linux/drivers/base/core.c
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   1/*
   2 * drivers/base/core.c - core driver model code (device registration, etc)
   3 *
   4 * Copyright (c) 2002-3 Patrick Mochel
   5 * Copyright (c) 2002-3 Open Source Development Labs
   6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
   7 * Copyright (c) 2006 Novell, Inc.
   8 *
   9 * This file is released under the GPLv2
  10 *
  11 */
  12
  13#include <linux/device.h>
  14#include <linux/err.h>
  15#include <linux/init.h>
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/string.h>
  19#include <linux/kdev_t.h>
  20#include <linux/notifier.h>
  21#include <linux/genhd.h>
  22#include <linux/kallsyms.h>
  23#include <linux/semaphore.h>
  24#include <linux/mutex.h>
  25
  26#include "base.h"
  27#include "power/power.h"
  28
  29int (*platform_notify)(struct device *dev) = NULL;
  30int (*platform_notify_remove)(struct device *dev) = NULL;
  31static struct kobject *dev_kobj;
  32struct kobject *sysfs_dev_char_kobj;
  33struct kobject *sysfs_dev_block_kobj;
  34
  35#ifdef CONFIG_BLOCK
  36static inline int device_is_not_partition(struct device *dev)
  37{
  38        return !(dev->type == &part_type);
  39}
  40#else
  41static inline int device_is_not_partition(struct device *dev)
  42{
  43        return 1;
  44}
  45#endif
  46
  47/**
  48 * dev_driver_string - Return a device's driver name, if at all possible
  49 * @dev: struct device to get the name of
  50 *
  51 * Will return the device's driver's name if it is bound to a device.  If
  52 * the device is not bound to a device, it will return the name of the bus
  53 * it is attached to.  If it is not attached to a bus either, an empty
  54 * string will be returned.
  55 */
  56const char *dev_driver_string(const struct device *dev)
  57{
  58        return dev->driver ? dev->driver->name :
  59                        (dev->bus ? dev->bus->name :
  60                        (dev->class ? dev->class->name : ""));
  61}
  62EXPORT_SYMBOL(dev_driver_string);
  63
  64#define to_dev(obj) container_of(obj, struct device, kobj)
  65#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
  66
  67static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
  68                             char *buf)
  69{
  70        struct device_attribute *dev_attr = to_dev_attr(attr);
  71        struct device *dev = to_dev(kobj);
  72        ssize_t ret = -EIO;
  73
  74        if (dev_attr->show)
  75                ret = dev_attr->show(dev, dev_attr, buf);
  76        if (ret >= (ssize_t)PAGE_SIZE) {
  77                print_symbol("dev_attr_show: %s returned bad count\n",
  78                                (unsigned long)dev_attr->show);
  79        }
  80        return ret;
  81}
  82
  83static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
  84                              const char *buf, size_t count)
  85{
  86        struct device_attribute *dev_attr = to_dev_attr(attr);
  87        struct device *dev = to_dev(kobj);
  88        ssize_t ret = -EIO;
  89
  90        if (dev_attr->store)
  91                ret = dev_attr->store(dev, dev_attr, buf, count);
  92        return ret;
  93}
  94
  95static struct sysfs_ops dev_sysfs_ops = {
  96        .show   = dev_attr_show,
  97        .store  = dev_attr_store,
  98};
  99
 100
 101/**
 102 *      device_release - free device structure.
 103 *      @kobj:  device's kobject.
 104 *
 105 *      This is called once the reference count for the object
 106 *      reaches 0. We forward the call to the device's release
 107 *      method, which should handle actually freeing the structure.
 108 */
 109static void device_release(struct kobject *kobj)
 110{
 111        struct device *dev = to_dev(kobj);
 112
 113        if (dev->release)
 114                dev->release(dev);
 115        else if (dev->type && dev->type->release)
 116                dev->type->release(dev);
 117        else if (dev->class && dev->class->dev_release)
 118                dev->class->dev_release(dev);
 119        else
 120                WARN(1, KERN_ERR "Device '%s' does not have a release() "
 121                        "function, it is broken and must be fixed.\n",
 122                        dev->bus_id);
 123}
 124
 125static struct kobj_type device_ktype = {
 126        .release        = device_release,
 127        .sysfs_ops      = &dev_sysfs_ops,
 128};
 129
 130
 131static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 132{
 133        struct kobj_type *ktype = get_ktype(kobj);
 134
 135        if (ktype == &device_ktype) {
 136                struct device *dev = to_dev(kobj);
 137                if (dev->uevent_suppress)
 138                        return 0;
 139                if (dev->bus)
 140                        return 1;
 141                if (dev->class)
 142                        return 1;
 143        }
 144        return 0;
 145}
 146
 147static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 148{
 149        struct device *dev = to_dev(kobj);
 150
 151        if (dev->bus)
 152                return dev->bus->name;
 153        if (dev->class)
 154                return dev->class->name;
 155        return NULL;
 156}
 157
 158static int dev_uevent(struct kset *kset, struct kobject *kobj,
 159                      struct kobj_uevent_env *env)
 160{
 161        struct device *dev = to_dev(kobj);
 162        int retval = 0;
 163
 164        /* add the major/minor if present */
 165        if (MAJOR(dev->devt)) {
 166                add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 167                add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 168        }
 169
 170        if (dev->type && dev->type->name)
 171                add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 172
 173        if (dev->driver)
 174                add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 175
 176#ifdef CONFIG_SYSFS_DEPRECATED
 177        if (dev->class) {
 178                struct device *parent = dev->parent;
 179
 180                /* find first bus device in parent chain */
 181                while (parent && !parent->bus)
 182                        parent = parent->parent;
 183                if (parent && parent->bus) {
 184                        const char *path;
 185
 186                        path = kobject_get_path(&parent->kobj, GFP_KERNEL);
 187                        if (path) {
 188                                add_uevent_var(env, "PHYSDEVPATH=%s", path);
 189                                kfree(path);
 190                        }
 191
 192                        add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
 193
 194                        if (parent->driver)
 195                                add_uevent_var(env, "PHYSDEVDRIVER=%s",
 196                                               parent->driver->name);
 197                }
 198        } else if (dev->bus) {
 199                add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
 200
 201                if (dev->driver)
 202                        add_uevent_var(env, "PHYSDEVDRIVER=%s",
 203                                       dev->driver->name);
 204        }
 205#endif
 206
 207        /* have the bus specific function add its stuff */
 208        if (dev->bus && dev->bus->uevent) {
 209                retval = dev->bus->uevent(dev, env);
 210                if (retval)
 211                        pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 212                                 dev->bus_id, __func__, retval);
 213        }
 214
 215        /* have the class specific function add its stuff */
 216        if (dev->class && dev->class->dev_uevent) {
 217                retval = dev->class->dev_uevent(dev, env);
 218                if (retval)
 219                        pr_debug("device: '%s': %s: class uevent() "
 220                                 "returned %d\n", dev->bus_id,
 221                                 __func__, retval);
 222        }
 223
 224        /* have the device type specific fuction add its stuff */
 225        if (dev->type && dev->type->uevent) {
 226                retval = dev->type->uevent(dev, env);
 227                if (retval)
 228                        pr_debug("device: '%s': %s: dev_type uevent() "
 229                                 "returned %d\n", dev->bus_id,
 230                                 __func__, retval);
 231        }
 232
 233        return retval;
 234}
 235
 236static struct kset_uevent_ops device_uevent_ops = {
 237        .filter =       dev_uevent_filter,
 238        .name =         dev_uevent_name,
 239        .uevent =       dev_uevent,
 240};
 241
 242static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
 243                           char *buf)
 244{
 245        struct kobject *top_kobj;
 246        struct kset *kset;
 247        struct kobj_uevent_env *env = NULL;
 248        int i;
 249        size_t count = 0;
 250        int retval;
 251
 252        /* search the kset, the device belongs to */
 253        top_kobj = &dev->kobj;
 254        while (!top_kobj->kset && top_kobj->parent)
 255                top_kobj = top_kobj->parent;
 256        if (!top_kobj->kset)
 257                goto out;
 258
 259        kset = top_kobj->kset;
 260        if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 261                goto out;
 262
 263        /* respect filter */
 264        if (kset->uevent_ops && kset->uevent_ops->filter)
 265                if (!kset->uevent_ops->filter(kset, &dev->kobj))
 266                        goto out;
 267
 268        env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 269        if (!env)
 270                return -ENOMEM;
 271
 272        /* let the kset specific function add its keys */
 273        retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 274        if (retval)
 275                goto out;
 276
 277        /* copy keys to file */
 278        for (i = 0; i < env->envp_idx; i++)
 279                count += sprintf(&buf[count], "%s\n", env->envp[i]);
 280out:
 281        kfree(env);
 282        return count;
 283}
 284
 285static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
 286                            const char *buf, size_t count)
 287{
 288        enum kobject_action action;
 289
 290        if (kobject_action_type(buf, count, &action) == 0) {
 291                kobject_uevent(&dev->kobj, action);
 292                goto out;
 293        }
 294
 295        dev_err(dev, "uevent: unsupported action-string; this will "
 296                     "be ignored in a future kernel version\n");
 297        kobject_uevent(&dev->kobj, KOBJ_ADD);
 298out:
 299        return count;
 300}
 301
 302static struct device_attribute uevent_attr =
 303        __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
 304
 305static int device_add_attributes(struct device *dev,
 306                                 struct device_attribute *attrs)
 307{
 308        int error = 0;
 309        int i;
 310
 311        if (attrs) {
 312                for (i = 0; attr_name(attrs[i]); i++) {
 313                        error = device_create_file(dev, &attrs[i]);
 314                        if (error)
 315                                break;
 316                }
 317                if (error)
 318                        while (--i >= 0)
 319                                device_remove_file(dev, &attrs[i]);
 320        }
 321        return error;
 322}
 323
 324static void device_remove_attributes(struct device *dev,
 325                                     struct device_attribute *attrs)
 326{
 327        int i;
 328
 329        if (attrs)
 330                for (i = 0; attr_name(attrs[i]); i++)
 331                        device_remove_file(dev, &attrs[i]);
 332}
 333
 334static int device_add_groups(struct device *dev,
 335                             struct attribute_group **groups)
 336{
 337        int error = 0;
 338        int i;
 339
 340        if (groups) {
 341                for (i = 0; groups[i]; i++) {
 342                        error = sysfs_create_group(&dev->kobj, groups[i]);
 343                        if (error) {
 344                                while (--i >= 0)
 345                                        sysfs_remove_group(&dev->kobj,
 346                                                           groups[i]);
 347                                break;
 348                        }
 349                }
 350        }
 351        return error;
 352}
 353
 354static void device_remove_groups(struct device *dev,
 355                                 struct attribute_group **groups)
 356{
 357        int i;
 358
 359        if (groups)
 360                for (i = 0; groups[i]; i++)
 361                        sysfs_remove_group(&dev->kobj, groups[i]);
 362}
 363
 364static int device_add_attrs(struct device *dev)
 365{
 366        struct class *class = dev->class;
 367        struct device_type *type = dev->type;
 368        int error;
 369
 370        if (class) {
 371                error = device_add_attributes(dev, class->dev_attrs);
 372                if (error)
 373                        return error;
 374        }
 375
 376        if (type) {
 377                error = device_add_groups(dev, type->groups);
 378                if (error)
 379                        goto err_remove_class_attrs;
 380        }
 381
 382        error = device_add_groups(dev, dev->groups);
 383        if (error)
 384                goto err_remove_type_groups;
 385
 386        return 0;
 387
 388 err_remove_type_groups:
 389        if (type)
 390                device_remove_groups(dev, type->groups);
 391 err_remove_class_attrs:
 392        if (class)
 393                device_remove_attributes(dev, class->dev_attrs);
 394
 395        return error;
 396}
 397
 398static void device_remove_attrs(struct device *dev)
 399{
 400        struct class *class = dev->class;
 401        struct device_type *type = dev->type;
 402
 403        device_remove_groups(dev, dev->groups);
 404
 405        if (type)
 406                device_remove_groups(dev, type->groups);
 407
 408        if (class)
 409                device_remove_attributes(dev, class->dev_attrs);
 410}
 411
 412
 413static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
 414                        char *buf)
 415{
 416        return print_dev_t(buf, dev->devt);
 417}
 418
 419static struct device_attribute devt_attr =
 420        __ATTR(dev, S_IRUGO, show_dev, NULL);
 421
 422/* kset to create /sys/devices/  */
 423struct kset *devices_kset;
 424
 425/**
 426 * device_create_file - create sysfs attribute file for device.
 427 * @dev: device.
 428 * @attr: device attribute descriptor.
 429 */
 430int device_create_file(struct device *dev, struct device_attribute *attr)
 431{
 432        int error = 0;
 433        if (dev)
 434                error = sysfs_create_file(&dev->kobj, &attr->attr);
 435        return error;
 436}
 437
 438/**
 439 * device_remove_file - remove sysfs attribute file.
 440 * @dev: device.
 441 * @attr: device attribute descriptor.
 442 */
 443void device_remove_file(struct device *dev, struct device_attribute *attr)
 444{
 445        if (dev)
 446                sysfs_remove_file(&dev->kobj, &attr->attr);
 447}
 448
 449/**
 450 * device_create_bin_file - create sysfs binary attribute file for device.
 451 * @dev: device.
 452 * @attr: device binary attribute descriptor.
 453 */
 454int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
 455{
 456        int error = -EINVAL;
 457        if (dev)
 458                error = sysfs_create_bin_file(&dev->kobj, attr);
 459        return error;
 460}
 461EXPORT_SYMBOL_GPL(device_create_bin_file);
 462
 463/**
 464 * device_remove_bin_file - remove sysfs binary attribute file
 465 * @dev: device.
 466 * @attr: device binary attribute descriptor.
 467 */
 468void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
 469{
 470        if (dev)
 471                sysfs_remove_bin_file(&dev->kobj, attr);
 472}
 473EXPORT_SYMBOL_GPL(device_remove_bin_file);
 474
 475/**
 476 * device_schedule_callback_owner - helper to schedule a callback for a device
 477 * @dev: device.
 478 * @func: callback function to invoke later.
 479 * @owner: module owning the callback routine
 480 *
 481 * Attribute methods must not unregister themselves or their parent device
 482 * (which would amount to the same thing).  Attempts to do so will deadlock,
 483 * since unregistration is mutually exclusive with driver callbacks.
 484 *
 485 * Instead methods can call this routine, which will attempt to allocate
 486 * and schedule a workqueue request to call back @func with @dev as its
 487 * argument in the workqueue's process context.  @dev will be pinned until
 488 * @func returns.
 489 *
 490 * This routine is usually called via the inline device_schedule_callback(),
 491 * which automatically sets @owner to THIS_MODULE.
 492 *
 493 * Returns 0 if the request was submitted, -ENOMEM if storage could not
 494 * be allocated, -ENODEV if a reference to @owner isn't available.
 495 *
 496 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 497 * underlying sysfs routine (since it is intended for use by attribute
 498 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 499 */
 500int device_schedule_callback_owner(struct device *dev,
 501                void (*func)(struct device *), struct module *owner)
 502{
 503        return sysfs_schedule_callback(&dev->kobj,
 504                        (void (*)(void *)) func, dev, owner);
 505}
 506EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
 507
 508static void klist_children_get(struct klist_node *n)
 509{
 510        struct device *dev = container_of(n, struct device, knode_parent);
 511
 512        get_device(dev);
 513}
 514
 515static void klist_children_put(struct klist_node *n)
 516{
 517        struct device *dev = container_of(n, struct device, knode_parent);
 518
 519        put_device(dev);
 520}
 521
 522/**
 523 * device_initialize - init device structure.
 524 * @dev: device.
 525 *
 526 * This prepares the device for use by other layers,
 527 * including adding it to the device hierarchy.
 528 * It is the first half of device_register(), if called by
 529 * that, though it can also be called separately, so one
 530 * may use @dev's fields (e.g. the refcount).
 531 */
 532void device_initialize(struct device *dev)
 533{
 534        dev->kobj.kset = devices_kset;
 535        kobject_init(&dev->kobj, &device_ktype);
 536        klist_init(&dev->klist_children, klist_children_get,
 537                   klist_children_put);
 538        INIT_LIST_HEAD(&dev->dma_pools);
 539        INIT_LIST_HEAD(&dev->node);
 540        init_MUTEX(&dev->sem);
 541        spin_lock_init(&dev->devres_lock);
 542        INIT_LIST_HEAD(&dev->devres_head);
 543        device_init_wakeup(dev, 0);
 544        device_pm_init(dev);
 545        set_dev_node(dev, -1);
 546}
 547
 548#ifdef CONFIG_SYSFS_DEPRECATED
 549static struct kobject *get_device_parent(struct device *dev,
 550                                         struct device *parent)
 551{
 552        /* class devices without a parent live in /sys/class/<classname>/ */
 553        if (dev->class && (!parent || parent->class != dev->class))
 554                return &dev->class->p->class_subsys.kobj;
 555        /* all other devices keep their parent */
 556        else if (parent)
 557                return &parent->kobj;
 558
 559        return NULL;
 560}
 561
 562static inline void cleanup_device_parent(struct device *dev) {}
 563static inline void cleanup_glue_dir(struct device *dev,
 564                                    struct kobject *glue_dir) {}
 565#else
 566static struct kobject *virtual_device_parent(struct device *dev)
 567{
 568        static struct kobject *virtual_dir = NULL;
 569
 570        if (!virtual_dir)
 571                virtual_dir = kobject_create_and_add("virtual",
 572                                                     &devices_kset->kobj);
 573
 574        return virtual_dir;
 575}
 576
 577static struct kobject *get_device_parent(struct device *dev,
 578                                         struct device *parent)
 579{
 580        int retval;
 581
 582        if (dev->class) {
 583                struct kobject *kobj = NULL;
 584                struct kobject *parent_kobj;
 585                struct kobject *k;
 586
 587                /*
 588                 * If we have no parent, we live in "virtual".
 589                 * Class-devices with a non class-device as parent, live
 590                 * in a "glue" directory to prevent namespace collisions.
 591                 */
 592                if (parent == NULL)
 593                        parent_kobj = virtual_device_parent(dev);
 594                else if (parent->class)
 595                        return &parent->kobj;
 596                else
 597                        parent_kobj = &parent->kobj;
 598
 599                /* find our class-directory at the parent and reference it */
 600                spin_lock(&dev->class->p->class_dirs.list_lock);
 601                list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
 602                        if (k->parent == parent_kobj) {
 603                                kobj = kobject_get(k);
 604                                break;
 605                        }
 606                spin_unlock(&dev->class->p->class_dirs.list_lock);
 607                if (kobj)
 608                        return kobj;
 609
 610                /* or create a new class-directory at the parent device */
 611                k = kobject_create();
 612                if (!k)
 613                        return NULL;
 614                k->kset = &dev->class->p->class_dirs;
 615                retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
 616                if (retval < 0) {
 617                        kobject_put(k);
 618                        return NULL;
 619                }
 620                /* do not emit an uevent for this simple "glue" directory */
 621                return k;
 622        }
 623
 624        if (parent)
 625                return &parent->kobj;
 626        return NULL;
 627}
 628
 629static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 630{
 631        /* see if we live in a "glue" directory */
 632        if (!glue_dir || !dev->class ||
 633            glue_dir->kset != &dev->class->p->class_dirs)
 634                return;
 635
 636        kobject_put(glue_dir);
 637}
 638
 639static void cleanup_device_parent(struct device *dev)
 640{
 641        cleanup_glue_dir(dev, dev->kobj.parent);
 642}
 643#endif
 644
 645static void setup_parent(struct device *dev, struct device *parent)
 646{
 647        struct kobject *kobj;
 648        kobj = get_device_parent(dev, parent);
 649        if (kobj)
 650                dev->kobj.parent = kobj;
 651}
 652
 653static int device_add_class_symlinks(struct device *dev)
 654{
 655        int error;
 656
 657        if (!dev->class)
 658                return 0;
 659
 660        error = sysfs_create_link(&dev->kobj,
 661                                  &dev->class->p->class_subsys.kobj,
 662                                  "subsystem");
 663        if (error)
 664                goto out;
 665
 666#ifdef CONFIG_SYSFS_DEPRECATED
 667        /* stacked class devices need a symlink in the class directory */
 668        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 669            device_is_not_partition(dev)) {
 670                error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 671                                          &dev->kobj, dev->bus_id);
 672                if (error)
 673                        goto out_subsys;
 674        }
 675
 676        if (dev->parent && device_is_not_partition(dev)) {
 677                struct device *parent = dev->parent;
 678                char *class_name;
 679
 680                /*
 681                 * stacked class devices have the 'device' link
 682                 * pointing to the bus device instead of the parent
 683                 */
 684                while (parent->class && !parent->bus && parent->parent)
 685                        parent = parent->parent;
 686
 687                error = sysfs_create_link(&dev->kobj,
 688                                          &parent->kobj,
 689                                          "device");
 690                if (error)
 691                        goto out_busid;
 692
 693                class_name = make_class_name(dev->class->name,
 694                                                &dev->kobj);
 695                if (class_name)
 696                        error = sysfs_create_link(&dev->parent->kobj,
 697                                                &dev->kobj, class_name);
 698                kfree(class_name);
 699                if (error)
 700                        goto out_device;
 701        }
 702        return 0;
 703
 704out_device:
 705        if (dev->parent && device_is_not_partition(dev))
 706                sysfs_remove_link(&dev->kobj, "device");
 707out_busid:
 708        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 709            device_is_not_partition(dev))
 710                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
 711                                  dev->bus_id);
 712#else
 713        /* link in the class directory pointing to the device */
 714        error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 715                                  &dev->kobj, dev->bus_id);
 716        if (error)
 717                goto out_subsys;
 718
 719        if (dev->parent && device_is_not_partition(dev)) {
 720                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 721                                          "device");
 722                if (error)
 723                        goto out_busid;
 724        }
 725        return 0;
 726
 727out_busid:
 728        sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
 729#endif
 730
 731out_subsys:
 732        sysfs_remove_link(&dev->kobj, "subsystem");
 733out:
 734        return error;
 735}
 736
 737static void device_remove_class_symlinks(struct device *dev)
 738{
 739        if (!dev->class)
 740                return;
 741
 742#ifdef CONFIG_SYSFS_DEPRECATED
 743        if (dev->parent && device_is_not_partition(dev)) {
 744                char *class_name;
 745
 746                class_name = make_class_name(dev->class->name, &dev->kobj);
 747                if (class_name) {
 748                        sysfs_remove_link(&dev->parent->kobj, class_name);
 749                        kfree(class_name);
 750                }
 751                sysfs_remove_link(&dev->kobj, "device");
 752        }
 753
 754        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 755            device_is_not_partition(dev))
 756                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
 757                                  dev->bus_id);
 758#else
 759        if (dev->parent && device_is_not_partition(dev))
 760                sysfs_remove_link(&dev->kobj, "device");
 761
 762        sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
 763#endif
 764
 765        sysfs_remove_link(&dev->kobj, "subsystem");
 766}
 767
 768/**
 769 * dev_set_name - set a device name
 770 * @dev: device
 771 * @fmt: format string for the device's name
 772 */
 773int dev_set_name(struct device *dev, const char *fmt, ...)
 774{
 775        va_list vargs;
 776
 777        va_start(vargs, fmt);
 778        vsnprintf(dev->bus_id, sizeof(dev->bus_id), fmt, vargs);
 779        va_end(vargs);
 780        return 0;
 781}
 782EXPORT_SYMBOL_GPL(dev_set_name);
 783
 784/**
 785 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 786 * @dev: device
 787 *
 788 * By default we select char/ for new entries.  Setting class->dev_obj
 789 * to NULL prevents an entry from being created.  class->dev_kobj must
 790 * be set (or cleared) before any devices are registered to the class
 791 * otherwise device_create_sys_dev_entry() and
 792 * device_remove_sys_dev_entry() will disagree about the the presence
 793 * of the link.
 794 */
 795static struct kobject *device_to_dev_kobj(struct device *dev)
 796{
 797        struct kobject *kobj;
 798
 799        if (dev->class)
 800                kobj = dev->class->dev_kobj;
 801        else
 802                kobj = sysfs_dev_char_kobj;
 803
 804        return kobj;
 805}
 806
 807static int device_create_sys_dev_entry(struct device *dev)
 808{
 809        struct kobject *kobj = device_to_dev_kobj(dev);
 810        int error = 0;
 811        char devt_str[15];
 812
 813        if (kobj) {
 814                format_dev_t(devt_str, dev->devt);
 815                error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 816        }
 817
 818        return error;
 819}
 820
 821static void device_remove_sys_dev_entry(struct device *dev)
 822{
 823        struct kobject *kobj = device_to_dev_kobj(dev);
 824        char devt_str[15];
 825
 826        if (kobj) {
 827                format_dev_t(devt_str, dev->devt);
 828                sysfs_remove_link(kobj, devt_str);
 829        }
 830}
 831
 832/**
 833 * device_add - add device to device hierarchy.
 834 * @dev: device.
 835 *
 836 * This is part 2 of device_register(), though may be called
 837 * separately _iff_ device_initialize() has been called separately.
 838 *
 839 * This adds it to the kobject hierarchy via kobject_add(), adds it
 840 * to the global and sibling lists for the device, then
 841 * adds it to the other relevant subsystems of the driver model.
 842 */
 843int device_add(struct device *dev)
 844{
 845        struct device *parent = NULL;
 846        struct class_interface *class_intf;
 847        int error = -EINVAL;
 848
 849        dev = get_device(dev);
 850        if (!dev)
 851                goto done;
 852
 853        /* Temporarily support init_name if it is set.
 854         * It will override bus_id for now */
 855        if (dev->init_name)
 856                dev_set_name(dev, "%s", dev->init_name);
 857
 858        if (!strlen(dev->bus_id))
 859                goto done;
 860
 861        pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
 862
 863        parent = get_device(dev->parent);
 864        setup_parent(dev, parent);
 865
 866        /* use parent numa_node */
 867        if (parent)
 868                set_dev_node(dev, dev_to_node(parent));
 869
 870        /* first, register with generic layer. */
 871        error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
 872        if (error)
 873                goto Error;
 874
 875        /* notify platform of device entry */
 876        if (platform_notify)
 877                platform_notify(dev);
 878
 879        /* notify clients of device entry (new way) */
 880        if (dev->bus)
 881                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 882                                             BUS_NOTIFY_ADD_DEVICE, dev);
 883
 884        error = device_create_file(dev, &uevent_attr);
 885        if (error)
 886                goto attrError;
 887
 888        if (MAJOR(dev->devt)) {
 889                error = device_create_file(dev, &devt_attr);
 890                if (error)
 891                        goto ueventattrError;
 892
 893                error = device_create_sys_dev_entry(dev);
 894                if (error)
 895                        goto devtattrError;
 896        }
 897
 898        error = device_add_class_symlinks(dev);
 899        if (error)
 900                goto SymlinkError;
 901        error = device_add_attrs(dev);
 902        if (error)
 903                goto AttrsError;
 904        error = bus_add_device(dev);
 905        if (error)
 906                goto BusError;
 907        error = dpm_sysfs_add(dev);
 908        if (error)
 909                goto DPMError;
 910        device_pm_add(dev);
 911        kobject_uevent(&dev->kobj, KOBJ_ADD);
 912        bus_attach_device(dev);
 913        if (parent)
 914                klist_add_tail(&dev->knode_parent, &parent->klist_children);
 915
 916        if (dev->class) {
 917                mutex_lock(&dev->class->p->class_mutex);
 918                /* tie the class to the device */
 919                list_add_tail(&dev->node, &dev->class->p->class_devices);
 920
 921                /* notify any interfaces that the device is here */
 922                list_for_each_entry(class_intf,
 923                                    &dev->class->p->class_interfaces, node)
 924                        if (class_intf->add_dev)
 925                                class_intf->add_dev(dev, class_intf);
 926                mutex_unlock(&dev->class->p->class_mutex);
 927        }
 928done:
 929        put_device(dev);
 930        return error;
 931 DPMError:
 932        bus_remove_device(dev);
 933 BusError:
 934        if (dev->bus)
 935                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 936                                             BUS_NOTIFY_DEL_DEVICE, dev);
 937        device_remove_attrs(dev);
 938 AttrsError:
 939        device_remove_class_symlinks(dev);
 940 SymlinkError:
 941        if (MAJOR(dev->devt))
 942                device_remove_sys_dev_entry(dev);
 943 devtattrError:
 944        if (MAJOR(dev->devt))
 945                device_remove_file(dev, &devt_attr);
 946 ueventattrError:
 947        device_remove_file(dev, &uevent_attr);
 948 attrError:
 949        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 950        kobject_del(&dev->kobj);
 951 Error:
 952        cleanup_device_parent(dev);
 953        if (parent)
 954                put_device(parent);
 955        goto done;
 956}
 957
 958/**
 959 * device_register - register a device with the system.
 960 * @dev: pointer to the device structure
 961 *
 962 * This happens in two clean steps - initialize the device
 963 * and add it to the system. The two steps can be called
 964 * separately, but this is the easiest and most common.
 965 * I.e. you should only call the two helpers separately if
 966 * have a clearly defined need to use and refcount the device
 967 * before it is added to the hierarchy.
 968 */
 969int device_register(struct device *dev)
 970{
 971        device_initialize(dev);
 972        return device_add(dev);
 973}
 974
 975/**
 976 * get_device - increment reference count for device.
 977 * @dev: device.
 978 *
 979 * This simply forwards the call to kobject_get(), though
 980 * we do take care to provide for the case that we get a NULL
 981 * pointer passed in.
 982 */
 983struct device *get_device(struct device *dev)
 984{
 985        return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
 986}
 987
 988/**
 989 * put_device - decrement reference count.
 990 * @dev: device in question.
 991 */
 992void put_device(struct device *dev)
 993{
 994        /* might_sleep(); */
 995        if (dev)
 996                kobject_put(&dev->kobj);
 997}
 998
 999/**
1000 * device_del - delete device from system.
1001 * @dev: device.
1002 *
1003 * This is the first part of the device unregistration
1004 * sequence. This removes the device from the lists we control
1005 * from here, has it removed from the other driver model
1006 * subsystems it was added to in device_add(), and removes it
1007 * from the kobject hierarchy.
1008 *
1009 * NOTE: this should be called manually _iff_ device_add() was
1010 * also called manually.
1011 */
1012void device_del(struct device *dev)
1013{
1014        struct device *parent = dev->parent;
1015        struct class_interface *class_intf;
1016
1017        device_pm_remove(dev);
1018        dpm_sysfs_remove(dev);
1019        if (parent)
1020                klist_del(&dev->knode_parent);
1021        if (MAJOR(dev->devt)) {
1022                device_remove_sys_dev_entry(dev);
1023                device_remove_file(dev, &devt_attr);
1024        }
1025        if (dev->class) {
1026                device_remove_class_symlinks(dev);
1027
1028                mutex_lock(&dev->class->p->class_mutex);
1029                /* notify any interfaces that the device is now gone */
1030                list_for_each_entry(class_intf,
1031                                    &dev->class->p->class_interfaces, node)
1032                        if (class_intf->remove_dev)
1033                                class_intf->remove_dev(dev, class_intf);
1034                /* remove the device from the class list */
1035                list_del_init(&dev->node);
1036                mutex_unlock(&dev->class->p->class_mutex);
1037        }
1038        device_remove_file(dev, &uevent_attr);
1039        device_remove_attrs(dev);
1040        bus_remove_device(dev);
1041
1042        /*
1043         * Some platform devices are driven without driver attached
1044         * and managed resources may have been acquired.  Make sure
1045         * all resources are released.
1046         */
1047        devres_release_all(dev);
1048
1049        /* Notify the platform of the removal, in case they
1050         * need to do anything...
1051         */
1052        if (platform_notify_remove)
1053                platform_notify_remove(dev);
1054        if (dev->bus)
1055                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1056                                             BUS_NOTIFY_DEL_DEVICE, dev);
1057        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1058        cleanup_device_parent(dev);
1059        kobject_del(&dev->kobj);
1060        put_device(parent);
1061}
1062
1063/**
1064 * device_unregister - unregister device from system.
1065 * @dev: device going away.
1066 *
1067 * We do this in two parts, like we do device_register(). First,
1068 * we remove it from all the subsystems with device_del(), then
1069 * we decrement the reference count via put_device(). If that
1070 * is the final reference count, the device will be cleaned up
1071 * via device_release() above. Otherwise, the structure will
1072 * stick around until the final reference to the device is dropped.
1073 */
1074void device_unregister(struct device *dev)
1075{
1076        pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1077        device_del(dev);
1078        put_device(dev);
1079}
1080
1081static struct device *next_device(struct klist_iter *i)
1082{
1083        struct klist_node *n = klist_next(i);
1084        return n ? container_of(n, struct device, knode_parent) : NULL;
1085}
1086
1087/**
1088 * device_for_each_child - device child iterator.
1089 * @parent: parent struct device.
1090 * @data: data for the callback.
1091 * @fn: function to be called for each device.
1092 *
1093 * Iterate over @parent's child devices, and call @fn for each,
1094 * passing it @data.
1095 *
1096 * We check the return of @fn each time. If it returns anything
1097 * other than 0, we break out and return that value.
1098 */
1099int device_for_each_child(struct device *parent, void *data,
1100                          int (*fn)(struct device *dev, void *data))
1101{
1102        struct klist_iter i;
1103        struct device *child;
1104        int error = 0;
1105
1106        klist_iter_init(&parent->klist_children, &i);
1107        while ((child = next_device(&i)) && !error)
1108                error = fn(child, data);
1109        klist_iter_exit(&i);
1110        return error;
1111}
1112
1113/**
1114 * device_find_child - device iterator for locating a particular device.
1115 * @parent: parent struct device
1116 * @data: Data to pass to match function
1117 * @match: Callback function to check device
1118 *
1119 * This is similar to the device_for_each_child() function above, but it
1120 * returns a reference to a device that is 'found' for later use, as
1121 * determined by the @match callback.
1122 *
1123 * The callback should return 0 if the device doesn't match and non-zero
1124 * if it does.  If the callback returns non-zero and a reference to the
1125 * current device can be obtained, this function will return to the caller
1126 * and not iterate over any more devices.
1127 */
1128struct device *device_find_child(struct device *parent, void *data,
1129                                 int (*match)(struct device *dev, void *data))
1130{
1131        struct klist_iter i;
1132        struct device *child;
1133
1134        if (!parent)
1135                return NULL;
1136
1137        klist_iter_init(&parent->klist_children, &i);
1138        while ((child = next_device(&i)))
1139                if (match(child, data) && get_device(child))
1140                        break;
1141        klist_iter_exit(&i);
1142        return child;
1143}
1144
1145int __init devices_init(void)
1146{
1147        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1148        if (!devices_kset)
1149                return -ENOMEM;
1150        dev_kobj = kobject_create_and_add("dev", NULL);
1151        if (!dev_kobj)
1152                goto dev_kobj_err;
1153        sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1154        if (!sysfs_dev_block_kobj)
1155                goto block_kobj_err;
1156        sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1157        if (!sysfs_dev_char_kobj)
1158                goto char_kobj_err;
1159
1160        return 0;
1161
1162 char_kobj_err:
1163        kobject_put(sysfs_dev_block_kobj);
1164 block_kobj_err:
1165        kobject_put(dev_kobj);
1166 dev_kobj_err:
1167        kset_unregister(devices_kset);
1168        return -ENOMEM;
1169}
1170
1171EXPORT_SYMBOL_GPL(device_for_each_child);
1172EXPORT_SYMBOL_GPL(device_find_child);
1173
1174EXPORT_SYMBOL_GPL(device_initialize);
1175EXPORT_SYMBOL_GPL(device_add);
1176EXPORT_SYMBOL_GPL(device_register);
1177
1178EXPORT_SYMBOL_GPL(device_del);
1179EXPORT_SYMBOL_GPL(device_unregister);
1180EXPORT_SYMBOL_GPL(get_device);
1181EXPORT_SYMBOL_GPL(put_device);
1182
1183EXPORT_SYMBOL_GPL(device_create_file);
1184EXPORT_SYMBOL_GPL(device_remove_file);
1185
1186
1187static void device_create_release(struct device *dev)
1188{
1189        pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1190        kfree(dev);
1191}
1192
1193/**
1194 * device_create_vargs - creates a device and registers it with sysfs
1195 * @class: pointer to the struct class that this device should be registered to
1196 * @parent: pointer to the parent struct device of this new device, if any
1197 * @devt: the dev_t for the char device to be added
1198 * @drvdata: the data to be added to the device for callbacks
1199 * @fmt: string for the device's name
1200 * @args: va_list for the device's name
1201 *
1202 * This function can be used by char device classes.  A struct device
1203 * will be created in sysfs, registered to the specified class.
1204 *
1205 * A "dev" file will be created, showing the dev_t for the device, if
1206 * the dev_t is not 0,0.
1207 * If a pointer to a parent struct device is passed in, the newly created
1208 * struct device will be a child of that device in sysfs.
1209 * The pointer to the struct device will be returned from the call.
1210 * Any further sysfs files that might be required can be created using this
1211 * pointer.
1212 *
1213 * Note: the struct class passed to this function must have previously
1214 * been created with a call to class_create().
1215 */
1216struct device *device_create_vargs(struct class *class, struct device *parent,
1217                                   dev_t devt, void *drvdata, const char *fmt,
1218                                   va_list args)
1219{
1220        struct device *dev = NULL;
1221        int retval = -ENODEV;
1222
1223        if (class == NULL || IS_ERR(class))
1224                goto error;
1225
1226        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1227        if (!dev) {
1228                retval = -ENOMEM;
1229                goto error;
1230        }
1231
1232        dev->devt = devt;
1233        dev->class = class;
1234        dev->parent = parent;
1235        dev->release = device_create_release;
1236        dev_set_drvdata(dev, drvdata);
1237
1238        vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1239        retval = device_register(dev);
1240        if (retval)
1241                goto error;
1242
1243        return dev;
1244
1245error:
1246        kfree(dev);
1247        return ERR_PTR(retval);
1248}
1249EXPORT_SYMBOL_GPL(device_create_vargs);
1250
1251/**
1252 * device_create - creates a device and registers it with sysfs
1253 * @class: pointer to the struct class that this device should be registered to
1254 * @parent: pointer to the parent struct device of this new device, if any
1255 * @devt: the dev_t for the char device to be added
1256 * @drvdata: the data to be added to the device for callbacks
1257 * @fmt: string for the device's name
1258 *
1259 * This function can be used by char device classes.  A struct device
1260 * will be created in sysfs, registered to the specified class.
1261 *
1262 * A "dev" file will be created, showing the dev_t for the device, if
1263 * the dev_t is not 0,0.
1264 * If a pointer to a parent struct device is passed in, the newly created
1265 * struct device will be a child of that device in sysfs.
1266 * The pointer to the struct device will be returned from the call.
1267 * Any further sysfs files that might be required can be created using this
1268 * pointer.
1269 *
1270 * Note: the struct class passed to this function must have previously
1271 * been created with a call to class_create().
1272 */
1273struct device *device_create(struct class *class, struct device *parent,
1274                             dev_t devt, void *drvdata, const char *fmt, ...)
1275{
1276        va_list vargs;
1277        struct device *dev;
1278
1279        va_start(vargs, fmt);
1280        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1281        va_end(vargs);
1282        return dev;
1283}
1284EXPORT_SYMBOL_GPL(device_create);
1285
1286static int __match_devt(struct device *dev, void *data)
1287{
1288        dev_t *devt = data;
1289
1290        return dev->devt == *devt;
1291}
1292
1293/**
1294 * device_destroy - removes a device that was created with device_create()
1295 * @class: pointer to the struct class that this device was registered with
1296 * @devt: the dev_t of the device that was previously registered
1297 *
1298 * This call unregisters and cleans up a device that was created with a
1299 * call to device_create().
1300 */
1301void device_destroy(struct class *class, dev_t devt)
1302{
1303        struct device *dev;
1304
1305        dev = class_find_device(class, NULL, &devt, __match_devt);
1306        if (dev) {
1307                put_device(dev);
1308                device_unregister(dev);
1309        }
1310}
1311EXPORT_SYMBOL_GPL(device_destroy);
1312
1313/**
1314 * device_rename - renames a device
1315 * @dev: the pointer to the struct device to be renamed
1316 * @new_name: the new name of the device
1317 */
1318int device_rename(struct device *dev, char *new_name)
1319{
1320        char *old_class_name = NULL;
1321        char *new_class_name = NULL;
1322        char *old_device_name = NULL;
1323        int error;
1324
1325        dev = get_device(dev);
1326        if (!dev)
1327                return -EINVAL;
1328
1329        pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1330                 __func__, new_name);
1331
1332#ifdef CONFIG_SYSFS_DEPRECATED
1333        if ((dev->class) && (dev->parent))
1334                old_class_name = make_class_name(dev->class->name, &dev->kobj);
1335#endif
1336
1337        old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1338        if (!old_device_name) {
1339                error = -ENOMEM;
1340                goto out;
1341        }
1342        strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1343        strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1344
1345        error = kobject_rename(&dev->kobj, new_name);
1346        if (error) {
1347                strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
1348                goto out;
1349        }
1350
1351#ifdef CONFIG_SYSFS_DEPRECATED
1352        if (old_class_name) {
1353                new_class_name = make_class_name(dev->class->name, &dev->kobj);
1354                if (new_class_name) {
1355                        error = sysfs_create_link_nowarn(&dev->parent->kobj,
1356                                                         &dev->kobj,
1357                                                         new_class_name);
1358                        if (error)
1359                                goto out;
1360                        sysfs_remove_link(&dev->parent->kobj, old_class_name);
1361                }
1362        }
1363#else
1364        if (dev->class) {
1365                error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
1366                                                 &dev->kobj, dev->bus_id);
1367                if (error)
1368                        goto out;
1369                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1370                                  old_device_name);
1371        }
1372#endif
1373
1374out:
1375        put_device(dev);
1376
1377        kfree(new_class_name);
1378        kfree(old_class_name);
1379        kfree(old_device_name);
1380
1381        return error;
1382}
1383EXPORT_SYMBOL_GPL(device_rename);
1384
1385static int device_move_class_links(struct device *dev,
1386                                   struct device *old_parent,
1387                                   struct device *new_parent)
1388{
1389        int error = 0;
1390#ifdef CONFIG_SYSFS_DEPRECATED
1391        char *class_name;
1392
1393        class_name = make_class_name(dev->class->name, &dev->kobj);
1394        if (!class_name) {
1395                error = -ENOMEM;
1396                goto out;
1397        }
1398        if (old_parent) {
1399                sysfs_remove_link(&dev->kobj, "device");
1400                sysfs_remove_link(&old_parent->kobj, class_name);
1401        }
1402        if (new_parent) {
1403                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1404                                          "device");
1405                if (error)
1406                        goto out;
1407                error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1408                                          class_name);
1409                if (error)
1410                        sysfs_remove_link(&dev->kobj, "device");
1411        } else
1412                error = 0;
1413out:
1414        kfree(class_name);
1415        return error;
1416#else
1417        if (old_parent)
1418                sysfs_remove_link(&dev->kobj, "device");
1419        if (new_parent)
1420                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1421                                          "device");
1422        return error;
1423#endif
1424}
1425
1426/**
1427 * device_move - moves a device to a new parent
1428 * @dev: the pointer to the struct device to be moved
1429 * @new_parent: the new parent of the device (can by NULL)
1430 */
1431int device_move(struct device *dev, struct device *new_parent)
1432{
1433        int error;
1434        struct device *old_parent;
1435        struct kobject *new_parent_kobj;
1436
1437        dev = get_device(dev);
1438        if (!dev)
1439                return -EINVAL;
1440
1441        new_parent = get_device(new_parent);
1442        new_parent_kobj = get_device_parent(dev, new_parent);
1443
1444        pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1445                 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1446        error = kobject_move(&dev->kobj, new_parent_kobj);
1447        if (error) {
1448                cleanup_glue_dir(dev, new_parent_kobj);
1449                put_device(new_parent);
1450                goto out;
1451        }
1452        old_parent = dev->parent;
1453        dev->parent = new_parent;
1454        if (old_parent)
1455                klist_remove(&dev->knode_parent);
1456        if (new_parent) {
1457                klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1458                set_dev_node(dev, dev_to_node(new_parent));
1459        }
1460
1461        if (!dev->class)
1462                goto out_put;
1463        error = device_move_class_links(dev, old_parent, new_parent);
1464        if (error) {
1465                /* We ignore errors on cleanup since we're hosed anyway... */
1466                device_move_class_links(dev, new_parent, old_parent);
1467                if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1468                        if (new_parent)
1469                                klist_remove(&dev->knode_parent);
1470                        dev->parent = old_parent;
1471                        if (old_parent) {
1472                                klist_add_tail(&dev->knode_parent,
1473                                               &old_parent->klist_children);
1474                                set_dev_node(dev, dev_to_node(old_parent));
1475                        }
1476                }
1477                cleanup_glue_dir(dev, new_parent_kobj);
1478                put_device(new_parent);
1479                goto out;
1480        }
1481out_put:
1482        put_device(old_parent);
1483out:
1484        put_device(dev);
1485        return error;
1486}
1487EXPORT_SYMBOL_GPL(device_move);
1488
1489/**
1490 * device_shutdown - call ->shutdown() on each device to shutdown.
1491 */
1492void device_shutdown(void)
1493{
1494        struct device *dev, *devn;
1495
1496        list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1497                                kobj.entry) {
1498                if (dev->bus && dev->bus->shutdown) {
1499                        dev_dbg(dev, "shutdown\n");
1500                        dev->bus->shutdown(dev);
1501                } else if (dev->driver && dev->driver->shutdown) {
1502                        dev_dbg(dev, "shutdown\n");
1503                        dev->driver->shutdown(dev);
1504                }
1505        }
1506        kobject_put(sysfs_dev_char_kobj);
1507        kobject_put(sysfs_dev_block_kobj);
1508        kobject_put(dev_kobj);
1509}
1510