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