drivers/acpi/processor_driver.c

   1 /*
   2  * acpi_processor.c - ACPI Processor Driver ($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  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  *  TBD:
  28  *      1. Make # power states dynamic.
  29  *      2. Support duty_cycle values that span bit 4.
  30  *      3. Optimize by having scheduler determine business instead of
  31  *         having us try to calculate it here.
  32  *      4. Need C1 timing -- must modify kernel (IRQ handler) to get this.
  33  */
  34
  35 #include <linux/kernel.h>
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/types.h>
  39 #include <linux/pci.h>
  40 #include <linux/pm.h>
  41 #include <linux/cpufreq.h>
  42 #include <linux/cpu.h>
  43 #include <linux/dmi.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cpuidle.h>
  46 #include <linux/slab.h>
  47
  48 #include <asm/io.h>
  49 #include <asm/system.h>
  50 #include <asm/cpu.h>
  51 #include <asm/delay.h>
  52 #include <asm/uaccess.h>
  53 #include <asm/processor.h>
  54 #include <asm/smp.h>
  55 #include <asm/acpi.h>
  56
  57 #include <acpi/acpi_bus.h>
  58 #include <acpi/acpi_drivers.h>
  59 #include <acpi/processor.h>
  60
  61 #define PREFIX "ACPI: "
  62
  63 #define ACPI_PROCESSOR_CLASS            "processor"
  64 #define ACPI_PROCESSOR_DEVICE_NAME      "Processor"
  65 #define ACPI_PROCESSOR_FILE_INFO        "info"
  66 #define ACPI_PROCESSOR_FILE_THROTTLING  "throttling"
  67 #define ACPI_PROCESSOR_FILE_LIMIT       "limit"
  68 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
  69 #define ACPI_PROCESSOR_NOTIFY_POWER     0x81
  70 #define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
  71
  72 #define ACPI_PROCESSOR_LIMIT_USER       0
  73 #define ACPI_PROCESSOR_LIMIT_THERMAL    1
  74
  75 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  76 ACPI_MODULE_NAME("processor_driver");
  77
  78 MODULE_AUTHOR("Paul Diefenbaugh");
  79 MODULE_DESCRIPTION("ACPI Processor Driver");
  80 MODULE_LICENSE("GPL");
  81
  82 static int acpi_processor_add(struct acpi_device *device);
  83 static int acpi_processor_remove(struct acpi_device *device, int type);
  84 static void acpi_processor_notify(struct acpi_device *device, u32 event);
  85 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
  86 static int acpi_processor_handle_eject(struct acpi_processor *pr);
  87
  88
  89 static const struct acpi_device_id processor_device_ids[] = {
  90         {ACPI_PROCESSOR_OBJECT_HID, 0},
  91         {"ACPI0007", 0},
  92         {"", 0},
  93 };
  94 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  95
  96 static struct acpi_driver acpi_processor_driver = {
  97         .name = "processor",
  98         .class = ACPI_PROCESSOR_CLASS,
  99         .ids = processor_device_ids,
 100         .ops = {
 101                 .add = acpi_processor_add,
 102                 .remove = acpi_processor_remove,
 103                 .suspend = acpi_processor_suspend,
 104                 .resume = acpi_processor_resume,
 105                 .notify = acpi_processor_notify,
 106                 },
 107 };
 108
 109 #define INSTALL_NOTIFY_HANDLER          1
 110 #define UNINSTALL_NOTIFY_HANDLER        2
 111
 112 DEFINE_PER_CPU(struct acpi_processor *, processors);
 113 EXPORT_PER_CPU_SYMBOL(processors);
 114
 115 struct acpi_processor_errata errata __read_mostly;
 116
 117 /* --------------------------------------------------------------------------
 118                                 Errata Handling
 119    -------------------------------------------------------------------------- */
 120
 121 static int acpi_processor_errata_piix4(struct pci_dev *dev)
 122 {
 123         u8 value1 = 0;
 124         u8 value2 = 0;
 125
 126
 127         if (!dev)
 128                 return -EINVAL;
 129
 130         /*
 131          * Note that 'dev' references the PIIX4 ACPI Controller.
 132          */
 133
 134         switch (dev->revision) {
 135         case 0:
 136                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
 137                 break;
 138         case 1:
 139                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
 140                 break;
 141         case 2:
 142                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
 143                 break;
 144         case 3:
 145                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
 146                 break;
 147         default:
 148                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
 149                 break;
 150         }
 151
 152         switch (dev->revision) {
 153
 154         case 0:         /* PIIX4 A-step */
 155         case 1:         /* PIIX4 B-step */
 156                 /*
 157                  * See specification changes #13 ("Manual Throttle Duty Cycle")
 158                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
 159                  * erratum #5 ("STPCLK# Deassertion Time") from the January
 160                  * 2002 PIIX4 specification update.  Applies to only older
 161                  * PIIX4 models.
 162                  */
 163                 errata.piix4.throttle = 1;
 164
 165         case 2:         /* PIIX4E */
 166         case 3:         /* PIIX4M */
 167                 /*
 168                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
 169                  * Livelock") from the January 2002 PIIX4 specification update.
 170                  * Applies to all PIIX4 models.
 171                  */
 172
 173                 /*
 174                  * BM-IDE
 175                  * ------
 176                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
 177                  * Status register address.  We'll use this later to read
 178                  * each IDE controller's DMA status to make sure we catch all
 179                  * DMA activity.
 180                  */
 181                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 182                                      PCI_DEVICE_ID_INTEL_82371AB,
 183                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 184                 if (dev) {
 185                         errata.piix4.bmisx = pci_resource_start(dev, 4);
 186                         pci_dev_put(dev);
 187                 }
 188
 189                 /*
 190                  * Type-F DMA
 191                  * ----------
 192                  * Find the PIIX4 ISA Controller and read the Motherboard
 193                  * DMA controller's status to see if Type-F (Fast) DMA mode
 194                  * is enabled (bit 7) on either channel.  Note that we'll
 195                  * disable C3 support if this is enabled, as some legacy
 196                  * devices won't operate well if fast DMA is disabled.
 197                  */
 198                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 199                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 200                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 201                 if (dev) {
 202                         pci_read_config_byte(dev, 0x76, &value1);
 203                         pci_read_config_byte(dev, 0x77, &value2);
 204                         if ((value1 & 0x80) || (value2 & 0x80))
 205                                 errata.piix4.fdma = 1;
 206                         pci_dev_put(dev);
 207                 }
 208
 209                 break;
 210         }
 211
 212         if (errata.piix4.bmisx)
 213                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 214                                   "Bus master activity detection (BM-IDE) erratum enabled\n"));
 215         if (errata.piix4.fdma)
 216                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 217                                   "Type-F DMA livelock erratum (C3 disabled)\n"));
 218
 219         return 0;
 220 }
 221
 222 static int acpi_processor_errata(struct acpi_processor *pr)
 223 {
 224         int result = 0;
 225         struct pci_dev *dev = NULL;
 226
 227
 228         if (!pr)
 229                 return -EINVAL;
 230
 231         /*
 232          * PIIX4
 233          */
 234         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 235                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 236                              PCI_ANY_ID, NULL);
 237         if (dev) {
 238                 result = acpi_processor_errata_piix4(dev);
 239                 pci_dev_put(dev);
 240         }
 241
 242         return result;
 243 }
 244
 245 /* --------------------------------------------------------------------------
 246                                  Driver Interface
 247    -------------------------------------------------------------------------- */
 248
 249 static int acpi_processor_get_info(struct acpi_device *device)
 250 {
 251         acpi_status status = 0;
 252         union acpi_object object = { 0 };
 253         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 254         struct acpi_processor *pr;
 255         int cpu_index, device_declaration = 0;
 256         static int cpu0_initialized;
 257
 258         pr = acpi_driver_data(device);
 259         if (!pr)
 260                 return -EINVAL;
 261
 262         if (num_online_cpus() > 1)
 263                 errata.smp = TRUE;
 264
 265         acpi_processor_errata(pr);
 266
 267         /*
 268          * Check to see if we have bus mastering arbitration control.  This
 269          * is required for proper C3 usage (to maintain cache coherency).
 270          */
 271         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 272                 pr->flags.bm_control = 1;
 273                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 274                                   "Bus mastering arbitration control present\n"));
 275         } else
 276                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 277                                   "No bus mastering arbitration control\n"));
 278
 279         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 280                 /* Declared with "Processor" statement; match ProcessorID */
 281                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 282                 if (ACPI_FAILURE(status)) {
 283                         printk(KERN_ERR PREFIX "Evaluating processor object\n");
 284                         return -ENODEV;
 285                 }
 286
 287                 /*
 288                  * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
 289                  *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
 290                  *      arch/xxx/acpi.c
 291                  */
 292                 pr->acpi_id = object.processor.proc_id;
 293         } else {
 294                 /*
 295                  * Declared with "Device" statement; match _UID.
 296                  * Note that we don't handle string _UIDs yet.
 297                  */
 298                 unsigned long long value;
 299                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 300                                                 NULL, &value);
 301                 if (ACPI_FAILURE(status)) {
 302                         printk(KERN_ERR PREFIX
 303                             "Evaluating processor _UID [%#x]\n", status);
 304                         return -ENODEV;
 305                 }
 306                 device_declaration = 1;
 307                 pr->acpi_id = value;
 308         }
 309         cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
 310
 311         /* Handle UP system running SMP kernel, with no LAPIC in MADT */
 312         if (!cpu0_initialized && (cpu_index == -1) &&
 313             (num_online_cpus() == 1)) {
 314                 cpu_index = 0;
 315         }
 316
 317         cpu0_initialized = 1;
 318
 319         pr->id = cpu_index;
 320
 321         /*
 322          *  Extra Processor objects may be enumerated on MP systems with
 323          *  less than the max # of CPUs. They should be ignored _iff
 324          *  they are physically not present.
 325          */
 326         if (pr->id == -1) {
 327                 if (ACPI_FAILURE
 328                     (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
 329                         return -ENODEV;
 330                 }
 331         }
 332         /*
 333          * On some boxes several processors use the same processor bus id.
 334          * But they are located in different scope. For example:
 335          * \_SB.SCK0.CPU0
 336          * \_SB.SCK1.CPU0
 337          * Rename the processor device bus id. And the new bus id will be
 338          * generated as the following format:
 339          * CPU+CPU ID.
 340          */
 341         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 342         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 343                           pr->acpi_id));
 344
 345         if (!object.processor.pblk_address)
 346                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 347         else if (object.processor.pblk_length != 6)
 348                 printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
 349                             object.processor.pblk_length);
 350         else {
 351                 pr->throttling.address = object.processor.pblk_address;
 352                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 353                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 354
 355                 pr->pblk = object.processor.pblk_address;
 356
 357                 /*
 358                  * We don't care about error returns - we just try to mark
 359                  * these reserved so that nobody else is confused into thinking
 360                  * that this region might be unused..
 361                  *
 362                  * (In particular, allocating the IO range for Cardbus)
 363                  */
 364                 request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 365         }
 366
 367         /*
 368          * If ACPI describes a slot number for this CPU, we can use it
 369          * ensure we get the right value in the "physical id" field
 370          * of /proc/cpuinfo
 371          */
 372         status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
 373         if (ACPI_SUCCESS(status))
 374                 arch_fix_phys_package_id(pr->id, object.integer.value);
 375
 376         return 0;
 377 }
 378
 379 static DEFINE_PER_CPU(void *, processor_device_array);
 380
 381 static void acpi_processor_notify(struct acpi_device *device, u32 event)
 382 {
 383         struct acpi_processor *pr = acpi_driver_data(device);
 384         int saved;
 385
 386         if (!pr)
 387                 return;
 388
 389         switch (event) {
 390         case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
 391                 saved = pr->performance_platform_limit;
 392                 acpi_processor_ppc_has_changed(pr, 1);
 393                 if (saved == pr->performance_platform_limit)
 394                         break;
 395                 acpi_bus_generate_proc_event(device, event,
 396                                         pr->performance_platform_limit);
 397                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 398                                                   dev_name(&device->dev), event,
 399                                                   pr->performance_platform_limit);
 400                 break;
 401         case ACPI_PROCESSOR_NOTIFY_POWER:
 402                 acpi_processor_cst_has_changed(pr);
 403                 acpi_bus_generate_proc_event(device, event, 0);
 404                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 405                                                   dev_name(&device->dev), event, 0);
 406                 break;
 407         case ACPI_PROCESSOR_NOTIFY_THROTTLING:
 408                 acpi_processor_tstate_has_changed(pr);
 409                 acpi_bus_generate_proc_event(device, event, 0);
 410                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 411                                                   dev_name(&device->dev), event, 0);
 412         default:
 413                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 414                                   "Unsupported event [0x%x]\n", event));
 415                 break;
 416         }
 417
 418         return;
 419 }
 420
 421 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
 422                 unsigned long action, void *hcpu)
 423 {
 424         unsigned int cpu = (unsigned long)hcpu;
 425         struct acpi_processor *pr = per_cpu(processors, cpu);
 426
 427         if (action == CPU_ONLINE && pr) {
 428                 acpi_processor_ppc_has_changed(pr, 0);
 429                 acpi_processor_hotplug(pr);
 430                 acpi_processor_reevaluate_tstate(pr, action);
 431                 acpi_processor_tstate_has_changed(pr);
 432         }
 433         if (action == CPU_DEAD && pr) {
 434                 /* invalidate the flag.throttling after one CPU is offline */
 435                 acpi_processor_reevaluate_tstate(pr, action);
 436         }
 437         return NOTIFY_OK;
 438 }
 439
 440 static struct notifier_block acpi_cpu_notifier =
 441 {
 442             .notifier_call = acpi_cpu_soft_notify,
 443 };
 444
 445 static int __cpuinit acpi_processor_add(struct acpi_device *device)
 446 {
 447         struct acpi_processor *pr = NULL;
 448         int result = 0;
 449         struct sys_device *sysdev;
 450
 451         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 452         if (!pr)
 453                 return -ENOMEM;
 454
 455         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 456                 kfree(pr);
 457                 return -ENOMEM;
 458         }
 459
 460         pr->handle = device->handle;
 461         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 462         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 463         device->driver_data = pr;
 464
 465         result = acpi_processor_get_info(device);
 466         if (result) {
 467                 /* Processor is physically not present */
 468                 return 0;
 469         }
 470
 471 #ifdef CONFIG_SMP
 472         if (pr->id >= setup_max_cpus && pr->id != 0)
 473                 return 0;
 474 #endif
 475
 476         BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
 477
 478         /*
 479          * Buggy BIOS check
 480          * ACPI id of processors can be reported wrongly by the BIOS.
 481          * Don't trust it blindly
 482          */
 483         if (per_cpu(processor_device_array, pr->id) != NULL &&
 484             per_cpu(processor_device_array, pr->id) != device) {
 485                 printk(KERN_WARNING "BIOS reported wrong ACPI id "
 486                         "for the processor\n");
 487                 result = -ENODEV;
 488                 goto err_free_cpumask;
 489         }
 490         per_cpu(processor_device_array, pr->id) = device;
 491
 492         per_cpu(processors, pr->id) = pr;
 493
 494         sysdev = get_cpu_sysdev(pr->id);
 495         if (sysfs_create_link(&device->dev.kobj, &sysdev->kobj, "sysdev")) {
 496                 result = -EFAULT;
 497                 goto err_free_cpumask;
 498         }
 499
 500 #ifdef CONFIG_CPU_FREQ
 501         acpi_processor_ppc_has_changed(pr, 0);
 502 #endif
 503         acpi_processor_get_throttling_info(pr);
 504         acpi_processor_get_limit_info(pr);
 505
 506         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 507                 acpi_processor_power_init(pr, device);
 508
 509         pr->cdev = thermal_cooling_device_register("Processor", device,
 510                                                 &processor_cooling_ops);
 511         if (IS_ERR(pr->cdev)) {
 512                 result = PTR_ERR(pr->cdev);
 513                 goto err_power_exit;
 514         }
 515
 516         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 517                  pr->cdev->id);
 518
 519         result = sysfs_create_link(&device->dev.kobj,
 520                                    &pr->cdev->device.kobj,
 521                                    "thermal_cooling");
 522         if (result) {
 523                 printk(KERN_ERR PREFIX "Create sysfs link\n");
 524                 goto err_thermal_unregister;
 525         }
 526         result = sysfs_create_link(&pr->cdev->device.kobj,
 527                                    &device->dev.kobj,
 528                                    "device");
 529         if (result) {
 530                 printk(KERN_ERR PREFIX "Create sysfs link\n");
 531                 goto err_remove_sysfs;
 532         }
 533
 534         return 0;
 535
 536 err_remove_sysfs:
 537         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 538 err_thermal_unregister:
 539         thermal_cooling_device_unregister(pr->cdev);
 540 err_power_exit:
 541         acpi_processor_power_exit(pr, device);
 542 err_free_cpumask:
 543         free_cpumask_var(pr->throttling.shared_cpu_map);
 544
 545         return result;
 546 }
 547
 548 static int acpi_processor_remove(struct acpi_device *device, int type)
 549 {
 550         struct acpi_processor *pr = NULL;
 551
 552
 553         if (!device || !acpi_driver_data(device))
 554                 return -EINVAL;
 555
 556         pr = acpi_driver_data(device);
 557
 558         if (pr->id >= nr_cpu_ids)
 559                 goto free;
 560
 561         if (type == ACPI_BUS_REMOVAL_EJECT) {
 562                 if (acpi_processor_handle_eject(pr))
 563                         return -EINVAL;
 564         }
 565
 566         acpi_processor_power_exit(pr, device);
 567
 568         sysfs_remove_link(&device->dev.kobj, "sysdev");
 569
 570         if (pr->cdev) {
 571                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 572                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 573                 thermal_cooling_device_unregister(pr->cdev);
 574                 pr->cdev = NULL;
 575         }
 576
 577         per_cpu(processors, pr->id) = NULL;
 578         per_cpu(processor_device_array, pr->id) = NULL;
 579
 580 free:
 581         free_cpumask_var(pr->throttling.shared_cpu_map);
 582         kfree(pr);
 583
 584         return 0;
 585 }
 586
 587 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 588 /****************************************************************************
 589  *      Acpi processor hotplug support                                      *
 590  ****************************************************************************/
 591
 592 static int is_processor_present(acpi_handle handle)
 593 {
 594         acpi_status status;
 595         unsigned long long sta = 0;
 596
 597
 598         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 599
 600         if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
 601                 return 1;
 602
 603         /*
 604          * _STA is mandatory for a processor that supports hot plug
 605          */
 606         if (status == AE_NOT_FOUND)
 607                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 608                                 "Processor does not support hot plug\n"));
 609         else
 610                 ACPI_EXCEPTION((AE_INFO, status,
 611                                 "Processor Device is not present"));
 612         return 0;
 613 }
 614
 615 static
 616 int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
 617 {
 618         acpi_handle phandle;
 619         struct acpi_device *pdev;
 620
 621
 622         if (acpi_get_parent(handle, &phandle)) {
 623                 return -ENODEV;
 624         }
 625
 626         if (acpi_bus_get_device(phandle, &pdev)) {
 627                 return -ENODEV;
 628         }
 629
 630         if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
 631                 return -ENODEV;
 632         }
 633
 634         return 0;
 635 }
 636
 637 static void acpi_processor_hotplug_notify(acpi_handle handle,
 638                                           u32 event, void *data)
 639 {
 640         struct acpi_processor *pr;
 641         struct acpi_device *device = NULL;
 642         int result;
 643
 644
 645         switch (event) {
 646         case ACPI_NOTIFY_BUS_CHECK:
 647         case ACPI_NOTIFY_DEVICE_CHECK:
 648                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 649                 "Processor driver received %s event\n",
 650                        (event == ACPI_NOTIFY_BUS_CHECK) ?
 651                        "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
 652
 653                 if (!is_processor_present(handle))
 654                         break;
 655
 656                 if (acpi_bus_get_device(handle, &device)) {
 657                         result = acpi_processor_device_add(handle, &device);
 658                         if (result)
 659                                 printk(KERN_ERR PREFIX
 660                                             "Unable to add the device\n");
 661                         break;
 662                 }
 663                 break;
 664         case ACPI_NOTIFY_EJECT_REQUEST:
 665                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 666                                   "received ACPI_NOTIFY_EJECT_REQUEST\n"));
 667
 668                 if (acpi_bus_get_device(handle, &device)) {
 669                         printk(KERN_ERR PREFIX
 670                                     "Device don't exist, dropping EJECT\n");
 671                         break;
 672                 }
 673                 pr = acpi_driver_data(device);
 674                 if (!pr) {
 675                         printk(KERN_ERR PREFIX
 676                                     "Driver data is NULL, dropping EJECT\n");
 677                         return;
 678                 }
 679                 break;
 680         default:
 681                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 682                                   "Unsupported event [0x%x]\n", event));
 683                 break;
 684         }
 685
 686         return;
 687 }
 688
 689 static acpi_status
 690 processor_walk_namespace_cb(acpi_handle handle,
 691                             u32 lvl, void *context, void **rv)
 692 {
 693         acpi_status status;
 694         int *action = context;
 695         acpi_object_type type = 0;
 696
 697         status = acpi_get_type(handle, &type);
 698         if (ACPI_FAILURE(status))
 699                 return (AE_OK);
 700
 701         if (type != ACPI_TYPE_PROCESSOR)
 702                 return (AE_OK);
 703
 704         switch (*action) {
 705         case INSTALL_NOTIFY_HANDLER:
 706                 acpi_install_notify_handler(handle,
 707                                             ACPI_SYSTEM_NOTIFY,
 708                                             acpi_processor_hotplug_notify,
 709                                             NULL);
 710                 break;
 711         case UNINSTALL_NOTIFY_HANDLER:
 712                 acpi_remove_notify_handler(handle,
 713                                            ACPI_SYSTEM_NOTIFY,
 714                                            acpi_processor_hotplug_notify);
 715                 break;
 716         default:
 717                 break;
 718         }
 719
 720         return (AE_OK);
 721 }
 722
 723 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
 724 {
 725
 726         if (!is_processor_present(handle)) {
 727                 return AE_ERROR;
 728         }
 729
 730         if (acpi_map_lsapic(handle, p_cpu))
 731                 return AE_ERROR;
 732
 733         if (arch_register_cpu(*p_cpu)) {
 734                 acpi_unmap_lsapic(*p_cpu);
 735                 return AE_ERROR;
 736         }
 737
 738         return AE_OK;
 739 }
 740
 741 static int acpi_processor_handle_eject(struct acpi_processor *pr)
 742 {
 743         if (cpu_online(pr->id))
 744                 cpu_down(pr->id);
 745
 746         arch_unregister_cpu(pr->id);
 747         acpi_unmap_lsapic(pr->id);
 748         return (0);
 749 }
 750 #else
 751 static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
 752 {
 753         return AE_ERROR;
 754 }
 755 static int acpi_processor_handle_eject(struct acpi_processor *pr)
 756 {
 757         return (-EINVAL);
 758 }
 759 #endif
 760
 761 static
 762 void acpi_processor_install_hotplug_notify(void)
 763 {
 764 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 765         int action = INSTALL_NOTIFY_HANDLER;
 766         acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
 767                             ACPI_ROOT_OBJECT,
 768                             ACPI_UINT32_MAX,
 769                             processor_walk_namespace_cb, NULL, &action, NULL);
 770 #endif
 771         register_hotcpu_notifier(&acpi_cpu_notifier);
 772 }
 773
 774 static
 775 void acpi_processor_uninstall_hotplug_notify(void)
 776 {
 777 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 778         int action = UNINSTALL_NOTIFY_HANDLER;
 779         acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
 780                             ACPI_ROOT_OBJECT,
 781                             ACPI_UINT32_MAX,
 782                             processor_walk_namespace_cb, NULL, &action, NULL);
 783 #endif
 784         unregister_hotcpu_notifier(&acpi_cpu_notifier);
 785 }
 786
 787 /*
 788  * We keep the driver loaded even when ACPI is not running.
 789  * This is needed for the powernow-k8 driver, that works even without
 790  * ACPI, but needs symbols from this driver
 791  */
 792
 793 static int __init acpi_processor_init(void)
 794 {
 795         int result = 0;
 796
 797         if (acpi_disabled)
 798                 return 0;
 799
 800         memset(&errata, 0, sizeof(errata));
 801
 802         result = acpi_bus_register_driver(&acpi_processor_driver);
 803         if (result < 0)
 804                 return result;
 805
 806         acpi_processor_install_hotplug_notify();
 807
 808         acpi_thermal_cpufreq_init();
 809
 810         acpi_processor_ppc_init();
 811
 812         acpi_processor_throttling_init();
 813
 814         return 0;
 815 }
 816
 817 static void __exit acpi_processor_exit(void)
 818 {
 819         if (acpi_disabled)
 820                 return;
 821
 822         acpi_processor_ppc_exit();
 823
 824         acpi_thermal_cpufreq_exit();
 825
 826         acpi_processor_uninstall_hotplug_notify();
 827
 828         acpi_bus_unregister_driver(&acpi_processor_driver);
 829
 830         cpuidle_unregister_driver(&acpi_idle_driver);
 831
 832         return;
 833 }
 834
 835 module_init(acpi_processor_init);
 836 module_exit(acpi_processor_exit);
 837
 838 MODULE_ALIAS("processor");