182                  */
 183                 if (retval) {
 184                         pthrottling = &(pr->throttling);
 185                         cpus_clear(pthrottling->shared_cpu_map);
 186                         cpu_set(i, pthrottling->shared_cpu_map);
 187                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 188                 }
 189         }
 190
 191         return retval;
 192 }
 193
 194 /*
 195  * Update the T-state coordination after the _TSD
 196  * data for all cpus is obtained.
 197  */
 198 void acpi_processor_throttling_init(void)
 199 {
 200         if (acpi_processor_update_tsd_coord())
 201                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 202                         "Assume no T-state coordination\n"));
 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 = 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 tpc = 0;
 278
 279         if (!pr)
 280                 return -EINVAL;
 281         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 282         if (ACPI_FAILURE(status)) {
 283                 if (status != AE_NOT_FOUND) {
 284                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 285                 }
 286                 return -ENODEV;
 287         }
 288         pr->throttling_platform_limit = (int)tpc;
 289         return 0;
 290 }
 291
 292 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 293 {
 294         int result = 0;
 295         int throttling_limit;
 296         int current_state;
 297         struct acpi_processor_limit *limit;
 298         int target_state;
 299
 300         result = acpi_processor_get_platform_limit(pr);
 301         if (result) {
 302                 /* Throttling Limit is unsupported */
 303                 return result;
 304         }
 305
 306         throttling_limit = pr->throttling_platform_limit;
 307         if (throttling_limit >= pr->throttling.state_count) {
 308                 /* Uncorrect Throttling Limit */
 309                 return -EINVAL;
 310         }
 311
 312         current_state = pr->throttling.state;
 313         if (current_state > throttling_limit) {
 314                 /*
 315                  * The current state can meet the requirement of
 316                  * _TPC limit. But it is reasonable that OSPM changes
 317                  * t-states from high to low for better performance.
 318                  * Of course the limit condition of thermal
 319                  * and user should be considered.
 320                  */
 321                 limit = &pr->limit;
 322                 target_state = throttling_limit;
 323                 if (limit->thermal.tx > target_state)
 324                         target_state = limit->thermal.tx;
 325                 if (limit->user.tx > target_state)
 326                         target_state = limit->user.tx;
 327         } else if (current_state == throttling_limit) {
 328                 /*
 329                  * Unnecessary to change the throttling state
 330                  */
 331                 return 0;
 332         } else {
 333                 /*
 334                  * If the current state is lower than the limit of _TPC, it
 335                  * will be forced to switch to the throttling state defined
 336                  * by throttling_platfor_limit.
 337                  * Because the previous state meets with the limit condition
 338                  * of thermal and user, it is unnecessary to check it again.
 339                  */
 340                 target_state = throttling_limit;
 341         }
 342         return acpi_processor_set_throttling(pr, target_state);
 343 }
 344
 345 /*
 346  * _PTC - Processor Throttling Control (and status) register location
 347  */
 348 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 349 {
 350         int result = 0;
 351         acpi_status status = 0;
 352         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 353         union acpi_object *ptc = NULL;
 354         union acpi_object obj = { 0 };
 355         struct acpi_processor_throttling *throttling;
 356
 357         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 358         if (ACPI_FAILURE(status)) {
 359                 if (status != AE_NOT_FOUND) {
 360                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 361                 }
 362                 return -ENODEV;
 363         }
 364
 365         ptc = (union acpi_object *)buffer.pointer;
 366         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 367             || (ptc->package.count != 2)) {
 368                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 369                 result = -EFAULT;
 370                 goto end;
 371         }
 372
 373         /*
 374          * control_register
 375          */
 376
 377         obj = ptc->package.elements[0];
 378
 379         if ((obj.type != ACPI_TYPE_BUFFER)
 380             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 381             || (obj.buffer.pointer == NULL)) {
 382                 printk(KERN_ERR PREFIX
 383                        "Invalid _PTC data (control_register)\n");
 384                 result = -EFAULT;
 385                 goto end;
 386         }
 387         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 388                sizeof(struct acpi_ptc_register));
 389
 390         /*
 391          * status_register
 392          */
 393
 394         obj = ptc->package.elements[1];
 395
 396         if ((obj.type != ACPI_TYPE_BUFFER)
 397             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 398             || (obj.buffer.pointer == NULL)) {
 399                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 400                 result = -EFAULT;
 401                 goto end;
 402         }
 403
 404         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 405                sizeof(struct acpi_ptc_register));
 406
 407         throttling = &pr->throttling;
 408
 409         if ((throttling->control_register.bit_width +
 410                 throttling->control_register.bit_offset) > 32) {
 411                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 412                 result = -EFAULT;
 413                 goto end;
 414         }
 415
 416         if ((throttling->status_register.bit_width +
 417                 throttling->status_register.bit_offset) > 32) {
 418                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 419                 result = -EFAULT;
 420                 goto end;
 421         }
 422
 423       end:
 424         kfree(buffer.pointer);
 425
 426         return result;
 427 }
 428
 429 /*
 430  * _TSS - Throttling Supported States
 431  */
 432 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 433 {
 434         int result = 0;
 435         acpi_status status = AE_OK;
 436         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 437         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 438         struct acpi_buffer state = { 0, NULL };
 439         union acpi_object *tss = NULL;
 440         int i;
 441
 442         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 443         if (ACPI_FAILURE(status)) {
 444                 if (status != AE_NOT_FOUND) {
 445                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 446                 }
 447                 return -ENODEV;
 448         }
 449
 450         tss = buffer.pointer;
 451         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 452                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 453                 result = -EFAULT;
 454                 goto end;
 455         }
 456
 457         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 458                           tss->package.count));
 459
 460         pr->throttling.state_count = tss->package.count;
 461         pr->throttling.states_tss =
 462             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 463                     GFP_KERNEL);
 464         if (!pr->throttling.states_tss) {
 465                 result = -ENOMEM;
 466                 goto end;
 467         }
 468
 469         for (i = 0; i < pr->throttling.state_count; i++) {
 470
 471                 struct acpi_processor_tx_tss *tx =
 472                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 473                                                       states_tss[i]);
 474
 475                 state.length = sizeof(struct acpi_processor_tx_tss);
 476                 state.pointer = tx;
 477
 478                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 479
 480                 status = acpi_extract_package(&(tss->package.elements[i]),
 481                                               &format, &state);
 482                 if (ACPI_FAILURE(status)) {
 483                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 484                         result = -EFAULT;
 485                         kfree(pr->throttling.states_tss);
 486                         goto end;
 487                 }
 488
 489                 if (!tx->freqpercentage) {
 490                         printk(KERN_ERR PREFIX
 491                                "Invalid _TSS data: freq is zero\n");
 492                         result = -EFAULT;
 493                         kfree(pr->throttling.states_tss);
 494                         goto end;
 495                 }
 496         }
 497
 498       end:
 499         kfree(buffer.pointer);
 500
 501         return result;
 502 }
 503
 504 /*
 505  * _TSD - T-State Dependencies
 506  */
 507 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 508 {
 509         int result = 0;
 510         acpi_status status = AE_OK;
 511         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 512         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 513         struct acpi_buffer state = { 0, NULL };
 514         union acpi_object *tsd = NULL;
 515         struct acpi_tsd_package *pdomain;
 516         struct acpi_processor_throttling *pthrottling;
 517
 518         pthrottling = &pr->throttling;
 519         pthrottling->tsd_valid_flag = 0;
 520
 521         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 522         if (ACPI_FAILURE(status)) {
 523                 if (status != AE_NOT_FOUND) {
 524                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 525                 }
 526                 return -ENODEV;
 527         }
 528
 529         tsd = buffer.pointer;
 530         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 531                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 532                 result = -EFAULT;
 533                 goto end;
 534         }
 535
 536         if (tsd->package.count != 1) {
 537                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 538                 result = -EFAULT;
 539                 goto end;
 540         }
 541
 542         pdomain = &(pr->throttling.domain_info);
 543
 544         state.length = sizeof(struct acpi_tsd_package);
 545         state.pointer = pdomain;
 546
 547         status = acpi_extract_package(&(tsd->package.elements[0]),
 548                                       &format, &state);
 549         if (ACPI_FAILURE(status)) {
 550                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 551                 result = -EFAULT;
 552                 goto end;
 553         }
 554
 555         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 556                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:num_entries\n"));
 557                 result = -EFAULT;
 558                 goto end;
 559         }
 560
 561         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 562                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:revision\n"));
 563                 result = -EFAULT;
 564                 goto end;
 565         }
 566
 567         pthrottling = &pr->throttling;
 568         pthrottling->tsd_valid_flag = 1;
 569         pthrottling->shared_type = pdomain->coord_type;
 570         cpu_set(pr->id, pthrottling->shared_cpu_map);
 571         /*
 572          * If the coordination type is not defined in ACPI spec,
 573          * the tsd_valid_flag will be clear and coordination type
 574          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 575          */
 576         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 577                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 578                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 579                 pthrottling->tsd_valid_flag = 0;
 580                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 581         }
 582
 583       end:
 584         kfree(buffer.pointer);
 585         return result;
 586 }
 587
 588 /* --------------------------------------------------------------------------
 589                               Throttling Control
 590    -------------------------------------------------------------------------- */
 591 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 592 {
 593         int state = 0;
 594         u32 value = 0;
 595         u32 duty_mask = 0;
 596         u32 duty_value = 0;
 597
 598         if (!pr)
 599                 return -EINVAL;
 600
 601         if (!pr->flags.throttling)
 602                 return -ENODEV;
 603
 604         pr->throttling.state = 0;
 605
 606         duty_mask = pr->throttling.state_count - 1;
 607
 608         duty_mask <<= pr->throttling.duty_offset;
 609
 610         local_irq_disable();
 611
 612         value = inl(pr->throttling.address);
 613
 614         /*
 615          * Compute the current throttling state when throttling is enabled
 616          * (bit 4 is on).
 617          */
 618         if (value & 0x10) {
 619                 duty_value = value & duty_mask;
 620                 duty_value >>= pr->throttling.duty_offset;
 621
 622                 if (duty_value)
 623                         state = pr->throttling.state_count - duty_value;
 624         }
 625
 626         pr->throttling.state = state;
 627
 628         local_irq_enable();
 629
 630         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 631                           "Throttling state is T%d (%d%% throttling applied)\n",
 632                           state, pr->throttling.states[state].performance));
 633
 634         return 0;
 635 }
 636
 637 #ifdef CONFIG_X86
 638 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 639                                         acpi_integer * value)
 640 {
 641         struct cpuinfo_x86 *c;
 642         u64 msr_high, msr_low;
 643         unsigned int cpu;
 644         u64 msr = 0;
 645         int ret = -1;
 646
 647         cpu = pr->id;
 648         c = &cpu_data(cpu);
 649
 650         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 651                 !cpu_has(c, X86_FEATURE_ACPI)) {
 652                 printk(KERN_ERR PREFIX
 653                         "HARDWARE addr space,NOT supported yet\n");
 654         } else {
 655                 msr_low = 0;
 656                 msr_high = 0;
 657                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 658                         (u32 *)&msr_low , (u32 *) &msr_high);
 659                 msr = (msr_high << 32) | msr_low;
 660                 *value = (acpi_integer) msr;
 661                 ret = 0;
 662         }
 663         return ret;
 664 }
 665
 666 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 667 {
 668         struct cpuinfo_x86 *c;
 669         unsigned int cpu;
 670         int ret = -1;
 671         u64 msr;
 672
 673         cpu = pr->id;
 674         c = &cpu_data(cpu);
 675
 676         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 677                 !cpu_has(c, X86_FEATURE_ACPI)) {
 678                 printk(KERN_ERR PREFIX
 679                         "HARDWARE addr space,NOT supported yet\n");
 680         } else {
 681                 msr = value;
 682                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 683                         msr & 0xffffffff, msr >> 32);
 684                 ret = 0;
 685         }
 686         return ret;
 687 }
 688 #else
 689 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 690                                 acpi_integer * value)
 691 {
 692         printk(KERN_ERR PREFIX
 693                 "HARDWARE addr space,NOT supported yet\n");
 694         return -1;
 695 }
 696
 697 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 698 {
 699         printk(KERN_ERR PREFIX
 700                 "HARDWARE addr space,NOT supported yet\n");
 701         return -1;
 702 }
 703 #endif
 704
 705 static int acpi_read_throttling_status(struct acpi_processor *pr,
 706                                         acpi_integer *value)
 707 {
 708         u32 bit_width, bit_offset;
 709         u64 ptc_value;
 710         u64 ptc_mask;
 711         struct acpi_processor_throttling *throttling;
 712         int ret = -1;
 713
 714         throttling = &pr->throttling;
 715         switch (throttling->status_register.space_id) {
 716         case ACPI_ADR_SPACE_SYSTEM_IO:
 717                 ptc_value = 0;
 718                 bit_width = throttling->status_register.bit_width;
 719                 bit_offset = throttling->status_register.bit_offset;
 720
 721                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 722                                   address, (u32 *) &ptc_value,
 723                                   (u32) (bit_width + bit_offset));
 724                 ptc_mask = (1 << bit_width) - 1;
 725                 *value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);
 726                 ret = 0;
 727                 break;
 728         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 729                 ret = acpi_throttling_rdmsr(pr, value);
 730                 break;
 731         default:
 732                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 733                        (u32) (throttling->status_register.space_id));
 734         }
 735         return ret;
 736 }
 737
 738 static int acpi_write_throttling_state(struct acpi_processor *pr,
 739                                 acpi_integer value)
 740 {
 741         u32 bit_width, bit_offset;
 742         u64 ptc_value;
 743         u64 ptc_mask;
 744         struct acpi_processor_throttling *throttling;
 745         int ret = -1;
 746
 747         throttling = &pr->throttling;
 748         switch (throttling->control_register.space_id) {
 749         case ACPI_ADR_SPACE_SYSTEM_IO:
 750                 bit_width = throttling->control_register.bit_width;
 751                 bit_offset = throttling->control_register.bit_offset;
 752                 ptc_mask = (1 << bit_width) - 1;
 753                 ptc_value = value & ptc_mask;
 754
 755                 acpi_os_write_port((acpi_io_address) throttling->
 756                                         control_register.address,
 757                                         (u32) (ptc_value << bit_offset),
 758                                         (u32) (bit_width + bit_offset));
 759                 ret = 0;
 760                 break;
 761         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 762                 ret = acpi_throttling_wrmsr(pr, value);
 763                 break;
 764         default:
 765                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 766                        (u32) (throttling->control_register.space_id));
 767         }
 768         return ret;
 769 }
 770
 771 static int acpi_get_throttling_state(struct acpi_processor *pr,
 772                                 acpi_integer value)
 773 {
 774         int i;
 775
 776         for (i = 0; i < pr->throttling.state_count; i++) {
 777                 struct acpi_processor_tx_tss *tx =
 778                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 779                                                       states_tss[i]);
 780                 if (tx->control == value)
 781                         break;
 782         }
 783         if (i > pr->throttling.state_count)
 784                 i = -1;
 785         return i;
 786 }
 787
 788 static int acpi_get_throttling_value(struct acpi_processor *pr,
 789                         int state, acpi_integer *value)
 790 {
 791         int ret = -1;
 792
 793         if (state >= 0 && state <= pr->throttling.state_count) {
 794                 struct acpi_processor_tx_tss *tx =
 795                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 796                                                       states_tss[state]);
 797                 *value = tx->control;
 798                 ret = 0;
 799         }
 800         return ret;
 801 }
 802
 803 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 804 {
 805         int state = 0;
 806         int ret;
 807         acpi_integer value;
 808
 809         if (!pr)
 810                 return -EINVAL;
 811
 812         if (!pr->flags.throttling)
 813                 return -ENODEV;
 814
 815         pr->throttling.state = 0;
 816
 817         value = 0;
 818         ret = acpi_read_throttling_status(pr, &value);
 819         if (ret >= 0) {
 820                 state = acpi_get_throttling_state(pr, value);
 821                 pr->throttling.state = state;
 822         }
 823
 824         return 0;
 825 }
 826
 827 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 828 {
 829         cpumask_t saved_mask;
 830         int ret;
 831
 832         if (!pr)
 833                 return -EINVAL;
 834
 835         if (!pr->flags.throttling)
 836                 return -ENODEV;
 837         /*
 838          * Migrate task to the cpu pointed by pr.
 839          */
 840         saved_mask = current->cpus_allowed;
 841         set_cpus_allowed_ptr(current, &cpumask_of_cpu(pr->id));
 842         ret = pr->throttling.acpi_processor_get_throttling(pr);
 843         /* restore the previous state */
 844         set_cpus_allowed_ptr(current, &saved_mask);
 845
 846         return ret;
 847 }
 848
 849 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 850 {
 851         int i, step;
 852
 853         if (!pr->throttling.address) {
 854                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 855                 return -EINVAL;
 856         } else if (!pr->throttling.duty_width) {
 857                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 858                 return -EINVAL;
 859         }
 860         /* TBD: Support duty_cycle values that span bit 4. */
 861         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 862                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 863                 return -EINVAL;
 864         }
 865
 866         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 867
 868         /*
 869          * Compute state values. Note that throttling displays a linear power
 870          * performance relationship (at 50% performance the CPU will consume
 871          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 872          */
 873
 874         step = (1000 / pr->throttling.state_count);
 875
 876         for (i = 0; i < pr->throttling.state_count; i++) {
 877                 pr->throttling.states[i].performance = 1000 - step * i;
 878                 pr->throttling.states[i].power = 1000 - step * i;
 879         }
 880         return 0;
 881 }
 882
 883 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 884                                               int state)
 885 {
 886         u32 value = 0;
 887         u32 duty_mask = 0;
 888         u32 duty_value = 0;
 889
 890         if (!pr)
 891                 return -EINVAL;
 892
 893         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 894                 return -EINVAL;
 895
 896         if (!pr->flags.throttling)
 897                 return -ENODEV;
 898
 899         if (state == pr->throttling.state)
 900                 return 0;
 901
 902         if (state < pr->throttling_platform_limit)
 903                 return -EPERM;
 904         /*
 905          * Calculate the duty_value and duty_mask.
 906          */
 907         if (state) {
 908                 duty_value = pr->throttling.state_count - state;
 909
 910                 duty_value <<= pr->throttling.duty_offset;
 911
 912                 /* Used to clear all duty_value bits */
 913                 duty_mask = pr->throttling.state_count - 1;
 914
 915                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 916                 duty_mask = ~duty_mask;
 917         }
 918
 919         local_irq_disable();
 920
 921         /*
 922          * Disable throttling by writing a 0 to bit 4.  Note that we must
 923          * turn it off before you can change the duty_value.
 924          */
 925         value = inl(pr->throttling.address);
 926         if (value & 0x10) {
 927                 value &= 0xFFFFFFEF;
 928                 outl(value, pr->throttling.address);
 929         }
 930
 931         /*
 932          * Write the new duty_value and then enable throttling.  Note
 933          * that a state value of 0 leaves throttling disabled.
 934          */
 935         if (state) {
 936                 value &= duty_mask;
 937                 value |= duty_value;
 938                 outl(value, pr->throttling.address);
 939
 940                 value |= 0x00000010;
 941                 outl(value, pr->throttling.address);
 942         }
 943
 944         pr->throttling.state = state;
 945
 946         local_irq_enable();
 947
 948         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 949                           "Throttling state set to T%d (%d%%)\n", state,
 950                           (pr->throttling.states[state].performance ? pr->
 951                            throttling.states[state].performance / 10 : 0)));
 952
 953         return 0;
 954 }
 955
 956 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 957                                              int state)
 958 {
 959         int ret;
 960         acpi_integer value;
 961
 962         if (!pr)
 963                 return -EINVAL;
 964
 965         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 966                 return -EINVAL;
 967
 968         if (!pr->flags.throttling)
 969                 return -ENODEV;
 970
 971         if (state == pr->throttling.state)
 972                 return 0;
 973
 974         if (state < pr->throttling_platform_limit)
 975                 return -EPERM;
 976
 977         value = 0;
 978         ret = acpi_get_throttling_value(pr, state, &value);
 979         if (ret >= 0) {
 980                 acpi_write_throttling_state(pr, value);
 981                 pr->throttling.state = state;
 982         }
 983
 984         return 0;
 985 }
 986
 987 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
 988 {
 989         cpumask_t saved_mask;
 990         int ret = 0;
 991         unsigned int i;
 992         struct acpi_processor *match_pr;
 993         struct acpi_processor_throttling *p_throttling;
 994         struct throttling_tstate t_state;
 995         cpumask_t online_throttling_cpus;
 996
 997         if (!pr)
 998                 return -EINVAL;
 999
1000         if (!pr->flags.throttling)
1001                 return -ENODEV;
1002
1003         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1004                 return -EINVAL;
1005
1006         saved_mask = current->cpus_allowed;
1007         t_state.target_state = state;
1008         p_throttling = &(pr->throttling);
1009         cpus_and(online_throttling_cpus, cpu_online_map,
1010                         p_throttling->shared_cpu_map);
1011         /*
1012          * The throttling notifier will be called for every
1013          * affected cpu in order to get one proper T-state.
1014          * The notifier event is THROTTLING_PRECHANGE.
1015          */
1016         for_each_cpu_mask(i, online_throttling_cpus) {
1017                 t_state.cpu = i;
1018                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1019                                                         &t_state);
1020         }
1021         /*
1022          * The function of acpi_processor_set_throttling will be called
1023          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1024          * it is necessary to call it for every affected cpu. Otherwise
1025          * it can be called only for the cpu pointed by pr.
1026          */
1027         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1028                 set_cpus_allowed_ptr(current, &cpumask_of_cpu(pr->id));
1029                 ret = p_throttling->acpi_processor_set_throttling(pr,
1030                                                 t_state.target_state);
1031         } else {
1032                 /*
1033                  * When the T-state coordination is SW_ALL or HW_ALL,
1034                  * it is necessary to set T-state for every affected
1035                  * cpus.
1036                  */
1037                 for_each_cpu_mask(i, online_throttling_cpus) {
1038                         match_pr = processors[i];
1039                         /*
1040                          * If the pointer is invalid, we will report the
1041                          * error message and continue.
1042                          */
1043                         if (!match_pr) {
1044                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1045                                         "Invalid Pointer for CPU %d\n", i));
1046                                 continue;
1047                         }
1048                         /*
1049                          * If the throttling control is unsupported on CPU i,
1050                          * we will report the error message and continue.
1051                          */
1052                         if (!match_pr->flags.throttling) {
1053                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1054                                         "Throttling Controll is unsupported "
1055                                         "on CPU %d\n", i));
1056                                 continue;
1057                         }
1058                         t_state.cpu = i;
1059                         set_cpus_allowed_ptr(current, &cpumask_of_cpu(i));
1060                         ret = match_pr->throttling.
1061                                 acpi_processor_set_throttling(
1062                                 match_pr, t_state.target_state);
1063                 }
1064         }
1065         /*
1066          * After the set_throttling is called, the
1067          * throttling notifier is called for every
1068          * affected cpu to update the T-states.
1069          * The notifier event is THROTTLING_POSTCHANGE
1070          */
1071         for_each_cpu_mask(i, online_throttling_cpus) {
1072                 t_state.cpu = i;
1073                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1074                                                         &t_state);
1075         }
1076         /* restore the previous state */
1077         set_cpus_allowed_ptr(current, &saved_mask);
1078         return ret;
1079 }
1080
1081 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1082 {
1083         int result = 0;
1084         struct acpi_processor_throttling *pthrottling;
1085
1086         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1087                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1088                           pr->throttling.address,
1089                           pr->throttling.duty_offset,
1090                           pr->throttling.duty_width));
1091
1092         if (!pr)
1093                 return -EINVAL;
1094
1095         /*
1096          * Evaluate _PTC, _TSS and _TPC
1097          * They must all be present or none of them can be used.
1098          */
1099         if (acpi_processor_get_throttling_control(pr) ||
1100                 acpi_processor_get_throttling_states(pr) ||
1101                 acpi_processor_get_platform_limit(pr))
1102         {
1103                 pr->throttling.acpi_processor_get_throttling =
1104                     &acpi_processor_get_throttling_fadt;
1105                 pr->throttling.acpi_processor_set_throttling =
1106                     &acpi_processor_set_throttling_fadt;
1107                 if (acpi_processor_get_fadt_info(pr))
1108                         return 0;
1109         } else {
1110                 pr->throttling.acpi_processor_get_throttling =
1111                     &acpi_processor_get_throttling_ptc;
1112                 pr->throttling.acpi_processor_set_throttling =
1113                     &acpi_processor_set_throttling_ptc;
1114         }
1115
1116         /*
1117          * If TSD package for one CPU can't be parsed successfully, it means
1118          * that this CPU will have no coordination with other CPUs.
1119          */
1120         if (acpi_processor_get_tsd(pr)) {
1121                 pthrottling = &pr->throttling;
1122                 pthrottling->tsd_valid_flag = 0;
1123                 cpu_set(pr->id, pthrottling->shared_cpu_map);
1124                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1125         }
1126
1127         /*
1128          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1129          * This shouldn't be an issue as few (if any) mobile systems ever
1130          * used this part.
1131          */
1132         if (errata.piix4.throttle) {
1133                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1134                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1135                 return 0;
1136         }
1137
1138         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1139                           pr->throttling.state_count));
1140
1141         pr->flags.throttling = 1;
1142
1143         /*
1144          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1145          * thermal) decide to lower performance if it so chooses, but for now
1146          * we'll crank up the speed.
1147          */
1148
1149         result = acpi_processor_get_throttling(pr);
1150         if (result)
1151                 goto end;
1152
1153         if (pr->throttling.state) {
1154                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1155                                   "Disabling throttling (was T%d)\n",
1156                                   pr->throttling.state));
1157                 result = acpi_processor_set_throttling(pr, 0);
1158                 if (result)
1159                         goto end;
1160         }
1161
1162       end:
1163         if (result)
1164                 pr->flags.throttling = 0;
1165
1166         return result;
1167 }
1168
1169 /* proc interface */
1170
1171 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1172                                               void *offset)
1173 {
1174         struct acpi_processor *pr = seq->private;
1175         int i = 0;
1176         int result = 0;
1177
1178         if (!pr)
1179                 goto end;
1180
1181         if (!(pr->throttling.state_count > 0)) {
1182                 seq_puts(seq, "<not supported>\n");
1183                 goto end;
1184         }
1185
1186         result = acpi_processor_get_throttling(pr);
1187
1188         if (result) {
1189                 seq_puts(seq,
1190                          "Could not determine current throttling state.\n");
1191                 goto end;
1192         }
1193
1194         seq_printf(seq, "state count:             %d\n"
1195                    "active state:            T%d\n"
1196                    "state available: T%d to T%d\n",
1197                    pr->throttling.state_count, pr->throttling.state,
1198                    pr->throttling_platform_limit,
1199                    pr->throttling.state_count - 1);
1200
1201         seq_puts(seq, "states:\n");
1202         if (pr->throttling.acpi_processor_get_throttling ==
1203                         acpi_processor_get_throttling_fadt) {
1204                 for (i = 0; i < pr->throttling.state_count; i++)
1205                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1206                                    (i == pr->throttling.state ? '*' : ' '), i,
1207                                    (pr->throttling.states[i].performance ? pr->
1208                                     throttling.states[i].performance / 10 : 0));
1209         } else {
1210                 for (i = 0; i < pr->throttling.state_count; i++)
1211                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1212                                    (i == pr->throttling.state ? '*' : ' '), i,
1213                                    (int)pr->throttling.states_tss[i].
1214                                    freqpercentage);
1215         }
1216
1217       end:
1218         return 0;
1219 }
1220
1221 static int acpi_processor_throttling_open_fs(struct inode *inode,
1222                                              struct file *file)
1223 {
1224         return single_open(file, acpi_processor_throttling_seq_show,
1225                            PDE(inode)->data);
1226 }
1227
1228 static ssize_t acpi_processor_write_throttling(struct file *file,
1229                                                const char __user * buffer,
1230                                                size_t count, loff_t * data)
1231 {
1232         int result = 0;
1233         struct seq_file *m = file->private_data;
1234         struct acpi_processor *pr = m->private;
1235         char state_string[12] = { '\0' };
1236
1237         if (!pr || (count > sizeof(state_string) - 1))
1238                 return -EINVAL;
1239
1240         if (copy_from_user(state_string, buffer, count))
1241                 return -EFAULT;
1242
1243         state_string[count] = '\0';
1244
1245         result = acpi_processor_set_throttling(pr,
1246                                                simple_strtoul(state_string,
1247                                                               NULL, 0));
1248         if (result)
1249                 return result;
1250
1251         return count;
1252 }
1253
1254 struct file_operations acpi_processor_throttling_fops = {
1255         .open = acpi_processor_throttling_open_fs,
1256         .read = seq_read,
1257         .write = acpi_processor_write_throttling,
1258         .llseek = seq_lseek,
1259         .release = single_release,
1260 };