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 *limit = pr->performance->states[pr->performance_platform_limit]. 146 core_frequency * 1000; 147 return 0; 148 } 149 EXPORT_SYMBOL(acpi_processor_get_bios_limit); 150 151 void acpi_processor_ignore_ppc_init(void) 152 { 153 if (ignore_ppc < 0) 154 ignore_ppc = 0; 155 } 156 157 void acpi_processor_ppc_init(struct cpufreq_policy *policy) 158 { 159 unsigned int cpu; 160 161 for_each_cpu(cpu, policy->related_cpus) { 162 struct acpi_processor *pr = per_cpu(processors, cpu); 163 int ret; 164 165 if (!pr) 166 continue; 167 168 ret = freq_qos_add_request(&policy->constraints, 169 &pr->perflib_req, 170 FREQ_QOS_MAX, INT_MAX); 171 if (ret < 0) 172 pr_err("Failed to add freq constraint for CPU%d (%d)\n", 173 cpu, ret); 174 } 175 } 176 177 void acpi_processor_ppc_exit(struct cpufreq_policy *policy) 178 { 179 unsigned int cpu; 180 181 for_each_cpu(cpu, policy->related_cpus) { 182 struct acpi_processor *pr = per_cpu(processors, cpu); 183 184 if (pr) 185 freq_qos_remove_request(&pr->perflib_req); 186 } 187 } 188 189 static int acpi_processor_get_performance_control(struct acpi_processor *pr) 190 { 191 int result = 0; 192 acpi_status status = 0; 193 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 194 union acpi_object *pct = NULL; 195 union acpi_object obj = { 0 }; 196 197 status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer); 198 if (ACPI_FAILURE(status)) { 199 acpi_evaluation_failure_warn(pr->handle, "_PCT", status); 200 return -ENODEV; 201 } 202 203 pct = (union acpi_object *)buffer.pointer; 204 if (!pct || (pct->type != ACPI_TYPE_PACKAGE) 205 || (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.type != ACPI_TYPE_BUFFER) 218 || (obj.buffer.length < sizeof(struct acpi_pct_register)) 219 || (obj.buffer.pointer == NULL)) { 220 pr_err("Invalid _PCT data (control_register)\n"); 221 result = -EFAULT; 222 goto end; 223 } 224 memcpy(&pr->performance->control_register, obj.buffer.pointer, 225 sizeof(struct acpi_pct_register)); 226 227 /* 228 * status_register 229 */ 230 231 obj = pct->package.elements[1]; 232 233 if ((obj.type != ACPI_TYPE_BUFFER) 234 || (obj.buffer.length < sizeof(struct acpi_pct_register)) 235 || (obj.buffer.pointer == NULL)) { 236 pr_err("Invalid _PCT data (status_register)\n"); 237 result = -EFAULT; 238 goto end; 239 } 240 241 memcpy(&pr->performance->status_register, obj.buffer.pointer, 242 sizeof(struct acpi_pct_register)); 243 244 end: 245 kfree(buffer.pointer); 246 247 return result; 248 } 249 250 #ifdef CONFIG_X86 251 /* 252 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding 253 * in their ACPI data. Calculate the real values and fix up the _PSS data. 254 */ 255 static void amd_fixup_frequency(struct acpi_processor_px *px, int i) 256 { 257 u32 hi, lo, fid, did; 258 int index = px->control & 0x00000007; 259 260 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 261 return; 262 263 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) 264 || boot_cpu_data.x86 == 0x11) { 265 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi); 266 /* 267 * MSR C001_0064+: 268 * Bit 63: PstateEn. Read-write. If set, the P-state is valid. 269 */ 270 if (!(hi & BIT(31))) 271 return; 272 273 fid = lo & 0x3f; 274 did = (lo >> 6) & 7; 275 if (boot_cpu_data.x86 == 0x10) 276 px->core_frequency = (100 * (fid + 0x10)) >> did; 277 else 278 px->core_frequency = (100 * (fid + 8)) >> did; 279 } 280 } 281 #else 282 static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {}; 283 #endif 284 285 static int acpi_processor_get_performance_states(struct acpi_processor *pr) 286 { 287 int result = 0; 288 acpi_status status = AE_OK; 289 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 290 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" }; 291 struct acpi_buffer state = { 0, NULL }; 292 union acpi_object *pss = NULL; 293 int i; 294 int last_invalid = -1; 295 296 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer); 297 if (ACPI_FAILURE(status)) { 298 acpi_evaluation_failure_warn(pr->handle, "_PSS", status); 299 return -ENODEV; 300 } 301 302 pss = buffer.pointer; 303 if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) { 304 pr_err("Invalid _PSS data\n"); 305 result = -EFAULT; 306 goto end; 307 } 308 309 acpi_handle_debug(pr->handle, "Found %d performance states\n", 310 pss->package.count); 311 312 pr->performance->state_count = pss->package.count; 313 pr->performance->states = 314 kmalloc_array(pss->package.count, 315 sizeof(struct acpi_processor_px), 316 GFP_KERNEL); 317 if (!pr->performance->states) { 318 result = -ENOMEM; 319 goto end; 320 } 321 322 for (i = 0; i < pr->performance->state_count; i++) { 323 324 struct acpi_processor_px *px = &(pr->performance->states[i]); 325 326 state.length = sizeof(struct acpi_processor_px); 327 state.pointer = px; 328 329 acpi_handle_debug(pr->handle, "Extracting state %d\n", i); 330 331 status = acpi_extract_package(&(pss->package.elements[i]), 332 &format, &state); 333 if (ACPI_FAILURE(status)) { 334 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n", 335 acpi_format_exception(status)); 336 result = -EFAULT; 337 kfree(pr->performance->states); 338 goto end; 339 } 340 341 amd_fixup_frequency(px, i); 342 343 acpi_handle_debug(pr->handle, 344 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n", 345 i, 346 (u32) px->core_frequency, 347 (u32) px->power, 348 (u32) px->transition_latency, 349 (u32) px->bus_master_latency, 350 (u32) px->control, (u32) px->status); 351 352 /* 353 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq 354 */ 355 if (!px->core_frequency || 356 ((u32)(px->core_frequency * 1000) != 357 (px->core_frequency * 1000))) { 358 pr_err(FW_BUG 359 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n", 360 pr->id, px->core_frequency); 361 if (last_invalid == -1) 362 last_invalid = i; 363 } else { 364 if (last_invalid != -1) { 365 /* 366 * Copy this valid entry over last_invalid entry 367 */ 368 memcpy(&(pr->performance->states[last_invalid]), 369 px, sizeof(struct acpi_processor_px)); 370 ++last_invalid; 371 } 372 } 373 } 374 375 if (last_invalid == 0) { 376 pr_err(FW_BUG 377 "No valid BIOS _PSS frequency found for processor %d\n", pr->id); 378 result = -EFAULT; 379 kfree(pr->performance->states); 380 pr->performance->states = NULL; 381 } 382 383 if (last_invalid > 0) 384 pr->performance->state_count = last_invalid; 385 386 end: 387 kfree(buffer.pointer); 388 389 return result; 390 } 391 392 int acpi_processor_get_performance_info(struct acpi_processor *pr) 393 { 394 int result = 0; 395 396 if (!pr || !pr->performance || !pr->handle) 397 return -EINVAL; 398 399 if (!acpi_has_method(pr->handle, "_PCT")) { 400 acpi_handle_debug(pr->handle, 401 "ACPI-based processor performance control unavailable\n"); 402 return -ENODEV; 403 } 404 405 result = acpi_processor_get_performance_control(pr); 406 if (result) 407 goto update_bios; 408 409 result = acpi_processor_get_performance_states(pr); 410 if (result) 411 goto update_bios; 412 413 /* We need to call _PPC once when cpufreq starts */ 414 if (ignore_ppc != 1) 415 result = acpi_processor_get_platform_limit(pr); 416 417 return result; 418 419 /* 420 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that 421 * the BIOS is older than the CPU and does not know its frequencies 422 */ 423 update_bios: 424 #ifdef CONFIG_X86 425 if (acpi_has_method(pr->handle, "_PPC")) { 426 if(boot_cpu_has(X86_FEATURE_EST)) 427 pr_warn(FW_BUG "BIOS needs update for CPU " 428 "frequency support\n"); 429 } 430 #endif 431 return result; 432 } 433 EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info); 434 435 int acpi_processor_pstate_control(void) 436 { 437 acpi_status status; 438 439 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control) 440 return 0; 441 442 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n", 443 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command); 444 445 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 446 (u32)acpi_gbl_FADT.pstate_control, 8); 447 if (ACPI_SUCCESS(status)) 448 return 1; 449 450 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n", 451 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command, 452 acpi_format_exception(status)); 453 return -EIO; 454 } 455 456 int acpi_processor_notify_smm(struct module *calling_module) 457 { 458 static int is_done; 459 int result; 460 461 if (!acpi_processor_cpufreq_init) 462 return -EBUSY; 463 464 if (!try_module_get(calling_module)) 465 return -EINVAL; 466 467 /* is_done is set to negative if an error occurred, 468 * and to postitive if _no_ error occurred, but SMM 469 * was already notified. This avoids double notification 470 * which might lead to unexpected results... 471 */ 472 if (is_done > 0) { 473 module_put(calling_module); 474 return 0; 475 } else if (is_done < 0) { 476 module_put(calling_module); 477 return is_done; 478 } 479 480 is_done = -EIO; 481 482 result = acpi_processor_pstate_control(); 483 if (!result) { 484 pr_debug("No SMI port or pstate_control\n"); 485 module_put(calling_module); 486 return 0; 487 } 488 if (result < 0) { 489 module_put(calling_module); 490 return result; 491 } 492 493 /* Success. If there's no _PPC, we need to fear nothing, so 494 * we can allow the cpufreq driver to be rmmod'ed. */ 495 is_done = 1; 496 497 if (!acpi_processor_ppc_in_use) 498 module_put(calling_module); 499 500 return 0; 501 } 502 503 EXPORT_SYMBOL(acpi_processor_notify_smm); 504 505 int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain) 506 { 507 int result = 0; 508 acpi_status status = AE_OK; 509 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 510 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 511 struct acpi_buffer state = {0, NULL}; 512 union acpi_object *psd = NULL; 513 514 status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer); 515 if (ACPI_FAILURE(status)) { 516 return -ENODEV; 517 } 518 519 psd = buffer.pointer; 520 if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) { 521 pr_err("Invalid _PSD data\n"); 522 result = -EFAULT; 523 goto end; 524 } 525 526 if (psd->package.count != 1) { 527 pr_err("Invalid _PSD data\n"); 528 result = -EFAULT; 529 goto end; 530 } 531 532 state.length = sizeof(struct acpi_psd_package); 533 state.pointer = pdomain; 534 535 status = acpi_extract_package(&(psd->package.elements[0]), 536 &format, &state); 537 if (ACPI_FAILURE(status)) { 538 pr_err("Invalid _PSD data\n"); 539 result = -EFAULT; 540 goto end; 541 } 542 543 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 544 pr_err("Unknown _PSD:num_entries\n"); 545 result = -EFAULT; 546 goto end; 547 } 548 549 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 550 pr_err("Unknown _PSD:revision\n"); 551 result = -EFAULT; 552 goto end; 553 } 554 555 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 556 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 557 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 558 pr_err("Invalid _PSD:coord_type\n"); 559 result = -EFAULT; 560 goto end; 561 } 562 end: 563 kfree(buffer.pointer); 564 return result; 565 } 566 EXPORT_SYMBOL(acpi_processor_get_psd); 567 568 int acpi_processor_preregister_performance( 569 struct acpi_processor_performance __percpu *performance) 570 { 571 int count_target; 572 int retval = 0; 573 unsigned int i, j; 574 cpumask_var_t covered_cpus; 575 struct acpi_processor *pr; 576 struct acpi_psd_package *pdomain; 577 struct acpi_processor *match_pr; 578 struct acpi_psd_package *match_pdomain; 579 580 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 581 return -ENOMEM; 582 583 mutex_lock(&performance_mutex); 584 585 /* 586 * Check if another driver has already registered, and abort before 587 * changing pr->performance if it has. Check input data as well. 588 */ 589 for_each_possible_cpu(i) { 590 pr = per_cpu(processors, i); 591 if (!pr) { 592 /* Look only at processors in ACPI namespace */ 593 continue; 594 } 595 596 if (pr->performance) { 597 retval = -EBUSY; 598 goto err_out; 599 } 600 601 if (!performance || !per_cpu_ptr(performance, i)) { 602 retval = -EINVAL; 603 goto err_out; 604 } 605 } 606 607 /* Call _PSD for all CPUs */ 608 for_each_possible_cpu(i) { 609 pr = per_cpu(processors, i); 610 if (!pr) 611 continue; 612 613 pr->performance = per_cpu_ptr(performance, i); 614 pdomain = &(pr->performance->domain_info); 615 if (acpi_processor_get_psd(pr->handle, pdomain)) { 616 retval = -EINVAL; 617 continue; 618 } 619 } 620 if (retval) 621 goto err_ret; 622 623 /* 624 * Now that we have _PSD data from all CPUs, lets setup P-state 625 * domain info. 626 */ 627 for_each_possible_cpu(i) { 628 pr = per_cpu(processors, i); 629 if (!pr) 630 continue; 631 632 if (cpumask_test_cpu(i, covered_cpus)) 633 continue; 634 635 pdomain = &(pr->performance->domain_info); 636 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 637 cpumask_set_cpu(i, covered_cpus); 638 if (pdomain->num_processors <= 1) 639 continue; 640 641 /* Validate the Domain info */ 642 count_target = pdomain->num_processors; 643 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 644 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL; 645 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 646 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW; 647 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 648 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY; 649 650 for_each_possible_cpu(j) { 651 if (i == j) 652 continue; 653 654 match_pr = per_cpu(processors, j); 655 if (!match_pr) 656 continue; 657 658 match_pdomain = &(match_pr->performance->domain_info); 659 if (match_pdomain->domain != pdomain->domain) 660 continue; 661 662 /* Here i and j are in the same domain */ 663 664 if (match_pdomain->num_processors != count_target) { 665 retval = -EINVAL; 666 goto err_ret; 667 } 668 669 if (pdomain->coord_type != match_pdomain->coord_type) { 670 retval = -EINVAL; 671 goto err_ret; 672 } 673 674 cpumask_set_cpu(j, covered_cpus); 675 cpumask_set_cpu(j, pr->performance->shared_cpu_map); 676 } 677 678 for_each_possible_cpu(j) { 679 if (i == j) 680 continue; 681 682 match_pr = per_cpu(processors, j); 683 if (!match_pr) 684 continue; 685 686 match_pdomain = &(match_pr->performance->domain_info); 687 if (match_pdomain->domain != pdomain->domain) 688 continue; 689 690 match_pr->performance->shared_type = 691 pr->performance->shared_type; 692 cpumask_copy(match_pr->performance->shared_cpu_map, 693 pr->performance->shared_cpu_map); 694 } 695 } 696 697 err_ret: 698 for_each_possible_cpu(i) { 699 pr = per_cpu(processors, i); 700 if (!pr || !pr->performance) 701 continue; 702 703 /* Assume no coordination on any error parsing domain info */ 704 if (retval) { 705 cpumask_clear(pr->performance->shared_cpu_map); 706 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 707 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE; 708 } 709 pr->performance = NULL; /* Will be set for real in register */ 710 } 711 712 err_out: 713 mutex_unlock(&performance_mutex); 714 free_cpumask_var(covered_cpus); 715 return retval; 716 } 717 EXPORT_SYMBOL(acpi_processor_preregister_performance); 718 719 int 720 acpi_processor_register_performance(struct acpi_processor_performance 721 *performance, unsigned int cpu) 722 { 723 struct acpi_processor *pr; 724 725 if (!acpi_processor_cpufreq_init) 726 return -EINVAL; 727 728 mutex_lock(&performance_mutex); 729 730 pr = per_cpu(processors, cpu); 731 if (!pr) { 732 mutex_unlock(&performance_mutex); 733 return -ENODEV; 734 } 735 736 if (pr->performance) { 737 mutex_unlock(&performance_mutex); 738 return -EBUSY; 739 } 740 741 WARN_ON(!performance); 742 743 pr->performance = performance; 744 745 if (acpi_processor_get_performance_info(pr)) { 746 pr->performance = NULL; 747 mutex_unlock(&performance_mutex); 748 return -EIO; 749 } 750 751 mutex_unlock(&performance_mutex); 752 return 0; 753 } 754 755 EXPORT_SYMBOL(acpi_processor_register_performance); 756 757 void acpi_processor_unregister_performance(unsigned int cpu) 758 { 759 struct acpi_processor *pr; 760 761 mutex_lock(&performance_mutex); 762 763 pr = per_cpu(processors, cpu); 764 if (!pr) { 765 mutex_unlock(&performance_mutex); 766 return; 767 } 768 769 if (pr->performance) 770 kfree(pr->performance->states); 771 pr->performance = NULL; 772 773 mutex_unlock(&performance_mutex); 774 775 return; 776 } 777 778 EXPORT_SYMBOL(acpi_processor_unregister_performance); 779