drivers/acpi/processor

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
acpi_processor_update_tsd_coord
acpi_processor_throttling_init
acpi_processor_throttling_notifier
acpi_processor_get_platform_limit
acpi_processor_tstate_has_changed
acpi_processor_reevaluate_tstate
acpi_processor_get_throttling_control
acpi_processor_get_throttling_states
acpi_processor_get_tsd
acpi_processor_get_throttling_fadt
acpi_throttling_rdmsr
acpi_throttling_wrmsr
acpi_throttling_rdmsr
acpi_throttling_wrmsr
acpi_read_throttling_status
acpi_write_throttling_state
acpi_get_throttling_state
acpi_get_throttling_value
acpi_processor_get_throttling_ptc
__acpi_processor_get_throttling
acpi_processor_get_throttling
acpi_processor_get_fadt_info
acpi_processor_set_throttling_fadt
acpi_processor_set_throttling_ptc
acpi_processor_throttling_fn
__acpi_processor_set_throttling
acpi_processor_set_throttling
acpi_processor_get_throttling_info
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * processor_throttling.c - Throttling submodule of the ACPI processor driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   9  *                      - Added processor hotplug support
  10  */
  11 
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/init.h>
  16 #include <linux/sched.h>
  17 #include <linux/cpufreq.h>
  18 #include <linux/acpi.h>
  19 #include <acpi/processor.h>
  20 #include <asm/io.h>
  21 #include <linux/uaccess.h>
  22 
  23 #define PREFIX "ACPI: "
  24 
  25 #define ACPI_PROCESSOR_CLASS            "processor"
  26 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  27 ACPI_MODULE_NAME("processor_throttling");
  28 
  29 /* ignore_tpc:
  30  *  0 -> acpi processor driver doesn't ignore _TPC values
  31  *  1 -> acpi processor driver ignores _TPC values
  32  */
  33 static int ignore_tpc;
  34 module_param(ignore_tpc, int, 0644);
  35 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  36 
  37 struct throttling_tstate {
  38         unsigned int cpu;               /* cpu nr */
  39         int target_state;               /* target T-state */
  40 };
  41 
  42 struct acpi_processor_throttling_arg {
  43         struct acpi_processor *pr;
  44         int target_state;
  45         bool force;
  46 };
  47 
  48 #define THROTTLING_PRECHANGE       (1)
  49 #define THROTTLING_POSTCHANGE      (2)
  50 
  51 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  52 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
  53                                            int state, bool force, bool direct);
  54 
  55 static int acpi_processor_update_tsd_coord(void)
  56 {
  57         int count, count_target;
  58         int retval = 0;
  59         unsigned int i, j;
  60         cpumask_var_t covered_cpus;
  61         struct acpi_processor *pr, *match_pr;
  62         struct acpi_tsd_package *pdomain, *match_pdomain;
  63         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  64 
  65         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  66                 return -ENOMEM;
  67 
  68         /*
  69          * Now that we have _TSD data from all CPUs, lets setup T-state
  70          * coordination between all CPUs.
  71          */
  72         for_each_possible_cpu(i) {
  73                 pr = per_cpu(processors, i);
  74                 if (!pr)
  75                         continue;
  76 
  77                 /* Basic validity check for domain info */
  78                 pthrottling = &(pr->throttling);
  79 
  80                 /*
  81                  * If tsd package for one cpu is invalid, the coordination
  82                  * among all CPUs is thought as invalid.
  83                  * Maybe it is ugly.
  84                  */
  85                 if (!pthrottling->tsd_valid_flag) {
  86                         retval = -EINVAL;
  87                         break;
  88                 }
  89         }
  90         if (retval)
  91                 goto err_ret;
  92 
  93         for_each_possible_cpu(i) {
  94                 pr = per_cpu(processors, i);
  95                 if (!pr)
  96                         continue;
  97 
  98                 if (cpumask_test_cpu(i, covered_cpus))
  99                         continue;
 100                 pthrottling = &pr->throttling;
 101 
 102                 pdomain = &(pthrottling->domain_info);
 103                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 104                 cpumask_set_cpu(i, covered_cpus);
 105                 /*
 106                  * If the number of processor in the TSD domain is 1, it is
 107                  * unnecessary to parse the coordination for this CPU.
 108                  */
 109                 if (pdomain->num_processors <= 1)
 110                         continue;
 111 
 112                 /* Validate the Domain info */
 113                 count_target = pdomain->num_processors;
 114                 count = 1;
 115 
 116                 for_each_possible_cpu(j) {
 117                         if (i == j)
 118                                 continue;
 119 
 120                         match_pr = per_cpu(processors, j);
 121                         if (!match_pr)
 122                                 continue;
 123 
 124                         match_pthrottling = &(match_pr->throttling);
 125                         match_pdomain = &(match_pthrottling->domain_info);
 126                         if (match_pdomain->domain != pdomain->domain)
 127                                 continue;
 128 
 129                         /* Here i and j are in the same domain.
 130                          * If two TSD packages have the same domain, they
 131                          * should have the same num_porcessors and
 132                          * coordination type. Otherwise it will be regarded
 133                          * as illegal.
 134                          */
 135                         if (match_pdomain->num_processors != count_target) {
 136                                 retval = -EINVAL;
 137                                 goto err_ret;
 138                         }
 139 
 140                         if (pdomain->coord_type != match_pdomain->coord_type) {
 141                                 retval = -EINVAL;
 142                                 goto err_ret;
 143                         }
 144 
 145                         cpumask_set_cpu(j, covered_cpus);
 146                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 147                         count++;
 148                 }
 149                 for_each_possible_cpu(j) {
 150                         if (i == j)
 151                                 continue;
 152 
 153                         match_pr = per_cpu(processors, j);
 154                         if (!match_pr)
 155                                 continue;
 156 
 157                         match_pthrottling = &(match_pr->throttling);
 158                         match_pdomain = &(match_pthrottling->domain_info);
 159                         if (match_pdomain->domain != pdomain->domain)
 160                                 continue;
 161 
 162                         /*
 163                          * If some CPUS have the same domain, they
 164                          * will have the same shared_cpu_map.
 165                          */
 166                         cpumask_copy(match_pthrottling->shared_cpu_map,
 167                                      pthrottling->shared_cpu_map);
 168                 }
 169         }
 170 
 171 err_ret:
 172         free_cpumask_var(covered_cpus);
 173 
 174         for_each_possible_cpu(i) {
 175                 pr = per_cpu(processors, i);
 176                 if (!pr)
 177                         continue;
 178 
 179                 /*
 180                  * Assume no coordination on any error parsing domain info.
 181                  * The coordination type will be forced as SW_ALL.
 182                  */
 183                 if (retval) {
 184                         pthrottling = &(pr->throttling);
 185                         cpumask_clear(pthrottling->shared_cpu_map);
 186                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 187                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 188                 }
 189         }
 190 
 191         return retval;
 192 }
 193 
 194 /*
 195  * Update the T-state coordination after the _TSD
 196  * data for all cpus is obtained.
 197  */
 198 void acpi_processor_throttling_init(void)
 199 {
 200         if (acpi_processor_update_tsd_coord()) {
 201                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 202                         "Assume no T-state coordination\n"));
 203         }
 204 
 205         return;
 206 }
 207 
 208 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 209 {
 210         struct throttling_tstate *p_tstate = data;
 211         struct acpi_processor *pr;
 212         unsigned int cpu ;
 213         int target_state;
 214         struct acpi_processor_limit *p_limit;
 215         struct acpi_processor_throttling *p_throttling;
 216 
 217         cpu = p_tstate->cpu;
 218         pr = per_cpu(processors, cpu);
 219         if (!pr) {
 220                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 221                 return 0;
 222         }
 223         if (!pr->flags.throttling) {
 224                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 225                                 "unsupported on CPU %d\n", cpu));
 226                 return 0;
 227         }
 228         target_state = p_tstate->target_state;
 229         p_throttling = &(pr->throttling);
 230         switch (event) {
 231         case THROTTLING_PRECHANGE:
 232                 /*
 233                  * Prechange event is used to choose one proper t-state,
 234                  * which meets the limits of thermal, user and _TPC.
 235                  */
 236                 p_limit = &pr->limit;
 237                 if (p_limit->thermal.tx > target_state)
 238                         target_state = p_limit->thermal.tx;
 239                 if (p_limit->user.tx > target_state)
 240                         target_state = p_limit->user.tx;
 241                 if (pr->throttling_platform_limit > target_state)
 242                         target_state = pr->throttling_platform_limit;
 243                 if (target_state >= p_throttling->state_count) {
 244                         printk(KERN_WARNING
 245                                 "Exceed the limit of T-state \n");
 246                         target_state = p_throttling->state_count - 1;
 247                 }
 248                 p_tstate->target_state = target_state;
 249                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 250                                 "target T-state of CPU %d is T%d\n",
 251                                 cpu, target_state));
 252                 break;
 253         case THROTTLING_POSTCHANGE:
 254                 /*
 255                  * Postchange event is only used to update the
 256                  * T-state flag of acpi_processor_throttling.
 257                  */
 258                 p_throttling->state = target_state;
 259                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 260                                 "CPU %d is switched to T%d\n",
 261                                 cpu, target_state));
 262                 break;
 263         default:
 264                 printk(KERN_WARNING
 265                         "Unsupported Throttling notifier event\n");
 266                 break;
 267         }
 268 
 269         return 0;
 270 }
 271 
 272 /*
 273  * _TPC - Throttling Present Capabilities
 274  */
 275 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 276 {
 277         acpi_status status = 0;
 278         unsigned long long tpc = 0;
 279 
 280         if (!pr)
 281                 return -EINVAL;
 282 
 283         if (ignore_tpc)
 284                 goto end;
 285 
 286         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 287         if (ACPI_FAILURE(status)) {
 288                 if (status != AE_NOT_FOUND) {
 289                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 290                 }
 291                 return -ENODEV;
 292         }
 293 
 294 end:
 295         pr->throttling_platform_limit = (int)tpc;
 296         return 0;
 297 }
 298 
 299 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 300 {
 301         int result = 0;
 302         int throttling_limit;
 303         int current_state;
 304         struct acpi_processor_limit *limit;
 305         int target_state;
 306 
 307         if (ignore_tpc)
 308                 return 0;
 309 
 310         result = acpi_processor_get_platform_limit(pr);
 311         if (result) {
 312                 /* Throttling Limit is unsupported */
 313                 return result;
 314         }
 315 
 316         throttling_limit = pr->throttling_platform_limit;
 317         if (throttling_limit >= pr->throttling.state_count) {
 318                 /* Uncorrect Throttling Limit */
 319                 return -EINVAL;
 320         }
 321 
 322         current_state = pr->throttling.state;
 323         if (current_state > throttling_limit) {
 324                 /*
 325                  * The current state can meet the requirement of
 326                  * _TPC limit. But it is reasonable that OSPM changes
 327                  * t-states from high to low for better performance.
 328                  * Of course the limit condition of thermal
 329                  * and user should be considered.
 330                  */
 331                 limit = &pr->limit;
 332                 target_state = throttling_limit;
 333                 if (limit->thermal.tx > target_state)
 334                         target_state = limit->thermal.tx;
 335                 if (limit->user.tx > target_state)
 336                         target_state = limit->user.tx;
 337         } else if (current_state == throttling_limit) {
 338                 /*
 339                  * Unnecessary to change the throttling state
 340                  */
 341                 return 0;
 342         } else {
 343                 /*
 344                  * If the current state is lower than the limit of _TPC, it
 345                  * will be forced to switch to the throttling state defined
 346                  * by throttling_platfor_limit.
 347                  * Because the previous state meets with the limit condition
 348                  * of thermal and user, it is unnecessary to check it again.
 349                  */
 350                 target_state = throttling_limit;
 351         }
 352         return acpi_processor_set_throttling(pr, target_state, false);
 353 }
 354 
 355 /*
 356  * This function is used to reevaluate whether the T-state is valid
 357  * after one CPU is onlined/offlined.
 358  * It is noted that it won't reevaluate the following properties for
 359  * the T-state.
 360  *      1. Control method.
 361  *      2. the number of supported T-state
 362  *      3. TSD domain
 363  */
 364 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
 365                                         bool is_dead)
 366 {
 367         int result = 0;
 368 
 369         if (is_dead) {
 370                 /* When one CPU is offline, the T-state throttling
 371                  * will be invalidated.
 372                  */
 373                 pr->flags.throttling = 0;
 374                 return;
 375         }
 376         /* the following is to recheck whether the T-state is valid for
 377          * the online CPU
 378          */
 379         if (!pr->throttling.state_count) {
 380                 /* If the number of T-state is invalid, it is
 381                  * invalidated.
 382                  */
 383                 pr->flags.throttling = 0;
 384                 return;
 385         }
 386         pr->flags.throttling = 1;
 387 
 388         /* Disable throttling (if enabled).  We'll let subsequent
 389          * policy (e.g.thermal) decide to lower performance if it
 390          * so chooses, but for now we'll crank up the speed.
 391          */
 392 
 393         result = acpi_processor_get_throttling(pr);
 394         if (result)
 395                 goto end;
 396 
 397         if (pr->throttling.state) {
 398                 result = acpi_processor_set_throttling(pr, 0, false);
 399                 if (result)
 400                         goto end;
 401         }
 402 
 403 end:
 404         if (result)
 405                 pr->flags.throttling = 0;
 406 }
 407 /*
 408  * _PTC - Processor Throttling Control (and status) register location
 409  */
 410 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 411 {
 412         int result = 0;
 413         acpi_status status = 0;
 414         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 415         union acpi_object *ptc = NULL;
 416         union acpi_object obj = { 0 };
 417         struct acpi_processor_throttling *throttling;
 418 
 419         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 420         if (ACPI_FAILURE(status)) {
 421                 if (status != AE_NOT_FOUND) {
 422                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 423                 }
 424                 return -ENODEV;
 425         }
 426 
 427         ptc = (union acpi_object *)buffer.pointer;
 428         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 429             || (ptc->package.count != 2)) {
 430                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 431                 result = -EFAULT;
 432                 goto end;
 433         }
 434 
 435         /*
 436          * control_register
 437          */
 438 
 439         obj = ptc->package.elements[0];
 440 
 441         if ((obj.type != ACPI_TYPE_BUFFER)
 442             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 443             || (obj.buffer.pointer == NULL)) {
 444                 printk(KERN_ERR PREFIX
 445                        "Invalid _PTC data (control_register)\n");
 446                 result = -EFAULT;
 447                 goto end;
 448         }
 449         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 450                sizeof(struct acpi_ptc_register));
 451 
 452         /*
 453          * status_register
 454          */
 455 
 456         obj = ptc->package.elements[1];
 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 "Invalid _PTC data (status_register)\n");
 462                 result = -EFAULT;
 463                 goto end;
 464         }
 465 
 466         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 467                sizeof(struct acpi_ptc_register));
 468 
 469         throttling = &pr->throttling;
 470 
 471         if ((throttling->control_register.bit_width +
 472                 throttling->control_register.bit_offset) > 32) {
 473                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 474                 result = -EFAULT;
 475                 goto end;
 476         }
 477 
 478         if ((throttling->status_register.bit_width +
 479                 throttling->status_register.bit_offset) > 32) {
 480                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 481                 result = -EFAULT;
 482                 goto end;
 483         }
 484 
 485       end:
 486         kfree(buffer.pointer);
 487 
 488         return result;
 489 }
 490 
 491 /*
 492  * _TSS - Throttling Supported States
 493  */
 494 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 495 {
 496         int result = 0;
 497         acpi_status status = AE_OK;
 498         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 499         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 500         struct acpi_buffer state = { 0, NULL };
 501         union acpi_object *tss = NULL;
 502         int i;
 503 
 504         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 505         if (ACPI_FAILURE(status)) {
 506                 if (status != AE_NOT_FOUND) {
 507                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 508                 }
 509                 return -ENODEV;
 510         }
 511 
 512         tss = buffer.pointer;
 513         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 514                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 515                 result = -EFAULT;
 516                 goto end;
 517         }
 518 
 519         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 520                           tss->package.count));
 521 
 522         pr->throttling.state_count = tss->package.count;
 523         pr->throttling.states_tss =
 524             kmalloc_array(tss->package.count,
 525                           sizeof(struct acpi_processor_tx_tss),
 526                           GFP_KERNEL);
 527         if (!pr->throttling.states_tss) {
 528                 result = -ENOMEM;
 529                 goto end;
 530         }
 531 
 532         for (i = 0; i < pr->throttling.state_count; i++) {
 533 
 534                 struct acpi_processor_tx_tss *tx =
 535                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 536                                                       states_tss[i]);
 537 
 538                 state.length = sizeof(struct acpi_processor_tx_tss);
 539                 state.pointer = tx;
 540 
 541                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 542 
 543                 status = acpi_extract_package(&(tss->package.elements[i]),
 544                                               &format, &state);
 545                 if (ACPI_FAILURE(status)) {
 546                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 547                         result = -EFAULT;
 548                         kfree(pr->throttling.states_tss);
 549                         goto end;
 550                 }
 551 
 552                 if (!tx->freqpercentage) {
 553                         printk(KERN_ERR PREFIX
 554                                "Invalid _TSS data: freq is zero\n");
 555                         result = -EFAULT;
 556                         kfree(pr->throttling.states_tss);
 557                         goto end;
 558                 }
 559         }
 560 
 561       end:
 562         kfree(buffer.pointer);
 563 
 564         return result;
 565 }
 566 
 567 /*
 568  * _TSD - T-State Dependencies
 569  */
 570 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 571 {
 572         int result = 0;
 573         acpi_status status = AE_OK;
 574         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 575         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 576         struct acpi_buffer state = { 0, NULL };
 577         union acpi_object *tsd = NULL;
 578         struct acpi_tsd_package *pdomain;
 579         struct acpi_processor_throttling *pthrottling;
 580 
 581         pthrottling = &pr->throttling;
 582         pthrottling->tsd_valid_flag = 0;
 583 
 584         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 585         if (ACPI_FAILURE(status)) {
 586                 if (status != AE_NOT_FOUND) {
 587                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 588                 }
 589                 return -ENODEV;
 590         }
 591 
 592         tsd = buffer.pointer;
 593         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 594                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 595                 result = -EFAULT;
 596                 goto end;
 597         }
 598 
 599         if (tsd->package.count != 1) {
 600                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 601                 result = -EFAULT;
 602                 goto end;
 603         }
 604 
 605         pdomain = &(pr->throttling.domain_info);
 606 
 607         state.length = sizeof(struct acpi_tsd_package);
 608         state.pointer = pdomain;
 609 
 610         status = acpi_extract_package(&(tsd->package.elements[0]),
 611                                       &format, &state);
 612         if (ACPI_FAILURE(status)) {
 613                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 614                 result = -EFAULT;
 615                 goto end;
 616         }
 617 
 618         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 619                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 620                 result = -EFAULT;
 621                 goto end;
 622         }
 623 
 624         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 625                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 626                 result = -EFAULT;
 627                 goto end;
 628         }
 629 
 630         pthrottling = &pr->throttling;
 631         pthrottling->tsd_valid_flag = 1;
 632         pthrottling->shared_type = pdomain->coord_type;
 633         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 634         /*
 635          * If the coordination type is not defined in ACPI spec,
 636          * the tsd_valid_flag will be clear and coordination type
 637          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 638          */
 639         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 640                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 641                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 642                 pthrottling->tsd_valid_flag = 0;
 643                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 644         }
 645 
 646       end:
 647         kfree(buffer.pointer);
 648         return result;
 649 }
 650 
 651 /* --------------------------------------------------------------------------
 652                               Throttling Control
 653    -------------------------------------------------------------------------- */
 654 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 655 {
 656         int state = 0;
 657         u32 value = 0;
 658         u32 duty_mask = 0;
 659         u32 duty_value = 0;
 660 
 661         if (!pr)
 662                 return -EINVAL;
 663 
 664         if (!pr->flags.throttling)
 665                 return -ENODEV;
 666 
 667         /*
 668          * We don't care about error returns - we just try to mark
 669          * these reserved so that nobody else is confused into thinking
 670          * that this region might be unused..
 671          *
 672          * (In particular, allocating the IO range for Cardbus)
 673          */
 674         request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 675 
 676         pr->throttling.state = 0;
 677 
 678         duty_mask = pr->throttling.state_count - 1;
 679 
 680         duty_mask <<= pr->throttling.duty_offset;
 681 
 682         local_irq_disable();
 683 
 684         value = inl(pr->throttling.address);
 685 
 686         /*
 687          * Compute the current throttling state when throttling is enabled
 688          * (bit 4 is on).
 689          */
 690         if (value & 0x10) {
 691                 duty_value = value & duty_mask;
 692                 duty_value >>= pr->throttling.duty_offset;
 693 
 694                 if (duty_value)
 695                         state = pr->throttling.state_count - duty_value;
 696         }
 697 
 698         pr->throttling.state = state;
 699 
 700         local_irq_enable();
 701 
 702         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 703                           "Throttling state is T%d (%d%% throttling applied)\n",
 704                           state, pr->throttling.states[state].performance));
 705 
 706         return 0;
 707 }
 708 
 709 #ifdef CONFIG_X86
 710 static int acpi_throttling_rdmsr(u64 *value)
 711 {
 712         u64 msr_high, msr_low;
 713         u64 msr = 0;
 714         int ret = -1;
 715 
 716         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 717                 !this_cpu_has(X86_FEATURE_ACPI)) {
 718                 printk(KERN_ERR PREFIX
 719                         "HARDWARE addr space,NOT supported yet\n");
 720         } else {
 721                 msr_low = 0;
 722                 msr_high = 0;
 723                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 724                         (u32 *)&msr_low , (u32 *) &msr_high);
 725                 msr = (msr_high << 32) | msr_low;
 726                 *value = (u64) msr;
 727                 ret = 0;
 728         }
 729         return ret;
 730 }
 731 
 732 static int acpi_throttling_wrmsr(u64 value)
 733 {
 734         int ret = -1;
 735         u64 msr;
 736 
 737         if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) ||
 738                 !this_cpu_has(X86_FEATURE_ACPI)) {
 739                 printk(KERN_ERR PREFIX
 740                         "HARDWARE addr space,NOT supported yet\n");
 741         } else {
 742                 msr = value;
 743                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 744                         msr & 0xffffffff, msr >> 32);
 745                 ret = 0;
 746         }
 747         return ret;
 748 }
 749 #else
 750 static int acpi_throttling_rdmsr(u64 *value)
 751 {
 752         printk(KERN_ERR PREFIX
 753                 "HARDWARE addr space,NOT supported yet\n");
 754         return -1;
 755 }
 756 
 757 static int acpi_throttling_wrmsr(u64 value)
 758 {
 759         printk(KERN_ERR PREFIX
 760                 "HARDWARE addr space,NOT supported yet\n");
 761         return -1;
 762 }
 763 #endif
 764 
 765 static int acpi_read_throttling_status(struct acpi_processor *pr,
 766                                         u64 *value)
 767 {
 768         u32 bit_width, bit_offset;
 769         u32 ptc_value;
 770         u64 ptc_mask;
 771         struct acpi_processor_throttling *throttling;
 772         int ret = -1;
 773 
 774         throttling = &pr->throttling;
 775         switch (throttling->status_register.space_id) {
 776         case ACPI_ADR_SPACE_SYSTEM_IO:
 777                 bit_width = throttling->status_register.bit_width;
 778                 bit_offset = throttling->status_register.bit_offset;
 779 
 780                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 781                                   address, &ptc_value,
 782                                   (u32) (bit_width + bit_offset));
 783                 ptc_mask = (1 << bit_width) - 1;
 784                 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask);
 785                 ret = 0;
 786                 break;
 787         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 788                 ret = acpi_throttling_rdmsr(value);
 789                 break;
 790         default:
 791                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 792                        (u32) (throttling->status_register.space_id));
 793         }
 794         return ret;
 795 }
 796 
 797 static int acpi_write_throttling_state(struct acpi_processor *pr,
 798                                 u64 value)
 799 {
 800         u32 bit_width, bit_offset;
 801         u64 ptc_value;
 802         u64 ptc_mask;
 803         struct acpi_processor_throttling *throttling;
 804         int ret = -1;
 805 
 806         throttling = &pr->throttling;
 807         switch (throttling->control_register.space_id) {
 808         case ACPI_ADR_SPACE_SYSTEM_IO:
 809                 bit_width = throttling->control_register.bit_width;
 810                 bit_offset = throttling->control_register.bit_offset;
 811                 ptc_mask = (1 << bit_width) - 1;
 812                 ptc_value = value & ptc_mask;
 813 
 814                 acpi_os_write_port((acpi_io_address) throttling->
 815                                         control_register.address,
 816                                         (u32) (ptc_value << bit_offset),
 817                                         (u32) (bit_width + bit_offset));
 818                 ret = 0;
 819                 break;
 820         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 821                 ret = acpi_throttling_wrmsr(value);
 822                 break;
 823         default:
 824                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 825                        (u32) (throttling->control_register.space_id));
 826         }
 827         return ret;
 828 }
 829 
 830 static int acpi_get_throttling_state(struct acpi_processor *pr,
 831                                 u64 value)
 832 {
 833         int i;
 834 
 835         for (i = 0; i < pr->throttling.state_count; i++) {
 836                 struct acpi_processor_tx_tss *tx =
 837                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 838                                                       states_tss[i]);
 839                 if (tx->control == value)
 840                         return i;
 841         }
 842         return -1;
 843 }
 844 
 845 static int acpi_get_throttling_value(struct acpi_processor *pr,
 846                         int state, u64 *value)
 847 {
 848         int ret = -1;
 849 
 850         if (state >= 0 && state <= pr->throttling.state_count) {
 851                 struct acpi_processor_tx_tss *tx =
 852                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 853                                                       states_tss[state]);
 854                 *value = tx->control;
 855                 ret = 0;
 856         }
 857         return ret;
 858 }
 859 
 860 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 861 {
 862         int state = 0;
 863         int ret;
 864         u64 value;
 865 
 866         if (!pr)
 867                 return -EINVAL;
 868 
 869         if (!pr->flags.throttling)
 870                 return -ENODEV;
 871 
 872         pr->throttling.state = 0;
 873 
 874         value = 0;
 875         ret = acpi_read_throttling_status(pr, &value);
 876         if (ret >= 0) {
 877                 state = acpi_get_throttling_state(pr, value);
 878                 if (state == -1) {
 879                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 880                                 "Invalid throttling state, reset\n"));
 881                         state = 0;
 882                         ret = __acpi_processor_set_throttling(pr, state, true,
 883                                                               true);
 884                         if (ret)
 885                                 return ret;
 886                 }
 887                 pr->throttling.state = state;
 888         }
 889 
 890         return 0;
 891 }
 892 
 893 static long __acpi_processor_get_throttling(void *data)
 894 {
 895         struct acpi_processor *pr = data;
 896 
 897         return pr->throttling.acpi_processor_get_throttling(pr);
 898 }
 899 
 900 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 901 {
 902         if (!pr)
 903                 return -EINVAL;
 904 
 905         if (!pr->flags.throttling)
 906                 return -ENODEV;
 907 
 908         /*
 909          * This is either called from the CPU hotplug callback of
 910          * processor_driver or via the ACPI probe function. In the latter
 911          * case the CPU is not guaranteed to be online. Both call sites are
 912          * protected against CPU hotplug.
 913          */
 914         if (!cpu_online(pr->id))
 915                 return -ENODEV;
 916 
 917         return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false);
 918 }
 919 
 920 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 921 {
 922         int i, step;
 923 
 924         if (!pr->throttling.address) {
 925                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 926                 return -EINVAL;
 927         } else if (!pr->throttling.duty_width) {
 928                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 929                 return -EINVAL;
 930         }
 931         /* TBD: Support duty_cycle values that span bit 4. */
 932         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 933                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 934                 return -EINVAL;
 935         }
 936 
 937         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 938 
 939         /*
 940          * Compute state values. Note that throttling displays a linear power
 941          * performance relationship (at 50% performance the CPU will consume
 942          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 943          */
 944 
 945         step = (1000 / pr->throttling.state_count);
 946 
 947         for (i = 0; i < pr->throttling.state_count; i++) {
 948                 pr->throttling.states[i].performance = 1000 - step * i;
 949                 pr->throttling.states[i].power = 1000 - step * i;
 950         }
 951         return 0;
 952 }
 953 
 954 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 955                                               int state, bool force)
 956 {
 957         u32 value = 0;
 958         u32 duty_mask = 0;
 959         u32 duty_value = 0;
 960 
 961         if (!pr)
 962                 return -EINVAL;
 963 
 964         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 965                 return -EINVAL;
 966 
 967         if (!pr->flags.throttling)
 968                 return -ENODEV;
 969 
 970         if (!force && (state == pr->throttling.state))
 971                 return 0;
 972 
 973         if (state < pr->throttling_platform_limit)
 974                 return -EPERM;
 975         /*
 976          * Calculate the duty_value and duty_mask.
 977          */
 978         if (state) {
 979                 duty_value = pr->throttling.state_count - state;
 980 
 981                 duty_value <<= pr->throttling.duty_offset;
 982 
 983                 /* Used to clear all duty_value bits */
 984                 duty_mask = pr->throttling.state_count - 1;
 985 
 986                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 987                 duty_mask = ~duty_mask;
 988         }
 989 
 990         local_irq_disable();
 991 
 992         /*
 993          * Disable throttling by writing a 0 to bit 4.  Note that we must
 994          * turn it off before you can change the duty_value.
 995          */
 996         value = inl(pr->throttling.address);
 997         if (value & 0x10) {
 998                 value &= 0xFFFFFFEF;
 999                 outl(value, pr->throttling.address);
1000         }
1001 
1002         /*
1003          * Write the new duty_value and then enable throttling.  Note
1004          * that a state value of 0 leaves throttling disabled.
1005          */
1006         if (state) {
1007                 value &= duty_mask;
1008                 value |= duty_value;
1009                 outl(value, pr->throttling.address);
1010 
1011                 value |= 0x00000010;
1012                 outl(value, pr->throttling.address);
1013         }
1014 
1015         pr->throttling.state = state;
1016 
1017         local_irq_enable();
1018 
1019         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1020                           "Throttling state set to T%d (%d%%)\n", state,
1021                           (pr->throttling.states[state].performance ? pr->
1022                            throttling.states[state].performance / 10 : 0)));
1023 
1024         return 0;
1025 }
1026 
1027 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
1028                                              int state, bool force)
1029 {
1030         int ret;
1031         u64 value;
1032 
1033         if (!pr)
1034                 return -EINVAL;
1035 
1036         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1037                 return -EINVAL;
1038 
1039         if (!pr->flags.throttling)
1040                 return -ENODEV;
1041 
1042         if (!force && (state == pr->throttling.state))
1043                 return 0;
1044 
1045         if (state < pr->throttling_platform_limit)
1046                 return -EPERM;
1047 
1048         value = 0;
1049         ret = acpi_get_throttling_value(pr, state, &value);
1050         if (ret >= 0) {
1051                 acpi_write_throttling_state(pr, value);
1052                 pr->throttling.state = state;
1053         }
1054 
1055         return 0;
1056 }
1057 
1058 static long acpi_processor_throttling_fn(void *data)
1059 {
1060         struct acpi_processor_throttling_arg *arg = data;
1061         struct acpi_processor *pr = arg->pr;
1062 
1063         return pr->throttling.acpi_processor_set_throttling(pr,
1064                         arg->target_state, arg->force);
1065 }
1066 
1067 static int __acpi_processor_set_throttling(struct acpi_processor *pr,
1068                                            int state, bool force, bool direct)
1069 {
1070         int ret = 0;
1071         unsigned int i;
1072         struct acpi_processor *match_pr;
1073         struct acpi_processor_throttling *p_throttling;
1074         struct acpi_processor_throttling_arg arg;
1075         struct throttling_tstate t_state;
1076 
1077         if (!pr)
1078                 return -EINVAL;
1079 
1080         if (!pr->flags.throttling)
1081                 return -ENODEV;
1082 
1083         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1084                 return -EINVAL;
1085 
1086         if (cpu_is_offline(pr->id)) {
1087                 /*
1088                  * the cpu pointed by pr->id is offline. Unnecessary to change
1089                  * the throttling state any more.
1090                  */
1091                 return -ENODEV;
1092         }
1093 
1094         t_state.target_state = state;
1095         p_throttling = &(pr->throttling);
1096 
1097         /*
1098          * The throttling notifier will be called for every
1099          * affected cpu in order to get one proper T-state.
1100          * The notifier event is THROTTLING_PRECHANGE.
1101          */
1102         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1103                 t_state.cpu = i;
1104                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1105                                                         &t_state);
1106         }
1107         /*
1108          * The function of acpi_processor_set_throttling will be called
1109          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1110          * it is necessary to call it for every affected cpu. Otherwise
1111          * it can be called only for the cpu pointed by pr.
1112          */
1113         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1114                 arg.pr = pr;
1115                 arg.target_state = state;
1116                 arg.force = force;
1117                 ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg,
1118                                   direct);
1119         } else {
1120                 /*
1121                  * When the T-state coordination is SW_ALL or HW_ALL,
1122                  * it is necessary to set T-state for every affected
1123                  * cpus.
1124                  */
1125                 for_each_cpu_and(i, cpu_online_mask,
1126                     p_throttling->shared_cpu_map) {
1127                         match_pr = per_cpu(processors, i);
1128                         /*
1129                          * If the pointer is invalid, we will report the
1130                          * error message and continue.
1131                          */
1132                         if (!match_pr) {
1133                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1134                                         "Invalid Pointer for CPU %d\n", i));
1135                                 continue;
1136                         }
1137                         /*
1138                          * If the throttling control is unsupported on CPU i,
1139                          * we will report the error message and continue.
1140                          */
1141                         if (!match_pr->flags.throttling) {
1142                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1143                                         "Throttling Control is unsupported "
1144                                         "on CPU %d\n", i));
1145                                 continue;
1146                         }
1147 
1148                         arg.pr = match_pr;
1149                         arg.target_state = state;
1150                         arg.force = force;
1151                         ret = call_on_cpu(pr->id, acpi_processor_throttling_fn,
1152                                           &arg, direct);
1153                 }
1154         }
1155         /*
1156          * After the set_throttling is called, the
1157          * throttling notifier is called for every
1158          * affected cpu to update the T-states.
1159          * The notifier event is THROTTLING_POSTCHANGE
1160          */
1161         for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) {
1162                 t_state.cpu = i;
1163                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1164                                                         &t_state);
1165         }
1166 
1167         return ret;
1168 }
1169 
1170 int acpi_processor_set_throttling(struct acpi_processor *pr, int state,
1171                                   bool force)
1172 {
1173         return __acpi_processor_set_throttling(pr, state, force, false);
1174 }
1175 
1176 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1177 {
1178         int result = 0;
1179         struct acpi_processor_throttling *pthrottling;
1180 
1181         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1182                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1183                           pr->throttling.address,
1184                           pr->throttling.duty_offset,
1185                           pr->throttling.duty_width));
1186 
1187         /*
1188          * Evaluate _PTC, _TSS and _TPC
1189          * They must all be present or none of them can be used.
1190          */
1191         if (acpi_processor_get_throttling_control(pr) ||
1192                 acpi_processor_get_throttling_states(pr) ||
1193                 acpi_processor_get_platform_limit(pr))
1194         {
1195                 pr->throttling.acpi_processor_get_throttling =
1196                     &acpi_processor_get_throttling_fadt;
1197                 pr->throttling.acpi_processor_set_throttling =
1198                     &acpi_processor_set_throttling_fadt;
1199                 if (acpi_processor_get_fadt_info(pr))
1200                         return 0;
1201         } else {
1202                 pr->throttling.acpi_processor_get_throttling =
1203                     &acpi_processor_get_throttling_ptc;
1204                 pr->throttling.acpi_processor_set_throttling =
1205                     &acpi_processor_set_throttling_ptc;
1206         }
1207 
1208         /*
1209          * If TSD package for one CPU can't be parsed successfully, it means
1210          * that this CPU will have no coordination with other CPUs.
1211          */
1212         if (acpi_processor_get_tsd(pr)) {
1213                 pthrottling = &pr->throttling;
1214                 pthrottling->tsd_valid_flag = 0;
1215                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1216                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1217         }
1218 
1219         /*
1220          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1221          * This shouldn't be an issue as few (if any) mobile systems ever
1222          * used this part.
1223          */
1224         if (errata.piix4.throttle) {
1225                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1226                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1227                 return 0;
1228         }
1229 
1230         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1231                           pr->throttling.state_count));
1232 
1233         pr->flags.throttling = 1;
1234 
1235         /*
1236          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1237          * thermal) decide to lower performance if it so chooses, but for now
1238          * we'll crank up the speed.
1239          */
1240 
1241         result = acpi_processor_get_throttling(pr);
1242         if (result)
1243                 goto end;
1244 
1245         if (pr->throttling.state) {
1246                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1247                                   "Disabling throttling (was T%d)\n",
1248                                   pr->throttling.state));
1249                 result = acpi_processor_set_throttling(pr, 0, false);
1250                 if (result)
1251                         goto end;
1252         }
1253 
1254       end:
1255         if (result)
1256                 pr->flags.throttling = 0;
1257 
1258         return result;
1259 }
1260
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/acpi/processor_throttling.c

DEFINITIONS
