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