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   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
  30 #include <linux/kernel.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/cpufreq.h>
  34
  35 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
  36 #include <linux/proc_fs.h>
  37 #include <linux/seq_file.h>
  38
  39 #include <asm/uaccess.h>
  40 #endif
  41
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/processor.h>
  44
  45
  46 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
  49 #define ACPI_PROCESSOR_FILE_PERFORMANCE "performance"
  50 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  51 ACPI_MODULE_NAME                ("acpi_processor")
  52
  53
  54 static DECLARE_MUTEX(performance_sem);
  55
  56 /*
  57  * _PPC support is implemented as a CPUfreq policy notifier:
  58  * This means each time a CPUfreq driver registered also with
  59  * the ACPI core is asked to change the speed policy, the maximum
  60  * value is adjusted so that it is within the platform limit.
  61  *
  62  * Also, when a new platform limit value is detected, the CPUfreq
  63  * policy is adjusted accordingly.
  64  */
  65
  66 #define PPC_REGISTERED   1
  67 #define PPC_IN_USE       2
  68
  69 static int acpi_processor_ppc_status = 0;
  70
  71 static int acpi_processor_ppc_notifier(struct notifier_block *nb,
  72         unsigned long event,
  73         void *data)
  74 {
  75         struct cpufreq_policy *policy = data;
  76         struct acpi_processor *pr;
  77         unsigned int ppc = 0;
  78
  79         down(&performance_sem);
  80
  81         if (event != CPUFREQ_INCOMPATIBLE)
  82                 goto out;
  83
  84         pr = processors[policy->cpu];
  85         if (!pr || !pr->performance)
  86                 goto out;
  87
  88         ppc = (unsigned int) pr->performance_platform_limit;
  89         if (!ppc)
  90                 goto out;
  91
  92         if (ppc > pr->performance->state_count)
  93                 goto out;
  94
  95         cpufreq_verify_within_limits(policy, 0,
  96                 pr->performance->states[ppc].core_frequency * 1000);
  97
  98  out:
  99         up(&performance_sem);
 100
 101         return 0;
 102 }
 103
 104
 105 static struct notifier_block acpi_ppc_notifier_block = {
 106         .notifier_call = acpi_processor_ppc_notifier,
 107 };
 108
 109
 110 static int
 111 acpi_processor_get_platform_limit (
 112         struct acpi_processor*  pr)
 113 {
 114         acpi_status             status = 0;
 115         unsigned long           ppc = 0;
 116
 117         ACPI_FUNCTION_TRACE("acpi_processor_get_platform_limit");
 118
 119         if (!pr)
 120                 return_VALUE(-EINVAL);
 121
 122         /*
 123          * _PPC indicates the maximum state currently supported by the platform
 124          * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
 125          */
 126         status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
 127
 128         if (status != AE_NOT_FOUND)
 129                 acpi_processor_ppc_status |= PPC_IN_USE;
 130
 131         if(ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 132                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PPC\n"));
 133                 return_VALUE(-ENODEV);
 134         }
 135
 136         pr->performance_platform_limit = (int) ppc;
 137
 138         return_VALUE(0);
 139 }
 140
 141
 142 int acpi_processor_ppc_has_changed(
 143         struct acpi_processor *pr)
 144 {
 145         int ret = acpi_processor_get_platform_limit(pr);
 146         if (ret < 0)
 147                 return (ret);
 148         else
 149                 return cpufreq_update_policy(pr->id);
 150 }
 151
 152
 153 void acpi_processor_ppc_init(void) {
 154         if (!cpufreq_register_notifier(&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
 155                 acpi_processor_ppc_status |= PPC_REGISTERED;
 156         else
 157                 printk(KERN_DEBUG "Warning: Processor Platform Limit not supported.\n");
 158 }
 159
 160
 161 void acpi_processor_ppc_exit(void) {
 162         if (acpi_processor_ppc_status & PPC_REGISTERED)
 163                 cpufreq_unregister_notifier(&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER);
 164
 165         acpi_processor_ppc_status &= ~PPC_REGISTERED;
 166 }
 167
 168 /*
 169  * when registering a cpufreq driver with this ACPI processor driver, the
 170  * _PCT and _PSS structures are read out and written into struct
 171  * acpi_processor_performance.
 172  */
 173 static int acpi_processor_set_pdc (struct acpi_processor *pr)
 174 {
 175         acpi_status             status = AE_OK;
 176         u32                     arg0_buf[3];
 177         union acpi_object       arg0 = {ACPI_TYPE_BUFFER};
 178         struct acpi_object_list no_object = {1, &arg0};
 179         struct acpi_object_list *pdc;
 180
 181         ACPI_FUNCTION_TRACE("acpi_processor_set_pdc");
 182
 183         arg0.buffer.length = 12;
 184         arg0.buffer.pointer = (u8 *) arg0_buf;
 185         arg0_buf[0] = ACPI_PDC_REVISION_ID;
 186         arg0_buf[1] = 0;
 187         arg0_buf[2] = 0;
 188
 189         pdc = (pr->performance->pdc) ? pr->performance->pdc : &no_object;
 190
 191         status = acpi_evaluate_object(pr->handle, "_PDC", pdc, NULL);
 192
 193         if ((ACPI_FAILURE(status)) && (pr->performance->pdc))
 194                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Error evaluating _PDC, using legacy perf. control...\n"));
 195
 196         return_VALUE(status);
 197 }
 198
 199
 200 static int
 201 acpi_processor_get_performance_control (
 202         struct acpi_processor *pr)
 203 {
 204         int                     result = 0;
 205         acpi_status             status = 0;
 206         struct acpi_buffer      buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 207         union acpi_object       *pct = NULL;
 208         union acpi_object       obj = {0};
 209
 210         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_control");
 211
 212         status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
 213         if(ACPI_FAILURE(status)) {
 214                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PCT\n"));
 215                 return_VALUE(-ENODEV);
 216         }
 217
 218         pct = (union acpi_object *) buffer.pointer;
 219         if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
 220                 || (pct->package.count != 2)) {
 221                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PCT data\n"));
 222                 result = -EFAULT;
 223                 goto end;
 224         }
 225
 226         /*
 227          * control_register
 228          */
 229
 230         obj = pct->package.elements[0];
 231
 232         if ((obj.type != ACPI_TYPE_BUFFER)
 233                 || (obj.buffer.length < sizeof(struct acpi_pct_register))
 234                 || (obj.buffer.pointer == NULL)) {
 235                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 236                         "Invalid _PCT data (control_register)\n"));
 237                 result = -EFAULT;
 238                 goto end;
 239         }
 240         memcpy(&pr->performance->control_register, obj.buffer.pointer, sizeof(struct acpi_pct_register));
 241
 242
 243         /*
 244          * status_register
 245          */
 246
 247         obj = pct->package.elements[1];
 248
 249         if ((obj.type != ACPI_TYPE_BUFFER)
 250                 || (obj.buffer.length < sizeof(struct acpi_pct_register))
 251                 || (obj.buffer.pointer == NULL)) {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 253                         "Invalid _PCT data (status_register)\n"));
 254                 result = -EFAULT;
 255                 goto end;
 256         }
 257
 258         memcpy(&pr->performance->status_register, obj.buffer.pointer, sizeof(struct acpi_pct_register));
 259
 260 end:
 261         acpi_os_free(buffer.pointer);
 262
 263         return_VALUE(result);
 264 }
 265
 266
 267 static int
 268 acpi_processor_get_performance_states (
 269         struct acpi_processor   *pr)
 270 {
 271         int                     result = 0;
 272         acpi_status             status = AE_OK;
 273         struct acpi_buffer      buffer = {ACPI_ALLOCATE_BUFFER, NULL};
 274         struct acpi_buffer      format = {sizeof("NNNNNN"), "NNNNNN"};
 275         struct acpi_buffer      state = {0, NULL};
 276         union acpi_object       *pss = NULL;
 277         int                     i;
 278
 279         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");
 280
 281         status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
 282         if(ACPI_FAILURE(status)) {
 283                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PSS\n"));
 284                 return_VALUE(-ENODEV);
 285         }
 286
 287         pss = (union acpi_object *) buffer.pointer;
 288         if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
 289                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
 290                 result = -EFAULT;
 291                 goto end;
 292         }
 293
 294         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
 295                 pss->package.count));
 296
 297         pr->performance->state_count = pss->package.count;
 298         pr->performance->states = kmalloc(sizeof(struct acpi_processor_px) * pss->package.count, GFP_KERNEL);
 299         if (!pr->performance->states) {
 300                 result = -ENOMEM;
 301                 goto end;
 302         }
 303
 304         for (i = 0; i < pr->performance->state_count; i++) {
 305
 306                 struct acpi_processor_px *px = &(pr->performance->states[i]);
 307
 308                 state.length = sizeof(struct acpi_processor_px);
 309                 state.pointer = px;
 310
 311                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 312
 313                 status = acpi_extract_package(&(pss->package.elements[i]),
 314                         &format, &state);
 315                 if (ACPI_FAILURE(status)) {
 316                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
 317                         result = -EFAULT;
 318                         kfree(pr->performance->states);
 319                         goto end;
 320                 }
 321
 322                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 323                         "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
 324                         i,
 325                         (u32) px->core_frequency,
 326                         (u32) px->power,
 327                         (u32) px->transition_latency,
 328                         (u32) px->bus_master_latency,
 329                         (u32) px->control,
 330                         (u32) px->status));
 331
 332                 if (!px->core_frequency) {
 333                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data: freq is zero\n"));
 334                         result = -EFAULT;
 335                         kfree(pr->performance->states);
 336                         goto end;
 337                 }
 338         }
 339
 340 end:
 341         acpi_os_free(buffer.pointer);
 342
 343         return_VALUE(result);
 344 }
 345
 346
 347 static int
 348 acpi_processor_get_performance_info (
 349         struct acpi_processor   *pr)
 350 {
 351         int                     result = 0;
 352         acpi_status             status = AE_OK;
 353         acpi_handle             handle = NULL;
 354
 355         ACPI_FUNCTION_TRACE("acpi_processor_get_performance_info");
 356
 357         if (!pr || !pr->performance || !pr->handle)
 358                 return_VALUE(-EINVAL);
 359
 360         acpi_processor_set_pdc(pr);
 361
 362         status = acpi_get_handle(pr->handle, "_PCT", &handle);
 363         if (ACPI_FAILURE(status)) {
 364                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 365                         "ACPI-based processor performance control unavailable\n"));
 366                 return_VALUE(-ENODEV);
 367         }
 368
 369         result = acpi_processor_get_performance_control(pr);
 370         if (result)
 371                 return_VALUE(result);
 372
 373         result = acpi_processor_get_performance_states(pr);
 374         if (result)
 375                 return_VALUE(result);
 376
 377         result = acpi_processor_get_platform_limit(pr);
 378         if (result)
 379                 return_VALUE(result);
 380
 381         return_VALUE(0);
 382 }
 383
 384
 385 int acpi_processor_notify_smm(struct module *calling_module) {
 386         acpi_status             status;
 387         static int              is_done = 0;
 388
 389         ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
 390
 391         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 392                 return_VALUE(-EBUSY);
 393
 394         if (!try_module_get(calling_module))
 395                 return_VALUE(-EINVAL);
 396
 397         /* is_done is set to negative if an error occured,
 398          * and to postitive if _no_ error occured, but SMM
 399          * was already notified. This avoids double notification
 400          * which might lead to unexpected results...
 401          */
 402         if (is_done > 0) {
 403                 module_put(calling_module);
 404                 return_VALUE(0);
 405         }
 406         else if (is_done < 0) {
 407                 module_put(calling_module);
 408                 return_VALUE(is_done);
 409         }
 410
 411         is_done = -EIO;
 412
 413         /* Can't write pstate_cnt to smi_cmd if either value is zero */
 414         if ((!acpi_fadt.smi_cmd) ||
 415             (!acpi_fadt.pstate_cnt)) {
 416                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 417                         "No SMI port or pstate_cnt\n"));
 418                 module_put(calling_module);
 419                 return_VALUE(0);
 420         }
 421
 422         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
 423
 424         /* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
 425          * it anyway, so we need to support it... */
 426         if (acpi_fadt_is_v1) {
 427                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Using v1.0 FADT reserved value for pstate_cnt\n"));
 428         }
 429
 430         status = acpi_os_write_port (acpi_fadt.smi_cmd,
 431                                      (u32) acpi_fadt.pstate_cnt, 8);
 432         if (ACPI_FAILURE (status)) {
 433                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 434                                   "Failed to write pstate_cnt [0x%x] to "
 435                                   "smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
 436                 module_put(calling_module);
 437                 return_VALUE(status);
 438         }
 439
 440         /* Success. If there's no _PPC, we need to fear nothing, so
 441          * we can allow the cpufreq driver to be rmmod'ed. */
 442         is_done = 1;
 443
 444         if (!(acpi_processor_ppc_status & PPC_IN_USE))
 445                 module_put(calling_module);
 446
 447         return_VALUE(0);
 448 }
 449 EXPORT_SYMBOL(acpi_processor_notify_smm);
 450
 451
 452 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
 453 /* /proc/acpi/processor/../performance interface (DEPRECATED) */
 454
 455 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
 456 static struct file_operations acpi_processor_perf_fops = {
 457         .open           = acpi_processor_perf_open_fs,
 458         .read           = seq_read,
 459         .llseek         = seq_lseek,
 460         .release        = single_release,
 461 };
 462
 463 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
 464 {
 465         struct acpi_processor   *pr = (struct acpi_processor *)seq->private;
 466         int                     i;
 467
 468         ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
 469
 470         if (!pr)
 471                 goto end;
 472
 473         if (!pr->performance) {
 474                 seq_puts(seq, "<not supported>\n");
 475                 goto end;
 476         }
 477
 478         seq_printf(seq, "state count:             %d\n"
 479                         "active state:            P%d\n",
 480                         pr->performance->state_count,
 481                         pr->performance->state);
 482
 483         seq_puts(seq, "states:\n");
 484         for (i = 0; i < pr->performance->state_count; i++)
 485                 seq_printf(seq, "   %cP%d:                  %d MHz, %d mW, %d uS\n",
 486                         (i == pr->performance->state?'*':' '), i,
 487                         (u32) pr->performance->states[i].core_frequency,
 488                         (u32) pr->performance->states[i].power,
 489                         (u32) pr->performance->states[i].transition_latency);
 490
 491 end:
 492         return_VALUE(0);
 493 }
 494
 495 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
 496 {
 497         return single_open(file, acpi_processor_perf_seq_show,
 498                                                 PDE(inode)->data);
 499 }
 500
 501 static ssize_t
 502 acpi_processor_write_performance (
 503         struct file             *file,
 504         const char              __user *buffer,
 505         size_t                  count,
 506         loff_t                  *data)
 507 {
 508         int                     result = 0;
 509         struct seq_file         *m = (struct seq_file *) file->private_data;
 510         struct acpi_processor   *pr = (struct acpi_processor *) m->private;
 511         struct acpi_processor_performance *perf;
 512         char                    state_string[12] = {'\0'};
 513         unsigned int            new_state = 0;
 514         struct cpufreq_policy   policy;
 515
 516         ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
 517
 518         if (!pr || (count > sizeof(state_string) - 1))
 519                 return_VALUE(-EINVAL);
 520
 521         perf = pr->performance;
 522         if (!perf)
 523                 return_VALUE(-EINVAL);
 524
 525         if (copy_from_user(state_string, buffer, count))
 526                 return_VALUE(-EFAULT);
 527
 528         state_string[count] = '\0';
 529         new_state = simple_strtoul(state_string, NULL, 0);
 530
 531         if (new_state >= perf->state_count)
 532                 return_VALUE(-EINVAL);
 533
 534         cpufreq_get_policy(&policy, pr->id);
 535
 536         policy.cpu = pr->id;
 537         policy.min = perf->states[new_state].core_frequency * 1000;
 538         policy.max = perf->states[new_state].core_frequency * 1000;
 539
 540         result = cpufreq_set_policy(&policy);
 541         if (result)
 542                 return_VALUE(result);
 543
 544         return_VALUE(count);
 545 }
 546
 547 static void
 548 acpi_cpufreq_add_file (
 549         struct acpi_processor *pr)
 550 {
 551         struct proc_dir_entry   *entry = NULL;
 552         struct acpi_device      *device = NULL;
 553
 554         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 555
 556         if (acpi_bus_get_device(pr->handle, &device))
 557                 return_VOID;
 558
 559         /* add file 'performance' [R/W] */
 560         entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 561                   S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
 562         if (!entry)
 563                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 564                         "Unable to create '%s' fs entry\n",
 565                         ACPI_PROCESSOR_FILE_PERFORMANCE));
 566         else {
 567                 entry->proc_fops = &acpi_processor_perf_fops;
 568                 entry->proc_fops->write = acpi_processor_write_performance;
 569                 entry->data = acpi_driver_data(device);
 570                 entry->owner = THIS_MODULE;
 571         }
 572         return_VOID;
 573 }
 574
 575 static void
 576 acpi_cpufreq_remove_file (
 577         struct acpi_processor *pr)
 578 {
 579         struct acpi_device      *device = NULL;
 580
 581         ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
 582
 583         if (acpi_bus_get_device(pr->handle, &device))
 584                 return_VOID;
 585
 586         /* remove file 'performance' */
 587         remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
 588                   acpi_device_dir(device));
 589
 590         return_VOID;
 591 }
 592
 593 #else
 594 static void acpi_cpufreq_add_file (struct acpi_processor *pr) { return; }
 595 static void acpi_cpufreq_remove_file (struct acpi_processor *pr) { return; }
 596 #endif /* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
 597
 598
 599 int
 600 acpi_processor_register_performance (
 601         struct acpi_processor_performance * performance,
 602         unsigned int cpu)
 603 {
 604         struct acpi_processor *pr;
 605
 606         ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
 607
 608         if (!(acpi_processor_ppc_status & PPC_REGISTERED))
 609                 return_VALUE(-EINVAL);
 610
 611         down(&performance_sem);
 612
 613         pr = processors[cpu];
 614         if (!pr) {
 615                 up(&performance_sem);
 616                 return_VALUE(-ENODEV);
 617         }
 618
 619         if (pr->performance) {
 620                 up(&performance_sem);
 621                 return_VALUE(-EBUSY);
 622         }
 623
 624         pr->performance = performance;
 625
 626         if (acpi_processor_get_performance_info(pr)) {
 627                 pr->performance = NULL;
 628                 up(&performance_sem);
 629                 return_VALUE(-EIO);
 630         }
 631
 632         acpi_cpufreq_add_file(pr);
 633
 634         up(&performance_sem);
 635         return_VALUE(0);
 636 }
 637 EXPORT_SYMBOL(acpi_processor_register_performance);
 638
 639
 640 void
 641 acpi_processor_unregister_performance (
 642         struct acpi_processor_performance * performance,
 643         unsigned int cpu)
 644 {
 645         struct acpi_processor *pr;
 646
 647         ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
 648
 649         down(&performance_sem);
 650
 651         pr = processors[cpu];
 652         if (!pr) {
 653                 up(&performance_sem);
 654                 return_VOID;
 655         }
 656
 657         kfree(pr->performance->states);
 658         pr->performance = NULL;
 659
 660         acpi_cpufreq_remove_file(pr);
 661
 662         up(&performance_sem);
 663
 664         return_VOID;
 665 }
 666 EXPORT_SYMBOL(acpi_processor_unregister_performance);