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 PREFIX "ACPI: "
  43
  44 #define ACPI_PROCESSOR_CLASS            "processor"
  45 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
  46 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  47 ACPI_MODULE_NAME("processor_perflib");
  48
  49 static DEFINE_MUTEX(performance_mutex);
  50
  51 /* Use cpufreq debug layer for _PPC changes. */
  52 #define cpufreq_printk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \
  53                                                 "cpufreq-core", msg)
  54
  55 /*
  56  * _PPC support is implemented as a CPUfreq policy notifier:
  57  * This means each time a CPUfreq driver registered also with
  58  * the ACPI core is asked to change the speed policy, the maximum
  59  * value is adjusted so that it is within the platform limit.
  60  *
  61  * Also, when a new platform limit value is detected, the CPUfreq
  62  * policy is adjusted accordingly.
  63  */
  64
  65 /* ignore_ppc:
  66  * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
  67  *       ignore _PPC
  68  *  0 -> cpufreq low level drivers initialized -> consider _PPC values
  69  *  1 -> ignore _PPC totally -> forced by user through boot param
  70  */
  71 static int ignore_ppc = -1;
  72 module_param(ignore_ppc, int, 0644);
  73 MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
  74                  "limited by BIOS, this should help");
  75
  76 #define PPC_REGISTERED   1
  77 #define PPC_IN_USE       2
  78
  79 static int acpi_processor_ppc_status;
  80
  81 static int acpi_processor_ppc_notifier(struct notifier_block *nb,
  82                                        unsigned long event, void *data)
  83 {
  84         struct cpufreq_policy *policy = data;
  85         struct acpi_processor *pr;
  86         unsigned int ppc = 0;
  87
  88         if (event == CPUFREQ_START && ignore_ppc <= 0) {
  89                 ignore_ppc = 0;
  90                 return 0;
  91         }
  92
  93         if (ignore_ppc)
  94                 return 0;
  95
  96         if (event != CPUFREQ_INCOMPATIBLE)
  97                 return 0;
  98
  99         mutex_lock(&performance_mutex);
 100
 101         pr = per_cpu(processors, policy->cpu);
 102         if (!pr || !pr->performance)
 103                 goto out;
 104
 105         ppc = (unsigned int)pr->performance_platform_limit;
 106
 107         if (ppc >= pr->performance->state_count)
 108                 goto out;
 109
 110         cpufreq_verify_within_limits(policy, 0,
 111                                      pr->performance->states[ppc].
 112                                      core_frequency * 1000);
 113
 114       out:
 115         mutex_unlock(&performance_mutex);
 116
 117         return 0;
 118 }
 119
 120 static struct notifier_block acpi_ppc_notifier_block = {
 121         .notifier_call = acpi_processor_ppc_notifier,
 122 };
 123
 124 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 125 {
 126         acpi_status status = 0;
 127         unsigned long long ppc = 0;
 128
 129
 130         if (!pr)
 131                 return -EINVAL;
 132
 133         /*
 134          * _PPC indicates the maximum state currently supported by the platform
 135          * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
 136          */
 137         status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
 138
 139         if (status != AE_NOT_FOUND)
 140                 acpi_processor_ppc_status |= PPC_IN_USE;
 141
 142         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 143                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC"));
 144                 return -ENODEV;
 145         }
 146
 147         cpufreq_printk("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
 148                        (int)ppc, ppc ? "" : "not");
 149
 150         pr->performance_platform_limit = (int)ppc;
 151
 152         return 0;
 153 }
 154
 155 int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
 156 {
 157         int ret;
 158
 159         if (ignore_ppc)
 160                 return 0;
 161
 162         ret = acpi_processor_get_platform_limit(pr);
 163
 164         if (ret < 0)
 165                 return (ret);
 166         else
 167                 return cpufreq_update_policy(pr->id);
 168 }
 169
 170 void acpi_processor_ppc_init(void)
 171 {
 172         if (!cpufreq_register_notifier
 173             (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
 174                 acpi_processor_ppc_status |= PPC_REGISTERED;
 175         else
 176                 printk(KERN_DEBUG
 177                        "Warning: Processor Platform Limit not supported.\n");
 178 }
 179
 180 void acpi_processor_ppc_exit(void)
 181 {
 182         if (acpi_processor_ppc_status & PPC_REGISTERED)
 183                 cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
 184                                             CPUFREQ_POLICY_NOTIFIER);
 185
 186         acpi_processor_ppc_status &= ~PPC_REGISTERED;
 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_EXCEPTION((AE_INFO, status, "Evaluating _PCT"));
 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 static int acpi_processor_get_performance_states(struct acpi_processor *pr)
 252 {
 253         int result = 0;
 254         acpi_status status = AE_OK;
 255         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 256         struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
 257         struct acpi_buffer state = { 0, NULL };
 258         union acpi_object *pss = NULL;
 259         int i;
 260
 261
 262         status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
 263         if (ACPI_FAILURE(status)) {
 264                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PSS"));
 265                 return -ENODEV;
 266         }
 267
 268         pss = buffer.pointer;
 269         if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
 270                 printk(KERN_ERR PREFIX "Invalid _PSS data\n");
 271                 result = -EFAULT;
 272                 goto end;
 273         }
 274
 275         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
 276                           pss->package.count));
 277
 278         pr->performance->state_count = pss->package.count;
 279         pr->performance->states =
 280             kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
 281                     GFP_KERNEL);
 282         if (!pr->performance->states) {
 283                 result = -ENOMEM;
 284                 goto end;
 285         }
 286
 287         for (i = 0; i < pr->performance->state_count; i++) {
 288
 289                 struct acpi_processor_px *px = &(pr->performance->states[i]);
 290
 291                 state.length = sizeof(struct acpi_processor_px);
 292                 state.pointer = px;
 293
 294                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 295
 296                 status = acpi_extract_package(&(pss->package.elements[i]),
 297                                               &format, &state);
 298                 if (ACPI_FAILURE(status)) {
 299                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _PSS data"));
 300                         result = -EFAULT;
 301                         kfree(pr->performance->states);
 302                         goto end;
 303                 }
 304
 305                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 306                                   "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
 307                                   i,
 308                                   (u32) px->core_frequency,
 309                                   (u32) px->power,
 310                                   (u32) px->transition_latency,
 311                                   (u32) px->bus_master_latency,
 312                                   (u32) px->control, (u32) px->status));
 313
 314                 /*
 315                  * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
 316                  */
 317                 if (!px->core_frequency ||
 318                     ((u32)(px->core_frequency * 1000) !=
 319                      (px->core_frequency * 1000))) {
 320                         printk(KERN_ERR FW_BUG PREFIX
 321                                "Invalid BIOS _PSS frequency: 0x%llx MHz\n",
 322                                px->core_frequency);
 323                         result = -EFAULT;
 324                         kfree(pr->performance->states);
 325                         goto end;
 326                 }
 327         }
 328
 329       end:
 330         kfree(buffer.pointer);
 331
 332         return result;
 333 }
 334
 335 static int acpi_processor_get_performance_info(struct acpi_processor *pr)
 336 {
 337         int result = 0;
 338         acpi_status status = AE_OK;
 339         acpi_handle handle = NULL;
 340
 341         if (!pr || !pr->performance || !pr->handle)
 342                 return -EINVAL;
 343
 344         status = acpi_get_handle(pr->handle, "_PCT", &handle);
 345         if (ACPI_FAILURE(status)) {
 346                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 347                                   "ACPI-based processor performance control unavailable\n"));
 348                 return -ENODEV;
 349         }
 350
 351         result = acpi_processor_get_performance_control(pr);
 352         if (result)
 353                 goto update_bios;
 354
 355         result = acpi_processor_get_performance_states(pr);
 356         if (result)
 357                 goto update_bios;
 358
 359         return 0;
 360
 361         /*
 362          * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
 363          * the BIOS is older than the CPU and does not know its frequencies
 364          */
 365  update_bios:
 366 #ifdef CONFIG_X86
 367         if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
 368                 if(boot_cpu_has(X86_FEATURE_EST))
 369                         printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
 370                                "frequency support\n");
 371         }
 372 #endif
 373         return result;
 374 }
 375
 376 int acpi_processor_notify_smm(struct module *calling_module)
 377 {
 378         acpi_status status;
 379         static int is_done = 0;
 380
 381
 382         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 383                 return -EBUSY;
 384
 385         if (!try_module_get(calling_module))
 386                 return -EINVAL;
 387
 388         /* is_done is set to negative if an error occured,
 389          * and to postitive if _no_ error occured, but SMM
 390          * was already notified. This avoids double notification
 391          * which might lead to unexpected results...
 392          */
 393         if (is_done > 0) {
 394                 module_put(calling_module);
 395                 return 0;
 396         } else if (is_done < 0) {
 397                 module_put(calling_module);
 398                 return is_done;
 399         }
 400
 401         is_done = -EIO;
 402
 403         /* Can't write pstate_control to smi_command if either value is zero */
 404         if ((!acpi_gbl_FADT.smi_command) || (!acpi_gbl_FADT.pstate_control)) {
 405                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_control\n"));
 406                 module_put(calling_module);
 407                 return 0;
 408         }
 409
 410         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 411                           "Writing pstate_control [0x%x] to smi_command [0x%x]\n",
 412                           acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));
 413
 414         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 415                                     (u32) acpi_gbl_FADT.pstate_control, 8);
 416         if (ACPI_FAILURE(status)) {
 417                 ACPI_EXCEPTION((AE_INFO, status,
 418                                 "Failed to write pstate_control [0x%x] to "
 419                                 "smi_command [0x%x]", acpi_gbl_FADT.pstate_control,
 420                                 acpi_gbl_FADT.smi_command));
 421                 module_put(calling_module);
 422                 return status;
 423         }
 424
 425         /* Success. If there's no _PPC, we need to fear nothing, so
 426          * we can allow the cpufreq driver to be rmmod'ed. */
 427         is_done = 1;
 428
 429         if (!(acpi_processor_ppc_status & PPC_IN_USE))
 430                 module_put(calling_module);
 431
 432         return 0;
 433 }
 434
 435 EXPORT_SYMBOL(acpi_processor_notify_smm);
 436
 437 static int acpi_processor_get_psd(struct acpi_processor *pr)
 438 {
 439         int result = 0;
 440         acpi_status status = AE_OK;
 441         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 442         struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
 443         struct acpi_buffer state = {0, NULL};
 444         union acpi_object  *psd = NULL;
 445         struct acpi_psd_package *pdomain;
 446
 447         status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
 448         if (ACPI_FAILURE(status)) {
 449                 return -ENODEV;
 450         }
 451
 452         psd = buffer.pointer;
 453         if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
 454                 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
 455                 result = -EFAULT;
 456                 goto end;
 457         }
 458
 459         if (psd->package.count != 1) {
 460                 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
 461                 result = -EFAULT;
 462                 goto end;
 463         }
 464
 465         pdomain = &(pr->performance->domain_info);
 466
 467         state.length = sizeof(struct acpi_psd_package);
 468         state.pointer = pdomain;
 469
 470         status = acpi_extract_package(&(psd->package.elements[0]),
 471                 &format, &state);
 472         if (ACPI_FAILURE(status)) {
 473                 printk(KERN_ERR PREFIX "Invalid _PSD data\n");
 474                 result = -EFAULT;
 475                 goto end;
 476         }
 477
 478         if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
 479                 printk(KERN_ERR PREFIX "Unknown _PSD:num_entries\n");
 480                 result = -EFAULT;
 481                 goto end;
 482         }
 483
 484         if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
 485                 printk(KERN_ERR PREFIX "Unknown _PSD:revision\n");
 486                 result = -EFAULT;
 487                 goto end;
 488         }
 489
 490         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 491             pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 492             pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 493                 printk(KERN_ERR PREFIX "Invalid _PSD:coord_type\n");
 494                 result = -EFAULT;
 495                 goto end;
 496         }
 497 end:
 498         kfree(buffer.pointer);
 499         return result;
 500 }
 501
 502 int acpi_processor_preregister_performance(
 503                 struct acpi_processor_performance *performance)
 504 {
 505         int count, count_target;
 506         int retval = 0;
 507         unsigned int i, j;
 508         cpumask_var_t covered_cpus;
 509         struct acpi_processor *pr;
 510         struct acpi_psd_package *pdomain;
 511         struct acpi_processor *match_pr;
 512         struct acpi_psd_package *match_pdomain;
 513
 514         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
 515                 return -ENOMEM;
 516
 517         mutex_lock(&performance_mutex);
 518
 519         /*
 520          * Check if another driver has already registered, and abort before
 521          * changing pr->performance if it has. Check input data as well.
 522          */
 523         for_each_possible_cpu(i) {
 524                 pr = per_cpu(processors, i);
 525                 if (!pr) {
 526                         /* Look only at processors in ACPI namespace */
 527                         continue;
 528                 }
 529
 530                 if (pr->performance) {
 531                         retval = -EBUSY;
 532                         goto err_out;
 533                 }
 534
 535                 if (!performance || !per_cpu_ptr(performance, i)) {
 536                         retval = -EINVAL;
 537                         goto err_out;
 538                 }
 539         }
 540
 541         /* Call _PSD for all CPUs */
 542         for_each_possible_cpu(i) {
 543                 pr = per_cpu(processors, i);
 544                 if (!pr)
 545                         continue;
 546
 547                 pr->performance = per_cpu_ptr(performance, i);
 548                 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
 549                 if (acpi_processor_get_psd(pr)) {
 550                         retval = -EINVAL;
 551                         continue;
 552                 }
 553         }
 554         if (retval)
 555                 goto err_ret;
 556
 557         /*
 558          * Now that we have _PSD data from all CPUs, lets setup P-state
 559          * domain info.
 560          */
 561         for_each_possible_cpu(i) {
 562                 pr = per_cpu(processors, i);
 563                 if (!pr)
 564                         continue;
 565
 566                 if (cpumask_test_cpu(i, covered_cpus))
 567                         continue;
 568
 569                 pdomain = &(pr->performance->domain_info);
 570                 cpumask_set_cpu(i, pr->performance->shared_cpu_map);
 571                 cpumask_set_cpu(i, covered_cpus);
 572                 if (pdomain->num_processors <= 1)
 573                         continue;
 574
 575                 /* Validate the Domain info */
 576                 count_target = pdomain->num_processors;
 577                 count = 1;
 578                 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
 579                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 580                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
 581                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
 582                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
 583                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;
 584
 585                 for_each_possible_cpu(j) {
 586                         if (i == j)
 587                                 continue;
 588
 589                         match_pr = per_cpu(processors, j);
 590                         if (!match_pr)
 591                                 continue;
 592
 593                         match_pdomain = &(match_pr->performance->domain_info);
 594                         if (match_pdomain->domain != pdomain->domain)
 595                                 continue;
 596
 597                         /* Here i and j are in the same domain */
 598
 599                         if (match_pdomain->num_processors != count_target) {
 600                                 retval = -EINVAL;
 601                                 goto err_ret;
 602                         }
 603
 604                         if (pdomain->coord_type != match_pdomain->coord_type) {
 605                                 retval = -EINVAL;
 606                                 goto err_ret;
 607                         }
 608
 609                         cpumask_set_cpu(j, covered_cpus);
 610                         cpumask_set_cpu(j, pr->performance->shared_cpu_map);
 611                         count++;
 612                 }
 613
 614                 for_each_possible_cpu(j) {
 615                         if (i == j)
 616                                 continue;
 617
 618                         match_pr = per_cpu(processors, j);
 619                         if (!match_pr)
 620                                 continue;
 621
 622                         match_pdomain = &(match_pr->performance->domain_info);
 623                         if (match_pdomain->domain != pdomain->domain)
 624                                 continue;
 625
 626                         match_pr->performance->shared_type =
 627                                         pr->performance->shared_type;
 628                         cpumask_copy(match_pr->performance->shared_cpu_map,
 629                                      pr->performance->shared_cpu_map);
 630                 }
 631         }
 632
 633 err_ret:
 634         for_each_possible_cpu(i) {
 635                 pr = per_cpu(processors, i);
 636                 if (!pr || !pr->performance)
 637                         continue;
 638
 639                 /* Assume no coordination on any error parsing domain info */
 640                 if (retval) {
 641                         cpumask_clear(pr->performance->shared_cpu_map);
 642                         cpumask_set_cpu(i, pr->performance->shared_cpu_map);
 643                         pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 644                 }
 645                 pr->performance = NULL; /* Will be set for real in register */
 646         }
 647
 648 err_out:
 649         mutex_unlock(&performance_mutex);
 650         free_cpumask_var(covered_cpus);
 651         return retval;
 652 }
 653 EXPORT_SYMBOL(acpi_processor_preregister_performance);
 654
 655 int
 656 acpi_processor_register_performance(struct acpi_processor_performance
 657                                     *performance, unsigned int cpu)
 658 {
 659         struct acpi_processor *pr;
 660
 661         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 662                 return -EINVAL;
 663
 664         mutex_lock(&performance_mutex);
 665
 666         pr = per_cpu(processors, cpu);
 667         if (!pr) {
 668                 mutex_unlock(&performance_mutex);
 669                 return -ENODEV;
 670         }
 671
 672         if (pr->performance) {
 673                 mutex_unlock(&performance_mutex);
 674                 return -EBUSY;
 675         }
 676
 677         WARN_ON(!performance);
 678
 679         pr->performance = performance;
 680
 681         if (acpi_processor_get_performance_info(pr)) {
 682                 pr->performance = NULL;
 683                 mutex_unlock(&performance_mutex);
 684                 return -EIO;
 685         }
 686
 687         mutex_unlock(&performance_mutex);
 688         return 0;
 689 }
 690
 691 EXPORT_SYMBOL(acpi_processor_register_performance);
 692
 693 void
 694 acpi_processor_unregister_performance(struct acpi_processor_performance
 695                                       *performance, unsigned int cpu)
 696 {
 697         struct acpi_processor *pr;
 698
 699         mutex_lock(&performance_mutex);
 700
 701         pr = per_cpu(processors, cpu);
 702         if (!pr) {
 703                 mutex_unlock(&performance_mutex);
 704                 return;
 705         }
 706
 707         if (pr->performance)
 708                 kfree(pr->performance->states);
 709         pr->performance = NULL;
 710
 711         mutex_unlock(&performance_mutex);
 712
 713         return;
 714 }
 715
 716 EXPORT_SYMBOL(acpi_processor_unregister_performance);