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/of.h>
  22#include <linux/of_device.h>
  23#include <linux/genhd.h>
  24#include <linux/kallsyms.h>
  25#include <linux/mutex.h>
  26#include <linux/async.h>
  27#include <linux/pm_runtime.h>
  28#include <linux/netdevice.h>
  29
  30#include "base.h"
  31#include "power/power.h"
  32
  33#ifdef CONFIG_SYSFS_DEPRECATED
  34#ifdef CONFIG_SYSFS_DEPRECATED_V2
  35long sysfs_deprecated = 1;
  36#else
  37long sysfs_deprecated = 0;
  38#endif
  39static __init int sysfs_deprecated_setup(char *arg)
  40{
  41        return strict_strtol(arg, 10, &sysfs_deprecated);
  42}
  43early_param("sysfs.deprecated", sysfs_deprecated_setup);
  44#endif
  45
  46int (*platform_notify)(struct device *dev) = NULL;
  47int (*platform_notify_remove)(struct device *dev) = NULL;
  48static struct kobject *dev_kobj;
  49struct kobject *sysfs_dev_char_kobj;
  50struct kobject *sysfs_dev_block_kobj;
  51
  52#ifdef CONFIG_BLOCK
  53static inline int device_is_not_partition(struct device *dev)
  54{
  55        return !(dev->type == &part_type);
  56}
  57#else
  58static inline int device_is_not_partition(struct device *dev)
  59{
  60        return 1;
  61}
  62#endif
  63
  64/**
  65 * dev_driver_string - Return a device's driver name, if at all possible
  66 * @dev: struct device to get the name of
  67 *
  68 * Will return the device's driver's name if it is bound to a device.  If
  69 * the device is not bound to a driver, it will return the name of the bus
  70 * it is attached to.  If it is not attached to a bus either, an empty
  71 * string will be returned.
  72 */
  73const char *dev_driver_string(const struct device *dev)
  74{
  75        struct device_driver *drv;
  76
  77        /* dev->driver can change to NULL underneath us because of unbinding,
  78         * so be careful about accessing it.  dev->bus and dev->class should
  79         * never change once they are set, so they don't need special care.
  80         */
  81        drv = ACCESS_ONCE(dev->driver);
  82        return drv ? drv->name :
  83                        (dev->bus ? dev->bus->name :
  84                        (dev->class ? dev->class->name : ""));
  85}
  86EXPORT_SYMBOL(dev_driver_string);
  87
  88#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
  89
  90static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
  91                             char *buf)
  92{
  93        struct device_attribute *dev_attr = to_dev_attr(attr);
  94        struct device *dev = kobj_to_dev(kobj);
  95        ssize_t ret = -EIO;
  96
  97        if (dev_attr->show)
  98                ret = dev_attr->show(dev, dev_attr, buf);
  99        if (ret >= (ssize_t)PAGE_SIZE) {
 100                print_symbol("dev_attr_show: %s returned bad count\n",
 101                                (unsigned long)dev_attr->show);
 102        }
 103        return ret;
 104}
 105
 106static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
 107                              const char *buf, size_t count)
 108{
 109        struct device_attribute *dev_attr = to_dev_attr(attr);
 110        struct device *dev = kobj_to_dev(kobj);
 111        ssize_t ret = -EIO;
 112
 113        if (dev_attr->store)
 114                ret = dev_attr->store(dev, dev_attr, buf, count);
 115        return ret;
 116}
 117
 118static const struct sysfs_ops dev_sysfs_ops = {
 119        .show   = dev_attr_show,
 120        .store  = dev_attr_store,
 121};
 122
 123#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
 124
 125ssize_t device_store_ulong(struct device *dev,
 126                           struct device_attribute *attr,
 127                           const char *buf, size_t size)
 128{
 129        struct dev_ext_attribute *ea = to_ext_attr(attr);
 130        char *end;
 131        unsigned long new = simple_strtoul(buf, &end, 0);
 132        if (end == buf)
 133                return -EINVAL;
 134        *(unsigned long *)(ea->var) = new;
 135        /* Always return full write size even if we didn't consume all */
 136        return size;
 137}
 138EXPORT_SYMBOL_GPL(device_store_ulong);
 139
 140ssize_t device_show_ulong(struct device *dev,
 141                          struct device_attribute *attr,
 142                          char *buf)
 143{
 144        struct dev_ext_attribute *ea = to_ext_attr(attr);
 145        return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
 146}
 147EXPORT_SYMBOL_GPL(device_show_ulong);
 148
 149ssize_t device_store_int(struct device *dev,
 150                         struct device_attribute *attr,
 151                         const char *buf, size_t size)
 152{
 153        struct dev_ext_attribute *ea = to_ext_attr(attr);
 154        char *end;
 155        long new = simple_strtol(buf, &end, 0);
 156        if (end == buf || new > INT_MAX || new < INT_MIN)
 157                return -EINVAL;
 158        *(int *)(ea->var) = new;
 159        /* Always return full write size even if we didn't consume all */
 160        return size;
 161}
 162EXPORT_SYMBOL_GPL(device_store_int);
 163
 164ssize_t device_show_int(struct device *dev,
 165                        struct device_attribute *attr,
 166                        char *buf)
 167{
 168        struct dev_ext_attribute *ea = to_ext_attr(attr);
 169
 170        return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
 171}
 172EXPORT_SYMBOL_GPL(device_show_int);
 173
 174ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 175                          const char *buf, size_t size)
 176{
 177        struct dev_ext_attribute *ea = to_ext_attr(attr);
 178
 179        if (strtobool(buf, ea->var) < 0)
 180                return -EINVAL;
 181
 182        return size;
 183}
 184EXPORT_SYMBOL_GPL(device_store_bool);
 185
 186ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 187                         char *buf)
 188{
 189        struct dev_ext_attribute *ea = to_ext_attr(attr);
 190
 191        return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
 192}
 193EXPORT_SYMBOL_GPL(device_show_bool);
 194
 195/**
 196 *      device_release - free device structure.
 197 *      @kobj:  device's kobject.
 198 *
 199 *      This is called once the reference count for the object
 200 *      reaches 0. We forward the call to the device's release
 201 *      method, which should handle actually freeing the structure.
 202 */
 203static void device_release(struct kobject *kobj)
 204{
 205        struct device *dev = kobj_to_dev(kobj);
 206        struct device_private *p = dev->p;
 207
 208        /*
 209         * Some platform devices are driven without driver attached
 210         * and managed resources may have been acquired.  Make sure
 211         * all resources are released.
 212         *
 213         * Drivers still can add resources into device after device
 214         * is deleted but alive, so release devres here to avoid
 215         * possible memory leak.
 216         */
 217        devres_release_all(dev);
 218
 219        if (dev->release)
 220                dev->release(dev);
 221        else if (dev->type && dev->type->release)
 222                dev->type->release(dev);
 223        else if (dev->class && dev->class->dev_release)
 224                dev->class->dev_release(dev);
 225        else
 226                WARN(1, KERN_ERR "Device '%s' does not have a release() "
 227                        "function, it is broken and must be fixed.\n",
 228                        dev_name(dev));
 229        kfree(p);
 230}
 231
 232static const void *device_namespace(struct kobject *kobj)
 233{
 234        struct device *dev = kobj_to_dev(kobj);
 235        const void *ns = NULL;
 236
 237        if (dev->class && dev->class->ns_type)
 238                ns = dev->class->namespace(dev);
 239
 240        return ns;
 241}
 242
 243static struct kobj_type device_ktype = {
 244        .release        = device_release,
 245        .sysfs_ops      = &dev_sysfs_ops,
 246        .namespace      = device_namespace,
 247};
 248
 249
 250static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 251{
 252        struct kobj_type *ktype = get_ktype(kobj);
 253
 254        if (ktype == &device_ktype) {
 255                struct device *dev = kobj_to_dev(kobj);
 256                if (dev->bus)
 257                        return 1;
 258                if (dev->class)
 259                        return 1;
 260        }
 261        return 0;
 262}
 263
 264static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 265{
 266        struct device *dev = kobj_to_dev(kobj);
 267
 268        if (dev->bus)
 269                return dev->bus->name;
 270        if (dev->class)
 271                return dev->class->name;
 272        return NULL;
 273}
 274
 275static int dev_uevent(struct kset *kset, struct kobject *kobj,
 276                      struct kobj_uevent_env *env)
 277{
 278        struct device *dev = kobj_to_dev(kobj);
 279        int retval = 0;
 280
 281        /* add device node properties if present */
 282        if (MAJOR(dev->devt)) {
 283                const char *tmp;
 284                const char *name;
 285                umode_t mode = 0;
 286
 287                add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 288                add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 289                name = device_get_devnode(dev, &mode, &tmp);
 290                if (name) {
 291                        add_uevent_var(env, "DEVNAME=%s", name);
 292                        kfree(tmp);
 293                        if (mode)
 294                                add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
 295                }
 296        }
 297
 298        if (dev->type && dev->type->name)
 299                add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 300
 301        if (dev->driver)
 302                add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 303
 304        /* Add common DT information about the device */
 305        of_device_uevent(dev, env);
 306
 307        /* have the bus specific function add its stuff */
 308        if (dev->bus && dev->bus->uevent) {
 309                retval = dev->bus->uevent(dev, env);
 310                if (retval)
 311                        pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 312                                 dev_name(dev), __func__, retval);
 313        }
 314
 315        /* have the class specific function add its stuff */
 316        if (dev->class && dev->class->dev_uevent) {
 317                retval = dev->class->dev_uevent(dev, env);
 318                if (retval)
 319                        pr_debug("device: '%s': %s: class uevent() "
 320                                 "returned %d\n", dev_name(dev),
 321                                 __func__, retval);
 322        }
 323
 324        /* have the device type specific function add its stuff */
 325        if (dev->type && dev->type->uevent) {
 326                retval = dev->type->uevent(dev, env);
 327                if (retval)
 328                        pr_debug("device: '%s': %s: dev_type uevent() "
 329                                 "returned %d\n", dev_name(dev),
 330                                 __func__, retval);
 331        }
 332
 333        return retval;
 334}
 335
 336static const struct kset_uevent_ops device_uevent_ops = {
 337        .filter =       dev_uevent_filter,
 338        .name =         dev_uevent_name,
 339        .uevent =       dev_uevent,
 340};
 341
 342static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
 343                           char *buf)
 344{
 345        struct kobject *top_kobj;
 346        struct kset *kset;
 347        struct kobj_uevent_env *env = NULL;
 348        int i;
 349        size_t count = 0;
 350        int retval;
 351
 352        /* search the kset, the device belongs to */
 353        top_kobj = &dev->kobj;
 354        while (!top_kobj->kset && top_kobj->parent)
 355                top_kobj = top_kobj->parent;
 356        if (!top_kobj->kset)
 357                goto out;
 358
 359        kset = top_kobj->kset;
 360        if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 361                goto out;
 362
 363        /* respect filter */
 364        if (kset->uevent_ops && kset->uevent_ops->filter)
 365                if (!kset->uevent_ops->filter(kset, &dev->kobj))
 366                        goto out;
 367
 368        env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 369        if (!env)
 370                return -ENOMEM;
 371
 372        /* let the kset specific function add its keys */
 373        retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 374        if (retval)
 375                goto out;
 376
 377        /* copy keys to file */
 378        for (i = 0; i < env->envp_idx; i++)
 379                count += sprintf(&buf[count], "%s\n", env->envp[i]);
 380out:
 381        kfree(env);
 382        return count;
 383}
 384
 385static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
 386                            const char *buf, size_t count)
 387{
 388        enum kobject_action action;
 389
 390        if (kobject_action_type(buf, count, &action) == 0)
 391                kobject_uevent(&dev->kobj, action);
 392        else
 393                dev_err(dev, "uevent: unknown action-string\n");
 394        return count;
 395}
 396
 397static struct device_attribute uevent_attr =
 398        __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
 399
 400static int device_add_attributes(struct device *dev,
 401                                 struct device_attribute *attrs)
 402{
 403        int error = 0;
 404        int i;
 405
 406        if (attrs) {
 407                for (i = 0; attr_name(attrs[i]); i++) {
 408                        error = device_create_file(dev, &attrs[i]);
 409                        if (error)
 410                                break;
 411                }
 412                if (error)
 413                        while (--i >= 0)
 414                                device_remove_file(dev, &attrs[i]);
 415        }
 416        return error;
 417}
 418
 419static void device_remove_attributes(struct device *dev,
 420                                     struct device_attribute *attrs)
 421{
 422        int i;
 423
 424        if (attrs)
 425                for (i = 0; attr_name(attrs[i]); i++)
 426                        device_remove_file(dev, &attrs[i]);
 427}
 428
 429static int device_add_bin_attributes(struct device *dev,
 430                                     struct bin_attribute *attrs)
 431{
 432        int error = 0;
 433        int i;
 434
 435        if (attrs) {
 436                for (i = 0; attr_name(attrs[i]); i++) {
 437                        error = device_create_bin_file(dev, &attrs[i]);
 438                        if (error)
 439                                break;
 440                }
 441                if (error)
 442                        while (--i >= 0)
 443                                device_remove_bin_file(dev, &attrs[i]);
 444        }
 445        return error;
 446}
 447
 448static void device_remove_bin_attributes(struct device *dev,
 449                                         struct bin_attribute *attrs)
 450{
 451        int i;
 452
 453        if (attrs)
 454                for (i = 0; attr_name(attrs[i]); i++)
 455                        device_remove_bin_file(dev, &attrs[i]);
 456}
 457
 458static int device_add_groups(struct device *dev,
 459                             const struct attribute_group **groups)
 460{
 461        int error = 0;
 462        int i;
 463
 464        if (groups) {
 465                for (i = 0; groups[i]; i++) {
 466                        error = sysfs_create_group(&dev->kobj, groups[i]);
 467                        if (error) {
 468                                while (--i >= 0)
 469                                        sysfs_remove_group(&dev->kobj,
 470                                                           groups[i]);
 471                                break;
 472                        }
 473                }
 474        }
 475        return error;
 476}
 477
 478static void device_remove_groups(struct device *dev,
 479                                 const struct attribute_group **groups)
 480{
 481        int i;
 482
 483        if (groups)
 484                for (i = 0; groups[i]; i++)
 485                        sysfs_remove_group(&dev->kobj, groups[i]);
 486}
 487
 488static int device_add_attrs(struct device *dev)
 489{
 490        struct class *class = dev->class;
 491        const struct device_type *type = dev->type;
 492        int error;
 493
 494        if (class) {
 495                error = device_add_attributes(dev, class->dev_attrs);
 496                if (error)
 497                        return error;
 498                error = device_add_bin_attributes(dev, class->dev_bin_attrs);
 499                if (error)
 500                        goto err_remove_class_attrs;
 501        }
 502
 503        if (type) {
 504                error = device_add_groups(dev, type->groups);
 505                if (error)
 506                        goto err_remove_class_bin_attrs;
 507        }
 508
 509        error = device_add_groups(dev, dev->groups);
 510        if (error)
 511                goto err_remove_type_groups;
 512
 513        return 0;
 514
 515 err_remove_type_groups:
 516        if (type)
 517                device_remove_groups(dev, type->groups);
 518 err_remove_class_bin_attrs:
 519        if (class)
 520                device_remove_bin_attributes(dev, class->dev_bin_attrs);
 521 err_remove_class_attrs:
 522        if (class)
 523                device_remove_attributes(dev, class->dev_attrs);
 524
 525        return error;
 526}
 527
 528static void device_remove_attrs(struct device *dev)
 529{
 530        struct class *class = dev->class;
 531        const struct device_type *type = dev->type;
 532
 533        device_remove_groups(dev, dev->groups);
 534
 535        if (type)
 536                device_remove_groups(dev, type->groups);
 537
 538        if (class) {
 539                device_remove_attributes(dev, class->dev_attrs);
 540                device_remove_bin_attributes(dev, class->dev_bin_attrs);
 541        }
 542}
 543
 544
 545static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
 546                        char *buf)
 547{
 548        return print_dev_t(buf, dev->devt);
 549}
 550
 551static struct device_attribute devt_attr =
 552        __ATTR(dev, S_IRUGO, show_dev, NULL);
 553
 554/* /sys/devices/ */
 555struct kset *devices_kset;
 556
 557/**
 558 * device_create_file - create sysfs attribute file for device.
 559 * @dev: device.
 560 * @attr: device attribute descriptor.
 561 */
 562int device_create_file(struct device *dev,
 563                       const struct device_attribute *attr)
 564{
 565        int error = 0;
 566        if (dev)
 567                error = sysfs_create_file(&dev->kobj, &attr->attr);
 568        return error;
 569}
 570
 571/**
 572 * device_remove_file - remove sysfs attribute file.
 573 * @dev: device.
 574 * @attr: device attribute descriptor.
 575 */
 576void device_remove_file(struct device *dev,
 577                        const struct device_attribute *attr)
 578{
 579        if (dev)
 580                sysfs_remove_file(&dev->kobj, &attr->attr);
 581}
 582
 583/**
 584 * device_create_bin_file - create sysfs binary attribute file for device.
 585 * @dev: device.
 586 * @attr: device binary attribute descriptor.
 587 */
 588int device_create_bin_file(struct device *dev,
 589                           const struct bin_attribute *attr)
 590{
 591        int error = -EINVAL;
 592        if (dev)
 593                error = sysfs_create_bin_file(&dev->kobj, attr);
 594        return error;
 595}
 596EXPORT_SYMBOL_GPL(device_create_bin_file);
 597
 598/**
 599 * device_remove_bin_file - remove sysfs binary attribute file
 600 * @dev: device.
 601 * @attr: device binary attribute descriptor.
 602 */
 603void device_remove_bin_file(struct device *dev,
 604                            const struct bin_attribute *attr)
 605{
 606        if (dev)
 607                sysfs_remove_bin_file(&dev->kobj, attr);
 608}
 609EXPORT_SYMBOL_GPL(device_remove_bin_file);
 610
 611/**
 612 * device_schedule_callback_owner - helper to schedule a callback for a device
 613 * @dev: device.
 614 * @func: callback function to invoke later.
 615 * @owner: module owning the callback routine
 616 *
 617 * Attribute methods must not unregister themselves or their parent device
 618 * (which would amount to the same thing).  Attempts to do so will deadlock,
 619 * since unregistration is mutually exclusive with driver callbacks.
 620 *
 621 * Instead methods can call this routine, which will attempt to allocate
 622 * and schedule a workqueue request to call back @func with @dev as its
 623 * argument in the workqueue's process context.  @dev will be pinned until
 624 * @func returns.
 625 *
 626 * This routine is usually called via the inline device_schedule_callback(),
 627 * which automatically sets @owner to THIS_MODULE.
 628 *
 629 * Returns 0 if the request was submitted, -ENOMEM if storage could not
 630 * be allocated, -ENODEV if a reference to @owner isn't available.
 631 *
 632 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 633 * underlying sysfs routine (since it is intended for use by attribute
 634 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 635 */
 636int device_schedule_callback_owner(struct device *dev,
 637                void (*func)(struct device *), struct module *owner)
 638{
 639        return sysfs_schedule_callback(&dev->kobj,
 640                        (void (*)(void *)) func, dev, owner);
 641}
 642EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
 643
 644static void klist_children_get(struct klist_node *n)
 645{
 646        struct device_private *p = to_device_private_parent(n);
 647        struct device *dev = p->device;
 648
 649        get_device(dev);
 650}
 651
 652static void klist_children_put(struct klist_node *n)
 653{
 654        struct device_private *p = to_device_private_parent(n);
 655        struct device *dev = p->device;
 656
 657        put_device(dev);
 658}
 659
 660/**
 661 * device_initialize - init device structure.
 662 * @dev: device.
 663 *
 664 * This prepares the device for use by other layers by initializing
 665 * its fields.
 666 * It is the first half of device_register(), if called by
 667 * that function, though it can also be called separately, so one
 668 * may use @dev's fields. In particular, get_device()/put_device()
 669 * may be used for reference counting of @dev after calling this
 670 * function.
 671 *
 672 * All fields in @dev must be initialized by the caller to 0, except
 673 * for those explicitly set to some other value.  The simplest
 674 * approach is to use kzalloc() to allocate the structure containing
 675 * @dev.
 676 *
 677 * NOTE: Use put_device() to give up your reference instead of freeing
 678 * @dev directly once you have called this function.
 679 */
 680void device_initialize(struct device *dev)
 681{
 682        dev->kobj.kset = devices_kset;
 683        kobject_init(&dev->kobj, &device_ktype);
 684        INIT_LIST_HEAD(&dev->dma_pools);
 685        mutex_init(&dev->mutex);
 686        lockdep_set_novalidate_class(&dev->mutex);
 687        spin_lock_init(&dev->devres_lock);
 688        INIT_LIST_HEAD(&dev->devres_head);
 689        device_pm_init(dev);
 690        set_dev_node(dev, -1);
 691}
 692
 693static struct kobject *virtual_device_parent(struct device *dev)
 694{
 695        static struct kobject *virtual_dir = NULL;
 696
 697        if (!virtual_dir)
 698                virtual_dir = kobject_create_and_add("virtual",
 699                                                     &devices_kset->kobj);
 700
 701        return virtual_dir;
 702}
 703
 704struct class_dir {
 705        struct kobject kobj;
 706        struct class *class;
 707};
 708
 709#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
 710
 711static void class_dir_release(struct kobject *kobj)
 712{
 713        struct class_dir *dir = to_class_dir(kobj);
 714        kfree(dir);
 715}
 716
 717static const
 718struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
 719{
 720        struct class_dir *dir = to_class_dir(kobj);
 721        return dir->class->ns_type;
 722}
 723
 724static struct kobj_type class_dir_ktype = {
 725        .release        = class_dir_release,
 726        .sysfs_ops      = &kobj_sysfs_ops,
 727        .child_ns_type  = class_dir_child_ns_type
 728};
 729
 730static struct kobject *
 731class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 732{
 733        struct class_dir *dir;
 734        int retval;
 735
 736        dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 737        if (!dir)
 738                return NULL;
 739
 740        dir->class = class;
 741        kobject_init(&dir->kobj, &class_dir_ktype);
 742
 743        dir->kobj.kset = &class->p->glue_dirs;
 744
 745        retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
 746        if (retval < 0) {
 747                kobject_put(&dir->kobj);
 748                return NULL;
 749        }
 750        return &dir->kobj;
 751}
 752
 753
 754static struct kobject *get_device_parent(struct device *dev,
 755                                         struct device *parent)
 756{
 757        if (dev->class) {
 758                static DEFINE_MUTEX(gdp_mutex);
 759                struct kobject *kobj = NULL;
 760                struct kobject *parent_kobj;
 761                struct kobject *k;
 762
 763#ifdef CONFIG_BLOCK
 764                /* block disks show up in /sys/block */
 765                if (sysfs_deprecated && dev->class == &block_class) {
 766                        if (parent && parent->class == &block_class)
 767                                return &parent->kobj;
 768                        return &block_class.p->subsys.kobj;
 769                }
 770#endif
 771
 772                /*
 773                 * If we have no parent, we live in "virtual".
 774                 * Class-devices with a non class-device as parent, live
 775                 * in a "glue" directory to prevent namespace collisions.
 776                 */
 777                if (parent == NULL)
 778                        parent_kobj = virtual_device_parent(dev);
 779                else if (parent->class && !dev->class->ns_type)
 780                        return &parent->kobj;
 781                else
 782                        parent_kobj = &parent->kobj;
 783
 784                mutex_lock(&gdp_mutex);
 785
 786                /* find our class-directory at the parent and reference it */
 787                spin_lock(&dev->class->p->glue_dirs.list_lock);
 788                list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
 789                        if (k->parent == parent_kobj) {
 790                                kobj = kobject_get(k);
 791                                break;
 792                        }
 793                spin_unlock(&dev->class->p->glue_dirs.list_lock);
 794                if (kobj) {
 795                        mutex_unlock(&gdp_mutex);
 796                        return kobj;
 797                }
 798
 799                /* or create a new class-directory at the parent device */
 800                k = class_dir_create_and_add(dev->class, parent_kobj);
 801                /* do not emit an uevent for this simple "glue" directory */
 802                mutex_unlock(&gdp_mutex);
 803                return k;
 804        }
 805
 806        /* subsystems can specify a default root directory for their devices */
 807        if (!parent && dev->bus && dev->bus->dev_root)
 808                return &dev->bus->dev_root->kobj;
 809
 810        if (parent)
 811                return &parent->kobj;
 812        return NULL;
 813}
 814
 815static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 816{
 817        /* see if we live in a "glue" directory */
 818        if (!glue_dir || !dev->class ||
 819            glue_dir->kset != &dev->class->p->glue_dirs)
 820                return;
 821
 822        kobject_put(glue_dir);
 823}
 824
 825static void cleanup_device_parent(struct device *dev)
 826{
 827        cleanup_glue_dir(dev, dev->kobj.parent);
 828}
 829
 830static int device_add_class_symlinks(struct device *dev)
 831{
 832        int error;
 833
 834        if (!dev->class)
 835                return 0;
 836
 837        error = sysfs_create_link(&dev->kobj,
 838                                  &dev->class->p->subsys.kobj,
 839                                  "subsystem");
 840        if (error)
 841                goto out;
 842
 843        if (dev->parent && device_is_not_partition(dev)) {
 844                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 845                                          "device");
 846                if (error)
 847                        goto out_subsys;
 848        }
 849
 850#ifdef CONFIG_BLOCK
 851        /* /sys/block has directories and does not need symlinks */
 852        if (sysfs_deprecated && dev->class == &block_class)
 853                return 0;
 854#endif
 855
 856        /* link in the class directory pointing to the device */
 857        error = sysfs_create_link(&dev->class->p->subsys.kobj,
 858                                  &dev->kobj, dev_name(dev));
 859        if (error)
 860                goto out_device;
 861
 862        return 0;
 863
 864out_device:
 865        sysfs_remove_link(&dev->kobj, "device");
 866
 867out_subsys:
 868        sysfs_remove_link(&dev->kobj, "subsystem");
 869out:
 870        return error;
 871}
 872
 873static void device_remove_class_symlinks(struct device *dev)
 874{
 875        if (!dev->class)
 876                return;
 877
 878        if (dev->parent && device_is_not_partition(dev))
 879                sysfs_remove_link(&dev->kobj, "device");
 880        sysfs_remove_link(&dev->kobj, "subsystem");
 881#ifdef CONFIG_BLOCK
 882        if (sysfs_deprecated && dev->class == &block_class)
 883                return;
 884#endif
 885        sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
 886}
 887
 888/**
 889 * dev_set_name - set a device name
 890 * @dev: device
 891 * @fmt: format string for the device's name
 892 */
 893int dev_set_name(struct device *dev, const char *fmt, ...)
 894{
 895        va_list vargs;
 896        int err;
 897
 898        va_start(vargs, fmt);
 899        err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
 900        va_end(vargs);
 901        return err;
 902}
 903EXPORT_SYMBOL_GPL(dev_set_name);
 904
 905/**
 906 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 907 * @dev: device
 908 *
 909 * By default we select char/ for new entries.  Setting class->dev_obj
 910 * to NULL prevents an entry from being created.  class->dev_kobj must
 911 * be set (or cleared) before any devices are registered to the class
 912 * otherwise device_create_sys_dev_entry() and
 913 * device_remove_sys_dev_entry() will disagree about the presence of
 914 * the link.
 915 */
 916static struct kobject *device_to_dev_kobj(struct device *dev)
 917{
 918        struct kobject *kobj;
 919
 920        if (dev->class)
 921                kobj = dev->class->dev_kobj;
 922        else
 923                kobj = sysfs_dev_char_kobj;
 924
 925        return kobj;
 926}
 927
 928static int device_create_sys_dev_entry(struct device *dev)
 929{
 930        struct kobject *kobj = device_to_dev_kobj(dev);
 931        int error = 0;
 932        char devt_str[15];
 933
 934        if (kobj) {
 935                format_dev_t(devt_str, dev->devt);
 936                error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 937        }
 938
 939        return error;
 940}
 941
 942static void device_remove_sys_dev_entry(struct device *dev)
 943{
 944        struct kobject *kobj = device_to_dev_kobj(dev);
 945        char devt_str[15];
 946
 947        if (kobj) {
 948                format_dev_t(devt_str, dev->devt);
 949                sysfs_remove_link(kobj, devt_str);
 950        }
 951}
 952
 953int device_private_init(struct device *dev)
 954{
 955        dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
 956        if (!dev->p)
 957                return -ENOMEM;
 958        dev->p->device = dev;
 959        klist_init(&dev->p->klist_children, klist_children_get,
 960                   klist_children_put);
 961        INIT_LIST_HEAD(&dev->p->deferred_probe);
 962        return 0;
 963}
 964
 965/**
 966 * device_add - add device to device hierarchy.
 967 * @dev: device.
 968 *
 969 * This is part 2 of device_register(), though may be called
 970 * separately _iff_ device_initialize() has been called separately.
 971 *
 972 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
 973 * to the global and sibling lists for the device, then
 974 * adds it to the other relevant subsystems of the driver model.
 975 *
 976 * Do not call this routine or device_register() more than once for
 977 * any device structure.  The driver model core is not designed to work
 978 * with devices that get unregistered and then spring back to life.
 979 * (Among other things, it's very hard to guarantee that all references
 980 * to the previous incarnation of @dev have been dropped.)  Allocate
 981 * and register a fresh new struct device instead.
 982 *
 983 * NOTE: _Never_ directly free @dev after calling this function, even
 984 * if it returned an error! Always use put_device() to give up your
 985 * reference instead.
 986 */
 987int device_add(struct device *dev)
 988{
 989        struct device *parent = NULL;
 990        struct kobject *kobj;
 991        struct class_interface *class_intf;
 992        int error = -EINVAL;
 993
 994        dev = get_device(dev);
 995        if (!dev)
 996                goto done;
 997
 998        if (!dev->p) {
 999                error = device_private_init(dev);
1000                if (error)
1001                        goto done;
1002        }
1003
1004        /*
1005         * for statically allocated devices, which should all be converted
1006         * some day, we need to initialize the name. We prevent reading back
1007         * the name, and force the use of dev_name()
1008         */
1009        if (dev->init_name) {
1010                dev_set_name(dev, "%s", dev->init_name);
1011                dev->init_name = NULL;
1012        }
1013
1014        /* subsystems can specify simple device enumeration */
1015        if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1016                dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1017
1018        if (!dev_name(dev)) {
1019                error = -EINVAL;
1020                goto name_error;
1021        }
1022
1023        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1024
1025        parent = get_device(dev->parent);
1026        kobj = get_device_parent(dev, parent);
1027        if (kobj)
1028                dev->kobj.parent = kobj;
1029
1030        /* use parent numa_node */
1031        if (parent)
1032                set_dev_node(dev, dev_to_node(parent));
1033
1034        /* first, register with generic layer. */
1035        /* we require the name to be set before, and pass NULL */
1036        error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1037        if (error)
1038                goto Error;
1039
1040        /* notify platform of device entry */
1041        if (platform_notify)
1042                platform_notify(dev);
1043
1044        error = device_create_file(dev, &uevent_attr);
1045        if (error)
1046                goto attrError;
1047
1048        if (MAJOR(dev->devt)) {
1049                error = device_create_file(dev, &devt_attr);
1050                if (error)
1051                        goto ueventattrError;
1052
1053                error = device_create_sys_dev_entry(dev);
1054                if (error)
1055                        goto devtattrError;
1056
1057                devtmpfs_create_node(dev);
1058        }
1059
1060        error = device_add_class_symlinks(dev);
1061        if (error)
1062                goto SymlinkError;
1063        error = device_add_attrs(dev);
1064        if (error)
1065                goto AttrsError;
1066        error = bus_add_device(dev);
1067        if (error)
1068                goto BusError;
1069        error = dpm_sysfs_add(dev);
1070        if (error)
1071                goto DPMError;
1072        device_pm_add(dev);
1073
1074        /* Notify clients of device addition.  This call must come
1075         * after dpm_sysfs_add() and before kobject_uevent().
1076         */
1077        if (dev->bus)
1078                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1079                                             BUS_NOTIFY_ADD_DEVICE, dev);
1080
1081        kobject_uevent(&dev->kobj, KOBJ_ADD);
1082        bus_probe_device(dev);
1083        if (parent)
1084                klist_add_tail(&dev->p->knode_parent,
1085                               &parent->p->klist_children);
1086
1087        if (dev->class) {
1088                mutex_lock(&dev->class->p->mutex);
1089                /* tie the class to the device */
1090                klist_add_tail(&dev->knode_class,
1091                               &dev->class->p->klist_devices);
1092
1093                /* notify any interfaces that the device is here */
1094                list_for_each_entry(class_intf,
1095                                    &dev->class->p->interfaces, node)
1096                        if (class_intf->add_dev)
1097                                class_intf->add_dev(dev, class_intf);
1098                mutex_unlock(&dev->class->p->mutex);
1099        }
1100done:
1101        put_device(dev);
1102        return error;
1103 DPMError:
1104        bus_remove_device(dev);
1105 BusError:
1106        device_remove_attrs(dev);
1107 AttrsError:
1108        device_remove_class_symlinks(dev);
1109 SymlinkError:
1110        if (MAJOR(dev->devt))
1111                devtmpfs_delete_node(dev);
1112        if (MAJOR(dev->devt))
1113                device_remove_sys_dev_entry(dev);
1114 devtattrError:
1115        if (MAJOR(dev->devt))
1116                device_remove_file(dev, &devt_attr);
1117 ueventattrError:
1118        device_remove_file(dev, &uevent_attr);
1119 attrError:
1120        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1121        kobject_del(&dev->kobj);
1122 Error:
1123        cleanup_device_parent(dev);
1124        if (parent)
1125                put_device(parent);
1126name_error:
1127        kfree(dev->p);
1128        dev->p = NULL;
1129        goto done;
1130}
1131
1132/**
1133 * device_register - register a device with the system.
1134 * @dev: pointer to the device structure
1135 *
1136 * This happens in two clean steps - initialize the device
1137 * and add it to the system. The two steps can be called
1138 * separately, but this is the easiest and most common.
1139 * I.e. you should only call the two helpers separately if
1140 * have a clearly defined need to use and refcount the device
1141 * before it is added to the hierarchy.
1142 *
1143 * For more information, see the kerneldoc for device_initialize()
1144 * and device_add().
1145 *
1146 * NOTE: _Never_ directly free @dev after calling this function, even
1147 * if it returned an error! Always use put_device() to give up the
1148 * reference initialized in this function instead.
1149 */
1150int device_register(struct device *dev)
1151{
1152        device_initialize(dev);
1153        return device_add(dev);
1154}
1155
1156/**
1157 * get_device - increment reference count for device.
1158 * @dev: device.
1159 *
1160 * This simply forwards the call to kobject_get(), though
1161 * we do take care to provide for the case that we get a NULL
1162 * pointer passed in.
1163 */
1164struct device *get_device(struct device *dev)
1165{
1166        return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1167}
1168
1169/**
1170 * put_device - decrement reference count.
1171 * @dev: device in question.
1172 */
1173void put_device(struct device *dev)
1174{
1175        /* might_sleep(); */
1176        if (dev)
1177                kobject_put(&dev->kobj);
1178}
1179
1180/**
1181 * device_del - delete device from system.
1182 * @dev: device.
1183 *
1184 * This is the first part of the device unregistration
1185 * sequence. This removes the device from the lists we control
1186 * from here, has it removed from the other driver model
1187 * subsystems it was added to in device_add(), and removes it
1188 * from the kobject hierarchy.
1189 *
1190 * NOTE: this should be called manually _iff_ device_add() was
1191 * also called manually.
1192 */
1193void device_del(struct device *dev)
1194{
1195        struct device *parent = dev->parent;
1196        struct class_interface *class_intf;
1197
1198        /* Notify clients of device removal.  This call must come
1199         * before dpm_sysfs_remove().
1200         */
1201        if (dev->bus)
1202                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1203                                             BUS_NOTIFY_DEL_DEVICE, dev);
1204        dpm_sysfs_remove(dev);
1205        if (parent)
1206                klist_del(&dev->p->knode_parent);
1207        if (MAJOR(dev->devt)) {
1208                devtmpfs_delete_node(dev);
1209                device_remove_sys_dev_entry(dev);
1210                device_remove_file(dev, &devt_attr);
1211        }
1212        if (dev->class) {
1213                device_remove_class_symlinks(dev);
1214
1215                mutex_lock(&dev->class->p->mutex);
1216                /* notify any interfaces that the device is now gone */
1217                list_for_each_entry(class_intf,
1218                                    &dev->class->p->interfaces, node)
1219                        if (class_intf->remove_dev)
1220                                class_intf->remove_dev(dev, class_intf);
1221                /* remove the device from the class list */
1222                klist_del(&dev->knode_class);
1223                mutex_unlock(&dev->class->p->mutex);
1224        }
1225        device_remove_file(dev, &uevent_attr);
1226        device_remove_attrs(dev);
1227        bus_remove_device(dev);
1228        device_pm_remove(dev);
1229        driver_deferred_probe_del(dev);
1230
1231        /* Notify the platform of the removal, in case they
1232         * need to do anything...
1233         */
1234        if (platform_notify_remove)
1235                platform_notify_remove(dev);
1236        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1237        cleanup_device_parent(dev);
1238        kobject_del(&dev->kobj);
1239        put_device(parent);
1240}
1241
1242/**
1243 * device_unregister - unregister device from system.
1244 * @dev: device going away.
1245 *
1246 * We do this in two parts, like we do device_register(). First,
1247 * we remove it from all the subsystems with device_del(), then
1248 * we decrement the reference count via put_device(). If that
1249 * is the final reference count, the device will be cleaned up
1250 * via device_release() above. Otherwise, the structure will
1251 * stick around until the final reference to the device is dropped.
1252 */
1253void device_unregister(struct device *dev)
1254{
1255        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1256        device_del(dev);
1257        put_device(dev);
1258}
1259
1260static struct device *next_device(struct klist_iter *i)
1261{
1262        struct klist_node *n = klist_next(i);
1263        struct device *dev = NULL;
1264        struct device_private *p;
1265
1266        if (n) {
1267                p = to_device_private_parent(n);
1268                dev = p->device;
1269        }
1270        return dev;
1271}
1272
1273/**
1274 * device_get_devnode - path of device node file
1275 * @dev: device
1276 * @mode: returned file access mode
1277 * @tmp: possibly allocated string
1278 *
1279 * Return the relative path of a possible device node.
1280 * Non-default names may need to allocate a memory to compose
1281 * a name. This memory is returned in tmp and needs to be
1282 * freed by the caller.
1283 */
1284const char *device_get_devnode(struct device *dev,
1285                               umode_t *mode, const char **tmp)
1286{
1287        char *s;
1288
1289        *tmp = NULL;
1290
1291        /* the device type may provide a specific name */
1292        if (dev->type && dev->type->devnode)
1293                *tmp = dev->type->devnode(dev, mode);
1294        if (*tmp)
1295                return *tmp;
1296
1297        /* the class may provide a specific name */
1298        if (dev->class && dev->class->devnode)
1299                *tmp = dev->class->devnode(dev, mode);
1300        if (*tmp)
1301                return *tmp;
1302
1303        /* return name without allocation, tmp == NULL */
1304        if (strchr(dev_name(dev), '!') == NULL)
1305                return dev_name(dev);
1306
1307        /* replace '!' in the name with '/' */
1308        *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1309        if (!*tmp)
1310                return NULL;
1311        while ((s = strchr(*tmp, '!')))
1312                s[0] = '/';
1313        return *tmp;
1314}
1315
1316/**
1317 * device_for_each_child - device child iterator.
1318 * @parent: parent struct device.
1319 * @data: data for the callback.
1320 * @fn: function to be called for each device.
1321 *
1322 * Iterate over @parent's child devices, and call @fn for each,
1323 * passing it @data.
1324 *
1325 * We check the return of @fn each time. If it returns anything
1326 * other than 0, we break out and return that value.
1327 */
1328int device_for_each_child(struct device *parent, void *data,
1329                          int (*fn)(struct device *dev, void *data))
1330{
1331        struct klist_iter i;
1332        struct device *child;
1333        int error = 0;
1334
1335        if (!parent->p)
1336                return 0;
1337
1338        klist_iter_init(&parent->p->klist_children, &i);
1339        while ((child = next_device(&i)) && !error)
1340                error = fn(child, data);
1341        klist_iter_exit(&i);
1342        return error;
1343}
1344
1345/**
1346 * device_find_child - device iterator for locating a particular device.
1347 * @parent: parent struct device
1348 * @data: Data to pass to match function
1349 * @match: Callback function to check device
1350 *
1351 * This is similar to the device_for_each_child() function above, but it
1352 * returns a reference to a device that is 'found' for later use, as
1353 * determined by the @match callback.
1354 *
1355 * The callback should return 0 if the device doesn't match and non-zero
1356 * if it does.  If the callback returns non-zero and a reference to the
1357 * current device can be obtained, this function will return to the caller
1358 * and not iterate over any more devices.
1359 */
1360struct device *device_find_child(struct device *parent, void *data,
1361                                 int (*match)(struct device *dev, void *data))
1362{
1363        struct klist_iter i;
1364        struct device *child;
1365
1366        if (!parent)
1367                return NULL;
1368
1369        klist_iter_init(&parent->p->klist_children, &i);
1370        while ((child = next_device(&i)))
1371                if (match(child, data) && get_device(child))
1372                        break;
1373        klist_iter_exit(&i);
1374        return child;
1375}
1376
1377int __init devices_init(void)
1378{
1379        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1380        if (!devices_kset)
1381                return -ENOMEM;
1382        dev_kobj = kobject_create_and_add("dev", NULL);
1383        if (!dev_kobj)
1384                goto dev_kobj_err;
1385        sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1386        if (!sysfs_dev_block_kobj)
1387                goto block_kobj_err;
1388        sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1389        if (!sysfs_dev_char_kobj)
1390                goto char_kobj_err;
1391
1392        return 0;
1393
1394 char_kobj_err:
1395        kobject_put(sysfs_dev_block_kobj);
1396 block_kobj_err:
1397        kobject_put(dev_kobj);
1398 dev_kobj_err:
1399        kset_unregister(devices_kset);
1400        return -ENOMEM;
1401}
1402
1403EXPORT_SYMBOL_GPL(device_for_each_child);
1404EXPORT_SYMBOL_GPL(device_find_child);
1405
1406EXPORT_SYMBOL_GPL(device_initialize);
1407EXPORT_SYMBOL_GPL(device_add);
1408EXPORT_SYMBOL_GPL(device_register);
1409
1410EXPORT_SYMBOL_GPL(device_del);
1411EXPORT_SYMBOL_GPL(device_unregister);
1412EXPORT_SYMBOL_GPL(get_device);
1413EXPORT_SYMBOL_GPL(put_device);
1414
1415EXPORT_SYMBOL_GPL(device_create_file);
1416EXPORT_SYMBOL_GPL(device_remove_file);
1417
1418struct root_device {
1419        struct device dev;
1420        struct module *owner;
1421};
1422
1423static inline struct root_device *to_root_device(struct device *d)
1424{
1425        return container_of(d, struct root_device, dev);
1426}
1427
1428static void root_device_release(struct device *dev)
1429{
1430        kfree(to_root_device(dev));
1431}
1432
1433/**
1434 * __root_device_register - allocate and register a root device
1435 * @name: root device name
1436 * @owner: owner module of the root device, usually THIS_MODULE
1437 *
1438 * This function allocates a root device and registers it
1439 * using device_register(). In order to free the returned
1440 * device, use root_device_unregister().
1441 *
1442 * Root devices are dummy devices which allow other devices
1443 * to be grouped under /sys/devices. Use this function to
1444 * allocate a root device and then use it as the parent of
1445 * any device which should appear under /sys/devices/{name}
1446 *
1447 * The /sys/devices/{name} directory will also contain a
1448 * 'module' symlink which points to the @owner directory
1449 * in sysfs.
1450 *
1451 * Returns &struct device pointer on success, or ERR_PTR() on error.
1452 *
1453 * Note: You probably want to use root_device_register().
1454 */
1455struct device *__root_device_register(const char *name, struct module *owner)
1456{
1457        struct root_device *root;
1458        int err = -ENOMEM;
1459
1460        root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1461        if (!root)
1462                return ERR_PTR(err);
1463
1464        err = dev_set_name(&root->dev, "%s", name);
1465        if (err) {
1466                kfree(root);
1467                return ERR_PTR(err);
1468        }
1469
1470        root->dev.release = root_device_release;
1471
1472        err = device_register(&root->dev);
1473        if (err) {
1474                put_device(&root->dev);
1475                return ERR_PTR(err);
1476        }
1477
1478#ifdef CONFIG_MODULES   /* gotta find a "cleaner" way to do this */
1479        if (owner) {
1480                struct module_kobject *mk = &owner->mkobj;
1481
1482                err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1483                if (err) {
1484                        device_unregister(&root->dev);
1485                        return ERR_PTR(err);
1486                }
1487                root->owner = owner;
1488        }
1489#endif
1490
1491        return &root->dev;
1492}
1493EXPORT_SYMBOL_GPL(__root_device_register);
1494
1495/**
1496 * root_device_unregister - unregister and free a root device
1497 * @dev: device going away
1498 *
1499 * This function unregisters and cleans up a device that was created by
1500 * root_device_register().
1501 */
1502void root_device_unregister(struct device *dev)
1503{
1504        struct root_device *root = to_root_device(dev);
1505
1506        if (root->owner)
1507                sysfs_remove_link(&root->dev.kobj, "module");
1508
1509        device_unregister(dev);
1510}
1511EXPORT_SYMBOL_GPL(root_device_unregister);
1512
1513
1514static void device_create_release(struct device *dev)
1515{
1516        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1517        kfree(dev);
1518}
1519
1520/**
1521 * device_create_vargs - creates a device and registers it with sysfs
1522 * @class: pointer to the struct class that this device should be registered to
1523 * @parent: pointer to the parent struct device of this new device, if any
1524 * @devt: the dev_t for the char device to be added
1525 * @drvdata: the data to be added to the device for callbacks
1526 * @fmt: string for the device's name
1527 * @args: va_list for the device's name
1528 *
1529 * This function can be used by char device classes.  A struct device
1530 * will be created in sysfs, registered to the specified class.
1531 *
1532 * A "dev" file will be created, showing the dev_t for the device, if
1533 * the dev_t is not 0,0.
1534 * If a pointer to a parent struct device is passed in, the newly created
1535 * struct device will be a child of that device in sysfs.
1536 * The pointer to the struct device will be returned from the call.
1537 * Any further sysfs files that might be required can be created using this
1538 * pointer.
1539 *
1540 * Returns &struct device pointer on success, or ERR_PTR() on error.
1541 *
1542 * Note: the struct class passed to this function must have previously
1543 * been created with a call to class_create().
1544 */
1545struct device *device_create_vargs(struct class *class, struct device *parent,
1546                                   dev_t devt, void *drvdata, const char *fmt,
1547                                   va_list args)
1548{
1549        struct device *dev = NULL;
1550        int retval = -ENODEV;
1551
1552        if (class == NULL || IS_ERR(class))
1553                goto error;
1554
1555        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1556        if (!dev) {
1557                retval = -ENOMEM;
1558                goto error;
1559        }
1560
1561        dev->devt = devt;
1562        dev->class = class;
1563        dev->parent = parent;
1564        dev->release = device_create_release;
1565        dev_set_drvdata(dev, drvdata);
1566
1567        retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1568        if (retval)
1569                goto error;
1570
1571        retval = device_register(dev);
1572        if (retval)
1573                goto error;
1574
1575        return dev;
1576
1577error:
1578        put_device(dev);
1579        return ERR_PTR(retval);
1580}
1581EXPORT_SYMBOL_GPL(device_create_vargs);
1582
1583/**
1584 * device_create - creates a device and registers it with sysfs
1585 * @class: pointer to the struct class that this device should be registered to
1586 * @parent: pointer to the parent struct device of this new device, if any
1587 * @devt: the dev_t for the char device to be added
1588 * @drvdata: the data to be added to the device for callbacks
1589 * @fmt: string for the device's name
1590 *
1591 * This function can be used by char device classes.  A struct device
1592 * will be created in sysfs, registered to the specified class.
1593 *
1594 * A "dev" file will be created, showing the dev_t for the device, if
1595 * the dev_t is not 0,0.
1596 * If a pointer to a parent struct device is passed in, the newly created
1597 * struct device will be a child of that device in sysfs.
1598 * The pointer to the struct device will be returned from the call.
1599 * Any further sysfs files that might be required can be created using this
1600 * pointer.
1601 *
1602 * Returns &struct device pointer on success, or ERR_PTR() on error.
1603 *
1604 * Note: the struct class passed to this function must have previously
1605 * been created with a call to class_create().
1606 */
1607struct device *device_create(struct class *class, struct device *parent,
1608                             dev_t devt, void *drvdata, const char *fmt, ...)
1609{
1610        va_list vargs;
1611        struct device *dev;
1612
1613        va_start(vargs, fmt);
1614        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1615        va_end(vargs);
1616        return dev;
1617}
1618EXPORT_SYMBOL_GPL(device_create);
1619
1620static int __match_devt(struct device *dev, const void *data)
1621{
1622        const dev_t *devt = data;
1623
1624        return dev->devt == *devt;
1625}
1626
1627/**
1628 * device_destroy - removes a device that was created with device_create()
1629 * @class: pointer to the struct class that this device was registered with
1630 * @devt: the dev_t of the device that was previously registered
1631 *
1632 * This call unregisters and cleans up a device that was created with a
1633 * call to device_create().
1634 */
1635void device_destroy(struct class *class, dev_t devt)
1636{
1637        struct device *dev;
1638
1639        dev = class_find_device(class, NULL, &devt, __match_devt);
1640        if (dev) {
1641                put_device(dev);
1642                device_unregister(dev);
1643        }
1644}
1645EXPORT_SYMBOL_GPL(device_destroy);
1646
1647/**
1648 * device_rename - renames a device
1649 * @dev: the pointer to the struct device to be renamed
1650 * @new_name: the new name of the device
1651 *
1652 * It is the responsibility of the caller to provide mutual
1653 * exclusion between two different calls of device_rename
1654 * on the same device to ensure that new_name is valid and
1655 * won't conflict with other devices.
1656 *
1657 * Note: Don't call this function.  Currently, the networking layer calls this
1658 * function, but that will change.  The following text from Kay Sievers offers
1659 * some insight:
1660 *
1661 * Renaming devices is racy at many levels, symlinks and other stuff are not
1662 * replaced atomically, and you get a "move" uevent, but it's not easy to
1663 * connect the event to the old and new device. Device nodes are not renamed at
1664 * all, there isn't even support for that in the kernel now.
1665 *
1666 * In the meantime, during renaming, your target name might be taken by another
1667 * driver, creating conflicts. Or the old name is taken directly after you
1668 * renamed it -- then you get events for the same DEVPATH, before you even see
1669 * the "move" event. It's just a mess, and nothing new should ever rely on
1670 * kernel device renaming. Besides that, it's not even implemented now for
1671 * other things than (driver-core wise very simple) network devices.
1672 *
1673 * We are currently about to change network renaming in udev to completely
1674 * disallow renaming of devices in the same namespace as the kernel uses,
1675 * because we can't solve the problems properly, that arise with swapping names
1676 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1677 * be allowed to some other name than eth[0-9]*, for the aforementioned
1678 * reasons.
1679 *
1680 * Make up a "real" name in the driver before you register anything, or add
1681 * some other attributes for userspace to find the device, or use udev to add
1682 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1683 * don't even want to get into that and try to implement the missing pieces in
1684 * the core. We really have other pieces to fix in the driver core mess. :)
1685 */
1686int device_rename(struct device *dev, const char *new_name)
1687{
1688        char *old_device_name = NULL;
1689        int error;
1690
1691        dev = get_device(dev);
1692        if (!dev)
1693                return -EINVAL;
1694
1695        pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1696                 __func__, new_name);
1697
1698        old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1699        if (!old_device_name) {
1700                error = -ENOMEM;
1701                goto out;
1702        }
1703
1704        if (dev->class) {
1705                error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1706                        &dev->kobj, old_device_name, new_name);
1707                if (error)
1708                        goto out;
1709        }
1710
1711        error = kobject_rename(&dev->kobj, new_name);
1712        if (error)
1713                goto out;
1714
1715out:
1716        put_device(dev);
1717
1718        kfree(old_device_name);
1719
1720        return error;
1721}
1722EXPORT_SYMBOL_GPL(device_rename);
1723
1724static int device_move_class_links(struct device *dev,
1725                                   struct device *old_parent,
1726                                   struct device *new_parent)
1727{
1728        int error = 0;
1729
1730        if (old_parent)
1731                sysfs_remove_link(&dev->kobj, "device");
1732        if (new_parent)
1733                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1734                                          "device");
1735        return error;
1736}
1737
1738/**
1739 * device_move - moves a device to a new parent
1740 * @dev: the pointer to the struct device to be moved
1741 * @new_parent: the new parent of the device (can by NULL)
1742 * @dpm_order: how to reorder the dpm_list
1743 */
1744int device_move(struct device *dev, struct device *new_parent,
1745                enum dpm_order dpm_order)
1746{
1747        int error;
1748        struct device *old_parent;
1749        struct kobject *new_parent_kobj;
1750
1751        dev = get_device(dev);
1752        if (!dev)
1753                return -EINVAL;
1754
1755        device_pm_lock();
1756        new_parent = get_device(new_parent);
1757        new_parent_kobj = get_device_parent(dev, new_parent);
1758
1759        pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1760                 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1761        error = kobject_move(&dev->kobj, new_parent_kobj);
1762        if (error) {
1763                cleanup_glue_dir(dev, new_parent_kobj);
1764                put_device(new_parent);
1765                goto out;
1766        }
1767        old_parent = dev->parent;
1768        dev->parent = new_parent;
1769        if (old_parent)
1770                klist_remove(&dev->p->knode_parent);
1771        if (new_parent) {
1772                klist_add_tail(&dev->p->knode_parent,
1773                               &new_parent->p->klist_children);
1774                set_dev_node(dev, dev_to_node(new_parent));
1775        }
1776
1777        if (dev->class) {
1778                error = device_move_class_links(dev, old_parent, new_parent);
1779                if (error) {
1780                        /* We ignore errors on cleanup since we're hosed anyway... */
1781                        device_move_class_links(dev, new_parent, old_parent);
1782                        if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1783                                if (new_parent)
1784                                        klist_remove(&dev->p->knode_parent);
1785                                dev->parent = old_parent;
1786                                if (old_parent) {
1787                                        klist_add_tail(&dev->p->knode_parent,
1788                                                       &old_parent->p->klist_children);
1789                                        set_dev_node(dev, dev_to_node(old_parent));
1790                                }
1791                        }
1792                        cleanup_glue_dir(dev, new_parent_kobj);
1793                        put_device(new_parent);
1794                        goto out;
1795                }
1796        }
1797        switch (dpm_order) {
1798        case DPM_ORDER_NONE:
1799                break;
1800        case DPM_ORDER_DEV_AFTER_PARENT:
1801                device_pm_move_after(dev, new_parent);
1802                break;
1803        case DPM_ORDER_PARENT_BEFORE_DEV:
1804                device_pm_move_before(new_parent, dev);
1805                break;
1806        case DPM_ORDER_DEV_LAST:
1807                device_pm_move_last(dev);
1808                break;
1809        }
1810
1811        put_device(old_parent);
1812out:
1813        device_pm_unlock();
1814        put_device(dev);
1815        return error;
1816}
1817EXPORT_SYMBOL_GPL(device_move);
1818
1819/**
1820 * device_shutdown - call ->shutdown() on each device to shutdown.
1821 */
1822void device_shutdown(void)
1823{
1824        struct device *dev;
1825
1826        spin_lock(&devices_kset->list_lock);
1827        /*
1828         * Walk the devices list backward, shutting down each in turn.
1829         * Beware that device unplug events may also start pulling
1830         * devices offline, even as the system is shutting down.
1831         */
1832        while (!list_empty(&devices_kset->list)) {
1833                dev = list_entry(devices_kset->list.prev, struct device,
1834                                kobj.entry);
1835
1836                /*
1837                 * hold reference count of device's parent to
1838                 * prevent it from being freed because parent's
1839                 * lock is to be held
1840                 */
1841                get_device(dev->parent);
1842                get_device(dev);
1843                /*
1844                 * Make sure the device is off the kset list, in the
1845                 * event that dev->*->shutdown() doesn't remove it.
1846                 */
1847                list_del_init(&dev->kobj.entry);
1848                spin_unlock(&devices_kset->list_lock);
1849
1850                /* hold lock to avoid race with probe/release */
1851                if (dev->parent)
1852                        device_lock(dev->parent);
1853                device_lock(dev);
1854
1855                /* Don't allow any more runtime suspends */
1856                pm_runtime_get_noresume(dev);
1857                pm_runtime_barrier(dev);
1858
1859                if (dev->bus && dev->bus->shutdown) {
1860                        if (initcall_debug)
1861                                dev_info(dev, "shutdown\n");
1862                        dev->bus->shutdown(dev);
1863                } else if (dev->driver && dev->driver->shutdown) {
1864                        if (initcall_debug)
1865                                dev_info(dev, "shutdown\n");
1866                        dev->driver->shutdown(dev);
1867                }
1868
1869                device_unlock(dev);
1870                if (dev->parent)
1871                        device_unlock(dev->parent);
1872
1873                put_device(dev);
1874                put_device(dev->parent);
1875
1876                spin_lock(&devices_kset->list_lock);
1877        }
1878        spin_unlock(&devices_kset->list_lock);
1879        async_synchronize_full();
1880}
1881
1882/*
1883 * Device logging functions
1884 */
1885
1886#ifdef CONFIG_PRINTK
1887static int
1888create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
1889{
1890        const char *subsys;
1891        size_t pos = 0;
1892
1893        if (dev->class)
1894                subsys = dev->class->name;
1895        else if (dev->bus)
1896                subsys = dev->bus->name;
1897        else
1898                return 0;
1899
1900        pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
1901
1902        /*
1903         * Add device identifier DEVICE=:
1904         *   b12:8         block dev_t
1905         *   c127:3        char dev_t
1906         *   n8            netdev ifindex
1907         *   +sound:card0  subsystem:devname
1908         */
1909        if (MAJOR(dev->devt)) {
1910                char c;
1911
1912                if (strcmp(subsys, "block") == 0)
1913                        c = 'b';
1914                else
1915                        c = 'c';
1916                pos++;
1917                pos += snprintf(hdr + pos, hdrlen - pos,
1918                                "DEVICE=%c%u:%u",
1919                                c, MAJOR(dev->devt), MINOR(dev->devt));
1920        } else if (strcmp(subsys, "net") == 0) {
1921                struct net_device *net = to_net_dev(dev);
1922
1923                pos++;
1924                pos += snprintf(hdr + pos, hdrlen - pos,
1925                                "DEVICE=n%u", net->ifindex);
1926        } else {
1927                pos++;
1928                pos += snprintf(hdr + pos, hdrlen - pos,
1929                                "DEVICE=+%s:%s", subsys, dev_name(dev));
1930        }
1931
1932        return pos;
1933}
1934EXPORT_SYMBOL(create_syslog_header);
1935
1936int dev_vprintk_emit(int level, const struct device *dev,
1937                     const char *fmt, va_list args)
1938{
1939        char hdr[128];
1940        size_t hdrlen;
1941
1942        hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
1943
1944        return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
1945}
1946EXPORT_SYMBOL(dev_vprintk_emit);
1947
1948int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1949{
1950        va_list args;
1951        int r;
1952
1953        va_start(args, fmt);
1954
1955        r = dev_vprintk_emit(level, dev, fmt, args);
1956
1957        va_end(args);
1958
1959        return r;
1960}
1961EXPORT_SYMBOL(dev_printk_emit);
1962
1963static int __dev_printk(const char *level, const struct device *dev,
1964                        struct va_format *vaf)
1965{
1966        if (!dev)
1967                return printk("%s(NULL device *): %pV", level, vaf);
1968
1969        return dev_printk_emit(level[1] - '0', dev,
1970                               "%s %s: %pV",
1971                               dev_driver_string(dev), dev_name(dev), vaf);
1972}
1973
1974int dev_printk(const char *level, const struct device *dev,
1975               const char *fmt, ...)
1976{
1977        struct va_format vaf;
1978        va_list args;
1979        int r;
1980
1981        va_start(args, fmt);
1982
1983        vaf.fmt = fmt;
1984        vaf.va = &args;
1985
1986        r = __dev_printk(level, dev, &vaf);
1987
1988        va_end(args);
1989
1990        return r;
1991}
1992EXPORT_SYMBOL(dev_printk);
1993
1994#define define_dev_printk_level(func, kern_level)               \
1995int func(const struct device *dev, const char *fmt, ...)        \
1996{                                                               \
1997        struct va_format vaf;                                   \
1998        va_list args;                                           \
1999        int r;                                                  \
2000                                                                \
2001        va_start(args, fmt);                                    \
2002                                                                \
2003        vaf.fmt = fmt;                                          \
2004        vaf.va = &args;                                         \
2005                                                                \
2006        r = __dev_printk(kern_level, dev, &vaf);                \
2007                                                                \
2008        va_end(args);                                           \
2009                                                                \
2010        return r;                                               \
2011}                                                               \
2012EXPORT_SYMBOL(func);
2013
2014define_dev_printk_level(dev_emerg, KERN_EMERG);
2015define_dev_printk_level(dev_alert, KERN_ALERT);
2016define_dev_printk_level(dev_crit, KERN_CRIT);
2017define_dev_printk_level(dev_err, KERN_ERR);
2018define_dev_printk_level(dev_warn, KERN_WARNING);
2019define_dev_printk_level(dev_notice, KERN_NOTICE);
2020define_dev_printk_level(_dev_info, KERN_INFO);
2021
2022#endif
2023
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