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