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/slab.h>
  32 #include <linux/init.h>
  33 #include <linux/sched.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/proc_fs.h>
  36 #include <linux/seq_file.h>
  37
  38 #include <asm/io.h>
  39 #include <asm/uaccess.h>
  40
  41 #include <acpi/acpi_bus.h>
  42 #include <acpi/acpi_drivers.h>
  43 #include <acpi/processor.h>
  44
  45 #define PREFIX "ACPI: "
  46
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  49 ACPI_MODULE_NAME("processor_throttling");
  50
  51 /* ignore_tpc:
  52  *  0 -> acpi processor driver doesn't ignore _TPC values
  53  *  1 -> acpi processor driver ignores _TPC values
  54  */
  55 static int ignore_tpc;
  56 module_param(ignore_tpc, int, 0644);
  57 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  58
  59 struct throttling_tstate {
  60         unsigned int cpu;               /* cpu nr */
  61         int target_state;               /* target T-state */
  62 };
  63
  64 #define THROTTLING_PRECHANGE       (1)
  65 #define THROTTLING_POSTCHANGE      (2)
  66
  67 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  68 int acpi_processor_set_throttling(struct acpi_processor *pr,
  69                                                 int state, bool force);
  70
  71 static int acpi_processor_update_tsd_coord(void)
  72 {
  73         int count, count_target;
  74         int retval = 0;
  75         unsigned int i, j;
  76         cpumask_var_t covered_cpus;
  77         struct acpi_processor *pr, *match_pr;
  78         struct acpi_tsd_package *pdomain, *match_pdomain;
  79         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  80
  81         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  82                 return -ENOMEM;
  83
  84         /*
  85          * Now that we have _TSD data from all CPUs, lets setup T-state
  86          * coordination between all CPUs.
  87          */
  88         for_each_possible_cpu(i) {
  89                 pr = per_cpu(processors, i);
  90                 if (!pr)
  91                         continue;
  92
  93                 /* Basic validity check for domain info */
  94                 pthrottling = &(pr->throttling);
  95
  96                 /*
  97                  * If tsd package for one cpu is invalid, the coordination
  98                  * among all CPUs is thought as invalid.
  99                  * Maybe it is ugly.
 100                  */
 101                 if (!pthrottling->tsd_valid_flag) {
 102                         retval = -EINVAL;
 103                         break;
 104                 }
 105         }
 106         if (retval)
 107                 goto err_ret;
 108
 109         for_each_possible_cpu(i) {
 110                 pr = per_cpu(processors, i);
 111                 if (!pr)
 112                         continue;
 113
 114                 if (cpumask_test_cpu(i, covered_cpus))
 115                         continue;
 116                 pthrottling = &pr->throttling;
 117
 118                 pdomain = &(pthrottling->domain_info);
 119                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 120                 cpumask_set_cpu(i, covered_cpus);
 121                 /*
 122                  * If the number of processor in the TSD domain is 1, it is
 123                  * unnecessary to parse the coordination for this CPU.
 124                  */
 125                 if (pdomain->num_processors <= 1)
 126                         continue;
 127
 128                 /* Validate the Domain info */
 129                 count_target = pdomain->num_processors;
 130                 count = 1;
 131
 132                 for_each_possible_cpu(j) {
 133                         if (i == j)
 134                                 continue;
 135
 136                         match_pr = per_cpu(processors, j);
 137                         if (!match_pr)
 138                                 continue;
 139
 140                         match_pthrottling = &(match_pr->throttling);
 141                         match_pdomain = &(match_pthrottling->domain_info);
 142                         if (match_pdomain->domain != pdomain->domain)
 143                                 continue;
 144
 145                         /* Here i and j are in the same domain.
 146                          * If two TSD packages have the same domain, they
 147                          * should have the same num_porcessors and
 148                          * coordination type. Otherwise it will be regarded
 149                          * as illegal.
 150                          */
 151                         if (match_pdomain->num_processors != count_target) {
 152                                 retval = -EINVAL;
 153                                 goto err_ret;
 154                         }
 155
 156                         if (pdomain->coord_type != match_pdomain->coord_type) {
 157                                 retval = -EINVAL;
 158                                 goto err_ret;
 159                         }
 160
 161                         cpumask_set_cpu(j, covered_cpus);
 162                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 163                         count++;
 164                 }
 165                 for_each_possible_cpu(j) {
 166                         if (i == j)
 167                                 continue;
 168
 169                         match_pr = per_cpu(processors, j);
 170                         if (!match_pr)
 171                                 continue;
 172
 173                         match_pthrottling = &(match_pr->throttling);
 174                         match_pdomain = &(match_pthrottling->domain_info);
 175                         if (match_pdomain->domain != pdomain->domain)
 176                                 continue;
 177
 178                         /*
 179                          * If some CPUS have the same domain, they
 180                          * will have the same shared_cpu_map.
 181                          */
 182                         cpumask_copy(match_pthrottling->shared_cpu_map,
 183                                      pthrottling->shared_cpu_map);
 184                 }
 185         }
 186
 187 err_ret:
 188         free_cpumask_var(covered_cpus);
 189
 190         for_each_possible_cpu(i) {
 191                 pr = per_cpu(processors, i);
 192                 if (!pr)
 193                         continue;
 194
 195                 /*
 196                  * Assume no coordination on any error parsing domain info.
 197                  * The coordination type will be forced as SW_ALL.
 198                  */
 199                 if (retval) {
 200                         pthrottling = &(pr->throttling);
 201                         cpumask_clear(pthrottling->shared_cpu_map);
 202                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 203                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 204                 }
 205         }
 206
 207         return retval;
 208 }
 209
 210 /*
 211  * Update the T-state coordination after the _TSD
 212  * data for all cpus is obtained.
 213  */
 214 void acpi_processor_throttling_init(void)
 215 {
 216         if (acpi_processor_update_tsd_coord())
 217                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 218                         "Assume no T-state coordination\n"));
 219
 220         return;
 221 }
 222
 223 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 224 {
 225         struct throttling_tstate *p_tstate = data;
 226         struct acpi_processor *pr;
 227         unsigned int cpu ;
 228         int target_state;
 229         struct acpi_processor_limit *p_limit;
 230         struct acpi_processor_throttling *p_throttling;
 231
 232         cpu = p_tstate->cpu;
 233         pr = per_cpu(processors, cpu);
 234         if (!pr) {
 235                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 236                 return 0;
 237         }
 238         if (!pr->flags.throttling) {
 239                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 240                                 "unsupported on CPU %d\n", cpu));
 241                 return 0;
 242         }
 243         target_state = p_tstate->target_state;
 244         p_throttling = &(pr->throttling);
 245         switch (event) {
 246         case THROTTLING_PRECHANGE:
 247                 /*
 248                  * Prechange event is used to choose one proper t-state,
 249                  * which meets the limits of thermal, user and _TPC.
 250                  */
 251                 p_limit = &pr->limit;
 252                 if (p_limit->thermal.tx > target_state)
 253                         target_state = p_limit->thermal.tx;
 254                 if (p_limit->user.tx > target_state)
 255                         target_state = p_limit->user.tx;
 256                 if (pr->throttling_platform_limit > target_state)
 257                         target_state = pr->throttling_platform_limit;
 258                 if (target_state >= p_throttling->state_count) {
 259                         printk(KERN_WARNING
 260                                 "Exceed the limit of T-state \n");
 261                         target_state = p_throttling->state_count - 1;
 262                 }
 263                 p_tstate->target_state = target_state;
 264                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 265                                 "target T-state of CPU %d is T%d\n",
 266                                 cpu, target_state));
 267                 break;
 268         case THROTTLING_POSTCHANGE:
 269                 /*
 270                  * Postchange event is only used to update the
 271                  * T-state flag of acpi_processor_throttling.
 272                  */
 273                 p_throttling->state = target_state;
 274                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 275                                 "CPU %d is switched to T%d\n",
 276                                 cpu, target_state));
 277                 break;
 278         default:
 279                 printk(KERN_WARNING
 280                         "Unsupported Throttling notifier event\n");
 281                 break;
 282         }
 283
 284         return 0;
 285 }
 286
 287 /*
 288  * _TPC - Throttling Present Capabilities
 289  */
 290 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 291 {
 292         acpi_status status = 0;
 293         unsigned long long tpc = 0;
 294
 295         if (!pr)
 296                 return -EINVAL;
 297
 298         if (ignore_tpc)
 299                 goto end;
 300
 301         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 302         if (ACPI_FAILURE(status)) {
 303                 if (status != AE_NOT_FOUND) {
 304                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 305                 }
 306                 return -ENODEV;
 307         }
 308
 309 end:
 310         pr->throttling_platform_limit = (int)tpc;
 311         return 0;
 312 }
 313
 314 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 315 {
 316         int result = 0;
 317         int throttling_limit;
 318         int current_state;
 319         struct acpi_processor_limit *limit;
 320         int target_state;
 321
 322         if (ignore_tpc)
 323                 return 0;
 324
 325         result = acpi_processor_get_platform_limit(pr);
 326         if (result) {
 327                 /* Throttling Limit is unsupported */
 328                 return result;
 329         }
 330
 331         throttling_limit = pr->throttling_platform_limit;
 332         if (throttling_limit >= pr->throttling.state_count) {
 333                 /* Uncorrect Throttling Limit */
 334                 return -EINVAL;
 335         }
 336
 337         current_state = pr->throttling.state;
 338         if (current_state > throttling_limit) {
 339                 /*
 340                  * The current state can meet the requirement of
 341                  * _TPC limit. But it is reasonable that OSPM changes
 342                  * t-states from high to low for better performance.
 343                  * Of course the limit condition of thermal
 344                  * and user should be considered.
 345                  */
 346                 limit = &pr->limit;
 347                 target_state = throttling_limit;
 348                 if (limit->thermal.tx > target_state)
 349                         target_state = limit->thermal.tx;
 350                 if (limit->user.tx > target_state)
 351                         target_state = limit->user.tx;
 352         } else if (current_state == throttling_limit) {
 353                 /*
 354                  * Unnecessary to change the throttling state
 355                  */
 356                 return 0;
 357         } else {
 358                 /*
 359                  * If the current state is lower than the limit of _TPC, it
 360                  * will be forced to switch to the throttling state defined
 361                  * by throttling_platfor_limit.
 362                  * Because the previous state meets with the limit condition
 363                  * of thermal and user, it is unnecessary to check it again.
 364                  */
 365                 target_state = throttling_limit;
 366         }
 367         return acpi_processor_set_throttling(pr, target_state, false);
 368 }
 369
 370 /*
 371  * _PTC - Processor Throttling Control (and status) register location
 372  */
 373 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 374 {
 375         int result = 0;
 376         acpi_status status = 0;
 377         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 378         union acpi_object *ptc = NULL;
 379         union acpi_object obj = { 0 };
 380         struct acpi_processor_throttling *throttling;
 381
 382         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 383         if (ACPI_FAILURE(status)) {
 384                 if (status != AE_NOT_FOUND) {
 385                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 386                 }
 387                 return -ENODEV;
 388         }
 389
 390         ptc = (union acpi_object *)buffer.pointer;
 391         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 392             || (ptc->package.count != 2)) {
 393                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 394                 result = -EFAULT;
 395                 goto end;
 396         }
 397
 398         /*
 399          * control_register
 400          */
 401
 402         obj = ptc->package.elements[0];
 403
 404         if ((obj.type != ACPI_TYPE_BUFFER)
 405             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 406             || (obj.buffer.pointer == NULL)) {
 407                 printk(KERN_ERR PREFIX
 408                        "Invalid _PTC data (control_register)\n");
 409                 result = -EFAULT;
 410                 goto end;
 411         }
 412         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 413                sizeof(struct acpi_ptc_register));
 414
 415         /*
 416          * status_register
 417          */
 418
 419         obj = ptc->package.elements[1];
 420
 421         if ((obj.type != ACPI_TYPE_BUFFER)
 422             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 423             || (obj.buffer.pointer == NULL)) {
 424                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 425                 result = -EFAULT;
 426                 goto end;
 427         }
 428
 429         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 430                sizeof(struct acpi_ptc_register));
 431
 432         throttling = &pr->throttling;
 433
 434         if ((throttling->control_register.bit_width +
 435                 throttling->control_register.bit_offset) > 32) {
 436                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 437                 result = -EFAULT;
 438                 goto end;
 439         }
 440
 441         if ((throttling->status_register.bit_width +
 442                 throttling->status_register.bit_offset) > 32) {
 443                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 444                 result = -EFAULT;
 445                 goto end;
 446         }
 447
 448       end:
 449         kfree(buffer.pointer);
 450
 451         return result;
 452 }
 453
 454 /*
 455  * _TSS - Throttling Supported States
 456  */
 457 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 458 {
 459         int result = 0;
 460         acpi_status status = AE_OK;
 461         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 462         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 463         struct acpi_buffer state = { 0, NULL };
 464         union acpi_object *tss = NULL;
 465         int i;
 466
 467         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 468         if (ACPI_FAILURE(status)) {
 469                 if (status != AE_NOT_FOUND) {
 470                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 471                 }
 472                 return -ENODEV;
 473         }
 474
 475         tss = buffer.pointer;
 476         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 477                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 478                 result = -EFAULT;
 479                 goto end;
 480         }
 481
 482         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 483                           tss->package.count));
 484
 485         pr->throttling.state_count = tss->package.count;
 486         pr->throttling.states_tss =
 487             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 488                     GFP_KERNEL);
 489         if (!pr->throttling.states_tss) {
 490                 result = -ENOMEM;
 491                 goto end;
 492         }
 493
 494         for (i = 0; i < pr->throttling.state_count; i++) {
 495
 496                 struct acpi_processor_tx_tss *tx =
 497                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 498                                                       states_tss[i]);
 499
 500                 state.length = sizeof(struct acpi_processor_tx_tss);
 501                 state.pointer = tx;
 502
 503                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 504
 505                 status = acpi_extract_package(&(tss->package.elements[i]),
 506                                               &format, &state);
 507                 if (ACPI_FAILURE(status)) {
 508                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 509                         result = -EFAULT;
 510                         kfree(pr->throttling.states_tss);
 511                         goto end;
 512                 }
 513
 514                 if (!tx->freqpercentage) {
 515                         printk(KERN_ERR PREFIX
 516                                "Invalid _TSS data: freq is zero\n");
 517                         result = -EFAULT;
 518                         kfree(pr->throttling.states_tss);
 519                         goto end;
 520                 }
 521         }
 522
 523       end:
 524         kfree(buffer.pointer);
 525
 526         return result;
 527 }
 528
 529 /*
 530  * _TSD - T-State Dependencies
 531  */
 532 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 533 {
 534         int result = 0;
 535         acpi_status status = AE_OK;
 536         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 537         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 538         struct acpi_buffer state = { 0, NULL };
 539         union acpi_object *tsd = NULL;
 540         struct acpi_tsd_package *pdomain;
 541         struct acpi_processor_throttling *pthrottling;
 542
 543         pthrottling = &pr->throttling;
 544         pthrottling->tsd_valid_flag = 0;
 545
 546         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 547         if (ACPI_FAILURE(status)) {
 548                 if (status != AE_NOT_FOUND) {
 549                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 550                 }
 551                 return -ENODEV;
 552         }
 553
 554         tsd = buffer.pointer;
 555         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 556                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 557                 result = -EFAULT;
 558                 goto end;
 559         }
 560
 561         if (tsd->package.count != 1) {
 562                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 563                 result = -EFAULT;
 564                 goto end;
 565         }
 566
 567         pdomain = &(pr->throttling.domain_info);
 568
 569         state.length = sizeof(struct acpi_tsd_package);
 570         state.pointer = pdomain;
 571
 572         status = acpi_extract_package(&(tsd->package.elements[0]),
 573                                       &format, &state);
 574         if (ACPI_FAILURE(status)) {
 575                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 576                 result = -EFAULT;
 577                 goto end;
 578         }
 579
 580         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 581                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 582                 result = -EFAULT;
 583                 goto end;
 584         }
 585
 586         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 587                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 588                 result = -EFAULT;
 589                 goto end;
 590         }
 591
 592         pthrottling = &pr->throttling;
 593         pthrottling->tsd_valid_flag = 1;
 594         pthrottling->shared_type = pdomain->coord_type;
 595         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 596         /*
 597          * If the coordination type is not defined in ACPI spec,
 598          * the tsd_valid_flag will be clear and coordination type
 599          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 600          */
 601         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 602                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 603                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 604                 pthrottling->tsd_valid_flag = 0;
 605                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 606         }
 607
 608       end:
 609         kfree(buffer.pointer);
 610         return result;
 611 }
 612
 613 /* --------------------------------------------------------------------------
 614                               Throttling Control
 615    -------------------------------------------------------------------------- */
 616 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 617 {
 618         int state = 0;
 619         u32 value = 0;
 620         u32 duty_mask = 0;
 621         u32 duty_value = 0;
 622
 623         if (!pr)
 624                 return -EINVAL;
 625
 626         if (!pr->flags.throttling)
 627                 return -ENODEV;
 628
 629         pr->throttling.state = 0;
 630
 631         duty_mask = pr->throttling.state_count - 1;
 632
 633         duty_mask <<= pr->throttling.duty_offset;
 634
 635         local_irq_disable();
 636
 637         value = inl(pr->throttling.address);
 638
 639         /*
 640          * Compute the current throttling state when throttling is enabled
 641          * (bit 4 is on).
 642          */
 643         if (value & 0x10) {
 644                 duty_value = value & duty_mask;
 645                 duty_value >>= pr->throttling.duty_offset;
 646
 647                 if (duty_value)
 648                         state = pr->throttling.state_count - duty_value;
 649         }
 650
 651         pr->throttling.state = state;
 652
 653         local_irq_enable();
 654
 655         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 656                           "Throttling state is T%d (%d%% throttling applied)\n",
 657                           state, pr->throttling.states[state].performance));
 658
 659         return 0;
 660 }
 661
 662 #ifdef CONFIG_X86
 663 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 664                                         u64 *value)
 665 {
 666         struct cpuinfo_x86 *c;
 667         u64 msr_high, msr_low;
 668         unsigned int cpu;
 669         u64 msr = 0;
 670         int ret = -1;
 671
 672         cpu = pr->id;
 673         c = &cpu_data(cpu);
 674
 675         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 676                 !cpu_has(c, X86_FEATURE_ACPI)) {
 677                 printk(KERN_ERR PREFIX
 678                         "HARDWARE addr space,NOT supported yet\n");
 679         } else {
 680                 msr_low = 0;
 681                 msr_high = 0;
 682                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 683                         (u32 *)&msr_low , (u32 *) &msr_high);
 684                 msr = (msr_high << 32) | msr_low;
 685                 *value = (u64) msr;
 686                 ret = 0;
 687         }
 688         return ret;
 689 }
 690
 691 static int acpi_throttling_wrmsr(struct acpi_processor *pr, u64 value)
 692 {
 693         struct cpuinfo_x86 *c;
 694         unsigned int cpu;
 695         int ret = -1;
 696         u64 msr;
 697
 698         cpu = pr->id;
 699         c = &cpu_data(cpu);
 700
 701         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 702                 !cpu_has(c, X86_FEATURE_ACPI)) {
 703                 printk(KERN_ERR PREFIX
 704                         "HARDWARE addr space,NOT supported yet\n");
 705         } else {
 706                 msr = value;
 707                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 708                         msr & 0xffffffff, msr >> 32);
 709                 ret = 0;
 710         }
 711         return ret;
 712 }
 713 #else
 714 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 715                                 u64 *value)
 716 {
 717         printk(KERN_ERR PREFIX
 718                 "HARDWARE addr space,NOT supported yet\n");
 719         return -1;
 720 }
 721
 722 static int acpi_throttling_wrmsr(struct acpi_processor *pr, u64 value)
 723 {
 724         printk(KERN_ERR PREFIX
 725                 "HARDWARE addr space,NOT supported yet\n");
 726         return -1;
 727 }
 728 #endif
 729
 730 static int acpi_read_throttling_status(struct acpi_processor *pr,
 731                                         u64 *value)
 732 {
 733         u32 bit_width, bit_offset;
 734         u64 ptc_value;
 735         u64 ptc_mask;
 736         struct acpi_processor_throttling *throttling;
 737         int ret = -1;
 738
 739         throttling = &pr->throttling;
 740         switch (throttling->status_register.space_id) {
 741         case ACPI_ADR_SPACE_SYSTEM_IO:
 742                 ptc_value = 0;
 743                 bit_width = throttling->status_register.bit_width;
 744                 bit_offset = throttling->status_register.bit_offset;
 745
 746                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 747                                   address, (u32 *) &ptc_value,
 748                                   (u32) (bit_width + bit_offset));
 749                 ptc_mask = (1 << bit_width) - 1;
 750                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 751                 ret = 0;
 752                 break;
 753         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 754                 ret = acpi_throttling_rdmsr(pr, value);
 755                 break;
 756         default:
 757                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 758                        (u32) (throttling->status_register.space_id));
 759         }
 760         return ret;
 761 }
 762
 763 static int acpi_write_throttling_state(struct acpi_processor *pr,
 764                                 u64 value)
 765 {
 766         u32 bit_width, bit_offset;
 767         u64 ptc_value;
 768         u64 ptc_mask;
 769         struct acpi_processor_throttling *throttling;
 770         int ret = -1;
 771
 772         throttling = &pr->throttling;
 773         switch (throttling->control_register.space_id) {
 774         case ACPI_ADR_SPACE_SYSTEM_IO:
 775                 bit_width = throttling->control_register.bit_width;
 776                 bit_offset = throttling->control_register.bit_offset;
 777                 ptc_mask = (1 << bit_width) - 1;
 778                 ptc_value = value & ptc_mask;
 779
 780                 acpi_os_write_port((acpi_io_address) throttling->
 781                                         control_register.address,
 782                                         (u32) (ptc_value << bit_offset),
 783                                         (u32) (bit_width + bit_offset));
 784                 ret = 0;
 785                 break;
 786         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 787                 ret = acpi_throttling_wrmsr(pr, value);
 788                 break;
 789         default:
 790                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 791                        (u32) (throttling->control_register.space_id));
 792         }
 793         return ret;
 794 }
 795
 796 static int acpi_get_throttling_state(struct acpi_processor *pr,
 797                                 u64 value)
 798 {
 799         int i;
 800
 801         for (i = 0; i < pr->throttling.state_count; i++) {
 802                 struct acpi_processor_tx_tss *tx =
 803                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 804                                                       states_tss[i]);
 805                 if (tx->control == value)
 806                         return i;
 807         }
 808         return -1;
 809 }
 810
 811 static int acpi_get_throttling_value(struct acpi_processor *pr,
 812                         int state, u64 *value)
 813 {
 814         int ret = -1;
 815
 816         if (state >= 0 && state <= pr->throttling.state_count) {
 817                 struct acpi_processor_tx_tss *tx =
 818                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 819                                                       states_tss[state]);
 820                 *value = tx->control;
 821                 ret = 0;
 822         }
 823         return ret;
 824 }
 825
 826 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 827 {
 828         int state = 0;
 829         int ret;
 830         u64 value;
 831
 832         if (!pr)
 833                 return -EINVAL;
 834
 835         if (!pr->flags.throttling)
 836                 return -ENODEV;
 837
 838         pr->throttling.state = 0;
 839
 840         value = 0;
 841         ret = acpi_read_throttling_status(pr, &value);
 842         if (ret >= 0) {
 843                 state = acpi_get_throttling_state(pr, value);
 844                 if (state == -1) {
 845                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 846                                 "Invalid throttling state, reset\n"));
 847                         state = 0;
 848                         ret = acpi_processor_set_throttling(pr, state, true);
 849                         if (ret)
 850                                 return ret;
 851                 }
 852                 pr->throttling.state = state;
 853         }
 854
 855         return 0;
 856 }
 857
 858 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 859 {
 860         cpumask_var_t saved_mask;
 861         int ret;
 862
 863         if (!pr)
 864                 return -EINVAL;
 865
 866         if (!pr->flags.throttling)
 867                 return -ENODEV;
 868
 869         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 870                 return -ENOMEM;
 871
 872         /*
 873          * Migrate task to the cpu pointed by pr.
 874          */
 875         cpumask_copy(saved_mask, &current->cpus_allowed);
 876         /* FIXME: use work_on_cpu() */
 877         set_cpus_allowed_ptr(current, cpumask_of(pr->id));
 878         ret = pr->throttling.acpi_processor_get_throttling(pr);
 879         /* restore the previous state */
 880         set_cpus_allowed_ptr(current, saved_mask);
 881         free_cpumask_var(saved_mask);
 882
 883         return ret;
 884 }
 885
 886 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 887 {
 888         int i, step;
 889
 890         if (!pr->throttling.address) {
 891                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 892                 return -EINVAL;
 893         } else if (!pr->throttling.duty_width) {
 894                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 895                 return -EINVAL;
 896         }
 897         /* TBD: Support duty_cycle values that span bit 4. */
 898         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 899                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 900                 return -EINVAL;
 901         }
 902
 903         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 904
 905         /*
 906          * Compute state values. Note that throttling displays a linear power
 907          * performance relationship (at 50% performance the CPU will consume
 908          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 909          */
 910
 911         step = (1000 / pr->throttling.state_count);
 912
 913         for (i = 0; i < pr->throttling.state_count; i++) {
 914                 pr->throttling.states[i].performance = 1000 - step * i;
 915                 pr->throttling.states[i].power = 1000 - step * i;
 916         }
 917         return 0;
 918 }
 919
 920 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 921                                               int state, bool force)
 922 {
 923         u32 value = 0;
 924         u32 duty_mask = 0;
 925         u32 duty_value = 0;
 926
 927         if (!pr)
 928                 return -EINVAL;
 929
 930         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 931                 return -EINVAL;
 932
 933         if (!pr->flags.throttling)
 934                 return -ENODEV;
 935
 936         if (!force && (state == pr->throttling.state))
 937                 return 0;
 938
 939         if (state < pr->throttling_platform_limit)
 940                 return -EPERM;
 941         /*
 942          * Calculate the duty_value and duty_mask.
 943          */
 944         if (state) {
 945                 duty_value = pr->throttling.state_count - state;
 946
 947                 duty_value <<= pr->throttling.duty_offset;
 948
 949                 /* Used to clear all duty_value bits */
 950                 duty_mask = pr->throttling.state_count - 1;
 951
 952                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 953                 duty_mask = ~duty_mask;
 954         }
 955
 956         local_irq_disable();
 957
 958         /*
 959          * Disable throttling by writing a 0 to bit 4.  Note that we must
 960          * turn it off before you can change the duty_value.
 961          */
 962         value = inl(pr->throttling.address);
 963         if (value & 0x10) {
 964                 value &= 0xFFFFFFEF;
 965                 outl(value, pr->throttling.address);
 966         }
 967
 968         /*
 969          * Write the new duty_value and then enable throttling.  Note
 970          * that a state value of 0 leaves throttling disabled.
 971          */
 972         if (state) {
 973                 value &= duty_mask;
 974                 value |= duty_value;
 975                 outl(value, pr->throttling.address);
 976
 977                 value |= 0x00000010;
 978                 outl(value, pr->throttling.address);
 979         }
 980
 981         pr->throttling.state = state;
 982
 983         local_irq_enable();
 984
 985         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 986                           "Throttling state set to T%d (%d%%)\n", state,
 987                           (pr->throttling.states[state].performance ? pr->
 988                            throttling.states[state].performance / 10 : 0)));
 989
 990         return 0;
 991 }
 992
 993 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 994                                              int state, bool force)
 995 {
 996         int ret;
 997         u64 value;
 998
 999         if (!pr)
1000                 return -EINVAL;
1001
1002         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1003                 return -EINVAL;
1004
1005         if (!pr->flags.throttling)
1006                 return -ENODEV;
1007
1008         if (!force && (state == pr->throttling.state))
1009                 return 0;
1010
1011         if (state < pr->throttling_platform_limit)
1012                 return -EPERM;
1013
1014         value = 0;
1015         ret = acpi_get_throttling_value(pr, state, &value);
1016         if (ret >= 0) {
1017                 acpi_write_throttling_state(pr, value);
1018                 pr->throttling.state = state;
1019         }
1020
1021         return 0;
1022 }
1023
1024 int acpi_processor_set_throttling(struct acpi_processor *pr,
1025                                                 int state, bool force)
1026 {
1027         cpumask_var_t saved_mask;
1028         int ret = 0;
1029         unsigned int i;
1030         struct acpi_processor *match_pr;
1031         struct acpi_processor_throttling *p_throttling;
1032         struct throttling_tstate t_state;
1033         cpumask_var_t online_throttling_cpus;
1034
1035         if (!pr)
1036                 return -EINVAL;
1037
1038         if (!pr->flags.throttling)
1039                 return -ENODEV;
1040
1041         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1042                 return -EINVAL;
1043
1044         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1045                 return -ENOMEM;
1046
1047         if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1048                 free_cpumask_var(saved_mask);
1049                 return -ENOMEM;
1050         }
1051
1052         cpumask_copy(saved_mask, &current->cpus_allowed);
1053         t_state.target_state = state;
1054         p_throttling = &(pr->throttling);
1055         cpumask_and(online_throttling_cpus, cpu_online_mask,
1056                     p_throttling->shared_cpu_map);
1057         /*
1058          * The throttling notifier will be called for every
1059          * affected cpu in order to get one proper T-state.
1060          * The notifier event is THROTTLING_PRECHANGE.
1061          */
1062         for_each_cpu(i, online_throttling_cpus) {
1063                 t_state.cpu = i;
1064                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1065                                                         &t_state);
1066         }
1067         /*
1068          * The function of acpi_processor_set_throttling will be called
1069          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1070          * it is necessary to call it for every affected cpu. Otherwise
1071          * it can be called only for the cpu pointed by pr.
1072          */
1073         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1074                 /* FIXME: use work_on_cpu() */
1075                 set_cpus_allowed_ptr(current, cpumask_of(pr->id));
1076                 ret = p_throttling->acpi_processor_set_throttling(pr,
1077                                                 t_state.target_state, force);
1078         } else {
1079                 /*
1080                  * When the T-state coordination is SW_ALL or HW_ALL,
1081                  * it is necessary to set T-state for every affected
1082                  * cpus.
1083                  */
1084                 for_each_cpu(i, online_throttling_cpus) {
1085                         match_pr = per_cpu(processors, i);
1086                         /*
1087                          * If the pointer is invalid, we will report the
1088                          * error message and continue.
1089                          */
1090                         if (!match_pr) {
1091                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1092                                         "Invalid Pointer for CPU %d\n", i));
1093                                 continue;
1094                         }
1095                         /*
1096                          * If the throttling control is unsupported on CPU i,
1097                          * we will report the error message and continue.
1098                          */
1099                         if (!match_pr->flags.throttling) {
1100                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1101                                         "Throttling Controll is unsupported "
1102                                         "on CPU %d\n", i));
1103                                 continue;
1104                         }
1105                         t_state.cpu = i;
1106                         /* FIXME: use work_on_cpu() */
1107                         set_cpus_allowed_ptr(current, cpumask_of(i));
1108                         ret = match_pr->throttling.
1109                                 acpi_processor_set_throttling(
1110                                 match_pr, t_state.target_state, force);
1111                 }
1112         }
1113         /*
1114          * After the set_throttling is called, the
1115          * throttling notifier is called for every
1116          * affected cpu to update the T-states.
1117          * The notifier event is THROTTLING_POSTCHANGE
1118          */
1119         for_each_cpu(i, online_throttling_cpus) {
1120                 t_state.cpu = i;
1121                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1122                                                         &t_state);
1123         }
1124         /* restore the previous state */
1125         /* FIXME: use work_on_cpu() */
1126         set_cpus_allowed_ptr(current, saved_mask);
1127         free_cpumask_var(online_throttling_cpus);
1128         free_cpumask_var(saved_mask);
1129         return ret;
1130 }
1131
1132 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1133 {
1134         int result = 0;
1135         struct acpi_processor_throttling *pthrottling;
1136
1137         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1138                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1139                           pr->throttling.address,
1140                           pr->throttling.duty_offset,
1141                           pr->throttling.duty_width));
1142
1143         /*
1144          * Evaluate _PTC, _TSS and _TPC
1145          * They must all be present or none of them can be used.
1146          */
1147         if (acpi_processor_get_throttling_control(pr) ||
1148                 acpi_processor_get_throttling_states(pr) ||
1149                 acpi_processor_get_platform_limit(pr))
1150         {
1151                 pr->throttling.acpi_processor_get_throttling =
1152                     &acpi_processor_get_throttling_fadt;
1153                 pr->throttling.acpi_processor_set_throttling =
1154                     &acpi_processor_set_throttling_fadt;
1155                 if (acpi_processor_get_fadt_info(pr))
1156                         return 0;
1157         } else {
1158                 pr->throttling.acpi_processor_get_throttling =
1159                     &acpi_processor_get_throttling_ptc;
1160                 pr->throttling.acpi_processor_set_throttling =
1161                     &acpi_processor_set_throttling_ptc;
1162         }
1163
1164         /*
1165          * If TSD package for one CPU can't be parsed successfully, it means
1166          * that this CPU will have no coordination with other CPUs.
1167          */
1168         if (acpi_processor_get_tsd(pr)) {
1169                 pthrottling = &pr->throttling;
1170                 pthrottling->tsd_valid_flag = 0;
1171                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1172                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1173         }
1174
1175         /*
1176          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1177          * This shouldn't be an issue as few (if any) mobile systems ever
1178          * used this part.
1179          */
1180         if (errata.piix4.throttle) {
1181                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1182                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1183                 return 0;
1184         }
1185
1186         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1187                           pr->throttling.state_count));
1188
1189         pr->flags.throttling = 1;
1190
1191         /*
1192          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1193          * thermal) decide to lower performance if it so chooses, but for now
1194          * we'll crank up the speed.
1195          */
1196
1197         result = acpi_processor_get_throttling(pr);
1198         if (result)
1199                 goto end;
1200
1201         if (pr->throttling.state) {
1202                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1203                                   "Disabling throttling (was T%d)\n",
1204                                   pr->throttling.state));
1205                 result = acpi_processor_set_throttling(pr, 0, false);
1206                 if (result)
1207                         goto end;
1208         }
1209
1210       end:
1211         if (result)
1212                 pr->flags.throttling = 0;
1213
1214         return result;
1215 }
1216
1217 /* proc interface */
1218 #ifdef CONFIG_ACPI_PROCFS
1219 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1220                                               void *offset)
1221 {
1222         struct acpi_processor *pr = seq->private;
1223         int i = 0;
1224         int result = 0;
1225
1226         if (!pr)
1227                 goto end;
1228
1229         if (!(pr->throttling.state_count > 0)) {
1230                 seq_puts(seq, "<not supported>\n");
1231                 goto end;
1232         }
1233
1234         result = acpi_processor_get_throttling(pr);
1235
1236         if (result) {
1237                 seq_puts(seq,
1238                          "Could not determine current throttling state.\n");
1239                 goto end;
1240         }
1241
1242         seq_printf(seq, "state count:             %d\n"
1243                    "active state:            T%d\n"
1244                    "state available: T%d to T%d\n",
1245                    pr->throttling.state_count, pr->throttling.state,
1246                    pr->throttling_platform_limit,
1247                    pr->throttling.state_count - 1);
1248
1249         seq_puts(seq, "states:\n");
1250         if (pr->throttling.acpi_processor_get_throttling ==
1251                         acpi_processor_get_throttling_fadt) {
1252                 for (i = 0; i < pr->throttling.state_count; i++)
1253                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1254                                    (i == pr->throttling.state ? '*' : ' '), i,
1255                                    (pr->throttling.states[i].performance ? pr->
1256                                     throttling.states[i].performance / 10 : 0));
1257         } else {
1258                 for (i = 0; i < pr->throttling.state_count; i++)
1259                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1260                                    (i == pr->throttling.state ? '*' : ' '), i,
1261                                    (int)pr->throttling.states_tss[i].
1262                                    freqpercentage);
1263         }
1264
1265       end:
1266         return 0;
1267 }
1268
1269 static int acpi_processor_throttling_open_fs(struct inode *inode,
1270                                              struct file *file)
1271 {
1272         return single_open(file, acpi_processor_throttling_seq_show,
1273                            PDE(inode)->data);
1274 }
1275
1276 static ssize_t acpi_processor_write_throttling(struct file *file,
1277                                                const char __user * buffer,
1278                                                size_t count, loff_t * data)
1279 {
1280         int result = 0;
1281         struct seq_file *m = file->private_data;
1282         struct acpi_processor *pr = m->private;
1283         char state_string[5] = "";
1284         char *charp = NULL;
1285         size_t state_val = 0;
1286         char tmpbuf[5] = "";
1287
1288         if (!pr || (count > sizeof(state_string) - 1))
1289                 return -EINVAL;
1290
1291         if (copy_from_user(state_string, buffer, count))
1292                 return -EFAULT;
1293
1294         state_string[count] = '\0';
1295         if ((count > 0) && (state_string[count-1] == '\n'))
1296                 state_string[count-1] = '\0';
1297
1298         charp = state_string;
1299         if ((state_string[0] == 't') || (state_string[0] == 'T'))
1300                 charp++;
1301
1302         state_val = simple_strtoul(charp, NULL, 0);
1303         if (state_val >= pr->throttling.state_count)
1304                 return -EINVAL;
1305
1306         snprintf(tmpbuf, 5, "%zu", state_val);
1307
1308         if (strcmp(tmpbuf, charp) != 0)
1309                 return -EINVAL;
1310
1311         result = acpi_processor_set_throttling(pr, state_val, false);
1312         if (result)
1313                 return result;
1314
1315         return count;
1316 }
1317
1318 const struct file_operations acpi_processor_throttling_fops = {
1319         .owner = THIS_MODULE,
1320         .open = acpi_processor_throttling_open_fs,
1321         .read = seq_read,
1322         .write = acpi_processor_write_throttling,
1323         .llseek = seq_lseek,
1324         .release = single_release,
1325 };
1326 #endif