core.c 32.4 KB
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/*
 * drivers/base/core.c - core driver model code (device registration, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
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 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2006 Novell, Inc.
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 *
 * This file is released under the GPLv2
 *
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
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#include <linux/kdev_t.h>
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#include <linux/notifier.h>
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#include <asm/semaphore.h>

#include "base.h"
#include "power/power.h"

int (*platform_notify)(struct device * dev) = NULL;
int (*platform_notify_remove)(struct device * dev) = NULL;

/*
 * sysfs bindings for devices.
 */

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/**
 * dev_driver_string - Return a device's driver name, if at all possible
 * @dev: struct device to get the name of
 *
 * Will return the device's driver's name if it is bound to a device.  If
 * the device is not bound to a device, it will return the name of the bus
 * it is attached to.  If it is not attached to a bus either, an empty
 * string will be returned.
 */
const char *dev_driver_string(struct device *dev)
{
	return dev->driver ? dev->driver->name :
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			(dev->bus ? dev->bus->name :
			(dev->class ? dev->class->name : ""));
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}
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EXPORT_SYMBOL(dev_driver_string);
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#define to_dev(obj) container_of(obj, struct device, kobj)
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)

static ssize_t
dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
	struct device_attribute * dev_attr = to_dev_attr(attr);
	struct device * dev = to_dev(kobj);
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	ssize_t ret = -EIO;
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	if (dev_attr->show)
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		ret = dev_attr->show(dev, dev_attr, buf);
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	return ret;
}

static ssize_t
dev_attr_store(struct kobject * kobj, struct attribute * attr,
	       const char * buf, size_t count)
{
	struct device_attribute * dev_attr = to_dev_attr(attr);
	struct device * dev = to_dev(kobj);
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	ssize_t ret = -EIO;
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	if (dev_attr->store)
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		ret = dev_attr->store(dev, dev_attr, buf, count);
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	return ret;
}

static struct sysfs_ops dev_sysfs_ops = {
	.show	= dev_attr_show,
	.store	= dev_attr_store,
};


/**
 *	device_release - free device structure.
 *	@kobj:	device's kobject.
 *
 *	This is called once the reference count for the object
 *	reaches 0. We forward the call to the device's release
 *	method, which should handle actually freeing the structure.
 */
static void device_release(struct kobject * kobj)
{
	struct device * dev = to_dev(kobj);

	if (dev->release)
		dev->release(dev);
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	else if (dev->type && dev->type->release)
		dev->type->release(dev);
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	else if (dev->class && dev->class->dev_release)
		dev->class->dev_release(dev);
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	else {
		printk(KERN_ERR "Device '%s' does not have a release() function, "
			"it is broken and must be fixed.\n",
			dev->bus_id);
		WARN_ON(1);
	}
}

static struct kobj_type ktype_device = {
	.release	= device_release,
	.sysfs_ops	= &dev_sysfs_ops,
};


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static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
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{
	struct kobj_type *ktype = get_ktype(kobj);

	if (ktype == &ktype_device) {
		struct device *dev = to_dev(kobj);
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		if (dev->uevent_suppress)
			return 0;
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		if (dev->bus)
			return 1;
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		if (dev->class)
			return 1;
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	}
	return 0;
}

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static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
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{
	struct device *dev = to_dev(kobj);

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	if (dev->bus)
		return dev->bus->name;
	if (dev->class)
		return dev->class->name;
	return NULL;
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}

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static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
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			int num_envp, char *buffer, int buffer_size)
{
	struct device *dev = to_dev(kobj);
	int i = 0;
	int length = 0;
	int retval = 0;

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	/* add the major/minor if present */
	if (MAJOR(dev->devt)) {
		add_uevent_var(envp, num_envp, &i,
			       buffer, buffer_size, &length,
			       "MAJOR=%u", MAJOR(dev->devt));
		add_uevent_var(envp, num_envp, &i,
			       buffer, buffer_size, &length,
			       "MINOR=%u", MINOR(dev->devt));
	}

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	if (dev->type && dev->type->name)
		add_uevent_var(envp, num_envp, &i,
			       buffer, buffer_size, &length,
			       "DEVTYPE=%s", dev->type->name);

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	if (dev->driver)
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		add_uevent_var(envp, num_envp, &i,
			       buffer, buffer_size, &length,
			       "DRIVER=%s", dev->driver->name);
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#ifdef CONFIG_SYSFS_DEPRECATED
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	if (dev->class) {
		struct device *parent = dev->parent;

		/* find first bus device in parent chain */
		while (parent && !parent->bus)
			parent = parent->parent;
		if (parent && parent->bus) {
			const char *path;

			path = kobject_get_path(&parent->kobj, GFP_KERNEL);
			add_uevent_var(envp, num_envp, &i,
				       buffer, buffer_size, &length,
				       "PHYSDEVPATH=%s", path);
			kfree(path);

			add_uevent_var(envp, num_envp, &i,
				       buffer, buffer_size, &length,
				       "PHYSDEVBUS=%s", parent->bus->name);

			if (parent->driver)
				add_uevent_var(envp, num_envp, &i,
					       buffer, buffer_size, &length,
					       "PHYSDEVDRIVER=%s", parent->driver->name);
		}
	} else if (dev->bus) {
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		add_uevent_var(envp, num_envp, &i,
			       buffer, buffer_size, &length,
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			       "PHYSDEVBUS=%s", dev->bus->name);

		if (dev->driver)
			add_uevent_var(envp, num_envp, &i,
				       buffer, buffer_size, &length,
				       "PHYSDEVDRIVER=%s", dev->driver->name);
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	}
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#endif
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	/* terminate, set to next free slot, shrink available space */
	envp[i] = NULL;
	envp = &envp[i];
	num_envp -= i;
	buffer = &buffer[length];
	buffer_size -= length;

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	if (dev->bus && dev->bus->uevent) {
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		/* have the bus specific function add its stuff */
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		retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size);
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		if (retval)
			pr_debug ("%s: bus uevent() returned %d\n",
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				  __FUNCTION__, retval);
	}

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	if (dev->class && dev->class->dev_uevent) {
		/* have the class specific function add its stuff */
		retval = dev->class->dev_uevent(dev, envp, num_envp, buffer, buffer_size);
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		if (retval)
			pr_debug("%s: class uevent() returned %d\n",
				 __FUNCTION__, retval);
	}

	if (dev->type && dev->type->uevent) {
		/* have the device type specific fuction add its stuff */
		retval = dev->type->uevent(dev, envp, num_envp, buffer, buffer_size);
		if (retval)
			pr_debug("%s: dev_type uevent() returned %d\n",
				 __FUNCTION__, retval);
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	}

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	return retval;
}

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static struct kset_uevent_ops device_uevent_ops = {
	.filter =	dev_uevent_filter,
	.name =		dev_uevent_name,
	.uevent =	dev_uevent,
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};

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static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct kobject *top_kobj;
	struct kset *kset;
	char *envp[32];
	char data[PAGE_SIZE];
	char *pos;
	int i;
	size_t count = 0;
	int retval;

	/* search the kset, the device belongs to */
	top_kobj = &dev->kobj;
	if (!top_kobj->kset && top_kobj->parent) {
		do {
			top_kobj = top_kobj->parent;
		} while (!top_kobj->kset && top_kobj->parent);
	}
	if (!top_kobj->kset)
		goto out;
	kset = top_kobj->kset;
	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
		goto out;

	/* respect filter */
	if (kset->uevent_ops && kset->uevent_ops->filter)
		if (!kset->uevent_ops->filter(kset, &dev->kobj))
			goto out;

	/* let the kset specific function add its keys */
	pos = data;
	retval = kset->uevent_ops->uevent(kset, &dev->kobj,
					  envp, ARRAY_SIZE(envp),
					  pos, PAGE_SIZE);
	if (retval)
		goto out;

	/* copy keys to file */
	for (i = 0; envp[i]; i++) {
		pos = &buf[count];
		count += sprintf(pos, "%s\n", envp[i]);
	}
out:
	return count;
}

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static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
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	if (memcmp(buf, "add", 3) != 0)
		dev_err(dev, "uevent: unsupported action-string; this will "
			"be ignored in a future kernel version");
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	kobject_uevent(&dev->kobj, KOBJ_ADD);
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	return count;
}

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static int device_add_attributes(struct device *dev,
				 struct device_attribute *attrs)
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{
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	int error = 0;
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	int i;
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	if (attrs) {
		for (i = 0; attr_name(attrs[i]); i++) {
			error = device_create_file(dev, &attrs[i]);
			if (error)
				break;
		}
		if (error)
			while (--i >= 0)
				device_remove_file(dev, &attrs[i]);
	}
	return error;
}

static void device_remove_attributes(struct device *dev,
				     struct device_attribute *attrs)
{
	int i;

	if (attrs)
		for (i = 0; attr_name(attrs[i]); i++)
			device_remove_file(dev, &attrs[i]);
}

static int device_add_groups(struct device *dev,
			     struct attribute_group **groups)
{
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	int error = 0;
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	int i;
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	if (groups) {
		for (i = 0; groups[i]; i++) {
			error = sysfs_create_group(&dev->kobj, groups[i]);
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			if (error) {
				while (--i >= 0)
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					sysfs_remove_group(&dev->kobj, groups[i]);
				break;
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			}
		}
	}
	return error;
}

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static void device_remove_groups(struct device *dev,
				 struct attribute_group **groups)
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{
	int i;
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	if (groups)
		for (i = 0; groups[i]; i++)
			sysfs_remove_group(&dev->kobj, groups[i]);
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}

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static int device_add_attrs(struct device *dev)
{
	struct class *class = dev->class;
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	struct device_type *type = dev->type;
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	int error;
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	if (class) {
		error = device_add_attributes(dev, class->dev_attrs);
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		if (error)
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			return error;
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	}
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	if (type) {
		error = device_add_groups(dev, type->groups);
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		if (error)
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			goto err_remove_class_attrs;
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	}

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	error = device_add_groups(dev, dev->groups);
	if (error)
		goto err_remove_type_groups;

	return 0;

 err_remove_type_groups:
	if (type)
		device_remove_groups(dev, type->groups);
 err_remove_class_attrs:
	if (class)
		device_remove_attributes(dev, class->dev_attrs);

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	return error;
}

static void device_remove_attrs(struct device *dev)
{
	struct class *class = dev->class;
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	struct device_type *type = dev->type;
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	device_remove_groups(dev, dev->groups);
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	if (type)
		device_remove_groups(dev, type->groups);

	if (class)
		device_remove_attributes(dev, class->dev_attrs);
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}


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static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	return print_dev_t(buf, dev->devt);
}

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/*
 *	devices_subsys - structure to be registered with kobject core.
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 */

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decl_subsys(devices, &ktype_device, &device_uevent_ops);
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/**
 *	device_create_file - create sysfs attribute file for device.
 *	@dev:	device.
 *	@attr:	device attribute descriptor.
 */

int device_create_file(struct device * dev, struct device_attribute * attr)
{
	int error = 0;
	if (get_device(dev)) {
		error = sysfs_create_file(&dev->kobj, &attr->attr);
		put_device(dev);
	}
	return error;
}

/**
 *	device_remove_file - remove sysfs attribute file.
 *	@dev:	device.
 *	@attr:	device attribute descriptor.
 */

void device_remove_file(struct device * dev, struct device_attribute * attr)
{
	if (get_device(dev)) {
		sysfs_remove_file(&dev->kobj, &attr->attr);
		put_device(dev);
	}
}

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/**
 * device_create_bin_file - create sysfs binary attribute file for device.
 * @dev: device.
 * @attr: device binary attribute descriptor.
 */
int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
{
	int error = -EINVAL;
	if (dev)
		error = sysfs_create_bin_file(&dev->kobj, attr);
	return error;
}
EXPORT_SYMBOL_GPL(device_create_bin_file);

/**
 * device_remove_bin_file - remove sysfs binary attribute file
 * @dev: device.
 * @attr: device binary attribute descriptor.
 */
void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
{
	if (dev)
		sysfs_remove_bin_file(&dev->kobj, attr);
}
EXPORT_SYMBOL_GPL(device_remove_bin_file);

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/**
 * device_schedule_callback - helper to schedule a callback for a device
 * @dev: device.
 * @func: callback function to invoke later.
 *
 * Attribute methods must not unregister themselves or their parent device
 * (which would amount to the same thing).  Attempts to do so will deadlock,
 * since unregistration is mutually exclusive with driver callbacks.
 *
 * Instead methods can call this routine, which will attempt to allocate
 * and schedule a workqueue request to call back @func with @dev as its
 * argument in the workqueue's process context.  @dev will be pinned until
 * @func returns.
 *
 * Returns 0 if the request was submitted, -ENOMEM if storage could not
 * be allocated.
 *
 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 * underlying sysfs routine (since it is intended for use by attribute
 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 */
int device_schedule_callback(struct device *dev,
		void (*func)(struct device *))
{
	return sysfs_schedule_callback(&dev->kobj,
			(void (*)(void *)) func, dev);
}
EXPORT_SYMBOL_GPL(device_schedule_callback);

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static void klist_children_get(struct klist_node *n)
{
	struct device *dev = container_of(n, struct device, knode_parent);

	get_device(dev);
}

static void klist_children_put(struct klist_node *n)
{
	struct device *dev = container_of(n, struct device, knode_parent);

	put_device(dev);
}

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/**
 *	device_initialize - init device structure.
 *	@dev:	device.
 *
 *	This prepares the device for use by other layers,
 *	including adding it to the device hierarchy.
 *	It is the first half of device_register(), if called by
 *	that, though it can also be called separately, so one
 *	may use @dev's fields (e.g. the refcount).
 */

void device_initialize(struct device *dev)
{
	kobj_set_kset_s(dev, devices_subsys);
	kobject_init(&dev->kobj);
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	klist_init(&dev->klist_children, klist_children_get,
		   klist_children_put);
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	INIT_LIST_HEAD(&dev->dma_pools);
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	INIT_LIST_HEAD(&dev->node);
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	init_MUTEX(&dev->sem);
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	spin_lock_init(&dev->devres_lock);
	INIT_LIST_HEAD(&dev->devres_head);
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	device_init_wakeup(dev, 0);
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	set_dev_node(dev, -1);
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}

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#ifdef CONFIG_SYSFS_DEPRECATED
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static struct kobject * get_device_parent(struct device *dev,
					  struct device *parent)
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{
	/* Set the parent to the class, not the parent device */
	/* this keeps sysfs from having a symlink to make old udevs happy */
	if (dev->class)
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		return &dev->class->subsys.kset.kobj;
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	else if (parent)
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		return &parent->kobj;
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	return NULL;
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}
#else
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static struct kobject *virtual_device_parent(struct device *dev)
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{
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	static struct kobject *virtual_dir = NULL;
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	if (!virtual_dir)
		virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
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	return virtual_dir;
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}

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static struct kobject * get_device_parent(struct device *dev,
					  struct device *parent)
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{
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	if (dev->class) {
		struct kobject *kobj = NULL;
		struct kobject *parent_kobj;
		struct kobject *k;

		/*
		 * If we have no parent, we live in "virtual".
		 * Class-devices with a bus-device as parent, live
		 * in a class-directory to prevent namespace collisions.
		 */
		if (parent == NULL)
			parent_kobj = virtual_device_parent(dev);
		else if (parent->class)
			return &parent->kobj;
		else
			parent_kobj = &parent->kobj;

		/* find our class-directory at the parent and reference it */
		spin_lock(&dev->class->class_dirs.list_lock);
		list_for_each_entry(k, &dev->class->class_dirs.list, entry)
			if (k->parent == parent_kobj) {
				kobj = kobject_get(k);
				break;
			}
		spin_unlock(&dev->class->class_dirs.list_lock);
		if (kobj)
			return kobj;

		/* or create a new class-directory at the parent device */
		return kobject_kset_add_dir(&dev->class->class_dirs,
					    parent_kobj, dev->class->name);
	}

	if (parent)
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		return &parent->kobj;
	return NULL;
}
#endif
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static int setup_parent(struct device *dev, struct device *parent)
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (IS_ERR(kobj))
		return PTR_ERR(kobj);
	if (kobj)
		dev->kobj.parent = kobj;
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	return 0;
}

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/**
 *	device_add - add device to device hierarchy.
 *	@dev:	device.
 *
 *	This is part 2 of device_register(), though may be called
 *	separately _iff_ device_initialize() has been called separately.
 *
 *	This adds it to the kobject hierarchy via kobject_add(), adds it
 *	to the global and sibling lists for the device, then
 *	adds it to the other relevant subsystems of the driver model.
 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
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	char *class_name = NULL;
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	struct class_interface *class_intf;
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	int error = -EINVAL;

	dev = get_device(dev);
	if (!dev || !strlen(dev->bus_id))
		goto Error;

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	pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
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	parent = get_device(dev->parent);
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	error = setup_parent(dev, parent);
	if (error)
		goto Error;
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	/* first, register with generic layer. */
	kobject_set_name(&dev->kobj, "%s", dev->bus_id);
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	error = kobject_add(&dev->kobj);
	if (error)
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		goto Error;
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	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

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	/* notify clients of device entry (new way) */
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_ADD_DEVICE, dev);

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	dev->uevent_attr.attr.name = "uevent";
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	dev->uevent_attr.attr.mode = S_IRUGO | S_IWUSR;
675 676 677
	if (dev->driver)
		dev->uevent_attr.attr.owner = dev->driver->owner;
	dev->uevent_attr.store = store_uevent;
678
	dev->uevent_attr.show = show_uevent;
679 680 681
	error = device_create_file(dev, &dev->uevent_attr);
	if (error)
		goto attrError;
682

683 684 685 686 687
	if (MAJOR(dev->devt)) {
		struct device_attribute *attr;
		attr = kzalloc(sizeof(*attr), GFP_KERNEL);
		if (!attr) {
			error = -ENOMEM;
688
			goto ueventattrError;
689 690 691 692 693 694 695 696 697
		}
		attr->attr.name = "dev";
		attr->attr.mode = S_IRUGO;
		if (dev->driver)
			attr->attr.owner = dev->driver->owner;
		attr->show = show_dev;
		error = device_create_file(dev, attr);
		if (error) {
			kfree(attr);
698
			goto ueventattrError;
699 700 701 702 703
		}

		dev->devt_attr = attr;
	}

704 705 706
	if (dev->class) {
		sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
				  "subsystem");
707 708 709 710 711
		/* If this is not a "fake" compatible device, then create the
		 * symlink from the class to the device. */
		if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
			sysfs_create_link(&dev->class->subsys.kset.kobj,
					  &dev->kobj, dev->bus_id);
712
		if (parent) {
713 714
			sysfs_create_link(&dev->kobj, &dev->parent->kobj,
							"device");
715
#ifdef CONFIG_SYSFS_DEPRECATED
716 717 718 719 720
			class_name = make_class_name(dev->class->name,
							&dev->kobj);
			if (class_name)
				sysfs_create_link(&dev->parent->kobj,
						  &dev->kobj, class_name);
721
#endif
722
		}
723
	}
724

725 726
	if ((error = device_add_attrs(dev)))
		goto AttrsError;
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	if ((error = device_pm_add(dev)))
		goto PMError;
	if ((error = bus_add_device(dev)))
		goto BusError;
731
	kobject_uevent(&dev->kobj, KOBJ_ADD);
732
	bus_attach_device(dev);
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	if (parent)
734
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
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736 737
	if (dev->class) {
		down(&dev->class->sem);
738
		/* tie the class to the device */
739
		list_add_tail(&dev->node, &dev->class->devices);
740 741 742 743 744

		/* notify any interfaces that the device is here */
		list_for_each_entry(class_intf, &dev->class->interfaces, node)
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
745 746
		up(&dev->class->sem);
	}
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 Done:
748
	kfree(class_name);
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	put_device(dev);
	return error;
 BusError:
	device_pm_remove(dev);
 PMError:
754 755 756
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
757
	device_remove_attrs(dev);
758
 AttrsError:
759 760 761 762
	if (dev->devt_attr) {
		device_remove_file(dev, dev->devt_attr);
		kfree(dev->devt_attr);
	}
763 764 765 766 767 768 769 770 771

	if (dev->class) {
		sysfs_remove_link(&dev->kobj, "subsystem");
		/* If this is not a "fake" compatible device, remove the
		 * symlink from the class to the device. */
		if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
			sysfs_remove_link(&dev->class->subsys.kset.kobj,
					  dev->bus_id);
		if (parent) {
772
#ifdef CONFIG_SYSFS_DEPRECATED
773 774 775 776 777 778
			char *class_name = make_class_name(dev->class->name,
							   &dev->kobj);
			if (class_name)
				sysfs_remove_link(&dev->parent->kobj,
						  class_name);
			kfree(class_name);
779
#endif
780 781 782
			sysfs_remove_link(&dev->kobj, "device");
		}
	}
783 784
 ueventattrError:
	device_remove_file(dev, &dev->uevent_attr);
785
 attrError:
786
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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	kobject_del(&dev->kobj);
 Error:
	if (parent)
		put_device(parent);
	goto Done;
}


/**
 *	device_register - register a device with the system.
 *	@dev:	pointer to the device structure
 *
 *	This happens in two clean steps - initialize the device
 *	and add it to the system. The two steps can be called
 *	separately, but this is the easiest and most common.
 *	I.e. you should only call the two helpers separately if
 *	have a clearly defined need to use and refcount the device
 *	before it is added to the hierarchy.
 */

int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}


/**
 *	get_device - increment reference count for device.
 *	@dev:	device.
 *
 *	This simply forwards the call to kobject_get(), though
 *	we do take care to provide for the case that we get a NULL
 *	pointer passed in.
 */

struct device * get_device(struct device * dev)
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}


/**
 *	put_device - decrement reference count.
 *	@dev:	device in question.
 */
void put_device(struct device * dev)
{
	if (dev)
		kobject_put(&dev->kobj);
}


/**
 *	device_del - delete device from system.
 *	@dev:	device.
 *
 *	This is the first part of the device unregistration
 *	sequence. This removes the device from the lists we control
 *	from here, has it removed from the other driver model
 *	subsystems it was added to in device_add(), and removes it
 *	from the kobject hierarchy.
 *
 *	NOTE: this should be called manually _iff_ device_add() was
 *	also called manually.
 */

void device_del(struct device * dev)
{
	struct device * parent = dev->parent;
857
	struct class_interface *class_intf;
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	if (parent)
860
		klist_del(&dev->knode_parent);
861
	if (dev->devt_attr) {
862
		device_remove_file(dev, dev->devt_attr);
863 864
		kfree(dev->devt_attr);
	}
865 866
	if (dev->class) {
		sysfs_remove_link(&dev->kobj, "subsystem");
867 868 869 870 871
		/* If this is not a "fake" compatible device, remove the
		 * symlink from the class to the device. */
		if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
			sysfs_remove_link(&dev->class->subsys.kset.kobj,
					  dev->bus_id);
872
		if (parent) {
873
#ifdef CONFIG_SYSFS_DEPRECATED
874 875
			char *class_name = make_class_name(dev->class->name,
							   &dev->kobj);
876 877 878
			if (class_name)
				sysfs_remove_link(&dev->parent->kobj,
						  class_name);
879
			kfree(class_name);
880
#endif
881
			sysfs_remove_link(&dev->kobj, "device");
882
		}
883

884
		down(&dev->class->sem);
885 886 887 888 889
		/* notify any interfaces that the device is now gone */
		list_for_each_entry(class_intf, &dev->class->interfaces, node)
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
890 891
		list_del_init(&dev->node);
		up(&dev->class->sem);
892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916

		/* If we live in a parent class-directory, unreference it */
		if (dev->kobj.parent->kset == &dev->class->class_dirs) {
			struct device *d;
			int other = 0;

			/*
			 * if we are the last child of our class, delete
			 * our class-directory at this parent
			 */
			down(&dev->class->sem);
			list_for_each_entry(d, &dev->class->devices, node) {
				if (d == dev)
					continue;
				if (d->kobj.parent == dev->kobj.parent) {
					other = 1;
					break;
				}
			}
			if (!other)
				kobject_del(dev->kobj.parent);

			kobject_put(dev->kobj.parent);
			up(&dev->class->sem);
		}
917
	}
918
	device_remove_file(dev, &dev->uevent_attr);
919
	device_remove_attrs(dev);
920
	bus_remove_device(dev);
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921

922 923 924 925 926 927 928
	/*
	 * Some platform devices are driven without driver attached
	 * and managed resources may have been acquired.  Make sure
	 * all resources are released.
	 */
	devres_release_all(dev);

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929 930 931 932 933
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
934 935 936
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
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	device_pm_remove(dev);
938
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962
	kobject_del(&dev->kobj);
	if (parent)
		put_device(parent);
}

/**
 *	device_unregister - unregister device from system.
 *	@dev:	device going away.
 *
 *	We do this in two parts, like we do device_register(). First,
 *	we remove it from all the subsystems with device_del(), then
 *	we decrement the reference count via put_device(). If that
 *	is the final reference count, the device will be cleaned up
 *	via device_release() above. Otherwise, the structure will
 *	stick around until the final reference to the device is dropped.
 */
void device_unregister(struct device * dev)
{
	pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
	device_del(dev);
	put_device(dev);
}


963 964 965 966 967 968
static struct device * next_device(struct klist_iter * i)
{
	struct klist_node * n = klist_next(i);
	return n ? container_of(n, struct device, knode_parent) : NULL;
}

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/**
 *	device_for_each_child - device child iterator.
971
 *	@parent: parent struct device.
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972 973 974
 *	@data:	data for the callback.
 *	@fn:	function to be called for each device.
 *
975
 *	Iterate over @parent's child devices, and call @fn for each,
L
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976 977 978 979 980
 *	passing it @data.
 *
 *	We check the return of @fn each time. If it returns anything
 *	other than 0, we break out and return that value.
 */
981
int device_for_each_child(struct device * parent, void * data,
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982 983
		     int (*fn)(struct device *, void *))
{
984
	struct klist_iter i;
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985 986 987
	struct device * child;
	int error = 0;

988 989 990 991
	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)) && !error)
		error = fn(child, data);
	klist_iter_exit(&i);
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992 993 994
	return error;
}

995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
/**
 * device_find_child - device iterator for locating a particular device.
 * @parent: parent struct device
 * @data: Data to pass to match function
 * @match: Callback function to check device
 *
 * This is similar to the device_for_each_child() function above, but it
 * returns a reference to a device that is 'found' for later use, as
 * determined by the @match callback.
 *
 * The callback should return 0 if the device doesn't match and non-zero
 * if it does.  If the callback returns non-zero and a reference to the
 * current device can be obtained, this function will return to the caller
 * and not iterate over any more devices.
 */
struct device * device_find_child(struct device *parent, void *data,
				  int (*match)(struct device *, void *))
{
	struct klist_iter i;
	struct device *child;

	if (!parent)
		return NULL;

	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)))
		if (match(child, data) && get_device(child))
			break;
	klist_iter_exit(&i);
	return child;
}

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1027 1028 1029 1030 1031 1032
int __init devices_init(void)
{
	return subsystem_register(&devices_subsys);
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1033
EXPORT_SYMBOL_GPL(device_find_child);
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1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045

EXPORT_SYMBOL_GPL(device_initialize);
EXPORT_SYMBOL_GPL(device_add);
EXPORT_SYMBOL_GPL(device_register);

EXPORT_SYMBOL_GPL(device_del);
EXPORT_SYMBOL_GPL(device_unregister);
EXPORT_SYMBOL_GPL(get_device);
EXPORT_SYMBOL_GPL(put_device);

EXPORT_SYMBOL_GPL(device_create_file);
EXPORT_SYMBOL_GPL(device_remove_file);
1046 1047 1048 1049 1050 1051 1052 1053 1054 1055


static void device_create_release(struct device *dev)
{
	pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
	kfree(dev);
}

/**
 * device_create - creates a device and registers it with sysfs
1056 1057 1058 1059 1060 1061 1062
 * @class: pointer to the struct class that this device should be registered to
 * @parent: pointer to the parent struct device of this new device, if any
 * @devt: the dev_t for the char device to be added
 * @fmt: string for the device's name
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1063 1064 1065
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1066 1067 1068 1069
 * If a pointer to a parent struct device is passed in, the newly created
 * struct device will be a child of that device in sysfs.
 * The pointer to the struct device will be returned from the call.
 * Any further sysfs files that might be required can be created using this
1070 1071 1072 1073 1074 1075
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
struct device *device_create(struct class *class, struct device *parent,
1076
			     dev_t devt, const char *fmt, ...)
1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
{
	va_list args;
	struct device *dev = NULL;
	int retval = -ENODEV;

	if (class == NULL || IS_ERR(class))
		goto error;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev) {
		retval = -ENOMEM;
		goto error;
	}

	dev->devt = devt;
	dev->class = class;
	dev->parent = parent;
	dev->release = device_create_release;

	va_start(args, fmt);
	vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
	va_end(args);
	retval = device_register(dev);
	if (retval)
		goto error;

	return dev;

error:
	kfree(dev);
	return ERR_PTR(retval);
}
EXPORT_SYMBOL_GPL(device_create);

/**
 * device_destroy - removes a device that was created with device_create()
1113 1114
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
1115
 *
1116 1117
 * This call unregisters and cleans up a device that was created with a
 * call to device_create().
1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132
 */
void device_destroy(struct class *class, dev_t devt)
{
	struct device *dev = NULL;
	struct device *dev_tmp;

	down(&class->sem);
	list_for_each_entry(dev_tmp, &class->devices, node) {
		if (dev_tmp->devt == devt) {
			dev = dev_tmp;
			break;
		}
	}
	up(&class->sem);

1133
	if (dev)
1134 1135 1136
		device_unregister(dev);
}
EXPORT_SYMBOL_GPL(device_destroy);
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155

/**
 * device_rename - renames a device
 * @dev: the pointer to the struct device to be renamed
 * @new_name: the new name of the device
 */
int device_rename(struct device *dev, char *new_name)
{
	char *old_class_name = NULL;
	char *new_class_name = NULL;
	char *old_symlink_name = NULL;
	int error;

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

	pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);

1156
#ifdef CONFIG_SYSFS_DEPRECATED
1157 1158
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1159
#endif
1160 1161 1162

	if (dev->class) {
		old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1163 1164 1165 1166
		if (!old_symlink_name) {
			error = -ENOMEM;
			goto out_free_old_class;
		}
1167 1168 1169 1170 1171 1172 1173
		strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
	}

	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);

1174
#ifdef CONFIG_SYSFS_DEPRECATED
1175 1176 1177 1178 1179 1180 1181 1182
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
			sysfs_create_link(&dev->parent->kobj, &dev->kobj,
					  new_class_name);
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1183 1184
#endif

1185 1186 1187 1188 1189 1190 1191 1192 1193 1194
	if (dev->class) {
		sysfs_remove_link(&dev->class->subsys.kset.kobj,
				  old_symlink_name);
		sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
				  dev->bus_id);
	}
	put_device(dev);

	kfree(new_class_name);
	kfree(old_symlink_name);
1195 1196
 out_free_old_class:
	kfree(old_class_name);
1197 1198 1199

	return error;
}
1200
EXPORT_SYMBOL_GPL(device_rename);
1201 1202 1203 1204 1205

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1206
	int error = 0;
1207 1208 1209 1210 1211
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1212
		error = -ENOMEM;
1213 1214 1215 1216 1217 1218
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230
	if (new_parent) {
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
		if (error)
			goto out;
		error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
					  class_name);
		if (error)
			sysfs_remove_link(&dev->kobj, "device");
	}
	else
		error = 0;
1231 1232 1233 1234
out:
	kfree(class_name);
	return error;
#else
1235 1236 1237 1238 1239 1240
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1241 1242 1243 1244 1245 1246
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1247
 * @new_parent: the new parent of the device (can by NULL)
1248 1249 1250 1251 1252
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1253
	struct kobject *new_parent_kobj;
1254 1255 1256 1257 1258 1259

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

	new_parent = get_device(new_parent);
1260 1261 1262 1263
	new_parent_kobj = get_device_parent (dev, new_parent);
	if (IS_ERR(new_parent_kobj)) {
		error = PTR_ERR(new_parent_kobj);
		put_device(new_parent);
1264 1265 1266
		goto out;
	}
	pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1267 1268
		 new_parent ? new_parent->bus_id : "<NULL>");
	error = kobject_move(&dev->kobj, new_parent_kobj);
1269 1270 1271 1272 1273 1274 1275
	if (error) {
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1276
		klist_remove(&dev->knode_parent);
1277 1278
	if (new_parent)
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1279 1280 1281 1282 1283 1284 1285
	if (!dev->class)
		goto out_put;
	error = device_move_class_links(dev, old_parent, new_parent);
	if (error) {
		/* We ignore errors on cleanup since we're hosed anyway... */
		device_move_class_links(dev, new_parent, old_parent);
		if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1286 1287
			if (new_parent)
				klist_remove(&dev->knode_parent);
1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302
			if (old_parent)
				klist_add_tail(&dev->knode_parent,
					       &old_parent->klist_children);
		}
		put_device(new_parent);
		goto out;
	}
out_put:
	put_device(old_parent);
out:
	put_device(dev);
	return error;
}

EXPORT_SYMBOL_GPL(device_move);