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 /* ignore_tpc: 26 * 0 -> acpi processor driver doesn't ignore _TPC values 27 * 1 -> acpi processor driver ignores _TPC values 28 */ 29 static int ignore_tpc; 30 module_param(ignore_tpc, int, 0644); 31 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support"); 32 33 struct throttling_tstate { 34 unsigned int cpu; /* cpu nr */ 35 int target_state; /* target T-state */ 36 }; 37 38 struct acpi_processor_throttling_arg { 39 struct acpi_processor *pr; 40 int target_state; 41 bool force; 42 }; 43 44 #define THROTTLING_PRECHANGE (1) 45 #define THROTTLING_POSTCHANGE (2) 46 47 static int acpi_processor_get_throttling(struct acpi_processor *pr); 48 static int __acpi_processor_set_throttling(struct acpi_processor *pr, 49 int state, bool force, bool direct); 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_var_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 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 62 return -ENOMEM; 63 64 /* 65 * Now that we have _TSD data from all CPUs, lets setup T-state 66 * coordination between all CPUs. 67 */ 68 for_each_possible_cpu(i) { 69 pr = per_cpu(processors, i); 70 if (!pr) 71 continue; 72 73 /* Basic validity check for domain info */ 74 pthrottling = &(pr->throttling); 75 76 /* 77 * If tsd package for one cpu is invalid, the coordination 78 * among all CPUs is thought as invalid. 79 * Maybe it is ugly. 80 */ 81 if (!pthrottling->tsd_valid_flag) { 82 retval = -EINVAL; 83 break; 84 } 85 } 86 if (retval) 87 goto err_ret; 88 89 for_each_possible_cpu(i) { 90 pr = per_cpu(processors, i); 91 if (!pr) 92 continue; 93 94 if (cpumask_test_cpu(i, covered_cpus)) 95 continue; 96 pthrottling = &pr->throttling; 97 98 pdomain = &(pthrottling->domain_info); 99 cpumask_set_cpu(i, pthrottling->shared_cpu_map); 100 cpumask_set_cpu(i, covered_cpus); 101 /* 102 * If the number of processor in the TSD domain is 1, it is 103 * unnecessary to parse the coordination for this CPU. 104 */ 105 if (pdomain->num_processors <= 1) 106 continue; 107 108 /* Validate the Domain info */ 109 count_target = pdomain->num_processors; 110 count = 1; 111 112 for_each_possible_cpu(j) { 113 if (i == j) 114 continue; 115 116 match_pr = per_cpu(processors, j); 117 if (!match_pr) 118 continue; 119 120 match_pthrottling = &(match_pr->throttling); 121 match_pdomain = &(match_pthrottling->domain_info); 122 if (match_pdomain->domain != pdomain->domain) 123 continue; 124 125 /* Here i and j are in the same domain. 126 * If two TSD packages have the same domain, they 127 * should have the same num_porcessors and 128 * coordination type. Otherwise it will be regarded 129 * as illegal. 130 */ 131 if (match_pdomain->num_processors != count_target) { 132 retval = -EINVAL; 133 goto err_ret; 134 } 135 136 if (pdomain->coord_type != match_pdomain->coord_type) { 137 retval = -EINVAL; 138 goto err_ret; 139 } 140 141 cpumask_set_cpu(j, covered_cpus); 142 cpumask_set_cpu(j, pthrottling->shared_cpu_map); 143 count++; 144 } 145 for_each_possible_cpu(j) { 146 if (i == j) 147 continue; 148 149 match_pr = per_cpu(processors, j); 150 if (!match_pr) 151 continue; 152 153 match_pthrottling = &(match_pr->throttling); 154 match_pdomain = &(match_pthrottling->domain_info); 155 if (match_pdomain->domain != pdomain->domain) 156 continue; 157 158 /* 159 * If some CPUS have the same domain, they 160 * will have the same shared_cpu_map. 161 */ 162 cpumask_copy(match_pthrottling->shared_cpu_map, 163 pthrottling->shared_cpu_map); 164 } 165 } 166 167 err_ret: 168 free_cpumask_var(covered_cpus); 169 170 for_each_possible_cpu(i) { 171 pr = per_cpu(processors, i); 172 if (!pr) 173 continue; 174 175 /* 176 * Assume no coordination on any error parsing domain info. 177 * The coordination type will be forced as SW_ALL. 178 */ 179 if (retval) { 180 pthrottling = &(pr->throttling); 181 cpumask_clear(pthrottling->shared_cpu_map); 182 cpumask_set_cpu(i, pthrottling->shared_cpu_map); 183 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL; 184 } 185 } 186 187 return retval; 188 } 189 190 /* 191 * Update the T-state coordination after the _TSD 192 * data for all cpus is obtained. 193 */ 194 void acpi_processor_throttling_init(void) 195 { 196 if (acpi_processor_update_tsd_coord()) 197 pr_debug("Assume no T-state coordination\n"); 198 199 return; 200 } 201 202 static int acpi_processor_throttling_notifier(unsigned long event, void *data) 203 { 204 struct throttling_tstate *p_tstate = data; 205 struct acpi_processor *pr; 206 unsigned int cpu ; 207 int target_state; 208 struct acpi_processor_limit *p_limit; 209 struct acpi_processor_throttling *p_throttling; 210 211 cpu = p_tstate->cpu; 212 pr = per_cpu(processors, cpu); 213 if (!pr) { 214 pr_debug("Invalid pr pointer\n"); 215 return 0; 216 } 217 if (!pr->flags.throttling) { 218 acpi_handle_debug(pr->handle, 219 "Throttling control unsupported on CPU %d\n", 220 cpu); 221 return 0; 222 } 223 target_state = p_tstate->target_state; 224 p_throttling = &(pr->throttling); 225 switch (event) { 226 case THROTTLING_PRECHANGE: 227 /* 228 * Prechange event is used to choose one proper t-state, 229 * which meets the limits of thermal, user and _TPC. 230 */ 231 p_limit = &pr->limit; 232 if (p_limit->thermal.tx > target_state) 233 target_state = p_limit->thermal.tx; 234 if (p_limit->user.tx > target_state) 235 target_state = p_limit->user.tx; 236 if (pr->throttling_platform_limit > target_state) 237 target_state = pr->throttling_platform_limit; 238 if (target_state >= p_throttling->state_count) { 239 printk(KERN_WARNING 240 "Exceed the limit of T-state \n"); 241 target_state = p_throttling->state_count - 1; 242 } 243 p_tstate->target_state = target_state; 244 acpi_handle_debug(pr->handle, 245 "PreChange Event: target T-state of CPU %d is T%d\n", 246 cpu, target_state); 247 break; 248 case THROTTLING_POSTCHANGE: 249 /* 250 * Postchange event is only used to update the 251 * T-state flag of acpi_processor_throttling. 252 */ 253 p_throttling->state = target_state; 254 acpi_handle_debug(pr->handle, 255 "PostChange Event: CPU %d is switched to T%d\n", 256 cpu, target_state); 257 break; 258 default: 259 printk(KERN_WARNING 260 "Unsupported Throttling notifier event\n"); 261 break; 262 } 263 264 return 0; 265 } 266 267 /* 268 * _TPC - Throttling Present Capabilities 269 */ 270 static int acpi_processor_get_platform_limit(struct acpi_processor *pr) 271 { 272 acpi_status status = 0; 273 unsigned long long tpc = 0; 274 275 if (!pr) 276 return -EINVAL; 277 278 if (ignore_tpc) 279 goto end; 280 281 status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc); 282 if (ACPI_FAILURE(status)) { 283 if (status != AE_NOT_FOUND) 284 acpi_evaluation_failure_warn(pr->handle, "_TPC", status); 285 286 return -ENODEV; 287 } 288 289 end: 290 pr->throttling_platform_limit = (int)tpc; 291 return 0; 292 } 293 294 int acpi_processor_tstate_has_changed(struct acpi_processor *pr) 295 { 296 int result = 0; 297 int throttling_limit; 298 int current_state; 299 struct acpi_processor_limit *limit; 300 int target_state; 301 302 if (ignore_tpc) 303 return 0; 304 305 result = acpi_processor_get_platform_limit(pr); 306 if (result) { 307 /* Throttling Limit is unsupported */ 308 return result; 309 } 310 311 throttling_limit = pr->throttling_platform_limit; 312 if (throttling_limit >= pr->throttling.state_count) { 313 /* Uncorrect Throttling Limit */ 314 return -EINVAL; 315 } 316 317 current_state = pr->throttling.state; 318 if (current_state > throttling_limit) { 319 /* 320 * The current state can meet the requirement of 321 * _TPC limit. But it is reasonable that OSPM changes 322 * t-states from high to low for better performance. 323 * Of course the limit condition of thermal 324 * and user should be considered. 325 */ 326 limit = &pr->limit; 327 target_state = throttling_limit; 328 if (limit->thermal.tx > target_state) 329 target_state = limit->thermal.tx; 330 if (limit->user.tx > target_state) 331 target_state = limit->user.tx; 332 } else if (current_state == throttling_limit) { 333 /* 334 * Unnecessary to change the throttling state 335 */ 336 return 0; 337 } else { 338 /* 339 * If the current state is lower than the limit of _TPC, it 340 * will be forced to switch to the throttling state defined 341 * by throttling_platfor_limit. 342 * Because the previous state meets with the limit condition 343 * of thermal and user, it is unnecessary to check it again. 344 */ 345 target_state = throttling_limit; 346 } 347 return acpi_processor_set_throttling(pr, target_state, false); 348 } 349 350 /* 351 * This function is used to reevaluate whether the T-state is valid 352 * after one CPU is onlined/offlined. 353 * It is noted that it won't reevaluate the following properties for 354 * the T-state. 355 * 1. Control method. 356 * 2. the number of supported T-state 357 * 3. TSD domain 358 */ 359 void acpi_processor_reevaluate_tstate(struct acpi_processor *pr, 360 bool is_dead) 361 { 362 int result = 0; 363 364 if (is_dead) { 365 /* When one CPU is offline, the T-state throttling 366 * will be invalidated. 367 */ 368 pr->flags.throttling = 0; 369 return; 370 } 371 /* the following is to recheck whether the T-state is valid for 372 * the online CPU 373 */ 374 if (!pr->throttling.state_count) { 375 /* If the number of T-state is invalid, it is 376 * invalidated. 377 */ 378 pr->flags.throttling = 0; 379 return; 380 } 381 pr->flags.throttling = 1; 382 383 /* Disable throttling (if enabled). We'll let subsequent 384 * policy (e.g.thermal) decide to lower performance if it 385 * so chooses, but for now we'll crank up the speed. 386 */ 387 388 result = acpi_processor_get_throttling(pr); 389 if (result) 390 goto end; 391 392 if (pr->throttling.state) { 393 result = acpi_processor_set_throttling(pr, 0, false); 394 if (result) 395 goto end; 396 } 397 398 end: 399 if (result) 400 pr->flags.throttling = 0; 401 } 402 /* 403 * _PTC - Processor Throttling Control (and status) register location 404 */ 405 static int acpi_processor_get_throttling_control(struct acpi_processor *pr) 406 { 407 int result = 0; 408 acpi_status status = 0; 409 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 410 union acpi_object *ptc = NULL; 411 union acpi_object obj = { 0 }; 412 struct acpi_processor_throttling *throttling; 413 414 status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer); 415 if (ACPI_FAILURE(status)) { 416 if (status != AE_NOT_FOUND) 417 acpi_evaluation_failure_warn(pr->handle, "_PTC", status); 418 419 return -ENODEV; 420 } 421 422 ptc = (union acpi_object *)buffer.pointer; 423 if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE) 424 || (ptc->package.count != 2)) { 425 printk(KERN_ERR PREFIX "Invalid _PTC data\n"); 426 result = -EFAULT; 427 goto end; 428 } 429 430 /* 431 * control_register 432 */ 433 434 obj = ptc->package.elements[0]; 435 436 if ((obj.type != ACPI_TYPE_BUFFER) 437 || (obj.buffer.length < sizeof(struct acpi_ptc_register)) 438 || (obj.buffer.pointer == NULL)) { 439 printk(KERN_ERR PREFIX 440 "Invalid _PTC data (control_register)\n"); 441 result = -EFAULT; 442 goto end; 443 } 444 memcpy(&pr->throttling.control_register, obj.buffer.pointer, 445 sizeof(struct acpi_ptc_register)); 446 447 /* 448 * status_register 449 */ 450 451 obj = ptc->package.elements[1]; 452 453 if ((obj.type != ACPI_TYPE_BUFFER) 454 || (obj.buffer.length < sizeof(struct acpi_ptc_register)) 455 || (obj.buffer.pointer == NULL)) { 456 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n"); 457 result = -EFAULT; 458 goto end; 459 } 460 461 memcpy(&pr->throttling.status_register, obj.buffer.pointer, 462 sizeof(struct acpi_ptc_register)); 463 464 throttling = &pr->throttling; 465 466 if ((throttling->control_register.bit_width + 467 throttling->control_register.bit_offset) > 32) { 468 printk(KERN_ERR PREFIX "Invalid _PTC control register\n"); 469 result = -EFAULT; 470 goto end; 471 } 472 473 if ((throttling->status_register.bit_width + 474 throttling->status_register.bit_offset) > 32) { 475 printk(KERN_ERR PREFIX "Invalid _PTC status register\n"); 476 result = -EFAULT; 477 goto end; 478 } 479 480 end: 481 kfree(buffer.pointer); 482 483 return result; 484 } 485 486 /* 487 * _TSS - Throttling Supported States 488 */ 489 static int acpi_processor_get_throttling_states(struct acpi_processor *pr) 490 { 491 int result = 0; 492 acpi_status status = AE_OK; 493 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 494 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" }; 495 struct acpi_buffer state = { 0, NULL }; 496 union acpi_object *tss = NULL; 497 int i; 498 499 status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer); 500 if (ACPI_FAILURE(status)) { 501 if (status != AE_NOT_FOUND) 502 acpi_evaluation_failure_warn(pr->handle, "_TSS", status); 503 504 return -ENODEV; 505 } 506 507 tss = buffer.pointer; 508 if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) { 509 printk(KERN_ERR PREFIX "Invalid _TSS data\n"); 510 result = -EFAULT; 511 goto end; 512 } 513 514 acpi_handle_debug(pr->handle, "Found %d throttling states\n", 515 tss->package.count); 516 517 pr->throttling.state_count = tss->package.count; 518 pr->throttling.states_tss = 519 kmalloc_array(tss->package.count, 520 sizeof(struct acpi_processor_tx_tss), 521 GFP_KERNEL); 522 if (!pr->throttling.states_tss) { 523 result = -ENOMEM; 524 goto end; 525 } 526 527 for (i = 0; i < pr->throttling.state_count; i++) { 528 529 struct acpi_processor_tx_tss *tx = 530 (struct acpi_processor_tx_tss *)&(pr->throttling. 531 states_tss[i]); 532 533 state.length = sizeof(struct acpi_processor_tx_tss); 534 state.pointer = tx; 535 536 acpi_handle_debug(pr->handle, "Extracting state %d\n", i); 537 538 status = acpi_extract_package(&(tss->package.elements[i]), 539 &format, &state); 540 if (ACPI_FAILURE(status)) { 541 acpi_handle_warn(pr->handle, "Invalid _TSS data: %s\n", 542 acpi_format_exception(status)); 543 result = -EFAULT; 544 kfree(pr->throttling.states_tss); 545 goto end; 546 } 547 548 if (!tx->freqpercentage) { 549 printk(KERN_ERR PREFIX 550 "Invalid _TSS data: freq is zero\n"); 551 result = -EFAULT; 552 kfree(pr->throttling.states_tss); 553 goto end; 554 } 555 } 556 557 end: 558 kfree(buffer.pointer); 559 560 return result; 561 } 562 563 /* 564 * _TSD - T-State Dependencies 565 */ 566 static int acpi_processor_get_tsd(struct acpi_processor *pr) 567 { 568 int result = 0; 569 acpi_status status = AE_OK; 570 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 571 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" }; 572 struct acpi_buffer state = { 0, NULL }; 573 union acpi_object *tsd = NULL; 574 struct acpi_tsd_package *pdomain; 575 struct acpi_processor_throttling *pthrottling; 576 577 pthrottling = &pr->throttling; 578 pthrottling->tsd_valid_flag = 0; 579 580 status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer); 581 if (ACPI_FAILURE(status)) { 582 if (status != AE_NOT_FOUND) 583 acpi_evaluation_failure_warn(pr->handle, "_TSD", status); 584 585 return -ENODEV; 586 } 587 588 tsd = buffer.pointer; 589 if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) { 590 printk(KERN_ERR PREFIX "Invalid _TSD data\n"); 591 result = -EFAULT; 592 goto end; 593 } 594 595 if (tsd->package.count != 1) { 596 printk(KERN_ERR PREFIX "Invalid _TSD data\n"); 597 result = -EFAULT; 598 goto end; 599 } 600 601 pdomain = &(pr->throttling.domain_info); 602 603 state.length = sizeof(struct acpi_tsd_package); 604 state.pointer = pdomain; 605 606 status = acpi_extract_package(&(tsd->package.elements[0]), 607 &format, &state); 608 if (ACPI_FAILURE(status)) { 609 printk(KERN_ERR PREFIX "Invalid _TSD data\n"); 610 result = -EFAULT; 611 goto end; 612 } 613 614 if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) { 615 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n"); 616 result = -EFAULT; 617 goto end; 618 } 619 620 if (pdomain->revision != ACPI_TSD_REV0_REVISION) { 621 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n"); 622 result = -EFAULT; 623 goto end; 624 } 625 626 pthrottling = &pr->throttling; 627 pthrottling->tsd_valid_flag = 1; 628 pthrottling->shared_type = pdomain->coord_type; 629 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map); 630 /* 631 * If the coordination type is not defined in ACPI spec, 632 * the tsd_valid_flag will be clear and coordination type 633 * will be forecd as DOMAIN_COORD_TYPE_SW_ALL. 634 */ 635 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 636 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 637 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 638 pthrottling->tsd_valid_flag = 0; 639 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL; 640 } 641 642 end: 643 kfree(buffer.pointer); 644 return result; 645 } 646 647 /* -------------------------------------------------------------------------- 648 Throttling Control 649 -------------------------------------------------------------------------- */ 650 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr) 651 { 652 int state = 0; 653 u32 value = 0; 654 u32 duty_mask = 0; 655 u32 duty_value = 0; 656 657 if (!pr) 658 return -EINVAL; 659 660 if (!pr->flags.throttling) 661 return -ENODEV; 662 663 /* 664 * We don't care about error returns - we just try to mark 665 * these reserved so that nobody else is confused into thinking 666 * that this region might be unused.. 667 * 668 * (In particular, allocating the IO range for Cardbus) 669 */ 670 request_region(pr->throttling.address, 6, "ACPI CPU throttle"); 671 672 pr->throttling.state = 0; 673 674 duty_mask = pr->throttling.state_count - 1; 675 676 duty_mask <<= pr->throttling.duty_offset; 677 678 local_irq_disable(); 679 680 value = inl(pr->throttling.address); 681 682 /* 683 * Compute the current throttling state when throttling is enabled 684 * (bit 4 is on). 685 */ 686 if (value & 0x10) { 687 duty_value = value & duty_mask; 688 duty_value >>= pr->throttling.duty_offset; 689 690 if (duty_value) 691 state = pr->throttling.state_count - duty_value; 692 } 693 694 pr->throttling.state = state; 695 696 local_irq_enable(); 697 698 acpi_handle_debug(pr->handle, 699 "Throttling state is T%d (%d%% throttling applied)\n", 700 state, pr->throttling.states[state].performance); 701 702 return 0; 703 } 704 705 #ifdef CONFIG_X86 706 static int acpi_throttling_rdmsr(u64 *value) 707 { 708 u64 msr_high, msr_low; 709 u64 msr = 0; 710 int ret = -1; 711 712 if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) || 713 !this_cpu_has(X86_FEATURE_ACPI)) { 714 printk(KERN_ERR PREFIX 715 "HARDWARE addr space,NOT supported yet\n"); 716 } else { 717 msr_low = 0; 718 msr_high = 0; 719 rdmsr_safe(MSR_IA32_THERM_CONTROL, 720 (u32 *)&msr_low , (u32 *) &msr_high); 721 msr = (msr_high << 32) | msr_low; 722 *value = (u64) msr; 723 ret = 0; 724 } 725 return ret; 726 } 727 728 static int acpi_throttling_wrmsr(u64 value) 729 { 730 int ret = -1; 731 u64 msr; 732 733 if ((this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_INTEL) || 734 !this_cpu_has(X86_FEATURE_ACPI)) { 735 printk(KERN_ERR PREFIX 736 "HARDWARE addr space,NOT supported yet\n"); 737 } else { 738 msr = value; 739 wrmsr_safe(MSR_IA32_THERM_CONTROL, 740 msr & 0xffffffff, msr >> 32); 741 ret = 0; 742 } 743 return ret; 744 } 745 #else 746 static int acpi_throttling_rdmsr(u64 *value) 747 { 748 printk(KERN_ERR PREFIX 749 "HARDWARE addr space,NOT supported yet\n"); 750 return -1; 751 } 752 753 static int acpi_throttling_wrmsr(u64 value) 754 { 755 printk(KERN_ERR PREFIX 756 "HARDWARE addr space,NOT supported yet\n"); 757 return -1; 758 } 759 #endif 760 761 static int acpi_read_throttling_status(struct acpi_processor *pr, 762 u64 *value) 763 { 764 u32 bit_width, bit_offset; 765 u32 ptc_value; 766 u64 ptc_mask; 767 struct acpi_processor_throttling *throttling; 768 int ret = -1; 769 770 throttling = &pr->throttling; 771 switch (throttling->status_register.space_id) { 772 case ACPI_ADR_SPACE_SYSTEM_IO: 773 bit_width = throttling->status_register.bit_width; 774 bit_offset = throttling->status_register.bit_offset; 775 776 acpi_os_read_port((acpi_io_address) throttling->status_register. 777 address, &ptc_value, 778 (u32) (bit_width + bit_offset)); 779 ptc_mask = (1 << bit_width) - 1; 780 *value = (u64) ((ptc_value >> bit_offset) & ptc_mask); 781 ret = 0; 782 break; 783 case ACPI_ADR_SPACE_FIXED_HARDWARE: 784 ret = acpi_throttling_rdmsr(value); 785 break; 786 default: 787 printk(KERN_ERR PREFIX "Unknown addr space %d\n", 788 (u32) (throttling->status_register.space_id)); 789 } 790 return ret; 791 } 792 793 static int acpi_write_throttling_state(struct acpi_processor *pr, 794 u64 value) 795 { 796 u32 bit_width, bit_offset; 797 u64 ptc_value; 798 u64 ptc_mask; 799 struct acpi_processor_throttling *throttling; 800 int ret = -1; 801 802 throttling = &pr->throttling; 803 switch (throttling->control_register.space_id) { 804 case ACPI_ADR_SPACE_SYSTEM_IO: 805 bit_width = throttling->control_register.bit_width; 806 bit_offset = throttling->control_register.bit_offset; 807 ptc_mask = (1 << bit_width) - 1; 808 ptc_value = value & ptc_mask; 809 810 acpi_os_write_port((acpi_io_address) throttling-> 811 control_register.address, 812 (u32) (ptc_value << bit_offset), 813 (u32) (bit_width + bit_offset)); 814 ret = 0; 815 break; 816 case ACPI_ADR_SPACE_FIXED_HARDWARE: 817 ret = acpi_throttling_wrmsr(value); 818 break; 819 default: 820 printk(KERN_ERR PREFIX "Unknown addr space %d\n", 821 (u32) (throttling->control_register.space_id)); 822 } 823 return ret; 824 } 825 826 static int acpi_get_throttling_state(struct acpi_processor *pr, 827 u64 value) 828 { 829 int i; 830 831 for (i = 0; i < pr->throttling.state_count; i++) { 832 struct acpi_processor_tx_tss *tx = 833 (struct acpi_processor_tx_tss *)&(pr->throttling. 834 states_tss[i]); 835 if (tx->control == value) 836 return i; 837 } 838 return -1; 839 } 840 841 static int acpi_get_throttling_value(struct acpi_processor *pr, 842 int state, u64 *value) 843 { 844 int ret = -1; 845 846 if (state >= 0 && state <= pr->throttling.state_count) { 847 struct acpi_processor_tx_tss *tx = 848 (struct acpi_processor_tx_tss *)&(pr->throttling. 849 states_tss[state]); 850 *value = tx->control; 851 ret = 0; 852 } 853 return ret; 854 } 855 856 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr) 857 { 858 int state = 0; 859 int ret; 860 u64 value; 861 862 if (!pr) 863 return -EINVAL; 864 865 if (!pr->flags.throttling) 866 return -ENODEV; 867 868 pr->throttling.state = 0; 869 870 value = 0; 871 ret = acpi_read_throttling_status(pr, &value); 872 if (ret >= 0) { 873 state = acpi_get_throttling_state(pr, value); 874 if (state == -1) { 875 acpi_handle_debug(pr->handle, 876 "Invalid throttling state, reset\n"); 877 state = 0; 878 ret = __acpi_processor_set_throttling(pr, state, true, 879 true); 880 if (ret) 881 return ret; 882 } 883 pr->throttling.state = state; 884 } 885 886 return 0; 887 } 888 889 static long __acpi_processor_get_throttling(void *data) 890 { 891 struct acpi_processor *pr = data; 892 893 return pr->throttling.acpi_processor_get_throttling(pr); 894 } 895 896 static int acpi_processor_get_throttling(struct acpi_processor *pr) 897 { 898 if (!pr) 899 return -EINVAL; 900 901 if (!pr->flags.throttling) 902 return -ENODEV; 903 904 /* 905 * This is either called from the CPU hotplug callback of 906 * processor_driver or via the ACPI probe function. In the latter 907 * case the CPU is not guaranteed to be online. Both call sites are 908 * protected against CPU hotplug. 909 */ 910 if (!cpu_online(pr->id)) 911 return -ENODEV; 912 913 return call_on_cpu(pr->id, __acpi_processor_get_throttling, pr, false); 914 } 915 916 static int acpi_processor_get_fadt_info(struct acpi_processor *pr) 917 { 918 int i, step; 919 920 if (!pr->throttling.address) { 921 acpi_handle_debug(pr->handle, "No throttling register\n"); 922 return -EINVAL; 923 } else if (!pr->throttling.duty_width) { 924 acpi_handle_debug(pr->handle, "No throttling states\n"); 925 return -EINVAL; 926 } 927 /* TBD: Support duty_cycle values that span bit 4. */ 928 else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) { 929 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n"); 930 return -EINVAL; 931 } 932 933 pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width; 934 935 /* 936 * Compute state values. Note that throttling displays a linear power 937 * performance relationship (at 50% performance the CPU will consume 938 * 50% power). Values are in 1/10th of a percent to preserve accuracy. 939 */ 940 941 step = (1000 / pr->throttling.state_count); 942 943 for (i = 0; i < pr->throttling.state_count; i++) { 944 pr->throttling.states[i].performance = 1000 - step * i; 945 pr->throttling.states[i].power = 1000 - step * i; 946 } 947 return 0; 948 } 949 950 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr, 951 int state, bool force) 952 { 953 u32 value = 0; 954 u32 duty_mask = 0; 955 u32 duty_value = 0; 956 957 if (!pr) 958 return -EINVAL; 959 960 if ((state < 0) || (state > (pr->throttling.state_count - 1))) 961 return -EINVAL; 962 963 if (!pr->flags.throttling) 964 return -ENODEV; 965 966 if (!force && (state == pr->throttling.state)) 967 return 0; 968 969 if (state < pr->throttling_platform_limit) 970 return -EPERM; 971 /* 972 * Calculate the duty_value and duty_mask. 973 */ 974 if (state) { 975 duty_value = pr->throttling.state_count - state; 976 977 duty_value <<= pr->throttling.duty_offset; 978 979 /* Used to clear all duty_value bits */ 980 duty_mask = pr->throttling.state_count - 1; 981 982 duty_mask <<= acpi_gbl_FADT.duty_offset; 983 duty_mask = ~duty_mask; 984 } 985 986 local_irq_disable(); 987 988 /* 989 * Disable throttling by writing a 0 to bit 4. Note that we must 990 * turn it off before you can change the duty_value. 991 */ 992 value = inl(pr->throttling.address); 993 if (value & 0x10) { 994 value &= 0xFFFFFFEF; 995 outl(value, pr->throttling.address); 996 } 997 998 /* 999 * Write the new duty_value and then enable throttling. Note 1000 * that a state value of 0 leaves throttling disabled. 1001 */ 1002 if (state) { 1003 value &= duty_mask; 1004 value |= duty_value; 1005 outl(value, pr->throttling.address); 1006 1007 value |= 0x00000010; 1008 outl(value, pr->throttling.address); 1009 } 1010 1011 pr->throttling.state = state; 1012 1013 local_irq_enable(); 1014 1015 acpi_handle_debug(pr->handle, 1016 "Throttling state set to T%d (%d%%)\n", state, 1017 (pr->throttling.states[state].performance ? pr-> 1018 throttling.states[state].performance / 10 : 0)); 1019 1020 return 0; 1021 } 1022 1023 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr, 1024 int state, bool force) 1025 { 1026 int ret; 1027 u64 value; 1028 1029 if (!pr) 1030 return -EINVAL; 1031 1032 if ((state < 0) || (state > (pr->throttling.state_count - 1))) 1033 return -EINVAL; 1034 1035 if (!pr->flags.throttling) 1036 return -ENODEV; 1037 1038 if (!force && (state == pr->throttling.state)) 1039 return 0; 1040 1041 if (state < pr->throttling_platform_limit) 1042 return -EPERM; 1043 1044 value = 0; 1045 ret = acpi_get_throttling_value(pr, state, &value); 1046 if (ret >= 0) { 1047 acpi_write_throttling_state(pr, value); 1048 pr->throttling.state = state; 1049 } 1050 1051 return 0; 1052 } 1053 1054 static long acpi_processor_throttling_fn(void *data) 1055 { 1056 struct acpi_processor_throttling_arg *arg = data; 1057 struct acpi_processor *pr = arg->pr; 1058 1059 return pr->throttling.acpi_processor_set_throttling(pr, 1060 arg->target_state, arg->force); 1061 } 1062 1063 static int __acpi_processor_set_throttling(struct acpi_processor *pr, 1064 int state, bool force, bool direct) 1065 { 1066 int ret = 0; 1067 unsigned int i; 1068 struct acpi_processor *match_pr; 1069 struct acpi_processor_throttling *p_throttling; 1070 struct acpi_processor_throttling_arg arg; 1071 struct throttling_tstate t_state; 1072 1073 if (!pr) 1074 return -EINVAL; 1075 1076 if (!pr->flags.throttling) 1077 return -ENODEV; 1078 1079 if ((state < 0) || (state > (pr->throttling.state_count - 1))) 1080 return -EINVAL; 1081 1082 if (cpu_is_offline(pr->id)) { 1083 /* 1084 * the cpu pointed by pr->id is offline. Unnecessary to change 1085 * the throttling state any more. 1086 */ 1087 return -ENODEV; 1088 } 1089 1090 t_state.target_state = state; 1091 p_throttling = &(pr->throttling); 1092 1093 /* 1094 * The throttling notifier will be called for every 1095 * affected cpu in order to get one proper T-state. 1096 * The notifier event is THROTTLING_PRECHANGE. 1097 */ 1098 for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) { 1099 t_state.cpu = i; 1100 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE, 1101 &t_state); 1102 } 1103 /* 1104 * The function of acpi_processor_set_throttling will be called 1105 * to switch T-state. If the coordination type is SW_ALL or HW_ALL, 1106 * it is necessary to call it for every affected cpu. Otherwise 1107 * it can be called only for the cpu pointed by pr. 1108 */ 1109 if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) { 1110 arg.pr = pr; 1111 arg.target_state = state; 1112 arg.force = force; 1113 ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, &arg, 1114 direct); 1115 } else { 1116 /* 1117 * When the T-state coordination is SW_ALL or HW_ALL, 1118 * it is necessary to set T-state for every affected 1119 * cpus. 1120 */ 1121 for_each_cpu_and(i, cpu_online_mask, 1122 p_throttling->shared_cpu_map) { 1123 match_pr = per_cpu(processors, i); 1124 /* 1125 * If the pointer is invalid, we will report the 1126 * error message and continue. 1127 */ 1128 if (!match_pr) { 1129 acpi_handle_debug(pr->handle, 1130 "Invalid Pointer for CPU %d\n", i); 1131 continue; 1132 } 1133 /* 1134 * If the throttling control is unsupported on CPU i, 1135 * we will report the error message and continue. 1136 */ 1137 if (!match_pr->flags.throttling) { 1138 acpi_handle_debug(pr->handle, 1139 "Throttling Control unsupported on CPU %d\n", i); 1140 continue; 1141 } 1142 1143 arg.pr = match_pr; 1144 arg.target_state = state; 1145 arg.force = force; 1146 ret = call_on_cpu(pr->id, acpi_processor_throttling_fn, 1147 &arg, direct); 1148 } 1149 } 1150 /* 1151 * After the set_throttling is called, the 1152 * throttling notifier is called for every 1153 * affected cpu to update the T-states. 1154 * The notifier event is THROTTLING_POSTCHANGE 1155 */ 1156 for_each_cpu_and(i, cpu_online_mask, p_throttling->shared_cpu_map) { 1157 t_state.cpu = i; 1158 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE, 1159 &t_state); 1160 } 1161 1162 return ret; 1163 } 1164 1165 int acpi_processor_set_throttling(struct acpi_processor *pr, int state, 1166 bool force) 1167 { 1168 return __acpi_processor_set_throttling(pr, state, force, false); 1169 } 1170 1171 int acpi_processor_get_throttling_info(struct acpi_processor *pr) 1172 { 1173 int result = 0; 1174 struct acpi_processor_throttling *pthrottling; 1175 1176 acpi_handle_debug(pr->handle, 1177 "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n", 1178 pr->throttling.address, 1179 pr->throttling.duty_offset, 1180 pr->throttling.duty_width); 1181 1182 /* 1183 * Evaluate _PTC, _TSS and _TPC 1184 * They must all be present or none of them can be used. 1185 */ 1186 if (acpi_processor_get_throttling_control(pr) || 1187 acpi_processor_get_throttling_states(pr) || 1188 acpi_processor_get_platform_limit(pr)) 1189 { 1190 pr->throttling.acpi_processor_get_throttling = 1191 &acpi_processor_get_throttling_fadt; 1192 pr->throttling.acpi_processor_set_throttling = 1193 &acpi_processor_set_throttling_fadt; 1194 if (acpi_processor_get_fadt_info(pr)) 1195 return 0; 1196 } else { 1197 pr->throttling.acpi_processor_get_throttling = 1198 &acpi_processor_get_throttling_ptc; 1199 pr->throttling.acpi_processor_set_throttling = 1200 &acpi_processor_set_throttling_ptc; 1201 } 1202 1203 /* 1204 * If TSD package for one CPU can't be parsed successfully, it means 1205 * that this CPU will have no coordination with other CPUs. 1206 */ 1207 if (acpi_processor_get_tsd(pr)) { 1208 pthrottling = &pr->throttling; 1209 pthrottling->tsd_valid_flag = 0; 1210 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map); 1211 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL; 1212 } 1213 1214 /* 1215 * PIIX4 Errata: We don't support throttling on the original PIIX4. 1216 * This shouldn't be an issue as few (if any) mobile systems ever 1217 * used this part. 1218 */ 1219 if (errata.piix4.throttle) { 1220 acpi_handle_debug(pr->handle, 1221 "Throttling not supported on PIIX4 A- or B-step\n"); 1222 return 0; 1223 } 1224 1225 acpi_handle_debug(pr->handle, "Found %d throttling states\n", 1226 pr->throttling.state_count); 1227 1228 pr->flags.throttling = 1; 1229 1230 /* 1231 * Disable throttling (if enabled). We'll let subsequent policy (e.g. 1232 * thermal) decide to lower performance if it so chooses, but for now 1233 * we'll crank up the speed. 1234 */ 1235 1236 result = acpi_processor_get_throttling(pr); 1237 if (result) 1238 goto end; 1239 1240 if (pr->throttling.state) { 1241 acpi_handle_debug(pr->handle, 1242 "Disabling throttling (was T%d)\n", 1243 pr->throttling.state); 1244 result = acpi_processor_set_throttling(pr, 0, false); 1245 if (result) 1246 goto end; 1247 } 1248 1249 end: 1250 if (result) 1251 pr->flags.throttling = 0; 1252 1253 return result; 1254 } 1255 1256