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 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
  51 {
  52         acpi_status status = 0;
  53         unsigned long tpc = 0;
  54
  55         if (!pr)
  56                 return -EINVAL;
  57         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
  58         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
  59                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
  60                 return -ENODEV;
  61         }
  62         pr->throttling_platform_limit = (int)tpc;
  63         return 0;
  64 }
  65
  66 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
  67 {
  68         return acpi_processor_get_platform_limit(pr);
  69 }
  70
  71 /* --------------------------------------------------------------------------
  72                              _PTC, _TSS, _TSD support
  73    -------------------------------------------------------------------------- */
  74 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
  75 {
  76         int result = 0;
  77         acpi_status status = 0;
  78         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  79         union acpi_object *ptc = NULL;
  80         union acpi_object obj = { 0 };
  81
  82         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
  83         if (ACPI_FAILURE(status)) {
  84                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
  85                 return -ENODEV;
  86         }
  87
  88         ptc = (union acpi_object *)buffer.pointer;
  89         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
  90             || (ptc->package.count != 2)) {
  91                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
  92                 result = -EFAULT;
  93                 goto end;
  94         }
  95
  96         /*
  97          * control_register
  98          */
  99
 100         obj = ptc->package.elements[0];
 101
 102         if ((obj.type != ACPI_TYPE_BUFFER)
 103             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 104             || (obj.buffer.pointer == NULL)) {
 105                 printk(KERN_ERR PREFIX
 106                        "Invalid _PTC data (control_register)\n");
 107                 result = -EFAULT;
 108                 goto end;
 109         }
 110         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 111                sizeof(struct acpi_ptc_register));
 112
 113         /*
 114          * status_register
 115          */
 116
 117         obj = ptc->package.elements[1];
 118
 119         if ((obj.type != ACPI_TYPE_BUFFER)
 120             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 121             || (obj.buffer.pointer == NULL)) {
 122                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 123                 result = -EFAULT;
 124                 goto end;
 125         }
 126
 127         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 128                sizeof(struct acpi_ptc_register));
 129
 130       end:
 131         kfree(buffer.pointer);
 132
 133         return result;
 134 }
 135 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 136 {
 137         int result = 0;
 138         acpi_status status = AE_OK;
 139         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 140         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 141         struct acpi_buffer state = { 0, NULL };
 142         union acpi_object *tss = NULL;
 143         int i;
 144
 145         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 146         if (ACPI_FAILURE(status)) {
 147                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 148                 return -ENODEV;
 149         }
 150
 151         tss = buffer.pointer;
 152         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 153                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 154                 result = -EFAULT;
 155                 goto end;
 156         }
 157
 158         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 159                           tss->package.count));
 160
 161         pr->throttling.state_count = tss->package.count;
 162         pr->throttling.states_tss =
 163             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 164                     GFP_KERNEL);
 165         if (!pr->throttling.states_tss) {
 166                 result = -ENOMEM;
 167                 goto end;
 168         }
 169
 170         for (i = 0; i < pr->throttling.state_count; i++) {
 171
 172                 struct acpi_processor_tx_tss *tx =
 173                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 174                                                       states_tss[i]);
 175
 176                 state.length = sizeof(struct acpi_processor_tx_tss);
 177                 state.pointer = tx;
 178
 179                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 180
 181                 status = acpi_extract_package(&(tss->package.elements[i]),
 182                                               &format, &state);
 183                 if (ACPI_FAILURE(status)) {
 184                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 185                         result = -EFAULT;
 186                         kfree(pr->throttling.states_tss);
 187                         goto end;
 188                 }
 189
 190                 if (!tx->freqpercentage) {
 191                         printk(KERN_ERR PREFIX
 192                                "Invalid _TSS data: freq is zero\n");
 193                         result = -EFAULT;
 194                         kfree(pr->throttling.states_tss);
 195                         goto end;
 196                 }
 197         }
 198
 199       end:
 200         kfree(buffer.pointer);
 201
 202         return result;
 203 }
 204 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 205 {
 206         int result = 0;
 207         acpi_status status = AE_OK;
 208         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 209         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 210         struct acpi_buffer state = { 0, NULL };
 211         union acpi_object *tsd = NULL;
 212         struct acpi_tsd_package *pdomain;
 213
 214         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 215         if (ACPI_FAILURE(status)) {
 216                 return -ENODEV;
 217         }
 218
 219         tsd = buffer.pointer;
 220         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 221                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 222                 result = -EFAULT;
 223                 goto end;
 224         }
 225
 226         if (tsd->package.count != 1) {
 227                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 228                 result = -EFAULT;
 229                 goto end;
 230         }
 231
 232         pdomain = &(pr->throttling.domain_info);
 233
 234         state.length = sizeof(struct acpi_tsd_package);
 235         state.pointer = pdomain;
 236
 237         status = acpi_extract_package(&(tsd->package.elements[0]),
 238                                       &format, &state);
 239         if (ACPI_FAILURE(status)) {
 240                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 241                 result = -EFAULT;
 242                 goto end;
 243         }
 244
 245         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 246                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:num_entries\n"));
 247                 result = -EFAULT;
 248                 goto end;
 249         }
 250
 251         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:revision\n"));
 253                 result = -EFAULT;
 254                 goto end;
 255         }
 256
 257       end:
 258         kfree(buffer.pointer);
 259         return result;
 260 }
 261
 262 /* --------------------------------------------------------------------------
 263                               Throttling Control
 264    -------------------------------------------------------------------------- */
 265 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 266 {
 267         int state = 0;
 268         u32 value = 0;
 269         u32 duty_mask = 0;
 270         u32 duty_value = 0;
 271
 272         if (!pr)
 273                 return -EINVAL;
 274
 275         if (!pr->flags.throttling)
 276                 return -ENODEV;
 277
 278         pr->throttling.state = 0;
 279
 280         duty_mask = pr->throttling.state_count - 1;
 281
 282         duty_mask <<= pr->throttling.duty_offset;
 283
 284         local_irq_disable();
 285
 286         value = inl(pr->throttling.address);
 287
 288         /*
 289          * Compute the current throttling state when throttling is enabled
 290          * (bit 4 is on).
 291          */
 292         if (value & 0x10) {
 293                 duty_value = value & duty_mask;
 294                 duty_value >>= pr->throttling.duty_offset;
 295
 296                 if (duty_value)
 297                         state = pr->throttling.state_count - duty_value;
 298         }
 299
 300         pr->throttling.state = state;
 301
 302         local_irq_enable();
 303
 304         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 305                           "Throttling state is T%d (%d%% throttling applied)\n",
 306                           state, pr->throttling.states[state].performance));
 307
 308         return 0;
 309 }
 310
 311 static int acpi_read_throttling_status(struct acpi_processor_throttling
 312                                        *throttling)
 313 {
 314         int value = -1;
 315         switch (throttling->status_register.space_id) {
 316         case ACPI_ADR_SPACE_SYSTEM_IO:
 317                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 318                                   address, &value,
 319                                   (u32) throttling->status_register.bit_width *
 320                                   8);
 321                 break;
 322         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 323                 printk(KERN_ERR PREFIX
 324                        "HARDWARE addr space,NOT supported yet\n");
 325                 break;
 326         default:
 327                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 328                        (u32) (throttling->status_register.space_id));
 329         }
 330         return value;
 331 }
 332
 333 static int acpi_write_throttling_state(struct acpi_processor_throttling
 334                                        *throttling, int value)
 335 {
 336         int ret = -1;
 337
 338         switch (throttling->control_register.space_id) {
 339         case ACPI_ADR_SPACE_SYSTEM_IO:
 340                 acpi_os_write_port((acpi_io_address) throttling->
 341                                    control_register.address, value,
 342                                    (u32) throttling->control_register.
 343                                    bit_width * 8);
 344                 ret = 0;
 345                 break;
 346         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 347                 printk(KERN_ERR PREFIX
 348                        "HARDWARE addr space,NOT supported yet\n");
 349                 break;
 350         default:
 351                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 352                        (u32) (throttling->control_register.space_id));
 353         }
 354         return ret;
 355 }
 356
 357 static int acpi_get_throttling_state(struct acpi_processor *pr, int value)
 358 {
 359         int i;
 360
 361         for (i = 0; i < pr->throttling.state_count; i++) {
 362                 struct acpi_processor_tx_tss *tx =
 363                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 364                                                       states_tss[i]);
 365                 if (tx->control == value)
 366                         break;
 367         }
 368         if (i > pr->throttling.state_count)
 369                 i = -1;
 370         return i;
 371 }
 372
 373 static int acpi_get_throttling_value(struct acpi_processor *pr, int state)
 374 {
 375         int value = -1;
 376         if (state >= 0 && state <= pr->throttling.state_count) {
 377                 struct acpi_processor_tx_tss *tx =
 378                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 379                                                       states_tss[state]);
 380                 value = tx->control;
 381         }
 382         return value;
 383 }
 384
 385 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 386 {
 387         int state = 0;
 388         u32 value = 0;
 389
 390         if (!pr)
 391                 return -EINVAL;
 392
 393         if (!pr->flags.throttling)
 394                 return -ENODEV;
 395
 396         pr->throttling.state = 0;
 397         local_irq_disable();
 398         value = acpi_read_throttling_status(&pr->throttling);
 399         if (value >= 0) {
 400                 state = acpi_get_throttling_state(pr, value);
 401                 pr->throttling.state = state;
 402         }
 403         local_irq_enable();
 404
 405         return 0;
 406 }
 407
 408 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 409 {
 410         return pr->throttling.acpi_processor_get_throttling(pr);
 411 }
 412
 413 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 414                                               int state)
 415 {
 416         u32 value = 0;
 417         u32 duty_mask = 0;
 418         u32 duty_value = 0;
 419
 420         if (!pr)
 421                 return -EINVAL;
 422
 423         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 424                 return -EINVAL;
 425
 426         if (!pr->flags.throttling)
 427                 return -ENODEV;
 428
 429         if (state == pr->throttling.state)
 430                 return 0;
 431
 432         if (state < pr->throttling_platform_limit)
 433                 return -EPERM;
 434         /*
 435          * Calculate the duty_value and duty_mask.
 436          */
 437         if (state) {
 438                 duty_value = pr->throttling.state_count - state;
 439
 440                 duty_value <<= pr->throttling.duty_offset;
 441
 442                 /* Used to clear all duty_value bits */
 443                 duty_mask = pr->throttling.state_count - 1;
 444
 445                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 446                 duty_mask = ~duty_mask;
 447         }
 448
 449         local_irq_disable();
 450
 451         /*
 452          * Disable throttling by writing a 0 to bit 4.  Note that we must
 453          * turn it off before you can change the duty_value.
 454          */
 455         value = inl(pr->throttling.address);
 456         if (value & 0x10) {
 457                 value &= 0xFFFFFFEF;
 458                 outl(value, pr->throttling.address);
 459         }
 460
 461         /*
 462          * Write the new duty_value and then enable throttling.  Note
 463          * that a state value of 0 leaves throttling disabled.
 464          */
 465         if (state) {
 466                 value &= duty_mask;
 467                 value |= duty_value;
 468                 outl(value, pr->throttling.address);
 469
 470                 value |= 0x00000010;
 471                 outl(value, pr->throttling.address);
 472         }
 473
 474         pr->throttling.state = state;
 475
 476         local_irq_enable();
 477
 478         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 479                           "Throttling state set to T%d (%d%%)\n", state,
 480                           (pr->throttling.states[state].performance ? pr->
 481                            throttling.states[state].performance / 10 : 0)));
 482
 483         return 0;
 484 }
 485
 486 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 487                                              int state)
 488 {
 489         u32 value = 0;
 490
 491         if (!pr)
 492                 return -EINVAL;
 493
 494         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 495                 return -EINVAL;
 496
 497         if (!pr->flags.throttling)
 498                 return -ENODEV;
 499
 500         if (state == pr->throttling.state)
 501                 return 0;
 502
 503         if (state < pr->throttling_platform_limit)
 504                 return -EPERM;
 505
 506         local_irq_disable();
 507
 508         value = acpi_get_throttling_value(pr, state);
 509         if (value >= 0) {
 510                 acpi_write_throttling_state(&pr->throttling, value);
 511                 pr->throttling.state = state;
 512         }
 513         local_irq_enable();
 514
 515         return 0;
 516 }
 517
 518 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
 519 {
 520         return pr->throttling.acpi_processor_set_throttling(pr, state);
 521 }
 522
 523 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
 524 {
 525         int result = 0;
 526         int step = 0;
 527         int i = 0;
 528         int no_ptc = 0;
 529         int no_tss = 0;
 530         int no_tsd = 0;
 531
 532         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 533                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
 534                           pr->throttling.address,
 535                           pr->throttling.duty_offset,
 536                           pr->throttling.duty_width));
 537
 538         if (!pr)
 539                 return -EINVAL;
 540
 541         /* TBD: Support ACPI 2.0 objects */
 542         no_ptc = acpi_processor_get_throttling_control(pr);
 543         no_tss = acpi_processor_get_throttling_states(pr);
 544         no_tsd = acpi_processor_get_tsd(pr);
 545
 546         if (no_ptc || no_tss) {
 547                 pr->throttling.acpi_processor_get_throttling =
 548                     &acpi_processor_get_throttling_fadt;
 549                 pr->throttling.acpi_processor_set_throttling =
 550                     &acpi_processor_set_throttling_fadt;
 551         } else {
 552                 pr->throttling.acpi_processor_get_throttling =
 553                     &acpi_processor_get_throttling_ptc;
 554                 pr->throttling.acpi_processor_set_throttling =
 555                     &acpi_processor_set_throttling_ptc;
 556         }
 557
 558         if (!pr->throttling.address) {
 559                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 560                 return 0;
 561         } else if (!pr->throttling.duty_width) {
 562                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 563                 return 0;
 564         }
 565         /* TBD: Support duty_cycle values that span bit 4. */
 566         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 567                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 568                 return 0;
 569         }
 570
 571         /*
 572          * PIIX4 Errata: We don't support throttling on the original PIIX4.
 573          * This shouldn't be an issue as few (if any) mobile systems ever
 574          * used this part.
 575          */
 576         if (errata.piix4.throttle) {
 577                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 578                                   "Throttling not supported on PIIX4 A- or B-step\n"));
 579                 return 0;
 580         }
 581
 582         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 583
 584         /*
 585          * Compute state values. Note that throttling displays a linear power/
 586          * performance relationship (at 50% performance the CPU will consume
 587          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 588          */
 589
 590         step = (1000 / pr->throttling.state_count);
 591
 592         for (i = 0; i < pr->throttling.state_count; i++) {
 593                 pr->throttling.states[i].performance = step * i;
 594                 pr->throttling.states[i].power = step * i;
 595         }
 596
 597         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 598                           pr->throttling.state_count));
 599
 600         pr->flags.throttling = 1;
 601
 602         /*
 603          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
 604          * thermal) decide to lower performance if it so chooses, but for now
 605          * we'll crank up the speed.
 606          */
 607
 608         result = acpi_processor_get_throttling(pr);
 609         if (result)
 610                 goto end;
 611
 612         if (pr->throttling.state) {
 613                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 614                                   "Disabling throttling (was T%d)\n",
 615                                   pr->throttling.state));
 616                 result = acpi_processor_set_throttling(pr, 0);
 617                 if (result)
 618                         goto end;
 619         }
 620
 621       end:
 622         if (result)
 623                 pr->flags.throttling = 0;
 624
 625         return result;
 626 }
 627
 628 /* proc interface */
 629
 630 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
 631                                               void *offset)
 632 {
 633         struct acpi_processor *pr = seq->private;
 634         int i = 0;
 635         int result = 0;
 636
 637         if (!pr)
 638                 goto end;
 639
 640         if (!(pr->throttling.state_count > 0)) {
 641                 seq_puts(seq, "<not supported>\n");
 642                 goto end;
 643         }
 644
 645         result = acpi_processor_get_throttling(pr);
 646
 647         if (result) {
 648                 seq_puts(seq,
 649                          "Could not determine current throttling state.\n");
 650                 goto end;
 651         }
 652
 653         seq_printf(seq, "state count:             %d\n"
 654                    "active state:            T%d\n"
 655                    "state available: T%d to T%d\n",
 656                    pr->throttling.state_count, pr->throttling.state,
 657                    pr->throttling_platform_limit,
 658                    pr->throttling.state_count - 1);
 659
 660         seq_puts(seq, "states:\n");
 661         if (acpi_processor_get_throttling == acpi_processor_get_throttling_fadt)
 662                 for (i = 0; i < pr->throttling.state_count; i++)
 663                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
 664                                    (i == pr->throttling.state ? '*' : ' '), i,
 665                                    (pr->throttling.states[i].performance ? pr->
 666                                     throttling.states[i].performance / 10 : 0));
 667         else
 668                 for (i = 0; i < pr->throttling.state_count; i++)
 669                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
 670                                    (i == pr->throttling.state ? '*' : ' '), i,
 671                                    (int)pr->throttling.states_tss[i].
 672                                    freqpercentage);
 673
 674       end:
 675         return 0;
 676 }
 677
 678 static int acpi_processor_throttling_open_fs(struct inode *inode,
 679                                              struct file *file)
 680 {
 681         return single_open(file, acpi_processor_throttling_seq_show,
 682                            PDE(inode)->data);
 683 }
 684
 685 static ssize_t acpi_processor_write_throttling(struct file *file,
 686                                                const char __user * buffer,
 687                                                size_t count, loff_t * data)
 688 {
 689         int result = 0;
 690         struct seq_file *m = file->private_data;
 691         struct acpi_processor *pr = m->private;
 692         char state_string[12] = { '\0' };
 693
 694         if (!pr || (count > sizeof(state_string) - 1))
 695                 return -EINVAL;
 696
 697         if (copy_from_user(state_string, buffer, count))
 698                 return -EFAULT;
 699
 700         state_string[count] = '\0';
 701
 702         result = acpi_processor_set_throttling(pr,
 703                                                simple_strtoul(state_string,
 704                                                               NULL, 0));
 705         if (result)
 706                 return result;
 707
 708         return count;
 709 }
 710
 711 struct file_operations acpi_processor_throttling_fops = {
 712         .open = acpi_processor_throttling_open_fs,
 713         .read = seq_read,
 714         .write = acpi_processor_write_throttling,
 715         .llseek = seq_lseek,
 716         .release = single_release,
 717 };