Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * drivers/base/core.c - core driver model code (device registration, etc)
4 : *
5 : * Copyright (c) 2002-3 Patrick Mochel
6 : * Copyright (c) 2002-3 Open Source Development Labs
7 : * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
8 : * Copyright (c) 2006 Novell, Inc.
9 : */
10 :
11 : #include <linux/acpi.h>
12 : #include <linux/cpufreq.h>
13 : #include <linux/device.h>
14 : #include <linux/err.h>
15 : #include <linux/fwnode.h>
16 : #include <linux/init.h>
17 : #include <linux/kstrtox.h>
18 : #include <linux/module.h>
19 : #include <linux/slab.h>
20 : #include <linux/string.h>
21 : #include <linux/kdev_t.h>
22 : #include <linux/notifier.h>
23 : #include <linux/of.h>
24 : #include <linux/of_device.h>
25 : #include <linux/blkdev.h>
26 : #include <linux/mutex.h>
27 : #include <linux/pm_runtime.h>
28 : #include <linux/netdevice.h>
29 : #include <linux/sched/signal.h>
30 : #include <linux/sched/mm.h>
31 : #include <linux/swiotlb.h>
32 : #include <linux/sysfs.h>
33 : #include <linux/dma-map-ops.h> /* for dma_default_coherent */
34 :
35 : #include "base.h"
36 : #include "physical_location.h"
37 : #include "power/power.h"
38 :
39 : /* Device links support. */
40 : static LIST_HEAD(deferred_sync);
41 : static unsigned int defer_sync_state_count = 1;
42 : static DEFINE_MUTEX(fwnode_link_lock);
43 : static bool fw_devlink_is_permissive(void);
44 : static void __fw_devlink_link_to_consumers(struct device *dev);
45 : static bool fw_devlink_drv_reg_done;
46 : static bool fw_devlink_best_effort;
47 :
48 : /**
49 : * __fwnode_link_add - Create a link between two fwnode_handles.
50 : * @con: Consumer end of the link.
51 : * @sup: Supplier end of the link.
52 : *
53 : * Create a fwnode link between fwnode handles @con and @sup. The fwnode link
54 : * represents the detail that the firmware lists @sup fwnode as supplying a
55 : * resource to @con.
56 : *
57 : * The driver core will use the fwnode link to create a device link between the
58 : * two device objects corresponding to @con and @sup when they are created. The
59 : * driver core will automatically delete the fwnode link between @con and @sup
60 : * after doing that.
61 : *
62 : * Attempts to create duplicate links between the same pair of fwnode handles
63 : * are ignored and there is no reference counting.
64 : */
65 0 : static int __fwnode_link_add(struct fwnode_handle *con,
66 : struct fwnode_handle *sup, u8 flags)
67 : {
68 : struct fwnode_link *link;
69 :
70 0 : list_for_each_entry(link, &sup->consumers, s_hook)
71 0 : if (link->consumer == con) {
72 0 : link->flags |= flags;
73 0 : return 0;
74 : }
75 :
76 0 : link = kzalloc(sizeof(*link), GFP_KERNEL);
77 0 : if (!link)
78 : return -ENOMEM;
79 :
80 0 : link->supplier = sup;
81 0 : INIT_LIST_HEAD(&link->s_hook);
82 0 : link->consumer = con;
83 0 : INIT_LIST_HEAD(&link->c_hook);
84 0 : link->flags = flags;
85 :
86 0 : list_add(&link->s_hook, &sup->consumers);
87 0 : list_add(&link->c_hook, &con->suppliers);
88 : pr_debug("%pfwf Linked as a fwnode consumer to %pfwf\n",
89 : con, sup);
90 :
91 0 : return 0;
92 : }
93 :
94 0 : int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
95 : {
96 : int ret;
97 :
98 0 : mutex_lock(&fwnode_link_lock);
99 0 : ret = __fwnode_link_add(con, sup, 0);
100 0 : mutex_unlock(&fwnode_link_lock);
101 0 : return ret;
102 : }
103 :
104 : /**
105 : * __fwnode_link_del - Delete a link between two fwnode_handles.
106 : * @link: the fwnode_link to be deleted
107 : *
108 : * The fwnode_link_lock needs to be held when this function is called.
109 : */
110 0 : static void __fwnode_link_del(struct fwnode_link *link)
111 : {
112 : pr_debug("%pfwf Dropping the fwnode link to %pfwf\n",
113 : link->consumer, link->supplier);
114 0 : list_del(&link->s_hook);
115 0 : list_del(&link->c_hook);
116 0 : kfree(link);
117 0 : }
118 :
119 : /**
120 : * __fwnode_link_cycle - Mark a fwnode link as being part of a cycle.
121 : * @link: the fwnode_link to be marked
122 : *
123 : * The fwnode_link_lock needs to be held when this function is called.
124 : */
125 : static void __fwnode_link_cycle(struct fwnode_link *link)
126 : {
127 : pr_debug("%pfwf: Relaxing link with %pfwf\n",
128 : link->consumer, link->supplier);
129 0 : link->flags |= FWLINK_FLAG_CYCLE;
130 : }
131 :
132 : /**
133 : * fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle.
134 : * @fwnode: fwnode whose supplier links need to be deleted
135 : *
136 : * Deletes all supplier links connecting directly to @fwnode.
137 : */
138 0 : static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode)
139 : {
140 : struct fwnode_link *link, *tmp;
141 :
142 0 : mutex_lock(&fwnode_link_lock);
143 0 : list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook)
144 0 : __fwnode_link_del(link);
145 0 : mutex_unlock(&fwnode_link_lock);
146 0 : }
147 :
148 : /**
149 : * fwnode_links_purge_consumers - Delete all consumer links of fwnode_handle.
150 : * @fwnode: fwnode whose consumer links need to be deleted
151 : *
152 : * Deletes all consumer links connecting directly to @fwnode.
153 : */
154 0 : static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode)
155 : {
156 : struct fwnode_link *link, *tmp;
157 :
158 0 : mutex_lock(&fwnode_link_lock);
159 0 : list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook)
160 0 : __fwnode_link_del(link);
161 0 : mutex_unlock(&fwnode_link_lock);
162 0 : }
163 :
164 : /**
165 : * fwnode_links_purge - Delete all links connected to a fwnode_handle.
166 : * @fwnode: fwnode whose links needs to be deleted
167 : *
168 : * Deletes all links connecting directly to a fwnode.
169 : */
170 0 : void fwnode_links_purge(struct fwnode_handle *fwnode)
171 : {
172 0 : fwnode_links_purge_suppliers(fwnode);
173 0 : fwnode_links_purge_consumers(fwnode);
174 0 : }
175 :
176 0 : void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
177 : {
178 : struct fwnode_handle *child;
179 :
180 : /* Don't purge consumer links of an added child */
181 0 : if (fwnode->dev)
182 : return;
183 :
184 0 : fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
185 0 : fwnode_links_purge_consumers(fwnode);
186 :
187 0 : fwnode_for_each_available_child_node(fwnode, child)
188 0 : fw_devlink_purge_absent_suppliers(child);
189 : }
190 : EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers);
191 :
192 : /**
193 : * __fwnode_links_move_consumers - Move consumer from @from to @to fwnode_handle
194 : * @from: move consumers away from this fwnode
195 : * @to: move consumers to this fwnode
196 : *
197 : * Move all consumer links from @from fwnode to @to fwnode.
198 : */
199 0 : static void __fwnode_links_move_consumers(struct fwnode_handle *from,
200 : struct fwnode_handle *to)
201 : {
202 : struct fwnode_link *link, *tmp;
203 :
204 0 : list_for_each_entry_safe(link, tmp, &from->consumers, s_hook) {
205 0 : __fwnode_link_add(link->consumer, to, link->flags);
206 0 : __fwnode_link_del(link);
207 : }
208 0 : }
209 :
210 : /**
211 : * __fw_devlink_pickup_dangling_consumers - Pick up dangling consumers
212 : * @fwnode: fwnode from which to pick up dangling consumers
213 : * @new_sup: fwnode of new supplier
214 : *
215 : * If the @fwnode has a corresponding struct device and the device supports
216 : * probing (that is, added to a bus), then we want to let fw_devlink create
217 : * MANAGED device links to this device, so leave @fwnode and its descendant's
218 : * fwnode links alone.
219 : *
220 : * Otherwise, move its consumers to the new supplier @new_sup.
221 : */
222 0 : static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
223 : struct fwnode_handle *new_sup)
224 : {
225 : struct fwnode_handle *child;
226 :
227 0 : if (fwnode->dev && fwnode->dev->bus)
228 : return;
229 :
230 0 : fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
231 0 : __fwnode_links_move_consumers(fwnode, new_sup);
232 :
233 0 : fwnode_for_each_available_child_node(fwnode, child)
234 0 : __fw_devlink_pickup_dangling_consumers(child, new_sup);
235 : }
236 :
237 : static DEFINE_MUTEX(device_links_lock);
238 : DEFINE_STATIC_SRCU(device_links_srcu);
239 :
240 : static inline void device_links_write_lock(void)
241 : {
242 28 : mutex_lock(&device_links_lock);
243 : }
244 :
245 : static inline void device_links_write_unlock(void)
246 : {
247 28 : mutex_unlock(&device_links_lock);
248 : }
249 :
250 10 : int device_links_read_lock(void) __acquires(&device_links_srcu)
251 : {
252 10 : return srcu_read_lock(&device_links_srcu);
253 : }
254 :
255 10 : void device_links_read_unlock(int idx) __releases(&device_links_srcu)
256 : {
257 10 : srcu_read_unlock(&device_links_srcu, idx);
258 10 : }
259 :
260 0 : int device_links_read_lock_held(void)
261 : {
262 0 : return srcu_read_lock_held(&device_links_srcu);
263 : }
264 :
265 : static void device_link_synchronize_removal(void)
266 : {
267 0 : synchronize_srcu(&device_links_srcu);
268 : }
269 :
270 : static void device_link_remove_from_lists(struct device_link *link)
271 : {
272 0 : list_del_rcu(&link->s_node);
273 0 : list_del_rcu(&link->c_node);
274 : }
275 :
276 : static bool device_is_ancestor(struct device *dev, struct device *target)
277 : {
278 0 : while (target->parent) {
279 0 : target = target->parent;
280 0 : if (dev == target)
281 : return true;
282 : }
283 : return false;
284 : }
285 :
286 : static inline bool device_link_flag_is_sync_state_only(u32 flags)
287 : {
288 0 : return (flags & ~(DL_FLAG_INFERRED | DL_FLAG_CYCLE)) ==
289 : (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED);
290 : }
291 :
292 : /**
293 : * device_is_dependent - Check if one device depends on another one
294 : * @dev: Device to check dependencies for.
295 : * @target: Device to check against.
296 : *
297 : * Check if @target depends on @dev or any device dependent on it (its child or
298 : * its consumer etc). Return 1 if that is the case or 0 otherwise.
299 : */
300 0 : int device_is_dependent(struct device *dev, void *target)
301 : {
302 : struct device_link *link;
303 : int ret;
304 :
305 : /*
306 : * The "ancestors" check is needed to catch the case when the target
307 : * device has not been completely initialized yet and it is still
308 : * missing from the list of children of its parent device.
309 : */
310 0 : if (dev == target || device_is_ancestor(dev, target))
311 : return 1;
312 :
313 0 : ret = device_for_each_child(dev, target, device_is_dependent);
314 0 : if (ret)
315 : return ret;
316 :
317 0 : list_for_each_entry(link, &dev->links.consumers, s_node) {
318 0 : if (device_link_flag_is_sync_state_only(link->flags))
319 0 : continue;
320 :
321 0 : if (link->consumer == target)
322 : return 1;
323 :
324 0 : ret = device_is_dependent(link->consumer, target);
325 0 : if (ret)
326 : break;
327 : }
328 : return ret;
329 : }
330 :
331 0 : static void device_link_init_status(struct device_link *link,
332 : struct device *consumer,
333 : struct device *supplier)
334 : {
335 0 : switch (supplier->links.status) {
336 : case DL_DEV_PROBING:
337 0 : switch (consumer->links.status) {
338 : case DL_DEV_PROBING:
339 : /*
340 : * A consumer driver can create a link to a supplier
341 : * that has not completed its probing yet as long as it
342 : * knows that the supplier is already functional (for
343 : * example, it has just acquired some resources from the
344 : * supplier).
345 : */
346 0 : link->status = DL_STATE_CONSUMER_PROBE;
347 : break;
348 : default:
349 0 : link->status = DL_STATE_DORMANT;
350 : break;
351 : }
352 : break;
353 : case DL_DEV_DRIVER_BOUND:
354 0 : switch (consumer->links.status) {
355 : case DL_DEV_PROBING:
356 0 : link->status = DL_STATE_CONSUMER_PROBE;
357 : break;
358 : case DL_DEV_DRIVER_BOUND:
359 0 : link->status = DL_STATE_ACTIVE;
360 : break;
361 : default:
362 0 : link->status = DL_STATE_AVAILABLE;
363 : break;
364 : }
365 : break;
366 : case DL_DEV_UNBINDING:
367 0 : link->status = DL_STATE_SUPPLIER_UNBIND;
368 : break;
369 : default:
370 0 : link->status = DL_STATE_DORMANT;
371 : break;
372 : }
373 0 : }
374 :
375 0 : static int device_reorder_to_tail(struct device *dev, void *not_used)
376 : {
377 : struct device_link *link;
378 :
379 : /*
380 : * Devices that have not been registered yet will be put to the ends
381 : * of the lists during the registration, so skip them here.
382 : */
383 0 : if (device_is_registered(dev))
384 : devices_kset_move_last(dev);
385 :
386 0 : if (device_pm_initialized(dev))
387 0 : device_pm_move_last(dev);
388 :
389 0 : device_for_each_child(dev, NULL, device_reorder_to_tail);
390 0 : list_for_each_entry(link, &dev->links.consumers, s_node) {
391 0 : if (device_link_flag_is_sync_state_only(link->flags))
392 0 : continue;
393 0 : device_reorder_to_tail(link->consumer, NULL);
394 : }
395 :
396 0 : return 0;
397 : }
398 :
399 : /**
400 : * device_pm_move_to_tail - Move set of devices to the end of device lists
401 : * @dev: Device to move
402 : *
403 : * This is a device_reorder_to_tail() wrapper taking the requisite locks.
404 : *
405 : * It moves the @dev along with all of its children and all of its consumers
406 : * to the ends of the device_kset and dpm_list, recursively.
407 : */
408 0 : void device_pm_move_to_tail(struct device *dev)
409 : {
410 : int idx;
411 :
412 0 : idx = device_links_read_lock();
413 0 : device_pm_lock();
414 0 : device_reorder_to_tail(dev, NULL);
415 0 : device_pm_unlock();
416 0 : device_links_read_unlock(idx);
417 0 : }
418 :
419 : #define to_devlink(dev) container_of((dev), struct device_link, link_dev)
420 :
421 0 : static ssize_t status_show(struct device *dev,
422 : struct device_attribute *attr, char *buf)
423 : {
424 : const char *output;
425 :
426 0 : switch (to_devlink(dev)->status) {
427 : case DL_STATE_NONE:
428 : output = "not tracked";
429 : break;
430 : case DL_STATE_DORMANT:
431 : output = "dormant";
432 : break;
433 : case DL_STATE_AVAILABLE:
434 : output = "available";
435 : break;
436 : case DL_STATE_CONSUMER_PROBE:
437 : output = "consumer probing";
438 : break;
439 : case DL_STATE_ACTIVE:
440 : output = "active";
441 : break;
442 : case DL_STATE_SUPPLIER_UNBIND:
443 : output = "supplier unbinding";
444 : break;
445 : default:
446 : output = "unknown";
447 : break;
448 : }
449 :
450 0 : return sysfs_emit(buf, "%s\n", output);
451 : }
452 : static DEVICE_ATTR_RO(status);
453 :
454 0 : static ssize_t auto_remove_on_show(struct device *dev,
455 : struct device_attribute *attr, char *buf)
456 : {
457 0 : struct device_link *link = to_devlink(dev);
458 : const char *output;
459 :
460 0 : if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
461 : output = "supplier unbind";
462 0 : else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
463 : output = "consumer unbind";
464 : else
465 0 : output = "never";
466 :
467 0 : return sysfs_emit(buf, "%s\n", output);
468 : }
469 : static DEVICE_ATTR_RO(auto_remove_on);
470 :
471 0 : static ssize_t runtime_pm_show(struct device *dev,
472 : struct device_attribute *attr, char *buf)
473 : {
474 0 : struct device_link *link = to_devlink(dev);
475 :
476 0 : return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
477 : }
478 : static DEVICE_ATTR_RO(runtime_pm);
479 :
480 0 : static ssize_t sync_state_only_show(struct device *dev,
481 : struct device_attribute *attr, char *buf)
482 : {
483 0 : struct device_link *link = to_devlink(dev);
484 :
485 0 : return sysfs_emit(buf, "%d\n",
486 0 : !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
487 : }
488 : static DEVICE_ATTR_RO(sync_state_only);
489 :
490 : static struct attribute *devlink_attrs[] = {
491 : &dev_attr_status.attr,
492 : &dev_attr_auto_remove_on.attr,
493 : &dev_attr_runtime_pm.attr,
494 : &dev_attr_sync_state_only.attr,
495 : NULL,
496 : };
497 : ATTRIBUTE_GROUPS(devlink);
498 :
499 0 : static void device_link_release_fn(struct work_struct *work)
500 : {
501 0 : struct device_link *link = container_of(work, struct device_link, rm_work);
502 :
503 : /* Ensure that all references to the link object have been dropped. */
504 : device_link_synchronize_removal();
505 :
506 0 : pm_runtime_release_supplier(link);
507 : /*
508 : * If supplier_preactivated is set, the link has been dropped between
509 : * the pm_runtime_get_suppliers() and pm_runtime_put_suppliers() calls
510 : * in __driver_probe_device(). In that case, drop the supplier's
511 : * PM-runtime usage counter to remove the reference taken by
512 : * pm_runtime_get_suppliers().
513 : */
514 0 : if (link->supplier_preactivated)
515 0 : pm_runtime_put_noidle(link->supplier);
516 :
517 0 : pm_request_idle(link->supplier);
518 :
519 0 : put_device(link->consumer);
520 0 : put_device(link->supplier);
521 0 : kfree(link);
522 0 : }
523 :
524 0 : static void devlink_dev_release(struct device *dev)
525 : {
526 0 : struct device_link *link = to_devlink(dev);
527 :
528 0 : INIT_WORK(&link->rm_work, device_link_release_fn);
529 : /*
530 : * It may take a while to complete this work because of the SRCU
531 : * synchronization in device_link_release_fn() and if the consumer or
532 : * supplier devices get deleted when it runs, so put it into the "long"
533 : * workqueue.
534 : */
535 0 : queue_work(system_long_wq, &link->rm_work);
536 0 : }
537 :
538 : static struct class devlink_class = {
539 : .name = "devlink",
540 : .dev_groups = devlink_groups,
541 : .dev_release = devlink_dev_release,
542 : };
543 :
544 0 : static int devlink_add_symlinks(struct device *dev)
545 : {
546 : int ret;
547 : size_t len;
548 0 : struct device_link *link = to_devlink(dev);
549 0 : struct device *sup = link->supplier;
550 0 : struct device *con = link->consumer;
551 : char *buf;
552 :
553 0 : len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
554 : strlen(dev_bus_name(con)) + strlen(dev_name(con)));
555 0 : len += strlen(":");
556 0 : len += strlen("supplier:") + 1;
557 0 : buf = kzalloc(len, GFP_KERNEL);
558 0 : if (!buf)
559 : return -ENOMEM;
560 :
561 0 : ret = sysfs_create_link(&link->link_dev.kobj, &sup->kobj, "supplier");
562 0 : if (ret)
563 : goto out;
564 :
565 0 : ret = sysfs_create_link(&link->link_dev.kobj, &con->kobj, "consumer");
566 0 : if (ret)
567 : goto err_con;
568 :
569 0 : snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
570 0 : ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf);
571 0 : if (ret)
572 : goto err_con_dev;
573 :
574 0 : snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
575 0 : ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf);
576 0 : if (ret)
577 : goto err_sup_dev;
578 :
579 : goto out;
580 :
581 : err_sup_dev:
582 0 : snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
583 0 : sysfs_remove_link(&sup->kobj, buf);
584 : err_con_dev:
585 0 : sysfs_remove_link(&link->link_dev.kobj, "consumer");
586 : err_con:
587 0 : sysfs_remove_link(&link->link_dev.kobj, "supplier");
588 : out:
589 0 : kfree(buf);
590 0 : return ret;
591 : }
592 :
593 0 : static void devlink_remove_symlinks(struct device *dev)
594 : {
595 0 : struct device_link *link = to_devlink(dev);
596 : size_t len;
597 0 : struct device *sup = link->supplier;
598 0 : struct device *con = link->consumer;
599 : char *buf;
600 :
601 0 : sysfs_remove_link(&link->link_dev.kobj, "consumer");
602 0 : sysfs_remove_link(&link->link_dev.kobj, "supplier");
603 :
604 0 : len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
605 : strlen(dev_bus_name(con)) + strlen(dev_name(con)));
606 0 : len += strlen(":");
607 0 : len += strlen("supplier:") + 1;
608 0 : buf = kzalloc(len, GFP_KERNEL);
609 0 : if (!buf) {
610 0 : WARN(1, "Unable to properly free device link symlinks!\n");
611 0 : return;
612 : }
613 :
614 0 : if (device_is_registered(con)) {
615 0 : snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
616 0 : sysfs_remove_link(&con->kobj, buf);
617 : }
618 0 : snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
619 0 : sysfs_remove_link(&sup->kobj, buf);
620 0 : kfree(buf);
621 : }
622 :
623 : static struct class_interface devlink_class_intf = {
624 : .class = &devlink_class,
625 : .add_dev = devlink_add_symlinks,
626 : .remove_dev = devlink_remove_symlinks,
627 : };
628 :
629 1 : static int __init devlink_class_init(void)
630 : {
631 : int ret;
632 :
633 1 : ret = class_register(&devlink_class);
634 1 : if (ret)
635 : return ret;
636 :
637 1 : ret = class_interface_register(&devlink_class_intf);
638 1 : if (ret)
639 0 : class_unregister(&devlink_class);
640 :
641 : return ret;
642 : }
643 : postcore_initcall(devlink_class_init);
644 :
645 : #define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
646 : DL_FLAG_AUTOREMOVE_SUPPLIER | \
647 : DL_FLAG_AUTOPROBE_CONSUMER | \
648 : DL_FLAG_SYNC_STATE_ONLY | \
649 : DL_FLAG_INFERRED | \
650 : DL_FLAG_CYCLE)
651 :
652 : #define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
653 : DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
654 :
655 : /**
656 : * device_link_add - Create a link between two devices.
657 : * @consumer: Consumer end of the link.
658 : * @supplier: Supplier end of the link.
659 : * @flags: Link flags.
660 : *
661 : * The caller is responsible for the proper synchronization of the link creation
662 : * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
663 : * runtime PM framework to take the link into account. Second, if the
664 : * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
665 : * be forced into the active meta state and reference-counted upon the creation
666 : * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
667 : * ignored.
668 : *
669 : * If DL_FLAG_STATELESS is set in @flags, the caller of this function is
670 : * expected to release the link returned by it directly with the help of either
671 : * device_link_del() or device_link_remove().
672 : *
673 : * If that flag is not set, however, the caller of this function is handing the
674 : * management of the link over to the driver core entirely and its return value
675 : * can only be used to check whether or not the link is present. In that case,
676 : * the DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER device link
677 : * flags can be used to indicate to the driver core when the link can be safely
678 : * deleted. Namely, setting one of them in @flags indicates to the driver core
679 : * that the link is not going to be used (by the given caller of this function)
680 : * after unbinding the consumer or supplier driver, respectively, from its
681 : * device, so the link can be deleted at that point. If none of them is set,
682 : * the link will be maintained until one of the devices pointed to by it (either
683 : * the consumer or the supplier) is unregistered.
684 : *
685 : * Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and
686 : * DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent
687 : * managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can
688 : * be used to request the driver core to automatically probe for a consumer
689 : * driver after successfully binding a driver to the supplier device.
690 : *
691 : * The combination of DL_FLAG_STATELESS and one of DL_FLAG_AUTOREMOVE_CONSUMER,
692 : * DL_FLAG_AUTOREMOVE_SUPPLIER, or DL_FLAG_AUTOPROBE_CONSUMER set in @flags at
693 : * the same time is invalid and will cause NULL to be returned upfront.
694 : * However, if a device link between the given @consumer and @supplier pair
695 : * exists already when this function is called for them, the existing link will
696 : * be returned regardless of its current type and status (the link's flags may
697 : * be modified then). The caller of this function is then expected to treat
698 : * the link as though it has just been created, so (in particular) if
699 : * DL_FLAG_STATELESS was passed in @flags, the link needs to be released
700 : * explicitly when not needed any more (as stated above).
701 : *
702 : * A side effect of the link creation is re-ordering of dpm_list and the
703 : * devices_kset list by moving the consumer device and all devices depending
704 : * on it to the ends of these lists (that does not happen to devices that have
705 : * not been registered when this function is called).
706 : *
707 : * The supplier device is required to be registered when this function is called
708 : * and NULL will be returned if that is not the case. The consumer device need
709 : * not be registered, however.
710 : */
711 0 : struct device_link *device_link_add(struct device *consumer,
712 : struct device *supplier, u32 flags)
713 : {
714 : struct device_link *link;
715 :
716 0 : if (!consumer || !supplier || consumer == supplier ||
717 0 : flags & ~DL_ADD_VALID_FLAGS ||
718 0 : (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
719 0 : (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
720 : flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
721 : DL_FLAG_AUTOREMOVE_SUPPLIER)))
722 : return NULL;
723 :
724 0 : if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
725 0 : if (pm_runtime_get_sync(supplier) < 0) {
726 : pm_runtime_put_noidle(supplier);
727 : return NULL;
728 : }
729 : }
730 :
731 0 : if (!(flags & DL_FLAG_STATELESS))
732 0 : flags |= DL_FLAG_MANAGED;
733 :
734 0 : if (flags & DL_FLAG_SYNC_STATE_ONLY &&
735 0 : !device_link_flag_is_sync_state_only(flags))
736 : return NULL;
737 :
738 : device_links_write_lock();
739 0 : device_pm_lock();
740 :
741 : /*
742 : * If the supplier has not been fully registered yet or there is a
743 : * reverse (non-SYNC_STATE_ONLY) dependency between the consumer and
744 : * the supplier already in the graph, return NULL. If the link is a
745 : * SYNC_STATE_ONLY link, we don't check for reverse dependencies
746 : * because it only affects sync_state() callbacks.
747 : */
748 0 : if (!device_pm_initialized(supplier)
749 0 : || (!(flags & DL_FLAG_SYNC_STATE_ONLY) &&
750 0 : device_is_dependent(consumer, supplier))) {
751 : link = NULL;
752 : goto out;
753 : }
754 :
755 : /*
756 : * SYNC_STATE_ONLY links are useless once a consumer device has probed.
757 : * So, only create it if the consumer hasn't probed yet.
758 : */
759 0 : if (flags & DL_FLAG_SYNC_STATE_ONLY &&
760 0 : consumer->links.status != DL_DEV_NO_DRIVER &&
761 : consumer->links.status != DL_DEV_PROBING) {
762 : link = NULL;
763 : goto out;
764 : }
765 :
766 : /*
767 : * DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed
768 : * longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both
769 : * together doesn't make sense, so prefer DL_FLAG_AUTOREMOVE_SUPPLIER.
770 : */
771 0 : if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
772 0 : flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
773 :
774 0 : list_for_each_entry(link, &supplier->links.consumers, s_node) {
775 0 : if (link->consumer != consumer)
776 0 : continue;
777 :
778 0 : if (link->flags & DL_FLAG_INFERRED &&
779 : !(flags & DL_FLAG_INFERRED))
780 0 : link->flags &= ~DL_FLAG_INFERRED;
781 :
782 0 : if (flags & DL_FLAG_PM_RUNTIME) {
783 0 : if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
784 0 : pm_runtime_new_link(consumer);
785 0 : link->flags |= DL_FLAG_PM_RUNTIME;
786 : }
787 0 : if (flags & DL_FLAG_RPM_ACTIVE)
788 0 : refcount_inc(&link->rpm_active);
789 : }
790 :
791 0 : if (flags & DL_FLAG_STATELESS) {
792 0 : kref_get(&link->kref);
793 0 : if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
794 : !(link->flags & DL_FLAG_STATELESS)) {
795 0 : link->flags |= DL_FLAG_STATELESS;
796 0 : goto reorder;
797 : } else {
798 0 : link->flags |= DL_FLAG_STATELESS;
799 0 : goto out;
800 : }
801 : }
802 :
803 : /*
804 : * If the life time of the link following from the new flags is
805 : * longer than indicated by the flags of the existing link,
806 : * update the existing link to stay around longer.
807 : */
808 0 : if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) {
809 0 : if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
810 0 : link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
811 0 : link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
812 : }
813 0 : } else if (!(flags & DL_FLAG_AUTOREMOVE_CONSUMER)) {
814 0 : link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER |
815 : DL_FLAG_AUTOREMOVE_SUPPLIER);
816 : }
817 0 : if (!(link->flags & DL_FLAG_MANAGED)) {
818 0 : kref_get(&link->kref);
819 0 : link->flags |= DL_FLAG_MANAGED;
820 0 : device_link_init_status(link, consumer, supplier);
821 : }
822 0 : if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
823 : !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
824 0 : link->flags &= ~DL_FLAG_SYNC_STATE_ONLY;
825 0 : goto reorder;
826 : }
827 :
828 : goto out;
829 : }
830 :
831 0 : link = kzalloc(sizeof(*link), GFP_KERNEL);
832 0 : if (!link)
833 : goto out;
834 :
835 0 : refcount_set(&link->rpm_active, 1);
836 :
837 0 : get_device(supplier);
838 0 : link->supplier = supplier;
839 0 : INIT_LIST_HEAD(&link->s_node);
840 0 : get_device(consumer);
841 0 : link->consumer = consumer;
842 0 : INIT_LIST_HEAD(&link->c_node);
843 0 : link->flags = flags;
844 0 : kref_init(&link->kref);
845 :
846 0 : link->link_dev.class = &devlink_class;
847 0 : device_set_pm_not_required(&link->link_dev);
848 0 : dev_set_name(&link->link_dev, "%s:%s--%s:%s",
849 : dev_bus_name(supplier), dev_name(supplier),
850 : dev_bus_name(consumer), dev_name(consumer));
851 0 : if (device_register(&link->link_dev)) {
852 0 : put_device(&link->link_dev);
853 : link = NULL;
854 : goto out;
855 : }
856 :
857 0 : if (flags & DL_FLAG_PM_RUNTIME) {
858 0 : if (flags & DL_FLAG_RPM_ACTIVE)
859 0 : refcount_inc(&link->rpm_active);
860 :
861 0 : pm_runtime_new_link(consumer);
862 : }
863 :
864 : /* Determine the initial link state. */
865 0 : if (flags & DL_FLAG_STATELESS)
866 0 : link->status = DL_STATE_NONE;
867 : else
868 0 : device_link_init_status(link, consumer, supplier);
869 :
870 : /*
871 : * Some callers expect the link creation during consumer driver probe to
872 : * resume the supplier even without DL_FLAG_RPM_ACTIVE.
873 : */
874 0 : if (link->status == DL_STATE_CONSUMER_PROBE &&
875 : flags & DL_FLAG_PM_RUNTIME)
876 : pm_runtime_resume(supplier);
877 :
878 0 : list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
879 0 : list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
880 :
881 0 : if (flags & DL_FLAG_SYNC_STATE_ONLY) {
882 : dev_dbg(consumer,
883 : "Linked as a sync state only consumer to %s\n",
884 : dev_name(supplier));
885 : goto out;
886 : }
887 :
888 : reorder:
889 : /*
890 : * Move the consumer and all of the devices depending on it to the end
891 : * of dpm_list and the devices_kset list.
892 : *
893 : * It is necessary to hold dpm_list locked throughout all that or else
894 : * we may end up suspending with a wrong ordering of it.
895 : */
896 0 : device_reorder_to_tail(consumer, NULL);
897 :
898 : dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
899 :
900 : out:
901 0 : device_pm_unlock();
902 : device_links_write_unlock();
903 :
904 0 : if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link)
905 : pm_runtime_put(supplier);
906 :
907 : return link;
908 : }
909 : EXPORT_SYMBOL_GPL(device_link_add);
910 :
911 0 : static void __device_link_del(struct kref *kref)
912 : {
913 0 : struct device_link *link = container_of(kref, struct device_link, kref);
914 :
915 : dev_dbg(link->consumer, "Dropping the link to %s\n",
916 : dev_name(link->supplier));
917 :
918 0 : pm_runtime_drop_link(link);
919 :
920 0 : device_link_remove_from_lists(link);
921 0 : device_unregister(&link->link_dev);
922 0 : }
923 :
924 0 : static void device_link_put_kref(struct device_link *link)
925 : {
926 0 : if (link->flags & DL_FLAG_STATELESS)
927 0 : kref_put(&link->kref, __device_link_del);
928 0 : else if (!device_is_registered(link->consumer))
929 0 : __device_link_del(&link->kref);
930 : else
931 0 : WARN(1, "Unable to drop a managed device link reference\n");
932 0 : }
933 :
934 : /**
935 : * device_link_del - Delete a stateless link between two devices.
936 : * @link: Device link to delete.
937 : *
938 : * The caller must ensure proper synchronization of this function with runtime
939 : * PM. If the link was added multiple times, it needs to be deleted as often.
940 : * Care is required for hotplugged devices: Their links are purged on removal
941 : * and calling device_link_del() is then no longer allowed.
942 : */
943 0 : void device_link_del(struct device_link *link)
944 : {
945 : device_links_write_lock();
946 0 : device_link_put_kref(link);
947 : device_links_write_unlock();
948 0 : }
949 : EXPORT_SYMBOL_GPL(device_link_del);
950 :
951 : /**
952 : * device_link_remove - Delete a stateless link between two devices.
953 : * @consumer: Consumer end of the link.
954 : * @supplier: Supplier end of the link.
955 : *
956 : * The caller must ensure proper synchronization of this function with runtime
957 : * PM.
958 : */
959 0 : void device_link_remove(void *consumer, struct device *supplier)
960 : {
961 : struct device_link *link;
962 :
963 0 : if (WARN_ON(consumer == supplier))
964 : return;
965 :
966 : device_links_write_lock();
967 :
968 0 : list_for_each_entry(link, &supplier->links.consumers, s_node) {
969 0 : if (link->consumer == consumer) {
970 0 : device_link_put_kref(link);
971 0 : break;
972 : }
973 : }
974 :
975 : device_links_write_unlock();
976 : }
977 : EXPORT_SYMBOL_GPL(device_link_remove);
978 :
979 0 : static void device_links_missing_supplier(struct device *dev)
980 : {
981 : struct device_link *link;
982 :
983 0 : list_for_each_entry(link, &dev->links.suppliers, c_node) {
984 0 : if (link->status != DL_STATE_CONSUMER_PROBE)
985 0 : continue;
986 :
987 0 : if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
988 0 : WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
989 : } else {
990 0 : WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
991 0 : WRITE_ONCE(link->status, DL_STATE_DORMANT);
992 : }
993 : }
994 0 : }
995 :
996 : static bool dev_is_best_effort(struct device *dev)
997 : {
998 0 : return (fw_devlink_best_effort && dev->can_match) ||
999 0 : (dev->fwnode && (dev->fwnode->flags & FWNODE_FLAG_BEST_EFFORT));
1000 : }
1001 :
1002 : static struct fwnode_handle *fwnode_links_check_suppliers(
1003 : struct fwnode_handle *fwnode)
1004 : {
1005 : struct fwnode_link *link;
1006 :
1007 5 : if (!fwnode || fw_devlink_is_permissive())
1008 : return NULL;
1009 :
1010 0 : list_for_each_entry(link, &fwnode->suppliers, c_hook)
1011 0 : if (!(link->flags & FWLINK_FLAG_CYCLE))
1012 0 : return link->supplier;
1013 :
1014 : return NULL;
1015 : }
1016 :
1017 : /**
1018 : * device_links_check_suppliers - Check presence of supplier drivers.
1019 : * @dev: Consumer device.
1020 : *
1021 : * Check links from this device to any suppliers. Walk the list of the device's
1022 : * links to suppliers and see if all of them are available. If not, simply
1023 : * return -EPROBE_DEFER.
1024 : *
1025 : * We need to guarantee that the supplier will not go away after the check has
1026 : * been positive here. It only can go away in __device_release_driver() and
1027 : * that function checks the device's links to consumers. This means we need to
1028 : * mark the link as "consumer probe in progress" to make the supplier removal
1029 : * wait for us to complete (or bad things may happen).
1030 : *
1031 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1032 : */
1033 5 : int device_links_check_suppliers(struct device *dev)
1034 : {
1035 : struct device_link *link;
1036 5 : int ret = 0, fwnode_ret = 0;
1037 : struct fwnode_handle *sup_fw;
1038 :
1039 : /*
1040 : * Device waiting for supplier to become available is not allowed to
1041 : * probe.
1042 : */
1043 5 : mutex_lock(&fwnode_link_lock);
1044 10 : sup_fw = fwnode_links_check_suppliers(dev->fwnode);
1045 5 : if (sup_fw) {
1046 0 : if (!dev_is_best_effort(dev)) {
1047 0 : fwnode_ret = -EPROBE_DEFER;
1048 0 : dev_err_probe(dev, -EPROBE_DEFER,
1049 : "wait for supplier %pfwf\n", sup_fw);
1050 : } else {
1051 : fwnode_ret = -EAGAIN;
1052 : }
1053 : }
1054 5 : mutex_unlock(&fwnode_link_lock);
1055 5 : if (fwnode_ret == -EPROBE_DEFER)
1056 : return fwnode_ret;
1057 :
1058 : device_links_write_lock();
1059 :
1060 5 : list_for_each_entry(link, &dev->links.suppliers, c_node) {
1061 0 : if (!(link->flags & DL_FLAG_MANAGED))
1062 0 : continue;
1063 :
1064 0 : if (link->status != DL_STATE_AVAILABLE &&
1065 : !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
1066 :
1067 0 : if (dev_is_best_effort(dev) &&
1068 0 : link->flags & DL_FLAG_INFERRED &&
1069 0 : !link->supplier->can_match) {
1070 0 : ret = -EAGAIN;
1071 0 : continue;
1072 : }
1073 :
1074 0 : device_links_missing_supplier(dev);
1075 0 : dev_err_probe(dev, -EPROBE_DEFER,
1076 : "supplier %s not ready\n",
1077 0 : dev_name(link->supplier));
1078 0 : ret = -EPROBE_DEFER;
1079 0 : break;
1080 : }
1081 0 : WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
1082 : }
1083 5 : dev->links.status = DL_DEV_PROBING;
1084 :
1085 : device_links_write_unlock();
1086 :
1087 5 : return ret ? ret : fwnode_ret;
1088 : }
1089 :
1090 : /**
1091 : * __device_links_queue_sync_state - Queue a device for sync_state() callback
1092 : * @dev: Device to call sync_state() on
1093 : * @list: List head to queue the @dev on
1094 : *
1095 : * Queues a device for a sync_state() callback when the device links write lock
1096 : * isn't held. This allows the sync_state() execution flow to use device links
1097 : * APIs. The caller must ensure this function is called with
1098 : * device_links_write_lock() held.
1099 : *
1100 : * This function does a get_device() to make sure the device is not freed while
1101 : * on this list.
1102 : *
1103 : * So the caller must also ensure that device_links_flush_sync_list() is called
1104 : * as soon as the caller releases device_links_write_lock(). This is necessary
1105 : * to make sure the sync_state() is called in a timely fashion and the
1106 : * put_device() is called on this device.
1107 : */
1108 5 : static void __device_links_queue_sync_state(struct device *dev,
1109 : struct list_head *list)
1110 : {
1111 : struct device_link *link;
1112 :
1113 5 : if (!dev_has_sync_state(dev))
1114 : return;
1115 0 : if (dev->state_synced)
1116 : return;
1117 :
1118 0 : list_for_each_entry(link, &dev->links.consumers, s_node) {
1119 0 : if (!(link->flags & DL_FLAG_MANAGED))
1120 0 : continue;
1121 0 : if (link->status != DL_STATE_ACTIVE)
1122 : return;
1123 : }
1124 :
1125 : /*
1126 : * Set the flag here to avoid adding the same device to a list more
1127 : * than once. This can happen if new consumers get added to the device
1128 : * and probed before the list is flushed.
1129 : */
1130 0 : dev->state_synced = true;
1131 :
1132 0 : if (WARN_ON(!list_empty(&dev->links.defer_sync)))
1133 : return;
1134 :
1135 0 : get_device(dev);
1136 0 : list_add_tail(&dev->links.defer_sync, list);
1137 : }
1138 :
1139 : /**
1140 : * device_links_flush_sync_list - Call sync_state() on a list of devices
1141 : * @list: List of devices to call sync_state() on
1142 : * @dont_lock_dev: Device for which lock is already held by the caller
1143 : *
1144 : * Calls sync_state() on all the devices that have been queued for it. This
1145 : * function is used in conjunction with __device_links_queue_sync_state(). The
1146 : * @dont_lock_dev parameter is useful when this function is called from a
1147 : * context where a device lock is already held.
1148 : */
1149 7 : static void device_links_flush_sync_list(struct list_head *list,
1150 : struct device *dont_lock_dev)
1151 : {
1152 : struct device *dev, *tmp;
1153 :
1154 7 : list_for_each_entry_safe(dev, tmp, list, links.defer_sync) {
1155 0 : list_del_init(&dev->links.defer_sync);
1156 :
1157 0 : if (dev != dont_lock_dev)
1158 : device_lock(dev);
1159 :
1160 0 : dev_sync_state(dev);
1161 :
1162 0 : if (dev != dont_lock_dev)
1163 : device_unlock(dev);
1164 :
1165 0 : put_device(dev);
1166 : }
1167 7 : }
1168 :
1169 0 : void device_links_supplier_sync_state_pause(void)
1170 : {
1171 : device_links_write_lock();
1172 0 : defer_sync_state_count++;
1173 : device_links_write_unlock();
1174 0 : }
1175 :
1176 1 : void device_links_supplier_sync_state_resume(void)
1177 : {
1178 : struct device *dev, *tmp;
1179 1 : LIST_HEAD(sync_list);
1180 :
1181 : device_links_write_lock();
1182 1 : if (!defer_sync_state_count) {
1183 0 : WARN(true, "Unmatched sync_state pause/resume!");
1184 0 : goto out;
1185 : }
1186 1 : defer_sync_state_count--;
1187 1 : if (defer_sync_state_count)
1188 : goto out;
1189 :
1190 1 : list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) {
1191 : /*
1192 : * Delete from deferred_sync list before queuing it to
1193 : * sync_list because defer_sync is used for both lists.
1194 : */
1195 0 : list_del_init(&dev->links.defer_sync);
1196 0 : __device_links_queue_sync_state(dev, &sync_list);
1197 : }
1198 : out:
1199 : device_links_write_unlock();
1200 :
1201 1 : device_links_flush_sync_list(&sync_list, NULL);
1202 1 : }
1203 :
1204 1 : static int sync_state_resume_initcall(void)
1205 : {
1206 1 : device_links_supplier_sync_state_resume();
1207 1 : return 0;
1208 : }
1209 : late_initcall(sync_state_resume_initcall);
1210 :
1211 0 : static void __device_links_supplier_defer_sync(struct device *sup)
1212 : {
1213 0 : if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup))
1214 0 : list_add_tail(&sup->links.defer_sync, &deferred_sync);
1215 0 : }
1216 :
1217 : static void device_link_drop_managed(struct device_link *link)
1218 : {
1219 0 : link->flags &= ~DL_FLAG_MANAGED;
1220 0 : WRITE_ONCE(link->status, DL_STATE_NONE);
1221 0 : kref_put(&link->kref, __device_link_del);
1222 : }
1223 :
1224 0 : static ssize_t waiting_for_supplier_show(struct device *dev,
1225 : struct device_attribute *attr,
1226 : char *buf)
1227 : {
1228 : bool val;
1229 :
1230 0 : device_lock(dev);
1231 0 : mutex_lock(&fwnode_link_lock);
1232 0 : val = !!fwnode_links_check_suppliers(dev->fwnode);
1233 0 : mutex_unlock(&fwnode_link_lock);
1234 0 : device_unlock(dev);
1235 0 : return sysfs_emit(buf, "%u\n", val);
1236 : }
1237 : static DEVICE_ATTR_RO(waiting_for_supplier);
1238 :
1239 : /**
1240 : * device_links_force_bind - Prepares device to be force bound
1241 : * @dev: Consumer device.
1242 : *
1243 : * device_bind_driver() force binds a device to a driver without calling any
1244 : * driver probe functions. So the consumer really isn't going to wait for any
1245 : * supplier before it's bound to the driver. We still want the device link
1246 : * states to be sensible when this happens.
1247 : *
1248 : * In preparation for device_bind_driver(), this function goes through each
1249 : * supplier device links and checks if the supplier is bound. If it is, then
1250 : * the device link status is set to CONSUMER_PROBE. Otherwise, the device link
1251 : * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored.
1252 : */
1253 0 : void device_links_force_bind(struct device *dev)
1254 : {
1255 : struct device_link *link, *ln;
1256 :
1257 : device_links_write_lock();
1258 :
1259 0 : list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
1260 0 : if (!(link->flags & DL_FLAG_MANAGED))
1261 0 : continue;
1262 :
1263 0 : if (link->status != DL_STATE_AVAILABLE) {
1264 0 : device_link_drop_managed(link);
1265 0 : continue;
1266 : }
1267 0 : WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
1268 : }
1269 0 : dev->links.status = DL_DEV_PROBING;
1270 :
1271 : device_links_write_unlock();
1272 0 : }
1273 :
1274 : /**
1275 : * device_links_driver_bound - Update device links after probing its driver.
1276 : * @dev: Device to update the links for.
1277 : *
1278 : * The probe has been successful, so update links from this device to any
1279 : * consumers by changing their status to "available".
1280 : *
1281 : * Also change the status of @dev's links to suppliers to "active".
1282 : *
1283 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1284 : */
1285 5 : void device_links_driver_bound(struct device *dev)
1286 : {
1287 : struct device_link *link, *ln;
1288 5 : LIST_HEAD(sync_list);
1289 :
1290 : /*
1291 : * If a device binds successfully, it's expected to have created all
1292 : * the device links it needs to or make new device links as it needs
1293 : * them. So, fw_devlink no longer needs to create device links to any
1294 : * of the device's suppliers.
1295 : *
1296 : * Also, if a child firmware node of this bound device is not added as a
1297 : * device by now, assume it is never going to be added. Make this bound
1298 : * device the fallback supplier to the dangling consumers of the child
1299 : * firmware node because this bound device is probably implementing the
1300 : * child firmware node functionality and we don't want the dangling
1301 : * consumers to defer probe indefinitely waiting for a device for the
1302 : * child firmware node.
1303 : */
1304 5 : if (dev->fwnode && dev->fwnode->dev == dev) {
1305 : struct fwnode_handle *child;
1306 0 : fwnode_links_purge_suppliers(dev->fwnode);
1307 0 : mutex_lock(&fwnode_link_lock);
1308 0 : fwnode_for_each_available_child_node(dev->fwnode, child)
1309 0 : __fw_devlink_pickup_dangling_consumers(child,
1310 : dev->fwnode);
1311 0 : __fw_devlink_link_to_consumers(dev);
1312 0 : mutex_unlock(&fwnode_link_lock);
1313 : }
1314 5 : device_remove_file(dev, &dev_attr_waiting_for_supplier);
1315 :
1316 : device_links_write_lock();
1317 :
1318 5 : list_for_each_entry(link, &dev->links.consumers, s_node) {
1319 0 : if (!(link->flags & DL_FLAG_MANAGED))
1320 0 : continue;
1321 :
1322 : /*
1323 : * Links created during consumer probe may be in the "consumer
1324 : * probe" state to start with if the supplier is still probing
1325 : * when they are created and they may become "active" if the
1326 : * consumer probe returns first. Skip them here.
1327 : */
1328 0 : if (link->status == DL_STATE_CONSUMER_PROBE ||
1329 : link->status == DL_STATE_ACTIVE)
1330 0 : continue;
1331 :
1332 0 : WARN_ON(link->status != DL_STATE_DORMANT);
1333 0 : WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
1334 :
1335 0 : if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
1336 0 : driver_deferred_probe_add(link->consumer);
1337 : }
1338 :
1339 5 : if (defer_sync_state_count)
1340 0 : __device_links_supplier_defer_sync(dev);
1341 : else
1342 5 : __device_links_queue_sync_state(dev, &sync_list);
1343 :
1344 5 : list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
1345 : struct device *supplier;
1346 :
1347 0 : if (!(link->flags & DL_FLAG_MANAGED))
1348 0 : continue;
1349 :
1350 0 : supplier = link->supplier;
1351 0 : if (link->flags & DL_FLAG_SYNC_STATE_ONLY) {
1352 : /*
1353 : * When DL_FLAG_SYNC_STATE_ONLY is set, it means no
1354 : * other DL_MANAGED_LINK_FLAGS have been set. So, it's
1355 : * save to drop the managed link completely.
1356 : */
1357 : device_link_drop_managed(link);
1358 0 : } else if (dev_is_best_effort(dev) &&
1359 0 : link->flags & DL_FLAG_INFERRED &&
1360 0 : link->status != DL_STATE_CONSUMER_PROBE &&
1361 0 : !link->supplier->can_match) {
1362 : /*
1363 : * When dev_is_best_effort() is true, we ignore device
1364 : * links to suppliers that don't have a driver. If the
1365 : * consumer device still managed to probe, there's no
1366 : * point in maintaining a device link in a weird state
1367 : * (consumer probed before supplier). So delete it.
1368 : */
1369 : device_link_drop_managed(link);
1370 : } else {
1371 0 : WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
1372 0 : WRITE_ONCE(link->status, DL_STATE_ACTIVE);
1373 : }
1374 :
1375 : /*
1376 : * This needs to be done even for the deleted
1377 : * DL_FLAG_SYNC_STATE_ONLY device link in case it was the last
1378 : * device link that was preventing the supplier from getting a
1379 : * sync_state() call.
1380 : */
1381 0 : if (defer_sync_state_count)
1382 0 : __device_links_supplier_defer_sync(supplier);
1383 : else
1384 0 : __device_links_queue_sync_state(supplier, &sync_list);
1385 : }
1386 :
1387 5 : dev->links.status = DL_DEV_DRIVER_BOUND;
1388 :
1389 : device_links_write_unlock();
1390 :
1391 5 : device_links_flush_sync_list(&sync_list, dev);
1392 5 : }
1393 :
1394 : /**
1395 : * __device_links_no_driver - Update links of a device without a driver.
1396 : * @dev: Device without a drvier.
1397 : *
1398 : * Delete all non-persistent links from this device to any suppliers.
1399 : *
1400 : * Persistent links stay around, but their status is changed to "available",
1401 : * unless they already are in the "supplier unbind in progress" state in which
1402 : * case they need not be updated.
1403 : *
1404 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1405 : */
1406 5 : static void __device_links_no_driver(struct device *dev)
1407 : {
1408 : struct device_link *link, *ln;
1409 :
1410 5 : list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
1411 0 : if (!(link->flags & DL_FLAG_MANAGED))
1412 0 : continue;
1413 :
1414 0 : if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
1415 0 : device_link_drop_managed(link);
1416 0 : continue;
1417 : }
1418 :
1419 0 : if (link->status != DL_STATE_CONSUMER_PROBE &&
1420 : link->status != DL_STATE_ACTIVE)
1421 0 : continue;
1422 :
1423 0 : if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
1424 0 : WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
1425 : } else {
1426 0 : WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
1427 0 : WRITE_ONCE(link->status, DL_STATE_DORMANT);
1428 : }
1429 : }
1430 :
1431 5 : dev->links.status = DL_DEV_NO_DRIVER;
1432 5 : }
1433 :
1434 : /**
1435 : * device_links_no_driver - Update links after failing driver probe.
1436 : * @dev: Device whose driver has just failed to probe.
1437 : *
1438 : * Clean up leftover links to consumers for @dev and invoke
1439 : * %__device_links_no_driver() to update links to suppliers for it as
1440 : * appropriate.
1441 : *
1442 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1443 : */
1444 0 : void device_links_no_driver(struct device *dev)
1445 : {
1446 : struct device_link *link;
1447 :
1448 : device_links_write_lock();
1449 :
1450 0 : list_for_each_entry(link, &dev->links.consumers, s_node) {
1451 0 : if (!(link->flags & DL_FLAG_MANAGED))
1452 0 : continue;
1453 :
1454 : /*
1455 : * The probe has failed, so if the status of the link is
1456 : * "consumer probe" or "active", it must have been added by
1457 : * a probing consumer while this device was still probing.
1458 : * Change its state to "dormant", as it represents a valid
1459 : * relationship, but it is not functionally meaningful.
1460 : */
1461 0 : if (link->status == DL_STATE_CONSUMER_PROBE ||
1462 : link->status == DL_STATE_ACTIVE)
1463 0 : WRITE_ONCE(link->status, DL_STATE_DORMANT);
1464 : }
1465 :
1466 0 : __device_links_no_driver(dev);
1467 :
1468 : device_links_write_unlock();
1469 0 : }
1470 :
1471 : /**
1472 : * device_links_driver_cleanup - Update links after driver removal.
1473 : * @dev: Device whose driver has just gone away.
1474 : *
1475 : * Update links to consumers for @dev by changing their status to "dormant" and
1476 : * invoke %__device_links_no_driver() to update links to suppliers for it as
1477 : * appropriate.
1478 : *
1479 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1480 : */
1481 5 : void device_links_driver_cleanup(struct device *dev)
1482 : {
1483 : struct device_link *link, *ln;
1484 :
1485 : device_links_write_lock();
1486 :
1487 5 : list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) {
1488 0 : if (!(link->flags & DL_FLAG_MANAGED))
1489 0 : continue;
1490 :
1491 0 : WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);
1492 0 : WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
1493 :
1494 : /*
1495 : * autoremove the links between this @dev and its consumer
1496 : * devices that are not active, i.e. where the link state
1497 : * has moved to DL_STATE_SUPPLIER_UNBIND.
1498 : */
1499 0 : if (link->status == DL_STATE_SUPPLIER_UNBIND &&
1500 0 : link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
1501 : device_link_drop_managed(link);
1502 :
1503 0 : WRITE_ONCE(link->status, DL_STATE_DORMANT);
1504 : }
1505 :
1506 10 : list_del_init(&dev->links.defer_sync);
1507 5 : __device_links_no_driver(dev);
1508 :
1509 : device_links_write_unlock();
1510 5 : }
1511 :
1512 : /**
1513 : * device_links_busy - Check if there are any busy links to consumers.
1514 : * @dev: Device to check.
1515 : *
1516 : * Check each consumer of the device and return 'true' if its link's status
1517 : * is one of "consumer probe" or "active" (meaning that the given consumer is
1518 : * probing right now or its driver is present). Otherwise, change the link
1519 : * state to "supplier unbind" to prevent the consumer from being probed
1520 : * successfully going forward.
1521 : *
1522 : * Return 'false' if there are no probing or active consumers.
1523 : *
1524 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1525 : */
1526 5 : bool device_links_busy(struct device *dev)
1527 : {
1528 : struct device_link *link;
1529 5 : bool ret = false;
1530 :
1531 : device_links_write_lock();
1532 :
1533 5 : list_for_each_entry(link, &dev->links.consumers, s_node) {
1534 0 : if (!(link->flags & DL_FLAG_MANAGED))
1535 0 : continue;
1536 :
1537 0 : if (link->status == DL_STATE_CONSUMER_PROBE
1538 0 : || link->status == DL_STATE_ACTIVE) {
1539 : ret = true;
1540 : break;
1541 : }
1542 0 : WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
1543 : }
1544 :
1545 5 : dev->links.status = DL_DEV_UNBINDING;
1546 :
1547 : device_links_write_unlock();
1548 5 : return ret;
1549 : }
1550 :
1551 : /**
1552 : * device_links_unbind_consumers - Force unbind consumers of the given device.
1553 : * @dev: Device to unbind the consumers of.
1554 : *
1555 : * Walk the list of links to consumers for @dev and if any of them is in the
1556 : * "consumer probe" state, wait for all device probes in progress to complete
1557 : * and start over.
1558 : *
1559 : * If that's not the case, change the status of the link to "supplier unbind"
1560 : * and check if the link was in the "active" state. If so, force the consumer
1561 : * driver to unbind and start over (the consumer will not re-probe as we have
1562 : * changed the state of the link already).
1563 : *
1564 : * Links without the DL_FLAG_MANAGED flag set are ignored.
1565 : */
1566 0 : void device_links_unbind_consumers(struct device *dev)
1567 : {
1568 : struct device_link *link;
1569 :
1570 : start:
1571 : device_links_write_lock();
1572 :
1573 0 : list_for_each_entry(link, &dev->links.consumers, s_node) {
1574 : enum device_link_state status;
1575 :
1576 0 : if (!(link->flags & DL_FLAG_MANAGED) ||
1577 : link->flags & DL_FLAG_SYNC_STATE_ONLY)
1578 0 : continue;
1579 :
1580 0 : status = link->status;
1581 0 : if (status == DL_STATE_CONSUMER_PROBE) {
1582 : device_links_write_unlock();
1583 :
1584 0 : wait_for_device_probe();
1585 0 : goto start;
1586 : }
1587 0 : WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
1588 0 : if (status == DL_STATE_ACTIVE) {
1589 0 : struct device *consumer = link->consumer;
1590 :
1591 0 : get_device(consumer);
1592 :
1593 : device_links_write_unlock();
1594 :
1595 0 : device_release_driver_internal(consumer, NULL,
1596 : consumer->parent);
1597 : put_device(consumer);
1598 : goto start;
1599 : }
1600 : }
1601 :
1602 : device_links_write_unlock();
1603 0 : }
1604 :
1605 : /**
1606 : * device_links_purge - Delete existing links to other devices.
1607 : * @dev: Target device.
1608 : */
1609 5 : static void device_links_purge(struct device *dev)
1610 : {
1611 : struct device_link *link, *ln;
1612 :
1613 5 : if (dev->class == &devlink_class)
1614 : return;
1615 :
1616 : /*
1617 : * Delete all of the remaining links from this device to any other
1618 : * devices (either consumers or suppliers).
1619 : */
1620 : device_links_write_lock();
1621 :
1622 5 : list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
1623 0 : WARN_ON(link->status == DL_STATE_ACTIVE);
1624 0 : __device_link_del(&link->kref);
1625 : }
1626 :
1627 5 : list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
1628 0 : WARN_ON(link->status != DL_STATE_DORMANT &&
1629 : link->status != DL_STATE_NONE);
1630 0 : __device_link_del(&link->kref);
1631 : }
1632 :
1633 : device_links_write_unlock();
1634 : }
1635 :
1636 : #define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \
1637 : DL_FLAG_SYNC_STATE_ONLY)
1638 : #define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \
1639 : DL_FLAG_AUTOPROBE_CONSUMER)
1640 : #define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \
1641 : DL_FLAG_PM_RUNTIME)
1642 :
1643 : static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
1644 0 : static int __init fw_devlink_setup(char *arg)
1645 : {
1646 0 : if (!arg)
1647 : return -EINVAL;
1648 :
1649 0 : if (strcmp(arg, "off") == 0) {
1650 0 : fw_devlink_flags = 0;
1651 0 : } else if (strcmp(arg, "permissive") == 0) {
1652 0 : fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
1653 0 : } else if (strcmp(arg, "on") == 0) {
1654 0 : fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
1655 0 : } else if (strcmp(arg, "rpm") == 0) {
1656 0 : fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
1657 : }
1658 : return 0;
1659 : }
1660 : early_param("fw_devlink", fw_devlink_setup);
1661 :
1662 : static bool fw_devlink_strict;
1663 0 : static int __init fw_devlink_strict_setup(char *arg)
1664 : {
1665 0 : return kstrtobool(arg, &fw_devlink_strict);
1666 : }
1667 : early_param("fw_devlink.strict", fw_devlink_strict_setup);
1668 :
1669 : #define FW_DEVLINK_SYNC_STATE_STRICT 0
1670 : #define FW_DEVLINK_SYNC_STATE_TIMEOUT 1
1671 :
1672 : #ifndef CONFIG_FW_DEVLINK_SYNC_STATE_TIMEOUT
1673 : static int fw_devlink_sync_state;
1674 : #else
1675 : static int fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_TIMEOUT;
1676 : #endif
1677 :
1678 0 : static int __init fw_devlink_sync_state_setup(char *arg)
1679 : {
1680 0 : if (!arg)
1681 : return -EINVAL;
1682 :
1683 0 : if (strcmp(arg, "strict") == 0) {
1684 0 : fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_STRICT;
1685 0 : return 0;
1686 0 : } else if (strcmp(arg, "timeout") == 0) {
1687 0 : fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_TIMEOUT;
1688 0 : return 0;
1689 : }
1690 : return -EINVAL;
1691 : }
1692 : early_param("fw_devlink.sync_state", fw_devlink_sync_state_setup);
1693 :
1694 : static inline u32 fw_devlink_get_flags(u8 fwlink_flags)
1695 : {
1696 0 : if (fwlink_flags & FWLINK_FLAG_CYCLE)
1697 : return FW_DEVLINK_FLAGS_PERMISSIVE | DL_FLAG_CYCLE;
1698 :
1699 0 : return fw_devlink_flags;
1700 : }
1701 :
1702 : static bool fw_devlink_is_permissive(void)
1703 : {
1704 0 : return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE;
1705 : }
1706 :
1707 0 : bool fw_devlink_is_strict(void)
1708 : {
1709 0 : return fw_devlink_strict && !fw_devlink_is_permissive();
1710 : }
1711 :
1712 0 : static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
1713 : {
1714 0 : if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED)
1715 : return;
1716 :
1717 0 : fwnode_call_int_op(fwnode, add_links);
1718 0 : fwnode->flags |= FWNODE_FLAG_LINKS_ADDED;
1719 : }
1720 :
1721 0 : static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
1722 : {
1723 0 : struct fwnode_handle *child = NULL;
1724 :
1725 0 : fw_devlink_parse_fwnode(fwnode);
1726 :
1727 0 : while ((child = fwnode_get_next_available_child_node(fwnode, child)))
1728 0 : fw_devlink_parse_fwtree(child);
1729 0 : }
1730 :
1731 : static void fw_devlink_relax_link(struct device_link *link)
1732 : {
1733 0 : if (!(link->flags & DL_FLAG_INFERRED))
1734 : return;
1735 :
1736 0 : if (device_link_flag_is_sync_state_only(link->flags))
1737 : return;
1738 :
1739 0 : pm_runtime_drop_link(link);
1740 0 : link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
1741 : dev_dbg(link->consumer, "Relaxing link with %s\n",
1742 : dev_name(link->supplier));
1743 : }
1744 :
1745 0 : static int fw_devlink_no_driver(struct device *dev, void *data)
1746 : {
1747 0 : struct device_link *link = to_devlink(dev);
1748 :
1749 0 : if (!link->supplier->can_match)
1750 : fw_devlink_relax_link(link);
1751 :
1752 0 : return 0;
1753 : }
1754 :
1755 1 : void fw_devlink_drivers_done(void)
1756 : {
1757 1 : fw_devlink_drv_reg_done = true;
1758 : device_links_write_lock();
1759 1 : class_for_each_device(&devlink_class, NULL, NULL,
1760 : fw_devlink_no_driver);
1761 : device_links_write_unlock();
1762 1 : }
1763 :
1764 0 : static int fw_devlink_dev_sync_state(struct device *dev, void *data)
1765 : {
1766 0 : struct device_link *link = to_devlink(dev);
1767 0 : struct device *sup = link->supplier;
1768 :
1769 0 : if (!(link->flags & DL_FLAG_MANAGED) ||
1770 0 : link->status == DL_STATE_ACTIVE || sup->state_synced ||
1771 0 : !dev_has_sync_state(sup))
1772 : return 0;
1773 :
1774 0 : if (fw_devlink_sync_state == FW_DEVLINK_SYNC_STATE_STRICT) {
1775 0 : dev_warn(sup, "sync_state() pending due to %s\n",
1776 : dev_name(link->consumer));
1777 0 : return 0;
1778 : }
1779 :
1780 0 : if (!list_empty(&sup->links.defer_sync))
1781 : return 0;
1782 :
1783 0 : dev_warn(sup, "Timed out. Forcing sync_state()\n");
1784 0 : sup->state_synced = true;
1785 0 : get_device(sup);
1786 0 : list_add_tail(&sup->links.defer_sync, data);
1787 :
1788 0 : return 0;
1789 : }
1790 :
1791 1 : void fw_devlink_probing_done(void)
1792 : {
1793 1 : LIST_HEAD(sync_list);
1794 :
1795 : device_links_write_lock();
1796 1 : class_for_each_device(&devlink_class, NULL, &sync_list,
1797 : fw_devlink_dev_sync_state);
1798 : device_links_write_unlock();
1799 1 : device_links_flush_sync_list(&sync_list, NULL);
1800 1 : }
1801 :
1802 : /**
1803 : * wait_for_init_devices_probe - Try to probe any device needed for init
1804 : *
1805 : * Some devices might need to be probed and bound successfully before the kernel
1806 : * boot sequence can finish and move on to init/userspace. For example, a
1807 : * network interface might need to be bound to be able to mount a NFS rootfs.
1808 : *
1809 : * With fw_devlink=on by default, some of these devices might be blocked from
1810 : * probing because they are waiting on a optional supplier that doesn't have a
1811 : * driver. While fw_devlink will eventually identify such devices and unblock
1812 : * the probing automatically, it might be too late by the time it unblocks the
1813 : * probing of devices. For example, the IP4 autoconfig might timeout before
1814 : * fw_devlink unblocks probing of the network interface.
1815 : *
1816 : * This function is available to temporarily try and probe all devices that have
1817 : * a driver even if some of their suppliers haven't been added or don't have
1818 : * drivers.
1819 : *
1820 : * The drivers can then decide which of the suppliers are optional vs mandatory
1821 : * and probe the device if possible. By the time this function returns, all such
1822 : * "best effort" probes are guaranteed to be completed. If a device successfully
1823 : * probes in this mode, we delete all fw_devlink discovered dependencies of that
1824 : * device where the supplier hasn't yet probed successfully because they have to
1825 : * be optional dependencies.
1826 : *
1827 : * Any devices that didn't successfully probe go back to being treated as if
1828 : * this function was never called.
1829 : *
1830 : * This also means that some devices that aren't needed for init and could have
1831 : * waited for their optional supplier to probe (when the supplier's module is
1832 : * loaded later on) would end up probing prematurely with limited functionality.
1833 : * So call this function only when boot would fail without it.
1834 : */
1835 0 : void __init wait_for_init_devices_probe(void)
1836 : {
1837 0 : if (!fw_devlink_flags || fw_devlink_is_permissive())
1838 : return;
1839 :
1840 : /*
1841 : * Wait for all ongoing probes to finish so that the "best effort" is
1842 : * only applied to devices that can't probe otherwise.
1843 : */
1844 0 : wait_for_device_probe();
1845 :
1846 0 : pr_info("Trying to probe devices needed for running init ...\n");
1847 0 : fw_devlink_best_effort = true;
1848 0 : driver_deferred_probe_trigger();
1849 :
1850 : /*
1851 : * Wait for all "best effort" probes to finish before going back to
1852 : * normal enforcement.
1853 : */
1854 0 : wait_for_device_probe();
1855 0 : fw_devlink_best_effort = false;
1856 : }
1857 :
1858 0 : static void fw_devlink_unblock_consumers(struct device *dev)
1859 : {
1860 : struct device_link *link;
1861 :
1862 0 : if (!fw_devlink_flags || fw_devlink_is_permissive())
1863 : return;
1864 :
1865 : device_links_write_lock();
1866 0 : list_for_each_entry(link, &dev->links.consumers, s_node)
1867 0 : fw_devlink_relax_link(link);
1868 : device_links_write_unlock();
1869 : }
1870 :
1871 :
1872 0 : static bool fwnode_init_without_drv(struct fwnode_handle *fwnode)
1873 : {
1874 : struct device *dev;
1875 : bool ret;
1876 :
1877 0 : if (!(fwnode->flags & FWNODE_FLAG_INITIALIZED))
1878 : return false;
1879 :
1880 0 : dev = get_dev_from_fwnode(fwnode);
1881 0 : ret = !dev || dev->links.status == DL_DEV_NO_DRIVER;
1882 : put_device(dev);
1883 :
1884 : return ret;
1885 : }
1886 :
1887 0 : static bool fwnode_ancestor_init_without_drv(struct fwnode_handle *fwnode)
1888 : {
1889 : struct fwnode_handle *parent;
1890 :
1891 0 : fwnode_for_each_parent_node(fwnode, parent) {
1892 0 : if (fwnode_init_without_drv(parent)) {
1893 0 : fwnode_handle_put(parent);
1894 0 : return true;
1895 : }
1896 : }
1897 :
1898 : return false;
1899 : }
1900 :
1901 : /**
1902 : * __fw_devlink_relax_cycles - Relax and mark dependency cycles.
1903 : * @con: Potential consumer device.
1904 : * @sup_handle: Potential supplier's fwnode.
1905 : *
1906 : * Needs to be called with fwnode_lock and device link lock held.
1907 : *
1908 : * Check if @sup_handle or any of its ancestors or suppliers direct/indirectly
1909 : * depend on @con. This function can detect multiple cyles between @sup_handle
1910 : * and @con. When such dependency cycles are found, convert all device links
1911 : * created solely by fw_devlink into SYNC_STATE_ONLY device links. Also, mark
1912 : * all fwnode links in the cycle with FWLINK_FLAG_CYCLE so that when they are
1913 : * converted into a device link in the future, they are created as
1914 : * SYNC_STATE_ONLY device links. This is the equivalent of doing
1915 : * fw_devlink=permissive just between the devices in the cycle. We need to do
1916 : * this because, at this point, fw_devlink can't tell which of these
1917 : * dependencies is not a real dependency.
1918 : *
1919 : * Return true if one or more cycles were found. Otherwise, return false.
1920 : */
1921 0 : static bool __fw_devlink_relax_cycles(struct device *con,
1922 : struct fwnode_handle *sup_handle)
1923 : {
1924 0 : struct device *sup_dev = NULL, *par_dev = NULL;
1925 : struct fwnode_link *link;
1926 : struct device_link *dev_link;
1927 0 : bool ret = false;
1928 :
1929 0 : if (!sup_handle)
1930 : return false;
1931 :
1932 : /*
1933 : * We aren't trying to find all cycles. Just a cycle between con and
1934 : * sup_handle.
1935 : */
1936 0 : if (sup_handle->flags & FWNODE_FLAG_VISITED)
1937 : return false;
1938 :
1939 0 : sup_handle->flags |= FWNODE_FLAG_VISITED;
1940 :
1941 0 : sup_dev = get_dev_from_fwnode(sup_handle);
1942 :
1943 : /* Termination condition. */
1944 0 : if (sup_dev == con) {
1945 : ret = true;
1946 : goto out;
1947 : }
1948 :
1949 : /*
1950 : * If sup_dev is bound to a driver and @con hasn't started binding to a
1951 : * driver, sup_dev can't be a consumer of @con. So, no need to check
1952 : * further.
1953 : */
1954 0 : if (sup_dev && sup_dev->links.status == DL_DEV_DRIVER_BOUND &&
1955 0 : con->links.status == DL_DEV_NO_DRIVER) {
1956 : ret = false;
1957 : goto out;
1958 : }
1959 :
1960 0 : list_for_each_entry(link, &sup_handle->suppliers, c_hook) {
1961 0 : if (__fw_devlink_relax_cycles(con, link->supplier)) {
1962 0 : __fwnode_link_cycle(link);
1963 0 : ret = true;
1964 : }
1965 : }
1966 :
1967 : /*
1968 : * Give priority to device parent over fwnode parent to account for any
1969 : * quirks in how fwnodes are converted to devices.
1970 : */
1971 0 : if (sup_dev)
1972 0 : par_dev = get_device(sup_dev->parent);
1973 : else
1974 0 : par_dev = fwnode_get_next_parent_dev(sup_handle);
1975 :
1976 0 : if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode))
1977 0 : ret = true;
1978 :
1979 0 : if (!sup_dev)
1980 : goto out;
1981 :
1982 0 : list_for_each_entry(dev_link, &sup_dev->links.suppliers, c_node) {
1983 : /*
1984 : * Ignore a SYNC_STATE_ONLY flag only if it wasn't marked as
1985 : * such due to a cycle.
1986 : */
1987 0 : if (device_link_flag_is_sync_state_only(dev_link->flags) &&
1988 : !(dev_link->flags & DL_FLAG_CYCLE))
1989 0 : continue;
1990 :
1991 0 : if (__fw_devlink_relax_cycles(con,
1992 0 : dev_link->supplier->fwnode)) {
1993 0 : fw_devlink_relax_link(dev_link);
1994 0 : dev_link->flags |= DL_FLAG_CYCLE;
1995 0 : ret = true;
1996 : }
1997 : }
1998 :
1999 : out:
2000 0 : sup_handle->flags &= ~FWNODE_FLAG_VISITED;
2001 0 : put_device(sup_dev);
2002 : put_device(par_dev);
2003 : return ret;
2004 : }
2005 :
2006 : /**
2007 : * fw_devlink_create_devlink - Create a device link from a consumer to fwnode
2008 : * @con: consumer device for the device link
2009 : * @sup_handle: fwnode handle of supplier
2010 : * @link: fwnode link that's being converted to a device link
2011 : *
2012 : * This function will try to create a device link between the consumer device
2013 : * @con and the supplier device represented by @sup_handle.
2014 : *
2015 : * The supplier has to be provided as a fwnode because incorrect cycles in
2016 : * fwnode links can sometimes cause the supplier device to never be created.
2017 : * This function detects such cases and returns an error if it cannot create a
2018 : * device link from the consumer to a missing supplier.
2019 : *
2020 : * Returns,
2021 : * 0 on successfully creating a device link
2022 : * -EINVAL if the device link cannot be created as expected
2023 : * -EAGAIN if the device link cannot be created right now, but it may be
2024 : * possible to do that in the future
2025 : */
2026 0 : static int fw_devlink_create_devlink(struct device *con,
2027 : struct fwnode_handle *sup_handle,
2028 : struct fwnode_link *link)
2029 : {
2030 : struct device *sup_dev;
2031 0 : int ret = 0;
2032 : u32 flags;
2033 :
2034 0 : if (con->fwnode == link->consumer)
2035 0 : flags = fw_devlink_get_flags(link->flags);
2036 : else
2037 : flags = FW_DEVLINK_FLAGS_PERMISSIVE;
2038 :
2039 : /*
2040 : * In some cases, a device P might also be a supplier to its child node
2041 : * C. However, this would defer the probe of C until the probe of P
2042 : * completes successfully. This is perfectly fine in the device driver
2043 : * model. device_add() doesn't guarantee probe completion of the device
2044 : * by the time it returns.
2045 : *
2046 : * However, there are a few drivers that assume C will finish probing
2047 : * as soon as it's added and before P finishes probing. So, we provide
2048 : * a flag to let fw_devlink know not to delay the probe of C until the
2049 : * probe of P completes successfully.
2050 : *
2051 : * When such a flag is set, we can't create device links where P is the
2052 : * supplier of C as that would delay the probe of C.
2053 : */
2054 0 : if (sup_handle->flags & FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD &&
2055 0 : fwnode_is_ancestor_of(sup_handle, con->fwnode))
2056 : return -EINVAL;
2057 :
2058 : /*
2059 : * SYNC_STATE_ONLY device links don't block probing and supports cycles.
2060 : * So cycle detection isn't necessary and shouldn't be done.
2061 : */
2062 0 : if (!(flags & DL_FLAG_SYNC_STATE_ONLY)) {
2063 : device_links_write_lock();
2064 0 : if (__fw_devlink_relax_cycles(con, sup_handle)) {
2065 0 : __fwnode_link_cycle(link);
2066 0 : flags = fw_devlink_get_flags(link->flags);
2067 0 : dev_info(con, "Fixed dependency cycle(s) with %pfwf\n",
2068 : sup_handle);
2069 : }
2070 : device_links_write_unlock();
2071 : }
2072 :
2073 0 : if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE)
2074 0 : sup_dev = fwnode_get_next_parent_dev(sup_handle);
2075 : else
2076 0 : sup_dev = get_dev_from_fwnode(sup_handle);
2077 :
2078 0 : if (sup_dev) {
2079 : /*
2080 : * If it's one of those drivers that don't actually bind to
2081 : * their device using driver core, then don't wait on this
2082 : * supplier device indefinitely.
2083 : */
2084 0 : if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
2085 0 : sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
2086 : dev_dbg(con,
2087 : "Not linking %pfwf - dev might never probe\n",
2088 : sup_handle);
2089 : ret = -EINVAL;
2090 : goto out;
2091 : }
2092 :
2093 0 : if (con != sup_dev && !device_link_add(con, sup_dev, flags)) {
2094 0 : dev_err(con, "Failed to create device link (0x%x) with %s\n",
2095 : flags, dev_name(sup_dev));
2096 0 : ret = -EINVAL;
2097 : }
2098 :
2099 : goto out;
2100 : }
2101 :
2102 : /*
2103 : * Supplier or supplier's ancestor already initialized without a struct
2104 : * device or being probed by a driver.
2105 : */
2106 0 : if (fwnode_init_without_drv(sup_handle) ||
2107 0 : fwnode_ancestor_init_without_drv(sup_handle)) {
2108 : dev_dbg(con, "Not linking %pfwf - might never become dev\n",
2109 : sup_handle);
2110 : return -EINVAL;
2111 : }
2112 :
2113 : ret = -EAGAIN;
2114 : out:
2115 : put_device(sup_dev);
2116 : return ret;
2117 : }
2118 :
2119 : /**
2120 : * __fw_devlink_link_to_consumers - Create device links to consumers of a device
2121 : * @dev: Device that needs to be linked to its consumers
2122 : *
2123 : * This function looks at all the consumer fwnodes of @dev and creates device
2124 : * links between the consumer device and @dev (supplier).
2125 : *
2126 : * If the consumer device has not been added yet, then this function creates a
2127 : * SYNC_STATE_ONLY link between @dev (supplier) and the closest ancestor device
2128 : * of the consumer fwnode. This is necessary to make sure @dev doesn't get a
2129 : * sync_state() callback before the real consumer device gets to be added and
2130 : * then probed.
2131 : *
2132 : * Once device links are created from the real consumer to @dev (supplier), the
2133 : * fwnode links are deleted.
2134 : */
2135 0 : static void __fw_devlink_link_to_consumers(struct device *dev)
2136 : {
2137 0 : struct fwnode_handle *fwnode = dev->fwnode;
2138 : struct fwnode_link *link, *tmp;
2139 :
2140 0 : list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
2141 : struct device *con_dev;
2142 0 : bool own_link = true;
2143 : int ret;
2144 :
2145 0 : con_dev = get_dev_from_fwnode(link->consumer);
2146 : /*
2147 : * If consumer device is not available yet, make a "proxy"
2148 : * SYNC_STATE_ONLY link from the consumer's parent device to
2149 : * the supplier device. This is necessary to make sure the
2150 : * supplier doesn't get a sync_state() callback before the real
2151 : * consumer can create a device link to the supplier.
2152 : *
2153 : * This proxy link step is needed to handle the case where the
2154 : * consumer's parent device is added before the supplier.
2155 : */
2156 0 : if (!con_dev) {
2157 0 : con_dev = fwnode_get_next_parent_dev(link->consumer);
2158 : /*
2159 : * However, if the consumer's parent device is also the
2160 : * parent of the supplier, don't create a
2161 : * consumer-supplier link from the parent to its child
2162 : * device. Such a dependency is impossible.
2163 : */
2164 0 : if (con_dev &&
2165 0 : fwnode_is_ancestor_of(con_dev->fwnode, fwnode)) {
2166 0 : put_device(con_dev);
2167 0 : con_dev = NULL;
2168 : } else {
2169 : own_link = false;
2170 : }
2171 : }
2172 :
2173 0 : if (!con_dev)
2174 0 : continue;
2175 :
2176 0 : ret = fw_devlink_create_devlink(con_dev, fwnode, link);
2177 0 : put_device(con_dev);
2178 0 : if (!own_link || ret == -EAGAIN)
2179 0 : continue;
2180 :
2181 0 : __fwnode_link_del(link);
2182 : }
2183 0 : }
2184 :
2185 : /**
2186 : * __fw_devlink_link_to_suppliers - Create device links to suppliers of a device
2187 : * @dev: The consumer device that needs to be linked to its suppliers
2188 : * @fwnode: Root of the fwnode tree that is used to create device links
2189 : *
2190 : * This function looks at all the supplier fwnodes of fwnode tree rooted at
2191 : * @fwnode and creates device links between @dev (consumer) and all the
2192 : * supplier devices of the entire fwnode tree at @fwnode.
2193 : *
2194 : * The function creates normal (non-SYNC_STATE_ONLY) device links between @dev
2195 : * and the real suppliers of @dev. Once these device links are created, the
2196 : * fwnode links are deleted.
2197 : *
2198 : * In addition, it also looks at all the suppliers of the entire fwnode tree
2199 : * because some of the child devices of @dev that have not been added yet
2200 : * (because @dev hasn't probed) might already have their suppliers added to
2201 : * driver core. So, this function creates SYNC_STATE_ONLY device links between
2202 : * @dev (consumer) and these suppliers to make sure they don't execute their
2203 : * sync_state() callbacks before these child devices have a chance to create
2204 : * their device links. The fwnode links that correspond to the child devices
2205 : * aren't delete because they are needed later to create the device links
2206 : * between the real consumer and supplier devices.
2207 : */
2208 0 : static void __fw_devlink_link_to_suppliers(struct device *dev,
2209 : struct fwnode_handle *fwnode)
2210 : {
2211 0 : bool own_link = (dev->fwnode == fwnode);
2212 : struct fwnode_link *link, *tmp;
2213 0 : struct fwnode_handle *child = NULL;
2214 :
2215 0 : list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
2216 : int ret;
2217 0 : struct fwnode_handle *sup = link->supplier;
2218 :
2219 0 : ret = fw_devlink_create_devlink(dev, sup, link);
2220 0 : if (!own_link || ret == -EAGAIN)
2221 0 : continue;
2222 :
2223 0 : __fwnode_link_del(link);
2224 : }
2225 :
2226 : /*
2227 : * Make "proxy" SYNC_STATE_ONLY device links to represent the needs of
2228 : * all the descendants. This proxy link step is needed to handle the
2229 : * case where the supplier is added before the consumer's parent device
2230 : * (@dev).
2231 : */
2232 0 : while ((child = fwnode_get_next_available_child_node(fwnode, child)))
2233 0 : __fw_devlink_link_to_suppliers(dev, child);
2234 0 : }
2235 :
2236 0 : static void fw_devlink_link_device(struct device *dev)
2237 : {
2238 0 : struct fwnode_handle *fwnode = dev->fwnode;
2239 :
2240 0 : if (!fw_devlink_flags)
2241 : return;
2242 :
2243 0 : fw_devlink_parse_fwtree(fwnode);
2244 :
2245 0 : mutex_lock(&fwnode_link_lock);
2246 0 : __fw_devlink_link_to_consumers(dev);
2247 0 : __fw_devlink_link_to_suppliers(dev, fwnode);
2248 0 : mutex_unlock(&fwnode_link_lock);
2249 : }
2250 :
2251 : /* Device links support end. */
2252 :
2253 : int (*platform_notify)(struct device *dev) = NULL;
2254 : int (*platform_notify_remove)(struct device *dev) = NULL;
2255 : static struct kobject *dev_kobj;
2256 :
2257 : /* /sys/dev/char */
2258 : static struct kobject *sysfs_dev_char_kobj;
2259 :
2260 : /* /sys/dev/block */
2261 : static struct kobject *sysfs_dev_block_kobj;
2262 :
2263 : static DEFINE_MUTEX(device_hotplug_lock);
2264 :
2265 0 : void lock_device_hotplug(void)
2266 : {
2267 0 : mutex_lock(&device_hotplug_lock);
2268 0 : }
2269 :
2270 0 : void unlock_device_hotplug(void)
2271 : {
2272 0 : mutex_unlock(&device_hotplug_lock);
2273 0 : }
2274 :
2275 0 : int lock_device_hotplug_sysfs(void)
2276 : {
2277 0 : if (mutex_trylock(&device_hotplug_lock))
2278 : return 0;
2279 :
2280 : /* Avoid busy looping (5 ms of sleep should do). */
2281 0 : msleep(5);
2282 0 : return restart_syscall();
2283 : }
2284 :
2285 : #ifdef CONFIG_BLOCK
2286 : static inline int device_is_not_partition(struct device *dev)
2287 : {
2288 : return !(dev->type == &part_type);
2289 : }
2290 : #else
2291 : static inline int device_is_not_partition(struct device *dev)
2292 : {
2293 : return 1;
2294 : }
2295 : #endif
2296 :
2297 : static void device_platform_notify(struct device *dev)
2298 : {
2299 540 : acpi_device_notify(dev);
2300 :
2301 540 : software_node_notify(dev);
2302 :
2303 540 : if (platform_notify)
2304 0 : platform_notify(dev);
2305 : }
2306 :
2307 : static void device_platform_notify_remove(struct device *dev)
2308 : {
2309 5 : acpi_device_notify_remove(dev);
2310 :
2311 5 : software_node_notify_remove(dev);
2312 :
2313 5 : if (platform_notify_remove)
2314 0 : platform_notify_remove(dev);
2315 : }
2316 :
2317 : /**
2318 : * dev_driver_string - Return a device's driver name, if at all possible
2319 : * @dev: struct device to get the name of
2320 : *
2321 : * Will return the device's driver's name if it is bound to a device. If
2322 : * the device is not bound to a driver, it will return the name of the bus
2323 : * it is attached to. If it is not attached to a bus either, an empty
2324 : * string will be returned.
2325 : */
2326 0 : const char *dev_driver_string(const struct device *dev)
2327 : {
2328 : struct device_driver *drv;
2329 :
2330 : /* dev->driver can change to NULL underneath us because of unbinding,
2331 : * so be careful about accessing it. dev->bus and dev->class should
2332 : * never change once they are set, so they don't need special care.
2333 : */
2334 0 : drv = READ_ONCE(dev->driver);
2335 0 : return drv ? drv->name : dev_bus_name(dev);
2336 : }
2337 : EXPORT_SYMBOL(dev_driver_string);
2338 :
2339 : #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
2340 :
2341 0 : static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
2342 : char *buf)
2343 : {
2344 0 : struct device_attribute *dev_attr = to_dev_attr(attr);
2345 0 : struct device *dev = kobj_to_dev(kobj);
2346 0 : ssize_t ret = -EIO;
2347 :
2348 0 : if (dev_attr->show)
2349 0 : ret = dev_attr->show(dev, dev_attr, buf);
2350 0 : if (ret >= (ssize_t)PAGE_SIZE) {
2351 0 : printk("dev_attr_show: %pS returned bad count\n",
2352 : dev_attr->show);
2353 : }
2354 0 : return ret;
2355 : }
2356 :
2357 0 : static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
2358 : const char *buf, size_t count)
2359 : {
2360 0 : struct device_attribute *dev_attr = to_dev_attr(attr);
2361 0 : struct device *dev = kobj_to_dev(kobj);
2362 0 : ssize_t ret = -EIO;
2363 :
2364 0 : if (dev_attr->store)
2365 0 : ret = dev_attr->store(dev, dev_attr, buf, count);
2366 0 : return ret;
2367 : }
2368 :
2369 : static const struct sysfs_ops dev_sysfs_ops = {
2370 : .show = dev_attr_show,
2371 : .store = dev_attr_store,
2372 : };
2373 :
2374 : #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
2375 :
2376 0 : ssize_t device_store_ulong(struct device *dev,
2377 : struct device_attribute *attr,
2378 : const char *buf, size_t size)
2379 : {
2380 0 : struct dev_ext_attribute *ea = to_ext_attr(attr);
2381 : int ret;
2382 : unsigned long new;
2383 :
2384 0 : ret = kstrtoul(buf, 0, &new);
2385 0 : if (ret)
2386 0 : return ret;
2387 0 : *(unsigned long *)(ea->var) = new;
2388 : /* Always return full write size even if we didn't consume all */
2389 0 : return size;
2390 : }
2391 : EXPORT_SYMBOL_GPL(device_store_ulong);
2392 :
2393 0 : ssize_t device_show_ulong(struct device *dev,
2394 : struct device_attribute *attr,
2395 : char *buf)
2396 : {
2397 0 : struct dev_ext_attribute *ea = to_ext_attr(attr);
2398 0 : return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
2399 : }
2400 : EXPORT_SYMBOL_GPL(device_show_ulong);
2401 :
2402 0 : ssize_t device_store_int(struct device *dev,
2403 : struct device_attribute *attr,
2404 : const char *buf, size_t size)
2405 : {
2406 0 : struct dev_ext_attribute *ea = to_ext_attr(attr);
2407 : int ret;
2408 : long new;
2409 :
2410 0 : ret = kstrtol(buf, 0, &new);
2411 0 : if (ret)
2412 0 : return ret;
2413 :
2414 0 : if (new > INT_MAX || new < INT_MIN)
2415 : return -EINVAL;
2416 0 : *(int *)(ea->var) = new;
2417 : /* Always return full write size even if we didn't consume all */
2418 0 : return size;
2419 : }
2420 : EXPORT_SYMBOL_GPL(device_store_int);
2421 :
2422 0 : ssize_t device_show_int(struct device *dev,
2423 : struct device_attribute *attr,
2424 : char *buf)
2425 : {
2426 0 : struct dev_ext_attribute *ea = to_ext_attr(attr);
2427 :
2428 0 : return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
2429 : }
2430 : EXPORT_SYMBOL_GPL(device_show_int);
2431 :
2432 0 : ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
2433 : const char *buf, size_t size)
2434 : {
2435 0 : struct dev_ext_attribute *ea = to_ext_attr(attr);
2436 :
2437 0 : if (kstrtobool(buf, ea->var) < 0)
2438 : return -EINVAL;
2439 :
2440 0 : return size;
2441 : }
2442 : EXPORT_SYMBOL_GPL(device_store_bool);
2443 :
2444 0 : ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
2445 : char *buf)
2446 : {
2447 0 : struct dev_ext_attribute *ea = to_ext_attr(attr);
2448 :
2449 0 : return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
2450 : }
2451 : EXPORT_SYMBOL_GPL(device_show_bool);
2452 :
2453 : /**
2454 : * device_release - free device structure.
2455 : * @kobj: device's kobject.
2456 : *
2457 : * This is called once the reference count for the object
2458 : * reaches 0. We forward the call to the device's release
2459 : * method, which should handle actually freeing the structure.
2460 : */
2461 10 : static void device_release(struct kobject *kobj)
2462 : {
2463 10 : struct device *dev = kobj_to_dev(kobj);
2464 10 : struct device_private *p = dev->p;
2465 :
2466 : /*
2467 : * Some platform devices are driven without driver attached
2468 : * and managed resources may have been acquired. Make sure
2469 : * all resources are released.
2470 : *
2471 : * Drivers still can add resources into device after device
2472 : * is deleted but alive, so release devres here to avoid
2473 : * possible memory leak.
2474 : */
2475 10 : devres_release_all(dev);
2476 :
2477 10 : kfree(dev->dma_range_map);
2478 :
2479 10 : if (dev->release)
2480 10 : dev->release(dev);
2481 0 : else if (dev->type && dev->type->release)
2482 0 : dev->type->release(dev);
2483 0 : else if (dev->class && dev->class->dev_release)
2484 0 : dev->class->dev_release(dev);
2485 : else
2486 0 : WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
2487 : dev_name(dev));
2488 10 : kfree(p);
2489 10 : }
2490 :
2491 0 : static const void *device_namespace(const struct kobject *kobj)
2492 : {
2493 0 : const struct device *dev = kobj_to_dev(kobj);
2494 0 : const void *ns = NULL;
2495 :
2496 0 : if (dev->class && dev->class->ns_type)
2497 0 : ns = dev->class->namespace(dev);
2498 :
2499 0 : return ns;
2500 : }
2501 :
2502 2704 : static void device_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid)
2503 : {
2504 2704 : const struct device *dev = kobj_to_dev(kobj);
2505 :
2506 2704 : if (dev->class && dev->class->get_ownership)
2507 0 : dev->class->get_ownership(dev, uid, gid);
2508 2704 : }
2509 :
2510 : static const struct kobj_type device_ktype = {
2511 : .release = device_release,
2512 : .sysfs_ops = &dev_sysfs_ops,
2513 : .namespace = device_namespace,
2514 : .get_ownership = device_get_ownership,
2515 : };
2516 :
2517 :
2518 555 : static int dev_uevent_filter(const struct kobject *kobj)
2519 : {
2520 555 : const struct kobj_type *ktype = get_ktype(kobj);
2521 :
2522 555 : if (ktype == &device_ktype) {
2523 555 : const struct device *dev = kobj_to_dev(kobj);
2524 555 : if (dev->bus)
2525 : return 1;
2526 531 : if (dev->class)
2527 : return 1;
2528 : }
2529 6 : return 0;
2530 : }
2531 :
2532 549 : static const char *dev_uevent_name(const struct kobject *kobj)
2533 : {
2534 549 : const struct device *dev = kobj_to_dev(kobj);
2535 :
2536 549 : if (dev->bus)
2537 24 : return dev->bus->name;
2538 525 : if (dev->class)
2539 525 : return dev->class->name;
2540 : return NULL;
2541 : }
2542 :
2543 549 : static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)
2544 : {
2545 549 : const struct device *dev = kobj_to_dev(kobj);
2546 549 : int retval = 0;
2547 :
2548 : /* add device node properties if present */
2549 549 : if (MAJOR(dev->devt)) {
2550 : const char *tmp;
2551 : const char *name;
2552 525 : umode_t mode = 0;
2553 525 : kuid_t uid = GLOBAL_ROOT_UID;
2554 525 : kgid_t gid = GLOBAL_ROOT_GID;
2555 :
2556 525 : add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
2557 525 : add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
2558 525 : name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
2559 525 : if (name) {
2560 525 : add_uevent_var(env, "DEVNAME=%s", name);
2561 525 : if (mode)
2562 8 : add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
2563 525 : if (!uid_eq(uid, GLOBAL_ROOT_UID))
2564 0 : add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
2565 525 : if (!gid_eq(gid, GLOBAL_ROOT_GID))
2566 0 : add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
2567 525 : kfree(tmp);
2568 : }
2569 : }
2570 :
2571 549 : if (dev->type && dev->type->name)
2572 0 : add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
2573 :
2574 549 : if (dev->driver)
2575 5 : add_uevent_var(env, "DRIVER=%s", dev->driver->name);
2576 :
2577 : /* Add common DT information about the device */
2578 549 : of_device_uevent(dev, env);
2579 :
2580 : /* have the bus specific function add its stuff */
2581 549 : if (dev->bus && dev->bus->uevent) {
2582 20 : retval = dev->bus->uevent(dev, env);
2583 : if (retval)
2584 : pr_debug("device: '%s': %s: bus uevent() returned %d\n",
2585 : dev_name(dev), __func__, retval);
2586 : }
2587 :
2588 : /* have the class specific function add its stuff */
2589 549 : if (dev->class && dev->class->dev_uevent) {
2590 0 : retval = dev->class->dev_uevent(dev, env);
2591 : if (retval)
2592 : pr_debug("device: '%s': %s: class uevent() "
2593 : "returned %d\n", dev_name(dev),
2594 : __func__, retval);
2595 : }
2596 :
2597 : /* have the device type specific function add its stuff */
2598 549 : if (dev->type && dev->type->uevent) {
2599 0 : retval = dev->type->uevent(dev, env);
2600 : if (retval)
2601 : pr_debug("device: '%s': %s: dev_type uevent() "
2602 : "returned %d\n", dev_name(dev),
2603 : __func__, retval);
2604 : }
2605 :
2606 549 : return retval;
2607 : }
2608 :
2609 : static const struct kset_uevent_ops device_uevent_ops = {
2610 : .filter = dev_uevent_filter,
2611 : .name = dev_uevent_name,
2612 : .uevent = dev_uevent,
2613 : };
2614 :
2615 0 : static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
2616 : char *buf)
2617 : {
2618 : struct kobject *top_kobj;
2619 : struct kset *kset;
2620 0 : struct kobj_uevent_env *env = NULL;
2621 : int i;
2622 0 : int len = 0;
2623 : int retval;
2624 :
2625 : /* search the kset, the device belongs to */
2626 0 : top_kobj = &dev->kobj;
2627 0 : while (!top_kobj->kset && top_kobj->parent)
2628 : top_kobj = top_kobj->parent;
2629 0 : if (!top_kobj->kset)
2630 : goto out;
2631 :
2632 0 : kset = top_kobj->kset;
2633 0 : if (!kset->uevent_ops || !kset->uevent_ops->uevent)
2634 : goto out;
2635 :
2636 : /* respect filter */
2637 0 : if (kset->uevent_ops && kset->uevent_ops->filter)
2638 0 : if (!kset->uevent_ops->filter(&dev->kobj))
2639 : goto out;
2640 :
2641 0 : env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
2642 0 : if (!env)
2643 : return -ENOMEM;
2644 :
2645 : /* let the kset specific function add its keys */
2646 0 : retval = kset->uevent_ops->uevent(&dev->kobj, env);
2647 0 : if (retval)
2648 : goto out;
2649 :
2650 : /* copy keys to file */
2651 0 : for (i = 0; i < env->envp_idx; i++)
2652 0 : len += sysfs_emit_at(buf, len, "%s\n", env->envp[i]);
2653 : out:
2654 0 : kfree(env);
2655 0 : return len;
2656 : }
2657 :
2658 0 : static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
2659 : const char *buf, size_t count)
2660 : {
2661 : int rc;
2662 :
2663 0 : rc = kobject_synth_uevent(&dev->kobj, buf, count);
2664 :
2665 0 : if (rc) {
2666 0 : dev_err(dev, "uevent: failed to send synthetic uevent: %d\n", rc);
2667 0 : return rc;
2668 : }
2669 :
2670 0 : return count;
2671 : }
2672 : static DEVICE_ATTR_RW(uevent);
2673 :
2674 0 : static ssize_t online_show(struct device *dev, struct device_attribute *attr,
2675 : char *buf)
2676 : {
2677 : bool val;
2678 :
2679 0 : device_lock(dev);
2680 0 : val = !dev->offline;
2681 0 : device_unlock(dev);
2682 0 : return sysfs_emit(buf, "%u\n", val);
2683 : }
2684 :
2685 0 : static ssize_t online_store(struct device *dev, struct device_attribute *attr,
2686 : const char *buf, size_t count)
2687 : {
2688 : bool val;
2689 : int ret;
2690 :
2691 0 : ret = kstrtobool(buf, &val);
2692 0 : if (ret < 0)
2693 0 : return ret;
2694 :
2695 0 : ret = lock_device_hotplug_sysfs();
2696 0 : if (ret)
2697 0 : return ret;
2698 :
2699 0 : ret = val ? device_online(dev) : device_offline(dev);
2700 : unlock_device_hotplug();
2701 0 : return ret < 0 ? ret : count;
2702 : }
2703 : static DEVICE_ATTR_RW(online);
2704 :
2705 0 : static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
2706 : char *buf)
2707 : {
2708 : const char *loc;
2709 :
2710 0 : switch (dev->removable) {
2711 : case DEVICE_REMOVABLE:
2712 : loc = "removable";
2713 : break;
2714 : case DEVICE_FIXED:
2715 0 : loc = "fixed";
2716 0 : break;
2717 : default:
2718 0 : loc = "unknown";
2719 : }
2720 0 : return sysfs_emit(buf, "%s\n", loc);
2721 : }
2722 : static DEVICE_ATTR_RO(removable);
2723 :
2724 14 : int device_add_groups(struct device *dev, const struct attribute_group **groups)
2725 : {
2726 1079 : return sysfs_create_groups(&dev->kobj, groups);
2727 : }
2728 : EXPORT_SYMBOL_GPL(device_add_groups);
2729 :
2730 10 : void device_remove_groups(struct device *dev,
2731 : const struct attribute_group **groups)
2732 : {
2733 15 : sysfs_remove_groups(&dev->kobj, groups);
2734 10 : }
2735 : EXPORT_SYMBOL_GPL(device_remove_groups);
2736 :
2737 : union device_attr_group_devres {
2738 : const struct attribute_group *group;
2739 : const struct attribute_group **groups;
2740 : };
2741 :
2742 0 : static void devm_attr_group_remove(struct device *dev, void *res)
2743 : {
2744 0 : union device_attr_group_devres *devres = res;
2745 0 : const struct attribute_group *group = devres->group;
2746 :
2747 : dev_dbg(dev, "%s: removing group %p\n", __func__, group);
2748 0 : sysfs_remove_group(&dev->kobj, group);
2749 0 : }
2750 :
2751 0 : static void devm_attr_groups_remove(struct device *dev, void *res)
2752 : {
2753 0 : union device_attr_group_devres *devres = res;
2754 0 : const struct attribute_group **groups = devres->groups;
2755 :
2756 : dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
2757 0 : sysfs_remove_groups(&dev->kobj, groups);
2758 0 : }
2759 :
2760 : /**
2761 : * devm_device_add_group - given a device, create a managed attribute group
2762 : * @dev: The device to create the group for
2763 : * @grp: The attribute group to create
2764 : *
2765 : * This function creates a group for the first time. It will explicitly
2766 : * warn and error if any of the attribute files being created already exist.
2767 : *
2768 : * Returns 0 on success or error code on failure.
2769 : */
2770 0 : int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
2771 : {
2772 : union device_attr_group_devres *devres;
2773 : int error;
2774 :
2775 0 : devres = devres_alloc(devm_attr_group_remove,
2776 : sizeof(*devres), GFP_KERNEL);
2777 0 : if (!devres)
2778 : return -ENOMEM;
2779 :
2780 0 : error = sysfs_create_group(&dev->kobj, grp);
2781 0 : if (error) {
2782 0 : devres_free(devres);
2783 0 : return error;
2784 : }
2785 :
2786 0 : devres->group = grp;
2787 0 : devres_add(dev, devres);
2788 0 : return 0;
2789 : }
2790 : EXPORT_SYMBOL_GPL(devm_device_add_group);
2791 :
2792 : /**
2793 : * devm_device_add_groups - create a bunch of managed attribute groups
2794 : * @dev: The device to create the group for
2795 : * @groups: The attribute groups to create, NULL terminated
2796 : *
2797 : * This function creates a bunch of managed attribute groups. If an error
2798 : * occurs when creating a group, all previously created groups will be
2799 : * removed, unwinding everything back to the original state when this
2800 : * function was called. It will explicitly warn and error if any of the
2801 : * attribute files being created already exist.
2802 : *
2803 : * Returns 0 on success or error code from sysfs_create_group on failure.
2804 : */
2805 0 : int devm_device_add_groups(struct device *dev,
2806 : const struct attribute_group **groups)
2807 : {
2808 : union device_attr_group_devres *devres;
2809 : int error;
2810 :
2811 0 : devres = devres_alloc(devm_attr_groups_remove,
2812 : sizeof(*devres), GFP_KERNEL);
2813 0 : if (!devres)
2814 : return -ENOMEM;
2815 :
2816 0 : error = sysfs_create_groups(&dev->kobj, groups);
2817 0 : if (error) {
2818 0 : devres_free(devres);
2819 0 : return error;
2820 : }
2821 :
2822 0 : devres->groups = groups;
2823 0 : devres_add(dev, devres);
2824 0 : return 0;
2825 : }
2826 : EXPORT_SYMBOL_GPL(devm_device_add_groups);
2827 :
2828 540 : static int device_add_attrs(struct device *dev)
2829 : {
2830 540 : const struct class *class = dev->class;
2831 540 : const struct device_type *type = dev->type;
2832 : int error;
2833 :
2834 540 : if (class) {
2835 1050 : error = device_add_groups(dev, class->dev_groups);
2836 525 : if (error)
2837 : return error;
2838 : }
2839 :
2840 540 : if (type) {
2841 0 : error = device_add_groups(dev, type->groups);
2842 0 : if (error)
2843 : goto err_remove_class_groups;
2844 : }
2845 :
2846 1080 : error = device_add_groups(dev, dev->groups);
2847 540 : if (error)
2848 : goto err_remove_type_groups;
2849 :
2850 1080 : if (device_supports_offline(dev) && !dev->offline_disabled) {
2851 0 : error = device_create_file(dev, &dev_attr_online);
2852 0 : if (error)
2853 : goto err_remove_dev_groups;
2854 : }
2855 :
2856 540 : if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) {
2857 0 : error = device_create_file(dev, &dev_attr_waiting_for_supplier);
2858 0 : if (error)
2859 : goto err_remove_dev_online;
2860 : }
2861 :
2862 540 : if (dev_removable_is_valid(dev)) {
2863 0 : error = device_create_file(dev, &dev_attr_removable);
2864 0 : if (error)
2865 : goto err_remove_dev_waiting_for_supplier;
2866 : }
2867 :
2868 : if (dev_add_physical_location(dev)) {
2869 : error = device_add_group(dev,
2870 : &dev_attr_physical_location_group);
2871 : if (error)
2872 : goto err_remove_dev_removable;
2873 : }
2874 :
2875 : return 0;
2876 :
2877 : err_remove_dev_removable:
2878 : device_remove_file(dev, &dev_attr_removable);
2879 : err_remove_dev_waiting_for_supplier:
2880 : device_remove_file(dev, &dev_attr_waiting_for_supplier);
2881 : err_remove_dev_online:
2882 : device_remove_file(dev, &dev_attr_online);
2883 : err_remove_dev_groups:
2884 0 : device_remove_groups(dev, dev->groups);
2885 : err_remove_type_groups:
2886 0 : if (type)
2887 0 : device_remove_groups(dev, type->groups);
2888 : err_remove_class_groups:
2889 0 : if (class)
2890 0 : device_remove_groups(dev, class->dev_groups);
2891 :
2892 : return error;
2893 : }
2894 :
2895 5 : static void device_remove_attrs(struct device *dev)
2896 : {
2897 5 : const struct class *class = dev->class;
2898 5 : const struct device_type *type = dev->type;
2899 :
2900 5 : if (dev->physical_location) {
2901 0 : device_remove_group(dev, &dev_attr_physical_location_group);
2902 0 : kfree(dev->physical_location);
2903 : }
2904 :
2905 5 : device_remove_file(dev, &dev_attr_removable);
2906 5 : device_remove_file(dev, &dev_attr_waiting_for_supplier);
2907 5 : device_remove_file(dev, &dev_attr_online);
2908 10 : device_remove_groups(dev, dev->groups);
2909 :
2910 5 : if (type)
2911 0 : device_remove_groups(dev, type->groups);
2912 :
2913 5 : if (class)
2914 0 : device_remove_groups(dev, class->dev_groups);
2915 5 : }
2916 :
2917 0 : static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
2918 : char *buf)
2919 : {
2920 0 : return print_dev_t(buf, dev->devt);
2921 : }
2922 : static DEVICE_ATTR_RO(dev);
2923 :
2924 : /* /sys/devices/ */
2925 : struct kset *devices_kset;
2926 :
2927 : /**
2928 : * devices_kset_move_before - Move device in the devices_kset's list.
2929 : * @deva: Device to move.
2930 : * @devb: Device @deva should come before.
2931 : */
2932 : static void devices_kset_move_before(struct device *deva, struct device *devb)
2933 : {
2934 0 : if (!devices_kset)
2935 : return;
2936 : pr_debug("devices_kset: Moving %s before %s\n",
2937 : dev_name(deva), dev_name(devb));
2938 0 : spin_lock(&devices_kset->list_lock);
2939 0 : list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
2940 0 : spin_unlock(&devices_kset->list_lock);
2941 : }
2942 :
2943 : /**
2944 : * devices_kset_move_after - Move device in the devices_kset's list.
2945 : * @deva: Device to move
2946 : * @devb: Device @deva should come after.
2947 : */
2948 : static void devices_kset_move_after(struct device *deva, struct device *devb)
2949 : {
2950 0 : if (!devices_kset)
2951 : return;
2952 : pr_debug("devices_kset: Moving %s after %s\n",
2953 : dev_name(deva), dev_name(devb));
2954 0 : spin_lock(&devices_kset->list_lock);
2955 0 : list_move(&deva->kobj.entry, &devb->kobj.entry);
2956 0 : spin_unlock(&devices_kset->list_lock);
2957 : }
2958 :
2959 : /**
2960 : * devices_kset_move_last - move the device to the end of devices_kset's list.
2961 : * @dev: device to move
2962 : */
2963 0 : void devices_kset_move_last(struct device *dev)
2964 : {
2965 0 : if (!devices_kset)
2966 : return;
2967 : pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
2968 0 : spin_lock(&devices_kset->list_lock);
2969 0 : list_move_tail(&dev->kobj.entry, &devices_kset->list);
2970 0 : spin_unlock(&devices_kset->list_lock);
2971 : }
2972 :
2973 : /**
2974 : * device_create_file - create sysfs attribute file for device.
2975 : * @dev: device.
2976 : * @attr: device attribute descriptor.
2977 : */
2978 1072 : int device_create_file(struct device *dev,
2979 : const struct device_attribute *attr)
2980 : {
2981 1072 : int error = 0;
2982 :
2983 1072 : if (dev) {
2984 1072 : WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
2985 : "Attribute %s: write permission without 'store'\n",
2986 : attr->attr.name);
2987 1072 : WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
2988 : "Attribute %s: read permission without 'show'\n",
2989 : attr->attr.name);
2990 2144 : error = sysfs_create_file(&dev->kobj, &attr->attr);
2991 : }
2992 :
2993 1072 : return error;
2994 : }
2995 : EXPORT_SYMBOL_GPL(device_create_file);
2996 :
2997 : /**
2998 : * device_remove_file - remove sysfs attribute file.
2999 : * @dev: device.
3000 : * @attr: device attribute descriptor.
3001 : */
3002 5 : void device_remove_file(struct device *dev,
3003 : const struct device_attribute *attr)
3004 : {
3005 30 : if (dev)
3006 30 : sysfs_remove_file(&dev->kobj, &attr->attr);
3007 5 : }
3008 : EXPORT_SYMBOL_GPL(device_remove_file);
3009 :
3010 : /**
3011 : * device_remove_file_self - remove sysfs attribute file from its own method.
3012 : * @dev: device.
3013 : * @attr: device attribute descriptor.
3014 : *
3015 : * See kernfs_remove_self() for details.
3016 : */
3017 0 : bool device_remove_file_self(struct device *dev,
3018 : const struct device_attribute *attr)
3019 : {
3020 0 : if (dev)
3021 0 : return sysfs_remove_file_self(&dev->kobj, &attr->attr);
3022 : else
3023 : return false;
3024 : }
3025 : EXPORT_SYMBOL_GPL(device_remove_file_self);
3026 :
3027 : /**
3028 : * device_create_bin_file - create sysfs binary attribute file for device.
3029 : * @dev: device.
3030 : * @attr: device binary attribute descriptor.
3031 : */
3032 0 : int device_create_bin_file(struct device *dev,
3033 : const struct bin_attribute *attr)
3034 : {
3035 0 : int error = -EINVAL;
3036 0 : if (dev)
3037 0 : error = sysfs_create_bin_file(&dev->kobj, attr);
3038 0 : return error;
3039 : }
3040 : EXPORT_SYMBOL_GPL(device_create_bin_file);
3041 :
3042 : /**
3043 : * device_remove_bin_file - remove sysfs binary attribute file
3044 : * @dev: device.
3045 : * @attr: device binary attribute descriptor.
3046 : */
3047 0 : void device_remove_bin_file(struct device *dev,
3048 : const struct bin_attribute *attr)
3049 : {
3050 0 : if (dev)
3051 0 : sysfs_remove_bin_file(&dev->kobj, attr);
3052 0 : }
3053 : EXPORT_SYMBOL_GPL(device_remove_bin_file);
3054 :
3055 5 : static void klist_children_get(struct klist_node *n)
3056 : {
3057 5 : struct device_private *p = to_device_private_parent(n);
3058 5 : struct device *dev = p->device;
3059 :
3060 5 : get_device(dev);
3061 5 : }
3062 :
3063 5 : static void klist_children_put(struct klist_node *n)
3064 : {
3065 5 : struct device_private *p = to_device_private_parent(n);
3066 5 : struct device *dev = p->device;
3067 :
3068 5 : put_device(dev);
3069 5 : }
3070 :
3071 : /**
3072 : * device_initialize - init device structure.
3073 : * @dev: device.
3074 : *
3075 : * This prepares the device for use by other layers by initializing
3076 : * its fields.
3077 : * It is the first half of device_register(), if called by
3078 : * that function, though it can also be called separately, so one
3079 : * may use @dev's fields. In particular, get_device()/put_device()
3080 : * may be used for reference counting of @dev after calling this
3081 : * function.
3082 : *
3083 : * All fields in @dev must be initialized by the caller to 0, except
3084 : * for those explicitly set to some other value. The simplest
3085 : * approach is to use kzalloc() to allocate the structure containing
3086 : * @dev.
3087 : *
3088 : * NOTE: Use put_device() to give up your reference instead of freeing
3089 : * @dev directly once you have called this function.
3090 : */
3091 545 : void device_initialize(struct device *dev)
3092 : {
3093 545 : dev->kobj.kset = devices_kset;
3094 545 : kobject_init(&dev->kobj, &device_ktype);
3095 1090 : INIT_LIST_HEAD(&dev->dma_pools);
3096 545 : mutex_init(&dev->mutex);
3097 : lockdep_set_novalidate_class(&dev->mutex);
3098 545 : spin_lock_init(&dev->devres_lock);
3099 1090 : INIT_LIST_HEAD(&dev->devres_head);
3100 545 : device_pm_init(dev);
3101 545 : set_dev_node(dev, NUMA_NO_NODE);
3102 1090 : INIT_LIST_HEAD(&dev->links.consumers);
3103 1090 : INIT_LIST_HEAD(&dev->links.suppliers);
3104 1090 : INIT_LIST_HEAD(&dev->links.defer_sync);
3105 545 : dev->links.status = DL_DEV_NO_DRIVER;
3106 : #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
3107 : defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
3108 : defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
3109 : dev->dma_coherent = dma_default_coherent;
3110 : #endif
3111 : #ifdef CONFIG_SWIOTLB
3112 : dev->dma_io_tlb_mem = &io_tlb_default_mem;
3113 : #endif
3114 545 : }
3115 : EXPORT_SYMBOL_GPL(device_initialize);
3116 :
3117 1 : struct kobject *virtual_device_parent(struct device *dev)
3118 : {
3119 : static struct kobject *virtual_dir = NULL;
3120 :
3121 526 : if (!virtual_dir)
3122 1 : virtual_dir = kobject_create_and_add("virtual",
3123 1 : &devices_kset->kobj);
3124 :
3125 526 : return virtual_dir;
3126 : }
3127 :
3128 : struct class_dir {
3129 : struct kobject kobj;
3130 : const struct class *class;
3131 : };
3132 :
3133 : #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
3134 :
3135 0 : static void class_dir_release(struct kobject *kobj)
3136 : {
3137 0 : struct class_dir *dir = to_class_dir(kobj);
3138 0 : kfree(dir);
3139 0 : }
3140 :
3141 : static const
3142 528 : struct kobj_ns_type_operations *class_dir_child_ns_type(const struct kobject *kobj)
3143 : {
3144 528 : const struct class_dir *dir = to_class_dir(kobj);
3145 528 : return dir->class->ns_type;
3146 : }
3147 :
3148 : static const struct kobj_type class_dir_ktype = {
3149 : .release = class_dir_release,
3150 : .sysfs_ops = &kobj_sysfs_ops,
3151 : .child_ns_type = class_dir_child_ns_type
3152 : };
3153 :
3154 3 : static struct kobject *class_dir_create_and_add(struct subsys_private *sp,
3155 : struct kobject *parent_kobj)
3156 : {
3157 : struct class_dir *dir;
3158 : int retval;
3159 :
3160 3 : dir = kzalloc(sizeof(*dir), GFP_KERNEL);
3161 3 : if (!dir)
3162 : return ERR_PTR(-ENOMEM);
3163 :
3164 3 : dir->class = sp->class;
3165 3 : kobject_init(&dir->kobj, &class_dir_ktype);
3166 :
3167 3 : dir->kobj.kset = &sp->glue_dirs;
3168 :
3169 3 : retval = kobject_add(&dir->kobj, parent_kobj, "%s", sp->class->name);
3170 3 : if (retval < 0) {
3171 0 : kobject_put(&dir->kobj);
3172 0 : return ERR_PTR(retval);
3173 : }
3174 : return &dir->kobj;
3175 : }
3176 :
3177 : static DEFINE_MUTEX(gdp_mutex);
3178 :
3179 540 : static struct kobject *get_device_parent(struct device *dev,
3180 : struct device *parent)
3181 : {
3182 540 : struct subsys_private *sp = class_to_subsys(dev->class);
3183 540 : struct kobject *kobj = NULL;
3184 :
3185 540 : if (sp) {
3186 : struct kobject *parent_kobj;
3187 : struct kobject *k;
3188 :
3189 : /*
3190 : * If we have no parent, we live in "virtual".
3191 : * Class-devices with a non class-device as parent, live
3192 : * in a "glue" directory to prevent namespace collisions.
3193 : */
3194 525 : if (parent == NULL)
3195 525 : parent_kobj = virtual_device_parent(dev);
3196 0 : else if (parent->class && !dev->class->ns_type) {
3197 0 : subsys_put(sp);
3198 0 : return &parent->kobj;
3199 : } else {
3200 0 : parent_kobj = &parent->kobj;
3201 : }
3202 :
3203 525 : mutex_lock(&gdp_mutex);
3204 :
3205 : /* find our class-directory at the parent and reference it */
3206 1050 : spin_lock(&sp->glue_dirs.list_lock);
3207 525 : list_for_each_entry(k, &sp->glue_dirs.list, entry)
3208 522 : if (k->parent == parent_kobj) {
3209 522 : kobj = kobject_get(k);
3210 : break;
3211 : }
3212 1050 : spin_unlock(&sp->glue_dirs.list_lock);
3213 525 : if (kobj) {
3214 522 : mutex_unlock(&gdp_mutex);
3215 522 : subsys_put(sp);
3216 : return kobj;
3217 : }
3218 :
3219 : /* or create a new class-directory at the parent device */
3220 3 : k = class_dir_create_and_add(sp, parent_kobj);
3221 : /* do not emit an uevent for this simple "glue" directory */
3222 3 : mutex_unlock(&gdp_mutex);
3223 3 : subsys_put(sp);
3224 : return k;
3225 : }
3226 :
3227 : /* subsystems can specify a default root directory for their devices */
3228 15 : if (!parent && dev->bus) {
3229 4 : struct device *dev_root = bus_get_dev_root(dev->bus);
3230 :
3231 4 : if (dev_root) {
3232 4 : kobj = &dev_root->kobj;
3233 4 : put_device(dev_root);
3234 : return kobj;
3235 : }
3236 : }
3237 :
3238 11 : if (parent)
3239 5 : return &parent->kobj;
3240 : return NULL;
3241 : }
3242 :
3243 5 : static inline bool live_in_glue_dir(struct kobject *kobj,
3244 : struct device *dev)
3245 : {
3246 : struct subsys_private *sp;
3247 : bool retval;
3248 :
3249 5 : if (!kobj || !dev->class)
3250 : return false;
3251 :
3252 0 : sp = class_to_subsys(dev->class);
3253 0 : if (!sp)
3254 : return false;
3255 :
3256 0 : if (kobj->kset == &sp->glue_dirs)
3257 : retval = true;
3258 : else
3259 0 : retval = false;
3260 :
3261 0 : subsys_put(sp);
3262 : return retval;
3263 : }
3264 :
3265 : static inline struct kobject *get_glue_dir(struct device *dev)
3266 : {
3267 : return dev->kobj.parent;
3268 : }
3269 :
3270 : /**
3271 : * kobject_has_children - Returns whether a kobject has children.
3272 : * @kobj: the object to test
3273 : *
3274 : * This will return whether a kobject has other kobjects as children.
3275 : *
3276 : * It does NOT account for the presence of attribute files, only sub
3277 : * directories. It also assumes there is no concurrent addition or
3278 : * removal of such children, and thus relies on external locking.
3279 : */
3280 0 : static inline bool kobject_has_children(struct kobject *kobj)
3281 : {
3282 0 : WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
3283 :
3284 0 : return kobj->sd && kobj->sd->dir.subdirs;
3285 : }
3286 :
3287 : /*
3288 : * make sure cleaning up dir as the last step, we need to make
3289 : * sure .release handler of kobject is run with holding the
3290 : * global lock
3291 : */
3292 5 : static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
3293 : {
3294 : unsigned int ref;
3295 :
3296 : /* see if we live in a "glue" directory */
3297 5 : if (!live_in_glue_dir(glue_dir, dev))
3298 : return;
3299 :
3300 0 : mutex_lock(&gdp_mutex);
3301 : /**
3302 : * There is a race condition between removing glue directory
3303 : * and adding a new device under the glue directory.
3304 : *
3305 : * CPU1: CPU2:
3306 : *
3307 : * device_add()
3308 : * get_device_parent()
3309 : * class_dir_create_and_add()
3310 : * kobject_add_internal()
3311 : * create_dir() // create glue_dir
3312 : *
3313 : * device_add()
3314 : * get_device_parent()
3315 : * kobject_get() // get glue_dir
3316 : *
3317 : * device_del()
3318 : * cleanup_glue_dir()
3319 : * kobject_del(glue_dir)
3320 : *
3321 : * kobject_add()
3322 : * kobject_add_internal()
3323 : * create_dir() // in glue_dir
3324 : * sysfs_create_dir_ns()
3325 : * kernfs_create_dir_ns(sd)
3326 : *
3327 : * sysfs_remove_dir() // glue_dir->sd=NULL
3328 : * sysfs_put() // free glue_dir->sd
3329 : *
3330 : * // sd is freed
3331 : * kernfs_new_node(sd)
3332 : * kernfs_get(glue_dir)
3333 : * kernfs_add_one()
3334 : * kernfs_put()
3335 : *
3336 : * Before CPU1 remove last child device under glue dir, if CPU2 add
3337 : * a new device under glue dir, the glue_dir kobject reference count
3338 : * will be increase to 2 in kobject_get(k). And CPU2 has been called
3339 : * kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir()
3340 : * and sysfs_put(). This result in glue_dir->sd is freed.
3341 : *
3342 : * Then the CPU2 will see a stale "empty" but still potentially used
3343 : * glue dir around in kernfs_new_node().
3344 : *
3345 : * In order to avoid this happening, we also should make sure that
3346 : * kernfs_node for glue_dir is released in CPU1 only when refcount
3347 : * for glue_dir kobj is 1.
3348 : */
3349 0 : ref = kref_read(&glue_dir->kref);
3350 0 : if (!kobject_has_children(glue_dir) && !--ref)
3351 0 : kobject_del(glue_dir);
3352 0 : kobject_put(glue_dir);
3353 0 : mutex_unlock(&gdp_mutex);
3354 : }
3355 :
3356 540 : static int device_add_class_symlinks(struct device *dev)
3357 : {
3358 540 : struct device_node *of_node = dev_of_node(dev);
3359 : struct subsys_private *sp;
3360 : int error;
3361 :
3362 : if (of_node) {
3363 : error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
3364 : if (error)
3365 : dev_warn(dev, "Error %d creating of_node link\n",error);
3366 : /* An error here doesn't warrant bringing down the device */
3367 : }
3368 :
3369 540 : sp = class_to_subsys(dev->class);
3370 540 : if (!sp)
3371 : return 0;
3372 :
3373 525 : error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem");
3374 525 : if (error)
3375 : goto out_devnode;
3376 :
3377 525 : if (dev->parent && device_is_not_partition(dev)) {
3378 0 : error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
3379 : "device");
3380 0 : if (error)
3381 : goto out_subsys;
3382 : }
3383 :
3384 : /* link in the class directory pointing to the device */
3385 525 : error = sysfs_create_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev));
3386 525 : if (error)
3387 : goto out_device;
3388 : goto exit;
3389 :
3390 : out_device:
3391 0 : sysfs_remove_link(&dev->kobj, "device");
3392 : out_subsys:
3393 0 : sysfs_remove_link(&dev->kobj, "subsystem");
3394 : out_devnode:
3395 0 : sysfs_remove_link(&dev->kobj, "of_node");
3396 : exit:
3397 525 : subsys_put(sp);
3398 525 : return error;
3399 : }
3400 :
3401 0 : static void device_remove_class_symlinks(struct device *dev)
3402 : {
3403 0 : struct subsys_private *sp = class_to_subsys(dev->class);
3404 :
3405 0 : if (dev_of_node(dev))
3406 : sysfs_remove_link(&dev->kobj, "of_node");
3407 :
3408 0 : if (!sp)
3409 : return;
3410 :
3411 0 : if (dev->parent && device_is_not_partition(dev))
3412 0 : sysfs_remove_link(&dev->kobj, "device");
3413 0 : sysfs_remove_link(&dev->kobj, "subsystem");
3414 0 : sysfs_delete_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev));
3415 : subsys_put(sp);
3416 : }
3417 :
3418 : /**
3419 : * dev_set_name - set a device name
3420 : * @dev: device
3421 : * @fmt: format string for the device's name
3422 : */
3423 533 : int dev_set_name(struct device *dev, const char *fmt, ...)
3424 : {
3425 : va_list vargs;
3426 : int err;
3427 :
3428 533 : va_start(vargs, fmt);
3429 533 : err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
3430 533 : va_end(vargs);
3431 533 : return err;
3432 : }
3433 : EXPORT_SYMBOL_GPL(dev_set_name);
3434 :
3435 : /* select a /sys/dev/ directory for the device */
3436 : static struct kobject *device_to_dev_kobj(struct device *dev)
3437 : {
3438 525 : if (is_blockdev(dev))
3439 0 : return sysfs_dev_block_kobj;
3440 : else
3441 525 : return sysfs_dev_char_kobj;
3442 : }
3443 :
3444 525 : static int device_create_sys_dev_entry(struct device *dev)
3445 : {
3446 525 : struct kobject *kobj = device_to_dev_kobj(dev);
3447 525 : int error = 0;
3448 : char devt_str[15];
3449 :
3450 525 : if (kobj) {
3451 525 : format_dev_t(devt_str, dev->devt);
3452 525 : error = sysfs_create_link(kobj, &dev->kobj, devt_str);
3453 : }
3454 :
3455 525 : return error;
3456 : }
3457 :
3458 0 : static void device_remove_sys_dev_entry(struct device *dev)
3459 : {
3460 0 : struct kobject *kobj = device_to_dev_kobj(dev);
3461 : char devt_str[15];
3462 :
3463 0 : if (kobj) {
3464 0 : format_dev_t(devt_str, dev->devt);
3465 0 : sysfs_remove_link(kobj, devt_str);
3466 : }
3467 0 : }
3468 :
3469 540 : static int device_private_init(struct device *dev)
3470 : {
3471 540 : dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
3472 540 : if (!dev->p)
3473 : return -ENOMEM;
3474 540 : dev->p->device = dev;
3475 540 : klist_init(&dev->p->klist_children, klist_children_get,
3476 : klist_children_put);
3477 1080 : INIT_LIST_HEAD(&dev->p->deferred_probe);
3478 540 : return 0;
3479 : }
3480 :
3481 : /**
3482 : * device_add - add device to device hierarchy.
3483 : * @dev: device.
3484 : *
3485 : * This is part 2 of device_register(), though may be called
3486 : * separately _iff_ device_initialize() has been called separately.
3487 : *
3488 : * This adds @dev to the kobject hierarchy via kobject_add(), adds it
3489 : * to the global and sibling lists for the device, then
3490 : * adds it to the other relevant subsystems of the driver model.
3491 : *
3492 : * Do not call this routine or device_register() more than once for
3493 : * any device structure. The driver model core is not designed to work
3494 : * with devices that get unregistered and then spring back to life.
3495 : * (Among other things, it's very hard to guarantee that all references
3496 : * to the previous incarnation of @dev have been dropped.) Allocate
3497 : * and register a fresh new struct device instead.
3498 : *
3499 : * NOTE: _Never_ directly free @dev after calling this function, even
3500 : * if it returned an error! Always use put_device() to give up your
3501 : * reference instead.
3502 : *
3503 : * Rule of thumb is: if device_add() succeeds, you should call
3504 : * device_del() when you want to get rid of it. If device_add() has
3505 : * *not* succeeded, use *only* put_device() to drop the reference
3506 : * count.
3507 : */
3508 540 : int device_add(struct device *dev)
3509 : {
3510 : struct subsys_private *sp;
3511 : struct device *parent;
3512 : struct kobject *kobj;
3513 : struct class_interface *class_intf;
3514 540 : int error = -EINVAL;
3515 540 : struct kobject *glue_dir = NULL;
3516 :
3517 540 : dev = get_device(dev);
3518 540 : if (!dev)
3519 : goto done;
3520 :
3521 540 : if (!dev->p) {
3522 540 : error = device_private_init(dev);
3523 540 : if (error)
3524 : goto done;
3525 : }
3526 :
3527 : /*
3528 : * for statically allocated devices, which should all be converted
3529 : * some day, we need to initialize the name. We prevent reading back
3530 : * the name, and force the use of dev_name()
3531 : */
3532 540 : if (dev->init_name) {
3533 1 : dev_set_name(dev, "%s", dev->init_name);
3534 1 : dev->init_name = NULL;
3535 : }
3536 :
3537 : /* subsystems can specify simple device enumeration */
3538 540 : if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
3539 3 : dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
3540 :
3541 540 : if (!dev_name(dev)) {
3542 : error = -EINVAL;
3543 : goto name_error;
3544 : }
3545 :
3546 : pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
3547 :
3548 1080 : parent = get_device(dev->parent);
3549 540 : kobj = get_device_parent(dev, parent);
3550 540 : if (IS_ERR(kobj)) {
3551 0 : error = PTR_ERR(kobj);
3552 0 : goto parent_error;
3553 : }
3554 540 : if (kobj)
3555 534 : dev->kobj.parent = kobj;
3556 :
3557 : /* use parent numa_node */
3558 : if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
3559 : set_dev_node(dev, dev_to_node(parent));
3560 :
3561 : /* first, register with generic layer. */
3562 : /* we require the name to be set before, and pass NULL */
3563 540 : error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
3564 540 : if (error) {
3565 : glue_dir = kobj;
3566 : goto Error;
3567 : }
3568 :
3569 : /* notify platform of device entry */
3570 540 : device_platform_notify(dev);
3571 :
3572 540 : error = device_create_file(dev, &dev_attr_uevent);
3573 540 : if (error)
3574 : goto attrError;
3575 :
3576 540 : error = device_add_class_symlinks(dev);
3577 540 : if (error)
3578 : goto SymlinkError;
3579 540 : error = device_add_attrs(dev);
3580 540 : if (error)
3581 : goto AttrsError;
3582 540 : error = bus_add_device(dev);
3583 540 : if (error)
3584 : goto BusError;
3585 540 : error = dpm_sysfs_add(dev);
3586 540 : if (error)
3587 : goto DPMError;
3588 540 : device_pm_add(dev);
3589 :
3590 540 : if (MAJOR(dev->devt)) {
3591 525 : error = device_create_file(dev, &dev_attr_dev);
3592 525 : if (error)
3593 : goto DevAttrError;
3594 :
3595 525 : error = device_create_sys_dev_entry(dev);
3596 525 : if (error)
3597 : goto SysEntryError;
3598 :
3599 : devtmpfs_create_node(dev);
3600 : }
3601 :
3602 : /* Notify clients of device addition. This call must come
3603 : * after dpm_sysfs_add() and before kobject_uevent().
3604 : */
3605 540 : bus_notify(dev, BUS_NOTIFY_ADD_DEVICE);
3606 540 : kobject_uevent(&dev->kobj, KOBJ_ADD);
3607 :
3608 : /*
3609 : * Check if any of the other devices (consumers) have been waiting for
3610 : * this device (supplier) to be added so that they can create a device
3611 : * link to it.
3612 : *
3613 : * This needs to happen after device_pm_add() because device_link_add()
3614 : * requires the supplier be registered before it's called.
3615 : *
3616 : * But this also needs to happen before bus_probe_device() to make sure
3617 : * waiting consumers can link to it before the driver is bound to the
3618 : * device and the driver sync_state callback is called for this device.
3619 : */
3620 540 : if (dev->fwnode && !dev->fwnode->dev) {
3621 0 : dev->fwnode->dev = dev;
3622 0 : fw_devlink_link_device(dev);
3623 : }
3624 :
3625 540 : bus_probe_device(dev);
3626 :
3627 : /*
3628 : * If all driver registration is done and a newly added device doesn't
3629 : * match with any driver, don't block its consumers from probing in
3630 : * case the consumer device is able to operate without this supplier.
3631 : */
3632 540 : if (dev->fwnode && fw_devlink_drv_reg_done && !dev->can_match)
3633 0 : fw_devlink_unblock_consumers(dev);
3634 :
3635 540 : if (parent)
3636 5 : klist_add_tail(&dev->p->knode_parent,
3637 5 : &parent->p->klist_children);
3638 :
3639 540 : sp = class_to_subsys(dev->class);
3640 540 : if (sp) {
3641 525 : mutex_lock(&sp->mutex);
3642 : /* tie the class to the device */
3643 525 : klist_add_tail(&dev->p->knode_class, &sp->klist_devices);
3644 :
3645 : /* notify any interfaces that the device is here */
3646 525 : list_for_each_entry(class_intf, &sp->interfaces, node)
3647 0 : if (class_intf->add_dev)
3648 0 : class_intf->add_dev(dev);
3649 525 : mutex_unlock(&sp->mutex);
3650 : subsys_put(sp);
3651 : }
3652 : done:
3653 540 : put_device(dev);
3654 540 : return error;
3655 : SysEntryError:
3656 0 : if (MAJOR(dev->devt))
3657 : device_remove_file(dev, &dev_attr_dev);
3658 : DevAttrError:
3659 0 : device_pm_remove(dev);
3660 0 : dpm_sysfs_remove(dev);
3661 : DPMError:
3662 0 : dev->driver = NULL;
3663 0 : bus_remove_device(dev);
3664 : BusError:
3665 0 : device_remove_attrs(dev);
3666 : AttrsError:
3667 0 : device_remove_class_symlinks(dev);
3668 : SymlinkError:
3669 : device_remove_file(dev, &dev_attr_uevent);
3670 : attrError:
3671 0 : device_platform_notify_remove(dev);
3672 0 : kobject_uevent(&dev->kobj, KOBJ_REMOVE);
3673 0 : glue_dir = get_glue_dir(dev);
3674 0 : kobject_del(&dev->kobj);
3675 : Error:
3676 0 : cleanup_glue_dir(dev, glue_dir);
3677 : parent_error:
3678 : put_device(parent);
3679 : name_error:
3680 0 : kfree(dev->p);
3681 0 : dev->p = NULL;
3682 0 : goto done;
3683 : }
3684 : EXPORT_SYMBOL_GPL(device_add);
3685 :
3686 : /**
3687 : * device_register - register a device with the system.
3688 : * @dev: pointer to the device structure
3689 : *
3690 : * This happens in two clean steps - initialize the device
3691 : * and add it to the system. The two steps can be called
3692 : * separately, but this is the easiest and most common.
3693 : * I.e. you should only call the two helpers separately if
3694 : * have a clearly defined need to use and refcount the device
3695 : * before it is added to the hierarchy.
3696 : *
3697 : * For more information, see the kerneldoc for device_initialize()
3698 : * and device_add().
3699 : *
3700 : * NOTE: _Never_ directly free @dev after calling this function, even
3701 : * if it returned an error! Always use put_device() to give up the
3702 : * reference initialized in this function instead.
3703 : */
3704 523 : int device_register(struct device *dev)
3705 : {
3706 523 : device_initialize(dev);
3707 523 : return device_add(dev);
3708 : }
3709 : EXPORT_SYMBOL_GPL(device_register);
3710 :
3711 : /**
3712 : * get_device - increment reference count for device.
3713 : * @dev: device.
3714 : *
3715 : * This simply forwards the call to kobject_get(), though
3716 : * we do take care to provide for the case that we get a NULL
3717 : * pointer passed in.
3718 : */
3719 544 : struct device *get_device(struct device *dev)
3720 : {
3721 2699 : return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
3722 : }
3723 : EXPORT_SYMBOL_GPL(get_device);
3724 :
3725 : /**
3726 : * put_device - decrement reference count.
3727 : * @dev: device in question.
3728 : */
3729 21 : void put_device(struct device *dev)
3730 : {
3731 : /* might_sleep(); */
3732 1641 : if (dev)
3733 1110 : kobject_put(&dev->kobj);
3734 21 : }
3735 : EXPORT_SYMBOL_GPL(put_device);
3736 :
3737 0 : bool kill_device(struct device *dev)
3738 : {
3739 : /*
3740 : * Require the device lock and set the "dead" flag to guarantee that
3741 : * the update behavior is consistent with the other bitfields near
3742 : * it and that we cannot have an asynchronous probe routine trying
3743 : * to run while we are tearing out the bus/class/sysfs from
3744 : * underneath the device.
3745 : */
3746 5 : device_lock_assert(dev);
3747 :
3748 5 : if (dev->p->dead)
3749 : return false;
3750 5 : dev->p->dead = true;
3751 0 : return true;
3752 : }
3753 : EXPORT_SYMBOL_GPL(kill_device);
3754 :
3755 : /**
3756 : * device_del - delete device from system.
3757 : * @dev: device.
3758 : *
3759 : * This is the first part of the device unregistration
3760 : * sequence. This removes the device from the lists we control
3761 : * from here, has it removed from the other driver model
3762 : * subsystems it was added to in device_add(), and removes it
3763 : * from the kobject hierarchy.
3764 : *
3765 : * NOTE: this should be called manually _iff_ device_add() was
3766 : * also called manually.
3767 : */
3768 5 : void device_del(struct device *dev)
3769 : {
3770 : struct subsys_private *sp;
3771 5 : struct device *parent = dev->parent;
3772 5 : struct kobject *glue_dir = NULL;
3773 : struct class_interface *class_intf;
3774 : unsigned int noio_flag;
3775 :
3776 5 : device_lock(dev);
3777 5 : kill_device(dev);
3778 5 : device_unlock(dev);
3779 :
3780 5 : if (dev->fwnode && dev->fwnode->dev == dev)
3781 0 : dev->fwnode->dev = NULL;
3782 :
3783 : /* Notify clients of device removal. This call must come
3784 : * before dpm_sysfs_remove().
3785 : */
3786 5 : noio_flag = memalloc_noio_save();
3787 5 : bus_notify(dev, BUS_NOTIFY_DEL_DEVICE);
3788 :
3789 5 : dpm_sysfs_remove(dev);
3790 5 : if (parent)
3791 5 : klist_del(&dev->p->knode_parent);
3792 5 : if (MAJOR(dev->devt)) {
3793 0 : devtmpfs_delete_node(dev);
3794 0 : device_remove_sys_dev_entry(dev);
3795 : device_remove_file(dev, &dev_attr_dev);
3796 : }
3797 :
3798 5 : sp = class_to_subsys(dev->class);
3799 5 : if (sp) {
3800 0 : device_remove_class_symlinks(dev);
3801 :
3802 0 : mutex_lock(&sp->mutex);
3803 : /* notify any interfaces that the device is now gone */
3804 0 : list_for_each_entry(class_intf, &sp->interfaces, node)
3805 0 : if (class_intf->remove_dev)
3806 0 : class_intf->remove_dev(dev);
3807 : /* remove the device from the class list */
3808 0 : klist_del(&dev->p->knode_class);
3809 0 : mutex_unlock(&sp->mutex);
3810 : subsys_put(sp);
3811 : }
3812 5 : device_remove_file(dev, &dev_attr_uevent);
3813 5 : device_remove_attrs(dev);
3814 5 : bus_remove_device(dev);
3815 5 : device_pm_remove(dev);
3816 5 : driver_deferred_probe_del(dev);
3817 5 : device_platform_notify_remove(dev);
3818 5 : device_links_purge(dev);
3819 :
3820 5 : bus_notify(dev, BUS_NOTIFY_REMOVED_DEVICE);
3821 5 : kobject_uevent(&dev->kobj, KOBJ_REMOVE);
3822 5 : glue_dir = get_glue_dir(dev);
3823 5 : kobject_del(&dev->kobj);
3824 5 : cleanup_glue_dir(dev, glue_dir);
3825 5 : memalloc_noio_restore(noio_flag);
3826 5 : put_device(parent);
3827 5 : }
3828 : EXPORT_SYMBOL_GPL(device_del);
3829 :
3830 : /**
3831 : * device_unregister - unregister device from system.
3832 : * @dev: device going away.
3833 : *
3834 : * We do this in two parts, like we do device_register(). First,
3835 : * we remove it from all the subsystems with device_del(), then
3836 : * we decrement the reference count via put_device(). If that
3837 : * is the final reference count, the device will be cleaned up
3838 : * via device_release() above. Otherwise, the structure will
3839 : * stick around until the final reference to the device is dropped.
3840 : */
3841 0 : void device_unregister(struct device *dev)
3842 : {
3843 : pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
3844 0 : device_del(dev);
3845 0 : put_device(dev);
3846 0 : }
3847 : EXPORT_SYMBOL_GPL(device_unregister);
3848 :
3849 : static struct device *prev_device(struct klist_iter *i)
3850 : {
3851 0 : struct klist_node *n = klist_prev(i);
3852 0 : struct device *dev = NULL;
3853 : struct device_private *p;
3854 :
3855 0 : if (n) {
3856 0 : p = to_device_private_parent(n);
3857 0 : dev = p->device;
3858 : }
3859 : return dev;
3860 : }
3861 :
3862 : static struct device *next_device(struct klist_iter *i)
3863 : {
3864 0 : struct klist_node *n = klist_next(i);
3865 0 : struct device *dev = NULL;
3866 : struct device_private *p;
3867 :
3868 0 : if (n) {
3869 0 : p = to_device_private_parent(n);
3870 0 : dev = p->device;
3871 : }
3872 : return dev;
3873 : }
3874 :
3875 : /**
3876 : * device_get_devnode - path of device node file
3877 : * @dev: device
3878 : * @mode: returned file access mode
3879 : * @uid: returned file owner
3880 : * @gid: returned file group
3881 : * @tmp: possibly allocated string
3882 : *
3883 : * Return the relative path of a possible device node.
3884 : * Non-default names may need to allocate a memory to compose
3885 : * a name. This memory is returned in tmp and needs to be
3886 : * freed by the caller.
3887 : */
3888 525 : const char *device_get_devnode(const struct device *dev,
3889 : umode_t *mode, kuid_t *uid, kgid_t *gid,
3890 : const char **tmp)
3891 : {
3892 : char *s;
3893 :
3894 525 : *tmp = NULL;
3895 :
3896 : /* the device type may provide a specific name */
3897 525 : if (dev->type && dev->type->devnode)
3898 0 : *tmp = dev->type->devnode(dev, mode, uid, gid);
3899 525 : if (*tmp)
3900 : return *tmp;
3901 :
3902 : /* the class may provide a specific name */
3903 525 : if (dev->class && dev->class->devnode)
3904 525 : *tmp = dev->class->devnode(dev, mode);
3905 525 : if (*tmp)
3906 : return *tmp;
3907 :
3908 : /* return name without allocation, tmp == NULL */
3909 524 : if (strchr(dev_name(dev), '!') == NULL)
3910 : return dev_name(dev);
3911 :
3912 : /* replace '!' in the name with '/' */
3913 0 : s = kstrdup(dev_name(dev), GFP_KERNEL);
3914 0 : if (!s)
3915 : return NULL;
3916 0 : strreplace(s, '!', '/');
3917 0 : return *tmp = s;
3918 : }
3919 :
3920 : /**
3921 : * device_for_each_child - device child iterator.
3922 : * @parent: parent struct device.
3923 : * @fn: function to be called for each device.
3924 : * @data: data for the callback.
3925 : *
3926 : * Iterate over @parent's child devices, and call @fn for each,
3927 : * passing it @data.
3928 : *
3929 : * We check the return of @fn each time. If it returns anything
3930 : * other than 0, we break out and return that value.
3931 : */
3932 0 : int device_for_each_child(struct device *parent, void *data,
3933 : int (*fn)(struct device *dev, void *data))
3934 : {
3935 : struct klist_iter i;
3936 : struct device *child;
3937 0 : int error = 0;
3938 :
3939 0 : if (!parent->p)
3940 : return 0;
3941 :
3942 0 : klist_iter_init(&parent->p->klist_children, &i);
3943 0 : while (!error && (child = next_device(&i)))
3944 0 : error = fn(child, data);
3945 0 : klist_iter_exit(&i);
3946 0 : return error;
3947 : }
3948 : EXPORT_SYMBOL_GPL(device_for_each_child);
3949 :
3950 : /**
3951 : * device_for_each_child_reverse - device child iterator in reversed order.
3952 : * @parent: parent struct device.
3953 : * @fn: function to be called for each device.
3954 : * @data: data for the callback.
3955 : *
3956 : * Iterate over @parent's child devices, and call @fn for each,
3957 : * passing it @data.
3958 : *
3959 : * We check the return of @fn each time. If it returns anything
3960 : * other than 0, we break out and return that value.
3961 : */
3962 0 : int device_for_each_child_reverse(struct device *parent, void *data,
3963 : int (*fn)(struct device *dev, void *data))
3964 : {
3965 : struct klist_iter i;
3966 : struct device *child;
3967 0 : int error = 0;
3968 :
3969 0 : if (!parent->p)
3970 : return 0;
3971 :
3972 0 : klist_iter_init(&parent->p->klist_children, &i);
3973 0 : while ((child = prev_device(&i)) && !error)
3974 0 : error = fn(child, data);
3975 0 : klist_iter_exit(&i);
3976 0 : return error;
3977 : }
3978 : EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
3979 :
3980 : /**
3981 : * device_find_child - device iterator for locating a particular device.
3982 : * @parent: parent struct device
3983 : * @match: Callback function to check device
3984 : * @data: Data to pass to match function
3985 : *
3986 : * This is similar to the device_for_each_child() function above, but it
3987 : * returns a reference to a device that is 'found' for later use, as
3988 : * determined by the @match callback.
3989 : *
3990 : * The callback should return 0 if the device doesn't match and non-zero
3991 : * if it does. If the callback returns non-zero and a reference to the
3992 : * current device can be obtained, this function will return to the caller
3993 : * and not iterate over any more devices.
3994 : *
3995 : * NOTE: you will need to drop the reference with put_device() after use.
3996 : */
3997 0 : struct device *device_find_child(struct device *parent, void *data,
3998 : int (*match)(struct device *dev, void *data))
3999 : {
4000 : struct klist_iter i;
4001 : struct device *child;
4002 :
4003 0 : if (!parent)
4004 : return NULL;
4005 :
4006 0 : klist_iter_init(&parent->p->klist_children, &i);
4007 0 : while ((child = next_device(&i)))
4008 0 : if (match(child, data) && get_device(child))
4009 : break;
4010 0 : klist_iter_exit(&i);
4011 0 : return child;
4012 : }
4013 : EXPORT_SYMBOL_GPL(device_find_child);
4014 :
4015 : /**
4016 : * device_find_child_by_name - device iterator for locating a child device.
4017 : * @parent: parent struct device
4018 : * @name: name of the child device
4019 : *
4020 : * This is similar to the device_find_child() function above, but it
4021 : * returns a reference to a device that has the name @name.
4022 : *
4023 : * NOTE: you will need to drop the reference with put_device() after use.
4024 : */
4025 0 : struct device *device_find_child_by_name(struct device *parent,
4026 : const char *name)
4027 : {
4028 : struct klist_iter i;
4029 : struct device *child;
4030 :
4031 0 : if (!parent)
4032 : return NULL;
4033 :
4034 0 : klist_iter_init(&parent->p->klist_children, &i);
4035 0 : while ((child = next_device(&i)))
4036 0 : if (sysfs_streq(dev_name(child), name) && get_device(child))
4037 : break;
4038 0 : klist_iter_exit(&i);
4039 0 : return child;
4040 : }
4041 : EXPORT_SYMBOL_GPL(device_find_child_by_name);
4042 :
4043 0 : static int match_any(struct device *dev, void *unused)
4044 : {
4045 0 : return 1;
4046 : }
4047 :
4048 : /**
4049 : * device_find_any_child - device iterator for locating a child device, if any.
4050 : * @parent: parent struct device
4051 : *
4052 : * This is similar to the device_find_child() function above, but it
4053 : * returns a reference to a child device, if any.
4054 : *
4055 : * NOTE: you will need to drop the reference with put_device() after use.
4056 : */
4057 0 : struct device *device_find_any_child(struct device *parent)
4058 : {
4059 0 : return device_find_child(parent, NULL, match_any);
4060 : }
4061 : EXPORT_SYMBOL_GPL(device_find_any_child);
4062 :
4063 1 : int __init devices_init(void)
4064 : {
4065 1 : devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
4066 1 : if (!devices_kset)
4067 : return -ENOMEM;
4068 1 : dev_kobj = kobject_create_and_add("dev", NULL);
4069 1 : if (!dev_kobj)
4070 : goto dev_kobj_err;
4071 1 : sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
4072 1 : if (!sysfs_dev_block_kobj)
4073 : goto block_kobj_err;
4074 1 : sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
4075 1 : if (!sysfs_dev_char_kobj)
4076 : goto char_kobj_err;
4077 :
4078 : return 0;
4079 :
4080 : char_kobj_err:
4081 0 : kobject_put(sysfs_dev_block_kobj);
4082 : block_kobj_err:
4083 0 : kobject_put(dev_kobj);
4084 : dev_kobj_err:
4085 0 : kset_unregister(devices_kset);
4086 0 : return -ENOMEM;
4087 : }
4088 :
4089 0 : static int device_check_offline(struct device *dev, void *not_used)
4090 : {
4091 : int ret;
4092 :
4093 0 : ret = device_for_each_child(dev, NULL, device_check_offline);
4094 0 : if (ret)
4095 : return ret;
4096 :
4097 0 : return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
4098 : }
4099 :
4100 : /**
4101 : * device_offline - Prepare the device for hot-removal.
4102 : * @dev: Device to be put offline.
4103 : *
4104 : * Execute the device bus type's .offline() callback, if present, to prepare
4105 : * the device for a subsequent hot-removal. If that succeeds, the device must
4106 : * not be used until either it is removed or its bus type's .online() callback
4107 : * is executed.
4108 : *
4109 : * Call under device_hotplug_lock.
4110 : */
4111 0 : int device_offline(struct device *dev)
4112 : {
4113 : int ret;
4114 :
4115 0 : if (dev->offline_disabled)
4116 : return -EPERM;
4117 :
4118 0 : ret = device_for_each_child(dev, NULL, device_check_offline);
4119 0 : if (ret)
4120 : return ret;
4121 :
4122 0 : device_lock(dev);
4123 0 : if (device_supports_offline(dev)) {
4124 0 : if (dev->offline) {
4125 : ret = 1;
4126 : } else {
4127 0 : ret = dev->bus->offline(dev);
4128 0 : if (!ret) {
4129 0 : kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
4130 0 : dev->offline = true;
4131 : }
4132 : }
4133 : }
4134 0 : device_unlock(dev);
4135 :
4136 0 : return ret;
4137 : }
4138 :
4139 : /**
4140 : * device_online - Put the device back online after successful device_offline().
4141 : * @dev: Device to be put back online.
4142 : *
4143 : * If device_offline() has been successfully executed for @dev, but the device
4144 : * has not been removed subsequently, execute its bus type's .online() callback
4145 : * to indicate that the device can be used again.
4146 : *
4147 : * Call under device_hotplug_lock.
4148 : */
4149 0 : int device_online(struct device *dev)
4150 : {
4151 0 : int ret = 0;
4152 :
4153 0 : device_lock(dev);
4154 0 : if (device_supports_offline(dev)) {
4155 0 : if (dev->offline) {
4156 0 : ret = dev->bus->online(dev);
4157 0 : if (!ret) {
4158 0 : kobject_uevent(&dev->kobj, KOBJ_ONLINE);
4159 0 : dev->offline = false;
4160 : }
4161 : } else {
4162 : ret = 1;
4163 : }
4164 : }
4165 0 : device_unlock(dev);
4166 :
4167 0 : return ret;
4168 : }
4169 :
4170 : struct root_device {
4171 : struct device dev;
4172 : struct module *owner;
4173 : };
4174 :
4175 : static inline struct root_device *to_root_device(struct device *d)
4176 : {
4177 0 : return container_of(d, struct root_device, dev);
4178 : }
4179 :
4180 0 : static void root_device_release(struct device *dev)
4181 : {
4182 0 : kfree(to_root_device(dev));
4183 0 : }
4184 :
4185 : /**
4186 : * __root_device_register - allocate and register a root device
4187 : * @name: root device name
4188 : * @owner: owner module of the root device, usually THIS_MODULE
4189 : *
4190 : * This function allocates a root device and registers it
4191 : * using device_register(). In order to free the returned
4192 : * device, use root_device_unregister().
4193 : *
4194 : * Root devices are dummy devices which allow other devices
4195 : * to be grouped under /sys/devices. Use this function to
4196 : * allocate a root device and then use it as the parent of
4197 : * any device which should appear under /sys/devices/{name}
4198 : *
4199 : * The /sys/devices/{name} directory will also contain a
4200 : * 'module' symlink which points to the @owner directory
4201 : * in sysfs.
4202 : *
4203 : * Returns &struct device pointer on success, or ERR_PTR() on error.
4204 : *
4205 : * Note: You probably want to use root_device_register().
4206 : */
4207 0 : struct device *__root_device_register(const char *name, struct module *owner)
4208 : {
4209 : struct root_device *root;
4210 0 : int err = -ENOMEM;
4211 :
4212 0 : root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
4213 0 : if (!root)
4214 : return ERR_PTR(err);
4215 :
4216 0 : err = dev_set_name(&root->dev, "%s", name);
4217 0 : if (err) {
4218 0 : kfree(root);
4219 0 : return ERR_PTR(err);
4220 : }
4221 :
4222 0 : root->dev.release = root_device_release;
4223 :
4224 0 : err = device_register(&root->dev);
4225 0 : if (err) {
4226 0 : put_device(&root->dev);
4227 0 : return ERR_PTR(err);
4228 : }
4229 :
4230 : #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
4231 : if (owner) {
4232 : struct module_kobject *mk = &owner->mkobj;
4233 :
4234 : err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
4235 : if (err) {
4236 : device_unregister(&root->dev);
4237 : return ERR_PTR(err);
4238 : }
4239 : root->owner = owner;
4240 : }
4241 : #endif
4242 :
4243 : return &root->dev;
4244 : }
4245 : EXPORT_SYMBOL_GPL(__root_device_register);
4246 :
4247 : /**
4248 : * root_device_unregister - unregister and free a root device
4249 : * @dev: device going away
4250 : *
4251 : * This function unregisters and cleans up a device that was created by
4252 : * root_device_register().
4253 : */
4254 0 : void root_device_unregister(struct device *dev)
4255 : {
4256 0 : struct root_device *root = to_root_device(dev);
4257 :
4258 0 : if (root->owner)
4259 0 : sysfs_remove_link(&root->dev.kobj, "module");
4260 :
4261 0 : device_unregister(dev);
4262 0 : }
4263 : EXPORT_SYMBOL_GPL(root_device_unregister);
4264 :
4265 :
4266 0 : static void device_create_release(struct device *dev)
4267 : {
4268 : pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
4269 0 : kfree(dev);
4270 0 : }
4271 :
4272 : static __printf(6, 0) struct device *
4273 12 : device_create_groups_vargs(const struct class *class, struct device *parent,
4274 : dev_t devt, void *drvdata,
4275 : const struct attribute_group **groups,
4276 : const char *fmt, va_list args)
4277 : {
4278 12 : struct device *dev = NULL;
4279 12 : int retval = -ENODEV;
4280 :
4281 12 : if (IS_ERR_OR_NULL(class))
4282 : goto error;
4283 :
4284 12 : dev = kzalloc(sizeof(*dev), GFP_KERNEL);
4285 12 : if (!dev) {
4286 : retval = -ENOMEM;
4287 : goto error;
4288 : }
4289 :
4290 12 : device_initialize(dev);
4291 12 : dev->devt = devt;
4292 12 : dev->class = class;
4293 12 : dev->parent = parent;
4294 12 : dev->groups = groups;
4295 12 : dev->release = device_create_release;
4296 24 : dev_set_drvdata(dev, drvdata);
4297 :
4298 12 : retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
4299 12 : if (retval)
4300 : goto error;
4301 :
4302 12 : retval = device_add(dev);
4303 12 : if (retval)
4304 : goto error;
4305 :
4306 : return dev;
4307 :
4308 : error:
4309 0 : put_device(dev);
4310 0 : return ERR_PTR(retval);
4311 : }
4312 :
4313 : /**
4314 : * device_create - creates a device and registers it with sysfs
4315 : * @class: pointer to the struct class that this device should be registered to
4316 : * @parent: pointer to the parent struct device of this new device, if any
4317 : * @devt: the dev_t for the char device to be added
4318 : * @drvdata: the data to be added to the device for callbacks
4319 : * @fmt: string for the device's name
4320 : *
4321 : * This function can be used by char device classes. A struct device
4322 : * will be created in sysfs, registered to the specified class.
4323 : *
4324 : * A "dev" file will be created, showing the dev_t for the device, if
4325 : * the dev_t is not 0,0.
4326 : * If a pointer to a parent struct device is passed in, the newly created
4327 : * struct device will be a child of that device in sysfs.
4328 : * The pointer to the struct device will be returned from the call.
4329 : * Any further sysfs files that might be required can be created using this
4330 : * pointer.
4331 : *
4332 : * Returns &struct device pointer on success, or ERR_PTR() on error.
4333 : */
4334 9 : struct device *device_create(const struct class *class, struct device *parent,
4335 : dev_t devt, void *drvdata, const char *fmt, ...)
4336 : {
4337 : va_list vargs;
4338 : struct device *dev;
4339 :
4340 9 : va_start(vargs, fmt);
4341 9 : dev = device_create_groups_vargs(class, parent, devt, drvdata, NULL,
4342 : fmt, vargs);
4343 9 : va_end(vargs);
4344 9 : return dev;
4345 : }
4346 : EXPORT_SYMBOL_GPL(device_create);
4347 :
4348 : /**
4349 : * device_create_with_groups - creates a device and registers it with sysfs
4350 : * @class: pointer to the struct class that this device should be registered to
4351 : * @parent: pointer to the parent struct device of this new device, if any
4352 : * @devt: the dev_t for the char device to be added
4353 : * @drvdata: the data to be added to the device for callbacks
4354 : * @groups: NULL-terminated list of attribute groups to be created
4355 : * @fmt: string for the device's name
4356 : *
4357 : * This function can be used by char device classes. A struct device
4358 : * will be created in sysfs, registered to the specified class.
4359 : * Additional attributes specified in the groups parameter will also
4360 : * be created automatically.
4361 : *
4362 : * A "dev" file will be created, showing the dev_t for the device, if
4363 : * the dev_t is not 0,0.
4364 : * If a pointer to a parent struct device is passed in, the newly created
4365 : * struct device will be a child of that device in sysfs.
4366 : * The pointer to the struct device will be returned from the call.
4367 : * Any further sysfs files that might be required can be created using this
4368 : * pointer.
4369 : *
4370 : * Returns &struct device pointer on success, or ERR_PTR() on error.
4371 : */
4372 3 : struct device *device_create_with_groups(const struct class *class,
4373 : struct device *parent, dev_t devt,
4374 : void *drvdata,
4375 : const struct attribute_group **groups,
4376 : const char *fmt, ...)
4377 : {
4378 : va_list vargs;
4379 : struct device *dev;
4380 :
4381 3 : va_start(vargs, fmt);
4382 3 : dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
4383 : fmt, vargs);
4384 3 : va_end(vargs);
4385 3 : return dev;
4386 : }
4387 : EXPORT_SYMBOL_GPL(device_create_with_groups);
4388 :
4389 : /**
4390 : * device_destroy - removes a device that was created with device_create()
4391 : * @class: pointer to the struct class that this device was registered with
4392 : * @devt: the dev_t of the device that was previously registered
4393 : *
4394 : * This call unregisters and cleans up a device that was created with a
4395 : * call to device_create().
4396 : */
4397 0 : void device_destroy(const struct class *class, dev_t devt)
4398 : {
4399 : struct device *dev;
4400 :
4401 0 : dev = class_find_device_by_devt(class, devt);
4402 0 : if (dev) {
4403 0 : put_device(dev);
4404 : device_unregister(dev);
4405 : }
4406 0 : }
4407 : EXPORT_SYMBOL_GPL(device_destroy);
4408 :
4409 : /**
4410 : * device_rename - renames a device
4411 : * @dev: the pointer to the struct device to be renamed
4412 : * @new_name: the new name of the device
4413 : *
4414 : * It is the responsibility of the caller to provide mutual
4415 : * exclusion between two different calls of device_rename
4416 : * on the same device to ensure that new_name is valid and
4417 : * won't conflict with other devices.
4418 : *
4419 : * Note: given that some subsystems (networking and infiniband) use this
4420 : * function, with no immediate plans for this to change, we cannot assume or
4421 : * require that this function not be called at all.
4422 : *
4423 : * However, if you're writing new code, do not call this function. The following
4424 : * text from Kay Sievers offers some insight:
4425 : *
4426 : * Renaming devices is racy at many levels, symlinks and other stuff are not
4427 : * replaced atomically, and you get a "move" uevent, but it's not easy to
4428 : * connect the event to the old and new device. Device nodes are not renamed at
4429 : * all, there isn't even support for that in the kernel now.
4430 : *
4431 : * In the meantime, during renaming, your target name might be taken by another
4432 : * driver, creating conflicts. Or the old name is taken directly after you
4433 : * renamed it -- then you get events for the same DEVPATH, before you even see
4434 : * the "move" event. It's just a mess, and nothing new should ever rely on
4435 : * kernel device renaming. Besides that, it's not even implemented now for
4436 : * other things than (driver-core wise very simple) network devices.
4437 : *
4438 : * Make up a "real" name in the driver before you register anything, or add
4439 : * some other attributes for userspace to find the device, or use udev to add
4440 : * symlinks -- but never rename kernel devices later, it's a complete mess. We
4441 : * don't even want to get into that and try to implement the missing pieces in
4442 : * the core. We really have other pieces to fix in the driver core mess. :)
4443 : */
4444 0 : int device_rename(struct device *dev, const char *new_name)
4445 : {
4446 0 : struct kobject *kobj = &dev->kobj;
4447 0 : char *old_device_name = NULL;
4448 : int error;
4449 :
4450 0 : dev = get_device(dev);
4451 0 : if (!dev)
4452 : return -EINVAL;
4453 :
4454 : dev_dbg(dev, "renaming to %s\n", new_name);
4455 :
4456 0 : old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
4457 0 : if (!old_device_name) {
4458 : error = -ENOMEM;
4459 : goto out;
4460 : }
4461 :
4462 0 : if (dev->class) {
4463 0 : struct subsys_private *sp = class_to_subsys(dev->class);
4464 :
4465 0 : if (!sp) {
4466 : error = -EINVAL;
4467 : goto out;
4468 : }
4469 :
4470 0 : error = sysfs_rename_link_ns(&sp->subsys.kobj, kobj, old_device_name,
4471 : new_name, kobject_namespace(kobj));
4472 0 : subsys_put(sp);
4473 0 : if (error)
4474 : goto out;
4475 : }
4476 :
4477 0 : error = kobject_rename(kobj, new_name);
4478 : if (error)
4479 : goto out;
4480 :
4481 : out:
4482 0 : put_device(dev);
4483 :
4484 0 : kfree(old_device_name);
4485 :
4486 0 : return error;
4487 : }
4488 : EXPORT_SYMBOL_GPL(device_rename);
4489 :
4490 0 : static int device_move_class_links(struct device *dev,
4491 : struct device *old_parent,
4492 : struct device *new_parent)
4493 : {
4494 0 : int error = 0;
4495 :
4496 0 : if (old_parent)
4497 0 : sysfs_remove_link(&dev->kobj, "device");
4498 0 : if (new_parent)
4499 0 : error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
4500 : "device");
4501 0 : return error;
4502 : }
4503 :
4504 : /**
4505 : * device_move - moves a device to a new parent
4506 : * @dev: the pointer to the struct device to be moved
4507 : * @new_parent: the new parent of the device (can be NULL)
4508 : * @dpm_order: how to reorder the dpm_list
4509 : */
4510 0 : int device_move(struct device *dev, struct device *new_parent,
4511 : enum dpm_order dpm_order)
4512 : {
4513 : int error;
4514 : struct device *old_parent;
4515 : struct kobject *new_parent_kobj;
4516 :
4517 0 : dev = get_device(dev);
4518 0 : if (!dev)
4519 : return -EINVAL;
4520 :
4521 0 : device_pm_lock();
4522 0 : new_parent = get_device(new_parent);
4523 0 : new_parent_kobj = get_device_parent(dev, new_parent);
4524 0 : if (IS_ERR(new_parent_kobj)) {
4525 0 : error = PTR_ERR(new_parent_kobj);
4526 : put_device(new_parent);
4527 : goto out;
4528 : }
4529 :
4530 : pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
4531 : __func__, new_parent ? dev_name(new_parent) : "<NULL>");
4532 0 : error = kobject_move(&dev->kobj, new_parent_kobj);
4533 0 : if (error) {
4534 0 : cleanup_glue_dir(dev, new_parent_kobj);
4535 : put_device(new_parent);
4536 : goto out;
4537 : }
4538 0 : old_parent = dev->parent;
4539 0 : dev->parent = new_parent;
4540 0 : if (old_parent)
4541 0 : klist_remove(&dev->p->knode_parent);
4542 0 : if (new_parent) {
4543 0 : klist_add_tail(&dev->p->knode_parent,
4544 0 : &new_parent->p->klist_children);
4545 : set_dev_node(dev, dev_to_node(new_parent));
4546 : }
4547 :
4548 0 : if (dev->class) {
4549 0 : error = device_move_class_links(dev, old_parent, new_parent);
4550 0 : if (error) {
4551 : /* We ignore errors on cleanup since we're hosed anyway... */
4552 0 : device_move_class_links(dev, new_parent, old_parent);
4553 0 : if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
4554 0 : if (new_parent)
4555 0 : klist_remove(&dev->p->knode_parent);
4556 0 : dev->parent = old_parent;
4557 0 : if (old_parent) {
4558 0 : klist_add_tail(&dev->p->knode_parent,
4559 0 : &old_parent->p->klist_children);
4560 0 : set_dev_node(dev, dev_to_node(old_parent));
4561 : }
4562 : }
4563 0 : cleanup_glue_dir(dev, new_parent_kobj);
4564 : put_device(new_parent);
4565 : goto out;
4566 : }
4567 : }
4568 0 : switch (dpm_order) {
4569 : case DPM_ORDER_NONE:
4570 : break;
4571 : case DPM_ORDER_DEV_AFTER_PARENT:
4572 0 : device_pm_move_after(dev, new_parent);
4573 : devices_kset_move_after(dev, new_parent);
4574 : break;
4575 : case DPM_ORDER_PARENT_BEFORE_DEV:
4576 0 : device_pm_move_before(new_parent, dev);
4577 : devices_kset_move_before(new_parent, dev);
4578 : break;
4579 : case DPM_ORDER_DEV_LAST:
4580 0 : device_pm_move_last(dev);
4581 : devices_kset_move_last(dev);
4582 : break;
4583 : }
4584 :
4585 : put_device(old_parent);
4586 : out:
4587 0 : device_pm_unlock();
4588 0 : put_device(dev);
4589 0 : return error;
4590 : }
4591 : EXPORT_SYMBOL_GPL(device_move);
4592 :
4593 0 : static int device_attrs_change_owner(struct device *dev, kuid_t kuid,
4594 : kgid_t kgid)
4595 : {
4596 0 : struct kobject *kobj = &dev->kobj;
4597 0 : const struct class *class = dev->class;
4598 0 : const struct device_type *type = dev->type;
4599 : int error;
4600 :
4601 0 : if (class) {
4602 : /*
4603 : * Change the device groups of the device class for @dev to
4604 : * @kuid/@kgid.
4605 : */
4606 0 : error = sysfs_groups_change_owner(kobj, class->dev_groups, kuid,
4607 : kgid);
4608 0 : if (error)
4609 : return error;
4610 : }
4611 :
4612 0 : if (type) {
4613 : /*
4614 : * Change the device groups of the device type for @dev to
4615 : * @kuid/@kgid.
4616 : */
4617 0 : error = sysfs_groups_change_owner(kobj, type->groups, kuid,
4618 : kgid);
4619 0 : if (error)
4620 : return error;
4621 : }
4622 :
4623 : /* Change the device groups of @dev to @kuid/@kgid. */
4624 0 : error = sysfs_groups_change_owner(kobj, dev->groups, kuid, kgid);
4625 0 : if (error)
4626 : return error;
4627 :
4628 0 : if (device_supports_offline(dev) && !dev->offline_disabled) {
4629 : /* Change online device attributes of @dev to @kuid/@kgid. */
4630 0 : error = sysfs_file_change_owner(kobj, dev_attr_online.attr.name,
4631 : kuid, kgid);
4632 0 : if (error)
4633 : return error;
4634 : }
4635 :
4636 : return 0;
4637 : }
4638 :
4639 : /**
4640 : * device_change_owner - change the owner of an existing device.
4641 : * @dev: device.
4642 : * @kuid: new owner's kuid
4643 : * @kgid: new owner's kgid
4644 : *
4645 : * This changes the owner of @dev and its corresponding sysfs entries to
4646 : * @kuid/@kgid. This function closely mirrors how @dev was added via driver
4647 : * core.
4648 : *
4649 : * Returns 0 on success or error code on failure.
4650 : */
4651 0 : int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
4652 : {
4653 : int error;
4654 0 : struct kobject *kobj = &dev->kobj;
4655 : struct subsys_private *sp;
4656 :
4657 0 : dev = get_device(dev);
4658 0 : if (!dev)
4659 : return -EINVAL;
4660 :
4661 : /*
4662 : * Change the kobject and the default attributes and groups of the
4663 : * ktype associated with it to @kuid/@kgid.
4664 : */
4665 0 : error = sysfs_change_owner(kobj, kuid, kgid);
4666 0 : if (error)
4667 : goto out;
4668 :
4669 : /*
4670 : * Change the uevent file for @dev to the new owner. The uevent file
4671 : * was created in a separate step when @dev got added and we mirror
4672 : * that step here.
4673 : */
4674 0 : error = sysfs_file_change_owner(kobj, dev_attr_uevent.attr.name, kuid,
4675 : kgid);
4676 0 : if (error)
4677 : goto out;
4678 :
4679 : /*
4680 : * Change the device groups, the device groups associated with the
4681 : * device class, and the groups associated with the device type of @dev
4682 : * to @kuid/@kgid.
4683 : */
4684 0 : error = device_attrs_change_owner(dev, kuid, kgid);
4685 0 : if (error)
4686 : goto out;
4687 :
4688 0 : error = dpm_sysfs_change_owner(dev, kuid, kgid);
4689 0 : if (error)
4690 : goto out;
4691 :
4692 : /*
4693 : * Change the owner of the symlink located in the class directory of
4694 : * the device class associated with @dev which points to the actual
4695 : * directory entry for @dev to @kuid/@kgid. This ensures that the
4696 : * symlink shows the same permissions as its target.
4697 : */
4698 0 : sp = class_to_subsys(dev->class);
4699 0 : if (!sp) {
4700 : error = -EINVAL;
4701 : goto out;
4702 : }
4703 0 : error = sysfs_link_change_owner(&sp->subsys.kobj, &dev->kobj, dev_name(dev), kuid, kgid);
4704 : subsys_put(sp);
4705 :
4706 : out:
4707 0 : put_device(dev);
4708 0 : return error;
4709 : }
4710 : EXPORT_SYMBOL_GPL(device_change_owner);
4711 :
4712 : /**
4713 : * device_shutdown - call ->shutdown() on each device to shutdown.
4714 : */
4715 1 : void device_shutdown(void)
4716 : {
4717 : struct device *dev, *parent;
4718 :
4719 1 : wait_for_device_probe();
4720 1 : device_block_probing();
4721 :
4722 : cpufreq_suspend();
4723 :
4724 1 : spin_lock(&devices_kset->list_lock);
4725 : /*
4726 : * Walk the devices list backward, shutting down each in turn.
4727 : * Beware that device unplug events may also start pulling
4728 : * devices offline, even as the system is shutting down.
4729 : */
4730 1072 : while (!list_empty(&devices_kset->list)) {
4731 535 : dev = list_entry(devices_kset->list.prev, struct device,
4732 : kobj.entry);
4733 :
4734 : /*
4735 : * hold reference count of device's parent to
4736 : * prevent it from being freed because parent's
4737 : * lock is to be held
4738 : */
4739 1070 : parent = get_device(dev->parent);
4740 535 : get_device(dev);
4741 : /*
4742 : * Make sure the device is off the kset list, in the
4743 : * event that dev->*->shutdown() doesn't remove it.
4744 : */
4745 1070 : list_del_init(&dev->kobj.entry);
4746 1070 : spin_unlock(&devices_kset->list_lock);
4747 :
4748 : /* hold lock to avoid race with probe/release */
4749 535 : if (parent)
4750 : device_lock(parent);
4751 535 : device_lock(dev);
4752 :
4753 : /* Don't allow any more runtime suspends */
4754 535 : pm_runtime_get_noresume(dev);
4755 535 : pm_runtime_barrier(dev);
4756 :
4757 535 : if (dev->class && dev->class->shutdown_pre) {
4758 0 : if (initcall_debug)
4759 0 : dev_info(dev, "shutdown_pre\n");
4760 0 : dev->class->shutdown_pre(dev);
4761 : }
4762 535 : if (dev->bus && dev->bus->shutdown) {
4763 0 : if (initcall_debug)
4764 0 : dev_info(dev, "shutdown\n");
4765 0 : dev->bus->shutdown(dev);
4766 535 : } else if (dev->driver && dev->driver->shutdown) {
4767 0 : if (initcall_debug)
4768 0 : dev_info(dev, "shutdown\n");
4769 0 : dev->driver->shutdown(dev);
4770 : }
4771 :
4772 535 : device_unlock(dev);
4773 535 : if (parent)
4774 : device_unlock(parent);
4775 :
4776 535 : put_device(dev);
4777 535 : put_device(parent);
4778 :
4779 535 : spin_lock(&devices_kset->list_lock);
4780 : }
4781 2 : spin_unlock(&devices_kset->list_lock);
4782 1 : }
4783 :
4784 : /*
4785 : * Device logging functions
4786 : */
4787 :
4788 : #ifdef CONFIG_PRINTK
4789 : static void
4790 0 : set_dev_info(const struct device *dev, struct dev_printk_info *dev_info)
4791 : {
4792 : const char *subsys;
4793 :
4794 0 : memset(dev_info, 0, sizeof(*dev_info));
4795 :
4796 0 : if (dev->class)
4797 0 : subsys = dev->class->name;
4798 0 : else if (dev->bus)
4799 0 : subsys = dev->bus->name;
4800 : else
4801 : return;
4802 :
4803 0 : strscpy(dev_info->subsystem, subsys, sizeof(dev_info->subsystem));
4804 :
4805 : /*
4806 : * Add device identifier DEVICE=:
4807 : * b12:8 block dev_t
4808 : * c127:3 char dev_t
4809 : * n8 netdev ifindex
4810 : * +sound:card0 subsystem:devname
4811 : */
4812 0 : if (MAJOR(dev->devt)) {
4813 : char c;
4814 :
4815 0 : if (strcmp(subsys, "block") == 0)
4816 : c = 'b';
4817 : else
4818 0 : c = 'c';
4819 :
4820 0 : snprintf(dev_info->device, sizeof(dev_info->device),
4821 0 : "%c%u:%u", c, MAJOR(dev->devt), MINOR(dev->devt));
4822 0 : } else if (strcmp(subsys, "net") == 0) {
4823 0 : struct net_device *net = to_net_dev(dev);
4824 :
4825 0 : snprintf(dev_info->device, sizeof(dev_info->device),
4826 : "n%u", net->ifindex);
4827 : } else {
4828 0 : snprintf(dev_info->device, sizeof(dev_info->device),
4829 : "+%s:%s", subsys, dev_name(dev));
4830 : }
4831 : }
4832 :
4833 0 : int dev_vprintk_emit(int level, const struct device *dev,
4834 : const char *fmt, va_list args)
4835 : {
4836 : struct dev_printk_info dev_info;
4837 :
4838 0 : set_dev_info(dev, &dev_info);
4839 :
4840 0 : return vprintk_emit(0, level, &dev_info, fmt, args);
4841 : }
4842 : EXPORT_SYMBOL(dev_vprintk_emit);
4843 :
4844 0 : int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
4845 : {
4846 : va_list args;
4847 : int r;
4848 :
4849 0 : va_start(args, fmt);
4850 :
4851 0 : r = dev_vprintk_emit(level, dev, fmt, args);
4852 :
4853 0 : va_end(args);
4854 :
4855 0 : return r;
4856 : }
4857 : EXPORT_SYMBOL(dev_printk_emit);
4858 :
4859 0 : static void __dev_printk(const char *level, const struct device *dev,
4860 : struct va_format *vaf)
4861 : {
4862 0 : if (dev)
4863 0 : dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
4864 : dev_driver_string(dev), dev_name(dev), vaf);
4865 : else
4866 0 : printk("%s(NULL device *): %pV", level, vaf);
4867 0 : }
4868 :
4869 0 : void _dev_printk(const char *level, const struct device *dev,
4870 : const char *fmt, ...)
4871 : {
4872 : struct va_format vaf;
4873 : va_list args;
4874 :
4875 0 : va_start(args, fmt);
4876 :
4877 0 : vaf.fmt = fmt;
4878 0 : vaf.va = &args;
4879 :
4880 0 : __dev_printk(level, dev, &vaf);
4881 :
4882 0 : va_end(args);
4883 0 : }
4884 : EXPORT_SYMBOL(_dev_printk);
4885 :
4886 : #define define_dev_printk_level(func, kern_level) \
4887 : void func(const struct device *dev, const char *fmt, ...) \
4888 : { \
4889 : struct va_format vaf; \
4890 : va_list args; \
4891 : \
4892 : va_start(args, fmt); \
4893 : \
4894 : vaf.fmt = fmt; \
4895 : vaf.va = &args; \
4896 : \
4897 : __dev_printk(kern_level, dev, &vaf); \
4898 : \
4899 : va_end(args); \
4900 : } \
4901 : EXPORT_SYMBOL(func);
4902 :
4903 0 : define_dev_printk_level(_dev_emerg, KERN_EMERG);
4904 0 : define_dev_printk_level(_dev_alert, KERN_ALERT);
4905 0 : define_dev_printk_level(_dev_crit, KERN_CRIT);
4906 0 : define_dev_printk_level(_dev_err, KERN_ERR);
4907 0 : define_dev_printk_level(_dev_warn, KERN_WARNING);
4908 0 : define_dev_printk_level(_dev_notice, KERN_NOTICE);
4909 0 : define_dev_printk_level(_dev_info, KERN_INFO);
4910 :
4911 : #endif
4912 :
4913 : /**
4914 : * dev_err_probe - probe error check and log helper
4915 : * @dev: the pointer to the struct device
4916 : * @err: error value to test
4917 : * @fmt: printf-style format string
4918 : * @...: arguments as specified in the format string
4919 : *
4920 : * This helper implements common pattern present in probe functions for error
4921 : * checking: print debug or error message depending if the error value is
4922 : * -EPROBE_DEFER and propagate error upwards.
4923 : * In case of -EPROBE_DEFER it sets also defer probe reason, which can be
4924 : * checked later by reading devices_deferred debugfs attribute.
4925 : * It replaces code sequence::
4926 : *
4927 : * if (err != -EPROBE_DEFER)
4928 : * dev_err(dev, ...);
4929 : * else
4930 : * dev_dbg(dev, ...);
4931 : * return err;
4932 : *
4933 : * with::
4934 : *
4935 : * return dev_err_probe(dev, err, ...);
4936 : *
4937 : * Note that it is deemed acceptable to use this function for error
4938 : * prints during probe even if the @err is known to never be -EPROBE_DEFER.
4939 : * The benefit compared to a normal dev_err() is the standardized format
4940 : * of the error code and the fact that the error code is returned.
4941 : *
4942 : * Returns @err.
4943 : *
4944 : */
4945 0 : int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
4946 : {
4947 : struct va_format vaf;
4948 : va_list args;
4949 :
4950 0 : va_start(args, fmt);
4951 0 : vaf.fmt = fmt;
4952 0 : vaf.va = &args;
4953 :
4954 0 : if (err != -EPROBE_DEFER) {
4955 0 : dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
4956 : } else {
4957 0 : device_set_deferred_probe_reason(dev, &vaf);
4958 : dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
4959 : }
4960 :
4961 0 : va_end(args);
4962 :
4963 0 : return err;
4964 : }
4965 : EXPORT_SYMBOL_GPL(dev_err_probe);
4966 :
4967 : static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
4968 : {
4969 0 : return fwnode && !IS_ERR(fwnode->secondary);
4970 : }
4971 :
4972 : /**
4973 : * set_primary_fwnode - Change the primary firmware node of a given device.
4974 : * @dev: Device to handle.
4975 : * @fwnode: New primary firmware node of the device.
4976 : *
4977 : * Set the device's firmware node pointer to @fwnode, but if a secondary
4978 : * firmware node of the device is present, preserve it.
4979 : *
4980 : * Valid fwnode cases are:
4981 : * - primary --> secondary --> -ENODEV
4982 : * - primary --> NULL
4983 : * - secondary --> -ENODEV
4984 : * - NULL
4985 : */
4986 0 : void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
4987 : {
4988 0 : struct device *parent = dev->parent;
4989 0 : struct fwnode_handle *fn = dev->fwnode;
4990 :
4991 0 : if (fwnode) {
4992 0 : if (fwnode_is_primary(fn))
4993 0 : fn = fn->secondary;
4994 :
4995 0 : if (fn) {
4996 0 : WARN_ON(fwnode->secondary);
4997 0 : fwnode->secondary = fn;
4998 : }
4999 0 : dev->fwnode = fwnode;
5000 : } else {
5001 0 : if (fwnode_is_primary(fn)) {
5002 0 : dev->fwnode = fn->secondary;
5003 :
5004 : /* Skip nullifying fn->secondary if the primary is shared */
5005 0 : if (parent && fn == parent->fwnode)
5006 : return;
5007 :
5008 : /* Set fn->secondary = NULL, so fn remains the primary fwnode */
5009 0 : fn->secondary = NULL;
5010 : } else {
5011 0 : dev->fwnode = NULL;
5012 : }
5013 : }
5014 : }
5015 : EXPORT_SYMBOL_GPL(set_primary_fwnode);
5016 :
5017 : /**
5018 : * set_secondary_fwnode - Change the secondary firmware node of a given device.
5019 : * @dev: Device to handle.
5020 : * @fwnode: New secondary firmware node of the device.
5021 : *
5022 : * If a primary firmware node of the device is present, set its secondary
5023 : * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
5024 : * @fwnode.
5025 : */
5026 0 : void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
5027 : {
5028 0 : if (fwnode)
5029 0 : fwnode->secondary = ERR_PTR(-ENODEV);
5030 :
5031 0 : if (fwnode_is_primary(dev->fwnode))
5032 0 : dev->fwnode->secondary = fwnode;
5033 : else
5034 0 : dev->fwnode = fwnode;
5035 0 : }
5036 : EXPORT_SYMBOL_GPL(set_secondary_fwnode);
5037 :
5038 : /**
5039 : * device_set_of_node_from_dev - reuse device-tree node of another device
5040 : * @dev: device whose device-tree node is being set
5041 : * @dev2: device whose device-tree node is being reused
5042 : *
5043 : * Takes another reference to the new device-tree node after first dropping
5044 : * any reference held to the old node.
5045 : */
5046 0 : void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
5047 : {
5048 0 : of_node_put(dev->of_node);
5049 0 : dev->of_node = of_node_get(dev2->of_node);
5050 0 : dev->of_node_reused = true;
5051 0 : }
5052 : EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
5053 :
5054 0 : void device_set_node(struct device *dev, struct fwnode_handle *fwnode)
5055 : {
5056 0 : dev->fwnode = fwnode;
5057 0 : dev->of_node = to_of_node(fwnode);
5058 0 : }
5059 : EXPORT_SYMBOL_GPL(device_set_node);
5060 :
5061 0 : int device_match_name(struct device *dev, const void *name)
5062 : {
5063 0 : return sysfs_streq(dev_name(dev), name);
5064 : }
5065 : EXPORT_SYMBOL_GPL(device_match_name);
5066 :
5067 0 : int device_match_of_node(struct device *dev, const void *np)
5068 : {
5069 0 : return dev->of_node == np;
5070 : }
5071 : EXPORT_SYMBOL_GPL(device_match_of_node);
5072 :
5073 0 : int device_match_fwnode(struct device *dev, const void *fwnode)
5074 : {
5075 0 : return dev_fwnode(dev) == fwnode;
5076 : }
5077 : EXPORT_SYMBOL_GPL(device_match_fwnode);
5078 :
5079 0 : int device_match_devt(struct device *dev, const void *pdevt)
5080 : {
5081 0 : return dev->devt == *(dev_t *)pdevt;
5082 : }
5083 : EXPORT_SYMBOL_GPL(device_match_devt);
5084 :
5085 0 : int device_match_acpi_dev(struct device *dev, const void *adev)
5086 : {
5087 0 : return ACPI_COMPANION(dev) == adev;
5088 : }
5089 : EXPORT_SYMBOL(device_match_acpi_dev);
5090 :
5091 0 : int device_match_acpi_handle(struct device *dev, const void *handle)
5092 : {
5093 0 : return ACPI_HANDLE(dev) == handle;
5094 : }
5095 : EXPORT_SYMBOL(device_match_acpi_handle);
5096 :
5097 0 : int device_match_any(struct device *dev, const void *unused)
5098 : {
5099 0 : return 1;
5100 : }
5101 : EXPORT_SYMBOL_GPL(device_match_any);
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