linux/drivers/acpi/processor_driver.c
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   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#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
  78ACPI_MODULE_NAME("processor_driver");
  79
  80MODULE_AUTHOR("Paul Diefenbaugh");
  81MODULE_DESCRIPTION("ACPI Processor Driver");
  82MODULE_LICENSE("GPL");
  83
  84static int acpi_processor_add(struct acpi_device *device);
  85static int acpi_processor_remove(struct acpi_device *device);
  86static void acpi_processor_notify(struct acpi_device *device, u32 event);
  87static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr);
  88static int acpi_processor_handle_eject(struct acpi_processor *pr);
  89static int acpi_processor_start(struct acpi_processor *pr);
  90
  91static const struct acpi_device_id processor_device_ids[] = {
  92        {ACPI_PROCESSOR_OBJECT_HID, 0},
  93        {ACPI_PROCESSOR_DEVICE_HID, 0},
  94        {"", 0},
  95};
  96MODULE_DEVICE_TABLE(acpi, processor_device_ids);
  97
  98static SIMPLE_DEV_PM_OPS(acpi_processor_pm,
  99                         acpi_processor_suspend, acpi_processor_resume);
 100
 101static 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
 116DEFINE_PER_CPU(struct acpi_processor *, processors);
 117EXPORT_PER_CPU_SYMBOL(processors);
 118
 119struct acpi_processor_errata errata __read_mostly;
 120
 121/* --------------------------------------------------------------------------
 122                                Errata Handling
 123   -------------------------------------------------------------------------- */
 124
 125static 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
 226static 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
 253static 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
 384static DEFINE_PER_CPU(void *, processor_device_array);
 385
 386static 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
 427static 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
 458static 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 */
 471static __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
 515err_remove_sysfs_thermal:
 516        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 517err_thermal_unregister:
 518        thermal_cooling_device_unregister(pr->cdev);
 519err_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 */
 531static 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
 600err_remove_sysfs:
 601        sysfs_remove_link(&device->dev.kobj, "sysdev");
 602err_clear_processor:
 603        /*
 604         * processor_device_array is not cleared to allow checks for buggy BIOS
 605         */ 
 606        per_cpu(processors, pr->id) = NULL;
 607err_free_cpumask:
 608        free_cpumask_var(pr->throttling.shared_cpu_map);
 609err_free_pr:
 610        kfree(pr);
 611        return result;
 612}
 613
 614static 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
 647free:
 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
 659static 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
 682static 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
 769static 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
 799static acpi_status
 800processor_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
 830static 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
 860static 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
 884static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
 885{
 886        return AE_ERROR;
 887}
 888static int acpi_processor_handle_eject(struct acpi_processor *pr)
 889{
 890        return (-EINVAL);
 891}
 892#endif
 893
 894static
 895void 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
 907static
 908void 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
 926static 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
 948static 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
 964module_init(acpi_processor_init);
 965module_exit(acpi_processor_exit);
 966
 967MODULE_ALIAS("processor");
 968
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