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 ssize_t show_online(struct device *dev, struct device_attribute *attr,
 407                           char *buf)
 408{
 409        bool val;
 410
 411        lock_device_hotplug();
 412        val = !dev->offline;
 413        unlock_device_hotplug();
 414        return sprintf(buf, "%u\n", val);
 415}
 416
 417static ssize_t store_online(struct device *dev, struct device_attribute *attr,
 418                            const char *buf, size_t count)
 419{
 420        bool val;
 421        int ret;
 422
 423        ret = strtobool(buf, &val);
 424        if (ret < 0)
 425                return ret;
 426
 427        lock_device_hotplug();
 428        ret = val ? device_online(dev) : device_offline(dev);
 429        unlock_device_hotplug();
 430        return ret < 0 ? ret : count;
 431}
 432
 433static struct device_attribute online_attr =
 434        __ATTR(online, S_IRUGO | S_IWUSR, show_online, store_online);
 435
 436static int device_add_attributes(struct device *dev,
 437                                 struct device_attribute *attrs)
 438{
 439        int error = 0;
 440        int i;
 441
 442        if (attrs) {
 443                for (i = 0; attr_name(attrs[i]); i++) {
 444                        error = device_create_file(dev, &attrs[i]);
 445                        if (error)
 446                                break;
 447                }
 448                if (error)
 449                        while (--i >= 0)
 450                                device_remove_file(dev, &attrs[i]);
 451        }
 452        return error;
 453}
 454
 455static void device_remove_attributes(struct device *dev,
 456                                     struct device_attribute *attrs)
 457{
 458        int i;
 459
 460        if (attrs)
 461                for (i = 0; attr_name(attrs[i]); i++)
 462                        device_remove_file(dev, &attrs[i]);
 463}
 464
 465static int device_add_bin_attributes(struct device *dev,
 466                                     struct bin_attribute *attrs)
 467{
 468        int error = 0;
 469        int i;
 470
 471        if (attrs) {
 472                for (i = 0; attr_name(attrs[i]); i++) {
 473                        error = device_create_bin_file(dev, &attrs[i]);
 474                        if (error)
 475                                break;
 476                }
 477                if (error)
 478                        while (--i >= 0)
 479                                device_remove_bin_file(dev, &attrs[i]);
 480        }
 481        return error;
 482}
 483
 484static void device_remove_bin_attributes(struct device *dev,
 485                                         struct bin_attribute *attrs)
 486{
 487        int i;
 488
 489        if (attrs)
 490                for (i = 0; attr_name(attrs[i]); i++)
 491                        device_remove_bin_file(dev, &attrs[i]);
 492}
 493
 494static int device_add_groups(struct device *dev,
 495                             const struct attribute_group **groups)
 496{
 497        int error = 0;
 498        int i;
 499
 500        if (groups) {
 501                for (i = 0; groups[i]; i++) {
 502                        error = sysfs_create_group(&dev->kobj, groups[i]);
 503                        if (error) {
 504                                while (--i >= 0)
 505                                        sysfs_remove_group(&dev->kobj,
 506                                                           groups[i]);
 507                                break;
 508                        }
 509                }
 510        }
 511        return error;
 512}
 513
 514static void device_remove_groups(struct device *dev,
 515                                 const struct attribute_group **groups)
 516{
 517        int i;
 518
 519        if (groups)
 520                for (i = 0; groups[i]; i++)
 521                        sysfs_remove_group(&dev->kobj, groups[i]);
 522}
 523
 524static int device_add_attrs(struct device *dev)
 525{
 526        struct class *class = dev->class;
 527        const struct device_type *type = dev->type;
 528        int error;
 529
 530        if (class) {
 531                error = device_add_groups(dev, class->dev_groups);
 532                if (error)
 533                        return error;
 534                error = device_add_attributes(dev, class->dev_attrs);
 535                if (error)
 536                        goto err_remove_class_groups;
 537                error = device_add_bin_attributes(dev, class->dev_bin_attrs);
 538                if (error)
 539                        goto err_remove_class_attrs;
 540        }
 541
 542        if (type) {
 543                error = device_add_groups(dev, type->groups);
 544                if (error)
 545                        goto err_remove_class_bin_attrs;
 546        }
 547
 548        error = device_add_groups(dev, dev->groups);
 549        if (error)
 550                goto err_remove_type_groups;
 551
 552        if (device_supports_offline(dev) && !dev->offline_disabled) {
 553                error = device_create_file(dev, &online_attr);
 554                if (error)
 555                        goto err_remove_type_groups;
 556        }
 557
 558        return 0;
 559
 560 err_remove_type_groups:
 561        if (type)
 562                device_remove_groups(dev, type->groups);
 563 err_remove_class_bin_attrs:
 564        if (class)
 565                device_remove_bin_attributes(dev, class->dev_bin_attrs);
 566 err_remove_class_attrs:
 567        if (class)
 568                device_remove_attributes(dev, class->dev_attrs);
 569 err_remove_class_groups:
 570        if (class)
 571                device_remove_groups(dev, class->dev_groups);
 572
 573        return error;
 574}
 575
 576static void device_remove_attrs(struct device *dev)
 577{
 578        struct class *class = dev->class;
 579        const struct device_type *type = dev->type;
 580
 581        device_remove_file(dev, &online_attr);
 582        device_remove_groups(dev, dev->groups);
 583
 584        if (type)
 585                device_remove_groups(dev, type->groups);
 586
 587        if (class) {
 588                device_remove_attributes(dev, class->dev_attrs);
 589                device_remove_bin_attributes(dev, class->dev_bin_attrs);
 590                device_remove_groups(dev, class->dev_groups);
 591        }
 592}
 593
 594
 595static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
 596                        char *buf)
 597{
 598        return print_dev_t(buf, dev->devt);
 599}
 600
 601static struct device_attribute devt_attr =
 602        __ATTR(dev, S_IRUGO, show_dev, NULL);
 603
 604/* /sys/devices/ */
 605struct kset *devices_kset;
 606
 607/**
 608 * device_create_file - create sysfs attribute file for device.
 609 * @dev: device.
 610 * @attr: device attribute descriptor.
 611 */
 612int device_create_file(struct device *dev,
 613                       const struct device_attribute *attr)
 614{
 615        int error = 0;
 616
 617        if (dev) {
 618                WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
 619                        "Attribute %s: write permission without 'store'\n",
 620                        attr->attr.name);
 621                WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
 622                        "Attribute %s: read permission without 'show'\n",
 623                        attr->attr.name);
 624                error = sysfs_create_file(&dev->kobj, &attr->attr);
 625        }
 626
 627        return error;
 628}
 629
 630/**
 631 * device_remove_file - remove sysfs attribute file.
 632 * @dev: device.
 633 * @attr: device attribute descriptor.
 634 */
 635void device_remove_file(struct device *dev,
 636                        const struct device_attribute *attr)
 637{
 638        if (dev)
 639                sysfs_remove_file(&dev->kobj, &attr->attr);
 640}
 641
 642/**
 643 * device_create_bin_file - create sysfs binary attribute file for device.
 644 * @dev: device.
 645 * @attr: device binary attribute descriptor.
 646 */
 647int device_create_bin_file(struct device *dev,
 648                           const struct bin_attribute *attr)
 649{
 650        int error = -EINVAL;
 651        if (dev)
 652                error = sysfs_create_bin_file(&dev->kobj, attr);
 653        return error;
 654}
 655EXPORT_SYMBOL_GPL(device_create_bin_file);
 656
 657/**
 658 * device_remove_bin_file - remove sysfs binary attribute file
 659 * @dev: device.
 660 * @attr: device binary attribute descriptor.
 661 */
 662void device_remove_bin_file(struct device *dev,
 663                            const struct bin_attribute *attr)
 664{
 665        if (dev)
 666                sysfs_remove_bin_file(&dev->kobj, attr);
 667}
 668EXPORT_SYMBOL_GPL(device_remove_bin_file);
 669
 670/**
 671 * device_schedule_callback_owner - helper to schedule a callback for a device
 672 * @dev: device.
 673 * @func: callback function to invoke later.
 674 * @owner: module owning the callback routine
 675 *
 676 * Attribute methods must not unregister themselves or their parent device
 677 * (which would amount to the same thing).  Attempts to do so will deadlock,
 678 * since unregistration is mutually exclusive with driver callbacks.
 679 *
 680 * Instead methods can call this routine, which will attempt to allocate
 681 * and schedule a workqueue request to call back @func with @dev as its
 682 * argument in the workqueue's process context.  @dev will be pinned until
 683 * @func returns.
 684 *
 685 * This routine is usually called via the inline device_schedule_callback(),
 686 * which automatically sets @owner to THIS_MODULE.
 687 *
 688 * Returns 0 if the request was submitted, -ENOMEM if storage could not
 689 * be allocated, -ENODEV if a reference to @owner isn't available.
 690 *
 691 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 692 * underlying sysfs routine (since it is intended for use by attribute
 693 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 694 */
 695int device_schedule_callback_owner(struct device *dev,
 696                void (*func)(struct device *), struct module *owner)
 697{
 698        return sysfs_schedule_callback(&dev->kobj,
 699                        (void (*)(void *)) func, dev, owner);
 700}
 701EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
 702
 703static void klist_children_get(struct klist_node *n)
 704{
 705        struct device_private *p = to_device_private_parent(n);
 706        struct device *dev = p->device;
 707
 708        get_device(dev);
 709}
 710
 711static void klist_children_put(struct klist_node *n)
 712{
 713        struct device_private *p = to_device_private_parent(n);
 714        struct device *dev = p->device;
 715
 716        put_device(dev);
 717}
 718
 719/**
 720 * device_initialize - init device structure.
 721 * @dev: device.
 722 *
 723 * This prepares the device for use by other layers by initializing
 724 * its fields.
 725 * It is the first half of device_register(), if called by
 726 * that function, though it can also be called separately, so one
 727 * may use @dev's fields. In particular, get_device()/put_device()
 728 * may be used for reference counting of @dev after calling this
 729 * function.
 730 *
 731 * All fields in @dev must be initialized by the caller to 0, except
 732 * for those explicitly set to some other value.  The simplest
 733 * approach is to use kzalloc() to allocate the structure containing
 734 * @dev.
 735 *
 736 * NOTE: Use put_device() to give up your reference instead of freeing
 737 * @dev directly once you have called this function.
 738 */
 739void device_initialize(struct device *dev)
 740{
 741        dev->kobj.kset = devices_kset;
 742        kobject_init(&dev->kobj, &device_ktype);
 743        INIT_LIST_HEAD(&dev->dma_pools);
 744        mutex_init(&dev->mutex);
 745        lockdep_set_novalidate_class(&dev->mutex);
 746        spin_lock_init(&dev->devres_lock);
 747        INIT_LIST_HEAD(&dev->devres_head);
 748        device_pm_init(dev);
 749        set_dev_node(dev, -1);
 750}
 751
 752struct kobject *virtual_device_parent(struct device *dev)
 753{
 754        static struct kobject *virtual_dir = NULL;
 755
 756        if (!virtual_dir)
 757                virtual_dir = kobject_create_and_add("virtual",
 758                                                     &devices_kset->kobj);
 759
 760        return virtual_dir;
 761}
 762
 763struct class_dir {
 764        struct kobject kobj;
 765        struct class *class;
 766};
 767
 768#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
 769
 770static void class_dir_release(struct kobject *kobj)
 771{
 772        struct class_dir *dir = to_class_dir(kobj);
 773        kfree(dir);
 774}
 775
 776static const
 777struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
 778{
 779        struct class_dir *dir = to_class_dir(kobj);
 780        return dir->class->ns_type;
 781}
 782
 783static struct kobj_type class_dir_ktype = {
 784        .release        = class_dir_release,
 785        .sysfs_ops      = &kobj_sysfs_ops,
 786        .child_ns_type  = class_dir_child_ns_type
 787};
 788
 789static struct kobject *
 790class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 791{
 792        struct class_dir *dir;
 793        int retval;
 794
 795        dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 796        if (!dir)
 797                return NULL;
 798
 799        dir->class = class;
 800        kobject_init(&dir->kobj, &class_dir_ktype);
 801
 802        dir->kobj.kset = &class->p->glue_dirs;
 803
 804        retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
 805        if (retval < 0) {
 806                kobject_put(&dir->kobj);
 807                return NULL;
 808        }
 809        return &dir->kobj;
 810}
 811
 812
 813static struct kobject *get_device_parent(struct device *dev,
 814                                         struct device *parent)
 815{
 816        if (dev->class) {
 817                static DEFINE_MUTEX(gdp_mutex);
 818                struct kobject *kobj = NULL;
 819                struct kobject *parent_kobj;
 820                struct kobject *k;
 821
 822#ifdef CONFIG_BLOCK
 823                /* block disks show up in /sys/block */
 824                if (sysfs_deprecated && dev->class == &block_class) {
 825                        if (parent && parent->class == &block_class)
 826                                return &parent->kobj;
 827                        return &block_class.p->subsys.kobj;
 828                }
 829#endif
 830
 831                /*
 832                 * If we have no parent, we live in "virtual".
 833                 * Class-devices with a non class-device as parent, live
 834                 * in a "glue" directory to prevent namespace collisions.
 835                 */
 836                if (parent == NULL)
 837                        parent_kobj = virtual_device_parent(dev);
 838                else if (parent->class && !dev->class->ns_type)
 839                        return &parent->kobj;
 840                else
 841                        parent_kobj = &parent->kobj;
 842
 843                mutex_lock(&gdp_mutex);
 844
 845                /* find our class-directory at the parent and reference it */
 846                spin_lock(&dev->class->p->glue_dirs.list_lock);
 847                list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
 848                        if (k->parent == parent_kobj) {
 849                                kobj = kobject_get(k);
 850                                break;
 851                        }
 852                spin_unlock(&dev->class->p->glue_dirs.list_lock);
 853                if (kobj) {
 854                        mutex_unlock(&gdp_mutex);
 855                        return kobj;
 856                }
 857
 858                /* or create a new class-directory at the parent device */
 859                k = class_dir_create_and_add(dev->class, parent_kobj);
 860                /* do not emit an uevent for this simple "glue" directory */
 861                mutex_unlock(&gdp_mutex);
 862                return k;
 863        }
 864
 865        /* subsystems can specify a default root directory for their devices */
 866        if (!parent && dev->bus && dev->bus->dev_root)
 867                return &dev->bus->dev_root->kobj;
 868
 869        if (parent)
 870                return &parent->kobj;
 871        return NULL;
 872}
 873
 874static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 875{
 876        /* see if we live in a "glue" directory */
 877        if (!glue_dir || !dev->class ||
 878            glue_dir->kset != &dev->class->p->glue_dirs)
 879                return;
 880
 881        kobject_put(glue_dir);
 882}
 883
 884static void cleanup_device_parent(struct device *dev)
 885{
 886        cleanup_glue_dir(dev, dev->kobj.parent);
 887}
 888
 889static int device_add_class_symlinks(struct device *dev)
 890{
 891        int error;
 892
 893        if (!dev->class)
 894                return 0;
 895
 896        error = sysfs_create_link(&dev->kobj,
 897                                  &dev->class->p->subsys.kobj,
 898                                  "subsystem");
 899        if (error)
 900                goto out;
 901
 902        if (dev->parent && device_is_not_partition(dev)) {
 903                error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 904                                          "device");
 905                if (error)
 906                        goto out_subsys;
 907        }
 908
 909#ifdef CONFIG_BLOCK
 910        /* /sys/block has directories and does not need symlinks */
 911        if (sysfs_deprecated && dev->class == &block_class)
 912                return 0;
 913#endif
 914
 915        /* link in the class directory pointing to the device */
 916        error = sysfs_create_link(&dev->class->p->subsys.kobj,
 917                                  &dev->kobj, dev_name(dev));
 918        if (error)
 919                goto out_device;
 920
 921        return 0;
 922
 923out_device:
 924        sysfs_remove_link(&dev->kobj, "device");
 925
 926out_subsys:
 927        sysfs_remove_link(&dev->kobj, "subsystem");
 928out:
 929        return error;
 930}
 931
 932static void device_remove_class_symlinks(struct device *dev)
 933{
 934        if (!dev->class)
 935                return;
 936
 937        if (dev->parent && device_is_not_partition(dev))
 938                sysfs_remove_link(&dev->kobj, "device");
 939        sysfs_remove_link(&dev->kobj, "subsystem");
 940#ifdef CONFIG_BLOCK
 941        if (sysfs_deprecated && dev->class == &block_class)
 942                return;
 943#endif
 944        sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
 945}
 946
 947/**
 948 * dev_set_name - set a device name
 949 * @dev: device
 950 * @fmt: format string for the device's name
 951 */
 952int dev_set_name(struct device *dev, const char *fmt, ...)
 953{
 954        va_list vargs;
 955        int err;
 956
 957        va_start(vargs, fmt);
 958        err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
 959        va_end(vargs);
 960        return err;
 961}
 962EXPORT_SYMBOL_GPL(dev_set_name);
 963
 964/**
 965 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 966 * @dev: device
 967 *
 968 * By default we select char/ for new entries.  Setting class->dev_obj
 969 * to NULL prevents an entry from being created.  class->dev_kobj must
 970 * be set (or cleared) before any devices are registered to the class
 971 * otherwise device_create_sys_dev_entry() and
 972 * device_remove_sys_dev_entry() will disagree about the presence of
 973 * the link.
 974 */
 975static struct kobject *device_to_dev_kobj(struct device *dev)
 976{
 977        struct kobject *kobj;
 978
 979        if (dev->class)
 980                kobj = dev->class->dev_kobj;
 981        else
 982                kobj = sysfs_dev_char_kobj;
 983
 984        return kobj;
 985}
 986
 987static int device_create_sys_dev_entry(struct device *dev)
 988{
 989        struct kobject *kobj = device_to_dev_kobj(dev);
 990        int error = 0;
 991        char devt_str[15];
 992
 993        if (kobj) {
 994                format_dev_t(devt_str, dev->devt);
 995                error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 996        }
 997
 998        return error;
 999}
1000
1001static void device_remove_sys_dev_entry(struct device *dev)
1002{
1003        struct kobject *kobj = device_to_dev_kobj(dev);
1004        char devt_str[15];
1005
1006        if (kobj) {
1007                format_dev_t(devt_str, dev->devt);
1008                sysfs_remove_link(kobj, devt_str);
1009        }
1010}
1011
1012int device_private_init(struct device *dev)
1013{
1014        dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
1015        if (!dev->p)
1016                return -ENOMEM;
1017        dev->p->device = dev;
1018        klist_init(&dev->p->klist_children, klist_children_get,
1019                   klist_children_put);
1020        INIT_LIST_HEAD(&dev->p->deferred_probe);
1021        return 0;
1022}
1023
1024/**
1025 * device_add - add device to device hierarchy.
1026 * @dev: device.
1027 *
1028 * This is part 2 of device_register(), though may be called
1029 * separately _iff_ device_initialize() has been called separately.
1030 *
1031 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1032 * to the global and sibling lists for the device, then
1033 * adds it to the other relevant subsystems of the driver model.
1034 *
1035 * Do not call this routine or device_register() more than once for
1036 * any device structure.  The driver model core is not designed to work
1037 * with devices that get unregistered and then spring back to life.
1038 * (Among other things, it's very hard to guarantee that all references
1039 * to the previous incarnation of @dev have been dropped.)  Allocate
1040 * and register a fresh new struct device instead.
1041 *
1042 * NOTE: _Never_ directly free @dev after calling this function, even
1043 * if it returned an error! Always use put_device() to give up your
1044 * reference instead.
1045 */
1046int device_add(struct device *dev)
1047{
1048        struct device *parent = NULL;
1049        struct kobject *kobj;
1050        struct class_interface *class_intf;
1051        int error = -EINVAL;
1052
1053        dev = get_device(dev);
1054        if (!dev)
1055                goto done;
1056
1057        if (!dev->p) {
1058                error = device_private_init(dev);
1059                if (error)
1060                        goto done;
1061        }
1062
1063        /*
1064         * for statically allocated devices, which should all be converted
1065         * some day, we need to initialize the name. We prevent reading back
1066         * the name, and force the use of dev_name()
1067         */
1068        if (dev->init_name) {
1069                dev_set_name(dev, "%s", dev->init_name);
1070                dev->init_name = NULL;
1071        }
1072
1073        /* subsystems can specify simple device enumeration */
1074        if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1075                dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1076
1077        if (!dev_name(dev)) {
1078                error = -EINVAL;
1079                goto name_error;
1080        }
1081
1082        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1083
1084        parent = get_device(dev->parent);
1085        kobj = get_device_parent(dev, parent);
1086        if (kobj)
1087                dev->kobj.parent = kobj;
1088
1089        /* use parent numa_node */
1090        if (parent)
1091                set_dev_node(dev, dev_to_node(parent));
1092
1093        /* first, register with generic layer. */
1094        /* we require the name to be set before, and pass NULL */
1095        error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1096        if (error)
1097                goto Error;
1098
1099        /* notify platform of device entry */
1100        if (platform_notify)
1101                platform_notify(dev);
1102
1103        error = device_create_file(dev, &uevent_attr);
1104        if (error)
1105                goto attrError;
1106
1107        if (MAJOR(dev->devt)) {
1108                error = device_create_file(dev, &devt_attr);
1109                if (error)
1110                        goto ueventattrError;
1111
1112                error = device_create_sys_dev_entry(dev);
1113                if (error)
1114                        goto devtattrError;
1115
1116                devtmpfs_create_node(dev);
1117        }
1118
1119        error = device_add_class_symlinks(dev);
1120        if (error)
1121                goto SymlinkError;
1122        error = device_add_attrs(dev);
1123        if (error)
1124                goto AttrsError;
1125        error = bus_add_device(dev);
1126        if (error)
1127                goto BusError;
1128        error = dpm_sysfs_add(dev);
1129        if (error)
1130                goto DPMError;
1131        device_pm_add(dev);
1132
1133        /* Notify clients of device addition.  This call must come
1134         * after dpm_sysfs_add() and before kobject_uevent().
1135         */
1136        if (dev->bus)
1137                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1138                                             BUS_NOTIFY_ADD_DEVICE, dev);
1139
1140        kobject_uevent(&dev->kobj, KOBJ_ADD);
1141        bus_probe_device(dev);
1142        if (parent)
1143                klist_add_tail(&dev->p->knode_parent,
1144                               &parent->p->klist_children);
1145
1146        if (dev->class) {
1147                mutex_lock(&dev->class->p->mutex);
1148                /* tie the class to the device */
1149                klist_add_tail(&dev->knode_class,
1150                               &dev->class->p->klist_devices);
1151
1152                /* notify any interfaces that the device is here */
1153                list_for_each_entry(class_intf,
1154                                    &dev->class->p->interfaces, node)
1155                        if (class_intf->add_dev)
1156                                class_intf->add_dev(dev, class_intf);
1157                mutex_unlock(&dev->class->p->mutex);
1158        }
1159done:
1160        put_device(dev);
1161        return error;
1162 DPMError:
1163        bus_remove_device(dev);
1164 BusError:
1165        device_remove_attrs(dev);
1166 AttrsError:
1167        device_remove_class_symlinks(dev);
1168 SymlinkError:
1169        if (MAJOR(dev->devt))
1170                devtmpfs_delete_node(dev);
1171        if (MAJOR(dev->devt))
1172                device_remove_sys_dev_entry(dev);
1173 devtattrError:
1174        if (MAJOR(dev->devt))
1175                device_remove_file(dev, &devt_attr);
1176 ueventattrError:
1177        device_remove_file(dev, &uevent_attr);
1178 attrError:
1179        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1180        kobject_del(&dev->kobj);
1181 Error:
1182        cleanup_device_parent(dev);
1183        if (parent)
1184                put_device(parent);
1185name_error:
1186        kfree(dev->p);
1187        dev->p = NULL;
1188        goto done;
1189}
1190
1191/**
1192 * device_register - register a device with the system.
1193 * @dev: pointer to the device structure
1194 *
1195 * This happens in two clean steps - initialize the device
1196 * and add it to the system. The two steps can be called
1197 * separately, but this is the easiest and most common.
1198 * I.e. you should only call the two helpers separately if
1199 * have a clearly defined need to use and refcount the device
1200 * before it is added to the hierarchy.
1201 *
1202 * For more information, see the kerneldoc for device_initialize()
1203 * and device_add().
1204 *
1205 * NOTE: _Never_ directly free @dev after calling this function, even
1206 * if it returned an error! Always use put_device() to give up the
1207 * reference initialized in this function instead.
1208 */
1209int device_register(struct device *dev)
1210{
1211        device_initialize(dev);
1212        return device_add(dev);
1213}
1214
1215/**
1216 * get_device - increment reference count for device.
1217 * @dev: device.
1218 *
1219 * This simply forwards the call to kobject_get(), though
1220 * we do take care to provide for the case that we get a NULL
1221 * pointer passed in.
1222 */
1223struct device *get_device(struct device *dev)
1224{
1225        return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1226}
1227
1228/**
1229 * put_device - decrement reference count.
1230 * @dev: device in question.
1231 */
1232void put_device(struct device *dev)
1233{
1234        /* might_sleep(); */
1235        if (dev)
1236                kobject_put(&dev->kobj);
1237}
1238
1239/**
1240 * device_del - delete device from system.
1241 * @dev: device.
1242 *
1243 * This is the first part of the device unregistration
1244 * sequence. This removes the device from the lists we control
1245 * from here, has it removed from the other driver model
1246 * subsystems it was added to in device_add(), and removes it
1247 * from the kobject hierarchy.
1248 *
1249 * NOTE: this should be called manually _iff_ device_add() was
1250 * also called manually.
1251 */
1252void device_del(struct device *dev)
1253{
1254        struct device *parent = dev->parent;
1255        struct class_interface *class_intf;
1256
1257        /* Notify clients of device removal.  This call must come
1258         * before dpm_sysfs_remove().
1259         */
1260        if (dev->bus)
1261                blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1262                                             BUS_NOTIFY_DEL_DEVICE, dev);
1263        dpm_sysfs_remove(dev);
1264        if (parent)
1265                klist_del(&dev->p->knode_parent);
1266        if (MAJOR(dev->devt)) {
1267                devtmpfs_delete_node(dev);
1268                device_remove_sys_dev_entry(dev);
1269                device_remove_file(dev, &devt_attr);
1270        }
1271        if (dev->class) {
1272                device_remove_class_symlinks(dev);
1273
1274                mutex_lock(&dev->class->p->mutex);
1275                /* notify any interfaces that the device is now gone */
1276                list_for_each_entry(class_intf,
1277                                    &dev->class->p->interfaces, node)
1278                        if (class_intf->remove_dev)
1279                                class_intf->remove_dev(dev, class_intf);
1280                /* remove the device from the class list */
1281                klist_del(&dev->knode_class);
1282                mutex_unlock(&dev->class->p->mutex);
1283        }
1284        device_remove_file(dev, &uevent_attr);
1285        device_remove_attrs(dev);
1286        bus_remove_device(dev);
1287        device_pm_remove(dev);
1288        driver_deferred_probe_del(dev);
1289
1290        /* Notify the platform of the removal, in case they
1291         * need to do anything...
1292         */
1293        if (platform_notify_remove)
1294                platform_notify_remove(dev);
1295        kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1296        cleanup_device_parent(dev);
1297        kobject_del(&dev->kobj);
1298        put_device(parent);
1299}
1300
1301/**
1302 * device_unregister - unregister device from system.
1303 * @dev: device going away.
1304 *
1305 * We do this in two parts, like we do device_register(). First,
1306 * we remove it from all the subsystems with device_del(), then
1307 * we decrement the reference count via put_device(). If that
1308 * is the final reference count, the device will be cleaned up
1309 * via device_release() above. Otherwise, the structure will
1310 * stick around until the final reference to the device is dropped.
1311 */
1312void device_unregister(struct device *dev)
1313{
1314        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1315        device_del(dev);
1316        put_device(dev);
1317}
1318
1319static struct device *next_device(struct klist_iter *i)
1320{
1321        struct klist_node *n = klist_next(i);
1322        struct device *dev = NULL;
1323        struct device_private *p;
1324
1325        if (n) {
1326                p = to_device_private_parent(n);
1327                dev = p->device;
1328        }
1329        return dev;
1330}
1331
1332/**
1333 * device_get_devnode - path of device node file
1334 * @dev: device
1335 * @mode: returned file access mode
1336 * @uid: returned file owner
1337 * @gid: returned file group
1338 * @tmp: possibly allocated string
1339 *
1340 * Return the relative path of a possible device node.
1341 * Non-default names may need to allocate a memory to compose
1342 * a name. This memory is returned in tmp and needs to be
1343 * freed by the caller.
1344 */
1345const char *device_get_devnode(struct device *dev,
1346                               umode_t *mode, kuid_t *uid, kgid_t *gid,
1347                               const char **tmp)
1348{
1349        char *s;
1350
1351        *tmp = NULL;
1352
1353        /* the device type may provide a specific name */
1354        if (dev->type && dev->type->devnode)
1355                *tmp = dev->type->devnode(dev, mode, uid, gid);
1356        if (*tmp)
1357                return *tmp;
1358
1359        /* the class may provide a specific name */
1360        if (dev->class && dev->class->devnode)
1361                *tmp = dev->class->devnode(dev, mode);
1362        if (*tmp)
1363                return *tmp;
1364
1365        /* return name without allocation, tmp == NULL */
1366        if (strchr(dev_name(dev), '!') == NULL)
1367                return dev_name(dev);
1368
1369        /* replace '!' in the name with '/' */
1370        *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1371        if (!*tmp)
1372                return NULL;
1373        while ((s = strchr(*tmp, '!')))
1374                s[0] = '/';
1375        return *tmp;
1376}
1377
1378/**
1379 * device_for_each_child - device child iterator.
1380 * @parent: parent struct device.
1381 * @fn: function to be called for each device.
1382 * @data: data for the callback.
1383 *
1384 * Iterate over @parent's child devices, and call @fn for each,
1385 * passing it @data.
1386 *
1387 * We check the return of @fn each time. If it returns anything
1388 * other than 0, we break out and return that value.
1389 */
1390int device_for_each_child(struct device *parent, void *data,
1391                          int (*fn)(struct device *dev, void *data))
1392{
1393        struct klist_iter i;
1394        struct device *child;
1395        int error = 0;
1396
1397        if (!parent->p)
1398                return 0;
1399
1400        klist_iter_init(&parent->p->klist_children, &i);
1401        while ((child = next_device(&i)) && !error)
1402                error = fn(child, data);
1403        klist_iter_exit(&i);
1404        return error;
1405}
1406
1407/**
1408 * device_find_child - device iterator for locating a particular device.
1409 * @parent: parent struct device
1410 * @match: Callback function to check device
1411 * @data: Data to pass to match function
1412 *
1413 * This is similar to the device_for_each_child() function above, but it
1414 * returns a reference to a device that is 'found' for later use, as
1415 * determined by the @match callback.
1416 *
1417 * The callback should return 0 if the device doesn't match and non-zero
1418 * if it does.  If the callback returns non-zero and a reference to the
1419 * current device can be obtained, this function will return to the caller
1420 * and not iterate over any more devices.
1421 *
1422 * NOTE: you will need to drop the reference with put_device() after use.
1423 */
1424struct device *device_find_child(struct device *parent, void *data,
1425                                 int (*match)(struct device *dev, void *data))
1426{
1427        struct klist_iter i;
1428        struct device *child;
1429
1430        if (!parent)
1431                return NULL;
1432
1433        klist_iter_init(&parent->p->klist_children, &i);
1434        while ((child = next_device(&i)))
1435                if (match(child, data) && get_device(child))
1436                        break;
1437        klist_iter_exit(&i);
1438        return child;
1439}
1440
1441int __init devices_init(void)
1442{
1443        devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1444        if (!devices_kset)
1445                return -ENOMEM;
1446        dev_kobj = kobject_create_and_add("dev", NULL);
1447        if (!dev_kobj)
1448                goto dev_kobj_err;
1449        sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1450        if (!sysfs_dev_block_kobj)
1451                goto block_kobj_err;
1452        sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1453        if (!sysfs_dev_char_kobj)
1454                goto char_kobj_err;
1455
1456        return 0;
1457
1458 char_kobj_err:
1459        kobject_put(sysfs_dev_block_kobj);
1460 block_kobj_err:
1461        kobject_put(dev_kobj);
1462 dev_kobj_err:
1463        kset_unregister(devices_kset);
1464        return -ENOMEM;
1465}
1466
1467EXPORT_SYMBOL_GPL(device_for_each_child);
1468EXPORT_SYMBOL_GPL(device_find_child);
1469
1470EXPORT_SYMBOL_GPL(device_initialize);
1471EXPORT_SYMBOL_GPL(device_add);
1472EXPORT_SYMBOL_GPL(device_register);
1473
1474EXPORT_SYMBOL_GPL(device_del);
1475EXPORT_SYMBOL_GPL(device_unregister);
1476EXPORT_SYMBOL_GPL(get_device);
1477EXPORT_SYMBOL_GPL(put_device);
1478
1479EXPORT_SYMBOL_GPL(device_create_file);
1480EXPORT_SYMBOL_GPL(device_remove_file);
1481
1482static DEFINE_MUTEX(device_hotplug_lock);
1483
1484void lock_device_hotplug(void)
1485{
1486        mutex_lock(&device_hotplug_lock);
1487}
1488
1489void unlock_device_hotplug(void)
1490{
1491        mutex_unlock(&device_hotplug_lock);
1492}
1493
1494static int device_check_offline(struct device *dev, void *not_used)
1495{
1496        int ret;
1497
1498        ret = device_for_each_child(dev, NULL, device_check_offline);
1499        if (ret)
1500                return ret;
1501
1502        return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1503}
1504
1505/**
1506 * device_offline - Prepare the device for hot-removal.
1507 * @dev: Device to be put offline.
1508 *
1509 * Execute the device bus type's .offline() callback, if present, to prepare
1510 * the device for a subsequent hot-removal.  If that succeeds, the device must
1511 * not be used until either it is removed or its bus type's .online() callback
1512 * is executed.
1513 *
1514 * Call under device_hotplug_lock.
1515 */
1516int device_offline(struct device *dev)
1517{
1518        int ret;
1519
1520        if (dev->offline_disabled)
1521                return -EPERM;
1522
1523        ret = device_for_each_child(dev, NULL, device_check_offline);
1524        if (ret)
1525                return ret;
1526
1527        device_lock(dev);
1528        if (device_supports_offline(dev)) {
1529                if (dev->offline) {
1530                        ret = 1;
1531                } else {
1532                        ret = dev->bus->offline(dev);
1533                        if (!ret) {
1534                                kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1535                                dev->offline = true;
1536                        }
1537                }
1538        }
1539        device_unlock(dev);
1540
1541        return ret;
1542}
1543
1544/**
1545 * device_online - Put the device back online after successful device_offline().
1546 * @dev: Device to be put back online.
1547 *
1548 * If device_offline() has been successfully executed for @dev, but the device
1549 * has not been removed subsequently, execute its bus type's .online() callback
1550 * to indicate that the device can be used again.
1551 *
1552 * Call under device_hotplug_lock.
1553 */
1554int device_online(struct device *dev)
1555{
1556        int ret = 0;
1557
1558        device_lock(dev);
1559        if (device_supports_offline(dev)) {
1560                if (dev->offline) {
1561                        ret = dev->bus->online(dev);
1562                        if (!ret) {
1563                                kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1564                                dev->offline = false;
1565                        }
1566                } else {
1567                        ret = 1;
1568                }
1569        }
1570        device_unlock(dev);
1571
1572        return ret;
1573}
1574
1575struct root_device {
1576        struct device dev;
1577        struct module *owner;
1578};
1579
1580static inline struct root_device *to_root_device(struct device *d)
1581{
1582        return container_of(d, struct root_device, dev);
1583}
1584
1585static void root_device_release(struct device *dev)
1586{
1587        kfree(to_root_device(dev));
1588}
1589
1590/**
1591 * __root_device_register - allocate and register a root device
1592 * @name: root device name
1593 * @owner: owner module of the root device, usually THIS_MODULE
1594 *
1595 * This function allocates a root device and registers it
1596 * using device_register(). In order to free the returned
1597 * device, use root_device_unregister().
1598 *
1599 * Root devices are dummy devices which allow other devices
1600 * to be grouped under /sys/devices. Use this function to
1601 * allocate a root device and then use it as the parent of
1602 * any device which should appear under /sys/devices/{name}
1603 *
1604 * The /sys/devices/{name} directory will also contain a
1605 * 'module' symlink which points to the @owner directory
1606 * in sysfs.
1607 *
1608 * Returns &struct device pointer on success, or ERR_PTR() on error.
1609 *
1610 * Note: You probably want to use root_device_register().
1611 */
1612struct device *__root_device_register(const char *name, struct module *owner)
1613{
1614        struct root_device *root;
1615        int err = -ENOMEM;
1616
1617        root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1618        if (!root)
1619                return ERR_PTR(err);
1620
1621        err = dev_set_name(&root->dev, "%s", name);
1622        if (err) {
1623                kfree(root);
1624                return ERR_PTR(err);
1625        }
1626
1627        root->dev.release = root_device_release;
1628
1629        err = device_register(&root->dev);
1630        if (err) {
1631                put_device(&root->dev);
1632                return ERR_PTR(err);
1633        }
1634
1635#ifdef CONFIG_MODULES   /* gotta find a "cleaner" way to do this */
1636        if (owner) {
1637                struct module_kobject *mk = &owner->mkobj;
1638
1639                err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1640                if (err) {
1641                        device_unregister(&root->dev);
1642                        return ERR_PTR(err);
1643                }
1644                root->owner = owner;
1645        }
1646#endif
1647
1648        return &root->dev;
1649}
1650EXPORT_SYMBOL_GPL(__root_device_register);
1651
1652/**
1653 * root_device_unregister - unregister and free a root device
1654 * @dev: device going away
1655 *
1656 * This function unregisters and cleans up a device that was created by
1657 * root_device_register().
1658 */
1659void root_device_unregister(struct device *dev)
1660{
1661        struct root_device *root = to_root_device(dev);
1662
1663        if (root->owner)
1664                sysfs_remove_link(&root->dev.kobj, "module");
1665
1666        device_unregister(dev);
1667}
1668EXPORT_SYMBOL_GPL(root_device_unregister);
1669
1670
1671static void device_create_release(struct device *dev)
1672{
1673        pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1674        kfree(dev);
1675}
1676
1677static struct device *
1678device_create_groups_vargs(struct class *class, struct device *parent,
1679                           dev_t devt, void *drvdata,
1680                           const struct attribute_group **groups,
1681                           const char *fmt, va_list args)
1682{
1683        struct device *dev = NULL;
1684        int retval = -ENODEV;
1685
1686        if (class == NULL || IS_ERR(class))
1687                goto error;
1688
1689        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1690        if (!dev) {
1691                retval = -ENOMEM;
1692                goto error;
1693        }
1694
1695        dev->devt = devt;
1696        dev->class = class;
1697        dev->parent = parent;
1698        dev->groups = groups;
1699        dev->release = device_create_release;
1700        dev_set_drvdata(dev, drvdata);
1701
1702        retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1703        if (retval)
1704                goto error;
1705
1706        retval = device_register(dev);
1707        if (retval)
1708                goto error;
1709
1710        return dev;
1711
1712error:
1713        put_device(dev);
1714        return ERR_PTR(retval);
1715}
1716
1717/**
1718 * device_create_vargs - creates a device and registers it with sysfs
1719 * @class: pointer to the struct class that this device should be registered to
1720 * @parent: pointer to the parent struct device of this new device, if any
1721 * @devt: the dev_t for the char device to be added
1722 * @drvdata: the data to be added to the device for callbacks
1723 * @fmt: string for the device's name
1724 * @args: va_list for the device's name
1725 *
1726 * This function can be used by char device classes.  A struct device
1727 * will be created in sysfs, registered to the specified class.
1728 *
1729 * A "dev" file will be created, showing the dev_t for the device, if
1730 * the dev_t is not 0,0.
1731 * If a pointer to a parent struct device is passed in, the newly created
1732 * struct device will be a child of that device in sysfs.
1733 * The pointer to the struct device will be returned from the call.
1734 * Any further sysfs files that might be required can be created using this
1735 * pointer.
1736 *
1737 * Returns &struct device pointer on success, or ERR_PTR() on error.
1738 *
1739 * Note: the struct class passed to this function must have previously
1740 * been created with a call to class_create().
1741 */
1742struct device *device_create_vargs(struct class *class, struct device *parent,
1743                                   dev_t devt, void *drvdata, const char *fmt,
1744                                   va_list args)
1745{
1746        return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1747                                          fmt, args);
1748}
1749EXPORT_SYMBOL_GPL(device_create_vargs);
1750
1751/**
1752 * device_create - creates a device and registers it with sysfs
1753 * @class: pointer to the struct class that this device should be registered to
1754 * @parent: pointer to the parent struct device of this new device, if any
1755 * @devt: the dev_t for the char device to be added
1756 * @drvdata: the data to be added to the device for callbacks
1757 * @fmt: string for the device's name
1758 *
1759 * This function can be used by char device classes.  A struct device
1760 * will be created in sysfs, registered to the specified class.
1761 *
1762 * A "dev" file will be created, showing the dev_t for the device, if
1763 * the dev_t is not 0,0.
1764 * If a pointer to a parent struct device is passed in, the newly created
1765 * struct device will be a child of that device in sysfs.
1766 * The pointer to the struct device will be returned from the call.
1767 * Any further sysfs files that might be required can be created using this
1768 * pointer.
1769 *
1770 * Returns &struct device pointer on success, or ERR_PTR() on error.
1771 *
1772 * Note: the struct class passed to this function must have previously
1773 * been created with a call to class_create().
1774 */
1775struct device *device_create(struct class *class, struct device *parent,
1776                             dev_t devt, void *drvdata, const char *fmt, ...)
1777{
1778        va_list vargs;
1779        struct device *dev;
1780
1781        va_start(vargs, fmt);
1782        dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1783        va_end(vargs);
1784        return dev;
1785}
1786EXPORT_SYMBOL_GPL(device_create);
1787
1788/**
1789 * device_create_with_groups - creates a device and registers it with sysfs
1790 * @class: pointer to the struct class that this device should be registered to
1791 * @parent: pointer to the parent struct device of this new device, if any
1792 * @devt: the dev_t for the char device to be added
1793 * @drvdata: the data to be added to the device for callbacks
1794 * @groups: NULL-terminated list of attribute groups to be created
1795 * @fmt: string for the device's name
1796 *
1797 * This function can be used by char device classes.  A struct device
1798 * will be created in sysfs, registered to the specified class.
1799 * Additional attributes specified in the groups parameter will also
1800 * be created automatically.
1801 *
1802 * A "dev" file will be created, showing the dev_t for the device, if
1803 * the dev_t is not 0,0.
1804 * If a pointer to a parent struct device is passed in, the newly created
1805 * struct device will be a child of that device in sysfs.
1806 * The pointer to the struct device will be returned from the call.
1807 * Any further sysfs files that might be required can be created using this
1808 * pointer.
1809 *
1810 * Returns &struct device pointer on success, or ERR_PTR() on error.
1811 *
1812 * Note: the struct class passed to this function must have previously
1813 * been created with a call to class_create().
1814 */
1815struct device *device_create_with_groups(struct class *class,
1816                                         struct device *parent, dev_t devt,
1817                                         void *drvdata,
1818                                         const struct attribute_group **groups,
1819                                         const char *fmt, ...)
1820{
1821        va_list vargs;
1822        struct device *dev;
1823
1824        va_start(vargs, fmt);
1825        dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1826                                         fmt, vargs);
1827        va_end(vargs);
1828        return dev;
1829}
1830EXPORT_SYMBOL_GPL(device_create_with_groups);
1831
1832static int __match_devt(struct device *dev, const void *data)
1833{
1834        const dev_t *devt = data;
1835
1836        return dev->devt == *devt;
1837}
1838
1839/**
1840 * device_destroy - removes a device that was created with device_create()
1841 * @class: pointer to the struct class that this device was registered with
1842 * @devt: the dev_t of the device that was previously registered
1843 *
1844 * This call unregisters and cleans up a device that was created with a
1845 * call to device_create().
1846 */
1847void device_destroy(struct class *class, dev_t devt)
1848{
1849        struct device *dev;
1850
1851        dev = class_find_device(class, NULL, &devt, __match_devt);
1852        if (dev) {
1853                put_device(dev);
1854                device_unregister(dev);
1855        }
1856}
1857EXPORT_SYMBOL_GPL(device_destroy);
1858
1859/**
1860 * device_rename - renames a device
1861 * @dev: the pointer to the struct device to be renamed
1862 * @new_name: the new name of the device
1863 *
1864 * It is the responsibility of the caller to provide mutual
1865 * exclusion between two different calls of device_rename
1866 * on the same device to ensure that new_name is valid and
1867 * won't conflict with other devices.
1868 *
1869 * Note: Don't call this function.  Currently, the networking layer calls this
1870 * function, but that will change.  The following text from Kay Sievers offers
1871 * some insight:
1872 *
1873 * Renaming devices is racy at many levels, symlinks and other stuff are not
1874 * replaced atomically, and you get a "move" uevent, but it's not easy to
1875 * connect the event to the old and new device. Device nodes are not renamed at
1876 * all, there isn't even support for that in the kernel now.
1877 *
1878 * In the meantime, during renaming, your target name might be taken by another
1879 * driver, creating conflicts. Or the old name is taken directly after you
1880 * renamed it -- then you get events for the same DEVPATH, before you even see
1881 * the "move" event. It's just a mess, and nothing new should ever rely on
1882 * kernel device renaming. Besides that, it's not even implemented now for
1883 * other things than (driver-core wise very simple) network devices.
1884 *
1885 * We are currently about to change network renaming in udev to completely
1886 * disallow renaming of devices in the same namespace as the kernel uses,
1887 * because we can't solve the problems properly, that arise with swapping names
1888 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1889 * be allowed to some other name than eth[0-9]*, for the aforementioned
1890 * reasons.
1891 *
1892 * Make up a "real" name in the driver before you register anything, or add
1893 * some other attributes for userspace to find the device, or use udev to add
1894 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1895 * don't even want to get into that and try to implement the missing pieces in
1896 * the core. We really have other pieces to fix in the driver core mess. :)
1897 */
1898int device_rename(struct device *dev, const char *new_name)
1899{
1900        char *old_device_name = NULL;
1901        int error;
1902
1903        dev = get_device(dev);
1904        if (!dev)
1905                return -EINVAL;
1906
1907        pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1908                 __func__, new_name);
1909
1910        old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1911        if (!old_device_name) {
1912                error = -ENOMEM;
1913                goto out;
1914        }
1915
1916        if (dev->class) {
1917                error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1918                        &dev->kobj, old_device_name, new_name);
1919                if (error)
1920                        goto out;
1921        }
1922
1923        error = kobject_rename(&dev->kobj, new_name);
1924        if (error)
1925                goto out;
1926
1927out:
1928        put_device(dev);
1929
1930        kfree(old_device_name);
1931
1932        return error;
1933}
1934EXPORT_SYMBOL_GPL(device_rename);
1935
1936static int device_move_class_links(struct device *dev,
1937                                   struct device *old_parent,
1938                                   struct device *new_parent)
1939{
1940        int error = 0;
1941
1942        if (old_parent)
1943                sysfs_remove_link(&dev->kobj, "device");
1944        if (new_parent)
1945                error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1946                                          "device");
1947        return error;
1948}
1949
1950/**
1951 * device_move - moves a device to a new parent
1952 * @dev: the pointer to the struct device to be moved
1953 * @new_parent: the new parent of the device (can by NULL)
1954 * @dpm_order: how to reorder the dpm_list
1955 */
1956int device_move(struct device *dev, struct device *new_parent,
1957                enum dpm_order dpm_order)
1958{
1959        int error;
1960        struct device *old_parent;
1961        struct kobject *new_parent_kobj;
1962
1963        dev = get_device(dev);
1964        if (!dev)
1965                return -EINVAL;
1966
1967        device_pm_lock();
1968        new_parent = get_device(new_parent);
1969        new_parent_kobj = get_device_parent(dev, new_parent);
1970
1971        pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1972                 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1973        error = kobject_move(&dev->kobj, new_parent_kobj);
1974        if (error) {
1975                cleanup_glue_dir(dev, new_parent_kobj);
1976                put_device(new_parent);
1977                goto out;
1978        }
1979        old_parent = dev->parent;
1980        dev->parent = new_parent;
1981        if (old_parent)
1982                klist_remove(&dev->p->knode_parent);
1983        if (new_parent) {
1984                klist_add_tail(&dev->p->knode_parent,
1985                               &new_parent->p->klist_children);
1986                set_dev_node(dev, dev_to_node(new_parent));
1987        }
1988
1989        if (dev->class) {
1990                error = device_move_class_links(dev, old_parent, new_parent);
1991                if (error) {
1992                        /* We ignore errors on cleanup since we're hosed anyway... */
1993                        device_move_class_links(dev, new_parent, old_parent);
1994                        if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1995                                if (new_parent)
1996                                        klist_remove(&dev->p->knode_parent);
1997                                dev->parent = old_parent;
1998                                if (old_parent) {
1999                                        klist_add_tail(&dev->p->knode_parent,
2000                                                       &old_parent->p->klist_children);
2001                                        set_dev_node(dev, dev_to_node(old_parent));
2002                                }
2003                        }
2004                        cleanup_glue_dir(dev, new_parent_kobj);
2005                        put_device(new_parent);
2006                        goto out;
2007                }
2008        }
2009        switch (dpm_order) {
2010        case DPM_ORDER_NONE:
2011                break;
2012        case DPM_ORDER_DEV_AFTER_PARENT:
2013                device_pm_move_after(dev, new_parent);
2014                break;
2015        case DPM_ORDER_PARENT_BEFORE_DEV:
2016                device_pm_move_before(new_parent, dev);
2017                break;
2018        case DPM_ORDER_DEV_LAST:
2019                device_pm_move_last(dev);
2020                break;
2021        }
2022
2023        put_device(old_parent);
2024out:
2025        device_pm_unlock();
2026        put_device(dev);
2027        return error;
2028}
2029EXPORT_SYMBOL_GPL(device_move);
2030
2031/**
2032 * device_shutdown - call ->shutdown() on each device to shutdown.
2033 */
2034void device_shutdown(void)
2035{
2036        struct device *dev;
2037
2038        spin_lock(&devices_kset->list_lock);
2039        /*
2040         * Walk the devices list backward, shutting down each in turn.
2041         * Beware that device unplug events may also start pulling
2042         * devices offline, even as the system is shutting down.
2043         */
2044        while (!list_empty(&devices_kset->list)) {
2045                dev = list_entry(devices_kset->list.prev, struct device,
2046                                kobj.entry);
2047
2048                /*
2049                 * hold reference count of device's parent to
2050                 * prevent it from being freed because parent's
2051                 * lock is to be held
2052                 */
2053                get_device(dev->parent);
2054                get_device(dev);
2055                /*
2056                 * Make sure the device is off the kset list, in the
2057                 * event that dev->*->shutdown() doesn't remove it.
2058                 */
2059                list_del_init(&dev->kobj.entry);
2060                spin_unlock(&devices_kset->list_lock);
2061
2062                /* hold lock to avoid race with probe/release */
2063                if (dev->parent)
2064                        device_lock(dev->parent);
2065                device_lock(dev);
2066
2067                /* Don't allow any more runtime suspends */
2068                pm_runtime_get_noresume(dev);
2069                pm_runtime_barrier(dev);
2070
2071                if (dev->bus && dev->bus->shutdown) {
2072                        if (initcall_debug)
2073                                dev_info(dev, "shutdown\n");
2074                        dev->bus->shutdown(dev);
2075                } else if (dev->driver && dev->driver->shutdown) {
2076                        if (initcall_debug)
2077                                dev_info(dev, "shutdown\n");
2078                        dev->driver->shutdown(dev);
2079                }
2080
2081                device_unlock(dev);
2082                if (dev->parent)
2083                        device_unlock(dev->parent);
2084
2085                put_device(dev);
2086                put_device(dev->parent);
2087
2088                spin_lock(&devices_kset->list_lock);
2089        }
2090        spin_unlock(&devices_kset->list_lock);
2091        async_synchronize_full();
2092}
2093
2094/*
2095 * Device logging functions
2096 */
2097
2098#ifdef CONFIG_PRINTK
2099static int
2100create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2101{
2102        const char *subsys;
2103        size_t pos = 0;
2104
2105        if (dev->class)
2106                subsys = dev->class->name;
2107        else if (dev->bus)
2108                subsys = dev->bus->name;
2109        else
2110                return 0;
2111
2112        pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2113
2114        /*
2115         * Add device identifier DEVICE=:
2116         *   b12:8         block dev_t
2117         *   c127:3        char dev_t
2118         *   n8            netdev ifindex
2119         *   +sound:card0  subsystem:devname
2120         */
2121        if (MAJOR(dev->devt)) {
2122                char c;
2123
2124                if (strcmp(subsys, "block") == 0)
2125                        c = 'b';
2126                else
2127                        c = 'c';
2128                pos++;
2129                pos += snprintf(hdr + pos, hdrlen - pos,
2130                                "DEVICE=%c%u:%u",
2131                                c, MAJOR(dev->devt), MINOR(dev->devt));
2132        } else if (strcmp(subsys, "net") == 0) {
2133                struct net_device *net = to_net_dev(dev);
2134
2135                pos++;
2136                pos += snprintf(hdr + pos, hdrlen - pos,
2137                                "DEVICE=n%u", net->ifindex);
2138        } else {
2139                pos++;
2140                pos += snprintf(hdr + pos, hdrlen - pos,
2141                                "DEVICE=+%s:%s", subsys, dev_name(dev));
2142        }
2143
2144        return pos;
2145}
2146EXPORT_SYMBOL(create_syslog_header);
2147
2148int dev_vprintk_emit(int level, const struct device *dev,
2149                     const char *fmt, va_list args)
2150{
2151        char hdr[128];
2152        size_t hdrlen;
2153
2154        hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2155
2156        return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2157}
2158EXPORT_SYMBOL(dev_vprintk_emit);
2159
2160int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2161{
2162        va_list args;
2163        int r;
2164
2165        va_start(args, fmt);
2166
2167        r = dev_vprintk_emit(level, dev, fmt, args);
2168
2169        va_end(args);
2170
2171        return r;
2172}
2173EXPORT_SYMBOL(dev_printk_emit);
2174
2175static int __dev_printk(const char *level, const struct device *dev,
2176                        struct va_format *vaf)
2177{
2178        if (!dev)
2179                return printk("%s(NULL device *): %pV", level, vaf);
2180
2181        return dev_printk_emit(level[1] - '0', dev,
2182                               "%s %s: %pV",
2183                               dev_driver_string(dev), dev_name(dev), vaf);
2184}
2185
2186int dev_printk(const char *level, const struct device *dev,
2187               const char *fmt, ...)
2188{
2189        struct va_format vaf;
2190        va_list args;
2191        int r;
2192
2193        va_start(args, fmt);
2194
2195        vaf.fmt = fmt;
2196        vaf.va = &args;
2197
2198        r = __dev_printk(level, dev, &vaf);
2199
2200        va_end(args);
2201
2202        return r;
2203}
2204EXPORT_SYMBOL(dev_printk);
2205
2206#define define_dev_printk_level(func, kern_level)               \
2207int func(const struct device *dev, const char *fmt, ...)        \
2208{                                                               \
2209        struct va_format vaf;                                   \
2210        va_list args;                                           \
2211        int r;                                                  \
2212                                                                \
2213        va_start(args, fmt);                                    \
2214                                                                \
2215        vaf.fmt = fmt;                                          \
2216        vaf.va = &args;                                         \
2217                                                                \
2218        r = __dev_printk(kern_level, dev, &vaf);                \
2219                                                                \
2220        va_end(args);                                           \
2221                                                                \
2222        return r;                                               \
2223}                                                               \
2224EXPORT_SYMBOL(func);
2225
2226define_dev_printk_level(dev_emerg, KERN_EMERG);
2227define_dev_printk_level(dev_alert, KERN_ALERT);
2228define_dev_printk_level(dev_crit, KERN_CRIT);
2229define_dev_printk_level(dev_err, KERN_ERR);
2230define_dev_printk_level(dev_warn, KERN_WARNING);
2231define_dev_printk_level(dev_notice, KERN_NOTICE);
2232define_dev_printk_level(_dev_info, KERN_INFO);
2233
2234#endif
2235
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