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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/genhd.h>
22#include <linux/kallsyms.h>
23#include <linux/mutex.h>
24#include <linux/async.h>
25
26#include "base.h"
27#include "power/power.h"
28
29#ifdef CONFIG_SYSFS_DEPRECATED
30#ifdef CONFIG_SYSFS_DEPRECATED_V2
31long sysfs_deprecated = 1;
32#else
33long sysfs_deprecated = 0;
34#endif
35static __init int sysfs_deprecated_setup(char *arg)
36{
37 return strict_strtol(arg, 10, &sysfs_deprecated);
38}
39early_param("sysfs.deprecated", sysfs_deprecated_setup);
40#endif
41
42int (*platform_notify)(struct device *dev) = NULL;
43int (*platform_notify_remove)(struct device *dev) = NULL;
44static struct kobject *dev_kobj;
45struct kobject *sysfs_dev_char_kobj;
46struct kobject *sysfs_dev_block_kobj;
47
48#ifdef CONFIG_BLOCK
49static inline int device_is_not_partition(struct device *dev)
50{
51 return !(dev->type == &part_type);
52}
53#else
54static inline int device_is_not_partition(struct device *dev)
55{
56 return 1;
57}
58#endif
59
60/**
61 * dev_driver_string - Return a device's driver name, if at all possible
62 * @dev: struct device to get the name of
63 *
64 * Will return the device's driver's name if it is bound to a device. If
65 * the device is not bound to a device, it will return the name of the bus
66 * it is attached to. If it is not attached to a bus either, an empty
67 * string will be returned.
68 */
69const char *dev_driver_string(const struct device *dev)
70{
71 struct device_driver *drv;
72
73 /* dev->driver can change to NULL underneath us because of unbinding,
74 * so be careful about accessing it. dev->bus and dev->class should
75 * never change once they are set, so they don't need special care.
76 */
77 drv = ACCESS_ONCE(dev->driver);
78 return drv ? drv->name :
79 (dev->bus ? dev->bus->name :
80 (dev->class ? dev->class->name : ""));
81}
82EXPORT_SYMBOL(dev_driver_string);
83
84#define to_dev(obj) container_of(obj, struct device, kobj)
85#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
86
87static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
88 char *buf)
89{
90 struct device_attribute *dev_attr = to_dev_attr(attr);
91 struct device *dev = to_dev(kobj);
92 ssize_t ret = -EIO;
93
94 if (dev_attr->show)
95 ret = dev_attr->show(dev, dev_attr, buf);
96 if (ret >= (ssize_t)PAGE_SIZE) {
97 print_symbol("dev_attr_show: %s returned bad count\n",
98 (unsigned long)dev_attr->show);
99 }
100 return ret;
101}
102
103static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
104 const char *buf, size_t count)
105{
106 struct device_attribute *dev_attr = to_dev_attr(attr);
107 struct device *dev = to_dev(kobj);
108 ssize_t ret = -EIO;
109
110 if (dev_attr->store)
111 ret = dev_attr->store(dev, dev_attr, buf, count);
112 return ret;
113}
114
115static const struct sysfs_ops dev_sysfs_ops = {
116 .show = dev_attr_show,
117 .store = dev_attr_store,
118};
119
120
121/**
122 * device_release - free device structure.
123 * @kobj: device's kobject.
124 *
125 * This is called once the reference count for the object
126 * reaches 0. We forward the call to the device's release
127 * method, which should handle actually freeing the structure.
128 */
129static void device_release(struct kobject *kobj)
130{
131 struct device *dev = to_dev(kobj);
132 struct device_private *p = dev->p;
133
134 if (dev->release)
135 dev->release(dev);
136 else if (dev->type && dev->type->release)
137 dev->type->release(dev);
138 else if (dev->class && dev->class->dev_release)
139 dev->class->dev_release(dev);
140 else
141 WARN(1, KERN_ERR "Device '%s' does not have a release() "
142 "function, it is broken and must be fixed.\n",
143 dev_name(dev));
144 kfree(p);
145}
146
147static const void *device_namespace(struct kobject *kobj)
148{
149 struct device *dev = to_dev(kobj);
150 const void *ns = NULL;
151
152 if (dev->class && dev->class->ns_type)
153 ns = dev->class->namespace(dev);
154
155 return ns;
156}
157
158static struct kobj_type device_ktype = {
159 .release = device_release,
160 .sysfs_ops = &dev_sysfs_ops,
161 .namespace = device_namespace,
162};
163
164
165static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
166{
167 struct kobj_type *ktype = get_ktype(kobj);
168
169 if (ktype == &device_ktype) {
170 struct device *dev = to_dev(kobj);
171 if (dev->bus)
172 return 1;
173 if (dev->class)
174 return 1;
175 }
176 return 0;
177}
178
179static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
180{
181 struct device *dev = to_dev(kobj);
182
183 if (dev->bus)
184 return dev->bus->name;
185 if (dev->class)
186 return dev->class->name;
187 return NULL;
188}
189
190static int dev_uevent(struct kset *kset, struct kobject *kobj,
191 struct kobj_uevent_env *env)
192{
193 struct device *dev = to_dev(kobj);
194 int retval = 0;
195
196 /* add device node properties if present */
197 if (MAJOR(dev->devt)) {
198 const char *tmp;
199 const char *name;
200 mode_t mode = 0;
201
202 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
203 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
204 name = device_get_devnode(dev, &mode, &tmp);
205 if (name) {
206 add_uevent_var(env, "DEVNAME=%s", name);
207 kfree(tmp);
208 if (mode)
209 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
210 }
211 }
212
213 if (dev->type && dev->type->name)
214 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
215
216 if (dev->driver)
217 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
218
219 /* have the bus specific function add its stuff */
220 if (dev->bus && dev->bus->uevent) {
221 retval = dev->bus->uevent(dev, env);
222 if (retval)
223 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
224 dev_name(dev), __func__, retval);
225 }
226
227 /* have the class specific function add its stuff */
228 if (dev->class && dev->class->dev_uevent) {
229 retval = dev->class->dev_uevent(dev, env);
230 if (retval)
231 pr_debug("device: '%s': %s: class uevent() "
232 "returned %d\n", dev_name(dev),
233 __func__, retval);
234 }
235
236 /* have the device type specific function add its stuff */
237 if (dev->type && dev->type->uevent) {
238 retval = dev->type->uevent(dev, env);
239 if (retval)
240 pr_debug("device: '%s': %s: dev_type uevent() "
241 "returned %d\n", dev_name(dev),
242 __func__, retval);
243 }
244
245 return retval;
246}
247
248static const struct kset_uevent_ops device_uevent_ops = {
249 .filter = dev_uevent_filter,
250 .name = dev_uevent_name,
251 .uevent = dev_uevent,
252};
253
254static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
255 char *buf)
256{
257 struct kobject *top_kobj;
258 struct kset *kset;
259 struct kobj_uevent_env *env = NULL;
260 int i;
261 size_t count = 0;
262 int retval;
263
264 /* search the kset, the device belongs to */
265 top_kobj = &dev->kobj;
266 while (!top_kobj->kset && top_kobj->parent)
267 top_kobj = top_kobj->parent;
268 if (!top_kobj->kset)
269 goto out;
270
271 kset = top_kobj->kset;
272 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
273 goto out;
274
275 /* respect filter */
276 if (kset->uevent_ops && kset->uevent_ops->filter)
277 if (!kset->uevent_ops->filter(kset, &dev->kobj))
278 goto out;
279
280 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
281 if (!env)
282 return -ENOMEM;
283
284 /* let the kset specific function add its keys */
285 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
286 if (retval)
287 goto out;
288
289 /* copy keys to file */
290 for (i = 0; i < env->envp_idx; i++)
291 count += sprintf(&buf[count], "%s\n", env->envp[i]);
292out:
293 kfree(env);
294 return count;
295}
296
297static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
298 const char *buf, size_t count)
299{
300 enum kobject_action action;
301
302 if (kobject_action_type(buf, count, &action) == 0)
303 kobject_uevent(&dev->kobj, action);
304 else
305 dev_err(dev, "uevent: unknown action-string\n");
306 return count;
307}
308
309static struct device_attribute uevent_attr =
310 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
311
312static int device_add_attributes(struct device *dev,
313 struct device_attribute *attrs)
314{
315 int error = 0;
316 int i;
317
318 if (attrs) {
319 for (i = 0; attr_name(attrs[i]); i++) {
320 error = device_create_file(dev, &attrs[i]);
321 if (error)
322 break;
323 }
324 if (error)
325 while (--i >= 0)
326 device_remove_file(dev, &attrs[i]);
327 }
328 return error;
329}
330
331static void device_remove_attributes(struct device *dev,
332 struct device_attribute *attrs)
333{
334 int i;
335
336 if (attrs)
337 for (i = 0; attr_name(attrs[i]); i++)
338 device_remove_file(dev, &attrs[i]);
339}
340
341static int device_add_bin_attributes(struct device *dev,
342 struct bin_attribute *attrs)
343{
344 int error = 0;
345 int i;
346
347 if (attrs) {
348 for (i = 0; attr_name(attrs[i]); i++) {
349 error = device_create_bin_file(dev, &attrs[i]);
350 if (error)
351 break;
352 }
353 if (error)
354 while (--i >= 0)
355 device_remove_bin_file(dev, &attrs[i]);
356 }
357 return error;
358}
359
360static void device_remove_bin_attributes(struct device *dev,
361 struct bin_attribute *attrs)
362{
363 int i;
364
365 if (attrs)
366 for (i = 0; attr_name(attrs[i]); i++)
367 device_remove_bin_file(dev, &attrs[i]);
368}
369
370static int device_add_groups(struct device *dev,
371 const struct attribute_group **groups)
372{
373 int error = 0;
374 int i;
375
376 if (groups) {
377 for (i = 0; groups[i]; i++) {
378 error = sysfs_create_group(&dev->kobj, groups[i]);
379 if (error) {
380 while (--i >= 0)
381 sysfs_remove_group(&dev->kobj,
382 groups[i]);
383 break;
384 }
385 }
386 }
387 return error;
388}
389
390static void device_remove_groups(struct device *dev,
391 const struct attribute_group **groups)
392{
393 int i;
394
395 if (groups)
396 for (i = 0; groups[i]; i++)
397 sysfs_remove_group(&dev->kobj, groups[i]);
398}
399
400static int device_add_attrs(struct device *dev)
401{
402 struct class *class = dev->class;
403 const struct device_type *type = dev->type;
404 int error;
405
406 if (class) {
407 error = device_add_attributes(dev, class->dev_attrs);
408 if (error)
409 return error;
410 error = device_add_bin_attributes(dev, class->dev_bin_attrs);
411 if (error)
412 goto err_remove_class_attrs;
413 }
414
415 if (type) {
416 error = device_add_groups(dev, type->groups);
417 if (error)
418 goto err_remove_class_bin_attrs;
419 }
420
421 error = device_add_groups(dev, dev->groups);
422 if (error)
423 goto err_remove_type_groups;
424
425 return 0;
426
427 err_remove_type_groups:
428 if (type)
429 device_remove_groups(dev, type->groups);
430 err_remove_class_bin_attrs:
431 if (class)
432 device_remove_bin_attributes(dev, class->dev_bin_attrs);
433 err_remove_class_attrs:
434 if (class)
435 device_remove_attributes(dev, class->dev_attrs);
436
437 return error;
438}
439
440static void device_remove_attrs(struct device *dev)
441{
442 struct class *class = dev->class;
443 const struct device_type *type = dev->type;
444
445 device_remove_groups(dev, dev->groups);
446
447 if (type)
448 device_remove_groups(dev, type->groups);
449
450 if (class) {
451 device_remove_attributes(dev, class->dev_attrs);
452 device_remove_bin_attributes(dev, class->dev_bin_attrs);
453 }
454}
455
456
457static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
458 char *buf)
459{
460 return print_dev_t(buf, dev->devt);
461}
462
463static struct device_attribute devt_attr =
464 __ATTR(dev, S_IRUGO, show_dev, NULL);
465
466/* kset to create /sys/devices/ */
467struct kset *devices_kset;
468
469/**
470 * device_create_file - create sysfs attribute file for device.
471 * @dev: device.
472 * @attr: device attribute descriptor.
473 */
474int device_create_file(struct device *dev,
475 const struct device_attribute *attr)
476{
477 int error = 0;
478 if (dev)
479 error = sysfs_create_file(&dev->kobj, &attr->attr);
480 return error;
481}
482
483/**
484 * device_remove_file - remove sysfs attribute file.
485 * @dev: device.
486 * @attr: device attribute descriptor.
487 */
488void device_remove_file(struct device *dev,
489 const struct device_attribute *attr)
490{
491 if (dev)
492 sysfs_remove_file(&dev->kobj, &attr->attr);
493}
494
495/**
496 * device_create_bin_file - create sysfs binary attribute file for device.
497 * @dev: device.
498 * @attr: device binary attribute descriptor.
499 */
500int device_create_bin_file(struct device *dev,
501 const struct bin_attribute *attr)
502{
503 int error = -EINVAL;
504 if (dev)
505 error = sysfs_create_bin_file(&dev->kobj, attr);
506 return error;
507}
508EXPORT_SYMBOL_GPL(device_create_bin_file);
509
510/**
511 * device_remove_bin_file - remove sysfs binary attribute file
512 * @dev: device.
513 * @attr: device binary attribute descriptor.
514 */
515void device_remove_bin_file(struct device *dev,
516 const struct bin_attribute *attr)
517{
518 if (dev)
519 sysfs_remove_bin_file(&dev->kobj, attr);
520}
521EXPORT_SYMBOL_GPL(device_remove_bin_file);
522
523/**
524 * device_schedule_callback_owner - helper to schedule a callback for a device
525 * @dev: device.
526 * @func: callback function to invoke later.
527 * @owner: module owning the callback routine
528 *
529 * Attribute methods must not unregister themselves or their parent device
530 * (which would amount to the same thing). Attempts to do so will deadlock,
531 * since unregistration is mutually exclusive with driver callbacks.
532 *
533 * Instead methods can call this routine, which will attempt to allocate
534 * and schedule a workqueue request to call back @func with @dev as its
535 * argument in the workqueue's process context. @dev will be pinned until
536 * @func returns.
537 *
538 * This routine is usually called via the inline device_schedule_callback(),
539 * which automatically sets @owner to THIS_MODULE.
540 *
541 * Returns 0 if the request was submitted, -ENOMEM if storage could not
542 * be allocated, -ENODEV if a reference to @owner isn't available.
543 *
544 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
545 * underlying sysfs routine (since it is intended for use by attribute
546 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
547 */
548int device_schedule_callback_owner(struct device *dev,
549 void (*func)(struct device *), struct module *owner)
550{
551 return sysfs_schedule_callback(&dev->kobj,
552 (void (*)(void *)) func, dev, owner);
553}
554EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
555
556static void klist_children_get(struct klist_node *n)
557{
558 struct device_private *p = to_device_private_parent(n);
559 struct device *dev = p->device;
560
561 get_device(dev);
562}
563
564static void klist_children_put(struct klist_node *n)
565{
566 struct device_private *p = to_device_private_parent(n);
567 struct device *dev = p->device;
568
569 put_device(dev);
570}
571
572/**
573 * device_initialize - init device structure.
574 * @dev: device.
575 *
576 * This prepares the device for use by other layers by initializing
577 * its fields.
578 * It is the first half of device_register(), if called by
579 * that function, though it can also be called separately, so one
580 * may use @dev's fields. In particular, get_device()/put_device()
581 * may be used for reference counting of @dev after calling this
582 * function.
583 *
584 * NOTE: Use put_device() to give up your reference instead of freeing
585 * @dev directly once you have called this function.
586 */
587void device_initialize(struct device *dev)
588{
589 dev->kobj.kset = devices_kset;
590 kobject_init(&dev->kobj, &device_ktype);
591 INIT_LIST_HEAD(&dev->dma_pools);
592 mutex_init(&dev->mutex);
593 lockdep_set_novalidate_class(&dev->mutex);
594 spin_lock_init(&dev->devres_lock);
595 INIT_LIST_HEAD(&dev->devres_head);
596 device_pm_init(dev);
597 set_dev_node(dev, -1);
598}
599
600static struct kobject *virtual_device_parent(struct device *dev)
601{
602 static struct kobject *virtual_dir = NULL;
603
604 if (!virtual_dir)
605 virtual_dir = kobject_create_and_add("virtual",
606 &devices_kset->kobj);
607
608 return virtual_dir;
609}
610
611struct class_dir {
612 struct kobject kobj;
613 struct class *class;
614};
615
616#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
617
618static void class_dir_release(struct kobject *kobj)
619{
620 struct class_dir *dir = to_class_dir(kobj);
621 kfree(dir);
622}
623
624static const
625struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
626{
627 struct class_dir *dir = to_class_dir(kobj);
628 return dir->class->ns_type;
629}
630
631static struct kobj_type class_dir_ktype = {
632 .release = class_dir_release,
633 .sysfs_ops = &kobj_sysfs_ops,
634 .child_ns_type = class_dir_child_ns_type
635};
636
637static struct kobject *
638class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
639{
640 struct class_dir *dir;
641 int retval;
642
643 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
644 if (!dir)
645 return NULL;
646
647 dir->class = class;
648 kobject_init(&dir->kobj, &class_dir_ktype);
649
650 dir->kobj.kset = &class->p->glue_dirs;
651
652 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
653 if (retval < 0) {
654 kobject_put(&dir->kobj);
655 return NULL;
656 }
657 return &dir->kobj;
658}
659
660
661static struct kobject *get_device_parent(struct device *dev,
662 struct device *parent)
663{
664 if (dev->class) {
665 static DEFINE_MUTEX(gdp_mutex);
666 struct kobject *kobj = NULL;
667 struct kobject *parent_kobj;
668 struct kobject *k;
669
670#ifdef CONFIG_BLOCK
671 /* block disks show up in /sys/block */
672 if (sysfs_deprecated && dev->class == &block_class) {
673 if (parent && parent->class == &block_class)
674 return &parent->kobj;
675 return &block_class.p->subsys.kobj;
676 }
677#endif
678
679 /*
680 * If we have no parent, we live in "virtual".
681 * Class-devices with a non class-device as parent, live
682 * in a "glue" directory to prevent namespace collisions.
683 */
684 if (parent == NULL)
685 parent_kobj = virtual_device_parent(dev);
686 else if (parent->class && !dev->class->ns_type)
687 return &parent->kobj;
688 else
689 parent_kobj = &parent->kobj;
690
691 mutex_lock(&gdp_mutex);
692
693 /* find our class-directory at the parent and reference it */
694 spin_lock(&dev->class->p->glue_dirs.list_lock);
695 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
696 if (k->parent == parent_kobj) {
697 kobj = kobject_get(k);
698 break;
699 }
700 spin_unlock(&dev->class->p->glue_dirs.list_lock);
701 if (kobj) {
702 mutex_unlock(&gdp_mutex);
703 return kobj;
704 }
705
706 /* or create a new class-directory at the parent device */
707 k = class_dir_create_and_add(dev->class, parent_kobj);
708 /* do not emit an uevent for this simple "glue" directory */
709 mutex_unlock(&gdp_mutex);
710 return k;
711 }
712
713 if (parent)
714 return &parent->kobj;
715 return NULL;
716}
717
718static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
719{
720 /* see if we live in a "glue" directory */
721 if (!glue_dir || !dev->class ||
722 glue_dir->kset != &dev->class->p->glue_dirs)
723 return;
724
725 kobject_put(glue_dir);
726}
727
728static void cleanup_device_parent(struct device *dev)
729{
730 cleanup_glue_dir(dev, dev->kobj.parent);
731}
732
733static void setup_parent(struct device *dev, struct device *parent)
734{
735 struct kobject *kobj;
736 kobj = get_device_parent(dev, parent);
737 if (kobj)
738 dev->kobj.parent = kobj;
739}
740
741static int device_add_class_symlinks(struct device *dev)
742{
743 int error;
744
745 if (!dev->class)
746 return 0;
747
748 error = sysfs_create_link(&dev->kobj,
749 &dev->class->p->subsys.kobj,
750 "subsystem");
751 if (error)
752 goto out;
753
754 if (dev->parent && device_is_not_partition(dev)) {
755 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
756 "device");
757 if (error)
758 goto out_subsys;
759 }
760
761#ifdef CONFIG_BLOCK
762 /* /sys/block has directories and does not need symlinks */
763 if (sysfs_deprecated && dev->class == &block_class)
764 return 0;
765#endif
766
767 /* link in the class directory pointing to the device */
768 error = sysfs_create_link(&dev->class->p->subsys.kobj,
769 &dev->kobj, dev_name(dev));
770 if (error)
771 goto out_device;
772
773 return 0;
774
775out_device:
776 sysfs_remove_link(&dev->kobj, "device");
777
778out_subsys:
779 sysfs_remove_link(&dev->kobj, "subsystem");
780out:
781 return error;
782}
783
784static void device_remove_class_symlinks(struct device *dev)
785{
786 if (!dev->class)
787 return;
788
789 if (dev->parent && device_is_not_partition(dev))
790 sysfs_remove_link(&dev->kobj, "device");
791 sysfs_remove_link(&dev->kobj, "subsystem");
792#ifdef CONFIG_BLOCK
793 if (sysfs_deprecated && dev->class == &block_class)
794 return;
795#endif
796 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
797}
798
799/**
800 * dev_set_name - set a device name
801 * @dev: device
802 * @fmt: format string for the device's name
803 */
804int dev_set_name(struct device *dev, const char *fmt, ...)
805{
806 va_list vargs;
807 int err;
808
809 va_start(vargs, fmt);
810 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
811 va_end(vargs);
812 return err;
813}
814EXPORT_SYMBOL_GPL(dev_set_name);
815
816/**
817 * device_to_dev_kobj - select a /sys/dev/ directory for the device
818 * @dev: device
819 *
820 * By default we select char/ for new entries. Setting class->dev_obj
821 * to NULL prevents an entry from being created. class->dev_kobj must
822 * be set (or cleared) before any devices are registered to the class
823 * otherwise device_create_sys_dev_entry() and
824 * device_remove_sys_dev_entry() will disagree about the the presence
825 * of the link.
826 */
827static struct kobject *device_to_dev_kobj(struct device *dev)
828{
829 struct kobject *kobj;
830
831 if (dev->class)
832 kobj = dev->class->dev_kobj;
833 else
834 kobj = sysfs_dev_char_kobj;
835
836 return kobj;
837}
838
839static int device_create_sys_dev_entry(struct device *dev)
840{
841 struct kobject *kobj = device_to_dev_kobj(dev);
842 int error = 0;
843 char devt_str[15];
844
845 if (kobj) {
846 format_dev_t(devt_str, dev->devt);
847 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
848 }
849
850 return error;
851}
852
853static void device_remove_sys_dev_entry(struct device *dev)
854{
855 struct kobject *kobj = device_to_dev_kobj(dev);
856 char devt_str[15];
857
858 if (kobj) {
859 format_dev_t(devt_str, dev->devt);
860 sysfs_remove_link(kobj, devt_str);
861 }
862}
863
864int device_private_init(struct device *dev)
865{
866 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
867 if (!dev->p)
868 return -ENOMEM;
869 dev->p->device = dev;
870 klist_init(&dev->p->klist_children, klist_children_get,
871 klist_children_put);
872 return 0;
873}
874
875/**
876 * device_add - add device to device hierarchy.
877 * @dev: device.
878 *
879 * This is part 2 of device_register(), though may be called
880 * separately _iff_ device_initialize() has been called separately.
881 *
882 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
883 * to the global and sibling lists for the device, then
884 * adds it to the other relevant subsystems of the driver model.
885 *
886 * NOTE: _Never_ directly free @dev after calling this function, even
887 * if it returned an error! Always use put_device() to give up your
888 * reference instead.
889 */
890int device_add(struct device *dev)
891{
892 struct device *parent = NULL;
893 struct class_interface *class_intf;
894 int error = -EINVAL;
895
896 dev = get_device(dev);
897 if (!dev)
898 goto done;
899
900 if (!dev->p) {
901 error = device_private_init(dev);
902 if (error)
903 goto done;
904 }
905
906 /*
907 * for statically allocated devices, which should all be converted
908 * some day, we need to initialize the name. We prevent reading back
909 * the name, and force the use of dev_name()
910 */
911 if (dev->init_name) {
912 dev_set_name(dev, "%s", dev->init_name);
913 dev->init_name = NULL;
914 }
915
916 if (!dev_name(dev)) {
917 error = -EINVAL;
918 goto name_error;
919 }
920
921 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
922
923 parent = get_device(dev->parent);
924 setup_parent(dev, parent);
925
926 /* use parent numa_node */
927 if (parent)
928 set_dev_node(dev, dev_to_node(parent));
929
930 /* first, register with generic layer. */
931 /* we require the name to be set before, and pass NULL */
932 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
933 if (error)
934 goto Error;
935
936 /* notify platform of device entry */
937 if (platform_notify)
938 platform_notify(dev);
939
940 error = device_create_file(dev, &uevent_attr);
941 if (error)
942 goto attrError;
943
944 if (MAJOR(dev->devt)) {
945 error = device_create_file(dev, &devt_attr);
946 if (error)
947 goto ueventattrError;
948
949 error = device_create_sys_dev_entry(dev);
950 if (error)
951 goto devtattrError;
952
953 devtmpfs_create_node(dev);
954 }
955
956 error = device_add_class_symlinks(dev);
957 if (error)
958 goto SymlinkError;
959 error = device_add_attrs(dev);
960 if (error)
961 goto AttrsError;
962 error = bus_add_device(dev);
963 if (error)
964 goto BusError;
965 error = dpm_sysfs_add(dev);
966 if (error)
967 goto DPMError;
968 device_pm_add(dev);
969
970 /* Notify clients of device addition. This call must come
971 * after dpm_sysf_add() and before kobject_uevent().
972 */
973 if (dev->bus)
974 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
975 BUS_NOTIFY_ADD_DEVICE, dev);
976
977 kobject_uevent(&dev->kobj, KOBJ_ADD);
978 bus_probe_device(dev);
979 if (parent)
980 klist_add_tail(&dev->p->knode_parent,
981 &parent->p->klist_children);
982
983 if (dev->class) {
984 mutex_lock(&dev->class->p->class_mutex);
985 /* tie the class to the device */
986 klist_add_tail(&dev->knode_class,
987 &dev->class->p->klist_devices);
988
989 /* notify any interfaces that the device is here */
990 list_for_each_entry(class_intf,
991 &dev->class->p->class_interfaces, node)
992 if (class_intf->add_dev)
993 class_intf->add_dev(dev, class_intf);
994 mutex_unlock(&dev->class->p->class_mutex);
995 }
996done:
997 put_device(dev);
998 return error;
999 DPMError:
1000 bus_remove_device(dev);
1001 BusError:
1002 device_remove_attrs(dev);
1003 AttrsError:
1004 device_remove_class_symlinks(dev);
1005 SymlinkError:
1006 if (MAJOR(dev->devt))
1007 devtmpfs_delete_node(dev);
1008 if (MAJOR(dev->devt))
1009 device_remove_sys_dev_entry(dev);
1010 devtattrError:
1011 if (MAJOR(dev->devt))
1012 device_remove_file(dev, &devt_attr);
1013 ueventattrError:
1014 device_remove_file(dev, &uevent_attr);
1015 attrError:
1016 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1017 kobject_del(&dev->kobj);
1018 Error:
1019 cleanup_device_parent(dev);
1020 if (parent)
1021 put_device(parent);
1022name_error:
1023 kfree(dev->p);
1024 dev->p = NULL;
1025 goto done;
1026}
1027
1028/**
1029 * device_register - register a device with the system.
1030 * @dev: pointer to the device structure
1031 *
1032 * This happens in two clean steps - initialize the device
1033 * and add it to the system. The two steps can be called
1034 * separately, but this is the easiest and most common.
1035 * I.e. you should only call the two helpers separately if
1036 * have a clearly defined need to use and refcount the device
1037 * before it is added to the hierarchy.
1038 *
1039 * NOTE: _Never_ directly free @dev after calling this function, even
1040 * if it returned an error! Always use put_device() to give up the
1041 * reference initialized in this function instead.
1042 */
1043int device_register(struct device *dev)
1044{
1045 device_initialize(dev);
1046 return device_add(dev);
1047}
1048
1049/**
1050 * get_device - increment reference count for device.
1051 * @dev: device.
1052 *
1053 * This simply forwards the call to kobject_get(), though
1054 * we do take care to provide for the case that we get a NULL
1055 * pointer passed in.
1056 */
1057struct device *get_device(struct device *dev)
1058{
1059 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
1060}
1061
1062/**
1063 * put_device - decrement reference count.
1064 * @dev: device in question.
1065 */
1066void put_device(struct device *dev)
1067{
1068 /* might_sleep(); */
1069 if (dev)
1070 kobject_put(&dev->kobj);
1071}
1072
1073/**
1074 * device_del - delete device from system.
1075 * @dev: device.
1076 *
1077 * This is the first part of the device unregistration
1078 * sequence. This removes the device from the lists we control
1079 * from here, has it removed from the other driver model
1080 * subsystems it was added to in device_add(), and removes it
1081 * from the kobject hierarchy.
1082 *
1083 * NOTE: this should be called manually _iff_ device_add() was
1084 * also called manually.
1085 */
1086void device_del(struct device *dev)
1087{
1088 struct device *parent = dev->parent;
1089 struct class_interface *class_intf;
1090
1091 /* Notify clients of device removal. This call must come
1092 * before dpm_sysfs_remove().
1093 */
1094 if (dev->bus)
1095 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1096 BUS_NOTIFY_DEL_DEVICE, dev);
1097 device_pm_remove(dev);
1098 dpm_sysfs_remove(dev);
1099 if (parent)
1100 klist_del(&dev->p->knode_parent);
1101 if (MAJOR(dev->devt)) {
1102 devtmpfs_delete_node(dev);
1103 device_remove_sys_dev_entry(dev);
1104 device_remove_file(dev, &devt_attr);
1105 }
1106 if (dev->class) {
1107 device_remove_class_symlinks(dev);
1108
1109 mutex_lock(&dev->class->p->class_mutex);
1110 /* notify any interfaces that the device is now gone */
1111 list_for_each_entry(class_intf,
1112 &dev->class->p->class_interfaces, node)
1113 if (class_intf->remove_dev)
1114 class_intf->remove_dev(dev, class_intf);
1115 /* remove the device from the class list */
1116 klist_del(&dev->knode_class);
1117 mutex_unlock(&dev->class->p->class_mutex);
1118 }
1119 device_remove_file(dev, &uevent_attr);
1120 device_remove_attrs(dev);
1121 bus_remove_device(dev);
1122
1123 /*
1124 * Some platform devices are driven without driver attached
1125 * and managed resources may have been acquired. Make sure
1126 * all resources are released.
1127 */
1128 devres_release_all(dev);
1129
1130 /* Notify the platform of the removal, in case they
1131 * need to do anything...
1132 */
1133 if (platform_notify_remove)
1134 platform_notify_remove(dev);
1135 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1136 cleanup_device_parent(dev);
1137 kobject_del(&dev->kobj);
1138 put_device(parent);
1139}
1140
1141/**
1142 * device_unregister - unregister device from system.
1143 * @dev: device going away.
1144 *
1145 * We do this in two parts, like we do device_register(). First,
1146 * we remove it from all the subsystems with device_del(), then
1147 * we decrement the reference count via put_device(). If that
1148 * is the final reference count, the device will be cleaned up
1149 * via device_release() above. Otherwise, the structure will
1150 * stick around until the final reference to the device is dropped.
1151 */
1152void device_unregister(struct device *dev)
1153{
1154 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1155 device_del(dev);
1156 put_device(dev);
1157}
1158
1159static struct device *next_device(struct klist_iter *i)
1160{
1161 struct klist_node *n = klist_next(i);
1162 struct device *dev = NULL;
1163 struct device_private *p;
1164
1165 if (n) {
1166 p = to_device_private_parent(n);
1167 dev = p->device;
1168 }
1169 return dev;
1170}
1171
1172/**
1173 * device_get_devnode - path of device node file
1174 * @dev: device
1175 * @mode: returned file access mode
1176 * @tmp: possibly allocated string
1177 *
1178 * Return the relative path of a possible device node.
1179 * Non-default names may need to allocate a memory to compose
1180 * a name. This memory is returned in tmp and needs to be
1181 * freed by the caller.
1182 */
1183const char *device_get_devnode(struct device *dev,
1184 mode_t *mode, const char **tmp)
1185{
1186 char *s;
1187
1188 *tmp = NULL;
1189
1190 /* the device type may provide a specific name */
1191 if (dev->type && dev->type->devnode)
1192 *tmp = dev->type->devnode(dev, mode);
1193 if (*tmp)
1194 return *tmp;
1195
1196 /* the class may provide a specific name */
1197 if (dev->class && dev->class->devnode)
1198 *tmp = dev->class->devnode(dev, mode);
1199 if (*tmp)
1200 return *tmp;
1201
1202 /* return name without allocation, tmp == NULL */
1203 if (strchr(dev_name(dev), '!') == NULL)
1204 return dev_name(dev);
1205
1206 /* replace '!' in the name with '/' */
1207 *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1208 if (!*tmp)
1209 return NULL;
1210 while ((s = strchr(*tmp, '!')))
1211 s[0] = '/';
1212 return *tmp;
1213}
1214
1215/**
1216 * device_for_each_child - device child iterator.
1217 * @parent: parent struct device.
1218 * @data: data for the callback.
1219 * @fn: function to be called for each device.
1220 *
1221 * Iterate over @parent's child devices, and call @fn for each,
1222 * passing it @data.
1223 *
1224 * We check the return of @fn each time. If it returns anything
1225 * other than 0, we break out and return that value.
1226 */
1227int device_for_each_child(struct device *parent, void *data,
1228 int (*fn)(struct device *dev, void *data))
1229{
1230 struct klist_iter i;
1231 struct device *child;
1232 int error = 0;
1233
1234 if (!parent->p)
1235 return 0;
1236
1237 klist_iter_init(&parent->p->klist_children, &i);
1238 while ((child = next_device(&i)) && !error)
1239 error = fn(child, data);
1240 klist_iter_exit(&i);
1241 return error;
1242}
1243
1244/**
1245 * device_find_child - device iterator for locating a particular device.
1246 * @parent: parent struct device
1247 * @data: Data to pass to match function
1248 * @match: Callback function to check device
1249 *
1250 * This is similar to the device_for_each_child() function above, but it
1251 * returns a reference to a device that is 'found' for later use, as
1252 * determined by the @match callback.
1253 *
1254 * The callback should return 0 if the device doesn't match and non-zero
1255 * if it does. If the callback returns non-zero and a reference to the
1256 * current device can be obtained, this function will return to the caller
1257 * and not iterate over any more devices.
1258 */
1259struct device *device_find_child(struct device *parent, void *data,
1260 int (*match)(struct device *dev, void *data))
1261{
1262 struct klist_iter i;
1263 struct device *child;
1264
1265 if (!parent)
1266 return NULL;
1267
1268 klist_iter_init(&parent->p->klist_children, &i);
1269 while ((child = next_device(&i)))
1270 if (match(child, data) && get_device(child))
1271 break;
1272 klist_iter_exit(&i);
1273 return child;
1274}
1275
1276int __init devices_init(void)
1277{
1278 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1279 if (!devices_kset)
1280 return -ENOMEM;
1281 dev_kobj = kobject_create_and_add("dev", NULL);
1282 if (!dev_kobj)
1283 goto dev_kobj_err;
1284 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1285 if (!sysfs_dev_block_kobj)
1286 goto block_kobj_err;
1287 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1288 if (!sysfs_dev_char_kobj)
1289 goto char_kobj_err;
1290
1291 return 0;
1292
1293 char_kobj_err:
1294 kobject_put(sysfs_dev_block_kobj);
1295 block_kobj_err:
1296 kobject_put(dev_kobj);
1297 dev_kobj_err:
1298 kset_unregister(devices_kset);
1299 return -ENOMEM;
1300}
1301
1302EXPORT_SYMBOL_GPL(device_for_each_child);
1303EXPORT_SYMBOL_GPL(device_find_child);
1304
1305EXPORT_SYMBOL_GPL(device_initialize);
1306EXPORT_SYMBOL_GPL(device_add);
1307EXPORT_SYMBOL_GPL(device_register);
1308
1309EXPORT_SYMBOL_GPL(device_del);
1310EXPORT_SYMBOL_GPL(device_unregister);
1311EXPORT_SYMBOL_GPL(get_device);
1312EXPORT_SYMBOL_GPL(put_device);
1313
1314EXPORT_SYMBOL_GPL(device_create_file);
1315EXPORT_SYMBOL_GPL(device_remove_file);
1316
1317struct root_device {
1318 struct device dev;
1319 struct module *owner;
1320};
1321
1322inline struct root_device *to_root_device(struct device *d)
1323{
1324 return container_of(d, struct root_device, dev);
1325}
1326
1327static void root_device_release(struct device *dev)
1328{
1329 kfree(to_root_device(dev));
1330}
1331
1332/**
1333 * __root_device_register - allocate and register a root device
1334 * @name: root device name
1335 * @owner: owner module of the root device, usually THIS_MODULE
1336 *
1337 * This function allocates a root device and registers it
1338 * using device_register(). In order to free the returned
1339 * device, use root_device_unregister().
1340 *
1341 * Root devices are dummy devices which allow other devices
1342 * to be grouped under /sys/devices. Use this function to
1343 * allocate a root device and then use it as the parent of
1344 * any device which should appear under /sys/devices/{name}
1345 *
1346 * The /sys/devices/{name} directory will also contain a
1347 * 'module' symlink which points to the @owner directory
1348 * in sysfs.
1349 *
1350 * Returns &struct device pointer on success, or ERR_PTR() on error.
1351 *
1352 * Note: You probably want to use root_device_register().
1353 */
1354struct device *__root_device_register(const char *name, struct module *owner)
1355{
1356 struct root_device *root;
1357 int err = -ENOMEM;
1358
1359 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1360 if (!root)
1361 return ERR_PTR(err);
1362
1363 err = dev_set_name(&root->dev, "%s", name);
1364 if (err) {
1365 kfree(root);
1366 return ERR_PTR(err);
1367 }
1368
1369 root->dev.release = root_device_release;
1370
1371 err = device_register(&root->dev);
1372 if (err) {
1373 put_device(&root->dev);
1374 return ERR_PTR(err);
1375 }
1376
1377#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1378 if (owner) {
1379 struct module_kobject *mk = &owner->mkobj;
1380
1381 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1382 if (err) {
1383 device_unregister(&root->dev);
1384 return ERR_PTR(err);
1385 }
1386 root->owner = owner;
1387 }
1388#endif
1389
1390 return &root->dev;
1391}
1392EXPORT_SYMBOL_GPL(__root_device_register);
1393
1394/**
1395 * root_device_unregister - unregister and free a root device
1396 * @dev: device going away
1397 *
1398 * This function unregisters and cleans up a device that was created by
1399 * root_device_register().
1400 */
1401void root_device_unregister(struct device *dev)
1402{
1403 struct root_device *root = to_root_device(dev);
1404
1405 if (root->owner)
1406 sysfs_remove_link(&root->dev.kobj, "module");
1407
1408 device_unregister(dev);
1409}
1410EXPORT_SYMBOL_GPL(root_device_unregister);
1411
1412
1413static void device_create_release(struct device *dev)
1414{
1415 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1416 kfree(dev);
1417}
1418
1419/**
1420 * device_create_vargs - creates a device and registers it with sysfs
1421 * @class: pointer to the struct class that this device should be registered to
1422 * @parent: pointer to the parent struct device of this new device, if any
1423 * @devt: the dev_t for the char device to be added
1424 * @drvdata: the data to be added to the device for callbacks
1425 * @fmt: string for the device's name
1426 * @args: va_list for the device's name
1427 *
1428 * This function can be used by char device classes. A struct device
1429 * will be created in sysfs, registered to the specified class.
1430 *
1431 * A "dev" file will be created, showing the dev_t for the device, if
1432 * the dev_t is not 0,0.
1433 * If a pointer to a parent struct device is passed in, the newly created
1434 * struct device will be a child of that device in sysfs.
1435 * The pointer to the struct device will be returned from the call.
1436 * Any further sysfs files that might be required can be created using this
1437 * pointer.
1438 *
1439 * Returns &struct device pointer on success, or ERR_PTR() on error.
1440 *
1441 * Note: the struct class passed to this function must have previously
1442 * been created with a call to class_create().
1443 */
1444struct device *device_create_vargs(struct class *class, struct device *parent,
1445 dev_t devt, void *drvdata, const char *fmt,
1446 va_list args)
1447{
1448 struct device *dev = NULL;
1449 int retval = -ENODEV;
1450
1451 if (class == NULL || IS_ERR(class))
1452 goto error;
1453
1454 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1455 if (!dev) {
1456 retval = -ENOMEM;
1457 goto error;
1458 }
1459
1460 dev->devt = devt;
1461 dev->class = class;
1462 dev->parent = parent;
1463 dev->release = device_create_release;
1464 dev_set_drvdata(dev, drvdata);
1465
1466 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1467 if (retval)
1468 goto error;
1469
1470 retval = device_register(dev);
1471 if (retval)
1472 goto error;
1473
1474 return dev;
1475
1476error:
1477 put_device(dev);
1478 return ERR_PTR(retval);
1479}
1480EXPORT_SYMBOL_GPL(device_create_vargs);
1481
1482/**
1483 * device_create - creates a device and registers it with sysfs
1484 * @class: pointer to the struct class that this device should be registered to
1485 * @parent: pointer to the parent struct device of this new device, if any
1486 * @devt: the dev_t for the char device to be added
1487 * @drvdata: the data to be added to the device for callbacks
1488 * @fmt: string for the device's name
1489 *
1490 * This function can be used by char device classes. A struct device
1491 * will be created in sysfs, registered to the specified class.
1492 *
1493 * A "dev" file will be created, showing the dev_t for the device, if
1494 * the dev_t is not 0,0.
1495 * If a pointer to a parent struct device is passed in, the newly created
1496 * struct device will be a child of that device in sysfs.
1497 * The pointer to the struct device will be returned from the call.
1498 * Any further sysfs files that might be required can be created using this
1499 * pointer.
1500 *
1501 * Returns &struct device pointer on success, or ERR_PTR() on error.
1502 *
1503 * Note: the struct class passed to this function must have previously
1504 * been created with a call to class_create().
1505 */
1506struct device *device_create(struct class *class, struct device *parent,
1507 dev_t devt, void *drvdata, const char *fmt, ...)
1508{
1509 va_list vargs;
1510 struct device *dev;
1511
1512 va_start(vargs, fmt);
1513 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1514 va_end(vargs);
1515 return dev;
1516}
1517EXPORT_SYMBOL_GPL(device_create);
1518
1519static int __match_devt(struct device *dev, void *data)
1520{
1521 dev_t *devt = data;
1522
1523 return dev->devt == *devt;
1524}
1525
1526/**
1527 * device_destroy - removes a device that was created with device_create()
1528 * @class: pointer to the struct class that this device was registered with
1529 * @devt: the dev_t of the device that was previously registered
1530 *
1531 * This call unregisters and cleans up a device that was created with a
1532 * call to device_create().
1533 */
1534void device_destroy(struct class *class, dev_t devt)
1535{
1536 struct device *dev;
1537
1538 dev = class_find_device(class, NULL, &devt, __match_devt);
1539 if (dev) {
1540 put_device(dev);
1541 device_unregister(dev);
1542 }
1543}
1544EXPORT_SYMBOL_GPL(device_destroy);
1545
1546/**
1547 * device_rename - renames a device
1548 * @dev: the pointer to the struct device to be renamed
1549 * @new_name: the new name of the device
1550 *
1551 * It is the responsibility of the caller to provide mutual
1552 * exclusion between two different calls of device_rename
1553 * on the same device to ensure that new_name is valid and
1554 * won't conflict with other devices.
1555 *
1556 * Note: Don't call this function. Currently, the networking layer calls this
1557 * function, but that will change. The following text from Kay Sievers offers
1558 * some insight:
1559 *
1560 * Renaming devices is racy at many levels, symlinks and other stuff are not
1561 * replaced atomically, and you get a "move" uevent, but it's not easy to
1562 * connect the event to the old and new device. Device nodes are not renamed at
1563 * all, there isn't even support for that in the kernel now.
1564 *
1565 * In the meantime, during renaming, your target name might be taken by another
1566 * driver, creating conflicts. Or the old name is taken directly after you
1567 * renamed it -- then you get events for the same DEVPATH, before you even see
1568 * the "move" event. It's just a mess, and nothing new should ever rely on
1569 * kernel device renaming. Besides that, it's not even implemented now for
1570 * other things than (driver-core wise very simple) network devices.
1571 *
1572 * We are currently about to change network renaming in udev to completely
1573 * disallow renaming of devices in the same namespace as the kernel uses,
1574 * because we can't solve the problems properly, that arise with swapping names
1575 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1576 * be allowed to some other name than eth[0-9]*, for the aforementioned
1577 * reasons.
1578 *
1579 * Make up a "real" name in the driver before you register anything, or add
1580 * some other attributes for userspace to find the device, or use udev to add
1581 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1582 * don't even want to get into that and try to implement the missing pieces in
1583 * the core. We really have other pieces to fix in the driver core mess. :)
1584 */
1585int device_rename(struct device *dev, const char *new_name)
1586{
1587 char *old_class_name = NULL;
1588 char *new_class_name = NULL;
1589 char *old_device_name = NULL;
1590 int error;
1591
1592 dev = get_device(dev);
1593 if (!dev)
1594 return -EINVAL;
1595
1596 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1597 __func__, new_name);
1598
1599 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1600 if (!old_device_name) {
1601 error = -ENOMEM;
1602 goto out;
1603 }
1604
1605 if (dev->class) {
1606 error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1607 &dev->kobj, old_device_name, new_name);
1608 if (error)
1609 goto out;
1610 }
1611
1612 error = kobject_rename(&dev->kobj, new_name);
1613 if (error)
1614 goto out;
1615
1616out:
1617 put_device(dev);
1618
1619 kfree(new_class_name);
1620 kfree(old_class_name);
1621 kfree(old_device_name);
1622
1623 return error;
1624}
1625EXPORT_SYMBOL_GPL(device_rename);
1626
1627static int device_move_class_links(struct device *dev,
1628 struct device *old_parent,
1629 struct device *new_parent)
1630{
1631 int error = 0;
1632
1633 if (old_parent)
1634 sysfs_remove_link(&dev->kobj, "device");
1635 if (new_parent)
1636 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1637 "device");
1638 return error;
1639}
1640
1641/**
1642 * device_move - moves a device to a new parent
1643 * @dev: the pointer to the struct device to be moved
1644 * @new_parent: the new parent of the device (can by NULL)
1645 * @dpm_order: how to reorder the dpm_list
1646 */
1647int device_move(struct device *dev, struct device *new_parent,
1648 enum dpm_order dpm_order)
1649{
1650 int error;
1651 struct device *old_parent;
1652 struct kobject *new_parent_kobj;
1653
1654 dev = get_device(dev);
1655 if (!dev)
1656 return -EINVAL;
1657
1658 device_pm_lock();
1659 new_parent = get_device(new_parent);
1660 new_parent_kobj = get_device_parent(dev, new_parent);
1661
1662 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1663 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1664 error = kobject_move(&dev->kobj, new_parent_kobj);
1665 if (error) {
1666 cleanup_glue_dir(dev, new_parent_kobj);
1667 put_device(new_parent);
1668 goto out;
1669 }
1670 old_parent = dev->parent;
1671 dev->parent = new_parent;
1672 if (old_parent)
1673 klist_remove(&dev->p->knode_parent);
1674 if (new_parent) {
1675 klist_add_tail(&dev->p->knode_parent,
1676 &new_parent->p->klist_children);
1677 set_dev_node(dev, dev_to_node(new_parent));
1678 }
1679
1680 if (!dev->class)
1681 goto out_put;
1682 error = device_move_class_links(dev, old_parent, new_parent);
1683 if (error) {
1684 /* We ignore errors on cleanup since we're hosed anyway... */
1685 device_move_class_links(dev, new_parent, old_parent);
1686 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1687 if (new_parent)
1688 klist_remove(&dev->p->knode_parent);
1689 dev->parent = old_parent;
1690 if (old_parent) {
1691 klist_add_tail(&dev->p->knode_parent,
1692 &old_parent->p->klist_children);
1693 set_dev_node(dev, dev_to_node(old_parent));
1694 }
1695 }
1696 cleanup_glue_dir(dev, new_parent_kobj);
1697 put_device(new_parent);
1698 goto out;
1699 }
1700 switch (dpm_order) {
1701 case DPM_ORDER_NONE:
1702 break;
1703 case DPM_ORDER_DEV_AFTER_PARENT:
1704 device_pm_move_after(dev, new_parent);
1705 break;
1706 case DPM_ORDER_PARENT_BEFORE_DEV:
1707 device_pm_move_before(new_parent, dev);
1708 break;
1709 case DPM_ORDER_DEV_LAST:
1710 device_pm_move_last(dev);
1711 break;
1712 }
1713out_put:
1714 put_device(old_parent);
1715out:
1716 device_pm_unlock();
1717 put_device(dev);
1718 return error;
1719}
1720EXPORT_SYMBOL_GPL(device_move);
1721
1722/**
1723 * device_shutdown - call ->shutdown() on each device to shutdown.
1724 */
1725void device_shutdown(void)
1726{
1727 struct device *dev;
1728
1729 spin_lock(&devices_kset->list_lock);
1730 /*
1731 * Walk the devices list backward, shutting down each in turn.
1732 * Beware that device unplug events may also start pulling
1733 * devices offline, even as the system is shutting down.
1734 */
1735 while (!list_empty(&devices_kset->list)) {
1736 dev = list_entry(devices_kset->list.prev, struct device,
1737 kobj.entry);
1738 get_device(dev);
1739 /*
1740 * Make sure the device is off the kset list, in the
1741 * event that dev->*->shutdown() doesn't remove it.
1742 */
1743 list_del_init(&dev->kobj.entry);
1744 spin_unlock(&devices_kset->list_lock);
1745
1746 if (dev->bus && dev->bus->shutdown) {
1747 dev_dbg(dev, "shutdown\n");
1748 dev->bus->shutdown(dev);
1749 } else if (dev->driver && dev->driver->shutdown) {
1750 dev_dbg(dev, "shutdown\n");
1751 dev->driver->shutdown(dev);
1752 }
1753 put_device(dev);
1754
1755 spin_lock(&devices_kset->list_lock);
1756 }
1757 spin_unlock(&devices_kset->list_lock);
1758 async_synchronize_full();
1759}
1760
1761/*
1762 * Device logging functions
1763 */
1764
1765#ifdef CONFIG_PRINTK
1766
1767static int __dev_printk(const char *level, const struct device *dev,
1768 struct va_format *vaf)
1769{
1770 if (!dev)
1771 return printk("%s(NULL device *): %pV", level, vaf);
1772
1773 return printk("%s%s %s: %pV",
1774 level, dev_driver_string(dev), dev_name(dev), vaf);
1775}
1776
1777int dev_printk(const char *level, const struct device *dev,
1778 const char *fmt, ...)
1779{
1780 struct va_format vaf;
1781 va_list args;
1782 int r;
1783
1784 va_start(args, fmt);
1785
1786 vaf.fmt = fmt;
1787 vaf.va = &args;
1788
1789 r = __dev_printk(level, dev, &vaf);
1790 va_end(args);
1791
1792 return r;
1793}
1794EXPORT_SYMBOL(dev_printk);
1795
1796#define define_dev_printk_level(func, kern_level) \
1797int func(const struct device *dev, const char *fmt, ...) \
1798{ \
1799 struct va_format vaf; \
1800 va_list args; \
1801 int r; \
1802 \
1803 va_start(args, fmt); \
1804 \
1805 vaf.fmt = fmt; \
1806 vaf.va = &args; \
1807 \
1808 r = __dev_printk(kern_level, dev, &vaf); \
1809 va_end(args); \
1810 \
1811 return r; \
1812} \
1813EXPORT_SYMBOL(func);
1814
1815define_dev_printk_level(dev_emerg, KERN_EMERG);
1816define_dev_printk_level(dev_alert, KERN_ALERT);
1817define_dev_printk_level(dev_crit, KERN_CRIT);
1818define_dev_printk_level(dev_err, KERN_ERR);
1819define_dev_printk_level(dev_warn, KERN_WARNING);
1820define_dev_printk_level(dev_notice, KERN_NOTICE);
1821define_dev_printk_level(_dev_info, KERN_INFO);
1822
1823#endif
1/*
2 * drivers/base/core.c - core driver model code (device registration, etc)
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
8 *
9 * This file is released under the GPLv2
10 *
11 */
12
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/fwnode.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/string.h>
20#include <linux/kdev_t.h>
21#include <linux/notifier.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/genhd.h>
25#include <linux/kallsyms.h>
26#include <linux/mutex.h>
27#include <linux/pm_runtime.h>
28#include <linux/netdevice.h>
29#include <linux/sysfs.h>
30
31#include "base.h"
32#include "power/power.h"
33
34#ifdef CONFIG_SYSFS_DEPRECATED
35#ifdef CONFIG_SYSFS_DEPRECATED_V2
36long sysfs_deprecated = 1;
37#else
38long sysfs_deprecated = 0;
39#endif
40static int __init sysfs_deprecated_setup(char *arg)
41{
42 return kstrtol(arg, 10, &sysfs_deprecated);
43}
44early_param("sysfs.deprecated", sysfs_deprecated_setup);
45#endif
46
47int (*platform_notify)(struct device *dev) = NULL;
48int (*platform_notify_remove)(struct device *dev) = NULL;
49static struct kobject *dev_kobj;
50struct kobject *sysfs_dev_char_kobj;
51struct kobject *sysfs_dev_block_kobj;
52
53static DEFINE_MUTEX(device_hotplug_lock);
54
55void lock_device_hotplug(void)
56{
57 mutex_lock(&device_hotplug_lock);
58}
59
60void unlock_device_hotplug(void)
61{
62 mutex_unlock(&device_hotplug_lock);
63}
64
65int lock_device_hotplug_sysfs(void)
66{
67 if (mutex_trylock(&device_hotplug_lock))
68 return 0;
69
70 /* Avoid busy looping (5 ms of sleep should do). */
71 msleep(5);
72 return restart_syscall();
73}
74
75#ifdef CONFIG_BLOCK
76static inline int device_is_not_partition(struct device *dev)
77{
78 return !(dev->type == &part_type);
79}
80#else
81static inline int device_is_not_partition(struct device *dev)
82{
83 return 1;
84}
85#endif
86
87/**
88 * dev_driver_string - Return a device's driver name, if at all possible
89 * @dev: struct device to get the name of
90 *
91 * Will return the device's driver's name if it is bound to a device. If
92 * the device is not bound to a driver, it will return the name of the bus
93 * it is attached to. If it is not attached to a bus either, an empty
94 * string will be returned.
95 */
96const char *dev_driver_string(const struct device *dev)
97{
98 struct device_driver *drv;
99
100 /* dev->driver can change to NULL underneath us because of unbinding,
101 * so be careful about accessing it. dev->bus and dev->class should
102 * never change once they are set, so they don't need special care.
103 */
104 drv = ACCESS_ONCE(dev->driver);
105 return drv ? drv->name :
106 (dev->bus ? dev->bus->name :
107 (dev->class ? dev->class->name : ""));
108}
109EXPORT_SYMBOL(dev_driver_string);
110
111#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
112
113static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
114 char *buf)
115{
116 struct device_attribute *dev_attr = to_dev_attr(attr);
117 struct device *dev = kobj_to_dev(kobj);
118 ssize_t ret = -EIO;
119
120 if (dev_attr->show)
121 ret = dev_attr->show(dev, dev_attr, buf);
122 if (ret >= (ssize_t)PAGE_SIZE) {
123 print_symbol("dev_attr_show: %s returned bad count\n",
124 (unsigned long)dev_attr->show);
125 }
126 return ret;
127}
128
129static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
130 const char *buf, size_t count)
131{
132 struct device_attribute *dev_attr = to_dev_attr(attr);
133 struct device *dev = kobj_to_dev(kobj);
134 ssize_t ret = -EIO;
135
136 if (dev_attr->store)
137 ret = dev_attr->store(dev, dev_attr, buf, count);
138 return ret;
139}
140
141static const struct sysfs_ops dev_sysfs_ops = {
142 .show = dev_attr_show,
143 .store = dev_attr_store,
144};
145
146#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
147
148ssize_t device_store_ulong(struct device *dev,
149 struct device_attribute *attr,
150 const char *buf, size_t size)
151{
152 struct dev_ext_attribute *ea = to_ext_attr(attr);
153 char *end;
154 unsigned long new = simple_strtoul(buf, &end, 0);
155 if (end == buf)
156 return -EINVAL;
157 *(unsigned long *)(ea->var) = new;
158 /* Always return full write size even if we didn't consume all */
159 return size;
160}
161EXPORT_SYMBOL_GPL(device_store_ulong);
162
163ssize_t device_show_ulong(struct device *dev,
164 struct device_attribute *attr,
165 char *buf)
166{
167 struct dev_ext_attribute *ea = to_ext_attr(attr);
168 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
169}
170EXPORT_SYMBOL_GPL(device_show_ulong);
171
172ssize_t device_store_int(struct device *dev,
173 struct device_attribute *attr,
174 const char *buf, size_t size)
175{
176 struct dev_ext_attribute *ea = to_ext_attr(attr);
177 char *end;
178 long new = simple_strtol(buf, &end, 0);
179 if (end == buf || new > INT_MAX || new < INT_MIN)
180 return -EINVAL;
181 *(int *)(ea->var) = new;
182 /* Always return full write size even if we didn't consume all */
183 return size;
184}
185EXPORT_SYMBOL_GPL(device_store_int);
186
187ssize_t device_show_int(struct device *dev,
188 struct device_attribute *attr,
189 char *buf)
190{
191 struct dev_ext_attribute *ea = to_ext_attr(attr);
192
193 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
194}
195EXPORT_SYMBOL_GPL(device_show_int);
196
197ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
198 const char *buf, size_t size)
199{
200 struct dev_ext_attribute *ea = to_ext_attr(attr);
201
202 if (strtobool(buf, ea->var) < 0)
203 return -EINVAL;
204
205 return size;
206}
207EXPORT_SYMBOL_GPL(device_store_bool);
208
209ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
210 char *buf)
211{
212 struct dev_ext_attribute *ea = to_ext_attr(attr);
213
214 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
215}
216EXPORT_SYMBOL_GPL(device_show_bool);
217
218/**
219 * device_release - free device structure.
220 * @kobj: device's kobject.
221 *
222 * This is called once the reference count for the object
223 * reaches 0. We forward the call to the device's release
224 * method, which should handle actually freeing the structure.
225 */
226static void device_release(struct kobject *kobj)
227{
228 struct device *dev = kobj_to_dev(kobj);
229 struct device_private *p = dev->p;
230
231 /*
232 * Some platform devices are driven without driver attached
233 * and managed resources may have been acquired. Make sure
234 * all resources are released.
235 *
236 * Drivers still can add resources into device after device
237 * is deleted but alive, so release devres here to avoid
238 * possible memory leak.
239 */
240 devres_release_all(dev);
241
242 if (dev->release)
243 dev->release(dev);
244 else if (dev->type && dev->type->release)
245 dev->type->release(dev);
246 else if (dev->class && dev->class->dev_release)
247 dev->class->dev_release(dev);
248 else
249 WARN(1, KERN_ERR "Device '%s' does not have a release() "
250 "function, it is broken and must be fixed.\n",
251 dev_name(dev));
252 kfree(p);
253}
254
255static const void *device_namespace(struct kobject *kobj)
256{
257 struct device *dev = kobj_to_dev(kobj);
258 const void *ns = NULL;
259
260 if (dev->class && dev->class->ns_type)
261 ns = dev->class->namespace(dev);
262
263 return ns;
264}
265
266static struct kobj_type device_ktype = {
267 .release = device_release,
268 .sysfs_ops = &dev_sysfs_ops,
269 .namespace = device_namespace,
270};
271
272
273static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
274{
275 struct kobj_type *ktype = get_ktype(kobj);
276
277 if (ktype == &device_ktype) {
278 struct device *dev = kobj_to_dev(kobj);
279 if (dev->bus)
280 return 1;
281 if (dev->class)
282 return 1;
283 }
284 return 0;
285}
286
287static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
288{
289 struct device *dev = kobj_to_dev(kobj);
290
291 if (dev->bus)
292 return dev->bus->name;
293 if (dev->class)
294 return dev->class->name;
295 return NULL;
296}
297
298static int dev_uevent(struct kset *kset, struct kobject *kobj,
299 struct kobj_uevent_env *env)
300{
301 struct device *dev = kobj_to_dev(kobj);
302 int retval = 0;
303
304 /* add device node properties if present */
305 if (MAJOR(dev->devt)) {
306 const char *tmp;
307 const char *name;
308 umode_t mode = 0;
309 kuid_t uid = GLOBAL_ROOT_UID;
310 kgid_t gid = GLOBAL_ROOT_GID;
311
312 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
313 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
314 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
315 if (name) {
316 add_uevent_var(env, "DEVNAME=%s", name);
317 if (mode)
318 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
319 if (!uid_eq(uid, GLOBAL_ROOT_UID))
320 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
321 if (!gid_eq(gid, GLOBAL_ROOT_GID))
322 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
323 kfree(tmp);
324 }
325 }
326
327 if (dev->type && dev->type->name)
328 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
329
330 if (dev->driver)
331 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
332
333 /* Add common DT information about the device */
334 of_device_uevent(dev, env);
335
336 /* have the bus specific function add its stuff */
337 if (dev->bus && dev->bus->uevent) {
338 retval = dev->bus->uevent(dev, env);
339 if (retval)
340 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
341 dev_name(dev), __func__, retval);
342 }
343
344 /* have the class specific function add its stuff */
345 if (dev->class && dev->class->dev_uevent) {
346 retval = dev->class->dev_uevent(dev, env);
347 if (retval)
348 pr_debug("device: '%s': %s: class uevent() "
349 "returned %d\n", dev_name(dev),
350 __func__, retval);
351 }
352
353 /* have the device type specific function add its stuff */
354 if (dev->type && dev->type->uevent) {
355 retval = dev->type->uevent(dev, env);
356 if (retval)
357 pr_debug("device: '%s': %s: dev_type uevent() "
358 "returned %d\n", dev_name(dev),
359 __func__, retval);
360 }
361
362 return retval;
363}
364
365static const struct kset_uevent_ops device_uevent_ops = {
366 .filter = dev_uevent_filter,
367 .name = dev_uevent_name,
368 .uevent = dev_uevent,
369};
370
371static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
372 char *buf)
373{
374 struct kobject *top_kobj;
375 struct kset *kset;
376 struct kobj_uevent_env *env = NULL;
377 int i;
378 size_t count = 0;
379 int retval;
380
381 /* search the kset, the device belongs to */
382 top_kobj = &dev->kobj;
383 while (!top_kobj->kset && top_kobj->parent)
384 top_kobj = top_kobj->parent;
385 if (!top_kobj->kset)
386 goto out;
387
388 kset = top_kobj->kset;
389 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
390 goto out;
391
392 /* respect filter */
393 if (kset->uevent_ops && kset->uevent_ops->filter)
394 if (!kset->uevent_ops->filter(kset, &dev->kobj))
395 goto out;
396
397 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
398 if (!env)
399 return -ENOMEM;
400
401 /* let the kset specific function add its keys */
402 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
403 if (retval)
404 goto out;
405
406 /* copy keys to file */
407 for (i = 0; i < env->envp_idx; i++)
408 count += sprintf(&buf[count], "%s\n", env->envp[i]);
409out:
410 kfree(env);
411 return count;
412}
413
414static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
415 const char *buf, size_t count)
416{
417 enum kobject_action action;
418
419 if (kobject_action_type(buf, count, &action) == 0)
420 kobject_uevent(&dev->kobj, action);
421 else
422 dev_err(dev, "uevent: unknown action-string\n");
423 return count;
424}
425static DEVICE_ATTR_RW(uevent);
426
427static ssize_t online_show(struct device *dev, struct device_attribute *attr,
428 char *buf)
429{
430 bool val;
431
432 device_lock(dev);
433 val = !dev->offline;
434 device_unlock(dev);
435 return sprintf(buf, "%u\n", val);
436}
437
438static ssize_t online_store(struct device *dev, struct device_attribute *attr,
439 const char *buf, size_t count)
440{
441 bool val;
442 int ret;
443
444 ret = strtobool(buf, &val);
445 if (ret < 0)
446 return ret;
447
448 ret = lock_device_hotplug_sysfs();
449 if (ret)
450 return ret;
451
452 ret = val ? device_online(dev) : device_offline(dev);
453 unlock_device_hotplug();
454 return ret < 0 ? ret : count;
455}
456static DEVICE_ATTR_RW(online);
457
458int device_add_groups(struct device *dev, const struct attribute_group **groups)
459{
460 return sysfs_create_groups(&dev->kobj, groups);
461}
462
463void device_remove_groups(struct device *dev,
464 const struct attribute_group **groups)
465{
466 sysfs_remove_groups(&dev->kobj, groups);
467}
468
469static int device_add_attrs(struct device *dev)
470{
471 struct class *class = dev->class;
472 const struct device_type *type = dev->type;
473 int error;
474
475 if (class) {
476 error = device_add_groups(dev, class->dev_groups);
477 if (error)
478 return error;
479 }
480
481 if (type) {
482 error = device_add_groups(dev, type->groups);
483 if (error)
484 goto err_remove_class_groups;
485 }
486
487 error = device_add_groups(dev, dev->groups);
488 if (error)
489 goto err_remove_type_groups;
490
491 if (device_supports_offline(dev) && !dev->offline_disabled) {
492 error = device_create_file(dev, &dev_attr_online);
493 if (error)
494 goto err_remove_dev_groups;
495 }
496
497 return 0;
498
499 err_remove_dev_groups:
500 device_remove_groups(dev, dev->groups);
501 err_remove_type_groups:
502 if (type)
503 device_remove_groups(dev, type->groups);
504 err_remove_class_groups:
505 if (class)
506 device_remove_groups(dev, class->dev_groups);
507
508 return error;
509}
510
511static void device_remove_attrs(struct device *dev)
512{
513 struct class *class = dev->class;
514 const struct device_type *type = dev->type;
515
516 device_remove_file(dev, &dev_attr_online);
517 device_remove_groups(dev, dev->groups);
518
519 if (type)
520 device_remove_groups(dev, type->groups);
521
522 if (class)
523 device_remove_groups(dev, class->dev_groups);
524}
525
526static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
527 char *buf)
528{
529 return print_dev_t(buf, dev->devt);
530}
531static DEVICE_ATTR_RO(dev);
532
533/* /sys/devices/ */
534struct kset *devices_kset;
535
536/**
537 * devices_kset_move_before - Move device in the devices_kset's list.
538 * @deva: Device to move.
539 * @devb: Device @deva should come before.
540 */
541static void devices_kset_move_before(struct device *deva, struct device *devb)
542{
543 if (!devices_kset)
544 return;
545 pr_debug("devices_kset: Moving %s before %s\n",
546 dev_name(deva), dev_name(devb));
547 spin_lock(&devices_kset->list_lock);
548 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
549 spin_unlock(&devices_kset->list_lock);
550}
551
552/**
553 * devices_kset_move_after - Move device in the devices_kset's list.
554 * @deva: Device to move
555 * @devb: Device @deva should come after.
556 */
557static void devices_kset_move_after(struct device *deva, struct device *devb)
558{
559 if (!devices_kset)
560 return;
561 pr_debug("devices_kset: Moving %s after %s\n",
562 dev_name(deva), dev_name(devb));
563 spin_lock(&devices_kset->list_lock);
564 list_move(&deva->kobj.entry, &devb->kobj.entry);
565 spin_unlock(&devices_kset->list_lock);
566}
567
568/**
569 * devices_kset_move_last - move the device to the end of devices_kset's list.
570 * @dev: device to move
571 */
572void devices_kset_move_last(struct device *dev)
573{
574 if (!devices_kset)
575 return;
576 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
577 spin_lock(&devices_kset->list_lock);
578 list_move_tail(&dev->kobj.entry, &devices_kset->list);
579 spin_unlock(&devices_kset->list_lock);
580}
581
582/**
583 * device_create_file - create sysfs attribute file for device.
584 * @dev: device.
585 * @attr: device attribute descriptor.
586 */
587int device_create_file(struct device *dev,
588 const struct device_attribute *attr)
589{
590 int error = 0;
591
592 if (dev) {
593 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
594 "Attribute %s: write permission without 'store'\n",
595 attr->attr.name);
596 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
597 "Attribute %s: read permission without 'show'\n",
598 attr->attr.name);
599 error = sysfs_create_file(&dev->kobj, &attr->attr);
600 }
601
602 return error;
603}
604EXPORT_SYMBOL_GPL(device_create_file);
605
606/**
607 * device_remove_file - remove sysfs attribute file.
608 * @dev: device.
609 * @attr: device attribute descriptor.
610 */
611void device_remove_file(struct device *dev,
612 const struct device_attribute *attr)
613{
614 if (dev)
615 sysfs_remove_file(&dev->kobj, &attr->attr);
616}
617EXPORT_SYMBOL_GPL(device_remove_file);
618
619/**
620 * device_remove_file_self - remove sysfs attribute file from its own method.
621 * @dev: device.
622 * @attr: device attribute descriptor.
623 *
624 * See kernfs_remove_self() for details.
625 */
626bool device_remove_file_self(struct device *dev,
627 const struct device_attribute *attr)
628{
629 if (dev)
630 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
631 else
632 return false;
633}
634EXPORT_SYMBOL_GPL(device_remove_file_self);
635
636/**
637 * device_create_bin_file - create sysfs binary attribute file for device.
638 * @dev: device.
639 * @attr: device binary attribute descriptor.
640 */
641int device_create_bin_file(struct device *dev,
642 const struct bin_attribute *attr)
643{
644 int error = -EINVAL;
645 if (dev)
646 error = sysfs_create_bin_file(&dev->kobj, attr);
647 return error;
648}
649EXPORT_SYMBOL_GPL(device_create_bin_file);
650
651/**
652 * device_remove_bin_file - remove sysfs binary attribute file
653 * @dev: device.
654 * @attr: device binary attribute descriptor.
655 */
656void device_remove_bin_file(struct device *dev,
657 const struct bin_attribute *attr)
658{
659 if (dev)
660 sysfs_remove_bin_file(&dev->kobj, attr);
661}
662EXPORT_SYMBOL_GPL(device_remove_bin_file);
663
664static void klist_children_get(struct klist_node *n)
665{
666 struct device_private *p = to_device_private_parent(n);
667 struct device *dev = p->device;
668
669 get_device(dev);
670}
671
672static void klist_children_put(struct klist_node *n)
673{
674 struct device_private *p = to_device_private_parent(n);
675 struct device *dev = p->device;
676
677 put_device(dev);
678}
679
680/**
681 * device_initialize - init device structure.
682 * @dev: device.
683 *
684 * This prepares the device for use by other layers by initializing
685 * its fields.
686 * It is the first half of device_register(), if called by
687 * that function, though it can also be called separately, so one
688 * may use @dev's fields. In particular, get_device()/put_device()
689 * may be used for reference counting of @dev after calling this
690 * function.
691 *
692 * All fields in @dev must be initialized by the caller to 0, except
693 * for those explicitly set to some other value. The simplest
694 * approach is to use kzalloc() to allocate the structure containing
695 * @dev.
696 *
697 * NOTE: Use put_device() to give up your reference instead of freeing
698 * @dev directly once you have called this function.
699 */
700void device_initialize(struct device *dev)
701{
702 dev->kobj.kset = devices_kset;
703 kobject_init(&dev->kobj, &device_ktype);
704 INIT_LIST_HEAD(&dev->dma_pools);
705 mutex_init(&dev->mutex);
706 lockdep_set_novalidate_class(&dev->mutex);
707 spin_lock_init(&dev->devres_lock);
708 INIT_LIST_HEAD(&dev->devres_head);
709 device_pm_init(dev);
710 set_dev_node(dev, -1);
711#ifdef CONFIG_GENERIC_MSI_IRQ
712 INIT_LIST_HEAD(&dev->msi_list);
713#endif
714}
715EXPORT_SYMBOL_GPL(device_initialize);
716
717struct kobject *virtual_device_parent(struct device *dev)
718{
719 static struct kobject *virtual_dir = NULL;
720
721 if (!virtual_dir)
722 virtual_dir = kobject_create_and_add("virtual",
723 &devices_kset->kobj);
724
725 return virtual_dir;
726}
727
728struct class_dir {
729 struct kobject kobj;
730 struct class *class;
731};
732
733#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
734
735static void class_dir_release(struct kobject *kobj)
736{
737 struct class_dir *dir = to_class_dir(kobj);
738 kfree(dir);
739}
740
741static const
742struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
743{
744 struct class_dir *dir = to_class_dir(kobj);
745 return dir->class->ns_type;
746}
747
748static struct kobj_type class_dir_ktype = {
749 .release = class_dir_release,
750 .sysfs_ops = &kobj_sysfs_ops,
751 .child_ns_type = class_dir_child_ns_type
752};
753
754static struct kobject *
755class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
756{
757 struct class_dir *dir;
758 int retval;
759
760 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
761 if (!dir)
762 return NULL;
763
764 dir->class = class;
765 kobject_init(&dir->kobj, &class_dir_ktype);
766
767 dir->kobj.kset = &class->p->glue_dirs;
768
769 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
770 if (retval < 0) {
771 kobject_put(&dir->kobj);
772 return NULL;
773 }
774 return &dir->kobj;
775}
776
777static DEFINE_MUTEX(gdp_mutex);
778
779static struct kobject *get_device_parent(struct device *dev,
780 struct device *parent)
781{
782 if (dev->class) {
783 struct kobject *kobj = NULL;
784 struct kobject *parent_kobj;
785 struct kobject *k;
786
787#ifdef CONFIG_BLOCK
788 /* block disks show up in /sys/block */
789 if (sysfs_deprecated && dev->class == &block_class) {
790 if (parent && parent->class == &block_class)
791 return &parent->kobj;
792 return &block_class.p->subsys.kobj;
793 }
794#endif
795
796 /*
797 * If we have no parent, we live in "virtual".
798 * Class-devices with a non class-device as parent, live
799 * in a "glue" directory to prevent namespace collisions.
800 */
801 if (parent == NULL)
802 parent_kobj = virtual_device_parent(dev);
803 else if (parent->class && !dev->class->ns_type)
804 return &parent->kobj;
805 else
806 parent_kobj = &parent->kobj;
807
808 mutex_lock(&gdp_mutex);
809
810 /* find our class-directory at the parent and reference it */
811 spin_lock(&dev->class->p->glue_dirs.list_lock);
812 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
813 if (k->parent == parent_kobj) {
814 kobj = kobject_get(k);
815 break;
816 }
817 spin_unlock(&dev->class->p->glue_dirs.list_lock);
818 if (kobj) {
819 mutex_unlock(&gdp_mutex);
820 return kobj;
821 }
822
823 /* or create a new class-directory at the parent device */
824 k = class_dir_create_and_add(dev->class, parent_kobj);
825 /* do not emit an uevent for this simple "glue" directory */
826 mutex_unlock(&gdp_mutex);
827 return k;
828 }
829
830 /* subsystems can specify a default root directory for their devices */
831 if (!parent && dev->bus && dev->bus->dev_root)
832 return &dev->bus->dev_root->kobj;
833
834 if (parent)
835 return &parent->kobj;
836 return NULL;
837}
838
839static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
840{
841 /* see if we live in a "glue" directory */
842 if (!glue_dir || !dev->class ||
843 glue_dir->kset != &dev->class->p->glue_dirs)
844 return;
845
846 mutex_lock(&gdp_mutex);
847 kobject_put(glue_dir);
848 mutex_unlock(&gdp_mutex);
849}
850
851static void cleanup_device_parent(struct device *dev)
852{
853 cleanup_glue_dir(dev, dev->kobj.parent);
854}
855
856static int device_add_class_symlinks(struct device *dev)
857{
858 struct device_node *of_node = dev_of_node(dev);
859 int error;
860
861 if (of_node) {
862 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
863 if (error)
864 dev_warn(dev, "Error %d creating of_node link\n",error);
865 /* An error here doesn't warrant bringing down the device */
866 }
867
868 if (!dev->class)
869 return 0;
870
871 error = sysfs_create_link(&dev->kobj,
872 &dev->class->p->subsys.kobj,
873 "subsystem");
874 if (error)
875 goto out_devnode;
876
877 if (dev->parent && device_is_not_partition(dev)) {
878 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
879 "device");
880 if (error)
881 goto out_subsys;
882 }
883
884#ifdef CONFIG_BLOCK
885 /* /sys/block has directories and does not need symlinks */
886 if (sysfs_deprecated && dev->class == &block_class)
887 return 0;
888#endif
889
890 /* link in the class directory pointing to the device */
891 error = sysfs_create_link(&dev->class->p->subsys.kobj,
892 &dev->kobj, dev_name(dev));
893 if (error)
894 goto out_device;
895
896 return 0;
897
898out_device:
899 sysfs_remove_link(&dev->kobj, "device");
900
901out_subsys:
902 sysfs_remove_link(&dev->kobj, "subsystem");
903out_devnode:
904 sysfs_remove_link(&dev->kobj, "of_node");
905 return error;
906}
907
908static void device_remove_class_symlinks(struct device *dev)
909{
910 if (dev_of_node(dev))
911 sysfs_remove_link(&dev->kobj, "of_node");
912
913 if (!dev->class)
914 return;
915
916 if (dev->parent && device_is_not_partition(dev))
917 sysfs_remove_link(&dev->kobj, "device");
918 sysfs_remove_link(&dev->kobj, "subsystem");
919#ifdef CONFIG_BLOCK
920 if (sysfs_deprecated && dev->class == &block_class)
921 return;
922#endif
923 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
924}
925
926/**
927 * dev_set_name - set a device name
928 * @dev: device
929 * @fmt: format string for the device's name
930 */
931int dev_set_name(struct device *dev, const char *fmt, ...)
932{
933 va_list vargs;
934 int err;
935
936 va_start(vargs, fmt);
937 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
938 va_end(vargs);
939 return err;
940}
941EXPORT_SYMBOL_GPL(dev_set_name);
942
943/**
944 * device_to_dev_kobj - select a /sys/dev/ directory for the device
945 * @dev: device
946 *
947 * By default we select char/ for new entries. Setting class->dev_obj
948 * to NULL prevents an entry from being created. class->dev_kobj must
949 * be set (or cleared) before any devices are registered to the class
950 * otherwise device_create_sys_dev_entry() and
951 * device_remove_sys_dev_entry() will disagree about the presence of
952 * the link.
953 */
954static struct kobject *device_to_dev_kobj(struct device *dev)
955{
956 struct kobject *kobj;
957
958 if (dev->class)
959 kobj = dev->class->dev_kobj;
960 else
961 kobj = sysfs_dev_char_kobj;
962
963 return kobj;
964}
965
966static int device_create_sys_dev_entry(struct device *dev)
967{
968 struct kobject *kobj = device_to_dev_kobj(dev);
969 int error = 0;
970 char devt_str[15];
971
972 if (kobj) {
973 format_dev_t(devt_str, dev->devt);
974 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
975 }
976
977 return error;
978}
979
980static void device_remove_sys_dev_entry(struct device *dev)
981{
982 struct kobject *kobj = device_to_dev_kobj(dev);
983 char devt_str[15];
984
985 if (kobj) {
986 format_dev_t(devt_str, dev->devt);
987 sysfs_remove_link(kobj, devt_str);
988 }
989}
990
991int device_private_init(struct device *dev)
992{
993 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
994 if (!dev->p)
995 return -ENOMEM;
996 dev->p->device = dev;
997 klist_init(&dev->p->klist_children, klist_children_get,
998 klist_children_put);
999 INIT_LIST_HEAD(&dev->p->deferred_probe);
1000 return 0;
1001}
1002
1003/**
1004 * device_add - add device to device hierarchy.
1005 * @dev: device.
1006 *
1007 * This is part 2 of device_register(), though may be called
1008 * separately _iff_ device_initialize() has been called separately.
1009 *
1010 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1011 * to the global and sibling lists for the device, then
1012 * adds it to the other relevant subsystems of the driver model.
1013 *
1014 * Do not call this routine or device_register() more than once for
1015 * any device structure. The driver model core is not designed to work
1016 * with devices that get unregistered and then spring back to life.
1017 * (Among other things, it's very hard to guarantee that all references
1018 * to the previous incarnation of @dev have been dropped.) Allocate
1019 * and register a fresh new struct device instead.
1020 *
1021 * NOTE: _Never_ directly free @dev after calling this function, even
1022 * if it returned an error! Always use put_device() to give up your
1023 * reference instead.
1024 */
1025int device_add(struct device *dev)
1026{
1027 struct device *parent = NULL;
1028 struct kobject *kobj;
1029 struct class_interface *class_intf;
1030 int error = -EINVAL;
1031
1032 dev = get_device(dev);
1033 if (!dev)
1034 goto done;
1035
1036 if (!dev->p) {
1037 error = device_private_init(dev);
1038 if (error)
1039 goto done;
1040 }
1041
1042 /*
1043 * for statically allocated devices, which should all be converted
1044 * some day, we need to initialize the name. We prevent reading back
1045 * the name, and force the use of dev_name()
1046 */
1047 if (dev->init_name) {
1048 dev_set_name(dev, "%s", dev->init_name);
1049 dev->init_name = NULL;
1050 }
1051
1052 /* subsystems can specify simple device enumeration */
1053 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1054 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1055
1056 if (!dev_name(dev)) {
1057 error = -EINVAL;
1058 goto name_error;
1059 }
1060
1061 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1062
1063 parent = get_device(dev->parent);
1064 kobj = get_device_parent(dev, parent);
1065 if (kobj)
1066 dev->kobj.parent = kobj;
1067
1068 /* use parent numa_node */
1069 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1070 set_dev_node(dev, dev_to_node(parent));
1071
1072 /* first, register with generic layer. */
1073 /* we require the name to be set before, and pass NULL */
1074 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1075 if (error)
1076 goto Error;
1077
1078 /* notify platform of device entry */
1079 if (platform_notify)
1080 platform_notify(dev);
1081
1082 error = device_create_file(dev, &dev_attr_uevent);
1083 if (error)
1084 goto attrError;
1085
1086 error = device_add_class_symlinks(dev);
1087 if (error)
1088 goto SymlinkError;
1089 error = device_add_attrs(dev);
1090 if (error)
1091 goto AttrsError;
1092 error = bus_add_device(dev);
1093 if (error)
1094 goto BusError;
1095 error = dpm_sysfs_add(dev);
1096 if (error)
1097 goto DPMError;
1098 device_pm_add(dev);
1099
1100 if (MAJOR(dev->devt)) {
1101 error = device_create_file(dev, &dev_attr_dev);
1102 if (error)
1103 goto DevAttrError;
1104
1105 error = device_create_sys_dev_entry(dev);
1106 if (error)
1107 goto SysEntryError;
1108
1109 devtmpfs_create_node(dev);
1110 }
1111
1112 /* Notify clients of device addition. This call must come
1113 * after dpm_sysfs_add() and before kobject_uevent().
1114 */
1115 if (dev->bus)
1116 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1117 BUS_NOTIFY_ADD_DEVICE, dev);
1118
1119 kobject_uevent(&dev->kobj, KOBJ_ADD);
1120 bus_probe_device(dev);
1121 if (parent)
1122 klist_add_tail(&dev->p->knode_parent,
1123 &parent->p->klist_children);
1124
1125 if (dev->class) {
1126 mutex_lock(&dev->class->p->mutex);
1127 /* tie the class to the device */
1128 klist_add_tail(&dev->knode_class,
1129 &dev->class->p->klist_devices);
1130
1131 /* notify any interfaces that the device is here */
1132 list_for_each_entry(class_intf,
1133 &dev->class->p->interfaces, node)
1134 if (class_intf->add_dev)
1135 class_intf->add_dev(dev, class_intf);
1136 mutex_unlock(&dev->class->p->mutex);
1137 }
1138done:
1139 put_device(dev);
1140 return error;
1141 SysEntryError:
1142 if (MAJOR(dev->devt))
1143 device_remove_file(dev, &dev_attr_dev);
1144 DevAttrError:
1145 device_pm_remove(dev);
1146 dpm_sysfs_remove(dev);
1147 DPMError:
1148 bus_remove_device(dev);
1149 BusError:
1150 device_remove_attrs(dev);
1151 AttrsError:
1152 device_remove_class_symlinks(dev);
1153 SymlinkError:
1154 device_remove_file(dev, &dev_attr_uevent);
1155 attrError:
1156 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1157 kobject_del(&dev->kobj);
1158 Error:
1159 cleanup_device_parent(dev);
1160 put_device(parent);
1161name_error:
1162 kfree(dev->p);
1163 dev->p = NULL;
1164 goto done;
1165}
1166EXPORT_SYMBOL_GPL(device_add);
1167
1168/**
1169 * device_register - register a device with the system.
1170 * @dev: pointer to the device structure
1171 *
1172 * This happens in two clean steps - initialize the device
1173 * and add it to the system. The two steps can be called
1174 * separately, but this is the easiest and most common.
1175 * I.e. you should only call the two helpers separately if
1176 * have a clearly defined need to use and refcount the device
1177 * before it is added to the hierarchy.
1178 *
1179 * For more information, see the kerneldoc for device_initialize()
1180 * and device_add().
1181 *
1182 * NOTE: _Never_ directly free @dev after calling this function, even
1183 * if it returned an error! Always use put_device() to give up the
1184 * reference initialized in this function instead.
1185 */
1186int device_register(struct device *dev)
1187{
1188 device_initialize(dev);
1189 return device_add(dev);
1190}
1191EXPORT_SYMBOL_GPL(device_register);
1192
1193/**
1194 * get_device - increment reference count for device.
1195 * @dev: device.
1196 *
1197 * This simply forwards the call to kobject_get(), though
1198 * we do take care to provide for the case that we get a NULL
1199 * pointer passed in.
1200 */
1201struct device *get_device(struct device *dev)
1202{
1203 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1204}
1205EXPORT_SYMBOL_GPL(get_device);
1206
1207/**
1208 * put_device - decrement reference count.
1209 * @dev: device in question.
1210 */
1211void put_device(struct device *dev)
1212{
1213 /* might_sleep(); */
1214 if (dev)
1215 kobject_put(&dev->kobj);
1216}
1217EXPORT_SYMBOL_GPL(put_device);
1218
1219/**
1220 * device_del - delete device from system.
1221 * @dev: device.
1222 *
1223 * This is the first part of the device unregistration
1224 * sequence. This removes the device from the lists we control
1225 * from here, has it removed from the other driver model
1226 * subsystems it was added to in device_add(), and removes it
1227 * from the kobject hierarchy.
1228 *
1229 * NOTE: this should be called manually _iff_ device_add() was
1230 * also called manually.
1231 */
1232void device_del(struct device *dev)
1233{
1234 struct device *parent = dev->parent;
1235 struct class_interface *class_intf;
1236
1237 /* Notify clients of device removal. This call must come
1238 * before dpm_sysfs_remove().
1239 */
1240 if (dev->bus)
1241 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1242 BUS_NOTIFY_DEL_DEVICE, dev);
1243 dpm_sysfs_remove(dev);
1244 if (parent)
1245 klist_del(&dev->p->knode_parent);
1246 if (MAJOR(dev->devt)) {
1247 devtmpfs_delete_node(dev);
1248 device_remove_sys_dev_entry(dev);
1249 device_remove_file(dev, &dev_attr_dev);
1250 }
1251 if (dev->class) {
1252 device_remove_class_symlinks(dev);
1253
1254 mutex_lock(&dev->class->p->mutex);
1255 /* notify any interfaces that the device is now gone */
1256 list_for_each_entry(class_intf,
1257 &dev->class->p->interfaces, node)
1258 if (class_intf->remove_dev)
1259 class_intf->remove_dev(dev, class_intf);
1260 /* remove the device from the class list */
1261 klist_del(&dev->knode_class);
1262 mutex_unlock(&dev->class->p->mutex);
1263 }
1264 device_remove_file(dev, &dev_attr_uevent);
1265 device_remove_attrs(dev);
1266 bus_remove_device(dev);
1267 device_pm_remove(dev);
1268 driver_deferred_probe_del(dev);
1269
1270 /* Notify the platform of the removal, in case they
1271 * need to do anything...
1272 */
1273 if (platform_notify_remove)
1274 platform_notify_remove(dev);
1275 if (dev->bus)
1276 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1277 BUS_NOTIFY_REMOVED_DEVICE, dev);
1278 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1279 cleanup_device_parent(dev);
1280 kobject_del(&dev->kobj);
1281 put_device(parent);
1282}
1283EXPORT_SYMBOL_GPL(device_del);
1284
1285/**
1286 * device_unregister - unregister device from system.
1287 * @dev: device going away.
1288 *
1289 * We do this in two parts, like we do device_register(). First,
1290 * we remove it from all the subsystems with device_del(), then
1291 * we decrement the reference count via put_device(). If that
1292 * is the final reference count, the device will be cleaned up
1293 * via device_release() above. Otherwise, the structure will
1294 * stick around until the final reference to the device is dropped.
1295 */
1296void device_unregister(struct device *dev)
1297{
1298 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1299 device_del(dev);
1300 put_device(dev);
1301}
1302EXPORT_SYMBOL_GPL(device_unregister);
1303
1304static struct device *prev_device(struct klist_iter *i)
1305{
1306 struct klist_node *n = klist_prev(i);
1307 struct device *dev = NULL;
1308 struct device_private *p;
1309
1310 if (n) {
1311 p = to_device_private_parent(n);
1312 dev = p->device;
1313 }
1314 return dev;
1315}
1316
1317static struct device *next_device(struct klist_iter *i)
1318{
1319 struct klist_node *n = klist_next(i);
1320 struct device *dev = NULL;
1321 struct device_private *p;
1322
1323 if (n) {
1324 p = to_device_private_parent(n);
1325 dev = p->device;
1326 }
1327 return dev;
1328}
1329
1330/**
1331 * device_get_devnode - path of device node file
1332 * @dev: device
1333 * @mode: returned file access mode
1334 * @uid: returned file owner
1335 * @gid: returned file group
1336 * @tmp: possibly allocated string
1337 *
1338 * Return the relative path of a possible device node.
1339 * Non-default names may need to allocate a memory to compose
1340 * a name. This memory is returned in tmp and needs to be
1341 * freed by the caller.
1342 */
1343const char *device_get_devnode(struct device *dev,
1344 umode_t *mode, kuid_t *uid, kgid_t *gid,
1345 const char **tmp)
1346{
1347 char *s;
1348
1349 *tmp = NULL;
1350
1351 /* the device type may provide a specific name */
1352 if (dev->type && dev->type->devnode)
1353 *tmp = dev->type->devnode(dev, mode, uid, gid);
1354 if (*tmp)
1355 return *tmp;
1356
1357 /* the class may provide a specific name */
1358 if (dev->class && dev->class->devnode)
1359 *tmp = dev->class->devnode(dev, mode);
1360 if (*tmp)
1361 return *tmp;
1362
1363 /* return name without allocation, tmp == NULL */
1364 if (strchr(dev_name(dev), '!') == NULL)
1365 return dev_name(dev);
1366
1367 /* replace '!' in the name with '/' */
1368 s = kstrdup(dev_name(dev), GFP_KERNEL);
1369 if (!s)
1370 return NULL;
1371 strreplace(s, '!', '/');
1372 return *tmp = s;
1373}
1374
1375/**
1376 * device_for_each_child - device child iterator.
1377 * @parent: parent struct device.
1378 * @fn: function to be called for each device.
1379 * @data: data for the callback.
1380 *
1381 * Iterate over @parent's child devices, and call @fn for each,
1382 * passing it @data.
1383 *
1384 * We check the return of @fn each time. If it returns anything
1385 * other than 0, we break out and return that value.
1386 */
1387int device_for_each_child(struct device *parent, void *data,
1388 int (*fn)(struct device *dev, void *data))
1389{
1390 struct klist_iter i;
1391 struct device *child;
1392 int error = 0;
1393
1394 if (!parent->p)
1395 return 0;
1396
1397 klist_iter_init(&parent->p->klist_children, &i);
1398 while ((child = next_device(&i)) && !error)
1399 error = fn(child, data);
1400 klist_iter_exit(&i);
1401 return error;
1402}
1403EXPORT_SYMBOL_GPL(device_for_each_child);
1404
1405/**
1406 * device_for_each_child_reverse - device child iterator in reversed order.
1407 * @parent: parent struct device.
1408 * @fn: function to be called for each device.
1409 * @data: data for the callback.
1410 *
1411 * Iterate over @parent's child devices, and call @fn for each,
1412 * passing it @data.
1413 *
1414 * We check the return of @fn each time. If it returns anything
1415 * other than 0, we break out and return that value.
1416 */
1417int device_for_each_child_reverse(struct device *parent, void *data,
1418 int (*fn)(struct device *dev, void *data))
1419{
1420 struct klist_iter i;
1421 struct device *child;
1422 int error = 0;
1423
1424 if (!parent->p)
1425 return 0;
1426
1427 klist_iter_init(&parent->p->klist_children, &i);
1428 while ((child = prev_device(&i)) && !error)
1429 error = fn(child, data);
1430 klist_iter_exit(&i);
1431 return error;
1432}
1433EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
1434
1435/**
1436 * device_find_child - device iterator for locating a particular device.
1437 * @parent: parent struct device
1438 * @match: Callback function to check device
1439 * @data: Data to pass to match function
1440 *
1441 * This is similar to the device_for_each_child() function above, but it
1442 * returns a reference to a device that is 'found' for later use, as
1443 * determined by the @match callback.
1444 *
1445 * The callback should return 0 if the device doesn't match and non-zero
1446 * if it does. If the callback returns non-zero and a reference to the
1447 * current device can be obtained, this function will return to the caller
1448 * and not iterate over any more devices.
1449 *
1450 * NOTE: you will need to drop the reference with put_device() after use.
1451 */
1452struct device *device_find_child(struct device *parent, void *data,
1453 int (*match)(struct device *dev, void *data))
1454{
1455 struct klist_iter i;
1456 struct device *child;
1457
1458 if (!parent)
1459 return NULL;
1460
1461 klist_iter_init(&parent->p->klist_children, &i);
1462 while ((child = next_device(&i)))
1463 if (match(child, data) && get_device(child))
1464 break;
1465 klist_iter_exit(&i);
1466 return child;
1467}
1468EXPORT_SYMBOL_GPL(device_find_child);
1469
1470int __init devices_init(void)
1471{
1472 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1473 if (!devices_kset)
1474 return -ENOMEM;
1475 dev_kobj = kobject_create_and_add("dev", NULL);
1476 if (!dev_kobj)
1477 goto dev_kobj_err;
1478 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1479 if (!sysfs_dev_block_kobj)
1480 goto block_kobj_err;
1481 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1482 if (!sysfs_dev_char_kobj)
1483 goto char_kobj_err;
1484
1485 return 0;
1486
1487 char_kobj_err:
1488 kobject_put(sysfs_dev_block_kobj);
1489 block_kobj_err:
1490 kobject_put(dev_kobj);
1491 dev_kobj_err:
1492 kset_unregister(devices_kset);
1493 return -ENOMEM;
1494}
1495
1496static int device_check_offline(struct device *dev, void *not_used)
1497{
1498 int ret;
1499
1500 ret = device_for_each_child(dev, NULL, device_check_offline);
1501 if (ret)
1502 return ret;
1503
1504 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1505}
1506
1507/**
1508 * device_offline - Prepare the device for hot-removal.
1509 * @dev: Device to be put offline.
1510 *
1511 * Execute the device bus type's .offline() callback, if present, to prepare
1512 * the device for a subsequent hot-removal. If that succeeds, the device must
1513 * not be used until either it is removed or its bus type's .online() callback
1514 * is executed.
1515 *
1516 * Call under device_hotplug_lock.
1517 */
1518int device_offline(struct device *dev)
1519{
1520 int ret;
1521
1522 if (dev->offline_disabled)
1523 return -EPERM;
1524
1525 ret = device_for_each_child(dev, NULL, device_check_offline);
1526 if (ret)
1527 return ret;
1528
1529 device_lock(dev);
1530 if (device_supports_offline(dev)) {
1531 if (dev->offline) {
1532 ret = 1;
1533 } else {
1534 ret = dev->bus->offline(dev);
1535 if (!ret) {
1536 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1537 dev->offline = true;
1538 }
1539 }
1540 }
1541 device_unlock(dev);
1542
1543 return ret;
1544}
1545
1546/**
1547 * device_online - Put the device back online after successful device_offline().
1548 * @dev: Device to be put back online.
1549 *
1550 * If device_offline() has been successfully executed for @dev, but the device
1551 * has not been removed subsequently, execute its bus type's .online() callback
1552 * to indicate that the device can be used again.
1553 *
1554 * Call under device_hotplug_lock.
1555 */
1556int device_online(struct device *dev)
1557{
1558 int ret = 0;
1559
1560 device_lock(dev);
1561 if (device_supports_offline(dev)) {
1562 if (dev->offline) {
1563 ret = dev->bus->online(dev);
1564 if (!ret) {
1565 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1566 dev->offline = false;
1567 }
1568 } else {
1569 ret = 1;
1570 }
1571 }
1572 device_unlock(dev);
1573
1574 return ret;
1575}
1576
1577struct root_device {
1578 struct device dev;
1579 struct module *owner;
1580};
1581
1582static inline struct root_device *to_root_device(struct device *d)
1583{
1584 return container_of(d, struct root_device, dev);
1585}
1586
1587static void root_device_release(struct device *dev)
1588{
1589 kfree(to_root_device(dev));
1590}
1591
1592/**
1593 * __root_device_register - allocate and register a root device
1594 * @name: root device name
1595 * @owner: owner module of the root device, usually THIS_MODULE
1596 *
1597 * This function allocates a root device and registers it
1598 * using device_register(). In order to free the returned
1599 * device, use root_device_unregister().
1600 *
1601 * Root devices are dummy devices which allow other devices
1602 * to be grouped under /sys/devices. Use this function to
1603 * allocate a root device and then use it as the parent of
1604 * any device which should appear under /sys/devices/{name}
1605 *
1606 * The /sys/devices/{name} directory will also contain a
1607 * 'module' symlink which points to the @owner directory
1608 * in sysfs.
1609 *
1610 * Returns &struct device pointer on success, or ERR_PTR() on error.
1611 *
1612 * Note: You probably want to use root_device_register().
1613 */
1614struct device *__root_device_register(const char *name, struct module *owner)
1615{
1616 struct root_device *root;
1617 int err = -ENOMEM;
1618
1619 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1620 if (!root)
1621 return ERR_PTR(err);
1622
1623 err = dev_set_name(&root->dev, "%s", name);
1624 if (err) {
1625 kfree(root);
1626 return ERR_PTR(err);
1627 }
1628
1629 root->dev.release = root_device_release;
1630
1631 err = device_register(&root->dev);
1632 if (err) {
1633 put_device(&root->dev);
1634 return ERR_PTR(err);
1635 }
1636
1637#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1638 if (owner) {
1639 struct module_kobject *mk = &owner->mkobj;
1640
1641 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1642 if (err) {
1643 device_unregister(&root->dev);
1644 return ERR_PTR(err);
1645 }
1646 root->owner = owner;
1647 }
1648#endif
1649
1650 return &root->dev;
1651}
1652EXPORT_SYMBOL_GPL(__root_device_register);
1653
1654/**
1655 * root_device_unregister - unregister and free a root device
1656 * @dev: device going away
1657 *
1658 * This function unregisters and cleans up a device that was created by
1659 * root_device_register().
1660 */
1661void root_device_unregister(struct device *dev)
1662{
1663 struct root_device *root = to_root_device(dev);
1664
1665 if (root->owner)
1666 sysfs_remove_link(&root->dev.kobj, "module");
1667
1668 device_unregister(dev);
1669}
1670EXPORT_SYMBOL_GPL(root_device_unregister);
1671
1672
1673static void device_create_release(struct device *dev)
1674{
1675 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1676 kfree(dev);
1677}
1678
1679static struct device *
1680device_create_groups_vargs(struct class *class, struct device *parent,
1681 dev_t devt, void *drvdata,
1682 const struct attribute_group **groups,
1683 const char *fmt, va_list args)
1684{
1685 struct device *dev = NULL;
1686 int retval = -ENODEV;
1687
1688 if (class == NULL || IS_ERR(class))
1689 goto error;
1690
1691 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1692 if (!dev) {
1693 retval = -ENOMEM;
1694 goto error;
1695 }
1696
1697 device_initialize(dev);
1698 dev->devt = devt;
1699 dev->class = class;
1700 dev->parent = parent;
1701 dev->groups = groups;
1702 dev->release = device_create_release;
1703 dev_set_drvdata(dev, drvdata);
1704
1705 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1706 if (retval)
1707 goto error;
1708
1709 retval = device_add(dev);
1710 if (retval)
1711 goto error;
1712
1713 return dev;
1714
1715error:
1716 put_device(dev);
1717 return ERR_PTR(retval);
1718}
1719
1720/**
1721 * device_create_vargs - creates a device and registers it with sysfs
1722 * @class: pointer to the struct class that this device should be registered to
1723 * @parent: pointer to the parent struct device of this new device, if any
1724 * @devt: the dev_t for the char device to be added
1725 * @drvdata: the data to be added to the device for callbacks
1726 * @fmt: string for the device's name
1727 * @args: va_list for the device's name
1728 *
1729 * This function can be used by char device classes. A struct device
1730 * will be created in sysfs, registered to the specified class.
1731 *
1732 * A "dev" file will be created, showing the dev_t for the device, if
1733 * the dev_t is not 0,0.
1734 * If a pointer to a parent struct device is passed in, the newly created
1735 * struct device will be a child of that device in sysfs.
1736 * The pointer to the struct device will be returned from the call.
1737 * Any further sysfs files that might be required can be created using this
1738 * pointer.
1739 *
1740 * Returns &struct device pointer on success, or ERR_PTR() on error.
1741 *
1742 * Note: the struct class passed to this function must have previously
1743 * been created with a call to class_create().
1744 */
1745struct device *device_create_vargs(struct class *class, struct device *parent,
1746 dev_t devt, void *drvdata, const char *fmt,
1747 va_list args)
1748{
1749 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1750 fmt, args);
1751}
1752EXPORT_SYMBOL_GPL(device_create_vargs);
1753
1754/**
1755 * device_create - creates a device and registers it with sysfs
1756 * @class: pointer to the struct class that this device should be registered to
1757 * @parent: pointer to the parent struct device of this new device, if any
1758 * @devt: the dev_t for the char device to be added
1759 * @drvdata: the data to be added to the device for callbacks
1760 * @fmt: string for the device's name
1761 *
1762 * This function can be used by char device classes. A struct device
1763 * will be created in sysfs, registered to the specified class.
1764 *
1765 * A "dev" file will be created, showing the dev_t for the device, if
1766 * the dev_t is not 0,0.
1767 * If a pointer to a parent struct device is passed in, the newly created
1768 * struct device will be a child of that device in sysfs.
1769 * The pointer to the struct device will be returned from the call.
1770 * Any further sysfs files that might be required can be created using this
1771 * pointer.
1772 *
1773 * Returns &struct device pointer on success, or ERR_PTR() on error.
1774 *
1775 * Note: the struct class passed to this function must have previously
1776 * been created with a call to class_create().
1777 */
1778struct device *device_create(struct class *class, struct device *parent,
1779 dev_t devt, void *drvdata, const char *fmt, ...)
1780{
1781 va_list vargs;
1782 struct device *dev;
1783
1784 va_start(vargs, fmt);
1785 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1786 va_end(vargs);
1787 return dev;
1788}
1789EXPORT_SYMBOL_GPL(device_create);
1790
1791/**
1792 * device_create_with_groups - creates a device and registers it with sysfs
1793 * @class: pointer to the struct class that this device should be registered to
1794 * @parent: pointer to the parent struct device of this new device, if any
1795 * @devt: the dev_t for the char device to be added
1796 * @drvdata: the data to be added to the device for callbacks
1797 * @groups: NULL-terminated list of attribute groups to be created
1798 * @fmt: string for the device's name
1799 *
1800 * This function can be used by char device classes. A struct device
1801 * will be created in sysfs, registered to the specified class.
1802 * Additional attributes specified in the groups parameter will also
1803 * be created automatically.
1804 *
1805 * A "dev" file will be created, showing the dev_t for the device, if
1806 * the dev_t is not 0,0.
1807 * If a pointer to a parent struct device is passed in, the newly created
1808 * struct device will be a child of that device in sysfs.
1809 * The pointer to the struct device will be returned from the call.
1810 * Any further sysfs files that might be required can be created using this
1811 * pointer.
1812 *
1813 * Returns &struct device pointer on success, or ERR_PTR() on error.
1814 *
1815 * Note: the struct class passed to this function must have previously
1816 * been created with a call to class_create().
1817 */
1818struct device *device_create_with_groups(struct class *class,
1819 struct device *parent, dev_t devt,
1820 void *drvdata,
1821 const struct attribute_group **groups,
1822 const char *fmt, ...)
1823{
1824 va_list vargs;
1825 struct device *dev;
1826
1827 va_start(vargs, fmt);
1828 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1829 fmt, vargs);
1830 va_end(vargs);
1831 return dev;
1832}
1833EXPORT_SYMBOL_GPL(device_create_with_groups);
1834
1835static int __match_devt(struct device *dev, const void *data)
1836{
1837 const dev_t *devt = data;
1838
1839 return dev->devt == *devt;
1840}
1841
1842/**
1843 * device_destroy - removes a device that was created with device_create()
1844 * @class: pointer to the struct class that this device was registered with
1845 * @devt: the dev_t of the device that was previously registered
1846 *
1847 * This call unregisters and cleans up a device that was created with a
1848 * call to device_create().
1849 */
1850void device_destroy(struct class *class, dev_t devt)
1851{
1852 struct device *dev;
1853
1854 dev = class_find_device(class, NULL, &devt, __match_devt);
1855 if (dev) {
1856 put_device(dev);
1857 device_unregister(dev);
1858 }
1859}
1860EXPORT_SYMBOL_GPL(device_destroy);
1861
1862/**
1863 * device_rename - renames a device
1864 * @dev: the pointer to the struct device to be renamed
1865 * @new_name: the new name of the device
1866 *
1867 * It is the responsibility of the caller to provide mutual
1868 * exclusion between two different calls of device_rename
1869 * on the same device to ensure that new_name is valid and
1870 * won't conflict with other devices.
1871 *
1872 * Note: Don't call this function. Currently, the networking layer calls this
1873 * function, but that will change. The following text from Kay Sievers offers
1874 * some insight:
1875 *
1876 * Renaming devices is racy at many levels, symlinks and other stuff are not
1877 * replaced atomically, and you get a "move" uevent, but it's not easy to
1878 * connect the event to the old and new device. Device nodes are not renamed at
1879 * all, there isn't even support for that in the kernel now.
1880 *
1881 * In the meantime, during renaming, your target name might be taken by another
1882 * driver, creating conflicts. Or the old name is taken directly after you
1883 * renamed it -- then you get events for the same DEVPATH, before you even see
1884 * the "move" event. It's just a mess, and nothing new should ever rely on
1885 * kernel device renaming. Besides that, it's not even implemented now for
1886 * other things than (driver-core wise very simple) network devices.
1887 *
1888 * We are currently about to change network renaming in udev to completely
1889 * disallow renaming of devices in the same namespace as the kernel uses,
1890 * because we can't solve the problems properly, that arise with swapping names
1891 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1892 * be allowed to some other name than eth[0-9]*, for the aforementioned
1893 * reasons.
1894 *
1895 * Make up a "real" name in the driver before you register anything, or add
1896 * some other attributes for userspace to find the device, or use udev to add
1897 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1898 * don't even want to get into that and try to implement the missing pieces in
1899 * the core. We really have other pieces to fix in the driver core mess. :)
1900 */
1901int device_rename(struct device *dev, const char *new_name)
1902{
1903 struct kobject *kobj = &dev->kobj;
1904 char *old_device_name = NULL;
1905 int error;
1906
1907 dev = get_device(dev);
1908 if (!dev)
1909 return -EINVAL;
1910
1911 dev_dbg(dev, "renaming to %s\n", new_name);
1912
1913 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1914 if (!old_device_name) {
1915 error = -ENOMEM;
1916 goto out;
1917 }
1918
1919 if (dev->class) {
1920 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1921 kobj, old_device_name,
1922 new_name, kobject_namespace(kobj));
1923 if (error)
1924 goto out;
1925 }
1926
1927 error = kobject_rename(kobj, new_name);
1928 if (error)
1929 goto out;
1930
1931out:
1932 put_device(dev);
1933
1934 kfree(old_device_name);
1935
1936 return error;
1937}
1938EXPORT_SYMBOL_GPL(device_rename);
1939
1940static int device_move_class_links(struct device *dev,
1941 struct device *old_parent,
1942 struct device *new_parent)
1943{
1944 int error = 0;
1945
1946 if (old_parent)
1947 sysfs_remove_link(&dev->kobj, "device");
1948 if (new_parent)
1949 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1950 "device");
1951 return error;
1952}
1953
1954/**
1955 * device_move - moves a device to a new parent
1956 * @dev: the pointer to the struct device to be moved
1957 * @new_parent: the new parent of the device (can by NULL)
1958 * @dpm_order: how to reorder the dpm_list
1959 */
1960int device_move(struct device *dev, struct device *new_parent,
1961 enum dpm_order dpm_order)
1962{
1963 int error;
1964 struct device *old_parent;
1965 struct kobject *new_parent_kobj;
1966
1967 dev = get_device(dev);
1968 if (!dev)
1969 return -EINVAL;
1970
1971 device_pm_lock();
1972 new_parent = get_device(new_parent);
1973 new_parent_kobj = get_device_parent(dev, new_parent);
1974
1975 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1976 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1977 error = kobject_move(&dev->kobj, new_parent_kobj);
1978 if (error) {
1979 cleanup_glue_dir(dev, new_parent_kobj);
1980 put_device(new_parent);
1981 goto out;
1982 }
1983 old_parent = dev->parent;
1984 dev->parent = new_parent;
1985 if (old_parent)
1986 klist_remove(&dev->p->knode_parent);
1987 if (new_parent) {
1988 klist_add_tail(&dev->p->knode_parent,
1989 &new_parent->p->klist_children);
1990 set_dev_node(dev, dev_to_node(new_parent));
1991 }
1992
1993 if (dev->class) {
1994 error = device_move_class_links(dev, old_parent, new_parent);
1995 if (error) {
1996 /* We ignore errors on cleanup since we're hosed anyway... */
1997 device_move_class_links(dev, new_parent, old_parent);
1998 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1999 if (new_parent)
2000 klist_remove(&dev->p->knode_parent);
2001 dev->parent = old_parent;
2002 if (old_parent) {
2003 klist_add_tail(&dev->p->knode_parent,
2004 &old_parent->p->klist_children);
2005 set_dev_node(dev, dev_to_node(old_parent));
2006 }
2007 }
2008 cleanup_glue_dir(dev, new_parent_kobj);
2009 put_device(new_parent);
2010 goto out;
2011 }
2012 }
2013 switch (dpm_order) {
2014 case DPM_ORDER_NONE:
2015 break;
2016 case DPM_ORDER_DEV_AFTER_PARENT:
2017 device_pm_move_after(dev, new_parent);
2018 devices_kset_move_after(dev, new_parent);
2019 break;
2020 case DPM_ORDER_PARENT_BEFORE_DEV:
2021 device_pm_move_before(new_parent, dev);
2022 devices_kset_move_before(new_parent, dev);
2023 break;
2024 case DPM_ORDER_DEV_LAST:
2025 device_pm_move_last(dev);
2026 devices_kset_move_last(dev);
2027 break;
2028 }
2029
2030 put_device(old_parent);
2031out:
2032 device_pm_unlock();
2033 put_device(dev);
2034 return error;
2035}
2036EXPORT_SYMBOL_GPL(device_move);
2037
2038/**
2039 * device_shutdown - call ->shutdown() on each device to shutdown.
2040 */
2041void device_shutdown(void)
2042{
2043 struct device *dev, *parent;
2044
2045 spin_lock(&devices_kset->list_lock);
2046 /*
2047 * Walk the devices list backward, shutting down each in turn.
2048 * Beware that device unplug events may also start pulling
2049 * devices offline, even as the system is shutting down.
2050 */
2051 while (!list_empty(&devices_kset->list)) {
2052 dev = list_entry(devices_kset->list.prev, struct device,
2053 kobj.entry);
2054
2055 /*
2056 * hold reference count of device's parent to
2057 * prevent it from being freed because parent's
2058 * lock is to be held
2059 */
2060 parent = get_device(dev->parent);
2061 get_device(dev);
2062 /*
2063 * Make sure the device is off the kset list, in the
2064 * event that dev->*->shutdown() doesn't remove it.
2065 */
2066 list_del_init(&dev->kobj.entry);
2067 spin_unlock(&devices_kset->list_lock);
2068
2069 /* hold lock to avoid race with probe/release */
2070 if (parent)
2071 device_lock(parent);
2072 device_lock(dev);
2073
2074 /* Don't allow any more runtime suspends */
2075 pm_runtime_get_noresume(dev);
2076 pm_runtime_barrier(dev);
2077
2078 if (dev->bus && dev->bus->shutdown) {
2079 if (initcall_debug)
2080 dev_info(dev, "shutdown\n");
2081 dev->bus->shutdown(dev);
2082 } else if (dev->driver && dev->driver->shutdown) {
2083 if (initcall_debug)
2084 dev_info(dev, "shutdown\n");
2085 dev->driver->shutdown(dev);
2086 }
2087
2088 device_unlock(dev);
2089 if (parent)
2090 device_unlock(parent);
2091
2092 put_device(dev);
2093 put_device(parent);
2094
2095 spin_lock(&devices_kset->list_lock);
2096 }
2097 spin_unlock(&devices_kset->list_lock);
2098}
2099
2100/*
2101 * Device logging functions
2102 */
2103
2104#ifdef CONFIG_PRINTK
2105static int
2106create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2107{
2108 const char *subsys;
2109 size_t pos = 0;
2110
2111 if (dev->class)
2112 subsys = dev->class->name;
2113 else if (dev->bus)
2114 subsys = dev->bus->name;
2115 else
2116 return 0;
2117
2118 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2119 if (pos >= hdrlen)
2120 goto overflow;
2121
2122 /*
2123 * Add device identifier DEVICE=:
2124 * b12:8 block dev_t
2125 * c127:3 char dev_t
2126 * n8 netdev ifindex
2127 * +sound:card0 subsystem:devname
2128 */
2129 if (MAJOR(dev->devt)) {
2130 char c;
2131
2132 if (strcmp(subsys, "block") == 0)
2133 c = 'b';
2134 else
2135 c = 'c';
2136 pos++;
2137 pos += snprintf(hdr + pos, hdrlen - pos,
2138 "DEVICE=%c%u:%u",
2139 c, MAJOR(dev->devt), MINOR(dev->devt));
2140 } else if (strcmp(subsys, "net") == 0) {
2141 struct net_device *net = to_net_dev(dev);
2142
2143 pos++;
2144 pos += snprintf(hdr + pos, hdrlen - pos,
2145 "DEVICE=n%u", net->ifindex);
2146 } else {
2147 pos++;
2148 pos += snprintf(hdr + pos, hdrlen - pos,
2149 "DEVICE=+%s:%s", subsys, dev_name(dev));
2150 }
2151
2152 if (pos >= hdrlen)
2153 goto overflow;
2154
2155 return pos;
2156
2157overflow:
2158 dev_WARN(dev, "device/subsystem name too long");
2159 return 0;
2160}
2161
2162int dev_vprintk_emit(int level, const struct device *dev,
2163 const char *fmt, va_list args)
2164{
2165 char hdr[128];
2166 size_t hdrlen;
2167
2168 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2169
2170 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2171}
2172EXPORT_SYMBOL(dev_vprintk_emit);
2173
2174int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2175{
2176 va_list args;
2177 int r;
2178
2179 va_start(args, fmt);
2180
2181 r = dev_vprintk_emit(level, dev, fmt, args);
2182
2183 va_end(args);
2184
2185 return r;
2186}
2187EXPORT_SYMBOL(dev_printk_emit);
2188
2189static void __dev_printk(const char *level, const struct device *dev,
2190 struct va_format *vaf)
2191{
2192 if (dev)
2193 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2194 dev_driver_string(dev), dev_name(dev), vaf);
2195 else
2196 printk("%s(NULL device *): %pV", level, vaf);
2197}
2198
2199void dev_printk(const char *level, const struct device *dev,
2200 const char *fmt, ...)
2201{
2202 struct va_format vaf;
2203 va_list args;
2204
2205 va_start(args, fmt);
2206
2207 vaf.fmt = fmt;
2208 vaf.va = &args;
2209
2210 __dev_printk(level, dev, &vaf);
2211
2212 va_end(args);
2213}
2214EXPORT_SYMBOL(dev_printk);
2215
2216#define define_dev_printk_level(func, kern_level) \
2217void func(const struct device *dev, const char *fmt, ...) \
2218{ \
2219 struct va_format vaf; \
2220 va_list args; \
2221 \
2222 va_start(args, fmt); \
2223 \
2224 vaf.fmt = fmt; \
2225 vaf.va = &args; \
2226 \
2227 __dev_printk(kern_level, dev, &vaf); \
2228 \
2229 va_end(args); \
2230} \
2231EXPORT_SYMBOL(func);
2232
2233define_dev_printk_level(dev_emerg, KERN_EMERG);
2234define_dev_printk_level(dev_alert, KERN_ALERT);
2235define_dev_printk_level(dev_crit, KERN_CRIT);
2236define_dev_printk_level(dev_err, KERN_ERR);
2237define_dev_printk_level(dev_warn, KERN_WARNING);
2238define_dev_printk_level(dev_notice, KERN_NOTICE);
2239define_dev_printk_level(_dev_info, KERN_INFO);
2240
2241#endif
2242
2243static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2244{
2245 return fwnode && !IS_ERR(fwnode->secondary);
2246}
2247
2248/**
2249 * set_primary_fwnode - Change the primary firmware node of a given device.
2250 * @dev: Device to handle.
2251 * @fwnode: New primary firmware node of the device.
2252 *
2253 * Set the device's firmware node pointer to @fwnode, but if a secondary
2254 * firmware node of the device is present, preserve it.
2255 */
2256void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2257{
2258 if (fwnode) {
2259 struct fwnode_handle *fn = dev->fwnode;
2260
2261 if (fwnode_is_primary(fn))
2262 fn = fn->secondary;
2263
2264 if (fn) {
2265 WARN_ON(fwnode->secondary);
2266 fwnode->secondary = fn;
2267 }
2268 dev->fwnode = fwnode;
2269 } else {
2270 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2271 dev->fwnode->secondary : NULL;
2272 }
2273}
2274EXPORT_SYMBOL_GPL(set_primary_fwnode);
2275
2276/**
2277 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2278 * @dev: Device to handle.
2279 * @fwnode: New secondary firmware node of the device.
2280 *
2281 * If a primary firmware node of the device is present, set its secondary
2282 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2283 * @fwnode.
2284 */
2285void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2286{
2287 if (fwnode)
2288 fwnode->secondary = ERR_PTR(-ENODEV);
2289
2290 if (fwnode_is_primary(dev->fwnode))
2291 dev->fwnode->secondary = fwnode;
2292 else
2293 dev->fwnode = fwnode;
2294}