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 #ifdef CONFIG_ACPI_PROCFS
  36 #include <linux/proc_fs.h>
  37 #include <linux/seq_file.h>
  38 #endif
  39
  40 #include <asm/io.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45 #include <acpi/processor.h>
  46
  47 #define PREFIX "ACPI: "
  48
  49 #define ACPI_PROCESSOR_CLASS            "processor"
  50 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  51 ACPI_MODULE_NAME("processor_throttling");
  52
  53 /* ignore_tpc:
  54  *  0 -> acpi processor driver doesn't ignore _TPC values
  55  *  1 -> acpi processor driver ignores _TPC values
  56  */
  57 static int ignore_tpc;
  58 module_param(ignore_tpc, int, 0644);
  59 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  60
  61 struct throttling_tstate {
  62         unsigned int cpu;               /* cpu nr */
  63         int target_state;               /* target T-state */
  64 };
  65
  66 #define THROTTLING_PRECHANGE       (1)
  67 #define THROTTLING_POSTCHANGE      (2)
  68
  69 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  70 int acpi_processor_set_throttling(struct acpi_processor *pr,
  71                                                 int state, bool force);
  72
  73 static int acpi_processor_update_tsd_coord(void)
  74 {
  75         int count, count_target;
  76         int retval = 0;
  77         unsigned int i, j;
  78         cpumask_var_t covered_cpus;
  79         struct acpi_processor *pr, *match_pr;
  80         struct acpi_tsd_package *pdomain, *match_pdomain;
  81         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  82
  83         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  84                 return -ENOMEM;
  85
  86         /*
  87          * Now that we have _TSD data from all CPUs, lets setup T-state
  88          * coordination between all CPUs.
  89          */
  90         for_each_possible_cpu(i) {
  91                 pr = per_cpu(processors, i);
  92                 if (!pr)
  93                         continue;
  94
  95                 /* Basic validity check for domain info */
  96                 pthrottling = &(pr->throttling);
  97
  98                 /*
  99                  * If tsd package for one cpu is invalid, the coordination
 100                  * among all CPUs is thought as invalid.
 101                  * Maybe it is ugly.
 102                  */
 103                 if (!pthrottling->tsd_valid_flag) {
 104                         retval = -EINVAL;
 105                         break;
 106                 }
 107         }
 108         if (retval)
 109                 goto err_ret;
 110
 111         for_each_possible_cpu(i) {
 112                 pr = per_cpu(processors, i);
 113                 if (!pr)
 114                         continue;
 115
 116                 if (cpumask_test_cpu(i, covered_cpus))
 117                         continue;
 118                 pthrottling = &pr->throttling;
 119
 120                 pdomain = &(pthrottling->domain_info);
 121                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 122                 cpumask_set_cpu(i, covered_cpus);
 123                 /*
 124                  * If the number of processor in the TSD domain is 1, it is
 125                  * unnecessary to parse the coordination for this CPU.
 126                  */
 127                 if (pdomain->num_processors <= 1)
 128                         continue;
 129
 130                 /* Validate the Domain info */
 131                 count_target = pdomain->num_processors;
 132                 count = 1;
 133
 134                 for_each_possible_cpu(j) {
 135                         if (i == j)
 136                                 continue;
 137
 138                         match_pr = per_cpu(processors, j);
 139                         if (!match_pr)
 140                                 continue;
 141
 142                         match_pthrottling = &(match_pr->throttling);
 143                         match_pdomain = &(match_pthrottling->domain_info);
 144                         if (match_pdomain->domain != pdomain->domain)
 145                                 continue;
 146
 147                         /* Here i and j are in the same domain.
 148                          * If two TSD packages have the same domain, they
 149                          * should have the same num_porcessors and
 150                          * coordination type. Otherwise it will be regarded
 151                          * as illegal.
 152                          */
 153                         if (match_pdomain->num_processors != count_target) {
 154                                 retval = -EINVAL;
 155                                 goto err_ret;
 156                         }
 157
 158                         if (pdomain->coord_type != match_pdomain->coord_type) {
 159                                 retval = -EINVAL;
 160                                 goto err_ret;
 161                         }
 162
 163                         cpumask_set_cpu(j, covered_cpus);
 164                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 165                         count++;
 166                 }
 167                 for_each_possible_cpu(j) {
 168                         if (i == j)
 169                                 continue;
 170
 171                         match_pr = per_cpu(processors, j);
 172                         if (!match_pr)
 173                                 continue;
 174
 175                         match_pthrottling = &(match_pr->throttling);
 176                         match_pdomain = &(match_pthrottling->domain_info);
 177                         if (match_pdomain->domain != pdomain->domain)
 178                                 continue;
 179
 180                         /*
 181                          * If some CPUS have the same domain, they
 182                          * will have the same shared_cpu_map.
 183                          */
 184                         cpumask_copy(match_pthrottling->shared_cpu_map,
 185                                      pthrottling->shared_cpu_map);
 186                 }
 187         }
 188
 189 err_ret:
 190         free_cpumask_var(covered_cpus);
 191
 192         for_each_possible_cpu(i) {
 193                 pr = per_cpu(processors, i);
 194                 if (!pr)
 195                         continue;
 196
 197                 /*
 198                  * Assume no coordination on any error parsing domain info.
 199                  * The coordination type will be forced as SW_ALL.
 200                  */
 201                 if (retval) {
 202                         pthrottling = &(pr->throttling);
 203                         cpumask_clear(pthrottling->shared_cpu_map);
 204                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 205                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 206                 }
 207         }
 208
 209         return retval;
 210 }
 211
 212 /*
 213  * Update the T-state coordination after the _TSD
 214  * data for all cpus is obtained.
 215  */
 216 void acpi_processor_throttling_init(void)
 217 {
 218         if (acpi_processor_update_tsd_coord())
 219                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 220                         "Assume no T-state coordination\n"));
 221
 222         return;
 223 }
 224
 225 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 226 {
 227         struct throttling_tstate *p_tstate = data;
 228         struct acpi_processor *pr;
 229         unsigned int cpu ;
 230         int target_state;
 231         struct acpi_processor_limit *p_limit;
 232         struct acpi_processor_throttling *p_throttling;
 233
 234         cpu = p_tstate->cpu;
 235         pr = per_cpu(processors, cpu);
 236         if (!pr) {
 237                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 238                 return 0;
 239         }
 240         if (!pr->flags.throttling) {
 241                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 242                                 "unsupported on CPU %d\n", cpu));
 243                 return 0;
 244         }
 245         target_state = p_tstate->target_state;
 246         p_throttling = &(pr->throttling);
 247         switch (event) {
 248         case THROTTLING_PRECHANGE:
 249                 /*
 250                  * Prechange event is used to choose one proper t-state,
 251                  * which meets the limits of thermal, user and _TPC.
 252                  */
 253                 p_limit = &pr->limit;
 254                 if (p_limit->thermal.tx > target_state)
 255                         target_state = p_limit->thermal.tx;
 256                 if (p_limit->user.tx > target_state)
 257                         target_state = p_limit->user.tx;
 258                 if (pr->throttling_platform_limit > target_state)
 259                         target_state = pr->throttling_platform_limit;
 260                 if (target_state >= p_throttling->state_count) {
 261                         printk(KERN_WARNING
 262                                 "Exceed the limit of T-state \n");
 263                         target_state = p_throttling->state_count - 1;
 264                 }
 265                 p_tstate->target_state = target_state;
 266                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 267                                 "target T-state of CPU %d is T%d\n",
 268                                 cpu, target_state));
 269                 break;
 270         case THROTTLING_POSTCHANGE:
 271                 /*
 272                  * Postchange event is only used to update the
 273                  * T-state flag of acpi_processor_throttling.
 274                  */
 275                 p_throttling->state = target_state;
 276                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 277                                 "CPU %d is switched to T%d\n",
 278                                 cpu, target_state));
 279                 break;
 280         default:
 281                 printk(KERN_WARNING
 282                         "Unsupported Throttling notifier event\n");
 283                 break;
 284         }
 285
 286         return 0;
 287 }
 288
 289 /*
 290  * _TPC - Throttling Present Capabilities
 291  */
 292 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 293 {
 294         acpi_status status = 0;
 295         unsigned long long tpc = 0;
 296
 297         if (!pr)
 298                 return -EINVAL;
 299
 300         if (ignore_tpc)
 301                 goto end;
 302
 303         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 304         if (ACPI_FAILURE(status)) {
 305                 if (status != AE_NOT_FOUND) {
 306                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 307                 }
 308                 return -ENODEV;
 309         }
 310
 311 end:
 312         pr->throttling_platform_limit = (int)tpc;
 313         return 0;
 314 }
 315
 316 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 317 {
 318         int result = 0;
 319         int throttling_limit;
 320         int current_state;
 321         struct acpi_processor_limit *limit;
 322         int target_state;
 323
 324         if (ignore_tpc)
 325                 return 0;
 326
 327         result = acpi_processor_get_platform_limit(pr);
 328         if (result) {
 329                 /* Throttling Limit is unsupported */
 330                 return result;
 331         }
 332
 333         throttling_limit = pr->throttling_platform_limit;
 334         if (throttling_limit >= pr->throttling.state_count) {
 335                 /* Uncorrect Throttling Limit */
 336                 return -EINVAL;
 337         }
 338
 339         current_state = pr->throttling.state;
 340         if (current_state > throttling_limit) {
 341                 /*
 342                  * The current state can meet the requirement of
 343                  * _TPC limit. But it is reasonable that OSPM changes
 344                  * t-states from high to low for better performance.
 345                  * Of course the limit condition of thermal
 346                  * and user should be considered.
 347                  */
 348                 limit = &pr->limit;
 349                 target_state = throttling_limit;
 350                 if (limit->thermal.tx > target_state)
 351                         target_state = limit->thermal.tx;
 352                 if (limit->user.tx > target_state)
 353                         target_state = limit->user.tx;
 354         } else if (current_state == throttling_limit) {
 355                 /*
 356                  * Unnecessary to change the throttling state
 357                  */
 358                 return 0;
 359         } else {
 360                 /*
 361                  * If the current state is lower than the limit of _TPC, it
 362                  * will be forced to switch to the throttling state defined
 363                  * by throttling_platfor_limit.
 364                  * Because the previous state meets with the limit condition
 365                  * of thermal and user, it is unnecessary to check it again.
 366                  */
 367                 target_state = throttling_limit;
 368         }
 369         return acpi_processor_set_throttling(pr, target_state, false);
 370 }
 371
 372 /*
 373  * _PTC - Processor Throttling Control (and status) register location
 374  */
 375 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 376 {
 377         int result = 0;
 378         acpi_status status = 0;
 379         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 380         union acpi_object *ptc = NULL;
 381         union acpi_object obj = { 0 };
 382         struct acpi_processor_throttling *throttling;
 383
 384         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 385         if (ACPI_FAILURE(status)) {
 386                 if (status != AE_NOT_FOUND) {
 387                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 388                 }
 389                 return -ENODEV;
 390         }
 391
 392         ptc = (union acpi_object *)buffer.pointer;
 393         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 394             || (ptc->package.count != 2)) {
 395                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 396                 result = -EFAULT;
 397                 goto end;
 398         }
 399
 400         /*
 401          * control_register
 402          */
 403
 404         obj = ptc->package.elements[0];
 405
 406         if ((obj.type != ACPI_TYPE_BUFFER)
 407             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 408             || (obj.buffer.pointer == NULL)) {
 409                 printk(KERN_ERR PREFIX
 410                        "Invalid _PTC data (control_register)\n");
 411                 result = -EFAULT;
 412                 goto end;
 413         }
 414         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 415                sizeof(struct acpi_ptc_register));
 416
 417         /*
 418          * status_register
 419          */
 420
 421         obj = ptc->package.elements[1];
 422
 423         if ((obj.type != ACPI_TYPE_BUFFER)
 424             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 425             || (obj.buffer.pointer == NULL)) {
 426                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 427                 result = -EFAULT;
 428                 goto end;
 429         }
 430
 431         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 432                sizeof(struct acpi_ptc_register));
 433
 434         throttling = &pr->throttling;
 435
 436         if ((throttling->control_register.bit_width +
 437                 throttling->control_register.bit_offset) > 32) {
 438                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 439                 result = -EFAULT;
 440                 goto end;
 441         }
 442
 443         if ((throttling->status_register.bit_width +
 444                 throttling->status_register.bit_offset) > 32) {
 445                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 446                 result = -EFAULT;
 447                 goto end;
 448         }
 449
 450       end:
 451         kfree(buffer.pointer);
 452
 453         return result;
 454 }
 455
 456 /*
 457  * _TSS - Throttling Supported States
 458  */
 459 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 460 {
 461         int result = 0;
 462         acpi_status status = AE_OK;
 463         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 464         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 465         struct acpi_buffer state = { 0, NULL };
 466         union acpi_object *tss = NULL;
 467         int i;
 468
 469         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 470         if (ACPI_FAILURE(status)) {
 471                 if (status != AE_NOT_FOUND) {
 472                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 473                 }
 474                 return -ENODEV;
 475         }
 476
 477         tss = buffer.pointer;
 478         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 479                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 480                 result = -EFAULT;
 481                 goto end;
 482         }
 483
 484         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 485                           tss->package.count));
 486
 487         pr->throttling.state_count = tss->package.count;
 488         pr->throttling.states_tss =
 489             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 490                     GFP_KERNEL);
 491         if (!pr->throttling.states_tss) {
 492                 result = -ENOMEM;
 493                 goto end;
 494         }
 495
 496         for (i = 0; i < pr->throttling.state_count; i++) {
 497
 498                 struct acpi_processor_tx_tss *tx =
 499                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 500                                                       states_tss[i]);
 501
 502                 state.length = sizeof(struct acpi_processor_tx_tss);
 503                 state.pointer = tx;
 504
 505                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 506
 507                 status = acpi_extract_package(&(tss->package.elements[i]),
 508                                               &format, &state);
 509                 if (ACPI_FAILURE(status)) {
 510                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 511                         result = -EFAULT;
 512                         kfree(pr->throttling.states_tss);
 513                         goto end;
 514                 }
 515
 516                 if (!tx->freqpercentage) {
 517                         printk(KERN_ERR PREFIX
 518                                "Invalid _TSS data: freq is zero\n");
 519                         result = -EFAULT;
 520                         kfree(pr->throttling.states_tss);
 521                         goto end;
 522                 }
 523         }
 524
 525       end:
 526         kfree(buffer.pointer);
 527
 528         return result;
 529 }
 530
 531 /*
 532  * _TSD - T-State Dependencies
 533  */
 534 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 535 {
 536         int result = 0;
 537         acpi_status status = AE_OK;
 538         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 539         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 540         struct acpi_buffer state = { 0, NULL };
 541         union acpi_object *tsd = NULL;
 542         struct acpi_tsd_package *pdomain;
 543         struct acpi_processor_throttling *pthrottling;
 544
 545         pthrottling = &pr->throttling;
 546         pthrottling->tsd_valid_flag = 0;
 547
 548         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 549         if (ACPI_FAILURE(status)) {
 550                 if (status != AE_NOT_FOUND) {
 551                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 552                 }
 553                 return -ENODEV;
 554         }
 555
 556         tsd = buffer.pointer;
 557         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 558                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 559                 result = -EFAULT;
 560                 goto end;
 561         }
 562
 563         if (tsd->package.count != 1) {
 564                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 565                 result = -EFAULT;
 566                 goto end;
 567         }
 568
 569         pdomain = &(pr->throttling.domain_info);
 570
 571         state.length = sizeof(struct acpi_tsd_package);
 572         state.pointer = pdomain;
 573
 574         status = acpi_extract_package(&(tsd->package.elements[0]),
 575                                       &format, &state);
 576         if (ACPI_FAILURE(status)) {
 577                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 578                 result = -EFAULT;
 579                 goto end;
 580         }
 581
 582         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 583                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 584                 result = -EFAULT;
 585                 goto end;
 586         }
 587
 588         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 589                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 590                 result = -EFAULT;
 591                 goto end;
 592         }
 593
 594         pthrottling = &pr->throttling;
 595         pthrottling->tsd_valid_flag = 1;
 596         pthrottling->shared_type = pdomain->coord_type;
 597         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 598         /*
 599          * If the coordination type is not defined in ACPI spec,
 600          * the tsd_valid_flag will be clear and coordination type
 601          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 602          */
 603         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 604                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 605                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 606                 pthrottling->tsd_valid_flag = 0;
 607                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 608         }
 609
 610       end:
 611         kfree(buffer.pointer);
 612         return result;
 613 }
 614
 615 /* --------------------------------------------------------------------------
 616                               Throttling Control
 617    -------------------------------------------------------------------------- */
 618 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 619 {
 620         int state = 0;
 621         u32 value = 0;
 622         u32 duty_mask = 0;
 623         u32 duty_value = 0;
 624
 625         if (!pr)
 626                 return -EINVAL;
 627
 628         if (!pr->flags.throttling)
 629                 return -ENODEV;
 630
 631         pr->throttling.state = 0;
 632
 633         duty_mask = pr->throttling.state_count - 1;
 634
 635         duty_mask <<= pr->throttling.duty_offset;
 636
 637         local_irq_disable();
 638
 639         value = inl(pr->throttling.address);
 640
 641         /*
 642          * Compute the current throttling state when throttling is enabled
 643          * (bit 4 is on).
 644          */
 645         if (value & 0x10) {
 646                 duty_value = value & duty_mask;
 647                 duty_value >>= pr->throttling.duty_offset;
 648
 649                 if (duty_value)
 650                         state = pr->throttling.state_count - duty_value;
 651         }
 652
 653         pr->throttling.state = state;
 654
 655         local_irq_enable();
 656
 657         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 658                           "Throttling state is T%d (%d%% throttling applied)\n",
 659                           state, pr->throttling.states[state].performance));
 660
 661         return 0;
 662 }
 663
 664 #ifdef CONFIG_X86
 665 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 666                                         u64 *value)
 667 {
 668         struct cpuinfo_x86 *c;
 669         u64 msr_high, msr_low;
 670         unsigned int cpu;
 671         u64 msr = 0;
 672         int ret = -1;
 673
 674         cpu = pr->id;
 675         c = &cpu_data(cpu);
 676
 677         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 678                 !cpu_has(c, X86_FEATURE_ACPI)) {
 679                 printk(KERN_ERR PREFIX
 680                         "HARDWARE addr space,NOT supported yet\n");
 681         } else {
 682                 msr_low = 0;
 683                 msr_high = 0;
 684                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 685                         (u32 *)&msr_low , (u32 *) &msr_high);
 686                 msr = (msr_high << 32) | msr_low;
 687                 *value = (u64) msr;
 688                 ret = 0;
 689         }
 690         return ret;
 691 }
 692
 693 static int acpi_throttling_wrmsr(struct acpi_processor *pr, u64 value)
 694 {
 695         struct cpuinfo_x86 *c;
 696         unsigned int cpu;
 697         int ret = -1;
 698         u64 msr;
 699
 700         cpu = pr->id;
 701         c = &cpu_data(cpu);
 702
 703         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 704                 !cpu_has(c, X86_FEATURE_ACPI)) {
 705                 printk(KERN_ERR PREFIX
 706                         "HARDWARE addr space,NOT supported yet\n");
 707         } else {
 708                 msr = value;
 709                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 710                         msr & 0xffffffff, msr >> 32);
 711                 ret = 0;
 712         }
 713         return ret;
 714 }
 715 #else
 716 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 717                                 u64 *value)
 718 {
 719         printk(KERN_ERR PREFIX
 720                 "HARDWARE addr space,NOT supported yet\n");
 721         return -1;
 722 }
 723
 724 static int acpi_throttling_wrmsr(struct acpi_processor *pr, u64 value)
 725 {
 726         printk(KERN_ERR PREFIX
 727                 "HARDWARE addr space,NOT supported yet\n");
 728         return -1;
 729 }
 730 #endif
 731
 732 static int acpi_read_throttling_status(struct acpi_processor *pr,
 733                                         u64 *value)
 734 {
 735         u32 bit_width, bit_offset;
 736         u64 ptc_value;
 737         u64 ptc_mask;
 738         struct acpi_processor_throttling *throttling;
 739         int ret = -1;
 740
 741         throttling = &pr->throttling;
 742         switch (throttling->status_register.space_id) {
 743         case ACPI_ADR_SPACE_SYSTEM_IO:
 744                 ptc_value = 0;
 745                 bit_width = throttling->status_register.bit_width;
 746                 bit_offset = throttling->status_register.bit_offset;
 747
 748                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 749                                   address, (u32 *) &ptc_value,
 750                                   (u32) (bit_width + bit_offset));
 751                 ptc_mask = (1 << bit_width) - 1;
 752                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 753                 ret = 0;
 754                 break;
 755         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 756                 ret = acpi_throttling_rdmsr(pr, value);
 757                 break;
 758         default:
 759                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 760                        (u32) (throttling->status_register.space_id));
 761         }
 762         return ret;
 763 }
 764
 765 static int acpi_write_throttling_state(struct acpi_processor *pr,
 766                                 u64 value)
 767 {
 768         u32 bit_width, bit_offset;
 769         u64 ptc_value;
 770         u64 ptc_mask;
 771         struct acpi_processor_throttling *throttling;
 772         int ret = -1;
 773
 774         throttling = &pr->throttling;
 775         switch (throttling->control_register.space_id) {
 776         case ACPI_ADR_SPACE_SYSTEM_IO:
 777                 bit_width = throttling->control_register.bit_width;
 778                 bit_offset = throttling->control_register.bit_offset;
 779                 ptc_mask = (1 << bit_width) - 1;
 780                 ptc_value = value & ptc_mask;
 781
 782                 acpi_os_write_port((acpi_io_address) throttling->
 783                                         control_register.address,
 784                                         (u32) (ptc_value << bit_offset),
 785                                         (u32) (bit_width + bit_offset));
 786                 ret = 0;
 787                 break;
 788         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 789                 ret = acpi_throttling_wrmsr(pr, value);
 790                 break;
 791         default:
 792                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 793                        (u32) (throttling->control_register.space_id));
 794         }
 795         return ret;
 796 }
 797
 798 static int acpi_get_throttling_state(struct acpi_processor *pr,
 799                                 u64 value)
 800 {
 801         int i;
 802
 803         for (i = 0; i < pr->throttling.state_count; i++) {
 804                 struct acpi_processor_tx_tss *tx =
 805                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 806                                                       states_tss[i]);
 807                 if (tx->control == value)
 808                         return i;
 809         }
 810         return -1;
 811 }
 812
 813 static int acpi_get_throttling_value(struct acpi_processor *pr,
 814                         int state, u64 *value)
 815 {
 816         int ret = -1;
 817
 818         if (state >= 0 && state <= pr->throttling.state_count) {
 819                 struct acpi_processor_tx_tss *tx =
 820                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 821                                                       states_tss[state]);
 822                 *value = tx->control;
 823                 ret = 0;
 824         }
 825         return ret;
 826 }
 827
 828 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 829 {
 830         int state = 0;
 831         int ret;
 832         u64 value;
 833
 834         if (!pr)
 835                 return -EINVAL;
 836
 837         if (!pr->flags.throttling)
 838                 return -ENODEV;
 839
 840         pr->throttling.state = 0;
 841
 842         value = 0;
 843         ret = acpi_read_throttling_status(pr, &value);
 844         if (ret >= 0) {
 845                 state = acpi_get_throttling_state(pr, value);
 846                 if (state == -1) {
 847                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 848                                 "Invalid throttling state, reset\n"));
 849                         state = 0;
 850                         ret = acpi_processor_set_throttling(pr, state, true);
 851                         if (ret)
 852                                 return ret;
 853                 }
 854                 pr->throttling.state = state;
 855         }
 856
 857         return 0;
 858 }
 859
 860 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 861 {
 862         cpumask_var_t saved_mask;
 863         int ret;
 864
 865         if (!pr)
 866                 return -EINVAL;
 867
 868         if (!pr->flags.throttling)
 869                 return -ENODEV;
 870
 871         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 872                 return -ENOMEM;
 873
 874         /*
 875          * Migrate task to the cpu pointed by pr.
 876          */
 877         cpumask_copy(saved_mask, &current->cpus_allowed);
 878         /* FIXME: use work_on_cpu() */
 879         set_cpus_allowed_ptr(current, cpumask_of(pr->id));
 880         ret = pr->throttling.acpi_processor_get_throttling(pr);
 881         /* restore the previous state */
 882         set_cpus_allowed_ptr(current, saved_mask);
 883         free_cpumask_var(saved_mask);
 884
 885         return ret;
 886 }
 887
 888 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 889 {
 890         int i, step;
 891
 892         if (!pr->throttling.address) {
 893                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 894                 return -EINVAL;
 895         } else if (!pr->throttling.duty_width) {
 896                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 897                 return -EINVAL;
 898         }
 899         /* TBD: Support duty_cycle values that span bit 4. */
 900         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 901                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 902                 return -EINVAL;
 903         }
 904
 905         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 906
 907         /*
 908          * Compute state values. Note that throttling displays a linear power
 909          * performance relationship (at 50% performance the CPU will consume
 910          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 911          */
 912
 913         step = (1000 / pr->throttling.state_count);
 914
 915         for (i = 0; i < pr->throttling.state_count; i++) {
 916                 pr->throttling.states[i].performance = 1000 - step * i;
 917                 pr->throttling.states[i].power = 1000 - step * i;
 918         }
 919         return 0;
 920 }
 921
 922 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 923                                               int state, bool force)
 924 {
 925         u32 value = 0;
 926         u32 duty_mask = 0;
 927         u32 duty_value = 0;
 928
 929         if (!pr)
 930                 return -EINVAL;
 931
 932         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 933                 return -EINVAL;
 934
 935         if (!pr->flags.throttling)
 936                 return -ENODEV;
 937
 938         if (!force && (state == pr->throttling.state))
 939                 return 0;
 940
 941         if (state < pr->throttling_platform_limit)
 942                 return -EPERM;
 943         /*
 944          * Calculate the duty_value and duty_mask.
 945          */
 946         if (state) {
 947                 duty_value = pr->throttling.state_count - state;
 948
 949                 duty_value <<= pr->throttling.duty_offset;
 950
 951                 /* Used to clear all duty_value bits */
 952                 duty_mask = pr->throttling.state_count - 1;
 953
 954                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 955                 duty_mask = ~duty_mask;
 956         }
 957
 958         local_irq_disable();
 959
 960         /*
 961          * Disable throttling by writing a 0 to bit 4.  Note that we must
 962          * turn it off before you can change the duty_value.
 963          */
 964         value = inl(pr->throttling.address);
 965         if (value & 0x10) {
 966                 value &= 0xFFFFFFEF;
 967                 outl(value, pr->throttling.address);
 968         }
 969
 970         /*
 971          * Write the new duty_value and then enable throttling.  Note
 972          * that a state value of 0 leaves throttling disabled.
 973          */
 974         if (state) {
 975                 value &= duty_mask;
 976                 value |= duty_value;
 977                 outl(value, pr->throttling.address);
 978
 979                 value |= 0x00000010;
 980                 outl(value, pr->throttling.address);
 981         }
 982
 983         pr->throttling.state = state;
 984
 985         local_irq_enable();
 986
 987         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 988                           "Throttling state set to T%d (%d%%)\n", state,
 989                           (pr->throttling.states[state].performance ? pr->
 990                            throttling.states[state].performance / 10 : 0)));
 991
 992         return 0;
 993 }
 994
 995 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 996                                              int state, bool force)
 997 {
 998         int ret;
 999         u64 value;
1000
1001         if (!pr)
1002                 return -EINVAL;
1003
1004         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1005                 return -EINVAL;
1006
1007         if (!pr->flags.throttling)
1008                 return -ENODEV;
1009
1010         if (!force && (state == pr->throttling.state))
1011                 return 0;
1012
1013         if (state < pr->throttling_platform_limit)
1014                 return -EPERM;
1015
1016         value = 0;
1017         ret = acpi_get_throttling_value(pr, state, &value);
1018         if (ret >= 0) {
1019                 acpi_write_throttling_state(pr, value);
1020                 pr->throttling.state = state;
1021         }
1022
1023         return 0;
1024 }
1025
1026 int acpi_processor_set_throttling(struct acpi_processor *pr,
1027                                                 int state, bool force)
1028 {
1029         cpumask_var_t saved_mask;
1030         int ret = 0;
1031         unsigned int i;
1032         struct acpi_processor *match_pr;
1033         struct acpi_processor_throttling *p_throttling;
1034         struct throttling_tstate t_state;
1035         cpumask_var_t online_throttling_cpus;
1036
1037         if (!pr)
1038                 return -EINVAL;
1039
1040         if (!pr->flags.throttling)
1041                 return -ENODEV;
1042
1043         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1044                 return -EINVAL;
1045
1046         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1047                 return -ENOMEM;
1048
1049         if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1050                 free_cpumask_var(saved_mask);
1051                 return -ENOMEM;
1052         }
1053
1054         cpumask_copy(saved_mask, &current->cpus_allowed);
1055         t_state.target_state = state;
1056         p_throttling = &(pr->throttling);
1057         cpumask_and(online_throttling_cpus, cpu_online_mask,
1058                     p_throttling->shared_cpu_map);
1059         /*
1060          * The throttling notifier will be called for every
1061          * affected cpu in order to get one proper T-state.
1062          * The notifier event is THROTTLING_PRECHANGE.
1063          */
1064         for_each_cpu(i, online_throttling_cpus) {
1065                 t_state.cpu = i;
1066                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1067                                                         &t_state);
1068         }
1069         /*
1070          * The function of acpi_processor_set_throttling will be called
1071          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1072          * it is necessary to call it for every affected cpu. Otherwise
1073          * it can be called only for the cpu pointed by pr.
1074          */
1075         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1076                 /* FIXME: use work_on_cpu() */
1077                 set_cpus_allowed_ptr(current, cpumask_of(pr->id));
1078                 ret = p_throttling->acpi_processor_set_throttling(pr,
1079                                                 t_state.target_state, force);
1080         } else {
1081                 /*
1082                  * When the T-state coordination is SW_ALL or HW_ALL,
1083                  * it is necessary to set T-state for every affected
1084                  * cpus.
1085                  */
1086                 for_each_cpu(i, online_throttling_cpus) {
1087                         match_pr = per_cpu(processors, i);
1088                         /*
1089                          * If the pointer is invalid, we will report the
1090                          * error message and continue.
1091                          */
1092                         if (!match_pr) {
1093                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1094                                         "Invalid Pointer for CPU %d\n", i));
1095                                 continue;
1096                         }
1097                         /*
1098                          * If the throttling control is unsupported on CPU i,
1099                          * we will report the error message and continue.
1100                          */
1101                         if (!match_pr->flags.throttling) {
1102                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1103                                         "Throttling Controll is unsupported "
1104                                         "on CPU %d\n", i));
1105                                 continue;
1106                         }
1107                         t_state.cpu = i;
1108                         /* FIXME: use work_on_cpu() */
1109                         set_cpus_allowed_ptr(current, cpumask_of(i));
1110                         ret = match_pr->throttling.
1111                                 acpi_processor_set_throttling(
1112                                 match_pr, t_state.target_state, force);
1113                 }
1114         }
1115         /*
1116          * After the set_throttling is called, the
1117          * throttling notifier is called for every
1118          * affected cpu to update the T-states.
1119          * The notifier event is THROTTLING_POSTCHANGE
1120          */
1121         for_each_cpu(i, online_throttling_cpus) {
1122                 t_state.cpu = i;
1123                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1124                                                         &t_state);
1125         }
1126         /* restore the previous state */
1127         /* FIXME: use work_on_cpu() */
1128         set_cpus_allowed_ptr(current, saved_mask);
1129         free_cpumask_var(online_throttling_cpus);
1130         free_cpumask_var(saved_mask);
1131         return ret;
1132 }
1133
1134 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1135 {
1136         int result = 0;
1137         struct acpi_processor_throttling *pthrottling;
1138
1139         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1140                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1141                           pr->throttling.address,
1142                           pr->throttling.duty_offset,
1143                           pr->throttling.duty_width));
1144
1145         /*
1146          * Evaluate _PTC, _TSS and _TPC
1147          * They must all be present or none of them can be used.
1148          */
1149         if (acpi_processor_get_throttling_control(pr) ||
1150                 acpi_processor_get_throttling_states(pr) ||
1151                 acpi_processor_get_platform_limit(pr))
1152         {
1153                 pr->throttling.acpi_processor_get_throttling =
1154                     &acpi_processor_get_throttling_fadt;
1155                 pr->throttling.acpi_processor_set_throttling =
1156                     &acpi_processor_set_throttling_fadt;
1157                 if (acpi_processor_get_fadt_info(pr))
1158                         return 0;
1159         } else {
1160                 pr->throttling.acpi_processor_get_throttling =
1161                     &acpi_processor_get_throttling_ptc;
1162                 pr->throttling.acpi_processor_set_throttling =
1163                     &acpi_processor_set_throttling_ptc;
1164         }
1165
1166         /*
1167          * If TSD package for one CPU can't be parsed successfully, it means
1168          * that this CPU will have no coordination with other CPUs.
1169          */
1170         if (acpi_processor_get_tsd(pr)) {
1171                 pthrottling = &pr->throttling;
1172                 pthrottling->tsd_valid_flag = 0;
1173                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1174                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1175         }
1176
1177         /*
1178          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1179          * This shouldn't be an issue as few (if any) mobile systems ever
1180          * used this part.
1181          */
1182         if (errata.piix4.throttle) {
1183                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1184                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1185                 return 0;
1186         }
1187
1188         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1189                           pr->throttling.state_count));
1190
1191         pr->flags.throttling = 1;
1192
1193         /*
1194          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1195          * thermal) decide to lower performance if it so chooses, but for now
1196          * we'll crank up the speed.
1197          */
1198
1199         result = acpi_processor_get_throttling(pr);
1200         if (result)
1201                 goto end;
1202
1203         if (pr->throttling.state) {
1204                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1205                                   "Disabling throttling (was T%d)\n",
1206                                   pr->throttling.state));
1207                 result = acpi_processor_set_throttling(pr, 0, false);
1208                 if (result)
1209                         goto end;
1210         }
1211
1212       end:
1213         if (result)
1214                 pr->flags.throttling = 0;
1215
1216         return result;
1217 }
1218
1219 #ifdef CONFIG_ACPI_PROCFS
1220 /* proc interface */
1221 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1222                                               void *offset)
1223 {
1224         struct acpi_processor *pr = seq->private;
1225         int i = 0;
1226         int result = 0;
1227
1228         if (!pr)
1229                 goto end;
1230
1231         if (!(pr->throttling.state_count > 0)) {
1232                 seq_puts(seq, "<not supported>\n");
1233                 goto end;
1234         }
1235
1236         result = acpi_processor_get_throttling(pr);
1237
1238         if (result) {
1239                 seq_puts(seq,
1240                          "Could not determine current throttling state.\n");
1241                 goto end;
1242         }
1243
1244         seq_printf(seq, "state count:             %d\n"
1245                    "active state:            T%d\n"
1246                    "state available: T%d to T%d\n",
1247                    pr->throttling.state_count, pr->throttling.state,
1248                    pr->throttling_platform_limit,
1249                    pr->throttling.state_count - 1);
1250
1251         seq_puts(seq, "states:\n");
1252         if (pr->throttling.acpi_processor_get_throttling ==
1253                         acpi_processor_get_throttling_fadt) {
1254                 for (i = 0; i < pr->throttling.state_count; i++)
1255                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1256                                    (i == pr->throttling.state ? '*' : ' '), i,
1257                                    (pr->throttling.states[i].performance ? pr->
1258                                     throttling.states[i].performance / 10 : 0));
1259         } else {
1260                 for (i = 0; i < pr->throttling.state_count; i++)
1261                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1262                                    (i == pr->throttling.state ? '*' : ' '), i,
1263                                    (int)pr->throttling.states_tss[i].
1264                                    freqpercentage);
1265         }
1266
1267       end:
1268         return 0;
1269 }
1270
1271 static int acpi_processor_throttling_open_fs(struct inode *inode,
1272                                              struct file *file)
1273 {
1274         return single_open(file, acpi_processor_throttling_seq_show,
1275                            PDE(inode)->data);
1276 }
1277
1278 static ssize_t acpi_processor_write_throttling(struct file *file,
1279                                                const char __user * buffer,
1280                                                size_t count, loff_t * data)
1281 {
1282         int result = 0;
1283         struct seq_file *m = file->private_data;
1284         struct acpi_processor *pr = m->private;
1285         char state_string[5] = "";
1286         char *charp = NULL;
1287         size_t state_val = 0;
1288         char tmpbuf[5] = "";
1289
1290         if (!pr || (count > sizeof(state_string) - 1))
1291                 return -EINVAL;
1292
1293         if (copy_from_user(state_string, buffer, count))
1294                 return -EFAULT;
1295
1296         state_string[count] = '\0';
1297         if ((count > 0) && (state_string[count-1] == '\n'))
1298                 state_string[count-1] = '\0';
1299
1300         charp = state_string;
1301         if ((state_string[0] == 't') || (state_string[0] == 'T'))
1302                 charp++;
1303
1304         state_val = simple_strtoul(charp, NULL, 0);
1305         if (state_val >= pr->throttling.state_count)
1306                 return -EINVAL;
1307
1308         snprintf(tmpbuf, 5, "%zu", state_val);
1309
1310         if (strcmp(tmpbuf, charp) != 0)
1311                 return -EINVAL;
1312
1313         result = acpi_processor_set_throttling(pr, state_val, false);
1314         if (result)
1315                 return result;
1316
1317         return count;
1318 }
1319
1320 const struct file_operations acpi_processor_throttling_fops = {
1321         .owner = THIS_MODULE,
1322         .open = acpi_processor_throttling_open_fs,
1323         .read = seq_read,
1324         .write = acpi_processor_write_throttling,
1325         .llseek = seq_lseek,
1326         .release = single_release,
1327 };
1328 #endif