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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/core.c - core driver model code (device registration, etc)
4 *
5 * Copyright (c) 2002-3 Patrick Mochel
6 * Copyright (c) 2002-3 Open Source Development Labs
7 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
8 * Copyright (c) 2006 Novell, Inc.
9 */
10
11#include <linux/device.h>
12#include <linux/err.h>
13#include <linux/fwnode.h>
14#include <linux/init.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/string.h>
18#include <linux/kdev_t.h>
19#include <linux/notifier.h>
20#include <linux/of.h>
21#include <linux/of_device.h>
22#include <linux/genhd.h>
23#include <linux/mutex.h>
24#include <linux/pm_runtime.h>
25#include <linux/netdevice.h>
26#include <linux/sched/signal.h>
27#include <linux/sysfs.h>
28
29#include "base.h"
30#include "power/power.h"
31
32#ifdef CONFIG_SYSFS_DEPRECATED
33#ifdef CONFIG_SYSFS_DEPRECATED_V2
34long sysfs_deprecated = 1;
35#else
36long sysfs_deprecated = 0;
37#endif
38static int __init sysfs_deprecated_setup(char *arg)
39{
40 return kstrtol(arg, 10, &sysfs_deprecated);
41}
42early_param("sysfs.deprecated", sysfs_deprecated_setup);
43#endif
44
45/* Device links support. */
46
47#ifdef CONFIG_SRCU
48static DEFINE_MUTEX(device_links_lock);
49DEFINE_STATIC_SRCU(device_links_srcu);
50
51static inline void device_links_write_lock(void)
52{
53 mutex_lock(&device_links_lock);
54}
55
56static inline void device_links_write_unlock(void)
57{
58 mutex_unlock(&device_links_lock);
59}
60
61int device_links_read_lock(void)
62{
63 return srcu_read_lock(&device_links_srcu);
64}
65
66void device_links_read_unlock(int idx)
67{
68 srcu_read_unlock(&device_links_srcu, idx);
69}
70#else /* !CONFIG_SRCU */
71static DECLARE_RWSEM(device_links_lock);
72
73static inline void device_links_write_lock(void)
74{
75 down_write(&device_links_lock);
76}
77
78static inline void device_links_write_unlock(void)
79{
80 up_write(&device_links_lock);
81}
82
83int device_links_read_lock(void)
84{
85 down_read(&device_links_lock);
86 return 0;
87}
88
89void device_links_read_unlock(int not_used)
90{
91 up_read(&device_links_lock);
92}
93#endif /* !CONFIG_SRCU */
94
95/**
96 * device_is_dependent - Check if one device depends on another one
97 * @dev: Device to check dependencies for.
98 * @target: Device to check against.
99 *
100 * Check if @target depends on @dev or any device dependent on it (its child or
101 * its consumer etc). Return 1 if that is the case or 0 otherwise.
102 */
103static int device_is_dependent(struct device *dev, void *target)
104{
105 struct device_link *link;
106 int ret;
107
108 if (WARN_ON(dev == target))
109 return 1;
110
111 ret = device_for_each_child(dev, target, device_is_dependent);
112 if (ret)
113 return ret;
114
115 list_for_each_entry(link, &dev->links.consumers, s_node) {
116 if (WARN_ON(link->consumer == target))
117 return 1;
118
119 ret = device_is_dependent(link->consumer, target);
120 if (ret)
121 break;
122 }
123 return ret;
124}
125
126static int device_reorder_to_tail(struct device *dev, void *not_used)
127{
128 struct device_link *link;
129
130 /*
131 * Devices that have not been registered yet will be put to the ends
132 * of the lists during the registration, so skip them here.
133 */
134 if (device_is_registered(dev))
135 devices_kset_move_last(dev);
136
137 if (device_pm_initialized(dev))
138 device_pm_move_last(dev);
139
140 device_for_each_child(dev, NULL, device_reorder_to_tail);
141 list_for_each_entry(link, &dev->links.consumers, s_node)
142 device_reorder_to_tail(link->consumer, NULL);
143
144 return 0;
145}
146
147/**
148 * device_link_add - Create a link between two devices.
149 * @consumer: Consumer end of the link.
150 * @supplier: Supplier end of the link.
151 * @flags: Link flags.
152 *
153 * The caller is responsible for the proper synchronization of the link creation
154 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
155 * runtime PM framework to take the link into account. Second, if the
156 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
157 * be forced into the active metastate and reference-counted upon the creation
158 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
159 * ignored.
160 *
161 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
162 * when the consumer device driver unbinds from it. The combination of both
163 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
164 * to be returned.
165 *
166 * A side effect of the link creation is re-ordering of dpm_list and the
167 * devices_kset list by moving the consumer device and all devices depending
168 * on it to the ends of these lists (that does not happen to devices that have
169 * not been registered when this function is called).
170 *
171 * The supplier device is required to be registered when this function is called
172 * and NULL will be returned if that is not the case. The consumer device need
173 * not be registered, however.
174 */
175struct device_link *device_link_add(struct device *consumer,
176 struct device *supplier, u32 flags)
177{
178 struct device_link *link;
179
180 if (!consumer || !supplier ||
181 ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE)))
182 return NULL;
183
184 device_links_write_lock();
185 device_pm_lock();
186
187 /*
188 * If the supplier has not been fully registered yet or there is a
189 * reverse dependency between the consumer and the supplier already in
190 * the graph, return NULL.
191 */
192 if (!device_pm_initialized(supplier)
193 || device_is_dependent(consumer, supplier)) {
194 link = NULL;
195 goto out;
196 }
197
198 list_for_each_entry(link, &supplier->links.consumers, s_node)
199 if (link->consumer == consumer) {
200 kref_get(&link->kref);
201 goto out;
202 }
203
204 link = kzalloc(sizeof(*link), GFP_KERNEL);
205 if (!link)
206 goto out;
207
208 if (flags & DL_FLAG_PM_RUNTIME) {
209 if (flags & DL_FLAG_RPM_ACTIVE) {
210 if (pm_runtime_get_sync(supplier) < 0) {
211 pm_runtime_put_noidle(supplier);
212 kfree(link);
213 link = NULL;
214 goto out;
215 }
216 link->rpm_active = true;
217 }
218 pm_runtime_new_link(consumer);
219 }
220 get_device(supplier);
221 link->supplier = supplier;
222 INIT_LIST_HEAD(&link->s_node);
223 get_device(consumer);
224 link->consumer = consumer;
225 INIT_LIST_HEAD(&link->c_node);
226 link->flags = flags;
227 kref_init(&link->kref);
228
229 /* Determine the initial link state. */
230 if (flags & DL_FLAG_STATELESS) {
231 link->status = DL_STATE_NONE;
232 } else {
233 switch (supplier->links.status) {
234 case DL_DEV_DRIVER_BOUND:
235 switch (consumer->links.status) {
236 case DL_DEV_PROBING:
237 /*
238 * Balance the decrementation of the supplier's
239 * runtime PM usage counter after consumer probe
240 * in driver_probe_device().
241 */
242 if (flags & DL_FLAG_PM_RUNTIME)
243 pm_runtime_get_sync(supplier);
244
245 link->status = DL_STATE_CONSUMER_PROBE;
246 break;
247 case DL_DEV_DRIVER_BOUND:
248 link->status = DL_STATE_ACTIVE;
249 break;
250 default:
251 link->status = DL_STATE_AVAILABLE;
252 break;
253 }
254 break;
255 case DL_DEV_UNBINDING:
256 link->status = DL_STATE_SUPPLIER_UNBIND;
257 break;
258 default:
259 link->status = DL_STATE_DORMANT;
260 break;
261 }
262 }
263
264 /*
265 * Move the consumer and all of the devices depending on it to the end
266 * of dpm_list and the devices_kset list.
267 *
268 * It is necessary to hold dpm_list locked throughout all that or else
269 * we may end up suspending with a wrong ordering of it.
270 */
271 device_reorder_to_tail(consumer, NULL);
272
273 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
274 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
275
276 dev_info(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
277
278 out:
279 device_pm_unlock();
280 device_links_write_unlock();
281 return link;
282}
283EXPORT_SYMBOL_GPL(device_link_add);
284
285static void device_link_free(struct device_link *link)
286{
287 put_device(link->consumer);
288 put_device(link->supplier);
289 kfree(link);
290}
291
292#ifdef CONFIG_SRCU
293static void __device_link_free_srcu(struct rcu_head *rhead)
294{
295 device_link_free(container_of(rhead, struct device_link, rcu_head));
296}
297
298static void __device_link_del(struct kref *kref)
299{
300 struct device_link *link = container_of(kref, struct device_link, kref);
301
302 dev_info(link->consumer, "Dropping the link to %s\n",
303 dev_name(link->supplier));
304
305 if (link->flags & DL_FLAG_PM_RUNTIME)
306 pm_runtime_drop_link(link->consumer);
307
308 list_del_rcu(&link->s_node);
309 list_del_rcu(&link->c_node);
310 call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
311}
312#else /* !CONFIG_SRCU */
313static void __device_link_del(struct kref *kref)
314{
315 struct device_link *link = container_of(kref, struct device_link, kref);
316
317 dev_info(link->consumer, "Dropping the link to %s\n",
318 dev_name(link->supplier));
319
320 if (link->flags & DL_FLAG_PM_RUNTIME)
321 pm_runtime_drop_link(link->consumer);
322
323 list_del(&link->s_node);
324 list_del(&link->c_node);
325 device_link_free(link);
326}
327#endif /* !CONFIG_SRCU */
328
329/**
330 * device_link_del - Delete a link between two devices.
331 * @link: Device link to delete.
332 *
333 * The caller must ensure proper synchronization of this function with runtime
334 * PM. If the link was added multiple times, it needs to be deleted as often.
335 * Care is required for hotplugged devices: Their links are purged on removal
336 * and calling device_link_del() is then no longer allowed.
337 */
338void device_link_del(struct device_link *link)
339{
340 device_links_write_lock();
341 device_pm_lock();
342 kref_put(&link->kref, __device_link_del);
343 device_pm_unlock();
344 device_links_write_unlock();
345}
346EXPORT_SYMBOL_GPL(device_link_del);
347
348static void device_links_missing_supplier(struct device *dev)
349{
350 struct device_link *link;
351
352 list_for_each_entry(link, &dev->links.suppliers, c_node)
353 if (link->status == DL_STATE_CONSUMER_PROBE)
354 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
355}
356
357/**
358 * device_links_check_suppliers - Check presence of supplier drivers.
359 * @dev: Consumer device.
360 *
361 * Check links from this device to any suppliers. Walk the list of the device's
362 * links to suppliers and see if all of them are available. If not, simply
363 * return -EPROBE_DEFER.
364 *
365 * We need to guarantee that the supplier will not go away after the check has
366 * been positive here. It only can go away in __device_release_driver() and
367 * that function checks the device's links to consumers. This means we need to
368 * mark the link as "consumer probe in progress" to make the supplier removal
369 * wait for us to complete (or bad things may happen).
370 *
371 * Links with the DL_FLAG_STATELESS flag set are ignored.
372 */
373int device_links_check_suppliers(struct device *dev)
374{
375 struct device_link *link;
376 int ret = 0;
377
378 device_links_write_lock();
379
380 list_for_each_entry(link, &dev->links.suppliers, c_node) {
381 if (link->flags & DL_FLAG_STATELESS)
382 continue;
383
384 if (link->status != DL_STATE_AVAILABLE) {
385 device_links_missing_supplier(dev);
386 ret = -EPROBE_DEFER;
387 break;
388 }
389 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
390 }
391 dev->links.status = DL_DEV_PROBING;
392
393 device_links_write_unlock();
394 return ret;
395}
396
397/**
398 * device_links_driver_bound - Update device links after probing its driver.
399 * @dev: Device to update the links for.
400 *
401 * The probe has been successful, so update links from this device to any
402 * consumers by changing their status to "available".
403 *
404 * Also change the status of @dev's links to suppliers to "active".
405 *
406 * Links with the DL_FLAG_STATELESS flag set are ignored.
407 */
408void device_links_driver_bound(struct device *dev)
409{
410 struct device_link *link;
411
412 device_links_write_lock();
413
414 list_for_each_entry(link, &dev->links.consumers, s_node) {
415 if (link->flags & DL_FLAG_STATELESS)
416 continue;
417
418 WARN_ON(link->status != DL_STATE_DORMANT);
419 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
420 }
421
422 list_for_each_entry(link, &dev->links.suppliers, c_node) {
423 if (link->flags & DL_FLAG_STATELESS)
424 continue;
425
426 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
427 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
428 }
429
430 dev->links.status = DL_DEV_DRIVER_BOUND;
431
432 device_links_write_unlock();
433}
434
435/**
436 * __device_links_no_driver - Update links of a device without a driver.
437 * @dev: Device without a drvier.
438 *
439 * Delete all non-persistent links from this device to any suppliers.
440 *
441 * Persistent links stay around, but their status is changed to "available",
442 * unless they already are in the "supplier unbind in progress" state in which
443 * case they need not be updated.
444 *
445 * Links with the DL_FLAG_STATELESS flag set are ignored.
446 */
447static void __device_links_no_driver(struct device *dev)
448{
449 struct device_link *link, *ln;
450
451 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
452 if (link->flags & DL_FLAG_STATELESS)
453 continue;
454
455 if (link->flags & DL_FLAG_AUTOREMOVE)
456 kref_put(&link->kref, __device_link_del);
457 else if (link->status != DL_STATE_SUPPLIER_UNBIND)
458 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
459 }
460
461 dev->links.status = DL_DEV_NO_DRIVER;
462}
463
464void device_links_no_driver(struct device *dev)
465{
466 device_links_write_lock();
467 __device_links_no_driver(dev);
468 device_links_write_unlock();
469}
470
471/**
472 * device_links_driver_cleanup - Update links after driver removal.
473 * @dev: Device whose driver has just gone away.
474 *
475 * Update links to consumers for @dev by changing their status to "dormant" and
476 * invoke %__device_links_no_driver() to update links to suppliers for it as
477 * appropriate.
478 *
479 * Links with the DL_FLAG_STATELESS flag set are ignored.
480 */
481void device_links_driver_cleanup(struct device *dev)
482{
483 struct device_link *link;
484
485 device_links_write_lock();
486
487 list_for_each_entry(link, &dev->links.consumers, s_node) {
488 if (link->flags & DL_FLAG_STATELESS)
489 continue;
490
491 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE);
492 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
493 WRITE_ONCE(link->status, DL_STATE_DORMANT);
494 }
495
496 __device_links_no_driver(dev);
497
498 device_links_write_unlock();
499}
500
501/**
502 * device_links_busy - Check if there are any busy links to consumers.
503 * @dev: Device to check.
504 *
505 * Check each consumer of the device and return 'true' if its link's status
506 * is one of "consumer probe" or "active" (meaning that the given consumer is
507 * probing right now or its driver is present). Otherwise, change the link
508 * state to "supplier unbind" to prevent the consumer from being probed
509 * successfully going forward.
510 *
511 * Return 'false' if there are no probing or active consumers.
512 *
513 * Links with the DL_FLAG_STATELESS flag set are ignored.
514 */
515bool device_links_busy(struct device *dev)
516{
517 struct device_link *link;
518 bool ret = false;
519
520 device_links_write_lock();
521
522 list_for_each_entry(link, &dev->links.consumers, s_node) {
523 if (link->flags & DL_FLAG_STATELESS)
524 continue;
525
526 if (link->status == DL_STATE_CONSUMER_PROBE
527 || link->status == DL_STATE_ACTIVE) {
528 ret = true;
529 break;
530 }
531 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
532 }
533
534 dev->links.status = DL_DEV_UNBINDING;
535
536 device_links_write_unlock();
537 return ret;
538}
539
540/**
541 * device_links_unbind_consumers - Force unbind consumers of the given device.
542 * @dev: Device to unbind the consumers of.
543 *
544 * Walk the list of links to consumers for @dev and if any of them is in the
545 * "consumer probe" state, wait for all device probes in progress to complete
546 * and start over.
547 *
548 * If that's not the case, change the status of the link to "supplier unbind"
549 * and check if the link was in the "active" state. If so, force the consumer
550 * driver to unbind and start over (the consumer will not re-probe as we have
551 * changed the state of the link already).
552 *
553 * Links with the DL_FLAG_STATELESS flag set are ignored.
554 */
555void device_links_unbind_consumers(struct device *dev)
556{
557 struct device_link *link;
558
559 start:
560 device_links_write_lock();
561
562 list_for_each_entry(link, &dev->links.consumers, s_node) {
563 enum device_link_state status;
564
565 if (link->flags & DL_FLAG_STATELESS)
566 continue;
567
568 status = link->status;
569 if (status == DL_STATE_CONSUMER_PROBE) {
570 device_links_write_unlock();
571
572 wait_for_device_probe();
573 goto start;
574 }
575 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
576 if (status == DL_STATE_ACTIVE) {
577 struct device *consumer = link->consumer;
578
579 get_device(consumer);
580
581 device_links_write_unlock();
582
583 device_release_driver_internal(consumer, NULL,
584 consumer->parent);
585 put_device(consumer);
586 goto start;
587 }
588 }
589
590 device_links_write_unlock();
591}
592
593/**
594 * device_links_purge - Delete existing links to other devices.
595 * @dev: Target device.
596 */
597static void device_links_purge(struct device *dev)
598{
599 struct device_link *link, *ln;
600
601 /*
602 * Delete all of the remaining links from this device to any other
603 * devices (either consumers or suppliers).
604 */
605 device_links_write_lock();
606
607 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
608 WARN_ON(link->status == DL_STATE_ACTIVE);
609 __device_link_del(&link->kref);
610 }
611
612 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
613 WARN_ON(link->status != DL_STATE_DORMANT &&
614 link->status != DL_STATE_NONE);
615 __device_link_del(&link->kref);
616 }
617
618 device_links_write_unlock();
619}
620
621/* Device links support end. */
622
623int (*platform_notify)(struct device *dev) = NULL;
624int (*platform_notify_remove)(struct device *dev) = NULL;
625static struct kobject *dev_kobj;
626struct kobject *sysfs_dev_char_kobj;
627struct kobject *sysfs_dev_block_kobj;
628
629static DEFINE_MUTEX(device_hotplug_lock);
630
631void lock_device_hotplug(void)
632{
633 mutex_lock(&device_hotplug_lock);
634}
635
636void unlock_device_hotplug(void)
637{
638 mutex_unlock(&device_hotplug_lock);
639}
640
641int lock_device_hotplug_sysfs(void)
642{
643 if (mutex_trylock(&device_hotplug_lock))
644 return 0;
645
646 /* Avoid busy looping (5 ms of sleep should do). */
647 msleep(5);
648 return restart_syscall();
649}
650
651#ifdef CONFIG_BLOCK
652static inline int device_is_not_partition(struct device *dev)
653{
654 return !(dev->type == &part_type);
655}
656#else
657static inline int device_is_not_partition(struct device *dev)
658{
659 return 1;
660}
661#endif
662
663/**
664 * dev_driver_string - Return a device's driver name, if at all possible
665 * @dev: struct device to get the name of
666 *
667 * Will return the device's driver's name if it is bound to a device. If
668 * the device is not bound to a driver, it will return the name of the bus
669 * it is attached to. If it is not attached to a bus either, an empty
670 * string will be returned.
671 */
672const char *dev_driver_string(const struct device *dev)
673{
674 struct device_driver *drv;
675
676 /* dev->driver can change to NULL underneath us because of unbinding,
677 * so be careful about accessing it. dev->bus and dev->class should
678 * never change once they are set, so they don't need special care.
679 */
680 drv = READ_ONCE(dev->driver);
681 return drv ? drv->name :
682 (dev->bus ? dev->bus->name :
683 (dev->class ? dev->class->name : ""));
684}
685EXPORT_SYMBOL(dev_driver_string);
686
687#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
688
689static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
690 char *buf)
691{
692 struct device_attribute *dev_attr = to_dev_attr(attr);
693 struct device *dev = kobj_to_dev(kobj);
694 ssize_t ret = -EIO;
695
696 if (dev_attr->show)
697 ret = dev_attr->show(dev, dev_attr, buf);
698 if (ret >= (ssize_t)PAGE_SIZE) {
699 printk("dev_attr_show: %pS returned bad count\n",
700 dev_attr->show);
701 }
702 return ret;
703}
704
705static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
706 const char *buf, size_t count)
707{
708 struct device_attribute *dev_attr = to_dev_attr(attr);
709 struct device *dev = kobj_to_dev(kobj);
710 ssize_t ret = -EIO;
711
712 if (dev_attr->store)
713 ret = dev_attr->store(dev, dev_attr, buf, count);
714 return ret;
715}
716
717static const struct sysfs_ops dev_sysfs_ops = {
718 .show = dev_attr_show,
719 .store = dev_attr_store,
720};
721
722#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
723
724ssize_t device_store_ulong(struct device *dev,
725 struct device_attribute *attr,
726 const char *buf, size_t size)
727{
728 struct dev_ext_attribute *ea = to_ext_attr(attr);
729 char *end;
730 unsigned long new = simple_strtoul(buf, &end, 0);
731 if (end == buf)
732 return -EINVAL;
733 *(unsigned long *)(ea->var) = new;
734 /* Always return full write size even if we didn't consume all */
735 return size;
736}
737EXPORT_SYMBOL_GPL(device_store_ulong);
738
739ssize_t device_show_ulong(struct device *dev,
740 struct device_attribute *attr,
741 char *buf)
742{
743 struct dev_ext_attribute *ea = to_ext_attr(attr);
744 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
745}
746EXPORT_SYMBOL_GPL(device_show_ulong);
747
748ssize_t device_store_int(struct device *dev,
749 struct device_attribute *attr,
750 const char *buf, size_t size)
751{
752 struct dev_ext_attribute *ea = to_ext_attr(attr);
753 char *end;
754 long new = simple_strtol(buf, &end, 0);
755 if (end == buf || new > INT_MAX || new < INT_MIN)
756 return -EINVAL;
757 *(int *)(ea->var) = new;
758 /* Always return full write size even if we didn't consume all */
759 return size;
760}
761EXPORT_SYMBOL_GPL(device_store_int);
762
763ssize_t device_show_int(struct device *dev,
764 struct device_attribute *attr,
765 char *buf)
766{
767 struct dev_ext_attribute *ea = to_ext_attr(attr);
768
769 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
770}
771EXPORT_SYMBOL_GPL(device_show_int);
772
773ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
774 const char *buf, size_t size)
775{
776 struct dev_ext_attribute *ea = to_ext_attr(attr);
777
778 if (strtobool(buf, ea->var) < 0)
779 return -EINVAL;
780
781 return size;
782}
783EXPORT_SYMBOL_GPL(device_store_bool);
784
785ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
786 char *buf)
787{
788 struct dev_ext_attribute *ea = to_ext_attr(attr);
789
790 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
791}
792EXPORT_SYMBOL_GPL(device_show_bool);
793
794/**
795 * device_release - free device structure.
796 * @kobj: device's kobject.
797 *
798 * This is called once the reference count for the object
799 * reaches 0. We forward the call to the device's release
800 * method, which should handle actually freeing the structure.
801 */
802static void device_release(struct kobject *kobj)
803{
804 struct device *dev = kobj_to_dev(kobj);
805 struct device_private *p = dev->p;
806
807 /*
808 * Some platform devices are driven without driver attached
809 * and managed resources may have been acquired. Make sure
810 * all resources are released.
811 *
812 * Drivers still can add resources into device after device
813 * is deleted but alive, so release devres here to avoid
814 * possible memory leak.
815 */
816 devres_release_all(dev);
817
818 if (dev->release)
819 dev->release(dev);
820 else if (dev->type && dev->type->release)
821 dev->type->release(dev);
822 else if (dev->class && dev->class->dev_release)
823 dev->class->dev_release(dev);
824 else
825 WARN(1, KERN_ERR "Device '%s' does not have a release() "
826 "function, it is broken and must be fixed.\n",
827 dev_name(dev));
828 kfree(p);
829}
830
831static const void *device_namespace(struct kobject *kobj)
832{
833 struct device *dev = kobj_to_dev(kobj);
834 const void *ns = NULL;
835
836 if (dev->class && dev->class->ns_type)
837 ns = dev->class->namespace(dev);
838
839 return ns;
840}
841
842static struct kobj_type device_ktype = {
843 .release = device_release,
844 .sysfs_ops = &dev_sysfs_ops,
845 .namespace = device_namespace,
846};
847
848
849static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
850{
851 struct kobj_type *ktype = get_ktype(kobj);
852
853 if (ktype == &device_ktype) {
854 struct device *dev = kobj_to_dev(kobj);
855 if (dev->bus)
856 return 1;
857 if (dev->class)
858 return 1;
859 }
860 return 0;
861}
862
863static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
864{
865 struct device *dev = kobj_to_dev(kobj);
866
867 if (dev->bus)
868 return dev->bus->name;
869 if (dev->class)
870 return dev->class->name;
871 return NULL;
872}
873
874static int dev_uevent(struct kset *kset, struct kobject *kobj,
875 struct kobj_uevent_env *env)
876{
877 struct device *dev = kobj_to_dev(kobj);
878 int retval = 0;
879
880 /* add device node properties if present */
881 if (MAJOR(dev->devt)) {
882 const char *tmp;
883 const char *name;
884 umode_t mode = 0;
885 kuid_t uid = GLOBAL_ROOT_UID;
886 kgid_t gid = GLOBAL_ROOT_GID;
887
888 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
889 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
890 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
891 if (name) {
892 add_uevent_var(env, "DEVNAME=%s", name);
893 if (mode)
894 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
895 if (!uid_eq(uid, GLOBAL_ROOT_UID))
896 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
897 if (!gid_eq(gid, GLOBAL_ROOT_GID))
898 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
899 kfree(tmp);
900 }
901 }
902
903 if (dev->type && dev->type->name)
904 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
905
906 if (dev->driver)
907 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
908
909 /* Add common DT information about the device */
910 of_device_uevent(dev, env);
911
912 /* have the bus specific function add its stuff */
913 if (dev->bus && dev->bus->uevent) {
914 retval = dev->bus->uevent(dev, env);
915 if (retval)
916 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
917 dev_name(dev), __func__, retval);
918 }
919
920 /* have the class specific function add its stuff */
921 if (dev->class && dev->class->dev_uevent) {
922 retval = dev->class->dev_uevent(dev, env);
923 if (retval)
924 pr_debug("device: '%s': %s: class uevent() "
925 "returned %d\n", dev_name(dev),
926 __func__, retval);
927 }
928
929 /* have the device type specific function add its stuff */
930 if (dev->type && dev->type->uevent) {
931 retval = dev->type->uevent(dev, env);
932 if (retval)
933 pr_debug("device: '%s': %s: dev_type uevent() "
934 "returned %d\n", dev_name(dev),
935 __func__, retval);
936 }
937
938 return retval;
939}
940
941static const struct kset_uevent_ops device_uevent_ops = {
942 .filter = dev_uevent_filter,
943 .name = dev_uevent_name,
944 .uevent = dev_uevent,
945};
946
947static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
948 char *buf)
949{
950 struct kobject *top_kobj;
951 struct kset *kset;
952 struct kobj_uevent_env *env = NULL;
953 int i;
954 size_t count = 0;
955 int retval;
956
957 /* search the kset, the device belongs to */
958 top_kobj = &dev->kobj;
959 while (!top_kobj->kset && top_kobj->parent)
960 top_kobj = top_kobj->parent;
961 if (!top_kobj->kset)
962 goto out;
963
964 kset = top_kobj->kset;
965 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
966 goto out;
967
968 /* respect filter */
969 if (kset->uevent_ops && kset->uevent_ops->filter)
970 if (!kset->uevent_ops->filter(kset, &dev->kobj))
971 goto out;
972
973 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
974 if (!env)
975 return -ENOMEM;
976
977 /* let the kset specific function add its keys */
978 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
979 if (retval)
980 goto out;
981
982 /* copy keys to file */
983 for (i = 0; i < env->envp_idx; i++)
984 count += sprintf(&buf[count], "%s\n", env->envp[i]);
985out:
986 kfree(env);
987 return count;
988}
989
990static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
991 const char *buf, size_t count)
992{
993 if (kobject_synth_uevent(&dev->kobj, buf, count))
994 dev_err(dev, "uevent: failed to send synthetic uevent\n");
995
996 return count;
997}
998static DEVICE_ATTR_RW(uevent);
999
1000static ssize_t online_show(struct device *dev, struct device_attribute *attr,
1001 char *buf)
1002{
1003 bool val;
1004
1005 device_lock(dev);
1006 val = !dev->offline;
1007 device_unlock(dev);
1008 return sprintf(buf, "%u\n", val);
1009}
1010
1011static ssize_t online_store(struct device *dev, struct device_attribute *attr,
1012 const char *buf, size_t count)
1013{
1014 bool val;
1015 int ret;
1016
1017 ret = strtobool(buf, &val);
1018 if (ret < 0)
1019 return ret;
1020
1021 ret = lock_device_hotplug_sysfs();
1022 if (ret)
1023 return ret;
1024
1025 ret = val ? device_online(dev) : device_offline(dev);
1026 unlock_device_hotplug();
1027 return ret < 0 ? ret : count;
1028}
1029static DEVICE_ATTR_RW(online);
1030
1031int device_add_groups(struct device *dev, const struct attribute_group **groups)
1032{
1033 return sysfs_create_groups(&dev->kobj, groups);
1034}
1035EXPORT_SYMBOL_GPL(device_add_groups);
1036
1037void device_remove_groups(struct device *dev,
1038 const struct attribute_group **groups)
1039{
1040 sysfs_remove_groups(&dev->kobj, groups);
1041}
1042EXPORT_SYMBOL_GPL(device_remove_groups);
1043
1044union device_attr_group_devres {
1045 const struct attribute_group *group;
1046 const struct attribute_group **groups;
1047};
1048
1049static int devm_attr_group_match(struct device *dev, void *res, void *data)
1050{
1051 return ((union device_attr_group_devres *)res)->group == data;
1052}
1053
1054static void devm_attr_group_remove(struct device *dev, void *res)
1055{
1056 union device_attr_group_devres *devres = res;
1057 const struct attribute_group *group = devres->group;
1058
1059 dev_dbg(dev, "%s: removing group %p\n", __func__, group);
1060 sysfs_remove_group(&dev->kobj, group);
1061}
1062
1063static void devm_attr_groups_remove(struct device *dev, void *res)
1064{
1065 union device_attr_group_devres *devres = res;
1066 const struct attribute_group **groups = devres->groups;
1067
1068 dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
1069 sysfs_remove_groups(&dev->kobj, groups);
1070}
1071
1072/**
1073 * devm_device_add_group - given a device, create a managed attribute group
1074 * @dev: The device to create the group for
1075 * @grp: The attribute group to create
1076 *
1077 * This function creates a group for the first time. It will explicitly
1078 * warn and error if any of the attribute files being created already exist.
1079 *
1080 * Returns 0 on success or error code on failure.
1081 */
1082int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
1083{
1084 union device_attr_group_devres *devres;
1085 int error;
1086
1087 devres = devres_alloc(devm_attr_group_remove,
1088 sizeof(*devres), GFP_KERNEL);
1089 if (!devres)
1090 return -ENOMEM;
1091
1092 error = sysfs_create_group(&dev->kobj, grp);
1093 if (error) {
1094 devres_free(devres);
1095 return error;
1096 }
1097
1098 devres->group = grp;
1099 devres_add(dev, devres);
1100 return 0;
1101}
1102EXPORT_SYMBOL_GPL(devm_device_add_group);
1103
1104/**
1105 * devm_device_remove_group: remove a managed group from a device
1106 * @dev: device to remove the group from
1107 * @grp: group to remove
1108 *
1109 * This function removes a group of attributes from a device. The attributes
1110 * previously have to have been created for this group, otherwise it will fail.
1111 */
1112void devm_device_remove_group(struct device *dev,
1113 const struct attribute_group *grp)
1114{
1115 WARN_ON(devres_release(dev, devm_attr_group_remove,
1116 devm_attr_group_match,
1117 /* cast away const */ (void *)grp));
1118}
1119EXPORT_SYMBOL_GPL(devm_device_remove_group);
1120
1121/**
1122 * devm_device_add_groups - create a bunch of managed attribute groups
1123 * @dev: The device to create the group for
1124 * @groups: The attribute groups to create, NULL terminated
1125 *
1126 * This function creates a bunch of managed attribute groups. If an error
1127 * occurs when creating a group, all previously created groups will be
1128 * removed, unwinding everything back to the original state when this
1129 * function was called. It will explicitly warn and error if any of the
1130 * attribute files being created already exist.
1131 *
1132 * Returns 0 on success or error code from sysfs_create_group on failure.
1133 */
1134int devm_device_add_groups(struct device *dev,
1135 const struct attribute_group **groups)
1136{
1137 union device_attr_group_devres *devres;
1138 int error;
1139
1140 devres = devres_alloc(devm_attr_groups_remove,
1141 sizeof(*devres), GFP_KERNEL);
1142 if (!devres)
1143 return -ENOMEM;
1144
1145 error = sysfs_create_groups(&dev->kobj, groups);
1146 if (error) {
1147 devres_free(devres);
1148 return error;
1149 }
1150
1151 devres->groups = groups;
1152 devres_add(dev, devres);
1153 return 0;
1154}
1155EXPORT_SYMBOL_GPL(devm_device_add_groups);
1156
1157/**
1158 * devm_device_remove_groups - remove a list of managed groups
1159 *
1160 * @dev: The device for the groups to be removed from
1161 * @groups: NULL terminated list of groups to be removed
1162 *
1163 * If groups is not NULL, remove the specified groups from the device.
1164 */
1165void devm_device_remove_groups(struct device *dev,
1166 const struct attribute_group **groups)
1167{
1168 WARN_ON(devres_release(dev, devm_attr_groups_remove,
1169 devm_attr_group_match,
1170 /* cast away const */ (void *)groups));
1171}
1172EXPORT_SYMBOL_GPL(devm_device_remove_groups);
1173
1174static int device_add_attrs(struct device *dev)
1175{
1176 struct class *class = dev->class;
1177 const struct device_type *type = dev->type;
1178 int error;
1179
1180 if (class) {
1181 error = device_add_groups(dev, class->dev_groups);
1182 if (error)
1183 return error;
1184 }
1185
1186 if (type) {
1187 error = device_add_groups(dev, type->groups);
1188 if (error)
1189 goto err_remove_class_groups;
1190 }
1191
1192 error = device_add_groups(dev, dev->groups);
1193 if (error)
1194 goto err_remove_type_groups;
1195
1196 if (device_supports_offline(dev) && !dev->offline_disabled) {
1197 error = device_create_file(dev, &dev_attr_online);
1198 if (error)
1199 goto err_remove_dev_groups;
1200 }
1201
1202 return 0;
1203
1204 err_remove_dev_groups:
1205 device_remove_groups(dev, dev->groups);
1206 err_remove_type_groups:
1207 if (type)
1208 device_remove_groups(dev, type->groups);
1209 err_remove_class_groups:
1210 if (class)
1211 device_remove_groups(dev, class->dev_groups);
1212
1213 return error;
1214}
1215
1216static void device_remove_attrs(struct device *dev)
1217{
1218 struct class *class = dev->class;
1219 const struct device_type *type = dev->type;
1220
1221 device_remove_file(dev, &dev_attr_online);
1222 device_remove_groups(dev, dev->groups);
1223
1224 if (type)
1225 device_remove_groups(dev, type->groups);
1226
1227 if (class)
1228 device_remove_groups(dev, class->dev_groups);
1229}
1230
1231static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
1232 char *buf)
1233{
1234 return print_dev_t(buf, dev->devt);
1235}
1236static DEVICE_ATTR_RO(dev);
1237
1238/* /sys/devices/ */
1239struct kset *devices_kset;
1240
1241/**
1242 * devices_kset_move_before - Move device in the devices_kset's list.
1243 * @deva: Device to move.
1244 * @devb: Device @deva should come before.
1245 */
1246static void devices_kset_move_before(struct device *deva, struct device *devb)
1247{
1248 if (!devices_kset)
1249 return;
1250 pr_debug("devices_kset: Moving %s before %s\n",
1251 dev_name(deva), dev_name(devb));
1252 spin_lock(&devices_kset->list_lock);
1253 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
1254 spin_unlock(&devices_kset->list_lock);
1255}
1256
1257/**
1258 * devices_kset_move_after - Move device in the devices_kset's list.
1259 * @deva: Device to move
1260 * @devb: Device @deva should come after.
1261 */
1262static void devices_kset_move_after(struct device *deva, struct device *devb)
1263{
1264 if (!devices_kset)
1265 return;
1266 pr_debug("devices_kset: Moving %s after %s\n",
1267 dev_name(deva), dev_name(devb));
1268 spin_lock(&devices_kset->list_lock);
1269 list_move(&deva->kobj.entry, &devb->kobj.entry);
1270 spin_unlock(&devices_kset->list_lock);
1271}
1272
1273/**
1274 * devices_kset_move_last - move the device to the end of devices_kset's list.
1275 * @dev: device to move
1276 */
1277void devices_kset_move_last(struct device *dev)
1278{
1279 if (!devices_kset)
1280 return;
1281 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
1282 spin_lock(&devices_kset->list_lock);
1283 list_move_tail(&dev->kobj.entry, &devices_kset->list);
1284 spin_unlock(&devices_kset->list_lock);
1285}
1286
1287/**
1288 * device_create_file - create sysfs attribute file for device.
1289 * @dev: device.
1290 * @attr: device attribute descriptor.
1291 */
1292int device_create_file(struct device *dev,
1293 const struct device_attribute *attr)
1294{
1295 int error = 0;
1296
1297 if (dev) {
1298 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
1299 "Attribute %s: write permission without 'store'\n",
1300 attr->attr.name);
1301 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
1302 "Attribute %s: read permission without 'show'\n",
1303 attr->attr.name);
1304 error = sysfs_create_file(&dev->kobj, &attr->attr);
1305 }
1306
1307 return error;
1308}
1309EXPORT_SYMBOL_GPL(device_create_file);
1310
1311/**
1312 * device_remove_file - remove sysfs attribute file.
1313 * @dev: device.
1314 * @attr: device attribute descriptor.
1315 */
1316void device_remove_file(struct device *dev,
1317 const struct device_attribute *attr)
1318{
1319 if (dev)
1320 sysfs_remove_file(&dev->kobj, &attr->attr);
1321}
1322EXPORT_SYMBOL_GPL(device_remove_file);
1323
1324/**
1325 * device_remove_file_self - remove sysfs attribute file from its own method.
1326 * @dev: device.
1327 * @attr: device attribute descriptor.
1328 *
1329 * See kernfs_remove_self() for details.
1330 */
1331bool device_remove_file_self(struct device *dev,
1332 const struct device_attribute *attr)
1333{
1334 if (dev)
1335 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
1336 else
1337 return false;
1338}
1339EXPORT_SYMBOL_GPL(device_remove_file_self);
1340
1341/**
1342 * device_create_bin_file - create sysfs binary attribute file for device.
1343 * @dev: device.
1344 * @attr: device binary attribute descriptor.
1345 */
1346int device_create_bin_file(struct device *dev,
1347 const struct bin_attribute *attr)
1348{
1349 int error = -EINVAL;
1350 if (dev)
1351 error = sysfs_create_bin_file(&dev->kobj, attr);
1352 return error;
1353}
1354EXPORT_SYMBOL_GPL(device_create_bin_file);
1355
1356/**
1357 * device_remove_bin_file - remove sysfs binary attribute file
1358 * @dev: device.
1359 * @attr: device binary attribute descriptor.
1360 */
1361void device_remove_bin_file(struct device *dev,
1362 const struct bin_attribute *attr)
1363{
1364 if (dev)
1365 sysfs_remove_bin_file(&dev->kobj, attr);
1366}
1367EXPORT_SYMBOL_GPL(device_remove_bin_file);
1368
1369static void klist_children_get(struct klist_node *n)
1370{
1371 struct device_private *p = to_device_private_parent(n);
1372 struct device *dev = p->device;
1373
1374 get_device(dev);
1375}
1376
1377static void klist_children_put(struct klist_node *n)
1378{
1379 struct device_private *p = to_device_private_parent(n);
1380 struct device *dev = p->device;
1381
1382 put_device(dev);
1383}
1384
1385/**
1386 * device_initialize - init device structure.
1387 * @dev: device.
1388 *
1389 * This prepares the device for use by other layers by initializing
1390 * its fields.
1391 * It is the first half of device_register(), if called by
1392 * that function, though it can also be called separately, so one
1393 * may use @dev's fields. In particular, get_device()/put_device()
1394 * may be used for reference counting of @dev after calling this
1395 * function.
1396 *
1397 * All fields in @dev must be initialized by the caller to 0, except
1398 * for those explicitly set to some other value. The simplest
1399 * approach is to use kzalloc() to allocate the structure containing
1400 * @dev.
1401 *
1402 * NOTE: Use put_device() to give up your reference instead of freeing
1403 * @dev directly once you have called this function.
1404 */
1405void device_initialize(struct device *dev)
1406{
1407 dev->kobj.kset = devices_kset;
1408 kobject_init(&dev->kobj, &device_ktype);
1409 INIT_LIST_HEAD(&dev->dma_pools);
1410 mutex_init(&dev->mutex);
1411 lockdep_set_novalidate_class(&dev->mutex);
1412 spin_lock_init(&dev->devres_lock);
1413 INIT_LIST_HEAD(&dev->devres_head);
1414 device_pm_init(dev);
1415 set_dev_node(dev, -1);
1416#ifdef CONFIG_GENERIC_MSI_IRQ
1417 INIT_LIST_HEAD(&dev->msi_list);
1418#endif
1419 INIT_LIST_HEAD(&dev->links.consumers);
1420 INIT_LIST_HEAD(&dev->links.suppliers);
1421 dev->links.status = DL_DEV_NO_DRIVER;
1422}
1423EXPORT_SYMBOL_GPL(device_initialize);
1424
1425struct kobject *virtual_device_parent(struct device *dev)
1426{
1427 static struct kobject *virtual_dir = NULL;
1428
1429 if (!virtual_dir)
1430 virtual_dir = kobject_create_and_add("virtual",
1431 &devices_kset->kobj);
1432
1433 return virtual_dir;
1434}
1435
1436struct class_dir {
1437 struct kobject kobj;
1438 struct class *class;
1439};
1440
1441#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1442
1443static void class_dir_release(struct kobject *kobj)
1444{
1445 struct class_dir *dir = to_class_dir(kobj);
1446 kfree(dir);
1447}
1448
1449static const
1450struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
1451{
1452 struct class_dir *dir = to_class_dir(kobj);
1453 return dir->class->ns_type;
1454}
1455
1456static struct kobj_type class_dir_ktype = {
1457 .release = class_dir_release,
1458 .sysfs_ops = &kobj_sysfs_ops,
1459 .child_ns_type = class_dir_child_ns_type
1460};
1461
1462static struct kobject *
1463class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
1464{
1465 struct class_dir *dir;
1466 int retval;
1467
1468 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1469 if (!dir)
1470 return NULL;
1471
1472 dir->class = class;
1473 kobject_init(&dir->kobj, &class_dir_ktype);
1474
1475 dir->kobj.kset = &class->p->glue_dirs;
1476
1477 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
1478 if (retval < 0) {
1479 kobject_put(&dir->kobj);
1480 return NULL;
1481 }
1482 return &dir->kobj;
1483}
1484
1485static DEFINE_MUTEX(gdp_mutex);
1486
1487static struct kobject *get_device_parent(struct device *dev,
1488 struct device *parent)
1489{
1490 if (dev->class) {
1491 struct kobject *kobj = NULL;
1492 struct kobject *parent_kobj;
1493 struct kobject *k;
1494
1495#ifdef CONFIG_BLOCK
1496 /* block disks show up in /sys/block */
1497 if (sysfs_deprecated && dev->class == &block_class) {
1498 if (parent && parent->class == &block_class)
1499 return &parent->kobj;
1500 return &block_class.p->subsys.kobj;
1501 }
1502#endif
1503
1504 /*
1505 * If we have no parent, we live in "virtual".
1506 * Class-devices with a non class-device as parent, live
1507 * in a "glue" directory to prevent namespace collisions.
1508 */
1509 if (parent == NULL)
1510 parent_kobj = virtual_device_parent(dev);
1511 else if (parent->class && !dev->class->ns_type)
1512 return &parent->kobj;
1513 else
1514 parent_kobj = &parent->kobj;
1515
1516 mutex_lock(&gdp_mutex);
1517
1518 /* find our class-directory at the parent and reference it */
1519 spin_lock(&dev->class->p->glue_dirs.list_lock);
1520 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
1521 if (k->parent == parent_kobj) {
1522 kobj = kobject_get(k);
1523 break;
1524 }
1525 spin_unlock(&dev->class->p->glue_dirs.list_lock);
1526 if (kobj) {
1527 mutex_unlock(&gdp_mutex);
1528 return kobj;
1529 }
1530
1531 /* or create a new class-directory at the parent device */
1532 k = class_dir_create_and_add(dev->class, parent_kobj);
1533 /* do not emit an uevent for this simple "glue" directory */
1534 mutex_unlock(&gdp_mutex);
1535 return k;
1536 }
1537
1538 /* subsystems can specify a default root directory for their devices */
1539 if (!parent && dev->bus && dev->bus->dev_root)
1540 return &dev->bus->dev_root->kobj;
1541
1542 if (parent)
1543 return &parent->kobj;
1544 return NULL;
1545}
1546
1547static inline bool live_in_glue_dir(struct kobject *kobj,
1548 struct device *dev)
1549{
1550 if (!kobj || !dev->class ||
1551 kobj->kset != &dev->class->p->glue_dirs)
1552 return false;
1553 return true;
1554}
1555
1556static inline struct kobject *get_glue_dir(struct device *dev)
1557{
1558 return dev->kobj.parent;
1559}
1560
1561/*
1562 * make sure cleaning up dir as the last step, we need to make
1563 * sure .release handler of kobject is run with holding the
1564 * global lock
1565 */
1566static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
1567{
1568 /* see if we live in a "glue" directory */
1569 if (!live_in_glue_dir(glue_dir, dev))
1570 return;
1571
1572 mutex_lock(&gdp_mutex);
1573 kobject_put(glue_dir);
1574 mutex_unlock(&gdp_mutex);
1575}
1576
1577static int device_add_class_symlinks(struct device *dev)
1578{
1579 struct device_node *of_node = dev_of_node(dev);
1580 int error;
1581
1582 if (of_node) {
1583 error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
1584 if (error)
1585 dev_warn(dev, "Error %d creating of_node link\n",error);
1586 /* An error here doesn't warrant bringing down the device */
1587 }
1588
1589 if (!dev->class)
1590 return 0;
1591
1592 error = sysfs_create_link(&dev->kobj,
1593 &dev->class->p->subsys.kobj,
1594 "subsystem");
1595 if (error)
1596 goto out_devnode;
1597
1598 if (dev->parent && device_is_not_partition(dev)) {
1599 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
1600 "device");
1601 if (error)
1602 goto out_subsys;
1603 }
1604
1605#ifdef CONFIG_BLOCK
1606 /* /sys/block has directories and does not need symlinks */
1607 if (sysfs_deprecated && dev->class == &block_class)
1608 return 0;
1609#endif
1610
1611 /* link in the class directory pointing to the device */
1612 error = sysfs_create_link(&dev->class->p->subsys.kobj,
1613 &dev->kobj, dev_name(dev));
1614 if (error)
1615 goto out_device;
1616
1617 return 0;
1618
1619out_device:
1620 sysfs_remove_link(&dev->kobj, "device");
1621
1622out_subsys:
1623 sysfs_remove_link(&dev->kobj, "subsystem");
1624out_devnode:
1625 sysfs_remove_link(&dev->kobj, "of_node");
1626 return error;
1627}
1628
1629static void device_remove_class_symlinks(struct device *dev)
1630{
1631 if (dev_of_node(dev))
1632 sysfs_remove_link(&dev->kobj, "of_node");
1633
1634 if (!dev->class)
1635 return;
1636
1637 if (dev->parent && device_is_not_partition(dev))
1638 sysfs_remove_link(&dev->kobj, "device");
1639 sysfs_remove_link(&dev->kobj, "subsystem");
1640#ifdef CONFIG_BLOCK
1641 if (sysfs_deprecated && dev->class == &block_class)
1642 return;
1643#endif
1644 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
1645}
1646
1647/**
1648 * dev_set_name - set a device name
1649 * @dev: device
1650 * @fmt: format string for the device's name
1651 */
1652int dev_set_name(struct device *dev, const char *fmt, ...)
1653{
1654 va_list vargs;
1655 int err;
1656
1657 va_start(vargs, fmt);
1658 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
1659 va_end(vargs);
1660 return err;
1661}
1662EXPORT_SYMBOL_GPL(dev_set_name);
1663
1664/**
1665 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1666 * @dev: device
1667 *
1668 * By default we select char/ for new entries. Setting class->dev_obj
1669 * to NULL prevents an entry from being created. class->dev_kobj must
1670 * be set (or cleared) before any devices are registered to the class
1671 * otherwise device_create_sys_dev_entry() and
1672 * device_remove_sys_dev_entry() will disagree about the presence of
1673 * the link.
1674 */
1675static struct kobject *device_to_dev_kobj(struct device *dev)
1676{
1677 struct kobject *kobj;
1678
1679 if (dev->class)
1680 kobj = dev->class->dev_kobj;
1681 else
1682 kobj = sysfs_dev_char_kobj;
1683
1684 return kobj;
1685}
1686
1687static int device_create_sys_dev_entry(struct device *dev)
1688{
1689 struct kobject *kobj = device_to_dev_kobj(dev);
1690 int error = 0;
1691 char devt_str[15];
1692
1693 if (kobj) {
1694 format_dev_t(devt_str, dev->devt);
1695 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
1696 }
1697
1698 return error;
1699}
1700
1701static void device_remove_sys_dev_entry(struct device *dev)
1702{
1703 struct kobject *kobj = device_to_dev_kobj(dev);
1704 char devt_str[15];
1705
1706 if (kobj) {
1707 format_dev_t(devt_str, dev->devt);
1708 sysfs_remove_link(kobj, devt_str);
1709 }
1710}
1711
1712int device_private_init(struct device *dev)
1713{
1714 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
1715 if (!dev->p)
1716 return -ENOMEM;
1717 dev->p->device = dev;
1718 klist_init(&dev->p->klist_children, klist_children_get,
1719 klist_children_put);
1720 INIT_LIST_HEAD(&dev->p->deferred_probe);
1721 return 0;
1722}
1723
1724/**
1725 * device_add - add device to device hierarchy.
1726 * @dev: device.
1727 *
1728 * This is part 2 of device_register(), though may be called
1729 * separately _iff_ device_initialize() has been called separately.
1730 *
1731 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1732 * to the global and sibling lists for the device, then
1733 * adds it to the other relevant subsystems of the driver model.
1734 *
1735 * Do not call this routine or device_register() more than once for
1736 * any device structure. The driver model core is not designed to work
1737 * with devices that get unregistered and then spring back to life.
1738 * (Among other things, it's very hard to guarantee that all references
1739 * to the previous incarnation of @dev have been dropped.) Allocate
1740 * and register a fresh new struct device instead.
1741 *
1742 * NOTE: _Never_ directly free @dev after calling this function, even
1743 * if it returned an error! Always use put_device() to give up your
1744 * reference instead.
1745 */
1746int device_add(struct device *dev)
1747{
1748 struct device *parent;
1749 struct kobject *kobj;
1750 struct class_interface *class_intf;
1751 int error = -EINVAL;
1752 struct kobject *glue_dir = NULL;
1753
1754 dev = get_device(dev);
1755 if (!dev)
1756 goto done;
1757
1758 if (!dev->p) {
1759 error = device_private_init(dev);
1760 if (error)
1761 goto done;
1762 }
1763
1764 /*
1765 * for statically allocated devices, which should all be converted
1766 * some day, we need to initialize the name. We prevent reading back
1767 * the name, and force the use of dev_name()
1768 */
1769 if (dev->init_name) {
1770 dev_set_name(dev, "%s", dev->init_name);
1771 dev->init_name = NULL;
1772 }
1773
1774 /* subsystems can specify simple device enumeration */
1775 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1776 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1777
1778 if (!dev_name(dev)) {
1779 error = -EINVAL;
1780 goto name_error;
1781 }
1782
1783 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1784
1785 parent = get_device(dev->parent);
1786 kobj = get_device_parent(dev, parent);
1787 if (kobj)
1788 dev->kobj.parent = kobj;
1789
1790 /* use parent numa_node */
1791 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1792 set_dev_node(dev, dev_to_node(parent));
1793
1794 /* first, register with generic layer. */
1795 /* we require the name to be set before, and pass NULL */
1796 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1797 if (error) {
1798 glue_dir = get_glue_dir(dev);
1799 goto Error;
1800 }
1801
1802 /* notify platform of device entry */
1803 if (platform_notify)
1804 platform_notify(dev);
1805
1806 error = device_create_file(dev, &dev_attr_uevent);
1807 if (error)
1808 goto attrError;
1809
1810 error = device_add_class_symlinks(dev);
1811 if (error)
1812 goto SymlinkError;
1813 error = device_add_attrs(dev);
1814 if (error)
1815 goto AttrsError;
1816 error = bus_add_device(dev);
1817 if (error)
1818 goto BusError;
1819 error = dpm_sysfs_add(dev);
1820 if (error)
1821 goto DPMError;
1822 device_pm_add(dev);
1823
1824 if (MAJOR(dev->devt)) {
1825 error = device_create_file(dev, &dev_attr_dev);
1826 if (error)
1827 goto DevAttrError;
1828
1829 error = device_create_sys_dev_entry(dev);
1830 if (error)
1831 goto SysEntryError;
1832
1833 devtmpfs_create_node(dev);
1834 }
1835
1836 /* Notify clients of device addition. This call must come
1837 * after dpm_sysfs_add() and before kobject_uevent().
1838 */
1839 if (dev->bus)
1840 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1841 BUS_NOTIFY_ADD_DEVICE, dev);
1842
1843 kobject_uevent(&dev->kobj, KOBJ_ADD);
1844 bus_probe_device(dev);
1845 if (parent)
1846 klist_add_tail(&dev->p->knode_parent,
1847 &parent->p->klist_children);
1848
1849 if (dev->class) {
1850 mutex_lock(&dev->class->p->mutex);
1851 /* tie the class to the device */
1852 klist_add_tail(&dev->knode_class,
1853 &dev->class->p->klist_devices);
1854
1855 /* notify any interfaces that the device is here */
1856 list_for_each_entry(class_intf,
1857 &dev->class->p->interfaces, node)
1858 if (class_intf->add_dev)
1859 class_intf->add_dev(dev, class_intf);
1860 mutex_unlock(&dev->class->p->mutex);
1861 }
1862done:
1863 put_device(dev);
1864 return error;
1865 SysEntryError:
1866 if (MAJOR(dev->devt))
1867 device_remove_file(dev, &dev_attr_dev);
1868 DevAttrError:
1869 device_pm_remove(dev);
1870 dpm_sysfs_remove(dev);
1871 DPMError:
1872 bus_remove_device(dev);
1873 BusError:
1874 device_remove_attrs(dev);
1875 AttrsError:
1876 device_remove_class_symlinks(dev);
1877 SymlinkError:
1878 device_remove_file(dev, &dev_attr_uevent);
1879 attrError:
1880 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1881 glue_dir = get_glue_dir(dev);
1882 kobject_del(&dev->kobj);
1883 Error:
1884 cleanup_glue_dir(dev, glue_dir);
1885 put_device(parent);
1886name_error:
1887 kfree(dev->p);
1888 dev->p = NULL;
1889 goto done;
1890}
1891EXPORT_SYMBOL_GPL(device_add);
1892
1893/**
1894 * device_register - register a device with the system.
1895 * @dev: pointer to the device structure
1896 *
1897 * This happens in two clean steps - initialize the device
1898 * and add it to the system. The two steps can be called
1899 * separately, but this is the easiest and most common.
1900 * I.e. you should only call the two helpers separately if
1901 * have a clearly defined need to use and refcount the device
1902 * before it is added to the hierarchy.
1903 *
1904 * For more information, see the kerneldoc for device_initialize()
1905 * and device_add().
1906 *
1907 * NOTE: _Never_ directly free @dev after calling this function, even
1908 * if it returned an error! Always use put_device() to give up the
1909 * reference initialized in this function instead.
1910 */
1911int device_register(struct device *dev)
1912{
1913 device_initialize(dev);
1914 return device_add(dev);
1915}
1916EXPORT_SYMBOL_GPL(device_register);
1917
1918/**
1919 * get_device - increment reference count for device.
1920 * @dev: device.
1921 *
1922 * This simply forwards the call to kobject_get(), though
1923 * we do take care to provide for the case that we get a NULL
1924 * pointer passed in.
1925 */
1926struct device *get_device(struct device *dev)
1927{
1928 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1929}
1930EXPORT_SYMBOL_GPL(get_device);
1931
1932/**
1933 * put_device - decrement reference count.
1934 * @dev: device in question.
1935 */
1936void put_device(struct device *dev)
1937{
1938 /* might_sleep(); */
1939 if (dev)
1940 kobject_put(&dev->kobj);
1941}
1942EXPORT_SYMBOL_GPL(put_device);
1943
1944/**
1945 * device_del - delete device from system.
1946 * @dev: device.
1947 *
1948 * This is the first part of the device unregistration
1949 * sequence. This removes the device from the lists we control
1950 * from here, has it removed from the other driver model
1951 * subsystems it was added to in device_add(), and removes it
1952 * from the kobject hierarchy.
1953 *
1954 * NOTE: this should be called manually _iff_ device_add() was
1955 * also called manually.
1956 */
1957void device_del(struct device *dev)
1958{
1959 struct device *parent = dev->parent;
1960 struct kobject *glue_dir = NULL;
1961 struct class_interface *class_intf;
1962
1963 /* Notify clients of device removal. This call must come
1964 * before dpm_sysfs_remove().
1965 */
1966 if (dev->bus)
1967 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1968 BUS_NOTIFY_DEL_DEVICE, dev);
1969
1970 dpm_sysfs_remove(dev);
1971 if (parent)
1972 klist_del(&dev->p->knode_parent);
1973 if (MAJOR(dev->devt)) {
1974 devtmpfs_delete_node(dev);
1975 device_remove_sys_dev_entry(dev);
1976 device_remove_file(dev, &dev_attr_dev);
1977 }
1978 if (dev->class) {
1979 device_remove_class_symlinks(dev);
1980
1981 mutex_lock(&dev->class->p->mutex);
1982 /* notify any interfaces that the device is now gone */
1983 list_for_each_entry(class_intf,
1984 &dev->class->p->interfaces, node)
1985 if (class_intf->remove_dev)
1986 class_intf->remove_dev(dev, class_intf);
1987 /* remove the device from the class list */
1988 klist_del(&dev->knode_class);
1989 mutex_unlock(&dev->class->p->mutex);
1990 }
1991 device_remove_file(dev, &dev_attr_uevent);
1992 device_remove_attrs(dev);
1993 bus_remove_device(dev);
1994 device_pm_remove(dev);
1995 driver_deferred_probe_del(dev);
1996 device_remove_properties(dev);
1997 device_links_purge(dev);
1998
1999 /* Notify the platform of the removal, in case they
2000 * need to do anything...
2001 */
2002 if (platform_notify_remove)
2003 platform_notify_remove(dev);
2004 if (dev->bus)
2005 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
2006 BUS_NOTIFY_REMOVED_DEVICE, dev);
2007 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
2008 glue_dir = get_glue_dir(dev);
2009 kobject_del(&dev->kobj);
2010 cleanup_glue_dir(dev, glue_dir);
2011 put_device(parent);
2012}
2013EXPORT_SYMBOL_GPL(device_del);
2014
2015/**
2016 * device_unregister - unregister device from system.
2017 * @dev: device going away.
2018 *
2019 * We do this in two parts, like we do device_register(). First,
2020 * we remove it from all the subsystems with device_del(), then
2021 * we decrement the reference count via put_device(). If that
2022 * is the final reference count, the device will be cleaned up
2023 * via device_release() above. Otherwise, the structure will
2024 * stick around until the final reference to the device is dropped.
2025 */
2026void device_unregister(struct device *dev)
2027{
2028 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2029 device_del(dev);
2030 put_device(dev);
2031}
2032EXPORT_SYMBOL_GPL(device_unregister);
2033
2034static struct device *prev_device(struct klist_iter *i)
2035{
2036 struct klist_node *n = klist_prev(i);
2037 struct device *dev = NULL;
2038 struct device_private *p;
2039
2040 if (n) {
2041 p = to_device_private_parent(n);
2042 dev = p->device;
2043 }
2044 return dev;
2045}
2046
2047static struct device *next_device(struct klist_iter *i)
2048{
2049 struct klist_node *n = klist_next(i);
2050 struct device *dev = NULL;
2051 struct device_private *p;
2052
2053 if (n) {
2054 p = to_device_private_parent(n);
2055 dev = p->device;
2056 }
2057 return dev;
2058}
2059
2060/**
2061 * device_get_devnode - path of device node file
2062 * @dev: device
2063 * @mode: returned file access mode
2064 * @uid: returned file owner
2065 * @gid: returned file group
2066 * @tmp: possibly allocated string
2067 *
2068 * Return the relative path of a possible device node.
2069 * Non-default names may need to allocate a memory to compose
2070 * a name. This memory is returned in tmp and needs to be
2071 * freed by the caller.
2072 */
2073const char *device_get_devnode(struct device *dev,
2074 umode_t *mode, kuid_t *uid, kgid_t *gid,
2075 const char **tmp)
2076{
2077 char *s;
2078
2079 *tmp = NULL;
2080
2081 /* the device type may provide a specific name */
2082 if (dev->type && dev->type->devnode)
2083 *tmp = dev->type->devnode(dev, mode, uid, gid);
2084 if (*tmp)
2085 return *tmp;
2086
2087 /* the class may provide a specific name */
2088 if (dev->class && dev->class->devnode)
2089 *tmp = dev->class->devnode(dev, mode);
2090 if (*tmp)
2091 return *tmp;
2092
2093 /* return name without allocation, tmp == NULL */
2094 if (strchr(dev_name(dev), '!') == NULL)
2095 return dev_name(dev);
2096
2097 /* replace '!' in the name with '/' */
2098 s = kstrdup(dev_name(dev), GFP_KERNEL);
2099 if (!s)
2100 return NULL;
2101 strreplace(s, '!', '/');
2102 return *tmp = s;
2103}
2104
2105/**
2106 * device_for_each_child - device child iterator.
2107 * @parent: parent struct device.
2108 * @fn: function to be called for each device.
2109 * @data: data for the callback.
2110 *
2111 * Iterate over @parent's child devices, and call @fn for each,
2112 * passing it @data.
2113 *
2114 * We check the return of @fn each time. If it returns anything
2115 * other than 0, we break out and return that value.
2116 */
2117int device_for_each_child(struct device *parent, void *data,
2118 int (*fn)(struct device *dev, void *data))
2119{
2120 struct klist_iter i;
2121 struct device *child;
2122 int error = 0;
2123
2124 if (!parent->p)
2125 return 0;
2126
2127 klist_iter_init(&parent->p->klist_children, &i);
2128 while (!error && (child = next_device(&i)))
2129 error = fn(child, data);
2130 klist_iter_exit(&i);
2131 return error;
2132}
2133EXPORT_SYMBOL_GPL(device_for_each_child);
2134
2135/**
2136 * device_for_each_child_reverse - device child iterator in reversed order.
2137 * @parent: parent struct device.
2138 * @fn: function to be called for each device.
2139 * @data: data for the callback.
2140 *
2141 * Iterate over @parent's child devices, and call @fn for each,
2142 * passing it @data.
2143 *
2144 * We check the return of @fn each time. If it returns anything
2145 * other than 0, we break out and return that value.
2146 */
2147int device_for_each_child_reverse(struct device *parent, void *data,
2148 int (*fn)(struct device *dev, void *data))
2149{
2150 struct klist_iter i;
2151 struct device *child;
2152 int error = 0;
2153
2154 if (!parent->p)
2155 return 0;
2156
2157 klist_iter_init(&parent->p->klist_children, &i);
2158 while ((child = prev_device(&i)) && !error)
2159 error = fn(child, data);
2160 klist_iter_exit(&i);
2161 return error;
2162}
2163EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
2164
2165/**
2166 * device_find_child - device iterator for locating a particular device.
2167 * @parent: parent struct device
2168 * @match: Callback function to check device
2169 * @data: Data to pass to match function
2170 *
2171 * This is similar to the device_for_each_child() function above, but it
2172 * returns a reference to a device that is 'found' for later use, as
2173 * determined by the @match callback.
2174 *
2175 * The callback should return 0 if the device doesn't match and non-zero
2176 * if it does. If the callback returns non-zero and a reference to the
2177 * current device can be obtained, this function will return to the caller
2178 * and not iterate over any more devices.
2179 *
2180 * NOTE: you will need to drop the reference with put_device() after use.
2181 */
2182struct device *device_find_child(struct device *parent, void *data,
2183 int (*match)(struct device *dev, void *data))
2184{
2185 struct klist_iter i;
2186 struct device *child;
2187
2188 if (!parent)
2189 return NULL;
2190
2191 klist_iter_init(&parent->p->klist_children, &i);
2192 while ((child = next_device(&i)))
2193 if (match(child, data) && get_device(child))
2194 break;
2195 klist_iter_exit(&i);
2196 return child;
2197}
2198EXPORT_SYMBOL_GPL(device_find_child);
2199
2200int __init devices_init(void)
2201{
2202 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
2203 if (!devices_kset)
2204 return -ENOMEM;
2205 dev_kobj = kobject_create_and_add("dev", NULL);
2206 if (!dev_kobj)
2207 goto dev_kobj_err;
2208 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
2209 if (!sysfs_dev_block_kobj)
2210 goto block_kobj_err;
2211 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
2212 if (!sysfs_dev_char_kobj)
2213 goto char_kobj_err;
2214
2215 return 0;
2216
2217 char_kobj_err:
2218 kobject_put(sysfs_dev_block_kobj);
2219 block_kobj_err:
2220 kobject_put(dev_kobj);
2221 dev_kobj_err:
2222 kset_unregister(devices_kset);
2223 return -ENOMEM;
2224}
2225
2226static int device_check_offline(struct device *dev, void *not_used)
2227{
2228 int ret;
2229
2230 ret = device_for_each_child(dev, NULL, device_check_offline);
2231 if (ret)
2232 return ret;
2233
2234 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
2235}
2236
2237/**
2238 * device_offline - Prepare the device for hot-removal.
2239 * @dev: Device to be put offline.
2240 *
2241 * Execute the device bus type's .offline() callback, if present, to prepare
2242 * the device for a subsequent hot-removal. If that succeeds, the device must
2243 * not be used until either it is removed or its bus type's .online() callback
2244 * is executed.
2245 *
2246 * Call under device_hotplug_lock.
2247 */
2248int device_offline(struct device *dev)
2249{
2250 int ret;
2251
2252 if (dev->offline_disabled)
2253 return -EPERM;
2254
2255 ret = device_for_each_child(dev, NULL, device_check_offline);
2256 if (ret)
2257 return ret;
2258
2259 device_lock(dev);
2260 if (device_supports_offline(dev)) {
2261 if (dev->offline) {
2262 ret = 1;
2263 } else {
2264 ret = dev->bus->offline(dev);
2265 if (!ret) {
2266 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2267 dev->offline = true;
2268 }
2269 }
2270 }
2271 device_unlock(dev);
2272
2273 return ret;
2274}
2275
2276/**
2277 * device_online - Put the device back online after successful device_offline().
2278 * @dev: Device to be put back online.
2279 *
2280 * If device_offline() has been successfully executed for @dev, but the device
2281 * has not been removed subsequently, execute its bus type's .online() callback
2282 * to indicate that the device can be used again.
2283 *
2284 * Call under device_hotplug_lock.
2285 */
2286int device_online(struct device *dev)
2287{
2288 int ret = 0;
2289
2290 device_lock(dev);
2291 if (device_supports_offline(dev)) {
2292 if (dev->offline) {
2293 ret = dev->bus->online(dev);
2294 if (!ret) {
2295 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2296 dev->offline = false;
2297 }
2298 } else {
2299 ret = 1;
2300 }
2301 }
2302 device_unlock(dev);
2303
2304 return ret;
2305}
2306
2307struct root_device {
2308 struct device dev;
2309 struct module *owner;
2310};
2311
2312static inline struct root_device *to_root_device(struct device *d)
2313{
2314 return container_of(d, struct root_device, dev);
2315}
2316
2317static void root_device_release(struct device *dev)
2318{
2319 kfree(to_root_device(dev));
2320}
2321
2322/**
2323 * __root_device_register - allocate and register a root device
2324 * @name: root device name
2325 * @owner: owner module of the root device, usually THIS_MODULE
2326 *
2327 * This function allocates a root device and registers it
2328 * using device_register(). In order to free the returned
2329 * device, use root_device_unregister().
2330 *
2331 * Root devices are dummy devices which allow other devices
2332 * to be grouped under /sys/devices. Use this function to
2333 * allocate a root device and then use it as the parent of
2334 * any device which should appear under /sys/devices/{name}
2335 *
2336 * The /sys/devices/{name} directory will also contain a
2337 * 'module' symlink which points to the @owner directory
2338 * in sysfs.
2339 *
2340 * Returns &struct device pointer on success, or ERR_PTR() on error.
2341 *
2342 * Note: You probably want to use root_device_register().
2343 */
2344struct device *__root_device_register(const char *name, struct module *owner)
2345{
2346 struct root_device *root;
2347 int err = -ENOMEM;
2348
2349 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
2350 if (!root)
2351 return ERR_PTR(err);
2352
2353 err = dev_set_name(&root->dev, "%s", name);
2354 if (err) {
2355 kfree(root);
2356 return ERR_PTR(err);
2357 }
2358
2359 root->dev.release = root_device_release;
2360
2361 err = device_register(&root->dev);
2362 if (err) {
2363 put_device(&root->dev);
2364 return ERR_PTR(err);
2365 }
2366
2367#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2368 if (owner) {
2369 struct module_kobject *mk = &owner->mkobj;
2370
2371 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
2372 if (err) {
2373 device_unregister(&root->dev);
2374 return ERR_PTR(err);
2375 }
2376 root->owner = owner;
2377 }
2378#endif
2379
2380 return &root->dev;
2381}
2382EXPORT_SYMBOL_GPL(__root_device_register);
2383
2384/**
2385 * root_device_unregister - unregister and free a root device
2386 * @dev: device going away
2387 *
2388 * This function unregisters and cleans up a device that was created by
2389 * root_device_register().
2390 */
2391void root_device_unregister(struct device *dev)
2392{
2393 struct root_device *root = to_root_device(dev);
2394
2395 if (root->owner)
2396 sysfs_remove_link(&root->dev.kobj, "module");
2397
2398 device_unregister(dev);
2399}
2400EXPORT_SYMBOL_GPL(root_device_unregister);
2401
2402
2403static void device_create_release(struct device *dev)
2404{
2405 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2406 kfree(dev);
2407}
2408
2409static struct device *
2410device_create_groups_vargs(struct class *class, struct device *parent,
2411 dev_t devt, void *drvdata,
2412 const struct attribute_group **groups,
2413 const char *fmt, va_list args)
2414{
2415 struct device *dev = NULL;
2416 int retval = -ENODEV;
2417
2418 if (class == NULL || IS_ERR(class))
2419 goto error;
2420
2421 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2422 if (!dev) {
2423 retval = -ENOMEM;
2424 goto error;
2425 }
2426
2427 device_initialize(dev);
2428 dev->devt = devt;
2429 dev->class = class;
2430 dev->parent = parent;
2431 dev->groups = groups;
2432 dev->release = device_create_release;
2433 dev_set_drvdata(dev, drvdata);
2434
2435 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
2436 if (retval)
2437 goto error;
2438
2439 retval = device_add(dev);
2440 if (retval)
2441 goto error;
2442
2443 return dev;
2444
2445error:
2446 put_device(dev);
2447 return ERR_PTR(retval);
2448}
2449
2450/**
2451 * device_create_vargs - creates a device and registers it with sysfs
2452 * @class: pointer to the struct class that this device should be registered to
2453 * @parent: pointer to the parent struct device of this new device, if any
2454 * @devt: the dev_t for the char device to be added
2455 * @drvdata: the data to be added to the device for callbacks
2456 * @fmt: string for the device's name
2457 * @args: va_list for the device's name
2458 *
2459 * This function can be used by char device classes. A struct device
2460 * will be created in sysfs, registered to the specified class.
2461 *
2462 * A "dev" file will be created, showing the dev_t for the device, if
2463 * the dev_t is not 0,0.
2464 * If a pointer to a parent struct device is passed in, the newly created
2465 * struct device will be a child of that device in sysfs.
2466 * The pointer to the struct device will be returned from the call.
2467 * Any further sysfs files that might be required can be created using this
2468 * pointer.
2469 *
2470 * Returns &struct device pointer on success, or ERR_PTR() on error.
2471 *
2472 * Note: the struct class passed to this function must have previously
2473 * been created with a call to class_create().
2474 */
2475struct device *device_create_vargs(struct class *class, struct device *parent,
2476 dev_t devt, void *drvdata, const char *fmt,
2477 va_list args)
2478{
2479 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
2480 fmt, args);
2481}
2482EXPORT_SYMBOL_GPL(device_create_vargs);
2483
2484/**
2485 * device_create - creates a device and registers it with sysfs
2486 * @class: pointer to the struct class that this device should be registered to
2487 * @parent: pointer to the parent struct device of this new device, if any
2488 * @devt: the dev_t for the char device to be added
2489 * @drvdata: the data to be added to the device for callbacks
2490 * @fmt: string for the device's name
2491 *
2492 * This function can be used by char device classes. A struct device
2493 * will be created in sysfs, registered to the specified class.
2494 *
2495 * A "dev" file will be created, showing the dev_t for the device, if
2496 * the dev_t is not 0,0.
2497 * If a pointer to a parent struct device is passed in, the newly created
2498 * struct device will be a child of that device in sysfs.
2499 * The pointer to the struct device will be returned from the call.
2500 * Any further sysfs files that might be required can be created using this
2501 * pointer.
2502 *
2503 * Returns &struct device pointer on success, or ERR_PTR() on error.
2504 *
2505 * Note: the struct class passed to this function must have previously
2506 * been created with a call to class_create().
2507 */
2508struct device *device_create(struct class *class, struct device *parent,
2509 dev_t devt, void *drvdata, const char *fmt, ...)
2510{
2511 va_list vargs;
2512 struct device *dev;
2513
2514 va_start(vargs, fmt);
2515 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
2516 va_end(vargs);
2517 return dev;
2518}
2519EXPORT_SYMBOL_GPL(device_create);
2520
2521/**
2522 * device_create_with_groups - creates a device and registers it with sysfs
2523 * @class: pointer to the struct class that this device should be registered to
2524 * @parent: pointer to the parent struct device of this new device, if any
2525 * @devt: the dev_t for the char device to be added
2526 * @drvdata: the data to be added to the device for callbacks
2527 * @groups: NULL-terminated list of attribute groups to be created
2528 * @fmt: string for the device's name
2529 *
2530 * This function can be used by char device classes. A struct device
2531 * will be created in sysfs, registered to the specified class.
2532 * Additional attributes specified in the groups parameter will also
2533 * be created automatically.
2534 *
2535 * A "dev" file will be created, showing the dev_t for the device, if
2536 * the dev_t is not 0,0.
2537 * If a pointer to a parent struct device is passed in, the newly created
2538 * struct device will be a child of that device in sysfs.
2539 * The pointer to the struct device will be returned from the call.
2540 * Any further sysfs files that might be required can be created using this
2541 * pointer.
2542 *
2543 * Returns &struct device pointer on success, or ERR_PTR() on error.
2544 *
2545 * Note: the struct class passed to this function must have previously
2546 * been created with a call to class_create().
2547 */
2548struct device *device_create_with_groups(struct class *class,
2549 struct device *parent, dev_t devt,
2550 void *drvdata,
2551 const struct attribute_group **groups,
2552 const char *fmt, ...)
2553{
2554 va_list vargs;
2555 struct device *dev;
2556
2557 va_start(vargs, fmt);
2558 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
2559 fmt, vargs);
2560 va_end(vargs);
2561 return dev;
2562}
2563EXPORT_SYMBOL_GPL(device_create_with_groups);
2564
2565static int __match_devt(struct device *dev, const void *data)
2566{
2567 const dev_t *devt = data;
2568
2569 return dev->devt == *devt;
2570}
2571
2572/**
2573 * device_destroy - removes a device that was created with device_create()
2574 * @class: pointer to the struct class that this device was registered with
2575 * @devt: the dev_t of the device that was previously registered
2576 *
2577 * This call unregisters and cleans up a device that was created with a
2578 * call to device_create().
2579 */
2580void device_destroy(struct class *class, dev_t devt)
2581{
2582 struct device *dev;
2583
2584 dev = class_find_device(class, NULL, &devt, __match_devt);
2585 if (dev) {
2586 put_device(dev);
2587 device_unregister(dev);
2588 }
2589}
2590EXPORT_SYMBOL_GPL(device_destroy);
2591
2592/**
2593 * device_rename - renames a device
2594 * @dev: the pointer to the struct device to be renamed
2595 * @new_name: the new name of the device
2596 *
2597 * It is the responsibility of the caller to provide mutual
2598 * exclusion between two different calls of device_rename
2599 * on the same device to ensure that new_name is valid and
2600 * won't conflict with other devices.
2601 *
2602 * Note: Don't call this function. Currently, the networking layer calls this
2603 * function, but that will change. The following text from Kay Sievers offers
2604 * some insight:
2605 *
2606 * Renaming devices is racy at many levels, symlinks and other stuff are not
2607 * replaced atomically, and you get a "move" uevent, but it's not easy to
2608 * connect the event to the old and new device. Device nodes are not renamed at
2609 * all, there isn't even support for that in the kernel now.
2610 *
2611 * In the meantime, during renaming, your target name might be taken by another
2612 * driver, creating conflicts. Or the old name is taken directly after you
2613 * renamed it -- then you get events for the same DEVPATH, before you even see
2614 * the "move" event. It's just a mess, and nothing new should ever rely on
2615 * kernel device renaming. Besides that, it's not even implemented now for
2616 * other things than (driver-core wise very simple) network devices.
2617 *
2618 * We are currently about to change network renaming in udev to completely
2619 * disallow renaming of devices in the same namespace as the kernel uses,
2620 * because we can't solve the problems properly, that arise with swapping names
2621 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2622 * be allowed to some other name than eth[0-9]*, for the aforementioned
2623 * reasons.
2624 *
2625 * Make up a "real" name in the driver before you register anything, or add
2626 * some other attributes for userspace to find the device, or use udev to add
2627 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2628 * don't even want to get into that and try to implement the missing pieces in
2629 * the core. We really have other pieces to fix in the driver core mess. :)
2630 */
2631int device_rename(struct device *dev, const char *new_name)
2632{
2633 struct kobject *kobj = &dev->kobj;
2634 char *old_device_name = NULL;
2635 int error;
2636
2637 dev = get_device(dev);
2638 if (!dev)
2639 return -EINVAL;
2640
2641 dev_dbg(dev, "renaming to %s\n", new_name);
2642
2643 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
2644 if (!old_device_name) {
2645 error = -ENOMEM;
2646 goto out;
2647 }
2648
2649 if (dev->class) {
2650 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
2651 kobj, old_device_name,
2652 new_name, kobject_namespace(kobj));
2653 if (error)
2654 goto out;
2655 }
2656
2657 error = kobject_rename(kobj, new_name);
2658 if (error)
2659 goto out;
2660
2661out:
2662 put_device(dev);
2663
2664 kfree(old_device_name);
2665
2666 return error;
2667}
2668EXPORT_SYMBOL_GPL(device_rename);
2669
2670static int device_move_class_links(struct device *dev,
2671 struct device *old_parent,
2672 struct device *new_parent)
2673{
2674 int error = 0;
2675
2676 if (old_parent)
2677 sysfs_remove_link(&dev->kobj, "device");
2678 if (new_parent)
2679 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
2680 "device");
2681 return error;
2682}
2683
2684/**
2685 * device_move - moves a device to a new parent
2686 * @dev: the pointer to the struct device to be moved
2687 * @new_parent: the new parent of the device (can by NULL)
2688 * @dpm_order: how to reorder the dpm_list
2689 */
2690int device_move(struct device *dev, struct device *new_parent,
2691 enum dpm_order dpm_order)
2692{
2693 int error;
2694 struct device *old_parent;
2695 struct kobject *new_parent_kobj;
2696
2697 dev = get_device(dev);
2698 if (!dev)
2699 return -EINVAL;
2700
2701 device_pm_lock();
2702 new_parent = get_device(new_parent);
2703 new_parent_kobj = get_device_parent(dev, new_parent);
2704
2705 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
2706 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
2707 error = kobject_move(&dev->kobj, new_parent_kobj);
2708 if (error) {
2709 cleanup_glue_dir(dev, new_parent_kobj);
2710 put_device(new_parent);
2711 goto out;
2712 }
2713 old_parent = dev->parent;
2714 dev->parent = new_parent;
2715 if (old_parent)
2716 klist_remove(&dev->p->knode_parent);
2717 if (new_parent) {
2718 klist_add_tail(&dev->p->knode_parent,
2719 &new_parent->p->klist_children);
2720 set_dev_node(dev, dev_to_node(new_parent));
2721 }
2722
2723 if (dev->class) {
2724 error = device_move_class_links(dev, old_parent, new_parent);
2725 if (error) {
2726 /* We ignore errors on cleanup since we're hosed anyway... */
2727 device_move_class_links(dev, new_parent, old_parent);
2728 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
2729 if (new_parent)
2730 klist_remove(&dev->p->knode_parent);
2731 dev->parent = old_parent;
2732 if (old_parent) {
2733 klist_add_tail(&dev->p->knode_parent,
2734 &old_parent->p->klist_children);
2735 set_dev_node(dev, dev_to_node(old_parent));
2736 }
2737 }
2738 cleanup_glue_dir(dev, new_parent_kobj);
2739 put_device(new_parent);
2740 goto out;
2741 }
2742 }
2743 switch (dpm_order) {
2744 case DPM_ORDER_NONE:
2745 break;
2746 case DPM_ORDER_DEV_AFTER_PARENT:
2747 device_pm_move_after(dev, new_parent);
2748 devices_kset_move_after(dev, new_parent);
2749 break;
2750 case DPM_ORDER_PARENT_BEFORE_DEV:
2751 device_pm_move_before(new_parent, dev);
2752 devices_kset_move_before(new_parent, dev);
2753 break;
2754 case DPM_ORDER_DEV_LAST:
2755 device_pm_move_last(dev);
2756 devices_kset_move_last(dev);
2757 break;
2758 }
2759
2760 put_device(old_parent);
2761out:
2762 device_pm_unlock();
2763 put_device(dev);
2764 return error;
2765}
2766EXPORT_SYMBOL_GPL(device_move);
2767
2768/**
2769 * device_shutdown - call ->shutdown() on each device to shutdown.
2770 */
2771void device_shutdown(void)
2772{
2773 struct device *dev, *parent;
2774
2775 spin_lock(&devices_kset->list_lock);
2776 /*
2777 * Walk the devices list backward, shutting down each in turn.
2778 * Beware that device unplug events may also start pulling
2779 * devices offline, even as the system is shutting down.
2780 */
2781 while (!list_empty(&devices_kset->list)) {
2782 dev = list_entry(devices_kset->list.prev, struct device,
2783 kobj.entry);
2784
2785 /*
2786 * hold reference count of device's parent to
2787 * prevent it from being freed because parent's
2788 * lock is to be held
2789 */
2790 parent = get_device(dev->parent);
2791 get_device(dev);
2792 /*
2793 * Make sure the device is off the kset list, in the
2794 * event that dev->*->shutdown() doesn't remove it.
2795 */
2796 list_del_init(&dev->kobj.entry);
2797 spin_unlock(&devices_kset->list_lock);
2798
2799 /* hold lock to avoid race with probe/release */
2800 if (parent)
2801 device_lock(parent);
2802 device_lock(dev);
2803
2804 /* Don't allow any more runtime suspends */
2805 pm_runtime_get_noresume(dev);
2806 pm_runtime_barrier(dev);
2807
2808 if (dev->class && dev->class->shutdown_pre) {
2809 if (initcall_debug)
2810 dev_info(dev, "shutdown_pre\n");
2811 dev->class->shutdown_pre(dev);
2812 }
2813 if (dev->bus && dev->bus->shutdown) {
2814 if (initcall_debug)
2815 dev_info(dev, "shutdown\n");
2816 dev->bus->shutdown(dev);
2817 } else if (dev->driver && dev->driver->shutdown) {
2818 if (initcall_debug)
2819 dev_info(dev, "shutdown\n");
2820 dev->driver->shutdown(dev);
2821 }
2822
2823 device_unlock(dev);
2824 if (parent)
2825 device_unlock(parent);
2826
2827 put_device(dev);
2828 put_device(parent);
2829
2830 spin_lock(&devices_kset->list_lock);
2831 }
2832 spin_unlock(&devices_kset->list_lock);
2833}
2834
2835/*
2836 * Device logging functions
2837 */
2838
2839#ifdef CONFIG_PRINTK
2840static int
2841create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2842{
2843 const char *subsys;
2844 size_t pos = 0;
2845
2846 if (dev->class)
2847 subsys = dev->class->name;
2848 else if (dev->bus)
2849 subsys = dev->bus->name;
2850 else
2851 return 0;
2852
2853 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2854 if (pos >= hdrlen)
2855 goto overflow;
2856
2857 /*
2858 * Add device identifier DEVICE=:
2859 * b12:8 block dev_t
2860 * c127:3 char dev_t
2861 * n8 netdev ifindex
2862 * +sound:card0 subsystem:devname
2863 */
2864 if (MAJOR(dev->devt)) {
2865 char c;
2866
2867 if (strcmp(subsys, "block") == 0)
2868 c = 'b';
2869 else
2870 c = 'c';
2871 pos++;
2872 pos += snprintf(hdr + pos, hdrlen - pos,
2873 "DEVICE=%c%u:%u",
2874 c, MAJOR(dev->devt), MINOR(dev->devt));
2875 } else if (strcmp(subsys, "net") == 0) {
2876 struct net_device *net = to_net_dev(dev);
2877
2878 pos++;
2879 pos += snprintf(hdr + pos, hdrlen - pos,
2880 "DEVICE=n%u", net->ifindex);
2881 } else {
2882 pos++;
2883 pos += snprintf(hdr + pos, hdrlen - pos,
2884 "DEVICE=+%s:%s", subsys, dev_name(dev));
2885 }
2886
2887 if (pos >= hdrlen)
2888 goto overflow;
2889
2890 return pos;
2891
2892overflow:
2893 dev_WARN(dev, "device/subsystem name too long");
2894 return 0;
2895}
2896
2897int dev_vprintk_emit(int level, const struct device *dev,
2898 const char *fmt, va_list args)
2899{
2900 char hdr[128];
2901 size_t hdrlen;
2902
2903 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2904
2905 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2906}
2907EXPORT_SYMBOL(dev_vprintk_emit);
2908
2909int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2910{
2911 va_list args;
2912 int r;
2913
2914 va_start(args, fmt);
2915
2916 r = dev_vprintk_emit(level, dev, fmt, args);
2917
2918 va_end(args);
2919
2920 return r;
2921}
2922EXPORT_SYMBOL(dev_printk_emit);
2923
2924static void __dev_printk(const char *level, const struct device *dev,
2925 struct va_format *vaf)
2926{
2927 if (dev)
2928 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2929 dev_driver_string(dev), dev_name(dev), vaf);
2930 else
2931 printk("%s(NULL device *): %pV", level, vaf);
2932}
2933
2934void dev_printk(const char *level, const struct device *dev,
2935 const char *fmt, ...)
2936{
2937 struct va_format vaf;
2938 va_list args;
2939
2940 va_start(args, fmt);
2941
2942 vaf.fmt = fmt;
2943 vaf.va = &args;
2944
2945 __dev_printk(level, dev, &vaf);
2946
2947 va_end(args);
2948}
2949EXPORT_SYMBOL(dev_printk);
2950
2951#define define_dev_printk_level(func, kern_level) \
2952void func(const struct device *dev, const char *fmt, ...) \
2953{ \
2954 struct va_format vaf; \
2955 va_list args; \
2956 \
2957 va_start(args, fmt); \
2958 \
2959 vaf.fmt = fmt; \
2960 vaf.va = &args; \
2961 \
2962 __dev_printk(kern_level, dev, &vaf); \
2963 \
2964 va_end(args); \
2965} \
2966EXPORT_SYMBOL(func);
2967
2968define_dev_printk_level(dev_emerg, KERN_EMERG);
2969define_dev_printk_level(dev_alert, KERN_ALERT);
2970define_dev_printk_level(dev_crit, KERN_CRIT);
2971define_dev_printk_level(dev_err, KERN_ERR);
2972define_dev_printk_level(dev_warn, KERN_WARNING);
2973define_dev_printk_level(dev_notice, KERN_NOTICE);
2974define_dev_printk_level(_dev_info, KERN_INFO);
2975
2976#endif
2977
2978static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2979{
2980 return fwnode && !IS_ERR(fwnode->secondary);
2981}
2982
2983/**
2984 * set_primary_fwnode - Change the primary firmware node of a given device.
2985 * @dev: Device to handle.
2986 * @fwnode: New primary firmware node of the device.
2987 *
2988 * Set the device's firmware node pointer to @fwnode, but if a secondary
2989 * firmware node of the device is present, preserve it.
2990 */
2991void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2992{
2993 if (fwnode) {
2994 struct fwnode_handle *fn = dev->fwnode;
2995
2996 if (fwnode_is_primary(fn))
2997 fn = fn->secondary;
2998
2999 if (fn) {
3000 WARN_ON(fwnode->secondary);
3001 fwnode->secondary = fn;
3002 }
3003 dev->fwnode = fwnode;
3004 } else {
3005 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
3006 dev->fwnode->secondary : NULL;
3007 }
3008}
3009EXPORT_SYMBOL_GPL(set_primary_fwnode);
3010
3011/**
3012 * set_secondary_fwnode - Change the secondary firmware node of a given device.
3013 * @dev: Device to handle.
3014 * @fwnode: New secondary firmware node of the device.
3015 *
3016 * If a primary firmware node of the device is present, set its secondary
3017 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
3018 * @fwnode.
3019 */
3020void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
3021{
3022 if (fwnode)
3023 fwnode->secondary = ERR_PTR(-ENODEV);
3024
3025 if (fwnode_is_primary(dev->fwnode))
3026 dev->fwnode->secondary = fwnode;
3027 else
3028 dev->fwnode = fwnode;
3029}
3030
3031/**
3032 * device_set_of_node_from_dev - reuse device-tree node of another device
3033 * @dev: device whose device-tree node is being set
3034 * @dev2: device whose device-tree node is being reused
3035 *
3036 * Takes another reference to the new device-tree node after first dropping
3037 * any reference held to the old node.
3038 */
3039void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
3040{
3041 of_node_put(dev->of_node);
3042 dev->of_node = of_node_get(dev2->of_node);
3043 dev->of_node_reused = true;
3044}
3045EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);