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