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 by initializing
 527 * its fields.
 528 * It is the first half of device_register(), if called by
 529 * that function, though it can also be called separately, so one
 530 * may use @dev's fields. In particular, get_device()/put_device()
 531 * may be used for reference counting of @dev after calling this
 532 * function.
 533 *
 534 * NOTE: Use put_device() to give up your reference instead of freeing
 535 * @dev directly once you have called this function.
 536 */
 537void device_initialize(struct device *dev)
 538{
 539        dev->kobj.kset = devices_kset;
 540        kobject_init(&dev->kobj, &device_ktype);
 541        klist_init(&dev->klist_children, klist_children_get,
 542                   klist_children_put);
 543        INIT_LIST_HEAD(&dev->dma_pools);
 544        init_MUTEX(&dev->sem);
 545        spin_lock_init(&dev->devres_lock);
 546        INIT_LIST_HEAD(&dev->devres_head);
 547        device_init_wakeup(dev, 0);
 548        device_pm_init(dev);
 549        set_dev_node(dev, -1);
 550}
 551
 552#ifdef CONFIG_SYSFS_DEPRECATED
 553static struct kobject *get_device_parent(struct device *dev,
 554                                         struct device *parent)
 555{
 556        /* class devices without a parent live in /sys/class/<classname>/ */
 557        if (dev->class && (!parent || parent->class != dev->class))
 558                return &dev->class->p->class_subsys.kobj;
 559        /* all other devices keep their parent */
 560        else if (parent)
 561                return &parent->kobj;
 562
 563        return NULL;
 564}
 565
 566static inline void cleanup_device_parent(struct device *dev) {}
 567static inline void cleanup_glue_dir(struct device *dev,
 568                                    struct kobject *glue_dir) {}
 569#else
 570static struct kobject *virtual_device_parent(struct device *dev)
 571{
 572        static struct kobject *virtual_dir = NULL;
 573
 574        if (!virtual_dir)
 575                virtual_dir = kobject_create_and_add("virtual",
 576                                                     &devices_kset->kobj);
 577
 578        return virtual_dir;
 579}
 580
 581static struct kobject *get_device_parent(struct device *dev,
 582                                         struct device *parent)
 583{
 584        int retval;
 585
 586        if (dev->class) {
 587                struct kobject *kobj = NULL;
 588                struct kobject *parent_kobj;
 589                struct kobject *k;
 590
 591                /*
 592                 * If we have no parent, we live in "virtual".
 593                 * Class-devices with a non class-device as parent, live
 594                 * in a "glue" directory to prevent namespace collisions.
 595                 */
 596                if (parent == NULL)
 597                        parent_kobj = virtual_device_parent(dev);
 598                else if (parent->class)
 599                        return &parent->kobj;
 600                else
 601                        parent_kobj = &parent->kobj;
 602
 603                /* find our class-directory at the parent and reference it */
 604                spin_lock(&dev->class->p->class_dirs.list_lock);
 605                list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
 606                        if (k->parent == parent_kobj) {
 607                                kobj = kobject_get(k);
 608                                break;
 609                        }
 610                spin_unlock(&dev->class->p->class_dirs.list_lock);
 611                if (kobj)
 612                        return kobj;
 613
 614                /* or create a new class-directory at the parent device */
 615                k = kobject_create();
 616                if (!k)
 617                        return NULL;
 618                k->kset = &dev->class->p->class_dirs;
 619                retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
 620                if (retval < 0) {
 621                        kobject_put(k);
 622                        return NULL;
 623                }
 624                /* do not emit an uevent for this simple "glue" directory */
 625                return k;
 626        }
 627
 628        if (parent)
 629                return &parent->kobj;
 630        return NULL;
 631}
 632
 633static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 634{
 635        /* see if we live in a "glue" directory */
 636        if (!glue_dir || !dev->class ||
 637            glue_dir->kset != &dev->class->p->class_dirs)
 638                return;
 639
 640        kobject_put(glue_dir);
 641}
 642
 643static void cleanup_device_parent(struct device *dev)
 644{
 645        cleanup_glue_dir(dev, dev->kobj.parent);
 646}
 647#endif
 648
 649static void setup_parent(struct device *dev, struct device *parent)
 650{
 651        struct kobject *kobj;
 652        kobj = get_device_parent(dev, parent);
 653        if (kobj)
 654                dev->kobj.parent = kobj;
 655}
 656
 657static int device_add_class_symlinks(struct device *dev)
 658{
 659        int error;
 660
 661        if (!dev->class)
 662                return 0;
 663
 664        error = sysfs_create_link(&dev->kobj,
 665                                  &dev->class->p->class_subsys.kobj,
 666                                  "subsystem");
 667        if (error)
 668                goto out;
 669
 670#ifdef CONFIG_SYSFS_DEPRECATED
 671        /* stacked class devices need a symlink in the class directory */
 672        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 673            device_is_not_partition(dev)) {
 674                error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 675                                          &dev->kobj, dev->bus_id);
 676                if (error)
 677                        goto out_subsys;
 678        }
 679
 680        if (dev->parent && device_is_not_partition(dev)) {
 681                struct device *parent = dev->parent;
 682                char *class_name;
 683
 684                /*
 685                 * stacked class devices have the 'device' link
 686                 * pointing to the bus device instead of the parent
 687                 */
 688                while (parent->class && !parent->bus && parent->parent)
 689                        parent = parent->parent;
 690
 691                error = sysfs_create_link(&dev->kobj,
 692                                          &parent->kobj,
 693                                          "device");
 694                if (error)
 695                        goto out_busid;
 696
 697                class_name = make_class_name(dev->class->name,
 698                                                &dev->kobj);
 699                if (class_name)
 700                        error = sysfs_create_link(&dev->parent->kobj,
 701                                                &dev->kobj, class_name);
 702                kfree(class_name);
 703                if (error)
 704                        goto out_device;
 705        }
 706        return 0;
 707
 708out_device:
 709        if (dev->parent && device_is_not_partition(dev))
 710                sysfs_remove_link(&dev->kobj, "device");
 711out_busid:
 712        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 713            device_is_not_partition(dev))
 714                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
 715                                  dev->bus_id);
 716#else
 717        /* link in the class directory pointing to the device */
 718        error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 719                                  &dev->kobj, dev->bus_id);
 720        if (error)
 721                goto out_subsys;
 722
 723        if (dev->parent && device_is_not_partition(dev)) {
 724                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 725                                          "device");
 726                if (error)
 727                        goto out_busid;
 728        }
 729        return 0;
 730
 731out_busid:
 732        sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
 733#endif
 734
 735out_subsys:
 736        sysfs_remove_link(&dev->kobj, "subsystem");
 737out:
 738        return error;
 739}
 740
 741static void device_remove_class_symlinks(struct device *dev)
 742{
 743        if (!dev->class)
 744                return;
 745
 746#ifdef CONFIG_SYSFS_DEPRECATED
 747        if (dev->parent && device_is_not_partition(dev)) {
 748                char *class_name;
 749
 750                class_name = make_class_name(dev->class->name, &dev->kobj);
 751                if (class_name) {
 752                        sysfs_remove_link(&dev->parent->kobj, class_name);
 753                        kfree(class_name);
 754                }
 755                sysfs_remove_link(&dev->kobj, "device");
 756        }
 757
 758        if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
 759            device_is_not_partition(dev))
 760                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
 761                                  dev->bus_id);
 762#else
 763        if (dev->parent && device_is_not_partition(dev))
 764                sysfs_remove_link(&dev->kobj, "device");
 765
 766        sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
 767#endif
 768
 769        sysfs_remove_link(&dev->kobj, "subsystem");
 770}
 771
 772/**
 773 * dev_set_name - set a device name
 774 * @dev: device
 775 * @fmt: format string for the device's name
 776 */
 777int dev_set_name(struct device *dev, const char *fmt, ...)
 778{
 779        va_list vargs;
 780
 781        va_start(vargs, fmt);
 782        vsnprintf(dev->bus_id, sizeof(dev->bus_id), fmt, vargs);
 783        va_end(vargs);
 784        return 0;
 785}
 786EXPORT_SYMBOL_GPL(dev_set_name);
 787
 788/**
 789 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 790 * @dev: device
 791 *
 792 * By default we select char/ for new entries.  Setting class->dev_obj
 793 * to NULL prevents an entry from being created.  class->dev_kobj must
 794 * be set (or cleared) before any devices are registered to the class
 795 * otherwise device_create_sys_dev_entry() and
 796 * device_remove_sys_dev_entry() will disagree about the the presence
 797 * of the link.
 798 */
 799static struct kobject *device_to_dev_kobj(struct device *dev)
 800{
 801        struct kobject *kobj;
 802
 803        if (dev->class)
 804                kobj = dev->class->dev_kobj;
 805        else
 806                kobj = sysfs_dev_char_kobj;
 807
 808        return kobj;
 809}
 810
 811static int device_create_sys_dev_entry(struct device *dev)
 812{
 813        struct kobject *kobj = device_to_dev_kobj(dev);
 814        int error = 0;
 815        char devt_str[15];
 816
 817        if (kobj) {
 818                format_dev_t(devt_str, dev->devt);
 819                error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 820        }
 821
 822        return error;
 823}
 824
 825static void device_remove_sys_dev_entry(struct device *dev)
 826{
 827        struct kobject *kobj = device_to_dev_kobj(dev);
 828        char devt_str[15];
 829
 830        if (kobj) {
 831                format_dev_t(devt_str, dev->devt);
 832                sysfs_remove_link(kobj, devt_str);
 833        }
 834}
 835
 836/**
 837 * device_add - add device to device hierarchy.
 838 * @dev: device.
 839 *
 840 * This is part 2 of device_register(), though may be called
 841 * separately _iff_ device_initialize() has been called separately.
 842 *
 843 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
 844 * to the global and sibling lists for the device, then
 845 * adds it to the other relevant subsystems of the driver model.
 846 *
 847 * NOTE: _Never_ directly free @dev after calling this function, even
 848 * if it returned an error! Always use put_device() to give up your
 849 * reference instead.
 850 */
 851int device_add(struct device *dev)
 852{
 853        struct device *parent = NULL;
 854        struct class_interface *class_intf;
 855        int error = -EINVAL;
 856
 857        dev = get_device(dev);
 858        if (!dev)
 859                goto done;
 860
 861        /* Temporarily support init_name if it is set.
 862         * It will override bus_id for now */
 863        if (dev->init_name)
 864                dev_set_name(dev, "%s", dev->init_name);
 865
 866        if (!strlen(dev->bus_id))
 867                goto done;
 868
 869        pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
 870
 871        parent = get_device(dev->parent);
 872        setup_parent(dev, parent);
 873
 874        /* use parent numa_node */
 875        if (parent)
 876                set_dev_node(dev, dev_to_node(parent));
 877
 878        /* first, register with generic layer. */
 879        error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
 880        if (error)
 881                goto Error;
 882
 883        /* notify platform of device entry */
 884        if (platform_notify)
 885                platform_notify(dev);
 886
 887        /* notify clients of device entry (new way) */
 888        if (dev->bus)
 889                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 890                                             BUS_NOTIFY_ADD_DEVICE, dev);
 891
 892        error = device_create_file(dev, &uevent_attr);
 893        if (error)
 894                goto attrError;
 895
 896        if (MAJOR(dev->devt)) {
 897                error = device_create_file(dev, &devt_attr);
 898                if (error)
 899                        goto ueventattrError;
 900
 901                error = device_create_sys_dev_entry(dev);
 902                if (error)
 903                        goto devtattrError;
 904        }
 905
 906        error = device_add_class_symlinks(dev);
 907        if (error)
 908                goto SymlinkError;
 909        error = device_add_attrs(dev);
 910        if (error)
 911                goto AttrsError;
 912        error = bus_add_device(dev);
 913        if (error)
 914                goto BusError;
 915        error = dpm_sysfs_add(dev);
 916        if (error)
 917                goto DPMError;
 918        device_pm_add(dev);
 919        kobject_uevent(&dev->kobj, KOBJ_ADD);
 920        bus_attach_device(dev);
 921        if (parent)
 922                klist_add_tail(&dev->knode_parent, &parent->klist_children);
 923
 924        if (dev->class) {
 925                mutex_lock(&dev->class->p->class_mutex);
 926                /* tie the class to the device */
 927                klist_add_tail(&dev->knode_class,
 928                               &dev->class->p->class_devices);
 929
 930                /* notify any interfaces that the device is here */
 931                list_for_each_entry(class_intf,
 932                                    &dev->class->p->class_interfaces, node)
 933                        if (class_intf->add_dev)
 934                                class_intf->add_dev(dev, class_intf);
 935                mutex_unlock(&dev->class->p->class_mutex);
 936        }
 937done:
 938        put_device(dev);
 939        return error;
 940 DPMError:
 941        bus_remove_device(dev);
 942 BusError:
 943        if (dev->bus)
 944                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 945                                             BUS_NOTIFY_DEL_DEVICE, dev);
 946        device_remove_attrs(dev);
 947 AttrsError:
 948        device_remove_class_symlinks(dev);
 949 SymlinkError:
 950        if (MAJOR(dev->devt))
 951                device_remove_sys_dev_entry(dev);
 952 devtattrError:
 953        if (MAJOR(dev->devt))
 954                device_remove_file(dev, &devt_attr);
 955 ueventattrError:
 956        device_remove_file(dev, &uevent_attr);
 957 attrError:
 958        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 959        kobject_del(&dev->kobj);
 960 Error:
 961        cleanup_device_parent(dev);
 962        if (parent)
 963                put_device(parent);
 964        goto done;
 965}
 966
 967/**
 968 * device_register - register a device with the system.
 969 * @dev: pointer to the device structure
 970 *
 971 * This happens in two clean steps - initialize the device
 972 * and add it to the system. The two steps can be called
 973 * separately, but this is the easiest and most common.
 974 * I.e. you should only call the two helpers separately if
 975 * have a clearly defined need to use and refcount the device
 976 * before it is added to the hierarchy.
 977 *
 978 * NOTE: _Never_ directly free @dev after calling this function, even
 979 * if it returned an error! Always use put_device() to give up the
 980 * reference initialized in this function instead.
 981 */
 982int device_register(struct device *dev)
 983{
 984        device_initialize(dev);
 985        return device_add(dev);
 986}
 987
 988/**
 989 * get_device - increment reference count for device.
 990 * @dev: device.
 991 *
 992 * This simply forwards the call to kobject_get(), though
 993 * we do take care to provide for the case that we get a NULL
 994 * pointer passed in.
 995 */
 996struct device *get_device(struct device *dev)
 997{
 998        return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
 999}
1000
1001/**
1002 * put_device - decrement reference count.
1003 * @dev: device in question.
1004 */
1005void put_device(struct device *dev)
1006{
1007        /* might_sleep(); */
1008        if (dev)
1009                kobject_put(&dev->kobj);
1010}
1011
1012/**
1013 * device_del - delete device from system.
1014 * @dev: device.
1015 *
1016 * This is the first part of the device unregistration
1017 * sequence. This removes the device from the lists we control
1018 * from here, has it removed from the other driver model
1019 * subsystems it was added to in device_add(), and removes it
1020 * from the kobject hierarchy.
1021 *
1022 * NOTE: this should be called manually _iff_ device_add() was
1023 * also called manually.
1024 */
1025void device_del(struct device *dev)
1026{
1027        struct device *parent = dev->parent;
1028        struct class_interface *class_intf;
1029
1030        device_pm_remove(dev);
1031        dpm_sysfs_remove(dev);
1032        if (parent)
1033                klist_del(&dev->knode_parent);
1034        if (MAJOR(dev->devt)) {
1035                device_remove_sys_dev_entry(dev);
1036                device_remove_file(dev, &devt_attr);
1037        }
1038        if (dev->class) {
1039                device_remove_class_symlinks(dev);
1040
1041                mutex_lock(&dev->class->p->class_mutex);
1042                /* notify any interfaces that the device is now gone */
1043                list_for_each_entry(class_intf,
1044                                    &dev->class->p->class_interfaces, node)
1045                        if (class_intf->remove_dev)
1046                                class_intf->remove_dev(dev, class_intf);
1047                /* remove the device from the class list */
1048                klist_del(&dev->knode_class);
1049                mutex_unlock(&dev->class->p->class_mutex);
1050        }
1051        device_remove_file(dev, &uevent_attr);
1052        device_remove_attrs(dev);
1053        bus_remove_device(dev);
1054
1055        /*
1056         * Some platform devices are driven without driver attached
1057         * and managed resources may have been acquired.  Make sure
1058         * all resources are released.
1059         */
1060        devres_release_all(dev);
1061
1062        /* Notify the platform of the removal, in case they
1063         * need to do anything...
1064         */
1065        if (platform_notify_remove)
1066                platform_notify_remove(dev);
1067        if (dev->bus)
1068                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1069                                             BUS_NOTIFY_DEL_DEVICE, dev);
1070        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1071        cleanup_device_parent(dev);
1072        kobject_del(&dev->kobj);
1073        put_device(parent);
1074}
1075
1076/**
1077 * device_unregister - unregister device from system.
1078 * @dev: device going away.
1079 *
1080 * We do this in two parts, like we do device_register(). First,
1081 * we remove it from all the subsystems with device_del(), then
1082 * we decrement the reference count via put_device(). If that
1083 * is the final reference count, the device will be cleaned up
1084 * via device_release() above. Otherwise, the structure will
1085 * stick around until the final reference to the device is dropped.
1086 */
1087void device_unregister(struct device *dev)
1088{
1089        pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1090        device_del(dev);
1091        put_device(dev);
1092}
1093
1094static struct device *next_device(struct klist_iter *i)
1095{
1096        struct klist_node *n = klist_next(i);
1097        return n ? container_of(n, struct device, knode_parent) : NULL;
1098}
1099
1100/**
1101 * device_for_each_child - device child iterator.
1102 * @parent: parent struct device.
1103 * @data: data for the callback.
1104 * @fn: function to be called for each device.
1105 *
1106 * Iterate over @parent's child devices, and call @fn for each,
1107 * passing it @data.
1108 *
1109 * We check the return of @fn each time. If it returns anything
1110 * other than 0, we break out and return that value.
1111 */
1112int device_for_each_child(struct device *parent, void *data,
1113                          int (*fn)(struct device *dev, void *data))
1114{
1115        struct klist_iter i;
1116        struct device *child;
1117        int error = 0;
1118
1119        klist_iter_init(&parent->klist_children, &i);
1120        while ((child = next_device(&i)) && !error)
1121                error = fn(child, data);
1122        klist_iter_exit(&i);
1123        return error;
1124}
1125
1126/**
1127 * device_find_child - device iterator for locating a particular device.
1128 * @parent: parent struct device
1129 * @data: Data to pass to match function
1130 * @match: Callback function to check device
1131 *
1132 * This is similar to the device_for_each_child() function above, but it
1133 * returns a reference to a device that is 'found' for later use, as
1134 * determined by the @match callback.
1135 *
1136 * The callback should return 0 if the device doesn't match and non-zero
1137 * if it does.  If the callback returns non-zero and a reference to the
1138 * current device can be obtained, this function will return to the caller
1139 * and not iterate over any more devices.
1140 */
1141struct device *device_find_child(struct device *parent, void *data,
1142                                 int (*match)(struct device *dev, void *data))
1143{
1144        struct klist_iter i;
1145        struct device *child;
1146
1147        if (!parent)
1148                return NULL;
1149
1150        klist_iter_init(&parent->klist_children, &i);
1151        while ((child = next_device(&i)))
1152                if (match(child, data) && get_device(child))
1153                        break;
1154        klist_iter_exit(&i);
1155        return child;
1156}
1157
1158int __init devices_init(void)
1159{
1160        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1161        if (!devices_kset)
1162                return -ENOMEM;
1163        dev_kobj = kobject_create_and_add("dev", NULL);
1164        if (!dev_kobj)
1165                goto dev_kobj_err;
1166        sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1167        if (!sysfs_dev_block_kobj)
1168                goto block_kobj_err;
1169        sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1170        if (!sysfs_dev_char_kobj)
1171                goto char_kobj_err;
1172
1173        return 0;
1174
1175 char_kobj_err:
1176        kobject_put(sysfs_dev_block_kobj);
1177 block_kobj_err:
1178        kobject_put(dev_kobj);
1179 dev_kobj_err:
1180        kset_unregister(devices_kset);
1181        return -ENOMEM;
1182}
1183
1184EXPORT_SYMBOL_GPL(device_for_each_child);
1185EXPORT_SYMBOL_GPL(device_find_child);
1186
1187EXPORT_SYMBOL_GPL(device_initialize);
1188EXPORT_SYMBOL_GPL(device_add);
1189EXPORT_SYMBOL_GPL(device_register);
1190
1191EXPORT_SYMBOL_GPL(device_del);
1192EXPORT_SYMBOL_GPL(device_unregister);
1193EXPORT_SYMBOL_GPL(get_device);
1194EXPORT_SYMBOL_GPL(put_device);
1195
1196EXPORT_SYMBOL_GPL(device_create_file);
1197EXPORT_SYMBOL_GPL(device_remove_file);
1198
1199
1200static void device_create_release(struct device *dev)
1201{
1202        pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1203        kfree(dev);
1204}
1205
1206/**
1207 * device_create_vargs - creates a device and registers it with sysfs
1208 * @class: pointer to the struct class that this device should be registered to
1209 * @parent: pointer to the parent struct device of this new device, if any
1210 * @devt: the dev_t for the char device to be added
1211 * @drvdata: the data to be added to the device for callbacks
1212 * @fmt: string for the device's name
1213 * @args: va_list for the device's name
1214 *
1215 * This function can be used by char device classes.  A struct device
1216 * will be created in sysfs, registered to the specified class.
1217 *
1218 * A "dev" file will be created, showing the dev_t for the device, if
1219 * the dev_t is not 0,0.
1220 * If a pointer to a parent struct device is passed in, the newly created
1221 * struct device will be a child of that device in sysfs.
1222 * The pointer to the struct device will be returned from the call.
1223 * Any further sysfs files that might be required can be created using this
1224 * pointer.
1225 *
1226 * Note: the struct class passed to this function must have previously
1227 * been created with a call to class_create().
1228 */
1229struct device *device_create_vargs(struct class *class, struct device *parent,
1230                                   dev_t devt, void *drvdata, const char *fmt,
1231                                   va_list args)
1232{
1233        struct device *dev = NULL;
1234        int retval = -ENODEV;
1235
1236        if (class == NULL || IS_ERR(class))
1237                goto error;
1238
1239        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1240        if (!dev) {
1241                retval = -ENOMEM;
1242                goto error;
1243        }
1244
1245        dev->devt = devt;
1246        dev->class = class;
1247        dev->parent = parent;
1248        dev->release = device_create_release;
1249        dev_set_drvdata(dev, drvdata);
1250
1251        vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1252        retval = device_register(dev);
1253        if (retval)
1254                goto error;
1255
1256        return dev;
1257
1258error:
1259        put_device(dev);
1260        return ERR_PTR(retval);
1261}
1262EXPORT_SYMBOL_GPL(device_create_vargs);
1263
1264/**
1265 * device_create - creates a device and registers it with sysfs
1266 * @class: pointer to the struct class that this device should be registered to
1267 * @parent: pointer to the parent struct device of this new device, if any
1268 * @devt: the dev_t for the char device to be added
1269 * @drvdata: the data to be added to the device for callbacks
1270 * @fmt: string for the device's name
1271 *
1272 * This function can be used by char device classes.  A struct device
1273 * will be created in sysfs, registered to the specified class.
1274 *
1275 * A "dev" file will be created, showing the dev_t for the device, if
1276 * the dev_t is not 0,0.
1277 * If a pointer to a parent struct device is passed in, the newly created
1278 * struct device will be a child of that device in sysfs.
1279 * The pointer to the struct device will be returned from the call.
1280 * Any further sysfs files that might be required can be created using this
1281 * pointer.
1282 *
1283 * Note: the struct class passed to this function must have previously
1284 * been created with a call to class_create().
1285 */
1286struct device *device_create(struct class *class, struct device *parent,
1287                             dev_t devt, void *drvdata, const char *fmt, ...)
1288{
1289        va_list vargs;
1290        struct device *dev;
1291
1292        va_start(vargs, fmt);
1293        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1294        va_end(vargs);
1295        return dev;
1296}
1297EXPORT_SYMBOL_GPL(device_create);
1298
1299static int __match_devt(struct device *dev, void *data)
1300{
1301        dev_t *devt = data;
1302
1303        return dev->devt == *devt;
1304}
1305
1306/**
1307 * device_destroy - removes a device that was created with device_create()
1308 * @class: pointer to the struct class that this device was registered with
1309 * @devt: the dev_t of the device that was previously registered
1310 *
1311 * This call unregisters and cleans up a device that was created with a
1312 * call to device_create().
1313 */
1314void device_destroy(struct class *class, dev_t devt)
1315{
1316        struct device *dev;
1317
1318        dev = class_find_device(class, NULL, &devt, __match_devt);
1319        if (dev) {
1320                put_device(dev);
1321                device_unregister(dev);
1322        }
1323}
1324EXPORT_SYMBOL_GPL(device_destroy);
1325
1326/**
1327 * device_rename - renames a device
1328 * @dev: the pointer to the struct device to be renamed
1329 * @new_name: the new name of the device
1330 *
1331 * It is the responsibility of the caller to provide mutual
1332 * exclusion between two different calls of device_rename
1333 * on the same device to ensure that new_name is valid and
1334 * won't conflict with other devices.
1335 */
1336int device_rename(struct device *dev, char *new_name)
1337{
1338        char *old_class_name = NULL;
1339        char *new_class_name = NULL;
1340        char *old_device_name = NULL;
1341        int error;
1342
1343        dev = get_device(dev);
1344        if (!dev)
1345                return -EINVAL;
1346
1347        pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1348                 __func__, new_name);
1349
1350#ifdef CONFIG_SYSFS_DEPRECATED
1351        if ((dev->class) && (dev->parent))
1352                old_class_name = make_class_name(dev->class->name, &dev->kobj);
1353#endif
1354
1355        old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1356        if (!old_device_name) {
1357                error = -ENOMEM;
1358                goto out;
1359        }
1360        strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1361        strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1362
1363        error = kobject_rename(&dev->kobj, new_name);
1364        if (error) {
1365                strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
1366                goto out;
1367        }
1368
1369#ifdef CONFIG_SYSFS_DEPRECATED
1370        if (old_class_name) {
1371                new_class_name = make_class_name(dev->class->name, &dev->kobj);
1372                if (new_class_name) {
1373                        error = sysfs_create_link_nowarn(&dev->parent->kobj,
1374                                                         &dev->kobj,
1375                                                         new_class_name);
1376                        if (error)
1377                                goto out;
1378                        sysfs_remove_link(&dev->parent->kobj, old_class_name);
1379                }
1380        }
1381#else
1382        if (dev->class) {
1383                error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
1384                                                 &dev->kobj, dev->bus_id);
1385                if (error)
1386                        goto out;
1387                sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1388                                  old_device_name);
1389        }
1390#endif
1391
1392out:
1393        put_device(dev);
1394
1395        kfree(new_class_name);
1396        kfree(old_class_name);
1397        kfree(old_device_name);
1398
1399        return error;
1400}
1401EXPORT_SYMBOL_GPL(device_rename);
1402
1403static int device_move_class_links(struct device *dev,
1404                                   struct device *old_parent,
1405                                   struct device *new_parent)
1406{
1407        int error = 0;
1408#ifdef CONFIG_SYSFS_DEPRECATED
1409        char *class_name;
1410
1411        class_name = make_class_name(dev->class->name, &dev->kobj);
1412        if (!class_name) {
1413                error = -ENOMEM;
1414                goto out;
1415        }
1416        if (old_parent) {
1417                sysfs_remove_link(&dev->kobj, "device");
1418                sysfs_remove_link(&old_parent->kobj, class_name);
1419        }
1420        if (new_parent) {
1421                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1422                                          "device");
1423                if (error)
1424                        goto out;
1425                error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1426                                          class_name);
1427                if (error)
1428                        sysfs_remove_link(&dev->kobj, "device");
1429        } else
1430                error = 0;
1431out:
1432        kfree(class_name);
1433        return error;
1434#else
1435        if (old_parent)
1436                sysfs_remove_link(&dev->kobj, "device");
1437        if (new_parent)
1438                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1439                                          "device");
1440        return error;
1441#endif
1442}
1443
1444/**
1445 * device_move - moves a device to a new parent
1446 * @dev: the pointer to the struct device to be moved
1447 * @new_parent: the new parent of the device (can by NULL)
1448 */
1449int device_move(struct device *dev, struct device *new_parent)
1450{
1451        int error;
1452        struct device *old_parent;
1453        struct kobject *new_parent_kobj;
1454
1455        dev = get_device(dev);
1456        if (!dev)
1457                return -EINVAL;
1458
1459        new_parent = get_device(new_parent);
1460        new_parent_kobj = get_device_parent(dev, new_parent);
1461
1462        pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1463                 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1464        error = kobject_move(&dev->kobj, new_parent_kobj);
1465        if (error) {
1466                cleanup_glue_dir(dev, new_parent_kobj);
1467                put_device(new_parent);
1468                goto out;
1469        }
1470        old_parent = dev->parent;
1471        dev->parent = new_parent;
1472        if (old_parent)
1473                klist_remove(&dev->knode_parent);
1474        if (new_parent) {
1475                klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1476                set_dev_node(dev, dev_to_node(new_parent));
1477        }
1478
1479        if (!dev->class)
1480                goto out_put;
1481        error = device_move_class_links(dev, old_parent, new_parent);
1482        if (error) {
1483                /* We ignore errors on cleanup since we're hosed anyway... */
1484                device_move_class_links(dev, new_parent, old_parent);
1485                if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1486                        if (new_parent)
1487                                klist_remove(&dev->knode_parent);
1488                        dev->parent = old_parent;
1489                        if (old_parent) {
1490                                klist_add_tail(&dev->knode_parent,
1491                                               &old_parent->klist_children);
1492                                set_dev_node(dev, dev_to_node(old_parent));
1493                        }
1494                }
1495                cleanup_glue_dir(dev, new_parent_kobj);
1496                put_device(new_parent);
1497                goto out;
1498        }
1499out_put:
1500        put_device(old_parent);
1501out:
1502        put_device(dev);
1503        return error;
1504}
1505EXPORT_SYMBOL_GPL(device_move);
1506
1507/**
1508 * device_shutdown - call ->shutdown() on each device to shutdown.
1509 */
1510void device_shutdown(void)
1511{
1512        struct device *dev, *devn;
1513
1514        list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1515                                kobj.entry) {
1516                if (dev->bus && dev->bus->shutdown) {
1517                        dev_dbg(dev, "shutdown\n");
1518                        dev->bus->shutdown(dev);
1519                } else if (dev->driver && dev->driver->shutdown) {
1520                        dev_dbg(dev, "shutdown\n");
1521                        dev->driver->shutdown(dev);
1522                }
1523        }
1524        kobject_put(sysfs_dev_char_kobj);
1525        kobject_put(sysfs_dev_block_kobj);
1526        kobject_put(dev_kobj);
1527}
1528