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1/*
2 * drivers/base/core.c - core driver model code (device registration, etc)
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
8 *
9 * This file is released under the GPLv2
10 *
11 */
12
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/string.h>
19#include <linux/kdev_t.h>
20#include <linux/notifier.h>
21#include <linux/genhd.h>
22#include <linux/kallsyms.h>
23#include <linux/mutex.h>
24#include <linux/async.h>
25
26#include "base.h"
27#include "power/power.h"
28
29#ifdef CONFIG_SYSFS_DEPRECATED
30#ifdef CONFIG_SYSFS_DEPRECATED_V2
31long sysfs_deprecated = 1;
32#else
33long sysfs_deprecated = 0;
34#endif
35static __init int sysfs_deprecated_setup(char *arg)
36{
37 return strict_strtol(arg, 10, &sysfs_deprecated);
38}
39early_param("sysfs.deprecated", sysfs_deprecated_setup);
40#endif
41
42int (*platform_notify)(struct device *dev) = NULL;
43int (*platform_notify_remove)(struct device *dev) = NULL;
44static struct kobject *dev_kobj;
45struct kobject *sysfs_dev_char_kobj;
46struct kobject *sysfs_dev_block_kobj;
47
48#ifdef CONFIG_BLOCK
49static inline int device_is_not_partition(struct device *dev)
50{
51 return !(dev->type == &part_type);
52}
53#else
54static inline int device_is_not_partition(struct device *dev)
55{
56 return 1;
57}
58#endif
59
60/**
61 * dev_driver_string - Return a device's driver name, if at all possible
62 * @dev: struct device to get the name of
63 *
64 * Will return the device's driver's name if it is bound to a device. If
65 * the device is not bound to a device, it will return the name of the bus
66 * it is attached to. If it is not attached to a bus either, an empty
67 * string will be returned.
68 */
69const char *dev_driver_string(const struct device *dev)
70{
71 struct device_driver *drv;
72
73 /* dev->driver can change to NULL underneath us because of unbinding,
74 * so be careful about accessing it. dev->bus and dev->class should
75 * never change once they are set, so they don't need special care.
76 */
77 drv = ACCESS_ONCE(dev->driver);
78 return drv ? drv->name :
79 (dev->bus ? dev->bus->name :
80 (dev->class ? dev->class->name : ""));
81}
82EXPORT_SYMBOL(dev_driver_string);
83
84#define to_dev(obj) container_of(obj, struct device, kobj)
85#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
86
87static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
88 char *buf)
89{
90 struct device_attribute *dev_attr = to_dev_attr(attr);
91 struct device *dev = to_dev(kobj);
92 ssize_t ret = -EIO;
93
94 if (dev_attr->show)
95 ret = dev_attr->show(dev, dev_attr, buf);
96 if (ret >= (ssize_t)PAGE_SIZE) {
97 print_symbol("dev_attr_show: %s returned bad count\n",
98 (unsigned long)dev_attr->show);
99 }
100 return ret;
101}
102
103static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
104 const char *buf, size_t count)
105{
106 struct device_attribute *dev_attr = to_dev_attr(attr);
107 struct device *dev = to_dev(kobj);
108 ssize_t ret = -EIO;
109
110 if (dev_attr->store)
111 ret = dev_attr->store(dev, dev_attr, buf, count);
112 return ret;
113}
114
115static const struct sysfs_ops dev_sysfs_ops = {
116 .show = dev_attr_show,
117 .store = dev_attr_store,
118};
119
120
121/**
122 * device_release - free device structure.
123 * @kobj: device's kobject.
124 *
125 * This is called once the reference count for the object
126 * reaches 0. We forward the call to the device's release
127 * method, which should handle actually freeing the structure.
128 */
129static void device_release(struct kobject *kobj)
130{
131 struct device *dev = to_dev(kobj);
132 struct device_private *p = dev->p;
133
134 if (dev->release)
135 dev->release(dev);
136 else if (dev->type && dev->type->release)
137 dev->type->release(dev);
138 else if (dev->class && dev->class->dev_release)
139 dev->class->dev_release(dev);
140 else
141 WARN(1, KERN_ERR "Device '%s' does not have a release() "
142 "function, it is broken and must be fixed.\n",
143 dev_name(dev));
144 kfree(p);
145}
146
147static const void *device_namespace(struct kobject *kobj)
148{
149 struct device *dev = to_dev(kobj);
150 const void *ns = NULL;
151
152 if (dev->class && dev->class->ns_type)
153 ns = dev->class->namespace(dev);
154
155 return ns;
156}
157
158static struct kobj_type device_ktype = {
159 .release = device_release,
160 .sysfs_ops = &dev_sysfs_ops,
161 .namespace = device_namespace,
162};
163
164
165static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
166{
167 struct kobj_type *ktype = get_ktype(kobj);
168
169 if (ktype == &device_ktype) {
170 struct device *dev = to_dev(kobj);
171 if (dev->bus)
172 return 1;
173 if (dev->class)
174 return 1;
175 }
176 return 0;
177}
178
179static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
180{
181 struct device *dev = to_dev(kobj);
182
183 if (dev->bus)
184 return dev->bus->name;
185 if (dev->class)
186 return dev->class->name;
187 return NULL;
188}
189
190static int dev_uevent(struct kset *kset, struct kobject *kobj,
191 struct kobj_uevent_env *env)
192{
193 struct device *dev = to_dev(kobj);
194 int retval = 0;
195
196 /* add device node properties if present */
197 if (MAJOR(dev->devt)) {
198 const char *tmp;
199 const char *name;
200 mode_t mode = 0;
201
202 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
203 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
204 name = device_get_devnode(dev, &mode, &tmp);
205 if (name) {
206 add_uevent_var(env, "DEVNAME=%s", name);
207 kfree(tmp);
208 if (mode)
209 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
210 }
211 }
212
213 if (dev->type && dev->type->name)
214 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
215
216 if (dev->driver)
217 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
218
219 /* have the bus specific function add its stuff */
220 if (dev->bus && dev->bus->uevent) {
221 retval = dev->bus->uevent(dev, env);
222 if (retval)
223 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
224 dev_name(dev), __func__, retval);
225 }
226
227 /* have the class specific function add its stuff */
228 if (dev->class && dev->class->dev_uevent) {
229 retval = dev->class->dev_uevent(dev, env);
230 if (retval)
231 pr_debug("device: '%s': %s: class uevent() "
232 "returned %d\n", dev_name(dev),
233 __func__, retval);
234 }
235
236 /* have the device type specific function add its stuff */
237 if (dev->type && dev->type->uevent) {
238 retval = dev->type->uevent(dev, env);
239 if (retval)
240 pr_debug("device: '%s': %s: dev_type uevent() "
241 "returned %d\n", dev_name(dev),
242 __func__, retval);
243 }
244
245 return retval;
246}
247
248static const struct kset_uevent_ops device_uevent_ops = {
249 .filter = dev_uevent_filter,
250 .name = dev_uevent_name,
251 .uevent = dev_uevent,
252};
253
254static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
255 char *buf)
256{
257 struct kobject *top_kobj;
258 struct kset *kset;
259 struct kobj_uevent_env *env = NULL;
260 int i;
261 size_t count = 0;
262 int retval;
263
264 /* search the kset, the device belongs to */
265 top_kobj = &dev->kobj;
266 while (!top_kobj->kset && top_kobj->parent)
267 top_kobj = top_kobj->parent;
268 if (!top_kobj->kset)
269 goto out;
270
271 kset = top_kobj->kset;
272 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
273 goto out;
274
275 /* respect filter */
276 if (kset->uevent_ops && kset->uevent_ops->filter)
277 if (!kset->uevent_ops->filter(kset, &dev->kobj))
278 goto out;
279
280 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
281 if (!env)
282 return -ENOMEM;
283
284 /* let the kset specific function add its keys */
285 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
286 if (retval)
287 goto out;
288
289 /* copy keys to file */
290 for (i = 0; i < env->envp_idx; i++)
291 count += sprintf(&buf[count], "%s\n", env->envp[i]);
292out:
293 kfree(env);
294 return count;
295}
296
297static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
298 const char *buf, size_t count)
299{
300 enum kobject_action action;
301
302 if (kobject_action_type(buf, count, &action) == 0)
303 kobject_uevent(&dev->kobj, action);
304 else
305 dev_err(dev, "uevent: unknown action-string\n");
306 return count;
307}
308
309static struct device_attribute uevent_attr =
310 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
311
312static int device_add_attributes(struct device *dev,
313 struct device_attribute *attrs)
314{
315 int error = 0;
316 int i;
317
318 if (attrs) {
319 for (i = 0; attr_name(attrs[i]); i++) {
320 error = device_create_file(dev, &attrs[i]);
321 if (error)
322 break;
323 }
324 if (error)
325 while (--i >= 0)
326 device_remove_file(dev, &attrs[i]);
327 }
328 return error;
329}
330
331static void device_remove_attributes(struct device *dev,
332 struct device_attribute *attrs)
333{
334 int i;
335
336 if (attrs)
337 for (i = 0; attr_name(attrs[i]); i++)
338 device_remove_file(dev, &attrs[i]);
339}
340
341static int device_add_bin_attributes(struct device *dev,
342 struct bin_attribute *attrs)
343{
344 int error = 0;
345 int i;
346
347 if (attrs) {
348 for (i = 0; attr_name(attrs[i]); i++) {
349 error = device_create_bin_file(dev, &attrs[i]);
350 if (error)
351 break;
352 }
353 if (error)
354 while (--i >= 0)
355 device_remove_bin_file(dev, &attrs[i]);
356 }
357 return error;
358}
359
360static void device_remove_bin_attributes(struct device *dev,
361 struct bin_attribute *attrs)
362{
363 int i;
364
365 if (attrs)
366 for (i = 0; attr_name(attrs[i]); i++)
367 device_remove_bin_file(dev, &attrs[i]);
368}
369
370static int device_add_groups(struct device *dev,
371 const struct attribute_group **groups)
372{
373 int error = 0;
374 int i;
375
376 if (groups) {
377 for (i = 0; groups[i]; i++) {
378 error = sysfs_create_group(&dev->kobj, groups[i]);
379 if (error) {
380 while (--i >= 0)
381 sysfs_remove_group(&dev->kobj,
382 groups[i]);
383 break;
384 }
385 }
386 }
387 return error;
388}
389
390static void device_remove_groups(struct device *dev,
391 const struct attribute_group **groups)
392{
393 int i;
394
395 if (groups)
396 for (i = 0; groups[i]; i++)
397 sysfs_remove_group(&dev->kobj, groups[i]);
398}
399
400static int device_add_attrs(struct device *dev)
401{
402 struct class *class = dev->class;
403 const struct device_type *type = dev->type;
404 int error;
405
406 if (class) {
407 error = device_add_attributes(dev, class->dev_attrs);
408 if (error)
409 return error;
410 error = device_add_bin_attributes(dev, class->dev_bin_attrs);
411 if (error)
412 goto err_remove_class_attrs;
413 }
414
415 if (type) {
416 error = device_add_groups(dev, type->groups);
417 if (error)
418 goto err_remove_class_bin_attrs;
419 }
420
421 error = device_add_groups(dev, dev->groups);
422 if (error)
423 goto err_remove_type_groups;
424
425 return 0;
426
427 err_remove_type_groups:
428 if (type)
429 device_remove_groups(dev, type->groups);
430 err_remove_class_bin_attrs:
431 if (class)
432 device_remove_bin_attributes(dev, class->dev_bin_attrs);
433 err_remove_class_attrs:
434 if (class)
435 device_remove_attributes(dev, class->dev_attrs);
436
437 return error;
438}
439
440static void device_remove_attrs(struct device *dev)
441{
442 struct class *class = dev->class;
443 const struct device_type *type = dev->type;
444
445 device_remove_groups(dev, dev->groups);
446
447 if (type)
448 device_remove_groups(dev, type->groups);
449
450 if (class) {
451 device_remove_attributes(dev, class->dev_attrs);
452 device_remove_bin_attributes(dev, class->dev_bin_attrs);
453 }
454}
455
456
457static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
458 char *buf)
459{
460 return print_dev_t(buf, dev->devt);
461}
462
463static struct device_attribute devt_attr =
464 __ATTR(dev, S_IRUGO, show_dev, NULL);
465
466/* kset to create /sys/devices/ */
467struct kset *devices_kset;
468
469/**
470 * device_create_file - create sysfs attribute file for device.
471 * @dev: device.
472 * @attr: device attribute descriptor.
473 */
474int device_create_file(struct device *dev,
475 const struct device_attribute *attr)
476{
477 int error = 0;
478 if (dev)
479 error = sysfs_create_file(&dev->kobj, &attr->attr);
480 return error;
481}
482
483/**
484 * device_remove_file - remove sysfs attribute file.
485 * @dev: device.
486 * @attr: device attribute descriptor.
487 */
488void device_remove_file(struct device *dev,
489 const struct device_attribute *attr)
490{
491 if (dev)
492 sysfs_remove_file(&dev->kobj, &attr->attr);
493}
494
495/**
496 * device_create_bin_file - create sysfs binary attribute file for device.
497 * @dev: device.
498 * @attr: device binary attribute descriptor.
499 */
500int device_create_bin_file(struct device *dev,
501 const struct bin_attribute *attr)
502{
503 int error = -EINVAL;
504 if (dev)
505 error = sysfs_create_bin_file(&dev->kobj, attr);
506 return error;
507}
508EXPORT_SYMBOL_GPL(device_create_bin_file);
509
510/**
511 * device_remove_bin_file - remove sysfs binary attribute file
512 * @dev: device.
513 * @attr: device binary attribute descriptor.
514 */
515void device_remove_bin_file(struct device *dev,
516 const struct bin_attribute *attr)
517{
518 if (dev)
519 sysfs_remove_bin_file(&dev->kobj, attr);
520}
521EXPORT_SYMBOL_GPL(device_remove_bin_file);
522
523/**
524 * device_schedule_callback_owner - helper to schedule a callback for a device
525 * @dev: device.
526 * @func: callback function to invoke later.
527 * @owner: module owning the callback routine
528 *
529 * Attribute methods must not unregister themselves or their parent device
530 * (which would amount to the same thing). Attempts to do so will deadlock,
531 * since unregistration is mutually exclusive with driver callbacks.
532 *
533 * Instead methods can call this routine, which will attempt to allocate
534 * and schedule a workqueue request to call back @func with @dev as its
535 * argument in the workqueue's process context. @dev will be pinned until
536 * @func returns.
537 *
538 * This routine is usually called via the inline device_schedule_callback(),
539 * which automatically sets @owner to THIS_MODULE.
540 *
541 * Returns 0 if the request was submitted, -ENOMEM if storage could not
542 * be allocated, -ENODEV if a reference to @owner isn't available.
543 *
544 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
545 * underlying sysfs routine (since it is intended for use by attribute
546 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
547 */
548int device_schedule_callback_owner(struct device *dev,
549 void (*func)(struct device *), struct module *owner)
550{
551 return sysfs_schedule_callback(&dev->kobj,
552 (void (*)(void *)) func, dev, owner);
553}
554EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
555
556static void klist_children_get(struct klist_node *n)
557{
558 struct device_private *p = to_device_private_parent(n);
559 struct device *dev = p->device;
560
561 get_device(dev);
562}
563
564static void klist_children_put(struct klist_node *n)
565{
566 struct device_private *p = to_device_private_parent(n);
567 struct device *dev = p->device;
568
569 put_device(dev);
570}
571
572/**
573 * device_initialize - init device structure.
574 * @dev: device.
575 *
576 * This prepares the device for use by other layers by initializing
577 * its fields.
578 * It is the first half of device_register(), if called by
579 * that function, though it can also be called separately, so one
580 * may use @dev's fields. In particular, get_device()/put_device()
581 * may be used for reference counting of @dev after calling this
582 * function.
583 *
584 * NOTE: Use put_device() to give up your reference instead of freeing
585 * @dev directly once you have called this function.
586 */
587void device_initialize(struct device *dev)
588{
589 dev->kobj.kset = devices_kset;
590 kobject_init(&dev->kobj, &device_ktype);
591 INIT_LIST_HEAD(&dev->dma_pools);
592 mutex_init(&dev->mutex);
593 lockdep_set_novalidate_class(&dev->mutex);
594 spin_lock_init(&dev->devres_lock);
595 INIT_LIST_HEAD(&dev->devres_head);
596 device_pm_init(dev);
597 set_dev_node(dev, -1);
598}
599
600static struct kobject *virtual_device_parent(struct device *dev)
601{
602 static struct kobject *virtual_dir = NULL;
603
604 if (!virtual_dir)
605 virtual_dir = kobject_create_and_add("virtual",
606 &devices_kset->kobj);
607
608 return virtual_dir;
609}
610
611struct class_dir {
612 struct kobject kobj;
613 struct class *class;
614};
615
616#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
617
618static void class_dir_release(struct kobject *kobj)
619{
620 struct class_dir *dir = to_class_dir(kobj);
621 kfree(dir);
622}
623
624static const
625struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
626{
627 struct class_dir *dir = to_class_dir(kobj);
628 return dir->class->ns_type;
629}
630
631static struct kobj_type class_dir_ktype = {
632 .release = class_dir_release,
633 .sysfs_ops = &kobj_sysfs_ops,
634 .child_ns_type = class_dir_child_ns_type
635};
636
637static struct kobject *
638class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
639{
640 struct class_dir *dir;
641 int retval;
642
643 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
644 if (!dir)
645 return NULL;
646
647 dir->class = class;
648 kobject_init(&dir->kobj, &class_dir_ktype);
649
650 dir->kobj.kset = &class->p->glue_dirs;
651
652 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
653 if (retval < 0) {
654 kobject_put(&dir->kobj);
655 return NULL;
656 }
657 return &dir->kobj;
658}
659
660
661static struct kobject *get_device_parent(struct device *dev,
662 struct device *parent)
663{
664 if (dev->class) {
665 static DEFINE_MUTEX(gdp_mutex);
666 struct kobject *kobj = NULL;
667 struct kobject *parent_kobj;
668 struct kobject *k;
669
670#ifdef CONFIG_BLOCK
671 /* block disks show up in /sys/block */
672 if (sysfs_deprecated && dev->class == &block_class) {
673 if (parent && parent->class == &block_class)
674 return &parent->kobj;
675 return &block_class.p->subsys.kobj;
676 }
677#endif
678
679 /*
680 * If we have no parent, we live in "virtual".
681 * Class-devices with a non class-device as parent, live
682 * in a "glue" directory to prevent namespace collisions.
683 */
684 if (parent == NULL)
685 parent_kobj = virtual_device_parent(dev);
686 else if (parent->class && !dev->class->ns_type)
687 return &parent->kobj;
688 else
689 parent_kobj = &parent->kobj;
690
691 mutex_lock(&gdp_mutex);
692
693 /* find our class-directory at the parent and reference it */
694 spin_lock(&dev->class->p->glue_dirs.list_lock);
695 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
696 if (k->parent == parent_kobj) {
697 kobj = kobject_get(k);
698 break;
699 }
700 spin_unlock(&dev->class->p->glue_dirs.list_lock);
701 if (kobj) {
702 mutex_unlock(&gdp_mutex);
703 return kobj;
704 }
705
706 /* or create a new class-directory at the parent device */
707 k = class_dir_create_and_add(dev->class, parent_kobj);
708 /* do not emit an uevent for this simple "glue" directory */
709 mutex_unlock(&gdp_mutex);
710 return k;
711 }
712
713 if (parent)
714 return &parent->kobj;
715 return NULL;
716}
717
718static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
719{
720 /* see if we live in a "glue" directory */
721 if (!glue_dir || !dev->class ||
722 glue_dir->kset != &dev->class->p->glue_dirs)
723 return;
724
725 kobject_put(glue_dir);
726}
727
728static void cleanup_device_parent(struct device *dev)
729{
730 cleanup_glue_dir(dev, dev->kobj.parent);
731}
732
733static void setup_parent(struct device *dev, struct device *parent)
734{
735 struct kobject *kobj;
736 kobj = get_device_parent(dev, parent);
737 if (kobj)
738 dev->kobj.parent = kobj;
739}
740
741static int device_add_class_symlinks(struct device *dev)
742{
743 int error;
744
745 if (!dev->class)
746 return 0;
747
748 error = sysfs_create_link(&dev->kobj,
749 &dev->class->p->subsys.kobj,
750 "subsystem");
751 if (error)
752 goto out;
753
754 if (dev->parent && device_is_not_partition(dev)) {
755 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
756 "device");
757 if (error)
758 goto out_subsys;
759 }
760
761#ifdef CONFIG_BLOCK
762 /* /sys/block has directories and does not need symlinks */
763 if (sysfs_deprecated && dev->class == &block_class)
764 return 0;
765#endif
766
767 /* link in the class directory pointing to the device */
768 error = sysfs_create_link(&dev->class->p->subsys.kobj,
769 &dev->kobj, dev_name(dev));
770 if (error)
771 goto out_device;
772
773 return 0;
774
775out_device:
776 sysfs_remove_link(&dev->kobj, "device");
777
778out_subsys:
779 sysfs_remove_link(&dev->kobj, "subsystem");
780out:
781 return error;
782}
783
784static void device_remove_class_symlinks(struct device *dev)
785{
786 if (!dev->class)
787 return;
788
789 if (dev->parent && device_is_not_partition(dev))
790 sysfs_remove_link(&dev->kobj, "device");
791 sysfs_remove_link(&dev->kobj, "subsystem");
792#ifdef CONFIG_BLOCK
793 if (sysfs_deprecated && dev->class == &block_class)
794 return;
795#endif
796 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
797}
798
799/**
800 * dev_set_name - set a device name
801 * @dev: device
802 * @fmt: format string for the device's name
803 */
804int dev_set_name(struct device *dev, const char *fmt, ...)
805{
806 va_list vargs;
807 int err;
808
809 va_start(vargs, fmt);
810 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
811 va_end(vargs);
812 return err;
813}
814EXPORT_SYMBOL_GPL(dev_set_name);
815
816/**
817 * device_to_dev_kobj - select a /sys/dev/ directory for the device
818 * @dev: device
819 *
820 * By default we select char/ for new entries. Setting class->dev_obj
821 * to NULL prevents an entry from being created. class->dev_kobj must
822 * be set (or cleared) before any devices are registered to the class
823 * otherwise device_create_sys_dev_entry() and
824 * device_remove_sys_dev_entry() will disagree about the the presence
825 * of the link.
826 */
827static struct kobject *device_to_dev_kobj(struct device *dev)
828{
829 struct kobject *kobj;
830
831 if (dev->class)
832 kobj = dev->class->dev_kobj;
833 else
834 kobj = sysfs_dev_char_kobj;
835
836 return kobj;
837}
838
839static int device_create_sys_dev_entry(struct device *dev)
840{
841 struct kobject *kobj = device_to_dev_kobj(dev);
842 int error = 0;
843 char devt_str[15];
844
845 if (kobj) {
846 format_dev_t(devt_str, dev->devt);
847 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
848 }
849
850 return error;
851}
852
853static void device_remove_sys_dev_entry(struct device *dev)
854{
855 struct kobject *kobj = device_to_dev_kobj(dev);
856 char devt_str[15];
857
858 if (kobj) {
859 format_dev_t(devt_str, dev->devt);
860 sysfs_remove_link(kobj, devt_str);
861 }
862}
863
864int device_private_init(struct device *dev)
865{
866 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
867 if (!dev->p)
868 return -ENOMEM;
869 dev->p->device = dev;
870 klist_init(&dev->p->klist_children, klist_children_get,
871 klist_children_put);
872 return 0;
873}
874
875/**
876 * device_add - add device to device hierarchy.
877 * @dev: device.
878 *
879 * This is part 2 of device_register(), though may be called
880 * separately _iff_ device_initialize() has been called separately.
881 *
882 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
883 * to the global and sibling lists for the device, then
884 * adds it to the other relevant subsystems of the driver model.
885 *
886 * NOTE: _Never_ directly free @dev after calling this function, even
887 * if it returned an error! Always use put_device() to give up your
888 * reference instead.
889 */
890int device_add(struct device *dev)
891{
892 struct device *parent = NULL;
893 struct class_interface *class_intf;
894 int error = -EINVAL;
895
896 dev = get_device(dev);
897 if (!dev)
898 goto done;
899
900 if (!dev->p) {
901 error = device_private_init(dev);
902 if (error)
903 goto done;
904 }
905
906 /*
907 * for statically allocated devices, which should all be converted
908 * some day, we need to initialize the name. We prevent reading back
909 * the name, and force the use of dev_name()
910 */
911 if (dev->init_name) {
912 dev_set_name(dev, "%s", dev->init_name);
913 dev->init_name = NULL;
914 }
915
916 if (!dev_name(dev)) {
917 error = -EINVAL;
918 goto name_error;
919 }
920
921 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
922
923 parent = get_device(dev->parent);
924 setup_parent(dev, parent);
925
926 /* use parent numa_node */
927 if (parent)
928 set_dev_node(dev, dev_to_node(parent));
929
930 /* first, register with generic layer. */
931 /* we require the name to be set before, and pass NULL */
932 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
933 if (error)
934 goto Error;
935
936 /* notify platform of device entry */
937 if (platform_notify)
938 platform_notify(dev);
939
940 error = device_create_file(dev, &uevent_attr);
941 if (error)
942 goto attrError;
943
944 if (MAJOR(dev->devt)) {
945 error = device_create_file(dev, &devt_attr);
946 if (error)
947 goto ueventattrError;
948
949 error = device_create_sys_dev_entry(dev);
950 if (error)
951 goto devtattrError;
952
953 devtmpfs_create_node(dev);
954 }
955
956 error = device_add_class_symlinks(dev);
957 if (error)
958 goto SymlinkError;
959 error = device_add_attrs(dev);
960 if (error)
961 goto AttrsError;
962 error = bus_add_device(dev);
963 if (error)
964 goto BusError;
965 error = dpm_sysfs_add(dev);
966 if (error)
967 goto DPMError;
968 device_pm_add(dev);
969
970 /* Notify clients of device addition. This call must come
971 * after dpm_sysf_add() and before kobject_uevent().
972 */
973 if (dev->bus)
974 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
975 BUS_NOTIFY_ADD_DEVICE, dev);
976
977 kobject_uevent(&dev->kobj, KOBJ_ADD);
978 bus_probe_device(dev);
979 if (parent)
980 klist_add_tail(&dev->p->knode_parent,
981 &parent->p->klist_children);
982
983 if (dev->class) {
984 mutex_lock(&dev->class->p->class_mutex);
985 /* tie the class to the device */
986 klist_add_tail(&dev->knode_class,
987 &dev->class->p->klist_devices);
988
989 /* notify any interfaces that the device is here */
990 list_for_each_entry(class_intf,
991 &dev->class->p->class_interfaces, node)
992 if (class_intf->add_dev)
993 class_intf->add_dev(dev, class_intf);
994 mutex_unlock(&dev->class->p->class_mutex);
995 }
996done:
997 put_device(dev);
998 return error;
999 DPMError:
1000 bus_remove_device(dev);
1001 BusError:
1002 device_remove_attrs(dev);
1003 AttrsError:
1004 device_remove_class_symlinks(dev);
1005 SymlinkError:
1006 if (MAJOR(dev->devt))
1007 devtmpfs_delete_node(dev);
1008 if (MAJOR(dev->devt))
1009 device_remove_sys_dev_entry(dev);
1010 devtattrError:
1011 if (MAJOR(dev->devt))
1012 device_remove_file(dev, &devt_attr);
1013 ueventattrError:
1014 device_remove_file(dev, &uevent_attr);
1015 attrError:
1016 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1017 kobject_del(&dev->kobj);
1018 Error:
1019 cleanup_device_parent(dev);
1020 if (parent)
1021 put_device(parent);
1022name_error:
1023 kfree(dev->p);
1024 dev->p = NULL;
1025 goto done;
1026}
1027
1028/**
1029 * device_register - register a device with the system.
1030 * @dev: pointer to the device structure
1031 *
1032 * This happens in two clean steps - initialize the device
1033 * and add it to the system. The two steps can be called
1034 * separately, but this is the easiest and most common.
1035 * I.e. you should only call the two helpers separately if
1036 * have a clearly defined need to use and refcount the device
1037 * before it is added to the hierarchy.
1038 *
1039 * NOTE: _Never_ directly free @dev after calling this function, even
1040 * if it returned an error! Always use put_device() to give up the
1041 * reference initialized in this function instead.
1042 */
1043int device_register(struct device *dev)
1044{
1045 device_initialize(dev);
1046 return device_add(dev);
1047}
1048
1049/**
1050 * get_device - increment reference count for device.
1051 * @dev: device.
1052 *
1053 * This simply forwards the call to kobject_get(), though
1054 * we do take care to provide for the case that we get a NULL
1055 * pointer passed in.
1056 */
1057struct device *get_device(struct device *dev)
1058{
1059 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
1060}
1061
1062/**
1063 * put_device - decrement reference count.
1064 * @dev: device in question.
1065 */
1066void put_device(struct device *dev)
1067{
1068 /* might_sleep(); */
1069 if (dev)
1070 kobject_put(&dev->kobj);
1071}
1072
1073/**
1074 * device_del - delete device from system.
1075 * @dev: device.
1076 *
1077 * This is the first part of the device unregistration
1078 * sequence. This removes the device from the lists we control
1079 * from here, has it removed from the other driver model
1080 * subsystems it was added to in device_add(), and removes it
1081 * from the kobject hierarchy.
1082 *
1083 * NOTE: this should be called manually _iff_ device_add() was
1084 * also called manually.
1085 */
1086void device_del(struct device *dev)
1087{
1088 struct device *parent = dev->parent;
1089 struct class_interface *class_intf;
1090
1091 /* Notify clients of device removal. This call must come
1092 * before dpm_sysfs_remove().
1093 */
1094 if (dev->bus)
1095 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1096 BUS_NOTIFY_DEL_DEVICE, dev);
1097 device_pm_remove(dev);
1098 dpm_sysfs_remove(dev);
1099 if (parent)
1100 klist_del(&dev->p->knode_parent);
1101 if (MAJOR(dev->devt)) {
1102 devtmpfs_delete_node(dev);
1103 device_remove_sys_dev_entry(dev);
1104 device_remove_file(dev, &devt_attr);
1105 }
1106 if (dev->class) {
1107 device_remove_class_symlinks(dev);
1108
1109 mutex_lock(&dev->class->p->class_mutex);
1110 /* notify any interfaces that the device is now gone */
1111 list_for_each_entry(class_intf,
1112 &dev->class->p->class_interfaces, node)
1113 if (class_intf->remove_dev)
1114 class_intf->remove_dev(dev, class_intf);
1115 /* remove the device from the class list */
1116 klist_del(&dev->knode_class);
1117 mutex_unlock(&dev->class->p->class_mutex);
1118 }
1119 device_remove_file(dev, &uevent_attr);
1120 device_remove_attrs(dev);
1121 bus_remove_device(dev);
1122
1123 /*
1124 * Some platform devices are driven without driver attached
1125 * and managed resources may have been acquired. Make sure
1126 * all resources are released.
1127 */
1128 devres_release_all(dev);
1129
1130 /* Notify the platform of the removal, in case they
1131 * need to do anything...
1132 */
1133 if (platform_notify_remove)
1134 platform_notify_remove(dev);
1135 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1136 cleanup_device_parent(dev);
1137 kobject_del(&dev->kobj);
1138 put_device(parent);
1139}
1140
1141/**
1142 * device_unregister - unregister device from system.
1143 * @dev: device going away.
1144 *
1145 * We do this in two parts, like we do device_register(). First,
1146 * we remove it from all the subsystems with device_del(), then
1147 * we decrement the reference count via put_device(). If that
1148 * is the final reference count, the device will be cleaned up
1149 * via device_release() above. Otherwise, the structure will
1150 * stick around until the final reference to the device is dropped.
1151 */
1152void device_unregister(struct device *dev)
1153{
1154 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1155 device_del(dev);
1156 put_device(dev);
1157}
1158
1159static struct device *next_device(struct klist_iter *i)
1160{
1161 struct klist_node *n = klist_next(i);
1162 struct device *dev = NULL;
1163 struct device_private *p;
1164
1165 if (n) {
1166 p = to_device_private_parent(n);
1167 dev = p->device;
1168 }
1169 return dev;
1170}
1171
1172/**
1173 * device_get_devnode - path of device node file
1174 * @dev: device
1175 * @mode: returned file access mode
1176 * @tmp: possibly allocated string
1177 *
1178 * Return the relative path of a possible device node.
1179 * Non-default names may need to allocate a memory to compose
1180 * a name. This memory is returned in tmp and needs to be
1181 * freed by the caller.
1182 */
1183const char *device_get_devnode(struct device *dev,
1184 mode_t *mode, const char **tmp)
1185{
1186 char *s;
1187
1188 *tmp = NULL;
1189
1190 /* the device type may provide a specific name */
1191 if (dev->type && dev->type->devnode)
1192 *tmp = dev->type->devnode(dev, mode);
1193 if (*tmp)
1194 return *tmp;
1195
1196 /* the class may provide a specific name */
1197 if (dev->class && dev->class->devnode)
1198 *tmp = dev->class->devnode(dev, mode);
1199 if (*tmp)
1200 return *tmp;
1201
1202 /* return name without allocation, tmp == NULL */
1203 if (strchr(dev_name(dev), '!') == NULL)
1204 return dev_name(dev);
1205
1206 /* replace '!' in the name with '/' */
1207 *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1208 if (!*tmp)
1209 return NULL;
1210 while ((s = strchr(*tmp, '!')))
1211 s[0] = '/';
1212 return *tmp;
1213}
1214
1215/**
1216 * device_for_each_child - device child iterator.
1217 * @parent: parent struct device.
1218 * @data: data for the callback.
1219 * @fn: function to be called for each device.
1220 *
1221 * Iterate over @parent's child devices, and call @fn for each,
1222 * passing it @data.
1223 *
1224 * We check the return of @fn each time. If it returns anything
1225 * other than 0, we break out and return that value.
1226 */
1227int device_for_each_child(struct device *parent, void *data,
1228 int (*fn)(struct device *dev, void *data))
1229{
1230 struct klist_iter i;
1231 struct device *child;
1232 int error = 0;
1233
1234 if (!parent->p)
1235 return 0;
1236
1237 klist_iter_init(&parent->p->klist_children, &i);
1238 while ((child = next_device(&i)) && !error)
1239 error = fn(child, data);
1240 klist_iter_exit(&i);
1241 return error;
1242}
1243
1244/**
1245 * device_find_child - device iterator for locating a particular device.
1246 * @parent: parent struct device
1247 * @data: Data to pass to match function
1248 * @match: Callback function to check device
1249 *
1250 * This is similar to the device_for_each_child() function above, but it
1251 * returns a reference to a device that is 'found' for later use, as
1252 * determined by the @match callback.
1253 *
1254 * The callback should return 0 if the device doesn't match and non-zero
1255 * if it does. If the callback returns non-zero and a reference to the
1256 * current device can be obtained, this function will return to the caller
1257 * and not iterate over any more devices.
1258 */
1259struct device *device_find_child(struct device *parent, void *data,
1260 int (*match)(struct device *dev, void *data))
1261{
1262 struct klist_iter i;
1263 struct device *child;
1264
1265 if (!parent)
1266 return NULL;
1267
1268 klist_iter_init(&parent->p->klist_children, &i);
1269 while ((child = next_device(&i)))
1270 if (match(child, data) && get_device(child))
1271 break;
1272 klist_iter_exit(&i);
1273 return child;
1274}
1275
1276int __init devices_init(void)
1277{
1278 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1279 if (!devices_kset)
1280 return -ENOMEM;
1281 dev_kobj = kobject_create_and_add("dev", NULL);
1282 if (!dev_kobj)
1283 goto dev_kobj_err;
1284 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1285 if (!sysfs_dev_block_kobj)
1286 goto block_kobj_err;
1287 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1288 if (!sysfs_dev_char_kobj)
1289 goto char_kobj_err;
1290
1291 return 0;
1292
1293 char_kobj_err:
1294 kobject_put(sysfs_dev_block_kobj);
1295 block_kobj_err:
1296 kobject_put(dev_kobj);
1297 dev_kobj_err:
1298 kset_unregister(devices_kset);
1299 return -ENOMEM;
1300}
1301
1302EXPORT_SYMBOL_GPL(device_for_each_child);
1303EXPORT_SYMBOL_GPL(device_find_child);
1304
1305EXPORT_SYMBOL_GPL(device_initialize);
1306EXPORT_SYMBOL_GPL(device_add);
1307EXPORT_SYMBOL_GPL(device_register);
1308
1309EXPORT_SYMBOL_GPL(device_del);
1310EXPORT_SYMBOL_GPL(device_unregister);
1311EXPORT_SYMBOL_GPL(get_device);
1312EXPORT_SYMBOL_GPL(put_device);
1313
1314EXPORT_SYMBOL_GPL(device_create_file);
1315EXPORT_SYMBOL_GPL(device_remove_file);
1316
1317struct root_device {
1318 struct device dev;
1319 struct module *owner;
1320};
1321
1322inline struct root_device *to_root_device(struct device *d)
1323{
1324 return container_of(d, struct root_device, dev);
1325}
1326
1327static void root_device_release(struct device *dev)
1328{
1329 kfree(to_root_device(dev));
1330}
1331
1332/**
1333 * __root_device_register - allocate and register a root device
1334 * @name: root device name
1335 * @owner: owner module of the root device, usually THIS_MODULE
1336 *
1337 * This function allocates a root device and registers it
1338 * using device_register(). In order to free the returned
1339 * device, use root_device_unregister().
1340 *
1341 * Root devices are dummy devices which allow other devices
1342 * to be grouped under /sys/devices. Use this function to
1343 * allocate a root device and then use it as the parent of
1344 * any device which should appear under /sys/devices/{name}
1345 *
1346 * The /sys/devices/{name} directory will also contain a
1347 * 'module' symlink which points to the @owner directory
1348 * in sysfs.
1349 *
1350 * Returns &struct device pointer on success, or ERR_PTR() on error.
1351 *
1352 * Note: You probably want to use root_device_register().
1353 */
1354struct device *__root_device_register(const char *name, struct module *owner)
1355{
1356 struct root_device *root;
1357 int err = -ENOMEM;
1358
1359 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1360 if (!root)
1361 return ERR_PTR(err);
1362
1363 err = dev_set_name(&root->dev, "%s", name);
1364 if (err) {
1365 kfree(root);
1366 return ERR_PTR(err);
1367 }
1368
1369 root->dev.release = root_device_release;
1370
1371 err = device_register(&root->dev);
1372 if (err) {
1373 put_device(&root->dev);
1374 return ERR_PTR(err);
1375 }
1376
1377#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1378 if (owner) {
1379 struct module_kobject *mk = &owner->mkobj;
1380
1381 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1382 if (err) {
1383 device_unregister(&root->dev);
1384 return ERR_PTR(err);
1385 }
1386 root->owner = owner;
1387 }
1388#endif
1389
1390 return &root->dev;
1391}
1392EXPORT_SYMBOL_GPL(__root_device_register);
1393
1394/**
1395 * root_device_unregister - unregister and free a root device
1396 * @dev: device going away
1397 *
1398 * This function unregisters and cleans up a device that was created by
1399 * root_device_register().
1400 */
1401void root_device_unregister(struct device *dev)
1402{
1403 struct root_device *root = to_root_device(dev);
1404
1405 if (root->owner)
1406 sysfs_remove_link(&root->dev.kobj, "module");
1407
1408 device_unregister(dev);
1409}
1410EXPORT_SYMBOL_GPL(root_device_unregister);
1411
1412
1413static void device_create_release(struct device *dev)
1414{
1415 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1416 kfree(dev);
1417}
1418
1419/**
1420 * device_create_vargs - creates a device and registers it with sysfs
1421 * @class: pointer to the struct class that this device should be registered to
1422 * @parent: pointer to the parent struct device of this new device, if any
1423 * @devt: the dev_t for the char device to be added
1424 * @drvdata: the data to be added to the device for callbacks
1425 * @fmt: string for the device's name
1426 * @args: va_list for the device's name
1427 *
1428 * This function can be used by char device classes. A struct device
1429 * will be created in sysfs, registered to the specified class.
1430 *
1431 * A "dev" file will be created, showing the dev_t for the device, if
1432 * the dev_t is not 0,0.
1433 * If a pointer to a parent struct device is passed in, the newly created
1434 * struct device will be a child of that device in sysfs.
1435 * The pointer to the struct device will be returned from the call.
1436 * Any further sysfs files that might be required can be created using this
1437 * pointer.
1438 *
1439 * Returns &struct device pointer on success, or ERR_PTR() on error.
1440 *
1441 * Note: the struct class passed to this function must have previously
1442 * been created with a call to class_create().
1443 */
1444struct device *device_create_vargs(struct class *class, struct device *parent,
1445 dev_t devt, void *drvdata, const char *fmt,
1446 va_list args)
1447{
1448 struct device *dev = NULL;
1449 int retval = -ENODEV;
1450
1451 if (class == NULL || IS_ERR(class))
1452 goto error;
1453
1454 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1455 if (!dev) {
1456 retval = -ENOMEM;
1457 goto error;
1458 }
1459
1460 dev->devt = devt;
1461 dev->class = class;
1462 dev->parent = parent;
1463 dev->release = device_create_release;
1464 dev_set_drvdata(dev, drvdata);
1465
1466 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1467 if (retval)
1468 goto error;
1469
1470 retval = device_register(dev);
1471 if (retval)
1472 goto error;
1473
1474 return dev;
1475
1476error:
1477 put_device(dev);
1478 return ERR_PTR(retval);
1479}
1480EXPORT_SYMBOL_GPL(device_create_vargs);
1481
1482/**
1483 * device_create - creates a device and registers it with sysfs
1484 * @class: pointer to the struct class that this device should be registered to
1485 * @parent: pointer to the parent struct device of this new device, if any
1486 * @devt: the dev_t for the char device to be added
1487 * @drvdata: the data to be added to the device for callbacks
1488 * @fmt: string for the device's name
1489 *
1490 * This function can be used by char device classes. A struct device
1491 * will be created in sysfs, registered to the specified class.
1492 *
1493 * A "dev" file will be created, showing the dev_t for the device, if
1494 * the dev_t is not 0,0.
1495 * If a pointer to a parent struct device is passed in, the newly created
1496 * struct device will be a child of that device in sysfs.
1497 * The pointer to the struct device will be returned from the call.
1498 * Any further sysfs files that might be required can be created using this
1499 * pointer.
1500 *
1501 * Returns &struct device pointer on success, or ERR_PTR() on error.
1502 *
1503 * Note: the struct class passed to this function must have previously
1504 * been created with a call to class_create().
1505 */
1506struct device *device_create(struct class *class, struct device *parent,
1507 dev_t devt, void *drvdata, const char *fmt, ...)
1508{
1509 va_list vargs;
1510 struct device *dev;
1511
1512 va_start(vargs, fmt);
1513 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1514 va_end(vargs);
1515 return dev;
1516}
1517EXPORT_SYMBOL_GPL(device_create);
1518
1519static int __match_devt(struct device *dev, void *data)
1520{
1521 dev_t *devt = data;
1522
1523 return dev->devt == *devt;
1524}
1525
1526/**
1527 * device_destroy - removes a device that was created with device_create()
1528 * @class: pointer to the struct class that this device was registered with
1529 * @devt: the dev_t of the device that was previously registered
1530 *
1531 * This call unregisters and cleans up a device that was created with a
1532 * call to device_create().
1533 */
1534void device_destroy(struct class *class, dev_t devt)
1535{
1536 struct device *dev;
1537
1538 dev = class_find_device(class, NULL, &devt, __match_devt);
1539 if (dev) {
1540 put_device(dev);
1541 device_unregister(dev);
1542 }
1543}
1544EXPORT_SYMBOL_GPL(device_destroy);
1545
1546/**
1547 * device_rename - renames a device
1548 * @dev: the pointer to the struct device to be renamed
1549 * @new_name: the new name of the device
1550 *
1551 * It is the responsibility of the caller to provide mutual
1552 * exclusion between two different calls of device_rename
1553 * on the same device to ensure that new_name is valid and
1554 * won't conflict with other devices.
1555 *
1556 * Note: Don't call this function. Currently, the networking layer calls this
1557 * function, but that will change. The following text from Kay Sievers offers
1558 * some insight:
1559 *
1560 * Renaming devices is racy at many levels, symlinks and other stuff are not
1561 * replaced atomically, and you get a "move" uevent, but it's not easy to
1562 * connect the event to the old and new device. Device nodes are not renamed at
1563 * all, there isn't even support for that in the kernel now.
1564 *
1565 * In the meantime, during renaming, your target name might be taken by another
1566 * driver, creating conflicts. Or the old name is taken directly after you
1567 * renamed it -- then you get events for the same DEVPATH, before you even see
1568 * the "move" event. It's just a mess, and nothing new should ever rely on
1569 * kernel device renaming. Besides that, it's not even implemented now for
1570 * other things than (driver-core wise very simple) network devices.
1571 *
1572 * We are currently about to change network renaming in udev to completely
1573 * disallow renaming of devices in the same namespace as the kernel uses,
1574 * because we can't solve the problems properly, that arise with swapping names
1575 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1576 * be allowed to some other name than eth[0-9]*, for the aforementioned
1577 * reasons.
1578 *
1579 * Make up a "real" name in the driver before you register anything, or add
1580 * some other attributes for userspace to find the device, or use udev to add
1581 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1582 * don't even want to get into that and try to implement the missing pieces in
1583 * the core. We really have other pieces to fix in the driver core mess. :)
1584 */
1585int device_rename(struct device *dev, const char *new_name)
1586{
1587 char *old_class_name = NULL;
1588 char *new_class_name = NULL;
1589 char *old_device_name = NULL;
1590 int error;
1591
1592 dev = get_device(dev);
1593 if (!dev)
1594 return -EINVAL;
1595
1596 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1597 __func__, new_name);
1598
1599 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1600 if (!old_device_name) {
1601 error = -ENOMEM;
1602 goto out;
1603 }
1604
1605 if (dev->class) {
1606 error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1607 &dev->kobj, old_device_name, new_name);
1608 if (error)
1609 goto out;
1610 }
1611
1612 error = kobject_rename(&dev->kobj, new_name);
1613 if (error)
1614 goto out;
1615
1616out:
1617 put_device(dev);
1618
1619 kfree(new_class_name);
1620 kfree(old_class_name);
1621 kfree(old_device_name);
1622
1623 return error;
1624}
1625EXPORT_SYMBOL_GPL(device_rename);
1626
1627static int device_move_class_links(struct device *dev,
1628 struct device *old_parent,
1629 struct device *new_parent)
1630{
1631 int error = 0;
1632
1633 if (old_parent)
1634 sysfs_remove_link(&dev->kobj, "device");
1635 if (new_parent)
1636 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1637 "device");
1638 return error;
1639}
1640
1641/**
1642 * device_move - moves a device to a new parent
1643 * @dev: the pointer to the struct device to be moved
1644 * @new_parent: the new parent of the device (can by NULL)
1645 * @dpm_order: how to reorder the dpm_list
1646 */
1647int device_move(struct device *dev, struct device *new_parent,
1648 enum dpm_order dpm_order)
1649{
1650 int error;
1651 struct device *old_parent;
1652 struct kobject *new_parent_kobj;
1653
1654 dev = get_device(dev);
1655 if (!dev)
1656 return -EINVAL;
1657
1658 device_pm_lock();
1659 new_parent = get_device(new_parent);
1660 new_parent_kobj = get_device_parent(dev, new_parent);
1661
1662 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1663 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1664 error = kobject_move(&dev->kobj, new_parent_kobj);
1665 if (error) {
1666 cleanup_glue_dir(dev, new_parent_kobj);
1667 put_device(new_parent);
1668 goto out;
1669 }
1670 old_parent = dev->parent;
1671 dev->parent = new_parent;
1672 if (old_parent)
1673 klist_remove(&dev->p->knode_parent);
1674 if (new_parent) {
1675 klist_add_tail(&dev->p->knode_parent,
1676 &new_parent->p->klist_children);
1677 set_dev_node(dev, dev_to_node(new_parent));
1678 }
1679
1680 if (!dev->class)
1681 goto out_put;
1682 error = device_move_class_links(dev, old_parent, new_parent);
1683 if (error) {
1684 /* We ignore errors on cleanup since we're hosed anyway... */
1685 device_move_class_links(dev, new_parent, old_parent);
1686 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1687 if (new_parent)
1688 klist_remove(&dev->p->knode_parent);
1689 dev->parent = old_parent;
1690 if (old_parent) {
1691 klist_add_tail(&dev->p->knode_parent,
1692 &old_parent->p->klist_children);
1693 set_dev_node(dev, dev_to_node(old_parent));
1694 }
1695 }
1696 cleanup_glue_dir(dev, new_parent_kobj);
1697 put_device(new_parent);
1698 goto out;
1699 }
1700 switch (dpm_order) {
1701 case DPM_ORDER_NONE:
1702 break;
1703 case DPM_ORDER_DEV_AFTER_PARENT:
1704 device_pm_move_after(dev, new_parent);
1705 break;
1706 case DPM_ORDER_PARENT_BEFORE_DEV:
1707 device_pm_move_before(new_parent, dev);
1708 break;
1709 case DPM_ORDER_DEV_LAST:
1710 device_pm_move_last(dev);
1711 break;
1712 }
1713out_put:
1714 put_device(old_parent);
1715out:
1716 device_pm_unlock();
1717 put_device(dev);
1718 return error;
1719}
1720EXPORT_SYMBOL_GPL(device_move);
1721
1722/**
1723 * device_shutdown - call ->shutdown() on each device to shutdown.
1724 */
1725void device_shutdown(void)
1726{
1727 struct device *dev;
1728
1729 spin_lock(&devices_kset->list_lock);
1730 /*
1731 * Walk the devices list backward, shutting down each in turn.
1732 * Beware that device unplug events may also start pulling
1733 * devices offline, even as the system is shutting down.
1734 */
1735 while (!list_empty(&devices_kset->list)) {
1736 dev = list_entry(devices_kset->list.prev, struct device,
1737 kobj.entry);
1738 get_device(dev);
1739 /*
1740 * Make sure the device is off the kset list, in the
1741 * event that dev->*->shutdown() doesn't remove it.
1742 */
1743 list_del_init(&dev->kobj.entry);
1744 spin_unlock(&devices_kset->list_lock);
1745
1746 if (dev->bus && dev->bus->shutdown) {
1747 dev_dbg(dev, "shutdown\n");
1748 dev->bus->shutdown(dev);
1749 } else if (dev->driver && dev->driver->shutdown) {
1750 dev_dbg(dev, "shutdown\n");
1751 dev->driver->shutdown(dev);
1752 }
1753 put_device(dev);
1754
1755 spin_lock(&devices_kset->list_lock);
1756 }
1757 spin_unlock(&devices_kset->list_lock);
1758 async_synchronize_full();
1759}
1760
1761/*
1762 * Device logging functions
1763 */
1764
1765#ifdef CONFIG_PRINTK
1766
1767static int __dev_printk(const char *level, const struct device *dev,
1768 struct va_format *vaf)
1769{
1770 if (!dev)
1771 return printk("%s(NULL device *): %pV", level, vaf);
1772
1773 return printk("%s%s %s: %pV",
1774 level, dev_driver_string(dev), dev_name(dev), vaf);
1775}
1776
1777int dev_printk(const char *level, const struct device *dev,
1778 const char *fmt, ...)
1779{
1780 struct va_format vaf;
1781 va_list args;
1782 int r;
1783
1784 va_start(args, fmt);
1785
1786 vaf.fmt = fmt;
1787 vaf.va = &args;
1788
1789 r = __dev_printk(level, dev, &vaf);
1790 va_end(args);
1791
1792 return r;
1793}
1794EXPORT_SYMBOL(dev_printk);
1795
1796#define define_dev_printk_level(func, kern_level) \
1797int func(const struct device *dev, const char *fmt, ...) \
1798{ \
1799 struct va_format vaf; \
1800 va_list args; \
1801 int r; \
1802 \
1803 va_start(args, fmt); \
1804 \
1805 vaf.fmt = fmt; \
1806 vaf.va = &args; \
1807 \
1808 r = __dev_printk(kern_level, dev, &vaf); \
1809 va_end(args); \
1810 \
1811 return r; \
1812} \
1813EXPORT_SYMBOL(func);
1814
1815define_dev_printk_level(dev_emerg, KERN_EMERG);
1816define_dev_printk_level(dev_alert, KERN_ALERT);
1817define_dev_printk_level(dev_crit, KERN_CRIT);
1818define_dev_printk_level(dev_err, KERN_ERR);
1819define_dev_printk_level(dev_warn, KERN_WARNING);
1820define_dev_printk_level(dev_notice, KERN_NOTICE);
1821define_dev_printk_level(_dev_info, KERN_INFO);
1822
1823#endif
1/*
2 * drivers/base/core.c - core driver model code (device registration, etc)
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
8 *
9 * This file is released under the GPLv2
10 *
11 */
12
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/fwnode.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/string.h>
20#include <linux/kdev_t.h>
21#include <linux/notifier.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/genhd.h>
25#include <linux/kallsyms.h>
26#include <linux/mutex.h>
27#include <linux/pm_runtime.h>
28#include <linux/netdevice.h>
29#include <linux/sysfs.h>
30
31#include "base.h"
32#include "power/power.h"
33
34#ifdef CONFIG_SYSFS_DEPRECATED
35#ifdef CONFIG_SYSFS_DEPRECATED_V2
36long sysfs_deprecated = 1;
37#else
38long sysfs_deprecated = 0;
39#endif
40static int __init sysfs_deprecated_setup(char *arg)
41{
42 return kstrtol(arg, 10, &sysfs_deprecated);
43}
44early_param("sysfs.deprecated", sysfs_deprecated_setup);
45#endif
46
47/* Device links support. */
48
49#ifdef CONFIG_SRCU
50static DEFINE_MUTEX(device_links_lock);
51DEFINE_STATIC_SRCU(device_links_srcu);
52
53static inline void device_links_write_lock(void)
54{
55 mutex_lock(&device_links_lock);
56}
57
58static inline void device_links_write_unlock(void)
59{
60 mutex_unlock(&device_links_lock);
61}
62
63int device_links_read_lock(void)
64{
65 return srcu_read_lock(&device_links_srcu);
66}
67
68void device_links_read_unlock(int idx)
69{
70 srcu_read_unlock(&device_links_srcu, idx);
71}
72#else /* !CONFIG_SRCU */
73static DECLARE_RWSEM(device_links_lock);
74
75static inline void device_links_write_lock(void)
76{
77 down_write(&device_links_lock);
78}
79
80static inline void device_links_write_unlock(void)
81{
82 up_write(&device_links_lock);
83}
84
85int device_links_read_lock(void)
86{
87 down_read(&device_links_lock);
88 return 0;
89}
90
91void device_links_read_unlock(int not_used)
92{
93 up_read(&device_links_lock);
94}
95#endif /* !CONFIG_SRCU */
96
97/**
98 * device_is_dependent - Check if one device depends on another one
99 * @dev: Device to check dependencies for.
100 * @target: Device to check against.
101 *
102 * Check if @target depends on @dev or any device dependent on it (its child or
103 * its consumer etc). Return 1 if that is the case or 0 otherwise.
104 */
105static int device_is_dependent(struct device *dev, void *target)
106{
107 struct device_link *link;
108 int ret;
109
110 if (WARN_ON(dev == target))
111 return 1;
112
113 ret = device_for_each_child(dev, target, device_is_dependent);
114 if (ret)
115 return ret;
116
117 list_for_each_entry(link, &dev->links.consumers, s_node) {
118 if (WARN_ON(link->consumer == target))
119 return 1;
120
121 ret = device_is_dependent(link->consumer, target);
122 if (ret)
123 break;
124 }
125 return ret;
126}
127
128static int device_reorder_to_tail(struct device *dev, void *not_used)
129{
130 struct device_link *link;
131
132 /*
133 * Devices that have not been registered yet will be put to the ends
134 * of the lists during the registration, so skip them here.
135 */
136 if (device_is_registered(dev))
137 devices_kset_move_last(dev);
138
139 if (device_pm_initialized(dev))
140 device_pm_move_last(dev);
141
142 device_for_each_child(dev, NULL, device_reorder_to_tail);
143 list_for_each_entry(link, &dev->links.consumers, s_node)
144 device_reorder_to_tail(link->consumer, NULL);
145
146 return 0;
147}
148
149/**
150 * device_link_add - Create a link between two devices.
151 * @consumer: Consumer end of the link.
152 * @supplier: Supplier end of the link.
153 * @flags: Link flags.
154 *
155 * The caller is responsible for the proper synchronization of the link creation
156 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
157 * runtime PM framework to take the link into account. Second, if the
158 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
159 * be forced into the active metastate and reference-counted upon the creation
160 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
161 * ignored.
162 *
163 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
164 * when the consumer device driver unbinds from it. The combination of both
165 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
166 * to be returned.
167 *
168 * A side effect of the link creation is re-ordering of dpm_list and the
169 * devices_kset list by moving the consumer device and all devices depending
170 * on it to the ends of these lists (that does not happen to devices that have
171 * not been registered when this function is called).
172 *
173 * The supplier device is required to be registered when this function is called
174 * and NULL will be returned if that is not the case. The consumer device need
175 * not be registered, however.
176 */
177struct device_link *device_link_add(struct device *consumer,
178 struct device *supplier, u32 flags)
179{
180 struct device_link *link;
181
182 if (!consumer || !supplier ||
183 ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE)))
184 return NULL;
185
186 device_links_write_lock();
187 device_pm_lock();
188
189 /*
190 * If the supplier has not been fully registered yet or there is a
191 * reverse dependency between the consumer and the supplier already in
192 * the graph, return NULL.
193 */
194 if (!device_pm_initialized(supplier)
195 || device_is_dependent(consumer, supplier)) {
196 link = NULL;
197 goto out;
198 }
199
200 list_for_each_entry(link, &supplier->links.consumers, s_node)
201 if (link->consumer == consumer)
202 goto out;
203
204 link = kzalloc(sizeof(*link), GFP_KERNEL);
205 if (!link)
206 goto out;
207
208 if (flags & DL_FLAG_PM_RUNTIME) {
209 if (flags & DL_FLAG_RPM_ACTIVE) {
210 if (pm_runtime_get_sync(supplier) < 0) {
211 pm_runtime_put_noidle(supplier);
212 kfree(link);
213 link = NULL;
214 goto out;
215 }
216 link->rpm_active = true;
217 }
218 pm_runtime_new_link(consumer);
219 }
220 get_device(supplier);
221 link->supplier = supplier;
222 INIT_LIST_HEAD(&link->s_node);
223 get_device(consumer);
224 link->consumer = consumer;
225 INIT_LIST_HEAD(&link->c_node);
226 link->flags = flags;
227
228 /* Determine the initial link state. */
229 if (flags & DL_FLAG_STATELESS) {
230 link->status = DL_STATE_NONE;
231 } else {
232 switch (supplier->links.status) {
233 case DL_DEV_DRIVER_BOUND:
234 switch (consumer->links.status) {
235 case DL_DEV_PROBING:
236 /*
237 * Balance the decrementation of the supplier's
238 * runtime PM usage counter after consumer probe
239 * in driver_probe_device().
240 */
241 if (flags & DL_FLAG_PM_RUNTIME)
242 pm_runtime_get_sync(supplier);
243
244 link->status = DL_STATE_CONSUMER_PROBE;
245 break;
246 case DL_DEV_DRIVER_BOUND:
247 link->status = DL_STATE_ACTIVE;
248 break;
249 default:
250 link->status = DL_STATE_AVAILABLE;
251 break;
252 }
253 break;
254 case DL_DEV_UNBINDING:
255 link->status = DL_STATE_SUPPLIER_UNBIND;
256 break;
257 default:
258 link->status = DL_STATE_DORMANT;
259 break;
260 }
261 }
262
263 /*
264 * Move the consumer and all of the devices depending on it to the end
265 * of dpm_list and the devices_kset list.
266 *
267 * It is necessary to hold dpm_list locked throughout all that or else
268 * we may end up suspending with a wrong ordering of it.
269 */
270 device_reorder_to_tail(consumer, NULL);
271
272 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
273 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
274
275 dev_info(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
276
277 out:
278 device_pm_unlock();
279 device_links_write_unlock();
280 return link;
281}
282EXPORT_SYMBOL_GPL(device_link_add);
283
284static void device_link_free(struct device_link *link)
285{
286 put_device(link->consumer);
287 put_device(link->supplier);
288 kfree(link);
289}
290
291#ifdef CONFIG_SRCU
292static void __device_link_free_srcu(struct rcu_head *rhead)
293{
294 device_link_free(container_of(rhead, struct device_link, rcu_head));
295}
296
297static void __device_link_del(struct device_link *link)
298{
299 dev_info(link->consumer, "Dropping the link to %s\n",
300 dev_name(link->supplier));
301
302 if (link->flags & DL_FLAG_PM_RUNTIME)
303 pm_runtime_drop_link(link->consumer);
304
305 list_del_rcu(&link->s_node);
306 list_del_rcu(&link->c_node);
307 call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
308}
309#else /* !CONFIG_SRCU */
310static void __device_link_del(struct device_link *link)
311{
312 dev_info(link->consumer, "Dropping the link to %s\n",
313 dev_name(link->supplier));
314
315 list_del(&link->s_node);
316 list_del(&link->c_node);
317 device_link_free(link);
318}
319#endif /* !CONFIG_SRCU */
320
321/**
322 * device_link_del - Delete a link between two devices.
323 * @link: Device link to delete.
324 *
325 * The caller must ensure proper synchronization of this function with runtime
326 * PM.
327 */
328void device_link_del(struct device_link *link)
329{
330 device_links_write_lock();
331 device_pm_lock();
332 __device_link_del(link);
333 device_pm_unlock();
334 device_links_write_unlock();
335}
336EXPORT_SYMBOL_GPL(device_link_del);
337
338static void device_links_missing_supplier(struct device *dev)
339{
340 struct device_link *link;
341
342 list_for_each_entry(link, &dev->links.suppliers, c_node)
343 if (link->status == DL_STATE_CONSUMER_PROBE)
344 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
345}
346
347/**
348 * device_links_check_suppliers - Check presence of supplier drivers.
349 * @dev: Consumer device.
350 *
351 * Check links from this device to any suppliers. Walk the list of the device's
352 * links to suppliers and see if all of them are available. If not, simply
353 * return -EPROBE_DEFER.
354 *
355 * We need to guarantee that the supplier will not go away after the check has
356 * been positive here. It only can go away in __device_release_driver() and
357 * that function checks the device's links to consumers. This means we need to
358 * mark the link as "consumer probe in progress" to make the supplier removal
359 * wait for us to complete (or bad things may happen).
360 *
361 * Links with the DL_FLAG_STATELESS flag set are ignored.
362 */
363int device_links_check_suppliers(struct device *dev)
364{
365 struct device_link *link;
366 int ret = 0;
367
368 device_links_write_lock();
369
370 list_for_each_entry(link, &dev->links.suppliers, c_node) {
371 if (link->flags & DL_FLAG_STATELESS)
372 continue;
373
374 if (link->status != DL_STATE_AVAILABLE) {
375 device_links_missing_supplier(dev);
376 ret = -EPROBE_DEFER;
377 break;
378 }
379 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
380 }
381 dev->links.status = DL_DEV_PROBING;
382
383 device_links_write_unlock();
384 return ret;
385}
386
387/**
388 * device_links_driver_bound - Update device links after probing its driver.
389 * @dev: Device to update the links for.
390 *
391 * The probe has been successful, so update links from this device to any
392 * consumers by changing their status to "available".
393 *
394 * Also change the status of @dev's links to suppliers to "active".
395 *
396 * Links with the DL_FLAG_STATELESS flag set are ignored.
397 */
398void device_links_driver_bound(struct device *dev)
399{
400 struct device_link *link;
401
402 device_links_write_lock();
403
404 list_for_each_entry(link, &dev->links.consumers, s_node) {
405 if (link->flags & DL_FLAG_STATELESS)
406 continue;
407
408 WARN_ON(link->status != DL_STATE_DORMANT);
409 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
410 }
411
412 list_for_each_entry(link, &dev->links.suppliers, c_node) {
413 if (link->flags & DL_FLAG_STATELESS)
414 continue;
415
416 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
417 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
418 }
419
420 dev->links.status = DL_DEV_DRIVER_BOUND;
421
422 device_links_write_unlock();
423}
424
425/**
426 * __device_links_no_driver - Update links of a device without a driver.
427 * @dev: Device without a drvier.
428 *
429 * Delete all non-persistent links from this device to any suppliers.
430 *
431 * Persistent links stay around, but their status is changed to "available",
432 * unless they already are in the "supplier unbind in progress" state in which
433 * case they need not be updated.
434 *
435 * Links with the DL_FLAG_STATELESS flag set are ignored.
436 */
437static void __device_links_no_driver(struct device *dev)
438{
439 struct device_link *link, *ln;
440
441 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
442 if (link->flags & DL_FLAG_STATELESS)
443 continue;
444
445 if (link->flags & DL_FLAG_AUTOREMOVE)
446 __device_link_del(link);
447 else if (link->status != DL_STATE_SUPPLIER_UNBIND)
448 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
449 }
450
451 dev->links.status = DL_DEV_NO_DRIVER;
452}
453
454void device_links_no_driver(struct device *dev)
455{
456 device_links_write_lock();
457 __device_links_no_driver(dev);
458 device_links_write_unlock();
459}
460
461/**
462 * device_links_driver_cleanup - Update links after driver removal.
463 * @dev: Device whose driver has just gone away.
464 *
465 * Update links to consumers for @dev by changing their status to "dormant" and
466 * invoke %__device_links_no_driver() to update links to suppliers for it as
467 * appropriate.
468 *
469 * Links with the DL_FLAG_STATELESS flag set are ignored.
470 */
471void device_links_driver_cleanup(struct device *dev)
472{
473 struct device_link *link;
474
475 device_links_write_lock();
476
477 list_for_each_entry(link, &dev->links.consumers, s_node) {
478 if (link->flags & DL_FLAG_STATELESS)
479 continue;
480
481 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE);
482 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
483 WRITE_ONCE(link->status, DL_STATE_DORMANT);
484 }
485
486 __device_links_no_driver(dev);
487
488 device_links_write_unlock();
489}
490
491/**
492 * device_links_busy - Check if there are any busy links to consumers.
493 * @dev: Device to check.
494 *
495 * Check each consumer of the device and return 'true' if its link's status
496 * is one of "consumer probe" or "active" (meaning that the given consumer is
497 * probing right now or its driver is present). Otherwise, change the link
498 * state to "supplier unbind" to prevent the consumer from being probed
499 * successfully going forward.
500 *
501 * Return 'false' if there are no probing or active consumers.
502 *
503 * Links with the DL_FLAG_STATELESS flag set are ignored.
504 */
505bool device_links_busy(struct device *dev)
506{
507 struct device_link *link;
508 bool ret = false;
509
510 device_links_write_lock();
511
512 list_for_each_entry(link, &dev->links.consumers, s_node) {
513 if (link->flags & DL_FLAG_STATELESS)
514 continue;
515
516 if (link->status == DL_STATE_CONSUMER_PROBE
517 || link->status == DL_STATE_ACTIVE) {
518 ret = true;
519 break;
520 }
521 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
522 }
523
524 dev->links.status = DL_DEV_UNBINDING;
525
526 device_links_write_unlock();
527 return ret;
528}
529
530/**
531 * device_links_unbind_consumers - Force unbind consumers of the given device.
532 * @dev: Device to unbind the consumers of.
533 *
534 * Walk the list of links to consumers for @dev and if any of them is in the
535 * "consumer probe" state, wait for all device probes in progress to complete
536 * and start over.
537 *
538 * If that's not the case, change the status of the link to "supplier unbind"
539 * and check if the link was in the "active" state. If so, force the consumer
540 * driver to unbind and start over (the consumer will not re-probe as we have
541 * changed the state of the link already).
542 *
543 * Links with the DL_FLAG_STATELESS flag set are ignored.
544 */
545void device_links_unbind_consumers(struct device *dev)
546{
547 struct device_link *link;
548
549 start:
550 device_links_write_lock();
551
552 list_for_each_entry(link, &dev->links.consumers, s_node) {
553 enum device_link_state status;
554
555 if (link->flags & DL_FLAG_STATELESS)
556 continue;
557
558 status = link->status;
559 if (status == DL_STATE_CONSUMER_PROBE) {
560 device_links_write_unlock();
561
562 wait_for_device_probe();
563 goto start;
564 }
565 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
566 if (status == DL_STATE_ACTIVE) {
567 struct device *consumer = link->consumer;
568
569 get_device(consumer);
570
571 device_links_write_unlock();
572
573 device_release_driver_internal(consumer, NULL,
574 consumer->parent);
575 put_device(consumer);
576 goto start;
577 }
578 }
579
580 device_links_write_unlock();
581}
582
583/**
584 * device_links_purge - Delete existing links to other devices.
585 * @dev: Target device.
586 */
587static void device_links_purge(struct device *dev)
588{
589 struct device_link *link, *ln;
590
591 /*
592 * Delete all of the remaining links from this device to any other
593 * devices (either consumers or suppliers).
594 */
595 device_links_write_lock();
596
597 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
598 WARN_ON(link->status == DL_STATE_ACTIVE);
599 __device_link_del(link);
600 }
601
602 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
603 WARN_ON(link->status != DL_STATE_DORMANT &&
604 link->status != DL_STATE_NONE);
605 __device_link_del(link);
606 }
607
608 device_links_write_unlock();
609}
610
611/* Device links support end. */
612
613int (*platform_notify)(struct device *dev) = NULL;
614int (*platform_notify_remove)(struct device *dev) = NULL;
615static struct kobject *dev_kobj;
616struct kobject *sysfs_dev_char_kobj;
617struct kobject *sysfs_dev_block_kobj;
618
619static DEFINE_MUTEX(device_hotplug_lock);
620
621void lock_device_hotplug(void)
622{
623 mutex_lock(&device_hotplug_lock);
624}
625
626void unlock_device_hotplug(void)
627{
628 mutex_unlock(&device_hotplug_lock);
629}
630
631int lock_device_hotplug_sysfs(void)
632{
633 if (mutex_trylock(&device_hotplug_lock))
634 return 0;
635
636 /* Avoid busy looping (5 ms of sleep should do). */
637 msleep(5);
638 return restart_syscall();
639}
640
641#ifdef CONFIG_BLOCK
642static inline int device_is_not_partition(struct device *dev)
643{
644 return !(dev->type == &part_type);
645}
646#else
647static inline int device_is_not_partition(struct device *dev)
648{
649 return 1;
650}
651#endif
652
653/**
654 * dev_driver_string - Return a device's driver name, if at all possible
655 * @dev: struct device to get the name of
656 *
657 * Will return the device's driver's name if it is bound to a device. If
658 * the device is not bound to a driver, it will return the name of the bus
659 * it is attached to. If it is not attached to a bus either, an empty
660 * string will be returned.
661 */
662const char *dev_driver_string(const struct device *dev)
663{
664 struct device_driver *drv;
665
666 /* dev->driver can change to NULL underneath us because of unbinding,
667 * so be careful about accessing it. dev->bus and dev->class should
668 * never change once they are set, so they don't need special care.
669 */
670 drv = ACCESS_ONCE(dev->driver);
671 return drv ? drv->name :
672 (dev->bus ? dev->bus->name :
673 (dev->class ? dev->class->name : ""));
674}
675EXPORT_SYMBOL(dev_driver_string);
676
677#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
678
679static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
680 char *buf)
681{
682 struct device_attribute *dev_attr = to_dev_attr(attr);
683 struct device *dev = kobj_to_dev(kobj);
684 ssize_t ret = -EIO;
685
686 if (dev_attr->show)
687 ret = dev_attr->show(dev, dev_attr, buf);
688 if (ret >= (ssize_t)PAGE_SIZE) {
689 print_symbol("dev_attr_show: %s returned bad count\n",
690 (unsigned long)dev_attr->show);
691 }
692 return ret;
693}
694
695static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
696 const char *buf, size_t count)
697{
698 struct device_attribute *dev_attr = to_dev_attr(attr);
699 struct device *dev = kobj_to_dev(kobj);
700 ssize_t ret = -EIO;
701
702 if (dev_attr->store)
703 ret = dev_attr->store(dev, dev_attr, buf, count);
704 return ret;
705}
706
707static const struct sysfs_ops dev_sysfs_ops = {
708 .show = dev_attr_show,
709 .store = dev_attr_store,
710};
711
712#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
713
714ssize_t device_store_ulong(struct device *dev,
715 struct device_attribute *attr,
716 const char *buf, size_t size)
717{
718 struct dev_ext_attribute *ea = to_ext_attr(attr);
719 char *end;
720 unsigned long new = simple_strtoul(buf, &end, 0);
721 if (end == buf)
722 return -EINVAL;
723 *(unsigned long *)(ea->var) = new;
724 /* Always return full write size even if we didn't consume all */
725 return size;
726}
727EXPORT_SYMBOL_GPL(device_store_ulong);
728
729ssize_t device_show_ulong(struct device *dev,
730 struct device_attribute *attr,
731 char *buf)
732{
733 struct dev_ext_attribute *ea = to_ext_attr(attr);
734 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
735}
736EXPORT_SYMBOL_GPL(device_show_ulong);
737
738ssize_t device_store_int(struct device *dev,
739 struct device_attribute *attr,
740 const char *buf, size_t size)
741{
742 struct dev_ext_attribute *ea = to_ext_attr(attr);
743 char *end;
744 long new = simple_strtol(buf, &end, 0);
745 if (end == buf || new > INT_MAX || new < INT_MIN)
746 return -EINVAL;
747 *(int *)(ea->var) = new;
748 /* Always return full write size even if we didn't consume all */
749 return size;
750}
751EXPORT_SYMBOL_GPL(device_store_int);
752
753ssize_t device_show_int(struct device *dev,
754 struct device_attribute *attr,
755 char *buf)
756{
757 struct dev_ext_attribute *ea = to_ext_attr(attr);
758
759 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
760}
761EXPORT_SYMBOL_GPL(device_show_int);
762
763ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
764 const char *buf, size_t size)
765{
766 struct dev_ext_attribute *ea = to_ext_attr(attr);
767
768 if (strtobool(buf, ea->var) < 0)
769 return -EINVAL;
770
771 return size;
772}
773EXPORT_SYMBOL_GPL(device_store_bool);
774
775ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
776 char *buf)
777{
778 struct dev_ext_attribute *ea = to_ext_attr(attr);
779
780 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
781}
782EXPORT_SYMBOL_GPL(device_show_bool);
783
784/**
785 * device_release - free device structure.
786 * @kobj: device's kobject.
787 *
788 * This is called once the reference count for the object
789 * reaches 0. We forward the call to the device's release
790 * method, which should handle actually freeing the structure.
791 */
792static void device_release(struct kobject *kobj)
793{
794 struct device *dev = kobj_to_dev(kobj);
795 struct device_private *p = dev->p;
796
797 /*
798 * Some platform devices are driven without driver attached
799 * and managed resources may have been acquired. Make sure
800 * all resources are released.
801 *
802 * Drivers still can add resources into device after device
803 * is deleted but alive, so release devres here to avoid
804 * possible memory leak.
805 */
806 devres_release_all(dev);
807
808 if (dev->release)
809 dev->release(dev);
810 else if (dev->type && dev->type->release)
811 dev->type->release(dev);
812 else if (dev->class && dev->class->dev_release)
813 dev->class->dev_release(dev);
814 else
815 WARN(1, KERN_ERR "Device '%s' does not have a release() "
816 "function, it is broken and must be fixed.\n",
817 dev_name(dev));
818 kfree(p);
819}
820
821static const void *device_namespace(struct kobject *kobj)
822{
823 struct device *dev = kobj_to_dev(kobj);
824 const void *ns = NULL;
825
826 if (dev->class && dev->class->ns_type)
827 ns = dev->class->namespace(dev);
828
829 return ns;
830}
831
832static struct kobj_type device_ktype = {
833 .release = device_release,
834 .sysfs_ops = &dev_sysfs_ops,
835 .namespace = device_namespace,
836};
837
838
839static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
840{
841 struct kobj_type *ktype = get_ktype(kobj);
842
843 if (ktype == &device_ktype) {
844 struct device *dev = kobj_to_dev(kobj);
845 if (dev->bus)
846 return 1;
847 if (dev->class)
848 return 1;
849 }
850 return 0;
851}
852
853static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
854{
855 struct device *dev = kobj_to_dev(kobj);
856
857 if (dev->bus)
858 return dev->bus->name;
859 if (dev->class)
860 return dev->class->name;
861 return NULL;
862}
863
864static int dev_uevent(struct kset *kset, struct kobject *kobj,
865 struct kobj_uevent_env *env)
866{
867 struct device *dev = kobj_to_dev(kobj);
868 int retval = 0;
869
870 /* add device node properties if present */
871 if (MAJOR(dev->devt)) {
872 const char *tmp;
873 const char *name;
874 umode_t mode = 0;
875 kuid_t uid = GLOBAL_ROOT_UID;
876 kgid_t gid = GLOBAL_ROOT_GID;
877
878 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
879 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
880 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
881 if (name) {
882 add_uevent_var(env, "DEVNAME=%s", name);
883 if (mode)
884 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
885 if (!uid_eq(uid, GLOBAL_ROOT_UID))
886 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
887 if (!gid_eq(gid, GLOBAL_ROOT_GID))
888 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
889 kfree(tmp);
890 }
891 }
892
893 if (dev->type && dev->type->name)
894 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
895
896 if (dev->driver)
897 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
898
899 /* Add common DT information about the device */
900 of_device_uevent(dev, env);
901
902 /* have the bus specific function add its stuff */
903 if (dev->bus && dev->bus->uevent) {
904 retval = dev->bus->uevent(dev, env);
905 if (retval)
906 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
907 dev_name(dev), __func__, retval);
908 }
909
910 /* have the class specific function add its stuff */
911 if (dev->class && dev->class->dev_uevent) {
912 retval = dev->class->dev_uevent(dev, env);
913 if (retval)
914 pr_debug("device: '%s': %s: class uevent() "
915 "returned %d\n", dev_name(dev),
916 __func__, retval);
917 }
918
919 /* have the device type specific function add its stuff */
920 if (dev->type && dev->type->uevent) {
921 retval = dev->type->uevent(dev, env);
922 if (retval)
923 pr_debug("device: '%s': %s: dev_type uevent() "
924 "returned %d\n", dev_name(dev),
925 __func__, retval);
926 }
927
928 return retval;
929}
930
931static const struct kset_uevent_ops device_uevent_ops = {
932 .filter = dev_uevent_filter,
933 .name = dev_uevent_name,
934 .uevent = dev_uevent,
935};
936
937static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
938 char *buf)
939{
940 struct kobject *top_kobj;
941 struct kset *kset;
942 struct kobj_uevent_env *env = NULL;
943 int i;
944 size_t count = 0;
945 int retval;
946
947 /* search the kset, the device belongs to */
948 top_kobj = &dev->kobj;
949 while (!top_kobj->kset && top_kobj->parent)
950 top_kobj = top_kobj->parent;
951 if (!top_kobj->kset)
952 goto out;
953
954 kset = top_kobj->kset;
955 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
956 goto out;
957
958 /* respect filter */
959 if (kset->uevent_ops && kset->uevent_ops->filter)
960 if (!kset->uevent_ops->filter(kset, &dev->kobj))
961 goto out;
962
963 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
964 if (!env)
965 return -ENOMEM;
966
967 /* let the kset specific function add its keys */
968 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
969 if (retval)
970 goto out;
971
972 /* copy keys to file */
973 for (i = 0; i < env->envp_idx; i++)
974 count += sprintf(&buf[count], "%s\n", env->envp[i]);
975out:
976 kfree(env);
977 return count;
978}
979
980static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
981 const char *buf, size_t count)
982{
983 enum kobject_action action;
984
985 if (kobject_action_type(buf, count, &action) == 0)
986 kobject_uevent(&dev->kobj, action);
987 else
988 dev_err(dev, "uevent: unknown action-string\n");
989 return count;
990}
991static DEVICE_ATTR_RW(uevent);
992
993static ssize_t online_show(struct device *dev, struct device_attribute *attr,
994 char *buf)
995{
996 bool val;
997
998 device_lock(dev);
999 val = !dev->offline;
1000 device_unlock(dev);
1001 return sprintf(buf, "%u\n", val);
1002}
1003
1004static ssize_t online_store(struct device *dev, struct device_attribute *attr,
1005 const char *buf, size_t count)
1006{
1007 bool val;
1008 int ret;
1009
1010 ret = strtobool(buf, &val);
1011 if (ret < 0)
1012 return ret;
1013
1014 ret = lock_device_hotplug_sysfs();
1015 if (ret)
1016 return ret;
1017
1018 ret = val ? device_online(dev) : device_offline(dev);
1019 unlock_device_hotplug();
1020 return ret < 0 ? ret : count;
1021}
1022static DEVICE_ATTR_RW(online);
1023
1024int device_add_groups(struct device *dev, const struct attribute_group **groups)
1025{
1026 return sysfs_create_groups(&dev->kobj, groups);
1027}
1028
1029void device_remove_groups(struct device *dev,
1030 const struct attribute_group **groups)
1031{
1032 sysfs_remove_groups(&dev->kobj, groups);
1033}
1034
1035static int device_add_attrs(struct device *dev)
1036{
1037 struct class *class = dev->class;
1038 const struct device_type *type = dev->type;
1039 int error;
1040
1041 if (class) {
1042 error = device_add_groups(dev, class->dev_groups);
1043 if (error)
1044 return error;
1045 }
1046
1047 if (type) {
1048 error = device_add_groups(dev, type->groups);
1049 if (error)
1050 goto err_remove_class_groups;
1051 }
1052
1053 error = device_add_groups(dev, dev->groups);
1054 if (error)
1055 goto err_remove_type_groups;
1056
1057 if (device_supports_offline(dev) && !dev->offline_disabled) {
1058 error = device_create_file(dev, &dev_attr_online);
1059 if (error)
1060 goto err_remove_dev_groups;
1061 }
1062
1063 return 0;
1064
1065 err_remove_dev_groups:
1066 device_remove_groups(dev, dev->groups);
1067 err_remove_type_groups:
1068 if (type)
1069 device_remove_groups(dev, type->groups);
1070 err_remove_class_groups:
1071 if (class)
1072 device_remove_groups(dev, class->dev_groups);
1073
1074 return error;
1075}
1076
1077static void device_remove_attrs(struct device *dev)
1078{
1079 struct class *class = dev->class;
1080 const struct device_type *type = dev->type;
1081
1082 device_remove_file(dev, &dev_attr_online);
1083 device_remove_groups(dev, dev->groups);
1084
1085 if (type)
1086 device_remove_groups(dev, type->groups);
1087
1088 if (class)
1089 device_remove_groups(dev, class->dev_groups);
1090}
1091
1092static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
1093 char *buf)
1094{
1095 return print_dev_t(buf, dev->devt);
1096}
1097static DEVICE_ATTR_RO(dev);
1098
1099/* /sys/devices/ */
1100struct kset *devices_kset;
1101
1102/**
1103 * devices_kset_move_before - Move device in the devices_kset's list.
1104 * @deva: Device to move.
1105 * @devb: Device @deva should come before.
1106 */
1107static void devices_kset_move_before(struct device *deva, struct device *devb)
1108{
1109 if (!devices_kset)
1110 return;
1111 pr_debug("devices_kset: Moving %s before %s\n",
1112 dev_name(deva), dev_name(devb));
1113 spin_lock(&devices_kset->list_lock);
1114 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
1115 spin_unlock(&devices_kset->list_lock);
1116}
1117
1118/**
1119 * devices_kset_move_after - Move device in the devices_kset's list.
1120 * @deva: Device to move
1121 * @devb: Device @deva should come after.
1122 */
1123static void devices_kset_move_after(struct device *deva, struct device *devb)
1124{
1125 if (!devices_kset)
1126 return;
1127 pr_debug("devices_kset: Moving %s after %s\n",
1128 dev_name(deva), dev_name(devb));
1129 spin_lock(&devices_kset->list_lock);
1130 list_move(&deva->kobj.entry, &devb->kobj.entry);
1131 spin_unlock(&devices_kset->list_lock);
1132}
1133
1134/**
1135 * devices_kset_move_last - move the device to the end of devices_kset's list.
1136 * @dev: device to move
1137 */
1138void devices_kset_move_last(struct device *dev)
1139{
1140 if (!devices_kset)
1141 return;
1142 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
1143 spin_lock(&devices_kset->list_lock);
1144 list_move_tail(&dev->kobj.entry, &devices_kset->list);
1145 spin_unlock(&devices_kset->list_lock);
1146}
1147
1148/**
1149 * device_create_file - create sysfs attribute file for device.
1150 * @dev: device.
1151 * @attr: device attribute descriptor.
1152 */
1153int device_create_file(struct device *dev,
1154 const struct device_attribute *attr)
1155{
1156 int error = 0;
1157
1158 if (dev) {
1159 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
1160 "Attribute %s: write permission without 'store'\n",
1161 attr->attr.name);
1162 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
1163 "Attribute %s: read permission without 'show'\n",
1164 attr->attr.name);
1165 error = sysfs_create_file(&dev->kobj, &attr->attr);
1166 }
1167
1168 return error;
1169}
1170EXPORT_SYMBOL_GPL(device_create_file);
1171
1172/**
1173 * device_remove_file - remove sysfs attribute file.
1174 * @dev: device.
1175 * @attr: device attribute descriptor.
1176 */
1177void device_remove_file(struct device *dev,
1178 const struct device_attribute *attr)
1179{
1180 if (dev)
1181 sysfs_remove_file(&dev->kobj, &attr->attr);
1182}
1183EXPORT_SYMBOL_GPL(device_remove_file);
1184
1185/**
1186 * device_remove_file_self - remove sysfs attribute file from its own method.
1187 * @dev: device.
1188 * @attr: device attribute descriptor.
1189 *
1190 * See kernfs_remove_self() for details.
1191 */
1192bool device_remove_file_self(struct device *dev,
1193 const struct device_attribute *attr)
1194{
1195 if (dev)
1196 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
1197 else
1198 return false;
1199}
1200EXPORT_SYMBOL_GPL(device_remove_file_self);
1201
1202/**
1203 * device_create_bin_file - create sysfs binary attribute file for device.
1204 * @dev: device.
1205 * @attr: device binary attribute descriptor.
1206 */
1207int device_create_bin_file(struct device *dev,
1208 const struct bin_attribute *attr)
1209{
1210 int error = -EINVAL;
1211 if (dev)
1212 error = sysfs_create_bin_file(&dev->kobj, attr);
1213 return error;
1214}
1215EXPORT_SYMBOL_GPL(device_create_bin_file);
1216
1217/**
1218 * device_remove_bin_file - remove sysfs binary attribute file
1219 * @dev: device.
1220 * @attr: device binary attribute descriptor.
1221 */
1222void device_remove_bin_file(struct device *dev,
1223 const struct bin_attribute *attr)
1224{
1225 if (dev)
1226 sysfs_remove_bin_file(&dev->kobj, attr);
1227}
1228EXPORT_SYMBOL_GPL(device_remove_bin_file);
1229
1230static void klist_children_get(struct klist_node *n)
1231{
1232 struct device_private *p = to_device_private_parent(n);
1233 struct device *dev = p->device;
1234
1235 get_device(dev);
1236}
1237
1238static void klist_children_put(struct klist_node *n)
1239{
1240 struct device_private *p = to_device_private_parent(n);
1241 struct device *dev = p->device;
1242
1243 put_device(dev);
1244}
1245
1246/**
1247 * device_initialize - init device structure.
1248 * @dev: device.
1249 *
1250 * This prepares the device for use by other layers by initializing
1251 * its fields.
1252 * It is the first half of device_register(), if called by
1253 * that function, though it can also be called separately, so one
1254 * may use @dev's fields. In particular, get_device()/put_device()
1255 * may be used for reference counting of @dev after calling this
1256 * function.
1257 *
1258 * All fields in @dev must be initialized by the caller to 0, except
1259 * for those explicitly set to some other value. The simplest
1260 * approach is to use kzalloc() to allocate the structure containing
1261 * @dev.
1262 *
1263 * NOTE: Use put_device() to give up your reference instead of freeing
1264 * @dev directly once you have called this function.
1265 */
1266void device_initialize(struct device *dev)
1267{
1268 dev->kobj.kset = devices_kset;
1269 kobject_init(&dev->kobj, &device_ktype);
1270 INIT_LIST_HEAD(&dev->dma_pools);
1271 mutex_init(&dev->mutex);
1272 lockdep_set_novalidate_class(&dev->mutex);
1273 spin_lock_init(&dev->devres_lock);
1274 INIT_LIST_HEAD(&dev->devres_head);
1275 device_pm_init(dev);
1276 set_dev_node(dev, -1);
1277#ifdef CONFIG_GENERIC_MSI_IRQ
1278 INIT_LIST_HEAD(&dev->msi_list);
1279#endif
1280 INIT_LIST_HEAD(&dev->links.consumers);
1281 INIT_LIST_HEAD(&dev->links.suppliers);
1282 dev->links.status = DL_DEV_NO_DRIVER;
1283}
1284EXPORT_SYMBOL_GPL(device_initialize);
1285
1286struct kobject *virtual_device_parent(struct device *dev)
1287{
1288 static struct kobject *virtual_dir = NULL;
1289
1290 if (!virtual_dir)
1291 virtual_dir = kobject_create_and_add("virtual",
1292 &devices_kset->kobj);
1293
1294 return virtual_dir;
1295}
1296
1297struct class_dir {
1298 struct kobject kobj;
1299 struct class *class;
1300};
1301
1302#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1303
1304static void class_dir_release(struct kobject *kobj)
1305{
1306 struct class_dir *dir = to_class_dir(kobj);
1307 kfree(dir);
1308}
1309
1310static const
1311struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
1312{
1313 struct class_dir *dir = to_class_dir(kobj);
1314 return dir->class->ns_type;
1315}
1316
1317static struct kobj_type class_dir_ktype = {
1318 .release = class_dir_release,
1319 .sysfs_ops = &kobj_sysfs_ops,
1320 .child_ns_type = class_dir_child_ns_type
1321};
1322
1323static struct kobject *
1324class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
1325{
1326 struct class_dir *dir;
1327 int retval;
1328
1329 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1330 if (!dir)
1331 return NULL;
1332
1333 dir->class = class;
1334 kobject_init(&dir->kobj, &class_dir_ktype);
1335
1336 dir->kobj.kset = &class->p->glue_dirs;
1337
1338 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
1339 if (retval < 0) {
1340 kobject_put(&dir->kobj);
1341 return NULL;
1342 }
1343 return &dir->kobj;
1344}
1345
1346static DEFINE_MUTEX(gdp_mutex);
1347
1348static struct kobject *get_device_parent(struct device *dev,
1349 struct device *parent)
1350{
1351 if (dev->class) {
1352 struct kobject *kobj = NULL;
1353 struct kobject *parent_kobj;
1354 struct kobject *k;
1355
1356#ifdef CONFIG_BLOCK
1357 /* block disks show up in /sys/block */
1358 if (sysfs_deprecated && dev->class == &block_class) {
1359 if (parent && parent->class == &block_class)
1360 return &parent->kobj;
1361 return &block_class.p->subsys.kobj;
1362 }
1363#endif
1364
1365 /*
1366 * If we have no parent, we live in "virtual".
1367 * Class-devices with a non class-device as parent, live
1368 * in a "glue" directory to prevent namespace collisions.
1369 */
1370 if (parent == NULL)
1371 parent_kobj = virtual_device_parent(dev);
1372 else if (parent->class && !dev->class->ns_type)
1373 return &parent->kobj;
1374 else
1375 parent_kobj = &parent->kobj;
1376
1377 mutex_lock(&gdp_mutex);
1378
1379 /* find our class-directory at the parent and reference it */
1380 spin_lock(&dev->class->p->glue_dirs.list_lock);
1381 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
1382 if (k->parent == parent_kobj) {
1383 kobj = kobject_get(k);
1384 break;
1385 }
1386 spin_unlock(&dev->class->p->glue_dirs.list_lock);
1387 if (kobj) {
1388 mutex_unlock(&gdp_mutex);
1389 return kobj;
1390 }
1391
1392 /* or create a new class-directory at the parent device */
1393 k = class_dir_create_and_add(dev->class, parent_kobj);
1394 /* do not emit an uevent for this simple "glue" directory */
1395 mutex_unlock(&gdp_mutex);
1396 return k;
1397 }
1398
1399 /* subsystems can specify a default root directory for their devices */
1400 if (!parent && dev->bus && dev->bus->dev_root)
1401 return &dev->bus->dev_root->kobj;
1402
1403 if (parent)
1404 return &parent->kobj;
1405 return NULL;
1406}
1407
1408static inline bool live_in_glue_dir(struct kobject *kobj,
1409 struct device *dev)
1410{
1411 if (!kobj || !dev->class ||
1412 kobj->kset != &dev->class->p->glue_dirs)
1413 return false;
1414 return true;
1415}
1416
1417static inline struct kobject *get_glue_dir(struct device *dev)
1418{
1419 return dev->kobj.parent;
1420}
1421
1422/*
1423 * make sure cleaning up dir as the last step, we need to make
1424 * sure .release handler of kobject is run with holding the
1425 * global lock
1426 */
1427static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
1428{
1429 /* see if we live in a "glue" directory */
1430 if (!live_in_glue_dir(glue_dir, dev))
1431 return;
1432
1433 mutex_lock(&gdp_mutex);
1434 kobject_put(glue_dir);
1435 mutex_unlock(&gdp_mutex);
1436}
1437
1438static int device_add_class_symlinks(struct device *dev)
1439{
1440 struct device_node *of_node = dev_of_node(dev);
1441 int error;
1442
1443 if (of_node) {
1444 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
1445 if (error)
1446 dev_warn(dev, "Error %d creating of_node link\n",error);
1447 /* An error here doesn't warrant bringing down the device */
1448 }
1449
1450 if (!dev->class)
1451 return 0;
1452
1453 error = sysfs_create_link(&dev->kobj,
1454 &dev->class->p->subsys.kobj,
1455 "subsystem");
1456 if (error)
1457 goto out_devnode;
1458
1459 if (dev->parent && device_is_not_partition(dev)) {
1460 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
1461 "device");
1462 if (error)
1463 goto out_subsys;
1464 }
1465
1466#ifdef CONFIG_BLOCK
1467 /* /sys/block has directories and does not need symlinks */
1468 if (sysfs_deprecated && dev->class == &block_class)
1469 return 0;
1470#endif
1471
1472 /* link in the class directory pointing to the device */
1473 error = sysfs_create_link(&dev->class->p->subsys.kobj,
1474 &dev->kobj, dev_name(dev));
1475 if (error)
1476 goto out_device;
1477
1478 return 0;
1479
1480out_device:
1481 sysfs_remove_link(&dev->kobj, "device");
1482
1483out_subsys:
1484 sysfs_remove_link(&dev->kobj, "subsystem");
1485out_devnode:
1486 sysfs_remove_link(&dev->kobj, "of_node");
1487 return error;
1488}
1489
1490static void device_remove_class_symlinks(struct device *dev)
1491{
1492 if (dev_of_node(dev))
1493 sysfs_remove_link(&dev->kobj, "of_node");
1494
1495 if (!dev->class)
1496 return;
1497
1498 if (dev->parent && device_is_not_partition(dev))
1499 sysfs_remove_link(&dev->kobj, "device");
1500 sysfs_remove_link(&dev->kobj, "subsystem");
1501#ifdef CONFIG_BLOCK
1502 if (sysfs_deprecated && dev->class == &block_class)
1503 return;
1504#endif
1505 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
1506}
1507
1508/**
1509 * dev_set_name - set a device name
1510 * @dev: device
1511 * @fmt: format string for the device's name
1512 */
1513int dev_set_name(struct device *dev, const char *fmt, ...)
1514{
1515 va_list vargs;
1516 int err;
1517
1518 va_start(vargs, fmt);
1519 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
1520 va_end(vargs);
1521 return err;
1522}
1523EXPORT_SYMBOL_GPL(dev_set_name);
1524
1525/**
1526 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1527 * @dev: device
1528 *
1529 * By default we select char/ for new entries. Setting class->dev_obj
1530 * to NULL prevents an entry from being created. class->dev_kobj must
1531 * be set (or cleared) before any devices are registered to the class
1532 * otherwise device_create_sys_dev_entry() and
1533 * device_remove_sys_dev_entry() will disagree about the presence of
1534 * the link.
1535 */
1536static struct kobject *device_to_dev_kobj(struct device *dev)
1537{
1538 struct kobject *kobj;
1539
1540 if (dev->class)
1541 kobj = dev->class->dev_kobj;
1542 else
1543 kobj = sysfs_dev_char_kobj;
1544
1545 return kobj;
1546}
1547
1548static int device_create_sys_dev_entry(struct device *dev)
1549{
1550 struct kobject *kobj = device_to_dev_kobj(dev);
1551 int error = 0;
1552 char devt_str[15];
1553
1554 if (kobj) {
1555 format_dev_t(devt_str, dev->devt);
1556 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
1557 }
1558
1559 return error;
1560}
1561
1562static void device_remove_sys_dev_entry(struct device *dev)
1563{
1564 struct kobject *kobj = device_to_dev_kobj(dev);
1565 char devt_str[15];
1566
1567 if (kobj) {
1568 format_dev_t(devt_str, dev->devt);
1569 sysfs_remove_link(kobj, devt_str);
1570 }
1571}
1572
1573int device_private_init(struct device *dev)
1574{
1575 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
1576 if (!dev->p)
1577 return -ENOMEM;
1578 dev->p->device = dev;
1579 klist_init(&dev->p->klist_children, klist_children_get,
1580 klist_children_put);
1581 INIT_LIST_HEAD(&dev->p->deferred_probe);
1582 return 0;
1583}
1584
1585/**
1586 * device_add - add device to device hierarchy.
1587 * @dev: device.
1588 *
1589 * This is part 2 of device_register(), though may be called
1590 * separately _iff_ device_initialize() has been called separately.
1591 *
1592 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1593 * to the global and sibling lists for the device, then
1594 * adds it to the other relevant subsystems of the driver model.
1595 *
1596 * Do not call this routine or device_register() more than once for
1597 * any device structure. The driver model core is not designed to work
1598 * with devices that get unregistered and then spring back to life.
1599 * (Among other things, it's very hard to guarantee that all references
1600 * to the previous incarnation of @dev have been dropped.) Allocate
1601 * and register a fresh new struct device instead.
1602 *
1603 * NOTE: _Never_ directly free @dev after calling this function, even
1604 * if it returned an error! Always use put_device() to give up your
1605 * reference instead.
1606 */
1607int device_add(struct device *dev)
1608{
1609 struct device *parent = NULL;
1610 struct kobject *kobj;
1611 struct class_interface *class_intf;
1612 int error = -EINVAL;
1613 struct kobject *glue_dir = NULL;
1614
1615 dev = get_device(dev);
1616 if (!dev)
1617 goto done;
1618
1619 if (!dev->p) {
1620 error = device_private_init(dev);
1621 if (error)
1622 goto done;
1623 }
1624
1625 /*
1626 * for statically allocated devices, which should all be converted
1627 * some day, we need to initialize the name. We prevent reading back
1628 * the name, and force the use of dev_name()
1629 */
1630 if (dev->init_name) {
1631 dev_set_name(dev, "%s", dev->init_name);
1632 dev->init_name = NULL;
1633 }
1634
1635 /* subsystems can specify simple device enumeration */
1636 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1637 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1638
1639 if (!dev_name(dev)) {
1640 error = -EINVAL;
1641 goto name_error;
1642 }
1643
1644 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1645
1646 parent = get_device(dev->parent);
1647 kobj = get_device_parent(dev, parent);
1648 if (kobj)
1649 dev->kobj.parent = kobj;
1650
1651 /* use parent numa_node */
1652 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1653 set_dev_node(dev, dev_to_node(parent));
1654
1655 /* first, register with generic layer. */
1656 /* we require the name to be set before, and pass NULL */
1657 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1658 if (error) {
1659 glue_dir = get_glue_dir(dev);
1660 goto Error;
1661 }
1662
1663 /* notify platform of device entry */
1664 if (platform_notify)
1665 platform_notify(dev);
1666
1667 error = device_create_file(dev, &dev_attr_uevent);
1668 if (error)
1669 goto attrError;
1670
1671 error = device_add_class_symlinks(dev);
1672 if (error)
1673 goto SymlinkError;
1674 error = device_add_attrs(dev);
1675 if (error)
1676 goto AttrsError;
1677 error = bus_add_device(dev);
1678 if (error)
1679 goto BusError;
1680 error = dpm_sysfs_add(dev);
1681 if (error)
1682 goto DPMError;
1683 device_pm_add(dev);
1684
1685 if (MAJOR(dev->devt)) {
1686 error = device_create_file(dev, &dev_attr_dev);
1687 if (error)
1688 goto DevAttrError;
1689
1690 error = device_create_sys_dev_entry(dev);
1691 if (error)
1692 goto SysEntryError;
1693
1694 devtmpfs_create_node(dev);
1695 }
1696
1697 /* Notify clients of device addition. This call must come
1698 * after dpm_sysfs_add() and before kobject_uevent().
1699 */
1700 if (dev->bus)
1701 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1702 BUS_NOTIFY_ADD_DEVICE, dev);
1703
1704 kobject_uevent(&dev->kobj, KOBJ_ADD);
1705 bus_probe_device(dev);
1706 if (parent)
1707 klist_add_tail(&dev->p->knode_parent,
1708 &parent->p->klist_children);
1709
1710 if (dev->class) {
1711 mutex_lock(&dev->class->p->mutex);
1712 /* tie the class to the device */
1713 klist_add_tail(&dev->knode_class,
1714 &dev->class->p->klist_devices);
1715
1716 /* notify any interfaces that the device is here */
1717 list_for_each_entry(class_intf,
1718 &dev->class->p->interfaces, node)
1719 if (class_intf->add_dev)
1720 class_intf->add_dev(dev, class_intf);
1721 mutex_unlock(&dev->class->p->mutex);
1722 }
1723done:
1724 put_device(dev);
1725 return error;
1726 SysEntryError:
1727 if (MAJOR(dev->devt))
1728 device_remove_file(dev, &dev_attr_dev);
1729 DevAttrError:
1730 device_pm_remove(dev);
1731 dpm_sysfs_remove(dev);
1732 DPMError:
1733 bus_remove_device(dev);
1734 BusError:
1735 device_remove_attrs(dev);
1736 AttrsError:
1737 device_remove_class_symlinks(dev);
1738 SymlinkError:
1739 device_remove_file(dev, &dev_attr_uevent);
1740 attrError:
1741 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1742 glue_dir = get_glue_dir(dev);
1743 kobject_del(&dev->kobj);
1744 Error:
1745 cleanup_glue_dir(dev, glue_dir);
1746 put_device(parent);
1747name_error:
1748 kfree(dev->p);
1749 dev->p = NULL;
1750 goto done;
1751}
1752EXPORT_SYMBOL_GPL(device_add);
1753
1754/**
1755 * device_register - register a device with the system.
1756 * @dev: pointer to the device structure
1757 *
1758 * This happens in two clean steps - initialize the device
1759 * and add it to the system. The two steps can be called
1760 * separately, but this is the easiest and most common.
1761 * I.e. you should only call the two helpers separately if
1762 * have a clearly defined need to use and refcount the device
1763 * before it is added to the hierarchy.
1764 *
1765 * For more information, see the kerneldoc for device_initialize()
1766 * and device_add().
1767 *
1768 * NOTE: _Never_ directly free @dev after calling this function, even
1769 * if it returned an error! Always use put_device() to give up the
1770 * reference initialized in this function instead.
1771 */
1772int device_register(struct device *dev)
1773{
1774 device_initialize(dev);
1775 return device_add(dev);
1776}
1777EXPORT_SYMBOL_GPL(device_register);
1778
1779/**
1780 * get_device - increment reference count for device.
1781 * @dev: device.
1782 *
1783 * This simply forwards the call to kobject_get(), though
1784 * we do take care to provide for the case that we get a NULL
1785 * pointer passed in.
1786 */
1787struct device *get_device(struct device *dev)
1788{
1789 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1790}
1791EXPORT_SYMBOL_GPL(get_device);
1792
1793/**
1794 * put_device - decrement reference count.
1795 * @dev: device in question.
1796 */
1797void put_device(struct device *dev)
1798{
1799 /* might_sleep(); */
1800 if (dev)
1801 kobject_put(&dev->kobj);
1802}
1803EXPORT_SYMBOL_GPL(put_device);
1804
1805/**
1806 * device_del - delete device from system.
1807 * @dev: device.
1808 *
1809 * This is the first part of the device unregistration
1810 * sequence. This removes the device from the lists we control
1811 * from here, has it removed from the other driver model
1812 * subsystems it was added to in device_add(), and removes it
1813 * from the kobject hierarchy.
1814 *
1815 * NOTE: this should be called manually _iff_ device_add() was
1816 * also called manually.
1817 */
1818void device_del(struct device *dev)
1819{
1820 struct device *parent = dev->parent;
1821 struct kobject *glue_dir = NULL;
1822 struct class_interface *class_intf;
1823
1824 /* Notify clients of device removal. This call must come
1825 * before dpm_sysfs_remove().
1826 */
1827 if (dev->bus)
1828 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1829 BUS_NOTIFY_DEL_DEVICE, dev);
1830
1831 device_links_purge(dev);
1832 dpm_sysfs_remove(dev);
1833 if (parent)
1834 klist_del(&dev->p->knode_parent);
1835 if (MAJOR(dev->devt)) {
1836 devtmpfs_delete_node(dev);
1837 device_remove_sys_dev_entry(dev);
1838 device_remove_file(dev, &dev_attr_dev);
1839 }
1840 if (dev->class) {
1841 device_remove_class_symlinks(dev);
1842
1843 mutex_lock(&dev->class->p->mutex);
1844 /* notify any interfaces that the device is now gone */
1845 list_for_each_entry(class_intf,
1846 &dev->class->p->interfaces, node)
1847 if (class_intf->remove_dev)
1848 class_intf->remove_dev(dev, class_intf);
1849 /* remove the device from the class list */
1850 klist_del(&dev->knode_class);
1851 mutex_unlock(&dev->class->p->mutex);
1852 }
1853 device_remove_file(dev, &dev_attr_uevent);
1854 device_remove_attrs(dev);
1855 bus_remove_device(dev);
1856 device_pm_remove(dev);
1857 driver_deferred_probe_del(dev);
1858 device_remove_properties(dev);
1859
1860 /* Notify the platform of the removal, in case they
1861 * need to do anything...
1862 */
1863 if (platform_notify_remove)
1864 platform_notify_remove(dev);
1865 if (dev->bus)
1866 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1867 BUS_NOTIFY_REMOVED_DEVICE, dev);
1868 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1869 glue_dir = get_glue_dir(dev);
1870 kobject_del(&dev->kobj);
1871 cleanup_glue_dir(dev, glue_dir);
1872 put_device(parent);
1873}
1874EXPORT_SYMBOL_GPL(device_del);
1875
1876/**
1877 * device_unregister - unregister device from system.
1878 * @dev: device going away.
1879 *
1880 * We do this in two parts, like we do device_register(). First,
1881 * we remove it from all the subsystems with device_del(), then
1882 * we decrement the reference count via put_device(). If that
1883 * is the final reference count, the device will be cleaned up
1884 * via device_release() above. Otherwise, the structure will
1885 * stick around until the final reference to the device is dropped.
1886 */
1887void device_unregister(struct device *dev)
1888{
1889 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1890 device_del(dev);
1891 put_device(dev);
1892}
1893EXPORT_SYMBOL_GPL(device_unregister);
1894
1895static struct device *prev_device(struct klist_iter *i)
1896{
1897 struct klist_node *n = klist_prev(i);
1898 struct device *dev = NULL;
1899 struct device_private *p;
1900
1901 if (n) {
1902 p = to_device_private_parent(n);
1903 dev = p->device;
1904 }
1905 return dev;
1906}
1907
1908static struct device *next_device(struct klist_iter *i)
1909{
1910 struct klist_node *n = klist_next(i);
1911 struct device *dev = NULL;
1912 struct device_private *p;
1913
1914 if (n) {
1915 p = to_device_private_parent(n);
1916 dev = p->device;
1917 }
1918 return dev;
1919}
1920
1921/**
1922 * device_get_devnode - path of device node file
1923 * @dev: device
1924 * @mode: returned file access mode
1925 * @uid: returned file owner
1926 * @gid: returned file group
1927 * @tmp: possibly allocated string
1928 *
1929 * Return the relative path of a possible device node.
1930 * Non-default names may need to allocate a memory to compose
1931 * a name. This memory is returned in tmp and needs to be
1932 * freed by the caller.
1933 */
1934const char *device_get_devnode(struct device *dev,
1935 umode_t *mode, kuid_t *uid, kgid_t *gid,
1936 const char **tmp)
1937{
1938 char *s;
1939
1940 *tmp = NULL;
1941
1942 /* the device type may provide a specific name */
1943 if (dev->type && dev->type->devnode)
1944 *tmp = dev->type->devnode(dev, mode, uid, gid);
1945 if (*tmp)
1946 return *tmp;
1947
1948 /* the class may provide a specific name */
1949 if (dev->class && dev->class->devnode)
1950 *tmp = dev->class->devnode(dev, mode);
1951 if (*tmp)
1952 return *tmp;
1953
1954 /* return name without allocation, tmp == NULL */
1955 if (strchr(dev_name(dev), '!') == NULL)
1956 return dev_name(dev);
1957
1958 /* replace '!' in the name with '/' */
1959 s = kstrdup(dev_name(dev), GFP_KERNEL);
1960 if (!s)
1961 return NULL;
1962 strreplace(s, '!', '/');
1963 return *tmp = s;
1964}
1965
1966/**
1967 * device_for_each_child - device child iterator.
1968 * @parent: parent struct device.
1969 * @fn: function to be called for each device.
1970 * @data: data for the callback.
1971 *
1972 * Iterate over @parent's child devices, and call @fn for each,
1973 * passing it @data.
1974 *
1975 * We check the return of @fn each time. If it returns anything
1976 * other than 0, we break out and return that value.
1977 */
1978int device_for_each_child(struct device *parent, void *data,
1979 int (*fn)(struct device *dev, void *data))
1980{
1981 struct klist_iter i;
1982 struct device *child;
1983 int error = 0;
1984
1985 if (!parent->p)
1986 return 0;
1987
1988 klist_iter_init(&parent->p->klist_children, &i);
1989 while ((child = next_device(&i)) && !error)
1990 error = fn(child, data);
1991 klist_iter_exit(&i);
1992 return error;
1993}
1994EXPORT_SYMBOL_GPL(device_for_each_child);
1995
1996/**
1997 * device_for_each_child_reverse - device child iterator in reversed order.
1998 * @parent: parent struct device.
1999 * @fn: function to be called for each device.
2000 * @data: data for the callback.
2001 *
2002 * Iterate over @parent's child devices, and call @fn for each,
2003 * passing it @data.
2004 *
2005 * We check the return of @fn each time. If it returns anything
2006 * other than 0, we break out and return that value.
2007 */
2008int device_for_each_child_reverse(struct device *parent, void *data,
2009 int (*fn)(struct device *dev, void *data))
2010{
2011 struct klist_iter i;
2012 struct device *child;
2013 int error = 0;
2014
2015 if (!parent->p)
2016 return 0;
2017
2018 klist_iter_init(&parent->p->klist_children, &i);
2019 while ((child = prev_device(&i)) && !error)
2020 error = fn(child, data);
2021 klist_iter_exit(&i);
2022 return error;
2023}
2024EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
2025
2026/**
2027 * device_find_child - device iterator for locating a particular device.
2028 * @parent: parent struct device
2029 * @match: Callback function to check device
2030 * @data: Data to pass to match function
2031 *
2032 * This is similar to the device_for_each_child() function above, but it
2033 * returns a reference to a device that is 'found' for later use, as
2034 * determined by the @match callback.
2035 *
2036 * The callback should return 0 if the device doesn't match and non-zero
2037 * if it does. If the callback returns non-zero and a reference to the
2038 * current device can be obtained, this function will return to the caller
2039 * and not iterate over any more devices.
2040 *
2041 * NOTE: you will need to drop the reference with put_device() after use.
2042 */
2043struct device *device_find_child(struct device *parent, void *data,
2044 int (*match)(struct device *dev, void *data))
2045{
2046 struct klist_iter i;
2047 struct device *child;
2048
2049 if (!parent)
2050 return NULL;
2051
2052 klist_iter_init(&parent->p->klist_children, &i);
2053 while ((child = next_device(&i)))
2054 if (match(child, data) && get_device(child))
2055 break;
2056 klist_iter_exit(&i);
2057 return child;
2058}
2059EXPORT_SYMBOL_GPL(device_find_child);
2060
2061int __init devices_init(void)
2062{
2063 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
2064 if (!devices_kset)
2065 return -ENOMEM;
2066 dev_kobj = kobject_create_and_add("dev", NULL);
2067 if (!dev_kobj)
2068 goto dev_kobj_err;
2069 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
2070 if (!sysfs_dev_block_kobj)
2071 goto block_kobj_err;
2072 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
2073 if (!sysfs_dev_char_kobj)
2074 goto char_kobj_err;
2075
2076 return 0;
2077
2078 char_kobj_err:
2079 kobject_put(sysfs_dev_block_kobj);
2080 block_kobj_err:
2081 kobject_put(dev_kobj);
2082 dev_kobj_err:
2083 kset_unregister(devices_kset);
2084 return -ENOMEM;
2085}
2086
2087static int device_check_offline(struct device *dev, void *not_used)
2088{
2089 int ret;
2090
2091 ret = device_for_each_child(dev, NULL, device_check_offline);
2092 if (ret)
2093 return ret;
2094
2095 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
2096}
2097
2098/**
2099 * device_offline - Prepare the device for hot-removal.
2100 * @dev: Device to be put offline.
2101 *
2102 * Execute the device bus type's .offline() callback, if present, to prepare
2103 * the device for a subsequent hot-removal. If that succeeds, the device must
2104 * not be used until either it is removed or its bus type's .online() callback
2105 * is executed.
2106 *
2107 * Call under device_hotplug_lock.
2108 */
2109int device_offline(struct device *dev)
2110{
2111 int ret;
2112
2113 if (dev->offline_disabled)
2114 return -EPERM;
2115
2116 ret = device_for_each_child(dev, NULL, device_check_offline);
2117 if (ret)
2118 return ret;
2119
2120 device_lock(dev);
2121 if (device_supports_offline(dev)) {
2122 if (dev->offline) {
2123 ret = 1;
2124 } else {
2125 ret = dev->bus->offline(dev);
2126 if (!ret) {
2127 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2128 dev->offline = true;
2129 }
2130 }
2131 }
2132 device_unlock(dev);
2133
2134 return ret;
2135}
2136
2137/**
2138 * device_online - Put the device back online after successful device_offline().
2139 * @dev: Device to be put back online.
2140 *
2141 * If device_offline() has been successfully executed for @dev, but the device
2142 * has not been removed subsequently, execute its bus type's .online() callback
2143 * to indicate that the device can be used again.
2144 *
2145 * Call under device_hotplug_lock.
2146 */
2147int device_online(struct device *dev)
2148{
2149 int ret = 0;
2150
2151 device_lock(dev);
2152 if (device_supports_offline(dev)) {
2153 if (dev->offline) {
2154 ret = dev->bus->online(dev);
2155 if (!ret) {
2156 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2157 dev->offline = false;
2158 }
2159 } else {
2160 ret = 1;
2161 }
2162 }
2163 device_unlock(dev);
2164
2165 return ret;
2166}
2167
2168struct root_device {
2169 struct device dev;
2170 struct module *owner;
2171};
2172
2173static inline struct root_device *to_root_device(struct device *d)
2174{
2175 return container_of(d, struct root_device, dev);
2176}
2177
2178static void root_device_release(struct device *dev)
2179{
2180 kfree(to_root_device(dev));
2181}
2182
2183/**
2184 * __root_device_register - allocate and register a root device
2185 * @name: root device name
2186 * @owner: owner module of the root device, usually THIS_MODULE
2187 *
2188 * This function allocates a root device and registers it
2189 * using device_register(). In order to free the returned
2190 * device, use root_device_unregister().
2191 *
2192 * Root devices are dummy devices which allow other devices
2193 * to be grouped under /sys/devices. Use this function to
2194 * allocate a root device and then use it as the parent of
2195 * any device which should appear under /sys/devices/{name}
2196 *
2197 * The /sys/devices/{name} directory will also contain a
2198 * 'module' symlink which points to the @owner directory
2199 * in sysfs.
2200 *
2201 * Returns &struct device pointer on success, or ERR_PTR() on error.
2202 *
2203 * Note: You probably want to use root_device_register().
2204 */
2205struct device *__root_device_register(const char *name, struct module *owner)
2206{
2207 struct root_device *root;
2208 int err = -ENOMEM;
2209
2210 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
2211 if (!root)
2212 return ERR_PTR(err);
2213
2214 err = dev_set_name(&root->dev, "%s", name);
2215 if (err) {
2216 kfree(root);
2217 return ERR_PTR(err);
2218 }
2219
2220 root->dev.release = root_device_release;
2221
2222 err = device_register(&root->dev);
2223 if (err) {
2224 put_device(&root->dev);
2225 return ERR_PTR(err);
2226 }
2227
2228#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2229 if (owner) {
2230 struct module_kobject *mk = &owner->mkobj;
2231
2232 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
2233 if (err) {
2234 device_unregister(&root->dev);
2235 return ERR_PTR(err);
2236 }
2237 root->owner = owner;
2238 }
2239#endif
2240
2241 return &root->dev;
2242}
2243EXPORT_SYMBOL_GPL(__root_device_register);
2244
2245/**
2246 * root_device_unregister - unregister and free a root device
2247 * @dev: device going away
2248 *
2249 * This function unregisters and cleans up a device that was created by
2250 * root_device_register().
2251 */
2252void root_device_unregister(struct device *dev)
2253{
2254 struct root_device *root = to_root_device(dev);
2255
2256 if (root->owner)
2257 sysfs_remove_link(&root->dev.kobj, "module");
2258
2259 device_unregister(dev);
2260}
2261EXPORT_SYMBOL_GPL(root_device_unregister);
2262
2263
2264static void device_create_release(struct device *dev)
2265{
2266 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2267 kfree(dev);
2268}
2269
2270static struct device *
2271device_create_groups_vargs(struct class *class, struct device *parent,
2272 dev_t devt, void *drvdata,
2273 const struct attribute_group **groups,
2274 const char *fmt, va_list args)
2275{
2276 struct device *dev = NULL;
2277 int retval = -ENODEV;
2278
2279 if (class == NULL || IS_ERR(class))
2280 goto error;
2281
2282 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2283 if (!dev) {
2284 retval = -ENOMEM;
2285 goto error;
2286 }
2287
2288 device_initialize(dev);
2289 dev->devt = devt;
2290 dev->class = class;
2291 dev->parent = parent;
2292 dev->groups = groups;
2293 dev->release = device_create_release;
2294 dev_set_drvdata(dev, drvdata);
2295
2296 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
2297 if (retval)
2298 goto error;
2299
2300 retval = device_add(dev);
2301 if (retval)
2302 goto error;
2303
2304 return dev;
2305
2306error:
2307 put_device(dev);
2308 return ERR_PTR(retval);
2309}
2310
2311/**
2312 * device_create_vargs - creates a device and registers it with sysfs
2313 * @class: pointer to the struct class that this device should be registered to
2314 * @parent: pointer to the parent struct device of this new device, if any
2315 * @devt: the dev_t for the char device to be added
2316 * @drvdata: the data to be added to the device for callbacks
2317 * @fmt: string for the device's name
2318 * @args: va_list for the device's name
2319 *
2320 * This function can be used by char device classes. A struct device
2321 * will be created in sysfs, registered to the specified class.
2322 *
2323 * A "dev" file will be created, showing the dev_t for the device, if
2324 * the dev_t is not 0,0.
2325 * If a pointer to a parent struct device is passed in, the newly created
2326 * struct device will be a child of that device in sysfs.
2327 * The pointer to the struct device will be returned from the call.
2328 * Any further sysfs files that might be required can be created using this
2329 * pointer.
2330 *
2331 * Returns &struct device pointer on success, or ERR_PTR() on error.
2332 *
2333 * Note: the struct class passed to this function must have previously
2334 * been created with a call to class_create().
2335 */
2336struct device *device_create_vargs(struct class *class, struct device *parent,
2337 dev_t devt, void *drvdata, const char *fmt,
2338 va_list args)
2339{
2340 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
2341 fmt, args);
2342}
2343EXPORT_SYMBOL_GPL(device_create_vargs);
2344
2345/**
2346 * device_create - creates a device and registers it with sysfs
2347 * @class: pointer to the struct class that this device should be registered to
2348 * @parent: pointer to the parent struct device of this new device, if any
2349 * @devt: the dev_t for the char device to be added
2350 * @drvdata: the data to be added to the device for callbacks
2351 * @fmt: string for the device's name
2352 *
2353 * This function can be used by char device classes. A struct device
2354 * will be created in sysfs, registered to the specified class.
2355 *
2356 * A "dev" file will be created, showing the dev_t for the device, if
2357 * the dev_t is not 0,0.
2358 * If a pointer to a parent struct device is passed in, the newly created
2359 * struct device will be a child of that device in sysfs.
2360 * The pointer to the struct device will be returned from the call.
2361 * Any further sysfs files that might be required can be created using this
2362 * pointer.
2363 *
2364 * Returns &struct device pointer on success, or ERR_PTR() on error.
2365 *
2366 * Note: the struct class passed to this function must have previously
2367 * been created with a call to class_create().
2368 */
2369struct device *device_create(struct class *class, struct device *parent,
2370 dev_t devt, void *drvdata, const char *fmt, ...)
2371{
2372 va_list vargs;
2373 struct device *dev;
2374
2375 va_start(vargs, fmt);
2376 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
2377 va_end(vargs);
2378 return dev;
2379}
2380EXPORT_SYMBOL_GPL(device_create);
2381
2382/**
2383 * device_create_with_groups - creates a device and registers it with sysfs
2384 * @class: pointer to the struct class that this device should be registered to
2385 * @parent: pointer to the parent struct device of this new device, if any
2386 * @devt: the dev_t for the char device to be added
2387 * @drvdata: the data to be added to the device for callbacks
2388 * @groups: NULL-terminated list of attribute groups to be created
2389 * @fmt: string for the device's name
2390 *
2391 * This function can be used by char device classes. A struct device
2392 * will be created in sysfs, registered to the specified class.
2393 * Additional attributes specified in the groups parameter will also
2394 * be created automatically.
2395 *
2396 * A "dev" file will be created, showing the dev_t for the device, if
2397 * the dev_t is not 0,0.
2398 * If a pointer to a parent struct device is passed in, the newly created
2399 * struct device will be a child of that device in sysfs.
2400 * The pointer to the struct device will be returned from the call.
2401 * Any further sysfs files that might be required can be created using this
2402 * pointer.
2403 *
2404 * Returns &struct device pointer on success, or ERR_PTR() on error.
2405 *
2406 * Note: the struct class passed to this function must have previously
2407 * been created with a call to class_create().
2408 */
2409struct device *device_create_with_groups(struct class *class,
2410 struct device *parent, dev_t devt,
2411 void *drvdata,
2412 const struct attribute_group **groups,
2413 const char *fmt, ...)
2414{
2415 va_list vargs;
2416 struct device *dev;
2417
2418 va_start(vargs, fmt);
2419 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
2420 fmt, vargs);
2421 va_end(vargs);
2422 return dev;
2423}
2424EXPORT_SYMBOL_GPL(device_create_with_groups);
2425
2426static int __match_devt(struct device *dev, const void *data)
2427{
2428 const dev_t *devt = data;
2429
2430 return dev->devt == *devt;
2431}
2432
2433/**
2434 * device_destroy - removes a device that was created with device_create()
2435 * @class: pointer to the struct class that this device was registered with
2436 * @devt: the dev_t of the device that was previously registered
2437 *
2438 * This call unregisters and cleans up a device that was created with a
2439 * call to device_create().
2440 */
2441void device_destroy(struct class *class, dev_t devt)
2442{
2443 struct device *dev;
2444
2445 dev = class_find_device(class, NULL, &devt, __match_devt);
2446 if (dev) {
2447 put_device(dev);
2448 device_unregister(dev);
2449 }
2450}
2451EXPORT_SYMBOL_GPL(device_destroy);
2452
2453/**
2454 * device_rename - renames a device
2455 * @dev: the pointer to the struct device to be renamed
2456 * @new_name: the new name of the device
2457 *
2458 * It is the responsibility of the caller to provide mutual
2459 * exclusion between two different calls of device_rename
2460 * on the same device to ensure that new_name is valid and
2461 * won't conflict with other devices.
2462 *
2463 * Note: Don't call this function. Currently, the networking layer calls this
2464 * function, but that will change. The following text from Kay Sievers offers
2465 * some insight:
2466 *
2467 * Renaming devices is racy at many levels, symlinks and other stuff are not
2468 * replaced atomically, and you get a "move" uevent, but it's not easy to
2469 * connect the event to the old and new device. Device nodes are not renamed at
2470 * all, there isn't even support for that in the kernel now.
2471 *
2472 * In the meantime, during renaming, your target name might be taken by another
2473 * driver, creating conflicts. Or the old name is taken directly after you
2474 * renamed it -- then you get events for the same DEVPATH, before you even see
2475 * the "move" event. It's just a mess, and nothing new should ever rely on
2476 * kernel device renaming. Besides that, it's not even implemented now for
2477 * other things than (driver-core wise very simple) network devices.
2478 *
2479 * We are currently about to change network renaming in udev to completely
2480 * disallow renaming of devices in the same namespace as the kernel uses,
2481 * because we can't solve the problems properly, that arise with swapping names
2482 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2483 * be allowed to some other name than eth[0-9]*, for the aforementioned
2484 * reasons.
2485 *
2486 * Make up a "real" name in the driver before you register anything, or add
2487 * some other attributes for userspace to find the device, or use udev to add
2488 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2489 * don't even want to get into that and try to implement the missing pieces in
2490 * the core. We really have other pieces to fix in the driver core mess. :)
2491 */
2492int device_rename(struct device *dev, const char *new_name)
2493{
2494 struct kobject *kobj = &dev->kobj;
2495 char *old_device_name = NULL;
2496 int error;
2497
2498 dev = get_device(dev);
2499 if (!dev)
2500 return -EINVAL;
2501
2502 dev_dbg(dev, "renaming to %s\n", new_name);
2503
2504 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
2505 if (!old_device_name) {
2506 error = -ENOMEM;
2507 goto out;
2508 }
2509
2510 if (dev->class) {
2511 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
2512 kobj, old_device_name,
2513 new_name, kobject_namespace(kobj));
2514 if (error)
2515 goto out;
2516 }
2517
2518 error = kobject_rename(kobj, new_name);
2519 if (error)
2520 goto out;
2521
2522out:
2523 put_device(dev);
2524
2525 kfree(old_device_name);
2526
2527 return error;
2528}
2529EXPORT_SYMBOL_GPL(device_rename);
2530
2531static int device_move_class_links(struct device *dev,
2532 struct device *old_parent,
2533 struct device *new_parent)
2534{
2535 int error = 0;
2536
2537 if (old_parent)
2538 sysfs_remove_link(&dev->kobj, "device");
2539 if (new_parent)
2540 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
2541 "device");
2542 return error;
2543}
2544
2545/**
2546 * device_move - moves a device to a new parent
2547 * @dev: the pointer to the struct device to be moved
2548 * @new_parent: the new parent of the device (can by NULL)
2549 * @dpm_order: how to reorder the dpm_list
2550 */
2551int device_move(struct device *dev, struct device *new_parent,
2552 enum dpm_order dpm_order)
2553{
2554 int error;
2555 struct device *old_parent;
2556 struct kobject *new_parent_kobj;
2557
2558 dev = get_device(dev);
2559 if (!dev)
2560 return -EINVAL;
2561
2562 device_pm_lock();
2563 new_parent = get_device(new_parent);
2564 new_parent_kobj = get_device_parent(dev, new_parent);
2565
2566 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
2567 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
2568 error = kobject_move(&dev->kobj, new_parent_kobj);
2569 if (error) {
2570 cleanup_glue_dir(dev, new_parent_kobj);
2571 put_device(new_parent);
2572 goto out;
2573 }
2574 old_parent = dev->parent;
2575 dev->parent = new_parent;
2576 if (old_parent)
2577 klist_remove(&dev->p->knode_parent);
2578 if (new_parent) {
2579 klist_add_tail(&dev->p->knode_parent,
2580 &new_parent->p->klist_children);
2581 set_dev_node(dev, dev_to_node(new_parent));
2582 }
2583
2584 if (dev->class) {
2585 error = device_move_class_links(dev, old_parent, new_parent);
2586 if (error) {
2587 /* We ignore errors on cleanup since we're hosed anyway... */
2588 device_move_class_links(dev, new_parent, old_parent);
2589 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
2590 if (new_parent)
2591 klist_remove(&dev->p->knode_parent);
2592 dev->parent = old_parent;
2593 if (old_parent) {
2594 klist_add_tail(&dev->p->knode_parent,
2595 &old_parent->p->klist_children);
2596 set_dev_node(dev, dev_to_node(old_parent));
2597 }
2598 }
2599 cleanup_glue_dir(dev, new_parent_kobj);
2600 put_device(new_parent);
2601 goto out;
2602 }
2603 }
2604 switch (dpm_order) {
2605 case DPM_ORDER_NONE:
2606 break;
2607 case DPM_ORDER_DEV_AFTER_PARENT:
2608 device_pm_move_after(dev, new_parent);
2609 devices_kset_move_after(dev, new_parent);
2610 break;
2611 case DPM_ORDER_PARENT_BEFORE_DEV:
2612 device_pm_move_before(new_parent, dev);
2613 devices_kset_move_before(new_parent, dev);
2614 break;
2615 case DPM_ORDER_DEV_LAST:
2616 device_pm_move_last(dev);
2617 devices_kset_move_last(dev);
2618 break;
2619 }
2620
2621 put_device(old_parent);
2622out:
2623 device_pm_unlock();
2624 put_device(dev);
2625 return error;
2626}
2627EXPORT_SYMBOL_GPL(device_move);
2628
2629/**
2630 * device_shutdown - call ->shutdown() on each device to shutdown.
2631 */
2632void device_shutdown(void)
2633{
2634 struct device *dev, *parent;
2635
2636 spin_lock(&devices_kset->list_lock);
2637 /*
2638 * Walk the devices list backward, shutting down each in turn.
2639 * Beware that device unplug events may also start pulling
2640 * devices offline, even as the system is shutting down.
2641 */
2642 while (!list_empty(&devices_kset->list)) {
2643 dev = list_entry(devices_kset->list.prev, struct device,
2644 kobj.entry);
2645
2646 /*
2647 * hold reference count of device's parent to
2648 * prevent it from being freed because parent's
2649 * lock is to be held
2650 */
2651 parent = get_device(dev->parent);
2652 get_device(dev);
2653 /*
2654 * Make sure the device is off the kset list, in the
2655 * event that dev->*->shutdown() doesn't remove it.
2656 */
2657 list_del_init(&dev->kobj.entry);
2658 spin_unlock(&devices_kset->list_lock);
2659
2660 /* hold lock to avoid race with probe/release */
2661 if (parent)
2662 device_lock(parent);
2663 device_lock(dev);
2664
2665 /* Don't allow any more runtime suspends */
2666 pm_runtime_get_noresume(dev);
2667 pm_runtime_barrier(dev);
2668
2669 if (dev->bus && dev->bus->shutdown) {
2670 if (initcall_debug)
2671 dev_info(dev, "shutdown\n");
2672 dev->bus->shutdown(dev);
2673 } else if (dev->driver && dev->driver->shutdown) {
2674 if (initcall_debug)
2675 dev_info(dev, "shutdown\n");
2676 dev->driver->shutdown(dev);
2677 }
2678
2679 device_unlock(dev);
2680 if (parent)
2681 device_unlock(parent);
2682
2683 put_device(dev);
2684 put_device(parent);
2685
2686 spin_lock(&devices_kset->list_lock);
2687 }
2688 spin_unlock(&devices_kset->list_lock);
2689}
2690
2691/*
2692 * Device logging functions
2693 */
2694
2695#ifdef CONFIG_PRINTK
2696static int
2697create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2698{
2699 const char *subsys;
2700 size_t pos = 0;
2701
2702 if (dev->class)
2703 subsys = dev->class->name;
2704 else if (dev->bus)
2705 subsys = dev->bus->name;
2706 else
2707 return 0;
2708
2709 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2710 if (pos >= hdrlen)
2711 goto overflow;
2712
2713 /*
2714 * Add device identifier DEVICE=:
2715 * b12:8 block dev_t
2716 * c127:3 char dev_t
2717 * n8 netdev ifindex
2718 * +sound:card0 subsystem:devname
2719 */
2720 if (MAJOR(dev->devt)) {
2721 char c;
2722
2723 if (strcmp(subsys, "block") == 0)
2724 c = 'b';
2725 else
2726 c = 'c';
2727 pos++;
2728 pos += snprintf(hdr + pos, hdrlen - pos,
2729 "DEVICE=%c%u:%u",
2730 c, MAJOR(dev->devt), MINOR(dev->devt));
2731 } else if (strcmp(subsys, "net") == 0) {
2732 struct net_device *net = to_net_dev(dev);
2733
2734 pos++;
2735 pos += snprintf(hdr + pos, hdrlen - pos,
2736 "DEVICE=n%u", net->ifindex);
2737 } else {
2738 pos++;
2739 pos += snprintf(hdr + pos, hdrlen - pos,
2740 "DEVICE=+%s:%s", subsys, dev_name(dev));
2741 }
2742
2743 if (pos >= hdrlen)
2744 goto overflow;
2745
2746 return pos;
2747
2748overflow:
2749 dev_WARN(dev, "device/subsystem name too long");
2750 return 0;
2751}
2752
2753int dev_vprintk_emit(int level, const struct device *dev,
2754 const char *fmt, va_list args)
2755{
2756 char hdr[128];
2757 size_t hdrlen;
2758
2759 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2760
2761 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2762}
2763EXPORT_SYMBOL(dev_vprintk_emit);
2764
2765int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2766{
2767 va_list args;
2768 int r;
2769
2770 va_start(args, fmt);
2771
2772 r = dev_vprintk_emit(level, dev, fmt, args);
2773
2774 va_end(args);
2775
2776 return r;
2777}
2778EXPORT_SYMBOL(dev_printk_emit);
2779
2780static void __dev_printk(const char *level, const struct device *dev,
2781 struct va_format *vaf)
2782{
2783 if (dev)
2784 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2785 dev_driver_string(dev), dev_name(dev), vaf);
2786 else
2787 printk("%s(NULL device *): %pV", level, vaf);
2788}
2789
2790void dev_printk(const char *level, const struct device *dev,
2791 const char *fmt, ...)
2792{
2793 struct va_format vaf;
2794 va_list args;
2795
2796 va_start(args, fmt);
2797
2798 vaf.fmt = fmt;
2799 vaf.va = &args;
2800
2801 __dev_printk(level, dev, &vaf);
2802
2803 va_end(args);
2804}
2805EXPORT_SYMBOL(dev_printk);
2806
2807#define define_dev_printk_level(func, kern_level) \
2808void func(const struct device *dev, const char *fmt, ...) \
2809{ \
2810 struct va_format vaf; \
2811 va_list args; \
2812 \
2813 va_start(args, fmt); \
2814 \
2815 vaf.fmt = fmt; \
2816 vaf.va = &args; \
2817 \
2818 __dev_printk(kern_level, dev, &vaf); \
2819 \
2820 va_end(args); \
2821} \
2822EXPORT_SYMBOL(func);
2823
2824define_dev_printk_level(dev_emerg, KERN_EMERG);
2825define_dev_printk_level(dev_alert, KERN_ALERT);
2826define_dev_printk_level(dev_crit, KERN_CRIT);
2827define_dev_printk_level(dev_err, KERN_ERR);
2828define_dev_printk_level(dev_warn, KERN_WARNING);
2829define_dev_printk_level(dev_notice, KERN_NOTICE);
2830define_dev_printk_level(_dev_info, KERN_INFO);
2831
2832#endif
2833
2834static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2835{
2836 return fwnode && !IS_ERR(fwnode->secondary);
2837}
2838
2839/**
2840 * set_primary_fwnode - Change the primary firmware node of a given device.
2841 * @dev: Device to handle.
2842 * @fwnode: New primary firmware node of the device.
2843 *
2844 * Set the device's firmware node pointer to @fwnode, but if a secondary
2845 * firmware node of the device is present, preserve it.
2846 */
2847void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2848{
2849 if (fwnode) {
2850 struct fwnode_handle *fn = dev->fwnode;
2851
2852 if (fwnode_is_primary(fn))
2853 fn = fn->secondary;
2854
2855 if (fn) {
2856 WARN_ON(fwnode->secondary);
2857 fwnode->secondary = fn;
2858 }
2859 dev->fwnode = fwnode;
2860 } else {
2861 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2862 dev->fwnode->secondary : NULL;
2863 }
2864}
2865EXPORT_SYMBOL_GPL(set_primary_fwnode);
2866
2867/**
2868 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2869 * @dev: Device to handle.
2870 * @fwnode: New secondary firmware node of the device.
2871 *
2872 * If a primary firmware node of the device is present, set its secondary
2873 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2874 * @fwnode.
2875 */
2876void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2877{
2878 if (fwnode)
2879 fwnode->secondary = ERR_PTR(-ENODEV);
2880
2881 if (fwnode_is_primary(dev->fwnode))
2882 dev->fwnode->secondary = fwnode;
2883 else
2884 dev->fwnode = fwnode;
2885}