drivers/acpi/processor_perflib.c

   1 /*
   2  * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *
  10  *
  11  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 2 of the License, or (at
  16  *  your option) any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful, but
  19  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  *  General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License along
  24  *  with this program; if not, write to the Free Software Foundation, Inc.,
  25  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  26  *
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/cpufreq.h>
  33
  34 #ifdef CONFIG_X86
  35 #include <asm/cpufeature.h>
  36 #endif
  37
  38 #include <acpi/acpi_bus.h>
  39 #include <acpi/acpi_drivers.h>
  40 #include <acpi/processor.h>
  41
  42 #define ACPI_PROCESSOR_CLASS            "processor"
  43 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
  44 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  45 ACPI_MODULE_NAME("processor_perflib");
  46
  47 static DEFINE_MUTEX(performance_mutex);
  48
  49 /* Use cpufreq debug layer for _PPC changes. */
  50 #define cpufreq_printk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \
  51                                                 "cpufreq-core", msg)
  52
  53 /*
  54  * _PPC support is implemented as a CPUfreq policy notifier:
  55  * This means each time a CPUfreq driver registered also with
  56  * the ACPI core is asked to change the speed policy, the maximum
  57  * value is adjusted so that it is within the platform limit.
  58  *
  59  * Also, when a new platform limit value is detected, the CPUfreq
  60  * policy is adjusted accordingly.
  61  */
  62
  63 /* ignore_ppc:
  64  * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
  65  *       ignore _PPC
  66  *  0 -> cpufreq low level drivers initialized -> consider _PPC values
  67  *  1 -> ignore _PPC totally -> forced by user through boot param
  68  */
  69 static int ignore_ppc = -1;
  70 module_param(ignore_ppc, int, 0644);
  71 MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
  72                  "limited by BIOS, this should help");
  73
  74 #define PPC_REGISTERED   1
  75 #define PPC_IN_USE       2
  76
  77 static int acpi_processor_ppc_status;
  78
  79 static int acpi_processor_ppc_notifier(struct notifier_block *nb,
  80                                        unsigned long event, void *data)
  81 {
  82         struct cpufreq_policy *policy = data;
  83         struct acpi_processor *pr;
  84         unsigned int ppc = 0;
  85
  86         if (event == CPUFREQ_START && ignore_ppc <= 0) {
  87                 ignore_ppc = 0;
  88                 return 0;
  89         }
  90
  91         if (ignore_ppc)
  92                 return 0;
  93
  94         if (event != CPUFREQ_INCOMPATIBLE)
  95                 return 0;
  96
  97         mutex_lock(&performance_mutex);
  98
  99         pr = per_cpu(processors, policy->cpu);
 100         if (!pr || !pr->performance)
 101                 goto out;
 102
 103         ppc = (unsigned int)pr->performance_platform_limit;
 104
 105         if (ppc >= pr->performance->state_count)
 106                 goto out;
 107
 108         cpufreq_verify_within_limits(policy, 0,
 109                                      pr->performance->states[ppc].
 110                                      core_frequency * 1000);
 111
 112       out:
 113         mutex_unlock(&performance_mutex);
 114
 115         return 0;
 116 }
 117
 118 static struct notifier_block acpi_ppc_notifier_block = {
 119         .notifier_call = acpi_processor_ppc_notifier,
 120 };
 121
 122 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 123 {
 124         acpi_status status = 0;
 125         unsigned long long ppc = 0;
 126
 127
 128         if (!pr)
 129                 return -EINVAL;
 130
 131         /*
 132          * _PPC indicates the maximum state currently supported by the platform
 133          * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
 134          */
 135         status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
 136
 137         if (status != AE_NOT_FOUND)
 138                 acpi_processor_ppc_status |= PPC_IN_USE;
 139
 140         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 141                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC"));
 142                 return -ENODEV;
 143         }
 144
 145         cpufreq_printk("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
 146                        (int)ppc, ppc ? "" : "not");
 147
 148         pr->performance_platform_limit = (int)ppc;
 149
 150         return 0;
 151 }
 152
 153 int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
 154 {
 155         int ret;
 156
 157         if (ignore_ppc)
 158                 return 0;
 159
 160         ret = acpi_processor_get_platform_limit(pr);
 161
 162         if (ret < 0)
 163                 return (ret);
 164         else
 165                 return cpufreq_update_policy(pr->id);
 166 }
 167
 168 void acpi_processor_ppc_init(void)
 169 {
 170         if (!cpufreq_register_notifier
 171             (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
 172                 acpi_processor_ppc_status |= PPC_REGISTERED;
 173         else
 174                 printk(KERN_DEBUG
 175                        "Warning: Processor Platform Limit not supported.\n");
 176 }
 177
 178 void acpi_processor_ppc_exit(void)
 179 {
 180         if (acpi_processor_ppc_status & PPC_REGISTERED)
 181                 cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
 182                                             CPUFREQ_POLICY_NOTIFIER);
 183
 184         acpi_processor_ppc_status &= ~PPC_REGISTERED;
 185 }
 186
 187 static int acpi_processor_get_performance_control(struct acpi_processor *pr)
 188 {
 189         int result = 0;
 190         acpi_status status = 0;
 191         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 192         union acpi_object *pct = NULL;
 193         union acpi_object obj = { 0 };
 194
 195
 196         status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
 197         if (ACPI_FAILURE(status)) {
 198                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PCT"));
 199                 return -ENODEV;
 200         }
 201
 202         pct = (union acpi_object *)buffer.pointer;
 203         if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
 204             || (pct->package.count != 2)) {
 205                 printk(KERN_ERR PREFIX "Invalid _PCT data\n");
 206                 result = -EFAULT;
 207                 goto end;
 208         }
 209
 210         /*
 211          * control_register
 212          */
 213
 214         obj = pct->package.elements[0];
 215
 216         if ((obj.type != ACPI_TYPE_BUFFER)
 217             || (obj.buffer.length < sizeof(struct acpi_pct_register))
 218             || (obj.buffer.pointer == NULL)) {
 219                 printk(KERN_ERR PREFIX "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.type != ACPI_TYPE_BUFFER)
 233             || (obj.buffer.length < sizeof(struct acpi_pct_register))
 234             || (obj.buffer.pointer == NULL)) {
 235                 printk(KERN_ERR PREFIX "Invalid _PCT data (status_register)\n");
 236                 result = -EFAULT;
 237                 goto end;
 238         }
 239
 240         memcpy(&pr->performance->status_register, obj.buffer.pointer,
 241                sizeof(struct acpi_pct_register));
 242
 243       end:
 244         kfree(buffer.pointer);
 245
 246         return result;
 247 }
 248
 249 static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 250 {
 251         int result = 0;
 252         acpi_status status = AE_OK;
 253         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 254         struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
 255         struct acpi_buffer state = { 0, NULL };
 256         union acpi_object *pss = NULL;
 257         int i;
 258
 259
 260         status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
 261         if (ACPI_FAILURE(status)) {
 262                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PSS"));
 263                 return -ENODEV;
 264         }
 265
 266         pss = buffer.pointer;
 267         if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
 268                 printk(KERN_ERR PREFIX "Invalid _PSS data\n");
 269                 result = -EFAULT;
 270                 goto end;
 271         }
 272
 273         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
 274                           pss->package.count));
 275
 276         pr->performance->state_count = pss->package.count;
 277         pr->performance->states =
 278             kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
 279                     GFP_KERNEL);
 280         if (!pr->performance->states) {
 281                 result = -ENOMEM;
 282                 goto end;
 283         }
 284
 285         for (i = 0; i < pr->performance->state_count; i++) {
 286
 287                 struct acpi_processor_px *px = &(pr->performance->states[i]);
 288
 289                 state.length = sizeof(struct acpi_processor_px);
 290                 state.pointer = px;
 291
 292                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 293
 294                 status = acpi_extract_package(&(pss->package.elements[i]),
 295                                               &format, &state);
 296                 if (ACPI_FAILURE(status)) {
 297                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _PSS data"));
 298                         result = -EFAULT;
 299                         kfree(pr->performance->states);
 300                         goto end;
 301                 }
 302
 303                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 304                                   "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
 305                                   i,
 306                                   (u32) px->core_frequency,
 307                                   (u32) px->power,
 308                                   (u32) px->transition_latency,
 309                                   (u32) px->bus_master_latency,
 310                                   (u32) px->control, (u32) px->status));
 311
 312                 if (!px->core_frequency) {
 313                         printk(KERN_ERR PREFIX
 314                                     "Invalid _PSS data: freq is zero\n");
 315                         result = -EFAULT;
 316                         kfree(pr->performance->states);
 317                         goto end;
 318                 }
 319         }
 320
 321       end:
 322         kfree(buffer.pointer);
 323
 324         return result;
 325 }
 326
 327 static int acpi_processor_get_performance_info(struct acpi_processor *pr)
 328 {
 329         int result = 0;
 330         acpi_status status = AE_OK;
 331         acpi_handle handle = NULL;
 332
 333         if (!pr || !pr->performance || !pr->handle)
 334                 return -EINVAL;
 335
 336         status = acpi_get_handle(pr->handle, "_PCT", &handle);
 337         if (ACPI_FAILURE(status)) {
 338                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 339                                   "ACPI-based processor performance control unavailable\n"));
 340                 return -ENODEV;
 341         }
 342
 343         result = acpi_processor_get_performance_control(pr);
 344         if (result)
 345                 goto update_bios;
 346
 347         result = acpi_processor_get_performance_states(pr);
 348         if (result)
 349                 goto update_bios;
 350
 351         return 0;
 352
 353         /*
 354          * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
 355          * the BIOS is older than the CPU and does not know its frequencies
 356          */
 357  update_bios:
 358 #ifdef CONFIG_X86
 359         if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
 360                 if(boot_cpu_has(X86_FEATURE_EST))
 361                         printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
 362                                "frequency support\n");
 363         }
 364 #endif
 365         return result;
 366 }
 367
 368 int acpi_processor_notify_smm(struct module *calling_module)
 369 {
 370         acpi_status status;
 371         static int is_done = 0;
 372
 373
 374         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 375                 return -EBUSY;
 376
 377         if (!try_module_get(calling_module))
 378                 return -EINVAL;
 379
 380         /* is_done is set to negative if an error occured,
 381          * and to postitive if _no_ error occured, but SMM
 382          * was already notified. This avoids double notification
 383          * which might lead to unexpected results...
 384          */
 385         if (is_done > 0) {
 386                 module_put(calling_module);
 387                 return 0;
 388         } else if (is_done < 0) {
 389                 module_put(calling_module);
 390                 return is_done;
 391         }
 392
 393         is_done = -EIO;
 394
 395         /* Can't write pstate_control to smi_command if either value is zero */
 396         if ((!acpi_gbl_FADT.smi_command) || (!acpi_gbl_FADT.pstate_control)) {
 397                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_control\n"));
 398                 module_put(calling_module);
 399                 return 0;
 400         }
 401
 402         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 403                           "Writing pstate_control [0x%x] to smi_command [0x%x]\n",
 404                           acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));
 405
 406         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 407                                     (u32) acpi_gbl_FADT.pstate_control, 8);
 408         if (ACPI_FAILURE(status)) {
 409                 ACPI_EXCEPTION((AE_INFO, status,
 410                                 "Failed to write pstate_control [0x%x] to "
 411                                 "smi_command [0x%x]", acpi_gbl_FADT.pstate_control,
 412                                 acpi_gbl_FADT.smi_command));
 413                 module_put(calling_module);
 414                 return status;
 415         }
 416
 417         /* Success. If there's no _PPC, we need to fear nothing, so
 418          * we can allow the cpufreq driver to be rmmod'ed. */
 419         is_done = 1;
 420
 421         if (!(acpi_processor_ppc_status & PPC_IN_USE))
 422                 module_put(calling_module);
 423
 424         return 0;
 425 }
 426
 427 EXPORT_SYMBOL(acpi_processor_notify_smm);
 428
 429 static int acpi_processor_get_psd(struct acpi_processor *pr)
 430 {
 431         int result = 0;
 432         acpi_status status = AE_OK;
 433         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 434         struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
 435         struct acpi_buffer state = {0, NULL};
 436         union acpi_object  *psd = NULL;
 437         struct acpi_psd_package *pdomain;
 438
 439         status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
 440         if (ACPI_FAILURE(status)) {
 441                 return -ENODEV;
 442         }
 443
 444         psd = buffer.pointer;
 445         if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
 446                 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
 447                 result = -EFAULT;
 448                 goto end;
 449         }
 450
 451         if (psd->package.count != 1) {
 452                 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
 453                 result = -EFAULT;
 454                 goto end;
 455         }
 456
 457         pdomain = &(pr->performance->domain_info);
 458
 459         state.length = sizeof(struct acpi_psd_package);
 460         state.pointer = pdomain;
 461
 462         status = acpi_extract_package(&(psd->package.elements[0]),
 463                 &format, &state);
 464         if (ACPI_FAILURE(status)) {
 465                 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
 466                 result = -EFAULT;
 467                 goto end;
 468         }
 469
 470         if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
 471                 printk(KERN_ERR PREFIX "Unknown _PSD:num_entries\n");
 472                 result = -EFAULT;
 473                 goto end;
 474         }
 475
 476         if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
 477                 printk(KERN_ERR PREFIX "Unknown _PSD:revision\n");
 478                 result = -EFAULT;
 479                 goto end;
 480         }
 481
 482         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 483             pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 484             pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 485                 printk(KERN_ERR PREFIX "Invalid _PSD:coord_type\n");
 486                 result = -EFAULT;
 487                 goto end;
 488         }
 489 end:
 490         kfree(buffer.pointer);
 491         return result;
 492 }
 493
 494 int acpi_processor_preregister_performance(
 495                 struct acpi_processor_performance *performance)
 496 {
 497         int count, count_target;
 498         int retval = 0;
 499         unsigned int i, j;
 500         cpumask_var_t covered_cpus;
 501         struct acpi_processor *pr;
 502         struct acpi_psd_package *pdomain;
 503         struct acpi_processor *match_pr;
 504         struct acpi_psd_package *match_pdomain;
 505
 506         if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))
 507                 return -ENOMEM;
 508
 509         mutex_lock(&performance_mutex);
 510
 511         /*
 512          * Check if another driver has already registered, and abort before
 513          * changing pr->performance if it has. Check input data as well.
 514          */
 515         for_each_possible_cpu(i) {
 516                 pr = per_cpu(processors, i);
 517                 if (!pr) {
 518                         /* Look only at processors in ACPI namespace */
 519                         continue;
 520                 }
 521
 522                 if (pr->performance) {
 523                         retval = -EBUSY;
 524                         goto err_out;
 525                 }
 526
 527                 if (!performance || !per_cpu_ptr(performance, i)) {
 528                         retval = -EINVAL;
 529                         goto err_out;
 530                 }
 531         }
 532
 533         /* Call _PSD for all CPUs */
 534         for_each_possible_cpu(i) {
 535                 pr = per_cpu(processors, i);
 536                 if (!pr)
 537                         continue;
 538
 539                 pr->performance = per_cpu_ptr(performance, i);
 540                 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
 541                 if (acpi_processor_get_psd(pr)) {
 542                         retval = -EINVAL;
 543                         continue;
 544                 }
 545         }
 546         if (retval)
 547                 goto err_ret;
 548
 549         /*
 550          * Now that we have _PSD data from all CPUs, lets setup P-state
 551          * domain info.
 552          */
 553         cpumask_clear(covered_cpus);
 554         for_each_possible_cpu(i) {
 555                 pr = per_cpu(processors, i);
 556                 if (!pr)
 557                         continue;
 558
 559                 if (cpumask_test_cpu(i, covered_cpus))
 560                         continue;
 561
 562                 pdomain = &(pr->performance->domain_info);
 563                 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
 564                 cpumask_set_cpu(i, covered_cpus);
 565                 if (pdomain->num_processors <= 1)
 566                         continue;
 567
 568                 /* Validate the Domain info */
 569                 count_target = pdomain->num_processors;
 570                 count = 1;
 571                 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
 572                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 573                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
 574                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
 575                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
 576                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
 577
 578                 for_each_possible_cpu(j) {
 579                         if (i == j)
 580                                 continue;
 581
 582                         match_pr = per_cpu(processors, j);
 583                         if (!match_pr)
 584                                 continue;
 585
 586                         match_pdomain = &(match_pr->performance->domain_info);
 587                         if (match_pdomain->domain != pdomain->domain)
 588                                 continue;
 589
 590                         /* Here i and j are in the same domain */
 591
 592                         if (match_pdomain->num_processors != count_target) {
 593                                 retval = -EINVAL;
 594                                 goto err_ret;
 595                         }
 596
 597                         if (pdomain->coord_type != match_pdomain->coord_type) {
 598                                 retval = -EINVAL;
 599                                 goto err_ret;
 600                         }
 601
 602                         cpumask_set_cpu(j, covered_cpus);
 603                         cpumask_set_cpu(j, pr->performance->shared_cpu_map);
 604                         count++;
 605                 }
 606
 607                 for_each_possible_cpu(j) {
 608                         if (i == j)
 609                                 continue;
 610
 611                         match_pr = per_cpu(processors, j);
 612                         if (!match_pr)
 613                                 continue;
 614
 615                         match_pdomain = &(match_pr->performance->domain_info);
 616                         if (match_pdomain->domain != pdomain->domain)
 617                                 continue;
 618
 619                         match_pr->performance->shared_type =
 620                                         pr->performance->shared_type;
 621                         cpumask_copy(match_pr->performance->shared_cpu_map,
 622                                      pr->performance->shared_cpu_map);
 623                 }
 624         }
 625
 626 err_ret:
 627         for_each_possible_cpu(i) {
 628                 pr = per_cpu(processors, i);
 629                 if (!pr || !pr->performance)
 630                         continue;
 631
 632                 /* Assume no coordination on any error parsing domain info */
 633                 if (retval) {
 634                         cpumask_clear(pr->performance->shared_cpu_map);
 635                         cpumask_set_cpu(i, pr->performance->shared_cpu_map);
 636                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 637                 }
 638                 pr->performance = NULL; /* Will be set for real in register */
 639         }
 640
 641 err_out:
 642         mutex_unlock(&performance_mutex);
 643         free_cpumask_var(covered_cpus);
 644         return retval;
 645 }
 646 EXPORT_SYMBOL(acpi_processor_preregister_performance);
 647
 648 int
 649 acpi_processor_register_performance(struct acpi_processor_performance
 650                                     *performance, unsigned int cpu)
 651 {
 652         struct acpi_processor *pr;
 653
 654         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 655                 return -EINVAL;
 656
 657         mutex_lock(&performance_mutex);
 658
 659         pr = per_cpu(processors, cpu);
 660         if (!pr) {
 661                 mutex_unlock(&performance_mutex);
 662                 return -ENODEV;
 663         }
 664
 665         if (pr->performance) {
 666                 mutex_unlock(&performance_mutex);
 667                 return -EBUSY;
 668         }
 669
 670         WARN_ON(!performance);
 671
 672         pr->performance = performance;
 673
 674         if (acpi_processor_get_performance_info(pr)) {
 675                 pr->performance = NULL;
 676                 mutex_unlock(&performance_mutex);
 677                 return -EIO;
 678         }
 679
 680         mutex_unlock(&performance_mutex);
 681         return 0;
 682 }
 683
 684 EXPORT_SYMBOL(acpi_processor_register_performance);
 685
 686 void
 687 acpi_processor_unregister_performance(struct acpi_processor_performance
 688                                       *performance, unsigned int cpu)
 689 {
 690         struct acpi_processor *pr;
 691
 692         mutex_lock(&performance_mutex);
 693
 694         pr = per_cpu(processors, cpu);
 695         if (!pr) {
 696                 mutex_unlock(&performance_mutex);
 697                 return;
 698         }
 699
 700         if (pr->performance)
 701                 kfree(pr->performance->states);
 702         pr->performance = NULL;
 703
 704         mutex_unlock(&performance_mutex);
 705
 706         return;
 707 }
 708
 709 EXPORT_SYMBOL(acpi_processor_unregister_performance);