1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $) 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 #define pr_fmt(fmt) "ACPI: " fmt 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/cpufreq.h> 18 #include <linux/slab.h> 19 #include <linux/acpi.h> 20 #include <acpi/processor.h> 21 #ifdef CONFIG_X86 22 #include <asm/cpufeature.h> 23 #endif 24 25 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance" 26 27 static DEFINE_MUTEX(performance_mutex); 28 29 /* 30 * _PPC support is implemented as a CPUfreq policy notifier: 31 * This means each time a CPUfreq driver registered also with 32 * the ACPI core is asked to change the speed policy, the maximum 33 * value is adjusted so that it is within the platform limit. 34 * 35 * Also, when a new platform limit value is detected, the CPUfreq 36 * policy is adjusted accordingly. 37 */ 38 39 /* ignore_ppc: 40 * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet 41 * ignore _PPC 42 * 0 -> cpufreq low level drivers initialized -> consider _PPC values 43 * 1 -> ignore _PPC totally -> forced by user through boot param 44 */ 45 static int ignore_ppc = -1; 46 module_param(ignore_ppc, int, 0644); 47 MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \ 48 "limited by BIOS, this should help"); 49 50 static bool acpi_processor_ppc_in_use; 51 52 static int acpi_processor_get_platform_limit(struct acpi_processor *pr) 53 { 54 acpi_status status = 0; 55 unsigned long long ppc = 0; 56 int ret; 57 58 if (!pr) 59 return -EINVAL; 60 61 /* 62 * _PPC indicates the maximum state currently supported by the platform 63 * (e.g. 0 = states 0..n; 1 = states 1..n; etc. 64 */ 65 status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc); 66 if (status != AE_NOT_FOUND) { 67 acpi_processor_ppc_in_use = true; 68 69 if (ACPI_FAILURE(status)) { 70 acpi_evaluation_failure_warn(pr->handle, "_PPC", status); 71 return -ENODEV; 72 } 73 } 74 75 pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id, 76 (int)ppc, ppc ? "" : "not"); 77 78 pr->performance_platform_limit = (int)ppc; 79 80 if (ppc >= pr->performance->state_count || 81 unlikely(!freq_qos_request_active(&pr->perflib_req))) 82 return 0; 83 84 ret = freq_qos_update_request(&pr->perflib_req, 85 pr->performance->states[ppc].core_frequency * 1000); 86 if (ret < 0) { 87 pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n", 88 pr->id, ret); 89 } 90 91 return 0; 92 } 93 94 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 95 /* 96 * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status 97 * @handle: ACPI processor handle 98 * @status: the status code of _PPC evaluation 99 * 0: success. OSPM is now using the performance state specified. 100 * 1: failure. OSPM has not changed the number of P-states in use 101 */ 102 static void acpi_processor_ppc_ost(acpi_handle handle, int status) 103 { 104 if (acpi_has_method(handle, "_OST")) 105 acpi_evaluate_ost(handle, ACPI_PROCESSOR_NOTIFY_PERFORMANCE, 106 status, NULL); 107 } 108 109 void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag) 110 { 111 int ret; 112 113 if (ignore_ppc || !pr->performance) { 114 /* 115 * Only when it is notification event, the _OST object 116 * will be evaluated. Otherwise it is skipped. 117 */ 118 if (event_flag) 119 acpi_processor_ppc_ost(pr->handle, 1); 120 return; 121 } 122 123 ret = acpi_processor_get_platform_limit(pr); 124 /* 125 * Only when it is notification event, the _OST object 126 * will be evaluated. Otherwise it is skipped. 127 */ 128 if (event_flag) { 129 if (ret < 0) 130 acpi_processor_ppc_ost(pr->handle, 1); 131 else 132 acpi_processor_ppc_ost(pr->handle, 0); 133 } 134 if (ret >= 0) 135 cpufreq_update_limits(pr->id); 136 } 137 138 int acpi_processor_get_bios_limit(int cpu, unsigned int *limit) 139 { 140 struct acpi_processor *pr; 141 142 pr = per_cpu(processors, cpu); 143 if (!pr || !pr->performance || !pr->performance->state_count) 144 return -ENODEV; 145 146 *limit = pr->performance->states[pr->performance_platform_limit]. 147 core_frequency * 1000; 148 return 0; 149 } 150 EXPORT_SYMBOL(acpi_processor_get_bios_limit); 151 152 void acpi_processor_ignore_ppc_init(void) 153 { 154 if (ignore_ppc < 0) 155 ignore_ppc = 0; 156 } 157 158 void acpi_processor_ppc_init(struct cpufreq_policy *policy) 159 { 160 unsigned int cpu; 161 162 for_each_cpu(cpu, policy->related_cpus) { 163 struct acpi_processor *pr = per_cpu(processors, cpu); 164 int ret; 165 166 if (!pr) 167 continue; 168 169 ret = freq_qos_add_request(&policy->constraints, 170 &pr->perflib_req, 171 FREQ_QOS_MAX, INT_MAX); 172 if (ret < 0) 173 pr_err("Failed to add freq constraint for CPU%d (%d)\n", 174 cpu, ret); 175 } 176 } 177 178 void acpi_processor_ppc_exit(struct cpufreq_policy *policy) 179 { 180 unsigned int cpu; 181 182 for_each_cpu(cpu, policy->related_cpus) { 183 struct acpi_processor *pr = per_cpu(processors, cpu); 184 185 if (pr) 186 freq_qos_remove_request(&pr->perflib_req); 187 } 188 } 189 190 static int acpi_processor_get_performance_control(struct acpi_processor *pr) 191 { 192 int result = 0; 193 acpi_status status = 0; 194 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 195 union acpi_object *pct = NULL; 196 union acpi_object obj = { 0 }; 197 198 status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer); 199 if (ACPI_FAILURE(status)) { 200 acpi_evaluation_failure_warn(pr->handle, "_PCT", status); 201 return -ENODEV; 202 } 203 204 pct = (union acpi_object *)buffer.pointer; 205 if (!pct || pct->type != ACPI_TYPE_PACKAGE || pct->package.count != 2) { 206 pr_err("Invalid _PCT data\n"); 207 result = -EFAULT; 208 goto end; 209 } 210 211 /* 212 * control_register 213 */ 214 215 obj = pct->package.elements[0]; 216 217 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER || 218 obj.buffer.length < sizeof(struct acpi_pct_register)) { 219 pr_err("Invalid _PCT data (control_register)\n"); 220 result = -EFAULT; 221 goto end; 222 } 223 memcpy(&pr->performance->control_register, obj.buffer.pointer, 224 sizeof(struct acpi_pct_register)); 225 226 /* 227 * status_register 228 */ 229 230 obj = pct->package.elements[1]; 231 232 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER || 233 obj.buffer.length < sizeof(struct acpi_pct_register)) { 234 pr_err("Invalid _PCT data (status_register)\n"); 235 result = -EFAULT; 236 goto end; 237 } 238 239 memcpy(&pr->performance->status_register, obj.buffer.pointer, 240 sizeof(struct acpi_pct_register)); 241 242 end: 243 kfree(buffer.pointer); 244 245 return result; 246 } 247 248 #ifdef CONFIG_X86 249 /* 250 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding 251 * in their ACPI data. Calculate the real values and fix up the _PSS data. 252 */ 253 static void amd_fixup_frequency(struct acpi_processor_px *px, int i) 254 { 255 u32 hi, lo, fid, did; 256 int index = px->control & 0x00000007; 257 258 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 259 return; 260 261 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) || 262 boot_cpu_data.x86 == 0x11) { 263 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi); 264 /* 265 * MSR C001_0064+: 266 * Bit 63: PstateEn. Read-write. If set, the P-state is valid. 267 */ 268 if (!(hi & BIT(31))) 269 return; 270 271 fid = lo & 0x3f; 272 did = (lo >> 6) & 7; 273 if (boot_cpu_data.x86 == 0x10) 274 px->core_frequency = (100 * (fid + 0x10)) >> did; 275 else 276 px->core_frequency = (100 * (fid + 8)) >> did; 277 } 278 } 279 #else 280 static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {}; 281 #endif 282 283 static int acpi_processor_get_performance_states(struct acpi_processor *pr) 284 { 285 int result = 0; 286 acpi_status status = AE_OK; 287 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 288 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" }; 289 struct acpi_buffer state = { 0, NULL }; 290 union acpi_object *pss = NULL; 291 int i; 292 int last_invalid = -1; 293 294 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer); 295 if (ACPI_FAILURE(status)) { 296 acpi_evaluation_failure_warn(pr->handle, "_PSS", status); 297 return -ENODEV; 298 } 299 300 pss = buffer.pointer; 301 if (!pss || pss->type != ACPI_TYPE_PACKAGE) { 302 pr_err("Invalid _PSS data\n"); 303 result = -EFAULT; 304 goto end; 305 } 306 307 acpi_handle_debug(pr->handle, "Found %d performance states\n", 308 pss->package.count); 309 310 pr->performance->state_count = pss->package.count; 311 pr->performance->states = 312 kmalloc_array(pss->package.count, 313 sizeof(struct acpi_processor_px), 314 GFP_KERNEL); 315 if (!pr->performance->states) { 316 result = -ENOMEM; 317 goto end; 318 } 319 320 for (i = 0; i < pr->performance->state_count; i++) { 321 322 struct acpi_processor_px *px = &(pr->performance->states[i]); 323 324 state.length = sizeof(struct acpi_processor_px); 325 state.pointer = px; 326 327 acpi_handle_debug(pr->handle, "Extracting state %d\n", i); 328 329 status = acpi_extract_package(&(pss->package.elements[i]), 330 &format, &state); 331 if (ACPI_FAILURE(status)) { 332 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n", 333 acpi_format_exception(status)); 334 result = -EFAULT; 335 kfree(pr->performance->states); 336 goto end; 337 } 338 339 amd_fixup_frequency(px, i); 340 341 acpi_handle_debug(pr->handle, 342 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n", 343 i, 344 (u32) px->core_frequency, 345 (u32) px->power, 346 (u32) px->transition_latency, 347 (u32) px->bus_master_latency, 348 (u32) px->control, (u32) px->status); 349 350 /* 351 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq 352 */ 353 if (!px->core_frequency || 354 (u32)(px->core_frequency * 1000) != px->core_frequency * 1000) { 355 pr_err(FW_BUG 356 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n", 357 pr->id, px->core_frequency); 358 if (last_invalid == -1) 359 last_invalid = i; 360 } else { 361 if (last_invalid != -1) { 362 /* 363 * Copy this valid entry over last_invalid entry 364 */ 365 memcpy(&(pr->performance->states[last_invalid]), 366 px, sizeof(struct acpi_processor_px)); 367 ++last_invalid; 368 } 369 } 370 } 371 372 if (last_invalid == 0) { 373 pr_err(FW_BUG 374 "No valid BIOS _PSS frequency found for processor %d\n", pr->id); 375 result = -EFAULT; 376 kfree(pr->performance->states); 377 pr->performance->states = NULL; 378 } 379 380 if (last_invalid > 0) 381 pr->performance->state_count = last_invalid; 382 383 end: 384 kfree(buffer.pointer); 385 386 return result; 387 } 388 389 int acpi_processor_get_performance_info(struct acpi_processor *pr) 390 { 391 int result = 0; 392 393 if (!pr || !pr->performance || !pr->handle) 394 return -EINVAL; 395 396 if (!acpi_has_method(pr->handle, "_PCT")) { 397 acpi_handle_debug(pr->handle, 398 "ACPI-based processor performance control unavailable\n"); 399 return -ENODEV; 400 } 401 402 result = acpi_processor_get_performance_control(pr); 403 if (result) 404 goto update_bios; 405 406 result = acpi_processor_get_performance_states(pr); 407 if (result) 408 goto update_bios; 409 410 /* We need to call _PPC once when cpufreq starts */ 411 if (ignore_ppc != 1) 412 result = acpi_processor_get_platform_limit(pr); 413 414 return result; 415 416 /* 417 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that 418 * the BIOS is older than the CPU and does not know its frequencies 419 */ 420 update_bios: 421 #ifdef CONFIG_X86 422 if (acpi_has_method(pr->handle, "_PPC")) { 423 if(boot_cpu_has(X86_FEATURE_EST)) 424 pr_warn(FW_BUG "BIOS needs update for CPU " 425 "frequency support\n"); 426 } 427 #endif 428 return result; 429 } 430 EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info); 431 432 int acpi_processor_pstate_control(void) 433 { 434 acpi_status status; 435 436 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control) 437 return 0; 438 439 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n", 440 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command); 441 442 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 443 (u32)acpi_gbl_FADT.pstate_control, 8); 444 if (ACPI_SUCCESS(status)) 445 return 1; 446 447 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n", 448 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command, 449 acpi_format_exception(status)); 450 return -EIO; 451 } 452 453 int acpi_processor_notify_smm(struct module *calling_module) 454 { 455 static int is_done; 456 int result = 0; 457 458 if (!acpi_processor_cpufreq_init) 459 return -EBUSY; 460 461 if (!try_module_get(calling_module)) 462 return -EINVAL; 463 464 /* 465 * is_done is set to negative if an error occurs and to 1 if no error 466 * occurrs, but SMM has been notified already. This avoids repeated 467 * notification which might lead to unexpected results. 468 */ 469 if (is_done != 0) { 470 if (is_done < 0) 471 result = is_done; 472 473 goto out_put; 474 } 475 476 result = acpi_processor_pstate_control(); 477 if (result <= 0) { 478 if (result) { 479 is_done = result; 480 } else { 481 pr_debug("No SMI port or pstate_control\n"); 482 is_done = 1; 483 } 484 goto out_put; 485 } 486 487 is_done = 1; 488 /* 489 * Success. If there _PPC, unloading the cpufreq driver would be risky, 490 * so disallow it in that case. 491 */ 492 if (acpi_processor_ppc_in_use) 493 return 0; 494 495 out_put: 496 module_put(calling_module); 497 return result; 498 } 499 EXPORT_SYMBOL(acpi_processor_notify_smm); 500 501 int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain) 502 { 503 int result = 0; 504 acpi_status status = AE_OK; 505 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 506 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 507 struct acpi_buffer state = {0, NULL}; 508 union acpi_object *psd = NULL; 509 510 status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer); 511 if (ACPI_FAILURE(status)) { 512 return -ENODEV; 513 } 514 515 psd = buffer.pointer; 516 if (!psd || psd->type != ACPI_TYPE_PACKAGE) { 517 pr_err("Invalid _PSD data\n"); 518 result = -EFAULT; 519 goto end; 520 } 521 522 if (psd->package.count != 1) { 523 pr_err("Invalid _PSD data\n"); 524 result = -EFAULT; 525 goto end; 526 } 527 528 state.length = sizeof(struct acpi_psd_package); 529 state.pointer = pdomain; 530 531 status = acpi_extract_package(&(psd->package.elements[0]), &format, &state); 532 if (ACPI_FAILURE(status)) { 533 pr_err("Invalid _PSD data\n"); 534 result = -EFAULT; 535 goto end; 536 } 537 538 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 539 pr_err("Unknown _PSD:num_entries\n"); 540 result = -EFAULT; 541 goto end; 542 } 543 544 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 545 pr_err("Unknown _PSD:revision\n"); 546 result = -EFAULT; 547 goto end; 548 } 549 550 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 551 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 552 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 553 pr_err("Invalid _PSD:coord_type\n"); 554 result = -EFAULT; 555 goto end; 556 } 557 end: 558 kfree(buffer.pointer); 559 return result; 560 } 561 EXPORT_SYMBOL(acpi_processor_get_psd); 562 563 int acpi_processor_preregister_performance( 564 struct acpi_processor_performance __percpu *performance) 565 { 566 int count_target; 567 int retval = 0; 568 unsigned int i, j; 569 cpumask_var_t covered_cpus; 570 struct acpi_processor *pr; 571 struct acpi_psd_package *pdomain; 572 struct acpi_processor *match_pr; 573 struct acpi_psd_package *match_pdomain; 574 575 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 576 return -ENOMEM; 577 578 mutex_lock(&performance_mutex); 579 580 /* 581 * Check if another driver has already registered, and abort before 582 * changing pr->performance if it has. Check input data as well. 583 */ 584 for_each_possible_cpu(i) { 585 pr = per_cpu(processors, i); 586 if (!pr) { 587 /* Look only at processors in ACPI namespace */ 588 continue; 589 } 590 591 if (pr->performance) { 592 retval = -EBUSY; 593 goto err_out; 594 } 595 596 if (!performance || !per_cpu_ptr(performance, i)) { 597 retval = -EINVAL; 598 goto err_out; 599 } 600 } 601 602 /* Call _PSD for all CPUs */ 603 for_each_possible_cpu(i) { 604 pr = per_cpu(processors, i); 605 if (!pr) 606 continue; 607 608 pr->performance = per_cpu_ptr(performance, i); 609 pdomain = &(pr->performance->domain_info); 610 if (acpi_processor_get_psd(pr->handle, pdomain)) { 611 retval = -EINVAL; 612 continue; 613 } 614 } 615 if (retval) 616 goto err_ret; 617 618 /* 619 * Now that we have _PSD data from all CPUs, lets setup P-state 620 * domain info. 621 */ 622 for_each_possible_cpu(i) { 623 pr = per_cpu(processors, i); 624 if (!pr) 625 continue; 626 627 if (cpumask_test_cpu(i, covered_cpus)) 628 continue; 629 630 pdomain = &(pr->performance->domain_info); 631 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 632 cpumask_set_cpu(i, covered_cpus); 633 if (pdomain->num_processors <= 1) 634 continue; 635 636 /* Validate the Domain info */ 637 count_target = pdomain->num_processors; 638 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 639 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL; 640 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 641 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW; 642 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 643 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY; 644 645 for_each_possible_cpu(j) { 646 if (i == j) 647 continue; 648 649 match_pr = per_cpu(processors, j); 650 if (!match_pr) 651 continue; 652 653 match_pdomain = &(match_pr->performance->domain_info); 654 if (match_pdomain->domain != pdomain->domain) 655 continue; 656 657 /* Here i and j are in the same domain */ 658 659 if (match_pdomain->num_processors != count_target) { 660 retval = -EINVAL; 661 goto err_ret; 662 } 663 664 if (pdomain->coord_type != match_pdomain->coord_type) { 665 retval = -EINVAL; 666 goto err_ret; 667 } 668 669 cpumask_set_cpu(j, covered_cpus); 670 cpumask_set_cpu(j, pr->performance->shared_cpu_map); 671 } 672 673 for_each_possible_cpu(j) { 674 if (i == j) 675 continue; 676 677 match_pr = per_cpu(processors, j); 678 if (!match_pr) 679 continue; 680 681 match_pdomain = &(match_pr->performance->domain_info); 682 if (match_pdomain->domain != pdomain->domain) 683 continue; 684 685 match_pr->performance->shared_type = 686 pr->performance->shared_type; 687 cpumask_copy(match_pr->performance->shared_cpu_map, 688 pr->performance->shared_cpu_map); 689 } 690 } 691 692 err_ret: 693 for_each_possible_cpu(i) { 694 pr = per_cpu(processors, i); 695 if (!pr || !pr->performance) 696 continue; 697 698 /* Assume no coordination on any error parsing domain info */ 699 if (retval) { 700 cpumask_clear(pr->performance->shared_cpu_map); 701 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 702 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE; 703 } 704 pr->performance = NULL; /* Will be set for real in register */ 705 } 706 707 err_out: 708 mutex_unlock(&performance_mutex); 709 free_cpumask_var(covered_cpus); 710 return retval; 711 } 712 EXPORT_SYMBOL(acpi_processor_preregister_performance); 713 714 int acpi_processor_register_performance(struct acpi_processor_performance 715 *performance, unsigned int cpu) 716 { 717 struct acpi_processor *pr; 718 719 if (!acpi_processor_cpufreq_init) 720 return -EINVAL; 721 722 mutex_lock(&performance_mutex); 723 724 pr = per_cpu(processors, cpu); 725 if (!pr) { 726 mutex_unlock(&performance_mutex); 727 return -ENODEV; 728 } 729 730 if (pr->performance) { 731 mutex_unlock(&performance_mutex); 732 return -EBUSY; 733 } 734 735 WARN_ON(!performance); 736 737 pr->performance = performance; 738 739 if (acpi_processor_get_performance_info(pr)) { 740 pr->performance = NULL; 741 mutex_unlock(&performance_mutex); 742 return -EIO; 743 } 744 745 mutex_unlock(&performance_mutex); 746 return 0; 747 } 748 EXPORT_SYMBOL(acpi_processor_register_performance); 749 750 void acpi_processor_unregister_performance(unsigned int cpu) 751 { 752 struct acpi_processor *pr; 753 754 mutex_lock(&performance_mutex); 755 756 pr = per_cpu(processors, cpu); 757 if (!pr) 758 goto unlock; 759 760 if (pr->performance) 761 kfree(pr->performance->states); 762 763 pr->performance = NULL; 764 765 unlock: 766 mutex_unlock(&performance_mutex); 767 } 768 EXPORT_SYMBOL(acpi_processor_unregister_performance); 769