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Root/drivers/base/core.c

1	/*
2	* drivers/base/core.c - core driver model code (device registration, etc)
3	*
4	* Copyright (c) 2002-3 Patrick Mochel
5	* Copyright (c) 2002-3 Open Source Development Labs
6	* Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7	* Copyright (c) 2006 Novell, Inc.
8	*
9	* This file is released under the GPLv2
10	*
11	*/
12
13	#include <linux/device.h>
14	#include <linux/err.h>
15	#include <linux/init.h>
16	#include <linux/module.h>
17	#include <linux/slab.h>
18	#include <linux/string.h>
19	#include <linux/kdev_t.h>
20	#include <linux/notifier.h>
21	#include <linux/of.h>
22	#include <linux/of_device.h>
23	#include <linux/genhd.h>
24	#include <linux/kallsyms.h>
25	#include <linux/mutex.h>
26	#include <linux/async.h>
27	#include <linux/pm_runtime.h>
28	#include <linux/netdevice.h>
29
30	#include "base.h"
31	#include "power/power.h"
32
33	#ifdef CONFIG_SYSFS_DEPRECATED
34	#ifdef CONFIG_SYSFS_DEPRECATED_V2
35	long sysfs_deprecated = 1;
36	#else
37	long sysfs_deprecated = 0;
38	#endif
39	static __init int sysfs_deprecated_setup(char *arg)
40	{
41	return strict_strtol(arg, 10, &sysfs_deprecated);
42	}
43	early_param("sysfs.deprecated", sysfs_deprecated_setup);
44	#endif
45
46	int (platform_notify)(struct device dev) = NULL;
47	int (platform_notify_remove)(struct device dev) = NULL;
48	static struct kobject *dev_kobj;
49	struct kobject *sysfs_dev_char_kobj;
50	struct kobject *sysfs_dev_block_kobj;
51
52	#ifdef CONFIG_BLOCK
53	static inline int device_is_not_partition(struct device *dev)
54	{
55	return !(dev->type == &part_type);
56	}
57	#else
58	static inline int device_is_not_partition(struct device *dev)
59	{
60	return 1;
61	}
62	#endif
63
64	/**
65	* dev_driver_string - Return a device's driver name, if at all possible
66	* @dev: struct device to get the name of
67	*
68	* Will return the device's driver's name if it is bound to a device. If
69	* the device is not bound to a driver, it will return the name of the bus
70	* it is attached to. If it is not attached to a bus either, an empty
71	* string will be returned.
72	*/
73	const char dev_driver_string(const struct device dev)
74	{
75	struct device_driver *drv;
76
77	/* dev->driver can change to NULL underneath us because of unbinding,
78	* so be careful about accessing it. dev->bus and dev->class should
79	* never change once they are set, so they don't need special care.
80	*/
81	drv = ACCESS_ONCE(dev->driver);
82	return drv ? drv->name :
83	(dev->bus ? dev->bus->name :
84	(dev->class ? dev->class->name : ""));
85	}
86	EXPORT_SYMBOL(dev_driver_string);
87
88	#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
89
90	static ssize_t dev_attr_show(struct kobject kobj, struct attribute attr,
91	char *buf)
92	{
93	struct device_attribute *dev_attr = to_dev_attr(attr);
94	struct device *dev = kobj_to_dev(kobj);
95	ssize_t ret = -EIO;
96
97	if (dev_attr->show)
98	ret = dev_attr->show(dev, dev_attr, buf);
99	if (ret >= (ssize_t)PAGE_SIZE) {
100	print_symbol("dev_attr_show: %s returned bad count\n",
101	(unsigned long)dev_attr->show);
102	}
103	return ret;
104	}
105
106	static ssize_t dev_attr_store(struct kobject kobj, struct attribute attr,
107	const char *buf, size_t count)
108	{
109	struct device_attribute *dev_attr = to_dev_attr(attr);
110	struct device *dev = kobj_to_dev(kobj);
111	ssize_t ret = -EIO;
112
113	if (dev_attr->store)
114	ret = dev_attr->store(dev, dev_attr, buf, count);
115	return ret;
116	}
117
118	static const struct sysfs_ops dev_sysfs_ops = {
119	.show = dev_attr_show,
120	.store = dev_attr_store,
121	};
122
123	#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
124
125	ssize_t device_store_ulong(struct device *dev,
126	struct device_attribute *attr,
127	const char *buf, size_t size)
128	{
129	struct dev_ext_attribute *ea = to_ext_attr(attr);
130	char *end;
131	unsigned long new = simple_strtoul(buf, &end, 0);
132	if (end == buf)
133	return -EINVAL;
134	(unsigned long )(ea->var) = new;
135	/* Always return full write size even if we didn't consume all */
136	return size;
137	}
138	EXPORT_SYMBOL_GPL(device_store_ulong);
139
140	ssize_t device_show_ulong(struct device *dev,
141	struct device_attribute *attr,
142	char *buf)
143	{
144	struct dev_ext_attribute *ea = to_ext_attr(attr);
145	return snprintf(buf, PAGE_SIZE, "%lx\n", (unsigned long )(ea->var));
146	}
147	EXPORT_SYMBOL_GPL(device_show_ulong);
148
149	ssize_t device_store_int(struct device *dev,
150	struct device_attribute *attr,
151	const char *buf, size_t size)
152	{
153	struct dev_ext_attribute *ea = to_ext_attr(attr);
154	char *end;
155	long new = simple_strtol(buf, &end, 0);
156	if (end == buf \|\| new > INT_MAX \|\| new < INT_MIN)
157	return -EINVAL;
158	(int )(ea->var) = new;
159	/* Always return full write size even if we didn't consume all */
160	return size;
161	}
162	EXPORT_SYMBOL_GPL(device_store_int);
163
164	ssize_t device_show_int(struct device *dev,
165	struct device_attribute *attr,
166	char *buf)
167	{
168	struct dev_ext_attribute *ea = to_ext_attr(attr);
169
170	return snprintf(buf, PAGE_SIZE, "%d\n", (int )(ea->var));
171	}
172	EXPORT_SYMBOL_GPL(device_show_int);
173
174	/**
175	* device_release - free device structure.
176	* @kobj: device's kobject.
177	*
178	* This is called once the reference count for the object
179	* reaches 0. We forward the call to the device's release
180	* method, which should handle actually freeing the structure.
181	*/
182	static void device_release(struct kobject *kobj)
183	{
184	struct device *dev = kobj_to_dev(kobj);
185	struct device_private *p = dev->p;
186
187	if (dev->release)
188	dev->release(dev);
189	else if (dev->type && dev->type->release)
190	dev->type->release(dev);
191	else if (dev->class && dev->class->dev_release)
192	dev->class->dev_release(dev);
193	else
194	WARN(1, KERN_ERR "Device '%s' does not have a release() "
195	"function, it is broken and must be fixed.\n",
196	dev_name(dev));
197	kfree(p);
198	}
199
200	static const void device_namespace(struct kobject kobj)
201	{
202	struct device *dev = kobj_to_dev(kobj);
203	const void *ns = NULL;
204
205	if (dev->class && dev->class->ns_type)
206	ns = dev->class->namespace(dev);
207
208	return ns;
209	}
210
211	static struct kobj_type device_ktype = {
212	.release = device_release,
213	.sysfs_ops = &dev_sysfs_ops,
214	.namespace = device_namespace,
215	};
216
217
218	static int dev_uevent_filter(struct kset kset, struct kobject kobj)
219	{
220	struct kobj_type *ktype = get_ktype(kobj);
221
222	if (ktype == &device_ktype) {
223	struct device *dev = kobj_to_dev(kobj);
224	if (dev->bus)
225	return 1;
226	if (dev->class)
227	return 1;
228	}
229	return 0;
230	}
231
232	static const char dev_uevent_name(struct kset kset, struct kobject *kobj)
233	{
234	struct device *dev = kobj_to_dev(kobj);
235
236	if (dev->bus)
237	return dev->bus->name;
238	if (dev->class)
239	return dev->class->name;
240	return NULL;
241	}
242
243	static int dev_uevent(struct kset kset, struct kobject kobj,
244	struct kobj_uevent_env *env)
245	{
246	struct device *dev = kobj_to_dev(kobj);
247	int retval = 0;
248
249	/* add device node properties if present */
250	if (MAJOR(dev->devt)) {
251	const char *tmp;
252	const char *name;
253	umode_t mode = 0;
254
255	add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
256	add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
257	name = device_get_devnode(dev, &mode, &tmp);
258	if (name) {
259	add_uevent_var(env, "DEVNAME=%s", name);
260	kfree(tmp);
261	if (mode)
262	add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
263	}
264	}
265
266	if (dev->type && dev->type->name)
267	add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
268
269	if (dev->driver)
270	add_uevent_var(env, "DRIVER=%s", dev->driver->name);
271
272	/* Add common DT information about the device */
273	of_device_uevent(dev, env);
274
275	/* have the bus specific function add its stuff */
276	if (dev->bus && dev->bus->uevent) {
277	retval = dev->bus->uevent(dev, env);
278	if (retval)
279	pr_debug("device: '%s': %s: bus uevent() returned %d\n",
280	dev_name(dev), __func__, retval);
281	}
282
283	/* have the class specific function add its stuff */
284	if (dev->class && dev->class->dev_uevent) {
285	retval = dev->class->dev_uevent(dev, env);
286	if (retval)
287	pr_debug("device: '%s': %s: class uevent() "
288	"returned %d\n", dev_name(dev),
289	__func__, retval);
290	}
291
292	/* have the device type specific function add its stuff */
293	if (dev->type && dev->type->uevent) {
294	retval = dev->type->uevent(dev, env);
295	if (retval)
296	pr_debug("device: '%s': %s: dev_type uevent() "
297	"returned %d\n", dev_name(dev),
298	__func__, retval);
299	}
300
301	return retval;
302	}
303
304	static const struct kset_uevent_ops device_uevent_ops = {
305	.filter = dev_uevent_filter,
306	.name = dev_uevent_name,
307	.uevent = dev_uevent,
308	};
309
310	static ssize_t show_uevent(struct device dev, struct device_attribute attr,
311	char *buf)
312	{
313	struct kobject *top_kobj;
314	struct kset *kset;
315	struct kobj_uevent_env *env = NULL;
316	int i;
317	size_t count = 0;
318	int retval;
319
320	/* search the kset, the device belongs to */
321	top_kobj = &dev->kobj;
322	while (!top_kobj->kset && top_kobj->parent)
323	top_kobj = top_kobj->parent;
324	if (!top_kobj->kset)
325	goto out;
326
327	kset = top_kobj->kset;
328	if (!kset->uevent_ops \|\| !kset->uevent_ops->uevent)
329	goto out;
330
331	/* respect filter */
332	if (kset->uevent_ops && kset->uevent_ops->filter)
333	if (!kset->uevent_ops->filter(kset, &dev->kobj))
334	goto out;
335
336	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
337	if (!env)
338	return -ENOMEM;
339
340	/* let the kset specific function add its keys */
341	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
342	if (retval)
343	goto out;
344
345	/* copy keys to file */
346	for (i = 0; i < env->envp_idx; i++)
347	count += sprintf(&buf[count], "%s\n", env->envp[i]);
348	out:
349	kfree(env);
350	return count;
351	}
352
353	static ssize_t store_uevent(struct device dev, struct device_attribute attr,
354	const char *buf, size_t count)
355	{
356	enum kobject_action action;
357
358	if (kobject_action_type(buf, count, &action) == 0)
359	kobject_uevent(&dev->kobj, action);
360	else
361	dev_err(dev, "uevent: unknown action-string\n");
362	return count;
363	}
364
365	static struct device_attribute uevent_attr =
366	__ATTR(uevent, S_IRUGO \| S_IWUSR, show_uevent, store_uevent);
367
368	static int device_add_attributes(struct device *dev,
369	struct device_attribute *attrs)
370	{
371	int error = 0;
372	int i;
373
374	if (attrs) {
375	for (i = 0; attr_name(attrs[i]); i++) {
376	error = device_create_file(dev, &attrs[i]);
377	if (error)
378	break;
379	}
380	if (error)
381	while (--i >= 0)
382	device_remove_file(dev, &attrs[i]);
383	}
384	return error;
385	}
386
387	static void device_remove_attributes(struct device *dev,
388	struct device_attribute *attrs)
389	{
390	int i;
391
392	if (attrs)
393	for (i = 0; attr_name(attrs[i]); i++)
394	device_remove_file(dev, &attrs[i]);
395	}
396
397	static int device_add_bin_attributes(struct device *dev,
398	struct bin_attribute *attrs)
399	{
400	int error = 0;
401	int i;
402
403	if (attrs) {
404	for (i = 0; attr_name(attrs[i]); i++) {
405	error = device_create_bin_file(dev, &attrs[i]);
406	if (error)
407	break;
408	}
409	if (error)
410	while (--i >= 0)
411	device_remove_bin_file(dev, &attrs[i]);
412	}
413	return error;
414	}
415
416	static void device_remove_bin_attributes(struct device *dev,
417	struct bin_attribute *attrs)
418	{
419	int i;
420
421	if (attrs)
422	for (i = 0; attr_name(attrs[i]); i++)
423	device_remove_bin_file(dev, &attrs[i]);
424	}
425
426	static int device_add_groups(struct device *dev,
427	const struct attribute_group **groups)
428	{
429	int error = 0;
430	int i;
431
432	if (groups) {
433	for (i = 0; groups[i]; i++) {
434	error = sysfs_create_group(&dev->kobj, groups[i]);
435	if (error) {
436	while (--i >= 0)
437	sysfs_remove_group(&dev->kobj,
438	groups[i]);
439	break;
440	}
441	}
442	}
443	return error;
444	}
445
446	static void device_remove_groups(struct device *dev,
447	const struct attribute_group **groups)
448	{
449	int i;
450
451	if (groups)
452	for (i = 0; groups[i]; i++)
453	sysfs_remove_group(&dev->kobj, groups[i]);
454	}
455
456	static int device_add_attrs(struct device *dev)
457	{
458	struct class *class = dev->class;
459	const struct device_type *type = dev->type;
460	int error;
461
462	if (class) {
463	error = device_add_attributes(dev, class->dev_attrs);
464	if (error)
465	return error;
466	error = device_add_bin_attributes(dev, class->dev_bin_attrs);
467	if (error)
468	goto err_remove_class_attrs;
469	}
470
471	if (type) {
472	error = device_add_groups(dev, type->groups);
473	if (error)
474	goto err_remove_class_bin_attrs;
475	}
476
477	error = device_add_groups(dev, dev->groups);
478	if (error)
479	goto err_remove_type_groups;
480
481	return 0;
482
483	err_remove_type_groups:
484	if (type)
485	device_remove_groups(dev, type->groups);
486	err_remove_class_bin_attrs:
487	if (class)
488	device_remove_bin_attributes(dev, class->dev_bin_attrs);
489	err_remove_class_attrs:
490	if (class)
491	device_remove_attributes(dev, class->dev_attrs);
492
493	return error;
494	}
495
496	static void device_remove_attrs(struct device *dev)
497	{
498	struct class *class = dev->class;
499	const struct device_type *type = dev->type;
500
501	device_remove_groups(dev, dev->groups);
502
503	if (type)
504	device_remove_groups(dev, type->groups);
505
506	if (class) {
507	device_remove_attributes(dev, class->dev_attrs);
508	device_remove_bin_attributes(dev, class->dev_bin_attrs);
509	}
510	}
511
512
513	static ssize_t show_dev(struct device dev, struct device_attribute attr,
514	char *buf)
515	{
516	return print_dev_t(buf, dev->devt);
517	}
518
519	static struct device_attribute devt_attr =
520	__ATTR(dev, S_IRUGO, show_dev, NULL);
521
522	/* /sys/devices/ */
523	struct kset *devices_kset;
524
525	/**
526	* device_create_file - create sysfs attribute file for device.
527	* @dev: device.
528	* @attr: device attribute descriptor.
529	*/
530	int device_create_file(struct device *dev,
531	const struct device_attribute *attr)
532	{
533	int error = 0;
534	if (dev)
535	error = sysfs_create_file(&dev->kobj, &attr->attr);
536	return error;
537	}
538
539	/**
540	* device_remove_file - remove sysfs attribute file.
541	* @dev: device.
542	* @attr: device attribute descriptor.
543	*/
544	void device_remove_file(struct device *dev,
545	const struct device_attribute *attr)
546	{
547	if (dev)
548	sysfs_remove_file(&dev->kobj, &attr->attr);
549	}
550
551	/**
552	* device_create_bin_file - create sysfs binary attribute file for device.
553	* @dev: device.
554	* @attr: device binary attribute descriptor.
555	*/
556	int device_create_bin_file(struct device *dev,
557	const struct bin_attribute *attr)
558	{
559	int error = -EINVAL;
560	if (dev)
561	error = sysfs_create_bin_file(&dev->kobj, attr);
562	return error;
563	}
564	EXPORT_SYMBOL_GPL(device_create_bin_file);
565
566	/**
567	* device_remove_bin_file - remove sysfs binary attribute file
568	* @dev: device.
569	* @attr: device binary attribute descriptor.
570	*/
571	void device_remove_bin_file(struct device *dev,
572	const struct bin_attribute *attr)
573	{
574	if (dev)
575	sysfs_remove_bin_file(&dev->kobj, attr);
576	}
577	EXPORT_SYMBOL_GPL(device_remove_bin_file);
578
579	/**
580	* device_schedule_callback_owner - helper to schedule a callback for a device
581	* @dev: device.
582	* @func: callback function to invoke later.
583	* @owner: module owning the callback routine
584	*
585	* Attribute methods must not unregister themselves or their parent device
586	* (which would amount to the same thing). Attempts to do so will deadlock,
587	* since unregistration is mutually exclusive with driver callbacks.
588	*
589	* Instead methods can call this routine, which will attempt to allocate
590	* and schedule a workqueue request to call back @func with @dev as its
591	* argument in the workqueue's process context. @dev will be pinned until
592	* @func returns.
593	*
594	* This routine is usually called via the inline device_schedule_callback(),
595	* which automatically sets @owner to THIS_MODULE.
596	*
597	* Returns 0 if the request was submitted, -ENOMEM if storage could not
598	* be allocated, -ENODEV if a reference to @owner isn't available.
599	*
600	* NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
601	* underlying sysfs routine (since it is intended for use by attribute
602	* methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
603	*/
604	int device_schedule_callback_owner(struct device *dev,
605	void (func)(struct device ), struct module *owner)
606	{
607	return sysfs_schedule_callback(&dev->kobj,
608	(void ()(void )) func, dev, owner);
609	}
610	EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
611
612	static void klist_children_get(struct klist_node *n)
613	{
614	struct device_private *p = to_device_private_parent(n);
615	struct device *dev = p->device;
616
617	get_device(dev);
618	}
619
620	static void klist_children_put(struct klist_node *n)
621	{
622	struct device_private *p = to_device_private_parent(n);
623	struct device *dev = p->device;
624
625	put_device(dev);
626	}
627
628	/**
629	* device_initialize - init device structure.
630	* @dev: device.
631	*
632	* This prepares the device for use by other layers by initializing
633	* its fields.
634	* It is the first half of device_register(), if called by
635	* that function, though it can also be called separately, so one
636	* may use @dev's fields. In particular, get_device()/put_device()
637	* may be used for reference counting of @dev after calling this
638	* function.
639	*
640	* All fields in @dev must be initialized by the caller to 0, except
641	* for those explicitly set to some other value. The simplest
642	* approach is to use kzalloc() to allocate the structure containing
643	* @dev.
644	*
645	* NOTE: Use put_device() to give up your reference instead of freeing
646	* @dev directly once you have called this function.
647	*/
648	void device_initialize(struct device *dev)
649	{
650	dev->kobj.kset = devices_kset;
651	kobject_init(&dev->kobj, &device_ktype);
652	INIT_LIST_HEAD(&dev->dma_pools);
653	mutex_init(&dev->mutex);
654	lockdep_set_novalidate_class(&dev->mutex);
655	spin_lock_init(&dev->devres_lock);
656	INIT_LIST_HEAD(&dev->devres_head);
657	device_pm_init(dev);
658	set_dev_node(dev, -1);
659	}
660
661	static struct kobject virtual_device_parent(struct device dev)
662	{
663	static struct kobject *virtual_dir = NULL;
664
665	if (!virtual_dir)
666	virtual_dir = kobject_create_and_add("virtual",
667	&devices_kset->kobj);
668
669	return virtual_dir;
670	}
671
672	struct class_dir {
673	struct kobject kobj;
674	struct class *class;
675	};
676
677	#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
678
679	static void class_dir_release(struct kobject *kobj)
680	{
681	struct class_dir *dir = to_class_dir(kobj);
682	kfree(dir);
683	}
684
685	static const
686	struct kobj_ns_type_operations class_dir_child_ns_type(struct kobject kobj)
687	{
688	struct class_dir *dir = to_class_dir(kobj);
689	return dir->class->ns_type;
690	}
691
692	static struct kobj_type class_dir_ktype = {
693	.release = class_dir_release,
694	.sysfs_ops = &kobj_sysfs_ops,
695	.child_ns_type = class_dir_child_ns_type
696	};
697
698	static struct kobject *
699	class_dir_create_and_add(struct class class, struct kobject parent_kobj)
700	{
701	struct class_dir *dir;
702	int retval;
703
704	dir = kzalloc(sizeof(*dir), GFP_KERNEL);
705	if (!dir)
706	return NULL;
707
708	dir->class = class;
709	kobject_init(&dir->kobj, &class_dir_ktype);
710
711	dir->kobj.kset = &class->p->glue_dirs;
712
713	retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
714	if (retval < 0) {
715	kobject_put(&dir->kobj);
716	return NULL;
717	}
718	return &dir->kobj;
719	}
720
721
722	static struct kobject get_device_parent(struct device dev,
723	struct device *parent)
724	{
725	if (dev->class) {
726	static DEFINE_MUTEX(gdp_mutex);
727	struct kobject *kobj = NULL;
728	struct kobject *parent_kobj;
729	struct kobject *k;
730
731	#ifdef CONFIG_BLOCK
732	/* block disks show up in /sys/block */
733	if (sysfs_deprecated && dev->class == &block_class) {
734	if (parent && parent->class == &block_class)
735	return &parent->kobj;
736	return &block_class.p->subsys.kobj;
737	}
738	#endif
739
740	/*
741	* If we have no parent, we live in "virtual".
742	* Class-devices with a non class-device as parent, live
743	* in a "glue" directory to prevent namespace collisions.
744	*/
745	if (parent == NULL)
746	parent_kobj = virtual_device_parent(dev);
747	else if (parent->class && !dev->class->ns_type)
748	return &parent->kobj;
749	else
750	parent_kobj = &parent->kobj;
751
752	mutex_lock(&gdp_mutex);
753
754	/* find our class-directory at the parent and reference it */
755	spin_lock(&dev->class->p->glue_dirs.list_lock);
756	list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
757	if (k->parent == parent_kobj) {
758	kobj = kobject_get(k);
759	break;
760	}
761	spin_unlock(&dev->class->p->glue_dirs.list_lock);
762	if (kobj) {
763	mutex_unlock(&gdp_mutex);
764	return kobj;
765	}
766
767	/* or create a new class-directory at the parent device */
768	k = class_dir_create_and_add(dev->class, parent_kobj);
769	/* do not emit an uevent for this simple "glue" directory */
770	mutex_unlock(&gdp_mutex);
771	return k;
772	}
773
774	/* subsystems can specify a default root directory for their devices */
775	if (!parent && dev->bus && dev->bus->dev_root)
776	return &dev->bus->dev_root->kobj;
777
778	if (parent)
779	return &parent->kobj;
780	return NULL;
781	}
782
783	static void cleanup_glue_dir(struct device dev, struct kobject glue_dir)
784	{
785	/* see if we live in a "glue" directory */
786	if (!glue_dir \|\| !dev->class \|\|
787	glue_dir->kset != &dev->class->p->glue_dirs)
788	return;
789
790	kobject_put(glue_dir);
791	}
792
793	static void cleanup_device_parent(struct device *dev)
794	{
795	cleanup_glue_dir(dev, dev->kobj.parent);
796	}
797
798	static int device_add_class_symlinks(struct device *dev)
799	{
800	int error;
801
802	if (!dev->class)
803	return 0;
804
805	error = sysfs_create_link(&dev->kobj,
806	&dev->class->p->subsys.kobj,
807	"subsystem");
808	if (error)
809	goto out;
810
811	if (dev->parent && device_is_not_partition(dev)) {
812	error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
813	"device");
814	if (error)
815	goto out_subsys;
816	}
817
818	#ifdef CONFIG_BLOCK
819	/* /sys/block has directories and does not need symlinks */
820	if (sysfs_deprecated && dev->class == &block_class)
821	return 0;
822	#endif
823
824	/* link in the class directory pointing to the device */
825	error = sysfs_create_link(&dev->class->p->subsys.kobj,
826	&dev->kobj, dev_name(dev));
827	if (error)
828	goto out_device;
829
830	return 0;
831
832	out_device:
833	sysfs_remove_link(&dev->kobj, "device");
834
835	out_subsys:
836	sysfs_remove_link(&dev->kobj, "subsystem");
837	out:
838	return error;
839	}
840
841	static void device_remove_class_symlinks(struct device *dev)
842	{
843	if (!dev->class)
844	return;
845
846	if (dev->parent && device_is_not_partition(dev))
847	sysfs_remove_link(&dev->kobj, "device");
848	sysfs_remove_link(&dev->kobj, "subsystem");
849	#ifdef CONFIG_BLOCK
850	if (sysfs_deprecated && dev->class == &block_class)
851	return;
852	#endif
853	sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
854	}
855
856	/**
857	* dev_set_name - set a device name
858	* @dev: device
859	* @fmt: format string for the device's name
860	*/
861	int dev_set_name(struct device dev, const char fmt, ...)
862	{
863	va_list vargs;
864	int err;
865
866	va_start(vargs, fmt);
867	err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
868	va_end(vargs);
869	return err;
870	}
871	EXPORT_SYMBOL_GPL(dev_set_name);
872
873	/**
874	* device_to_dev_kobj - select a /sys/dev/ directory for the device
875	* @dev: device
876	*
877	* By default we select char/ for new entries. Setting class->dev_obj
878	* to NULL prevents an entry from being created. class->dev_kobj must
879	* be set (or cleared) before any devices are registered to the class
880	* otherwise device_create_sys_dev_entry() and
881	* device_remove_sys_dev_entry() will disagree about the presence of
882	* the link.
883	*/
884	static struct kobject device_to_dev_kobj(struct device dev)
885	{
886	struct kobject *kobj;
887
888	if (dev->class)
889	kobj = dev->class->dev_kobj;
890	else
891	kobj = sysfs_dev_char_kobj;
892
893	return kobj;
894	}
895
896	static int device_create_sys_dev_entry(struct device *dev)
897	{
898	struct kobject *kobj = device_to_dev_kobj(dev);
899	int error = 0;
900	char devt_str[15];
901
902	if (kobj) {
903	format_dev_t(devt_str, dev->devt);
904	error = sysfs_create_link(kobj, &dev->kobj, devt_str);
905	}
906
907	return error;
908	}
909
910	static void device_remove_sys_dev_entry(struct device *dev)
911	{
912	struct kobject *kobj = device_to_dev_kobj(dev);
913	char devt_str[15];
914
915	if (kobj) {
916	format_dev_t(devt_str, dev->devt);
917	sysfs_remove_link(kobj, devt_str);
918	}
919	}
920
921	int device_private_init(struct device *dev)
922	{
923	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
924	if (!dev->p)
925	return -ENOMEM;
926	dev->p->device = dev;
927	klist_init(&dev->p->klist_children, klist_children_get,
928	klist_children_put);
929	INIT_LIST_HEAD(&dev->p->deferred_probe);
930	return 0;
931	}
932
933	/**
934	* device_add - add device to device hierarchy.
935	* @dev: device.
936	*
937	* This is part 2 of device_register(), though may be called
938	* separately _iff_ device_initialize() has been called separately.
939	*
940	* This adds @dev to the kobject hierarchy via kobject_add(), adds it
941	* to the global and sibling lists for the device, then
942	* adds it to the other relevant subsystems of the driver model.
943	*
944	* Do not call this routine or device_register() more than once for
945	* any device structure. The driver model core is not designed to work
946	* with devices that get unregistered and then spring back to life.
947	* (Among other things, it's very hard to guarantee that all references
948	* to the previous incarnation of @dev have been dropped.) Allocate
949	* and register a fresh new struct device instead.
950	*
951	* NOTE: _Never_ directly free @dev after calling this function, even
952	* if it returned an error! Always use put_device() to give up your
953	* reference instead.
954	*/
955	int device_add(struct device *dev)
956	{
957	struct device *parent = NULL;
958	struct kobject *kobj;
959	struct class_interface *class_intf;
960	int error = -EINVAL;
961
962	dev = get_device(dev);
963	if (!dev)
964	goto done;
965
966	if (!dev->p) {
967	error = device_private_init(dev);
968	if (error)
969	goto done;
970	}
971
972	/*
973	* for statically allocated devices, which should all be converted
974	* some day, we need to initialize the name. We prevent reading back
975	* the name, and force the use of dev_name()
976	*/
977	if (dev->init_name) {
978	dev_set_name(dev, "%s", dev->init_name);
979	dev->init_name = NULL;
980	}
981
982	/* subsystems can specify simple device enumeration */
983	if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
984	dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
985
986	if (!dev_name(dev)) {
987	error = -EINVAL;
988	goto name_error;
989	}
990
991	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
992
993	parent = get_device(dev->parent);
994	kobj = get_device_parent(dev, parent);
995	if (kobj)
996	dev->kobj.parent = kobj;
997
998	/* use parent numa_node */
999	if (parent)
1000	set_dev_node(dev, dev_to_node(parent));
1001
1002	/* first, register with generic layer. */
1003	/* we require the name to be set before, and pass NULL */
1004	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1005	if (error)
1006	goto Error;
1007
1008	/* notify platform of device entry */
1009	if (platform_notify)
1010	platform_notify(dev);
1011
1012	error = device_create_file(dev, &uevent_attr);
1013	if (error)
1014	goto attrError;
1015
1016	if (MAJOR(dev->devt)) {
1017	error = device_create_file(dev, &devt_attr);
1018	if (error)
1019	goto ueventattrError;
1020
1021	error = device_create_sys_dev_entry(dev);
1022	if (error)
1023	goto devtattrError;
1024
1025	devtmpfs_create_node(dev);
1026	}
1027
1028	error = device_add_class_symlinks(dev);
1029	if (error)
1030	goto SymlinkError;
1031	error = device_add_attrs(dev);
1032	if (error)
1033	goto AttrsError;
1034	error = bus_add_device(dev);
1035	if (error)
1036	goto BusError;
1037	error = dpm_sysfs_add(dev);
1038	if (error)
1039	goto DPMError;
1040	device_pm_add(dev);
1041
1042	/* Notify clients of device addition. This call must come
1043	* after dpm_sysfs_add() and before kobject_uevent().
1044	*/
1045	if (dev->bus)
1046	blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1047	BUS_NOTIFY_ADD_DEVICE, dev);
1048
1049	kobject_uevent(&dev->kobj, KOBJ_ADD);
1050	bus_probe_device(dev);
1051	if (parent)
1052	klist_add_tail(&dev->p->knode_parent,
1053	&parent->p->klist_children);
1054
1055	if (dev->class) {
1056	mutex_lock(&dev->class->p->mutex);
1057	/* tie the class to the device */
1058	klist_add_tail(&dev->knode_class,
1059	&dev->class->p->klist_devices);
1060
1061	/* notify any interfaces that the device is here */
1062	list_for_each_entry(class_intf,
1063	&dev->class->p->interfaces, node)
1064	if (class_intf->add_dev)
1065	class_intf->add_dev(dev, class_intf);
1066	mutex_unlock(&dev->class->p->mutex);
1067	}
1068	done:
1069	put_device(dev);
1070	return error;
1071	DPMError:
1072	bus_remove_device(dev);
1073	BusError:
1074	device_remove_attrs(dev);
1075	AttrsError:
1076	device_remove_class_symlinks(dev);
1077	SymlinkError:
1078	if (MAJOR(dev->devt))
1079	devtmpfs_delete_node(dev);
1080	if (MAJOR(dev->devt))
1081	device_remove_sys_dev_entry(dev);
1082	devtattrError:
1083	if (MAJOR(dev->devt))
1084	device_remove_file(dev, &devt_attr);
1085	ueventattrError:
1086	device_remove_file(dev, &uevent_attr);
1087	attrError:
1088	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1089	kobject_del(&dev->kobj);
1090	Error:
1091	cleanup_device_parent(dev);
1092	if (parent)
1093	put_device(parent);
1094	name_error:
1095	kfree(dev->p);
1096	dev->p = NULL;
1097	goto done;
1098	}
1099
1100	/**
1101	* device_register - register a device with the system.
1102	* @dev: pointer to the device structure
1103	*
1104	* This happens in two clean steps - initialize the device
1105	* and add it to the system. The two steps can be called
1106	* separately, but this is the easiest and most common.
1107	* I.e. you should only call the two helpers separately if
1108	* have a clearly defined need to use and refcount the device
1109	* before it is added to the hierarchy.
1110	*
1111	* For more information, see the kerneldoc for device_initialize()
1112	* and device_add().
1113	*
1114	* NOTE: _Never_ directly free @dev after calling this function, even
1115	* if it returned an error! Always use put_device() to give up the
1116	* reference initialized in this function instead.
1117	*/
1118	int device_register(struct device *dev)
1119	{
1120	device_initialize(dev);
1121	return device_add(dev);
1122	}
1123
1124	/**
1125	* get_device - increment reference count for device.
1126	* @dev: device.
1127	*
1128	* This simply forwards the call to kobject_get(), though
1129	* we do take care to provide for the case that we get a NULL
1130	* pointer passed in.
1131	*/
1132	struct device get_device(struct device dev)
1133	{
1134	return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1135	}
1136
1137	/**
1138	* put_device - decrement reference count.
1139	* @dev: device in question.
1140	*/
1141	void put_device(struct device *dev)
1142	{
1143	/* might_sleep(); */
1144	if (dev)
1145	kobject_put(&dev->kobj);
1146	}
1147
1148	/**
1149	* device_del - delete device from system.
1150	* @dev: device.
1151	*
1152	* This is the first part of the device unregistration
1153	* sequence. This removes the device from the lists we control
1154	* from here, has it removed from the other driver model
1155	* subsystems it was added to in device_add(), and removes it
1156	* from the kobject hierarchy.
1157	*
1158	* NOTE: this should be called manually _iff_ device_add() was
1159	* also called manually.
1160	*/
1161	void device_del(struct device *dev)
1162	{
1163	struct device *parent = dev->parent;
1164	struct class_interface *class_intf;
1165
1166	/* Notify clients of device removal. This call must come
1167	* before dpm_sysfs_remove().
1168	*/
1169	if (dev->bus)
1170	blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1171	BUS_NOTIFY_DEL_DEVICE, dev);
1172	device_pm_remove(dev);
1173	dpm_sysfs_remove(dev);
1174	if (parent)
1175	klist_del(&dev->p->knode_parent);
1176	if (MAJOR(dev->devt)) {
1177	devtmpfs_delete_node(dev);
1178	device_remove_sys_dev_entry(dev);
1179	device_remove_file(dev, &devt_attr);
1180	}
1181	if (dev->class) {
1182	device_remove_class_symlinks(dev);
1183
1184	mutex_lock(&dev->class->p->mutex);
1185	/* notify any interfaces that the device is now gone */
1186	list_for_each_entry(class_intf,
1187	&dev->class->p->interfaces, node)
1188	if (class_intf->remove_dev)
1189	class_intf->remove_dev(dev, class_intf);
1190	/* remove the device from the class list */
1191	klist_del(&dev->knode_class);
1192	mutex_unlock(&dev->class->p->mutex);
1193	}
1194	device_remove_file(dev, &uevent_attr);
1195	device_remove_attrs(dev);
1196	bus_remove_device(dev);
1197	driver_deferred_probe_del(dev);
1198
1199	/*
1200	* Some platform devices are driven without driver attached
1201	* and managed resources may have been acquired. Make sure
1202	* all resources are released.
1203	*/
1204	devres_release_all(dev);
1205
1206	/* Notify the platform of the removal, in case they
1207	* need to do anything...
1208	*/
1209	if (platform_notify_remove)
1210	platform_notify_remove(dev);
1211	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1212	cleanup_device_parent(dev);
1213	kobject_del(&dev->kobj);
1214	put_device(parent);
1215	}
1216
1217	/**
1218	* device_unregister - unregister device from system.
1219	* @dev: device going away.
1220	*
1221	* We do this in two parts, like we do device_register(). First,
1222	* we remove it from all the subsystems with device_del(), then
1223	* we decrement the reference count via put_device(). If that
1224	* is the final reference count, the device will be cleaned up
1225	* via device_release() above. Otherwise, the structure will
1226	* stick around until the final reference to the device is dropped.
1227	*/
1228	void device_unregister(struct device *dev)
1229	{
1230	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1231	device_del(dev);
1232	put_device(dev);
1233	}
1234
1235	static struct device next_device(struct klist_iter i)
1236	{
1237	struct klist_node *n = klist_next(i);
1238	struct device *dev = NULL;
1239	struct device_private *p;
1240
1241	if (n) {
1242	p = to_device_private_parent(n);
1243	dev = p->device;
1244	}
1245	return dev;
1246	}
1247
1248	/**
1249	* device_get_devnode - path of device node file
1250	* @dev: device
1251	* @mode: returned file access mode
1252	* @tmp: possibly allocated string
1253	*
1254	* Return the relative path of a possible device node.
1255	* Non-default names may need to allocate a memory to compose
1256	* a name. This memory is returned in tmp and needs to be
1257	* freed by the caller.
1258	*/
1259	const char device_get_devnode(struct device dev,
1260	umode_t mode, const char *tmp)
1261	{
1262	char *s;
1263
1264	*tmp = NULL;
1265
1266	/* the device type may provide a specific name */
1267	if (dev->type && dev->type->devnode)
1268	*tmp = dev->type->devnode(dev, mode);
1269	if (*tmp)
1270	return *tmp;
1271
1272	/* the class may provide a specific name */
1273	if (dev->class && dev->class->devnode)
1274	*tmp = dev->class->devnode(dev, mode);
1275	if (*tmp)
1276	return *tmp;
1277
1278	/* return name without allocation, tmp == NULL */
1279	if (strchr(dev_name(dev), '!') == NULL)
1280	return dev_name(dev);
1281
1282	/* replace '!' in the name with '/' */
1283	*tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1284	if (!*tmp)
1285	return NULL;
1286	while ((s = strchr(*tmp, '!')))
1287	s[0] = '/';
1288	return *tmp;
1289	}
1290
1291	/**
1292	* device_for_each_child - device child iterator.
1293	* @parent: parent struct device.
1294	* @data: data for the callback.
1295	* @fn: function to be called for each device.
1296	*
1297	* Iterate over @parent's child devices, and call @fn for each,
1298	* passing it @data.
1299	*
1300	* We check the return of @fn each time. If it returns anything
1301	* other than 0, we break out and return that value.
1302	*/
1303	int device_for_each_child(struct device parent, void data,
1304	int (fn)(struct device dev, void *data))
1305	{
1306	struct klist_iter i;
1307	struct device *child;
1308	int error = 0;
1309
1310	if (!parent->p)
1311	return 0;
1312
1313	klist_iter_init(&parent->p->klist_children, &i);
1314	while ((child = next_device(&i)) && !error)
1315	error = fn(child, data);
1316	klist_iter_exit(&i);
1317	return error;
1318	}
1319
1320	/**
1321	* device_find_child - device iterator for locating a particular device.
1322	* @parent: parent struct device
1323	* @data: Data to pass to match function
1324	* @match: Callback function to check device
1325	*
1326	* This is similar to the device_for_each_child() function above, but it
1327	* returns a reference to a device that is 'found' for later use, as
1328	* determined by the @match callback.
1329	*
1330	* The callback should return 0 if the device doesn't match and non-zero
1331	* if it does. If the callback returns non-zero and a reference to the
1332	* current device can be obtained, this function will return to the caller
1333	* and not iterate over any more devices.
1334	*/
1335	struct device device_find_child(struct device parent, void *data,
1336	int (match)(struct device dev, void *data))
1337	{
1338	struct klist_iter i;
1339	struct device *child;
1340
1341	if (!parent)
1342	return NULL;
1343
1344	klist_iter_init(&parent->p->klist_children, &i);
1345	while ((child = next_device(&i)))
1346	if (match(child, data) && get_device(child))
1347	break;
1348	klist_iter_exit(&i);
1349	return child;
1350	}
1351
1352	int __init devices_init(void)
1353	{
1354	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1355	if (!devices_kset)
1356	return -ENOMEM;
1357	dev_kobj = kobject_create_and_add("dev", NULL);
1358	if (!dev_kobj)
1359	goto dev_kobj_err;
1360	sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1361	if (!sysfs_dev_block_kobj)
1362	goto block_kobj_err;
1363	sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1364	if (!sysfs_dev_char_kobj)
1365	goto char_kobj_err;
1366
1367	return 0;
1368
1369	char_kobj_err:
1370	kobject_put(sysfs_dev_block_kobj);
1371	block_kobj_err:
1372	kobject_put(dev_kobj);
1373	dev_kobj_err:
1374	kset_unregister(devices_kset);
1375	return -ENOMEM;
1376	}
1377
1378	EXPORT_SYMBOL_GPL(device_for_each_child);
1379	EXPORT_SYMBOL_GPL(device_find_child);
1380
1381	EXPORT_SYMBOL_GPL(device_initialize);
1382	EXPORT_SYMBOL_GPL(device_add);
1383	EXPORT_SYMBOL_GPL(device_register);
1384
1385	EXPORT_SYMBOL_GPL(device_del);
1386	EXPORT_SYMBOL_GPL(device_unregister);
1387	EXPORT_SYMBOL_GPL(get_device);
1388	EXPORT_SYMBOL_GPL(put_device);
1389
1390	EXPORT_SYMBOL_GPL(device_create_file);
1391	EXPORT_SYMBOL_GPL(device_remove_file);
1392
1393	struct root_device {
1394	struct device dev;
1395	struct module *owner;
1396	};
1397
1398	inline struct root_device to_root_device(struct device d)
1399	{
1400	return container_of(d, struct root_device, dev);
1401	}
1402
1403	static void root_device_release(struct device *dev)
1404	{
1405	kfree(to_root_device(dev));
1406	}
1407
1408	/**
1409	* __root_device_register - allocate and register a root device
1410	* @name: root device name
1411	* @owner: owner module of the root device, usually THIS_MODULE
1412	*
1413	* This function allocates a root device and registers it
1414	* using device_register(). In order to free the returned
1415	* device, use root_device_unregister().
1416	*
1417	* Root devices are dummy devices which allow other devices
1418	* to be grouped under /sys/devices. Use this function to
1419	* allocate a root device and then use it as the parent of
1420	* any device which should appear under /sys/devices/{name}
1421	*
1422	* The /sys/devices/{name} directory will also contain a
1423	* 'module' symlink which points to the @owner directory
1424	* in sysfs.
1425	*
1426	* Returns &struct device pointer on success, or ERR_PTR() on error.
1427	*
1428	* Note: You probably want to use root_device_register().
1429	*/
1430	struct device __root_device_register(const char name, struct module *owner)
1431	{
1432	struct root_device *root;
1433	int err = -ENOMEM;
1434
1435	root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1436	if (!root)
1437	return ERR_PTR(err);
1438
1439	err = dev_set_name(&root->dev, "%s", name);
1440	if (err) {
1441	kfree(root);
1442	return ERR_PTR(err);
1443	}
1444
1445	root->dev.release = root_device_release;
1446
1447	err = device_register(&root->dev);
1448	if (err) {
1449	put_device(&root->dev);
1450	return ERR_PTR(err);
1451	}
1452
1453	#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1454	if (owner) {
1455	struct module_kobject *mk = &owner->mkobj;
1456
1457	err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1458	if (err) {
1459	device_unregister(&root->dev);
1460	return ERR_PTR(err);
1461	}
1462	root->owner = owner;
1463	}
1464	#endif
1465
1466	return &root->dev;
1467	}
1468	EXPORT_SYMBOL_GPL(__root_device_register);
1469
1470	/**
1471	* root_device_unregister - unregister and free a root device
1472	* @dev: device going away
1473	*
1474	* This function unregisters and cleans up a device that was created by
1475	* root_device_register().
1476	*/
1477	void root_device_unregister(struct device *dev)
1478	{
1479	struct root_device *root = to_root_device(dev);
1480
1481	if (root->owner)
1482	sysfs_remove_link(&root->dev.kobj, "module");
1483
1484	device_unregister(dev);
1485	}
1486	EXPORT_SYMBOL_GPL(root_device_unregister);
1487
1488
1489	static void device_create_release(struct device *dev)
1490	{
1491	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1492	kfree(dev);
1493	}
1494
1495	/**
1496	* device_create_vargs - creates a device and registers it with sysfs
1497	* @class: pointer to the struct class that this device should be registered to
1498	* @parent: pointer to the parent struct device of this new device, if any
1499	* @devt: the dev_t for the char device to be added
1500	* @drvdata: the data to be added to the device for callbacks
1501	* @fmt: string for the device's name
1502	* @args: va_list for the device's name
1503	*
1504	* This function can be used by char device classes. A struct device
1505	* will be created in sysfs, registered to the specified class.
1506	*
1507	* A "dev" file will be created, showing the dev_t for the device, if
1508	* the dev_t is not 0,0.
1509	* If a pointer to a parent struct device is passed in, the newly created
1510	* struct device will be a child of that device in sysfs.
1511	* The pointer to the struct device will be returned from the call.
1512	* Any further sysfs files that might be required can be created using this
1513	* pointer.
1514	*
1515	* Returns &struct device pointer on success, or ERR_PTR() on error.
1516	*
1517	* Note: the struct class passed to this function must have previously
1518	* been created with a call to class_create().
1519	*/
1520	struct device device_create_vargs(struct class class, struct device *parent,
1521	dev_t devt, void drvdata, const char fmt,
1522	va_list args)
1523	{
1524	struct device *dev = NULL;
1525	int retval = -ENODEV;
1526
1527	if (class == NULL \|\| IS_ERR(class))
1528	goto error;
1529
1530	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1531	if (!dev) {
1532	retval = -ENOMEM;
1533	goto error;
1534	}
1535
1536	dev->devt = devt;
1537	dev->class = class;
1538	dev->parent = parent;
1539	dev->release = device_create_release;
1540	dev_set_drvdata(dev, drvdata);
1541
1542	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1543	if (retval)
1544	goto error;
1545
1546	retval = device_register(dev);
1547	if (retval)
1548	goto error;
1549
1550	return dev;
1551
1552	error:
1553	put_device(dev);
1554	return ERR_PTR(retval);
1555	}
1556	EXPORT_SYMBOL_GPL(device_create_vargs);
1557
1558	/**
1559	* device_create - creates a device and registers it with sysfs
1560	* @class: pointer to the struct class that this device should be registered to
1561	* @parent: pointer to the parent struct device of this new device, if any
1562	* @devt: the dev_t for the char device to be added
1563	* @drvdata: the data to be added to the device for callbacks
1564	* @fmt: string for the device's name
1565	*
1566	* This function can be used by char device classes. A struct device
1567	* will be created in sysfs, registered to the specified class.
1568	*
1569	* A "dev" file will be created, showing the dev_t for the device, if
1570	* the dev_t is not 0,0.
1571	* If a pointer to a parent struct device is passed in, the newly created
1572	* struct device will be a child of that device in sysfs.
1573	* The pointer to the struct device will be returned from the call.
1574	* Any further sysfs files that might be required can be created using this
1575	* pointer.
1576	*
1577	* Returns &struct device pointer on success, or ERR_PTR() on error.
1578	*
1579	* Note: the struct class passed to this function must have previously
1580	* been created with a call to class_create().
1581	*/
1582	struct device device_create(struct class class, struct device *parent,
1583	dev_t devt, void drvdata, const char fmt, ...)
1584	{
1585	va_list vargs;
1586	struct device *dev;
1587
1588	va_start(vargs, fmt);
1589	dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1590	va_end(vargs);
1591	return dev;
1592	}
1593	EXPORT_SYMBOL_GPL(device_create);
1594
1595	static int __match_devt(struct device dev, void data)
1596	{
1597	dev_t *devt = data;
1598
1599	return dev->devt == *devt;
1600	}
1601
1602	/**
1603	* device_destroy - removes a device that was created with device_create()
1604	* @class: pointer to the struct class that this device was registered with
1605	* @devt: the dev_t of the device that was previously registered
1606	*
1607	* This call unregisters and cleans up a device that was created with a
1608	* call to device_create().
1609	*/
1610	void device_destroy(struct class *class, dev_t devt)
1611	{
1612	struct device *dev;
1613
1614	dev = class_find_device(class, NULL, &devt, __match_devt);
1615	if (dev) {
1616	put_device(dev);
1617	device_unregister(dev);
1618	}
1619	}
1620	EXPORT_SYMBOL_GPL(device_destroy);
1621
1622	/**
1623	* device_rename - renames a device
1624	* @dev: the pointer to the struct device to be renamed
1625	* @new_name: the new name of the device
1626	*
1627	* It is the responsibility of the caller to provide mutual
1628	* exclusion between two different calls of device_rename
1629	* on the same device to ensure that new_name is valid and
1630	* won't conflict with other devices.
1631	*
1632	* Note: Don't call this function. Currently, the networking layer calls this
1633	* function, but that will change. The following text from Kay Sievers offers
1634	* some insight:
1635	*
1636	* Renaming devices is racy at many levels, symlinks and other stuff are not
1637	* replaced atomically, and you get a "move" uevent, but it's not easy to
1638	* connect the event to the old and new device. Device nodes are not renamed at
1639	* all, there isn't even support for that in the kernel now.
1640	*
1641	* In the meantime, during renaming, your target name might be taken by another
1642	* driver, creating conflicts. Or the old name is taken directly after you
1643	* renamed it -- then you get events for the same DEVPATH, before you even see
1644	* the "move" event. It's just a mess, and nothing new should ever rely on
1645	* kernel device renaming. Besides that, it's not even implemented now for
1646	* other things than (driver-core wise very simple) network devices.
1647	*
1648	* We are currently about to change network renaming in udev to completely
1649	* disallow renaming of devices in the same namespace as the kernel uses,
1650	* because we can't solve the problems properly, that arise with swapping names
1651	* of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1652	* be allowed to some other name than eth[0-9]*, for the aforementioned
1653	* reasons.
1654	*
1655	* Make up a "real" name in the driver before you register anything, or add
1656	* some other attributes for userspace to find the device, or use udev to add
1657	* symlinks -- but never rename kernel devices later, it's a complete mess. We
1658	* don't even want to get into that and try to implement the missing pieces in
1659	* the core. We really have other pieces to fix in the driver core mess. :)
1660	*/
1661	int device_rename(struct device dev, const char new_name)
1662	{
1663	char *old_class_name = NULL;
1664	char *new_class_name = NULL;
1665	char *old_device_name = NULL;
1666	int error;
1667
1668	dev = get_device(dev);
1669	if (!dev)
1670	return -EINVAL;
1671
1672	pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1673	__func__, new_name);
1674
1675	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1676	if (!old_device_name) {
1677	error = -ENOMEM;
1678	goto out;
1679	}
1680
1681	if (dev->class) {
1682	error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1683	&dev->kobj, old_device_name, new_name);
1684	if (error)
1685	goto out;
1686	}
1687
1688	error = kobject_rename(&dev->kobj, new_name);
1689	if (error)
1690	goto out;
1691
1692	out:
1693	put_device(dev);
1694
1695	kfree(new_class_name);
1696	kfree(old_class_name);
1697	kfree(old_device_name);
1698
1699	return error;
1700	}
1701	EXPORT_SYMBOL_GPL(device_rename);
1702
1703	static int device_move_class_links(struct device *dev,
1704	struct device *old_parent,
1705	struct device *new_parent)
1706	{
1707	int error = 0;
1708
1709	if (old_parent)
1710	sysfs_remove_link(&dev->kobj, "device");
1711	if (new_parent)
1712	error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1713	"device");
1714	return error;
1715	}
1716
1717	/**
1718	* device_move - moves a device to a new parent
1719	* @dev: the pointer to the struct device to be moved
1720	* @new_parent: the new parent of the device (can by NULL)
1721	* @dpm_order: how to reorder the dpm_list
1722	*/
1723	int device_move(struct device dev, struct device new_parent,
1724	enum dpm_order dpm_order)
1725	{
1726	int error;
1727	struct device *old_parent;
1728	struct kobject *new_parent_kobj;
1729
1730	dev = get_device(dev);
1731	if (!dev)
1732	return -EINVAL;
1733
1734	device_pm_lock();
1735	new_parent = get_device(new_parent);
1736	new_parent_kobj = get_device_parent(dev, new_parent);
1737
1738	pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1739	__func__, new_parent ? dev_name(new_parent) : "<NULL>");
1740	error = kobject_move(&dev->kobj, new_parent_kobj);
1741	if (error) {
1742	cleanup_glue_dir(dev, new_parent_kobj);
1743	put_device(new_parent);
1744	goto out;
1745	}
1746	old_parent = dev->parent;
1747	dev->parent = new_parent;
1748	if (old_parent)
1749	klist_remove(&dev->p->knode_parent);
1750	if (new_parent) {
1751	klist_add_tail(&dev->p->knode_parent,
1752	&new_parent->p->klist_children);
1753	set_dev_node(dev, dev_to_node(new_parent));
1754	}
1755
1756	if (dev->class) {
1757	error = device_move_class_links(dev, old_parent, new_parent);
1758	if (error) {
1759	/* We ignore errors on cleanup since we're hosed anyway... */
1760	device_move_class_links(dev, new_parent, old_parent);
1761	if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1762	if (new_parent)
1763	klist_remove(&dev->p->knode_parent);
1764	dev->parent = old_parent;
1765	if (old_parent) {
1766	klist_add_tail(&dev->p->knode_parent,
1767	&old_parent->p->klist_children);
1768	set_dev_node(dev, dev_to_node(old_parent));
1769	}
1770	}
1771	cleanup_glue_dir(dev, new_parent_kobj);
1772	put_device(new_parent);
1773	goto out;
1774	}
1775	}
1776	switch (dpm_order) {
1777	case DPM_ORDER_NONE:
1778	break;
1779	case DPM_ORDER_DEV_AFTER_PARENT:
1780	device_pm_move_after(dev, new_parent);
1781	break;
1782	case DPM_ORDER_PARENT_BEFORE_DEV:
1783	device_pm_move_before(new_parent, dev);
1784	break;
1785	case DPM_ORDER_DEV_LAST:
1786	device_pm_move_last(dev);
1787	break;
1788	}
1789
1790	put_device(old_parent);
1791	out:
1792	device_pm_unlock();
1793	put_device(dev);
1794	return error;
1795	}
1796	EXPORT_SYMBOL_GPL(device_move);
1797
1798	/**
1799	* device_shutdown - call ->shutdown() on each device to shutdown.
1800	*/
1801	void device_shutdown(void)
1802	{
1803	struct device *dev;
1804
1805	spin_lock(&devices_kset->list_lock);
1806	/*
1807	* Walk the devices list backward, shutting down each in turn.
1808	* Beware that device unplug events may also start pulling
1809	* devices offline, even as the system is shutting down.
1810	*/
1811	while (!list_empty(&devices_kset->list)) {
1812	dev = list_entry(devices_kset->list.prev, struct device,
1813	kobj.entry);
1814
1815	/*
1816	* hold reference count of device's parent to
1817	* prevent it from being freed because parent's
1818	* lock is to be held
1819	*/
1820	get_device(dev->parent);
1821	get_device(dev);
1822	/*
1823	* Make sure the device is off the kset list, in the
1824	* event that dev->*->shutdown() doesn't remove it.
1825	*/
1826	list_del_init(&dev->kobj.entry);
1827	spin_unlock(&devices_kset->list_lock);
1828
1829	/* hold lock to avoid race with probe/release */
1830	if (dev->parent)
1831	device_lock(dev->parent);
1832	device_lock(dev);
1833
1834	/* Don't allow any more runtime suspends */
1835	pm_runtime_get_noresume(dev);
1836	pm_runtime_barrier(dev);
1837
1838	if (dev->bus && dev->bus->shutdown) {
1839	dev_dbg(dev, "shutdown\n");
1840	dev->bus->shutdown(dev);
1841	} else if (dev->driver && dev->driver->shutdown) {
1842	dev_dbg(dev, "shutdown\n");
1843	dev->driver->shutdown(dev);
1844	}
1845
1846	device_unlock(dev);
1847	if (dev->parent)
1848	device_unlock(dev->parent);
1849
1850	put_device(dev);
1851	put_device(dev->parent);
1852
1853	spin_lock(&devices_kset->list_lock);
1854	}
1855	spin_unlock(&devices_kset->list_lock);
1856	async_synchronize_full();
1857	}
1858
1859	/*
1860	* Device logging functions
1861	*/
1862
1863	#ifdef CONFIG_PRINTK
1864	int __dev_printk(const char level, const struct device dev,
1865	struct va_format *vaf)
1866	{
1867	char dict[128];
1868	const char *level_extra = "";
1869	size_t dictlen = 0;
1870	const char *subsys;
1871
1872	if (!dev)
1873	return printk("%s(NULL device *): %pV", level, vaf);
1874
1875	if (dev->class)
1876	subsys = dev->class->name;
1877	else if (dev->bus)
1878	subsys = dev->bus->name;
1879	else
1880	goto skip;
1881
1882	dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
1883	"SUBSYSTEM=%s", subsys);
1884
1885	/*
1886	* Add device identifier DEVICE=:
1887	* b12:8 block dev_t
1888	* c127:3 char dev_t
1889	* n8 netdev ifindex
1890	* +sound:card0 subsystem:devname
1891	*/
1892	if (MAJOR(dev->devt)) {
1893	char c;
1894
1895	if (strcmp(subsys, "block") == 0)
1896	c = 'b';
1897	else
1898	c = 'c';
1899	dictlen++;
1900	dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
1901	"DEVICE=%c%u:%u",
1902	c, MAJOR(dev->devt), MINOR(dev->devt));
1903	} else if (strcmp(subsys, "net") == 0) {
1904	struct net_device *net = to_net_dev(dev);
1905
1906	dictlen++;
1907	dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
1908	"DEVICE=n%u", net->ifindex);
1909	} else {
1910	dictlen++;
1911	dictlen += snprintf(dict + dictlen, sizeof(dict) - dictlen,
1912	"DEVICE=+%s:%s", subsys, dev_name(dev));
1913	}
1914	skip:
1915	if (level[2])
1916	level_extra = &level[2]; /* skip past KERN_SOH "L" */
1917
1918	return printk_emit(0, level[1] - '0',
1919	dictlen ? dict : NULL, dictlen,
1920	"%s %s: %s%pV",
1921	dev_driver_string(dev), dev_name(dev),
1922	level_extra, vaf);
1923	}
1924	EXPORT_SYMBOL(__dev_printk);
1925
1926	int dev_printk(const char level, const struct device dev,
1927	const char *fmt, ...)
1928	{
1929	struct va_format vaf;
1930	va_list args;
1931	int r;
1932
1933	va_start(args, fmt);
1934
1935	vaf.fmt = fmt;
1936	vaf.va = &args;
1937
1938	r = __dev_printk(level, dev, &vaf);
1939	va_end(args);
1940
1941	return r;
1942	}
1943	EXPORT_SYMBOL(dev_printk);
1944
1945	#define define_dev_printk_level(func, kern_level) \
1946	int func(const struct device dev, const char fmt, ...) \
1947	{ \
1948	struct va_format vaf; \
1949	va_list args; \
1950	int r; \
1951	\
1952	va_start(args, fmt); \
1953	\
1954	vaf.fmt = fmt; \
1955	vaf.va = &args; \
1956	\
1957	r = __dev_printk(kern_level, dev, &vaf); \
1958	va_end(args); \
1959	\
1960	return r; \
1961	} \
1962	EXPORT_SYMBOL(func);
1963
1964	define_dev_printk_level(dev_emerg, KERN_EMERG);
1965	define_dev_printk_level(dev_alert, KERN_ALERT);
1966	define_dev_printk_level(dev_crit, KERN_CRIT);
1967	define_dev_printk_level(dev_err, KERN_ERR);
1968	define_dev_printk_level(dev_warn, KERN_WARNING);
1969	define_dev_printk_level(dev_notice, KERN_NOTICE);
1970	define_dev_printk_level(_dev_info, KERN_INFO);
1971
1972	#endif
1973

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