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v3.15
   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/pm_runtime.h>
  27#include <linux/netdevice.h>
  28#include <linux/sysfs.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 int __init sysfs_deprecated_setup(char *arg)
  40{
  41	return kstrtol(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
  52static DEFINE_MUTEX(device_hotplug_lock);
  53
  54void lock_device_hotplug(void)
  55{
  56	mutex_lock(&device_hotplug_lock);
  57}
  58
  59void unlock_device_hotplug(void)
  60{
  61	mutex_unlock(&device_hotplug_lock);
  62}
  63
  64int lock_device_hotplug_sysfs(void)
  65{
  66	if (mutex_trylock(&device_hotplug_lock))
  67		return 0;
  68
  69	/* Avoid busy looping (5 ms of sleep should do). */
  70	msleep(5);
  71	return restart_syscall();
  72}
  73
  74#ifdef CONFIG_BLOCK
  75static inline int device_is_not_partition(struct device *dev)
  76{
  77	return !(dev->type == &part_type);
  78}
  79#else
  80static inline int device_is_not_partition(struct device *dev)
  81{
  82	return 1;
  83}
  84#endif
  85
  86/**
  87 * dev_driver_string - Return a device's driver name, if at all possible
  88 * @dev: struct device to get the name of
  89 *
  90 * Will return the device's driver's name if it is bound to a device.  If
  91 * the device is not bound to a driver, it will return the name of the bus
  92 * it is attached to.  If it is not attached to a bus either, an empty
  93 * string will be returned.
  94 */
  95const char *dev_driver_string(const struct device *dev)
  96{
  97	struct device_driver *drv;
  98
  99	/* dev->driver can change to NULL underneath us because of unbinding,
 100	 * so be careful about accessing it.  dev->bus and dev->class should
 101	 * never change once they are set, so they don't need special care.
 102	 */
 103	drv = ACCESS_ONCE(dev->driver);
 104	return drv ? drv->name :
 105			(dev->bus ? dev->bus->name :
 106			(dev->class ? dev->class->name : ""));
 107}
 108EXPORT_SYMBOL(dev_driver_string);
 109
 110#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
 111
 112static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
 113			     char *buf)
 114{
 115	struct device_attribute *dev_attr = to_dev_attr(attr);
 116	struct device *dev = kobj_to_dev(kobj);
 117	ssize_t ret = -EIO;
 118
 119	if (dev_attr->show)
 120		ret = dev_attr->show(dev, dev_attr, buf);
 121	if (ret >= (ssize_t)PAGE_SIZE) {
 122		print_symbol("dev_attr_show: %s returned bad count\n",
 123				(unsigned long)dev_attr->show);
 124	}
 125	return ret;
 126}
 127
 128static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
 129			      const char *buf, size_t count)
 130{
 131	struct device_attribute *dev_attr = to_dev_attr(attr);
 132	struct device *dev = kobj_to_dev(kobj);
 133	ssize_t ret = -EIO;
 134
 135	if (dev_attr->store)
 136		ret = dev_attr->store(dev, dev_attr, buf, count);
 137	return ret;
 138}
 139
 140static const struct sysfs_ops dev_sysfs_ops = {
 141	.show	= dev_attr_show,
 142	.store	= dev_attr_store,
 143};
 144
 145#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
 146
 147ssize_t device_store_ulong(struct device *dev,
 148			   struct device_attribute *attr,
 149			   const char *buf, size_t size)
 150{
 151	struct dev_ext_attribute *ea = to_ext_attr(attr);
 152	char *end;
 153	unsigned long new = simple_strtoul(buf, &end, 0);
 154	if (end == buf)
 155		return -EINVAL;
 156	*(unsigned long *)(ea->var) = new;
 157	/* Always return full write size even if we didn't consume all */
 158	return size;
 159}
 160EXPORT_SYMBOL_GPL(device_store_ulong);
 161
 162ssize_t device_show_ulong(struct device *dev,
 163			  struct device_attribute *attr,
 164			  char *buf)
 165{
 166	struct dev_ext_attribute *ea = to_ext_attr(attr);
 167	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
 168}
 169EXPORT_SYMBOL_GPL(device_show_ulong);
 170
 171ssize_t device_store_int(struct device *dev,
 172			 struct device_attribute *attr,
 173			 const char *buf, size_t size)
 174{
 175	struct dev_ext_attribute *ea = to_ext_attr(attr);
 176	char *end;
 177	long new = simple_strtol(buf, &end, 0);
 178	if (end == buf || new > INT_MAX || new < INT_MIN)
 179		return -EINVAL;
 180	*(int *)(ea->var) = new;
 181	/* Always return full write size even if we didn't consume all */
 182	return size;
 183}
 184EXPORT_SYMBOL_GPL(device_store_int);
 185
 186ssize_t device_show_int(struct device *dev,
 187			struct device_attribute *attr,
 188			char *buf)
 189{
 190	struct dev_ext_attribute *ea = to_ext_attr(attr);
 191
 192	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
 193}
 194EXPORT_SYMBOL_GPL(device_show_int);
 195
 196ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 197			  const char *buf, size_t size)
 198{
 199	struct dev_ext_attribute *ea = to_ext_attr(attr);
 200
 201	if (strtobool(buf, ea->var) < 0)
 202		return -EINVAL;
 203
 204	return size;
 205}
 206EXPORT_SYMBOL_GPL(device_store_bool);
 207
 208ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 209			 char *buf)
 210{
 211	struct dev_ext_attribute *ea = to_ext_attr(attr);
 212
 213	return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
 214}
 215EXPORT_SYMBOL_GPL(device_show_bool);
 216
 217/**
 218 * device_release - free device structure.
 219 * @kobj: device's kobject.
 220 *
 221 * This is called once the reference count for the object
 222 * reaches 0. We forward the call to the device's release
 223 * method, which should handle actually freeing the structure.
 224 */
 225static void device_release(struct kobject *kobj)
 226{
 227	struct device *dev = kobj_to_dev(kobj);
 228	struct device_private *p = dev->p;
 229
 230	/*
 231	 * Some platform devices are driven without driver attached
 232	 * and managed resources may have been acquired.  Make sure
 233	 * all resources are released.
 234	 *
 235	 * Drivers still can add resources into device after device
 236	 * is deleted but alive, so release devres here to avoid
 237	 * possible memory leak.
 238	 */
 239	devres_release_all(dev);
 240
 241	if (dev->release)
 242		dev->release(dev);
 243	else if (dev->type && dev->type->release)
 244		dev->type->release(dev);
 245	else if (dev->class && dev->class->dev_release)
 246		dev->class->dev_release(dev);
 247	else
 248		WARN(1, KERN_ERR "Device '%s' does not have a release() "
 249			"function, it is broken and must be fixed.\n",
 250			dev_name(dev));
 251	kfree(p);
 252}
 253
 254static const void *device_namespace(struct kobject *kobj)
 255{
 256	struct device *dev = kobj_to_dev(kobj);
 257	const void *ns = NULL;
 258
 259	if (dev->class && dev->class->ns_type)
 260		ns = dev->class->namespace(dev);
 261
 262	return ns;
 263}
 264
 265static struct kobj_type device_ktype = {
 266	.release	= device_release,
 267	.sysfs_ops	= &dev_sysfs_ops,
 268	.namespace	= device_namespace,
 269};
 270
 271
 272static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 273{
 274	struct kobj_type *ktype = get_ktype(kobj);
 275
 276	if (ktype == &device_ktype) {
 277		struct device *dev = kobj_to_dev(kobj);
 278		if (dev->bus)
 279			return 1;
 280		if (dev->class)
 281			return 1;
 282	}
 283	return 0;
 284}
 285
 286static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 287{
 288	struct device *dev = kobj_to_dev(kobj);
 289
 290	if (dev->bus)
 291		return dev->bus->name;
 292	if (dev->class)
 293		return dev->class->name;
 294	return NULL;
 295}
 296
 297static int dev_uevent(struct kset *kset, struct kobject *kobj,
 298		      struct kobj_uevent_env *env)
 299{
 300	struct device *dev = kobj_to_dev(kobj);
 301	int retval = 0;
 302
 303	/* add device node properties if present */
 304	if (MAJOR(dev->devt)) {
 305		const char *tmp;
 306		const char *name;
 307		umode_t mode = 0;
 308		kuid_t uid = GLOBAL_ROOT_UID;
 309		kgid_t gid = GLOBAL_ROOT_GID;
 310
 311		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 312		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 313		name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
 314		if (name) {
 315			add_uevent_var(env, "DEVNAME=%s", name);
 316			if (mode)
 317				add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
 318			if (!uid_eq(uid, GLOBAL_ROOT_UID))
 319				add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
 320			if (!gid_eq(gid, GLOBAL_ROOT_GID))
 321				add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
 322			kfree(tmp);
 323		}
 324	}
 325
 326	if (dev->type && dev->type->name)
 327		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 328
 329	if (dev->driver)
 330		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 331
 332	/* Add common DT information about the device */
 333	of_device_uevent(dev, env);
 334
 335	/* have the bus specific function add its stuff */
 336	if (dev->bus && dev->bus->uevent) {
 337		retval = dev->bus->uevent(dev, env);
 338		if (retval)
 339			pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 340				 dev_name(dev), __func__, retval);
 341	}
 342
 343	/* have the class specific function add its stuff */
 344	if (dev->class && dev->class->dev_uevent) {
 345		retval = dev->class->dev_uevent(dev, env);
 346		if (retval)
 347			pr_debug("device: '%s': %s: class uevent() "
 348				 "returned %d\n", dev_name(dev),
 349				 __func__, retval);
 350	}
 351
 352	/* have the device type specific function add its stuff */
 353	if (dev->type && dev->type->uevent) {
 354		retval = dev->type->uevent(dev, env);
 355		if (retval)
 356			pr_debug("device: '%s': %s: dev_type uevent() "
 357				 "returned %d\n", dev_name(dev),
 358				 __func__, retval);
 359	}
 360
 361	return retval;
 362}
 363
 364static const struct kset_uevent_ops device_uevent_ops = {
 365	.filter =	dev_uevent_filter,
 366	.name =		dev_uevent_name,
 367	.uevent =	dev_uevent,
 368};
 369
 370static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 371			   char *buf)
 372{
 373	struct kobject *top_kobj;
 374	struct kset *kset;
 375	struct kobj_uevent_env *env = NULL;
 376	int i;
 377	size_t count = 0;
 378	int retval;
 379
 380	/* search the kset, the device belongs to */
 381	top_kobj = &dev->kobj;
 382	while (!top_kobj->kset && top_kobj->parent)
 383		top_kobj = top_kobj->parent;
 384	if (!top_kobj->kset)
 385		goto out;
 386
 387	kset = top_kobj->kset;
 388	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 389		goto out;
 390
 391	/* respect filter */
 392	if (kset->uevent_ops && kset->uevent_ops->filter)
 393		if (!kset->uevent_ops->filter(kset, &dev->kobj))
 394			goto out;
 395
 396	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 397	if (!env)
 398		return -ENOMEM;
 399
 400	/* let the kset specific function add its keys */
 401	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 402	if (retval)
 403		goto out;
 404
 405	/* copy keys to file */
 406	for (i = 0; i < env->envp_idx; i++)
 407		count += sprintf(&buf[count], "%s\n", env->envp[i]);
 408out:
 409	kfree(env);
 410	return count;
 411}
 412
 413static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
 414			    const char *buf, size_t count)
 415{
 416	enum kobject_action action;
 417
 418	if (kobject_action_type(buf, count, &action) == 0)
 419		kobject_uevent(&dev->kobj, action);
 420	else
 421		dev_err(dev, "uevent: unknown action-string\n");
 422	return count;
 423}
 424static DEVICE_ATTR_RW(uevent);
 425
 426static ssize_t online_show(struct device *dev, struct device_attribute *attr,
 427			   char *buf)
 428{
 429	bool val;
 430
 431	device_lock(dev);
 432	val = !dev->offline;
 433	device_unlock(dev);
 434	return sprintf(buf, "%u\n", val);
 435}
 436
 437static ssize_t online_store(struct device *dev, struct device_attribute *attr,
 438			    const char *buf, size_t count)
 439{
 440	bool val;
 441	int ret;
 442
 443	ret = strtobool(buf, &val);
 444	if (ret < 0)
 445		return ret;
 446
 447	ret = lock_device_hotplug_sysfs();
 448	if (ret)
 449		return ret;
 450
 451	ret = val ? device_online(dev) : device_offline(dev);
 452	unlock_device_hotplug();
 453	return ret < 0 ? ret : count;
 454}
 455static DEVICE_ATTR_RW(online);
 456
 457int device_add_groups(struct device *dev, const struct attribute_group **groups)
 458{
 459	return sysfs_create_groups(&dev->kobj, groups);
 460}
 461
 462void device_remove_groups(struct device *dev,
 463			  const struct attribute_group **groups)
 464{
 465	sysfs_remove_groups(&dev->kobj, groups);
 466}
 467
 468static int device_add_attrs(struct device *dev)
 469{
 470	struct class *class = dev->class;
 471	const struct device_type *type = dev->type;
 472	int error;
 473
 474	if (class) {
 475		error = device_add_groups(dev, class->dev_groups);
 476		if (error)
 477			return error;
 478	}
 479
 480	if (type) {
 481		error = device_add_groups(dev, type->groups);
 482		if (error)
 483			goto err_remove_class_groups;
 484	}
 485
 486	error = device_add_groups(dev, dev->groups);
 487	if (error)
 488		goto err_remove_type_groups;
 489
 490	if (device_supports_offline(dev) && !dev->offline_disabled) {
 491		error = device_create_file(dev, &dev_attr_online);
 492		if (error)
 493			goto err_remove_dev_groups;
 494	}
 495
 496	return 0;
 497
 498 err_remove_dev_groups:
 499	device_remove_groups(dev, dev->groups);
 500 err_remove_type_groups:
 501	if (type)
 502		device_remove_groups(dev, type->groups);
 503 err_remove_class_groups:
 504	if (class)
 505		device_remove_groups(dev, class->dev_groups);
 506
 507	return error;
 508}
 509
 510static void device_remove_attrs(struct device *dev)
 511{
 512	struct class *class = dev->class;
 513	const struct device_type *type = dev->type;
 514
 515	device_remove_file(dev, &dev_attr_online);
 516	device_remove_groups(dev, dev->groups);
 517
 518	if (type)
 519		device_remove_groups(dev, type->groups);
 520
 521	if (class)
 522		device_remove_groups(dev, class->dev_groups);
 523}
 524
 525static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
 526			char *buf)
 527{
 528	return print_dev_t(buf, dev->devt);
 529}
 530static DEVICE_ATTR_RO(dev);
 531
 532/* /sys/devices/ */
 533struct kset *devices_kset;
 534
 535/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 536 * device_create_file - create sysfs attribute file for device.
 537 * @dev: device.
 538 * @attr: device attribute descriptor.
 539 */
 540int device_create_file(struct device *dev,
 541		       const struct device_attribute *attr)
 542{
 543	int error = 0;
 544
 545	if (dev) {
 546		WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
 547			"Attribute %s: write permission without 'store'\n",
 548			attr->attr.name);
 549		WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
 550			"Attribute %s: read permission without 'show'\n",
 551			attr->attr.name);
 552		error = sysfs_create_file(&dev->kobj, &attr->attr);
 553	}
 554
 555	return error;
 556}
 557EXPORT_SYMBOL_GPL(device_create_file);
 558
 559/**
 560 * device_remove_file - remove sysfs attribute file.
 561 * @dev: device.
 562 * @attr: device attribute descriptor.
 563 */
 564void device_remove_file(struct device *dev,
 565			const struct device_attribute *attr)
 566{
 567	if (dev)
 568		sysfs_remove_file(&dev->kobj, &attr->attr);
 569}
 570EXPORT_SYMBOL_GPL(device_remove_file);
 571
 572/**
 573 * device_remove_file_self - remove sysfs attribute file from its own method.
 574 * @dev: device.
 575 * @attr: device attribute descriptor.
 576 *
 577 * See kernfs_remove_self() for details.
 578 */
 579bool device_remove_file_self(struct device *dev,
 580			     const struct device_attribute *attr)
 581{
 582	if (dev)
 583		return sysfs_remove_file_self(&dev->kobj, &attr->attr);
 584	else
 585		return false;
 586}
 587EXPORT_SYMBOL_GPL(device_remove_file_self);
 588
 589/**
 590 * device_create_bin_file - create sysfs binary attribute file for device.
 591 * @dev: device.
 592 * @attr: device binary attribute descriptor.
 593 */
 594int device_create_bin_file(struct device *dev,
 595			   const struct bin_attribute *attr)
 596{
 597	int error = -EINVAL;
 598	if (dev)
 599		error = sysfs_create_bin_file(&dev->kobj, attr);
 600	return error;
 601}
 602EXPORT_SYMBOL_GPL(device_create_bin_file);
 603
 604/**
 605 * device_remove_bin_file - remove sysfs binary attribute file
 606 * @dev: device.
 607 * @attr: device binary attribute descriptor.
 608 */
 609void device_remove_bin_file(struct device *dev,
 610			    const struct bin_attribute *attr)
 611{
 612	if (dev)
 613		sysfs_remove_bin_file(&dev->kobj, attr);
 614}
 615EXPORT_SYMBOL_GPL(device_remove_bin_file);
 616
 617static void klist_children_get(struct klist_node *n)
 618{
 619	struct device_private *p = to_device_private_parent(n);
 620	struct device *dev = p->device;
 621
 622	get_device(dev);
 623}
 624
 625static void klist_children_put(struct klist_node *n)
 626{
 627	struct device_private *p = to_device_private_parent(n);
 628	struct device *dev = p->device;
 629
 630	put_device(dev);
 631}
 632
 633/**
 634 * device_initialize - init device structure.
 635 * @dev: device.
 636 *
 637 * This prepares the device for use by other layers by initializing
 638 * its fields.
 639 * It is the first half of device_register(), if called by
 640 * that function, though it can also be called separately, so one
 641 * may use @dev's fields. In particular, get_device()/put_device()
 642 * may be used for reference counting of @dev after calling this
 643 * function.
 644 *
 645 * All fields in @dev must be initialized by the caller to 0, except
 646 * for those explicitly set to some other value.  The simplest
 647 * approach is to use kzalloc() to allocate the structure containing
 648 * @dev.
 649 *
 650 * NOTE: Use put_device() to give up your reference instead of freeing
 651 * @dev directly once you have called this function.
 652 */
 653void device_initialize(struct device *dev)
 654{
 655	dev->kobj.kset = devices_kset;
 656	kobject_init(&dev->kobj, &device_ktype);
 657	INIT_LIST_HEAD(&dev->dma_pools);
 658	mutex_init(&dev->mutex);
 659	lockdep_set_novalidate_class(&dev->mutex);
 660	spin_lock_init(&dev->devres_lock);
 661	INIT_LIST_HEAD(&dev->devres_head);
 662	device_pm_init(dev);
 663	set_dev_node(dev, -1);
 
 
 
 
 
 
 664}
 665EXPORT_SYMBOL_GPL(device_initialize);
 666
 667struct kobject *virtual_device_parent(struct device *dev)
 668{
 669	static struct kobject *virtual_dir = NULL;
 670
 671	if (!virtual_dir)
 672		virtual_dir = kobject_create_and_add("virtual",
 673						     &devices_kset->kobj);
 674
 675	return virtual_dir;
 676}
 677
 678struct class_dir {
 679	struct kobject kobj;
 680	struct class *class;
 681};
 682
 683#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
 684
 685static void class_dir_release(struct kobject *kobj)
 686{
 687	struct class_dir *dir = to_class_dir(kobj);
 688	kfree(dir);
 689}
 690
 691static const
 692struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
 693{
 694	struct class_dir *dir = to_class_dir(kobj);
 695	return dir->class->ns_type;
 696}
 697
 698static struct kobj_type class_dir_ktype = {
 699	.release	= class_dir_release,
 700	.sysfs_ops	= &kobj_sysfs_ops,
 701	.child_ns_type	= class_dir_child_ns_type
 702};
 703
 704static struct kobject *
 705class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
 706{
 707	struct class_dir *dir;
 708	int retval;
 709
 710	dir = kzalloc(sizeof(*dir), GFP_KERNEL);
 711	if (!dir)
 712		return NULL;
 713
 714	dir->class = class;
 715	kobject_init(&dir->kobj, &class_dir_ktype);
 716
 717	dir->kobj.kset = &class->p->glue_dirs;
 718
 719	retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
 720	if (retval < 0) {
 721		kobject_put(&dir->kobj);
 722		return NULL;
 723	}
 724	return &dir->kobj;
 725}
 726
 
 727
 728static struct kobject *get_device_parent(struct device *dev,
 729					 struct device *parent)
 730{
 731	if (dev->class) {
 732		static DEFINE_MUTEX(gdp_mutex);
 733		struct kobject *kobj = NULL;
 734		struct kobject *parent_kobj;
 735		struct kobject *k;
 736
 737#ifdef CONFIG_BLOCK
 738		/* block disks show up in /sys/block */
 739		if (sysfs_deprecated && dev->class == &block_class) {
 740			if (parent && parent->class == &block_class)
 741				return &parent->kobj;
 742			return &block_class.p->subsys.kobj;
 743		}
 744#endif
 745
 746		/*
 747		 * If we have no parent, we live in "virtual".
 748		 * Class-devices with a non class-device as parent, live
 749		 * in a "glue" directory to prevent namespace collisions.
 750		 */
 751		if (parent == NULL)
 752			parent_kobj = virtual_device_parent(dev);
 753		else if (parent->class && !dev->class->ns_type)
 754			return &parent->kobj;
 755		else
 756			parent_kobj = &parent->kobj;
 757
 758		mutex_lock(&gdp_mutex);
 759
 760		/* find our class-directory at the parent and reference it */
 761		spin_lock(&dev->class->p->glue_dirs.list_lock);
 762		list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
 763			if (k->parent == parent_kobj) {
 764				kobj = kobject_get(k);
 765				break;
 766			}
 767		spin_unlock(&dev->class->p->glue_dirs.list_lock);
 768		if (kobj) {
 769			mutex_unlock(&gdp_mutex);
 770			return kobj;
 771		}
 772
 773		/* or create a new class-directory at the parent device */
 774		k = class_dir_create_and_add(dev->class, parent_kobj);
 775		/* do not emit an uevent for this simple "glue" directory */
 776		mutex_unlock(&gdp_mutex);
 777		return k;
 778	}
 779
 780	/* subsystems can specify a default root directory for their devices */
 781	if (!parent && dev->bus && dev->bus->dev_root)
 782		return &dev->bus->dev_root->kobj;
 783
 784	if (parent)
 785		return &parent->kobj;
 786	return NULL;
 787}
 788
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 789static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
 790{
 791	/* see if we live in a "glue" directory */
 792	if (!glue_dir || !dev->class ||
 793	    glue_dir->kset != &dev->class->p->glue_dirs)
 794		return;
 795
 
 796	kobject_put(glue_dir);
 797}
 798
 799static void cleanup_device_parent(struct device *dev)
 800{
 801	cleanup_glue_dir(dev, dev->kobj.parent);
 802}
 803
 804static int device_add_class_symlinks(struct device *dev)
 805{
 
 806	int error;
 807
 
 
 
 
 
 
 
 808	if (!dev->class)
 809		return 0;
 810
 811	error = sysfs_create_link(&dev->kobj,
 812				  &dev->class->p->subsys.kobj,
 813				  "subsystem");
 814	if (error)
 815		goto out;
 816
 817	if (dev->parent && device_is_not_partition(dev)) {
 818		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
 819					  "device");
 820		if (error)
 821			goto out_subsys;
 822	}
 823
 824#ifdef CONFIG_BLOCK
 825	/* /sys/block has directories and does not need symlinks */
 826	if (sysfs_deprecated && dev->class == &block_class)
 827		return 0;
 828#endif
 829
 830	/* link in the class directory pointing to the device */
 831	error = sysfs_create_link(&dev->class->p->subsys.kobj,
 832				  &dev->kobj, dev_name(dev));
 833	if (error)
 834		goto out_device;
 835
 836	return 0;
 837
 838out_device:
 839	sysfs_remove_link(&dev->kobj, "device");
 840
 841out_subsys:
 842	sysfs_remove_link(&dev->kobj, "subsystem");
 843out:
 
 844	return error;
 845}
 846
 847static void device_remove_class_symlinks(struct device *dev)
 848{
 
 
 
 849	if (!dev->class)
 850		return;
 851
 852	if (dev->parent && device_is_not_partition(dev))
 853		sysfs_remove_link(&dev->kobj, "device");
 854	sysfs_remove_link(&dev->kobj, "subsystem");
 855#ifdef CONFIG_BLOCK
 856	if (sysfs_deprecated && dev->class == &block_class)
 857		return;
 858#endif
 859	sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
 860}
 861
 862/**
 863 * dev_set_name - set a device name
 864 * @dev: device
 865 * @fmt: format string for the device's name
 866 */
 867int dev_set_name(struct device *dev, const char *fmt, ...)
 868{
 869	va_list vargs;
 870	int err;
 871
 872	va_start(vargs, fmt);
 873	err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
 874	va_end(vargs);
 875	return err;
 876}
 877EXPORT_SYMBOL_GPL(dev_set_name);
 878
 879/**
 880 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 881 * @dev: device
 882 *
 883 * By default we select char/ for new entries.  Setting class->dev_obj
 884 * to NULL prevents an entry from being created.  class->dev_kobj must
 885 * be set (or cleared) before any devices are registered to the class
 886 * otherwise device_create_sys_dev_entry() and
 887 * device_remove_sys_dev_entry() will disagree about the presence of
 888 * the link.
 889 */
 890static struct kobject *device_to_dev_kobj(struct device *dev)
 891{
 892	struct kobject *kobj;
 893
 894	if (dev->class)
 895		kobj = dev->class->dev_kobj;
 896	else
 897		kobj = sysfs_dev_char_kobj;
 898
 899	return kobj;
 900}
 901
 902static int device_create_sys_dev_entry(struct device *dev)
 903{
 904	struct kobject *kobj = device_to_dev_kobj(dev);
 905	int error = 0;
 906	char devt_str[15];
 907
 908	if (kobj) {
 909		format_dev_t(devt_str, dev->devt);
 910		error = sysfs_create_link(kobj, &dev->kobj, devt_str);
 911	}
 912
 913	return error;
 914}
 915
 916static void device_remove_sys_dev_entry(struct device *dev)
 917{
 918	struct kobject *kobj = device_to_dev_kobj(dev);
 919	char devt_str[15];
 920
 921	if (kobj) {
 922		format_dev_t(devt_str, dev->devt);
 923		sysfs_remove_link(kobj, devt_str);
 924	}
 925}
 926
 927int device_private_init(struct device *dev)
 928{
 929	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
 930	if (!dev->p)
 931		return -ENOMEM;
 932	dev->p->device = dev;
 933	klist_init(&dev->p->klist_children, klist_children_get,
 934		   klist_children_put);
 935	INIT_LIST_HEAD(&dev->p->deferred_probe);
 936	return 0;
 937}
 938
 939/**
 940 * device_add - add device to device hierarchy.
 941 * @dev: device.
 942 *
 943 * This is part 2 of device_register(), though may be called
 944 * separately _iff_ device_initialize() has been called separately.
 945 *
 946 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
 947 * to the global and sibling lists for the device, then
 948 * adds it to the other relevant subsystems of the driver model.
 949 *
 950 * Do not call this routine or device_register() more than once for
 951 * any device structure.  The driver model core is not designed to work
 952 * with devices that get unregistered and then spring back to life.
 953 * (Among other things, it's very hard to guarantee that all references
 954 * to the previous incarnation of @dev have been dropped.)  Allocate
 955 * and register a fresh new struct device instead.
 956 *
 957 * NOTE: _Never_ directly free @dev after calling this function, even
 958 * if it returned an error! Always use put_device() to give up your
 959 * reference instead.
 960 */
 961int device_add(struct device *dev)
 962{
 963	struct device *parent = NULL;
 964	struct kobject *kobj;
 965	struct class_interface *class_intf;
 966	int error = -EINVAL;
 
 967
 968	dev = get_device(dev);
 969	if (!dev)
 970		goto done;
 971
 972	if (!dev->p) {
 973		error = device_private_init(dev);
 974		if (error)
 975			goto done;
 976	}
 977
 978	/*
 979	 * for statically allocated devices, which should all be converted
 980	 * some day, we need to initialize the name. We prevent reading back
 981	 * the name, and force the use of dev_name()
 982	 */
 983	if (dev->init_name) {
 984		dev_set_name(dev, "%s", dev->init_name);
 985		dev->init_name = NULL;
 986	}
 987
 988	/* subsystems can specify simple device enumeration */
 989	if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
 990		dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
 991
 992	if (!dev_name(dev)) {
 993		error = -EINVAL;
 994		goto name_error;
 995	}
 996
 997	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 998
 999	parent = get_device(dev->parent);
1000	kobj = get_device_parent(dev, parent);
1001	if (kobj)
1002		dev->kobj.parent = kobj;
1003
1004	/* use parent numa_node */
1005	if (parent)
1006		set_dev_node(dev, dev_to_node(parent));
1007
1008	/* first, register with generic layer. */
1009	/* we require the name to be set before, and pass NULL */
1010	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1011	if (error)
 
1012		goto Error;
 
1013
1014	/* notify platform of device entry */
1015	if (platform_notify)
1016		platform_notify(dev);
1017
1018	error = device_create_file(dev, &dev_attr_uevent);
1019	if (error)
1020		goto attrError;
1021
1022	if (MAJOR(dev->devt)) {
1023		error = device_create_file(dev, &dev_attr_dev);
1024		if (error)
1025			goto ueventattrError;
1026
1027		error = device_create_sys_dev_entry(dev);
1028		if (error)
1029			goto devtattrError;
1030
1031		devtmpfs_create_node(dev);
1032	}
1033
1034	error = device_add_class_symlinks(dev);
1035	if (error)
1036		goto SymlinkError;
1037	error = device_add_attrs(dev);
1038	if (error)
1039		goto AttrsError;
1040	error = bus_add_device(dev);
1041	if (error)
1042		goto BusError;
1043	error = dpm_sysfs_add(dev);
1044	if (error)
1045		goto DPMError;
1046	device_pm_add(dev);
1047
 
 
 
 
 
 
 
 
 
 
 
 
1048	/* Notify clients of device addition.  This call must come
1049	 * after dpm_sysfs_add() and before kobject_uevent().
1050	 */
1051	if (dev->bus)
1052		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1053					     BUS_NOTIFY_ADD_DEVICE, dev);
1054
1055	kobject_uevent(&dev->kobj, KOBJ_ADD);
1056	bus_probe_device(dev);
1057	if (parent)
1058		klist_add_tail(&dev->p->knode_parent,
1059			       &parent->p->klist_children);
1060
1061	if (dev->class) {
1062		mutex_lock(&dev->class->p->mutex);
1063		/* tie the class to the device */
1064		klist_add_tail(&dev->knode_class,
1065			       &dev->class->p->klist_devices);
1066
1067		/* notify any interfaces that the device is here */
1068		list_for_each_entry(class_intf,
1069				    &dev->class->p->interfaces, node)
1070			if (class_intf->add_dev)
1071				class_intf->add_dev(dev, class_intf);
1072		mutex_unlock(&dev->class->p->mutex);
1073	}
1074done:
1075	put_device(dev);
1076	return error;
 
 
 
 
 
 
1077 DPMError:
1078	bus_remove_device(dev);
1079 BusError:
1080	device_remove_attrs(dev);
1081 AttrsError:
1082	device_remove_class_symlinks(dev);
1083 SymlinkError:
1084	if (MAJOR(dev->devt))
1085		devtmpfs_delete_node(dev);
1086	if (MAJOR(dev->devt))
1087		device_remove_sys_dev_entry(dev);
1088 devtattrError:
1089	if (MAJOR(dev->devt))
1090		device_remove_file(dev, &dev_attr_dev);
1091 ueventattrError:
1092	device_remove_file(dev, &dev_attr_uevent);
1093 attrError:
1094	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 
1095	kobject_del(&dev->kobj);
1096 Error:
1097	cleanup_device_parent(dev);
1098	if (parent)
1099		put_device(parent);
1100name_error:
1101	kfree(dev->p);
1102	dev->p = NULL;
1103	goto done;
1104}
1105EXPORT_SYMBOL_GPL(device_add);
1106
1107/**
1108 * device_register - register a device with the system.
1109 * @dev: pointer to the device structure
1110 *
1111 * This happens in two clean steps - initialize the device
1112 * and add it to the system. The two steps can be called
1113 * separately, but this is the easiest and most common.
1114 * I.e. you should only call the two helpers separately if
1115 * have a clearly defined need to use and refcount the device
1116 * before it is added to the hierarchy.
1117 *
1118 * For more information, see the kerneldoc for device_initialize()
1119 * and device_add().
1120 *
1121 * NOTE: _Never_ directly free @dev after calling this function, even
1122 * if it returned an error! Always use put_device() to give up the
1123 * reference initialized in this function instead.
1124 */
1125int device_register(struct device *dev)
1126{
1127	device_initialize(dev);
1128	return device_add(dev);
1129}
1130EXPORT_SYMBOL_GPL(device_register);
1131
1132/**
1133 * get_device - increment reference count for device.
1134 * @dev: device.
1135 *
1136 * This simply forwards the call to kobject_get(), though
1137 * we do take care to provide for the case that we get a NULL
1138 * pointer passed in.
1139 */
1140struct device *get_device(struct device *dev)
1141{
1142	return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1143}
1144EXPORT_SYMBOL_GPL(get_device);
1145
1146/**
1147 * put_device - decrement reference count.
1148 * @dev: device in question.
1149 */
1150void put_device(struct device *dev)
1151{
1152	/* might_sleep(); */
1153	if (dev)
1154		kobject_put(&dev->kobj);
1155}
1156EXPORT_SYMBOL_GPL(put_device);
1157
1158/**
1159 * device_del - delete device from system.
1160 * @dev: device.
1161 *
1162 * This is the first part of the device unregistration
1163 * sequence. This removes the device from the lists we control
1164 * from here, has it removed from the other driver model
1165 * subsystems it was added to in device_add(), and removes it
1166 * from the kobject hierarchy.
1167 *
1168 * NOTE: this should be called manually _iff_ device_add() was
1169 * also called manually.
1170 */
1171void device_del(struct device *dev)
1172{
1173	struct device *parent = dev->parent;
 
1174	struct class_interface *class_intf;
1175
1176	/* Notify clients of device removal.  This call must come
1177	 * before dpm_sysfs_remove().
1178	 */
1179	if (dev->bus)
1180		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1181					     BUS_NOTIFY_DEL_DEVICE, dev);
 
 
1182	dpm_sysfs_remove(dev);
1183	if (parent)
1184		klist_del(&dev->p->knode_parent);
1185	if (MAJOR(dev->devt)) {
1186		devtmpfs_delete_node(dev);
1187		device_remove_sys_dev_entry(dev);
1188		device_remove_file(dev, &dev_attr_dev);
1189	}
1190	if (dev->class) {
1191		device_remove_class_symlinks(dev);
1192
1193		mutex_lock(&dev->class->p->mutex);
1194		/* notify any interfaces that the device is now gone */
1195		list_for_each_entry(class_intf,
1196				    &dev->class->p->interfaces, node)
1197			if (class_intf->remove_dev)
1198				class_intf->remove_dev(dev, class_intf);
1199		/* remove the device from the class list */
1200		klist_del(&dev->knode_class);
1201		mutex_unlock(&dev->class->p->mutex);
1202	}
1203	device_remove_file(dev, &dev_attr_uevent);
1204	device_remove_attrs(dev);
1205	bus_remove_device(dev);
1206	device_pm_remove(dev);
1207	driver_deferred_probe_del(dev);
 
1208
1209	/* Notify the platform of the removal, in case they
1210	 * need to do anything...
1211	 */
1212	if (platform_notify_remove)
1213		platform_notify_remove(dev);
 
 
 
1214	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1215	cleanup_device_parent(dev);
1216	kobject_del(&dev->kobj);
 
1217	put_device(parent);
1218}
1219EXPORT_SYMBOL_GPL(device_del);
1220
1221/**
1222 * device_unregister - unregister device from system.
1223 * @dev: device going away.
1224 *
1225 * We do this in two parts, like we do device_register(). First,
1226 * we remove it from all the subsystems with device_del(), then
1227 * we decrement the reference count via put_device(). If that
1228 * is the final reference count, the device will be cleaned up
1229 * via device_release() above. Otherwise, the structure will
1230 * stick around until the final reference to the device is dropped.
1231 */
1232void device_unregister(struct device *dev)
1233{
1234	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1235	device_del(dev);
1236	put_device(dev);
1237}
1238EXPORT_SYMBOL_GPL(device_unregister);
1239
 
 
 
 
 
 
 
 
 
 
 
 
 
1240static struct device *next_device(struct klist_iter *i)
1241{
1242	struct klist_node *n = klist_next(i);
1243	struct device *dev = NULL;
1244	struct device_private *p;
1245
1246	if (n) {
1247		p = to_device_private_parent(n);
1248		dev = p->device;
1249	}
1250	return dev;
1251}
1252
1253/**
1254 * device_get_devnode - path of device node file
1255 * @dev: device
1256 * @mode: returned file access mode
1257 * @uid: returned file owner
1258 * @gid: returned file group
1259 * @tmp: possibly allocated string
1260 *
1261 * Return the relative path of a possible device node.
1262 * Non-default names may need to allocate a memory to compose
1263 * a name. This memory is returned in tmp and needs to be
1264 * freed by the caller.
1265 */
1266const char *device_get_devnode(struct device *dev,
1267			       umode_t *mode, kuid_t *uid, kgid_t *gid,
1268			       const char **tmp)
1269{
1270	char *s;
1271
1272	*tmp = NULL;
1273
1274	/* the device type may provide a specific name */
1275	if (dev->type && dev->type->devnode)
1276		*tmp = dev->type->devnode(dev, mode, uid, gid);
1277	if (*tmp)
1278		return *tmp;
1279
1280	/* the class may provide a specific name */
1281	if (dev->class && dev->class->devnode)
1282		*tmp = dev->class->devnode(dev, mode);
1283	if (*tmp)
1284		return *tmp;
1285
1286	/* return name without allocation, tmp == NULL */
1287	if (strchr(dev_name(dev), '!') == NULL)
1288		return dev_name(dev);
1289
1290	/* replace '!' in the name with '/' */
1291	*tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1292	if (!*tmp)
1293		return NULL;
1294	while ((s = strchr(*tmp, '!')))
1295		s[0] = '/';
1296	return *tmp;
1297}
1298
1299/**
1300 * device_for_each_child - device child iterator.
1301 * @parent: parent struct device.
1302 * @fn: function to be called for each device.
1303 * @data: data for the callback.
1304 *
1305 * Iterate over @parent's child devices, and call @fn for each,
1306 * passing it @data.
1307 *
1308 * We check the return of @fn each time. If it returns anything
1309 * other than 0, we break out and return that value.
1310 */
1311int device_for_each_child(struct device *parent, void *data,
1312			  int (*fn)(struct device *dev, void *data))
1313{
1314	struct klist_iter i;
1315	struct device *child;
1316	int error = 0;
1317
1318	if (!parent->p)
1319		return 0;
1320
1321	klist_iter_init(&parent->p->klist_children, &i);
1322	while ((child = next_device(&i)) && !error)
1323		error = fn(child, data);
1324	klist_iter_exit(&i);
1325	return error;
1326}
1327EXPORT_SYMBOL_GPL(device_for_each_child);
1328
1329/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1330 * device_find_child - device iterator for locating a particular device.
1331 * @parent: parent struct device
1332 * @match: Callback function to check device
1333 * @data: Data to pass to match function
1334 *
1335 * This is similar to the device_for_each_child() function above, but it
1336 * returns a reference to a device that is 'found' for later use, as
1337 * determined by the @match callback.
1338 *
1339 * The callback should return 0 if the device doesn't match and non-zero
1340 * if it does.  If the callback returns non-zero and a reference to the
1341 * current device can be obtained, this function will return to the caller
1342 * and not iterate over any more devices.
1343 *
1344 * NOTE: you will need to drop the reference with put_device() after use.
1345 */
1346struct device *device_find_child(struct device *parent, void *data,
1347				 int (*match)(struct device *dev, void *data))
1348{
1349	struct klist_iter i;
1350	struct device *child;
1351
1352	if (!parent)
1353		return NULL;
1354
1355	klist_iter_init(&parent->p->klist_children, &i);
1356	while ((child = next_device(&i)))
1357		if (match(child, data) && get_device(child))
1358			break;
1359	klist_iter_exit(&i);
1360	return child;
1361}
1362EXPORT_SYMBOL_GPL(device_find_child);
1363
1364int __init devices_init(void)
1365{
1366	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1367	if (!devices_kset)
1368		return -ENOMEM;
1369	dev_kobj = kobject_create_and_add("dev", NULL);
1370	if (!dev_kobj)
1371		goto dev_kobj_err;
1372	sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1373	if (!sysfs_dev_block_kobj)
1374		goto block_kobj_err;
1375	sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1376	if (!sysfs_dev_char_kobj)
1377		goto char_kobj_err;
1378
1379	return 0;
1380
1381 char_kobj_err:
1382	kobject_put(sysfs_dev_block_kobj);
1383 block_kobj_err:
1384	kobject_put(dev_kobj);
1385 dev_kobj_err:
1386	kset_unregister(devices_kset);
1387	return -ENOMEM;
1388}
1389
1390static int device_check_offline(struct device *dev, void *not_used)
1391{
1392	int ret;
1393
1394	ret = device_for_each_child(dev, NULL, device_check_offline);
1395	if (ret)
1396		return ret;
1397
1398	return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1399}
1400
1401/**
1402 * device_offline - Prepare the device for hot-removal.
1403 * @dev: Device to be put offline.
1404 *
1405 * Execute the device bus type's .offline() callback, if present, to prepare
1406 * the device for a subsequent hot-removal.  If that succeeds, the device must
1407 * not be used until either it is removed or its bus type's .online() callback
1408 * is executed.
1409 *
1410 * Call under device_hotplug_lock.
1411 */
1412int device_offline(struct device *dev)
1413{
1414	int ret;
1415
1416	if (dev->offline_disabled)
1417		return -EPERM;
1418
1419	ret = device_for_each_child(dev, NULL, device_check_offline);
1420	if (ret)
1421		return ret;
1422
1423	device_lock(dev);
1424	if (device_supports_offline(dev)) {
1425		if (dev->offline) {
1426			ret = 1;
1427		} else {
1428			ret = dev->bus->offline(dev);
1429			if (!ret) {
1430				kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1431				dev->offline = true;
1432			}
1433		}
1434	}
1435	device_unlock(dev);
1436
1437	return ret;
1438}
1439
1440/**
1441 * device_online - Put the device back online after successful device_offline().
1442 * @dev: Device to be put back online.
1443 *
1444 * If device_offline() has been successfully executed for @dev, but the device
1445 * has not been removed subsequently, execute its bus type's .online() callback
1446 * to indicate that the device can be used again.
1447 *
1448 * Call under device_hotplug_lock.
1449 */
1450int device_online(struct device *dev)
1451{
1452	int ret = 0;
1453
1454	device_lock(dev);
1455	if (device_supports_offline(dev)) {
1456		if (dev->offline) {
1457			ret = dev->bus->online(dev);
1458			if (!ret) {
1459				kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1460				dev->offline = false;
1461			}
1462		} else {
1463			ret = 1;
1464		}
1465	}
1466	device_unlock(dev);
1467
1468	return ret;
1469}
1470
1471struct root_device {
1472	struct device dev;
1473	struct module *owner;
1474};
1475
1476static inline struct root_device *to_root_device(struct device *d)
1477{
1478	return container_of(d, struct root_device, dev);
1479}
1480
1481static void root_device_release(struct device *dev)
1482{
1483	kfree(to_root_device(dev));
1484}
1485
1486/**
1487 * __root_device_register - allocate and register a root device
1488 * @name: root device name
1489 * @owner: owner module of the root device, usually THIS_MODULE
1490 *
1491 * This function allocates a root device and registers it
1492 * using device_register(). In order to free the returned
1493 * device, use root_device_unregister().
1494 *
1495 * Root devices are dummy devices which allow other devices
1496 * to be grouped under /sys/devices. Use this function to
1497 * allocate a root device and then use it as the parent of
1498 * any device which should appear under /sys/devices/{name}
1499 *
1500 * The /sys/devices/{name} directory will also contain a
1501 * 'module' symlink which points to the @owner directory
1502 * in sysfs.
1503 *
1504 * Returns &struct device pointer on success, or ERR_PTR() on error.
1505 *
1506 * Note: You probably want to use root_device_register().
1507 */
1508struct device *__root_device_register(const char *name, struct module *owner)
1509{
1510	struct root_device *root;
1511	int err = -ENOMEM;
1512
1513	root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1514	if (!root)
1515		return ERR_PTR(err);
1516
1517	err = dev_set_name(&root->dev, "%s", name);
1518	if (err) {
1519		kfree(root);
1520		return ERR_PTR(err);
1521	}
1522
1523	root->dev.release = root_device_release;
1524
1525	err = device_register(&root->dev);
1526	if (err) {
1527		put_device(&root->dev);
1528		return ERR_PTR(err);
1529	}
1530
1531#ifdef CONFIG_MODULES	/* gotta find a "cleaner" way to do this */
1532	if (owner) {
1533		struct module_kobject *mk = &owner->mkobj;
1534
1535		err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1536		if (err) {
1537			device_unregister(&root->dev);
1538			return ERR_PTR(err);
1539		}
1540		root->owner = owner;
1541	}
1542#endif
1543
1544	return &root->dev;
1545}
1546EXPORT_SYMBOL_GPL(__root_device_register);
1547
1548/**
1549 * root_device_unregister - unregister and free a root device
1550 * @dev: device going away
1551 *
1552 * This function unregisters and cleans up a device that was created by
1553 * root_device_register().
1554 */
1555void root_device_unregister(struct device *dev)
1556{
1557	struct root_device *root = to_root_device(dev);
1558
1559	if (root->owner)
1560		sysfs_remove_link(&root->dev.kobj, "module");
1561
1562	device_unregister(dev);
1563}
1564EXPORT_SYMBOL_GPL(root_device_unregister);
1565
1566
1567static void device_create_release(struct device *dev)
1568{
1569	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1570	kfree(dev);
1571}
1572
1573static struct device *
1574device_create_groups_vargs(struct class *class, struct device *parent,
1575			   dev_t devt, void *drvdata,
1576			   const struct attribute_group **groups,
1577			   const char *fmt, va_list args)
1578{
1579	struct device *dev = NULL;
1580	int retval = -ENODEV;
1581
1582	if (class == NULL || IS_ERR(class))
1583		goto error;
1584
1585	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1586	if (!dev) {
1587		retval = -ENOMEM;
1588		goto error;
1589	}
1590
1591	device_initialize(dev);
1592	dev->devt = devt;
1593	dev->class = class;
1594	dev->parent = parent;
1595	dev->groups = groups;
1596	dev->release = device_create_release;
1597	dev_set_drvdata(dev, drvdata);
1598
1599	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1600	if (retval)
1601		goto error;
1602
1603	retval = device_add(dev);
1604	if (retval)
1605		goto error;
1606
1607	return dev;
1608
1609error:
1610	put_device(dev);
1611	return ERR_PTR(retval);
1612}
1613
1614/**
1615 * device_create_vargs - creates a device and registers it with sysfs
1616 * @class: pointer to the struct class that this device should be registered to
1617 * @parent: pointer to the parent struct device of this new device, if any
1618 * @devt: the dev_t for the char device to be added
1619 * @drvdata: the data to be added to the device for callbacks
1620 * @fmt: string for the device's name
1621 * @args: va_list for the device's name
1622 *
1623 * This function can be used by char device classes.  A struct device
1624 * will be created in sysfs, registered to the specified class.
1625 *
1626 * A "dev" file will be created, showing the dev_t for the device, if
1627 * the dev_t is not 0,0.
1628 * If a pointer to a parent struct device is passed in, the newly created
1629 * struct device will be a child of that device in sysfs.
1630 * The pointer to the struct device will be returned from the call.
1631 * Any further sysfs files that might be required can be created using this
1632 * pointer.
1633 *
1634 * Returns &struct device pointer on success, or ERR_PTR() on error.
1635 *
1636 * Note: the struct class passed to this function must have previously
1637 * been created with a call to class_create().
1638 */
1639struct device *device_create_vargs(struct class *class, struct device *parent,
1640				   dev_t devt, void *drvdata, const char *fmt,
1641				   va_list args)
1642{
1643	return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1644					  fmt, args);
1645}
1646EXPORT_SYMBOL_GPL(device_create_vargs);
1647
1648/**
1649 * device_create - creates a device and registers it with sysfs
1650 * @class: pointer to the struct class that this device should be registered to
1651 * @parent: pointer to the parent struct device of this new device, if any
1652 * @devt: the dev_t for the char device to be added
1653 * @drvdata: the data to be added to the device for callbacks
1654 * @fmt: string for the device's name
1655 *
1656 * This function can be used by char device classes.  A struct device
1657 * will be created in sysfs, registered to the specified class.
1658 *
1659 * A "dev" file will be created, showing the dev_t for the device, if
1660 * the dev_t is not 0,0.
1661 * If a pointer to a parent struct device is passed in, the newly created
1662 * struct device will be a child of that device in sysfs.
1663 * The pointer to the struct device will be returned from the call.
1664 * Any further sysfs files that might be required can be created using this
1665 * pointer.
1666 *
1667 * Returns &struct device pointer on success, or ERR_PTR() on error.
1668 *
1669 * Note: the struct class passed to this function must have previously
1670 * been created with a call to class_create().
1671 */
1672struct device *device_create(struct class *class, struct device *parent,
1673			     dev_t devt, void *drvdata, const char *fmt, ...)
1674{
1675	va_list vargs;
1676	struct device *dev;
1677
1678	va_start(vargs, fmt);
1679	dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1680	va_end(vargs);
1681	return dev;
1682}
1683EXPORT_SYMBOL_GPL(device_create);
1684
1685/**
1686 * device_create_with_groups - creates a device and registers it with sysfs
1687 * @class: pointer to the struct class that this device should be registered to
1688 * @parent: pointer to the parent struct device of this new device, if any
1689 * @devt: the dev_t for the char device to be added
1690 * @drvdata: the data to be added to the device for callbacks
1691 * @groups: NULL-terminated list of attribute groups to be created
1692 * @fmt: string for the device's name
1693 *
1694 * This function can be used by char device classes.  A struct device
1695 * will be created in sysfs, registered to the specified class.
1696 * Additional attributes specified in the groups parameter will also
1697 * be created automatically.
1698 *
1699 * A "dev" file will be created, showing the dev_t for the device, if
1700 * the dev_t is not 0,0.
1701 * If a pointer to a parent struct device is passed in, the newly created
1702 * struct device will be a child of that device in sysfs.
1703 * The pointer to the struct device will be returned from the call.
1704 * Any further sysfs files that might be required can be created using this
1705 * pointer.
1706 *
1707 * Returns &struct device pointer on success, or ERR_PTR() on error.
1708 *
1709 * Note: the struct class passed to this function must have previously
1710 * been created with a call to class_create().
1711 */
1712struct device *device_create_with_groups(struct class *class,
1713					 struct device *parent, dev_t devt,
1714					 void *drvdata,
1715					 const struct attribute_group **groups,
1716					 const char *fmt, ...)
1717{
1718	va_list vargs;
1719	struct device *dev;
1720
1721	va_start(vargs, fmt);
1722	dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1723					 fmt, vargs);
1724	va_end(vargs);
1725	return dev;
1726}
1727EXPORT_SYMBOL_GPL(device_create_with_groups);
1728
1729static int __match_devt(struct device *dev, const void *data)
1730{
1731	const dev_t *devt = data;
1732
1733	return dev->devt == *devt;
1734}
1735
1736/**
1737 * device_destroy - removes a device that was created with device_create()
1738 * @class: pointer to the struct class that this device was registered with
1739 * @devt: the dev_t of the device that was previously registered
1740 *
1741 * This call unregisters and cleans up a device that was created with a
1742 * call to device_create().
1743 */
1744void device_destroy(struct class *class, dev_t devt)
1745{
1746	struct device *dev;
1747
1748	dev = class_find_device(class, NULL, &devt, __match_devt);
1749	if (dev) {
1750		put_device(dev);
1751		device_unregister(dev);
1752	}
1753}
1754EXPORT_SYMBOL_GPL(device_destroy);
1755
1756/**
1757 * device_rename - renames a device
1758 * @dev: the pointer to the struct device to be renamed
1759 * @new_name: the new name of the device
1760 *
1761 * It is the responsibility of the caller to provide mutual
1762 * exclusion between two different calls of device_rename
1763 * on the same device to ensure that new_name is valid and
1764 * won't conflict with other devices.
1765 *
1766 * Note: Don't call this function.  Currently, the networking layer calls this
1767 * function, but that will change.  The following text from Kay Sievers offers
1768 * some insight:
1769 *
1770 * Renaming devices is racy at many levels, symlinks and other stuff are not
1771 * replaced atomically, and you get a "move" uevent, but it's not easy to
1772 * connect the event to the old and new device. Device nodes are not renamed at
1773 * all, there isn't even support for that in the kernel now.
1774 *
1775 * In the meantime, during renaming, your target name might be taken by another
1776 * driver, creating conflicts. Or the old name is taken directly after you
1777 * renamed it -- then you get events for the same DEVPATH, before you even see
1778 * the "move" event. It's just a mess, and nothing new should ever rely on
1779 * kernel device renaming. Besides that, it's not even implemented now for
1780 * other things than (driver-core wise very simple) network devices.
1781 *
1782 * We are currently about to change network renaming in udev to completely
1783 * disallow renaming of devices in the same namespace as the kernel uses,
1784 * because we can't solve the problems properly, that arise with swapping names
1785 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1786 * be allowed to some other name than eth[0-9]*, for the aforementioned
1787 * reasons.
1788 *
1789 * Make up a "real" name in the driver before you register anything, or add
1790 * some other attributes for userspace to find the device, or use udev to add
1791 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1792 * don't even want to get into that and try to implement the missing pieces in
1793 * the core. We really have other pieces to fix in the driver core mess. :)
1794 */
1795int device_rename(struct device *dev, const char *new_name)
1796{
1797	struct kobject *kobj = &dev->kobj;
1798	char *old_device_name = NULL;
1799	int error;
1800
1801	dev = get_device(dev);
1802	if (!dev)
1803		return -EINVAL;
1804
1805	dev_dbg(dev, "renaming to %s\n", new_name);
1806
1807	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1808	if (!old_device_name) {
1809		error = -ENOMEM;
1810		goto out;
1811	}
1812
1813	if (dev->class) {
1814		error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1815					     kobj, old_device_name,
1816					     new_name, kobject_namespace(kobj));
1817		if (error)
1818			goto out;
1819	}
1820
1821	error = kobject_rename(kobj, new_name);
1822	if (error)
1823		goto out;
1824
1825out:
1826	put_device(dev);
1827
1828	kfree(old_device_name);
1829
1830	return error;
1831}
1832EXPORT_SYMBOL_GPL(device_rename);
1833
1834static int device_move_class_links(struct device *dev,
1835				   struct device *old_parent,
1836				   struct device *new_parent)
1837{
1838	int error = 0;
1839
1840	if (old_parent)
1841		sysfs_remove_link(&dev->kobj, "device");
1842	if (new_parent)
1843		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1844					  "device");
1845	return error;
1846}
1847
1848/**
1849 * device_move - moves a device to a new parent
1850 * @dev: the pointer to the struct device to be moved
1851 * @new_parent: the new parent of the device (can by NULL)
1852 * @dpm_order: how to reorder the dpm_list
1853 */
1854int device_move(struct device *dev, struct device *new_parent,
1855		enum dpm_order dpm_order)
1856{
1857	int error;
1858	struct device *old_parent;
1859	struct kobject *new_parent_kobj;
1860
1861	dev = get_device(dev);
1862	if (!dev)
1863		return -EINVAL;
1864
1865	device_pm_lock();
1866	new_parent = get_device(new_parent);
1867	new_parent_kobj = get_device_parent(dev, new_parent);
1868
1869	pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1870		 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1871	error = kobject_move(&dev->kobj, new_parent_kobj);
1872	if (error) {
1873		cleanup_glue_dir(dev, new_parent_kobj);
1874		put_device(new_parent);
1875		goto out;
1876	}
1877	old_parent = dev->parent;
1878	dev->parent = new_parent;
1879	if (old_parent)
1880		klist_remove(&dev->p->knode_parent);
1881	if (new_parent) {
1882		klist_add_tail(&dev->p->knode_parent,
1883			       &new_parent->p->klist_children);
1884		set_dev_node(dev, dev_to_node(new_parent));
1885	}
1886
1887	if (dev->class) {
1888		error = device_move_class_links(dev, old_parent, new_parent);
1889		if (error) {
1890			/* We ignore errors on cleanup since we're hosed anyway... */
1891			device_move_class_links(dev, new_parent, old_parent);
1892			if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1893				if (new_parent)
1894					klist_remove(&dev->p->knode_parent);
1895				dev->parent = old_parent;
1896				if (old_parent) {
1897					klist_add_tail(&dev->p->knode_parent,
1898						       &old_parent->p->klist_children);
1899					set_dev_node(dev, dev_to_node(old_parent));
1900				}
1901			}
1902			cleanup_glue_dir(dev, new_parent_kobj);
1903			put_device(new_parent);
1904			goto out;
1905		}
1906	}
1907	switch (dpm_order) {
1908	case DPM_ORDER_NONE:
1909		break;
1910	case DPM_ORDER_DEV_AFTER_PARENT:
1911		device_pm_move_after(dev, new_parent);
 
1912		break;
1913	case DPM_ORDER_PARENT_BEFORE_DEV:
1914		device_pm_move_before(new_parent, dev);
 
1915		break;
1916	case DPM_ORDER_DEV_LAST:
1917		device_pm_move_last(dev);
 
1918		break;
1919	}
1920
1921	put_device(old_parent);
1922out:
1923	device_pm_unlock();
1924	put_device(dev);
1925	return error;
1926}
1927EXPORT_SYMBOL_GPL(device_move);
1928
1929/**
1930 * device_shutdown - call ->shutdown() on each device to shutdown.
1931 */
1932void device_shutdown(void)
1933{
1934	struct device *dev, *parent;
1935
1936	spin_lock(&devices_kset->list_lock);
1937	/*
1938	 * Walk the devices list backward, shutting down each in turn.
1939	 * Beware that device unplug events may also start pulling
1940	 * devices offline, even as the system is shutting down.
1941	 */
1942	while (!list_empty(&devices_kset->list)) {
1943		dev = list_entry(devices_kset->list.prev, struct device,
1944				kobj.entry);
1945
1946		/*
1947		 * hold reference count of device's parent to
1948		 * prevent it from being freed because parent's
1949		 * lock is to be held
1950		 */
1951		parent = get_device(dev->parent);
1952		get_device(dev);
1953		/*
1954		 * Make sure the device is off the kset list, in the
1955		 * event that dev->*->shutdown() doesn't remove it.
1956		 */
1957		list_del_init(&dev->kobj.entry);
1958		spin_unlock(&devices_kset->list_lock);
1959
1960		/* hold lock to avoid race with probe/release */
1961		if (parent)
1962			device_lock(parent);
1963		device_lock(dev);
1964
1965		/* Don't allow any more runtime suspends */
1966		pm_runtime_get_noresume(dev);
1967		pm_runtime_barrier(dev);
1968
1969		if (dev->bus && dev->bus->shutdown) {
1970			if (initcall_debug)
1971				dev_info(dev, "shutdown\n");
1972			dev->bus->shutdown(dev);
1973		} else if (dev->driver && dev->driver->shutdown) {
1974			if (initcall_debug)
1975				dev_info(dev, "shutdown\n");
1976			dev->driver->shutdown(dev);
1977		}
1978
1979		device_unlock(dev);
1980		if (parent)
1981			device_unlock(parent);
1982
1983		put_device(dev);
1984		put_device(parent);
1985
1986		spin_lock(&devices_kset->list_lock);
1987	}
1988	spin_unlock(&devices_kset->list_lock);
1989}
1990
1991/*
1992 * Device logging functions
1993 */
1994
1995#ifdef CONFIG_PRINTK
1996static int
1997create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
1998{
1999	const char *subsys;
2000	size_t pos = 0;
2001
2002	if (dev->class)
2003		subsys = dev->class->name;
2004	else if (dev->bus)
2005		subsys = dev->bus->name;
2006	else
2007		return 0;
2008
2009	pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
 
 
2010
2011	/*
2012	 * Add device identifier DEVICE=:
2013	 *   b12:8         block dev_t
2014	 *   c127:3        char dev_t
2015	 *   n8            netdev ifindex
2016	 *   +sound:card0  subsystem:devname
2017	 */
2018	if (MAJOR(dev->devt)) {
2019		char c;
2020
2021		if (strcmp(subsys, "block") == 0)
2022			c = 'b';
2023		else
2024			c = 'c';
2025		pos++;
2026		pos += snprintf(hdr + pos, hdrlen - pos,
2027				"DEVICE=%c%u:%u",
2028				c, MAJOR(dev->devt), MINOR(dev->devt));
2029	} else if (strcmp(subsys, "net") == 0) {
2030		struct net_device *net = to_net_dev(dev);
2031
2032		pos++;
2033		pos += snprintf(hdr + pos, hdrlen - pos,
2034				"DEVICE=n%u", net->ifindex);
2035	} else {
2036		pos++;
2037		pos += snprintf(hdr + pos, hdrlen - pos,
2038				"DEVICE=+%s:%s", subsys, dev_name(dev));
2039	}
2040
 
 
 
2041	return pos;
 
 
 
 
2042}
2043
2044int dev_vprintk_emit(int level, const struct device *dev,
2045		     const char *fmt, va_list args)
2046{
2047	char hdr[128];
2048	size_t hdrlen;
2049
2050	hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2051
2052	return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2053}
2054EXPORT_SYMBOL(dev_vprintk_emit);
2055
2056int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2057{
2058	va_list args;
2059	int r;
2060
2061	va_start(args, fmt);
2062
2063	r = dev_vprintk_emit(level, dev, fmt, args);
2064
2065	va_end(args);
2066
2067	return r;
2068}
2069EXPORT_SYMBOL(dev_printk_emit);
2070
2071static int __dev_printk(const char *level, const struct device *dev,
2072			struct va_format *vaf)
2073{
2074	if (!dev)
2075		return printk("%s(NULL device *): %pV", level, vaf);
2076
2077	return dev_printk_emit(level[1] - '0', dev,
2078			       "%s %s: %pV",
2079			       dev_driver_string(dev), dev_name(dev), vaf);
2080}
2081
2082int dev_printk(const char *level, const struct device *dev,
2083	       const char *fmt, ...)
2084{
2085	struct va_format vaf;
2086	va_list args;
2087	int r;
2088
2089	va_start(args, fmt);
2090
2091	vaf.fmt = fmt;
2092	vaf.va = &args;
2093
2094	r = __dev_printk(level, dev, &vaf);
2095
2096	va_end(args);
2097
2098	return r;
2099}
2100EXPORT_SYMBOL(dev_printk);
2101
2102#define define_dev_printk_level(func, kern_level)		\
2103int func(const struct device *dev, const char *fmt, ...)	\
2104{								\
2105	struct va_format vaf;					\
2106	va_list args;						\
2107	int r;							\
2108								\
2109	va_start(args, fmt);					\
2110								\
2111	vaf.fmt = fmt;						\
2112	vaf.va = &args;						\
2113								\
2114	r = __dev_printk(kern_level, dev, &vaf);		\
2115								\
2116	va_end(args);						\
2117								\
2118	return r;						\
2119}								\
2120EXPORT_SYMBOL(func);
2121
2122define_dev_printk_level(dev_emerg, KERN_EMERG);
2123define_dev_printk_level(dev_alert, KERN_ALERT);
2124define_dev_printk_level(dev_crit, KERN_CRIT);
2125define_dev_printk_level(dev_err, KERN_ERR);
2126define_dev_printk_level(dev_warn, KERN_WARNING);
2127define_dev_printk_level(dev_notice, KERN_NOTICE);
2128define_dev_printk_level(_dev_info, KERN_INFO);
2129
2130#endif
v4.10.11
   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
  47/* Device links support. */
  48
  49#ifdef CONFIG_SRCU
  50static DEFINE_MUTEX(device_links_lock);
  51DEFINE_STATIC_SRCU(device_links_srcu);
  52
  53static inline void device_links_write_lock(void)
  54{
  55	mutex_lock(&device_links_lock);
  56}
  57
  58static inline void device_links_write_unlock(void)
  59{
  60	mutex_unlock(&device_links_lock);
  61}
  62
  63int device_links_read_lock(void)
  64{
  65	return srcu_read_lock(&device_links_srcu);
  66}
  67
  68void device_links_read_unlock(int idx)
  69{
  70	srcu_read_unlock(&device_links_srcu, idx);
  71}
  72#else /* !CONFIG_SRCU */
  73static DECLARE_RWSEM(device_links_lock);
  74
  75static inline void device_links_write_lock(void)
  76{
  77	down_write(&device_links_lock);
  78}
  79
  80static inline void device_links_write_unlock(void)
  81{
  82	up_write(&device_links_lock);
  83}
  84
  85int device_links_read_lock(void)
  86{
  87	down_read(&device_links_lock);
  88	return 0;
  89}
  90
  91void device_links_read_unlock(int not_used)
  92{
  93	up_read(&device_links_lock);
  94}
  95#endif /* !CONFIG_SRCU */
  96
  97/**
  98 * device_is_dependent - Check if one device depends on another one
  99 * @dev: Device to check dependencies for.
 100 * @target: Device to check against.
 101 *
 102 * Check if @target depends on @dev or any device dependent on it (its child or
 103 * its consumer etc).  Return 1 if that is the case or 0 otherwise.
 104 */
 105static int device_is_dependent(struct device *dev, void *target)
 106{
 107	struct device_link *link;
 108	int ret;
 109
 110	if (WARN_ON(dev == target))
 111		return 1;
 112
 113	ret = device_for_each_child(dev, target, device_is_dependent);
 114	if (ret)
 115		return ret;
 116
 117	list_for_each_entry(link, &dev->links.consumers, s_node) {
 118		if (WARN_ON(link->consumer == target))
 119			return 1;
 120
 121		ret = device_is_dependent(link->consumer, target);
 122		if (ret)
 123			break;
 124	}
 125	return ret;
 126}
 127
 128static int device_reorder_to_tail(struct device *dev, void *not_used)
 129{
 130	struct device_link *link;
 131
 132	/*
 133	 * Devices that have not been registered yet will be put to the ends
 134	 * of the lists during the registration, so skip them here.
 135	 */
 136	if (device_is_registered(dev))
 137		devices_kset_move_last(dev);
 138
 139	if (device_pm_initialized(dev))
 140		device_pm_move_last(dev);
 141
 142	device_for_each_child(dev, NULL, device_reorder_to_tail);
 143	list_for_each_entry(link, &dev->links.consumers, s_node)
 144		device_reorder_to_tail(link->consumer, NULL);
 145
 146	return 0;
 147}
 148
 149/**
 150 * device_link_add - Create a link between two devices.
 151 * @consumer: Consumer end of the link.
 152 * @supplier: Supplier end of the link.
 153 * @flags: Link flags.
 154 *
 155 * The caller is responsible for the proper synchronization of the link creation
 156 * with runtime PM.  First, setting the DL_FLAG_PM_RUNTIME flag will cause the
 157 * runtime PM framework to take the link into account.  Second, if the
 158 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
 159 * be forced into the active metastate and reference-counted upon the creation
 160 * of the link.  If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
 161 * ignored.
 162 *
 163 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
 164 * when the consumer device driver unbinds from it.  The combination of both
 165 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
 166 * to be returned.
 167 *
 168 * A side effect of the link creation is re-ordering of dpm_list and the
 169 * devices_kset list by moving the consumer device and all devices depending
 170 * on it to the ends of these lists (that does not happen to devices that have
 171 * not been registered when this function is called).
 172 *
 173 * The supplier device is required to be registered when this function is called
 174 * and NULL will be returned if that is not the case.  The consumer device need
 175 * not be registered, however.
 176 */
 177struct device_link *device_link_add(struct device *consumer,
 178				    struct device *supplier, u32 flags)
 179{
 180	struct device_link *link;
 181
 182	if (!consumer || !supplier ||
 183	    ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE)))
 184		return NULL;
 185
 186	device_links_write_lock();
 187	device_pm_lock();
 188
 189	/*
 190	 * If the supplier has not been fully registered yet or there is a
 191	 * reverse dependency between the consumer and the supplier already in
 192	 * the graph, return NULL.
 193	 */
 194	if (!device_pm_initialized(supplier)
 195	    || device_is_dependent(consumer, supplier)) {
 196		link = NULL;
 197		goto out;
 198	}
 199
 200	list_for_each_entry(link, &supplier->links.consumers, s_node)
 201		if (link->consumer == consumer)
 202			goto out;
 203
 204	link = kzalloc(sizeof(*link), GFP_KERNEL);
 205	if (!link)
 206		goto out;
 207
 208	if (flags & DL_FLAG_PM_RUNTIME) {
 209		if (flags & DL_FLAG_RPM_ACTIVE) {
 210			if (pm_runtime_get_sync(supplier) < 0) {
 211				pm_runtime_put_noidle(supplier);
 212				kfree(link);
 213				link = NULL;
 214				goto out;
 215			}
 216			link->rpm_active = true;
 217		}
 218		pm_runtime_new_link(consumer);
 219	}
 220	get_device(supplier);
 221	link->supplier = supplier;
 222	INIT_LIST_HEAD(&link->s_node);
 223	get_device(consumer);
 224	link->consumer = consumer;
 225	INIT_LIST_HEAD(&link->c_node);
 226	link->flags = flags;
 227
 228	/* Determine the initial link state. */
 229	if (flags & DL_FLAG_STATELESS) {
 230		link->status = DL_STATE_NONE;
 231	} else {
 232		switch (supplier->links.status) {
 233		case DL_DEV_DRIVER_BOUND:
 234			switch (consumer->links.status) {
 235			case DL_DEV_PROBING:
 236				/*
 237				 * Balance the decrementation of the supplier's
 238				 * runtime PM usage counter after consumer probe
 239				 * in driver_probe_device().
 240				 */
 241				if (flags & DL_FLAG_PM_RUNTIME)
 242					pm_runtime_get_sync(supplier);
 243
 244				link->status = DL_STATE_CONSUMER_PROBE;
 245				break;
 246			case DL_DEV_DRIVER_BOUND:
 247				link->status = DL_STATE_ACTIVE;
 248				break;
 249			default:
 250				link->status = DL_STATE_AVAILABLE;
 251				break;
 252			}
 253			break;
 254		case DL_DEV_UNBINDING:
 255			link->status = DL_STATE_SUPPLIER_UNBIND;
 256			break;
 257		default:
 258			link->status = DL_STATE_DORMANT;
 259			break;
 260		}
 261	}
 262
 263	/*
 264	 * Move the consumer and all of the devices depending on it to the end
 265	 * of dpm_list and the devices_kset list.
 266	 *
 267	 * It is necessary to hold dpm_list locked throughout all that or else
 268	 * we may end up suspending with a wrong ordering of it.
 269	 */
 270	device_reorder_to_tail(consumer, NULL);
 271
 272	list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
 273	list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
 274
 275	dev_info(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
 276
 277 out:
 278	device_pm_unlock();
 279	device_links_write_unlock();
 280	return link;
 281}
 282EXPORT_SYMBOL_GPL(device_link_add);
 283
 284static void device_link_free(struct device_link *link)
 285{
 286	put_device(link->consumer);
 287	put_device(link->supplier);
 288	kfree(link);
 289}
 290
 291#ifdef CONFIG_SRCU
 292static void __device_link_free_srcu(struct rcu_head *rhead)
 293{
 294	device_link_free(container_of(rhead, struct device_link, rcu_head));
 295}
 296
 297static void __device_link_del(struct device_link *link)
 298{
 299	dev_info(link->consumer, "Dropping the link to %s\n",
 300		 dev_name(link->supplier));
 301
 302	if (link->flags & DL_FLAG_PM_RUNTIME)
 303		pm_runtime_drop_link(link->consumer);
 304
 305	list_del_rcu(&link->s_node);
 306	list_del_rcu(&link->c_node);
 307	call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
 308}
 309#else /* !CONFIG_SRCU */
 310static void __device_link_del(struct device_link *link)
 311{
 312	dev_info(link->consumer, "Dropping the link to %s\n",
 313		 dev_name(link->supplier));
 314
 315	list_del(&link->s_node);
 316	list_del(&link->c_node);
 317	device_link_free(link);
 318}
 319#endif /* !CONFIG_SRCU */
 320
 321/**
 322 * device_link_del - Delete a link between two devices.
 323 * @link: Device link to delete.
 324 *
 325 * The caller must ensure proper synchronization of this function with runtime
 326 * PM.
 327 */
 328void device_link_del(struct device_link *link)
 329{
 330	device_links_write_lock();
 331	device_pm_lock();
 332	__device_link_del(link);
 333	device_pm_unlock();
 334	device_links_write_unlock();
 335}
 336EXPORT_SYMBOL_GPL(device_link_del);
 337
 338static void device_links_missing_supplier(struct device *dev)
 339{
 340	struct device_link *link;
 341
 342	list_for_each_entry(link, &dev->links.suppliers, c_node)
 343		if (link->status == DL_STATE_CONSUMER_PROBE)
 344			WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
 345}
 346
 347/**
 348 * device_links_check_suppliers - Check presence of supplier drivers.
 349 * @dev: Consumer device.
 350 *
 351 * Check links from this device to any suppliers.  Walk the list of the device's
 352 * links to suppliers and see if all of them are available.  If not, simply
 353 * return -EPROBE_DEFER.
 354 *
 355 * We need to guarantee that the supplier will not go away after the check has
 356 * been positive here.  It only can go away in __device_release_driver() and
 357 * that function  checks the device's links to consumers.  This means we need to
 358 * mark the link as "consumer probe in progress" to make the supplier removal
 359 * wait for us to complete (or bad things may happen).
 360 *
 361 * Links with the DL_FLAG_STATELESS flag set are ignored.
 362 */
 363int device_links_check_suppliers(struct device *dev)
 364{
 365	struct device_link *link;
 366	int ret = 0;
 367
 368	device_links_write_lock();
 369
 370	list_for_each_entry(link, &dev->links.suppliers, c_node) {
 371		if (link->flags & DL_FLAG_STATELESS)
 372			continue;
 373
 374		if (link->status != DL_STATE_AVAILABLE) {
 375			device_links_missing_supplier(dev);
 376			ret = -EPROBE_DEFER;
 377			break;
 378		}
 379		WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
 380	}
 381	dev->links.status = DL_DEV_PROBING;
 382
 383	device_links_write_unlock();
 384	return ret;
 385}
 386
 387/**
 388 * device_links_driver_bound - Update device links after probing its driver.
 389 * @dev: Device to update the links for.
 390 *
 391 * The probe has been successful, so update links from this device to any
 392 * consumers by changing their status to "available".
 393 *
 394 * Also change the status of @dev's links to suppliers to "active".
 395 *
 396 * Links with the DL_FLAG_STATELESS flag set are ignored.
 397 */
 398void device_links_driver_bound(struct device *dev)
 399{
 400	struct device_link *link;
 401
 402	device_links_write_lock();
 403
 404	list_for_each_entry(link, &dev->links.consumers, s_node) {
 405		if (link->flags & DL_FLAG_STATELESS)
 406			continue;
 407
 408		WARN_ON(link->status != DL_STATE_DORMANT);
 409		WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
 410	}
 411
 412	list_for_each_entry(link, &dev->links.suppliers, c_node) {
 413		if (link->flags & DL_FLAG_STATELESS)
 414			continue;
 415
 416		WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
 417		WRITE_ONCE(link->status, DL_STATE_ACTIVE);
 418	}
 419
 420	dev->links.status = DL_DEV_DRIVER_BOUND;
 421
 422	device_links_write_unlock();
 423}
 424
 425/**
 426 * __device_links_no_driver - Update links of a device without a driver.
 427 * @dev: Device without a drvier.
 428 *
 429 * Delete all non-persistent links from this device to any suppliers.
 430 *
 431 * Persistent links stay around, but their status is changed to "available",
 432 * unless they already are in the "supplier unbind in progress" state in which
 433 * case they need not be updated.
 434 *
 435 * Links with the DL_FLAG_STATELESS flag set are ignored.
 436 */
 437static void __device_links_no_driver(struct device *dev)
 438{
 439	struct device_link *link, *ln;
 440
 441	list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
 442		if (link->flags & DL_FLAG_STATELESS)
 443			continue;
 444
 445		if (link->flags & DL_FLAG_AUTOREMOVE)
 446			__device_link_del(link);
 447		else if (link->status != DL_STATE_SUPPLIER_UNBIND)
 448			WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
 449	}
 450
 451	dev->links.status = DL_DEV_NO_DRIVER;
 452}
 453
 454void device_links_no_driver(struct device *dev)
 455{
 456	device_links_write_lock();
 457	__device_links_no_driver(dev);
 458	device_links_write_unlock();
 459}
 460
 461/**
 462 * device_links_driver_cleanup - Update links after driver removal.
 463 * @dev: Device whose driver has just gone away.
 464 *
 465 * Update links to consumers for @dev by changing their status to "dormant" and
 466 * invoke %__device_links_no_driver() to update links to suppliers for it as
 467 * appropriate.
 468 *
 469 * Links with the DL_FLAG_STATELESS flag set are ignored.
 470 */
 471void device_links_driver_cleanup(struct device *dev)
 472{
 473	struct device_link *link;
 474
 475	device_links_write_lock();
 476
 477	list_for_each_entry(link, &dev->links.consumers, s_node) {
 478		if (link->flags & DL_FLAG_STATELESS)
 479			continue;
 480
 481		WARN_ON(link->flags & DL_FLAG_AUTOREMOVE);
 482		WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
 483		WRITE_ONCE(link->status, DL_STATE_DORMANT);
 484	}
 485
 486	__device_links_no_driver(dev);
 487
 488	device_links_write_unlock();
 489}
 490
 491/**
 492 * device_links_busy - Check if there are any busy links to consumers.
 493 * @dev: Device to check.
 494 *
 495 * Check each consumer of the device and return 'true' if its link's status
 496 * is one of "consumer probe" or "active" (meaning that the given consumer is
 497 * probing right now or its driver is present).  Otherwise, change the link
 498 * state to "supplier unbind" to prevent the consumer from being probed
 499 * successfully going forward.
 500 *
 501 * Return 'false' if there are no probing or active consumers.
 502 *
 503 * Links with the DL_FLAG_STATELESS flag set are ignored.
 504 */
 505bool device_links_busy(struct device *dev)
 506{
 507	struct device_link *link;
 508	bool ret = false;
 509
 510	device_links_write_lock();
 511
 512	list_for_each_entry(link, &dev->links.consumers, s_node) {
 513		if (link->flags & DL_FLAG_STATELESS)
 514			continue;
 515
 516		if (link->status == DL_STATE_CONSUMER_PROBE
 517		    || link->status == DL_STATE_ACTIVE) {
 518			ret = true;
 519			break;
 520		}
 521		WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
 522	}
 523
 524	dev->links.status = DL_DEV_UNBINDING;
 525
 526	device_links_write_unlock();
 527	return ret;
 528}
 529
 530/**
 531 * device_links_unbind_consumers - Force unbind consumers of the given device.
 532 * @dev: Device to unbind the consumers of.
 533 *
 534 * Walk the list of links to consumers for @dev and if any of them is in the
 535 * "consumer probe" state, wait for all device probes in progress to complete
 536 * and start over.
 537 *
 538 * If that's not the case, change the status of the link to "supplier unbind"
 539 * and check if the link was in the "active" state.  If so, force the consumer
 540 * driver to unbind and start over (the consumer will not re-probe as we have
 541 * changed the state of the link already).
 542 *
 543 * Links with the DL_FLAG_STATELESS flag set are ignored.
 544 */
 545void device_links_unbind_consumers(struct device *dev)
 546{
 547	struct device_link *link;
 548
 549 start:
 550	device_links_write_lock();
 551
 552	list_for_each_entry(link, &dev->links.consumers, s_node) {
 553		enum device_link_state status;
 554
 555		if (link->flags & DL_FLAG_STATELESS)
 556			continue;
 557
 558		status = link->status;
 559		if (status == DL_STATE_CONSUMER_PROBE) {
 560			device_links_write_unlock();
 561
 562			wait_for_device_probe();
 563			goto start;
 564		}
 565		WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
 566		if (status == DL_STATE_ACTIVE) {
 567			struct device *consumer = link->consumer;
 568
 569			get_device(consumer);
 570
 571			device_links_write_unlock();
 572
 573			device_release_driver_internal(consumer, NULL,
 574						       consumer->parent);
 575			put_device(consumer);
 576			goto start;
 577		}
 578	}
 579
 580	device_links_write_unlock();
 581}
 582
 583/**
 584 * device_links_purge - Delete existing links to other devices.
 585 * @dev: Target device.
 586 */
 587static void device_links_purge(struct device *dev)
 588{
 589	struct device_link *link, *ln;
 590
 591	/*
 592	 * Delete all of the remaining links from this device to any other
 593	 * devices (either consumers or suppliers).
 594	 */
 595	device_links_write_lock();
 596
 597	list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
 598		WARN_ON(link->status == DL_STATE_ACTIVE);
 599		__device_link_del(link);
 600	}
 601
 602	list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
 603		WARN_ON(link->status != DL_STATE_DORMANT &&
 604			link->status != DL_STATE_NONE);
 605		__device_link_del(link);
 606	}
 607
 608	device_links_write_unlock();
 609}
 610
 611/* Device links support end. */
 612
 613int (*platform_notify)(struct device *dev) = NULL;
 614int (*platform_notify_remove)(struct device *dev) = NULL;
 615static struct kobject *dev_kobj;
 616struct kobject *sysfs_dev_char_kobj;
 617struct kobject *sysfs_dev_block_kobj;
 618
 619static DEFINE_MUTEX(device_hotplug_lock);
 620
 621void lock_device_hotplug(void)
 622{
 623	mutex_lock(&device_hotplug_lock);
 624}
 625
 626void unlock_device_hotplug(void)
 627{
 628	mutex_unlock(&device_hotplug_lock);
 629}
 630
 631int lock_device_hotplug_sysfs(void)
 632{
 633	if (mutex_trylock(&device_hotplug_lock))
 634		return 0;
 635
 636	/* Avoid busy looping (5 ms of sleep should do). */
 637	msleep(5);
 638	return restart_syscall();
 639}
 640
 641#ifdef CONFIG_BLOCK
 642static inline int device_is_not_partition(struct device *dev)
 643{
 644	return !(dev->type == &part_type);
 645}
 646#else
 647static inline int device_is_not_partition(struct device *dev)
 648{
 649	return 1;
 650}
 651#endif
 652
 653/**
 654 * dev_driver_string - Return a device's driver name, if at all possible
 655 * @dev: struct device to get the name of
 656 *
 657 * Will return the device's driver's name if it is bound to a device.  If
 658 * the device is not bound to a driver, it will return the name of the bus
 659 * it is attached to.  If it is not attached to a bus either, an empty
 660 * string will be returned.
 661 */
 662const char *dev_driver_string(const struct device *dev)
 663{
 664	struct device_driver *drv;
 665
 666	/* dev->driver can change to NULL underneath us because of unbinding,
 667	 * so be careful about accessing it.  dev->bus and dev->class should
 668	 * never change once they are set, so they don't need special care.
 669	 */
 670	drv = ACCESS_ONCE(dev->driver);
 671	return drv ? drv->name :
 672			(dev->bus ? dev->bus->name :
 673			(dev->class ? dev->class->name : ""));
 674}
 675EXPORT_SYMBOL(dev_driver_string);
 676
 677#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
 678
 679static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
 680			     char *buf)
 681{
 682	struct device_attribute *dev_attr = to_dev_attr(attr);
 683	struct device *dev = kobj_to_dev(kobj);
 684	ssize_t ret = -EIO;
 685
 686	if (dev_attr->show)
 687		ret = dev_attr->show(dev, dev_attr, buf);
 688	if (ret >= (ssize_t)PAGE_SIZE) {
 689		print_symbol("dev_attr_show: %s returned bad count\n",
 690				(unsigned long)dev_attr->show);
 691	}
 692	return ret;
 693}
 694
 695static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
 696			      const char *buf, size_t count)
 697{
 698	struct device_attribute *dev_attr = to_dev_attr(attr);
 699	struct device *dev = kobj_to_dev(kobj);
 700	ssize_t ret = -EIO;
 701
 702	if (dev_attr->store)
 703		ret = dev_attr->store(dev, dev_attr, buf, count);
 704	return ret;
 705}
 706
 707static const struct sysfs_ops dev_sysfs_ops = {
 708	.show	= dev_attr_show,
 709	.store	= dev_attr_store,
 710};
 711
 712#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
 713
 714ssize_t device_store_ulong(struct device *dev,
 715			   struct device_attribute *attr,
 716			   const char *buf, size_t size)
 717{
 718	struct dev_ext_attribute *ea = to_ext_attr(attr);
 719	char *end;
 720	unsigned long new = simple_strtoul(buf, &end, 0);
 721	if (end == buf)
 722		return -EINVAL;
 723	*(unsigned long *)(ea->var) = new;
 724	/* Always return full write size even if we didn't consume all */
 725	return size;
 726}
 727EXPORT_SYMBOL_GPL(device_store_ulong);
 728
 729ssize_t device_show_ulong(struct device *dev,
 730			  struct device_attribute *attr,
 731			  char *buf)
 732{
 733	struct dev_ext_attribute *ea = to_ext_attr(attr);
 734	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
 735}
 736EXPORT_SYMBOL_GPL(device_show_ulong);
 737
 738ssize_t device_store_int(struct device *dev,
 739			 struct device_attribute *attr,
 740			 const char *buf, size_t size)
 741{
 742	struct dev_ext_attribute *ea = to_ext_attr(attr);
 743	char *end;
 744	long new = simple_strtol(buf, &end, 0);
 745	if (end == buf || new > INT_MAX || new < INT_MIN)
 746		return -EINVAL;
 747	*(int *)(ea->var) = new;
 748	/* Always return full write size even if we didn't consume all */
 749	return size;
 750}
 751EXPORT_SYMBOL_GPL(device_store_int);
 752
 753ssize_t device_show_int(struct device *dev,
 754			struct device_attribute *attr,
 755			char *buf)
 756{
 757	struct dev_ext_attribute *ea = to_ext_attr(attr);
 758
 759	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
 760}
 761EXPORT_SYMBOL_GPL(device_show_int);
 762
 763ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 764			  const char *buf, size_t size)
 765{
 766	struct dev_ext_attribute *ea = to_ext_attr(attr);
 767
 768	if (strtobool(buf, ea->var) < 0)
 769		return -EINVAL;
 770
 771	return size;
 772}
 773EXPORT_SYMBOL_GPL(device_store_bool);
 774
 775ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 776			 char *buf)
 777{
 778	struct dev_ext_attribute *ea = to_ext_attr(attr);
 779
 780	return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
 781}
 782EXPORT_SYMBOL_GPL(device_show_bool);
 783
 784/**
 785 * device_release - free device structure.
 786 * @kobj: device's kobject.
 787 *
 788 * This is called once the reference count for the object
 789 * reaches 0. We forward the call to the device's release
 790 * method, which should handle actually freeing the structure.
 791 */
 792static void device_release(struct kobject *kobj)
 793{
 794	struct device *dev = kobj_to_dev(kobj);
 795	struct device_private *p = dev->p;
 796
 797	/*
 798	 * Some platform devices are driven without driver attached
 799	 * and managed resources may have been acquired.  Make sure
 800	 * all resources are released.
 801	 *
 802	 * Drivers still can add resources into device after device
 803	 * is deleted but alive, so release devres here to avoid
 804	 * possible memory leak.
 805	 */
 806	devres_release_all(dev);
 807
 808	if (dev->release)
 809		dev->release(dev);
 810	else if (dev->type && dev->type->release)
 811		dev->type->release(dev);
 812	else if (dev->class && dev->class->dev_release)
 813		dev->class->dev_release(dev);
 814	else
 815		WARN(1, KERN_ERR "Device '%s' does not have a release() "
 816			"function, it is broken and must be fixed.\n",
 817			dev_name(dev));
 818	kfree(p);
 819}
 820
 821static const void *device_namespace(struct kobject *kobj)
 822{
 823	struct device *dev = kobj_to_dev(kobj);
 824	const void *ns = NULL;
 825
 826	if (dev->class && dev->class->ns_type)
 827		ns = dev->class->namespace(dev);
 828
 829	return ns;
 830}
 831
 832static struct kobj_type device_ktype = {
 833	.release	= device_release,
 834	.sysfs_ops	= &dev_sysfs_ops,
 835	.namespace	= device_namespace,
 836};
 837
 838
 839static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 840{
 841	struct kobj_type *ktype = get_ktype(kobj);
 842
 843	if (ktype == &device_ktype) {
 844		struct device *dev = kobj_to_dev(kobj);
 845		if (dev->bus)
 846			return 1;
 847		if (dev->class)
 848			return 1;
 849	}
 850	return 0;
 851}
 852
 853static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 854{
 855	struct device *dev = kobj_to_dev(kobj);
 856
 857	if (dev->bus)
 858		return dev->bus->name;
 859	if (dev->class)
 860		return dev->class->name;
 861	return NULL;
 862}
 863
 864static int dev_uevent(struct kset *kset, struct kobject *kobj,
 865		      struct kobj_uevent_env *env)
 866{
 867	struct device *dev = kobj_to_dev(kobj);
 868	int retval = 0;
 869
 870	/* add device node properties if present */
 871	if (MAJOR(dev->devt)) {
 872		const char *tmp;
 873		const char *name;
 874		umode_t mode = 0;
 875		kuid_t uid = GLOBAL_ROOT_UID;
 876		kgid_t gid = GLOBAL_ROOT_GID;
 877
 878		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
 879		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
 880		name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
 881		if (name) {
 882			add_uevent_var(env, "DEVNAME=%s", name);
 883			if (mode)
 884				add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
 885			if (!uid_eq(uid, GLOBAL_ROOT_UID))
 886				add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
 887			if (!gid_eq(gid, GLOBAL_ROOT_GID))
 888				add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
 889			kfree(tmp);
 890		}
 891	}
 892
 893	if (dev->type && dev->type->name)
 894		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
 895
 896	if (dev->driver)
 897		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
 898
 899	/* Add common DT information about the device */
 900	of_device_uevent(dev, env);
 901
 902	/* have the bus specific function add its stuff */
 903	if (dev->bus && dev->bus->uevent) {
 904		retval = dev->bus->uevent(dev, env);
 905		if (retval)
 906			pr_debug("device: '%s': %s: bus uevent() returned %d\n",
 907				 dev_name(dev), __func__, retval);
 908	}
 909
 910	/* have the class specific function add its stuff */
 911	if (dev->class && dev->class->dev_uevent) {
 912		retval = dev->class->dev_uevent(dev, env);
 913		if (retval)
 914			pr_debug("device: '%s': %s: class uevent() "
 915				 "returned %d\n", dev_name(dev),
 916				 __func__, retval);
 917	}
 918
 919	/* have the device type specific function add its stuff */
 920	if (dev->type && dev->type->uevent) {
 921		retval = dev->type->uevent(dev, env);
 922		if (retval)
 923			pr_debug("device: '%s': %s: dev_type uevent() "
 924				 "returned %d\n", dev_name(dev),
 925				 __func__, retval);
 926	}
 927
 928	return retval;
 929}
 930
 931static const struct kset_uevent_ops device_uevent_ops = {
 932	.filter =	dev_uevent_filter,
 933	.name =		dev_uevent_name,
 934	.uevent =	dev_uevent,
 935};
 936
 937static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
 938			   char *buf)
 939{
 940	struct kobject *top_kobj;
 941	struct kset *kset;
 942	struct kobj_uevent_env *env = NULL;
 943	int i;
 944	size_t count = 0;
 945	int retval;
 946
 947	/* search the kset, the device belongs to */
 948	top_kobj = &dev->kobj;
 949	while (!top_kobj->kset && top_kobj->parent)
 950		top_kobj = top_kobj->parent;
 951	if (!top_kobj->kset)
 952		goto out;
 953
 954	kset = top_kobj->kset;
 955	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
 956		goto out;
 957
 958	/* respect filter */
 959	if (kset->uevent_ops && kset->uevent_ops->filter)
 960		if (!kset->uevent_ops->filter(kset, &dev->kobj))
 961			goto out;
 962
 963	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 964	if (!env)
 965		return -ENOMEM;
 966
 967	/* let the kset specific function add its keys */
 968	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
 969	if (retval)
 970		goto out;
 971
 972	/* copy keys to file */
 973	for (i = 0; i < env->envp_idx; i++)
 974		count += sprintf(&buf[count], "%s\n", env->envp[i]);
 975out:
 976	kfree(env);
 977	return count;
 978}
 979
 980static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
 981			    const char *buf, size_t count)
 982{
 983	enum kobject_action action;
 984
 985	if (kobject_action_type(buf, count, &action) == 0)
 986		kobject_uevent(&dev->kobj, action);
 987	else
 988		dev_err(dev, "uevent: unknown action-string\n");
 989	return count;
 990}
 991static DEVICE_ATTR_RW(uevent);
 992
 993static ssize_t online_show(struct device *dev, struct device_attribute *attr,
 994			   char *buf)
 995{
 996	bool val;
 997
 998	device_lock(dev);
 999	val = !dev->offline;
1000	device_unlock(dev);
1001	return sprintf(buf, "%u\n", val);
1002}
1003
1004static ssize_t online_store(struct device *dev, struct device_attribute *attr,
1005			    const char *buf, size_t count)
1006{
1007	bool val;
1008	int ret;
1009
1010	ret = strtobool(buf, &val);
1011	if (ret < 0)
1012		return ret;
1013
1014	ret = lock_device_hotplug_sysfs();
1015	if (ret)
1016		return ret;
1017
1018	ret = val ? device_online(dev) : device_offline(dev);
1019	unlock_device_hotplug();
1020	return ret < 0 ? ret : count;
1021}
1022static DEVICE_ATTR_RW(online);
1023
1024int device_add_groups(struct device *dev, const struct attribute_group **groups)
1025{
1026	return sysfs_create_groups(&dev->kobj, groups);
1027}
1028
1029void device_remove_groups(struct device *dev,
1030			  const struct attribute_group **groups)
1031{
1032	sysfs_remove_groups(&dev->kobj, groups);
1033}
1034
1035static int device_add_attrs(struct device *dev)
1036{
1037	struct class *class = dev->class;
1038	const struct device_type *type = dev->type;
1039	int error;
1040
1041	if (class) {
1042		error = device_add_groups(dev, class->dev_groups);
1043		if (error)
1044			return error;
1045	}
1046
1047	if (type) {
1048		error = device_add_groups(dev, type->groups);
1049		if (error)
1050			goto err_remove_class_groups;
1051	}
1052
1053	error = device_add_groups(dev, dev->groups);
1054	if (error)
1055		goto err_remove_type_groups;
1056
1057	if (device_supports_offline(dev) && !dev->offline_disabled) {
1058		error = device_create_file(dev, &dev_attr_online);
1059		if (error)
1060			goto err_remove_dev_groups;
1061	}
1062
1063	return 0;
1064
1065 err_remove_dev_groups:
1066	device_remove_groups(dev, dev->groups);
1067 err_remove_type_groups:
1068	if (type)
1069		device_remove_groups(dev, type->groups);
1070 err_remove_class_groups:
1071	if (class)
1072		device_remove_groups(dev, class->dev_groups);
1073
1074	return error;
1075}
1076
1077static void device_remove_attrs(struct device *dev)
1078{
1079	struct class *class = dev->class;
1080	const struct device_type *type = dev->type;
1081
1082	device_remove_file(dev, &dev_attr_online);
1083	device_remove_groups(dev, dev->groups);
1084
1085	if (type)
1086		device_remove_groups(dev, type->groups);
1087
1088	if (class)
1089		device_remove_groups(dev, class->dev_groups);
1090}
1091
1092static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
1093			char *buf)
1094{
1095	return print_dev_t(buf, dev->devt);
1096}
1097static DEVICE_ATTR_RO(dev);
1098
1099/* /sys/devices/ */
1100struct kset *devices_kset;
1101
1102/**
1103 * devices_kset_move_before - Move device in the devices_kset's list.
1104 * @deva: Device to move.
1105 * @devb: Device @deva should come before.
1106 */
1107static void devices_kset_move_before(struct device *deva, struct device *devb)
1108{
1109	if (!devices_kset)
1110		return;
1111	pr_debug("devices_kset: Moving %s before %s\n",
1112		 dev_name(deva), dev_name(devb));
1113	spin_lock(&devices_kset->list_lock);
1114	list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
1115	spin_unlock(&devices_kset->list_lock);
1116}
1117
1118/**
1119 * devices_kset_move_after - Move device in the devices_kset's list.
1120 * @deva: Device to move
1121 * @devb: Device @deva should come after.
1122 */
1123static void devices_kset_move_after(struct device *deva, struct device *devb)
1124{
1125	if (!devices_kset)
1126		return;
1127	pr_debug("devices_kset: Moving %s after %s\n",
1128		 dev_name(deva), dev_name(devb));
1129	spin_lock(&devices_kset->list_lock);
1130	list_move(&deva->kobj.entry, &devb->kobj.entry);
1131	spin_unlock(&devices_kset->list_lock);
1132}
1133
1134/**
1135 * devices_kset_move_last - move the device to the end of devices_kset's list.
1136 * @dev: device to move
1137 */
1138void devices_kset_move_last(struct device *dev)
1139{
1140	if (!devices_kset)
1141		return;
1142	pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
1143	spin_lock(&devices_kset->list_lock);
1144	list_move_tail(&dev->kobj.entry, &devices_kset->list);
1145	spin_unlock(&devices_kset->list_lock);
1146}
1147
1148/**
1149 * device_create_file - create sysfs attribute file for device.
1150 * @dev: device.
1151 * @attr: device attribute descriptor.
1152 */
1153int device_create_file(struct device *dev,
1154		       const struct device_attribute *attr)
1155{
1156	int error = 0;
1157
1158	if (dev) {
1159		WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
1160			"Attribute %s: write permission without 'store'\n",
1161			attr->attr.name);
1162		WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
1163			"Attribute %s: read permission without 'show'\n",
1164			attr->attr.name);
1165		error = sysfs_create_file(&dev->kobj, &attr->attr);
1166	}
1167
1168	return error;
1169}
1170EXPORT_SYMBOL_GPL(device_create_file);
1171
1172/**
1173 * device_remove_file - remove sysfs attribute file.
1174 * @dev: device.
1175 * @attr: device attribute descriptor.
1176 */
1177void device_remove_file(struct device *dev,
1178			const struct device_attribute *attr)
1179{
1180	if (dev)
1181		sysfs_remove_file(&dev->kobj, &attr->attr);
1182}
1183EXPORT_SYMBOL_GPL(device_remove_file);
1184
1185/**
1186 * device_remove_file_self - remove sysfs attribute file from its own method.
1187 * @dev: device.
1188 * @attr: device attribute descriptor.
1189 *
1190 * See kernfs_remove_self() for details.
1191 */
1192bool device_remove_file_self(struct device *dev,
1193			     const struct device_attribute *attr)
1194{
1195	if (dev)
1196		return sysfs_remove_file_self(&dev->kobj, &attr->attr);
1197	else
1198		return false;
1199}
1200EXPORT_SYMBOL_GPL(device_remove_file_self);
1201
1202/**
1203 * device_create_bin_file - create sysfs binary attribute file for device.
1204 * @dev: device.
1205 * @attr: device binary attribute descriptor.
1206 */
1207int device_create_bin_file(struct device *dev,
1208			   const struct bin_attribute *attr)
1209{
1210	int error = -EINVAL;
1211	if (dev)
1212		error = sysfs_create_bin_file(&dev->kobj, attr);
1213	return error;
1214}
1215EXPORT_SYMBOL_GPL(device_create_bin_file);
1216
1217/**
1218 * device_remove_bin_file - remove sysfs binary attribute file
1219 * @dev: device.
1220 * @attr: device binary attribute descriptor.
1221 */
1222void device_remove_bin_file(struct device *dev,
1223			    const struct bin_attribute *attr)
1224{
1225	if (dev)
1226		sysfs_remove_bin_file(&dev->kobj, attr);
1227}
1228EXPORT_SYMBOL_GPL(device_remove_bin_file);
1229
1230static void klist_children_get(struct klist_node *n)
1231{
1232	struct device_private *p = to_device_private_parent(n);
1233	struct device *dev = p->device;
1234
1235	get_device(dev);
1236}
1237
1238static void klist_children_put(struct klist_node *n)
1239{
1240	struct device_private *p = to_device_private_parent(n);
1241	struct device *dev = p->device;
1242
1243	put_device(dev);
1244}
1245
1246/**
1247 * device_initialize - init device structure.
1248 * @dev: device.
1249 *
1250 * This prepares the device for use by other layers by initializing
1251 * its fields.
1252 * It is the first half of device_register(), if called by
1253 * that function, though it can also be called separately, so one
1254 * may use @dev's fields. In particular, get_device()/put_device()
1255 * may be used for reference counting of @dev after calling this
1256 * function.
1257 *
1258 * All fields in @dev must be initialized by the caller to 0, except
1259 * for those explicitly set to some other value.  The simplest
1260 * approach is to use kzalloc() to allocate the structure containing
1261 * @dev.
1262 *
1263 * NOTE: Use put_device() to give up your reference instead of freeing
1264 * @dev directly once you have called this function.
1265 */
1266void device_initialize(struct device *dev)
1267{
1268	dev->kobj.kset = devices_kset;
1269	kobject_init(&dev->kobj, &device_ktype);
1270	INIT_LIST_HEAD(&dev->dma_pools);
1271	mutex_init(&dev->mutex);
1272	lockdep_set_novalidate_class(&dev->mutex);
1273	spin_lock_init(&dev->devres_lock);
1274	INIT_LIST_HEAD(&dev->devres_head);
1275	device_pm_init(dev);
1276	set_dev_node(dev, -1);
1277#ifdef CONFIG_GENERIC_MSI_IRQ
1278	INIT_LIST_HEAD(&dev->msi_list);
1279#endif
1280	INIT_LIST_HEAD(&dev->links.consumers);
1281	INIT_LIST_HEAD(&dev->links.suppliers);
1282	dev->links.status = DL_DEV_NO_DRIVER;
1283}
1284EXPORT_SYMBOL_GPL(device_initialize);
1285
1286struct kobject *virtual_device_parent(struct device *dev)
1287{
1288	static struct kobject *virtual_dir = NULL;
1289
1290	if (!virtual_dir)
1291		virtual_dir = kobject_create_and_add("virtual",
1292						     &devices_kset->kobj);
1293
1294	return virtual_dir;
1295}
1296
1297struct class_dir {
1298	struct kobject kobj;
1299	struct class *class;
1300};
1301
1302#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1303
1304static void class_dir_release(struct kobject *kobj)
1305{
1306	struct class_dir *dir = to_class_dir(kobj);
1307	kfree(dir);
1308}
1309
1310static const
1311struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
1312{
1313	struct class_dir *dir = to_class_dir(kobj);
1314	return dir->class->ns_type;
1315}
1316
1317static struct kobj_type class_dir_ktype = {
1318	.release	= class_dir_release,
1319	.sysfs_ops	= &kobj_sysfs_ops,
1320	.child_ns_type	= class_dir_child_ns_type
1321};
1322
1323static struct kobject *
1324class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
1325{
1326	struct class_dir *dir;
1327	int retval;
1328
1329	dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1330	if (!dir)
1331		return NULL;
1332
1333	dir->class = class;
1334	kobject_init(&dir->kobj, &class_dir_ktype);
1335
1336	dir->kobj.kset = &class->p->glue_dirs;
1337
1338	retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
1339	if (retval < 0) {
1340		kobject_put(&dir->kobj);
1341		return NULL;
1342	}
1343	return &dir->kobj;
1344}
1345
1346static DEFINE_MUTEX(gdp_mutex);
1347
1348static struct kobject *get_device_parent(struct device *dev,
1349					 struct device *parent)
1350{
1351	if (dev->class) {
 
1352		struct kobject *kobj = NULL;
1353		struct kobject *parent_kobj;
1354		struct kobject *k;
1355
1356#ifdef CONFIG_BLOCK
1357		/* block disks show up in /sys/block */
1358		if (sysfs_deprecated && dev->class == &block_class) {
1359			if (parent && parent->class == &block_class)
1360				return &parent->kobj;
1361			return &block_class.p->subsys.kobj;
1362		}
1363#endif
1364
1365		/*
1366		 * If we have no parent, we live in "virtual".
1367		 * Class-devices with a non class-device as parent, live
1368		 * in a "glue" directory to prevent namespace collisions.
1369		 */
1370		if (parent == NULL)
1371			parent_kobj = virtual_device_parent(dev);
1372		else if (parent->class && !dev->class->ns_type)
1373			return &parent->kobj;
1374		else
1375			parent_kobj = &parent->kobj;
1376
1377		mutex_lock(&gdp_mutex);
1378
1379		/* find our class-directory at the parent and reference it */
1380		spin_lock(&dev->class->p->glue_dirs.list_lock);
1381		list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
1382			if (k->parent == parent_kobj) {
1383				kobj = kobject_get(k);
1384				break;
1385			}
1386		spin_unlock(&dev->class->p->glue_dirs.list_lock);
1387		if (kobj) {
1388			mutex_unlock(&gdp_mutex);
1389			return kobj;
1390		}
1391
1392		/* or create a new class-directory at the parent device */
1393		k = class_dir_create_and_add(dev->class, parent_kobj);
1394		/* do not emit an uevent for this simple "glue" directory */
1395		mutex_unlock(&gdp_mutex);
1396		return k;
1397	}
1398
1399	/* subsystems can specify a default root directory for their devices */
1400	if (!parent && dev->bus && dev->bus->dev_root)
1401		return &dev->bus->dev_root->kobj;
1402
1403	if (parent)
1404		return &parent->kobj;
1405	return NULL;
1406}
1407
1408static inline bool live_in_glue_dir(struct kobject *kobj,
1409				    struct device *dev)
1410{
1411	if (!kobj || !dev->class ||
1412	    kobj->kset != &dev->class->p->glue_dirs)
1413		return false;
1414	return true;
1415}
1416
1417static inline struct kobject *get_glue_dir(struct device *dev)
1418{
1419	return dev->kobj.parent;
1420}
1421
1422/*
1423 * make sure cleaning up dir as the last step, we need to make
1424 * sure .release handler of kobject is run with holding the
1425 * global lock
1426 */
1427static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
1428{
1429	/* see if we live in a "glue" directory */
1430	if (!live_in_glue_dir(glue_dir, dev))
 
1431		return;
1432
1433	mutex_lock(&gdp_mutex);
1434	kobject_put(glue_dir);
1435	mutex_unlock(&gdp_mutex);
 
 
 
 
1436}
1437
1438static int device_add_class_symlinks(struct device *dev)
1439{
1440	struct device_node *of_node = dev_of_node(dev);
1441	int error;
1442
1443	if (of_node) {
1444		error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
1445		if (error)
1446			dev_warn(dev, "Error %d creating of_node link\n",error);
1447		/* An error here doesn't warrant bringing down the device */
1448	}
1449
1450	if (!dev->class)
1451		return 0;
1452
1453	error = sysfs_create_link(&dev->kobj,
1454				  &dev->class->p->subsys.kobj,
1455				  "subsystem");
1456	if (error)
1457		goto out_devnode;
1458
1459	if (dev->parent && device_is_not_partition(dev)) {
1460		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
1461					  "device");
1462		if (error)
1463			goto out_subsys;
1464	}
1465
1466#ifdef CONFIG_BLOCK
1467	/* /sys/block has directories and does not need symlinks */
1468	if (sysfs_deprecated && dev->class == &block_class)
1469		return 0;
1470#endif
1471
1472	/* link in the class directory pointing to the device */
1473	error = sysfs_create_link(&dev->class->p->subsys.kobj,
1474				  &dev->kobj, dev_name(dev));
1475	if (error)
1476		goto out_device;
1477
1478	return 0;
1479
1480out_device:
1481	sysfs_remove_link(&dev->kobj, "device");
1482
1483out_subsys:
1484	sysfs_remove_link(&dev->kobj, "subsystem");
1485out_devnode:
1486	sysfs_remove_link(&dev->kobj, "of_node");
1487	return error;
1488}
1489
1490static void device_remove_class_symlinks(struct device *dev)
1491{
1492	if (dev_of_node(dev))
1493		sysfs_remove_link(&dev->kobj, "of_node");
1494
1495	if (!dev->class)
1496		return;
1497
1498	if (dev->parent && device_is_not_partition(dev))
1499		sysfs_remove_link(&dev->kobj, "device");
1500	sysfs_remove_link(&dev->kobj, "subsystem");
1501#ifdef CONFIG_BLOCK
1502	if (sysfs_deprecated && dev->class == &block_class)
1503		return;
1504#endif
1505	sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
1506}
1507
1508/**
1509 * dev_set_name - set a device name
1510 * @dev: device
1511 * @fmt: format string for the device's name
1512 */
1513int dev_set_name(struct device *dev, const char *fmt, ...)
1514{
1515	va_list vargs;
1516	int err;
1517
1518	va_start(vargs, fmt);
1519	err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
1520	va_end(vargs);
1521	return err;
1522}
1523EXPORT_SYMBOL_GPL(dev_set_name);
1524
1525/**
1526 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1527 * @dev: device
1528 *
1529 * By default we select char/ for new entries.  Setting class->dev_obj
1530 * to NULL prevents an entry from being created.  class->dev_kobj must
1531 * be set (or cleared) before any devices are registered to the class
1532 * otherwise device_create_sys_dev_entry() and
1533 * device_remove_sys_dev_entry() will disagree about the presence of
1534 * the link.
1535 */
1536static struct kobject *device_to_dev_kobj(struct device *dev)
1537{
1538	struct kobject *kobj;
1539
1540	if (dev->class)
1541		kobj = dev->class->dev_kobj;
1542	else
1543		kobj = sysfs_dev_char_kobj;
1544
1545	return kobj;
1546}
1547
1548static int device_create_sys_dev_entry(struct device *dev)
1549{
1550	struct kobject *kobj = device_to_dev_kobj(dev);
1551	int error = 0;
1552	char devt_str[15];
1553
1554	if (kobj) {
1555		format_dev_t(devt_str, dev->devt);
1556		error = sysfs_create_link(kobj, &dev->kobj, devt_str);
1557	}
1558
1559	return error;
1560}
1561
1562static void device_remove_sys_dev_entry(struct device *dev)
1563{
1564	struct kobject *kobj = device_to_dev_kobj(dev);
1565	char devt_str[15];
1566
1567	if (kobj) {
1568		format_dev_t(devt_str, dev->devt);
1569		sysfs_remove_link(kobj, devt_str);
1570	}
1571}
1572
1573int device_private_init(struct device *dev)
1574{
1575	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
1576	if (!dev->p)
1577		return -ENOMEM;
1578	dev->p->device = dev;
1579	klist_init(&dev->p->klist_children, klist_children_get,
1580		   klist_children_put);
1581	INIT_LIST_HEAD(&dev->p->deferred_probe);
1582	return 0;
1583}
1584
1585/**
1586 * device_add - add device to device hierarchy.
1587 * @dev: device.
1588 *
1589 * This is part 2 of device_register(), though may be called
1590 * separately _iff_ device_initialize() has been called separately.
1591 *
1592 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1593 * to the global and sibling lists for the device, then
1594 * adds it to the other relevant subsystems of the driver model.
1595 *
1596 * Do not call this routine or device_register() more than once for
1597 * any device structure.  The driver model core is not designed to work
1598 * with devices that get unregistered and then spring back to life.
1599 * (Among other things, it's very hard to guarantee that all references
1600 * to the previous incarnation of @dev have been dropped.)  Allocate
1601 * and register a fresh new struct device instead.
1602 *
1603 * NOTE: _Never_ directly free @dev after calling this function, even
1604 * if it returned an error! Always use put_device() to give up your
1605 * reference instead.
1606 */
1607int device_add(struct device *dev)
1608{
1609	struct device *parent = NULL;
1610	struct kobject *kobj;
1611	struct class_interface *class_intf;
1612	int error = -EINVAL;
1613	struct kobject *glue_dir = NULL;
1614
1615	dev = get_device(dev);
1616	if (!dev)
1617		goto done;
1618
1619	if (!dev->p) {
1620		error = device_private_init(dev);
1621		if (error)
1622			goto done;
1623	}
1624
1625	/*
1626	 * for statically allocated devices, which should all be converted
1627	 * some day, we need to initialize the name. We prevent reading back
1628	 * the name, and force the use of dev_name()
1629	 */
1630	if (dev->init_name) {
1631		dev_set_name(dev, "%s", dev->init_name);
1632		dev->init_name = NULL;
1633	}
1634
1635	/* subsystems can specify simple device enumeration */
1636	if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1637		dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1638
1639	if (!dev_name(dev)) {
1640		error = -EINVAL;
1641		goto name_error;
1642	}
1643
1644	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1645
1646	parent = get_device(dev->parent);
1647	kobj = get_device_parent(dev, parent);
1648	if (kobj)
1649		dev->kobj.parent = kobj;
1650
1651	/* use parent numa_node */
1652	if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1653		set_dev_node(dev, dev_to_node(parent));
1654
1655	/* first, register with generic layer. */
1656	/* we require the name to be set before, and pass NULL */
1657	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1658	if (error) {
1659		glue_dir = get_glue_dir(dev);
1660		goto Error;
1661	}
1662
1663	/* notify platform of device entry */
1664	if (platform_notify)
1665		platform_notify(dev);
1666
1667	error = device_create_file(dev, &dev_attr_uevent);
1668	if (error)
1669		goto attrError;
1670
 
 
 
 
 
 
 
 
 
 
 
 
1671	error = device_add_class_symlinks(dev);
1672	if (error)
1673		goto SymlinkError;
1674	error = device_add_attrs(dev);
1675	if (error)
1676		goto AttrsError;
1677	error = bus_add_device(dev);
1678	if (error)
1679		goto BusError;
1680	error = dpm_sysfs_add(dev);
1681	if (error)
1682		goto DPMError;
1683	device_pm_add(dev);
1684
1685	if (MAJOR(dev->devt)) {
1686		error = device_create_file(dev, &dev_attr_dev);
1687		if (error)
1688			goto DevAttrError;
1689
1690		error = device_create_sys_dev_entry(dev);
1691		if (error)
1692			goto SysEntryError;
1693
1694		devtmpfs_create_node(dev);
1695	}
1696
1697	/* Notify clients of device addition.  This call must come
1698	 * after dpm_sysfs_add() and before kobject_uevent().
1699	 */
1700	if (dev->bus)
1701		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1702					     BUS_NOTIFY_ADD_DEVICE, dev);
1703
1704	kobject_uevent(&dev->kobj, KOBJ_ADD);
1705	bus_probe_device(dev);
1706	if (parent)
1707		klist_add_tail(&dev->p->knode_parent,
1708			       &parent->p->klist_children);
1709
1710	if (dev->class) {
1711		mutex_lock(&dev->class->p->mutex);
1712		/* tie the class to the device */
1713		klist_add_tail(&dev->knode_class,
1714			       &dev->class->p->klist_devices);
1715
1716		/* notify any interfaces that the device is here */
1717		list_for_each_entry(class_intf,
1718				    &dev->class->p->interfaces, node)
1719			if (class_intf->add_dev)
1720				class_intf->add_dev(dev, class_intf);
1721		mutex_unlock(&dev->class->p->mutex);
1722	}
1723done:
1724	put_device(dev);
1725	return error;
1726 SysEntryError:
1727	if (MAJOR(dev->devt))
1728		device_remove_file(dev, &dev_attr_dev);
1729 DevAttrError:
1730	device_pm_remove(dev);
1731	dpm_sysfs_remove(dev);
1732 DPMError:
1733	bus_remove_device(dev);
1734 BusError:
1735	device_remove_attrs(dev);
1736 AttrsError:
1737	device_remove_class_symlinks(dev);
1738 SymlinkError:
 
 
 
 
 
 
 
 
1739	device_remove_file(dev, &dev_attr_uevent);
1740 attrError:
1741	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1742	glue_dir = get_glue_dir(dev);
1743	kobject_del(&dev->kobj);
1744 Error:
1745	cleanup_glue_dir(dev, glue_dir);
1746	put_device(parent);
 
1747name_error:
1748	kfree(dev->p);
1749	dev->p = NULL;
1750	goto done;
1751}
1752EXPORT_SYMBOL_GPL(device_add);
1753
1754/**
1755 * device_register - register a device with the system.
1756 * @dev: pointer to the device structure
1757 *
1758 * This happens in two clean steps - initialize the device
1759 * and add it to the system. The two steps can be called
1760 * separately, but this is the easiest and most common.
1761 * I.e. you should only call the two helpers separately if
1762 * have a clearly defined need to use and refcount the device
1763 * before it is added to the hierarchy.
1764 *
1765 * For more information, see the kerneldoc for device_initialize()
1766 * and device_add().
1767 *
1768 * NOTE: _Never_ directly free @dev after calling this function, even
1769 * if it returned an error! Always use put_device() to give up the
1770 * reference initialized in this function instead.
1771 */
1772int device_register(struct device *dev)
1773{
1774	device_initialize(dev);
1775	return device_add(dev);
1776}
1777EXPORT_SYMBOL_GPL(device_register);
1778
1779/**
1780 * get_device - increment reference count for device.
1781 * @dev: device.
1782 *
1783 * This simply forwards the call to kobject_get(), though
1784 * we do take care to provide for the case that we get a NULL
1785 * pointer passed in.
1786 */
1787struct device *get_device(struct device *dev)
1788{
1789	return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1790}
1791EXPORT_SYMBOL_GPL(get_device);
1792
1793/**
1794 * put_device - decrement reference count.
1795 * @dev: device in question.
1796 */
1797void put_device(struct device *dev)
1798{
1799	/* might_sleep(); */
1800	if (dev)
1801		kobject_put(&dev->kobj);
1802}
1803EXPORT_SYMBOL_GPL(put_device);
1804
1805/**
1806 * device_del - delete device from system.
1807 * @dev: device.
1808 *
1809 * This is the first part of the device unregistration
1810 * sequence. This removes the device from the lists we control
1811 * from here, has it removed from the other driver model
1812 * subsystems it was added to in device_add(), and removes it
1813 * from the kobject hierarchy.
1814 *
1815 * NOTE: this should be called manually _iff_ device_add() was
1816 * also called manually.
1817 */
1818void device_del(struct device *dev)
1819{
1820	struct device *parent = dev->parent;
1821	struct kobject *glue_dir = NULL;
1822	struct class_interface *class_intf;
1823
1824	/* Notify clients of device removal.  This call must come
1825	 * before dpm_sysfs_remove().
1826	 */
1827	if (dev->bus)
1828		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1829					     BUS_NOTIFY_DEL_DEVICE, dev);
1830
1831	device_links_purge(dev);
1832	dpm_sysfs_remove(dev);
1833	if (parent)
1834		klist_del(&dev->p->knode_parent);
1835	if (MAJOR(dev->devt)) {
1836		devtmpfs_delete_node(dev);
1837		device_remove_sys_dev_entry(dev);
1838		device_remove_file(dev, &dev_attr_dev);
1839	}
1840	if (dev->class) {
1841		device_remove_class_symlinks(dev);
1842
1843		mutex_lock(&dev->class->p->mutex);
1844		/* notify any interfaces that the device is now gone */
1845		list_for_each_entry(class_intf,
1846				    &dev->class->p->interfaces, node)
1847			if (class_intf->remove_dev)
1848				class_intf->remove_dev(dev, class_intf);
1849		/* remove the device from the class list */
1850		klist_del(&dev->knode_class);
1851		mutex_unlock(&dev->class->p->mutex);
1852	}
1853	device_remove_file(dev, &dev_attr_uevent);
1854	device_remove_attrs(dev);
1855	bus_remove_device(dev);
1856	device_pm_remove(dev);
1857	driver_deferred_probe_del(dev);
1858	device_remove_properties(dev);
1859
1860	/* Notify the platform of the removal, in case they
1861	 * need to do anything...
1862	 */
1863	if (platform_notify_remove)
1864		platform_notify_remove(dev);
1865	if (dev->bus)
1866		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1867					     BUS_NOTIFY_REMOVED_DEVICE, dev);
1868	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1869	glue_dir = get_glue_dir(dev);
1870	kobject_del(&dev->kobj);
1871	cleanup_glue_dir(dev, glue_dir);
1872	put_device(parent);
1873}
1874EXPORT_SYMBOL_GPL(device_del);
1875
1876/**
1877 * device_unregister - unregister device from system.
1878 * @dev: device going away.
1879 *
1880 * We do this in two parts, like we do device_register(). First,
1881 * we remove it from all the subsystems with device_del(), then
1882 * we decrement the reference count via put_device(). If that
1883 * is the final reference count, the device will be cleaned up
1884 * via device_release() above. Otherwise, the structure will
1885 * stick around until the final reference to the device is dropped.
1886 */
1887void device_unregister(struct device *dev)
1888{
1889	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1890	device_del(dev);
1891	put_device(dev);
1892}
1893EXPORT_SYMBOL_GPL(device_unregister);
1894
1895static struct device *prev_device(struct klist_iter *i)
1896{
1897	struct klist_node *n = klist_prev(i);
1898	struct device *dev = NULL;
1899	struct device_private *p;
1900
1901	if (n) {
1902		p = to_device_private_parent(n);
1903		dev = p->device;
1904	}
1905	return dev;
1906}
1907
1908static struct device *next_device(struct klist_iter *i)
1909{
1910	struct klist_node *n = klist_next(i);
1911	struct device *dev = NULL;
1912	struct device_private *p;
1913
1914	if (n) {
1915		p = to_device_private_parent(n);
1916		dev = p->device;
1917	}
1918	return dev;
1919}
1920
1921/**
1922 * device_get_devnode - path of device node file
1923 * @dev: device
1924 * @mode: returned file access mode
1925 * @uid: returned file owner
1926 * @gid: returned file group
1927 * @tmp: possibly allocated string
1928 *
1929 * Return the relative path of a possible device node.
1930 * Non-default names may need to allocate a memory to compose
1931 * a name. This memory is returned in tmp and needs to be
1932 * freed by the caller.
1933 */
1934const char *device_get_devnode(struct device *dev,
1935			       umode_t *mode, kuid_t *uid, kgid_t *gid,
1936			       const char **tmp)
1937{
1938	char *s;
1939
1940	*tmp = NULL;
1941
1942	/* the device type may provide a specific name */
1943	if (dev->type && dev->type->devnode)
1944		*tmp = dev->type->devnode(dev, mode, uid, gid);
1945	if (*tmp)
1946		return *tmp;
1947
1948	/* the class may provide a specific name */
1949	if (dev->class && dev->class->devnode)
1950		*tmp = dev->class->devnode(dev, mode);
1951	if (*tmp)
1952		return *tmp;
1953
1954	/* return name without allocation, tmp == NULL */
1955	if (strchr(dev_name(dev), '!') == NULL)
1956		return dev_name(dev);
1957
1958	/* replace '!' in the name with '/' */
1959	s = kstrdup(dev_name(dev), GFP_KERNEL);
1960	if (!s)
1961		return NULL;
1962	strreplace(s, '!', '/');
1963	return *tmp = s;
 
1964}
1965
1966/**
1967 * device_for_each_child - device child iterator.
1968 * @parent: parent struct device.
1969 * @fn: function to be called for each device.
1970 * @data: data for the callback.
1971 *
1972 * Iterate over @parent's child devices, and call @fn for each,
1973 * passing it @data.
1974 *
1975 * We check the return of @fn each time. If it returns anything
1976 * other than 0, we break out and return that value.
1977 */
1978int device_for_each_child(struct device *parent, void *data,
1979			  int (*fn)(struct device *dev, void *data))
1980{
1981	struct klist_iter i;
1982	struct device *child;
1983	int error = 0;
1984
1985	if (!parent->p)
1986		return 0;
1987
1988	klist_iter_init(&parent->p->klist_children, &i);
1989	while ((child = next_device(&i)) && !error)
1990		error = fn(child, data);
1991	klist_iter_exit(&i);
1992	return error;
1993}
1994EXPORT_SYMBOL_GPL(device_for_each_child);
1995
1996/**
1997 * device_for_each_child_reverse - device child iterator in reversed order.
1998 * @parent: parent struct device.
1999 * @fn: function to be called for each device.
2000 * @data: data for the callback.
2001 *
2002 * Iterate over @parent's child devices, and call @fn for each,
2003 * passing it @data.
2004 *
2005 * We check the return of @fn each time. If it returns anything
2006 * other than 0, we break out and return that value.
2007 */
2008int device_for_each_child_reverse(struct device *parent, void *data,
2009				  int (*fn)(struct device *dev, void *data))
2010{
2011	struct klist_iter i;
2012	struct device *child;
2013	int error = 0;
2014
2015	if (!parent->p)
2016		return 0;
2017
2018	klist_iter_init(&parent->p->klist_children, &i);
2019	while ((child = prev_device(&i)) && !error)
2020		error = fn(child, data);
2021	klist_iter_exit(&i);
2022	return error;
2023}
2024EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
2025
2026/**
2027 * device_find_child - device iterator for locating a particular device.
2028 * @parent: parent struct device
2029 * @match: Callback function to check device
2030 * @data: Data to pass to match function
2031 *
2032 * This is similar to the device_for_each_child() function above, but it
2033 * returns a reference to a device that is 'found' for later use, as
2034 * determined by the @match callback.
2035 *
2036 * The callback should return 0 if the device doesn't match and non-zero
2037 * if it does.  If the callback returns non-zero and a reference to the
2038 * current device can be obtained, this function will return to the caller
2039 * and not iterate over any more devices.
2040 *
2041 * NOTE: you will need to drop the reference with put_device() after use.
2042 */
2043struct device *device_find_child(struct device *parent, void *data,
2044				 int (*match)(struct device *dev, void *data))
2045{
2046	struct klist_iter i;
2047	struct device *child;
2048
2049	if (!parent)
2050		return NULL;
2051
2052	klist_iter_init(&parent->p->klist_children, &i);
2053	while ((child = next_device(&i)))
2054		if (match(child, data) && get_device(child))
2055			break;
2056	klist_iter_exit(&i);
2057	return child;
2058}
2059EXPORT_SYMBOL_GPL(device_find_child);
2060
2061int __init devices_init(void)
2062{
2063	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
2064	if (!devices_kset)
2065		return -ENOMEM;
2066	dev_kobj = kobject_create_and_add("dev", NULL);
2067	if (!dev_kobj)
2068		goto dev_kobj_err;
2069	sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
2070	if (!sysfs_dev_block_kobj)
2071		goto block_kobj_err;
2072	sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
2073	if (!sysfs_dev_char_kobj)
2074		goto char_kobj_err;
2075
2076	return 0;
2077
2078 char_kobj_err:
2079	kobject_put(sysfs_dev_block_kobj);
2080 block_kobj_err:
2081	kobject_put(dev_kobj);
2082 dev_kobj_err:
2083	kset_unregister(devices_kset);
2084	return -ENOMEM;
2085}
2086
2087static int device_check_offline(struct device *dev, void *not_used)
2088{
2089	int ret;
2090
2091	ret = device_for_each_child(dev, NULL, device_check_offline);
2092	if (ret)
2093		return ret;
2094
2095	return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
2096}
2097
2098/**
2099 * device_offline - Prepare the device for hot-removal.
2100 * @dev: Device to be put offline.
2101 *
2102 * Execute the device bus type's .offline() callback, if present, to prepare
2103 * the device for a subsequent hot-removal.  If that succeeds, the device must
2104 * not be used until either it is removed or its bus type's .online() callback
2105 * is executed.
2106 *
2107 * Call under device_hotplug_lock.
2108 */
2109int device_offline(struct device *dev)
2110{
2111	int ret;
2112
2113	if (dev->offline_disabled)
2114		return -EPERM;
2115
2116	ret = device_for_each_child(dev, NULL, device_check_offline);
2117	if (ret)
2118		return ret;
2119
2120	device_lock(dev);
2121	if (device_supports_offline(dev)) {
2122		if (dev->offline) {
2123			ret = 1;
2124		} else {
2125			ret = dev->bus->offline(dev);
2126			if (!ret) {
2127				kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2128				dev->offline = true;
2129			}
2130		}
2131	}
2132	device_unlock(dev);
2133
2134	return ret;
2135}
2136
2137/**
2138 * device_online - Put the device back online after successful device_offline().
2139 * @dev: Device to be put back online.
2140 *
2141 * If device_offline() has been successfully executed for @dev, but the device
2142 * has not been removed subsequently, execute its bus type's .online() callback
2143 * to indicate that the device can be used again.
2144 *
2145 * Call under device_hotplug_lock.
2146 */
2147int device_online(struct device *dev)
2148{
2149	int ret = 0;
2150
2151	device_lock(dev);
2152	if (device_supports_offline(dev)) {
2153		if (dev->offline) {
2154			ret = dev->bus->online(dev);
2155			if (!ret) {
2156				kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2157				dev->offline = false;
2158			}
2159		} else {
2160			ret = 1;
2161		}
2162	}
2163	device_unlock(dev);
2164
2165	return ret;
2166}
2167
2168struct root_device {
2169	struct device dev;
2170	struct module *owner;
2171};
2172
2173static inline struct root_device *to_root_device(struct device *d)
2174{
2175	return container_of(d, struct root_device, dev);
2176}
2177
2178static void root_device_release(struct device *dev)
2179{
2180	kfree(to_root_device(dev));
2181}
2182
2183/**
2184 * __root_device_register - allocate and register a root device
2185 * @name: root device name
2186 * @owner: owner module of the root device, usually THIS_MODULE
2187 *
2188 * This function allocates a root device and registers it
2189 * using device_register(). In order to free the returned
2190 * device, use root_device_unregister().
2191 *
2192 * Root devices are dummy devices which allow other devices
2193 * to be grouped under /sys/devices. Use this function to
2194 * allocate a root device and then use it as the parent of
2195 * any device which should appear under /sys/devices/{name}
2196 *
2197 * The /sys/devices/{name} directory will also contain a
2198 * 'module' symlink which points to the @owner directory
2199 * in sysfs.
2200 *
2201 * Returns &struct device pointer on success, or ERR_PTR() on error.
2202 *
2203 * Note: You probably want to use root_device_register().
2204 */
2205struct device *__root_device_register(const char *name, struct module *owner)
2206{
2207	struct root_device *root;
2208	int err = -ENOMEM;
2209
2210	root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
2211	if (!root)
2212		return ERR_PTR(err);
2213
2214	err = dev_set_name(&root->dev, "%s", name);
2215	if (err) {
2216		kfree(root);
2217		return ERR_PTR(err);
2218	}
2219
2220	root->dev.release = root_device_release;
2221
2222	err = device_register(&root->dev);
2223	if (err) {
2224		put_device(&root->dev);
2225		return ERR_PTR(err);
2226	}
2227
2228#ifdef CONFIG_MODULES	/* gotta find a "cleaner" way to do this */
2229	if (owner) {
2230		struct module_kobject *mk = &owner->mkobj;
2231
2232		err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
2233		if (err) {
2234			device_unregister(&root->dev);
2235			return ERR_PTR(err);
2236		}
2237		root->owner = owner;
2238	}
2239#endif
2240
2241	return &root->dev;
2242}
2243EXPORT_SYMBOL_GPL(__root_device_register);
2244
2245/**
2246 * root_device_unregister - unregister and free a root device
2247 * @dev: device going away
2248 *
2249 * This function unregisters and cleans up a device that was created by
2250 * root_device_register().
2251 */
2252void root_device_unregister(struct device *dev)
2253{
2254	struct root_device *root = to_root_device(dev);
2255
2256	if (root->owner)
2257		sysfs_remove_link(&root->dev.kobj, "module");
2258
2259	device_unregister(dev);
2260}
2261EXPORT_SYMBOL_GPL(root_device_unregister);
2262
2263
2264static void device_create_release(struct device *dev)
2265{
2266	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2267	kfree(dev);
2268}
2269
2270static struct device *
2271device_create_groups_vargs(struct class *class, struct device *parent,
2272			   dev_t devt, void *drvdata,
2273			   const struct attribute_group **groups,
2274			   const char *fmt, va_list args)
2275{
2276	struct device *dev = NULL;
2277	int retval = -ENODEV;
2278
2279	if (class == NULL || IS_ERR(class))
2280		goto error;
2281
2282	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2283	if (!dev) {
2284		retval = -ENOMEM;
2285		goto error;
2286	}
2287
2288	device_initialize(dev);
2289	dev->devt = devt;
2290	dev->class = class;
2291	dev->parent = parent;
2292	dev->groups = groups;
2293	dev->release = device_create_release;
2294	dev_set_drvdata(dev, drvdata);
2295
2296	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
2297	if (retval)
2298		goto error;
2299
2300	retval = device_add(dev);
2301	if (retval)
2302		goto error;
2303
2304	return dev;
2305
2306error:
2307	put_device(dev);
2308	return ERR_PTR(retval);
2309}
2310
2311/**
2312 * device_create_vargs - creates a device and registers it with sysfs
2313 * @class: pointer to the struct class that this device should be registered to
2314 * @parent: pointer to the parent struct device of this new device, if any
2315 * @devt: the dev_t for the char device to be added
2316 * @drvdata: the data to be added to the device for callbacks
2317 * @fmt: string for the device's name
2318 * @args: va_list for the device's name
2319 *
2320 * This function can be used by char device classes.  A struct device
2321 * will be created in sysfs, registered to the specified class.
2322 *
2323 * A "dev" file will be created, showing the dev_t for the device, if
2324 * the dev_t is not 0,0.
2325 * If a pointer to a parent struct device is passed in, the newly created
2326 * struct device will be a child of that device in sysfs.
2327 * The pointer to the struct device will be returned from the call.
2328 * Any further sysfs files that might be required can be created using this
2329 * pointer.
2330 *
2331 * Returns &struct device pointer on success, or ERR_PTR() on error.
2332 *
2333 * Note: the struct class passed to this function must have previously
2334 * been created with a call to class_create().
2335 */
2336struct device *device_create_vargs(struct class *class, struct device *parent,
2337				   dev_t devt, void *drvdata, const char *fmt,
2338				   va_list args)
2339{
2340	return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
2341					  fmt, args);
2342}
2343EXPORT_SYMBOL_GPL(device_create_vargs);
2344
2345/**
2346 * device_create - creates a device and registers it with sysfs
2347 * @class: pointer to the struct class that this device should be registered to
2348 * @parent: pointer to the parent struct device of this new device, if any
2349 * @devt: the dev_t for the char device to be added
2350 * @drvdata: the data to be added to the device for callbacks
2351 * @fmt: string for the device's name
2352 *
2353 * This function can be used by char device classes.  A struct device
2354 * will be created in sysfs, registered to the specified class.
2355 *
2356 * A "dev" file will be created, showing the dev_t for the device, if
2357 * the dev_t is not 0,0.
2358 * If a pointer to a parent struct device is passed in, the newly created
2359 * struct device will be a child of that device in sysfs.
2360 * The pointer to the struct device will be returned from the call.
2361 * Any further sysfs files that might be required can be created using this
2362 * pointer.
2363 *
2364 * Returns &struct device pointer on success, or ERR_PTR() on error.
2365 *
2366 * Note: the struct class passed to this function must have previously
2367 * been created with a call to class_create().
2368 */
2369struct device *device_create(struct class *class, struct device *parent,
2370			     dev_t devt, void *drvdata, const char *fmt, ...)
2371{
2372	va_list vargs;
2373	struct device *dev;
2374
2375	va_start(vargs, fmt);
2376	dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
2377	va_end(vargs);
2378	return dev;
2379}
2380EXPORT_SYMBOL_GPL(device_create);
2381
2382/**
2383 * device_create_with_groups - creates a device and registers it with sysfs
2384 * @class: pointer to the struct class that this device should be registered to
2385 * @parent: pointer to the parent struct device of this new device, if any
2386 * @devt: the dev_t for the char device to be added
2387 * @drvdata: the data to be added to the device for callbacks
2388 * @groups: NULL-terminated list of attribute groups to be created
2389 * @fmt: string for the device's name
2390 *
2391 * This function can be used by char device classes.  A struct device
2392 * will be created in sysfs, registered to the specified class.
2393 * Additional attributes specified in the groups parameter will also
2394 * be created automatically.
2395 *
2396 * A "dev" file will be created, showing the dev_t for the device, if
2397 * the dev_t is not 0,0.
2398 * If a pointer to a parent struct device is passed in, the newly created
2399 * struct device will be a child of that device in sysfs.
2400 * The pointer to the struct device will be returned from the call.
2401 * Any further sysfs files that might be required can be created using this
2402 * pointer.
2403 *
2404 * Returns &struct device pointer on success, or ERR_PTR() on error.
2405 *
2406 * Note: the struct class passed to this function must have previously
2407 * been created with a call to class_create().
2408 */
2409struct device *device_create_with_groups(struct class *class,
2410					 struct device *parent, dev_t devt,
2411					 void *drvdata,
2412					 const struct attribute_group **groups,
2413					 const char *fmt, ...)
2414{
2415	va_list vargs;
2416	struct device *dev;
2417
2418	va_start(vargs, fmt);
2419	dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
2420					 fmt, vargs);
2421	va_end(vargs);
2422	return dev;
2423}
2424EXPORT_SYMBOL_GPL(device_create_with_groups);
2425
2426static int __match_devt(struct device *dev, const void *data)
2427{
2428	const dev_t *devt = data;
2429
2430	return dev->devt == *devt;
2431}
2432
2433/**
2434 * device_destroy - removes a device that was created with device_create()
2435 * @class: pointer to the struct class that this device was registered with
2436 * @devt: the dev_t of the device that was previously registered
2437 *
2438 * This call unregisters and cleans up a device that was created with a
2439 * call to device_create().
2440 */
2441void device_destroy(struct class *class, dev_t devt)
2442{
2443	struct device *dev;
2444
2445	dev = class_find_device(class, NULL, &devt, __match_devt);
2446	if (dev) {
2447		put_device(dev);
2448		device_unregister(dev);
2449	}
2450}
2451EXPORT_SYMBOL_GPL(device_destroy);
2452
2453/**
2454 * device_rename - renames a device
2455 * @dev: the pointer to the struct device to be renamed
2456 * @new_name: the new name of the device
2457 *
2458 * It is the responsibility of the caller to provide mutual
2459 * exclusion between two different calls of device_rename
2460 * on the same device to ensure that new_name is valid and
2461 * won't conflict with other devices.
2462 *
2463 * Note: Don't call this function.  Currently, the networking layer calls this
2464 * function, but that will change.  The following text from Kay Sievers offers
2465 * some insight:
2466 *
2467 * Renaming devices is racy at many levels, symlinks and other stuff are not
2468 * replaced atomically, and you get a "move" uevent, but it's not easy to
2469 * connect the event to the old and new device. Device nodes are not renamed at
2470 * all, there isn't even support for that in the kernel now.
2471 *
2472 * In the meantime, during renaming, your target name might be taken by another
2473 * driver, creating conflicts. Or the old name is taken directly after you
2474 * renamed it -- then you get events for the same DEVPATH, before you even see
2475 * the "move" event. It's just a mess, and nothing new should ever rely on
2476 * kernel device renaming. Besides that, it's not even implemented now for
2477 * other things than (driver-core wise very simple) network devices.
2478 *
2479 * We are currently about to change network renaming in udev to completely
2480 * disallow renaming of devices in the same namespace as the kernel uses,
2481 * because we can't solve the problems properly, that arise with swapping names
2482 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2483 * be allowed to some other name than eth[0-9]*, for the aforementioned
2484 * reasons.
2485 *
2486 * Make up a "real" name in the driver before you register anything, or add
2487 * some other attributes for userspace to find the device, or use udev to add
2488 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2489 * don't even want to get into that and try to implement the missing pieces in
2490 * the core. We really have other pieces to fix in the driver core mess. :)
2491 */
2492int device_rename(struct device *dev, const char *new_name)
2493{
2494	struct kobject *kobj = &dev->kobj;
2495	char *old_device_name = NULL;
2496	int error;
2497
2498	dev = get_device(dev);
2499	if (!dev)
2500		return -EINVAL;
2501
2502	dev_dbg(dev, "renaming to %s\n", new_name);
2503
2504	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
2505	if (!old_device_name) {
2506		error = -ENOMEM;
2507		goto out;
2508	}
2509
2510	if (dev->class) {
2511		error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
2512					     kobj, old_device_name,
2513					     new_name, kobject_namespace(kobj));
2514		if (error)
2515			goto out;
2516	}
2517
2518	error = kobject_rename(kobj, new_name);
2519	if (error)
2520		goto out;
2521
2522out:
2523	put_device(dev);
2524
2525	kfree(old_device_name);
2526
2527	return error;
2528}
2529EXPORT_SYMBOL_GPL(device_rename);
2530
2531static int device_move_class_links(struct device *dev,
2532				   struct device *old_parent,
2533				   struct device *new_parent)
2534{
2535	int error = 0;
2536
2537	if (old_parent)
2538		sysfs_remove_link(&dev->kobj, "device");
2539	if (new_parent)
2540		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
2541					  "device");
2542	return error;
2543}
2544
2545/**
2546 * device_move - moves a device to a new parent
2547 * @dev: the pointer to the struct device to be moved
2548 * @new_parent: the new parent of the device (can by NULL)
2549 * @dpm_order: how to reorder the dpm_list
2550 */
2551int device_move(struct device *dev, struct device *new_parent,
2552		enum dpm_order dpm_order)
2553{
2554	int error;
2555	struct device *old_parent;
2556	struct kobject *new_parent_kobj;
2557
2558	dev = get_device(dev);
2559	if (!dev)
2560		return -EINVAL;
2561
2562	device_pm_lock();
2563	new_parent = get_device(new_parent);
2564	new_parent_kobj = get_device_parent(dev, new_parent);
2565
2566	pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
2567		 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
2568	error = kobject_move(&dev->kobj, new_parent_kobj);
2569	if (error) {
2570		cleanup_glue_dir(dev, new_parent_kobj);
2571		put_device(new_parent);
2572		goto out;
2573	}
2574	old_parent = dev->parent;
2575	dev->parent = new_parent;
2576	if (old_parent)
2577		klist_remove(&dev->p->knode_parent);
2578	if (new_parent) {
2579		klist_add_tail(&dev->p->knode_parent,
2580			       &new_parent->p->klist_children);
2581		set_dev_node(dev, dev_to_node(new_parent));
2582	}
2583
2584	if (dev->class) {
2585		error = device_move_class_links(dev, old_parent, new_parent);
2586		if (error) {
2587			/* We ignore errors on cleanup since we're hosed anyway... */
2588			device_move_class_links(dev, new_parent, old_parent);
2589			if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
2590				if (new_parent)
2591					klist_remove(&dev->p->knode_parent);
2592				dev->parent = old_parent;
2593				if (old_parent) {
2594					klist_add_tail(&dev->p->knode_parent,
2595						       &old_parent->p->klist_children);
2596					set_dev_node(dev, dev_to_node(old_parent));
2597				}
2598			}
2599			cleanup_glue_dir(dev, new_parent_kobj);
2600			put_device(new_parent);
2601			goto out;
2602		}
2603	}
2604	switch (dpm_order) {
2605	case DPM_ORDER_NONE:
2606		break;
2607	case DPM_ORDER_DEV_AFTER_PARENT:
2608		device_pm_move_after(dev, new_parent);
2609		devices_kset_move_after(dev, new_parent);
2610		break;
2611	case DPM_ORDER_PARENT_BEFORE_DEV:
2612		device_pm_move_before(new_parent, dev);
2613		devices_kset_move_before(new_parent, dev);
2614		break;
2615	case DPM_ORDER_DEV_LAST:
2616		device_pm_move_last(dev);
2617		devices_kset_move_last(dev);
2618		break;
2619	}
2620
2621	put_device(old_parent);
2622out:
2623	device_pm_unlock();
2624	put_device(dev);
2625	return error;
2626}
2627EXPORT_SYMBOL_GPL(device_move);
2628
2629/**
2630 * device_shutdown - call ->shutdown() on each device to shutdown.
2631 */
2632void device_shutdown(void)
2633{
2634	struct device *dev, *parent;
2635
2636	spin_lock(&devices_kset->list_lock);
2637	/*
2638	 * Walk the devices list backward, shutting down each in turn.
2639	 * Beware that device unplug events may also start pulling
2640	 * devices offline, even as the system is shutting down.
2641	 */
2642	while (!list_empty(&devices_kset->list)) {
2643		dev = list_entry(devices_kset->list.prev, struct device,
2644				kobj.entry);
2645
2646		/*
2647		 * hold reference count of device's parent to
2648		 * prevent it from being freed because parent's
2649		 * lock is to be held
2650		 */
2651		parent = get_device(dev->parent);
2652		get_device(dev);
2653		/*
2654		 * Make sure the device is off the kset list, in the
2655		 * event that dev->*->shutdown() doesn't remove it.
2656		 */
2657		list_del_init(&dev->kobj.entry);
2658		spin_unlock(&devices_kset->list_lock);
2659
2660		/* hold lock to avoid race with probe/release */
2661		if (parent)
2662			device_lock(parent);
2663		device_lock(dev);
2664
2665		/* Don't allow any more runtime suspends */
2666		pm_runtime_get_noresume(dev);
2667		pm_runtime_barrier(dev);
2668
2669		if (dev->bus && dev->bus->shutdown) {
2670			if (initcall_debug)
2671				dev_info(dev, "shutdown\n");
2672			dev->bus->shutdown(dev);
2673		} else if (dev->driver && dev->driver->shutdown) {
2674			if (initcall_debug)
2675				dev_info(dev, "shutdown\n");
2676			dev->driver->shutdown(dev);
2677		}
2678
2679		device_unlock(dev);
2680		if (parent)
2681			device_unlock(parent);
2682
2683		put_device(dev);
2684		put_device(parent);
2685
2686		spin_lock(&devices_kset->list_lock);
2687	}
2688	spin_unlock(&devices_kset->list_lock);
2689}
2690
2691/*
2692 * Device logging functions
2693 */
2694
2695#ifdef CONFIG_PRINTK
2696static int
2697create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2698{
2699	const char *subsys;
2700	size_t pos = 0;
2701
2702	if (dev->class)
2703		subsys = dev->class->name;
2704	else if (dev->bus)
2705		subsys = dev->bus->name;
2706	else
2707		return 0;
2708
2709	pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2710	if (pos >= hdrlen)
2711		goto overflow;
2712
2713	/*
2714	 * Add device identifier DEVICE=:
2715	 *   b12:8         block dev_t
2716	 *   c127:3        char dev_t
2717	 *   n8            netdev ifindex
2718	 *   +sound:card0  subsystem:devname
2719	 */
2720	if (MAJOR(dev->devt)) {
2721		char c;
2722
2723		if (strcmp(subsys, "block") == 0)
2724			c = 'b';
2725		else
2726			c = 'c';
2727		pos++;
2728		pos += snprintf(hdr + pos, hdrlen - pos,
2729				"DEVICE=%c%u:%u",
2730				c, MAJOR(dev->devt), MINOR(dev->devt));
2731	} else if (strcmp(subsys, "net") == 0) {
2732		struct net_device *net = to_net_dev(dev);
2733
2734		pos++;
2735		pos += snprintf(hdr + pos, hdrlen - pos,
2736				"DEVICE=n%u", net->ifindex);
2737	} else {
2738		pos++;
2739		pos += snprintf(hdr + pos, hdrlen - pos,
2740				"DEVICE=+%s:%s", subsys, dev_name(dev));
2741	}
2742
2743	if (pos >= hdrlen)
2744		goto overflow;
2745
2746	return pos;
2747
2748overflow:
2749	dev_WARN(dev, "device/subsystem name too long");
2750	return 0;
2751}
2752
2753int dev_vprintk_emit(int level, const struct device *dev,
2754		     const char *fmt, va_list args)
2755{
2756	char hdr[128];
2757	size_t hdrlen;
2758
2759	hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2760
2761	return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2762}
2763EXPORT_SYMBOL(dev_vprintk_emit);
2764
2765int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2766{
2767	va_list args;
2768	int r;
2769
2770	va_start(args, fmt);
2771
2772	r = dev_vprintk_emit(level, dev, fmt, args);
2773
2774	va_end(args);
2775
2776	return r;
2777}
2778EXPORT_SYMBOL(dev_printk_emit);
2779
2780static void __dev_printk(const char *level, const struct device *dev,
2781			struct va_format *vaf)
2782{
2783	if (dev)
2784		dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2785				dev_driver_string(dev), dev_name(dev), vaf);
2786	else
2787		printk("%s(NULL device *): %pV", level, vaf);
 
2788}
2789
2790void dev_printk(const char *level, const struct device *dev,
2791		const char *fmt, ...)
2792{
2793	struct va_format vaf;
2794	va_list args;
 
2795
2796	va_start(args, fmt);
2797
2798	vaf.fmt = fmt;
2799	vaf.va = &args;
2800
2801	__dev_printk(level, dev, &vaf);
2802
2803	va_end(args);
 
 
2804}
2805EXPORT_SYMBOL(dev_printk);
2806
2807#define define_dev_printk_level(func, kern_level)		\
2808void func(const struct device *dev, const char *fmt, ...)	\
2809{								\
2810	struct va_format vaf;					\
2811	va_list args;						\
 
2812								\
2813	va_start(args, fmt);					\
2814								\
2815	vaf.fmt = fmt;						\
2816	vaf.va = &args;						\
2817								\
2818	__dev_printk(kern_level, dev, &vaf);			\
2819								\
2820	va_end(args);						\
 
 
2821}								\
2822EXPORT_SYMBOL(func);
2823
2824define_dev_printk_level(dev_emerg, KERN_EMERG);
2825define_dev_printk_level(dev_alert, KERN_ALERT);
2826define_dev_printk_level(dev_crit, KERN_CRIT);
2827define_dev_printk_level(dev_err, KERN_ERR);
2828define_dev_printk_level(dev_warn, KERN_WARNING);
2829define_dev_printk_level(dev_notice, KERN_NOTICE);
2830define_dev_printk_level(_dev_info, KERN_INFO);
2831
2832#endif
2833
2834static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2835{
2836	return fwnode && !IS_ERR(fwnode->secondary);
2837}
2838
2839/**
2840 * set_primary_fwnode - Change the primary firmware node of a given device.
2841 * @dev: Device to handle.
2842 * @fwnode: New primary firmware node of the device.
2843 *
2844 * Set the device's firmware node pointer to @fwnode, but if a secondary
2845 * firmware node of the device is present, preserve it.
2846 */
2847void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2848{
2849	if (fwnode) {
2850		struct fwnode_handle *fn = dev->fwnode;
2851
2852		if (fwnode_is_primary(fn))
2853			fn = fn->secondary;
2854
2855		if (fn) {
2856			WARN_ON(fwnode->secondary);
2857			fwnode->secondary = fn;
2858		}
2859		dev->fwnode = fwnode;
2860	} else {
2861		dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2862			dev->fwnode->secondary : NULL;
2863	}
2864}
2865EXPORT_SYMBOL_GPL(set_primary_fwnode);
2866
2867/**
2868 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2869 * @dev: Device to handle.
2870 * @fwnode: New secondary firmware node of the device.
2871 *
2872 * If a primary firmware node of the device is present, set its secondary
2873 * pointer to @fwnode.  Otherwise, set the device's firmware node pointer to
2874 * @fwnode.
2875 */
2876void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2877{
2878	if (fwnode)
2879		fwnode->secondary = ERR_PTR(-ENODEV);
2880
2881	if (fwnode_is_primary(dev->fwnode))
2882		dev->fwnode->secondary = fwnode;
2883	else
2884		dev->fwnode = fwnode;
2885}