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 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/cpufreq.h> 16 #include <linux/slab.h> 17 #include <linux/acpi.h> 18 #include <acpi/processor.h> 19 #ifdef CONFIG_X86 20 #include <asm/cpufeature.h> 21 #endif 22 23 #define PREFIX "ACPI: " 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 }; 196 197 198 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) 206 || (pct->package.count != 2)) { 207 printk(KERN_ERR PREFIX "Invalid _PCT data\n"); 208 result = -EFAULT; 209 goto end; 210 } 211 212 /* 213 * control_register 214 */ 215 216 obj = pct->package.elements[0]; 217 218 if ((obj.type != ACPI_TYPE_BUFFER) 219 || (obj.buffer.length < sizeof(struct acpi_pct_register)) 220 || (obj.buffer.pointer == NULL)) { 221 printk(KERN_ERR PREFIX "Invalid _PCT data (control_register)\n"); 222 result = -EFAULT; 223 goto end; 224 } 225 memcpy(&pr->performance->control_register, obj.buffer.pointer, 226 sizeof(struct acpi_pct_register)); 227 228 /* 229 * status_register 230 */ 231 232 obj = pct->package.elements[1]; 233 234 if ((obj.type != ACPI_TYPE_BUFFER) 235 || (obj.buffer.length < sizeof(struct acpi_pct_register)) 236 || (obj.buffer.pointer == NULL)) { 237 printk(KERN_ERR PREFIX "Invalid _PCT data (status_register)\n"); 238 result = -EFAULT; 239 goto end; 240 } 241 242 memcpy(&pr->performance->status_register, obj.buffer.pointer, 243 sizeof(struct acpi_pct_register)); 244 245 end: 246 kfree(buffer.pointer); 247 248 return result; 249 } 250 251 #ifdef CONFIG_X86 252 /* 253 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding 254 * in their ACPI data. Calculate the real values and fix up the _PSS data. 255 */ 256 static void amd_fixup_frequency(struct acpi_processor_px *px, int i) 257 { 258 u32 hi, lo, fid, did; 259 int index = px->control & 0x00000007; 260 261 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 262 return; 263 264 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) 265 || boot_cpu_data.x86 == 0x11) { 266 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi); 267 /* 268 * MSR C001_0064+: 269 * Bit 63: PstateEn. Read-write. If set, the P-state is valid. 270 */ 271 if (!(hi & BIT(31))) 272 return; 273 274 fid = lo & 0x3f; 275 did = (lo >> 6) & 7; 276 if (boot_cpu_data.x86 == 0x10) 277 px->core_frequency = (100 * (fid + 0x10)) >> did; 278 else 279 px->core_frequency = (100 * (fid + 8)) >> did; 280 } 281 } 282 #else 283 static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {}; 284 #endif 285 286 static int acpi_processor_get_performance_states(struct acpi_processor *pr) 287 { 288 int result = 0; 289 acpi_status status = AE_OK; 290 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 291 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" }; 292 struct acpi_buffer state = { 0, NULL }; 293 union acpi_object *pss = NULL; 294 int i; 295 int last_invalid = -1; 296 297 298 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer); 299 if (ACPI_FAILURE(status)) { 300 acpi_evaluation_failure_warn(pr->handle, "_PSS", status); 301 return -ENODEV; 302 } 303 304 pss = buffer.pointer; 305 if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) { 306 printk(KERN_ERR PREFIX "Invalid _PSS data\n"); 307 result = -EFAULT; 308 goto end; 309 } 310 311 acpi_handle_debug(pr->handle, "Found %d performance states\n", 312 pss->package.count); 313 314 pr->performance->state_count = pss->package.count; 315 pr->performance->states = 316 kmalloc_array(pss->package.count, 317 sizeof(struct acpi_processor_px), 318 GFP_KERNEL); 319 if (!pr->performance->states) { 320 result = -ENOMEM; 321 goto end; 322 } 323 324 for (i = 0; i < pr->performance->state_count; i++) { 325 326 struct acpi_processor_px *px = &(pr->performance->states[i]); 327 328 state.length = sizeof(struct acpi_processor_px); 329 state.pointer = px; 330 331 acpi_handle_debug(pr->handle, "Extracting state %d\n", i); 332 333 status = acpi_extract_package(&(pss->package.elements[i]), 334 &format, &state); 335 if (ACPI_FAILURE(status)) { 336 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n", 337 acpi_format_exception(status)); 338 result = -EFAULT; 339 kfree(pr->performance->states); 340 goto end; 341 } 342 343 amd_fixup_frequency(px, i); 344 345 acpi_handle_debug(pr->handle, 346 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n", 347 i, 348 (u32) px->core_frequency, 349 (u32) px->power, 350 (u32) px->transition_latency, 351 (u32) px->bus_master_latency, 352 (u32) px->control, (u32) px->status); 353 354 /* 355 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq 356 */ 357 if (!px->core_frequency || 358 ((u32)(px->core_frequency * 1000) != 359 (px->core_frequency * 1000))) { 360 printk(KERN_ERR FW_BUG PREFIX 361 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n", 362 pr->id, px->core_frequency); 363 if (last_invalid == -1) 364 last_invalid = i; 365 } else { 366 if (last_invalid != -1) { 367 /* 368 * Copy this valid entry over last_invalid entry 369 */ 370 memcpy(&(pr->performance->states[last_invalid]), 371 px, sizeof(struct acpi_processor_px)); 372 ++last_invalid; 373 } 374 } 375 } 376 377 if (last_invalid == 0) { 378 printk(KERN_ERR FW_BUG PREFIX 379 "No valid BIOS _PSS frequency found for processor %d\n", pr->id); 380 result = -EFAULT; 381 kfree(pr->performance->states); 382 pr->performance->states = NULL; 383 } 384 385 if (last_invalid > 0) 386 pr->performance->state_count = last_invalid; 387 388 end: 389 kfree(buffer.pointer); 390 391 return result; 392 } 393 394 int acpi_processor_get_performance_info(struct acpi_processor *pr) 395 { 396 int result = 0; 397 398 if (!pr || !pr->performance || !pr->handle) 399 return -EINVAL; 400 401 if (!acpi_has_method(pr->handle, "_PCT")) { 402 acpi_handle_debug(pr->handle, 403 "ACPI-based processor performance control unavailable\n"); 404 return -ENODEV; 405 } 406 407 result = acpi_processor_get_performance_control(pr); 408 if (result) 409 goto update_bios; 410 411 result = acpi_processor_get_performance_states(pr); 412 if (result) 413 goto update_bios; 414 415 /* We need to call _PPC once when cpufreq starts */ 416 if (ignore_ppc != 1) 417 result = acpi_processor_get_platform_limit(pr); 418 419 return result; 420 421 /* 422 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that 423 * the BIOS is older than the CPU and does not know its frequencies 424 */ 425 update_bios: 426 #ifdef CONFIG_X86 427 if (acpi_has_method(pr->handle, "_PPC")) { 428 if(boot_cpu_has(X86_FEATURE_EST)) 429 printk(KERN_WARNING FW_BUG "BIOS needs update for CPU " 430 "frequency support\n"); 431 } 432 #endif 433 return result; 434 } 435 EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info); 436 437 int acpi_processor_pstate_control(void) 438 { 439 acpi_status status; 440 441 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control) 442 return 0; 443 444 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n", 445 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command); 446 447 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 448 (u32)acpi_gbl_FADT.pstate_control, 8); 449 if (ACPI_SUCCESS(status)) 450 return 1; 451 452 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n", 453 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command, 454 acpi_format_exception(status)); 455 return -EIO; 456 } 457 458 int acpi_processor_notify_smm(struct module *calling_module) 459 { 460 static int is_done; 461 int result; 462 463 if (!acpi_processor_cpufreq_init) 464 return -EBUSY; 465 466 if (!try_module_get(calling_module)) 467 return -EINVAL; 468 469 /* is_done is set to negative if an error occurred, 470 * and to postitive if _no_ error occurred, but SMM 471 * was already notified. This avoids double notification 472 * which might lead to unexpected results... 473 */ 474 if (is_done > 0) { 475 module_put(calling_module); 476 return 0; 477 } else if (is_done < 0) { 478 module_put(calling_module); 479 return is_done; 480 } 481 482 is_done = -EIO; 483 484 result = acpi_processor_pstate_control(); 485 if (!result) { 486 pr_debug("No SMI port or pstate_control\n"); 487 module_put(calling_module); 488 return 0; 489 } 490 if (result < 0) { 491 module_put(calling_module); 492 return result; 493 } 494 495 /* Success. If there's no _PPC, we need to fear nothing, so 496 * we can allow the cpufreq driver to be rmmod'ed. */ 497 is_done = 1; 498 499 if (!acpi_processor_ppc_in_use) 500 module_put(calling_module); 501 502 return 0; 503 } 504 505 EXPORT_SYMBOL(acpi_processor_notify_smm); 506 507 int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain) 508 { 509 int result = 0; 510 acpi_status status = AE_OK; 511 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 512 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 513 struct acpi_buffer state = {0, NULL}; 514 union acpi_object *psd = NULL; 515 516 status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer); 517 if (ACPI_FAILURE(status)) { 518 return -ENODEV; 519 } 520 521 psd = buffer.pointer; 522 if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) { 523 printk(KERN_ERR PREFIX "Invalid _PSD data\n"); 524 result = -EFAULT; 525 goto end; 526 } 527 528 if (psd->package.count != 1) { 529 printk(KERN_ERR PREFIX "Invalid _PSD data\n"); 530 result = -EFAULT; 531 goto end; 532 } 533 534 state.length = sizeof(struct acpi_psd_package); 535 state.pointer = pdomain; 536 537 status = acpi_extract_package(&(psd->package.elements[0]), 538 &format, &state); 539 if (ACPI_FAILURE(status)) { 540 printk(KERN_ERR PREFIX "Invalid _PSD data\n"); 541 result = -EFAULT; 542 goto end; 543 } 544 545 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 546 printk(KERN_ERR PREFIX "Unknown _PSD:num_entries\n"); 547 result = -EFAULT; 548 goto end; 549 } 550 551 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 552 printk(KERN_ERR PREFIX "Unknown _PSD:revision\n"); 553 result = -EFAULT; 554 goto end; 555 } 556 557 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 558 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 559 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 560 printk(KERN_ERR PREFIX "Invalid _PSD:coord_type\n"); 561 result = -EFAULT; 562 goto end; 563 } 564 end: 565 kfree(buffer.pointer); 566 return result; 567 } 568 EXPORT_SYMBOL(acpi_processor_get_psd); 569 570 int acpi_processor_preregister_performance( 571 struct acpi_processor_performance __percpu *performance) 572 { 573 int count_target; 574 int retval = 0; 575 unsigned int i, j; 576 cpumask_var_t covered_cpus; 577 struct acpi_processor *pr; 578 struct acpi_psd_package *pdomain; 579 struct acpi_processor *match_pr; 580 struct acpi_psd_package *match_pdomain; 581 582 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 583 return -ENOMEM; 584 585 mutex_lock(&performance_mutex); 586 587 /* 588 * Check if another driver has already registered, and abort before 589 * changing pr->performance if it has. Check input data as well. 590 */ 591 for_each_possible_cpu(i) { 592 pr = per_cpu(processors, i); 593 if (!pr) { 594 /* Look only at processors in ACPI namespace */ 595 continue; 596 } 597 598 if (pr->performance) { 599 retval = -EBUSY; 600 goto err_out; 601 } 602 603 if (!performance || !per_cpu_ptr(performance, i)) { 604 retval = -EINVAL; 605 goto err_out; 606 } 607 } 608 609 /* Call _PSD for all CPUs */ 610 for_each_possible_cpu(i) { 611 pr = per_cpu(processors, i); 612 if (!pr) 613 continue; 614 615 pr->performance = per_cpu_ptr(performance, i); 616 pdomain = &(pr->performance->domain_info); 617 if (acpi_processor_get_psd(pr->handle, pdomain)) { 618 retval = -EINVAL; 619 continue; 620 } 621 } 622 if (retval) 623 goto err_ret; 624 625 /* 626 * Now that we have _PSD data from all CPUs, lets setup P-state 627 * domain info. 628 */ 629 for_each_possible_cpu(i) { 630 pr = per_cpu(processors, i); 631 if (!pr) 632 continue; 633 634 if (cpumask_test_cpu(i, covered_cpus)) 635 continue; 636 637 pdomain = &(pr->performance->domain_info); 638 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 639 cpumask_set_cpu(i, covered_cpus); 640 if (pdomain->num_processors <= 1) 641 continue; 642 643 /* Validate the Domain info */ 644 count_target = pdomain->num_processors; 645 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 646 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL; 647 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 648 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW; 649 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 650 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY; 651 652 for_each_possible_cpu(j) { 653 if (i == j) 654 continue; 655 656 match_pr = per_cpu(processors, j); 657 if (!match_pr) 658 continue; 659 660 match_pdomain = &(match_pr->performance->domain_info); 661 if (match_pdomain->domain != pdomain->domain) 662 continue; 663 664 /* Here i and j are in the same domain */ 665 666 if (match_pdomain->num_processors != count_target) { 667 retval = -EINVAL; 668 goto err_ret; 669 } 670 671 if (pdomain->coord_type != match_pdomain->coord_type) { 672 retval = -EINVAL; 673 goto err_ret; 674 } 675 676 cpumask_set_cpu(j, covered_cpus); 677 cpumask_set_cpu(j, pr->performance->shared_cpu_map); 678 } 679 680 for_each_possible_cpu(j) { 681 if (i == j) 682 continue; 683 684 match_pr = per_cpu(processors, j); 685 if (!match_pr) 686 continue; 687 688 match_pdomain = &(match_pr->performance->domain_info); 689 if (match_pdomain->domain != pdomain->domain) 690 continue; 691 692 match_pr->performance->shared_type = 693 pr->performance->shared_type; 694 cpumask_copy(match_pr->performance->shared_cpu_map, 695 pr->performance->shared_cpu_map); 696 } 697 } 698 699 err_ret: 700 for_each_possible_cpu(i) { 701 pr = per_cpu(processors, i); 702 if (!pr || !pr->performance) 703 continue; 704 705 /* Assume no coordination on any error parsing domain info */ 706 if (retval) { 707 cpumask_clear(pr->performance->shared_cpu_map); 708 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 709 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE; 710 } 711 pr->performance = NULL; /* Will be set for real in register */ 712 } 713 714 err_out: 715 mutex_unlock(&performance_mutex); 716 free_cpumask_var(covered_cpus); 717 return retval; 718 } 719 EXPORT_SYMBOL(acpi_processor_preregister_performance); 720 721 int 722 acpi_processor_register_performance(struct acpi_processor_performance 723 *performance, unsigned int cpu) 724 { 725 struct acpi_processor *pr; 726 727 if (!acpi_processor_cpufreq_init) 728 return -EINVAL; 729 730 mutex_lock(&performance_mutex); 731 732 pr = per_cpu(processors, cpu); 733 if (!pr) { 734 mutex_unlock(&performance_mutex); 735 return -ENODEV; 736 } 737 738 if (pr->performance) { 739 mutex_unlock(&performance_mutex); 740 return -EBUSY; 741 } 742 743 WARN_ON(!performance); 744 745 pr->performance = performance; 746 747 if (acpi_processor_get_performance_info(pr)) { 748 pr->performance = NULL; 749 mutex_unlock(&performance_mutex); 750 return -EIO; 751 } 752 753 mutex_unlock(&performance_mutex); 754 return 0; 755 } 756 757 EXPORT_SYMBOL(acpi_processor_register_performance); 758 759 void acpi_processor_unregister_performance(unsigned int cpu) 760 { 761 struct acpi_processor *pr; 762 763 mutex_lock(&performance_mutex); 764 765 pr = per_cpu(processors, cpu); 766 if (!pr) { 767 mutex_unlock(&performance_mutex); 768 return; 769 } 770 771 if (pr->performance) 772 kfree(pr->performance->states); 773 pr->performance = NULL; 774 775 mutex_unlock(&performance_mutex); 776 777 return; 778 } 779 780 EXPORT_SYMBOL(acpi_processor_unregister_performance); 781