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                kuid_t uid = GLOBAL_ROOT_UID;
 287                kgid_t gid = GLOBAL_ROOT_GID;
 288
 289                add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 290                add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 291                name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
 292                if (name) {
 293                        add_uevent_var(env, "DEVNAME=%s", name);
 294                        if (mode)
 295                                add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
 296                        if (!uid_eq(uid, GLOBAL_ROOT_UID))
 297                                add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
 298                        if (!gid_eq(gid, GLOBAL_ROOT_GID))
 299                                add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
 300                        kfree(tmp);
 301                }
 302        }
 303
 304        if (dev->type && dev->type->name)
 305                add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 306
 307        if (dev->driver)
 308                add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 309
 310        /* Add common DT information about the device */
 311        of_device_uevent(dev, env);
 312
 313        /* have the bus specific function add its stuff */
 314        if (dev->bus && dev->bus->uevent) {
 315                retval = dev->bus->uevent(dev, env);
 316                if (retval)
 317                        pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 318                                 dev_name(dev), __func__, retval);
 319        }
 320
 321        /* have the class specific function add its stuff */
 322        if (dev->class && dev->class->dev_uevent) {
 323                retval = dev->class->dev_uevent(dev, env);
 324                if (retval)
 325                        pr_debug("device: '%s': %s: class uevent() "
 326                                 "returned %d\n", dev_name(dev),
 327                                 __func__, retval);
 328        }
 329
 330        /* have the device type specific function add its stuff */
 331        if (dev->type && dev->type->uevent) {
 332                retval = dev->type->uevent(dev, env);
 333                if (retval)
 334                        pr_debug("device: '%s': %s: dev_type uevent() "
 335                                 "returned %d\n", dev_name(dev),
 336                                 __func__, retval);
 337        }
 338
 339        return retval;
 340}
 341
 342static const struct kset_uevent_ops device_uevent_ops = {
 343        .filter =       dev_uevent_filter,
 344        .name =         dev_uevent_name,
 345        .uevent =       dev_uevent,
 346};
 347
 348static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
 349                           char *buf)
 350{
 351        struct kobject *top_kobj;
 352        struct kset *kset;
 353        struct kobj_uevent_env *env = NULL;
 354        int i;
 355        size_t count = 0;
 356        int retval;
 357
 358        /* search the kset, the device belongs to */
 359        top_kobj = &dev->kobj;
 360        while (!top_kobj->kset && top_kobj->parent)
 361                top_kobj = top_kobj->parent;
 362        if (!top_kobj->kset)
 363                goto out;
 364
 365        kset = top_kobj->kset;
 366        if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 367                goto out;
 368
 369        /* respect filter */
 370        if (kset->uevent_ops && kset->uevent_ops->filter)
 371                if (!kset->uevent_ops->filter(kset, &dev->kobj))
 372                        goto out;
 373
 374        env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 375        if (!env)
 376                return -ENOMEM;
 377
 378        /* let the kset specific function add its keys */
 379        retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 380        if (retval)
 381                goto out;
 382
 383        /* copy keys to file */
 384        for (i = 0; i < env->envp_idx; i++)
 385                count += sprintf(&buf[count], "%s\n", env->envp[i]);
 386out:
 387        kfree(env);
 388        return count;
 389}
 390
 391static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
 392                            const char *buf, size_t count)
 393{
 394        enum kobject_action action;
 395
 396        if (kobject_action_type(buf, count, &action) == 0)
 397                kobject_uevent(&dev->kobj, action);
 398        else
 399                dev_err(dev, "uevent: unknown action-string\n");
 400        return count;
 401}
 402
 403static struct device_attribute uevent_attr =
 404        __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
 405
 406static int device_add_attributes(struct device *dev,
 407                                 struct device_attribute *attrs)
 408{
 409        int error = 0;
 410        int i;
 411
 412        if (attrs) {
 413                for (i = 0; attr_name(attrs[i]); i++) {
 414                        error = device_create_file(dev, &attrs[i]);
 415                        if (error)
 416                                break;
 417                }
 418                if (error)
 419                        while (--i >= 0)
 420                                device_remove_file(dev, &attrs[i]);
 421        }
 422        return error;
 423}
 424
 425static void device_remove_attributes(struct device *dev,
 426                                     struct device_attribute *attrs)
 427{
 428        int i;
 429
 430        if (attrs)
 431                for (i = 0; attr_name(attrs[i]); i++)
 432                        device_remove_file(dev, &attrs[i]);
 433}
 434
 435static int device_add_bin_attributes(struct device *dev,
 436                                     struct bin_attribute *attrs)
 437{
 438        int error = 0;
 439        int i;
 440
 441        if (attrs) {
 442                for (i = 0; attr_name(attrs[i]); i++) {
 443                        error = device_create_bin_file(dev, &attrs[i]);
 444                        if (error)
 445                                break;
 446                }
 447                if (error)
 448                        while (--i >= 0)
 449                                device_remove_bin_file(dev, &attrs[i]);
 450        }
 451        return error;
 452}
 453
 454static void device_remove_bin_attributes(struct device *dev,
 455                                         struct bin_attribute *attrs)
 456{
 457        int i;
 458
 459        if (attrs)
 460                for (i = 0; attr_name(attrs[i]); i++)
 461                        device_remove_bin_file(dev, &attrs[i]);
 462}
 463
 464static int device_add_groups(struct device *dev,
 465                             const struct attribute_group **groups)
 466{
 467        int error = 0;
 468        int i;
 469
 470        if (groups) {
 471                for (i = 0; groups[i]; i++) {
 472                        error = sysfs_create_group(&dev->kobj, groups[i]);
 473                        if (error) {
 474                                while (--i >= 0)
 475                                        sysfs_remove_group(&dev->kobj,
 476                                                           groups[i]);
 477                                break;
 478                        }
 479                }
 480        }
 481        return error;
 482}
 483
 484static void device_remove_groups(struct device *dev,
 485                                 const struct attribute_group **groups)
 486{
 487        int i;
 488
 489        if (groups)
 490                for (i = 0; groups[i]; i++)
 491                        sysfs_remove_group(&dev->kobj, groups[i]);
 492}
 493
 494static int device_add_attrs(struct device *dev)
 495{
 496        struct class *class = dev->class;
 497        const struct device_type *type = dev->type;
 498        int error;
 499
 500        if (class) {
 501                error = device_add_attributes(dev, class->dev_attrs);
 502                if (error)
 503                        return error;
 504                error = device_add_bin_attributes(dev, class->dev_bin_attrs);
 505                if (error)
 506                        goto err_remove_class_attrs;
 507        }
 508
 509        if (type) {
 510                error = device_add_groups(dev, type->groups);
 511                if (error)
 512                        goto err_remove_class_bin_attrs;
 513        }
 514
 515        error = device_add_groups(dev, dev->groups);
 516        if (error)
 517                goto err_remove_type_groups;
 518
 519        return 0;
 520
 521 err_remove_type_groups:
 522        if (type)
 523                device_remove_groups(dev, type->groups);
 524 err_remove_class_bin_attrs:
 525        if (class)
 526                device_remove_bin_attributes(dev, class->dev_bin_attrs);
 527 err_remove_class_attrs:
 528        if (class)
 529                device_remove_attributes(dev, class->dev_attrs);
 530
 531        return error;
 532}
 533
 534static void device_remove_attrs(struct device *dev)
 535{
 536        struct class *class = dev->class;
 537        const struct device_type *type = dev->type;
 538
 539        device_remove_groups(dev, dev->groups);
 540
 541        if (type)
 542                device_remove_groups(dev, type->groups);
 543
 544        if (class) {
 545                device_remove_attributes(dev, class->dev_attrs);
 546                device_remove_bin_attributes(dev, class->dev_bin_attrs);
 547        }
 548}
 549
 550
 551static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
 552                        char *buf)
 553{
 554        return print_dev_t(buf, dev->devt);
 555}
 556
 557static struct device_attribute devt_attr =
 558        __ATTR(dev, S_IRUGO, show_dev, NULL);
 559
 560/* /sys/devices/ */
 561struct kset *devices_kset;
 562
 563/**
 564 * device_create_file - create sysfs attribute file for device.
 565 * @dev: device.
 566 * @attr: device attribute descriptor.
 567 */
 568int device_create_file(struct device *dev,
 569                       const struct device_attribute *attr)
 570{
 571        int error = 0;
 572
 573        if (dev) {
 574                WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
 575                        "Attribute %s: write permission without 'store'\n",
 576                        attr->attr.name);
 577                WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
 578                        "Attribute %s: read permission without 'show'\n",
 579                        attr->attr.name);
 580                error = sysfs_create_file(&dev->kobj, &attr->attr);
 581        }
 582
 583        return error;
 584}
 585
 586/**
 587 * device_remove_file - remove sysfs attribute file.
 588 * @dev: device.
 589 * @attr: device attribute descriptor.
 590 */
 591void device_remove_file(struct device *dev,
 592                        const struct device_attribute *attr)
 593{
 594        if (dev)
 595                sysfs_remove_file(&dev->kobj, &attr->attr);
 596}
 597
 598/**
 599 * device_create_bin_file - create sysfs binary attribute file for device.
 600 * @dev: device.
 601 * @attr: device binary attribute descriptor.
 602 */
 603int device_create_bin_file(struct device *dev,
 604                           const struct bin_attribute *attr)
 605{
 606        int error = -EINVAL;
 607        if (dev)
 608                error = sysfs_create_bin_file(&dev->kobj, attr);
 609        return error;
 610}
 611EXPORT_SYMBOL_GPL(device_create_bin_file);
 612
 613/**
 614 * device_remove_bin_file - remove sysfs binary attribute file
 615 * @dev: device.
 616 * @attr: device binary attribute descriptor.
 617 */
 618void device_remove_bin_file(struct device *dev,
 619                            const struct bin_attribute *attr)
 620{
 621        if (dev)
 622                sysfs_remove_bin_file(&dev->kobj, attr);
 623}
 624EXPORT_SYMBOL_GPL(device_remove_bin_file);
 625
 626/**
 627 * device_schedule_callback_owner - helper to schedule a callback for a device
 628 * @dev: device.
 629 * @func: callback function to invoke later.
 630 * @owner: module owning the callback routine
 631 *
 632 * Attribute methods must not unregister themselves or their parent device
 633 * (which would amount to the same thing).  Attempts to do so will deadlock,
 634 * since unregistration is mutually exclusive with driver callbacks.
 635 *
 636 * Instead methods can call this routine, which will attempt to allocate
 637 * and schedule a workqueue request to call back @func with @dev as its
 638 * argument in the workqueue's process context.  @dev will be pinned until
 639 * @func returns.
 640 *
 641 * This routine is usually called via the inline device_schedule_callback(),
 642 * which automatically sets @owner to THIS_MODULE.
 643 *
 644 * Returns 0 if the request was submitted, -ENOMEM if storage could not
 645 * be allocated, -ENODEV if a reference to @owner isn't available.
 646 *
 647 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 648 * underlying sysfs routine (since it is intended for use by attribute
 649 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 650 */
 651int device_schedule_callback_owner(struct device *dev,
 652                void (*func)(struct device *), struct module *owner)
 653{
 654        return sysfs_schedule_callback(&dev->kobj,
 655                        (void (*)(void *)) func, dev, owner);
 656}
 657EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
 658
 659static void klist_children_get(struct klist_node *n)
 660{
 661        struct device_private *p = to_device_private_parent(n);
 662        struct device *dev = p->device;
 663
 664        get_device(dev);
 665}
 666
 667static void klist_children_put(struct klist_node *n)
 668{
 669        struct device_private *p = to_device_private_parent(n);
 670        struct device *dev = p->device;
 671
 672        put_device(dev);
 673}
 674
 675/**
 676 * device_initialize - init device structure.
 677 * @dev: device.
 678 *
 679 * This prepares the device for use by other layers by initializing
 680 * its fields.
 681 * It is the first half of device_register(), if called by
 682 * that function, though it can also be called separately, so one
 683 * may use @dev's fields. In particular, get_device()/put_device()
 684 * may be used for reference counting of @dev after calling this
 685 * function.
 686 *
 687 * All fields in @dev must be initialized by the caller to 0, except
 688 * for those explicitly set to some other value.  The simplest
 689 * approach is to use kzalloc() to allocate the structure containing
 690 * @dev.
 691 *
 692 * NOTE: Use put_device() to give up your reference instead of freeing
 693 * @dev directly once you have called this function.
 694 */
 695void device_initialize(struct device *dev)
 696{
 697        dev->kobj.kset = devices_kset;
 698        kobject_init(&dev->kobj, &device_ktype);
 699        INIT_LIST_HEAD(&dev->dma_pools);
 700        mutex_init(&dev->mutex);
 701        lockdep_set_novalidate_class(&dev->mutex);
 702        spin_lock_init(&dev->devres_lock);
 703        INIT_LIST_HEAD(&dev->devres_head);
 704        device_pm_init(dev);
 705        set_dev_node(dev, -1);
 706}
 707
 708struct kobject *virtual_device_parent(struct device *dev)
 709{
 710        static struct kobject *virtual_dir = NULL;
 711
 712        if (!virtual_dir)
 713                virtual_dir = kobject_create_and_add("virtual",
 714                                                     &devices_kset->kobj);
 715
 716        return virtual_dir;
 717}
 718
 719struct class_dir {
 720        struct kobject kobj;
 721        struct class *class;
 722};
 723
 724#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
 725
 726static void class_dir_release(struct kobject *kobj)
 727{
 728        struct class_dir *dir = to_class_dir(kobj);
 729        kfree(dir);
 730}
 731
 732static const
 733struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
 734{
 735        struct class_dir *dir = to_class_dir(kobj);
 736        return dir->class->ns_type;
 737}
 738
 739static struct kobj_type class_dir_ktype = {
 740        .release        = class_dir_release,
 741        .sysfs_ops      = &kobj_sysfs_ops,
 742        .child_ns_type  = class_dir_child_ns_type
 743};
 744
 745static struct kobject *
 746class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 747{
 748        struct class_dir *dir;
 749        int retval;
 750
 751        dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 752        if (!dir)
 753                return NULL;
 754
 755        dir->class = class;
 756        kobject_init(&dir->kobj, &class_dir_ktype);
 757
 758        dir->kobj.kset = &class->p->glue_dirs;
 759
 760        retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
 761        if (retval < 0) {
 762                kobject_put(&dir->kobj);
 763                return NULL;
 764        }
 765        return &dir->kobj;
 766}
 767
 768
 769static struct kobject *get_device_parent(struct device *dev,
 770                                         struct device *parent)
 771{
 772        if (dev->class) {
 773                static DEFINE_MUTEX(gdp_mutex);
 774                struct kobject *kobj = NULL;
 775                struct kobject *parent_kobj;
 776                struct kobject *k;
 777
 778#ifdef CONFIG_BLOCK
 779                /* block disks show up in /sys/block */
 780                if (sysfs_deprecated && dev->class == &block_class) {
 781                        if (parent && parent->class == &block_class)
 782                                return &parent->kobj;
 783                        return &block_class.p->subsys.kobj;
 784                }
 785#endif
 786
 787                /*
 788                 * If we have no parent, we live in "virtual".
 789                 * Class-devices with a non class-device as parent, live
 790                 * in a "glue" directory to prevent namespace collisions.
 791                 */
 792                if (parent == NULL)
 793                        parent_kobj = virtual_device_parent(dev);
 794                else if (parent->class && !dev->class->ns_type)
 795                        return &parent->kobj;
 796                else
 797                        parent_kobj = &parent->kobj;
 798
 799                mutex_lock(&gdp_mutex);
 800
 801                /* find our class-directory at the parent and reference it */
 802                spin_lock(&dev->class->p->glue_dirs.list_lock);
 803                list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
 804                        if (k->parent == parent_kobj) {
 805                                kobj = kobject_get(k);
 806                                break;
 807                        }
 808                spin_unlock(&dev->class->p->glue_dirs.list_lock);
 809                if (kobj) {
 810                        mutex_unlock(&gdp_mutex);
 811                        return kobj;
 812                }
 813
 814                /* or create a new class-directory at the parent device */
 815                k = class_dir_create_and_add(dev->class, parent_kobj);
 816                /* do not emit an uevent for this simple "glue" directory */
 817                mutex_unlock(&gdp_mutex);
 818                return k;
 819        }
 820
 821        /* subsystems can specify a default root directory for their devices */
 822        if (!parent && dev->bus && dev->bus->dev_root)
 823                return &dev->bus->dev_root->kobj;
 824
 825        if (parent)
 826                return &parent->kobj;
 827        return NULL;
 828}
 829
 830static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 831{
 832        /* see if we live in a "glue" directory */
 833        if (!glue_dir || !dev->class ||
 834            glue_dir->kset != &dev->class->p->glue_dirs)
 835                return;
 836
 837        kobject_put(glue_dir);
 838}
 839
 840static void cleanup_device_parent(struct device *dev)
 841{
 842        cleanup_glue_dir(dev, dev->kobj.parent);
 843}
 844
 845static int device_add_class_symlinks(struct device *dev)
 846{
 847        int error;
 848
 849        if (!dev->class)
 850                return 0;
 851
 852        error = sysfs_create_link(&dev->kobj,
 853                                  &dev->class->p->subsys.kobj,
 854                                  "subsystem");
 855        if (error)
 856                goto out;
 857
 858        if (dev->parent && device_is_not_partition(dev)) {
 859                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 860                                          "device");
 861                if (error)
 862                        goto out_subsys;
 863        }
 864
 865#ifdef CONFIG_BLOCK
 866        /* /sys/block has directories and does not need symlinks */
 867        if (sysfs_deprecated && dev->class == &block_class)
 868                return 0;
 869#endif
 870
 871        /* link in the class directory pointing to the device */
 872        error = sysfs_create_link(&dev->class->p->subsys.kobj,
 873                                  &dev->kobj, dev_name(dev));
 874        if (error)
 875                goto out_device;
 876
 877        return 0;
 878
 879out_device:
 880        sysfs_remove_link(&dev->kobj, "device");
 881
 882out_subsys:
 883        sysfs_remove_link(&dev->kobj, "subsystem");
 884out:
 885        return error;
 886}
 887
 888static void device_remove_class_symlinks(struct device *dev)
 889{
 890        if (!dev->class)
 891                return;
 892
 893        if (dev->parent && device_is_not_partition(dev))
 894                sysfs_remove_link(&dev->kobj, "device");
 895        sysfs_remove_link(&dev->kobj, "subsystem");
 896#ifdef CONFIG_BLOCK
 897        if (sysfs_deprecated && dev->class == &block_class)
 898                return;
 899#endif
 900        sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
 901}
 902
 903/**
 904 * dev_set_name - set a device name
 905 * @dev: device
 906 * @fmt: format string for the device's name
 907 */
 908int dev_set_name(struct device *dev, const char *fmt, ...)
 909{
 910        va_list vargs;
 911        int err;
 912
 913        va_start(vargs, fmt);
 914        err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
 915        va_end(vargs);
 916        return err;
 917}
 918EXPORT_SYMBOL_GPL(dev_set_name);
 919
 920/**
 921 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 922 * @dev: device
 923 *
 924 * By default we select char/ for new entries.  Setting class->dev_obj
 925 * to NULL prevents an entry from being created.  class->dev_kobj must
 926 * be set (or cleared) before any devices are registered to the class
 927 * otherwise device_create_sys_dev_entry() and
 928 * device_remove_sys_dev_entry() will disagree about the presence of
 929 * the link.
 930 */
 931static struct kobject *device_to_dev_kobj(struct device *dev)
 932{
 933        struct kobject *kobj;
 934
 935        if (dev->class)
 936                kobj = dev->class->dev_kobj;
 937        else
 938                kobj = sysfs_dev_char_kobj;
 939
 940        return kobj;
 941}
 942
 943static int device_create_sys_dev_entry(struct device *dev)
 944{
 945        struct kobject *kobj = device_to_dev_kobj(dev);
 946        int error = 0;
 947        char devt_str[15];
 948
 949        if (kobj) {
 950                format_dev_t(devt_str, dev->devt);
 951                error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 952        }
 953
 954        return error;
 955}
 956
 957static void device_remove_sys_dev_entry(struct device *dev)
 958{
 959        struct kobject *kobj = device_to_dev_kobj(dev);
 960        char devt_str[15];
 961
 962        if (kobj) {
 963                format_dev_t(devt_str, dev->devt);
 964                sysfs_remove_link(kobj, devt_str);
 965        }
 966}
 967
 968int device_private_init(struct device *dev)
 969{
 970        dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
 971        if (!dev->p)
 972                return -ENOMEM;
 973        dev->p->device = dev;
 974        klist_init(&dev->p->klist_children, klist_children_get,
 975                   klist_children_put);
 976        INIT_LIST_HEAD(&dev->p->deferred_probe);
 977        return 0;
 978}
 979
 980/**
 981 * device_add - add device to device hierarchy.
 982 * @dev: device.
 983 *
 984 * This is part 2 of device_register(), though may be called
 985 * separately _iff_ device_initialize() has been called separately.
 986 *
 987 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
 988 * to the global and sibling lists for the device, then
 989 * adds it to the other relevant subsystems of the driver model.
 990 *
 991 * Do not call this routine or device_register() more than once for
 992 * any device structure.  The driver model core is not designed to work
 993 * with devices that get unregistered and then spring back to life.
 994 * (Among other things, it's very hard to guarantee that all references
 995 * to the previous incarnation of @dev have been dropped.)  Allocate
 996 * and register a fresh new struct device instead.
 997 *
 998 * NOTE: _Never_ directly free @dev after calling this function, even
 999 * if it returned an error! Always use put_device() to give up your
1000 * reference instead.
1001 */
1002int device_add(struct device *dev)
1003{
1004        struct device *parent = NULL;
1005        struct kobject *kobj;
1006        struct class_interface *class_intf;
1007        int error = -EINVAL;
1008
1009        dev = get_device(dev);
1010        if (!dev)
1011                goto done;
1012
1013        if (!dev->p) {
1014                error = device_private_init(dev);
1015                if (error)
1016                        goto done;
1017        }
1018
1019        /*
1020         * for statically allocated devices, which should all be converted
1021         * some day, we need to initialize the name. We prevent reading back
1022         * the name, and force the use of dev_name()
1023         */
1024        if (dev->init_name) {
1025                dev_set_name(dev, "%s", dev->init_name);
1026                dev->init_name = NULL;
1027        }
1028
1029        /* subsystems can specify simple device enumeration */
1030        if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1031                dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1032
1033        if (!dev_name(dev)) {
1034                error = -EINVAL;
1035                goto name_error;
1036        }
1037
1038        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1039
1040        parent = get_device(dev->parent);
1041        kobj = get_device_parent(dev, parent);
1042        if (kobj)
1043                dev->kobj.parent = kobj;
1044
1045        /* use parent numa_node */
1046        if (parent)
1047                set_dev_node(dev, dev_to_node(parent));
1048
1049        /* first, register with generic layer. */
1050        /* we require the name to be set before, and pass NULL */
1051        error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1052        if (error)
1053                goto Error;
1054
1055        /* notify platform of device entry */
1056        if (platform_notify)
1057                platform_notify(dev);
1058
1059        error = device_create_file(dev, &uevent_attr);
1060        if (error)
1061                goto attrError;
1062
1063        if (MAJOR(dev->devt)) {
1064                error = device_create_file(dev, &devt_attr);
1065                if (error)
1066                        goto ueventattrError;
1067
1068                error = device_create_sys_dev_entry(dev);
1069                if (error)
1070                        goto devtattrError;
1071
1072                devtmpfs_create_node(dev);
1073        }
1074
1075        error = device_add_class_symlinks(dev);
1076        if (error)
1077                goto SymlinkError;
1078        error = device_add_attrs(dev);
1079        if (error)
1080                goto AttrsError;
1081        error = bus_add_device(dev);
1082        if (error)
1083                goto BusError;
1084        error = dpm_sysfs_add(dev);
1085        if (error)
1086                goto DPMError;
1087        device_pm_add(dev);
1088
1089        /* Notify clients of device addition.  This call must come
1090         * after dpm_sysfs_add() and before kobject_uevent().
1091         */
1092        if (dev->bus)
1093                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1094                                             BUS_NOTIFY_ADD_DEVICE, dev);
1095
1096        kobject_uevent(&dev->kobj, KOBJ_ADD);
1097        bus_probe_device(dev);
1098        if (parent)
1099                klist_add_tail(&dev->p->knode_parent,
1100                               &parent->p->klist_children);
1101
1102        if (dev->class) {
1103                mutex_lock(&dev->class->p->mutex);
1104                /* tie the class to the device */
1105                klist_add_tail(&dev->knode_class,
1106                               &dev->class->p->klist_devices);
1107
1108                /* notify any interfaces that the device is here */
1109                list_for_each_entry(class_intf,
1110                                    &dev->class->p->interfaces, node)
1111                        if (class_intf->add_dev)
1112                                class_intf->add_dev(dev, class_intf);
1113                mutex_unlock(&dev->class->p->mutex);
1114        }
1115done:
1116        put_device(dev);
1117        return error;
1118 DPMError:
1119        bus_remove_device(dev);
1120 BusError:
1121        device_remove_attrs(dev);
1122 AttrsError:
1123        device_remove_class_symlinks(dev);
1124 SymlinkError:
1125        if (MAJOR(dev->devt))
1126                devtmpfs_delete_node(dev);
1127        if (MAJOR(dev->devt))
1128                device_remove_sys_dev_entry(dev);
1129 devtattrError:
1130        if (MAJOR(dev->devt))
1131                device_remove_file(dev, &devt_attr);
1132 ueventattrError:
1133        device_remove_file(dev, &uevent_attr);
1134 attrError:
1135        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1136        kobject_del(&dev->kobj);
1137 Error:
1138        cleanup_device_parent(dev);
1139        if (parent)
1140                put_device(parent);
1141name_error:
1142        kfree(dev->p);
1143        dev->p = NULL;
1144        goto done;
1145}
1146
1147/**
1148 * device_register - register a device with the system.
1149 * @dev: pointer to the device structure
1150 *
1151 * This happens in two clean steps - initialize the device
1152 * and add it to the system. The two steps can be called
1153 * separately, but this is the easiest and most common.
1154 * I.e. you should only call the two helpers separately if
1155 * have a clearly defined need to use and refcount the device
1156 * before it is added to the hierarchy.
1157 *
1158 * For more information, see the kerneldoc for device_initialize()
1159 * and device_add().
1160 *
1161 * NOTE: _Never_ directly free @dev after calling this function, even
1162 * if it returned an error! Always use put_device() to give up the
1163 * reference initialized in this function instead.
1164 */
1165int device_register(struct device *dev)
1166{
1167        device_initialize(dev);
1168        return device_add(dev);
1169}
1170
1171/**
1172 * get_device - increment reference count for device.
1173 * @dev: device.
1174 *
1175 * This simply forwards the call to kobject_get(), though
1176 * we do take care to provide for the case that we get a NULL
1177 * pointer passed in.
1178 */
1179struct device *get_device(struct device *dev)
1180{
1181        return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1182}
1183
1184/**
1185 * put_device - decrement reference count.
1186 * @dev: device in question.
1187 */
1188void put_device(struct device *dev)
1189{
1190        /* might_sleep(); */
1191        if (dev)
1192                kobject_put(&dev->kobj);
1193}
1194
1195/**
1196 * device_del - delete device from system.
1197 * @dev: device.
1198 *
1199 * This is the first part of the device unregistration
1200 * sequence. This removes the device from the lists we control
1201 * from here, has it removed from the other driver model
1202 * subsystems it was added to in device_add(), and removes it
1203 * from the kobject hierarchy.
1204 *
1205 * NOTE: this should be called manually _iff_ device_add() was
1206 * also called manually.
1207 */
1208void device_del(struct device *dev)
1209{
1210        struct device *parent = dev->parent;
1211        struct class_interface *class_intf;
1212
1213        /* Notify clients of device removal.  This call must come
1214         * before dpm_sysfs_remove().
1215         */
1216        if (dev->bus)
1217                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1218                                             BUS_NOTIFY_DEL_DEVICE, dev);
1219        dpm_sysfs_remove(dev);
1220        if (parent)
1221                klist_del(&dev->p->knode_parent);
1222        if (MAJOR(dev->devt)) {
1223                devtmpfs_delete_node(dev);
1224                device_remove_sys_dev_entry(dev);
1225                device_remove_file(dev, &devt_attr);
1226        }
1227        if (dev->class) {
1228                device_remove_class_symlinks(dev);
1229
1230                mutex_lock(&dev->class->p->mutex);
1231                /* notify any interfaces that the device is now gone */
1232                list_for_each_entry(class_intf,
1233                                    &dev->class->p->interfaces, node)
1234                        if (class_intf->remove_dev)
1235                                class_intf->remove_dev(dev, class_intf);
1236                /* remove the device from the class list */
1237                klist_del(&dev->knode_class);
1238                mutex_unlock(&dev->class->p->mutex);
1239        }
1240        device_remove_file(dev, &uevent_attr);
1241        device_remove_attrs(dev);
1242        bus_remove_device(dev);
1243        device_pm_remove(dev);
1244        driver_deferred_probe_del(dev);
1245
1246        /* Notify the platform of the removal, in case they
1247         * need to do anything...
1248         */
1249        if (platform_notify_remove)
1250                platform_notify_remove(dev);
1251        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1252        cleanup_device_parent(dev);
1253        kobject_del(&dev->kobj);
1254        put_device(parent);
1255}
1256
1257/**
1258 * device_unregister - unregister device from system.
1259 * @dev: device going away.
1260 *
1261 * We do this in two parts, like we do device_register(). First,
1262 * we remove it from all the subsystems with device_del(), then
1263 * we decrement the reference count via put_device(). If that
1264 * is the final reference count, the device will be cleaned up
1265 * via device_release() above. Otherwise, the structure will
1266 * stick around until the final reference to the device is dropped.
1267 */
1268void device_unregister(struct device *dev)
1269{
1270        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1271        device_del(dev);
1272        put_device(dev);
1273}
1274
1275static struct device *next_device(struct klist_iter *i)
1276{
1277        struct klist_node *n = klist_next(i);
1278        struct device *dev = NULL;
1279        struct device_private *p;
1280
1281        if (n) {
1282                p = to_device_private_parent(n);
1283                dev = p->device;
1284        }
1285        return dev;
1286}
1287
1288/**
1289 * device_get_devnode - path of device node file
1290 * @dev: device
1291 * @mode: returned file access mode
1292 * @uid: returned file owner
1293 * @gid: returned file group
1294 * @tmp: possibly allocated string
1295 *
1296 * Return the relative path of a possible device node.
1297 * Non-default names may need to allocate a memory to compose
1298 * a name. This memory is returned in tmp and needs to be
1299 * freed by the caller.
1300 */
1301const char *device_get_devnode(struct device *dev,
1302                               umode_t *mode, kuid_t *uid, kgid_t *gid,
1303                               const char **tmp)
1304{
1305        char *s;
1306
1307        *tmp = NULL;
1308
1309        /* the device type may provide a specific name */
1310        if (dev->type && dev->type->devnode)
1311                *tmp = dev->type->devnode(dev, mode, uid, gid);
1312        if (*tmp)
1313                return *tmp;
1314
1315        /* the class may provide a specific name */
1316        if (dev->class && dev->class->devnode)
1317                *tmp = dev->class->devnode(dev, mode);
1318        if (*tmp)
1319                return *tmp;
1320
1321        /* return name without allocation, tmp == NULL */
1322        if (strchr(dev_name(dev), '!') == NULL)
1323                return dev_name(dev);
1324
1325        /* replace '!' in the name with '/' */
1326        *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1327        if (!*tmp)
1328                return NULL;
1329        while ((s = strchr(*tmp, '!')))
1330                s[0] = '/';
1331        return *tmp;
1332}
1333
1334/**
1335 * device_for_each_child - device child iterator.
1336 * @parent: parent struct device.
1337 * @data: data for the callback.
1338 * @fn: function to be called for each device.
1339 *
1340 * Iterate over @parent's child devices, and call @fn for each,
1341 * passing it @data.
1342 *
1343 * We check the return of @fn each time. If it returns anything
1344 * other than 0, we break out and return that value.
1345 */
1346int device_for_each_child(struct device *parent, void *data,
1347                          int (*fn)(struct device *dev, void *data))
1348{
1349        struct klist_iter i;
1350        struct device *child;
1351        int error = 0;
1352
1353        if (!parent->p)
1354                return 0;
1355
1356        klist_iter_init(&parent->p->klist_children, &i);
1357        while ((child = next_device(&i)) && !error)
1358                error = fn(child, data);
1359        klist_iter_exit(&i);
1360        return error;
1361}
1362
1363/**
1364 * device_find_child - device iterator for locating a particular device.
1365 * @parent: parent struct device
1366 * @data: Data to pass to match function
1367 * @match: Callback function to check device
1368 *
1369 * This is similar to the device_for_each_child() function above, but it
1370 * returns a reference to a device that is 'found' for later use, as
1371 * determined by the @match callback.
1372 *
1373 * The callback should return 0 if the device doesn't match and non-zero
1374 * if it does.  If the callback returns non-zero and a reference to the
1375 * current device can be obtained, this function will return to the caller
1376 * and not iterate over any more devices.
1377 */
1378struct device *device_find_child(struct device *parent, void *data,
1379                                 int (*match)(struct device *dev, void *data))
1380{
1381        struct klist_iter i;
1382        struct device *child;
1383
1384        if (!parent)
1385                return NULL;
1386
1387        klist_iter_init(&parent->p->klist_children, &i);
1388        while ((child = next_device(&i)))
1389                if (match(child, data) && get_device(child))
1390                        break;
1391        klist_iter_exit(&i);
1392        return child;
1393}
1394
1395int __init devices_init(void)
1396{
1397        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1398        if (!devices_kset)
1399                return -ENOMEM;
1400        dev_kobj = kobject_create_and_add("dev", NULL);
1401        if (!dev_kobj)
1402                goto dev_kobj_err;
1403        sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1404        if (!sysfs_dev_block_kobj)
1405                goto block_kobj_err;
1406        sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1407        if (!sysfs_dev_char_kobj)
1408                goto char_kobj_err;
1409
1410        return 0;
1411
1412 char_kobj_err:
1413        kobject_put(sysfs_dev_block_kobj);
1414 block_kobj_err:
1415        kobject_put(dev_kobj);
1416 dev_kobj_err:
1417        kset_unregister(devices_kset);
1418        return -ENOMEM;
1419}
1420
1421EXPORT_SYMBOL_GPL(device_for_each_child);
1422EXPORT_SYMBOL_GPL(device_find_child);
1423
1424EXPORT_SYMBOL_GPL(device_initialize);
1425EXPORT_SYMBOL_GPL(device_add);
1426EXPORT_SYMBOL_GPL(device_register);
1427
1428EXPORT_SYMBOL_GPL(device_del);
1429EXPORT_SYMBOL_GPL(device_unregister);
1430EXPORT_SYMBOL_GPL(get_device);
1431EXPORT_SYMBOL_GPL(put_device);
1432
1433EXPORT_SYMBOL_GPL(device_create_file);
1434EXPORT_SYMBOL_GPL(device_remove_file);
1435
1436struct root_device {
1437        struct device dev;
1438        struct module *owner;
1439};
1440
1441static inline struct root_device *to_root_device(struct device *d)
1442{
1443        return container_of(d, struct root_device, dev);
1444}
1445
1446static void root_device_release(struct device *dev)
1447{
1448        kfree(to_root_device(dev));
1449}
1450
1451/**
1452 * __root_device_register - allocate and register a root device
1453 * @name: root device name
1454 * @owner: owner module of the root device, usually THIS_MODULE
1455 *
1456 * This function allocates a root device and registers it
1457 * using device_register(). In order to free the returned
1458 * device, use root_device_unregister().
1459 *
1460 * Root devices are dummy devices which allow other devices
1461 * to be grouped under /sys/devices. Use this function to
1462 * allocate a root device and then use it as the parent of
1463 * any device which should appear under /sys/devices/{name}
1464 *
1465 * The /sys/devices/{name} directory will also contain a
1466 * 'module' symlink which points to the @owner directory
1467 * in sysfs.
1468 *
1469 * Returns &struct device pointer on success, or ERR_PTR() on error.
1470 *
1471 * Note: You probably want to use root_device_register().
1472 */
1473struct device *__root_device_register(const char *name, struct module *owner)
1474{
1475        struct root_device *root;
1476        int err = -ENOMEM;
1477
1478        root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1479        if (!root)
1480                return ERR_PTR(err);
1481
1482        err = dev_set_name(&root->dev, "%s", name);
1483        if (err) {
1484                kfree(root);
1485                return ERR_PTR(err);
1486        }
1487
1488        root->dev.release = root_device_release;
1489
1490        err = device_register(&root->dev);
1491        if (err) {
1492                put_device(&root->dev);
1493                return ERR_PTR(err);
1494        }
1495
1496#ifdef CONFIG_MODULES   /* gotta find a "cleaner" way to do this */
1497        if (owner) {
1498                struct module_kobject *mk = &owner->mkobj;
1499
1500                err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1501                if (err) {
1502                        device_unregister(&root->dev);
1503                        return ERR_PTR(err);
1504                }
1505                root->owner = owner;
1506        }
1507#endif
1508
1509        return &root->dev;
1510}
1511EXPORT_SYMBOL_GPL(__root_device_register);
1512
1513/**
1514 * root_device_unregister - unregister and free a root device
1515 * @dev: device going away
1516 *
1517 * This function unregisters and cleans up a device that was created by
1518 * root_device_register().
1519 */
1520void root_device_unregister(struct device *dev)
1521{
1522        struct root_device *root = to_root_device(dev);
1523
1524        if (root->owner)
1525                sysfs_remove_link(&root->dev.kobj, "module");
1526
1527        device_unregister(dev);
1528}
1529EXPORT_SYMBOL_GPL(root_device_unregister);
1530
1531
1532static void device_create_release(struct device *dev)
1533{
1534        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1535        kfree(dev);
1536}
1537
1538/**
1539 * device_create_vargs - creates a device and registers it with sysfs
1540 * @class: pointer to the struct class that this device should be registered to
1541 * @parent: pointer to the parent struct device of this new device, if any
1542 * @devt: the dev_t for the char device to be added
1543 * @drvdata: the data to be added to the device for callbacks
1544 * @fmt: string for the device's name
1545 * @args: va_list for the device's name
1546 *
1547 * This function can be used by char device classes.  A struct device
1548 * will be created in sysfs, registered to the specified class.
1549 *
1550 * A "dev" file will be created, showing the dev_t for the device, if
1551 * the dev_t is not 0,0.
1552 * If a pointer to a parent struct device is passed in, the newly created
1553 * struct device will be a child of that device in sysfs.
1554 * The pointer to the struct device will be returned from the call.
1555 * Any further sysfs files that might be required can be created using this
1556 * pointer.
1557 *
1558 * Returns &struct device pointer on success, or ERR_PTR() on error.
1559 *
1560 * Note: the struct class passed to this function must have previously
1561 * been created with a call to class_create().
1562 */
1563struct device *device_create_vargs(struct class *class, struct device *parent,
1564                                   dev_t devt, void *drvdata, const char *fmt,
1565                                   va_list args)
1566{
1567        struct device *dev = NULL;
1568        int retval = -ENODEV;
1569
1570        if (class == NULL || IS_ERR(class))
1571                goto error;
1572
1573        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1574        if (!dev) {
1575                retval = -ENOMEM;
1576                goto error;
1577        }
1578
1579        dev->devt = devt;
1580        dev->class = class;
1581        dev->parent = parent;
1582        dev->release = device_create_release;
1583        dev_set_drvdata(dev, drvdata);
1584
1585        retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1586        if (retval)
1587                goto error;
1588
1589        retval = device_register(dev);
1590        if (retval)
1591                goto error;
1592
1593        return dev;
1594
1595error:
1596        put_device(dev);
1597        return ERR_PTR(retval);
1598}
1599EXPORT_SYMBOL_GPL(device_create_vargs);
1600
1601/**
1602 * device_create - creates a device and registers it with sysfs
1603 * @class: pointer to the struct class that this device should be registered to
1604 * @parent: pointer to the parent struct device of this new device, if any
1605 * @devt: the dev_t for the char device to be added
1606 * @drvdata: the data to be added to the device for callbacks
1607 * @fmt: string for the device's name
1608 *
1609 * This function can be used by char device classes.  A struct device
1610 * will be created in sysfs, registered to the specified class.
1611 *
1612 * A "dev" file will be created, showing the dev_t for the device, if
1613 * the dev_t is not 0,0.
1614 * If a pointer to a parent struct device is passed in, the newly created
1615 * struct device will be a child of that device in sysfs.
1616 * The pointer to the struct device will be returned from the call.
1617 * Any further sysfs files that might be required can be created using this
1618 * pointer.
1619 *
1620 * Returns &struct device pointer on success, or ERR_PTR() on error.
1621 *
1622 * Note: the struct class passed to this function must have previously
1623 * been created with a call to class_create().
1624 */
1625struct device *device_create(struct class *class, struct device *parent,
1626                             dev_t devt, void *drvdata, const char *fmt, ...)
1627{
1628        va_list vargs;
1629        struct device *dev;
1630
1631        va_start(vargs, fmt);
1632        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1633        va_end(vargs);
1634        return dev;
1635}
1636EXPORT_SYMBOL_GPL(device_create);
1637
1638static int __match_devt(struct device *dev, const void *data)
1639{
1640        const dev_t *devt = data;
1641
1642        return dev->devt == *devt;
1643}
1644
1645/**
1646 * device_destroy - removes a device that was created with device_create()
1647 * @class: pointer to the struct class that this device was registered with
1648 * @devt: the dev_t of the device that was previously registered
1649 *
1650 * This call unregisters and cleans up a device that was created with a
1651 * call to device_create().
1652 */
1653void device_destroy(struct class *class, dev_t devt)
1654{
1655        struct device *dev;
1656
1657        dev = class_find_device(class, NULL, &devt, __match_devt);
1658        if (dev) {
1659                put_device(dev);
1660                device_unregister(dev);
1661        }
1662}
1663EXPORT_SYMBOL_GPL(device_destroy);
1664
1665/**
1666 * device_rename - renames a device
1667 * @dev: the pointer to the struct device to be renamed
1668 * @new_name: the new name of the device
1669 *
1670 * It is the responsibility of the caller to provide mutual
1671 * exclusion between two different calls of device_rename
1672 * on the same device to ensure that new_name is valid and
1673 * won't conflict with other devices.
1674 *
1675 * Note: Don't call this function.  Currently, the networking layer calls this
1676 * function, but that will change.  The following text from Kay Sievers offers
1677 * some insight:
1678 *
1679 * Renaming devices is racy at many levels, symlinks and other stuff are not
1680 * replaced atomically, and you get a "move" uevent, but it's not easy to
1681 * connect the event to the old and new device. Device nodes are not renamed at
1682 * all, there isn't even support for that in the kernel now.
1683 *
1684 * In the meantime, during renaming, your target name might be taken by another
1685 * driver, creating conflicts. Or the old name is taken directly after you
1686 * renamed it -- then you get events for the same DEVPATH, before you even see
1687 * the "move" event. It's just a mess, and nothing new should ever rely on
1688 * kernel device renaming. Besides that, it's not even implemented now for
1689 * other things than (driver-core wise very simple) network devices.
1690 *
1691 * We are currently about to change network renaming in udev to completely
1692 * disallow renaming of devices in the same namespace as the kernel uses,
1693 * because we can't solve the problems properly, that arise with swapping names
1694 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1695 * be allowed to some other name than eth[0-9]*, for the aforementioned
1696 * reasons.
1697 *
1698 * Make up a "real" name in the driver before you register anything, or add
1699 * some other attributes for userspace to find the device, or use udev to add
1700 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1701 * don't even want to get into that and try to implement the missing pieces in
1702 * the core. We really have other pieces to fix in the driver core mess. :)
1703 */
1704int device_rename(struct device *dev, const char *new_name)
1705{
1706        char *old_device_name = NULL;
1707        int error;
1708
1709        dev = get_device(dev);
1710        if (!dev)
1711                return -EINVAL;
1712
1713        pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1714                 __func__, new_name);
1715
1716        old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1717        if (!old_device_name) {
1718                error = -ENOMEM;
1719                goto out;
1720        }
1721
1722        if (dev->class) {
1723                error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1724                        &dev->kobj, old_device_name, new_name);
1725                if (error)
1726                        goto out;
1727        }
1728
1729        error = kobject_rename(&dev->kobj, new_name);
1730        if (error)
1731                goto out;
1732
1733out:
1734        put_device(dev);
1735
1736        kfree(old_device_name);
1737
1738        return error;
1739}
1740EXPORT_SYMBOL_GPL(device_rename);
1741
1742static int device_move_class_links(struct device *dev,
1743                                   struct device *old_parent,
1744                                   struct device *new_parent)
1745{
1746        int error = 0;
1747
1748        if (old_parent)
1749                sysfs_remove_link(&dev->kobj, "device");
1750        if (new_parent)
1751                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1752                                          "device");
1753        return error;
1754}
1755
1756/**
1757 * device_move - moves a device to a new parent
1758 * @dev: the pointer to the struct device to be moved
1759 * @new_parent: the new parent of the device (can by NULL)
1760 * @dpm_order: how to reorder the dpm_list
1761 */
1762int device_move(struct device *dev, struct device *new_parent,
1763                enum dpm_order dpm_order)
1764{
1765        int error;
1766        struct device *old_parent;
1767        struct kobject *new_parent_kobj;
1768
1769        dev = get_device(dev);
1770        if (!dev)
1771                return -EINVAL;
1772
1773        device_pm_lock();
1774        new_parent = get_device(new_parent);
1775        new_parent_kobj = get_device_parent(dev, new_parent);
1776
1777        pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1778                 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1779        error = kobject_move(&dev->kobj, new_parent_kobj);
1780        if (error) {
1781                cleanup_glue_dir(dev, new_parent_kobj);
1782                put_device(new_parent);
1783                goto out;
1784        }
1785        old_parent = dev->parent;
1786        dev->parent = new_parent;
1787        if (old_parent)
1788                klist_remove(&dev->p->knode_parent);
1789        if (new_parent) {
1790                klist_add_tail(&dev->p->knode_parent,
1791                               &new_parent->p->klist_children);
1792                set_dev_node(dev, dev_to_node(new_parent));
1793        }
1794
1795        if (dev->class) {
1796                error = device_move_class_links(dev, old_parent, new_parent);
1797                if (error) {
1798                        /* We ignore errors on cleanup since we're hosed anyway... */
1799                        device_move_class_links(dev, new_parent, old_parent);
1800                        if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1801                                if (new_parent)
1802                                        klist_remove(&dev->p->knode_parent);
1803                                dev->parent = old_parent;
1804                                if (old_parent) {
1805                                        klist_add_tail(&dev->p->knode_parent,
1806                                                       &old_parent->p->klist_children);
1807                                        set_dev_node(dev, dev_to_node(old_parent));
1808                                }
1809                        }
1810                        cleanup_glue_dir(dev, new_parent_kobj);
1811                        put_device(new_parent);
1812                        goto out;
1813                }
1814        }
1815        switch (dpm_order) {
1816        case DPM_ORDER_NONE:
1817                break;
1818        case DPM_ORDER_DEV_AFTER_PARENT:
1819                device_pm_move_after(dev, new_parent);
1820                break;
1821        case DPM_ORDER_PARENT_BEFORE_DEV:
1822                device_pm_move_before(new_parent, dev);
1823                break;
1824        case DPM_ORDER_DEV_LAST:
1825                device_pm_move_last(dev);
1826                break;
1827        }
1828
1829        put_device(old_parent);
1830out:
1831        device_pm_unlock();
1832        put_device(dev);
1833        return error;
1834}
1835EXPORT_SYMBOL_GPL(device_move);
1836
1837/**
1838 * device_shutdown - call ->shutdown() on each device to shutdown.
1839 */
1840void device_shutdown(void)
1841{
1842        struct device *dev;
1843
1844        spin_lock(&devices_kset->list_lock);
1845        /*
1846         * Walk the devices list backward, shutting down each in turn.
1847         * Beware that device unplug events may also start pulling
1848         * devices offline, even as the system is shutting down.
1849         */
1850        while (!list_empty(&devices_kset->list)) {
1851                dev = list_entry(devices_kset->list.prev, struct device,
1852                                kobj.entry);
1853
1854                /*
1855                 * hold reference count of device's parent to
1856                 * prevent it from being freed because parent's
1857                 * lock is to be held
1858                 */
1859                get_device(dev->parent);
1860                get_device(dev);
1861                /*
1862                 * Make sure the device is off the kset list, in the
1863                 * event that dev->*->shutdown() doesn't remove it.
1864                 */
1865                list_del_init(&dev->kobj.entry);
1866                spin_unlock(&devices_kset->list_lock);
1867
1868                /* hold lock to avoid race with probe/release */
1869                if (dev->parent)
1870                        device_lock(dev->parent);
1871                device_lock(dev);
1872
1873                /* Don't allow any more runtime suspends */
1874                pm_runtime_get_noresume(dev);
1875                pm_runtime_barrier(dev);
1876
1877                if (dev->bus && dev->bus->shutdown) {
1878                        if (initcall_debug)
1879                                dev_info(dev, "shutdown\n");
1880                        dev->bus->shutdown(dev);
1881                } else if (dev->driver && dev->driver->shutdown) {
1882                        if (initcall_debug)
1883                                dev_info(dev, "shutdown\n");
1884                        dev->driver->shutdown(dev);
1885                }
1886
1887                device_unlock(dev);
1888                if (dev->parent)
1889                        device_unlock(dev->parent);
1890
1891                put_device(dev);
1892                put_device(dev->parent);
1893
1894                spin_lock(&devices_kset->list_lock);
1895        }
1896        spin_unlock(&devices_kset->list_lock);
1897        async_synchronize_full();
1898}
1899
1900/*
1901 * Device logging functions
1902 */
1903
1904#ifdef CONFIG_PRINTK
1905static int
1906create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
1907{
1908        const char *subsys;
1909        size_t pos = 0;
1910
1911        if (dev->class)
1912                subsys = dev->class->name;
1913        else if (dev->bus)
1914                subsys = dev->bus->name;
1915        else
1916                return 0;
1917
1918        pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
1919
1920        /*
1921         * Add device identifier DEVICE=:
1922         *   b12:8         block dev_t
1923         *   c127:3        char dev_t
1924         *   n8            netdev ifindex
1925         *   +sound:card0  subsystem:devname
1926         */
1927        if (MAJOR(dev->devt)) {
1928                char c;
1929
1930                if (strcmp(subsys, "block") == 0)
1931                        c = 'b';
1932                else
1933                        c = 'c';
1934                pos++;
1935                pos += snprintf(hdr + pos, hdrlen - pos,
1936                                "DEVICE=%c%u:%u",
1937                                c, MAJOR(dev->devt), MINOR(dev->devt));
1938        } else if (strcmp(subsys, "net") == 0) {
1939                struct net_device *net = to_net_dev(dev);
1940
1941                pos++;
1942                pos += snprintf(hdr + pos, hdrlen - pos,
1943                                "DEVICE=n%u", net->ifindex);
1944        } else {
1945                pos++;
1946                pos += snprintf(hdr + pos, hdrlen - pos,
1947                                "DEVICE=+%s:%s", subsys, dev_name(dev));
1948        }
1949
1950        return pos;
1951}
1952EXPORT_SYMBOL(create_syslog_header);
1953
1954int dev_vprintk_emit(int level, const struct device *dev,
1955                     const char *fmt, va_list args)
1956{
1957        char hdr[128];
1958        size_t hdrlen;
1959
1960        hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
1961
1962        return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
1963}
1964EXPORT_SYMBOL(dev_vprintk_emit);
1965
1966int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
1967{
1968        va_list args;
1969        int r;
1970
1971        va_start(args, fmt);
1972
1973        r = dev_vprintk_emit(level, dev, fmt, args);
1974
1975        va_end(args);
1976
1977        return r;
1978}
1979EXPORT_SYMBOL(dev_printk_emit);
1980
1981static int __dev_printk(const char *level, const struct device *dev,
1982                        struct va_format *vaf)
1983{
1984        if (!dev)
1985                return printk("%s(NULL device *): %pV", level, vaf);
1986
1987        return dev_printk_emit(level[1] - '0', dev,
1988                               "%s %s: %pV",
1989                               dev_driver_string(dev), dev_name(dev), vaf);
1990}
1991
1992int dev_printk(const char *level, const struct device *dev,
1993               const char *fmt, ...)
1994{
1995        struct va_format vaf;
1996        va_list args;
1997        int r;
1998
1999        va_start(args, fmt);
2000
2001        vaf.fmt = fmt;
2002        vaf.va = &args;
2003
2004        r = __dev_printk(level, dev, &vaf);
2005
2006        va_end(args);
2007
2008        return r;
2009}
2010EXPORT_SYMBOL(dev_printk);
2011
2012#define define_dev_printk_level(func, kern_level)               \
2013int func(const struct device *dev, const char *fmt, ...)        \
2014{                                                               \
2015        struct va_format vaf;                                   \
2016        va_list args;                                           \
2017        int r;                                                  \
2018                                                                \
2019        va_start(args, fmt);                                    \
2020                                                                \
2021        vaf.fmt = fmt;                                          \
2022        vaf.va = &args;                                         \
2023                                                                \
2024        r = __dev_printk(kern_level, dev, &vaf);                \
2025                                                                \
2026        va_end(args);                                           \
2027                                                                \
2028        return r;                                               \
2029}                                                               \
2030EXPORT_SYMBOL(func);
2031
2032define_dev_printk_level(dev_emerg, KERN_EMERG);
2033define_dev_printk_level(dev_alert, KERN_ALERT);
2034define_dev_printk_level(dev_crit, KERN_CRIT);
2035define_dev_printk_level(dev_err, KERN_ERR);
2036define_dev_printk_level(dev_warn, KERN_WARNING);
2037define_dev_printk_level(dev_notice, KERN_NOTICE);
2038define_dev_printk_level(_dev_info, KERN_INFO);
2039
2040#endif
2041
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