git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/processor_throttling.c

   1 /*
   2  * processor_throttling.c - Throttling submodule of the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/sched.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/seq_file.h>
  36
  37 #include <asm/io.h>
  38 #include <asm/uaccess.h>
  39
  40 #include <acpi/acpi_bus.h>
  41 #include <acpi/acpi_drivers.h>
  42 #include <acpi/processor.h>
  43
  44 #define ACPI_PROCESSOR_CLASS            "processor"
  45 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  46 ACPI_MODULE_NAME("processor_throttling");
  47
  48 /* ignore_tpc:
  49  *  0 -> acpi processor driver doesn't ignore _TPC values
  50  *  1 -> acpi processor driver ignores _TPC values
  51  */
  52 static int ignore_tpc;
  53 module_param(ignore_tpc, int, 0644);
  54 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  55
  56 struct throttling_tstate {
  57         unsigned int cpu;               /* cpu nr */
  58         int target_state;               /* target T-state */
  59 };
  60
  61 #define THROTTLING_PRECHANGE       (1)
  62 #define THROTTLING_POSTCHANGE      (2)
  63
  64 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  65 int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
  66
  67 static int acpi_processor_update_tsd_coord(void)
  68 {
  69         int count, count_target;
  70         int retval = 0;
  71         unsigned int i, j;
  72         cpumask_var_t covered_cpus;
  73         struct acpi_processor *pr, *match_pr;
  74         struct acpi_tsd_package *pdomain, *match_pdomain;
  75         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  76
  77         if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  78                 return -ENOMEM;
  79
  80         /*
  81          * Now that we have _TSD data from all CPUs, lets setup T-state
  82          * coordination between all CPUs.
  83          */
  84         for_each_possible_cpu(i) {
  85                 pr = per_cpu(processors, i);
  86                 if (!pr)
  87                         continue;
  88
  89                 /* Basic validity check for domain info */
  90                 pthrottling = &(pr->throttling);
  91
  92                 /*
  93                  * If tsd package for one cpu is invalid, the coordination
  94                  * among all CPUs is thought as invalid.
  95                  * Maybe it is ugly.
  96                  */
  97                 if (!pthrottling->tsd_valid_flag) {
  98                         retval = -EINVAL;
  99                         break;
 100                 }
 101         }
 102         if (retval)
 103                 goto err_ret;
 104
 105         cpumask_clear(covered_cpus);
 106         for_each_possible_cpu(i) {
 107                 pr = per_cpu(processors, i);
 108                 if (!pr)
 109                         continue;
 110
 111                 if (cpumask_test_cpu(i, covered_cpus))
 112                         continue;
 113                 pthrottling = &pr->throttling;
 114
 115                 pdomain = &(pthrottling->domain_info);
 116                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 117                 cpumask_set_cpu(i, covered_cpus);
 118                 /*
 119                  * If the number of processor in the TSD domain is 1, it is
 120                  * unnecessary to parse the coordination for this CPU.
 121                  */
 122                 if (pdomain->num_processors <= 1)
 123                         continue;
 124
 125                 /* Validate the Domain info */
 126                 count_target = pdomain->num_processors;
 127                 count = 1;
 128
 129                 for_each_possible_cpu(j) {
 130                         if (i == j)
 131                                 continue;
 132
 133                         match_pr = per_cpu(processors, j);
 134                         if (!match_pr)
 135                                 continue;
 136
 137                         match_pthrottling = &(match_pr->throttling);
 138                         match_pdomain = &(match_pthrottling->domain_info);
 139                         if (match_pdomain->domain != pdomain->domain)
 140                                 continue;
 141
 142                         /* Here i and j are in the same domain.
 143                          * If two TSD packages have the same domain, they
 144                          * should have the same num_porcessors and
 145                          * coordination type. Otherwise it will be regarded
 146                          * as illegal.
 147                          */
 148                         if (match_pdomain->num_processors != count_target) {
 149                                 retval = -EINVAL;
 150                                 goto err_ret;
 151                         }
 152
 153                         if (pdomain->coord_type != match_pdomain->coord_type) {
 154                                 retval = -EINVAL;
 155                                 goto err_ret;
 156                         }
 157
 158                         cpumask_set_cpu(j, covered_cpus);
 159                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 160                         count++;
 161                 }
 162                 for_each_possible_cpu(j) {
 163                         if (i == j)
 164                                 continue;
 165
 166                         match_pr = per_cpu(processors, j);
 167                         if (!match_pr)
 168                                 continue;
 169
 170                         match_pthrottling = &(match_pr->throttling);
 171                         match_pdomain = &(match_pthrottling->domain_info);
 172                         if (match_pdomain->domain != pdomain->domain)
 173                                 continue;
 174
 175                         /*
 176                          * If some CPUS have the same domain, they
 177                          * will have the same shared_cpu_map.
 178                          */
 179                         cpumask_copy(match_pthrottling->shared_cpu_map,
 180                                      pthrottling->shared_cpu_map);
 181                 }
 182         }
 183
 184 err_ret:
 185         free_cpumask_var(covered_cpus);
 186
 187         for_each_possible_cpu(i) {
 188                 pr = per_cpu(processors, i);
 189                 if (!pr)
 190                         continue;
 191
 192                 /*
 193                  * Assume no coordination on any error parsing domain info.
 194                  * The coordination type will be forced as SW_ALL.
 195                  */
 196                 if (retval) {
 197                         pthrottling = &(pr->throttling);
 198                         cpumask_clear(pthrottling->shared_cpu_map);
 199                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 200                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 201                 }
 202         }
 203
 204         return retval;
 205 }
 206
 207 /*
 208  * Update the T-state coordination after the _TSD
 209  * data for all cpus is obtained.
 210  */
 211 void acpi_processor_throttling_init(void)
 212 {
 213         if (acpi_processor_update_tsd_coord())
 214                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 215                         "Assume no T-state coordination\n"));
 216
 217         return;
 218 }
 219
 220 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 221 {
 222         struct throttling_tstate *p_tstate = data;
 223         struct acpi_processor *pr;
 224         unsigned int cpu ;
 225         int target_state;
 226         struct acpi_processor_limit *p_limit;
 227         struct acpi_processor_throttling *p_throttling;
 228
 229         cpu = p_tstate->cpu;
 230         pr = per_cpu(processors, cpu);
 231         if (!pr) {
 232                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 233                 return 0;
 234         }
 235         if (!pr->flags.throttling) {
 236                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 237                                 "unsupported on CPU %d\n", cpu));
 238                 return 0;
 239         }
 240         target_state = p_tstate->target_state;
 241         p_throttling = &(pr->throttling);
 242         switch (event) {
 243         case THROTTLING_PRECHANGE:
 244                 /*
 245                  * Prechange event is used to choose one proper t-state,
 246                  * which meets the limits of thermal, user and _TPC.
 247                  */
 248                 p_limit = &pr->limit;
 249                 if (p_limit->thermal.tx > target_state)
 250                         target_state = p_limit->thermal.tx;
 251                 if (p_limit->user.tx > target_state)
 252                         target_state = p_limit->user.tx;
 253                 if (pr->throttling_platform_limit > target_state)
 254                         target_state = pr->throttling_platform_limit;
 255                 if (target_state >= p_throttling->state_count) {
 256                         printk(KERN_WARNING
 257                                 "Exceed the limit of T-state \n");
 258                         target_state = p_throttling->state_count - 1;
 259                 }
 260                 p_tstate->target_state = target_state;
 261                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 262                                 "target T-state of CPU %d is T%d\n",
 263                                 cpu, target_state));
 264                 break;
 265         case THROTTLING_POSTCHANGE:
 266                 /*
 267                  * Postchange event is only used to update the
 268                  * T-state flag of acpi_processor_throttling.
 269                  */
 270                 p_throttling->state = target_state;
 271                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 272                                 "CPU %d is switched to T%d\n",
 273                                 cpu, target_state));
 274                 break;
 275         default:
 276                 printk(KERN_WARNING
 277                         "Unsupported Throttling notifier event\n");
 278                 break;
 279         }
 280
 281         return 0;
 282 }
 283
 284 /*
 285  * _TPC - Throttling Present Capabilities
 286  */
 287 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 288 {
 289         acpi_status status = 0;
 290         unsigned long long tpc = 0;
 291
 292         if (!pr)
 293                 return -EINVAL;
 294
 295         if (ignore_tpc)
 296                 goto end;
 297
 298         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 299         if (ACPI_FAILURE(status)) {
 300                 if (status != AE_NOT_FOUND) {
 301                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 302                 }
 303                 return -ENODEV;
 304         }
 305
 306 end:
 307         pr->throttling_platform_limit = (int)tpc;
 308         return 0;
 309 }
 310
 311 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 312 {
 313         int result = 0;
 314         int throttling_limit;
 315         int current_state;
 316         struct acpi_processor_limit *limit;
 317         int target_state;
 318
 319         if (ignore_tpc)
 320                 return 0;
 321
 322         result = acpi_processor_get_platform_limit(pr);
 323         if (result) {
 324                 /* Throttling Limit is unsupported */
 325                 return result;
 326         }
 327
 328         throttling_limit = pr->throttling_platform_limit;
 329         if (throttling_limit >= pr->throttling.state_count) {
 330                 /* Uncorrect Throttling Limit */
 331                 return -EINVAL;
 332         }
 333
 334         current_state = pr->throttling.state;
 335         if (current_state > throttling_limit) {
 336                 /*
 337                  * The current state can meet the requirement of
 338                  * _TPC limit. But it is reasonable that OSPM changes
 339                  * t-states from high to low for better performance.
 340                  * Of course the limit condition of thermal
 341                  * and user should be considered.
 342                  */
 343                 limit = &pr->limit;
 344                 target_state = throttling_limit;
 345                 if (limit->thermal.tx > target_state)
 346                         target_state = limit->thermal.tx;
 347                 if (limit->user.tx > target_state)
 348                         target_state = limit->user.tx;
 349         } else if (current_state == throttling_limit) {
 350                 /*
 351                  * Unnecessary to change the throttling state
 352                  */
 353                 return 0;
 354         } else {
 355                 /*
 356                  * If the current state is lower than the limit of _TPC, it
 357                  * will be forced to switch to the throttling state defined
 358                  * by throttling_platfor_limit.
 359                  * Because the previous state meets with the limit condition
 360                  * of thermal and user, it is unnecessary to check it again.
 361                  */
 362                 target_state = throttling_limit;
 363         }
 364         return acpi_processor_set_throttling(pr, target_state);
 365 }
 366
 367 /*
 368  * _PTC - Processor Throttling Control (and status) register location
 369  */
 370 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 371 {
 372         int result = 0;
 373         acpi_status status = 0;
 374         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 375         union acpi_object *ptc = NULL;
 376         union acpi_object obj = { 0 };
 377         struct acpi_processor_throttling *throttling;
 378
 379         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 380         if (ACPI_FAILURE(status)) {
 381                 if (status != AE_NOT_FOUND) {
 382                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 383                 }
 384                 return -ENODEV;
 385         }
 386
 387         ptc = (union acpi_object *)buffer.pointer;
 388         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 389             || (ptc->package.count != 2)) {
 390                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 391                 result = -EFAULT;
 392                 goto end;
 393         }
 394
 395         /*
 396          * control_register
 397          */
 398
 399         obj = ptc->package.elements[0];
 400
 401         if ((obj.type != ACPI_TYPE_BUFFER)
 402             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 403             || (obj.buffer.pointer == NULL)) {
 404                 printk(KERN_ERR PREFIX
 405                        "Invalid _PTC data (control_register)\n");
 406                 result = -EFAULT;
 407                 goto end;
 408         }
 409         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 410                sizeof(struct acpi_ptc_register));
 411
 412         /*
 413          * status_register
 414          */
 415
 416         obj = ptc->package.elements[1];
 417
 418         if ((obj.type != ACPI_TYPE_BUFFER)
 419             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 420             || (obj.buffer.pointer == NULL)) {
 421                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 422                 result = -EFAULT;
 423                 goto end;
 424         }
 425
 426         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 427                sizeof(struct acpi_ptc_register));
 428
 429         throttling = &pr->throttling;
 430
 431         if ((throttling->control_register.bit_width +
 432                 throttling->control_register.bit_offset) > 32) {
 433                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 434                 result = -EFAULT;
 435                 goto end;
 436         }
 437
 438         if ((throttling->status_register.bit_width +
 439                 throttling->status_register.bit_offset) > 32) {
 440                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 441                 result = -EFAULT;
 442                 goto end;
 443         }
 444
 445       end:
 446         kfree(buffer.pointer);
 447
 448         return result;
 449 }
 450
 451 /*
 452  * _TSS - Throttling Supported States
 453  */
 454 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 455 {
 456         int result = 0;
 457         acpi_status status = AE_OK;
 458         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 459         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 460         struct acpi_buffer state = { 0, NULL };
 461         union acpi_object *tss = NULL;
 462         int i;
 463
 464         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 465         if (ACPI_FAILURE(status)) {
 466                 if (status != AE_NOT_FOUND) {
 467                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 468                 }
 469                 return -ENODEV;
 470         }
 471
 472         tss = buffer.pointer;
 473         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 474                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 475                 result = -EFAULT;
 476                 goto end;
 477         }
 478
 479         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 480                           tss->package.count));
 481
 482         pr->throttling.state_count = tss->package.count;
 483         pr->throttling.states_tss =
 484             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 485                     GFP_KERNEL);
 486         if (!pr->throttling.states_tss) {
 487                 result = -ENOMEM;
 488                 goto end;
 489         }
 490
 491         for (i = 0; i < pr->throttling.state_count; i++) {
 492
 493                 struct acpi_processor_tx_tss *tx =
 494                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 495                                                       states_tss[i]);
 496
 497                 state.length = sizeof(struct acpi_processor_tx_tss);
 498                 state.pointer = tx;
 499
 500                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 501
 502                 status = acpi_extract_package(&(tss->package.elements[i]),
 503                                               &format, &state);
 504                 if (ACPI_FAILURE(status)) {
 505                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 506                         result = -EFAULT;
 507                         kfree(pr->throttling.states_tss);
 508                         goto end;
 509                 }
 510
 511                 if (!tx->freqpercentage) {
 512                         printk(KERN_ERR PREFIX
 513                                "Invalid _TSS data: freq is zero\n");
 514                         result = -EFAULT;
 515                         kfree(pr->throttling.states_tss);
 516                         goto end;
 517                 }
 518         }
 519
 520       end:
 521         kfree(buffer.pointer);
 522
 523         return result;
 524 }
 525
 526 /*
 527  * _TSD - T-State Dependencies
 528  */
 529 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 530 {
 531         int result = 0;
 532         acpi_status status = AE_OK;
 533         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 534         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 535         struct acpi_buffer state = { 0, NULL };
 536         union acpi_object *tsd = NULL;
 537         struct acpi_tsd_package *pdomain;
 538         struct acpi_processor_throttling *pthrottling;
 539
 540         pthrottling = &pr->throttling;
 541         pthrottling->tsd_valid_flag = 0;
 542
 543         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 544         if (ACPI_FAILURE(status)) {
 545                 if (status != AE_NOT_FOUND) {
 546                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 547                 }
 548                 return -ENODEV;
 549         }
 550
 551         tsd = buffer.pointer;
 552         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 553                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 554                 result = -EFAULT;
 555                 goto end;
 556         }
 557
 558         if (tsd->package.count != 1) {
 559                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 560                 result = -EFAULT;
 561                 goto end;
 562         }
 563
 564         pdomain = &(pr->throttling.domain_info);
 565
 566         state.length = sizeof(struct acpi_tsd_package);
 567         state.pointer = pdomain;
 568
 569         status = acpi_extract_package(&(tsd->package.elements[0]),
 570                                       &format, &state);
 571         if (ACPI_FAILURE(status)) {
 572                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 573                 result = -EFAULT;
 574                 goto end;
 575         }
 576
 577         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 578                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 579                 result = -EFAULT;
 580                 goto end;
 581         }
 582
 583         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 584                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 585                 result = -EFAULT;
 586                 goto end;
 587         }
 588
 589         pthrottling = &pr->throttling;
 590         pthrottling->tsd_valid_flag = 1;
 591         pthrottling->shared_type = pdomain->coord_type;
 592         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 593         /*
 594          * If the coordination type is not defined in ACPI spec,
 595          * the tsd_valid_flag will be clear and coordination type
 596          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 597          */
 598         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 599                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 600                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 601                 pthrottling->tsd_valid_flag = 0;
 602                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 603         }
 604
 605       end:
 606         kfree(buffer.pointer);
 607         return result;
 608 }
 609
 610 /* --------------------------------------------------------------------------
 611                               Throttling Control
 612    -------------------------------------------------------------------------- */
 613 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 614 {
 615         int state = 0;
 616         u32 value = 0;
 617         u32 duty_mask = 0;
 618         u32 duty_value = 0;
 619
 620         if (!pr)
 621                 return -EINVAL;
 622
 623         if (!pr->flags.throttling)
 624                 return -ENODEV;
 625
 626         pr->throttling.state = 0;
 627
 628         duty_mask = pr->throttling.state_count - 1;
 629
 630         duty_mask <<= pr->throttling.duty_offset;
 631
 632         local_irq_disable();
 633
 634         value = inl(pr->throttling.address);
 635
 636         /*
 637          * Compute the current throttling state when throttling is enabled
 638          * (bit 4 is on).
 639          */
 640         if (value & 0x10) {
 641                 duty_value = value & duty_mask;
 642                 duty_value >>= pr->throttling.duty_offset;
 643
 644                 if (duty_value)
 645                         state = pr->throttling.state_count - duty_value;
 646         }
 647
 648         pr->throttling.state = state;
 649
 650         local_irq_enable();
 651
 652         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 653                           "Throttling state is T%d (%d%% throttling applied)\n",
 654                           state, pr->throttling.states[state].performance));
 655
 656         return 0;
 657 }
 658
 659 #ifdef CONFIG_X86
 660 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 661                                         acpi_integer * value)
 662 {
 663         struct cpuinfo_x86 *c;
 664         u64 msr_high, msr_low;
 665         unsigned int cpu;
 666         u64 msr = 0;
 667         int ret = -1;
 668
 669         cpu = pr->id;
 670         c = &cpu_data(cpu);
 671
 672         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 673                 !cpu_has(c, X86_FEATURE_ACPI)) {
 674                 printk(KERN_ERR PREFIX
 675                         "HARDWARE addr space,NOT supported yet\n");
 676         } else {
 677                 msr_low = 0;
 678                 msr_high = 0;
 679                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 680                         (u32 *)&msr_low , (u32 *) &msr_high);
 681                 msr = (msr_high << 32) | msr_low;
 682                 *value = (acpi_integer) msr;
 683                 ret = 0;
 684         }
 685         return ret;
 686 }
 687
 688 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 689 {
 690         struct cpuinfo_x86 *c;
 691         unsigned int cpu;
 692         int ret = -1;
 693         u64 msr;
 694
 695         cpu = pr->id;
 696         c = &cpu_data(cpu);
 697
 698         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 699                 !cpu_has(c, X86_FEATURE_ACPI)) {
 700                 printk(KERN_ERR PREFIX
 701                         "HARDWARE addr space,NOT supported yet\n");
 702         } else {
 703                 msr = value;
 704                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 705                         msr & 0xffffffff, msr >> 32);
 706                 ret = 0;
 707         }
 708         return ret;
 709 }
 710 #else
 711 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 712                                 acpi_integer * value)
 713 {
 714         printk(KERN_ERR PREFIX
 715                 "HARDWARE addr space,NOT supported yet\n");
 716         return -1;
 717 }
 718
 719 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 720 {
 721         printk(KERN_ERR PREFIX
 722                 "HARDWARE addr space,NOT supported yet\n");
 723         return -1;
 724 }
 725 #endif
 726
 727 static int acpi_read_throttling_status(struct acpi_processor *pr,
 728                                         acpi_integer *value)
 729 {
 730         u32 bit_width, bit_offset;
 731         u64 ptc_value;
 732         u64 ptc_mask;
 733         struct acpi_processor_throttling *throttling;
 734         int ret = -1;
 735
 736         throttling = &pr->throttling;
 737         switch (throttling->status_register.space_id) {
 738         case ACPI_ADR_SPACE_SYSTEM_IO:
 739                 ptc_value = 0;
 740                 bit_width = throttling->status_register.bit_width;
 741                 bit_offset = throttling->status_register.bit_offset;
 742
 743                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 744                                   address, (u32 *) &ptc_value,
 745                                   (u32) (bit_width + bit_offset));
 746                 ptc_mask = (1 << bit_width) - 1;
 747                 *value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);
 748                 ret = 0;
 749                 break;
 750         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 751                 ret = acpi_throttling_rdmsr(pr, value);
 752                 break;
 753         default:
 754                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 755                        (u32) (throttling->status_register.space_id));
 756         }
 757         return ret;
 758 }
 759
 760 static int acpi_write_throttling_state(struct acpi_processor *pr,
 761                                 acpi_integer value)
 762 {
 763         u32 bit_width, bit_offset;
 764         u64 ptc_value;
 765         u64 ptc_mask;
 766         struct acpi_processor_throttling *throttling;
 767         int ret = -1;
 768
 769         throttling = &pr->throttling;
 770         switch (throttling->control_register.space_id) {
 771         case ACPI_ADR_SPACE_SYSTEM_IO:
 772                 bit_width = throttling->control_register.bit_width;
 773                 bit_offset = throttling->control_register.bit_offset;
 774                 ptc_mask = (1 << bit_width) - 1;
 775                 ptc_value = value & ptc_mask;
 776
 777                 acpi_os_write_port((acpi_io_address) throttling->
 778                                         control_register.address,
 779                                         (u32) (ptc_value << bit_offset),
 780                                         (u32) (bit_width + bit_offset));
 781                 ret = 0;
 782                 break;
 783         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 784                 ret = acpi_throttling_wrmsr(pr, value);
 785                 break;
 786         default:
 787                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 788                        (u32) (throttling->control_register.space_id));
 789         }
 790         return ret;
 791 }
 792
 793 static int acpi_get_throttling_state(struct acpi_processor *pr,
 794                                 acpi_integer value)
 795 {
 796         int i;
 797
 798         for (i = 0; i < pr->throttling.state_count; i++) {
 799                 struct acpi_processor_tx_tss *tx =
 800                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 801                                                       states_tss[i]);
 802                 if (tx->control == value)
 803                         return i;
 804         }
 805         return -1;
 806 }
 807
 808 static int acpi_get_throttling_value(struct acpi_processor *pr,
 809                         int state, acpi_integer *value)
 810 {
 811         int ret = -1;
 812
 813         if (state >= 0 && state <= pr->throttling.state_count) {
 814                 struct acpi_processor_tx_tss *tx =
 815                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 816                                                       states_tss[state]);
 817                 *value = tx->control;
 818                 ret = 0;
 819         }
 820         return ret;
 821 }
 822
 823 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 824 {
 825         int state = 0;
 826         int ret;
 827         acpi_integer value;
 828
 829         if (!pr)
 830                 return -EINVAL;
 831
 832         if (!pr->flags.throttling)
 833                 return -ENODEV;
 834
 835         pr->throttling.state = 0;
 836
 837         value = 0;
 838         ret = acpi_read_throttling_status(pr, &value);
 839         if (ret >= 0) {
 840                 state = acpi_get_throttling_state(pr, value);
 841                 if (state == -1) {
 842                         ACPI_WARNING((AE_INFO,
 843                                 "Invalid throttling state, reset\n"));
 844                         state = 0;
 845                         ret = acpi_processor_set_throttling(pr, state);
 846                         if (ret)
 847                                 return ret;
 848                 }
 849                 pr->throttling.state = state;
 850         }
 851
 852         return 0;
 853 }
 854
 855 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 856 {
 857         cpumask_var_t saved_mask;
 858         int ret;
 859
 860         if (!pr)
 861                 return -EINVAL;
 862
 863         if (!pr->flags.throttling)
 864                 return -ENODEV;
 865
 866         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 867                 return -ENOMEM;
 868
 869         /*
 870          * Migrate task to the cpu pointed by pr.
 871          */
 872         cpumask_copy(saved_mask, &current->cpus_allowed);
 873         /* FIXME: use work_on_cpu() */
 874         set_cpus_allowed_ptr(current, cpumask_of(pr->id));
 875         ret = pr->throttling.acpi_processor_get_throttling(pr);
 876         /* restore the previous state */
 877         set_cpus_allowed_ptr(current, saved_mask);
 878         free_cpumask_var(saved_mask);
 879
 880         return ret;
 881 }
 882
 883 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 884 {
 885         int i, step;
 886
 887         if (!pr->throttling.address) {
 888                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 889                 return -EINVAL;
 890         } else if (!pr->throttling.duty_width) {
 891                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 892                 return -EINVAL;
 893         }
 894         /* TBD: Support duty_cycle values that span bit 4. */
 895         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 896                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 897                 return -EINVAL;
 898         }
 899
 900         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 901
 902         /*
 903          * Compute state values. Note that throttling displays a linear power
 904          * performance relationship (at 50% performance the CPU will consume
 905          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 906          */
 907
 908         step = (1000 / pr->throttling.state_count);
 909
 910         for (i = 0; i < pr->throttling.state_count; i++) {
 911                 pr->throttling.states[i].performance = 1000 - step * i;
 912                 pr->throttling.states[i].power = 1000 - step * i;
 913         }
 914         return 0;
 915 }
 916
 917 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 918                                               int state)
 919 {
 920         u32 value = 0;
 921         u32 duty_mask = 0;
 922         u32 duty_value = 0;
 923
 924         if (!pr)
 925                 return -EINVAL;
 926
 927         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 928                 return -EINVAL;
 929
 930         if (!pr->flags.throttling)
 931                 return -ENODEV;
 932
 933         if (state == pr->throttling.state)
 934                 return 0;
 935
 936         if (state < pr->throttling_platform_limit)
 937                 return -EPERM;
 938         /*
 939          * Calculate the duty_value and duty_mask.
 940          */
 941         if (state) {
 942                 duty_value = pr->throttling.state_count - state;
 943
 944                 duty_value <<= pr->throttling.duty_offset;
 945
 946                 /* Used to clear all duty_value bits */
 947                 duty_mask = pr->throttling.state_count - 1;
 948
 949                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 950                 duty_mask = ~duty_mask;
 951         }
 952
 953         local_irq_disable();
 954
 955         /*
 956          * Disable throttling by writing a 0 to bit 4.  Note that we must
 957          * turn it off before you can change the duty_value.
 958          */
 959         value = inl(pr->throttling.address);
 960         if (value & 0x10) {
 961                 value &= 0xFFFFFFEF;
 962                 outl(value, pr->throttling.address);
 963         }
 964
 965         /*
 966          * Write the new duty_value and then enable throttling.  Note
 967          * that a state value of 0 leaves throttling disabled.
 968          */
 969         if (state) {
 970                 value &= duty_mask;
 971                 value |= duty_value;
 972                 outl(value, pr->throttling.address);
 973
 974                 value |= 0x00000010;
 975                 outl(value, pr->throttling.address);
 976         }
 977
 978         pr->throttling.state = state;
 979
 980         local_irq_enable();
 981
 982         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 983                           "Throttling state set to T%d (%d%%)\n", state,
 984                           (pr->throttling.states[state].performance ? pr->
 985                            throttling.states[state].performance / 10 : 0)));
 986
 987         return 0;
 988 }
 989
 990 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 991                                              int state)
 992 {
 993         int ret;
 994         acpi_integer value;
 995
 996         if (!pr)
 997                 return -EINVAL;
 998
 999         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1000                 return -EINVAL;
1001
1002         if (!pr->flags.throttling)
1003                 return -ENODEV;
1004
1005         if (state == pr->throttling.state)
1006                 return 0;
1007
1008         if (state < pr->throttling_platform_limit)
1009                 return -EPERM;
1010
1011         value = 0;
1012         ret = acpi_get_throttling_value(pr, state, &value);
1013         if (ret >= 0) {
1014                 acpi_write_throttling_state(pr, value);
1015                 pr->throttling.state = state;
1016         }
1017
1018         return 0;
1019 }
1020
1021 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
1022 {
1023         cpumask_var_t saved_mask;
1024         int ret = 0;
1025         unsigned int i;
1026         struct acpi_processor *match_pr;
1027         struct acpi_processor_throttling *p_throttling;
1028         struct throttling_tstate t_state;
1029         cpumask_var_t online_throttling_cpus;
1030
1031         if (!pr)
1032                 return -EINVAL;
1033
1034         if (!pr->flags.throttling)
1035                 return -ENODEV;
1036
1037         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1038                 return -EINVAL;
1039
1040         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1041                 return -ENOMEM;
1042
1043         if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1044                 free_cpumask_var(saved_mask);
1045                 return -ENOMEM;
1046         }
1047
1048         cpumask_copy(saved_mask, &current->cpus_allowed);
1049         t_state.target_state = state;
1050         p_throttling = &(pr->throttling);
1051         cpumask_and(online_throttling_cpus, cpu_online_mask,
1052                     p_throttling->shared_cpu_map);
1053         /*
1054          * The throttling notifier will be called for every
1055          * affected cpu in order to get one proper T-state.
1056          * The notifier event is THROTTLING_PRECHANGE.
1057          */
1058         for_each_cpu(i, online_throttling_cpus) {
1059                 t_state.cpu = i;
1060                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1061                                                         &t_state);
1062         }
1063         /*
1064          * The function of acpi_processor_set_throttling will be called
1065          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1066          * it is necessary to call it for every affected cpu. Otherwise
1067          * it can be called only for the cpu pointed by pr.
1068          */
1069         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1070                 /* FIXME: use work_on_cpu() */
1071                 set_cpus_allowed_ptr(current, cpumask_of(pr->id));
1072                 ret = p_throttling->acpi_processor_set_throttling(pr,
1073                                                 t_state.target_state);
1074         } else {
1075                 /*
1076                  * When the T-state coordination is SW_ALL or HW_ALL,
1077                  * it is necessary to set T-state for every affected
1078                  * cpus.
1079                  */
1080                 for_each_cpu(i, online_throttling_cpus) {
1081                         match_pr = per_cpu(processors, i);
1082                         /*
1083                          * If the pointer is invalid, we will report the
1084                          * error message and continue.
1085                          */
1086                         if (!match_pr) {
1087                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1088                                         "Invalid Pointer for CPU %d\n", i));
1089                                 continue;
1090                         }
1091                         /*
1092                          * If the throttling control is unsupported on CPU i,
1093                          * we will report the error message and continue.
1094                          */
1095                         if (!match_pr->flags.throttling) {
1096                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1097                                         "Throttling Controll is unsupported "
1098                                         "on CPU %d\n", i));
1099                                 continue;
1100                         }
1101                         t_state.cpu = i;
1102                         /* FIXME: use work_on_cpu() */
1103                         set_cpus_allowed_ptr(current, cpumask_of(i));
1104                         ret = match_pr->throttling.
1105                                 acpi_processor_set_throttling(
1106                                 match_pr, t_state.target_state);
1107                 }
1108         }
1109         /*
1110          * After the set_throttling is called, the
1111          * throttling notifier is called for every
1112          * affected cpu to update the T-states.
1113          * The notifier event is THROTTLING_POSTCHANGE
1114          */
1115         for_each_cpu(i, online_throttling_cpus) {
1116                 t_state.cpu = i;
1117                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1118                                                         &t_state);
1119         }
1120         /* restore the previous state */
1121         /* FIXME: use work_on_cpu() */
1122         set_cpus_allowed_ptr(current, saved_mask);
1123         free_cpumask_var(online_throttling_cpus);
1124         free_cpumask_var(saved_mask);
1125         return ret;
1126 }
1127
1128 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1129 {
1130         int result = 0;
1131         struct acpi_processor_throttling *pthrottling;
1132
1133         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1134                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1135                           pr->throttling.address,
1136                           pr->throttling.duty_offset,
1137                           pr->throttling.duty_width));
1138
1139         if (!pr)
1140                 return -EINVAL;
1141
1142         /*
1143          * Evaluate _PTC, _TSS and _TPC
1144          * They must all be present or none of them can be used.
1145          */
1146         if (acpi_processor_get_throttling_control(pr) ||
1147                 acpi_processor_get_throttling_states(pr) ||
1148                 acpi_processor_get_platform_limit(pr))
1149         {
1150                 pr->throttling.acpi_processor_get_throttling =
1151                     &acpi_processor_get_throttling_fadt;
1152                 pr->throttling.acpi_processor_set_throttling =
1153                     &acpi_processor_set_throttling_fadt;
1154                 if (acpi_processor_get_fadt_info(pr))
1155                         return 0;
1156         } else {
1157                 pr->throttling.acpi_processor_get_throttling =
1158                     &acpi_processor_get_throttling_ptc;
1159                 pr->throttling.acpi_processor_set_throttling =
1160                     &acpi_processor_set_throttling_ptc;
1161         }
1162
1163         /*
1164          * If TSD package for one CPU can't be parsed successfully, it means
1165          * that this CPU will have no coordination with other CPUs.
1166          */
1167         if (acpi_processor_get_tsd(pr)) {
1168                 pthrottling = &pr->throttling;
1169                 pthrottling->tsd_valid_flag = 0;
1170                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1171                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1172         }
1173
1174         /*
1175          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1176          * This shouldn't be an issue as few (if any) mobile systems ever
1177          * used this part.
1178          */
1179         if (errata.piix4.throttle) {
1180                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1181                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1182                 return 0;
1183         }
1184
1185         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1186                           pr->throttling.state_count));
1187
1188         pr->flags.throttling = 1;
1189
1190         /*
1191          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1192          * thermal) decide to lower performance if it so chooses, but for now
1193          * we'll crank up the speed.
1194          */
1195
1196         result = acpi_processor_get_throttling(pr);
1197         if (result)
1198                 goto end;
1199
1200         if (pr->throttling.state) {
1201                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1202                                   "Disabling throttling (was T%d)\n",
1203                                   pr->throttling.state));
1204                 result = acpi_processor_set_throttling(pr, 0);
1205                 if (result)
1206                         goto end;
1207         }
1208
1209       end:
1210         if (result)
1211                 pr->flags.throttling = 0;
1212
1213         return result;
1214 }
1215
1216 /* proc interface */
1217
1218 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1219                                               void *offset)
1220 {
1221         struct acpi_processor *pr = seq->private;
1222         int i = 0;
1223         int result = 0;
1224
1225         if (!pr)
1226                 goto end;
1227
1228         if (!(pr->throttling.state_count > 0)) {
1229                 seq_puts(seq, "<not supported>\n");
1230                 goto end;
1231         }
1232
1233         result = acpi_processor_get_throttling(pr);
1234
1235         if (result) {
1236                 seq_puts(seq,
1237                          "Could not determine current throttling state.\n");
1238                 goto end;
1239         }
1240
1241         seq_printf(seq, "state count:             %d\n"
1242                    "active state:            T%d\n"
1243                    "state available: T%d to T%d\n",
1244                    pr->throttling.state_count, pr->throttling.state,
1245                    pr->throttling_platform_limit,
1246                    pr->throttling.state_count - 1);
1247
1248         seq_puts(seq, "states:\n");
1249         if (pr->throttling.acpi_processor_get_throttling ==
1250                         acpi_processor_get_throttling_fadt) {
1251                 for (i = 0; i < pr->throttling.state_count; i++)
1252                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1253                                    (i == pr->throttling.state ? '*' : ' '), i,
1254                                    (pr->throttling.states[i].performance ? pr->
1255                                     throttling.states[i].performance / 10 : 0));
1256         } else {
1257                 for (i = 0; i < pr->throttling.state_count; i++)
1258                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1259                                    (i == pr->throttling.state ? '*' : ' '), i,
1260                                    (int)pr->throttling.states_tss[i].
1261                                    freqpercentage);
1262         }
1263
1264       end:
1265         return 0;
1266 }
1267
1268 static int acpi_processor_throttling_open_fs(struct inode *inode,
1269                                              struct file *file)
1270 {
1271         return single_open(file, acpi_processor_throttling_seq_show,
1272                            PDE(inode)->data);
1273 }
1274
1275 static ssize_t acpi_processor_write_throttling(struct file *file,
1276                                                const char __user * buffer,
1277                                                size_t count, loff_t * data)
1278 {
1279         int result = 0;
1280         struct seq_file *m = file->private_data;
1281         struct acpi_processor *pr = m->private;
1282         char state_string[5] = "";
1283         char *charp = NULL;
1284         size_t state_val = 0;
1285         char tmpbuf[5] = "";
1286
1287         if (!pr || (count > sizeof(state_string) - 1))
1288                 return -EINVAL;
1289
1290         if (copy_from_user(state_string, buffer, count))
1291                 return -EFAULT;
1292
1293         state_string[count] = '\0';
1294         if ((count > 0) && (state_string[count-1] == '\n'))
1295                 state_string[count-1] = '\0';
1296
1297         charp = state_string;
1298         if ((state_string[0] == 't') || (state_string[0] == 'T'))
1299                 charp++;
1300
1301         state_val = simple_strtoul(charp, NULL, 0);
1302         if (state_val >= pr->throttling.state_count)
1303                 return -EINVAL;
1304
1305         snprintf(tmpbuf, 5, "%zu", state_val);
1306
1307         if (strcmp(tmpbuf, charp) != 0)
1308                 return -EINVAL;
1309
1310         result = acpi_processor_set_throttling(pr, state_val);
1311         if (result)
1312                 return result;
1313
1314         return count;
1315 }
1316
1317 const struct file_operations acpi_processor_throttling_fops = {
1318         .owner = THIS_MODULE,
1319         .open = acpi_processor_throttling_open_fs,
1320         .read = seq_read,
1321         .write = acpi_processor_write_throttling,
1322         .llseek = seq_lseek,
1323         .release = single_release,
1324 };