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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/init.h>
  29 #include <linux/sched.h>
  30 #include <linux/cpufreq.h>
  31 #include <linux/acpi.h>
  32 #include <acpi/processor.h>
  33 #include <asm/io.h>
  34 #include <asm/uaccess.h>
  35
  36 #define PREFIX "ACPI: "
  37
  38 #define ACPI_PROCESSOR_CLASS            "processor"
  39 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  40 ACPI_MODULE_NAME("processor_throttling");
  41
  42 /* ignore_tpc:
  43  *  0 -> acpi processor driver doesn't ignore _TPC values
  44  *  1 -> acpi processor driver ignores _TPC values
  45  */
  46 static int ignore_tpc;
  47 module_param(ignore_tpc, int, 0644);
  48 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  49
  50 struct throttling_tstate {
  51         unsigned int cpu;               /* cpu nr */
  52         int target_state;               /* target T-state */
  53 };
  54
  55 struct acpi_processor_throttling_arg {
  56         struct acpi_processor *pr;
  57         int target_state;
  58         bool force;
  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 (!zalloc_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         for_each_possible_cpu(i) {
 107                 pr = per_cpu(processors, i);
 108                 if (!pr)
 109                         continue;
 110
 111                 if (cpumask_test_cpu(i, covered_cpus))
 112                         continue;
 113                 pthrottling = &pr->throttling;
 114
 115                 pdomain = &(pthrottling->domain_info);
 116                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 117                 cpumask_set_cpu(i, covered_cpus);
 118                 /*
 119                  * If the number of processor in the TSD domain is 1, it is
 120                  * unnecessary to parse the coordination for this CPU.
 121                  */
 122                 if (pdomain->num_processors <= 1)
 123                         continue;
 124
 125                 /* Validate the Domain info */
 126                 count_target = pdomain->num_processors;
 127                 count = 1;
 128
 129                 for_each_possible_cpu(j) {
 130                         if (i == j)
 131                                 continue;
 132
 133                         match_pr = per_cpu(processors, j);
 134                         if (!match_pr)
 135                                 continue;
 136
 137                         match_pthrottling = &(match_pr->throttling);
 138                         match_pdomain = &(match_pthrottling->domain_info);
 139                         if (match_pdomain->domain != pdomain->domain)
 140                                 continue;
 141
 142                         /* Here i and j are in the same domain.
 143                          * If two TSD packages have the same domain, they
 144                          * should have the same num_porcessors and
 145                          * coordination type. Otherwise it will be regarded
 146                          * as illegal.
 147                          */
 148                         if (match_pdomain->num_processors != count_target) {
 149                                 retval = -EINVAL;
 150                                 goto err_ret;
 151                         }
 152
 153                         if (pdomain->coord_type != match_pdomain->coord_type) {
 154                                 retval = -EINVAL;
 155                                 goto err_ret;
 156                         }
 157
 158                         cpumask_set_cpu(j, covered_cpus);
 159                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 160                         count++;
 161                 }
 162                 for_each_possible_cpu(j) {
 163                         if (i == j)
 164                                 continue;
 165
 166                         match_pr = per_cpu(processors, j);
 167                         if (!match_pr)
 168                                 continue;
 169
 170                         match_pthrottling = &(match_pr->throttling);
 171                         match_pdomain = &(match_pthrottling->domain_info);
 172                         if (match_pdomain->domain != pdomain->domain)
 173                                 continue;
 174
 175                         /*
 176                          * If some CPUS have the same domain, they
 177                          * will have the same shared_cpu_map.
 178                          */
 179                         cpumask_copy(match_pthrottling->shared_cpu_map,
 180                                      pthrottling->shared_cpu_map);
 181                 }
 182         }
 183
 184 err_ret:
 185         free_cpumask_var(covered_cpus);
 186
 187         for_each_possible_cpu(i) {
 188                 pr = per_cpu(processors, i);
 189                 if (!pr)
 190                         continue;
 191
 192                 /*
 193                  * Assume no coordination on any error parsing domain info.
 194                  * The coordination type will be forced as SW_ALL.
 195                  */
 196                 if (retval) {
 197                         pthrottling = &(pr->throttling);
 198                         cpumask_clear(pthrottling->shared_cpu_map);
 199                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 200                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 201                 }
 202         }
 203
 204         return retval;
 205 }
 206
 207 /*
 208  * Update the T-state coordination after the _TSD
 209  * data for all cpus is obtained.
 210  */
 211 void acpi_processor_throttling_init(void)
 212 {
 213         if (acpi_processor_update_tsd_coord()) {
 214                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 215                         "Assume no T-state coordination\n"));
 216         }
 217
 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  * This function is used to reevaluate whether the T-state is valid
 370  * after one CPU is onlined/offlined.
 371  * It is noted that it won't reevaluate the following properties for
 372  * the T-state.
 373  *      1. Control method.
 374  *      2. the number of supported T-state
 375  *      3. TSD domain
 376  */
 377 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 378                                         bool is_dead)
 379 {
 380         int result = 0;
 381
 382         if (is_dead) {
 383                 /* When one CPU is offline, the T-state throttling
 384                  * will be invalidated.
 385                  */
 386                 pr->flags.throttling = 0;
 387                 return;
 388         }
 389         /* the following is to recheck whether the T-state is valid for
 390          * the online CPU
 391          */
 392         if (!pr->throttling.state_count) {
 393                 /* If the number of T-state is invalid, it is
 394                  * invalidated.
 395                  */
 396                 pr->flags.throttling = 0;
 397                 return;
 398         }
 399         pr->flags.throttling = 1;
 400
 401         /* Disable throttling (if enabled).  We'll let subsequent
 402          * policy (e.g.thermal) decide to lower performance if it
 403          * so chooses, but for now we'll crank up the speed.
 404          */
 405
 406         result = acpi_processor_get_throttling(pr);
 407         if (result)
 408                 goto end;
 409
 410         if (pr->throttling.state) {
 411                 result = acpi_processor_set_throttling(pr, 0, false);
 412                 if (result)
 413                         goto end;
 414         }
 415
 416 end:
 417         if (result)
 418                 pr->flags.throttling = 0;
 419 }
 420 /*
 421  * _PTC - Processor Throttling Control (and status) register location
 422  */
 423 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 424 {
 425         int result = 0;
 426         acpi_status status = 0;
 427         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 428         union acpi_object *ptc = NULL;
 429         union acpi_object obj = { 0 };
 430         struct acpi_processor_throttling *throttling;
 431
 432         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 433         if (ACPI_FAILURE(status)) {
 434                 if (status != AE_NOT_FOUND) {
 435                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 436                 }
 437                 return -ENODEV;
 438         }
 439
 440         ptc = (union acpi_object *)buffer.pointer;
 441         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 442             || (ptc->package.count != 2)) {
 443                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 444                 result = -EFAULT;
 445                 goto end;
 446         }
 447
 448         /*
 449          * control_register
 450          */
 451
 452         obj = ptc->package.elements[0];
 453
 454         if ((obj.type != ACPI_TYPE_BUFFER)
 455             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 456             || (obj.buffer.pointer == NULL)) {
 457                 printk(KERN_ERR PREFIX
 458                        "Invalid _PTC data (control_register)\n");
 459                 result = -EFAULT;
 460                 goto end;
 461         }
 462         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 463                sizeof(struct acpi_ptc_register));
 464
 465         /*
 466          * status_register
 467          */
 468
 469         obj = ptc->package.elements[1];
 470
 471         if ((obj.type != ACPI_TYPE_BUFFER)
 472             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 473             || (obj.buffer.pointer == NULL)) {
 474                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 475                 result = -EFAULT;
 476                 goto end;
 477         }
 478
 479         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 480                sizeof(struct acpi_ptc_register));
 481
 482         throttling = &pr->throttling;
 483
 484         if ((throttling->control_register.bit_width +
 485                 throttling->control_register.bit_offset) > 32) {
 486                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 487                 result = -EFAULT;
 488                 goto end;
 489         }
 490
 491         if ((throttling->status_register.bit_width +
 492                 throttling->status_register.bit_offset) > 32) {
 493                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 494                 result = -EFAULT;
 495                 goto end;
 496         }
 497
 498       end:
 499         kfree(buffer.pointer);
 500
 501         return result;
 502 }
 503
 504 /*
 505  * _TSS - Throttling Supported States
 506  */
 507 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 508 {
 509         int result = 0;
 510         acpi_status status = AE_OK;
 511         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 512         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 513         struct acpi_buffer state = { 0, NULL };
 514         union acpi_object *tss = NULL;
 515         int i;
 516
 517         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 518         if (ACPI_FAILURE(status)) {
 519                 if (status != AE_NOT_FOUND) {
 520                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 521                 }
 522                 return -ENODEV;
 523         }
 524
 525         tss = buffer.pointer;
 526         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 527                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 528                 result = -EFAULT;
 529                 goto end;
 530         }
 531
 532         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 533                           tss->package.count));
 534
 535         pr->throttling.state_count = tss->package.count;
 536         pr->throttling.states_tss =
 537             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 538                     GFP_KERNEL);
 539         if (!pr->throttling.states_tss) {
 540                 result = -ENOMEM;
 541                 goto end;
 542         }
 543
 544         for (i = 0; i < pr->throttling.state_count; i++) {
 545
 546                 struct acpi_processor_tx_tss *tx =
 547                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 548                                                       states_tss[i]);
 549
 550                 state.length = sizeof(struct acpi_processor_tx_tss);
 551                 state.pointer = tx;
 552
 553                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 554
 555                 status = acpi_extract_package(&(tss->package.elements[i]),
 556                                               &format, &state);
 557                 if (ACPI_FAILURE(status)) {
 558                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 559                         result = -EFAULT;
 560                         kfree(pr->throttling.states_tss);
 561                         goto end;
 562                 }
 563
 564                 if (!tx->freqpercentage) {
 565                         printk(KERN_ERR PREFIX
 566                                "Invalid _TSS data: freq is zero\n");
 567                         result = -EFAULT;
 568                         kfree(pr->throttling.states_tss);
 569                         goto end;
 570                 }
 571         }
 572
 573       end:
 574         kfree(buffer.pointer);
 575
 576         return result;
 577 }
 578
 579 /*
 580  * _TSD - T-State Dependencies
 581  */
 582 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 583 {
 584         int result = 0;
 585         acpi_status status = AE_OK;
 586         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 587         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 588         struct acpi_buffer state = { 0, NULL };
 589         union acpi_object *tsd = NULL;
 590         struct acpi_tsd_package *pdomain;
 591         struct acpi_processor_throttling *pthrottling;
 592
 593         pthrottling = &pr->throttling;
 594         pthrottling->tsd_valid_flag = 0;
 595
 596         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 597         if (ACPI_FAILURE(status)) {
 598                 if (status != AE_NOT_FOUND) {
 599                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 600                 }
 601                 return -ENODEV;
 602         }
 603
 604         tsd = buffer.pointer;
 605         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 606                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 607                 result = -EFAULT;
 608                 goto end;
 609         }
 610
 611         if (tsd->package.count != 1) {
 612                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 613                 result = -EFAULT;
 614                 goto end;
 615         }
 616
 617         pdomain = &(pr->throttling.domain_info);
 618
 619         state.length = sizeof(struct acpi_tsd_package);
 620         state.pointer = pdomain;
 621
 622         status = acpi_extract_package(&(tsd->package.elements[0]),
 623                                       &format, &state);
 624         if (ACPI_FAILURE(status)) {
 625                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 626                 result = -EFAULT;
 627                 goto end;
 628         }
 629
 630         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 631                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 632                 result = -EFAULT;
 633                 goto end;
 634         }
 635
 636         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 637                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 638                 result = -EFAULT;
 639                 goto end;
 640         }
 641
 642         pthrottling = &pr->throttling;
 643         pthrottling->tsd_valid_flag = 1;
 644         pthrottling->shared_type = pdomain->coord_type;
 645         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 646         /*
 647          * If the coordination type is not defined in ACPI spec,
 648          * the tsd_valid_flag will be clear and coordination type
 649          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 650          */
 651         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 652                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 653                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 654                 pthrottling->tsd_valid_flag = 0;
 655                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 656         }
 657
 658       end:
 659         kfree(buffer.pointer);
 660         return result;
 661 }
 662
 663 /* --------------------------------------------------------------------------
 664                               Throttling Control
 665    -------------------------------------------------------------------------- */
 666 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 667 {
 668         int state = 0;
 669         u32 value = 0;
 670         u32 duty_mask = 0;
 671         u32 duty_value = 0;
 672
 673         if (!pr)
 674                 return -EINVAL;
 675
 676         if (!pr->flags.throttling)
 677                 return -ENODEV;
 678
 679         /*
 680          * We don't care about error returns - we just try to mark
 681          * these reserved so that nobody else is confused into thinking
 682          * that this region might be unused..
 683          *
 684          * (In particular, allocating the IO range for Cardbus)
 685          */
 686         request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 687
 688         pr->throttling.state = 0;
 689
 690         duty_mask = pr->throttling.state_count - 1;
 691
 692         duty_mask <<= pr->throttling.duty_offset;
 693
 694         local_irq_disable();
 695
 696         value = inl(pr->throttling.address);
 697
 698         /*
 699          * Compute the current throttling state when throttling is enabled
 700          * (bit 4 is on).
 701          */
 702         if (value & 0x10) {
 703                 duty_value = value & duty_mask;
 704                 duty_value >>= pr->throttling.duty_offset;
 705
 706                 if (duty_value)
 707                         state = pr->throttling.state_count - duty_value;
 708         }
 709
 710         pr->throttling.state = state;
 711
 712         local_irq_enable();
 713
 714         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 715                           "Throttling state is T%d (%d%% throttling applied)\n",
 716                           state, pr->throttling.states[state].performance));
 717
 718         return 0;
 719 }
 720
 721 #ifdef CONFIG_X86
 722 static int acpi_throttling_rdmsr(u64 *value)
 723 {
 724         u64 msr_high, msr_low;
 725         u64 msr = 0;
 726         int ret = -1;
 727
 728         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 729                 !this_cpu_has(X86_FEATURE_ACPI)) {
 730                 printk(KERN_ERR PREFIX
 731                         "HARDWARE addr space,NOT supported yet\n");
 732         } else {
 733                 msr_low = 0;
 734                 msr_high = 0;
 735                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 736                         (u32 *)&msr_low , (u32 *) &msr_high);
 737                 msr = (msr_high << 32) | msr_low;
 738                 *value = (u64) msr;
 739                 ret = 0;
 740         }
 741         return ret;
 742 }
 743
 744 static int acpi_throttling_wrmsr(u64 value)
 745 {
 746         int ret = -1;
 747         u64 msr;
 748
 749         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 750                 !this_cpu_has(X86_FEATURE_ACPI)) {
 751                 printk(KERN_ERR PREFIX
 752                         "HARDWARE addr space,NOT supported yet\n");
 753         } else {
 754                 msr = value;
 755                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 756                         msr & 0xffffffff, msr >> 32);
 757                 ret = 0;
 758         }
 759         return ret;
 760 }
 761 #else
 762 static int acpi_throttling_rdmsr(u64 *value)
 763 {
 764         printk(KERN_ERR PREFIX
 765                 "HARDWARE addr space,NOT supported yet\n");
 766         return -1;
 767 }
 768
 769 static int acpi_throttling_wrmsr(u64 value)
 770 {
 771         printk(KERN_ERR PREFIX
 772                 "HARDWARE addr space,NOT supported yet\n");
 773         return -1;
 774 }
 775 #endif
 776
 777 static int acpi_read_throttling_status(struct acpi_processor *pr,
 778                                         u64 *value)
 779 {
 780         u32 bit_width, bit_offset;
 781         u32 ptc_value;
 782         u64 ptc_mask;
 783         struct acpi_processor_throttling *throttling;
 784         int ret = -1;
 785
 786         throttling = &pr->throttling;
 787         switch (throttling->status_register.space_id) {
 788         case ACPI_ADR_SPACE_SYSTEM_IO:
 789                 bit_width = throttling->status_register.bit_width;
 790                 bit_offset = throttling->status_register.bit_offset;
 791
 792                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 793                                   address, &ptc_value,
 794                                   (u32) (bit_width + bit_offset));
 795                 ptc_mask = (1 << bit_width) - 1;
 796                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 797                 ret = 0;
 798                 break;
 799         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 800                 ret = acpi_throttling_rdmsr(value);
 801                 break;
 802         default:
 803                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 804                        (u32) (throttling->status_register.space_id));
 805         }
 806         return ret;
 807 }
 808
 809 static int acpi_write_throttling_state(struct acpi_processor *pr,
 810                                 u64 value)
 811 {
 812         u32 bit_width, bit_offset;
 813         u64 ptc_value;
 814         u64 ptc_mask;
 815         struct acpi_processor_throttling *throttling;
 816         int ret = -1;
 817
 818         throttling = &pr->throttling;
 819         switch (throttling->control_register.space_id) {
 820         case ACPI_ADR_SPACE_SYSTEM_IO:
 821                 bit_width = throttling->control_register.bit_width;
 822                 bit_offset = throttling->control_register.bit_offset;
 823                 ptc_mask = (1 << bit_width) - 1;
 824                 ptc_value = value & ptc_mask;
 825
 826                 acpi_os_write_port((acpi_io_address) throttling->
 827                                         control_register.address,
 828                                         (u32) (ptc_value << bit_offset),
 829                                         (u32) (bit_width + bit_offset));
 830                 ret = 0;
 831                 break;
 832         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 833                 ret = acpi_throttling_wrmsr(value);
 834                 break;
 835         default:
 836                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 837                        (u32) (throttling->control_register.space_id));
 838         }
 839         return ret;
 840 }
 841
 842 static int acpi_get_throttling_state(struct acpi_processor *pr,
 843                                 u64 value)
 844 {
 845         int i;
 846
 847         for (i = 0; i < pr->throttling.state_count; i++) {
 848                 struct acpi_processor_tx_tss *tx =
 849                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 850                                                       states_tss[i]);
 851                 if (tx->control == value)
 852                         return i;
 853         }
 854         return -1;
 855 }
 856
 857 static int acpi_get_throttling_value(struct acpi_processor *pr,
 858                         int state, u64 *value)
 859 {
 860         int ret = -1;
 861
 862         if (state >= 0 && state <= pr->throttling.state_count) {
 863                 struct acpi_processor_tx_tss *tx =
 864                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 865                                                       states_tss[state]);
 866                 *value = tx->control;
 867                 ret = 0;
 868         }
 869         return ret;
 870 }
 871
 872 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 873 {
 874         int state = 0;
 875         int ret;
 876         u64 value;
 877
 878         if (!pr)
 879                 return -EINVAL;
 880
 881         if (!pr->flags.throttling)
 882                 return -ENODEV;
 883
 884         pr->throttling.state = 0;
 885
 886         value = 0;
 887         ret = acpi_read_throttling_status(pr, &value);
 888         if (ret >= 0) {
 889                 state = acpi_get_throttling_state(pr, value);
 890                 if (state == -1) {
 891                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 892                                 "Invalid throttling state, reset\n"));
 893                         state = 0;
 894                         ret = acpi_processor_set_throttling(pr, state, true);
 895                         if (ret)
 896                                 return ret;
 897                 }
 898                 pr->throttling.state = state;
 899         }
 900
 901         return 0;
 902 }
 903
 904 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 905 {
 906         cpumask_var_t saved_mask;
 907         int ret;
 908
 909         if (!pr)
 910                 return -EINVAL;
 911
 912         if (!pr->flags.throttling)
 913                 return -ENODEV;
 914
 915         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 916                 return -ENOMEM;
 917
 918         /*
 919          * Migrate task to the cpu pointed by pr.
 920          */
 921         cpumask_copy(saved_mask, &current->cpus_allowed);
 922         /* FIXME: use work_on_cpu() */
 923         if (set_cpus_allowed_ptr(current, cpumask_of(pr->id))) {
 924                 /* Can't migrate to the target pr->id CPU. Exit */
 925                 free_cpumask_var(saved_mask);
 926                 return -ENODEV;
 927         }
 928         ret = pr->throttling.acpi_processor_get_throttling(pr);
 929         /* restore the previous state */
 930         set_cpus_allowed_ptr(current, saved_mask);
 931         free_cpumask_var(saved_mask);
 932
 933         return ret;
 934 }
 935
 936 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 937 {
 938         int i, step;
 939
 940         if (!pr->throttling.address) {
 941                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 942                 return -EINVAL;
 943         } else if (!pr->throttling.duty_width) {
 944                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 945                 return -EINVAL;
 946         }
 947         /* TBD: Support duty_cycle values that span bit 4. */
 948         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 949                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 950                 return -EINVAL;
 951         }
 952
 953         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 954
 955         /*
 956          * Compute state values. Note that throttling displays a linear power
 957          * performance relationship (at 50% performance the CPU will consume
 958          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 959          */
 960
 961         step = (1000 / pr->throttling.state_count);
 962
 963         for (i = 0; i < pr->throttling.state_count; i++) {
 964                 pr->throttling.states[i].performance = 1000 - step * i;
 965                 pr->throttling.states[i].power = 1000 - step * i;
 966         }
 967         return 0;
 968 }
 969
 970 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 971                                               int state, bool force)
 972 {
 973         u32 value = 0;
 974         u32 duty_mask = 0;
 975         u32 duty_value = 0;
 976
 977         if (!pr)
 978                 return -EINVAL;
 979
 980         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 981                 return -EINVAL;
 982
 983         if (!pr->flags.throttling)
 984                 return -ENODEV;
 985
 986         if (!force && (state == pr->throttling.state))
 987                 return 0;
 988
 989         if (state < pr->throttling_platform_limit)
 990                 return -EPERM;
 991         /*
 992          * Calculate the duty_value and duty_mask.
 993          */
 994         if (state) {
 995                 duty_value = pr->throttling.state_count - state;
 996
 997                 duty_value <<= pr->throttling.duty_offset;
 998
 999                 /* Used to clear all duty_value bits */
1000                 duty_mask = pr->throttling.state_count - 1;
1001
1002                 duty_mask <<= acpi_gbl_FADT.duty_offset;
1003                 duty_mask = ~duty_mask;
1004         }
1005
1006         local_irq_disable();
1007
1008         /*
1009          * Disable throttling by writing a 0 to bit 4.  Note that we must
1010          * turn it off before you can change the duty_value.
1011          */
1012         value = inl(pr->throttling.address);
1013         if (value & 0x10) {
1014                 value &= 0xFFFFFFEF;
1015                 outl(value, pr->throttling.address);
1016         }
1017
1018         /*
1019          * Write the new duty_value and then enable throttling.  Note
1020          * that a state value of 0 leaves throttling disabled.
1021          */
1022         if (state) {
1023                 value &= duty_mask;
1024                 value |= duty_value;
1025                 outl(value, pr->throttling.address);
1026
1027                 value |= 0x00000010;
1028                 outl(value, pr->throttling.address);
1029         }
1030
1031         pr->throttling.state = state;
1032
1033         local_irq_enable();
1034
1035         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1036                           "Throttling state set to T%d (%d%%)\n", state,
1037                           (pr->throttling.states[state].performance ? pr->
1038                            throttling.states[state].performance / 10 : 0)));
1039
1040         return 0;
1041 }
1042
1043 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1044                                              int state, bool force)
1045 {
1046         int ret;
1047         u64 value;
1048
1049         if (!pr)
1050                 return -EINVAL;
1051
1052         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1053                 return -EINVAL;
1054
1055         if (!pr->flags.throttling)
1056                 return -ENODEV;
1057
1058         if (!force && (state == pr->throttling.state))
1059                 return 0;
1060
1061         if (state < pr->throttling_platform_limit)
1062                 return -EPERM;
1063
1064         value = 0;
1065         ret = acpi_get_throttling_value(pr, state, &value);
1066         if (ret >= 0) {
1067                 acpi_write_throttling_state(pr, value);
1068                 pr->throttling.state = state;
1069         }
1070
1071         return 0;
1072 }
1073
1074 static long acpi_processor_throttling_fn(void *data)
1075 {
1076         struct acpi_processor_throttling_arg *arg = data;
1077         struct acpi_processor *pr = arg->pr;
1078
1079         return pr->throttling.acpi_processor_set_throttling(pr,
1080                         arg->target_state, arg->force);
1081 }
1082
1083 int acpi_processor_set_throttling(struct acpi_processor *pr,
1084                                                 int state, bool force)
1085 {
1086         int ret = 0;
1087         unsigned int i;
1088         struct acpi_processor *match_pr;
1089         struct acpi_processor_throttling *p_throttling;
1090         struct acpi_processor_throttling_arg arg;
1091         struct throttling_tstate t_state;
1092
1093         if (!pr)
1094                 return -EINVAL;
1095
1096         if (!pr->flags.throttling)
1097                 return -ENODEV;
1098
1099         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1100                 return -EINVAL;
1101
1102         if (cpu_is_offline(pr->id)) {
1103                 /*
1104                  * the cpu pointed by pr->id is offline. Unnecessary to change
1105                  * the throttling state any more.
1106                  */
1107                 return -ENODEV;
1108         }
1109
1110         t_state.target_state = state;
1111         p_throttling = &(pr->throttling);
1112
1113         /*
1114          * The throttling notifier will be called for every
1115          * affected cpu in order to get one proper T-state.
1116          * The notifier event is THROTTLING_PRECHANGE.
1117          */
1118         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1119                 t_state.cpu = i;
1120                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1121                                                         &t_state);
1122         }
1123         /*
1124          * The function of acpi_processor_set_throttling will be called
1125          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1126          * it is necessary to call it for every affected cpu. Otherwise
1127          * it can be called only for the cpu pointed by pr.
1128          */
1129         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1130                 arg.pr = pr;
1131                 arg.target_state = state;
1132                 arg.force = force;
1133                 ret = work_on_cpu(pr->id, acpi_processor_throttling_fn, &arg);
1134         } else {
1135                 /*
1136                  * When the T-state coordination is SW_ALL or HW_ALL,
1137                  * it is necessary to set T-state for every affected
1138                  * cpus.
1139                  */
1140                 for_each_cpu_and(i, cpu_online_mask,
1141                     p_throttling->shared_cpu_map) {
1142                         match_pr = per_cpu(processors, i);
1143                         /*
1144                          * If the pointer is invalid, we will report the
1145                          * error message and continue.
1146                          */
1147                         if (!match_pr) {
1148                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1149                                         "Invalid Pointer for CPU %d\n", i));
1150                                 continue;
1151                         }
1152                         /*
1153                          * If the throttling control is unsupported on CPU i,
1154                          * we will report the error message and continue.
1155                          */
1156                         if (!match_pr->flags.throttling) {
1157                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1158                                         "Throttling Control is unsupported "
1159                                         "on CPU %d\n", i));
1160                                 continue;
1161                         }
1162
1163                         arg.pr = match_pr;
1164                         arg.target_state = state;
1165                         arg.force = force;
1166                         ret = work_on_cpu(pr->id, acpi_processor_throttling_fn,
1167                                 &arg);
1168                 }
1169         }
1170         /*
1171          * After the set_throttling is called, the
1172          * throttling notifier is called for every
1173          * affected cpu to update the T-states.
1174          * The notifier event is THROTTLING_POSTCHANGE
1175          */
1176         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1177                 t_state.cpu = i;
1178                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1179                                                         &t_state);
1180         }
1181
1182         return ret;
1183 }
1184
1185 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1186 {
1187         int result = 0;
1188         struct acpi_processor_throttling *pthrottling;
1189
1190         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1191                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1192                           pr->throttling.address,
1193                           pr->throttling.duty_offset,
1194                           pr->throttling.duty_width));
1195
1196         /*
1197          * Evaluate _PTC, _TSS and _TPC
1198          * They must all be present or none of them can be used.
1199          */
1200         if (acpi_processor_get_throttling_control(pr) ||
1201                 acpi_processor_get_throttling_states(pr) ||
1202                 acpi_processor_get_platform_limit(pr))
1203         {
1204                 pr->throttling.acpi_processor_get_throttling =
1205                     &acpi_processor_get_throttling_fadt;
1206                 pr->throttling.acpi_processor_set_throttling =
1207                     &acpi_processor_set_throttling_fadt;
1208                 if (acpi_processor_get_fadt_info(pr))
1209                         return 0;
1210         } else {
1211                 pr->throttling.acpi_processor_get_throttling =
1212                     &acpi_processor_get_throttling_ptc;
1213                 pr->throttling.acpi_processor_set_throttling =
1214                     &acpi_processor_set_throttling_ptc;
1215         }
1216
1217         /*
1218          * If TSD package for one CPU can't be parsed successfully, it means
1219          * that this CPU will have no coordination with other CPUs.
1220          */
1221         if (acpi_processor_get_tsd(pr)) {
1222                 pthrottling = &pr->throttling;
1223                 pthrottling->tsd_valid_flag = 0;
1224                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1225                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1226         }
1227
1228         /*
1229          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1230          * This shouldn't be an issue as few (if any) mobile systems ever
1231          * used this part.
1232          */
1233         if (errata.piix4.throttle) {
1234                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1235                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1236                 return 0;
1237         }
1238
1239         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1240                           pr->throttling.state_count));
1241
1242         pr->flags.throttling = 1;
1243
1244         /*
1245          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1246          * thermal) decide to lower performance if it so chooses, but for now
1247          * we'll crank up the speed.
1248          */
1249
1250         result = acpi_processor_get_throttling(pr);
1251         if (result)
1252                 goto end;
1253
1254         if (pr->throttling.state) {
1255                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1256                                   "Disabling throttling (was T%d)\n",
1257                                   pr->throttling.state));
1258                 result = acpi_processor_set_throttling(pr, 0, false);
1259                 if (result)
1260                         goto end;
1261         }
1262
1263       end:
1264         if (result)
1265                 pr->flags.throttling = 0;
1266
1267         return result;
1268 }
1269