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