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/fwnode.h>
  16#include <linux/init.h>
  17#include <linux/module.h>
  18#include <linux/slab.h>
  19#include <linux/string.h>
  20#include <linux/kdev_t.h>
  21#include <linux/notifier.h>
  22#include <linux/of.h>
  23#include <linux/of_device.h>
  24#include <linux/genhd.h>
  25#include <linux/kallsyms.h>
  26#include <linux/mutex.h>
  27#include <linux/pm_runtime.h>
  28#include <linux/netdevice.h>
  29#include <linux/sysfs.h>
  30
  31#include "base.h"
  32#include "power/power.h"
  33
  34#ifdef CONFIG_SYSFS_DEPRECATED
  35#ifdef CONFIG_SYSFS_DEPRECATED_V2
  36long sysfs_deprecated = 1;
  37#else
  38long sysfs_deprecated = 0;
  39#endif
  40static int __init sysfs_deprecated_setup(char *arg)
  41{
  42	return kstrtol(arg, 10, &sysfs_deprecated);
  43}
  44early_param("sysfs.deprecated", sysfs_deprecated_setup);
  45#endif
  46
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  47int (*platform_notify)(struct device *dev) = NULL;
  48int (*platform_notify_remove)(struct device *dev) = NULL;
  49static struct kobject *dev_kobj;
  50struct kobject *sysfs_dev_char_kobj;
  51struct kobject *sysfs_dev_block_kobj;
  52
  53static DEFINE_MUTEX(device_hotplug_lock);
  54
  55void lock_device_hotplug(void)
  56{
  57	mutex_lock(&device_hotplug_lock);
  58}
  59
  60void unlock_device_hotplug(void)
  61{
  62	mutex_unlock(&device_hotplug_lock);
  63}
  64
  65int lock_device_hotplug_sysfs(void)
  66{
  67	if (mutex_trylock(&device_hotplug_lock))
  68		return 0;
  69
  70	/* Avoid busy looping (5 ms of sleep should do). */
  71	msleep(5);
  72	return restart_syscall();
  73}
  74
  75#ifdef CONFIG_BLOCK
  76static inline int device_is_not_partition(struct device *dev)
  77{
  78	return !(dev->type == &part_type);
  79}
  80#else
  81static inline int device_is_not_partition(struct device *dev)
  82{
  83	return 1;
  84}
  85#endif
  86
  87/**
  88 * dev_driver_string - Return a device's driver name, if at all possible
  89 * @dev: struct device to get the name of
  90 *
  91 * Will return the device's driver's name if it is bound to a device.  If
  92 * the device is not bound to a driver, it will return the name of the bus
  93 * it is attached to.  If it is not attached to a bus either, an empty
  94 * string will be returned.
  95 */
  96const char *dev_driver_string(const struct device *dev)
  97{
  98	struct device_driver *drv;
  99
 100	/* dev->driver can change to NULL underneath us because of unbinding,
 101	 * so be careful about accessing it.  dev->bus and dev->class should
 102	 * never change once they are set, so they don't need special care.
 103	 */
 104	drv = ACCESS_ONCE(dev->driver);
 105	return drv ? drv->name :
 106			(dev->bus ? dev->bus->name :
 107			(dev->class ? dev->class->name : ""));
 108}
 109EXPORT_SYMBOL(dev_driver_string);
 110
 111#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
 112
 113static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
 114			     char *buf)
 115{
 116	struct device_attribute *dev_attr = to_dev_attr(attr);
 117	struct device *dev = kobj_to_dev(kobj);
 118	ssize_t ret = -EIO;
 119
 120	if (dev_attr->show)
 121		ret = dev_attr->show(dev, dev_attr, buf);
 122	if (ret >= (ssize_t)PAGE_SIZE) {
 123		print_symbol("dev_attr_show: %s returned bad count\n",
 124				(unsigned long)dev_attr->show);
 125	}
 126	return ret;
 127}
 128
 129static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
 130			      const char *buf, size_t count)
 131{
 132	struct device_attribute *dev_attr = to_dev_attr(attr);
 133	struct device *dev = kobj_to_dev(kobj);
 134	ssize_t ret = -EIO;
 135
 136	if (dev_attr->store)
 137		ret = dev_attr->store(dev, dev_attr, buf, count);
 138	return ret;
 139}
 140
 141static const struct sysfs_ops dev_sysfs_ops = {
 142	.show	= dev_attr_show,
 143	.store	= dev_attr_store,
 144};
 145
 146#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
 147
 148ssize_t device_store_ulong(struct device *dev,
 149			   struct device_attribute *attr,
 150			   const char *buf, size_t size)
 151{
 152	struct dev_ext_attribute *ea = to_ext_attr(attr);
 153	char *end;
 154	unsigned long new = simple_strtoul(buf, &end, 0);
 155	if (end == buf)
 156		return -EINVAL;
 157	*(unsigned long *)(ea->var) = new;
 158	/* Always return full write size even if we didn't consume all */
 159	return size;
 160}
 161EXPORT_SYMBOL_GPL(device_store_ulong);
 162
 163ssize_t device_show_ulong(struct device *dev,
 164			  struct device_attribute *attr,
 165			  char *buf)
 166{
 167	struct dev_ext_attribute *ea = to_ext_attr(attr);
 168	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
 169}
 170EXPORT_SYMBOL_GPL(device_show_ulong);
 171
 172ssize_t device_store_int(struct device *dev,
 173			 struct device_attribute *attr,
 174			 const char *buf, size_t size)
 175{
 176	struct dev_ext_attribute *ea = to_ext_attr(attr);
 177	char *end;
 178	long new = simple_strtol(buf, &end, 0);
 179	if (end == buf || new > INT_MAX || new < INT_MIN)
 180		return -EINVAL;
 181	*(int *)(ea->var) = new;
 182	/* Always return full write size even if we didn't consume all */
 183	return size;
 184}
 185EXPORT_SYMBOL_GPL(device_store_int);
 186
 187ssize_t device_show_int(struct device *dev,
 188			struct device_attribute *attr,
 189			char *buf)
 190{
 191	struct dev_ext_attribute *ea = to_ext_attr(attr);
 192
 193	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
 194}
 195EXPORT_SYMBOL_GPL(device_show_int);
 196
 197ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 198			  const char *buf, size_t size)
 199{
 200	struct dev_ext_attribute *ea = to_ext_attr(attr);
 201
 202	if (strtobool(buf, ea->var) < 0)
 203		return -EINVAL;
 204
 205	return size;
 206}
 207EXPORT_SYMBOL_GPL(device_store_bool);
 208
 209ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 210			 char *buf)
 211{
 212	struct dev_ext_attribute *ea = to_ext_attr(attr);
 213
 214	return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
 215}
 216EXPORT_SYMBOL_GPL(device_show_bool);
 217
 218/**
 219 * device_release - free device structure.
 220 * @kobj: device's kobject.
 221 *
 222 * This is called once the reference count for the object
 223 * reaches 0. We forward the call to the device's release
 224 * method, which should handle actually freeing the structure.
 225 */
 226static void device_release(struct kobject *kobj)
 227{
 228	struct device *dev = kobj_to_dev(kobj);
 229	struct device_private *p = dev->p;
 230
 231	/*
 232	 * Some platform devices are driven without driver attached
 233	 * and managed resources may have been acquired.  Make sure
 234	 * all resources are released.
 235	 *
 236	 * Drivers still can add resources into device after device
 237	 * is deleted but alive, so release devres here to avoid
 238	 * possible memory leak.
 239	 */
 240	devres_release_all(dev);
 241
 242	if (dev->release)
 243		dev->release(dev);
 244	else if (dev->type && dev->type->release)
 245		dev->type->release(dev);
 246	else if (dev->class && dev->class->dev_release)
 247		dev->class->dev_release(dev);
 248	else
 249		WARN(1, KERN_ERR "Device '%s' does not have a release() "
 250			"function, it is broken and must be fixed.\n",
 251			dev_name(dev));
 252	kfree(p);
 253}
 254
 255static const void *device_namespace(struct kobject *kobj)
 256{
 257	struct device *dev = kobj_to_dev(kobj);
 258	const void *ns = NULL;
 259
 260	if (dev->class && dev->class->ns_type)
 261		ns = dev->class->namespace(dev);
 262
 263	return ns;
 264}
 265
 266static struct kobj_type device_ktype = {
 267	.release	= device_release,
 268	.sysfs_ops	= &dev_sysfs_ops,
 269	.namespace	= device_namespace,
 270};
 271
 272
 273static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 274{
 275	struct kobj_type *ktype = get_ktype(kobj);
 276
 277	if (ktype == &device_ktype) {
 278		struct device *dev = kobj_to_dev(kobj);
 279		if (dev->bus)
 280			return 1;
 281		if (dev->class)
 282			return 1;
 283	}
 284	return 0;
 285}
 286
 287static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 288{
 289	struct device *dev = kobj_to_dev(kobj);
 290
 291	if (dev->bus)
 292		return dev->bus->name;
 293	if (dev->class)
 294		return dev->class->name;
 295	return NULL;
 296}
 297
 298static int dev_uevent(struct kset *kset, struct kobject *kobj,
 299		      struct kobj_uevent_env *env)
 300{
 301	struct device *dev = kobj_to_dev(kobj);
 302	int retval = 0;
 303
 304	/* add device node properties if present */
 305	if (MAJOR(dev->devt)) {
 306		const char *tmp;
 307		const char *name;
 308		umode_t mode = 0;
 309		kuid_t uid = GLOBAL_ROOT_UID;
 310		kgid_t gid = GLOBAL_ROOT_GID;
 311
 312		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 313		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 314		name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
 315		if (name) {
 316			add_uevent_var(env, "DEVNAME=%s", name);
 317			if (mode)
 318				add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
 319			if (!uid_eq(uid, GLOBAL_ROOT_UID))
 320				add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
 321			if (!gid_eq(gid, GLOBAL_ROOT_GID))
 322				add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
 323			kfree(tmp);
 324		}
 325	}
 326
 327	if (dev->type && dev->type->name)
 328		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 329
 330	if (dev->driver)
 331		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 332
 333	/* Add common DT information about the device */
 334	of_device_uevent(dev, env);
 335
 336	/* have the bus specific function add its stuff */
 337	if (dev->bus && dev->bus->uevent) {
 338		retval = dev->bus->uevent(dev, env);
 339		if (retval)
 340			pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 341				 dev_name(dev), __func__, retval);
 342	}
 343
 344	/* have the class specific function add its stuff */
 345	if (dev->class && dev->class->dev_uevent) {
 346		retval = dev->class->dev_uevent(dev, env);
 347		if (retval)
 348			pr_debug("device: '%s': %s: class uevent() "
 349				 "returned %d\n", dev_name(dev),
 350				 __func__, retval);
 351	}
 352
 353	/* have the device type specific function add its stuff */
 354	if (dev->type && dev->type->uevent) {
 355		retval = dev->type->uevent(dev, env);
 356		if (retval)
 357			pr_debug("device: '%s': %s: dev_type uevent() "
 358				 "returned %d\n", dev_name(dev),
 359				 __func__, retval);
 360	}
 361
 362	return retval;
 363}
 364
 365static const struct kset_uevent_ops device_uevent_ops = {
 366	.filter =	dev_uevent_filter,
 367	.name =		dev_uevent_name,
 368	.uevent =	dev_uevent,
 369};
 370
 371static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 372			   char *buf)
 373{
 374	struct kobject *top_kobj;
 375	struct kset *kset;
 376	struct kobj_uevent_env *env = NULL;
 377	int i;
 378	size_t count = 0;
 379	int retval;
 380
 381	/* search the kset, the device belongs to */
 382	top_kobj = &dev->kobj;
 383	while (!top_kobj->kset && top_kobj->parent)
 384		top_kobj = top_kobj->parent;
 385	if (!top_kobj->kset)
 386		goto out;
 387
 388	kset = top_kobj->kset;
 389	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 390		goto out;
 391
 392	/* respect filter */
 393	if (kset->uevent_ops && kset->uevent_ops->filter)
 394		if (!kset->uevent_ops->filter(kset, &dev->kobj))
 395			goto out;
 396
 397	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 398	if (!env)
 399		return -ENOMEM;
 400
 401	/* let the kset specific function add its keys */
 402	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 403	if (retval)
 404		goto out;
 405
 406	/* copy keys to file */
 407	for (i = 0; i < env->envp_idx; i++)
 408		count += sprintf(&buf[count], "%s\n", env->envp[i]);
 409out:
 410	kfree(env);
 411	return count;
 412}
 413
 414static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
 415			    const char *buf, size_t count)
 416{
 417	enum kobject_action action;
 418
 419	if (kobject_action_type(buf, count, &action) == 0)
 420		kobject_uevent(&dev->kobj, action);
 421	else
 422		dev_err(dev, "uevent: unknown action-string\n");
 423	return count;
 424}
 425static DEVICE_ATTR_RW(uevent);
 426
 427static ssize_t online_show(struct device *dev, struct device_attribute *attr,
 428			   char *buf)
 429{
 430	bool val;
 431
 432	device_lock(dev);
 433	val = !dev->offline;
 434	device_unlock(dev);
 435	return sprintf(buf, "%u\n", val);
 436}
 437
 438static ssize_t online_store(struct device *dev, struct device_attribute *attr,
 439			    const char *buf, size_t count)
 440{
 441	bool val;
 442	int ret;
 443
 444	ret = strtobool(buf, &val);
 445	if (ret < 0)
 446		return ret;
 447
 448	ret = lock_device_hotplug_sysfs();
 449	if (ret)
 450		return ret;
 451
 452	ret = val ? device_online(dev) : device_offline(dev);
 453	unlock_device_hotplug();
 454	return ret < 0 ? ret : count;
 455}
 456static DEVICE_ATTR_RW(online);
 457
 458int device_add_groups(struct device *dev, const struct attribute_group **groups)
 459{
 460	return sysfs_create_groups(&dev->kobj, groups);
 461}
 462
 463void device_remove_groups(struct device *dev,
 464			  const struct attribute_group **groups)
 465{
 466	sysfs_remove_groups(&dev->kobj, groups);
 467}
 468
 469static int device_add_attrs(struct device *dev)
 470{
 471	struct class *class = dev->class;
 472	const struct device_type *type = dev->type;
 473	int error;
 474
 475	if (class) {
 476		error = device_add_groups(dev, class->dev_groups);
 477		if (error)
 478			return error;
 479	}
 480
 481	if (type) {
 482		error = device_add_groups(dev, type->groups);
 483		if (error)
 484			goto err_remove_class_groups;
 485	}
 486
 487	error = device_add_groups(dev, dev->groups);
 488	if (error)
 489		goto err_remove_type_groups;
 490
 491	if (device_supports_offline(dev) && !dev->offline_disabled) {
 492		error = device_create_file(dev, &dev_attr_online);
 493		if (error)
 494			goto err_remove_dev_groups;
 495	}
 496
 497	return 0;
 498
 499 err_remove_dev_groups:
 500	device_remove_groups(dev, dev->groups);
 501 err_remove_type_groups:
 502	if (type)
 503		device_remove_groups(dev, type->groups);
 504 err_remove_class_groups:
 505	if (class)
 506		device_remove_groups(dev, class->dev_groups);
 507
 508	return error;
 509}
 510
 511static void device_remove_attrs(struct device *dev)
 512{
 513	struct class *class = dev->class;
 514	const struct device_type *type = dev->type;
 515
 516	device_remove_file(dev, &dev_attr_online);
 517	device_remove_groups(dev, dev->groups);
 518
 519	if (type)
 520		device_remove_groups(dev, type->groups);
 521
 522	if (class)
 523		device_remove_groups(dev, class->dev_groups);
 524}
 525
 526static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
 527			char *buf)
 528{
 529	return print_dev_t(buf, dev->devt);
 530}
 531static DEVICE_ATTR_RO(dev);
 532
 533/* /sys/devices/ */
 534struct kset *devices_kset;
 535
 536/**
 537 * devices_kset_move_before - Move device in the devices_kset's list.
 538 * @deva: Device to move.
 539 * @devb: Device @deva should come before.
 540 */
 541static void devices_kset_move_before(struct device *deva, struct device *devb)
 542{
 543	if (!devices_kset)
 544		return;
 545	pr_debug("devices_kset: Moving %s before %s\n",
 546		 dev_name(deva), dev_name(devb));
 547	spin_lock(&devices_kset->list_lock);
 548	list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
 549	spin_unlock(&devices_kset->list_lock);
 550}
 551
 552/**
 553 * devices_kset_move_after - Move device in the devices_kset's list.
 554 * @deva: Device to move
 555 * @devb: Device @deva should come after.
 556 */
 557static void devices_kset_move_after(struct device *deva, struct device *devb)
 558{
 559	if (!devices_kset)
 560		return;
 561	pr_debug("devices_kset: Moving %s after %s\n",
 562		 dev_name(deva), dev_name(devb));
 563	spin_lock(&devices_kset->list_lock);
 564	list_move(&deva->kobj.entry, &devb->kobj.entry);
 565	spin_unlock(&devices_kset->list_lock);
 566}
 567
 568/**
 569 * devices_kset_move_last - move the device to the end of devices_kset's list.
 570 * @dev: device to move
 571 */
 572void devices_kset_move_last(struct device *dev)
 573{
 574	if (!devices_kset)
 575		return;
 576	pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
 577	spin_lock(&devices_kset->list_lock);
 578	list_move_tail(&dev->kobj.entry, &devices_kset->list);
 579	spin_unlock(&devices_kset->list_lock);
 580}
 581
 582/**
 583 * device_create_file - create sysfs attribute file for device.
 584 * @dev: device.
 585 * @attr: device attribute descriptor.
 586 */
 587int device_create_file(struct device *dev,
 588		       const struct device_attribute *attr)
 589{
 590	int error = 0;
 591
 592	if (dev) {
 593		WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
 594			"Attribute %s: write permission without 'store'\n",
 595			attr->attr.name);
 596		WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
 597			"Attribute %s: read permission without 'show'\n",
 598			attr->attr.name);
 599		error = sysfs_create_file(&dev->kobj, &attr->attr);
 600	}
 601
 602	return error;
 603}
 604EXPORT_SYMBOL_GPL(device_create_file);
 605
 606/**
 607 * device_remove_file - remove sysfs attribute file.
 608 * @dev: device.
 609 * @attr: device attribute descriptor.
 610 */
 611void device_remove_file(struct device *dev,
 612			const struct device_attribute *attr)
 613{
 614	if (dev)
 615		sysfs_remove_file(&dev->kobj, &attr->attr);
 616}
 617EXPORT_SYMBOL_GPL(device_remove_file);
 618
 619/**
 620 * device_remove_file_self - remove sysfs attribute file from its own method.
 621 * @dev: device.
 622 * @attr: device attribute descriptor.
 623 *
 624 * See kernfs_remove_self() for details.
 625 */
 626bool device_remove_file_self(struct device *dev,
 627			     const struct device_attribute *attr)
 628{
 629	if (dev)
 630		return sysfs_remove_file_self(&dev->kobj, &attr->attr);
 631	else
 632		return false;
 633}
 634EXPORT_SYMBOL_GPL(device_remove_file_self);
 635
 636/**
 637 * device_create_bin_file - create sysfs binary attribute file for device.
 638 * @dev: device.
 639 * @attr: device binary attribute descriptor.
 640 */
 641int device_create_bin_file(struct device *dev,
 642			   const struct bin_attribute *attr)
 643{
 644	int error = -EINVAL;
 645	if (dev)
 646		error = sysfs_create_bin_file(&dev->kobj, attr);
 647	return error;
 648}
 649EXPORT_SYMBOL_GPL(device_create_bin_file);
 650
 651/**
 652 * device_remove_bin_file - remove sysfs binary attribute file
 653 * @dev: device.
 654 * @attr: device binary attribute descriptor.
 655 */
 656void device_remove_bin_file(struct device *dev,
 657			    const struct bin_attribute *attr)
 658{
 659	if (dev)
 660		sysfs_remove_bin_file(&dev->kobj, attr);
 661}
 662EXPORT_SYMBOL_GPL(device_remove_bin_file);
 663
 664static void klist_children_get(struct klist_node *n)
 665{
 666	struct device_private *p = to_device_private_parent(n);
 667	struct device *dev = p->device;
 668
 669	get_device(dev);
 670}
 671
 672static void klist_children_put(struct klist_node *n)
 673{
 674	struct device_private *p = to_device_private_parent(n);
 675	struct device *dev = p->device;
 676
 677	put_device(dev);
 678}
 679
 680/**
 681 * device_initialize - init device structure.
 682 * @dev: device.
 683 *
 684 * This prepares the device for use by other layers by initializing
 685 * its fields.
 686 * It is the first half of device_register(), if called by
 687 * that function, though it can also be called separately, so one
 688 * may use @dev's fields. In particular, get_device()/put_device()
 689 * may be used for reference counting of @dev after calling this
 690 * function.
 691 *
 692 * All fields in @dev must be initialized by the caller to 0, except
 693 * for those explicitly set to some other value.  The simplest
 694 * approach is to use kzalloc() to allocate the structure containing
 695 * @dev.
 696 *
 697 * NOTE: Use put_device() to give up your reference instead of freeing
 698 * @dev directly once you have called this function.
 699 */
 700void device_initialize(struct device *dev)
 701{
 702	dev->kobj.kset = devices_kset;
 703	kobject_init(&dev->kobj, &device_ktype);
 704	INIT_LIST_HEAD(&dev->dma_pools);
 705	mutex_init(&dev->mutex);
 706	lockdep_set_novalidate_class(&dev->mutex);
 707	spin_lock_init(&dev->devres_lock);
 708	INIT_LIST_HEAD(&dev->devres_head);
 709	device_pm_init(dev);
 710	set_dev_node(dev, -1);
 711#ifdef CONFIG_GENERIC_MSI_IRQ
 712	INIT_LIST_HEAD(&dev->msi_list);
 713#endif
 
 
 
 714}
 715EXPORT_SYMBOL_GPL(device_initialize);
 716
 717struct kobject *virtual_device_parent(struct device *dev)
 718{
 719	static struct kobject *virtual_dir = NULL;
 720
 721	if (!virtual_dir)
 722		virtual_dir = kobject_create_and_add("virtual",
 723						     &devices_kset->kobj);
 724
 725	return virtual_dir;
 726}
 727
 728struct class_dir {
 729	struct kobject kobj;
 730	struct class *class;
 731};
 732
 733#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
 734
 735static void class_dir_release(struct kobject *kobj)
 736{
 737	struct class_dir *dir = to_class_dir(kobj);
 738	kfree(dir);
 739}
 740
 741static const
 742struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
 743{
 744	struct class_dir *dir = to_class_dir(kobj);
 745	return dir->class->ns_type;
 746}
 747
 748static struct kobj_type class_dir_ktype = {
 749	.release	= class_dir_release,
 750	.sysfs_ops	= &kobj_sysfs_ops,
 751	.child_ns_type	= class_dir_child_ns_type
 752};
 753
 754static struct kobject *
 755class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 756{
 757	struct class_dir *dir;
 758	int retval;
 759
 760	dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 761	if (!dir)
 762		return NULL;
 763
 764	dir->class = class;
 765	kobject_init(&dir->kobj, &class_dir_ktype);
 766
 767	dir->kobj.kset = &class->p->glue_dirs;
 768
 769	retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
 770	if (retval < 0) {
 771		kobject_put(&dir->kobj);
 772		return NULL;
 773	}
 774	return &dir->kobj;
 775}
 776
 777static DEFINE_MUTEX(gdp_mutex);
 778
 779static struct kobject *get_device_parent(struct device *dev,
 780					 struct device *parent)
 781{
 782	if (dev->class) {
 783		struct kobject *kobj = NULL;
 784		struct kobject *parent_kobj;
 785		struct kobject *k;
 786
 787#ifdef CONFIG_BLOCK
 788		/* block disks show up in /sys/block */
 789		if (sysfs_deprecated && dev->class == &block_class) {
 790			if (parent && parent->class == &block_class)
 791				return &parent->kobj;
 792			return &block_class.p->subsys.kobj;
 793		}
 794#endif
 795
 796		/*
 797		 * If we have no parent, we live in "virtual".
 798		 * Class-devices with a non class-device as parent, live
 799		 * in a "glue" directory to prevent namespace collisions.
 800		 */
 801		if (parent == NULL)
 802			parent_kobj = virtual_device_parent(dev);
 803		else if (parent->class && !dev->class->ns_type)
 804			return &parent->kobj;
 805		else
 806			parent_kobj = &parent->kobj;
 807
 808		mutex_lock(&gdp_mutex);
 809
 810		/* find our class-directory at the parent and reference it */
 811		spin_lock(&dev->class->p->glue_dirs.list_lock);
 812		list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
 813			if (k->parent == parent_kobj) {
 814				kobj = kobject_get(k);
 815				break;
 816			}
 817		spin_unlock(&dev->class->p->glue_dirs.list_lock);
 818		if (kobj) {
 819			mutex_unlock(&gdp_mutex);
 820			return kobj;
 821		}
 822
 823		/* or create a new class-directory at the parent device */
 824		k = class_dir_create_and_add(dev->class, parent_kobj);
 825		/* do not emit an uevent for this simple "glue" directory */
 826		mutex_unlock(&gdp_mutex);
 827		return k;
 828	}
 829
 830	/* subsystems can specify a default root directory for their devices */
 831	if (!parent && dev->bus && dev->bus->dev_root)
 832		return &dev->bus->dev_root->kobj;
 833
 834	if (parent)
 835		return &parent->kobj;
 836	return NULL;
 837}
 838
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 839static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 840{
 841	/* see if we live in a "glue" directory */
 842	if (!glue_dir || !dev->class ||
 843	    glue_dir->kset != &dev->class->p->glue_dirs)
 844		return;
 845
 846	mutex_lock(&gdp_mutex);
 847	kobject_put(glue_dir);
 848	mutex_unlock(&gdp_mutex);
 849}
 850
 851static void cleanup_device_parent(struct device *dev)
 852{
 853	cleanup_glue_dir(dev, dev->kobj.parent);
 854}
 855
 856static int device_add_class_symlinks(struct device *dev)
 857{
 858	struct device_node *of_node = dev_of_node(dev);
 859	int error;
 860
 861	if (of_node) {
 862		error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
 863		if (error)
 864			dev_warn(dev, "Error %d creating of_node link\n",error);
 865		/* An error here doesn't warrant bringing down the device */
 866	}
 867
 868	if (!dev->class)
 869		return 0;
 870
 871	error = sysfs_create_link(&dev->kobj,
 872				  &dev->class->p->subsys.kobj,
 873				  "subsystem");
 874	if (error)
 875		goto out_devnode;
 876
 877	if (dev->parent && device_is_not_partition(dev)) {
 878		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 879					  "device");
 880		if (error)
 881			goto out_subsys;
 882	}
 883
 884#ifdef CONFIG_BLOCK
 885	/* /sys/block has directories and does not need symlinks */
 886	if (sysfs_deprecated && dev->class == &block_class)
 887		return 0;
 888#endif
 889
 890	/* link in the class directory pointing to the device */
 891	error = sysfs_create_link(&dev->class->p->subsys.kobj,
 892				  &dev->kobj, dev_name(dev));
 893	if (error)
 894		goto out_device;
 895
 896	return 0;
 897
 898out_device:
 899	sysfs_remove_link(&dev->kobj, "device");
 900
 901out_subsys:
 902	sysfs_remove_link(&dev->kobj, "subsystem");
 903out_devnode:
 904	sysfs_remove_link(&dev->kobj, "of_node");
 905	return error;
 906}
 907
 908static void device_remove_class_symlinks(struct device *dev)
 909{
 910	if (dev_of_node(dev))
 911		sysfs_remove_link(&dev->kobj, "of_node");
 912
 913	if (!dev->class)
 914		return;
 915
 916	if (dev->parent && device_is_not_partition(dev))
 917		sysfs_remove_link(&dev->kobj, "device");
 918	sysfs_remove_link(&dev->kobj, "subsystem");
 919#ifdef CONFIG_BLOCK
 920	if (sysfs_deprecated && dev->class == &block_class)
 921		return;
 922#endif
 923	sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
 924}
 925
 926/**
 927 * dev_set_name - set a device name
 928 * @dev: device
 929 * @fmt: format string for the device's name
 930 */
 931int dev_set_name(struct device *dev, const char *fmt, ...)
 932{
 933	va_list vargs;
 934	int err;
 935
 936	va_start(vargs, fmt);
 937	err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
 938	va_end(vargs);
 939	return err;
 940}
 941EXPORT_SYMBOL_GPL(dev_set_name);
 942
 943/**
 944 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 945 * @dev: device
 946 *
 947 * By default we select char/ for new entries.  Setting class->dev_obj
 948 * to NULL prevents an entry from being created.  class->dev_kobj must
 949 * be set (or cleared) before any devices are registered to the class
 950 * otherwise device_create_sys_dev_entry() and
 951 * device_remove_sys_dev_entry() will disagree about the presence of
 952 * the link.
 953 */
 954static struct kobject *device_to_dev_kobj(struct device *dev)
 955{
 956	struct kobject *kobj;
 957
 958	if (dev->class)
 959		kobj = dev->class->dev_kobj;
 960	else
 961		kobj = sysfs_dev_char_kobj;
 962
 963	return kobj;
 964}
 965
 966static int device_create_sys_dev_entry(struct device *dev)
 967{
 968	struct kobject *kobj = device_to_dev_kobj(dev);
 969	int error = 0;
 970	char devt_str[15];
 971
 972	if (kobj) {
 973		format_dev_t(devt_str, dev->devt);
 974		error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 975	}
 976
 977	return error;
 978}
 979
 980static void device_remove_sys_dev_entry(struct device *dev)
 981{
 982	struct kobject *kobj = device_to_dev_kobj(dev);
 983	char devt_str[15];
 984
 985	if (kobj) {
 986		format_dev_t(devt_str, dev->devt);
 987		sysfs_remove_link(kobj, devt_str);
 988	}
 989}
 990
 991int device_private_init(struct device *dev)
 992{
 993	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
 994	if (!dev->p)
 995		return -ENOMEM;
 996	dev->p->device = dev;
 997	klist_init(&dev->p->klist_children, klist_children_get,
 998		   klist_children_put);
 999	INIT_LIST_HEAD(&dev->p->deferred_probe);
1000	return 0;
1001}
1002
1003/**
1004 * device_add - add device to device hierarchy.
1005 * @dev: device.
1006 *
1007 * This is part 2 of device_register(), though may be called
1008 * separately _iff_ device_initialize() has been called separately.
1009 *
1010 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1011 * to the global and sibling lists for the device, then
1012 * adds it to the other relevant subsystems of the driver model.
1013 *
1014 * Do not call this routine or device_register() more than once for
1015 * any device structure.  The driver model core is not designed to work
1016 * with devices that get unregistered and then spring back to life.
1017 * (Among other things, it's very hard to guarantee that all references
1018 * to the previous incarnation of @dev have been dropped.)  Allocate
1019 * and register a fresh new struct device instead.
1020 *
1021 * NOTE: _Never_ directly free @dev after calling this function, even
1022 * if it returned an error! Always use put_device() to give up your
1023 * reference instead.
1024 */
1025int device_add(struct device *dev)
1026{
1027	struct device *parent = NULL;
1028	struct kobject *kobj;
1029	struct class_interface *class_intf;
1030	int error = -EINVAL;
 
1031
1032	dev = get_device(dev);
1033	if (!dev)
1034		goto done;
1035
1036	if (!dev->p) {
1037		error = device_private_init(dev);
1038		if (error)
1039			goto done;
1040	}
1041
1042	/*
1043	 * for statically allocated devices, which should all be converted
1044	 * some day, we need to initialize the name. We prevent reading back
1045	 * the name, and force the use of dev_name()
1046	 */
1047	if (dev->init_name) {
1048		dev_set_name(dev, "%s", dev->init_name);
1049		dev->init_name = NULL;
1050	}
1051
1052	/* subsystems can specify simple device enumeration */
1053	if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1054		dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1055
1056	if (!dev_name(dev)) {
1057		error = -EINVAL;
1058		goto name_error;
1059	}
1060
1061	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1062
1063	parent = get_device(dev->parent);
1064	kobj = get_device_parent(dev, parent);
1065	if (kobj)
1066		dev->kobj.parent = kobj;
1067
1068	/* use parent numa_node */
1069	if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1070		set_dev_node(dev, dev_to_node(parent));
1071
1072	/* first, register with generic layer. */
1073	/* we require the name to be set before, and pass NULL */
1074	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1075	if (error)
 
1076		goto Error;
 
1077
1078	/* notify platform of device entry */
1079	if (platform_notify)
1080		platform_notify(dev);
1081
1082	error = device_create_file(dev, &dev_attr_uevent);
1083	if (error)
1084		goto attrError;
1085
1086	error = device_add_class_symlinks(dev);
1087	if (error)
1088		goto SymlinkError;
1089	error = device_add_attrs(dev);
1090	if (error)
1091		goto AttrsError;
1092	error = bus_add_device(dev);
1093	if (error)
1094		goto BusError;
1095	error = dpm_sysfs_add(dev);
1096	if (error)
1097		goto DPMError;
1098	device_pm_add(dev);
1099
1100	if (MAJOR(dev->devt)) {
1101		error = device_create_file(dev, &dev_attr_dev);
1102		if (error)
1103			goto DevAttrError;
1104
1105		error = device_create_sys_dev_entry(dev);
1106		if (error)
1107			goto SysEntryError;
1108
1109		devtmpfs_create_node(dev);
1110	}
1111
1112	/* Notify clients of device addition.  This call must come
1113	 * after dpm_sysfs_add() and before kobject_uevent().
1114	 */
1115	if (dev->bus)
1116		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1117					     BUS_NOTIFY_ADD_DEVICE, dev);
1118
1119	kobject_uevent(&dev->kobj, KOBJ_ADD);
1120	bus_probe_device(dev);
1121	if (parent)
1122		klist_add_tail(&dev->p->knode_parent,
1123			       &parent->p->klist_children);
1124
1125	if (dev->class) {
1126		mutex_lock(&dev->class->p->mutex);
1127		/* tie the class to the device */
1128		klist_add_tail(&dev->knode_class,
1129			       &dev->class->p->klist_devices);
1130
1131		/* notify any interfaces that the device is here */
1132		list_for_each_entry(class_intf,
1133				    &dev->class->p->interfaces, node)
1134			if (class_intf->add_dev)
1135				class_intf->add_dev(dev, class_intf);
1136		mutex_unlock(&dev->class->p->mutex);
1137	}
1138done:
1139	put_device(dev);
1140	return error;
1141 SysEntryError:
1142	if (MAJOR(dev->devt))
1143		device_remove_file(dev, &dev_attr_dev);
1144 DevAttrError:
1145	device_pm_remove(dev);
1146	dpm_sysfs_remove(dev);
1147 DPMError:
1148	bus_remove_device(dev);
1149 BusError:
1150	device_remove_attrs(dev);
1151 AttrsError:
1152	device_remove_class_symlinks(dev);
1153 SymlinkError:
1154	device_remove_file(dev, &dev_attr_uevent);
1155 attrError:
1156	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 
1157	kobject_del(&dev->kobj);
1158 Error:
1159	cleanup_device_parent(dev);
1160	put_device(parent);
1161name_error:
1162	kfree(dev->p);
1163	dev->p = NULL;
1164	goto done;
1165}
1166EXPORT_SYMBOL_GPL(device_add);
1167
1168/**
1169 * device_register - register a device with the system.
1170 * @dev: pointer to the device structure
1171 *
1172 * This happens in two clean steps - initialize the device
1173 * and add it to the system. The two steps can be called
1174 * separately, but this is the easiest and most common.
1175 * I.e. you should only call the two helpers separately if
1176 * have a clearly defined need to use and refcount the device
1177 * before it is added to the hierarchy.
1178 *
1179 * For more information, see the kerneldoc for device_initialize()
1180 * and device_add().
1181 *
1182 * NOTE: _Never_ directly free @dev after calling this function, even
1183 * if it returned an error! Always use put_device() to give up the
1184 * reference initialized in this function instead.
1185 */
1186int device_register(struct device *dev)
1187{
1188	device_initialize(dev);
1189	return device_add(dev);
1190}
1191EXPORT_SYMBOL_GPL(device_register);
1192
1193/**
1194 * get_device - increment reference count for device.
1195 * @dev: device.
1196 *
1197 * This simply forwards the call to kobject_get(), though
1198 * we do take care to provide for the case that we get a NULL
1199 * pointer passed in.
1200 */
1201struct device *get_device(struct device *dev)
1202{
1203	return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1204}
1205EXPORT_SYMBOL_GPL(get_device);
1206
1207/**
1208 * put_device - decrement reference count.
1209 * @dev: device in question.
1210 */
1211void put_device(struct device *dev)
1212{
1213	/* might_sleep(); */
1214	if (dev)
1215		kobject_put(&dev->kobj);
1216}
1217EXPORT_SYMBOL_GPL(put_device);
1218
1219/**
1220 * device_del - delete device from system.
1221 * @dev: device.
1222 *
1223 * This is the first part of the device unregistration
1224 * sequence. This removes the device from the lists we control
1225 * from here, has it removed from the other driver model
1226 * subsystems it was added to in device_add(), and removes it
1227 * from the kobject hierarchy.
1228 *
1229 * NOTE: this should be called manually _iff_ device_add() was
1230 * also called manually.
1231 */
1232void device_del(struct device *dev)
1233{
1234	struct device *parent = dev->parent;
 
1235	struct class_interface *class_intf;
1236
1237	/* Notify clients of device removal.  This call must come
1238	 * before dpm_sysfs_remove().
1239	 */
1240	if (dev->bus)
1241		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1242					     BUS_NOTIFY_DEL_DEVICE, dev);
 
 
1243	dpm_sysfs_remove(dev);
1244	if (parent)
1245		klist_del(&dev->p->knode_parent);
1246	if (MAJOR(dev->devt)) {
1247		devtmpfs_delete_node(dev);
1248		device_remove_sys_dev_entry(dev);
1249		device_remove_file(dev, &dev_attr_dev);
1250	}
1251	if (dev->class) {
1252		device_remove_class_symlinks(dev);
1253
1254		mutex_lock(&dev->class->p->mutex);
1255		/* notify any interfaces that the device is now gone */
1256		list_for_each_entry(class_intf,
1257				    &dev->class->p->interfaces, node)
1258			if (class_intf->remove_dev)
1259				class_intf->remove_dev(dev, class_intf);
1260		/* remove the device from the class list */
1261		klist_del(&dev->knode_class);
1262		mutex_unlock(&dev->class->p->mutex);
1263	}
1264	device_remove_file(dev, &dev_attr_uevent);
1265	device_remove_attrs(dev);
1266	bus_remove_device(dev);
1267	device_pm_remove(dev);
1268	driver_deferred_probe_del(dev);
 
1269
1270	/* Notify the platform of the removal, in case they
1271	 * need to do anything...
1272	 */
1273	if (platform_notify_remove)
1274		platform_notify_remove(dev);
1275	if (dev->bus)
1276		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1277					     BUS_NOTIFY_REMOVED_DEVICE, dev);
1278	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1279	cleanup_device_parent(dev);
1280	kobject_del(&dev->kobj);
 
1281	put_device(parent);
1282}
1283EXPORT_SYMBOL_GPL(device_del);
1284
1285/**
1286 * device_unregister - unregister device from system.
1287 * @dev: device going away.
1288 *
1289 * We do this in two parts, like we do device_register(). First,
1290 * we remove it from all the subsystems with device_del(), then
1291 * we decrement the reference count via put_device(). If that
1292 * is the final reference count, the device will be cleaned up
1293 * via device_release() above. Otherwise, the structure will
1294 * stick around until the final reference to the device is dropped.
1295 */
1296void device_unregister(struct device *dev)
1297{
1298	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1299	device_del(dev);
1300	put_device(dev);
1301}
1302EXPORT_SYMBOL_GPL(device_unregister);
1303
1304static struct device *prev_device(struct klist_iter *i)
1305{
1306	struct klist_node *n = klist_prev(i);
1307	struct device *dev = NULL;
1308	struct device_private *p;
1309
1310	if (n) {
1311		p = to_device_private_parent(n);
1312		dev = p->device;
1313	}
1314	return dev;
1315}
1316
1317static struct device *next_device(struct klist_iter *i)
1318{
1319	struct klist_node *n = klist_next(i);
1320	struct device *dev = NULL;
1321	struct device_private *p;
1322
1323	if (n) {
1324		p = to_device_private_parent(n);
1325		dev = p->device;
1326	}
1327	return dev;
1328}
1329
1330/**
1331 * device_get_devnode - path of device node file
1332 * @dev: device
1333 * @mode: returned file access mode
1334 * @uid: returned file owner
1335 * @gid: returned file group
1336 * @tmp: possibly allocated string
1337 *
1338 * Return the relative path of a possible device node.
1339 * Non-default names may need to allocate a memory to compose
1340 * a name. This memory is returned in tmp and needs to be
1341 * freed by the caller.
1342 */
1343const char *device_get_devnode(struct device *dev,
1344			       umode_t *mode, kuid_t *uid, kgid_t *gid,
1345			       const char **tmp)
1346{
1347	char *s;
1348
1349	*tmp = NULL;
1350
1351	/* the device type may provide a specific name */
1352	if (dev->type && dev->type->devnode)
1353		*tmp = dev->type->devnode(dev, mode, uid, gid);
1354	if (*tmp)
1355		return *tmp;
1356
1357	/* the class may provide a specific name */
1358	if (dev->class && dev->class->devnode)
1359		*tmp = dev->class->devnode(dev, mode);
1360	if (*tmp)
1361		return *tmp;
1362
1363	/* return name without allocation, tmp == NULL */
1364	if (strchr(dev_name(dev), '!') == NULL)
1365		return dev_name(dev);
1366
1367	/* replace '!' in the name with '/' */
1368	s = kstrdup(dev_name(dev), GFP_KERNEL);
1369	if (!s)
1370		return NULL;
1371	strreplace(s, '!', '/');
1372	return *tmp = s;
1373}
1374
1375/**
1376 * device_for_each_child - device child iterator.
1377 * @parent: parent struct device.
1378 * @fn: function to be called for each device.
1379 * @data: data for the callback.
1380 *
1381 * Iterate over @parent's child devices, and call @fn for each,
1382 * passing it @data.
1383 *
1384 * We check the return of @fn each time. If it returns anything
1385 * other than 0, we break out and return that value.
1386 */
1387int device_for_each_child(struct device *parent, void *data,
1388			  int (*fn)(struct device *dev, void *data))
1389{
1390	struct klist_iter i;
1391	struct device *child;
1392	int error = 0;
1393
1394	if (!parent->p)
1395		return 0;
1396
1397	klist_iter_init(&parent->p->klist_children, &i);
1398	while ((child = next_device(&i)) && !error)
1399		error = fn(child, data);
1400	klist_iter_exit(&i);
1401	return error;
1402}
1403EXPORT_SYMBOL_GPL(device_for_each_child);
1404
1405/**
1406 * device_for_each_child_reverse - device child iterator in reversed order.
1407 * @parent: parent struct device.
1408 * @fn: function to be called for each device.
1409 * @data: data for the callback.
1410 *
1411 * Iterate over @parent's child devices, and call @fn for each,
1412 * passing it @data.
1413 *
1414 * We check the return of @fn each time. If it returns anything
1415 * other than 0, we break out and return that value.
1416 */
1417int device_for_each_child_reverse(struct device *parent, void *data,
1418				  int (*fn)(struct device *dev, void *data))
1419{
1420	struct klist_iter i;
1421	struct device *child;
1422	int error = 0;
1423
1424	if (!parent->p)
1425		return 0;
1426
1427	klist_iter_init(&parent->p->klist_children, &i);
1428	while ((child = prev_device(&i)) && !error)
1429		error = fn(child, data);
1430	klist_iter_exit(&i);
1431	return error;
1432}
1433EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
1434
1435/**
1436 * device_find_child - device iterator for locating a particular device.
1437 * @parent: parent struct device
1438 * @match: Callback function to check device
1439 * @data: Data to pass to match function
1440 *
1441 * This is similar to the device_for_each_child() function above, but it
1442 * returns a reference to a device that is 'found' for later use, as
1443 * determined by the @match callback.
1444 *
1445 * The callback should return 0 if the device doesn't match and non-zero
1446 * if it does.  If the callback returns non-zero and a reference to the
1447 * current device can be obtained, this function will return to the caller
1448 * and not iterate over any more devices.
1449 *
1450 * NOTE: you will need to drop the reference with put_device() after use.
1451 */
1452struct device *device_find_child(struct device *parent, void *data,
1453				 int (*match)(struct device *dev, void *data))
1454{
1455	struct klist_iter i;
1456	struct device *child;
1457
1458	if (!parent)
1459		return NULL;
1460
1461	klist_iter_init(&parent->p->klist_children, &i);
1462	while ((child = next_device(&i)))
1463		if (match(child, data) && get_device(child))
1464			break;
1465	klist_iter_exit(&i);
1466	return child;
1467}
1468EXPORT_SYMBOL_GPL(device_find_child);
1469
1470int __init devices_init(void)
1471{
1472	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1473	if (!devices_kset)
1474		return -ENOMEM;
1475	dev_kobj = kobject_create_and_add("dev", NULL);
1476	if (!dev_kobj)
1477		goto dev_kobj_err;
1478	sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1479	if (!sysfs_dev_block_kobj)
1480		goto block_kobj_err;
1481	sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1482	if (!sysfs_dev_char_kobj)
1483		goto char_kobj_err;
1484
1485	return 0;
1486
1487 char_kobj_err:
1488	kobject_put(sysfs_dev_block_kobj);
1489 block_kobj_err:
1490	kobject_put(dev_kobj);
1491 dev_kobj_err:
1492	kset_unregister(devices_kset);
1493	return -ENOMEM;
1494}
1495
1496static int device_check_offline(struct device *dev, void *not_used)
1497{
1498	int ret;
1499
1500	ret = device_for_each_child(dev, NULL, device_check_offline);
1501	if (ret)
1502		return ret;
1503
1504	return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1505}
1506
1507/**
1508 * device_offline - Prepare the device for hot-removal.
1509 * @dev: Device to be put offline.
1510 *
1511 * Execute the device bus type's .offline() callback, if present, to prepare
1512 * the device for a subsequent hot-removal.  If that succeeds, the device must
1513 * not be used until either it is removed or its bus type's .online() callback
1514 * is executed.
1515 *
1516 * Call under device_hotplug_lock.
1517 */
1518int device_offline(struct device *dev)
1519{
1520	int ret;
1521
1522	if (dev->offline_disabled)
1523		return -EPERM;
1524
1525	ret = device_for_each_child(dev, NULL, device_check_offline);
1526	if (ret)
1527		return ret;
1528
1529	device_lock(dev);
1530	if (device_supports_offline(dev)) {
1531		if (dev->offline) {
1532			ret = 1;
1533		} else {
1534			ret = dev->bus->offline(dev);
1535			if (!ret) {
1536				kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1537				dev->offline = true;
1538			}
1539		}
1540	}
1541	device_unlock(dev);
1542
1543	return ret;
1544}
1545
1546/**
1547 * device_online - Put the device back online after successful device_offline().
1548 * @dev: Device to be put back online.
1549 *
1550 * If device_offline() has been successfully executed for @dev, but the device
1551 * has not been removed subsequently, execute its bus type's .online() callback
1552 * to indicate that the device can be used again.
1553 *
1554 * Call under device_hotplug_lock.
1555 */
1556int device_online(struct device *dev)
1557{
1558	int ret = 0;
1559
1560	device_lock(dev);
1561	if (device_supports_offline(dev)) {
1562		if (dev->offline) {
1563			ret = dev->bus->online(dev);
1564			if (!ret) {
1565				kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1566				dev->offline = false;
1567			}
1568		} else {
1569			ret = 1;
1570		}
1571	}
1572	device_unlock(dev);
1573
1574	return ret;
1575}
1576
1577struct root_device {
1578	struct device dev;
1579	struct module *owner;
1580};
1581
1582static inline struct root_device *to_root_device(struct device *d)
1583{
1584	return container_of(d, struct root_device, dev);
1585}
1586
1587static void root_device_release(struct device *dev)
1588{
1589	kfree(to_root_device(dev));
1590}
1591
1592/**
1593 * __root_device_register - allocate and register a root device
1594 * @name: root device name
1595 * @owner: owner module of the root device, usually THIS_MODULE
1596 *
1597 * This function allocates a root device and registers it
1598 * using device_register(). In order to free the returned
1599 * device, use root_device_unregister().
1600 *
1601 * Root devices are dummy devices which allow other devices
1602 * to be grouped under /sys/devices. Use this function to
1603 * allocate a root device and then use it as the parent of
1604 * any device which should appear under /sys/devices/{name}
1605 *
1606 * The /sys/devices/{name} directory will also contain a
1607 * 'module' symlink which points to the @owner directory
1608 * in sysfs.
1609 *
1610 * Returns &struct device pointer on success, or ERR_PTR() on error.
1611 *
1612 * Note: You probably want to use root_device_register().
1613 */
1614struct device *__root_device_register(const char *name, struct module *owner)
1615{
1616	struct root_device *root;
1617	int err = -ENOMEM;
1618
1619	root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1620	if (!root)
1621		return ERR_PTR(err);
1622
1623	err = dev_set_name(&root->dev, "%s", name);
1624	if (err) {
1625		kfree(root);
1626		return ERR_PTR(err);
1627	}
1628
1629	root->dev.release = root_device_release;
1630
1631	err = device_register(&root->dev);
1632	if (err) {
1633		put_device(&root->dev);
1634		return ERR_PTR(err);
1635	}
1636
1637#ifdef CONFIG_MODULES	/* gotta find a "cleaner" way to do this */
1638	if (owner) {
1639		struct module_kobject *mk = &owner->mkobj;
1640
1641		err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1642		if (err) {
1643			device_unregister(&root->dev);
1644			return ERR_PTR(err);
1645		}
1646		root->owner = owner;
1647	}
1648#endif
1649
1650	return &root->dev;
1651}
1652EXPORT_SYMBOL_GPL(__root_device_register);
1653
1654/**
1655 * root_device_unregister - unregister and free a root device
1656 * @dev: device going away
1657 *
1658 * This function unregisters and cleans up a device that was created by
1659 * root_device_register().
1660 */
1661void root_device_unregister(struct device *dev)
1662{
1663	struct root_device *root = to_root_device(dev);
1664
1665	if (root->owner)
1666		sysfs_remove_link(&root->dev.kobj, "module");
1667
1668	device_unregister(dev);
1669}
1670EXPORT_SYMBOL_GPL(root_device_unregister);
1671
1672
1673static void device_create_release(struct device *dev)
1674{
1675	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1676	kfree(dev);
1677}
1678
1679static struct device *
1680device_create_groups_vargs(struct class *class, struct device *parent,
1681			   dev_t devt, void *drvdata,
1682			   const struct attribute_group **groups,
1683			   const char *fmt, va_list args)
1684{
1685	struct device *dev = NULL;
1686	int retval = -ENODEV;
1687
1688	if (class == NULL || IS_ERR(class))
1689		goto error;
1690
1691	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1692	if (!dev) {
1693		retval = -ENOMEM;
1694		goto error;
1695	}
1696
1697	device_initialize(dev);
1698	dev->devt = devt;
1699	dev->class = class;
1700	dev->parent = parent;
1701	dev->groups = groups;
1702	dev->release = device_create_release;
1703	dev_set_drvdata(dev, drvdata);
1704
1705	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1706	if (retval)
1707		goto error;
1708
1709	retval = device_add(dev);
1710	if (retval)
1711		goto error;
1712
1713	return dev;
1714
1715error:
1716	put_device(dev);
1717	return ERR_PTR(retval);
1718}
1719
1720/**
1721 * device_create_vargs - creates a device and registers it with sysfs
1722 * @class: pointer to the struct class that this device should be registered to
1723 * @parent: pointer to the parent struct device of this new device, if any
1724 * @devt: the dev_t for the char device to be added
1725 * @drvdata: the data to be added to the device for callbacks
1726 * @fmt: string for the device's name
1727 * @args: va_list for the device's name
1728 *
1729 * This function can be used by char device classes.  A struct device
1730 * will be created in sysfs, registered to the specified class.
1731 *
1732 * A "dev" file will be created, showing the dev_t for the device, if
1733 * the dev_t is not 0,0.
1734 * If a pointer to a parent struct device is passed in, the newly created
1735 * struct device will be a child of that device in sysfs.
1736 * The pointer to the struct device will be returned from the call.
1737 * Any further sysfs files that might be required can be created using this
1738 * pointer.
1739 *
1740 * Returns &struct device pointer on success, or ERR_PTR() on error.
1741 *
1742 * Note: the struct class passed to this function must have previously
1743 * been created with a call to class_create().
1744 */
1745struct device *device_create_vargs(struct class *class, struct device *parent,
1746				   dev_t devt, void *drvdata, const char *fmt,
1747				   va_list args)
1748{
1749	return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1750					  fmt, args);
1751}
1752EXPORT_SYMBOL_GPL(device_create_vargs);
1753
1754/**
1755 * device_create - creates a device and registers it with sysfs
1756 * @class: pointer to the struct class that this device should be registered to
1757 * @parent: pointer to the parent struct device of this new device, if any
1758 * @devt: the dev_t for the char device to be added
1759 * @drvdata: the data to be added to the device for callbacks
1760 * @fmt: string for the device's name
1761 *
1762 * This function can be used by char device classes.  A struct device
1763 * will be created in sysfs, registered to the specified class.
1764 *
1765 * A "dev" file will be created, showing the dev_t for the device, if
1766 * the dev_t is not 0,0.
1767 * If a pointer to a parent struct device is passed in, the newly created
1768 * struct device will be a child of that device in sysfs.
1769 * The pointer to the struct device will be returned from the call.
1770 * Any further sysfs files that might be required can be created using this
1771 * pointer.
1772 *
1773 * Returns &struct device pointer on success, or ERR_PTR() on error.
1774 *
1775 * Note: the struct class passed to this function must have previously
1776 * been created with a call to class_create().
1777 */
1778struct device *device_create(struct class *class, struct device *parent,
1779			     dev_t devt, void *drvdata, const char *fmt, ...)
1780{
1781	va_list vargs;
1782	struct device *dev;
1783
1784	va_start(vargs, fmt);
1785	dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1786	va_end(vargs);
1787	return dev;
1788}
1789EXPORT_SYMBOL_GPL(device_create);
1790
1791/**
1792 * device_create_with_groups - creates a device and registers it with sysfs
1793 * @class: pointer to the struct class that this device should be registered to
1794 * @parent: pointer to the parent struct device of this new device, if any
1795 * @devt: the dev_t for the char device to be added
1796 * @drvdata: the data to be added to the device for callbacks
1797 * @groups: NULL-terminated list of attribute groups to be created
1798 * @fmt: string for the device's name
1799 *
1800 * This function can be used by char device classes.  A struct device
1801 * will be created in sysfs, registered to the specified class.
1802 * Additional attributes specified in the groups parameter will also
1803 * be created automatically.
1804 *
1805 * A "dev" file will be created, showing the dev_t for the device, if
1806 * the dev_t is not 0,0.
1807 * If a pointer to a parent struct device is passed in, the newly created
1808 * struct device will be a child of that device in sysfs.
1809 * The pointer to the struct device will be returned from the call.
1810 * Any further sysfs files that might be required can be created using this
1811 * pointer.
1812 *
1813 * Returns &struct device pointer on success, or ERR_PTR() on error.
1814 *
1815 * Note: the struct class passed to this function must have previously
1816 * been created with a call to class_create().
1817 */
1818struct device *device_create_with_groups(struct class *class,
1819					 struct device *parent, dev_t devt,
1820					 void *drvdata,
1821					 const struct attribute_group **groups,
1822					 const char *fmt, ...)
1823{
1824	va_list vargs;
1825	struct device *dev;
1826
1827	va_start(vargs, fmt);
1828	dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1829					 fmt, vargs);
1830	va_end(vargs);
1831	return dev;
1832}
1833EXPORT_SYMBOL_GPL(device_create_with_groups);
1834
1835static int __match_devt(struct device *dev, const void *data)
1836{
1837	const dev_t *devt = data;
1838
1839	return dev->devt == *devt;
1840}
1841
1842/**
1843 * device_destroy - removes a device that was created with device_create()
1844 * @class: pointer to the struct class that this device was registered with
1845 * @devt: the dev_t of the device that was previously registered
1846 *
1847 * This call unregisters and cleans up a device that was created with a
1848 * call to device_create().
1849 */
1850void device_destroy(struct class *class, dev_t devt)
1851{
1852	struct device *dev;
1853
1854	dev = class_find_device(class, NULL, &devt, __match_devt);
1855	if (dev) {
1856		put_device(dev);
1857		device_unregister(dev);
1858	}
1859}
1860EXPORT_SYMBOL_GPL(device_destroy);
1861
1862/**
1863 * device_rename - renames a device
1864 * @dev: the pointer to the struct device to be renamed
1865 * @new_name: the new name of the device
1866 *
1867 * It is the responsibility of the caller to provide mutual
1868 * exclusion between two different calls of device_rename
1869 * on the same device to ensure that new_name is valid and
1870 * won't conflict with other devices.
1871 *
1872 * Note: Don't call this function.  Currently, the networking layer calls this
1873 * function, but that will change.  The following text from Kay Sievers offers
1874 * some insight:
1875 *
1876 * Renaming devices is racy at many levels, symlinks and other stuff are not
1877 * replaced atomically, and you get a "move" uevent, but it's not easy to
1878 * connect the event to the old and new device. Device nodes are not renamed at
1879 * all, there isn't even support for that in the kernel now.
1880 *
1881 * In the meantime, during renaming, your target name might be taken by another
1882 * driver, creating conflicts. Or the old name is taken directly after you
1883 * renamed it -- then you get events for the same DEVPATH, before you even see
1884 * the "move" event. It's just a mess, and nothing new should ever rely on
1885 * kernel device renaming. Besides that, it's not even implemented now for
1886 * other things than (driver-core wise very simple) network devices.
1887 *
1888 * We are currently about to change network renaming in udev to completely
1889 * disallow renaming of devices in the same namespace as the kernel uses,
1890 * because we can't solve the problems properly, that arise with swapping names
1891 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1892 * be allowed to some other name than eth[0-9]*, for the aforementioned
1893 * reasons.
1894 *
1895 * Make up a "real" name in the driver before you register anything, or add
1896 * some other attributes for userspace to find the device, or use udev to add
1897 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1898 * don't even want to get into that and try to implement the missing pieces in
1899 * the core. We really have other pieces to fix in the driver core mess. :)
1900 */
1901int device_rename(struct device *dev, const char *new_name)
1902{
1903	struct kobject *kobj = &dev->kobj;
1904	char *old_device_name = NULL;
1905	int error;
1906
1907	dev = get_device(dev);
1908	if (!dev)
1909		return -EINVAL;
1910
1911	dev_dbg(dev, "renaming to %s\n", new_name);
1912
1913	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1914	if (!old_device_name) {
1915		error = -ENOMEM;
1916		goto out;
1917	}
1918
1919	if (dev->class) {
1920		error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1921					     kobj, old_device_name,
1922					     new_name, kobject_namespace(kobj));
1923		if (error)
1924			goto out;
1925	}
1926
1927	error = kobject_rename(kobj, new_name);
1928	if (error)
1929		goto out;
1930
1931out:
1932	put_device(dev);
1933
1934	kfree(old_device_name);
1935
1936	return error;
1937}
1938EXPORT_SYMBOL_GPL(device_rename);
1939
1940static int device_move_class_links(struct device *dev,
1941				   struct device *old_parent,
1942				   struct device *new_parent)
1943{
1944	int error = 0;
1945
1946	if (old_parent)
1947		sysfs_remove_link(&dev->kobj, "device");
1948	if (new_parent)
1949		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1950					  "device");
1951	return error;
1952}
1953
1954/**
1955 * device_move - moves a device to a new parent
1956 * @dev: the pointer to the struct device to be moved
1957 * @new_parent: the new parent of the device (can by NULL)
1958 * @dpm_order: how to reorder the dpm_list
1959 */
1960int device_move(struct device *dev, struct device *new_parent,
1961		enum dpm_order dpm_order)
1962{
1963	int error;
1964	struct device *old_parent;
1965	struct kobject *new_parent_kobj;
1966
1967	dev = get_device(dev);
1968	if (!dev)
1969		return -EINVAL;
1970
1971	device_pm_lock();
1972	new_parent = get_device(new_parent);
1973	new_parent_kobj = get_device_parent(dev, new_parent);
1974
1975	pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1976		 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1977	error = kobject_move(&dev->kobj, new_parent_kobj);
1978	if (error) {
1979		cleanup_glue_dir(dev, new_parent_kobj);
1980		put_device(new_parent);
1981		goto out;
1982	}
1983	old_parent = dev->parent;
1984	dev->parent = new_parent;
1985	if (old_parent)
1986		klist_remove(&dev->p->knode_parent);
1987	if (new_parent) {
1988		klist_add_tail(&dev->p->knode_parent,
1989			       &new_parent->p->klist_children);
1990		set_dev_node(dev, dev_to_node(new_parent));
1991	}
1992
1993	if (dev->class) {
1994		error = device_move_class_links(dev, old_parent, new_parent);
1995		if (error) {
1996			/* We ignore errors on cleanup since we're hosed anyway... */
1997			device_move_class_links(dev, new_parent, old_parent);
1998			if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1999				if (new_parent)
2000					klist_remove(&dev->p->knode_parent);
2001				dev->parent = old_parent;
2002				if (old_parent) {
2003					klist_add_tail(&dev->p->knode_parent,
2004						       &old_parent->p->klist_children);
2005					set_dev_node(dev, dev_to_node(old_parent));
2006				}
2007			}
2008			cleanup_glue_dir(dev, new_parent_kobj);
2009			put_device(new_parent);
2010			goto out;
2011		}
2012	}
2013	switch (dpm_order) {
2014	case DPM_ORDER_NONE:
2015		break;
2016	case DPM_ORDER_DEV_AFTER_PARENT:
2017		device_pm_move_after(dev, new_parent);
2018		devices_kset_move_after(dev, new_parent);
2019		break;
2020	case DPM_ORDER_PARENT_BEFORE_DEV:
2021		device_pm_move_before(new_parent, dev);
2022		devices_kset_move_before(new_parent, dev);
2023		break;
2024	case DPM_ORDER_DEV_LAST:
2025		device_pm_move_last(dev);
2026		devices_kset_move_last(dev);
2027		break;
2028	}
2029
2030	put_device(old_parent);
2031out:
2032	device_pm_unlock();
2033	put_device(dev);
2034	return error;
2035}
2036EXPORT_SYMBOL_GPL(device_move);
2037
2038/**
2039 * device_shutdown - call ->shutdown() on each device to shutdown.
2040 */
2041void device_shutdown(void)
2042{
2043	struct device *dev, *parent;
2044
2045	spin_lock(&devices_kset->list_lock);
2046	/*
2047	 * Walk the devices list backward, shutting down each in turn.
2048	 * Beware that device unplug events may also start pulling
2049	 * devices offline, even as the system is shutting down.
2050	 */
2051	while (!list_empty(&devices_kset->list)) {
2052		dev = list_entry(devices_kset->list.prev, struct device,
2053				kobj.entry);
2054
2055		/*
2056		 * hold reference count of device's parent to
2057		 * prevent it from being freed because parent's
2058		 * lock is to be held
2059		 */
2060		parent = get_device(dev->parent);
2061		get_device(dev);
2062		/*
2063		 * Make sure the device is off the kset list, in the
2064		 * event that dev->*->shutdown() doesn't remove it.
2065		 */
2066		list_del_init(&dev->kobj.entry);
2067		spin_unlock(&devices_kset->list_lock);
2068
2069		/* hold lock to avoid race with probe/release */
2070		if (parent)
2071			device_lock(parent);
2072		device_lock(dev);
2073
2074		/* Don't allow any more runtime suspends */
2075		pm_runtime_get_noresume(dev);
2076		pm_runtime_barrier(dev);
2077
2078		if (dev->bus && dev->bus->shutdown) {
2079			if (initcall_debug)
2080				dev_info(dev, "shutdown\n");
2081			dev->bus->shutdown(dev);
2082		} else if (dev->driver && dev->driver->shutdown) {
2083			if (initcall_debug)
2084				dev_info(dev, "shutdown\n");
2085			dev->driver->shutdown(dev);
2086		}
2087
2088		device_unlock(dev);
2089		if (parent)
2090			device_unlock(parent);
2091
2092		put_device(dev);
2093		put_device(parent);
2094
2095		spin_lock(&devices_kset->list_lock);
2096	}
2097	spin_unlock(&devices_kset->list_lock);
2098}
2099
2100/*
2101 * Device logging functions
2102 */
2103
2104#ifdef CONFIG_PRINTK
2105static int
2106create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2107{
2108	const char *subsys;
2109	size_t pos = 0;
2110
2111	if (dev->class)
2112		subsys = dev->class->name;
2113	else if (dev->bus)
2114		subsys = dev->bus->name;
2115	else
2116		return 0;
2117
2118	pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2119	if (pos >= hdrlen)
2120		goto overflow;
2121
2122	/*
2123	 * Add device identifier DEVICE=:
2124	 *   b12:8         block dev_t
2125	 *   c127:3        char dev_t
2126	 *   n8            netdev ifindex
2127	 *   +sound:card0  subsystem:devname
2128	 */
2129	if (MAJOR(dev->devt)) {
2130		char c;
2131
2132		if (strcmp(subsys, "block") == 0)
2133			c = 'b';
2134		else
2135			c = 'c';
2136		pos++;
2137		pos += snprintf(hdr + pos, hdrlen - pos,
2138				"DEVICE=%c%u:%u",
2139				c, MAJOR(dev->devt), MINOR(dev->devt));
2140	} else if (strcmp(subsys, "net") == 0) {
2141		struct net_device *net = to_net_dev(dev);
2142
2143		pos++;
2144		pos += snprintf(hdr + pos, hdrlen - pos,
2145				"DEVICE=n%u", net->ifindex);
2146	} else {
2147		pos++;
2148		pos += snprintf(hdr + pos, hdrlen - pos,
2149				"DEVICE=+%s:%s", subsys, dev_name(dev));
2150	}
2151
2152	if (pos >= hdrlen)
2153		goto overflow;
2154
2155	return pos;
2156
2157overflow:
2158	dev_WARN(dev, "device/subsystem name too long");
2159	return 0;
2160}
2161
2162int dev_vprintk_emit(int level, const struct device *dev,
2163		     const char *fmt, va_list args)
2164{
2165	char hdr[128];
2166	size_t hdrlen;
2167
2168	hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2169
2170	return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2171}
2172EXPORT_SYMBOL(dev_vprintk_emit);
2173
2174int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2175{
2176	va_list args;
2177	int r;
2178
2179	va_start(args, fmt);
2180
2181	r = dev_vprintk_emit(level, dev, fmt, args);
2182
2183	va_end(args);
2184
2185	return r;
2186}
2187EXPORT_SYMBOL(dev_printk_emit);
2188
2189static void __dev_printk(const char *level, const struct device *dev,
2190			struct va_format *vaf)
2191{
2192	if (dev)
2193		dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2194				dev_driver_string(dev), dev_name(dev), vaf);
2195	else
2196		printk("%s(NULL device *): %pV", level, vaf);
2197}
2198
2199void dev_printk(const char *level, const struct device *dev,
2200		const char *fmt, ...)
2201{
2202	struct va_format vaf;
2203	va_list args;
2204
2205	va_start(args, fmt);
2206
2207	vaf.fmt = fmt;
2208	vaf.va = &args;
2209
2210	__dev_printk(level, dev, &vaf);
2211
2212	va_end(args);
2213}
2214EXPORT_SYMBOL(dev_printk);
2215
2216#define define_dev_printk_level(func, kern_level)		\
2217void func(const struct device *dev, const char *fmt, ...)	\
2218{								\
2219	struct va_format vaf;					\
2220	va_list args;						\
2221								\
2222	va_start(args, fmt);					\
2223								\
2224	vaf.fmt = fmt;						\
2225	vaf.va = &args;						\
2226								\
2227	__dev_printk(kern_level, dev, &vaf);			\
2228								\
2229	va_end(args);						\
2230}								\
2231EXPORT_SYMBOL(func);
2232
2233define_dev_printk_level(dev_emerg, KERN_EMERG);
2234define_dev_printk_level(dev_alert, KERN_ALERT);
2235define_dev_printk_level(dev_crit, KERN_CRIT);
2236define_dev_printk_level(dev_err, KERN_ERR);
2237define_dev_printk_level(dev_warn, KERN_WARNING);
2238define_dev_printk_level(dev_notice, KERN_NOTICE);
2239define_dev_printk_level(_dev_info, KERN_INFO);
2240
2241#endif
2242
2243static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2244{
2245	return fwnode && !IS_ERR(fwnode->secondary);
2246}
2247
2248/**
2249 * set_primary_fwnode - Change the primary firmware node of a given device.
2250 * @dev: Device to handle.
2251 * @fwnode: New primary firmware node of the device.
2252 *
2253 * Set the device's firmware node pointer to @fwnode, but if a secondary
2254 * firmware node of the device is present, preserve it.
2255 */
2256void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2257{
2258	if (fwnode) {
2259		struct fwnode_handle *fn = dev->fwnode;
2260
2261		if (fwnode_is_primary(fn))
2262			fn = fn->secondary;
2263
2264		if (fn) {
2265			WARN_ON(fwnode->secondary);
2266			fwnode->secondary = fn;
2267		}
2268		dev->fwnode = fwnode;
2269	} else {
2270		dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2271			dev->fwnode->secondary : NULL;
2272	}
2273}
2274EXPORT_SYMBOL_GPL(set_primary_fwnode);
2275
2276/**
2277 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2278 * @dev: Device to handle.
2279 * @fwnode: New secondary firmware node of the device.
2280 *
2281 * If a primary firmware node of the device is present, set its secondary
2282 * pointer to @fwnode.  Otherwise, set the device's firmware node pointer to
2283 * @fwnode.
2284 */
2285void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2286{
2287	if (fwnode)
2288		fwnode->secondary = ERR_PTR(-ENODEV);
2289
2290	if (fwnode_is_primary(dev->fwnode))
2291		dev->fwnode->secondary = fwnode;
2292	else
2293		dev->fwnode = fwnode;
2294}