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/acpi_drivers.h> 42 #include <acpi/processor.h> 43 44 #define ACPI_PROCESSOR_CLASS "processor" 45 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 46 ACPI_MODULE_NAME("processor_throttling"); 47 48 /* ignore_tpc: 49 * 0 -> acpi processor driver doesn't ignore _TPC values 50 * 1 -> acpi processor driver ignores _TPC values 51 */ 52 static int ignore_tpc; 53 module_param(ignore_tpc, int, 0644); 54 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support"); 55 56 struct throttling_tstate { 57 unsigned int cpu; /* cpu nr */ 58 int target_state; /* target T-state */ 59 }; 60 61 #define THROTTLING_PRECHANGE (1) 62 #define THROTTLING_POSTCHANGE (2) 63 64 static int acpi_processor_get_throttling(struct acpi_processor *pr); 65 int acpi_processor_set_throttling(struct acpi_processor *pr, 66 int state, bool force); 67 68 static int acpi_processor_update_tsd_coord(void) 69 { 70 int count, count_target; 71 int retval = 0; 72 unsigned int i, j; 73 cpumask_var_t covered_cpus; 74 struct acpi_processor *pr, *match_pr; 75 struct acpi_tsd_package *pdomain, *match_pdomain; 76 struct acpi_processor_throttling *pthrottling, *match_pthrottling; 77 78 if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 79 return -ENOMEM; 80 81 /* 82 * Now that we have _TSD data from all CPUs, lets setup T-state 83 * coordination between all CPUs. 84 */ 85 for_each_possible_cpu(i) { 86 pr = per_cpu(processors, i); 87 if (!pr) 88 continue; 89 90 /* Basic validity check for domain info */ 91 pthrottling = &(pr->throttling); 92 93 /* 94 * If tsd package for one cpu is invalid, the coordination 95 * among all CPUs is thought as invalid. 96 * Maybe it is ugly. 97 */ 98 if (!pthrottling->tsd_valid_flag) { 99 retval = -EINVAL; 100 break; 101 } 102 } 103 if (retval) 104 goto err_ret; 105 106 cpumask_clear(covered_cpus); 107 for_each_possible_cpu(i) { 108 pr = per_cpu(processors, i); 109 if (!pr) 110 continue; 111 112 if (cpumask_test_cpu(i, covered_cpus)) 113 continue; 114 pthrottling = &pr->throttling; 115 116 pdomain = &(pthrottling->domain_info); 117 cpumask_set_cpu(i, pthrottling->shared_cpu_map); 118 cpumask_set_cpu(i, covered_cpus); 119 /* 120 * If the number of processor in the TSD domain is 1, it is 121 * unnecessary to parse the coordination for this CPU. 122 */ 123 if (pdomain->num_processors <= 1) 124 continue; 125 126 /* Validate the Domain info */ 127 count_target = pdomain->num_processors; 128 count = 1; 129 130 for_each_possible_cpu(j) { 131 if (i == j) 132 continue; 133 134 match_pr = per_cpu(processors, j); 135 if (!match_pr) 136 continue; 137 138 match_pthrottling = &(match_pr->throttling); 139 match_pdomain = &(match_pthrottling->domain_info); 140 if (match_pdomain->domain != pdomain->domain) 141 continue; 142 143 /* Here i and j are in the same domain. 144 * If two TSD packages have the same domain, they 145 * should have the same num_porcessors and 146 * coordination type. Otherwise it will be regarded 147 * as illegal. 148 */ 149 if (match_pdomain->num_processors != count_target) { 150 retval = -EINVAL; 151 goto err_ret; 152 } 153 154 if (pdomain->coord_type != match_pdomain->coord_type) { 155 retval = -EINVAL; 156 goto err_ret; 157 } 158 159 cpumask_set_cpu(j, covered_cpus); 160 cpumask_set_cpu(j, pthrottling->shared_cpu_map); 161 count++; 162 } 163 for_each_possible_cpu(j) { 164 if (i == j) 165 continue; 166 167 match_pr = per_cpu(processors, j); 168 if (!match_pr) 169 continue; 170 171 match_pthrottling = &(match_pr->throttling); 172 match_pdomain = &(match_pthrottling->domain_info); 173 if (match_pdomain->domain != pdomain->domain) 174 continue; 175 176 /* 177 * If some CPUS have the same domain, they 178 * will have the same shared_cpu_map. 179 */ 180 cpumask_copy(match_pthrottling->shared_cpu_map, 181 pthrottling->shared_cpu_map); 182 } 183 } 184 185 err_ret: 186 free_cpumask_var(covered_cpus); 187 188 for_each_possible_cpu(i) { 189 pr = per_cpu(processors, i); 190 if (!pr) 191 continue; 192 193 /* 194 * Assume no coordination on any error parsing domain info. 195 * The coordination type will be forced as SW_ALL. 196 */ 197 if (retval) { 198 pthrottling = &(pr->throttling); 199 cpumask_clear(pthrottling->shared_cpu_map); 200 cpumask_set_cpu(i, pthrottling->shared_cpu_map); 201 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL; 202 } 203 } 204 205 return retval; 206 } 207 208 /* 209 * Update the T-state coordination after the _TSD 210 * data for all cpus is obtained. 211 */ 212 void acpi_processor_throttling_init(void) 213 { 214 if (acpi_processor_update_tsd_coord()) 215 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 216 "Assume no T-state coordination\n")); 217 218 return; 219 } 220 221 static int acpi_processor_throttling_notifier(unsigned long event, void *data) 222 { 223 struct throttling_tstate *p_tstate = data; 224 struct acpi_processor *pr; 225 unsigned int cpu ; 226 int target_state; 227 struct acpi_processor_limit *p_limit; 228 struct acpi_processor_throttling *p_throttling; 229 230 cpu = p_tstate->cpu; 231 pr = per_cpu(processors, cpu); 232 if (!pr) { 233 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n")); 234 return 0; 235 } 236 if (!pr->flags.throttling) { 237 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is " 238 "unsupported on CPU %d\n", cpu)); 239 return 0; 240 } 241 target_state = p_tstate->target_state; 242 p_throttling = &(pr->throttling); 243 switch (event) { 244 case THROTTLING_PRECHANGE: 245 /* 246 * Prechange event is used to choose one proper t-state, 247 * which meets the limits of thermal, user and _TPC. 248 */ 249 p_limit = &pr->limit; 250 if (p_limit->thermal.tx > target_state) 251 target_state = p_limit->thermal.tx; 252 if (p_limit->user.tx > target_state) 253 target_state = p_limit->user.tx; 254 if (pr->throttling_platform_limit > target_state) 255 target_state = pr->throttling_platform_limit; 256 if (target_state >= p_throttling->state_count) { 257 printk(KERN_WARNING 258 "Exceed the limit of T-state \n"); 259 target_state = p_throttling->state_count - 1; 260 } 261 p_tstate->target_state = target_state; 262 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:" 263 "target T-state of CPU %d is T%d\n", 264 cpu, target_state)); 265 break; 266 case THROTTLING_POSTCHANGE: 267 /* 268 * Postchange event is only used to update the 269 * T-state flag of acpi_processor_throttling. 270 */ 271 p_throttling->state = target_state; 272 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:" 273 "CPU %d is switched to T%d\n", 274 cpu, target_state)); 275 break; 276 default: 277 printk(KERN_WARNING 278 "Unsupported Throttling notifier event\n"); 279 break; 280 } 281 282 return 0; 283 } 284 285 /* 286 * _TPC - Throttling Present Capabilities 287 */ 288 static int acpi_processor_get_platform_limit(struct acpi_processor *pr) 289 { 290 acpi_status status = 0; 291 unsigned long long tpc = 0; 292 293 if (!pr) 294 return -EINVAL; 295 296 if (ignore_tpc) 297 goto end; 298 299 status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc); 300 if (ACPI_FAILURE(status)) { 301 if (status != AE_NOT_FOUND) { 302 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC")); 303 } 304 return -ENODEV; 305 } 306 307 end: 308 pr->throttling_platform_limit = (int)tpc; 309 return 0; 310 } 311 312 int acpi_processor_tstate_has_changed(struct acpi_processor *pr) 313 { 314 int result = 0; 315 int throttling_limit; 316 int current_state; 317 struct acpi_processor_limit *limit; 318 int target_state; 319 320 if (ignore_tpc) 321 return 0; 322 323 result = acpi_processor_get_platform_limit(pr); 324 if (result) { 325 /* Throttling Limit is unsupported */ 326 return result; 327 } 328 329 throttling_limit = pr->throttling_platform_limit; 330 if (throttling_limit >= pr->throttling.state_count) { 331 /* Uncorrect Throttling Limit */ 332 return -EINVAL; 333 } 334 335 current_state = pr->throttling.state; 336 if (current_state > throttling_limit) { 337 /* 338 * The current state can meet the requirement of 339 * _TPC limit. But it is reasonable that OSPM changes 340 * t-states from high to low for better performance. 341 * Of course the limit condition of thermal 342 * and user should be considered. 343 */ 344 limit = &pr->limit; 345 target_state = throttling_limit; 346 if (limit->thermal.tx > target_state) 347 target_state = limit->thermal.tx; 348 if (limit->user.tx > target_state) 349 target_state = limit->user.tx; 350 } else if (current_state == throttling_limit) { 351 /* 352 * Unnecessary to change the throttling state 353 */ 354 return 0; 355 } else { 356 /* 357 * If the current state is lower than the limit of _TPC, it 358 * will be forced to switch to the throttling state defined 359 * by throttling_platfor_limit. 360 * Because the previous state meets with the limit condition 361 * of thermal and user, it is unnecessary to check it again. 362 */ 363 target_state = throttling_limit; 364 } 365 return acpi_processor_set_throttling(pr, target_state, false); 366 } 367 368 /* 369 * _PTC - Processor Throttling Control (and status) register location 370 */ 371 static int acpi_processor_get_throttling_control(struct acpi_processor *pr) 372 { 373 int result = 0; 374 acpi_status status = 0; 375 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 376 union acpi_object *ptc = NULL; 377 union acpi_object obj = { 0 }; 378 struct acpi_processor_throttling *throttling; 379 380 status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer); 381 if (ACPI_FAILURE(status)) { 382 if (status != AE_NOT_FOUND) { 383 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC")); 384 } 385 return -ENODEV; 386 } 387 388 ptc = (union acpi_object *)buffer.pointer; 389 if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE) 390 || (ptc->package.count != 2)) { 391 printk(KERN_ERR PREFIX "Invalid _PTC data\n"); 392 result = -EFAULT; 393 goto end; 394 } 395 396 /* 397 * control_register 398 */ 399 400 obj = ptc->package.elements[0]; 401 402 if ((obj.type != ACPI_TYPE_BUFFER) 403 || (obj.buffer.length < sizeof(struct acpi_ptc_register)) 404 || (obj.buffer.pointer == NULL)) { 405 printk(KERN_ERR PREFIX 406 "Invalid _PTC data (control_register)\n"); 407 result = -EFAULT; 408 goto end; 409 } 410 memcpy(&pr->throttling.control_register, obj.buffer.pointer, 411 sizeof(struct acpi_ptc_register)); 412 413 /* 414 * status_register 415 */ 416 417 obj = ptc->package.elements[1]; 418 419 if ((obj.type != ACPI_TYPE_BUFFER) 420 || (obj.buffer.length < sizeof(struct acpi_ptc_register)) 421 || (obj.buffer.pointer == NULL)) { 422 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n"); 423 result = -EFAULT; 424 goto end; 425 } 426 427 memcpy(&pr->throttling.status_register, obj.buffer.pointer, 428 sizeof(struct acpi_ptc_register)); 429 430 throttling = &pr->throttling; 431 432 if ((throttling->control_register.bit_width + 433 throttling->control_register.bit_offset) > 32) { 434 printk(KERN_ERR PREFIX "Invalid _PTC control register\n"); 435 result = -EFAULT; 436 goto end; 437 } 438 439 if ((throttling->status_register.bit_width + 440 throttling->status_register.bit_offset) > 32) { 441 printk(KERN_ERR PREFIX "Invalid _PTC status register\n"); 442 result = -EFAULT; 443 goto end; 444 } 445 446 end: 447 kfree(buffer.pointer); 448 449 return result; 450 } 451 452 /* 453 * _TSS - Throttling Supported States 454 */ 455 static int acpi_processor_get_throttling_states(struct acpi_processor *pr) 456 { 457 int result = 0; 458 acpi_status status = AE_OK; 459 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 460 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" }; 461 struct acpi_buffer state = { 0, NULL }; 462 union acpi_object *tss = NULL; 463 int i; 464 465 status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer); 466 if (ACPI_FAILURE(status)) { 467 if (status != AE_NOT_FOUND) { 468 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS")); 469 } 470 return -ENODEV; 471 } 472 473 tss = buffer.pointer; 474 if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) { 475 printk(KERN_ERR PREFIX "Invalid _TSS data\n"); 476 result = -EFAULT; 477 goto end; 478 } 479 480 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n", 481 tss->package.count)); 482 483 pr->throttling.state_count = tss->package.count; 484 pr->throttling.states_tss = 485 kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count, 486 GFP_KERNEL); 487 if (!pr->throttling.states_tss) { 488 result = -ENOMEM; 489 goto end; 490 } 491 492 for (i = 0; i < pr->throttling.state_count; i++) { 493 494 struct acpi_processor_tx_tss *tx = 495 (struct acpi_processor_tx_tss *)&(pr->throttling. 496 states_tss[i]); 497 498 state.length = sizeof(struct acpi_processor_tx_tss); 499 state.pointer = tx; 500 501 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i)); 502 503 status = acpi_extract_package(&(tss->package.elements[i]), 504 &format, &state); 505 if (ACPI_FAILURE(status)) { 506 ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data")); 507 result = -EFAULT; 508 kfree(pr->throttling.states_tss); 509 goto end; 510 } 511 512 if (!tx->freqpercentage) { 513 printk(KERN_ERR PREFIX 514 "Invalid _TSS data: freq is zero\n"); 515 result = -EFAULT; 516 kfree(pr->throttling.states_tss); 517 goto end; 518 } 519 } 520 521 end: 522 kfree(buffer.pointer); 523 524 return result; 525 } 526 527 /* 528 * _TSD - T-State Dependencies 529 */ 530 static int acpi_processor_get_tsd(struct acpi_processor *pr) 531 { 532 int result = 0; 533 acpi_status status = AE_OK; 534 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 535 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" }; 536 struct acpi_buffer state = { 0, NULL }; 537 union acpi_object *tsd = NULL; 538 struct acpi_tsd_package *pdomain; 539 struct acpi_processor_throttling *pthrottling; 540 541 pthrottling = &pr->throttling; 542 pthrottling->tsd_valid_flag = 0; 543 544 status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer); 545 if (ACPI_FAILURE(status)) { 546 if (status != AE_NOT_FOUND) { 547 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD")); 548 } 549 return -ENODEV; 550 } 551 552 tsd = buffer.pointer; 553 if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) { 554 printk(KERN_ERR PREFIX "Invalid _TSD data\n"); 555 result = -EFAULT; 556 goto end; 557 } 558 559 if (tsd->package.count != 1) { 560 printk(KERN_ERR PREFIX "Invalid _TSD data\n"); 561 result = -EFAULT; 562 goto end; 563 } 564 565 pdomain = &(pr->throttling.domain_info); 566 567 state.length = sizeof(struct acpi_tsd_package); 568 state.pointer = pdomain; 569 570 status = acpi_extract_package(&(tsd->package.elements[0]), 571 &format, &state); 572 if (ACPI_FAILURE(status)) { 573 printk(KERN_ERR PREFIX "Invalid _TSD data\n"); 574 result = -EFAULT; 575 goto end; 576 } 577 578 if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) { 579 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n"); 580 result = -EFAULT; 581 goto end; 582 } 583 584 if (pdomain->revision != ACPI_TSD_REV0_REVISION) { 585 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n"); 586 result = -EFAULT; 587 goto end; 588 } 589 590 pthrottling = &pr->throttling; 591 pthrottling->tsd_valid_flag = 1; 592 pthrottling->shared_type = pdomain->coord_type; 593 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map); 594 /* 595 * If the coordination type is not defined in ACPI spec, 596 * the tsd_valid_flag will be clear and coordination type 597 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL. 598 */ 599 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 600 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 601 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 602 pthrottling->tsd_valid_flag = 0; 603 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL; 604 } 605 606 end: 607 kfree(buffer.pointer); 608 return result; 609 } 610 611 /* -------------------------------------------------------------------------- 612 Throttling Control 613 -------------------------------------------------------------------------- */ 614 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr) 615 { 616 int state = 0; 617 u32 value = 0; 618 u32 duty_mask = 0; 619 u32 duty_value = 0; 620 621 if (!pr) 622 return -EINVAL; 623 624 if (!pr->flags.throttling) 625 return -ENODEV; 626 627 pr->throttling.state = 0; 628 629 duty_mask = pr->throttling.state_count - 1; 630 631 duty_mask <<= pr->throttling.duty_offset; 632 633 local_irq_disable(); 634 635 value = inl(pr->throttling.address); 636 637 /* 638 * Compute the current throttling state when throttling is enabled 639 * (bit 4 is on). 640 */ 641 if (value & 0x10) { 642 duty_value = value & duty_mask; 643 duty_value >>= pr->throttling.duty_offset; 644 645 if (duty_value) 646 state = pr->throttling.state_count - duty_value; 647 } 648 649 pr->throttling.state = state; 650 651 local_irq_enable(); 652 653 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 654 "Throttling state is T%d (%d%% throttling applied)\n", 655 state, pr->throttling.states[state].performance)); 656 657 return 0; 658 } 659 660 #ifdef CONFIG_X86 661 static int acpi_throttling_rdmsr(struct acpi_processor *pr, 662 acpi_integer * value) 663 { 664 struct cpuinfo_x86 *c; 665 u64 msr_high, msr_low; 666 unsigned int cpu; 667 u64 msr = 0; 668 int ret = -1; 669 670 cpu = pr->id; 671 c = &cpu_data(cpu); 672 673 if ((c->x86_vendor != X86_VENDOR_INTEL) || 674 !cpu_has(c, X86_FEATURE_ACPI)) { 675 printk(KERN_ERR PREFIX 676 "HARDWARE addr space,NOT supported yet\n"); 677 } else { 678 msr_low = 0; 679 msr_high = 0; 680 rdmsr_safe(MSR_IA32_THERM_CONTROL, 681 (u32 *)&msr_low , (u32 *) &msr_high); 682 msr = (msr_high << 32) | msr_low; 683 *value = (acpi_integer) msr; 684 ret = 0; 685 } 686 return ret; 687 } 688 689 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value) 690 { 691 struct cpuinfo_x86 *c; 692 unsigned int cpu; 693 int ret = -1; 694 u64 msr; 695 696 cpu = pr->id; 697 c = &cpu_data(cpu); 698 699 if ((c->x86_vendor != X86_VENDOR_INTEL) || 700 !cpu_has(c, X86_FEATURE_ACPI)) { 701 printk(KERN_ERR PREFIX 702 "HARDWARE addr space,NOT supported yet\n"); 703 } else { 704 msr = value; 705 wrmsr_safe(MSR_IA32_THERM_CONTROL, 706 msr & 0xffffffff, msr >> 32); 707 ret = 0; 708 } 709 return ret; 710 } 711 #else 712 static int acpi_throttling_rdmsr(struct acpi_processor *pr, 713 acpi_integer * value) 714 { 715 printk(KERN_ERR PREFIX 716 "HARDWARE addr space,NOT supported yet\n"); 717 return -1; 718 } 719 720 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value) 721 { 722 printk(KERN_ERR PREFIX 723 "HARDWARE addr space,NOT supported yet\n"); 724 return -1; 725 } 726 #endif 727 728 static int acpi_read_throttling_status(struct acpi_processor *pr, 729 acpi_integer *value) 730 { 731 u32 bit_width, bit_offset; 732 u64 ptc_value; 733 u64 ptc_mask; 734 struct acpi_processor_throttling *throttling; 735 int ret = -1; 736 737 throttling = &pr->throttling; 738 switch (throttling->status_register.space_id) { 739 case ACPI_ADR_SPACE_SYSTEM_IO: 740 ptc_value = 0; 741 bit_width = throttling->status_register.bit_width; 742 bit_offset = throttling->status_register.bit_offset; 743 744 acpi_os_read_port((acpi_io_address) throttling->status_register. 745 address, (u32 *) &ptc_value, 746 (u32) (bit_width + bit_offset)); 747 ptc_mask = (1 << bit_width) - 1; 748 *value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask); 749 ret = 0; 750 break; 751 case ACPI_ADR_SPACE_FIXED_HARDWARE: 752 ret = acpi_throttling_rdmsr(pr, value); 753 break; 754 default: 755 printk(KERN_ERR PREFIX "Unknown addr space %d\n", 756 (u32) (throttling->status_register.space_id)); 757 } 758 return ret; 759 } 760 761 static int acpi_write_throttling_state(struct acpi_processor *pr, 762 acpi_integer value) 763 { 764 u32 bit_width, bit_offset; 765 u64 ptc_value; 766 u64 ptc_mask; 767 struct acpi_processor_throttling *throttling; 768 int ret = -1; 769 770 throttling = &pr->throttling; 771 switch (throttling->control_register.space_id) { 772 case ACPI_ADR_SPACE_SYSTEM_IO: 773 bit_width = throttling->control_register.bit_width; 774 bit_offset = throttling->control_register.bit_offset; 775 ptc_mask = (1 << bit_width) - 1; 776 ptc_value = value & ptc_mask; 777 778 acpi_os_write_port((acpi_io_address) throttling-> 779 control_register.address, 780 (u32) (ptc_value << bit_offset), 781 (u32) (bit_width + bit_offset)); 782 ret = 0; 783 break; 784 case ACPI_ADR_SPACE_FIXED_HARDWARE: 785 ret = acpi_throttling_wrmsr(pr, value); 786 break; 787 default: 788 printk(KERN_ERR PREFIX "Unknown addr space %d\n", 789 (u32) (throttling->control_register.space_id)); 790 } 791 return ret; 792 } 793 794 static int acpi_get_throttling_state(struct acpi_processor *pr, 795 acpi_integer value) 796 { 797 int i; 798 799 for (i = 0; i < pr->throttling.state_count; i++) { 800 struct acpi_processor_tx_tss *tx = 801 (struct acpi_processor_tx_tss *)&(pr->throttling. 802 states_tss[i]); 803 if (tx->control == value) 804 return i; 805 } 806 return -1; 807 } 808 809 static int acpi_get_throttling_value(struct acpi_processor *pr, 810 int state, acpi_integer *value) 811 { 812 int ret = -1; 813 814 if (state >= 0 && state <= pr->throttling.state_count) { 815 struct acpi_processor_tx_tss *tx = 816 (struct acpi_processor_tx_tss *)&(pr->throttling. 817 states_tss[state]); 818 *value = tx->control; 819 ret = 0; 820 } 821 return ret; 822 } 823 824 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr) 825 { 826 int state = 0; 827 int ret; 828 acpi_integer value; 829 830 if (!pr) 831 return -EINVAL; 832 833 if (!pr->flags.throttling) 834 return -ENODEV; 835 836 pr->throttling.state = 0; 837 838 value = 0; 839 ret = acpi_read_throttling_status(pr, &value); 840 if (ret >= 0) { 841 state = acpi_get_throttling_state(pr, value); 842 if (state == -1) { 843 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 844 "Invalid throttling state, reset\n")); 845 state = 0; 846 ret = acpi_processor_set_throttling(pr, state, true); 847 if (ret) 848 return ret; 849 } 850 pr->throttling.state = state; 851 } 852 853 return 0; 854 } 855 856 static int acpi_processor_get_throttling(struct acpi_processor *pr) 857 { 858 cpumask_var_t saved_mask; 859 int ret; 860 861 if (!pr) 862 return -EINVAL; 863 864 if (!pr->flags.throttling) 865 return -ENODEV; 866 867 if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL)) 868 return -ENOMEM; 869 870 /* 871 * Migrate task to the cpu pointed by pr. 872 */ 873 cpumask_copy(saved_mask, ¤t->cpus_allowed); 874 /* FIXME: use work_on_cpu() */ 875 set_cpus_allowed_ptr(current, cpumask_of(pr->id)); 876 ret = pr->throttling.acpi_processor_get_throttling(pr); 877 /* restore the previous state */ 878 set_cpus_allowed_ptr(current, saved_mask); 879 free_cpumask_var(saved_mask); 880 881 return ret; 882 } 883 884 static int acpi_processor_get_fadt_info(struct acpi_processor *pr) 885 { 886 int i, step; 887 888 if (!pr->throttling.address) { 889 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n")); 890 return -EINVAL; 891 } else if (!pr->throttling.duty_width) { 892 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n")); 893 return -EINVAL; 894 } 895 /* TBD: Support duty_cycle values that span bit 4. */ 896 else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) { 897 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n"); 898 return -EINVAL; 899 } 900 901 pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width; 902 903 /* 904 * Compute state values. Note that throttling displays a linear power 905 * performance relationship (at 50% performance the CPU will consume 906 * 50% power). Values are in 1/10th of a percent to preserve accuracy. 907 */ 908 909 step = (1000 / pr->throttling.state_count); 910 911 for (i = 0; i < pr->throttling.state_count; i++) { 912 pr->throttling.states[i].performance = 1000 - step * i; 913 pr->throttling.states[i].power = 1000 - step * i; 914 } 915 return 0; 916 } 917 918 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr, 919 int state, bool force) 920 { 921 u32 value = 0; 922 u32 duty_mask = 0; 923 u32 duty_value = 0; 924 925 if (!pr) 926 return -EINVAL; 927 928 if ((state < 0) || (state > (pr->throttling.state_count - 1))) 929 return -EINVAL; 930 931 if (!pr->flags.throttling) 932 return -ENODEV; 933 934 if (!force && (state == pr->throttling.state)) 935 return 0; 936 937 if (state < pr->throttling_platform_limit) 938 return -EPERM; 939 /* 940 * Calculate the duty_value and duty_mask. 941 */ 942 if (state) { 943 duty_value = pr->throttling.state_count - state; 944 945 duty_value <<= pr->throttling.duty_offset; 946 947 /* Used to clear all duty_value bits */ 948 duty_mask = pr->throttling.state_count - 1; 949 950 duty_mask <<= acpi_gbl_FADT.duty_offset; 951 duty_mask = ~duty_mask; 952 } 953 954 local_irq_disable(); 955 956 /* 957 * Disable throttling by writing a 0 to bit 4. Note that we must 958 * turn it off before you can change the duty_value. 959 */ 960 value = inl(pr->throttling.address); 961 if (value & 0x10) { 962 value &= 0xFFFFFFEF; 963 outl(value, pr->throttling.address); 964 } 965 966 /* 967 * Write the new duty_value and then enable throttling. Note 968 * that a state value of 0 leaves throttling disabled. 969 */ 970 if (state) { 971 value &= duty_mask; 972 value |= duty_value; 973 outl(value, pr->throttling.address); 974 975 value |= 0x00000010; 976 outl(value, pr->throttling.address); 977 } 978 979 pr->throttling.state = state; 980 981 local_irq_enable(); 982 983 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 984 "Throttling state set to T%d (%d%%)\n", state, 985 (pr->throttling.states[state].performance ? pr-> 986 throttling.states[state].performance / 10 : 0))); 987 988 return 0; 989 } 990 991 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr, 992 int state, bool force) 993 { 994 int ret; 995 acpi_integer value; 996 997 if (!pr) 998 return -EINVAL; 999 1000 if ((state < 0) || (state > (pr->throttling.state_count - 1))) 1001 return -EINVAL; 1002 1003 if (!pr->flags.throttling) 1004 return -ENODEV; 1005 1006 if (!force && (state == pr->throttling.state)) 1007 return 0; 1008 1009 if (state < pr->throttling_platform_limit) 1010 return -EPERM; 1011 1012 value = 0; 1013 ret = acpi_get_throttling_value(pr, state, &value); 1014 if (ret >= 0) { 1015 acpi_write_throttling_state(pr, value); 1016 pr->throttling.state = state; 1017 } 1018 1019 return 0; 1020 } 1021 1022 int acpi_processor_set_throttling(struct acpi_processor *pr, 1023 int state, bool force) 1024 { 1025 cpumask_var_t saved_mask; 1026 int ret = 0; 1027 unsigned int i; 1028 struct acpi_processor *match_pr; 1029 struct acpi_processor_throttling *p_throttling; 1030 struct throttling_tstate t_state; 1031 cpumask_var_t online_throttling_cpus; 1032 1033 if (!pr) 1034 return -EINVAL; 1035 1036 if (!pr->flags.throttling) 1037 return -ENODEV; 1038 1039 if ((state < 0) || (state > (pr->throttling.state_count - 1))) 1040 return -EINVAL; 1041 1042 if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL)) 1043 return -ENOMEM; 1044 1045 if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) { 1046 free_cpumask_var(saved_mask); 1047 return -ENOMEM; 1048 } 1049 1050 cpumask_copy(saved_mask, ¤t->cpus_allowed); 1051 t_state.target_state = state; 1052 p_throttling = &(pr->throttling); 1053 cpumask_and(online_throttling_cpus, cpu_online_mask, 1054 p_throttling->shared_cpu_map); 1055 /* 1056 * The throttling notifier will be called for every 1057 * affected cpu in order to get one proper T-state. 1058 * The notifier event is THROTTLING_PRECHANGE. 1059 */ 1060 for_each_cpu(i, online_throttling_cpus) { 1061 t_state.cpu = i; 1062 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE, 1063 &t_state); 1064 } 1065 /* 1066 * The function of acpi_processor_set_throttling will be called 1067 * to switch T-state. If the coordination type is SW_ALL or HW_ALL, 1068 * it is necessary to call it for every affected cpu. Otherwise 1069 * it can be called only for the cpu pointed by pr. 1070 */ 1071 if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) { 1072 /* FIXME: use work_on_cpu() */ 1073 set_cpus_allowed_ptr(current, cpumask_of(pr->id)); 1074 ret = p_throttling->acpi_processor_set_throttling(pr, 1075 t_state.target_state, force); 1076 } else { 1077 /* 1078 * When the T-state coordination is SW_ALL or HW_ALL, 1079 * it is necessary to set T-state for every affected 1080 * cpus. 1081 */ 1082 for_each_cpu(i, online_throttling_cpus) { 1083 match_pr = per_cpu(processors, i); 1084 /* 1085 * If the pointer is invalid, we will report the 1086 * error message and continue. 1087 */ 1088 if (!match_pr) { 1089 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1090 "Invalid Pointer for CPU %d\n", i)); 1091 continue; 1092 } 1093 /* 1094 * If the throttling control is unsupported on CPU i, 1095 * we will report the error message and continue. 1096 */ 1097 if (!match_pr->flags.throttling) { 1098 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1099 "Throttling Controll is unsupported " 1100 "on CPU %d\n", i)); 1101 continue; 1102 } 1103 t_state.cpu = i; 1104 /* FIXME: use work_on_cpu() */ 1105 set_cpus_allowed_ptr(current, cpumask_of(i)); 1106 ret = match_pr->throttling. 1107 acpi_processor_set_throttling( 1108 match_pr, t_state.target_state, force); 1109 } 1110 } 1111 /* 1112 * After the set_throttling is called, the 1113 * throttling notifier is called for every 1114 * affected cpu to update the T-states. 1115 * The notifier event is THROTTLING_POSTCHANGE 1116 */ 1117 for_each_cpu(i, online_throttling_cpus) { 1118 t_state.cpu = i; 1119 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE, 1120 &t_state); 1121 } 1122 /* restore the previous state */ 1123 /* FIXME: use work_on_cpu() */ 1124 set_cpus_allowed_ptr(current, saved_mask); 1125 free_cpumask_var(online_throttling_cpus); 1126 free_cpumask_var(saved_mask); 1127 return ret; 1128 } 1129 1130 int acpi_processor_get_throttling_info(struct acpi_processor *pr) 1131 { 1132 int result = 0; 1133 struct acpi_processor_throttling *pthrottling; 1134 1135 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1136 "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n", 1137 pr->throttling.address, 1138 pr->throttling.duty_offset, 1139 pr->throttling.duty_width)); 1140 1141 if (!pr) 1142 return -EINVAL; 1143 1144 /* 1145 * Evaluate _PTC, _TSS and _TPC 1146 * They must all be present or none of them can be used. 1147 */ 1148 if (acpi_processor_get_throttling_control(pr) || 1149 acpi_processor_get_throttling_states(pr) || 1150 acpi_processor_get_platform_limit(pr)) 1151 { 1152 pr->throttling.acpi_processor_get_throttling = 1153 &acpi_processor_get_throttling_fadt; 1154 pr->throttling.acpi_processor_set_throttling = 1155 &acpi_processor_set_throttling_fadt; 1156 if (acpi_processor_get_fadt_info(pr)) 1157 return 0; 1158 } else { 1159 pr->throttling.acpi_processor_get_throttling = 1160 &acpi_processor_get_throttling_ptc; 1161 pr->throttling.acpi_processor_set_throttling = 1162 &acpi_processor_set_throttling_ptc; 1163 } 1164 1165 /* 1166 * If TSD package for one CPU can't be parsed successfully, it means 1167 * that this CPU will have no coordination with other CPUs. 1168 */ 1169 if (acpi_processor_get_tsd(pr)) { 1170 pthrottling = &pr->throttling; 1171 pthrottling->tsd_valid_flag = 0; 1172 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map); 1173 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL; 1174 } 1175 1176 /* 1177 * PIIX4 Errata: We don't support throttling on the original PIIX4. 1178 * This shouldn't be an issue as few (if any) mobile systems ever 1179 * used this part. 1180 */ 1181 if (errata.piix4.throttle) { 1182 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1183 "Throttling not supported on PIIX4 A- or B-step\n")); 1184 return 0; 1185 } 1186 1187 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n", 1188 pr->throttling.state_count)); 1189 1190 pr->flags.throttling = 1; 1191 1192 /* 1193 * Disable throttling (if enabled). We'll let subsequent policy (e.g. 1194 * thermal) decide to lower performance if it so chooses, but for now 1195 * we'll crank up the speed. 1196 */ 1197 1198 result = acpi_processor_get_throttling(pr); 1199 if (result) 1200 goto end; 1201 1202 if (pr->throttling.state) { 1203 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 1204 "Disabling throttling (was T%d)\n", 1205 pr->throttling.state)); 1206 result = acpi_processor_set_throttling(pr, 0, false); 1207 if (result) 1208 goto end; 1209 } 1210 1211 end: 1212 if (result) 1213 pr->flags.throttling = 0; 1214 1215 return result; 1216 } 1217 1218 /* proc interface */ 1219 1220 static int acpi_processor_throttling_seq_show(struct seq_file *seq, 1221 void *offset) 1222 { 1223 struct acpi_processor *pr = seq->private; 1224 int i = 0; 1225 int result = 0; 1226 1227 if (!pr) 1228 goto end; 1229 1230 if (!(pr->throttling.state_count > 0)) { 1231 seq_puts(seq, "<not supported>\n"); 1232 goto end; 1233 } 1234 1235 result = acpi_processor_get_throttling(pr); 1236 1237 if (result) { 1238 seq_puts(seq, 1239 "Could not determine current throttling state.\n"); 1240 goto end; 1241 } 1242 1243 seq_printf(seq, "state count: %d\n" 1244 "active state: T%d\n" 1245 "state available: T%d to T%d\n", 1246 pr->throttling.state_count, pr->throttling.state, 1247 pr->throttling_platform_limit, 1248 pr->throttling.state_count - 1); 1249 1250 seq_puts(seq, "states:\n"); 1251 if (pr->throttling.acpi_processor_get_throttling == 1252 acpi_processor_get_throttling_fadt) { 1253 for (i = 0; i < pr->throttling.state_count; i++) 1254 seq_printf(seq, " %cT%d: %02d%%\n", 1255 (i == pr->throttling.state ? '*' : ' '), i, 1256 (pr->throttling.states[i].performance ? pr-> 1257 throttling.states[i].performance / 10 : 0)); 1258 } else { 1259 for (i = 0; i < pr->throttling.state_count; i++) 1260 seq_printf(seq, " %cT%d: %02d%%\n", 1261 (i == pr->throttling.state ? '*' : ' '), i, 1262 (int)pr->throttling.states_tss[i]. 1263 freqpercentage); 1264 } 1265 1266 end: 1267 return 0; 1268 } 1269 1270 static int acpi_processor_throttling_open_fs(struct inode *inode, 1271 struct file *file) 1272 { 1273 return single_open(file, acpi_processor_throttling_seq_show, 1274 PDE(inode)->data); 1275 } 1276 1277 static ssize_t acpi_processor_write_throttling(struct file *file, 1278 const char __user * buffer, 1279 size_t count, loff_t * data) 1280 { 1281 int result = 0; 1282 struct seq_file *m = file->private_data; 1283 struct acpi_processor *pr = m->private; 1284 char state_string[5] = ""; 1285 char *charp = NULL; 1286 size_t state_val = 0; 1287 char tmpbuf[5] = ""; 1288 1289 if (!pr || (count > sizeof(state_string) - 1)) 1290 return -EINVAL; 1291 1292 if (copy_from_user(state_string, buffer, count)) 1293 return -EFAULT; 1294 1295 state_string[count] = '\0'; 1296 if ((count > 0) && (state_string[count-1] == '\n')) 1297 state_string[count-1] = '\0'; 1298 1299 charp = state_string; 1300 if ((state_string[0] == 't') || (state_string[0] == 'T')) 1301 charp++; 1302 1303 state_val = simple_strtoul(charp, NULL, 0); 1304 if (state_val >= pr->throttling.state_count) 1305 return -EINVAL; 1306 1307 snprintf(tmpbuf, 5, "%zu", state_val); 1308 1309 if (strcmp(tmpbuf, charp) != 0) 1310 return -EINVAL; 1311 1312 result = acpi_processor_set_throttling(pr, state_val, false); 1313 if (result) 1314 return result; 1315 1316 return count; 1317 } 1318 1319 const struct file_operations acpi_processor_throttling_fops = { 1320 .owner = THIS_MODULE, 1321 .open = acpi_processor_throttling_open_fs, 1322 .read = seq_read, 1323 .write = acpi_processor_write_throttling, 1324 .llseek = seq_lseek, 1325 .release = single_release, 1326 }; 1327