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/mutex.h>
  24#include <linux/async.h>
  25
  26#include "base.h"
  27#include "power/power.h"
  28
  29#ifdef CONFIG_SYSFS_DEPRECATED
  30#ifdef CONFIG_SYSFS_DEPRECATED_V2
  31long sysfs_deprecated = 1;
  32#else
  33long sysfs_deprecated = 0;
  34#endif
  35static __init int sysfs_deprecated_setup(char *arg)
  36{
  37        return strict_strtol(arg, 10, &sysfs_deprecated);
  38}
  39early_param("sysfs.deprecated", sysfs_deprecated_setup);
  40#endif
  41
  42int (*platform_notify)(struct device *dev) = NULL;
  43int (*platform_notify_remove)(struct device *dev) = NULL;
  44static struct kobject *dev_kobj;
  45struct kobject *sysfs_dev_char_kobj;
  46struct kobject *sysfs_dev_block_kobj;
  47
  48#ifdef CONFIG_BLOCK
  49static inline int device_is_not_partition(struct device *dev)
  50{
  51        return !(dev->type == &part_type);
  52}
  53#else
  54static inline int device_is_not_partition(struct device *dev)
  55{
  56        return 1;
  57}
  58#endif
  59
  60/**
  61 * dev_driver_string - Return a device's driver name, if at all possible
  62 * @dev: struct device to get the name of
  63 *
  64 * Will return the device's driver's name if it is bound to a device.  If
  65 * the device is not bound to a device, it will return the name of the bus
  66 * it is attached to.  If it is not attached to a bus either, an empty
  67 * string will be returned.
  68 */
  69const char *dev_driver_string(const struct device *dev)
  70{
  71        struct device_driver *drv;
  72
  73        /* dev->driver can change to NULL underneath us because of unbinding,
  74         * so be careful about accessing it.  dev->bus and dev->class should
  75         * never change once they are set, so they don't need special care.
  76         */
  77        drv = ACCESS_ONCE(dev->driver);
  78        return drv ? drv->name :
  79                        (dev->bus ? dev->bus->name :
  80                        (dev->class ? dev->class->name : ""));
  81}
  82EXPORT_SYMBOL(dev_driver_string);
  83
  84#define to_dev(obj) container_of(obj, struct device, kobj)
  85#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
  86
  87static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
  88                             char *buf)
  89{
  90        struct device_attribute *dev_attr = to_dev_attr(attr);
  91        struct device *dev = to_dev(kobj);
  92        ssize_t ret = -EIO;
  93
  94        if (dev_attr->show)
  95                ret = dev_attr->show(dev, dev_attr, buf);
  96        if (ret >= (ssize_t)PAGE_SIZE) {
  97                print_symbol("dev_attr_show: %s returned bad count\n",
  98                                (unsigned long)dev_attr->show);
  99        }
 100        return ret;
 101}
 102
 103static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
 104                              const char *buf, size_t count)
 105{
 106        struct device_attribute *dev_attr = to_dev_attr(attr);
 107        struct device *dev = to_dev(kobj);
 108        ssize_t ret = -EIO;
 109
 110        if (dev_attr->store)
 111                ret = dev_attr->store(dev, dev_attr, buf, count);
 112        return ret;
 113}
 114
 115static const struct sysfs_ops dev_sysfs_ops = {
 116        .show   = dev_attr_show,
 117        .store  = dev_attr_store,
 118};
 119
 120
 121/**
 122 *      device_release - free device structure.
 123 *      @kobj:  device's kobject.
 124 *
 125 *      This is called once the reference count for the object
 126 *      reaches 0. We forward the call to the device's release
 127 *      method, which should handle actually freeing the structure.
 128 */
 129static void device_release(struct kobject *kobj)
 130{
 131        struct device *dev = to_dev(kobj);
 132        struct device_private *p = dev->p;
 133
 134        if (dev->release)
 135                dev->release(dev);
 136        else if (dev->type && dev->type->release)
 137                dev->type->release(dev);
 138        else if (dev->class && dev->class->dev_release)
 139                dev->class->dev_release(dev);
 140        else
 141                WARN(1, KERN_ERR "Device '%s' does not have a release() "
 142                        "function, it is broken and must be fixed.\n",
 143                        dev_name(dev));
 144        kfree(p);
 145}
 146
 147static const void *device_namespace(struct kobject *kobj)
 148{
 149        struct device *dev = to_dev(kobj);
 150        const void *ns = NULL;
 151
 152        if (dev->class && dev->class->ns_type)
 153                ns = dev->class->namespace(dev);
 154
 155        return ns;
 156}
 157
 158static struct kobj_type device_ktype = {
 159        .release        = device_release,
 160        .sysfs_ops      = &dev_sysfs_ops,
 161        .namespace      = device_namespace,
 162};
 163
 164
 165static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 166{
 167        struct kobj_type *ktype = get_ktype(kobj);
 168
 169        if (ktype == &device_ktype) {
 170                struct device *dev = to_dev(kobj);
 171                if (dev->bus)
 172                        return 1;
 173                if (dev->class)
 174                        return 1;
 175        }
 176        return 0;
 177}
 178
 179static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 180{
 181        struct device *dev = to_dev(kobj);
 182
 183        if (dev->bus)
 184                return dev->bus->name;
 185        if (dev->class)
 186                return dev->class->name;
 187        return NULL;
 188}
 189
 190static int dev_uevent(struct kset *kset, struct kobject *kobj,
 191                      struct kobj_uevent_env *env)
 192{
 193        struct device *dev = to_dev(kobj);
 194        int retval = 0;
 195
 196        /* add device node properties if present */
 197        if (MAJOR(dev->devt)) {
 198                const char *tmp;
 199                const char *name;
 200                mode_t mode = 0;
 201
 202                add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 203                add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 204                name = device_get_devnode(dev, &mode, &tmp);
 205                if (name) {
 206                        add_uevent_var(env, "DEVNAME=%s", name);
 207                        kfree(tmp);
 208                        if (mode)
 209                                add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
 210                }
 211        }
 212
 213        if (dev->type && dev->type->name)
 214                add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 215
 216        if (dev->driver)
 217                add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 218
 219        /* have the bus specific function add its stuff */
 220        if (dev->bus && dev->bus->uevent) {
 221                retval = dev->bus->uevent(dev, env);
 222                if (retval)
 223                        pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 224                                 dev_name(dev), __func__, retval);
 225        }
 226
 227        /* have the class specific function add its stuff */
 228        if (dev->class && dev->class->dev_uevent) {
 229                retval = dev->class->dev_uevent(dev, env);
 230                if (retval)
 231                        pr_debug("device: '%s': %s: class uevent() "
 232                                 "returned %d\n", dev_name(dev),
 233                                 __func__, retval);
 234        }
 235
 236        /* have the device type specific function add its stuff */
 237        if (dev->type && dev->type->uevent) {
 238                retval = dev->type->uevent(dev, env);
 239                if (retval)
 240                        pr_debug("device: '%s': %s: dev_type uevent() "
 241                                 "returned %d\n", dev_name(dev),
 242                                 __func__, retval);
 243        }
 244
 245        return retval;
 246}
 247
 248static const struct kset_uevent_ops device_uevent_ops = {
 249        .filter =       dev_uevent_filter,
 250        .name =         dev_uevent_name,
 251        .uevent =       dev_uevent,
 252};
 253
 254static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
 255                           char *buf)
 256{
 257        struct kobject *top_kobj;
 258        struct kset *kset;
 259        struct kobj_uevent_env *env = NULL;
 260        int i;
 261        size_t count = 0;
 262        int retval;
 263
 264        /* search the kset, the device belongs to */
 265        top_kobj = &dev->kobj;
 266        while (!top_kobj->kset && top_kobj->parent)
 267                top_kobj = top_kobj->parent;
 268        if (!top_kobj->kset)
 269                goto out;
 270
 271        kset = top_kobj->kset;
 272        if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 273                goto out;
 274
 275        /* respect filter */
 276        if (kset->uevent_ops && kset->uevent_ops->filter)
 277                if (!kset->uevent_ops->filter(kset, &dev->kobj))
 278                        goto out;
 279
 280        env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 281        if (!env)
 282                return -ENOMEM;
 283
 284        /* let the kset specific function add its keys */
 285        retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 286        if (retval)
 287                goto out;
 288
 289        /* copy keys to file */
 290        for (i = 0; i < env->envp_idx; i++)
 291                count += sprintf(&buf[count], "%s\n", env->envp[i]);
 292out:
 293        kfree(env);
 294        return count;
 295}
 296
 297static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
 298                            const char *buf, size_t count)
 299{
 300        enum kobject_action action;
 301
 302        if (kobject_action_type(buf, count, &action) == 0)
 303                kobject_uevent(&dev->kobj, action);
 304        else
 305                dev_err(dev, "uevent: unknown action-string\n");
 306        return count;
 307}
 308
 309static struct device_attribute uevent_attr =
 310        __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
 311
 312static int device_add_attributes(struct device *dev,
 313                                 struct device_attribute *attrs)
 314{
 315        int error = 0;
 316        int i;
 317
 318        if (attrs) {
 319                for (i = 0; attr_name(attrs[i]); i++) {
 320                        error = device_create_file(dev, &attrs[i]);
 321                        if (error)
 322                                break;
 323                }
 324                if (error)
 325                        while (--i >= 0)
 326                                device_remove_file(dev, &attrs[i]);
 327        }
 328        return error;
 329}
 330
 331static void device_remove_attributes(struct device *dev,
 332                                     struct device_attribute *attrs)
 333{
 334        int i;
 335
 336        if (attrs)
 337                for (i = 0; attr_name(attrs[i]); i++)
 338                        device_remove_file(dev, &attrs[i]);
 339}
 340
 341static int device_add_groups(struct device *dev,
 342                             const struct attribute_group **groups)
 343{
 344        int error = 0;
 345        int i;
 346
 347        if (groups) {
 348                for (i = 0; groups[i]; i++) {
 349                        error = sysfs_create_group(&dev->kobj, groups[i]);
 350                        if (error) {
 351                                while (--i >= 0)
 352                                        sysfs_remove_group(&dev->kobj,
 353                                                           groups[i]);
 354                                break;
 355                        }
 356                }
 357        }
 358        return error;
 359}
 360
 361static void device_remove_groups(struct device *dev,
 362                                 const struct attribute_group **groups)
 363{
 364        int i;
 365
 366        if (groups)
 367                for (i = 0; groups[i]; i++)
 368                        sysfs_remove_group(&dev->kobj, groups[i]);
 369}
 370
 371static int device_add_attrs(struct device *dev)
 372{
 373        struct class *class = dev->class;
 374        struct device_type *type = dev->type;
 375        int error;
 376
 377        if (class) {
 378                error = device_add_attributes(dev, class->dev_attrs);
 379                if (error)
 380                        return error;
 381        }
 382
 383        if (type) {
 384                error = device_add_groups(dev, type->groups);
 385                if (error)
 386                        goto err_remove_class_attrs;
 387        }
 388
 389        error = device_add_groups(dev, dev->groups);
 390        if (error)
 391                goto err_remove_type_groups;
 392
 393        return 0;
 394
 395 err_remove_type_groups:
 396        if (type)
 397                device_remove_groups(dev, type->groups);
 398 err_remove_class_attrs:
 399        if (class)
 400                device_remove_attributes(dev, class->dev_attrs);
 401
 402        return error;
 403}
 404
 405static void device_remove_attrs(struct device *dev)
 406{
 407        struct class *class = dev->class;
 408        struct device_type *type = dev->type;
 409
 410        device_remove_groups(dev, dev->groups);
 411
 412        if (type)
 413                device_remove_groups(dev, type->groups);
 414
 415        if (class)
 416                device_remove_attributes(dev, class->dev_attrs);
 417}
 418
 419
 420static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
 421                        char *buf)
 422{
 423        return print_dev_t(buf, dev->devt);
 424}
 425
 426static struct device_attribute devt_attr =
 427        __ATTR(dev, S_IRUGO, show_dev, NULL);
 428
 429/* kset to create /sys/devices/  */
 430struct kset *devices_kset;
 431
 432/**
 433 * device_create_file - create sysfs attribute file for device.
 434 * @dev: device.
 435 * @attr: device attribute descriptor.
 436 */
 437int device_create_file(struct device *dev,
 438                       const struct device_attribute *attr)
 439{
 440        int error = 0;
 441        if (dev)
 442                error = sysfs_create_file(&dev->kobj, &attr->attr);
 443        return error;
 444}
 445
 446/**
 447 * device_remove_file - remove sysfs attribute file.
 448 * @dev: device.
 449 * @attr: device attribute descriptor.
 450 */
 451void device_remove_file(struct device *dev,
 452                        const struct device_attribute *attr)
 453{
 454        if (dev)
 455                sysfs_remove_file(&dev->kobj, &attr->attr);
 456}
 457
 458/**
 459 * device_create_bin_file - create sysfs binary attribute file for device.
 460 * @dev: device.
 461 * @attr: device binary attribute descriptor.
 462 */
 463int device_create_bin_file(struct device *dev,
 464                           const struct bin_attribute *attr)
 465{
 466        int error = -EINVAL;
 467        if (dev)
 468                error = sysfs_create_bin_file(&dev->kobj, attr);
 469        return error;
 470}
 471EXPORT_SYMBOL_GPL(device_create_bin_file);
 472
 473/**
 474 * device_remove_bin_file - remove sysfs binary attribute file
 475 * @dev: device.
 476 * @attr: device binary attribute descriptor.
 477 */
 478void device_remove_bin_file(struct device *dev,
 479                            const struct bin_attribute *attr)
 480{
 481        if (dev)
 482                sysfs_remove_bin_file(&dev->kobj, attr);
 483}
 484EXPORT_SYMBOL_GPL(device_remove_bin_file);
 485
 486/**
 487 * device_schedule_callback_owner - helper to schedule a callback for a device
 488 * @dev: device.
 489 * @func: callback function to invoke later.
 490 * @owner: module owning the callback routine
 491 *
 492 * Attribute methods must not unregister themselves or their parent device
 493 * (which would amount to the same thing).  Attempts to do so will deadlock,
 494 * since unregistration is mutually exclusive with driver callbacks.
 495 *
 496 * Instead methods can call this routine, which will attempt to allocate
 497 * and schedule a workqueue request to call back @func with @dev as its
 498 * argument in the workqueue's process context.  @dev will be pinned until
 499 * @func returns.
 500 *
 501 * This routine is usually called via the inline device_schedule_callback(),
 502 * which automatically sets @owner to THIS_MODULE.
 503 *
 504 * Returns 0 if the request was submitted, -ENOMEM if storage could not
 505 * be allocated, -ENODEV if a reference to @owner isn't available.
 506 *
 507 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 508 * underlying sysfs routine (since it is intended for use by attribute
 509 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 510 */
 511int device_schedule_callback_owner(struct device *dev,
 512                void (*func)(struct device *), struct module *owner)
 513{
 514        return sysfs_schedule_callback(&dev->kobj,
 515                        (void (*)(void *)) func, dev, owner);
 516}
 517EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
 518
 519static void klist_children_get(struct klist_node *n)
 520{
 521        struct device_private *p = to_device_private_parent(n);
 522        struct device *dev = p->device;
 523
 524        get_device(dev);
 525}
 526
 527static void klist_children_put(struct klist_node *n)
 528{
 529        struct device_private *p = to_device_private_parent(n);
 530        struct device *dev = p->device;
 531
 532        put_device(dev);
 533}
 534
 535/**
 536 * device_initialize - init device structure.
 537 * @dev: device.
 538 *
 539 * This prepares the device for use by other layers by initializing
 540 * its fields.
 541 * It is the first half of device_register(), if called by
 542 * that function, though it can also be called separately, so one
 543 * may use @dev's fields. In particular, get_device()/put_device()
 544 * may be used for reference counting of @dev after calling this
 545 * function.
 546 *
 547 * NOTE: Use put_device() to give up your reference instead of freeing
 548 * @dev directly once you have called this function.
 549 */
 550void device_initialize(struct device *dev)
 551{
 552        dev->kobj.kset = devices_kset;
 553        kobject_init(&dev->kobj, &device_ktype);
 554        INIT_LIST_HEAD(&dev->dma_pools);
 555        mutex_init(&dev->mutex);
 556        lockdep_set_novalidate_class(&dev->mutex);
 557        spin_lock_init(&dev->devres_lock);
 558        INIT_LIST_HEAD(&dev->devres_head);
 559        device_pm_init(dev);
 560        set_dev_node(dev, -1);
 561}
 562
 563static struct kobject *virtual_device_parent(struct device *dev)
 564{
 565        static struct kobject *virtual_dir = NULL;
 566
 567        if (!virtual_dir)
 568                virtual_dir = kobject_create_and_add("virtual",
 569                                                     &devices_kset->kobj);
 570
 571        return virtual_dir;
 572}
 573
 574struct class_dir {
 575        struct kobject kobj;
 576        struct class *class;
 577};
 578
 579#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
 580
 581static void class_dir_release(struct kobject *kobj)
 582{
 583        struct class_dir *dir = to_class_dir(kobj);
 584        kfree(dir);
 585}
 586
 587static const
 588struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
 589{
 590        struct class_dir *dir = to_class_dir(kobj);
 591        return dir->class->ns_type;
 592}
 593
 594static struct kobj_type class_dir_ktype = {
 595        .release        = class_dir_release,
 596        .sysfs_ops      = &kobj_sysfs_ops,
 597        .child_ns_type  = class_dir_child_ns_type
 598};
 599
 600static struct kobject *
 601class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 602{
 603        struct class_dir *dir;
 604        int retval;
 605
 606        dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 607        if (!dir)
 608                return NULL;
 609
 610        dir->class = class;
 611        kobject_init(&dir->kobj, &class_dir_ktype);
 612
 613        dir->kobj.kset = &class->p->class_dirs;
 614
 615        retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
 616        if (retval < 0) {
 617                kobject_put(&dir->kobj);
 618                return NULL;
 619        }
 620        return &dir->kobj;
 621}
 622
 623
 624static struct kobject *get_device_parent(struct device *dev,
 625                                         struct device *parent)
 626{
 627        if (dev->class) {
 628                static DEFINE_MUTEX(gdp_mutex);
 629                struct kobject *kobj = NULL;
 630                struct kobject *parent_kobj;
 631                struct kobject *k;
 632
 633#ifdef CONFIG_BLOCK
 634                /* block disks show up in /sys/block */
 635                if (sysfs_deprecated && dev->class == &block_class) {
 636                        if (parent && parent->class == &block_class)
 637                                return &parent->kobj;
 638                        return &block_class.p->class_subsys.kobj;
 639                }
 640#endif
 641
 642                /*
 643                 * If we have no parent, we live in "virtual".
 644                 * Class-devices with a non class-device as parent, live
 645                 * in a "glue" directory to prevent namespace collisions.
 646                 */
 647                if (parent == NULL)
 648                        parent_kobj = virtual_device_parent(dev);
 649                else if (parent->class && !dev->class->ns_type)
 650                        return &parent->kobj;
 651                else
 652                        parent_kobj = &parent->kobj;
 653
 654                mutex_lock(&gdp_mutex);
 655
 656                /* find our class-directory at the parent and reference it */
 657                spin_lock(&dev->class->p->class_dirs.list_lock);
 658                list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
 659                        if (k->parent == parent_kobj) {
 660                                kobj = kobject_get(k);
 661                                break;
 662                        }
 663                spin_unlock(&dev->class->p->class_dirs.list_lock);
 664                if (kobj) {
 665                        mutex_unlock(&gdp_mutex);
 666                        return kobj;
 667                }
 668
 669                /* or create a new class-directory at the parent device */
 670                k = class_dir_create_and_add(dev->class, parent_kobj);
 671                /* do not emit an uevent for this simple "glue" directory */
 672                mutex_unlock(&gdp_mutex);
 673                return k;
 674        }
 675
 676        if (parent)
 677                return &parent->kobj;
 678        return NULL;
 679}
 680
 681static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 682{
 683        /* see if we live in a "glue" directory */
 684        if (!glue_dir || !dev->class ||
 685            glue_dir->kset != &dev->class->p->class_dirs)
 686                return;
 687
 688        kobject_put(glue_dir);
 689}
 690
 691static void cleanup_device_parent(struct device *dev)
 692{
 693        cleanup_glue_dir(dev, dev->kobj.parent);
 694}
 695
 696static void setup_parent(struct device *dev, struct device *parent)
 697{
 698        struct kobject *kobj;
 699        kobj = get_device_parent(dev, parent);
 700        if (kobj)
 701                dev->kobj.parent = kobj;
 702}
 703
 704static int device_add_class_symlinks(struct device *dev)
 705{
 706        int error;
 707
 708        if (!dev->class)
 709                return 0;
 710
 711        error = sysfs_create_link(&dev->kobj,
 712                                  &dev->class->p->class_subsys.kobj,
 713                                  "subsystem");
 714        if (error)
 715                goto out;
 716
 717        if (dev->parent && device_is_not_partition(dev)) {
 718                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 719                                          "device");
 720                if (error)
 721                        goto out_subsys;
 722        }
 723
 724#ifdef CONFIG_BLOCK
 725        /* /sys/block has directories and does not need symlinks */
 726        if (sysfs_deprecated && dev->class == &block_class)
 727                return 0;
 728#endif
 729
 730        /* link in the class directory pointing to the device */
 731        error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
 732                                  &dev->kobj, dev_name(dev));
 733        if (error)
 734                goto out_device;
 735
 736        return 0;
 737
 738out_device:
 739        sysfs_remove_link(&dev->kobj, "device");
 740
 741out_subsys:
 742        sysfs_remove_link(&dev->kobj, "subsystem");
 743out:
 744        return error;
 745}
 746
 747static void device_remove_class_symlinks(struct device *dev)
 748{
 749        if (!dev->class)
 750                return;
 751
 752        if (dev->parent && device_is_not_partition(dev))
 753                sysfs_remove_link(&dev->kobj, "device");
 754        sysfs_remove_link(&dev->kobj, "subsystem");
 755#ifdef CONFIG_BLOCK
 756        if (sysfs_deprecated && dev->class == &block_class)
 757                return;
 758#endif
 759        sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev));
 760}
 761
 762/**
 763 * dev_set_name - set a device name
 764 * @dev: device
 765 * @fmt: format string for the device's name
 766 */
 767int dev_set_name(struct device *dev, const char *fmt, ...)
 768{
 769        va_list vargs;
 770        int err;
 771
 772        va_start(vargs, fmt);
 773        err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
 774        va_end(vargs);
 775        return err;
 776}
 777EXPORT_SYMBOL_GPL(dev_set_name);
 778
 779/**
 780 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 781 * @dev: device
 782 *
 783 * By default we select char/ for new entries.  Setting class->dev_obj
 784 * to NULL prevents an entry from being created.  class->dev_kobj must
 785 * be set (or cleared) before any devices are registered to the class
 786 * otherwise device_create_sys_dev_entry() and
 787 * device_remove_sys_dev_entry() will disagree about the the presence
 788 * of the link.
 789 */
 790static struct kobject *device_to_dev_kobj(struct device *dev)
 791{
 792        struct kobject *kobj;
 793
 794        if (dev->class)
 795                kobj = dev->class->dev_kobj;
 796        else
 797                kobj = sysfs_dev_char_kobj;
 798
 799        return kobj;
 800}
 801
 802static int device_create_sys_dev_entry(struct device *dev)
 803{
 804        struct kobject *kobj = device_to_dev_kobj(dev);
 805        int error = 0;
 806        char devt_str[15];
 807
 808        if (kobj) {
 809                format_dev_t(devt_str, dev->devt);
 810                error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 811        }
 812
 813        return error;
 814}
 815
 816static void device_remove_sys_dev_entry(struct device *dev)
 817{
 818        struct kobject *kobj = device_to_dev_kobj(dev);
 819        char devt_str[15];
 820
 821        if (kobj) {
 822                format_dev_t(devt_str, dev->devt);
 823                sysfs_remove_link(kobj, devt_str);
 824        }
 825}
 826
 827int device_private_init(struct device *dev)
 828{
 829        dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
 830        if (!dev->p)
 831                return -ENOMEM;
 832        dev->p->device = dev;
 833        klist_init(&dev->p->klist_children, klist_children_get,
 834                   klist_children_put);
 835        return 0;
 836}
 837
 838/**
 839 * device_add - add device to device hierarchy.
 840 * @dev: device.
 841 *
 842 * This is part 2 of device_register(), though may be called
 843 * separately _iff_ device_initialize() has been called separately.
 844 *
 845 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
 846 * to the global and sibling lists for the device, then
 847 * adds it to the other relevant subsystems of the driver model.
 848 *
 849 * NOTE: _Never_ directly free @dev after calling this function, even
 850 * if it returned an error! Always use put_device() to give up your
 851 * reference instead.
 852 */
 853int device_add(struct device *dev)
 854{
 855        struct device *parent = NULL;
 856        struct class_interface *class_intf;
 857        int error = -EINVAL;
 858
 859        dev = get_device(dev);
 860        if (!dev)
 861                goto done;
 862
 863        if (!dev->p) {
 864                error = device_private_init(dev);
 865                if (error)
 866                        goto done;
 867        }
 868
 869        /*
 870         * for statically allocated devices, which should all be converted
 871         * some day, we need to initialize the name. We prevent reading back
 872         * the name, and force the use of dev_name()
 873         */
 874        if (dev->init_name) {
 875                dev_set_name(dev, "%s", dev->init_name);
 876                dev->init_name = NULL;
 877        }
 878
 879        if (!dev_name(dev)) {
 880                error = -EINVAL;
 881                goto name_error;
 882        }
 883
 884        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 885
 886        parent = get_device(dev->parent);
 887        setup_parent(dev, parent);
 888
 889        /* use parent numa_node */
 890        if (parent)
 891                set_dev_node(dev, dev_to_node(parent));
 892
 893        /* first, register with generic layer. */
 894        /* we require the name to be set before, and pass NULL */
 895        error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
 896        if (error)
 897                goto Error;
 898
 899        /* notify platform of device entry */
 900        if (platform_notify)
 901                platform_notify(dev);
 902
 903        error = device_create_file(dev, &uevent_attr);
 904        if (error)
 905                goto attrError;
 906
 907        if (MAJOR(dev->devt)) {
 908                error = device_create_file(dev, &devt_attr);
 909                if (error)
 910                        goto ueventattrError;
 911
 912                error = device_create_sys_dev_entry(dev);
 913                if (error)
 914                        goto devtattrError;
 915
 916                devtmpfs_create_node(dev);
 917        }
 918
 919        error = device_add_class_symlinks(dev);
 920        if (error)
 921                goto SymlinkError;
 922        error = device_add_attrs(dev);
 923        if (error)
 924                goto AttrsError;
 925        error = bus_add_device(dev);
 926        if (error)
 927                goto BusError;
 928        error = dpm_sysfs_add(dev);
 929        if (error)
 930                goto DPMError;
 931        device_pm_add(dev);
 932
 933        /* Notify clients of device addition.  This call must come
 934         * after dpm_sysf_add() and before kobject_uevent().
 935         */
 936        if (dev->bus)
 937                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 938                                             BUS_NOTIFY_ADD_DEVICE, dev);
 939
 940        kobject_uevent(&dev->kobj, KOBJ_ADD);
 941        bus_probe_device(dev);
 942        if (parent)
 943                klist_add_tail(&dev->p->knode_parent,
 944                               &parent->p->klist_children);
 945
 946        if (dev->class) {
 947                mutex_lock(&dev->class->p->class_mutex);
 948                /* tie the class to the device */
 949                klist_add_tail(&dev->knode_class,
 950                               &dev->class->p->class_devices);
 951
 952                /* notify any interfaces that the device is here */
 953                list_for_each_entry(class_intf,
 954                                    &dev->class->p->class_interfaces, node)
 955                        if (class_intf->add_dev)
 956                                class_intf->add_dev(dev, class_intf);
 957                mutex_unlock(&dev->class->p->class_mutex);
 958        }
 959done:
 960        put_device(dev);
 961        return error;
 962 DPMError:
 963        bus_remove_device(dev);
 964 BusError:
 965        device_remove_attrs(dev);
 966 AttrsError:
 967        device_remove_class_symlinks(dev);
 968 SymlinkError:
 969        if (MAJOR(dev->devt))
 970                devtmpfs_delete_node(dev);
 971        if (MAJOR(dev->devt))
 972                device_remove_sys_dev_entry(dev);
 973 devtattrError:
 974        if (MAJOR(dev->devt))
 975                device_remove_file(dev, &devt_attr);
 976 ueventattrError:
 977        device_remove_file(dev, &uevent_attr);
 978 attrError:
 979        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 980        kobject_del(&dev->kobj);
 981 Error:
 982        cleanup_device_parent(dev);
 983        if (parent)
 984                put_device(parent);
 985name_error:
 986        kfree(dev->p);
 987        dev->p = NULL;
 988        goto done;
 989}
 990
 991/**
 992 * device_register - register a device with the system.
 993 * @dev: pointer to the device structure
 994 *
 995 * This happens in two clean steps - initialize the device
 996 * and add it to the system. The two steps can be called
 997 * separately, but this is the easiest and most common.
 998 * I.e. you should only call the two helpers separately if
 999 * have a clearly defined need to use and refcount the device
1000 * before it is added to the hierarchy.
1001 *
1002 * NOTE: _Never_ directly free @dev after calling this function, even
1003 * if it returned an error! Always use put_device() to give up the
1004 * reference initialized in this function instead.
1005 */
1006int device_register(struct device *dev)
1007{
1008        device_initialize(dev);
1009        return device_add(dev);
1010}
1011
1012/**
1013 * get_device - increment reference count for device.
1014 * @dev: device.
1015 *
1016 * This simply forwards the call to kobject_get(), though
1017 * we do take care to provide for the case that we get a NULL
1018 * pointer passed in.
1019 */
1020struct device *get_device(struct device *dev)
1021{
1022        return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
1023}
1024
1025/**
1026 * put_device - decrement reference count.
1027 * @dev: device in question.
1028 */
1029void put_device(struct device *dev)
1030{
1031        /* might_sleep(); */
1032        if (dev)
1033                kobject_put(&dev->kobj);
1034}
1035
1036/**
1037 * device_del - delete device from system.
1038 * @dev: device.
1039 *
1040 * This is the first part of the device unregistration
1041 * sequence. This removes the device from the lists we control
1042 * from here, has it removed from the other driver model
1043 * subsystems it was added to in device_add(), and removes it
1044 * from the kobject hierarchy.
1045 *
1046 * NOTE: this should be called manually _iff_ device_add() was
1047 * also called manually.
1048 */
1049void device_del(struct device *dev)
1050{
1051        struct device *parent = dev->parent;
1052        struct class_interface *class_intf;
1053
1054        /* Notify clients of device removal.  This call must come
1055         * before dpm_sysfs_remove().
1056         */
1057        if (dev->bus)
1058                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1059                                             BUS_NOTIFY_DEL_DEVICE, dev);
1060        device_pm_remove(dev);
1061        dpm_sysfs_remove(dev);
1062        if (parent)
1063                klist_del(&dev->p->knode_parent);
1064        if (MAJOR(dev->devt)) {
1065                devtmpfs_delete_node(dev);
1066                device_remove_sys_dev_entry(dev);
1067                device_remove_file(dev, &devt_attr);
1068        }
1069        if (dev->class) {
1070                device_remove_class_symlinks(dev);
1071
1072                mutex_lock(&dev->class->p->class_mutex);
1073                /* notify any interfaces that the device is now gone */
1074                list_for_each_entry(class_intf,
1075                                    &dev->class->p->class_interfaces, node)
1076                        if (class_intf->remove_dev)
1077                                class_intf->remove_dev(dev, class_intf);
1078                /* remove the device from the class list */
1079                klist_del(&dev->knode_class);
1080                mutex_unlock(&dev->class->p->class_mutex);
1081        }
1082        device_remove_file(dev, &uevent_attr);
1083        device_remove_attrs(dev);
1084        bus_remove_device(dev);
1085
1086        /*
1087         * Some platform devices are driven without driver attached
1088         * and managed resources may have been acquired.  Make sure
1089         * all resources are released.
1090         */
1091        devres_release_all(dev);
1092
1093        /* Notify the platform of the removal, in case they
1094         * need to do anything...
1095         */
1096        if (platform_notify_remove)
1097                platform_notify_remove(dev);
1098        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1099        cleanup_device_parent(dev);
1100        kobject_del(&dev->kobj);
1101        put_device(parent);
1102}
1103
1104/**
1105 * device_unregister - unregister device from system.
1106 * @dev: device going away.
1107 *
1108 * We do this in two parts, like we do device_register(). First,
1109 * we remove it from all the subsystems with device_del(), then
1110 * we decrement the reference count via put_device(). If that
1111 * is the final reference count, the device will be cleaned up
1112 * via device_release() above. Otherwise, the structure will
1113 * stick around until the final reference to the device is dropped.
1114 */
1115void device_unregister(struct device *dev)
1116{
1117        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1118        device_del(dev);
1119        put_device(dev);
1120}
1121
1122static struct device *next_device(struct klist_iter *i)
1123{
1124        struct klist_node *n = klist_next(i);
1125        struct device *dev = NULL;
1126        struct device_private *p;
1127
1128        if (n) {
1129                p = to_device_private_parent(n);
1130                dev = p->device;
1131        }
1132        return dev;
1133}
1134
1135/**
1136 * device_get_devnode - path of device node file
1137 * @dev: device
1138 * @mode: returned file access mode
1139 * @tmp: possibly allocated string
1140 *
1141 * Return the relative path of a possible device node.
1142 * Non-default names may need to allocate a memory to compose
1143 * a name. This memory is returned in tmp and needs to be
1144 * freed by the caller.
1145 */
1146const char *device_get_devnode(struct device *dev,
1147                               mode_t *mode, const char **tmp)
1148{
1149        char *s;
1150
1151        *tmp = NULL;
1152
1153        /* the device type may provide a specific name */
1154        if (dev->type && dev->type->devnode)
1155                *tmp = dev->type->devnode(dev, mode);
1156        if (*tmp)
1157                return *tmp;
1158
1159        /* the class may provide a specific name */
1160        if (dev->class && dev->class->devnode)
1161                *tmp = dev->class->devnode(dev, mode);
1162        if (*tmp)
1163                return *tmp;
1164
1165        /* return name without allocation, tmp == NULL */
1166        if (strchr(dev_name(dev), '!') == NULL)
1167                return dev_name(dev);
1168
1169        /* replace '!' in the name with '/' */
1170        *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1171        if (!*tmp)
1172                return NULL;
1173        while ((s = strchr(*tmp, '!')))
1174                s[0] = '/';
1175        return *tmp;
1176}
1177
1178/**
1179 * device_for_each_child - device child iterator.
1180 * @parent: parent struct device.
1181 * @data: data for the callback.
1182 * @fn: function to be called for each device.
1183 *
1184 * Iterate over @parent's child devices, and call @fn for each,
1185 * passing it @data.
1186 *
1187 * We check the return of @fn each time. If it returns anything
1188 * other than 0, we break out and return that value.
1189 */
1190int device_for_each_child(struct device *parent, void *data,
1191                          int (*fn)(struct device *dev, void *data))
1192{
1193        struct klist_iter i;
1194        struct device *child;
1195        int error = 0;
1196
1197        if (!parent->p)
1198                return 0;
1199
1200        klist_iter_init(&parent->p->klist_children, &i);
1201        while ((child = next_device(&i)) && !error)
1202                error = fn(child, data);
1203        klist_iter_exit(&i);
1204        return error;
1205}
1206
1207/**
1208 * device_find_child - device iterator for locating a particular device.
1209 * @parent: parent struct device
1210 * @data: Data to pass to match function
1211 * @match: Callback function to check device
1212 *
1213 * This is similar to the device_for_each_child() function above, but it
1214 * returns a reference to a device that is 'found' for later use, as
1215 * determined by the @match callback.
1216 *
1217 * The callback should return 0 if the device doesn't match and non-zero
1218 * if it does.  If the callback returns non-zero and a reference to the
1219 * current device can be obtained, this function will return to the caller
1220 * and not iterate over any more devices.
1221 */
1222struct device *device_find_child(struct device *parent, void *data,
1223                                 int (*match)(struct device *dev, void *data))
1224{
1225        struct klist_iter i;
1226        struct device *child;
1227
1228        if (!parent)
1229                return NULL;
1230
1231        klist_iter_init(&parent->p->klist_children, &i);
1232        while ((child = next_device(&i)))
1233                if (match(child, data) && get_device(child))
1234                        break;
1235        klist_iter_exit(&i);
1236        return child;
1237}
1238
1239int __init devices_init(void)
1240{
1241        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1242        if (!devices_kset)
1243                return -ENOMEM;
1244        dev_kobj = kobject_create_and_add("dev", NULL);
1245        if (!dev_kobj)
1246                goto dev_kobj_err;
1247        sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1248        if (!sysfs_dev_block_kobj)
1249                goto block_kobj_err;
1250        sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1251        if (!sysfs_dev_char_kobj)
1252                goto char_kobj_err;
1253
1254        return 0;
1255
1256 char_kobj_err:
1257        kobject_put(sysfs_dev_block_kobj);
1258 block_kobj_err:
1259        kobject_put(dev_kobj);
1260 dev_kobj_err:
1261        kset_unregister(devices_kset);
1262        return -ENOMEM;
1263}
1264
1265EXPORT_SYMBOL_GPL(device_for_each_child);
1266EXPORT_SYMBOL_GPL(device_find_child);
1267
1268EXPORT_SYMBOL_GPL(device_initialize);
1269EXPORT_SYMBOL_GPL(device_add);
1270EXPORT_SYMBOL_GPL(device_register);
1271
1272EXPORT_SYMBOL_GPL(device_del);
1273EXPORT_SYMBOL_GPL(device_unregister);
1274EXPORT_SYMBOL_GPL(get_device);
1275EXPORT_SYMBOL_GPL(put_device);
1276
1277EXPORT_SYMBOL_GPL(device_create_file);
1278EXPORT_SYMBOL_GPL(device_remove_file);
1279
1280struct root_device
1281{
1282        struct device dev;
1283        struct module *owner;
1284};
1285
1286#define to_root_device(dev) container_of(dev, struct root_device, dev)
1287
1288static void root_device_release(struct device *dev)
1289{
1290        kfree(to_root_device(dev));
1291}
1292
1293/**
1294 * __root_device_register - allocate and register a root device
1295 * @name: root device name
1296 * @owner: owner module of the root device, usually THIS_MODULE
1297 *
1298 * This function allocates a root device and registers it
1299 * using device_register(). In order to free the returned
1300 * device, use root_device_unregister().
1301 *
1302 * Root devices are dummy devices which allow other devices
1303 * to be grouped under /sys/devices. Use this function to
1304 * allocate a root device and then use it as the parent of
1305 * any device which should appear under /sys/devices/{name}
1306 *
1307 * The /sys/devices/{name} directory will also contain a
1308 * 'module' symlink which points to the @owner directory
1309 * in sysfs.
1310 *
1311 * Returns &struct device pointer on success, or ERR_PTR() on error.
1312 *
1313 * Note: You probably want to use root_device_register().
1314 */
1315struct device *__root_device_register(const char *name, struct module *owner)
1316{
1317        struct root_device *root;
1318        int err = -ENOMEM;
1319
1320        root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1321        if (!root)
1322                return ERR_PTR(err);
1323
1324        err = dev_set_name(&root->dev, "%s", name);
1325        if (err) {
1326                kfree(root);
1327                return ERR_PTR(err);
1328        }
1329
1330        root->dev.release = root_device_release;
1331
1332        err = device_register(&root->dev);
1333        if (err) {
1334                put_device(&root->dev);
1335                return ERR_PTR(err);
1336        }
1337
1338#ifdef CONFIG_MODULES   /* gotta find a "cleaner" way to do this */
1339        if (owner) {
1340                struct module_kobject *mk = &owner->mkobj;
1341
1342                err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1343                if (err) {
1344                        device_unregister(&root->dev);
1345                        return ERR_PTR(err);
1346                }
1347                root->owner = owner;
1348        }
1349#endif
1350
1351        return &root->dev;
1352}
1353EXPORT_SYMBOL_GPL(__root_device_register);
1354
1355/**
1356 * root_device_unregister - unregister and free a root device
1357 * @dev: device going away
1358 *
1359 * This function unregisters and cleans up a device that was created by
1360 * root_device_register().
1361 */
1362void root_device_unregister(struct device *dev)
1363{
1364        struct root_device *root = to_root_device(dev);
1365
1366        if (root->owner)
1367                sysfs_remove_link(&root->dev.kobj, "module");
1368
1369        device_unregister(dev);
1370}
1371EXPORT_SYMBOL_GPL(root_device_unregister);
1372
1373
1374static void device_create_release(struct device *dev)
1375{
1376        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1377        kfree(dev);
1378}
1379
1380/**
1381 * device_create_vargs - creates a device and registers it with sysfs
1382 * @class: pointer to the struct class that this device should be registered to
1383 * @parent: pointer to the parent struct device of this new device, if any
1384 * @devt: the dev_t for the char device to be added
1385 * @drvdata: the data to be added to the device for callbacks
1386 * @fmt: string for the device's name
1387 * @args: va_list for the device's name
1388 *
1389 * This function can be used by char device classes.  A struct device
1390 * will be created in sysfs, registered to the specified class.
1391 *
1392 * A "dev" file will be created, showing the dev_t for the device, if
1393 * the dev_t is not 0,0.
1394 * If a pointer to a parent struct device is passed in, the newly created
1395 * struct device will be a child of that device in sysfs.
1396 * The pointer to the struct device will be returned from the call.
1397 * Any further sysfs files that might be required can be created using this
1398 * pointer.
1399 *
1400 * Returns &struct device pointer on success, or ERR_PTR() on error.
1401 *
1402 * Note: the struct class passed to this function must have previously
1403 * been created with a call to class_create().
1404 */
1405struct device *device_create_vargs(struct class *class, struct device *parent,
1406                                   dev_t devt, void *drvdata, const char *fmt,
1407                                   va_list args)
1408{
1409        struct device *dev = NULL;
1410        int retval = -ENODEV;
1411
1412        if (class == NULL || IS_ERR(class))
1413                goto error;
1414
1415        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1416        if (!dev) {
1417                retval = -ENOMEM;
1418                goto error;
1419        }
1420
1421        dev->devt = devt;
1422        dev->class = class;
1423        dev->parent = parent;
1424        dev->release = device_create_release;
1425        dev_set_drvdata(dev, drvdata);
1426
1427        retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1428        if (retval)
1429                goto error;
1430
1431        retval = device_register(dev);
1432        if (retval)
1433                goto error;
1434
1435        return dev;
1436
1437error:
1438        put_device(dev);
1439        return ERR_PTR(retval);
1440}
1441EXPORT_SYMBOL_GPL(device_create_vargs);
1442
1443/**
1444 * device_create - creates a device and registers it with sysfs
1445 * @class: pointer to the struct class that this device should be registered to
1446 * @parent: pointer to the parent struct device of this new device, if any
1447 * @devt: the dev_t for the char device to be added
1448 * @drvdata: the data to be added to the device for callbacks
1449 * @fmt: string for the device's name
1450 *
1451 * This function can be used by char device classes.  A struct device
1452 * will be created in sysfs, registered to the specified class.
1453 *
1454 * A "dev" file will be created, showing the dev_t for the device, if
1455 * the dev_t is not 0,0.
1456 * If a pointer to a parent struct device is passed in, the newly created
1457 * struct device will be a child of that device in sysfs.
1458 * The pointer to the struct device will be returned from the call.
1459 * Any further sysfs files that might be required can be created using this
1460 * pointer.
1461 *
1462 * Returns &struct device pointer on success, or ERR_PTR() on error.
1463 *
1464 * Note: the struct class passed to this function must have previously
1465 * been created with a call to class_create().
1466 */
1467struct device *device_create(struct class *class, struct device *parent,
1468                             dev_t devt, void *drvdata, const char *fmt, ...)
1469{
1470        va_list vargs;
1471        struct device *dev;
1472
1473        va_start(vargs, fmt);
1474        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1475        va_end(vargs);
1476        return dev;
1477}
1478EXPORT_SYMBOL_GPL(device_create);
1479
1480static int __match_devt(struct device *dev, void *data)
1481{
1482        dev_t *devt = data;
1483
1484        return dev->devt == *devt;
1485}
1486
1487/**
1488 * device_destroy - removes a device that was created with device_create()
1489 * @class: pointer to the struct class that this device was registered with
1490 * @devt: the dev_t of the device that was previously registered
1491 *
1492 * This call unregisters and cleans up a device that was created with a
1493 * call to device_create().
1494 */
1495void device_destroy(struct class *class, dev_t devt)
1496{
1497        struct device *dev;
1498
1499        dev = class_find_device(class, NULL, &devt, __match_devt);
1500        if (dev) {
1501                put_device(dev);
1502                device_unregister(dev);
1503        }
1504}
1505EXPORT_SYMBOL_GPL(device_destroy);
1506
1507/**
1508 * device_rename - renames a device
1509 * @dev: the pointer to the struct device to be renamed
1510 * @new_name: the new name of the device
1511 *
1512 * It is the responsibility of the caller to provide mutual
1513 * exclusion between two different calls of device_rename
1514 * on the same device to ensure that new_name is valid and
1515 * won't conflict with other devices.
1516 */
1517int device_rename(struct device *dev, const char *new_name)
1518{
1519        char *old_class_name = NULL;
1520        char *new_class_name = NULL;
1521        char *old_device_name = NULL;
1522        int error;
1523
1524        dev = get_device(dev);
1525        if (!dev)
1526                return -EINVAL;
1527
1528        pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1529                 __func__, new_name);
1530
1531        old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1532        if (!old_device_name) {
1533                error = -ENOMEM;
1534                goto out;
1535        }
1536
1537        if (dev->class) {
1538                error = sysfs_rename_link(&dev->class->p->class_subsys.kobj,
1539                        &dev->kobj, old_device_name, new_name);
1540                if (error)
1541                        goto out;
1542        }
1543
1544        error = kobject_rename(&dev->kobj, new_name);
1545        if (error)
1546                goto out;
1547
1548out:
1549        put_device(dev);
1550
1551        kfree(new_class_name);
1552        kfree(old_class_name);
1553        kfree(old_device_name);
1554
1555        return error;
1556}
1557EXPORT_SYMBOL_GPL(device_rename);
1558
1559static int device_move_class_links(struct device *dev,
1560                                   struct device *old_parent,
1561                                   struct device *new_parent)
1562{
1563        int error = 0;
1564
1565        if (old_parent)
1566                sysfs_remove_link(&dev->kobj, "device");
1567        if (new_parent)
1568                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1569                                          "device");
1570        return error;
1571}
1572
1573/**
1574 * device_move - moves a device to a new parent
1575 * @dev: the pointer to the struct device to be moved
1576 * @new_parent: the new parent of the device (can by NULL)
1577 * @dpm_order: how to reorder the dpm_list
1578 */
1579int device_move(struct device *dev, struct device *new_parent,
1580                enum dpm_order dpm_order)
1581{
1582        int error;
1583        struct device *old_parent;
1584        struct kobject *new_parent_kobj;
1585
1586        dev = get_device(dev);
1587        if (!dev)
1588                return -EINVAL;
1589
1590        device_pm_lock();
1591        new_parent = get_device(new_parent);
1592        new_parent_kobj = get_device_parent(dev, new_parent);
1593
1594        pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1595                 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1596        error = kobject_move(&dev->kobj, new_parent_kobj);
1597        if (error) {
1598                cleanup_glue_dir(dev, new_parent_kobj);
1599                put_device(new_parent);
1600                goto out;
1601        }
1602        old_parent = dev->parent;
1603        dev->parent = new_parent;
1604        if (old_parent)
1605                klist_remove(&dev->p->knode_parent);
1606        if (new_parent) {
1607                klist_add_tail(&dev->p->knode_parent,
1608                               &new_parent->p->klist_children);
1609                set_dev_node(dev, dev_to_node(new_parent));
1610        }
1611
1612        if (!dev->class)
1613                goto out_put;
1614        error = device_move_class_links(dev, old_parent, new_parent);
1615        if (error) {
1616                /* We ignore errors on cleanup since we're hosed anyway... */
1617                device_move_class_links(dev, new_parent, old_parent);
1618                if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1619                        if (new_parent)
1620                                klist_remove(&dev->p->knode_parent);
1621                        dev->parent = old_parent;
1622                        if (old_parent) {
1623                                klist_add_tail(&dev->p->knode_parent,
1624                                               &old_parent->p->klist_children);
1625                                set_dev_node(dev, dev_to_node(old_parent));
1626                        }
1627                }
1628                cleanup_glue_dir(dev, new_parent_kobj);
1629                put_device(new_parent);
1630                goto out;
1631        }
1632        switch (dpm_order) {
1633        case DPM_ORDER_NONE:
1634                break;
1635        case DPM_ORDER_DEV_AFTER_PARENT:
1636                device_pm_move_after(dev, new_parent);
1637                break;
1638        case DPM_ORDER_PARENT_BEFORE_DEV:
1639                device_pm_move_before(new_parent, dev);
1640                break;
1641        case DPM_ORDER_DEV_LAST:
1642                device_pm_move_last(dev);
1643                break;
1644        }
1645out_put:
1646        put_device(old_parent);
1647out:
1648        device_pm_unlock();
1649        put_device(dev);
1650        return error;
1651}
1652EXPORT_SYMBOL_GPL(device_move);
1653
1654/**
1655 * device_shutdown - call ->shutdown() on each device to shutdown.
1656 */
1657void device_shutdown(void)
1658{
1659        struct device *dev;
1660
1661        spin_lock(&devices_kset->list_lock);
1662        /*
1663         * Walk the devices list backward, shutting down each in turn.
1664         * Beware that device unplug events may also start pulling
1665         * devices offline, even as the system is shutting down.
1666         */
1667        while (!list_empty(&devices_kset->list)) {
1668                dev = list_entry(devices_kset->list.prev, struct device,
1669                                kobj.entry);
1670                get_device(dev);
1671                /*
1672                 * Make sure the device is off the kset list, in the
1673                 * event that dev->*->shutdown() doesn't remove it.
1674                 */
1675                list_del_init(&dev->kobj.entry);
1676                spin_unlock(&devices_kset->list_lock);
1677
1678                if (dev->bus && dev->bus->shutdown) {
1679                        dev_dbg(dev, "shutdown\n");
1680                        dev->bus->shutdown(dev);
1681                } else if (dev->driver && dev->driver->shutdown) {
1682                        dev_dbg(dev, "shutdown\n");
1683                        dev->driver->shutdown(dev);
1684                }
1685                put_device(dev);
1686
1687                spin_lock(&devices_kset->list_lock);
1688        }
1689        spin_unlock(&devices_kset->list_lock);
1690        async_synchronize_full();
1691}
1692
1693/*
1694 * Device logging functions
1695 */
1696
1697#ifdef CONFIG_PRINTK
1698
1699static int __dev_printk(const char *level, const struct device *dev,
1700                        struct va_format *vaf)
1701{
1702        if (!dev)
1703                return printk("%s(NULL device *): %pV", level, vaf);
1704
1705        return printk("%s%s %s: %pV",
1706                      level, dev_driver_string(dev), dev_name(dev), vaf);
1707}
1708
1709int dev_printk(const char *level, const struct device *dev,
1710               const char *fmt, ...)
1711{
1712        struct va_format vaf;
1713        va_list args;
1714        int r;
1715
1716        va_start(args, fmt);
1717
1718        vaf.fmt = fmt;
1719        vaf.va = &args;
1720
1721        r = __dev_printk(level, dev, &vaf);
1722        va_end(args);
1723
1724        return r;
1725}
1726EXPORT_SYMBOL(dev_printk);
1727
1728#define define_dev_printk_level(func, kern_level)               \
1729int func(const struct device *dev, const char *fmt, ...)        \
1730{                                                               \
1731        struct va_format vaf;                                   \
1732        va_list args;                                           \
1733        int r;                                                  \
1734                                                                \
1735        va_start(args, fmt);                                    \
1736                                                                \
1737        vaf.fmt = fmt;                                          \
1738        vaf.va = &args;                                         \
1739                                                                \
1740        r = __dev_printk(kern_level, dev, &vaf);                \
1741        va_end(args);                                           \
1742                                                                \
1743        return r;                                               \
1744}                                                               \
1745EXPORT_SYMBOL(func);
1746
1747define_dev_printk_level(dev_emerg, KERN_EMERG);
1748define_dev_printk_level(dev_alert, KERN_ALERT);
1749define_dev_printk_level(dev_crit, KERN_CRIT);
1750define_dev_printk_level(dev_err, KERN_ERR);
1751define_dev_printk_level(dev_warn, KERN_WARNING);
1752define_dev_printk_level(dev_notice, KERN_NOTICE);
1753define_dev_printk_level(_dev_info, KERN_INFO);
1754
1755#endif
1756