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/cpufreq.h>
  33 #include <linux/proc_fs.h>
  34 #include <linux/seq_file.h>
  35
  36 #include <asm/io.h>
  37 #include <asm/uaccess.h>
  38
  39 #include <acpi/acpi_bus.h>
  40 #include <acpi/processor.h>
  41
  42 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  43 #define ACPI_PROCESSOR_CLASS            "processor"
  44 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  45 ACPI_MODULE_NAME("processor_throttling");
  46
  47 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  48 int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
  49
  50 /*
  51  * _TPC - Throttling Present Capabilities
  52  */
  53 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
  54 {
  55         acpi_status status = 0;
  56         unsigned long tpc = 0;
  57
  58         if (!pr)
  59                 return -EINVAL;
  60         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
  61         if (ACPI_FAILURE(status)) {
  62                 if (status != AE_NOT_FOUND) {
  63                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
  64                 }
  65                 return -ENODEV;
  66         }
  67         pr->throttling_platform_limit = (int)tpc;
  68         return 0;
  69 }
  70
  71 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
  72 {
  73         return acpi_processor_get_platform_limit(pr);
  74 }
  75
  76 /*
  77  * _PTC - Processor Throttling Control (and status) register location
  78  */
  79 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
  80 {
  81         int result = 0;
  82         acpi_status status = 0;
  83         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  84         union acpi_object *ptc = NULL;
  85         union acpi_object obj = { 0 };
  86
  87         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
  88         if (ACPI_FAILURE(status)) {
  89                 if (status != AE_NOT_FOUND) {
  90                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
  91                 }
  92                 return -ENODEV;
  93         }
  94
  95         ptc = (union acpi_object *)buffer.pointer;
  96         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
  97             || (ptc->package.count != 2)) {
  98                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
  99                 result = -EFAULT;
 100                 goto end;
 101         }
 102
 103         /*
 104          * control_register
 105          */
 106
 107         obj = ptc->package.elements[0];
 108
 109         if ((obj.type != ACPI_TYPE_BUFFER)
 110             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 111             || (obj.buffer.pointer == NULL)) {
 112                 printk(KERN_ERR PREFIX
 113                        "Invalid _PTC data (control_register)\n");
 114                 result = -EFAULT;
 115                 goto end;
 116         }
 117         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 118                sizeof(struct acpi_ptc_register));
 119
 120         /*
 121          * status_register
 122          */
 123
 124         obj = ptc->package.elements[1];
 125
 126         if ((obj.type != ACPI_TYPE_BUFFER)
 127             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 128             || (obj.buffer.pointer == NULL)) {
 129                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 130                 result = -EFAULT;
 131                 goto end;
 132         }
 133
 134         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 135                sizeof(struct acpi_ptc_register));
 136
 137       end:
 138         kfree(buffer.pointer);
 139
 140         return result;
 141 }
 142
 143 /*
 144  * _TSS - Throttling Supported States
 145  */
 146 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 147 {
 148         int result = 0;
 149         acpi_status status = AE_OK;
 150         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 151         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 152         struct acpi_buffer state = { 0, NULL };
 153         union acpi_object *tss = NULL;
 154         int i;
 155
 156         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 157         if (ACPI_FAILURE(status)) {
 158                 if (status != AE_NOT_FOUND) {
 159                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 160                 }
 161                 return -ENODEV;
 162         }
 163
 164         tss = buffer.pointer;
 165         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 166                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 167                 result = -EFAULT;
 168                 goto end;
 169         }
 170
 171         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 172                           tss->package.count));
 173
 174         pr->throttling.state_count = tss->package.count;
 175         pr->throttling.states_tss =
 176             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 177                     GFP_KERNEL);
 178         if (!pr->throttling.states_tss) {
 179                 result = -ENOMEM;
 180                 goto end;
 181         }
 182
 183         for (i = 0; i < pr->throttling.state_count; i++) {
 184
 185                 struct acpi_processor_tx_tss *tx =
 186                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 187                                                       states_tss[i]);
 188
 189                 state.length = sizeof(struct acpi_processor_tx_tss);
 190                 state.pointer = tx;
 191
 192                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 193
 194                 status = acpi_extract_package(&(tss->package.elements[i]),
 195                                               &format, &state);
 196                 if (ACPI_FAILURE(status)) {
 197                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 198                         result = -EFAULT;
 199                         kfree(pr->throttling.states_tss);
 200                         goto end;
 201                 }
 202
 203                 if (!tx->freqpercentage) {
 204                         printk(KERN_ERR PREFIX
 205                                "Invalid _TSS data: freq is zero\n");
 206                         result = -EFAULT;
 207                         kfree(pr->throttling.states_tss);
 208                         goto end;
 209                 }
 210         }
 211
 212       end:
 213         kfree(buffer.pointer);
 214
 215         return result;
 216 }
 217
 218 /*
 219  * _TSD - T-State Dependencies
 220  */
 221 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 222 {
 223         int result = 0;
 224         acpi_status status = AE_OK;
 225         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 226         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 227         struct acpi_buffer state = { 0, NULL };
 228         union acpi_object *tsd = NULL;
 229         struct acpi_tsd_package *pdomain;
 230
 231         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 232         if (ACPI_FAILURE(status)) {
 233                 if (status != AE_NOT_FOUND) {
 234                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 235                 }
 236                 return -ENODEV;
 237         }
 238
 239         tsd = buffer.pointer;
 240         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 241                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 242                 result = -EFAULT;
 243                 goto end;
 244         }
 245
 246         if (tsd->package.count != 1) {
 247                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 248                 result = -EFAULT;
 249                 goto end;
 250         }
 251
 252         pdomain = &(pr->throttling.domain_info);
 253
 254         state.length = sizeof(struct acpi_tsd_package);
 255         state.pointer = pdomain;
 256
 257         status = acpi_extract_package(&(tsd->package.elements[0]),
 258                                       &format, &state);
 259         if (ACPI_FAILURE(status)) {
 260                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 261                 result = -EFAULT;
 262                 goto end;
 263         }
 264
 265         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 266                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:num_entries\n"));
 267                 result = -EFAULT;
 268                 goto end;
 269         }
 270
 271         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 272                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:revision\n"));
 273                 result = -EFAULT;
 274                 goto end;
 275         }
 276
 277       end:
 278         kfree(buffer.pointer);
 279         return result;
 280 }
 281
 282 /* --------------------------------------------------------------------------
 283                               Throttling Control
 284    -------------------------------------------------------------------------- */
 285 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 286 {
 287         int state = 0;
 288         u32 value = 0;
 289         u32 duty_mask = 0;
 290         u32 duty_value = 0;
 291
 292         if (!pr)
 293                 return -EINVAL;
 294
 295         if (!pr->flags.throttling)
 296                 return -ENODEV;
 297
 298         pr->throttling.state = 0;
 299
 300         duty_mask = pr->throttling.state_count - 1;
 301
 302         duty_mask <<= pr->throttling.duty_offset;
 303
 304         local_irq_disable();
 305
 306         value = inl(pr->throttling.address);
 307
 308         /*
 309          * Compute the current throttling state when throttling is enabled
 310          * (bit 4 is on).
 311          */
 312         if (value & 0x10) {
 313                 duty_value = value & duty_mask;
 314                 duty_value >>= pr->throttling.duty_offset;
 315
 316                 if (duty_value)
 317                         state = pr->throttling.state_count - duty_value;
 318         }
 319
 320         pr->throttling.state = state;
 321
 322         local_irq_enable();
 323
 324         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 325                           "Throttling state is T%d (%d%% throttling applied)\n",
 326                           state, pr->throttling.states[state].performance));
 327
 328         return 0;
 329 }
 330
 331 static int acpi_read_throttling_status(struct acpi_processor_throttling
 332                                        *throttling)
 333 {
 334         int value = -1;
 335         switch (throttling->status_register.space_id) {
 336         case ACPI_ADR_SPACE_SYSTEM_IO:
 337                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 338                                   address, &value,
 339                                   (u32) throttling->status_register.bit_width *
 340                                   8);
 341                 break;
 342         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 343                 printk(KERN_ERR PREFIX
 344                        "HARDWARE addr space,NOT supported yet\n");
 345                 break;
 346         default:
 347                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 348                        (u32) (throttling->status_register.space_id));
 349         }
 350         return value;
 351 }
 352
 353 static int acpi_write_throttling_state(struct acpi_processor_throttling
 354                                        *throttling, int value)
 355 {
 356         int ret = -1;
 357
 358         switch (throttling->control_register.space_id) {
 359         case ACPI_ADR_SPACE_SYSTEM_IO:
 360                 acpi_os_write_port((acpi_io_address) throttling->
 361                                    control_register.address, value,
 362                                    (u32) throttling->control_register.
 363                                    bit_width * 8);
 364                 ret = 0;
 365                 break;
 366         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 367                 printk(KERN_ERR PREFIX
 368                        "HARDWARE addr space,NOT supported yet\n");
 369                 break;
 370         default:
 371                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 372                        (u32) (throttling->control_register.space_id));
 373         }
 374         return ret;
 375 }
 376
 377 static int acpi_get_throttling_state(struct acpi_processor *pr, int value)
 378 {
 379         int i;
 380
 381         for (i = 0; i < pr->throttling.state_count; i++) {
 382                 struct acpi_processor_tx_tss *tx =
 383                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 384                                                       states_tss[i]);
 385                 if (tx->control == value)
 386                         break;
 387         }
 388         if (i > pr->throttling.state_count)
 389                 i = -1;
 390         return i;
 391 }
 392
 393 static int acpi_get_throttling_value(struct acpi_processor *pr, int state)
 394 {
 395         int value = -1;
 396         if (state >= 0 && state <= pr->throttling.state_count) {
 397                 struct acpi_processor_tx_tss *tx =
 398                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 399                                                       states_tss[state]);
 400                 value = tx->control;
 401         }
 402         return value;
 403 }
 404
 405 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 406 {
 407         int state = 0;
 408         u32 value = 0;
 409
 410         if (!pr)
 411                 return -EINVAL;
 412
 413         if (!pr->flags.throttling)
 414                 return -ENODEV;
 415
 416         pr->throttling.state = 0;
 417         local_irq_disable();
 418         value = acpi_read_throttling_status(&pr->throttling);
 419         if (value >= 0) {
 420                 state = acpi_get_throttling_state(pr, value);
 421                 pr->throttling.state = state;
 422         }
 423         local_irq_enable();
 424
 425         return 0;
 426 }
 427
 428 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 429 {
 430         return pr->throttling.acpi_processor_get_throttling(pr);
 431 }
 432
 433 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 434                                               int state)
 435 {
 436         u32 value = 0;
 437         u32 duty_mask = 0;
 438         u32 duty_value = 0;
 439
 440         if (!pr)
 441                 return -EINVAL;
 442
 443         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 444                 return -EINVAL;
 445
 446         if (!pr->flags.throttling)
 447                 return -ENODEV;
 448
 449         if (state == pr->throttling.state)
 450                 return 0;
 451
 452         if (state < pr->throttling_platform_limit)
 453                 return -EPERM;
 454         /*
 455          * Calculate the duty_value and duty_mask.
 456          */
 457         if (state) {
 458                 duty_value = pr->throttling.state_count - state;
 459
 460                 duty_value <<= pr->throttling.duty_offset;
 461
 462                 /* Used to clear all duty_value bits */
 463                 duty_mask = pr->throttling.state_count - 1;
 464
 465                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 466                 duty_mask = ~duty_mask;
 467         }
 468
 469         local_irq_disable();
 470
 471         /*
 472          * Disable throttling by writing a 0 to bit 4.  Note that we must
 473          * turn it off before you can change the duty_value.
 474          */
 475         value = inl(pr->throttling.address);
 476         if (value & 0x10) {
 477                 value &= 0xFFFFFFEF;
 478                 outl(value, pr->throttling.address);
 479         }
 480
 481         /*
 482          * Write the new duty_value and then enable throttling.  Note
 483          * that a state value of 0 leaves throttling disabled.
 484          */
 485         if (state) {
 486                 value &= duty_mask;
 487                 value |= duty_value;
 488                 outl(value, pr->throttling.address);
 489
 490                 value |= 0x00000010;
 491                 outl(value, pr->throttling.address);
 492         }
 493
 494         pr->throttling.state = state;
 495
 496         local_irq_enable();
 497
 498         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 499                           "Throttling state set to T%d (%d%%)\n", state,
 500                           (pr->throttling.states[state].performance ? pr->
 501                            throttling.states[state].performance / 10 : 0)));
 502
 503         return 0;
 504 }
 505
 506 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 507                                              int state)
 508 {
 509         u32 value = 0;
 510
 511         if (!pr)
 512                 return -EINVAL;
 513
 514         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 515                 return -EINVAL;
 516
 517         if (!pr->flags.throttling)
 518                 return -ENODEV;
 519
 520         if (state == pr->throttling.state)
 521                 return 0;
 522
 523         if (state < pr->throttling_platform_limit)
 524                 return -EPERM;
 525
 526         local_irq_disable();
 527
 528         value = acpi_get_throttling_value(pr, state);
 529         if (value >= 0) {
 530                 acpi_write_throttling_state(&pr->throttling, value);
 531                 pr->throttling.state = state;
 532         }
 533         local_irq_enable();
 534
 535         return 0;
 536 }
 537
 538 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
 539 {
 540         return pr->throttling.acpi_processor_set_throttling(pr, state);
 541 }
 542
 543 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
 544 {
 545         int result = 0;
 546         int step = 0;
 547         int i = 0;
 548
 549         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 550                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
 551                           pr->throttling.address,
 552                           pr->throttling.duty_offset,
 553                           pr->throttling.duty_width));
 554
 555         if (!pr)
 556                 return -EINVAL;
 557
 558         /*
 559          * Evaluate _PTC, _TSS and _TPC
 560          * They must all be present or none of them can be used.
 561          */
 562         if (acpi_processor_get_throttling_control(pr) ||
 563                 acpi_processor_get_throttling_states(pr) ||
 564                 acpi_processor_get_platform_limit(pr))
 565         {
 566                 pr->throttling.acpi_processor_get_throttling =
 567                     &acpi_processor_get_throttling_fadt;
 568                 pr->throttling.acpi_processor_set_throttling =
 569                     &acpi_processor_set_throttling_fadt;
 570         } else {
 571                 pr->throttling.acpi_processor_get_throttling =
 572                     &acpi_processor_get_throttling_ptc;
 573                 pr->throttling.acpi_processor_set_throttling =
 574                     &acpi_processor_set_throttling_ptc;
 575         }
 576
 577         acpi_processor_get_tsd(pr);
 578
 579         if (!pr->throttling.address) {
 580                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 581                 return 0;
 582         } else if (!pr->throttling.duty_width) {
 583                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 584                 return 0;
 585         }
 586         /* TBD: Support duty_cycle values that span bit 4. */
 587         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 588                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 589                 return 0;
 590         }
 591
 592         /*
 593          * PIIX4 Errata: We don't support throttling on the original PIIX4.
 594          * This shouldn't be an issue as few (if any) mobile systems ever
 595          * used this part.
 596          */
 597         if (errata.piix4.throttle) {
 598                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 599                                   "Throttling not supported on PIIX4 A- or B-step\n"));
 600                 return 0;
 601         }
 602
 603         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 604
 605         /*
 606          * Compute state values. Note that throttling displays a linear power/
 607          * performance relationship (at 50% performance the CPU will consume
 608          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 609          */
 610
 611         step = (1000 / pr->throttling.state_count);
 612
 613         for (i = 0; i < pr->throttling.state_count; i++) {
 614                 pr->throttling.states[i].performance = step * i;
 615                 pr->throttling.states[i].power = step * i;
 616         }
 617
 618         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 619                           pr->throttling.state_count));
 620
 621         pr->flags.throttling = 1;
 622
 623         /*
 624          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
 625          * thermal) decide to lower performance if it so chooses, but for now
 626          * we'll crank up the speed.
 627          */
 628
 629         result = acpi_processor_get_throttling(pr);
 630         if (result)
 631                 goto end;
 632
 633         if (pr->throttling.state) {
 634                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 635                                   "Disabling throttling (was T%d)\n",
 636                                   pr->throttling.state));
 637                 result = acpi_processor_set_throttling(pr, 0);
 638                 if (result)
 639                         goto end;
 640         }
 641
 642       end:
 643         if (result)
 644                 pr->flags.throttling = 0;
 645
 646         return result;
 647 }
 648
 649 /* proc interface */
 650
 651 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
 652                                               void *offset)
 653 {
 654         struct acpi_processor *pr = seq->private;
 655         int i = 0;
 656         int result = 0;
 657
 658         if (!pr)
 659                 goto end;
 660
 661         if (!(pr->throttling.state_count > 0)) {
 662                 seq_puts(seq, "<not supported>\n");
 663                 goto end;
 664         }
 665
 666         result = acpi_processor_get_throttling(pr);
 667
 668         if (result) {
 669                 seq_puts(seq,
 670                          "Could not determine current throttling state.\n");
 671                 goto end;
 672         }
 673
 674         seq_printf(seq, "state count:             %d\n"
 675                    "active state:            T%d\n"
 676                    "state available: T%d to T%d\n",
 677                    pr->throttling.state_count, pr->throttling.state,
 678                    pr->throttling_platform_limit,
 679                    pr->throttling.state_count - 1);
 680
 681         seq_puts(seq, "states:\n");
 682         if (pr->throttling.acpi_processor_get_throttling ==
 683                         acpi_processor_get_throttling_fadt) {
 684                 for (i = 0; i < pr->throttling.state_count; i++)
 685                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
 686                                    (i == pr->throttling.state ? '*' : ' '), i,
 687                                    (pr->throttling.states[i].performance ? pr->
 688                                     throttling.states[i].performance / 10 : 0));
 689         } else {
 690                 for (i = 0; i < pr->throttling.state_count; i++)
 691                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
 692                                    (i == pr->throttling.state ? '*' : ' '), i,
 693                                    (int)pr->throttling.states_tss[i].
 694                                    freqpercentage);
 695         }
 696
 697       end:
 698         return 0;
 699 }
 700
 701 static int acpi_processor_throttling_open_fs(struct inode *inode,
 702                                              struct file *file)
 703 {
 704         return single_open(file, acpi_processor_throttling_seq_show,
 705                            PDE(inode)->data);
 706 }
 707
 708 static ssize_t acpi_processor_write_throttling(struct file *file,
 709                                                const char __user * buffer,
 710                                                size_t count, loff_t * data)
 711 {
 712         int result = 0;
 713         struct seq_file *m = file->private_data;
 714         struct acpi_processor *pr = m->private;
 715         char state_string[12] = { '\0' };
 716
 717         if (!pr || (count > sizeof(state_string) - 1))
 718                 return -EINVAL;
 719
 720         if (copy_from_user(state_string, buffer, count))
 721                 return -EFAULT;
 722
 723         state_string[count] = '\0';
 724
 725         result = acpi_processor_set_throttling(pr,
 726                                                simple_strtoul(state_string,
 727                                                               NULL, 0));
 728         if (result)
 729                 return result;
 730
 731         return count;
 732 }
 733
 734 struct file_operations acpi_processor_throttling_fops = {
 735         .open = acpi_processor_throttling_open_fs,
 736         .read = seq_read,
 737         .write = acpi_processor_write_throttling,
 738         .llseek = seq_lseek,
 739         .release = single_release,
 740 };