drivers/acpi/processor_driver.c

   1 /*
   2  * acpi_processor.c - ACPI Processor Driver ($Revision: 71 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
   6  *  Copyright (C) 2004       Dominik Brodowski <[email protected]>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <[email protected]>
   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 #include <linux/acpi.h>
  48 #include <linux/memory_hotplug.h>
  49
  50 #include <asm/io.h>
  51 #include <asm/cpu.h>
  52 #include <asm/delay.h>
  53 #include <asm/uaccess.h>
  54 #include <asm/processor.h>
  55 #include <asm/smp.h>
  56 #include <asm/acpi.h>
  57
  58 #include <acpi/acpi_bus.h>
  59 #include <acpi/acpi_drivers.h>
  60 #include <acpi/processor.h>
  61
  62 #define PREFIX "ACPI: "
  63
  64 #define ACPI_PROCESSOR_CLASS            "processor"
  65 #define ACPI_PROCESSOR_DEVICE_NAME      "Processor"
  66 #define ACPI_PROCESSOR_FILE_INFO        "info"
  67 #define ACPI_PROCESSOR_FILE_THROTTLING  "throttling"
  68 #define ACPI_PROCESSOR_FILE_LIMIT       "limit"
  69 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
  70 #define ACPI_PROCESSOR_NOTIFY_POWER     0x81
  71 #define ACPI_PROCESSOR_NOTIFY_THROTTLING        0x82
  72 #define ACPI_PROCESSOR_DEVICE_HID       "ACPI0007"
  73
  74 #define ACPI_PROCESSOR_LIMIT_USER       0
  75 #define ACPI_PROCESSOR_LIMIT_THERMAL    1
  76
  77 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  78 ACPI_MODULE_NAME("processor_driver");
  79
  80 MODULE_AUTHOR("Paul Diefenbaugh");
  81 MODULE_DESCRIPTION("ACPI Processor Driver");
  82 MODULE_LICENSE("GPL");
  83
  84 static int acpi_processor_add(struct acpi_device *device);
  85 static int acpi_processor_remove(struct acpi_device *device);
  86 static void acpi_processor_notify(struct acpi_device *device, u32 event);
  87 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr);
  88 static int acpi_processor_handle_eject(struct acpi_processor *pr);
  89 static int acpi_processor_start(struct acpi_processor *pr);
  90
  91 static const struct acpi_device_id processor_device_ids[] = {
  92         {ACPI_PROCESSOR_OBJECT_HID, 0},
  93         {ACPI_PROCESSOR_DEVICE_HID, 0},
  94         {"", 0},
  95 };
  96 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  97
  98 static SIMPLE_DEV_PM_OPS(acpi_processor_pm,
  99                          acpi_processor_suspend, acpi_processor_resume);
 100
 101 static struct acpi_driver acpi_processor_driver = {
 102         .name = "processor",
 103         .class = ACPI_PROCESSOR_CLASS,
 104         .ids = processor_device_ids,
 105         .ops = {
 106                 .add = acpi_processor_add,
 107                 .remove = acpi_processor_remove,
 108                 .notify = acpi_processor_notify,
 109                 },
 110         .drv.pm = &acpi_processor_pm,
 111 };
 112
 113 #define INSTALL_NOTIFY_HANDLER          1
 114 #define UNINSTALL_NOTIFY_HANDLER        2
 115
 116 DEFINE_PER_CPU(struct acpi_processor *, processors);
 117 EXPORT_PER_CPU_SYMBOL(processors);
 118
 119 struct acpi_processor_errata errata __read_mostly;
 120
 121 /* --------------------------------------------------------------------------
 122                                 Errata Handling
 123    -------------------------------------------------------------------------- */
 124
 125 static int acpi_processor_errata_piix4(struct pci_dev *dev)
 126 {
 127         u8 value1 = 0;
 128         u8 value2 = 0;
 129
 130
 131         if (!dev)
 132                 return -EINVAL;
 133
 134         /*
 135          * Note that 'dev' references the PIIX4 ACPI Controller.
 136          */
 137
 138         switch (dev->revision) {
 139         case 0:
 140                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
 141                 break;
 142         case 1:
 143                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
 144                 break;
 145         case 2:
 146                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
 147                 break;
 148         case 3:
 149                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
 150                 break;
 151         default:
 152                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
 153                 break;
 154         }
 155
 156         switch (dev->revision) {
 157
 158         case 0:         /* PIIX4 A-step */
 159         case 1:         /* PIIX4 B-step */
 160                 /*
 161                  * See specification changes #13 ("Manual Throttle Duty Cycle")
 162                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
 163                  * erratum #5 ("STPCLK# Deassertion Time") from the January
 164                  * 2002 PIIX4 specification update.  Applies to only older
 165                  * PIIX4 models.
 166                  */
 167                 errata.piix4.throttle = 1;
 168
 169         case 2:         /* PIIX4E */
 170         case 3:         /* PIIX4M */
 171                 /*
 172                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
 173                  * Livelock") from the January 2002 PIIX4 specification update.
 174                  * Applies to all PIIX4 models.
 175                  */
 176
 177                 /*
 178                  * BM-IDE
 179                  * ------
 180                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
 181                  * Status register address.  We'll use this later to read
 182                  * each IDE controller's DMA status to make sure we catch all
 183                  * DMA activity.
 184                  */
 185                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 186                                      PCI_DEVICE_ID_INTEL_82371AB,
 187                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 188                 if (dev) {
 189                         errata.piix4.bmisx = pci_resource_start(dev, 4);
 190                         pci_dev_put(dev);
 191                 }
 192
 193                 /*
 194                  * Type-F DMA
 195                  * ----------
 196                  * Find the PIIX4 ISA Controller and read the Motherboard
 197                  * DMA controller's status to see if Type-F (Fast) DMA mode
 198                  * is enabled (bit 7) on either channel.  Note that we'll
 199                  * disable C3 support if this is enabled, as some legacy
 200                  * devices won't operate well if fast DMA is disabled.
 201                  */
 202                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 203                                      PCI_DEVICE_ID_INTEL_82371AB_0,
 204                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
 205                 if (dev) {
 206                         pci_read_config_byte(dev, 0x76, &value1);
 207                         pci_read_config_byte(dev, 0x77, &value2);
 208                         if ((value1 & 0x80) || (value2 & 0x80))
 209                                 errata.piix4.fdma = 1;
 210                         pci_dev_put(dev);
 211                 }
 212
 213                 break;
 214         }
 215
 216         if (errata.piix4.bmisx)
 217                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 218                                   "Bus master activity detection (BM-IDE) erratum enabled\n"));
 219         if (errata.piix4.fdma)
 220                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 221                                   "Type-F DMA livelock erratum (C3 disabled)\n"));
 222
 223         return 0;
 224 }
 225
 226 static int acpi_processor_errata(struct acpi_processor *pr)
 227 {
 228         int result = 0;
 229         struct pci_dev *dev = NULL;
 230
 231
 232         if (!pr)
 233                 return -EINVAL;
 234
 235         /*
 236          * PIIX4
 237          */
 238         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 239                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 240                              PCI_ANY_ID, NULL);
 241         if (dev) {
 242                 result = acpi_processor_errata_piix4(dev);
 243                 pci_dev_put(dev);
 244         }
 245
 246         return result;
 247 }
 248
 249 /* --------------------------------------------------------------------------
 250                                  Driver Interface
 251    -------------------------------------------------------------------------- */
 252
 253 static int acpi_processor_get_info(struct acpi_device *device)
 254 {
 255         acpi_status status = 0;
 256         union acpi_object object = { 0 };
 257         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 258         struct acpi_processor *pr;
 259         int cpu_index, device_declaration = 0;
 260         static int cpu0_initialized;
 261
 262         pr = acpi_driver_data(device);
 263         if (!pr)
 264                 return -EINVAL;
 265
 266         if (num_online_cpus() > 1)
 267                 errata.smp = TRUE;
 268
 269         acpi_processor_errata(pr);
 270
 271         /*
 272          * Check to see if we have bus mastering arbitration control.  This
 273          * is required for proper C3 usage (to maintain cache coherency).
 274          */
 275         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 276                 pr->flags.bm_control = 1;
 277                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 278                                   "Bus mastering arbitration control present\n"));
 279         } else
 280                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 281                                   "No bus mastering arbitration control\n"));
 282
 283         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 284                 /* Declared with "Processor" statement; match ProcessorID */
 285                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 286                 if (ACPI_FAILURE(status)) {
 287                         dev_err(&device->dev,
 288                                 "Failed to evaluate processor object (0x%x)\n",
 289                                 status);
 290                         return -ENODEV;
 291                 }
 292
 293                 /*
 294                  * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
 295                  *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
 296                  *      arch/xxx/acpi.c
 297                  */
 298                 pr->acpi_id = object.processor.proc_id;
 299         } else {
 300                 /*
 301                  * Declared with "Device" statement; match _UID.
 302                  * Note that we don't handle string _UIDs yet.
 303                  */
 304                 unsigned long long value;
 305                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 306                                                 NULL, &value);
 307                 if (ACPI_FAILURE(status)) {
 308                         dev_err(&device->dev,
 309                                 "Failed to evaluate processor _UID (0x%x)\n",
 310                                 status);
 311                         return -ENODEV;
 312                 }
 313                 device_declaration = 1;
 314                 pr->acpi_id = value;
 315         }
 316         cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
 317
 318         /* Handle UP system running SMP kernel, with no LAPIC in MADT */
 319         if (!cpu0_initialized && (cpu_index == -1) &&
 320             (num_online_cpus() == 1)) {
 321                 cpu_index = 0;
 322         }
 323
 324         cpu0_initialized = 1;
 325
 326         pr->id = cpu_index;
 327
 328         /*
 329          *  Extra Processor objects may be enumerated on MP systems with
 330          *  less than the max # of CPUs. They should be ignored _iff
 331          *  they are physically not present.
 332          */
 333         if (pr->id == -1) {
 334                 if (ACPI_FAILURE(acpi_processor_hotadd_init(pr)))
 335                         return -ENODEV;
 336         }
 337         /*
 338          * On some boxes several processors use the same processor bus id.
 339          * But they are located in different scope. For example:
 340          * \_SB.SCK0.CPU0
 341          * \_SB.SCK1.CPU0
 342          * Rename the processor device bus id. And the new bus id will be
 343          * generated as the following format:
 344          * CPU+CPU ID.
 345          */
 346         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 347         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 348                           pr->acpi_id));
 349
 350         if (!object.processor.pblk_address)
 351                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 352         else if (object.processor.pblk_length != 6)
 353                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 354                             object.processor.pblk_length);
 355         else {
 356                 pr->throttling.address = object.processor.pblk_address;
 357                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 358                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 359
 360                 pr->pblk = object.processor.pblk_address;
 361
 362                 /*
 363                  * We don't care about error returns - we just try to mark
 364                  * these reserved so that nobody else is confused into thinking
 365                  * that this region might be unused..
 366                  *
 367                  * (In particular, allocating the IO range for Cardbus)
 368                  */
 369                 request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 370         }
 371
 372         /*
 373          * If ACPI describes a slot number for this CPU, we can use it
 374          * ensure we get the right value in the "physical id" field
 375          * of /proc/cpuinfo
 376          */
 377         status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
 378         if (ACPI_SUCCESS(status))
 379                 arch_fix_phys_package_id(pr->id, object.integer.value);
 380
 381         return 0;
 382 }
 383
 384 static DEFINE_PER_CPU(void *, processor_device_array);
 385
 386 static void acpi_processor_notify(struct acpi_device *device, u32 event)
 387 {
 388         struct acpi_processor *pr = acpi_driver_data(device);
 389         int saved;
 390
 391         if (!pr)
 392                 return;
 393
 394         switch (event) {
 395         case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
 396                 saved = pr->performance_platform_limit;
 397                 acpi_processor_ppc_has_changed(pr, 1);
 398                 if (saved == pr->performance_platform_limit)
 399                         break;
 400                 acpi_bus_generate_proc_event(device, event,
 401                                         pr->performance_platform_limit);
 402                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 403                                                   dev_name(&device->dev), event,
 404                                                   pr->performance_platform_limit);
 405                 break;
 406         case ACPI_PROCESSOR_NOTIFY_POWER:
 407                 acpi_processor_cst_has_changed(pr);
 408                 acpi_bus_generate_proc_event(device, event, 0);
 409                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 410                                                   dev_name(&device->dev), event, 0);
 411                 break;
 412         case ACPI_PROCESSOR_NOTIFY_THROTTLING:
 413                 acpi_processor_tstate_has_changed(pr);
 414                 acpi_bus_generate_proc_event(device, event, 0);
 415                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 416                                                   dev_name(&device->dev), event, 0);
 417                 break;
 418         default:
 419                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 420                                   "Unsupported event [0x%x]\n", event));
 421                 break;
 422         }
 423
 424         return;
 425 }
 426
 427 static int acpi_cpu_soft_notify(struct notifier_block *nfb,
 428                 unsigned long action, void *hcpu)
 429 {
 430         unsigned int cpu = (unsigned long)hcpu;
 431         struct acpi_processor *pr = per_cpu(processors, cpu);
 432
 433         if (action == CPU_ONLINE && pr) {
 434                 /* CPU got physically hotplugged and onlined the first time:
 435                  * Initialize missing things
 436                  */
 437                 if (pr->flags.need_hotplug_init) {
 438                         pr_info("Will online and init hotplugged CPU: %d\n",
 439                                 pr->id);
 440                         WARN(acpi_processor_start(pr), "Failed to start CPU:"
 441                                 " %d\n", pr->id);
 442                         pr->flags.need_hotplug_init = 0;
 443                 /* Normal CPU soft online event */
 444                 } else {
 445                         acpi_processor_ppc_has_changed(pr, 0);
 446                         acpi_processor_hotplug(pr);
 447                         acpi_processor_reevaluate_tstate(pr, action);
 448                         acpi_processor_tstate_has_changed(pr);
 449                 }
 450         }
 451         if (action == CPU_DEAD && pr) {
 452                 /* invalidate the flag.throttling after one CPU is offline */
 453                 acpi_processor_reevaluate_tstate(pr, action);
 454         }
 455         return NOTIFY_OK;
 456 }
 457
 458 static struct notifier_block acpi_cpu_notifier =
 459 {
 460             .notifier_call = acpi_cpu_soft_notify,
 461 };
 462
 463 /*
 464  * acpi_processor_start() is called by the cpu_hotplug_notifier func:
 465  * acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the
 466  * root cause seem to be that acpi_processor_uninstall_hotplug_notify()
 467  * is in the module_exit (__exit) func. Allowing acpi_processor_start()
 468  * to not be in __cpuinit section, but being called from __cpuinit funcs
 469  * via __ref looks like the right thing to do here.
 470  */
 471 static __ref int acpi_processor_start(struct acpi_processor *pr)
 472 {
 473         struct acpi_device *device = per_cpu(processor_device_array, pr->id);
 474         int result = 0;
 475
 476 #ifdef CONFIG_CPU_FREQ
 477         acpi_processor_ppc_has_changed(pr, 0);
 478         acpi_processor_load_module(pr);
 479 #endif
 480         acpi_processor_get_throttling_info(pr);
 481         acpi_processor_get_limit_info(pr);
 482
 483         if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 484                 acpi_processor_power_init(pr);
 485
 486         pr->cdev = thermal_cooling_device_register("Processor", device,
 487                                                    &processor_cooling_ops);
 488         if (IS_ERR(pr->cdev)) {
 489                 result = PTR_ERR(pr->cdev);
 490                 goto err_power_exit;
 491         }
 492
 493         dev_dbg(&device->dev, "registered as cooling_device%d\n",
 494                 pr->cdev->id);
 495
 496         result = sysfs_create_link(&device->dev.kobj,
 497                                    &pr->cdev->device.kobj,
 498                                    "thermal_cooling");
 499         if (result) {
 500                 dev_err(&device->dev,
 501                         "Failed to create sysfs link 'thermal_cooling'\n");
 502                 goto err_thermal_unregister;
 503         }
 504         result = sysfs_create_link(&pr->cdev->device.kobj,
 505                                    &device->dev.kobj,
 506                                    "device");
 507         if (result) {
 508                 dev_err(&pr->cdev->device,
 509                         "Failed to create sysfs link 'device'\n");
 510                 goto err_remove_sysfs_thermal;
 511         }
 512
 513         return 0;
 514
 515 err_remove_sysfs_thermal:
 516         sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 517 err_thermal_unregister:
 518         thermal_cooling_device_unregister(pr->cdev);
 519 err_power_exit:
 520         acpi_processor_power_exit(pr);
 521
 522         return result;
 523 }
 524
 525 /*
 526  * Do not put anything in here which needs the core to be online.
 527  * For example MSR access or setting up things which check for cpuinfo_x86
 528  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 529  * Such things have to be put in and set up above in acpi_processor_start()
 530  */
 531 static int __cpuinit acpi_processor_add(struct acpi_device *device)
 532 {
 533         struct acpi_processor *pr = NULL;
 534         int result = 0;
 535         struct device *dev;
 536
 537         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 538         if (!pr)
 539                 return -ENOMEM;
 540
 541         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 542                 result = -ENOMEM;
 543                 goto err_free_pr;
 544         }
 545
 546         pr->handle = device->handle;
 547         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 548         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 549         device->driver_data = pr;
 550
 551         result = acpi_processor_get_info(device);
 552         if (result) {
 553                 /* Processor is physically not present */
 554                 return 0;
 555         }
 556
 557 #ifdef CONFIG_SMP
 558         if (pr->id >= setup_max_cpus && pr->id != 0)
 559                 return 0;
 560 #endif
 561
 562         BUG_ON(pr->id >= nr_cpu_ids);
 563
 564         /*
 565          * Buggy BIOS check
 566          * ACPI id of processors can be reported wrongly by the BIOS.
 567          * Don't trust it blindly
 568          */
 569         if (per_cpu(processor_device_array, pr->id) != NULL &&
 570             per_cpu(processor_device_array, pr->id) != device) {
 571                 dev_warn(&device->dev,
 572                         "BIOS reported wrong ACPI id %d for the processor\n",
 573                         pr->id);
 574                 result = -ENODEV;
 575                 goto err_free_cpumask;
 576         }
 577         per_cpu(processor_device_array, pr->id) = device;
 578
 579         per_cpu(processors, pr->id) = pr;
 580
 581         dev = get_cpu_device(pr->id);
 582         if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
 583                 result = -EFAULT;
 584                 goto err_clear_processor;
 585         }
 586
 587         /*
 588          * Do not start hotplugged CPUs now, but when they
 589          * are onlined the first time
 590          */
 591         if (pr->flags.need_hotplug_init)
 592                 return 0;
 593
 594         result = acpi_processor_start(pr);
 595         if (result)
 596                 goto err_remove_sysfs;
 597
 598         return 0;
 599
 600 err_remove_sysfs:
 601         sysfs_remove_link(&device->dev.kobj, "sysdev");
 602 err_clear_processor:
 603         /*
 604          * processor_device_array is not cleared to allow checks for buggy BIOS
 605          */
 606         per_cpu(processors, pr->id) = NULL;
 607 err_free_cpumask:
 608         free_cpumask_var(pr->throttling.shared_cpu_map);
 609 err_free_pr:
 610         kfree(pr);
 611         return result;
 612 }
 613
 614 static int acpi_processor_remove(struct acpi_device *device)
 615 {
 616         struct acpi_processor *pr = NULL;
 617
 618
 619         if (!device || !acpi_driver_data(device))
 620                 return -EINVAL;
 621
 622         pr = acpi_driver_data(device);
 623
 624         if (pr->id >= nr_cpu_ids)
 625                 goto free;
 626
 627         if (device->removal_type == ACPI_BUS_REMOVAL_EJECT) {
 628                 if (acpi_processor_handle_eject(pr))
 629                         return -EINVAL;
 630         }
 631
 632         acpi_processor_power_exit(pr);
 633
 634         sysfs_remove_link(&device->dev.kobj, "sysdev");
 635
 636         if (pr->cdev) {
 637                 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 638                 sysfs_remove_link(&pr->cdev->device.kobj, "device");
 639                 thermal_cooling_device_unregister(pr->cdev);
 640                 pr->cdev = NULL;
 641         }
 642
 643         per_cpu(processors, pr->id) = NULL;
 644         per_cpu(processor_device_array, pr->id) = NULL;
 645         try_offline_node(cpu_to_node(pr->id));
 646
 647 free:
 648         free_cpumask_var(pr->throttling.shared_cpu_map);
 649         kfree(pr);
 650
 651         return 0;
 652 }
 653
 654 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 655 /****************************************************************************
 656  *      Acpi processor hotplug support                                      *
 657  ****************************************************************************/
 658
 659 static int is_processor_present(acpi_handle handle)
 660 {
 661         acpi_status status;
 662         unsigned long long sta = 0;
 663
 664
 665         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 666
 667         if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
 668                 return 1;
 669
 670         /*
 671          * _STA is mandatory for a processor that supports hot plug
 672          */
 673         if (status == AE_NOT_FOUND)
 674                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 675                                 "Processor does not support hot plug\n"));
 676         else
 677                 ACPI_EXCEPTION((AE_INFO, status,
 678                                 "Processor Device is not present"));
 679         return 0;
 680 }
 681
 682 static void acpi_processor_hotplug_notify(acpi_handle handle,
 683                                           u32 event, void *data)
 684 {
 685         struct acpi_device *device = NULL;
 686         struct acpi_eject_event *ej_event = NULL;
 687         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 688         acpi_status status;
 689         int result;
 690
 691         acpi_scan_lock_acquire();
 692
 693         switch (event) {
 694         case ACPI_NOTIFY_BUS_CHECK:
 695         case ACPI_NOTIFY_DEVICE_CHECK:
 696                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 697                 "Processor driver received %s event\n",
 698                        (event == ACPI_NOTIFY_BUS_CHECK) ?
 699                        "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
 700
 701                 if (!is_processor_present(handle))
 702                         break;
 703
 704                 if (!acpi_bus_get_device(handle, &device))
 705                         break;
 706
 707                 result = acpi_bus_scan(handle);
 708                 if (result) {
 709                         acpi_handle_err(handle, "Unable to add the device\n");
 710                         break;
 711                 }
 712                 result = acpi_bus_get_device(handle, &device);
 713                 if (result) {
 714                         acpi_handle_err(handle, "Missing device object\n");
 715                         break;
 716                 }
 717                 ost_code = ACPI_OST_SC_SUCCESS;
 718                 break;
 719
 720         case ACPI_NOTIFY_EJECT_REQUEST:
 721                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 722                                   "received ACPI_NOTIFY_EJECT_REQUEST\n"));
 723
 724                 if (acpi_bus_get_device(handle, &device)) {
 725                         acpi_handle_err(handle,
 726                                 "Device don't exist, dropping EJECT\n");
 727                         break;
 728                 }
 729                 if (!acpi_driver_data(device)) {
 730                         acpi_handle_err(handle,
 731                                 "Driver data is NULL, dropping EJECT\n");
 732                         break;
 733                 }
 734
 735                 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 736                 if (!ej_event) {
 737                         acpi_handle_err(handle, "No memory, dropping EJECT\n");
 738                         break;
 739                 }
 740
 741                 get_device(&device->dev);
 742                 ej_event->device = device;
 743                 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 744                 /* The eject is carried out asynchronously. */
 745                 status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
 746                                                  ej_event);
 747                 if (ACPI_FAILURE(status)) {
 748                         put_device(&device->dev);
 749                         kfree(ej_event);
 750                         break;
 751                 }
 752                 goto out;
 753
 754         default:
 755                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 756                                   "Unsupported event [0x%x]\n", event));
 757
 758                 /* non-hotplug event; possibly handled by other handler */
 759                 goto out;
 760         }
 761
 762         /* Inform firmware that the hotplug operation has completed */
 763         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 764
 765  out:
 766         acpi_scan_lock_release();
 767 }
 768
 769 static acpi_status is_processor_device(acpi_handle handle)
 770 {
 771         struct acpi_device_info *info;
 772         char *hid;
 773         acpi_status status;
 774
 775         status = acpi_get_object_info(handle, &info);
 776         if (ACPI_FAILURE(status))
 777                 return status;
 778
 779         if (info->type == ACPI_TYPE_PROCESSOR) {
 780                 kfree(info);
 781                 return AE_OK;   /* found a processor object */
 782         }
 783
 784         if (!(info->valid & ACPI_VALID_HID)) {
 785                 kfree(info);
 786                 return AE_ERROR;
 787         }
 788
 789         hid = info->hardware_id.string;
 790         if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
 791                 kfree(info);
 792                 return AE_ERROR;
 793         }
 794
 795         kfree(info);
 796         return AE_OK;   /* found a processor device object */
 797 }
 798
 799 static acpi_status
 800 processor_walk_namespace_cb(acpi_handle handle,
 801                             u32 lvl, void *context, void **rv)
 802 {
 803         acpi_status status;
 804         int *action = context;
 805
 806         status = is_processor_device(handle);
 807         if (ACPI_FAILURE(status))
 808                 return AE_OK;   /* not a processor; continue to walk */
 809
 810         switch (*action) {
 811         case INSTALL_NOTIFY_HANDLER:
 812                 acpi_install_notify_handler(handle,
 813                                             ACPI_SYSTEM_NOTIFY,
 814                                             acpi_processor_hotplug_notify,
 815                                             NULL);
 816                 break;
 817         case UNINSTALL_NOTIFY_HANDLER:
 818                 acpi_remove_notify_handler(handle,
 819                                            ACPI_SYSTEM_NOTIFY,
 820                                            acpi_processor_hotplug_notify);
 821                 break;
 822         default:
 823                 break;
 824         }
 825
 826         /* found a processor; skip walking underneath */
 827         return AE_CTRL_DEPTH;
 828 }
 829
 830 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
 831 {
 832         acpi_handle handle = pr->handle;
 833
 834         if (!is_processor_present(handle)) {
 835                 return AE_ERROR;
 836         }
 837
 838         if (acpi_map_lsapic(handle, &pr->id))
 839                 return AE_ERROR;
 840
 841         if (arch_register_cpu(pr->id)) {
 842                 acpi_unmap_lsapic(pr->id);
 843                 return AE_ERROR;
 844         }
 845
 846         /* CPU got hot-plugged, but cpu_data is not initialized yet
 847          * Set flag to delay cpu_idle/throttling initialization
 848          * in:
 849          * acpi_processor_add()
 850          *   acpi_processor_get_info()
 851          * and do it when the CPU gets online the first time
 852          * TBD: Cleanup above functions and try to do this more elegant.
 853          */
 854         pr_info("CPU %d got hotplugged\n", pr->id);
 855         pr->flags.need_hotplug_init = 1;
 856
 857         return AE_OK;
 858 }
 859
 860 static int acpi_processor_handle_eject(struct acpi_processor *pr)
 861 {
 862         if (cpu_online(pr->id))
 863                 cpu_down(pr->id);
 864
 865         get_online_cpus();
 866         /*
 867          * The cpu might become online again at this point. So we check whether
 868          * the cpu has been onlined or not. If the cpu became online, it means
 869          * that someone wants to use the cpu. So acpi_processor_handle_eject()
 870          * returns -EAGAIN.
 871          */
 872         if (unlikely(cpu_online(pr->id))) {
 873                 put_online_cpus();
 874                 pr_warn("Failed to remove CPU %d, because other task "
 875                         "brought the CPU back online\n", pr->id);
 876                 return -EAGAIN;
 877         }
 878         arch_unregister_cpu(pr->id);
 879         acpi_unmap_lsapic(pr->id);
 880         put_online_cpus();
 881         return (0);
 882 }
 883 #else
 884 static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
 885 {
 886         return AE_ERROR;
 887 }
 888 static int acpi_processor_handle_eject(struct acpi_processor *pr)
 889 {
 890         return (-EINVAL);
 891 }
 892 #endif
 893
 894 static
 895 void acpi_processor_install_hotplug_notify(void)
 896 {
 897 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 898         int action = INSTALL_NOTIFY_HANDLER;
 899         acpi_walk_namespace(ACPI_TYPE_ANY,
 900                             ACPI_ROOT_OBJECT,
 901                             ACPI_UINT32_MAX,
 902                             processor_walk_namespace_cb, NULL, &action, NULL);
 903 #endif
 904         register_hotcpu_notifier(&acpi_cpu_notifier);
 905 }
 906
 907 static
 908 void acpi_processor_uninstall_hotplug_notify(void)
 909 {
 910 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 911         int action = UNINSTALL_NOTIFY_HANDLER;
 912         acpi_walk_namespace(ACPI_TYPE_ANY,
 913                             ACPI_ROOT_OBJECT,
 914                             ACPI_UINT32_MAX,
 915                             processor_walk_namespace_cb, NULL, &action, NULL);
 916 #endif
 917         unregister_hotcpu_notifier(&acpi_cpu_notifier);
 918 }
 919
 920 /*
 921  * We keep the driver loaded even when ACPI is not running.
 922  * This is needed for the powernow-k8 driver, that works even without
 923  * ACPI, but needs symbols from this driver
 924  */
 925
 926 static int __init acpi_processor_init(void)
 927 {
 928         int result = 0;
 929
 930         if (acpi_disabled)
 931                 return 0;
 932
 933         result = acpi_bus_register_driver(&acpi_processor_driver);
 934         if (result < 0)
 935                 return result;
 936
 937         acpi_processor_install_hotplug_notify();
 938
 939         acpi_thermal_cpufreq_init();
 940
 941         acpi_processor_ppc_init();
 942
 943         acpi_processor_throttling_init();
 944
 945         return 0;
 946 }
 947
 948 static void __exit acpi_processor_exit(void)
 949 {
 950         if (acpi_disabled)
 951                 return;
 952
 953         acpi_processor_ppc_exit();
 954
 955         acpi_thermal_cpufreq_exit();
 956
 957         acpi_processor_uninstall_hotplug_notify();
 958
 959         acpi_bus_unregister_driver(&acpi_processor_driver);
 960
 961         return;
 962 }
 963
 964 module_init(acpi_processor_init);
 965 module_exit(acpi_processor_exit);
 966
 967 MODULE_ALIAS("processor");