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