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   1 /*
   2  * processor_throttling.c - Throttling submodule of the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/sched.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/seq_file.h>
  36
  37 #include <asm/io.h>
  38 #include <asm/uaccess.h>
  39
  40 #include <acpi/acpi_bus.h>
  41 #include <acpi/processor.h>
  42
  43 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  44 #define ACPI_PROCESSOR_CLASS            "processor"
  45 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  46 ACPI_MODULE_NAME("processor_throttling");
  47
  48 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  49 int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
  50
  51 static int acpi_processor_update_tsd_coord(void)
  52 {
  53         int count, count_target;
  54         int retval = 0;
  55         unsigned int i, j;
  56         cpumask_t covered_cpus;
  57         struct acpi_processor *pr, *match_pr;
  58         struct acpi_tsd_package *pdomain, *match_pdomain;
  59         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  60
  61         /*
  62          * Now that we have _TSD data from all CPUs, lets setup T-state
  63          * coordination among all CPUs.
  64          */
  65         for_each_possible_cpu(i) {
  66                 pr = processors[i];
  67                 if (!pr)
  68                         continue;
  69
  70                 /* Basic validity check for domain info */
  71                 pthrottling = &(pr->throttling);
  72
  73                 /*
  74                  * If tsd package for one cpu is invalid, the coordination
  75                  * among all CPUs is thought as invalid.
  76                  * Maybe it is ugly.
  77                  */
  78                 if (!pthrottling->tsd_valid_flag) {
  79                         retval = -EINVAL;
  80                         break;
  81                 }
  82         }
  83         if (retval)
  84                 goto err_ret;
  85
  86         cpus_clear(covered_cpus);
  87         for_each_possible_cpu(i) {
  88                 pr = processors[i];
  89                 if (!pr)
  90                         continue;
  91
  92                 if (cpu_isset(i, covered_cpus))
  93                         continue;
  94                 pthrottling = &pr->throttling;
  95
  96                 pdomain = &(pthrottling->domain_info);
  97                 cpu_set(i, pthrottling->shared_cpu_map);
  98                 cpu_set(i, covered_cpus);
  99                 /*
 100                  * If the number of processor in the TSD domain is 1, it is
 101                  * unnecessary to parse the coordination for this CPU.
 102                  */
 103                 if (pdomain->num_processors <= 1)
 104                         continue;
 105
 106                 /* Validate the Domain info */
 107                 count_target = pdomain->num_processors;
 108                 count = 1;
 109
 110                 for_each_possible_cpu(j) {
 111                         if (i == j)
 112                                 continue;
 113
 114                         match_pr = processors[j];
 115                         if (!match_pr)
 116                                 continue;
 117
 118                         match_pthrottling = &(match_pr->throttling);
 119                         match_pdomain = &(match_pthrottling->domain_info);
 120                         if (match_pdomain->domain != pdomain->domain)
 121                                 continue;
 122
 123                         /* Here i and j are in the same domain.
 124                          * If two TSD packages have the same domain, they
 125                          * should have the same num_porcessors and
 126                          * coordination type. Otherwise it will be regarded
 127                          * as illegal.
 128                          */
 129                         if (match_pdomain->num_processors != count_target) {
 130                                 retval = -EINVAL;
 131                                 goto err_ret;
 132                         }
 133
 134                         if (pdomain->coord_type != match_pdomain->coord_type) {
 135                                 retval = -EINVAL;
 136                                 goto err_ret;
 137                         }
 138
 139                         cpu_set(j, covered_cpus);
 140                         cpu_set(j, pthrottling->shared_cpu_map);
 141                         count++;
 142                 }
 143                 for_each_possible_cpu(j) {
 144                         if (i == j)
 145                                 continue;
 146
 147                         match_pr = processors[j];
 148                         if (!match_pr)
 149                                 continue;
 150
 151                         match_pthrottling = &(match_pr->throttling);
 152                         match_pdomain = &(match_pthrottling->domain_info);
 153                         if (match_pdomain->domain != pdomain->domain)
 154                                 continue;
 155
 156                         /*
 157                          * If some CPUS have the same domain, they
 158                          * will have the same shared_cpu_map.
 159                          */
 160                         match_pthrottling->shared_cpu_map =
 161                                 pthrottling->shared_cpu_map;
 162                 }
 163         }
 164
 165 err_ret:
 166         for_each_possible_cpu(i) {
 167                 pr = processors[i];
 168                 if (!pr)
 169                         continue;
 170
 171                 /*
 172                  * Assume no coordination on any error parsing domain info.
 173                  * The coordination type will be forced as SW_ALL.
 174                  */
 175                 if (retval) {
 176                         pthrottling = &(pr->throttling);
 177                         cpus_clear(pthrottling->shared_cpu_map);
 178                         cpu_set(i, pthrottling->shared_cpu_map);
 179                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 180                 }
 181         }
 182
 183         return retval;
 184 }
 185
 186 /*
 187  * Update the T-state coordination after the _TSD
 188  * data for all cpus is obtained.
 189  */
 190 void acpi_processor_throttling_init(void)
 191 {
 192         if (acpi_processor_update_tsd_coord())
 193                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 194                         "Assume no T-state coordination\n"));
 195
 196         return;
 197 }
 198
 199 /*
 200  * _TPC - Throttling Present Capabilities
 201  */
 202 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 203 {
 204         acpi_status status = 0;
 205         unsigned long tpc = 0;
 206
 207         if (!pr)
 208                 return -EINVAL;
 209         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 210         if (ACPI_FAILURE(status)) {
 211                 if (status != AE_NOT_FOUND) {
 212                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 213                 }
 214                 return -ENODEV;
 215         }
 216         pr->throttling_platform_limit = (int)tpc;
 217         return 0;
 218 }
 219
 220 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 221 {
 222         int result = 0;
 223         int throttling_limit;
 224         int current_state;
 225         struct acpi_processor_limit *limit;
 226         int target_state;
 227
 228         result = acpi_processor_get_platform_limit(pr);
 229         if (result) {
 230                 /* Throttling Limit is unsupported */
 231                 return result;
 232         }
 233
 234         throttling_limit = pr->throttling_platform_limit;
 235         if (throttling_limit >= pr->throttling.state_count) {
 236                 /* Uncorrect Throttling Limit */
 237                 return -EINVAL;
 238         }
 239
 240         current_state = pr->throttling.state;
 241         if (current_state > throttling_limit) {
 242                 /*
 243                  * The current state can meet the requirement of
 244                  * _TPC limit. But it is reasonable that OSPM changes
 245                  * t-states from high to low for better performance.
 246                  * Of course the limit condition of thermal
 247                  * and user should be considered.
 248                  */
 249                 limit = &pr->limit;
 250                 target_state = throttling_limit;
 251                 if (limit->thermal.tx > target_state)
 252                         target_state = limit->thermal.tx;
 253                 if (limit->user.tx > target_state)
 254                         target_state = limit->user.tx;
 255         } else if (current_state == throttling_limit) {
 256                 /*
 257                  * Unnecessary to change the throttling state
 258                  */
 259                 return 0;
 260         } else {
 261                 /*
 262                  * If the current state is lower than the limit of _TPC, it
 263                  * will be forced to switch to the throttling state defined
 264                  * by throttling_platfor_limit.
 265                  * Because the previous state meets with the limit condition
 266                  * of thermal and user, it is unnecessary to check it again.
 267                  */
 268                 target_state = throttling_limit;
 269         }
 270         return acpi_processor_set_throttling(pr, target_state);
 271 }
 272
 273 /*
 274  * _PTC - Processor Throttling Control (and status) register location
 275  */
 276 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 277 {
 278         int result = 0;
 279         acpi_status status = 0;
 280         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 281         union acpi_object *ptc = NULL;
 282         union acpi_object obj = { 0 };
 283         struct acpi_processor_throttling *throttling;
 284
 285         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 286         if (ACPI_FAILURE(status)) {
 287                 if (status != AE_NOT_FOUND) {
 288                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 289                 }
 290                 return -ENODEV;
 291         }
 292
 293         ptc = (union acpi_object *)buffer.pointer;
 294         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 295             || (ptc->package.count != 2)) {
 296                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 297                 result = -EFAULT;
 298                 goto end;
 299         }
 300
 301         /*
 302          * control_register
 303          */
 304
 305         obj = ptc->package.elements[0];
 306
 307         if ((obj.type != ACPI_TYPE_BUFFER)
 308             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 309             || (obj.buffer.pointer == NULL)) {
 310                 printk(KERN_ERR PREFIX
 311                        "Invalid _PTC data (control_register)\n");
 312                 result = -EFAULT;
 313                 goto end;
 314         }
 315         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 316                sizeof(struct acpi_ptc_register));
 317
 318         /*
 319          * status_register
 320          */
 321
 322         obj = ptc->package.elements[1];
 323
 324         if ((obj.type != ACPI_TYPE_BUFFER)
 325             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 326             || (obj.buffer.pointer == NULL)) {
 327                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 328                 result = -EFAULT;
 329                 goto end;
 330         }
 331
 332         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 333                sizeof(struct acpi_ptc_register));
 334
 335         throttling = &pr->throttling;
 336
 337         if ((throttling->control_register.bit_width +
 338                 throttling->control_register.bit_offset) > 32) {
 339                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 340                 result = -EFAULT;
 341                 goto end;
 342         }
 343
 344         if ((throttling->status_register.bit_width +
 345                 throttling->status_register.bit_offset) > 32) {
 346                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 347                 result = -EFAULT;
 348                 goto end;
 349         }
 350
 351       end:
 352         kfree(buffer.pointer);
 353
 354         return result;
 355 }
 356
 357 /*
 358  * _TSS - Throttling Supported States
 359  */
 360 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 361 {
 362         int result = 0;
 363         acpi_status status = AE_OK;
 364         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 365         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 366         struct acpi_buffer state = { 0, NULL };
 367         union acpi_object *tss = NULL;
 368         int i;
 369
 370         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 371         if (ACPI_FAILURE(status)) {
 372                 if (status != AE_NOT_FOUND) {
 373                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 374                 }
 375                 return -ENODEV;
 376         }
 377
 378         tss = buffer.pointer;
 379         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 380                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 381                 result = -EFAULT;
 382                 goto end;
 383         }
 384
 385         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 386                           tss->package.count));
 387
 388         pr->throttling.state_count = tss->package.count;
 389         pr->throttling.states_tss =
 390             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 391                     GFP_KERNEL);
 392         if (!pr->throttling.states_tss) {
 393                 result = -ENOMEM;
 394                 goto end;
 395         }
 396
 397         for (i = 0; i < pr->throttling.state_count; i++) {
 398
 399                 struct acpi_processor_tx_tss *tx =
 400                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 401                                                       states_tss[i]);
 402
 403                 state.length = sizeof(struct acpi_processor_tx_tss);
 404                 state.pointer = tx;
 405
 406                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 407
 408                 status = acpi_extract_package(&(tss->package.elements[i]),
 409                                               &format, &state);
 410                 if (ACPI_FAILURE(status)) {
 411                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 412                         result = -EFAULT;
 413                         kfree(pr->throttling.states_tss);
 414                         goto end;
 415                 }
 416
 417                 if (!tx->freqpercentage) {
 418                         printk(KERN_ERR PREFIX
 419                                "Invalid _TSS data: freq is zero\n");
 420                         result = -EFAULT;
 421                         kfree(pr->throttling.states_tss);
 422                         goto end;
 423                 }
 424         }
 425
 426       end:
 427         kfree(buffer.pointer);
 428
 429         return result;
 430 }
 431
 432 /*
 433  * _TSD - T-State Dependencies
 434  */
 435 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 436 {
 437         int result = 0;
 438         acpi_status status = AE_OK;
 439         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 440         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 441         struct acpi_buffer state = { 0, NULL };
 442         union acpi_object *tsd = NULL;
 443         struct acpi_tsd_package *pdomain;
 444         struct acpi_processor_throttling *pthrottling;
 445
 446         pthrottling = &pr->throttling;
 447         pthrottling->tsd_valid_flag = 0;
 448
 449         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 450         if (ACPI_FAILURE(status)) {
 451                 if (status != AE_NOT_FOUND) {
 452                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 453                 }
 454                 return -ENODEV;
 455         }
 456
 457         tsd = buffer.pointer;
 458         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 459                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 460                 result = -EFAULT;
 461                 goto end;
 462         }
 463
 464         if (tsd->package.count != 1) {
 465                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 466                 result = -EFAULT;
 467                 goto end;
 468         }
 469
 470         pdomain = &(pr->throttling.domain_info);
 471
 472         state.length = sizeof(struct acpi_tsd_package);
 473         state.pointer = pdomain;
 474
 475         status = acpi_extract_package(&(tsd->package.elements[0]),
 476                                       &format, &state);
 477         if (ACPI_FAILURE(status)) {
 478                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _TSD data\n"));
 479                 result = -EFAULT;
 480                 goto end;
 481         }
 482
 483         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 484                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:num_entries\n"));
 485                 result = -EFAULT;
 486                 goto end;
 487         }
 488
 489         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 490                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unknown _TSD:revision\n"));
 491                 result = -EFAULT;
 492                 goto end;
 493         }
 494
 495         pthrottling = &pr->throttling;
 496         pthrottling->tsd_valid_flag = 1;
 497         pthrottling->shared_type = pdomain->coord_type;
 498         cpu_set(pr->id, pthrottling->shared_cpu_map);
 499         /*
 500          * If the coordination type is not defined in ACPI spec,
 501          * the tsd_valid_flag will be clear and coordination type
 502          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 503          */
 504         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 505                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 506                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 507                 pthrottling->tsd_valid_flag = 0;
 508                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 509         }
 510
 511       end:
 512         kfree(buffer.pointer);
 513         return result;
 514 }
 515
 516 /* --------------------------------------------------------------------------
 517                               Throttling Control
 518    -------------------------------------------------------------------------- */
 519 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 520 {
 521         int state = 0;
 522         u32 value = 0;
 523         u32 duty_mask = 0;
 524         u32 duty_value = 0;
 525
 526         if (!pr)
 527                 return -EINVAL;
 528
 529         if (!pr->flags.throttling)
 530                 return -ENODEV;
 531
 532         pr->throttling.state = 0;
 533
 534         duty_mask = pr->throttling.state_count - 1;
 535
 536         duty_mask <<= pr->throttling.duty_offset;
 537
 538         local_irq_disable();
 539
 540         value = inl(pr->throttling.address);
 541
 542         /*
 543          * Compute the current throttling state when throttling is enabled
 544          * (bit 4 is on).
 545          */
 546         if (value & 0x10) {
 547                 duty_value = value & duty_mask;
 548                 duty_value >>= pr->throttling.duty_offset;
 549
 550                 if (duty_value)
 551                         state = pr->throttling.state_count - duty_value;
 552         }
 553
 554         pr->throttling.state = state;
 555
 556         local_irq_enable();
 557
 558         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 559                           "Throttling state is T%d (%d%% throttling applied)\n",
 560                           state, pr->throttling.states[state].performance));
 561
 562         return 0;
 563 }
 564
 565 #ifdef CONFIG_X86
 566 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 567                                         acpi_integer * value)
 568 {
 569         struct cpuinfo_x86 *c;
 570         u64 msr_high, msr_low;
 571         unsigned int cpu;
 572         u64 msr = 0;
 573         int ret = -1;
 574
 575         cpu = pr->id;
 576         c = &cpu_data(cpu);
 577
 578         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 579                 !cpu_has(c, X86_FEATURE_ACPI)) {
 580                 printk(KERN_ERR PREFIX
 581                         "HARDWARE addr space,NOT supported yet\n");
 582         } else {
 583                 msr_low = 0;
 584                 msr_high = 0;
 585                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 586                         (u32 *)&msr_low , (u32 *) &msr_high);
 587                 msr = (msr_high << 32) | msr_low;
 588                 *value = (acpi_integer) msr;
 589                 ret = 0;
 590         }
 591         return ret;
 592 }
 593
 594 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 595 {
 596         struct cpuinfo_x86 *c;
 597         unsigned int cpu;
 598         int ret = -1;
 599         u64 msr;
 600
 601         cpu = pr->id;
 602         c = &cpu_data(cpu);
 603
 604         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 605                 !cpu_has(c, X86_FEATURE_ACPI)) {
 606                 printk(KERN_ERR PREFIX
 607                         "HARDWARE addr space,NOT supported yet\n");
 608         } else {
 609                 msr = value;
 610                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 611                         msr & 0xffffffff, msr >> 32);
 612                 ret = 0;
 613         }
 614         return ret;
 615 }
 616 #else
 617 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 618                                 acpi_integer * value)
 619 {
 620         printk(KERN_ERR PREFIX
 621                 "HARDWARE addr space,NOT supported yet\n");
 622         return -1;
 623 }
 624
 625 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 626 {
 627         printk(KERN_ERR PREFIX
 628                 "HARDWARE addr space,NOT supported yet\n");
 629         return -1;
 630 }
 631 #endif
 632
 633 static int acpi_read_throttling_status(struct acpi_processor *pr,
 634                                         acpi_integer *value)
 635 {
 636         u32 bit_width, bit_offset;
 637         u64 ptc_value;
 638         u64 ptc_mask;
 639         struct acpi_processor_throttling *throttling;
 640         int ret = -1;
 641
 642         throttling = &pr->throttling;
 643         switch (throttling->status_register.space_id) {
 644         case ACPI_ADR_SPACE_SYSTEM_IO:
 645                 ptc_value = 0;
 646                 bit_width = throttling->status_register.bit_width;
 647                 bit_offset = throttling->status_register.bit_offset;
 648
 649                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 650                                   address, (u32 *) &ptc_value,
 651                                   (u32) (bit_width + bit_offset));
 652                 ptc_mask = (1 << bit_width) - 1;
 653                 *value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);
 654                 ret = 0;
 655                 break;
 656         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 657                 ret = acpi_throttling_rdmsr(pr, value);
 658                 break;
 659         default:
 660                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 661                        (u32) (throttling->status_register.space_id));
 662         }
 663         return ret;
 664 }
 665
 666 static int acpi_write_throttling_state(struct acpi_processor *pr,
 667                                 acpi_integer value)
 668 {
 669         u32 bit_width, bit_offset;
 670         u64 ptc_value;
 671         u64 ptc_mask;
 672         struct acpi_processor_throttling *throttling;
 673         int ret = -1;
 674
 675         throttling = &pr->throttling;
 676         switch (throttling->control_register.space_id) {
 677         case ACPI_ADR_SPACE_SYSTEM_IO:
 678                 bit_width = throttling->control_register.bit_width;
 679                 bit_offset = throttling->control_register.bit_offset;
 680                 ptc_mask = (1 << bit_width) - 1;
 681                 ptc_value = value & ptc_mask;
 682
 683                 acpi_os_write_port((acpi_io_address) throttling->
 684                                         control_register.address,
 685                                         (u32) (ptc_value << bit_offset),
 686                                         (u32) (bit_width + bit_offset));
 687                 ret = 0;
 688                 break;
 689         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 690                 ret = acpi_throttling_wrmsr(pr, value);
 691                 break;
 692         default:
 693                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 694                        (u32) (throttling->control_register.space_id));
 695         }
 696         return ret;
 697 }
 698
 699 static int acpi_get_throttling_state(struct acpi_processor *pr,
 700                                 acpi_integer value)
 701 {
 702         int i;
 703
 704         for (i = 0; i < pr->throttling.state_count; i++) {
 705                 struct acpi_processor_tx_tss *tx =
 706                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 707                                                       states_tss[i]);
 708                 if (tx->control == value)
 709                         break;
 710         }
 711         if (i > pr->throttling.state_count)
 712                 i = -1;
 713         return i;
 714 }
 715
 716 static int acpi_get_throttling_value(struct acpi_processor *pr,
 717                         int state, acpi_integer *value)
 718 {
 719         int ret = -1;
 720
 721         if (state >= 0 && state <= pr->throttling.state_count) {
 722                 struct acpi_processor_tx_tss *tx =
 723                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 724                                                       states_tss[state]);
 725                 *value = tx->control;
 726                 ret = 0;
 727         }
 728         return ret;
 729 }
 730
 731 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 732 {
 733         int state = 0;
 734         int ret;
 735         acpi_integer value;
 736
 737         if (!pr)
 738                 return -EINVAL;
 739
 740         if (!pr->flags.throttling)
 741                 return -ENODEV;
 742
 743         pr->throttling.state = 0;
 744
 745         value = 0;
 746         ret = acpi_read_throttling_status(pr, &value);
 747         if (ret >= 0) {
 748                 state = acpi_get_throttling_state(pr, value);
 749                 pr->throttling.state = state;
 750         }
 751
 752         return 0;
 753 }
 754
 755 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 756 {
 757         cpumask_t saved_mask;
 758         int ret;
 759
 760         if (!pr)
 761                 return -EINVAL;
 762
 763         if (!pr->flags.throttling)
 764                 return -ENODEV;
 765         /*
 766          * Migrate task to the cpu pointed by pr.
 767          */
 768         saved_mask = current->cpus_allowed;
 769         set_cpus_allowed(current, cpumask_of_cpu(pr->id));
 770         ret = pr->throttling.acpi_processor_get_throttling(pr);
 771         /* restore the previous state */
 772         set_cpus_allowed(current, saved_mask);
 773
 774         return ret;
 775 }
 776
 777 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 778 {
 779         int i, step;
 780
 781         if (!pr->throttling.address) {
 782                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 783                 return -EINVAL;
 784         } else if (!pr->throttling.duty_width) {
 785                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 786                 return -EINVAL;
 787         }
 788         /* TBD: Support duty_cycle values that span bit 4. */
 789         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 790                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 791                 return -EINVAL;
 792         }
 793
 794         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 795
 796         /*
 797          * Compute state values. Note that throttling displays a linear power
 798          * performance relationship (at 50% performance the CPU will consume
 799          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 800          */
 801
 802         step = (1000 / pr->throttling.state_count);
 803
 804         for (i = 0; i < pr->throttling.state_count; i++) {
 805                 pr->throttling.states[i].performance = 1000 - step * i;
 806                 pr->throttling.states[i].power = 1000 - step * i;
 807         }
 808         return 0;
 809 }
 810
 811 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 812                                               int state)
 813 {
 814         u32 value = 0;
 815         u32 duty_mask = 0;
 816         u32 duty_value = 0;
 817
 818         if (!pr)
 819                 return -EINVAL;
 820
 821         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 822                 return -EINVAL;
 823
 824         if (!pr->flags.throttling)
 825                 return -ENODEV;
 826
 827         if (state == pr->throttling.state)
 828                 return 0;
 829
 830         if (state < pr->throttling_platform_limit)
 831                 return -EPERM;
 832         /*
 833          * Calculate the duty_value and duty_mask.
 834          */
 835         if (state) {
 836                 duty_value = pr->throttling.state_count - state;
 837
 838                 duty_value <<= pr->throttling.duty_offset;
 839
 840                 /* Used to clear all duty_value bits */
 841                 duty_mask = pr->throttling.state_count - 1;
 842
 843                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 844                 duty_mask = ~duty_mask;
 845         }
 846
 847         local_irq_disable();
 848
 849         /*
 850          * Disable throttling by writing a 0 to bit 4.  Note that we must
 851          * turn it off before you can change the duty_value.
 852          */
 853         value = inl(pr->throttling.address);
 854         if (value & 0x10) {
 855                 value &= 0xFFFFFFEF;
 856                 outl(value, pr->throttling.address);
 857         }
 858
 859         /*
 860          * Write the new duty_value and then enable throttling.  Note
 861          * that a state value of 0 leaves throttling disabled.
 862          */
 863         if (state) {
 864                 value &= duty_mask;
 865                 value |= duty_value;
 866                 outl(value, pr->throttling.address);
 867
 868                 value |= 0x00000010;
 869                 outl(value, pr->throttling.address);
 870         }
 871
 872         pr->throttling.state = state;
 873
 874         local_irq_enable();
 875
 876         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 877                           "Throttling state set to T%d (%d%%)\n", state,
 878                           (pr->throttling.states[state].performance ? pr->
 879                            throttling.states[state].performance / 10 : 0)));
 880
 881         return 0;
 882 }
 883
 884 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 885                                              int state)
 886 {
 887         int ret;
 888         acpi_integer value;
 889
 890         if (!pr)
 891                 return -EINVAL;
 892
 893         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 894                 return -EINVAL;
 895
 896         if (!pr->flags.throttling)
 897                 return -ENODEV;
 898
 899         if (state == pr->throttling.state)
 900                 return 0;
 901
 902         if (state < pr->throttling_platform_limit)
 903                 return -EPERM;
 904
 905         value = 0;
 906         ret = acpi_get_throttling_value(pr, state, &value);
 907         if (ret >= 0) {
 908                 acpi_write_throttling_state(pr, value);
 909                 pr->throttling.state = state;
 910         }
 911
 912         return 0;
 913 }
 914
 915 int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
 916 {
 917         cpumask_t saved_mask;
 918         int ret;
 919
 920         if (!pr)
 921                 return -EINVAL;
 922
 923         if (!pr->flags.throttling)
 924                 return -ENODEV;
 925
 926         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 927                 return -EINVAL;
 928
 929         /*
 930          * Migrate task to the cpu pointed by pr.
 931          */
 932         saved_mask = current->cpus_allowed;
 933         set_cpus_allowed(current, cpumask_of_cpu(pr->id));
 934         ret = pr->throttling.acpi_processor_set_throttling(pr, state);
 935         /* restore the previous state */
 936         set_cpus_allowed(current, saved_mask);
 937         return ret;
 938 }
 939
 940 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
 941 {
 942         int result = 0;
 943         struct acpi_processor_throttling *pthrottling;
 944
 945         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 946                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
 947                           pr->throttling.address,
 948                           pr->throttling.duty_offset,
 949                           pr->throttling.duty_width));
 950
 951         if (!pr)
 952                 return -EINVAL;
 953
 954         /*
 955          * Evaluate _PTC, _TSS and _TPC
 956          * They must all be present or none of them can be used.
 957          */
 958         if (acpi_processor_get_throttling_control(pr) ||
 959                 acpi_processor_get_throttling_states(pr) ||
 960                 acpi_processor_get_platform_limit(pr))
 961         {
 962                 pr->throttling.acpi_processor_get_throttling =
 963                     &acpi_processor_get_throttling_fadt;
 964                 pr->throttling.acpi_processor_set_throttling =
 965                     &acpi_processor_set_throttling_fadt;
 966                 if (acpi_processor_get_fadt_info(pr))
 967                         return 0;
 968         } else {
 969                 pr->throttling.acpi_processor_get_throttling =
 970                     &acpi_processor_get_throttling_ptc;
 971                 pr->throttling.acpi_processor_set_throttling =
 972                     &acpi_processor_set_throttling_ptc;
 973         }
 974
 975         /*
 976          * If TSD package for one CPU can't be parsed successfully, it means
 977          * that this CPU will have no coordination with other CPUs.
 978          */
 979         if (acpi_processor_get_tsd(pr)) {
 980                 pthrottling = &pr->throttling;
 981                 pthrottling->tsd_valid_flag = 0;
 982                 cpu_set(pr->id, pthrottling->shared_cpu_map);
 983                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 984         }
 985
 986         /*
 987          * PIIX4 Errata: We don't support throttling on the original PIIX4.
 988          * This shouldn't be an issue as few (if any) mobile systems ever
 989          * used this part.
 990          */
 991         if (errata.piix4.throttle) {
 992                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 993                                   "Throttling not supported on PIIX4 A- or B-step\n"));
 994                 return 0;
 995         }
 996
 997         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 998                           pr->throttling.state_count));
 999
1000         pr->flags.throttling = 1;
1001
1002         /*
1003          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1004          * thermal) decide to lower performance if it so chooses, but for now
1005          * we'll crank up the speed.
1006          */
1007
1008         result = acpi_processor_get_throttling(pr);
1009         if (result)
1010                 goto end;
1011
1012         if (pr->throttling.state) {
1013                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1014                                   "Disabling throttling (was T%d)\n",
1015                                   pr->throttling.state));
1016                 result = acpi_processor_set_throttling(pr, 0);
1017                 if (result)
1018                         goto end;
1019         }
1020
1021       end:
1022         if (result)
1023                 pr->flags.throttling = 0;
1024
1025         return result;
1026 }
1027
1028 /* proc interface */
1029
1030 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1031                                               void *offset)
1032 {
1033         struct acpi_processor *pr = seq->private;
1034         int i = 0;
1035         int result = 0;
1036
1037         if (!pr)
1038                 goto end;
1039
1040         if (!(pr->throttling.state_count > 0)) {
1041                 seq_puts(seq, "<not supported>\n");
1042                 goto end;
1043         }
1044
1045         result = acpi_processor_get_throttling(pr);
1046
1047         if (result) {
1048                 seq_puts(seq,
1049                          "Could not determine current throttling state.\n");
1050                 goto end;
1051         }
1052
1053         seq_printf(seq, "state count:             %d\n"
1054                    "active state:            T%d\n"
1055                    "state available: T%d to T%d\n",
1056                    pr->throttling.state_count, pr->throttling.state,
1057                    pr->throttling_platform_limit,
1058                    pr->throttling.state_count - 1);
1059
1060         seq_puts(seq, "states:\n");
1061         if (pr->throttling.acpi_processor_get_throttling ==
1062                         acpi_processor_get_throttling_fadt) {
1063                 for (i = 0; i < pr->throttling.state_count; i++)
1064                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1065                                    (i == pr->throttling.state ? '*' : ' '), i,
1066                                    (pr->throttling.states[i].performance ? pr->
1067                                     throttling.states[i].performance / 10 : 0));
1068         } else {
1069                 for (i = 0; i < pr->throttling.state_count; i++)
1070                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1071                                    (i == pr->throttling.state ? '*' : ' '), i,
1072                                    (int)pr->throttling.states_tss[i].
1073                                    freqpercentage);
1074         }
1075
1076       end:
1077         return 0;
1078 }
1079
1080 static int acpi_processor_throttling_open_fs(struct inode *inode,
1081                                              struct file *file)
1082 {
1083         return single_open(file, acpi_processor_throttling_seq_show,
1084                            PDE(inode)->data);
1085 }
1086
1087 static ssize_t acpi_processor_write_throttling(struct file *file,
1088                                                const char __user * buffer,
1089                                                size_t count, loff_t * data)
1090 {
1091         int result = 0;
1092         struct seq_file *m = file->private_data;
1093         struct acpi_processor *pr = m->private;
1094         char state_string[12] = { '\0' };
1095
1096         if (!pr || (count > sizeof(state_string) - 1))
1097                 return -EINVAL;
1098
1099         if (copy_from_user(state_string, buffer, count))
1100                 return -EFAULT;
1101
1102         state_string[count] = '\0';
1103
1104         result = acpi_processor_set_throttling(pr,
1105                                                simple_strtoul(state_string,
1106                                                               NULL, 0));
1107         if (result)
1108                 return result;
1109
1110         return count;
1111 }
1112
1113 struct file_operations acpi_processor_throttling_fops = {
1114         .open = acpi_processor_throttling_open_fs,
1115         .read = seq_read,
1116         .write = acpi_processor_write_throttling,
1117         .llseek = seq_lseek,
1118         .release = single_release,
1119 };