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