blob: 85b8955717fc27dc67e1e166bb484f73dcdaf5d5 [file] [log] [blame]
Greg Kroah-Hartman989d42e2017-11-07 17:30:07 +01001// SPDX-License-Identifier: GPL-2.0
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
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
Greg Kroah-Hartman64bb5d22006-06-28 16:19:58 -07007 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
8 * Copyright (c) 2006 Novell, Inc.
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 */
10
Heikki Krogerus7847a142018-11-09 17:21:35 +030011#include <linux/acpi.h>
Rafael J. Wysocki65650b32019-10-09 01:29:10 +020012#include <linux/cpufreq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/device.h>
14#include <linux/err.h>
Rafael J. Wysocki97badf82015-04-03 23:23:37 +020015#include <linux/fwnode.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/string.h>
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -070020#include <linux/kdev_t.h>
Benjamin Herrenschmidt116af372006-10-25 13:44:59 +100021#include <linux/notifier.h>
Grant Likely07d57a32012-02-01 11:22:22 -070022#include <linux/of.h>
23#include <linux/of_device.h>
Kay Sieversda231fd2007-11-21 17:29:15 +010024#include <linux/genhd.h>
Dave Youngf75b1c62008-05-28 09:28:39 -070025#include <linux/mutex.h>
Peter Chenaf8db152011-11-15 21:52:29 +010026#include <linux/pm_runtime.h>
Kay Sieversc4e00da2012-05-03 02:29:59 +020027#include <linux/netdevice.h>
Ingo Molnar174cd4b2017-02-02 19:15:33 +010028#include <linux/sched/signal.h>
Oliver Neukumb8530012020-09-16 21:15:44 +020029#include <linux/sched/mm.h>
Claire Chang69031f52021-06-19 11:40:34 +080030#include <linux/swiotlb.h>
Greg Kroah-Hartman63967682013-08-27 10:24:15 -070031#include <linux/sysfs.h>
Christoph Hellwig6d4e9a82021-02-10 10:56:39 +010032#include <linux/dma-map-ops.h> /* for dma_default_coherent */
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#include "base.h"
35#include "power/power.h"
36
Andi Kleene52eec12010-09-08 16:54:17 +020037#ifdef CONFIG_SYSFS_DEPRECATED
38#ifdef CONFIG_SYSFS_DEPRECATED_V2
39long sysfs_deprecated = 1;
40#else
41long sysfs_deprecated = 0;
42#endif
Hanjun Guo3454bf92013-08-17 20:42:24 +080043static int __init sysfs_deprecated_setup(char *arg)
Andi Kleene52eec12010-09-08 16:54:17 +020044{
Jingoo Han34da5e62013-07-26 13:10:22 +090045 return kstrtol(arg, 10, &sysfs_deprecated);
Andi Kleene52eec12010-09-08 16:54:17 +020046}
47early_param("sysfs.deprecated", sysfs_deprecated_setup);
48#endif
49
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +010050/* Device links support. */
Saravana Kannanfc5a2512019-09-04 14:11:23 -070051static LIST_HEAD(deferred_sync);
52static unsigned int defer_sync_state_count = 1;
Saravana Kannan7b337cb2020-11-20 18:02:23 -080053static DEFINE_MUTEX(fwnode_link_lock);
Saravana Kannan25ac86c2020-11-20 18:02:28 -080054static bool fw_devlink_is_permissive(void);
Saravana Kannand46f3e32021-04-01 21:03:41 -070055static bool fw_devlink_drv_reg_done;
Saravana Kannan7b337cb2020-11-20 18:02:23 -080056
57/**
58 * fwnode_link_add - Create a link between two fwnode_handles.
59 * @con: Consumer end of the link.
60 * @sup: Supplier end of the link.
61 *
62 * Create a fwnode link between fwnode handles @con and @sup. The fwnode link
63 * represents the detail that the firmware lists @sup fwnode as supplying a
64 * resource to @con.
65 *
66 * The driver core will use the fwnode link to create a device link between the
67 * two device objects corresponding to @con and @sup when they are created. The
68 * driver core will automatically delete the fwnode link between @con and @sup
69 * after doing that.
70 *
71 * Attempts to create duplicate links between the same pair of fwnode handles
72 * are ignored and there is no reference counting.
73 */
74int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
75{
76 struct fwnode_link *link;
77 int ret = 0;
78
79 mutex_lock(&fwnode_link_lock);
80
81 list_for_each_entry(link, &sup->consumers, s_hook)
82 if (link->consumer == con)
83 goto out;
84
85 link = kzalloc(sizeof(*link), GFP_KERNEL);
86 if (!link) {
87 ret = -ENOMEM;
88 goto out;
89 }
90
91 link->supplier = sup;
92 INIT_LIST_HEAD(&link->s_hook);
93 link->consumer = con;
94 INIT_LIST_HEAD(&link->c_hook);
95
96 list_add(&link->s_hook, &sup->consumers);
97 list_add(&link->c_hook, &con->suppliers);
98out:
99 mutex_unlock(&fwnode_link_lock);
100
101 return ret;
102}
103
104/**
105 * fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle.
106 * @fwnode: fwnode whose supplier links need to be deleted
107 *
108 * Deletes all supplier links connecting directly to @fwnode.
109 */
110static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode)
111{
112 struct fwnode_link *link, *tmp;
113
114 mutex_lock(&fwnode_link_lock);
115 list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
116 list_del(&link->s_hook);
117 list_del(&link->c_hook);
118 kfree(link);
119 }
120 mutex_unlock(&fwnode_link_lock);
121}
122
123/**
124 * fwnode_links_purge_consumers - Delete all consumer links of fwnode_handle.
125 * @fwnode: fwnode whose consumer links need to be deleted
126 *
127 * Deletes all consumer links connecting directly to @fwnode.
128 */
129static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode)
130{
131 struct fwnode_link *link, *tmp;
132
133 mutex_lock(&fwnode_link_lock);
134 list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
135 list_del(&link->s_hook);
136 list_del(&link->c_hook);
137 kfree(link);
138 }
139 mutex_unlock(&fwnode_link_lock);
140}
141
142/**
143 * fwnode_links_purge - Delete all links connected to a fwnode_handle.
144 * @fwnode: fwnode whose links needs to be deleted
145 *
146 * Deletes all links connecting directly to a fwnode.
147 */
148void fwnode_links_purge(struct fwnode_handle *fwnode)
149{
150 fwnode_links_purge_suppliers(fwnode);
151 fwnode_links_purge_consumers(fwnode);
152}
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100153
Saravana Kannan28ec3442021-05-05 17:44:22 -0700154void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
Saravana Kannan9528e0d2021-02-05 14:26:37 -0800155{
156 struct fwnode_handle *child;
157
158 /* Don't purge consumer links of an added child */
159 if (fwnode->dev)
160 return;
161
162 fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
163 fwnode_links_purge_consumers(fwnode);
164
165 fwnode_for_each_available_child_node(fwnode, child)
166 fw_devlink_purge_absent_suppliers(child);
167}
Saravana Kannan28ec3442021-05-05 17:44:22 -0700168EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers);
Saravana Kannan9528e0d2021-02-05 14:26:37 -0800169
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100170#ifdef CONFIG_SRCU
171static DEFINE_MUTEX(device_links_lock);
172DEFINE_STATIC_SRCU(device_links_srcu);
173
174static inline void device_links_write_lock(void)
175{
176 mutex_lock(&device_links_lock);
177}
178
179static inline void device_links_write_unlock(void)
180{
181 mutex_unlock(&device_links_lock);
182}
183
Jules Irenge68464d72020-02-14 20:47:29 +0000184int device_links_read_lock(void) __acquires(&device_links_srcu)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100185{
186 return srcu_read_lock(&device_links_srcu);
187}
188
Jules Irengeab7789c2020-02-14 20:47:30 +0000189void device_links_read_unlock(int idx) __releases(&device_links_srcu)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100190{
191 srcu_read_unlock(&device_links_srcu, idx);
192}
Joel Fernandes (Google)c2fa1e12019-07-16 18:12:25 -0400193
194int device_links_read_lock_held(void)
195{
196 return srcu_read_lock_held(&device_links_srcu);
197}
Rafael J. Wysocki80dd33c2021-05-14 14:10:15 +0200198
199static void device_link_synchronize_removal(void)
200{
201 synchronize_srcu(&device_links_srcu);
202}
Rafael J. Wysocki0c871312021-05-14 14:11:19 +0200203
204static void device_link_remove_from_lists(struct device_link *link)
205{
206 list_del_rcu(&link->s_node);
207 list_del_rcu(&link->c_node);
208}
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100209#else /* !CONFIG_SRCU */
210static DECLARE_RWSEM(device_links_lock);
211
212static inline void device_links_write_lock(void)
213{
214 down_write(&device_links_lock);
215}
216
217static inline void device_links_write_unlock(void)
218{
219 up_write(&device_links_lock);
220}
221
222int device_links_read_lock(void)
223{
224 down_read(&device_links_lock);
225 return 0;
226}
227
228void device_links_read_unlock(int not_used)
229{
230 up_read(&device_links_lock);
231}
Joel Fernandes (Google)c2fa1e12019-07-16 18:12:25 -0400232
233#ifdef CONFIG_DEBUG_LOCK_ALLOC
234int device_links_read_lock_held(void)
235{
236 return lockdep_is_held(&device_links_lock);
237}
238#endif
Rafael J. Wysocki80dd33c2021-05-14 14:10:15 +0200239
240static inline void device_link_synchronize_removal(void)
241{
242}
Rafael J. Wysocki0c871312021-05-14 14:11:19 +0200243
244static void device_link_remove_from_lists(struct device_link *link)
245{
246 list_del(&link->s_node);
247 list_del(&link->c_node);
248}
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100249#endif /* !CONFIG_SRCU */
250
Rafael J. Wysocki3d1cf432021-01-15 19:30:51 +0100251static bool device_is_ancestor(struct device *dev, struct device *target)
252{
253 while (target->parent) {
254 target = target->parent;
255 if (dev == target)
256 return true;
257 }
258 return false;
259}
260
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100261/**
262 * device_is_dependent - Check if one device depends on another one
263 * @dev: Device to check dependencies for.
264 * @target: Device to check against.
265 *
266 * Check if @target depends on @dev or any device dependent on it (its child or
267 * its consumer etc). Return 1 if that is the case or 0 otherwise.
268 */
Saravana Kannan7d34ca32020-06-09 18:19:33 -0700269int device_is_dependent(struct device *dev, void *target)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100270{
271 struct device_link *link;
272 int ret;
273
Rafael J. Wysocki3d1cf432021-01-15 19:30:51 +0100274 /*
275 * The "ancestors" check is needed to catch the case when the target
276 * device has not been completely initialized yet and it is still
277 * missing from the list of children of its parent device.
278 */
279 if (dev == target || device_is_ancestor(dev, target))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100280 return 1;
281
282 ret = device_for_each_child(dev, target, device_is_dependent);
283 if (ret)
284 return ret;
285
286 list_for_each_entry(link, &dev->links.consumers, s_node) {
Saravana Kannan4b9bbb22020-12-17 19:17:00 -0800287 if ((link->flags & ~DL_FLAG_INFERRED) ==
288 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
Saravana Kannan05ef9832019-10-28 15:00:22 -0700289 continue;
290
Benjamin Gaignarde16f4f32018-07-16 13:37:44 +0200291 if (link->consumer == target)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100292 return 1;
293
294 ret = device_is_dependent(link->consumer, target);
295 if (ret)
296 break;
297 }
298 return ret;
299}
300
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200301static void device_link_init_status(struct device_link *link,
302 struct device *consumer,
303 struct device *supplier)
304{
305 switch (supplier->links.status) {
306 case DL_DEV_PROBING:
307 switch (consumer->links.status) {
308 case DL_DEV_PROBING:
309 /*
310 * A consumer driver can create a link to a supplier
311 * that has not completed its probing yet as long as it
312 * knows that the supplier is already functional (for
313 * example, it has just acquired some resources from the
314 * supplier).
315 */
316 link->status = DL_STATE_CONSUMER_PROBE;
317 break;
318 default:
319 link->status = DL_STATE_DORMANT;
320 break;
321 }
322 break;
323 case DL_DEV_DRIVER_BOUND:
324 switch (consumer->links.status) {
325 case DL_DEV_PROBING:
326 link->status = DL_STATE_CONSUMER_PROBE;
327 break;
328 case DL_DEV_DRIVER_BOUND:
329 link->status = DL_STATE_ACTIVE;
330 break;
331 default:
332 link->status = DL_STATE_AVAILABLE;
333 break;
334 }
335 break;
336 case DL_DEV_UNBINDING:
337 link->status = DL_STATE_SUPPLIER_UNBIND;
338 break;
339 default:
340 link->status = DL_STATE_DORMANT;
341 break;
342 }
343}
344
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100345static int device_reorder_to_tail(struct device *dev, void *not_used)
346{
347 struct device_link *link;
348
349 /*
350 * Devices that have not been registered yet will be put to the ends
351 * of the lists during the registration, so skip them here.
352 */
353 if (device_is_registered(dev))
354 devices_kset_move_last(dev);
355
356 if (device_pm_initialized(dev))
357 device_pm_move_last(dev);
358
359 device_for_each_child(dev, NULL, device_reorder_to_tail);
Saravana Kannan05ef9832019-10-28 15:00:22 -0700360 list_for_each_entry(link, &dev->links.consumers, s_node) {
Saravana Kannan4b9bbb22020-12-17 19:17:00 -0800361 if ((link->flags & ~DL_FLAG_INFERRED) ==
362 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
Saravana Kannan05ef9832019-10-28 15:00:22 -0700363 continue;
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100364 device_reorder_to_tail(link->consumer, NULL);
Saravana Kannan05ef9832019-10-28 15:00:22 -0700365 }
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100366
367 return 0;
368}
369
370/**
Feng Kan494fd7b2018-04-10 16:57:06 -0700371 * device_pm_move_to_tail - Move set of devices to the end of device lists
372 * @dev: Device to move
373 *
374 * This is a device_reorder_to_tail() wrapper taking the requisite locks.
375 *
376 * It moves the @dev along with all of its children and all of its consumers
377 * to the ends of the device_kset and dpm_list, recursively.
378 */
379void device_pm_move_to_tail(struct device *dev)
380{
381 int idx;
382
383 idx = device_links_read_lock();
384 device_pm_lock();
385 device_reorder_to_tail(dev, NULL);
386 device_pm_unlock();
387 device_links_read_unlock(idx);
388}
389
Saravana Kannan287905e2020-05-21 12:17:58 -0700390#define to_devlink(dev) container_of((dev), struct device_link, link_dev)
391
392static ssize_t status_show(struct device *dev,
Joe Perches948b3ed2020-09-16 13:40:42 -0700393 struct device_attribute *attr, char *buf)
Saravana Kannan287905e2020-05-21 12:17:58 -0700394{
Joe Perches948b3ed2020-09-16 13:40:42 -0700395 const char *output;
Saravana Kannan287905e2020-05-21 12:17:58 -0700396
397 switch (to_devlink(dev)->status) {
398 case DL_STATE_NONE:
Joe Perches948b3ed2020-09-16 13:40:42 -0700399 output = "not tracked";
400 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700401 case DL_STATE_DORMANT:
Joe Perches948b3ed2020-09-16 13:40:42 -0700402 output = "dormant";
403 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700404 case DL_STATE_AVAILABLE:
Joe Perches948b3ed2020-09-16 13:40:42 -0700405 output = "available";
406 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700407 case DL_STATE_CONSUMER_PROBE:
Joe Perches948b3ed2020-09-16 13:40:42 -0700408 output = "consumer probing";
409 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700410 case DL_STATE_ACTIVE:
Joe Perches948b3ed2020-09-16 13:40:42 -0700411 output = "active";
412 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700413 case DL_STATE_SUPPLIER_UNBIND:
Joe Perches948b3ed2020-09-16 13:40:42 -0700414 output = "supplier unbinding";
415 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700416 default:
Joe Perches948b3ed2020-09-16 13:40:42 -0700417 output = "unknown";
418 break;
Saravana Kannan287905e2020-05-21 12:17:58 -0700419 }
Joe Perches948b3ed2020-09-16 13:40:42 -0700420
421 return sysfs_emit(buf, "%s\n", output);
Saravana Kannan287905e2020-05-21 12:17:58 -0700422}
423static DEVICE_ATTR_RO(status);
424
425static ssize_t auto_remove_on_show(struct device *dev,
426 struct device_attribute *attr, char *buf)
427{
428 struct device_link *link = to_devlink(dev);
Joe Perches973c3912020-09-16 13:40:40 -0700429 const char *output;
Saravana Kannan287905e2020-05-21 12:17:58 -0700430
431 if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
Joe Perches973c3912020-09-16 13:40:40 -0700432 output = "supplier unbind";
Saravana Kannan287905e2020-05-21 12:17:58 -0700433 else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
Joe Perches973c3912020-09-16 13:40:40 -0700434 output = "consumer unbind";
Saravana Kannan287905e2020-05-21 12:17:58 -0700435 else
Joe Perches973c3912020-09-16 13:40:40 -0700436 output = "never";
Saravana Kannan287905e2020-05-21 12:17:58 -0700437
Joe Perches973c3912020-09-16 13:40:40 -0700438 return sysfs_emit(buf, "%s\n", output);
Saravana Kannan287905e2020-05-21 12:17:58 -0700439}
440static DEVICE_ATTR_RO(auto_remove_on);
441
442static ssize_t runtime_pm_show(struct device *dev,
443 struct device_attribute *attr, char *buf)
444{
445 struct device_link *link = to_devlink(dev);
446
Joe Perchesaa838892020-09-16 13:40:39 -0700447 return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
Saravana Kannan287905e2020-05-21 12:17:58 -0700448}
449static DEVICE_ATTR_RO(runtime_pm);
450
451static ssize_t sync_state_only_show(struct device *dev,
452 struct device_attribute *attr, char *buf)
453{
454 struct device_link *link = to_devlink(dev);
455
Joe Perchesaa838892020-09-16 13:40:39 -0700456 return sysfs_emit(buf, "%d\n",
457 !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
Saravana Kannan287905e2020-05-21 12:17:58 -0700458}
459static DEVICE_ATTR_RO(sync_state_only);
460
461static struct attribute *devlink_attrs[] = {
462 &dev_attr_status.attr,
463 &dev_attr_auto_remove_on.attr,
464 &dev_attr_runtime_pm.attr,
465 &dev_attr_sync_state_only.attr,
466 NULL,
467};
468ATTRIBUTE_GROUPS(devlink);
469
Rafael J. Wysocki80dd33c2021-05-14 14:10:15 +0200470static void device_link_release_fn(struct work_struct *work)
Saravana Kannan843e6002020-07-16 14:45:23 -0700471{
Rafael J. Wysocki80dd33c2021-05-14 14:10:15 +0200472 struct device_link *link = container_of(work, struct device_link, rm_work);
473
474 /* Ensure that all references to the link object have been dropped. */
475 device_link_synchronize_removal();
476
Saravana Kannan843e6002020-07-16 14:45:23 -0700477 while (refcount_dec_not_one(&link->rpm_active))
478 pm_runtime_put(link->supplier);
479
480 put_device(link->consumer);
481 put_device(link->supplier);
482 kfree(link);
483}
484
Saravana Kannan287905e2020-05-21 12:17:58 -0700485static void devlink_dev_release(struct device *dev)
486{
Saravana Kannan843e6002020-07-16 14:45:23 -0700487 struct device_link *link = to_devlink(dev);
488
Rafael J. Wysocki80dd33c2021-05-14 14:10:15 +0200489 INIT_WORK(&link->rm_work, device_link_release_fn);
490 /*
491 * It may take a while to complete this work because of the SRCU
492 * synchronization in device_link_release_fn() and if the consumer or
493 * supplier devices get deleted when it runs, so put it into the "long"
494 * workqueue.
495 */
496 queue_work(system_long_wq, &link->rm_work);
Saravana Kannan287905e2020-05-21 12:17:58 -0700497}
498
499static struct class devlink_class = {
500 .name = "devlink",
501 .owner = THIS_MODULE,
502 .dev_groups = devlink_groups,
503 .dev_release = devlink_dev_release,
504};
505
506static int devlink_add_symlinks(struct device *dev,
507 struct class_interface *class_intf)
508{
509 int ret;
510 size_t len;
511 struct device_link *link = to_devlink(dev);
512 struct device *sup = link->supplier;
513 struct device *con = link->consumer;
514 char *buf;
515
Saravana Kannane020ff62021-01-10 09:54:07 -0800516 len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
517 strlen(dev_bus_name(con)) + strlen(dev_name(con)));
518 len += strlen(":");
Saravana Kannan287905e2020-05-21 12:17:58 -0700519 len += strlen("supplier:") + 1;
520 buf = kzalloc(len, GFP_KERNEL);
521 if (!buf)
522 return -ENOMEM;
523
524 ret = sysfs_create_link(&link->link_dev.kobj, &sup->kobj, "supplier");
525 if (ret)
526 goto out;
527
528 ret = sysfs_create_link(&link->link_dev.kobj, &con->kobj, "consumer");
529 if (ret)
530 goto err_con;
531
Saravana Kannane020ff62021-01-10 09:54:07 -0800532 snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
Saravana Kannan287905e2020-05-21 12:17:58 -0700533 ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf);
534 if (ret)
535 goto err_con_dev;
536
Saravana Kannane020ff62021-01-10 09:54:07 -0800537 snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
Saravana Kannan287905e2020-05-21 12:17:58 -0700538 ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf);
539 if (ret)
540 goto err_sup_dev;
541
542 goto out;
543
544err_sup_dev:
Saravana Kannane020ff62021-01-10 09:54:07 -0800545 snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
Saravana Kannan287905e2020-05-21 12:17:58 -0700546 sysfs_remove_link(&sup->kobj, buf);
547err_con_dev:
548 sysfs_remove_link(&link->link_dev.kobj, "consumer");
549err_con:
550 sysfs_remove_link(&link->link_dev.kobj, "supplier");
551out:
552 kfree(buf);
553 return ret;
554}
555
556static void devlink_remove_symlinks(struct device *dev,
557 struct class_interface *class_intf)
558{
559 struct device_link *link = to_devlink(dev);
560 size_t len;
561 struct device *sup = link->supplier;
562 struct device *con = link->consumer;
563 char *buf;
564
565 sysfs_remove_link(&link->link_dev.kobj, "consumer");
566 sysfs_remove_link(&link->link_dev.kobj, "supplier");
567
Saravana Kannane020ff62021-01-10 09:54:07 -0800568 len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
569 strlen(dev_bus_name(con)) + strlen(dev_name(con)));
570 len += strlen(":");
Saravana Kannan287905e2020-05-21 12:17:58 -0700571 len += strlen("supplier:") + 1;
572 buf = kzalloc(len, GFP_KERNEL);
573 if (!buf) {
574 WARN(1, "Unable to properly free device link symlinks!\n");
575 return;
576 }
577
Adrian Huntere64daad2021-07-16 14:44:07 +0300578 if (device_is_registered(con)) {
579 snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
580 sysfs_remove_link(&con->kobj, buf);
581 }
Saravana Kannane020ff62021-01-10 09:54:07 -0800582 snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
Saravana Kannan287905e2020-05-21 12:17:58 -0700583 sysfs_remove_link(&sup->kobj, buf);
584 kfree(buf);
585}
586
587static struct class_interface devlink_class_intf = {
588 .class = &devlink_class,
589 .add_dev = devlink_add_symlinks,
590 .remove_dev = devlink_remove_symlinks,
591};
592
593static int __init devlink_class_init(void)
594{
595 int ret;
596
597 ret = class_register(&devlink_class);
598 if (ret)
599 return ret;
600
601 ret = class_interface_register(&devlink_class_intf);
602 if (ret)
603 class_unregister(&devlink_class);
604
605 return ret;
606}
607postcore_initcall(devlink_class_init);
608
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200609#define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
610 DL_FLAG_AUTOREMOVE_SUPPLIER | \
Saravana Kannan05ef9832019-10-28 15:00:22 -0700611 DL_FLAG_AUTOPROBE_CONSUMER | \
Saravana Kannan4b9bbb22020-12-17 19:17:00 -0800612 DL_FLAG_SYNC_STATE_ONLY | \
613 DL_FLAG_INFERRED)
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200614
Rafael J. Wysockifb583c82019-07-30 11:28:57 +0200615#define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
616 DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
617
Feng Kan494fd7b2018-04-10 16:57:06 -0700618/**
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100619 * device_link_add - Create a link between two devices.
620 * @consumer: Consumer end of the link.
621 * @supplier: Supplier end of the link.
622 * @flags: Link flags.
623 *
Rafael J. Wysocki21d5c572016-10-30 17:32:31 +0100624 * The caller is responsible for the proper synchronization of the link creation
625 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
626 * runtime PM framework to take the link into account. Second, if the
627 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
Thierry Redingd475f8e2020-11-27 11:46:30 +0100628 * be forced into the active meta state and reference-counted upon the creation
Rafael J. Wysocki21d5c572016-10-30 17:32:31 +0100629 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
630 * ignored.
631 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200632 * If DL_FLAG_STATELESS is set in @flags, the caller of this function is
633 * expected to release the link returned by it directly with the help of either
634 * device_link_del() or device_link_remove().
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100635 *
636 * If that flag is not set, however, the caller of this function is handing the
637 * management of the link over to the driver core entirely and its return value
638 * can only be used to check whether or not the link is present. In that case,
639 * the DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER device link
640 * flags can be used to indicate to the driver core when the link can be safely
641 * deleted. Namely, setting one of them in @flags indicates to the driver core
642 * that the link is not going to be used (by the given caller of this function)
643 * after unbinding the consumer or supplier driver, respectively, from its
644 * device, so the link can be deleted at that point. If none of them is set,
645 * the link will be maintained until one of the devices pointed to by it (either
646 * the consumer or the supplier) is unregistered.
Rafael J. Wysockic8d50982019-02-01 01:45:55 +0100647 *
Rafael J. Wysockie7dd4012019-02-01 01:59:42 +0100648 * Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and
649 * DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent
650 * managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can
Thierry Redingd475f8e2020-11-27 11:46:30 +0100651 * be used to request the driver core to automatically probe for a consumer
Rafael J. Wysockie7dd4012019-02-01 01:59:42 +0100652 * driver after successfully binding a driver to the supplier device.
653 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200654 * The combination of DL_FLAG_STATELESS and one of DL_FLAG_AUTOREMOVE_CONSUMER,
655 * DL_FLAG_AUTOREMOVE_SUPPLIER, or DL_FLAG_AUTOPROBE_CONSUMER set in @flags at
656 * the same time is invalid and will cause NULL to be returned upfront.
657 * However, if a device link between the given @consumer and @supplier pair
658 * exists already when this function is called for them, the existing link will
659 * be returned regardless of its current type and status (the link's flags may
660 * be modified then). The caller of this function is then expected to treat
661 * the link as though it has just been created, so (in particular) if
662 * DL_FLAG_STATELESS was passed in @flags, the link needs to be released
663 * explicitly when not needed any more (as stated above).
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100664 *
665 * A side effect of the link creation is re-ordering of dpm_list and the
666 * devices_kset list by moving the consumer device and all devices depending
667 * on it to the ends of these lists (that does not happen to devices that have
668 * not been registered when this function is called).
669 *
670 * The supplier device is required to be registered when this function is called
671 * and NULL will be returned if that is not the case. The consumer device need
Lukas Wunner64df1142016-12-04 13:10:04 +0100672 * not be registered, however.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100673 */
674struct device_link *device_link_add(struct device *consumer,
675 struct device *supplier, u32 flags)
676{
677 struct device_link *link;
678
Rafael J. Wysockifb583c82019-07-30 11:28:57 +0200679 if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS ||
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200680 (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
Saravana Kannan05ef9832019-10-28 15:00:22 -0700681 (flags & DL_FLAG_SYNC_STATE_ONLY &&
Saravana Kannan4b9bbb22020-12-17 19:17:00 -0800682 (flags & ~DL_FLAG_INFERRED) != DL_FLAG_SYNC_STATE_ONLY) ||
Rafael J. Wysockie7dd4012019-02-01 01:59:42 +0100683 (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
684 flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
685 DL_FLAG_AUTOREMOVE_SUPPLIER)))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100686 return NULL;
687
Rafael J. Wysocki5db25c92019-02-01 01:47:53 +0100688 if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
689 if (pm_runtime_get_sync(supplier) < 0) {
690 pm_runtime_put_noidle(supplier);
691 return NULL;
692 }
Rafael J. Wysocki5db25c92019-02-01 01:47:53 +0100693 }
694
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200695 if (!(flags & DL_FLAG_STATELESS))
696 flags |= DL_FLAG_MANAGED;
697
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100698 device_links_write_lock();
699 device_pm_lock();
700
701 /*
702 * If the supplier has not been fully registered yet or there is a
Saravana Kannan05ef9832019-10-28 15:00:22 -0700703 * reverse (non-SYNC_STATE_ONLY) dependency between the consumer and
704 * the supplier already in the graph, return NULL. If the link is a
705 * SYNC_STATE_ONLY link, we don't check for reverse dependencies
706 * because it only affects sync_state() callbacks.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100707 */
708 if (!device_pm_initialized(supplier)
Saravana Kannan05ef9832019-10-28 15:00:22 -0700709 || (!(flags & DL_FLAG_SYNC_STATE_ONLY) &&
710 device_is_dependent(consumer, supplier))) {
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100711 link = NULL;
712 goto out;
713 }
714
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100715 /*
Saravana Kannanac66c5b2020-11-20 18:02:24 -0800716 * SYNC_STATE_ONLY links are useless once a consumer device has probed.
717 * So, only create it if the consumer hasn't probed yet.
718 */
719 if (flags & DL_FLAG_SYNC_STATE_ONLY &&
720 consumer->links.status != DL_DEV_NO_DRIVER &&
721 consumer->links.status != DL_DEV_PROBING) {
722 link = NULL;
723 goto out;
724 }
725
726 /*
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100727 * DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed
728 * longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both
729 * together doesn't make sense, so prefer DL_FLAG_AUTOREMOVE_SUPPLIER.
730 */
731 if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
732 flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
733
Rafael J. Wysockif265df52019-02-01 01:46:54 +0100734 list_for_each_entry(link, &supplier->links.consumers, s_node) {
735 if (link->consumer != consumer)
736 continue;
737
Saravana Kannan4b9bbb22020-12-17 19:17:00 -0800738 if (link->flags & DL_FLAG_INFERRED &&
739 !(flags & DL_FLAG_INFERRED))
740 link->flags &= ~DL_FLAG_INFERRED;
741
Rafael J. Wysockie2f3cd82019-02-01 01:49:14 +0100742 if (flags & DL_FLAG_PM_RUNTIME) {
743 if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
Rafael J. Wysocki4c06c4e2019-02-12 13:08:10 +0100744 pm_runtime_new_link(consumer);
Rafael J. Wysockie2f3cd82019-02-01 01:49:14 +0100745 link->flags |= DL_FLAG_PM_RUNTIME;
746 }
747 if (flags & DL_FLAG_RPM_ACTIVE)
Rafael J. Wysocki36003d42019-02-19 17:53:26 +0100748 refcount_inc(&link->rpm_active);
Rafael J. Wysockie2f3cd82019-02-01 01:49:14 +0100749 }
750
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100751 if (flags & DL_FLAG_STATELESS) {
752 kref_get(&link->kref);
Saravana Kannan05ef9832019-10-28 15:00:22 -0700753 if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
Saravana Kannan44e96042020-05-19 21:36:26 -0700754 !(link->flags & DL_FLAG_STATELESS)) {
755 link->flags |= DL_FLAG_STATELESS;
Saravana Kannan05ef9832019-10-28 15:00:22 -0700756 goto reorder;
Saravana Kannan44e96042020-05-19 21:36:26 -0700757 } else {
758 link->flags |= DL_FLAG_STATELESS;
Saravana Kannan05ef9832019-10-28 15:00:22 -0700759 goto out;
Saravana Kannan44e96042020-05-19 21:36:26 -0700760 }
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100761 }
762
763 /*
764 * If the life time of the link following from the new flags is
765 * longer than indicated by the flags of the existing link,
766 * update the existing link to stay around longer.
767 */
768 if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) {
769 if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
770 link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
771 link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
772 }
773 } else if (!(flags & DL_FLAG_AUTOREMOVE_CONSUMER)) {
774 link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER |
775 DL_FLAG_AUTOREMOVE_SUPPLIER);
776 }
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200777 if (!(link->flags & DL_FLAG_MANAGED)) {
778 kref_get(&link->kref);
779 link->flags |= DL_FLAG_MANAGED;
780 device_link_init_status(link, consumer, supplier);
781 }
Saravana Kannan05ef9832019-10-28 15:00:22 -0700782 if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
783 !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
784 link->flags &= ~DL_FLAG_SYNC_STATE_ONLY;
785 goto reorder;
786 }
787
Rafael J. Wysockif265df52019-02-01 01:46:54 +0100788 goto out;
789 }
790
Rafael J. Wysocki21d5c572016-10-30 17:32:31 +0100791 link = kzalloc(sizeof(*link), GFP_KERNEL);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100792 if (!link)
793 goto out;
794
Rafael J. Wysockie2f3cd82019-02-01 01:49:14 +0100795 refcount_set(&link->rpm_active, 1);
796
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100797 get_device(supplier);
798 link->supplier = supplier;
799 INIT_LIST_HEAD(&link->s_node);
800 get_device(consumer);
801 link->consumer = consumer;
802 INIT_LIST_HEAD(&link->c_node);
803 link->flags = flags;
Lukas Wunneread18c22018-02-10 19:27:12 +0100804 kref_init(&link->kref);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100805
Saravana Kannan287905e2020-05-21 12:17:58 -0700806 link->link_dev.class = &devlink_class;
807 device_set_pm_not_required(&link->link_dev);
Saravana Kannane020ff62021-01-10 09:54:07 -0800808 dev_set_name(&link->link_dev, "%s:%s--%s:%s",
809 dev_bus_name(supplier), dev_name(supplier),
810 dev_bus_name(consumer), dev_name(consumer));
Saravana Kannan287905e2020-05-21 12:17:58 -0700811 if (device_register(&link->link_dev)) {
812 put_device(consumer);
813 put_device(supplier);
814 kfree(link);
815 link = NULL;
816 goto out;
817 }
818
819 if (flags & DL_FLAG_PM_RUNTIME) {
820 if (flags & DL_FLAG_RPM_ACTIVE)
821 refcount_inc(&link->rpm_active);
822
823 pm_runtime_new_link(consumer);
824 }
825
Lukas Wunner64df1142016-12-04 13:10:04 +0100826 /* Determine the initial link state. */
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200827 if (flags & DL_FLAG_STATELESS)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100828 link->status = DL_STATE_NONE;
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200829 else
830 device_link_init_status(link, consumer, supplier);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100831
832 /*
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +0100833 * Some callers expect the link creation during consumer driver probe to
834 * resume the supplier even without DL_FLAG_RPM_ACTIVE.
835 */
836 if (link->status == DL_STATE_CONSUMER_PROBE &&
837 flags & DL_FLAG_PM_RUNTIME)
838 pm_runtime_resume(supplier);
839
Saravana Kannan21c27f02020-05-18 23:30:00 -0700840 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
841 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
842
Saravana Kannan05ef9832019-10-28 15:00:22 -0700843 if (flags & DL_FLAG_SYNC_STATE_ONLY) {
844 dev_dbg(consumer,
845 "Linked as a sync state only consumer to %s\n",
846 dev_name(supplier));
847 goto out;
848 }
Saravana Kannan21c27f02020-05-18 23:30:00 -0700849
Saravana Kannan05ef9832019-10-28 15:00:22 -0700850reorder:
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +0100851 /*
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100852 * Move the consumer and all of the devices depending on it to the end
853 * of dpm_list and the devices_kset list.
854 *
855 * It is necessary to hold dpm_list locked throughout all that or else
856 * we may end up suspending with a wrong ordering of it.
857 */
858 device_reorder_to_tail(consumer, NULL);
859
Jerome Brunet8a4b3262018-12-21 17:23:41 +0100860 dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100861
Saravana Kannan21c27f02020-05-18 23:30:00 -0700862out:
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100863 device_pm_unlock();
864 device_links_write_unlock();
Rafael J. Wysocki5db25c92019-02-01 01:47:53 +0100865
Rafael J. Wysockie2f3cd82019-02-01 01:49:14 +0100866 if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link)
Rafael J. Wysocki5db25c92019-02-01 01:47:53 +0100867 pm_runtime_put(supplier);
868
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100869 return link;
870}
871EXPORT_SYMBOL_GPL(device_link_add);
872
Lukas Wunneread18c22018-02-10 19:27:12 +0100873static void __device_link_del(struct kref *kref)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100874{
Lukas Wunneread18c22018-02-10 19:27:12 +0100875 struct device_link *link = container_of(kref, struct device_link, kref);
876
Jerome Brunet8a4b3262018-12-21 17:23:41 +0100877 dev_dbg(link->consumer, "Dropping the link to %s\n",
878 dev_name(link->supplier));
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100879
Rafael J. Wysockie0e398e2020-10-21 21:12:15 +0200880 pm_runtime_drop_link(link);
Rafael J. Wysockibaa88092016-10-30 17:32:43 +0100881
Rafael J. Wysocki0c871312021-05-14 14:11:19 +0200882 device_link_remove_from_lists(link);
Saravana Kannan843e6002020-07-16 14:45:23 -0700883 device_unregister(&link->link_dev);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100884}
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100885
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100886static void device_link_put_kref(struct device_link *link)
887{
888 if (link->flags & DL_FLAG_STATELESS)
889 kref_put(&link->kref, __device_link_del);
Adrian Hunterbf259672021-08-06 16:04:41 +0300890 else if (!device_is_registered(link->consumer))
891 __device_link_del(&link->kref);
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100892 else
893 WARN(1, "Unable to drop a managed device link reference\n");
894}
895
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100896/**
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100897 * device_link_del - Delete a stateless link between two devices.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100898 * @link: Device link to delete.
899 *
900 * The caller must ensure proper synchronization of this function with runtime
Lukas Wunneread18c22018-02-10 19:27:12 +0100901 * PM. If the link was added multiple times, it needs to be deleted as often.
902 * Care is required for hotplugged devices: Their links are purged on removal
903 * and calling device_link_del() is then no longer allowed.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100904 */
905void device_link_del(struct device_link *link)
906{
907 device_links_write_lock();
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100908 device_link_put_kref(link);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100909 device_links_write_unlock();
910}
911EXPORT_SYMBOL_GPL(device_link_del);
912
pascal pailletd8842212018-07-05 14:25:56 +0000913/**
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100914 * device_link_remove - Delete a stateless link between two devices.
pascal pailletd8842212018-07-05 14:25:56 +0000915 * @consumer: Consumer end of the link.
916 * @supplier: Supplier end of the link.
917 *
918 * The caller must ensure proper synchronization of this function with runtime
919 * PM.
920 */
921void device_link_remove(void *consumer, struct device *supplier)
922{
923 struct device_link *link;
924
925 if (WARN_ON(consumer == supplier))
926 return;
927
928 device_links_write_lock();
pascal pailletd8842212018-07-05 14:25:56 +0000929
930 list_for_each_entry(link, &supplier->links.consumers, s_node) {
931 if (link->consumer == consumer) {
Rafael J. Wysocki72175d42019-02-01 01:58:33 +0100932 device_link_put_kref(link);
pascal pailletd8842212018-07-05 14:25:56 +0000933 break;
934 }
935 }
936
pascal pailletd8842212018-07-05 14:25:56 +0000937 device_links_write_unlock();
938}
939EXPORT_SYMBOL_GPL(device_link_remove);
940
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100941static void device_links_missing_supplier(struct device *dev)
942{
943 struct device_link *link;
944
Saravana Kannan8c3e3152020-05-26 15:09:27 -0700945 list_for_each_entry(link, &dev->links.suppliers, c_node) {
946 if (link->status != DL_STATE_CONSUMER_PROBE)
947 continue;
948
949 if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100950 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
Saravana Kannan8c3e3152020-05-26 15:09:27 -0700951 } else {
952 WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
953 WRITE_ONCE(link->status, DL_STATE_DORMANT);
954 }
955 }
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100956}
957
958/**
959 * device_links_check_suppliers - Check presence of supplier drivers.
960 * @dev: Consumer device.
961 *
962 * Check links from this device to any suppliers. Walk the list of the device's
963 * links to suppliers and see if all of them are available. If not, simply
964 * return -EPROBE_DEFER.
965 *
966 * We need to guarantee that the supplier will not go away after the check has
967 * been positive here. It only can go away in __device_release_driver() and
968 * that function checks the device's links to consumers. This means we need to
969 * mark the link as "consumer probe in progress" to make the supplier removal
970 * wait for us to complete (or bad things may happen).
971 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +0200972 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100973 */
974int device_links_check_suppliers(struct device *dev)
975{
976 struct device_link *link;
977 int ret = 0;
978
Saravana Kannane2ae9bc2019-09-04 14:11:21 -0700979 /*
980 * Device waiting for supplier to become available is not allowed to
981 * probe.
982 */
Saravana Kannan25ac86c2020-11-20 18:02:28 -0800983 mutex_lock(&fwnode_link_lock);
984 if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
985 !fw_devlink_is_permissive()) {
Saravana Kannan1f0dfa02020-12-17 19:16:59 -0800986 dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
987 list_first_entry(&dev->fwnode->suppliers,
988 struct fwnode_link,
989 c_hook)->supplier);
Saravana Kannan25ac86c2020-11-20 18:02:28 -0800990 mutex_unlock(&fwnode_link_lock);
Saravana Kannane2ae9bc2019-09-04 14:11:21 -0700991 return -EPROBE_DEFER;
992 }
Saravana Kannan25ac86c2020-11-20 18:02:28 -0800993 mutex_unlock(&fwnode_link_lock);
Saravana Kannane2ae9bc2019-09-04 14:11:21 -0700994
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100995 device_links_write_lock();
996
997 list_for_each_entry(link, &dev->links.suppliers, c_node) {
Saravana Kannan8c3e3152020-05-26 15:09:27 -0700998 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +0100999 continue;
1000
Saravana Kannan8c3e3152020-05-26 15:09:27 -07001001 if (link->status != DL_STATE_AVAILABLE &&
1002 !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001003 device_links_missing_supplier(dev);
Saravana Kannan1f0dfa02020-12-17 19:16:59 -08001004 dev_dbg(dev, "probe deferral - supplier %s not ready\n",
1005 dev_name(link->supplier));
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001006 ret = -EPROBE_DEFER;
1007 break;
1008 }
1009 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
1010 }
1011 dev->links.status = DL_DEV_PROBING;
1012
1013 device_links_write_unlock();
1014 return ret;
1015}
1016
Saravana Kannan26e77702019-11-14 14:56:45 -08001017/**
1018 * __device_links_queue_sync_state - Queue a device for sync_state() callback
1019 * @dev: Device to call sync_state() on
1020 * @list: List head to queue the @dev on
1021 *
1022 * Queues a device for a sync_state() callback when the device links write lock
1023 * isn't held. This allows the sync_state() execution flow to use device links
1024 * APIs. The caller must ensure this function is called with
1025 * device_links_write_lock() held.
1026 *
1027 * This function does a get_device() to make sure the device is not freed while
1028 * on this list.
1029 *
1030 * So the caller must also ensure that device_links_flush_sync_list() is called
1031 * as soon as the caller releases device_links_write_lock(). This is necessary
1032 * to make sure the sync_state() is called in a timely fashion and the
1033 * put_device() is called on this device.
1034 */
1035static void __device_links_queue_sync_state(struct device *dev,
1036 struct list_head *list)
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001037{
1038 struct device_link *link;
1039
Saravana Kannan77036162020-02-21 00:05:10 -08001040 if (!dev_has_sync_state(dev))
1041 return;
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001042 if (dev->state_synced)
1043 return;
1044
1045 list_for_each_entry(link, &dev->links.consumers, s_node) {
1046 if (!(link->flags & DL_FLAG_MANAGED))
1047 continue;
1048 if (link->status != DL_STATE_ACTIVE)
1049 return;
1050 }
1051
Saravana Kannan26e77702019-11-14 14:56:45 -08001052 /*
1053 * Set the flag here to avoid adding the same device to a list more
1054 * than once. This can happen if new consumers get added to the device
1055 * and probed before the list is flushed.
1056 */
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001057 dev->state_synced = true;
Saravana Kannan26e77702019-11-14 14:56:45 -08001058
Saravana Kannan3b052a32020-11-20 18:02:17 -08001059 if (WARN_ON(!list_empty(&dev->links.defer_sync)))
Saravana Kannan26e77702019-11-14 14:56:45 -08001060 return;
1061
1062 get_device(dev);
Saravana Kannan3b052a32020-11-20 18:02:17 -08001063 list_add_tail(&dev->links.defer_sync, list);
Saravana Kannan26e77702019-11-14 14:56:45 -08001064}
1065
1066/**
1067 * device_links_flush_sync_list - Call sync_state() on a list of devices
1068 * @list: List of devices to call sync_state() on
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001069 * @dont_lock_dev: Device for which lock is already held by the caller
Saravana Kannan26e77702019-11-14 14:56:45 -08001070 *
1071 * Calls sync_state() on all the devices that have been queued for it. This
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001072 * function is used in conjunction with __device_links_queue_sync_state(). The
1073 * @dont_lock_dev parameter is useful when this function is called from a
1074 * context where a device lock is already held.
Saravana Kannan26e77702019-11-14 14:56:45 -08001075 */
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001076static void device_links_flush_sync_list(struct list_head *list,
1077 struct device *dont_lock_dev)
Saravana Kannan26e77702019-11-14 14:56:45 -08001078{
1079 struct device *dev, *tmp;
1080
Saravana Kannan3b052a32020-11-20 18:02:17 -08001081 list_for_each_entry_safe(dev, tmp, list, links.defer_sync) {
1082 list_del_init(&dev->links.defer_sync);
Saravana Kannan26e77702019-11-14 14:56:45 -08001083
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001084 if (dev != dont_lock_dev)
1085 device_lock(dev);
Saravana Kannan26e77702019-11-14 14:56:45 -08001086
1087 if (dev->bus->sync_state)
1088 dev->bus->sync_state(dev);
1089 else if (dev->driver && dev->driver->sync_state)
1090 dev->driver->sync_state(dev);
1091
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001092 if (dev != dont_lock_dev)
1093 device_unlock(dev);
Saravana Kannan26e77702019-11-14 14:56:45 -08001094
1095 put_device(dev);
1096 }
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001097}
1098
1099void device_links_supplier_sync_state_pause(void)
1100{
1101 device_links_write_lock();
1102 defer_sync_state_count++;
1103 device_links_write_unlock();
1104}
1105
1106void device_links_supplier_sync_state_resume(void)
1107{
1108 struct device *dev, *tmp;
Saravana Kannan26e77702019-11-14 14:56:45 -08001109 LIST_HEAD(sync_list);
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001110
1111 device_links_write_lock();
1112 if (!defer_sync_state_count) {
1113 WARN(true, "Unmatched sync_state pause/resume!");
1114 goto out;
1115 }
1116 defer_sync_state_count--;
1117 if (defer_sync_state_count)
1118 goto out;
1119
Saravana Kannan3b052a32020-11-20 18:02:17 -08001120 list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) {
Saravana Kannan26e77702019-11-14 14:56:45 -08001121 /*
1122 * Delete from deferred_sync list before queuing it to
Saravana Kannan3b052a32020-11-20 18:02:17 -08001123 * sync_list because defer_sync is used for both lists.
Saravana Kannan26e77702019-11-14 14:56:45 -08001124 */
Saravana Kannan3b052a32020-11-20 18:02:17 -08001125 list_del_init(&dev->links.defer_sync);
Saravana Kannan26e77702019-11-14 14:56:45 -08001126 __device_links_queue_sync_state(dev, &sync_list);
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001127 }
1128out:
1129 device_links_write_unlock();
Saravana Kannan26e77702019-11-14 14:56:45 -08001130
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001131 device_links_flush_sync_list(&sync_list, NULL);
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001132}
1133
1134static int sync_state_resume_initcall(void)
1135{
1136 device_links_supplier_sync_state_resume();
1137 return 0;
1138}
1139late_initcall(sync_state_resume_initcall);
1140
1141static void __device_links_supplier_defer_sync(struct device *sup)
1142{
Saravana Kannan3b052a32020-11-20 18:02:17 -08001143 if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup))
1144 list_add_tail(&sup->links.defer_sync, &deferred_sync);
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001145}
1146
Saravana Kannan21c27f02020-05-18 23:30:00 -07001147static void device_link_drop_managed(struct device_link *link)
1148{
1149 link->flags &= ~DL_FLAG_MANAGED;
1150 WRITE_ONCE(link->status, DL_STATE_NONE);
1151 kref_put(&link->kref, __device_link_del);
1152}
1153
Saravana Kannanda6d6472020-05-21 12:18:00 -07001154static ssize_t waiting_for_supplier_show(struct device *dev,
1155 struct device_attribute *attr,
1156 char *buf)
1157{
1158 bool val;
1159
1160 device_lock(dev);
Saravana Kannan25ac86c2020-11-20 18:02:28 -08001161 val = !list_empty(&dev->fwnode->suppliers);
Saravana Kannanda6d6472020-05-21 12:18:00 -07001162 device_unlock(dev);
Joe Perchesaa838892020-09-16 13:40:39 -07001163 return sysfs_emit(buf, "%u\n", val);
Saravana Kannanda6d6472020-05-21 12:18:00 -07001164}
1165static DEVICE_ATTR_RO(waiting_for_supplier);
1166
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001167/**
Saravana Kannanb6f617d2021-03-02 13:11:31 -08001168 * device_links_force_bind - Prepares device to be force bound
1169 * @dev: Consumer device.
1170 *
1171 * device_bind_driver() force binds a device to a driver without calling any
1172 * driver probe functions. So the consumer really isn't going to wait for any
1173 * supplier before it's bound to the driver. We still want the device link
1174 * states to be sensible when this happens.
1175 *
1176 * In preparation for device_bind_driver(), this function goes through each
1177 * supplier device links and checks if the supplier is bound. If it is, then
1178 * the device link status is set to CONSUMER_PROBE. Otherwise, the device link
1179 * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored.
1180 */
1181void device_links_force_bind(struct device *dev)
1182{
1183 struct device_link *link, *ln;
1184
1185 device_links_write_lock();
1186
1187 list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
1188 if (!(link->flags & DL_FLAG_MANAGED))
1189 continue;
1190
1191 if (link->status != DL_STATE_AVAILABLE) {
1192 device_link_drop_managed(link);
1193 continue;
1194 }
1195 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
1196 }
1197 dev->links.status = DL_DEV_PROBING;
1198
1199 device_links_write_unlock();
1200}
1201
1202/**
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001203 * device_links_driver_bound - Update device links after probing its driver.
1204 * @dev: Device to update the links for.
1205 *
1206 * The probe has been successful, so update links from this device to any
1207 * consumers by changing their status to "available".
1208 *
1209 * Also change the status of @dev's links to suppliers to "active".
1210 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001211 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001212 */
1213void device_links_driver_bound(struct device *dev)
1214{
Saravana Kannan21c27f02020-05-18 23:30:00 -07001215 struct device_link *link, *ln;
Saravana Kannan26e77702019-11-14 14:56:45 -08001216 LIST_HEAD(sync_list);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001217
Saravana Kannanbcbbcfd2019-10-28 15:00:23 -07001218 /*
Saravana Kannan9528e0d2021-02-05 14:26:37 -08001219 * If a device binds successfully, it's expected to have created all
Saravana Kannanbcbbcfd2019-10-28 15:00:23 -07001220 * the device links it needs to or make new device links as it needs
Saravana Kannan9528e0d2021-02-05 14:26:37 -08001221 * them. So, fw_devlink no longer needs to create device links to any
1222 * of the device's suppliers.
1223 *
1224 * Also, if a child firmware node of this bound device is not added as
1225 * a device by now, assume it is never going to be added and make sure
1226 * other devices don't defer probe indefinitely by waiting for such a
1227 * child device.
Saravana Kannanbcbbcfd2019-10-28 15:00:23 -07001228 */
Saravana Kannan9528e0d2021-02-05 14:26:37 -08001229 if (dev->fwnode && dev->fwnode->dev == dev) {
1230 struct fwnode_handle *child;
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001231 fwnode_links_purge_suppliers(dev->fwnode);
Saravana Kannan9528e0d2021-02-05 14:26:37 -08001232 fwnode_for_each_available_child_node(dev->fwnode, child)
1233 fw_devlink_purge_absent_suppliers(child);
1234 }
Saravana Kannanda6d6472020-05-21 12:18:00 -07001235 device_remove_file(dev, &dev_attr_waiting_for_supplier);
Saravana Kannanbcbbcfd2019-10-28 15:00:23 -07001236
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001237 device_links_write_lock();
1238
1239 list_for_each_entry(link, &dev->links.consumers, s_node) {
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001240 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001241 continue;
1242
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001243 /*
1244 * Links created during consumer probe may be in the "consumer
1245 * probe" state to start with if the supplier is still probing
1246 * when they are created and they may become "active" if the
1247 * consumer probe returns first. Skip them here.
1248 */
1249 if (link->status == DL_STATE_CONSUMER_PROBE ||
1250 link->status == DL_STATE_ACTIVE)
1251 continue;
1252
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001253 WARN_ON(link->status != DL_STATE_DORMANT);
1254 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
Rafael J. Wysockie7dd4012019-02-01 01:59:42 +01001255
1256 if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
1257 driver_deferred_probe_add(link->consumer);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001258 }
1259
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001260 if (defer_sync_state_count)
1261 __device_links_supplier_defer_sync(dev);
1262 else
1263 __device_links_queue_sync_state(dev, &sync_list);
1264
Saravana Kannan21c27f02020-05-18 23:30:00 -07001265 list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
1266 struct device *supplier;
1267
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001268 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001269 continue;
1270
Saravana Kannan21c27f02020-05-18 23:30:00 -07001271 supplier = link->supplier;
1272 if (link->flags & DL_FLAG_SYNC_STATE_ONLY) {
1273 /*
1274 * When DL_FLAG_SYNC_STATE_ONLY is set, it means no
1275 * other DL_MANAGED_LINK_FLAGS have been set. So, it's
1276 * save to drop the managed link completely.
1277 */
1278 device_link_drop_managed(link);
1279 } else {
1280 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
1281 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
1282 }
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001283
Saravana Kannan21c27f02020-05-18 23:30:00 -07001284 /*
1285 * This needs to be done even for the deleted
1286 * DL_FLAG_SYNC_STATE_ONLY device link in case it was the last
1287 * device link that was preventing the supplier from getting a
1288 * sync_state() call.
1289 */
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001290 if (defer_sync_state_count)
Saravana Kannan21c27f02020-05-18 23:30:00 -07001291 __device_links_supplier_defer_sync(supplier);
Saravana Kannanfc5a2512019-09-04 14:11:23 -07001292 else
Saravana Kannan21c27f02020-05-18 23:30:00 -07001293 __device_links_queue_sync_state(supplier, &sync_list);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001294 }
1295
1296 dev->links.status = DL_DEV_DRIVER_BOUND;
1297
1298 device_links_write_unlock();
Saravana Kannan26e77702019-11-14 14:56:45 -08001299
Saravana Kannan21eb93f2020-02-21 00:05:08 -08001300 device_links_flush_sync_list(&sync_list, dev);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001301}
1302
1303/**
1304 * __device_links_no_driver - Update links of a device without a driver.
1305 * @dev: Device without a drvier.
1306 *
1307 * Delete all non-persistent links from this device to any suppliers.
1308 *
1309 * Persistent links stay around, but their status is changed to "available",
1310 * unless they already are in the "supplier unbind in progress" state in which
1311 * case they need not be updated.
1312 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001313 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001314 */
1315static void __device_links_no_driver(struct device *dev)
1316{
1317 struct device_link *link, *ln;
1318
1319 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001320 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001321 continue;
1322
Saravana Kannan8c3e3152020-05-26 15:09:27 -07001323 if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001324 device_link_drop_managed(link);
Saravana Kannan8c3e3152020-05-26 15:09:27 -07001325 continue;
1326 }
1327
1328 if (link->status != DL_STATE_CONSUMER_PROBE &&
1329 link->status != DL_STATE_ACTIVE)
1330 continue;
1331
1332 if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001333 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
Saravana Kannan8c3e3152020-05-26 15:09:27 -07001334 } else {
1335 WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
1336 WRITE_ONCE(link->status, DL_STATE_DORMANT);
1337 }
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001338 }
1339
1340 dev->links.status = DL_DEV_NO_DRIVER;
1341}
1342
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001343/**
1344 * device_links_no_driver - Update links after failing driver probe.
1345 * @dev: Device whose driver has just failed to probe.
1346 *
1347 * Clean up leftover links to consumers for @dev and invoke
1348 * %__device_links_no_driver() to update links to suppliers for it as
1349 * appropriate.
1350 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001351 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001352 */
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001353void device_links_no_driver(struct device *dev)
1354{
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001355 struct device_link *link;
1356
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001357 device_links_write_lock();
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001358
1359 list_for_each_entry(link, &dev->links.consumers, s_node) {
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001360 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001361 continue;
1362
1363 /*
1364 * The probe has failed, so if the status of the link is
1365 * "consumer probe" or "active", it must have been added by
1366 * a probing consumer while this device was still probing.
1367 * Change its state to "dormant", as it represents a valid
1368 * relationship, but it is not functionally meaningful.
1369 */
1370 if (link->status == DL_STATE_CONSUMER_PROBE ||
1371 link->status == DL_STATE_ACTIVE)
1372 WRITE_ONCE(link->status, DL_STATE_DORMANT);
1373 }
1374
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001375 __device_links_no_driver(dev);
Rafael J. Wysocki15cfb092019-02-01 01:50:39 +01001376
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001377 device_links_write_unlock();
1378}
1379
1380/**
1381 * device_links_driver_cleanup - Update links after driver removal.
1382 * @dev: Device whose driver has just gone away.
1383 *
1384 * Update links to consumers for @dev by changing their status to "dormant" and
1385 * invoke %__device_links_no_driver() to update links to suppliers for it as
1386 * appropriate.
1387 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001388 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001389 */
1390void device_links_driver_cleanup(struct device *dev)
1391{
Rafael J. Wysockic8d50982019-02-01 01:45:55 +01001392 struct device_link *link, *ln;
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001393
1394 device_links_write_lock();
1395
Rafael J. Wysockic8d50982019-02-01 01:45:55 +01001396 list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) {
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001397 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001398 continue;
1399
Vivek Gautame88728f2018-06-27 18:20:55 +05301400 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001401 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
Vivek Gautam1689cac2018-06-27 18:20:56 +05301402
1403 /*
1404 * autoremove the links between this @dev and its consumer
1405 * devices that are not active, i.e. where the link state
1406 * has moved to DL_STATE_SUPPLIER_UNBIND.
1407 */
1408 if (link->status == DL_STATE_SUPPLIER_UNBIND &&
1409 link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001410 device_link_drop_managed(link);
Vivek Gautam1689cac2018-06-27 18:20:56 +05301411
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001412 WRITE_ONCE(link->status, DL_STATE_DORMANT);
1413 }
1414
Saravana Kannan3b052a32020-11-20 18:02:17 -08001415 list_del_init(&dev->links.defer_sync);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001416 __device_links_no_driver(dev);
1417
1418 device_links_write_unlock();
1419}
1420
1421/**
1422 * device_links_busy - Check if there are any busy links to consumers.
1423 * @dev: Device to check.
1424 *
1425 * Check each consumer of the device and return 'true' if its link's status
1426 * is one of "consumer probe" or "active" (meaning that the given consumer is
1427 * probing right now or its driver is present). Otherwise, change the link
1428 * state to "supplier unbind" to prevent the consumer from being probed
1429 * successfully going forward.
1430 *
1431 * Return 'false' if there are no probing or active consumers.
1432 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001433 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001434 */
1435bool device_links_busy(struct device *dev)
1436{
1437 struct device_link *link;
1438 bool ret = false;
1439
1440 device_links_write_lock();
1441
1442 list_for_each_entry(link, &dev->links.consumers, s_node) {
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001443 if (!(link->flags & DL_FLAG_MANAGED))
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001444 continue;
1445
1446 if (link->status == DL_STATE_CONSUMER_PROBE
1447 || link->status == DL_STATE_ACTIVE) {
1448 ret = true;
1449 break;
1450 }
1451 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
1452 }
1453
1454 dev->links.status = DL_DEV_UNBINDING;
1455
1456 device_links_write_unlock();
1457 return ret;
1458}
1459
1460/**
1461 * device_links_unbind_consumers - Force unbind consumers of the given device.
1462 * @dev: Device to unbind the consumers of.
1463 *
1464 * Walk the list of links to consumers for @dev and if any of them is in the
1465 * "consumer probe" state, wait for all device probes in progress to complete
1466 * and start over.
1467 *
1468 * If that's not the case, change the status of the link to "supplier unbind"
1469 * and check if the link was in the "active" state. If so, force the consumer
1470 * driver to unbind and start over (the consumer will not re-probe as we have
1471 * changed the state of the link already).
1472 *
Rafael J. Wysocki515db262019-07-16 17:21:06 +02001473 * Links without the DL_FLAG_MANAGED flag set are ignored.
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001474 */
1475void device_links_unbind_consumers(struct device *dev)
1476{
1477 struct device_link *link;
1478
1479 start:
1480 device_links_write_lock();
1481
1482 list_for_each_entry(link, &dev->links.consumers, s_node) {
1483 enum device_link_state status;
1484
Saravana Kannan05ef9832019-10-28 15:00:22 -07001485 if (!(link->flags & DL_FLAG_MANAGED) ||
1486 link->flags & DL_FLAG_SYNC_STATE_ONLY)
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001487 continue;
1488
1489 status = link->status;
1490 if (status == DL_STATE_CONSUMER_PROBE) {
1491 device_links_write_unlock();
1492
1493 wait_for_device_probe();
1494 goto start;
1495 }
1496 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
1497 if (status == DL_STATE_ACTIVE) {
1498 struct device *consumer = link->consumer;
1499
1500 get_device(consumer);
1501
1502 device_links_write_unlock();
1503
1504 device_release_driver_internal(consumer, NULL,
1505 consumer->parent);
1506 put_device(consumer);
1507 goto start;
1508 }
1509 }
1510
1511 device_links_write_unlock();
1512}
1513
1514/**
1515 * device_links_purge - Delete existing links to other devices.
1516 * @dev: Target device.
1517 */
1518static void device_links_purge(struct device *dev)
1519{
1520 struct device_link *link, *ln;
1521
Saravana Kannan287905e2020-05-21 12:17:58 -07001522 if (dev->class == &devlink_class)
1523 return;
1524
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001525 /*
1526 * Delete all of the remaining links from this device to any other
1527 * devices (either consumers or suppliers).
1528 */
1529 device_links_write_lock();
1530
1531 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
1532 WARN_ON(link->status == DL_STATE_ACTIVE);
Lukas Wunneread18c22018-02-10 19:27:12 +01001533 __device_link_del(&link->kref);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001534 }
1535
1536 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
1537 WARN_ON(link->status != DL_STATE_DORMANT &&
1538 link->status != DL_STATE_NONE);
Lukas Wunneread18c22018-02-10 19:27:12 +01001539 __device_link_del(&link->kref);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001540 }
1541
1542 device_links_write_unlock();
1543}
1544
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001545#define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \
1546 DL_FLAG_SYNC_STATE_ONLY)
1547#define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \
1548 DL_FLAG_AUTOPROBE_CONSUMER)
1549#define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \
1550 DL_FLAG_PM_RUNTIME)
1551
Saravana Kannanea718c692021-03-02 13:11:32 -08001552static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
Saravana Kannan42926ac2020-05-14 22:34:57 -07001553static int __init fw_devlink_setup(char *arg)
1554{
1555 if (!arg)
1556 return -EINVAL;
1557
1558 if (strcmp(arg, "off") == 0) {
1559 fw_devlink_flags = 0;
1560 } else if (strcmp(arg, "permissive") == 0) {
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001561 fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
Saravana Kannan42926ac2020-05-14 22:34:57 -07001562 } else if (strcmp(arg, "on") == 0) {
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001563 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
Saravana Kannan42926ac2020-05-14 22:34:57 -07001564 } else if (strcmp(arg, "rpm") == 0) {
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001565 fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
Saravana Kannan42926ac2020-05-14 22:34:57 -07001566 }
1567 return 0;
1568}
1569early_param("fw_devlink", fw_devlink_setup);
1570
Saravana Kannan19d0f5f2021-02-05 14:26:39 -08001571static bool fw_devlink_strict;
1572static int __init fw_devlink_strict_setup(char *arg)
1573{
1574 return strtobool(arg, &fw_devlink_strict);
1575}
1576early_param("fw_devlink.strict", fw_devlink_strict_setup);
1577
Saravana Kannan42926ac2020-05-14 22:34:57 -07001578u32 fw_devlink_get_flags(void)
1579{
1580 return fw_devlink_flags;
1581}
1582
1583static bool fw_devlink_is_permissive(void)
1584{
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001585 return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE;
Saravana Kannan42926ac2020-05-14 22:34:57 -07001586}
1587
Saravana Kannan19d0f5f2021-02-05 14:26:39 -08001588bool fw_devlink_is_strict(void)
1589{
1590 return fw_devlink_strict && !fw_devlink_is_permissive();
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001591}
1592
Saravana Kannanc2c724c2020-11-20 18:02:27 -08001593static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
1594{
1595 if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED)
1596 return;
1597
Saravana Kannan2d09e6e2020-11-20 18:02:32 -08001598 fwnode_call_int_op(fwnode, add_links);
Saravana Kannanc2c724c2020-11-20 18:02:27 -08001599 fwnode->flags |= FWNODE_FLAG_LINKS_ADDED;
1600}
1601
1602static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
1603{
1604 struct fwnode_handle *child = NULL;
1605
1606 fw_devlink_parse_fwnode(fwnode);
1607
1608 while ((child = fwnode_get_next_available_child_node(fwnode, child)))
1609 fw_devlink_parse_fwtree(child);
1610}
1611
Saravana Kannand46f3e32021-04-01 21:03:41 -07001612static void fw_devlink_relax_link(struct device_link *link)
1613{
1614 if (!(link->flags & DL_FLAG_INFERRED))
1615 return;
1616
1617 if (link->flags == (DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE))
1618 return;
1619
1620 pm_runtime_drop_link(link);
1621 link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
1622 dev_dbg(link->consumer, "Relaxing link with %s\n",
1623 dev_name(link->supplier));
1624}
1625
1626static int fw_devlink_no_driver(struct device *dev, void *data)
1627{
1628 struct device_link *link = to_devlink(dev);
1629
1630 if (!link->supplier->can_match)
1631 fw_devlink_relax_link(link);
1632
1633 return 0;
1634}
1635
1636void fw_devlink_drivers_done(void)
1637{
1638 fw_devlink_drv_reg_done = true;
1639 device_links_write_lock();
1640 class_for_each_device(&devlink_class, NULL, NULL,
1641 fw_devlink_no_driver);
1642 device_links_write_unlock();
1643}
1644
1645static void fw_devlink_unblock_consumers(struct device *dev)
1646{
1647 struct device_link *link;
1648
1649 if (!fw_devlink_flags || fw_devlink_is_permissive())
1650 return;
1651
1652 device_links_write_lock();
1653 list_for_each_entry(link, &dev->links.consumers, s_node)
1654 fw_devlink_relax_link(link);
1655 device_links_write_unlock();
1656}
1657
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001658/**
Saravana Kannanb0e2fa42020-12-17 19:17:02 -08001659 * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
1660 * @con: Device to check dependencies for.
1661 * @sup: Device to check against.
1662 *
1663 * Check if @sup depends on @con or any device dependent on it (its child or
1664 * its consumer etc). When such a cyclic dependency is found, convert all
1665 * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
1666 * This is the equivalent of doing fw_devlink=permissive just between the
1667 * devices in the cycle. We need to do this because, at this point, fw_devlink
1668 * can't tell which of these dependencies is not a real dependency.
1669 *
1670 * Return 1 if a cycle is found. Otherwise, return 0.
1671 */
kernel test robotc13b8272020-12-18 14:39:35 +08001672static int fw_devlink_relax_cycle(struct device *con, void *sup)
Saravana Kannanb0e2fa42020-12-17 19:17:02 -08001673{
1674 struct device_link *link;
1675 int ret;
1676
1677 if (con == sup)
1678 return 1;
1679
1680 ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
1681 if (ret)
1682 return ret;
1683
1684 list_for_each_entry(link, &con->links.consumers, s_node) {
1685 if ((link->flags & ~DL_FLAG_INFERRED) ==
1686 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
1687 continue;
1688
1689 if (!fw_devlink_relax_cycle(link->consumer, sup))
1690 continue;
1691
1692 ret = 1;
1693
Saravana Kannand46f3e32021-04-01 21:03:41 -07001694 fw_devlink_relax_link(link);
Saravana Kannanb0e2fa42020-12-17 19:17:02 -08001695 }
1696 return ret;
1697}
1698
1699/**
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001700 * fw_devlink_create_devlink - Create a device link from a consumer to fwnode
Pierre-Louis Bossart37c52f72021-03-31 18:26:08 -05001701 * @con: consumer device for the device link
1702 * @sup_handle: fwnode handle of supplier
1703 * @flags: devlink flags
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001704 *
1705 * This function will try to create a device link between the consumer device
1706 * @con and the supplier device represented by @sup_handle.
1707 *
1708 * The supplier has to be provided as a fwnode because incorrect cycles in
1709 * fwnode links can sometimes cause the supplier device to never be created.
1710 * This function detects such cases and returns an error if it cannot create a
1711 * device link from the consumer to a missing supplier.
1712 *
1713 * Returns,
1714 * 0 on successfully creating a device link
1715 * -EINVAL if the device link cannot be created as expected
1716 * -EAGAIN if the device link cannot be created right now, but it may be
1717 * possible to do that in the future
1718 */
1719static int fw_devlink_create_devlink(struct device *con,
1720 struct fwnode_handle *sup_handle, u32 flags)
1721{
1722 struct device *sup_dev;
1723 int ret = 0;
1724
1725 sup_dev = get_dev_from_fwnode(sup_handle);
1726 if (sup_dev) {
1727 /*
Saravana Kannan74c782c2021-02-05 14:26:41 -08001728 * If it's one of those drivers that don't actually bind to
1729 * their device using driver core, then don't wait on this
1730 * supplier device indefinitely.
1731 */
1732 if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
1733 sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
1734 ret = -EINVAL;
1735 goto out;
1736 }
1737
1738 /*
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001739 * If this fails, it is due to cycles in device links. Just
1740 * give up on this link and treat it as invalid.
1741 */
Saravana Kannanb0e2fa42020-12-17 19:17:02 -08001742 if (!device_link_add(con, sup_dev, flags) &&
1743 !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
1744 dev_info(con, "Fixing up cyclic dependency with %s\n",
1745 dev_name(sup_dev));
1746 device_links_write_lock();
1747 fw_devlink_relax_cycle(con, sup_dev);
1748 device_links_write_unlock();
1749 device_link_add(con, sup_dev,
1750 FW_DEVLINK_FLAGS_PERMISSIVE);
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001751 ret = -EINVAL;
Saravana Kannanb0e2fa42020-12-17 19:17:02 -08001752 }
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001753
1754 goto out;
1755 }
1756
Saravana Kannan74c782c2021-02-05 14:26:41 -08001757 /* Supplier that's already initialized without a struct device. */
1758 if (sup_handle->flags & FWNODE_FLAG_INITIALIZED)
1759 return -EINVAL;
1760
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001761 /*
1762 * DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports
1763 * cycles. So cycle detection isn't necessary and shouldn't be
1764 * done.
1765 */
1766 if (flags & DL_FLAG_SYNC_STATE_ONLY)
1767 return -EAGAIN;
1768
1769 /*
1770 * If we can't find the supplier device from its fwnode, it might be
1771 * due to a cyclic dependency between fwnodes. Some of these cycles can
1772 * be broken by applying logic. Check for these types of cycles and
1773 * break them so that devices in the cycle probe properly.
1774 *
1775 * If the supplier's parent is dependent on the consumer, then
1776 * the consumer-supplier dependency is a false dependency. So,
1777 * treat it as an invalid link.
1778 */
1779 sup_dev = fwnode_get_next_parent_dev(sup_handle);
1780 if (sup_dev && device_is_dependent(con, sup_dev)) {
1781 dev_dbg(con, "Not linking to %pfwP - False link\n",
1782 sup_handle);
1783 ret = -EINVAL;
1784 } else {
1785 /*
1786 * Can't check for cycles or no cycles. So let's try
1787 * again later.
1788 */
1789 ret = -EAGAIN;
1790 }
1791
1792out:
1793 put_device(sup_dev);
1794 return ret;
1795}
1796
1797/**
1798 * __fw_devlink_link_to_consumers - Create device links to consumers of a device
Pierre-Louis Bossart37c52f72021-03-31 18:26:08 -05001799 * @dev: Device that needs to be linked to its consumers
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001800 *
1801 * This function looks at all the consumer fwnodes of @dev and creates device
1802 * links between the consumer device and @dev (supplier).
1803 *
1804 * If the consumer device has not been added yet, then this function creates a
1805 * SYNC_STATE_ONLY link between @dev (supplier) and the closest ancestor device
1806 * of the consumer fwnode. This is necessary to make sure @dev doesn't get a
1807 * sync_state() callback before the real consumer device gets to be added and
1808 * then probed.
1809 *
1810 * Once device links are created from the real consumer to @dev (supplier), the
1811 * fwnode links are deleted.
1812 */
1813static void __fw_devlink_link_to_consumers(struct device *dev)
1814{
1815 struct fwnode_handle *fwnode = dev->fwnode;
1816 struct fwnode_link *link, *tmp;
1817
1818 list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
1819 u32 dl_flags = fw_devlink_get_flags();
1820 struct device *con_dev;
1821 bool own_link = true;
1822 int ret;
1823
1824 con_dev = get_dev_from_fwnode(link->consumer);
1825 /*
1826 * If consumer device is not available yet, make a "proxy"
1827 * SYNC_STATE_ONLY link from the consumer's parent device to
1828 * the supplier device. This is necessary to make sure the
1829 * supplier doesn't get a sync_state() callback before the real
1830 * consumer can create a device link to the supplier.
1831 *
1832 * This proxy link step is needed to handle the case where the
1833 * consumer's parent device is added before the supplier.
1834 */
1835 if (!con_dev) {
1836 con_dev = fwnode_get_next_parent_dev(link->consumer);
1837 /*
1838 * However, if the consumer's parent device is also the
1839 * parent of the supplier, don't create a
1840 * consumer-supplier link from the parent to its child
1841 * device. Such a dependency is impossible.
1842 */
1843 if (con_dev &&
1844 fwnode_is_ancestor_of(con_dev->fwnode, fwnode)) {
1845 put_device(con_dev);
1846 con_dev = NULL;
1847 } else {
1848 own_link = false;
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001849 dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001850 }
1851 }
1852
1853 if (!con_dev)
1854 continue;
1855
1856 ret = fw_devlink_create_devlink(con_dev, fwnode, dl_flags);
1857 put_device(con_dev);
1858 if (!own_link || ret == -EAGAIN)
1859 continue;
1860
1861 list_del(&link->s_hook);
1862 list_del(&link->c_hook);
1863 kfree(link);
1864 }
1865}
1866
1867/**
1868 * __fw_devlink_link_to_suppliers - Create device links to suppliers of a device
Pierre-Louis Bossart37c52f72021-03-31 18:26:08 -05001869 * @dev: The consumer device that needs to be linked to its suppliers
1870 * @fwnode: Root of the fwnode tree that is used to create device links
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001871 *
1872 * This function looks at all the supplier fwnodes of fwnode tree rooted at
1873 * @fwnode and creates device links between @dev (consumer) and all the
1874 * supplier devices of the entire fwnode tree at @fwnode.
1875 *
1876 * The function creates normal (non-SYNC_STATE_ONLY) device links between @dev
1877 * and the real suppliers of @dev. Once these device links are created, the
1878 * fwnode links are deleted. When such device links are successfully created,
1879 * this function is called recursively on those supplier devices. This is
1880 * needed to detect and break some invalid cycles in fwnode links. See
1881 * fw_devlink_create_devlink() for more details.
1882 *
1883 * In addition, it also looks at all the suppliers of the entire fwnode tree
1884 * because some of the child devices of @dev that have not been added yet
1885 * (because @dev hasn't probed) might already have their suppliers added to
1886 * driver core. So, this function creates SYNC_STATE_ONLY device links between
1887 * @dev (consumer) and these suppliers to make sure they don't execute their
1888 * sync_state() callbacks before these child devices have a chance to create
1889 * their device links. The fwnode links that correspond to the child devices
1890 * aren't delete because they are needed later to create the device links
1891 * between the real consumer and supplier devices.
1892 */
1893static void __fw_devlink_link_to_suppliers(struct device *dev,
1894 struct fwnode_handle *fwnode)
1895{
1896 bool own_link = (dev->fwnode == fwnode);
1897 struct fwnode_link *link, *tmp;
1898 struct fwnode_handle *child = NULL;
1899 u32 dl_flags;
1900
1901 if (own_link)
1902 dl_flags = fw_devlink_get_flags();
1903 else
Saravana Kannanb90fb8f2020-12-17 19:17:01 -08001904 dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001905
1906 list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
1907 int ret;
1908 struct device *sup_dev;
1909 struct fwnode_handle *sup = link->supplier;
1910
1911 ret = fw_devlink_create_devlink(dev, sup, dl_flags);
1912 if (!own_link || ret == -EAGAIN)
1913 continue;
1914
1915 list_del(&link->s_hook);
1916 list_del(&link->c_hook);
1917 kfree(link);
1918
1919 /* If no device link was created, nothing more to do. */
1920 if (ret)
1921 continue;
1922
1923 /*
1924 * If a device link was successfully created to a supplier, we
1925 * now need to try and link the supplier to all its suppliers.
1926 *
1927 * This is needed to detect and delete false dependencies in
1928 * fwnode links that haven't been converted to a device link
1929 * yet. See comments in fw_devlink_create_devlink() for more
1930 * details on the false dependency.
1931 *
1932 * Without deleting these false dependencies, some devices will
1933 * never probe because they'll keep waiting for their false
1934 * dependency fwnode links to be converted to device links.
1935 */
1936 sup_dev = get_dev_from_fwnode(sup);
1937 __fw_devlink_link_to_suppliers(sup_dev, sup_dev->fwnode);
1938 put_device(sup_dev);
1939 }
1940
1941 /*
1942 * Make "proxy" SYNC_STATE_ONLY device links to represent the needs of
1943 * all the descendants. This proxy link step is needed to handle the
1944 * case where the supplier is added before the consumer's parent device
1945 * (@dev).
1946 */
1947 while ((child = fwnode_get_next_available_child_node(fwnode, child)))
1948 __fw_devlink_link_to_suppliers(dev, child);
1949}
1950
Saravana Kannan5f5377e2020-05-14 22:34:58 -07001951static void fw_devlink_link_device(struct device *dev)
1952{
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001953 struct fwnode_handle *fwnode = dev->fwnode;
Saravana Kannan5f5377e2020-05-14 22:34:58 -07001954
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001955 if (!fw_devlink_flags)
1956 return;
Saravana Kannanc84b9092020-11-20 18:02:21 -08001957
Saravana Kannanf9aa4602020-11-20 18:02:31 -08001958 fw_devlink_parse_fwtree(fwnode);
1959
1960 mutex_lock(&fwnode_link_lock);
1961 __fw_devlink_link_to_consumers(dev);
1962 __fw_devlink_link_to_suppliers(dev, fwnode);
1963 mutex_unlock(&fwnode_link_lock);
Saravana Kannan716a7a22020-05-14 22:34:59 -07001964}
Saravana Kannanc84b9092020-11-20 18:02:21 -08001965
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01001966/* Device links support end. */
1967
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08001968int (*platform_notify)(struct device *dev) = NULL;
1969int (*platform_notify_remove)(struct device *dev) = NULL;
Dan Williamse105b8b2008-04-21 10:51:07 -07001970static struct kobject *dev_kobj;
1971struct kobject *sysfs_dev_char_kobj;
1972struct kobject *sysfs_dev_block_kobj;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001973
Rafael J. Wysocki5e33bc42013-08-28 21:41:01 +02001974static DEFINE_MUTEX(device_hotplug_lock);
1975
1976void lock_device_hotplug(void)
1977{
1978 mutex_lock(&device_hotplug_lock);
1979}
1980
1981void unlock_device_hotplug(void)
1982{
1983 mutex_unlock(&device_hotplug_lock);
1984}
1985
1986int lock_device_hotplug_sysfs(void)
1987{
1988 if (mutex_trylock(&device_hotplug_lock))
1989 return 0;
1990
1991 /* Avoid busy looping (5 ms of sleep should do). */
1992 msleep(5);
1993 return restart_syscall();
1994}
1995
Greg Kroah-Hartman4e886c22008-01-27 12:12:43 -08001996#ifdef CONFIG_BLOCK
1997static inline int device_is_not_partition(struct device *dev)
1998{
1999 return !(dev->type == &part_type);
2000}
2001#else
2002static inline int device_is_not_partition(struct device *dev)
2003{
2004 return 1;
2005}
2006#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002007
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02002008static void device_platform_notify(struct device *dev)
Heikki Krogerus07de0e82018-11-09 17:21:34 +03002009{
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02002010 acpi_device_notify(dev);
Heikki Krogerus7847a142018-11-09 17:21:35 +03002011
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02002012 software_node_notify(dev);
Heikki Krogerus7847a142018-11-09 17:21:35 +03002013
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02002014 if (platform_notify)
Heikki Krogerus07de0e82018-11-09 17:21:34 +03002015 platform_notify(dev);
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02002016}
2017
2018static void device_platform_notify_remove(struct device *dev)
2019{
2020 acpi_device_notify_remove(dev);
2021
2022 software_node_notify_remove(dev);
2023
2024 if (platform_notify_remove)
Heikki Krogerus07de0e82018-11-09 17:21:34 +03002025 platform_notify_remove(dev);
Heikki Krogerus07de0e82018-11-09 17:21:34 +03002026}
2027
Alan Stern3e956372006-06-16 17:10:48 -04002028/**
2029 * dev_driver_string - Return a device's driver name, if at all possible
2030 * @dev: struct device to get the name of
2031 *
2032 * Will return the device's driver's name if it is bound to a device. If
yan9169c012012-04-20 21:08:45 +08002033 * the device is not bound to a driver, it will return the name of the bus
Alan Stern3e956372006-06-16 17:10:48 -04002034 * it is attached to. If it is not attached to a bus either, an empty
2035 * string will be returned.
2036 */
Jean Delvarebf9ca692008-07-30 12:29:21 -07002037const char *dev_driver_string(const struct device *dev)
Alan Stern3e956372006-06-16 17:10:48 -04002038{
Alan Stern35899722009-12-04 11:06:57 -05002039 struct device_driver *drv;
2040
2041 /* dev->driver can change to NULL underneath us because of unbinding,
2042 * so be careful about accessing it. dev->bus and dev->class should
2043 * never change once they are set, so they don't need special care.
2044 */
Mark Rutland6aa7de02017-10-23 14:07:29 -07002045 drv = READ_ONCE(dev->driver);
Saravana Kannane020ff62021-01-10 09:54:07 -08002046 return drv ? drv->name : dev_bus_name(dev);
Alan Stern3e956372006-06-16 17:10:48 -04002047}
Matthew Wilcox310a9222006-09-23 23:35:04 -06002048EXPORT_SYMBOL(dev_driver_string);
Alan Stern3e956372006-06-16 17:10:48 -04002049
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
2051
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002052static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
2053 char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002054{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002055 struct device_attribute *dev_attr = to_dev_attr(attr);
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002056 struct device *dev = kobj_to_dev(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -05002057 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002058
2059 if (dev_attr->show)
Yani Ioannou54b6f352005-05-17 06:39:34 -04002060 ret = dev_attr->show(dev, dev_attr, buf);
Andrew Morton815d2d52008-03-04 15:09:07 -08002061 if (ret >= (ssize_t)PAGE_SIZE) {
Sergey Senozhatskya52668c2017-12-11 21:50:21 +09002062 printk("dev_attr_show: %pS returned bad count\n",
2063 dev_attr->show);
Andrew Morton815d2d52008-03-04 15:09:07 -08002064 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065 return ret;
2066}
2067
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002068static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
2069 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002071 struct device_attribute *dev_attr = to_dev_attr(attr);
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002072 struct device *dev = kobj_to_dev(kobj);
Dmitry Torokhov4a0c20b2005-04-29 01:23:47 -05002073 ssize_t ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002074
2075 if (dev_attr->store)
Yani Ioannou54b6f352005-05-17 06:39:34 -04002076 ret = dev_attr->store(dev, dev_attr, buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077 return ret;
2078}
2079
Emese Revfy52cf25d2010-01-19 02:58:23 +01002080static const struct sysfs_ops dev_sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002081 .show = dev_attr_show,
2082 .store = dev_attr_store,
2083};
2084
Kay Sieversca22e562011-12-14 14:29:38 -08002085#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
2086
2087ssize_t device_store_ulong(struct device *dev,
2088 struct device_attribute *attr,
2089 const char *buf, size_t size)
2090{
2091 struct dev_ext_attribute *ea = to_ext_attr(attr);
Kaitao chengf88184b2018-11-06 08:34:54 -08002092 int ret;
2093 unsigned long new;
2094
2095 ret = kstrtoul(buf, 0, &new);
2096 if (ret)
2097 return ret;
Kay Sieversca22e562011-12-14 14:29:38 -08002098 *(unsigned long *)(ea->var) = new;
2099 /* Always return full write size even if we didn't consume all */
2100 return size;
2101}
2102EXPORT_SYMBOL_GPL(device_store_ulong);
2103
2104ssize_t device_show_ulong(struct device *dev,
2105 struct device_attribute *attr,
2106 char *buf)
2107{
2108 struct dev_ext_attribute *ea = to_ext_attr(attr);
Joe Perchesaa838892020-09-16 13:40:39 -07002109 return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
Kay Sieversca22e562011-12-14 14:29:38 -08002110}
2111EXPORT_SYMBOL_GPL(device_show_ulong);
2112
2113ssize_t device_store_int(struct device *dev,
2114 struct device_attribute *attr,
2115 const char *buf, size_t size)
2116{
2117 struct dev_ext_attribute *ea = to_ext_attr(attr);
Kaitao chengf88184b2018-11-06 08:34:54 -08002118 int ret;
2119 long new;
2120
2121 ret = kstrtol(buf, 0, &new);
2122 if (ret)
2123 return ret;
2124
2125 if (new > INT_MAX || new < INT_MIN)
Kay Sieversca22e562011-12-14 14:29:38 -08002126 return -EINVAL;
2127 *(int *)(ea->var) = new;
2128 /* Always return full write size even if we didn't consume all */
2129 return size;
2130}
2131EXPORT_SYMBOL_GPL(device_store_int);
2132
2133ssize_t device_show_int(struct device *dev,
2134 struct device_attribute *attr,
2135 char *buf)
2136{
2137 struct dev_ext_attribute *ea = to_ext_attr(attr);
2138
Joe Perchesaa838892020-09-16 13:40:39 -07002139 return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
Kay Sieversca22e562011-12-14 14:29:38 -08002140}
2141EXPORT_SYMBOL_GPL(device_show_int);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002142
Borislav Petkov91872392012-10-09 19:52:05 +02002143ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
2144 const char *buf, size_t size)
2145{
2146 struct dev_ext_attribute *ea = to_ext_attr(attr);
2147
2148 if (strtobool(buf, ea->var) < 0)
2149 return -EINVAL;
2150
2151 return size;
2152}
2153EXPORT_SYMBOL_GPL(device_store_bool);
2154
2155ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
2156 char *buf)
2157{
2158 struct dev_ext_attribute *ea = to_ext_attr(attr);
2159
Joe Perchesaa838892020-09-16 13:40:39 -07002160 return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
Borislav Petkov91872392012-10-09 19:52:05 +02002161}
2162EXPORT_SYMBOL_GPL(device_show_bool);
2163
Linus Torvalds1da177e2005-04-16 15:20:36 -07002164/**
Robert P. J. Dayf8878dc2013-06-01 20:17:34 -04002165 * device_release - free device structure.
2166 * @kobj: device's kobject.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167 *
Robert P. J. Dayf8878dc2013-06-01 20:17:34 -04002168 * This is called once the reference count for the object
2169 * reaches 0. We forward the call to the device's release
2170 * method, which should handle actually freeing the structure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002172static void device_release(struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002173{
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002174 struct device *dev = kobj_to_dev(kobj);
Greg Kroah-Hartmanfb069a52008-12-16 12:23:36 -08002175 struct device_private *p = dev->p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176
Ming Leia525a3d2012-07-25 01:42:29 +08002177 /*
2178 * Some platform devices are driven without driver attached
2179 * and managed resources may have been acquired. Make sure
2180 * all resources are released.
2181 *
2182 * Drivers still can add resources into device after device
2183 * is deleted but alive, so release devres here to avoid
2184 * possible memory leak.
2185 */
2186 devres_release_all(dev);
2187
Jim Quinlane0d07272020-09-17 18:43:40 +02002188 kfree(dev->dma_range_map);
2189
Linus Torvalds1da177e2005-04-16 15:20:36 -07002190 if (dev->release)
2191 dev->release(dev);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002192 else if (dev->type && dev->type->release)
2193 dev->type->release(dev);
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002194 else if (dev->class && dev->class->dev_release)
2195 dev->class->dev_release(dev);
Arjan van de Venf810a5c2008-07-25 19:45:39 -07002196 else
Mauro Carvalho Chehab0c1bc6b2020-04-14 18:48:37 +02002197 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",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01002198 dev_name(dev));
Greg Kroah-Hartmanfb069a52008-12-16 12:23:36 -08002199 kfree(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200}
2201
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002202static const void *device_namespace(struct kobject *kobj)
2203{
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002204 struct device *dev = kobj_to_dev(kobj);
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002205 const void *ns = NULL;
2206
2207 if (dev->class && dev->class->ns_type)
2208 ns = dev->class->namespace(dev);
2209
2210 return ns;
2211}
2212
Dmitry Torokhov9944e892018-07-20 21:56:50 +00002213static void device_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
2214{
2215 struct device *dev = kobj_to_dev(kobj);
2216
2217 if (dev->class && dev->class->get_ownership)
2218 dev->class->get_ownership(dev, uid, gid);
2219}
2220
Greg Kroah-Hartman8f4afc42007-10-11 10:47:49 -06002221static struct kobj_type device_ktype = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002222 .release = device_release,
2223 .sysfs_ops = &dev_sysfs_ops,
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002224 .namespace = device_namespace,
Dmitry Torokhov9944e892018-07-20 21:56:50 +00002225 .get_ownership = device_get_ownership,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002226};
2227
2228
Kay Sievers312c0042005-11-16 09:00:00 +01002229static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002230{
2231 struct kobj_type *ktype = get_ktype(kobj);
2232
Greg Kroah-Hartman8f4afc42007-10-11 10:47:49 -06002233 if (ktype == &device_ktype) {
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002234 struct device *dev = kobj_to_dev(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002235 if (dev->bus)
2236 return 1;
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07002237 if (dev->class)
2238 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002239 }
2240 return 0;
2241}
2242
Kay Sievers312c0042005-11-16 09:00:00 +01002243static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002244{
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002245 struct device *dev = kobj_to_dev(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002246
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07002247 if (dev->bus)
2248 return dev->bus->name;
2249 if (dev->class)
2250 return dev->class->name;
2251 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002252}
2253
Kay Sievers7eff2e72007-08-14 15:15:12 +02002254static int dev_uevent(struct kset *kset, struct kobject *kobj,
2255 struct kobj_uevent_env *env)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002256{
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02002257 struct device *dev = kobj_to_dev(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258 int retval = 0;
2259
Kay Sievers6fcf53a2009-04-30 15:23:42 +02002260 /* add device node properties if present */
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07002261 if (MAJOR(dev->devt)) {
Kay Sievers6fcf53a2009-04-30 15:23:42 +02002262 const char *tmp;
2263 const char *name;
Al Viro2c9ede52011-07-23 20:24:48 -04002264 umode_t mode = 0;
Greg Kroah-Hartman4e4098a2013-04-11 11:43:29 -07002265 kuid_t uid = GLOBAL_ROOT_UID;
2266 kgid_t gid = GLOBAL_ROOT_GID;
Kay Sievers6fcf53a2009-04-30 15:23:42 +02002267
Kay Sievers7eff2e72007-08-14 15:15:12 +02002268 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
2269 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
Kay Sievers3c2670e2013-04-06 09:56:00 -07002270 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
Kay Sievers6fcf53a2009-04-30 15:23:42 +02002271 if (name) {
2272 add_uevent_var(env, "DEVNAME=%s", name);
Kay Sieverse454cea2009-09-18 23:01:12 +02002273 if (mode)
2274 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
Greg Kroah-Hartman4e4098a2013-04-11 11:43:29 -07002275 if (!uid_eq(uid, GLOBAL_ROOT_UID))
2276 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
2277 if (!gid_eq(gid, GLOBAL_ROOT_GID))
2278 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
Kay Sievers3c2670e2013-04-06 09:56:00 -07002279 kfree(tmp);
Kay Sievers6fcf53a2009-04-30 15:23:42 +02002280 }
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07002281 }
2282
Kay Sievers414264f2007-03-12 21:08:57 +01002283 if (dev->type && dev->type->name)
Kay Sievers7eff2e72007-08-14 15:15:12 +02002284 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
Kay Sievers414264f2007-03-12 21:08:57 +01002285
Kay Sievers239378f2006-10-07 21:54:55 +02002286 if (dev->driver)
Kay Sievers7eff2e72007-08-14 15:15:12 +02002287 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
Kay Sievers239378f2006-10-07 21:54:55 +02002288
Grant Likely07d57a32012-02-01 11:22:22 -07002289 /* Add common DT information about the device */
2290 of_device_uevent(dev, env);
2291
Kay Sievers7eff2e72007-08-14 15:15:12 +02002292 /* have the bus specific function add its stuff */
Kay Sievers312c0042005-11-16 09:00:00 +01002293 if (dev->bus && dev->bus->uevent) {
Kay Sievers7eff2e72007-08-14 15:15:12 +02002294 retval = dev->bus->uevent(dev, env);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002295 if (retval)
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -08002296 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01002297 dev_name(dev), __func__, retval);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002298 }
2299
Kay Sievers7eff2e72007-08-14 15:15:12 +02002300 /* have the class specific function add its stuff */
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002301 if (dev->class && dev->class->dev_uevent) {
Kay Sievers7eff2e72007-08-14 15:15:12 +02002302 retval = dev->class->dev_uevent(dev, env);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002303 if (retval)
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -08002304 pr_debug("device: '%s': %s: class uevent() "
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01002305 "returned %d\n", dev_name(dev),
Harvey Harrison2b3a3022008-03-04 16:41:05 -08002306 __func__, retval);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002307 }
2308
Stefan Weileef35c22010-08-06 21:11:15 +02002309 /* have the device type specific function add its stuff */
Kay Sieversf9f852d2006-10-07 21:54:55 +02002310 if (dev->type && dev->type->uevent) {
Kay Sievers7eff2e72007-08-14 15:15:12 +02002311 retval = dev->type->uevent(dev, env);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002312 if (retval)
Greg Kroah-Hartman7dc72b22007-11-28 23:49:41 -08002313 pr_debug("device: '%s': %s: dev_type uevent() "
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01002314 "returned %d\n", dev_name(dev),
Harvey Harrison2b3a3022008-03-04 16:41:05 -08002315 __func__, retval);
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002316 }
2317
Linus Torvalds1da177e2005-04-16 15:20:36 -07002318 return retval;
2319}
2320
Emese Revfy9cd43612009-12-31 14:52:51 +01002321static const struct kset_uevent_ops device_uevent_ops = {
Kay Sievers312c0042005-11-16 09:00:00 +01002322 .filter = dev_uevent_filter,
2323 .name = dev_uevent_name,
2324 .uevent = dev_uevent,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002325};
2326
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002327static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
Kay Sievers16574dc2007-04-06 01:40:38 +02002328 char *buf)
2329{
2330 struct kobject *top_kobj;
2331 struct kset *kset;
Kay Sievers7eff2e72007-08-14 15:15:12 +02002332 struct kobj_uevent_env *env = NULL;
Kay Sievers16574dc2007-04-06 01:40:38 +02002333 int i;
Joe Perches948b3ed2020-09-16 13:40:42 -07002334 int len = 0;
Kay Sievers16574dc2007-04-06 01:40:38 +02002335 int retval;
2336
2337 /* search the kset, the device belongs to */
2338 top_kobj = &dev->kobj;
Kay Sievers5c5daf62007-08-12 20:43:55 +02002339 while (!top_kobj->kset && top_kobj->parent)
2340 top_kobj = top_kobj->parent;
Kay Sievers16574dc2007-04-06 01:40:38 +02002341 if (!top_kobj->kset)
2342 goto out;
Kay Sievers5c5daf62007-08-12 20:43:55 +02002343
Kay Sievers16574dc2007-04-06 01:40:38 +02002344 kset = top_kobj->kset;
2345 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
2346 goto out;
2347
2348 /* respect filter */
2349 if (kset->uevent_ops && kset->uevent_ops->filter)
2350 if (!kset->uevent_ops->filter(kset, &dev->kobj))
2351 goto out;
2352
Kay Sievers7eff2e72007-08-14 15:15:12 +02002353 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
2354 if (!env)
Greg Kroah-Hartmanc7308c82007-05-02 14:14:11 +02002355 return -ENOMEM;
2356
Kay Sievers16574dc2007-04-06 01:40:38 +02002357 /* let the kset specific function add its keys */
Kay Sievers7eff2e72007-08-14 15:15:12 +02002358 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
Kay Sievers16574dc2007-04-06 01:40:38 +02002359 if (retval)
2360 goto out;
2361
2362 /* copy keys to file */
Kay Sievers7eff2e72007-08-14 15:15:12 +02002363 for (i = 0; i < env->envp_idx; i++)
Joe Perches948b3ed2020-09-16 13:40:42 -07002364 len += sysfs_emit_at(buf, len, "%s\n", env->envp[i]);
Kay Sievers16574dc2007-04-06 01:40:38 +02002365out:
Kay Sievers7eff2e72007-08-14 15:15:12 +02002366 kfree(env);
Joe Perches948b3ed2020-09-16 13:40:42 -07002367 return len;
Kay Sievers16574dc2007-04-06 01:40:38 +02002368}
2369
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002370static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
Kay Sieversa7fd6702005-10-01 14:49:43 +02002371 const char *buf, size_t count)
2372{
Peter Rajnohadf44b472018-12-05 12:27:44 +01002373 int rc;
2374
2375 rc = kobject_synth_uevent(&dev->kobj, buf, count);
2376
2377 if (rc) {
Peter Rajnohaf36776f2017-05-09 15:22:30 +02002378 dev_err(dev, "uevent: failed to send synthetic uevent\n");
Peter Rajnohadf44b472018-12-05 12:27:44 +01002379 return rc;
2380 }
Kay Sievers60a96a52007-07-08 22:29:26 +02002381
Kay Sieversa7fd6702005-10-01 14:49:43 +02002382 return count;
2383}
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002384static DEVICE_ATTR_RW(uevent);
Kay Sieversa7fd6702005-10-01 14:49:43 +02002385
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002386static ssize_t online_show(struct device *dev, struct device_attribute *attr,
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002387 char *buf)
2388{
2389 bool val;
2390
Rafael J. Wysocki5e33bc42013-08-28 21:41:01 +02002391 device_lock(dev);
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002392 val = !dev->offline;
Rafael J. Wysocki5e33bc42013-08-28 21:41:01 +02002393 device_unlock(dev);
Joe Perchesaa838892020-09-16 13:40:39 -07002394 return sysfs_emit(buf, "%u\n", val);
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002395}
2396
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002397static ssize_t online_store(struct device *dev, struct device_attribute *attr,
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002398 const char *buf, size_t count)
2399{
2400 bool val;
2401 int ret;
2402
2403 ret = strtobool(buf, &val);
2404 if (ret < 0)
2405 return ret;
2406
Rafael J. Wysocki5e33bc42013-08-28 21:41:01 +02002407 ret = lock_device_hotplug_sysfs();
2408 if (ret)
2409 return ret;
2410
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002411 ret = val ? device_online(dev) : device_offline(dev);
2412 unlock_device_hotplug();
2413 return ret < 0 ? ret : count;
2414}
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002415static DEVICE_ATTR_RW(online);
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002416
Rajat Jain70f400d2021-05-24 10:18:11 -07002417static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
2418 char *buf)
2419{
2420 const char *loc;
2421
2422 switch (dev->removable) {
2423 case DEVICE_REMOVABLE:
2424 loc = "removable";
2425 break;
2426 case DEVICE_FIXED:
2427 loc = "fixed";
2428 break;
2429 default:
2430 loc = "unknown";
2431 }
2432 return sysfs_emit(buf, "%s\n", loc);
2433}
2434static DEVICE_ATTR_RO(removable);
2435
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -07002436int device_add_groups(struct device *dev, const struct attribute_group **groups)
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002437{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -07002438 return sysfs_create_groups(&dev->kobj, groups);
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002439}
Dmitry Torokhova7670d42017-07-19 17:24:31 -07002440EXPORT_SYMBOL_GPL(device_add_groups);
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002441
Greg Kroah-Hartmanfa6fdb32013-08-08 15:22:55 -07002442void device_remove_groups(struct device *dev,
2443 const struct attribute_group **groups)
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002444{
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -07002445 sysfs_remove_groups(&dev->kobj, groups);
Greg Kroah-Hartmande0ff002006-06-27 00:06:09 -07002446}
Dmitry Torokhova7670d42017-07-19 17:24:31 -07002447EXPORT_SYMBOL_GPL(device_remove_groups);
Greg Kroah-Hartmande0ff002006-06-27 00:06:09 -07002448
Dmitry Torokhov57b8ff02017-07-19 17:24:33 -07002449union device_attr_group_devres {
2450 const struct attribute_group *group;
2451 const struct attribute_group **groups;
2452};
2453
2454static int devm_attr_group_match(struct device *dev, void *res, void *data)
2455{
2456 return ((union device_attr_group_devres *)res)->group == data;
2457}
2458
2459static void devm_attr_group_remove(struct device *dev, void *res)
2460{
2461 union device_attr_group_devres *devres = res;
2462 const struct attribute_group *group = devres->group;
2463
2464 dev_dbg(dev, "%s: removing group %p\n", __func__, group);
2465 sysfs_remove_group(&dev->kobj, group);
2466}
2467
2468static void devm_attr_groups_remove(struct device *dev, void *res)
2469{
2470 union device_attr_group_devres *devres = res;
2471 const struct attribute_group **groups = devres->groups;
2472
2473 dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
2474 sysfs_remove_groups(&dev->kobj, groups);
2475}
2476
2477/**
2478 * devm_device_add_group - given a device, create a managed attribute group
2479 * @dev: The device to create the group for
2480 * @grp: The attribute group to create
2481 *
2482 * This function creates a group for the first time. It will explicitly
2483 * warn and error if any of the attribute files being created already exist.
2484 *
2485 * Returns 0 on success or error code on failure.
2486 */
2487int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
2488{
2489 union device_attr_group_devres *devres;
2490 int error;
2491
2492 devres = devres_alloc(devm_attr_group_remove,
2493 sizeof(*devres), GFP_KERNEL);
2494 if (!devres)
2495 return -ENOMEM;
2496
2497 error = sysfs_create_group(&dev->kobj, grp);
2498 if (error) {
2499 devres_free(devres);
2500 return error;
2501 }
2502
2503 devres->group = grp;
2504 devres_add(dev, devres);
2505 return 0;
2506}
2507EXPORT_SYMBOL_GPL(devm_device_add_group);
2508
2509/**
2510 * devm_device_remove_group: remove a managed group from a device
2511 * @dev: device to remove the group from
2512 * @grp: group to remove
2513 *
2514 * This function removes a group of attributes from a device. The attributes
2515 * previously have to have been created for this group, otherwise it will fail.
2516 */
2517void devm_device_remove_group(struct device *dev,
2518 const struct attribute_group *grp)
2519{
2520 WARN_ON(devres_release(dev, devm_attr_group_remove,
2521 devm_attr_group_match,
2522 /* cast away const */ (void *)grp));
2523}
2524EXPORT_SYMBOL_GPL(devm_device_remove_group);
2525
2526/**
2527 * devm_device_add_groups - create a bunch of managed attribute groups
2528 * @dev: The device to create the group for
2529 * @groups: The attribute groups to create, NULL terminated
2530 *
2531 * This function creates a bunch of managed attribute groups. If an error
2532 * occurs when creating a group, all previously created groups will be
2533 * removed, unwinding everything back to the original state when this
2534 * function was called. It will explicitly warn and error if any of the
2535 * attribute files being created already exist.
2536 *
2537 * Returns 0 on success or error code from sysfs_create_group on failure.
2538 */
2539int devm_device_add_groups(struct device *dev,
2540 const struct attribute_group **groups)
2541{
2542 union device_attr_group_devres *devres;
2543 int error;
2544
2545 devres = devres_alloc(devm_attr_groups_remove,
2546 sizeof(*devres), GFP_KERNEL);
2547 if (!devres)
2548 return -ENOMEM;
2549
2550 error = sysfs_create_groups(&dev->kobj, groups);
2551 if (error) {
2552 devres_free(devres);
2553 return error;
2554 }
2555
2556 devres->groups = groups;
2557 devres_add(dev, devres);
2558 return 0;
2559}
2560EXPORT_SYMBOL_GPL(devm_device_add_groups);
2561
2562/**
2563 * devm_device_remove_groups - remove a list of managed groups
2564 *
2565 * @dev: The device for the groups to be removed from
2566 * @groups: NULL terminated list of groups to be removed
2567 *
2568 * If groups is not NULL, remove the specified groups from the device.
2569 */
2570void devm_device_remove_groups(struct device *dev,
2571 const struct attribute_group **groups)
2572{
2573 WARN_ON(devres_release(dev, devm_attr_groups_remove,
2574 devm_attr_group_match,
2575 /* cast away const */ (void *)groups));
2576}
2577EXPORT_SYMBOL_GPL(devm_device_remove_groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002578
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002579static int device_add_attrs(struct device *dev)
2580{
2581 struct class *class = dev->class;
Stephen Hemmingeraed65af2011-03-28 09:12:52 -07002582 const struct device_type *type = dev->type;
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002583 int error;
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002584
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002585 if (class) {
Greg Kroah-Hartmand05a6f92013-07-14 16:05:58 -07002586 error = device_add_groups(dev, class->dev_groups);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002587 if (error)
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002588 return error;
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002589 }
Kay Sieversf9f852d2006-10-07 21:54:55 +02002590
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002591 if (type) {
2592 error = device_add_groups(dev, type->groups);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002593 if (error)
Greg Kroah-Hartmana6b01de2013-10-05 18:19:30 -07002594 goto err_remove_class_groups;
Kay Sieversf9f852d2006-10-07 21:54:55 +02002595 }
2596
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002597 error = device_add_groups(dev, dev->groups);
2598 if (error)
2599 goto err_remove_type_groups;
2600
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002601 if (device_supports_offline(dev) && !dev->offline_disabled) {
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002602 error = device_create_file(dev, &dev_attr_online);
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002603 if (error)
Rafael J. Wysockiecfbf6f2013-12-12 06:11:02 +01002604 goto err_remove_dev_groups;
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02002605 }
2606
Saravana Kannan25ac86c2020-11-20 18:02:28 -08002607 if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) {
Saravana Kannanda6d6472020-05-21 12:18:00 -07002608 error = device_create_file(dev, &dev_attr_waiting_for_supplier);
2609 if (error)
2610 goto err_remove_dev_online;
2611 }
2612
Rajat Jain70f400d2021-05-24 10:18:11 -07002613 if (dev_removable_is_valid(dev)) {
2614 error = device_create_file(dev, &dev_attr_removable);
2615 if (error)
2616 goto err_remove_dev_waiting_for_supplier;
2617 }
2618
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002619 return 0;
2620
Rajat Jain70f400d2021-05-24 10:18:11 -07002621 err_remove_dev_waiting_for_supplier:
2622 device_remove_file(dev, &dev_attr_waiting_for_supplier);
Saravana Kannanda6d6472020-05-21 12:18:00 -07002623 err_remove_dev_online:
2624 device_remove_file(dev, &dev_attr_online);
Rafael J. Wysockiecfbf6f2013-12-12 06:11:02 +01002625 err_remove_dev_groups:
2626 device_remove_groups(dev, dev->groups);
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002627 err_remove_type_groups:
2628 if (type)
2629 device_remove_groups(dev, type->groups);
Greg Kroah-Hartmand05a6f92013-07-14 16:05:58 -07002630 err_remove_class_groups:
2631 if (class)
2632 device_remove_groups(dev, class->dev_groups);
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002633
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002634 return error;
2635}
2636
2637static void device_remove_attrs(struct device *dev)
2638{
2639 struct class *class = dev->class;
Stephen Hemmingeraed65af2011-03-28 09:12:52 -07002640 const struct device_type *type = dev->type;
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002641
Rajat Jain70f400d2021-05-24 10:18:11 -07002642 device_remove_file(dev, &dev_attr_removable);
Saravana Kannanda6d6472020-05-21 12:18:00 -07002643 device_remove_file(dev, &dev_attr_waiting_for_supplier);
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002644 device_remove_file(dev, &dev_attr_online);
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002645 device_remove_groups(dev, dev->groups);
Kay Sieversf9f852d2006-10-07 21:54:55 +02002646
Dmitry Torokhov621a1672007-03-10 01:37:34 -05002647 if (type)
2648 device_remove_groups(dev, type->groups);
2649
Greg Kroah-Hartmana6b01de2013-10-05 18:19:30 -07002650 if (class)
Greg Kroah-Hartmand05a6f92013-07-14 16:05:58 -07002651 device_remove_groups(dev, class->dev_groups);
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07002652}
2653
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002654static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07002655 char *buf)
2656{
2657 return print_dev_t(buf, dev->devt);
2658}
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07002659static DEVICE_ATTR_RO(dev);
Tejun Heoad6a1e12007-06-14 03:45:17 +09002660
Kay Sieversca22e562011-12-14 14:29:38 -08002661/* /sys/devices/ */
Greg Kroah-Hartman881c6cfd2007-11-01 09:29:06 -06002662struct kset *devices_kset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002663
Linus Torvalds1da177e2005-04-16 15:20:36 -07002664/**
Grygorii Strashko52cdbdd2015-07-27 20:43:01 +03002665 * devices_kset_move_before - Move device in the devices_kset's list.
2666 * @deva: Device to move.
2667 * @devb: Device @deva should come before.
2668 */
2669static void devices_kset_move_before(struct device *deva, struct device *devb)
2670{
2671 if (!devices_kset)
2672 return;
2673 pr_debug("devices_kset: Moving %s before %s\n",
2674 dev_name(deva), dev_name(devb));
2675 spin_lock(&devices_kset->list_lock);
2676 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
2677 spin_unlock(&devices_kset->list_lock);
2678}
2679
2680/**
2681 * devices_kset_move_after - Move device in the devices_kset's list.
2682 * @deva: Device to move
2683 * @devb: Device @deva should come after.
2684 */
2685static void devices_kset_move_after(struct device *deva, struct device *devb)
2686{
2687 if (!devices_kset)
2688 return;
2689 pr_debug("devices_kset: Moving %s after %s\n",
2690 dev_name(deva), dev_name(devb));
2691 spin_lock(&devices_kset->list_lock);
2692 list_move(&deva->kobj.entry, &devb->kobj.entry);
2693 spin_unlock(&devices_kset->list_lock);
2694}
2695
2696/**
2697 * devices_kset_move_last - move the device to the end of devices_kset's list.
2698 * @dev: device to move
2699 */
2700void devices_kset_move_last(struct device *dev)
2701{
2702 if (!devices_kset)
2703 return;
2704 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
2705 spin_lock(&devices_kset->list_lock);
2706 list_move_tail(&dev->kobj.entry, &devices_kset->list);
2707 spin_unlock(&devices_kset->list_lock);
2708}
2709
2710/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002711 * device_create_file - create sysfs attribute file for device.
2712 * @dev: device.
2713 * @attr: device attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002714 */
Phil Carmody26579ab2009-12-18 15:34:19 +02002715int device_create_file(struct device *dev,
2716 const struct device_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002717{
2718 int error = 0;
Felipe Balbi8f46baa2013-02-20 10:31:42 +02002719
2720 if (dev) {
2721 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
dyoung@redhat.com97521972013-05-16 14:31:30 +08002722 "Attribute %s: write permission without 'store'\n",
2723 attr->attr.name);
Felipe Balbi8f46baa2013-02-20 10:31:42 +02002724 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
dyoung@redhat.com97521972013-05-16 14:31:30 +08002725 "Attribute %s: read permission without 'show'\n",
2726 attr->attr.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002727 error = sysfs_create_file(&dev->kobj, &attr->attr);
Felipe Balbi8f46baa2013-02-20 10:31:42 +02002728 }
2729
Linus Torvalds1da177e2005-04-16 15:20:36 -07002730 return error;
2731}
David Graham White86df2682013-07-21 20:41:14 -04002732EXPORT_SYMBOL_GPL(device_create_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002733
2734/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002735 * device_remove_file - remove sysfs attribute file.
2736 * @dev: device.
2737 * @attr: device attribute descriptor.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002738 */
Phil Carmody26579ab2009-12-18 15:34:19 +02002739void device_remove_file(struct device *dev,
2740 const struct device_attribute *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002741{
Cornelia Huck0c98b192008-01-31 10:39:38 +01002742 if (dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743 sysfs_remove_file(&dev->kobj, &attr->attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002744}
David Graham White86df2682013-07-21 20:41:14 -04002745EXPORT_SYMBOL_GPL(device_remove_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002746
Greg Kroah-Hartman2589f1882006-09-19 09:39:19 -07002747/**
Tejun Heo6b0afc22014-02-03 14:03:01 -05002748 * device_remove_file_self - remove sysfs attribute file from its own method.
2749 * @dev: device.
2750 * @attr: device attribute descriptor.
2751 *
2752 * See kernfs_remove_self() for details.
2753 */
2754bool device_remove_file_self(struct device *dev,
2755 const struct device_attribute *attr)
2756{
2757 if (dev)
2758 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
2759 else
2760 return false;
2761}
2762EXPORT_SYMBOL_GPL(device_remove_file_self);
2763
2764/**
Greg Kroah-Hartman2589f1882006-09-19 09:39:19 -07002765 * device_create_bin_file - create sysfs binary attribute file for device.
2766 * @dev: device.
2767 * @attr: device binary attribute descriptor.
2768 */
Phil Carmody66ecb922009-12-18 15:34:20 +02002769int device_create_bin_file(struct device *dev,
2770 const struct bin_attribute *attr)
Greg Kroah-Hartman2589f1882006-09-19 09:39:19 -07002771{
2772 int error = -EINVAL;
2773 if (dev)
2774 error = sysfs_create_bin_file(&dev->kobj, attr);
2775 return error;
2776}
2777EXPORT_SYMBOL_GPL(device_create_bin_file);
2778
2779/**
2780 * device_remove_bin_file - remove sysfs binary attribute file
2781 * @dev: device.
2782 * @attr: device binary attribute descriptor.
2783 */
Phil Carmody66ecb922009-12-18 15:34:20 +02002784void device_remove_bin_file(struct device *dev,
2785 const struct bin_attribute *attr)
Greg Kroah-Hartman2589f1882006-09-19 09:39:19 -07002786{
2787 if (dev)
2788 sysfs_remove_bin_file(&dev->kobj, attr);
2789}
2790EXPORT_SYMBOL_GPL(device_remove_bin_file);
2791
James Bottomley34bb61f2005-09-06 16:56:51 -07002792static void klist_children_get(struct klist_node *n)
2793{
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08002794 struct device_private *p = to_device_private_parent(n);
2795 struct device *dev = p->device;
James Bottomley34bb61f2005-09-06 16:56:51 -07002796
2797 get_device(dev);
2798}
2799
2800static void klist_children_put(struct klist_node *n)
2801{
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08002802 struct device_private *p = to_device_private_parent(n);
2803 struct device *dev = p->device;
James Bottomley34bb61f2005-09-06 16:56:51 -07002804
2805 put_device(dev);
2806}
2807
Linus Torvalds1da177e2005-04-16 15:20:36 -07002808/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002809 * device_initialize - init device structure.
2810 * @dev: device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002811 *
Cornelia Huck57394112008-09-03 18:26:40 +02002812 * This prepares the device for use by other layers by initializing
2813 * its fields.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08002814 * It is the first half of device_register(), if called by
Cornelia Huck57394112008-09-03 18:26:40 +02002815 * that function, though it can also be called separately, so one
2816 * may use @dev's fields. In particular, get_device()/put_device()
2817 * may be used for reference counting of @dev after calling this
2818 * function.
2819 *
Alan Sternb10d5ef2012-01-17 11:39:00 -05002820 * All fields in @dev must be initialized by the caller to 0, except
2821 * for those explicitly set to some other value. The simplest
2822 * approach is to use kzalloc() to allocate the structure containing
2823 * @dev.
2824 *
Cornelia Huck57394112008-09-03 18:26:40 +02002825 * NOTE: Use put_device() to give up your reference instead of freeing
2826 * @dev directly once you have called this function.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002827 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002828void device_initialize(struct device *dev)
2829{
Greg Kroah-Hartman881c6cfd2007-11-01 09:29:06 -06002830 dev->kobj.kset = devices_kset;
Greg Kroah-Hartmanf9cb0742007-12-17 23:05:35 -07002831 kobject_init(&dev->kobj, &device_ktype);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002832 INIT_LIST_HEAD(&dev->dma_pools);
Thomas Gleixner31427882010-01-29 20:39:02 +00002833 mutex_init(&dev->mutex);
Dan Williams87a30e12019-07-17 18:08:26 -07002834#ifdef CONFIG_PROVE_LOCKING
2835 mutex_init(&dev->lockdep_mutex);
2836#endif
Peter Zijlstra1704f472010-03-19 01:37:42 +01002837 lockdep_set_novalidate_class(&dev->mutex);
Tejun Heo9ac78492007-01-20 16:00:26 +09002838 spin_lock_init(&dev->devres_lock);
2839 INIT_LIST_HEAD(&dev->devres_head);
Alan Stern3b98aea2008-08-07 13:06:12 -04002840 device_pm_init(dev);
Christoph Hellwig87348132006-12-06 20:32:33 -08002841 set_dev_node(dev, -1);
Jiang Liu4a7cc832015-07-09 16:00:44 +08002842#ifdef CONFIG_GENERIC_MSI_IRQ
Thomas Gleixner77e89af2021-07-29 23:51:47 +02002843 raw_spin_lock_init(&dev->msi_lock);
Jiang Liu4a7cc832015-07-09 16:00:44 +08002844 INIT_LIST_HEAD(&dev->msi_list);
2845#endif
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01002846 INIT_LIST_HEAD(&dev->links.consumers);
2847 INIT_LIST_HEAD(&dev->links.suppliers);
Saravana Kannan3b052a32020-11-20 18:02:17 -08002848 INIT_LIST_HEAD(&dev->links.defer_sync);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01002849 dev->links.status = DL_DEV_NO_DRIVER;
Christoph Hellwig6d4e9a82021-02-10 10:56:39 +01002850#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
2851 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
2852 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
2853 dev->dma_coherent = dma_default_coherent;
2854#endif
Claire Chang69031f52021-06-19 11:40:34 +08002855#ifdef CONFIG_SWIOTLB
Will Deacon463e8622021-07-20 14:38:24 +01002856 dev->dma_io_tlb_mem = &io_tlb_default_mem;
Claire Chang69031f52021-06-19 11:40:34 +08002857#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002858}
David Graham White86df2682013-07-21 20:41:14 -04002859EXPORT_SYMBOL_GPL(device_initialize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002860
Tejun Heod73ce002013-03-12 11:30:05 -07002861struct kobject *virtual_device_parent(struct device *dev)
Greg Kroah-Hartmanf0ee61a2006-10-23 10:40:54 -07002862{
Kay Sievers86406242007-03-14 03:25:56 +01002863 static struct kobject *virtual_dir = NULL;
Greg Kroah-Hartmanf0ee61a2006-10-23 10:40:54 -07002864
Kay Sievers86406242007-03-14 03:25:56 +01002865 if (!virtual_dir)
Greg Kroah-Hartman4ff6abf2007-11-05 22:24:43 -08002866 virtual_dir = kobject_create_and_add("virtual",
Greg Kroah-Hartman881c6cfd2007-11-01 09:29:06 -06002867 &devices_kset->kobj);
Greg Kroah-Hartmanf0ee61a2006-10-23 10:40:54 -07002868
Kay Sievers86406242007-03-14 03:25:56 +01002869 return virtual_dir;
Greg Kroah-Hartmanf0ee61a2006-10-23 10:40:54 -07002870}
2871
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002872struct class_dir {
2873 struct kobject kobj;
2874 struct class *class;
2875};
2876
2877#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
2878
2879static void class_dir_release(struct kobject *kobj)
2880{
2881 struct class_dir *dir = to_class_dir(kobj);
2882 kfree(dir);
2883}
2884
2885static const
2886struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
2887{
2888 struct class_dir *dir = to_class_dir(kobj);
2889 return dir->class->ns_type;
2890}
2891
2892static struct kobj_type class_dir_ktype = {
2893 .release = class_dir_release,
2894 .sysfs_ops = &kobj_sysfs_ops,
2895 .child_ns_type = class_dir_child_ns_type
2896};
2897
2898static struct kobject *
2899class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
2900{
2901 struct class_dir *dir;
2902 int retval;
2903
2904 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
2905 if (!dir)
Tetsuo Handa84d0c272018-05-07 19:10:31 +09002906 return ERR_PTR(-ENOMEM);
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002907
2908 dir->class = class;
2909 kobject_init(&dir->kobj, &class_dir_ktype);
2910
Kay Sievers6b6e39a2010-11-15 23:13:18 +01002911 dir->kobj.kset = &class->p->glue_dirs;
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002912
2913 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
2914 if (retval < 0) {
2915 kobject_put(&dir->kobj);
Tetsuo Handa84d0c272018-05-07 19:10:31 +09002916 return ERR_PTR(retval);
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002917 }
2918 return &dir->kobj;
2919}
2920
Yijing Wange4a60d12014-11-07 12:05:49 +08002921static DEFINE_MUTEX(gdp_mutex);
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002922
Kay Sieversda231fd2007-11-21 17:29:15 +01002923static struct kobject *get_device_parent(struct device *dev,
2924 struct device *parent)
Greg Kroah-Hartman40fa5422006-10-24 00:37:58 +01002925{
Kay Sievers86406242007-03-14 03:25:56 +01002926 if (dev->class) {
2927 struct kobject *kobj = NULL;
2928 struct kobject *parent_kobj;
2929 struct kobject *k;
2930
Randy Dunlapead454f2010-09-24 14:36:49 -07002931#ifdef CONFIG_BLOCK
Kay Sievers39aba962010-09-04 22:33:14 -07002932 /* block disks show up in /sys/block */
Andi Kleene52eec12010-09-08 16:54:17 +02002933 if (sysfs_deprecated && dev->class == &block_class) {
Kay Sievers39aba962010-09-04 22:33:14 -07002934 if (parent && parent->class == &block_class)
2935 return &parent->kobj;
Kay Sievers6b6e39a2010-11-15 23:13:18 +01002936 return &block_class.p->subsys.kobj;
Kay Sievers39aba962010-09-04 22:33:14 -07002937 }
Randy Dunlapead454f2010-09-24 14:36:49 -07002938#endif
Andi Kleene52eec12010-09-08 16:54:17 +02002939
Kay Sievers86406242007-03-14 03:25:56 +01002940 /*
2941 * If we have no parent, we live in "virtual".
Kay Sievers0f4dafc2007-12-19 01:40:42 +01002942 * Class-devices with a non class-device as parent, live
2943 * in a "glue" directory to prevent namespace collisions.
Kay Sievers86406242007-03-14 03:25:56 +01002944 */
2945 if (parent == NULL)
2946 parent_kobj = virtual_device_parent(dev);
Eric W. Biederman24b14422010-07-24 22:43:35 -07002947 else if (parent->class && !dev->class->ns_type)
Kay Sievers86406242007-03-14 03:25:56 +01002948 return &parent->kobj;
2949 else
2950 parent_kobj = &parent->kobj;
2951
Tejun Heo77d3d7c2010-02-05 17:57:02 +09002952 mutex_lock(&gdp_mutex);
2953
Kay Sievers86406242007-03-14 03:25:56 +01002954 /* find our class-directory at the parent and reference it */
Kay Sievers6b6e39a2010-11-15 23:13:18 +01002955 spin_lock(&dev->class->p->glue_dirs.list_lock);
2956 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
Kay Sievers86406242007-03-14 03:25:56 +01002957 if (k->parent == parent_kobj) {
2958 kobj = kobject_get(k);
2959 break;
2960 }
Kay Sievers6b6e39a2010-11-15 23:13:18 +01002961 spin_unlock(&dev->class->p->glue_dirs.list_lock);
Tejun Heo77d3d7c2010-02-05 17:57:02 +09002962 if (kobj) {
2963 mutex_unlock(&gdp_mutex);
Kay Sievers86406242007-03-14 03:25:56 +01002964 return kobj;
Tejun Heo77d3d7c2010-02-05 17:57:02 +09002965 }
Kay Sievers86406242007-03-14 03:25:56 +01002966
2967 /* or create a new class-directory at the parent device */
Eric W. Biedermanbc451f22010-03-30 11:31:25 -07002968 k = class_dir_create_and_add(dev->class, parent_kobj);
Kay Sievers0f4dafc2007-12-19 01:40:42 +01002969 /* do not emit an uevent for this simple "glue" directory */
Tejun Heo77d3d7c2010-02-05 17:57:02 +09002970 mutex_unlock(&gdp_mutex);
Greg Kroah-Hartman43968d22007-11-05 22:24:43 -08002971 return k;
Kay Sievers86406242007-03-14 03:25:56 +01002972 }
2973
Kay Sieversca22e562011-12-14 14:29:38 -08002974 /* subsystems can specify a default root directory for their devices */
2975 if (!parent && dev->bus && dev->bus->dev_root)
2976 return &dev->bus->dev_root->kobj;
2977
Kay Sievers86406242007-03-14 03:25:56 +01002978 if (parent)
Cornelia Huckc744aeae2007-01-08 20:16:44 +01002979 return &parent->kobj;
2980 return NULL;
2981}
Kay Sieversda231fd2007-11-21 17:29:15 +01002982
Ming Leicebf8fd2016-07-10 19:27:36 +08002983static inline bool live_in_glue_dir(struct kobject *kobj,
2984 struct device *dev)
2985{
2986 if (!kobj || !dev->class ||
2987 kobj->kset != &dev->class->p->glue_dirs)
2988 return false;
2989 return true;
2990}
2991
2992static inline struct kobject *get_glue_dir(struct device *dev)
2993{
2994 return dev->kobj.parent;
2995}
2996
2997/*
2998 * make sure cleaning up dir as the last step, we need to make
2999 * sure .release handler of kobject is run with holding the
3000 * global lock
3001 */
Cornelia Huck63b69712008-01-21 16:09:44 +01003002static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
Kay Sieversda231fd2007-11-21 17:29:15 +01003003{
Muchun Songac434322019-07-27 11:21:22 +08003004 unsigned int ref;
3005
Kay Sievers0f4dafc2007-12-19 01:40:42 +01003006 /* see if we live in a "glue" directory */
Ming Leicebf8fd2016-07-10 19:27:36 +08003007 if (!live_in_glue_dir(glue_dir, dev))
Kay Sieversda231fd2007-11-21 17:29:15 +01003008 return;
3009
Yijing Wange4a60d12014-11-07 12:05:49 +08003010 mutex_lock(&gdp_mutex);
Muchun Songac434322019-07-27 11:21:22 +08003011 /**
3012 * There is a race condition between removing glue directory
3013 * and adding a new device under the glue directory.
3014 *
3015 * CPU1: CPU2:
3016 *
3017 * device_add()
3018 * get_device_parent()
3019 * class_dir_create_and_add()
3020 * kobject_add_internal()
3021 * create_dir() // create glue_dir
3022 *
3023 * device_add()
3024 * get_device_parent()
3025 * kobject_get() // get glue_dir
3026 *
3027 * device_del()
3028 * cleanup_glue_dir()
3029 * kobject_del(glue_dir)
3030 *
3031 * kobject_add()
3032 * kobject_add_internal()
3033 * create_dir() // in glue_dir
3034 * sysfs_create_dir_ns()
3035 * kernfs_create_dir_ns(sd)
3036 *
3037 * sysfs_remove_dir() // glue_dir->sd=NULL
3038 * sysfs_put() // free glue_dir->sd
3039 *
3040 * // sd is freed
3041 * kernfs_new_node(sd)
3042 * kernfs_get(glue_dir)
3043 * kernfs_add_one()
3044 * kernfs_put()
3045 *
3046 * Before CPU1 remove last child device under glue dir, if CPU2 add
3047 * a new device under glue dir, the glue_dir kobject reference count
3048 * will be increase to 2 in kobject_get(k). And CPU2 has been called
3049 * kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir()
3050 * and sysfs_put(). This result in glue_dir->sd is freed.
3051 *
3052 * Then the CPU2 will see a stale "empty" but still potentially used
3053 * glue dir around in kernfs_new_node().
3054 *
3055 * In order to avoid this happening, we also should make sure that
3056 * kernfs_node for glue_dir is released in CPU1 only when refcount
3057 * for glue_dir kobj is 1.
3058 */
3059 ref = kref_read(&glue_dir->kref);
3060 if (!kobject_has_children(glue_dir) && !--ref)
Benjamin Herrenschmidt726e4102018-07-10 10:29:10 +10003061 kobject_del(glue_dir);
Kay Sievers0f4dafc2007-12-19 01:40:42 +01003062 kobject_put(glue_dir);
Yijing Wange4a60d12014-11-07 12:05:49 +08003063 mutex_unlock(&gdp_mutex);
Kay Sieversda231fd2007-11-21 17:29:15 +01003064}
Cornelia Huck63b69712008-01-21 16:09:44 +01003065
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003066static int device_add_class_symlinks(struct device *dev)
3067{
Benjamin Herrenschmidt5590f312015-02-18 11:25:18 +11003068 struct device_node *of_node = dev_of_node(dev);
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003069 int error;
3070
Benjamin Herrenschmidt5590f312015-02-18 11:25:18 +11003071 if (of_node) {
Rob Herring0c3c2342017-10-04 14:04:01 -05003072 error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
Benjamin Herrenschmidt5590f312015-02-18 11:25:18 +11003073 if (error)
3074 dev_warn(dev, "Error %d creating of_node link\n",error);
3075 /* An error here doesn't warrant bringing down the device */
3076 }
3077
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003078 if (!dev->class)
3079 return 0;
Kay Sieversda231fd2007-11-21 17:29:15 +01003080
Greg Kroah-Hartman1fbfee62008-05-28 09:28:39 -07003081 error = sysfs_create_link(&dev->kobj,
Kay Sievers6b6e39a2010-11-15 23:13:18 +01003082 &dev->class->p->subsys.kobj,
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003083 "subsystem");
3084 if (error)
Benjamin Herrenschmidt5590f312015-02-18 11:25:18 +11003085 goto out_devnode;
Kay Sieversda231fd2007-11-21 17:29:15 +01003086
Greg Kroah-Hartman4e886c22008-01-27 12:12:43 -08003087 if (dev->parent && device_is_not_partition(dev)) {
Dmitry Torokhov4f01a752007-09-18 22:46:50 -07003088 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
3089 "device");
3090 if (error)
Kay Sievers39aba962010-09-04 22:33:14 -07003091 goto out_subsys;
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003092 }
Kay Sievers39aba962010-09-04 22:33:14 -07003093
Randy Dunlapead454f2010-09-24 14:36:49 -07003094#ifdef CONFIG_BLOCK
Kay Sievers39aba962010-09-04 22:33:14 -07003095 /* /sys/block has directories and does not need symlinks */
Andi Kleene52eec12010-09-08 16:54:17 +02003096 if (sysfs_deprecated && dev->class == &block_class)
Kay Sievers39aba962010-09-04 22:33:14 -07003097 return 0;
Randy Dunlapead454f2010-09-24 14:36:49 -07003098#endif
Kay Sievers39aba962010-09-04 22:33:14 -07003099
3100 /* link in the class directory pointing to the device */
Kay Sievers6b6e39a2010-11-15 23:13:18 +01003101 error = sysfs_create_link(&dev->class->p->subsys.kobj,
Kay Sievers39aba962010-09-04 22:33:14 -07003102 &dev->kobj, dev_name(dev));
3103 if (error)
3104 goto out_device;
3105
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003106 return 0;
3107
Kay Sievers39aba962010-09-04 22:33:14 -07003108out_device:
3109 sysfs_remove_link(&dev->kobj, "device");
Kay Sieversda231fd2007-11-21 17:29:15 +01003110
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003111out_subsys:
3112 sysfs_remove_link(&dev->kobj, "subsystem");
Benjamin Herrenschmidt5590f312015-02-18 11:25:18 +11003113out_devnode:
3114 sysfs_remove_link(&dev->kobj, "of_node");
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003115 return error;
3116}
3117
3118static void device_remove_class_symlinks(struct device *dev)
3119{
Benjamin Herrenschmidt5590f312015-02-18 11:25:18 +11003120 if (dev_of_node(dev))
3121 sysfs_remove_link(&dev->kobj, "of_node");
3122
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003123 if (!dev->class)
3124 return;
Kay Sieversda231fd2007-11-21 17:29:15 +01003125
Greg Kroah-Hartman4e886c22008-01-27 12:12:43 -08003126 if (dev->parent && device_is_not_partition(dev))
Kay Sieversda231fd2007-11-21 17:29:15 +01003127 sysfs_remove_link(&dev->kobj, "device");
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003128 sysfs_remove_link(&dev->kobj, "subsystem");
Randy Dunlapead454f2010-09-24 14:36:49 -07003129#ifdef CONFIG_BLOCK
Andi Kleene52eec12010-09-08 16:54:17 +02003130 if (sysfs_deprecated && dev->class == &block_class)
Kay Sievers39aba962010-09-04 22:33:14 -07003131 return;
Randy Dunlapead454f2010-09-24 14:36:49 -07003132#endif
Kay Sievers6b6e39a2010-11-15 23:13:18 +01003133 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003134}
3135
Linus Torvalds1da177e2005-04-16 15:20:36 -07003136/**
Stephen Rothwell413c2392008-05-30 10:16:40 +10003137 * dev_set_name - set a device name
3138 * @dev: device
Randy Dunlap46232362008-06-04 21:40:43 -07003139 * @fmt: format string for the device's name
Stephen Rothwell413c2392008-05-30 10:16:40 +10003140 */
3141int dev_set_name(struct device *dev, const char *fmt, ...)
3142{
3143 va_list vargs;
Kay Sievers1fa5ae82009-01-25 15:17:37 +01003144 int err;
Stephen Rothwell413c2392008-05-30 10:16:40 +10003145
3146 va_start(vargs, fmt);
Kay Sievers1fa5ae82009-01-25 15:17:37 +01003147 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
Stephen Rothwell413c2392008-05-30 10:16:40 +10003148 va_end(vargs);
Kay Sievers1fa5ae82009-01-25 15:17:37 +01003149 return err;
Stephen Rothwell413c2392008-05-30 10:16:40 +10003150}
3151EXPORT_SYMBOL_GPL(dev_set_name);
3152
3153/**
Dan Williamse105b8b2008-04-21 10:51:07 -07003154 * device_to_dev_kobj - select a /sys/dev/ directory for the device
3155 * @dev: device
3156 *
3157 * By default we select char/ for new entries. Setting class->dev_obj
3158 * to NULL prevents an entry from being created. class->dev_kobj must
3159 * be set (or cleared) before any devices are registered to the class
3160 * otherwise device_create_sys_dev_entry() and
Peter Korsgaard0d4e293c2012-04-17 12:12:57 +02003161 * device_remove_sys_dev_entry() will disagree about the presence of
3162 * the link.
Dan Williamse105b8b2008-04-21 10:51:07 -07003163 */
3164static struct kobject *device_to_dev_kobj(struct device *dev)
3165{
3166 struct kobject *kobj;
3167
3168 if (dev->class)
3169 kobj = dev->class->dev_kobj;
3170 else
3171 kobj = sysfs_dev_char_kobj;
3172
3173 return kobj;
3174}
3175
3176static int device_create_sys_dev_entry(struct device *dev)
3177{
3178 struct kobject *kobj = device_to_dev_kobj(dev);
3179 int error = 0;
3180 char devt_str[15];
3181
3182 if (kobj) {
3183 format_dev_t(devt_str, dev->devt);
3184 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
3185 }
3186
3187 return error;
3188}
3189
3190static void device_remove_sys_dev_entry(struct device *dev)
3191{
3192 struct kobject *kobj = device_to_dev_kobj(dev);
3193 char devt_str[15];
3194
3195 if (kobj) {
3196 format_dev_t(devt_str, dev->devt);
3197 sysfs_remove_link(kobj, devt_str);
3198 }
3199}
3200
Shaokun Zhang46d3a032018-07-15 18:08:56 +08003201static int device_private_init(struct device *dev)
Greg Kroah-Hartmanb4028432009-05-11 14:16:57 -07003202{
3203 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
3204 if (!dev->p)
3205 return -ENOMEM;
3206 dev->p->device = dev;
3207 klist_init(&dev->p->klist_children, klist_children_get,
3208 klist_children_put);
Greg Kroah-Hartmanef8a3fd2012-03-08 12:17:22 -08003209 INIT_LIST_HEAD(&dev->p->deferred_probe);
Greg Kroah-Hartmanb4028432009-05-11 14:16:57 -07003210 return 0;
3211}
3212
Dan Williamse105b8b2008-04-21 10:51:07 -07003213/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003214 * device_add - add device to device hierarchy.
3215 * @dev: device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003216 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003217 * This is part 2 of device_register(), though may be called
3218 * separately _iff_ device_initialize() has been called separately.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003219 *
Cornelia Huck57394112008-09-03 18:26:40 +02003220 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003221 * to the global and sibling lists for the device, then
3222 * adds it to the other relevant subsystems of the driver model.
Cornelia Huck57394112008-09-03 18:26:40 +02003223 *
Alan Sternb10d5ef2012-01-17 11:39:00 -05003224 * Do not call this routine or device_register() more than once for
3225 * any device structure. The driver model core is not designed to work
3226 * with devices that get unregistered and then spring back to life.
3227 * (Among other things, it's very hard to guarantee that all references
3228 * to the previous incarnation of @dev have been dropped.) Allocate
3229 * and register a fresh new struct device instead.
3230 *
Cornelia Huck57394112008-09-03 18:26:40 +02003231 * NOTE: _Never_ directly free @dev after calling this function, even
3232 * if it returned an error! Always use put_device() to give up your
3233 * reference instead.
Borislav Petkovaffada72019-04-18 19:41:56 +02003234 *
3235 * Rule of thumb is: if device_add() succeeds, you should call
3236 * device_del() when you want to get rid of it. If device_add() has
3237 * *not* succeeded, use *only* put_device() to drop the reference
3238 * count.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003239 */
3240int device_add(struct device *dev)
3241{
Viresh Kumar35dbf4e2017-03-17 12:24:22 +05303242 struct device *parent;
Kay Sieversca22e562011-12-14 14:29:38 -08003243 struct kobject *kobj;
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003244 struct class_interface *class_intf;
Saravana Kannan5f5377e2020-05-14 22:34:58 -07003245 int error = -EINVAL;
Ming Leicebf8fd2016-07-10 19:27:36 +08003246 struct kobject *glue_dir = NULL;
Rafael J. Wysocki775b64d2008-01-12 20:40:46 +01003247
Linus Torvalds1da177e2005-04-16 15:20:36 -07003248 dev = get_device(dev);
Greg Kroah-Hartmanc906a482008-05-30 10:45:12 -07003249 if (!dev)
3250 goto done;
3251
Greg Kroah-Hartmanfb069a52008-12-16 12:23:36 -08003252 if (!dev->p) {
Greg Kroah-Hartmanb4028432009-05-11 14:16:57 -07003253 error = device_private_init(dev);
3254 if (error)
3255 goto done;
Greg Kroah-Hartmanfb069a52008-12-16 12:23:36 -08003256 }
Greg Kroah-Hartmanfb069a52008-12-16 12:23:36 -08003257
Kay Sievers1fa5ae82009-01-25 15:17:37 +01003258 /*
3259 * for statically allocated devices, which should all be converted
3260 * some day, we need to initialize the name. We prevent reading back
3261 * the name, and force the use of dev_name()
3262 */
3263 if (dev->init_name) {
Greg Kroah-Hartmanacc0e902009-06-02 15:39:55 -07003264 dev_set_name(dev, "%s", dev->init_name);
Kay Sievers1fa5ae82009-01-25 15:17:37 +01003265 dev->init_name = NULL;
3266 }
Greg Kroah-Hartmanc906a482008-05-30 10:45:12 -07003267
Kay Sieversca22e562011-12-14 14:29:38 -08003268 /* subsystems can specify simple device enumeration */
3269 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
3270 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
3271
Thomas Gleixnere6309e72009-12-10 19:32:49 +00003272 if (!dev_name(dev)) {
3273 error = -EINVAL;
Kay Sievers5c8563d2009-05-28 14:24:07 -07003274 goto name_error;
Thomas Gleixnere6309e72009-12-10 19:32:49 +00003275 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003276
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01003277 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
Greg Kroah-Hartmanc205ef42006-08-07 22:19:37 -07003278
Linus Torvalds1da177e2005-04-16 15:20:36 -07003279 parent = get_device(dev->parent);
Kay Sieversca22e562011-12-14 14:29:38 -08003280 kobj = get_device_parent(dev, parent);
Tetsuo Handa84d0c272018-05-07 19:10:31 +09003281 if (IS_ERR(kobj)) {
3282 error = PTR_ERR(kobj);
3283 goto parent_error;
3284 }
Kay Sieversca22e562011-12-14 14:29:38 -08003285 if (kobj)
3286 dev->kobj.parent = kobj;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003287
Yinghai Lu0d358f22008-02-19 03:20:41 -08003288 /* use parent numa_node */
Zhen Lei56f2de82015-08-25 12:08:22 +08003289 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
Yinghai Lu0d358f22008-02-19 03:20:41 -08003290 set_dev_node(dev, dev_to_node(parent));
3291
Linus Torvalds1da177e2005-04-16 15:20:36 -07003292 /* first, register with generic layer. */
Kay Sievers8a577ff2009-04-18 15:05:45 -07003293 /* we require the name to be set before, and pass NULL */
3294 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
Ming Leicebf8fd2016-07-10 19:27:36 +08003295 if (error) {
3296 glue_dir = get_glue_dir(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003297 goto Error;
Ming Leicebf8fd2016-07-10 19:27:36 +08003298 }
Kay Sieversa7fd6702005-10-01 14:49:43 +02003299
Brian Walsh37022642006-08-14 22:43:19 -07003300 /* notify platform of device entry */
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02003301 device_platform_notify(dev);
Brian Walsh37022642006-08-14 22:43:19 -07003302
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07003303 error = device_create_file(dev, &dev_attr_uevent);
Cornelia Hucka306eea2006-09-22 11:37:13 +02003304 if (error)
3305 goto attrError;
Kay Sieversa7fd6702005-10-01 14:49:43 +02003306
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003307 error = device_add_class_symlinks(dev);
3308 if (error)
3309 goto SymlinkError;
Cornelia Huckdc0afa82007-07-09 11:39:18 -07003310 error = device_add_attrs(dev);
3311 if (error)
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07003312 goto AttrsError;
Cornelia Huckdc0afa82007-07-09 11:39:18 -07003313 error = bus_add_device(dev);
3314 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003315 goto BusError;
Alan Stern3b98aea2008-08-07 13:06:12 -04003316 error = dpm_sysfs_add(dev);
Rafael J. Wysocki57eee3d2008-03-12 00:59:38 +01003317 if (error)
Alan Stern3b98aea2008-08-07 13:06:12 -04003318 goto DPMError;
3319 device_pm_add(dev);
Alan Sternec0676ee2008-12-05 14:10:31 -05003320
Sergey Klyaus0cd75042014-10-08 11:31:54 +04003321 if (MAJOR(dev->devt)) {
3322 error = device_create_file(dev, &dev_attr_dev);
3323 if (error)
3324 goto DevAttrError;
3325
3326 error = device_create_sys_dev_entry(dev);
3327 if (error)
3328 goto SysEntryError;
3329
3330 devtmpfs_create_node(dev);
3331 }
3332
Alan Sternec0676ee2008-12-05 14:10:31 -05003333 /* Notify clients of device addition. This call must come
majianpeng268863f2012-01-11 15:12:06 +00003334 * after dpm_sysfs_add() and before kobject_uevent().
Alan Sternec0676ee2008-12-05 14:10:31 -05003335 */
3336 if (dev->bus)
3337 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
3338 BUS_NOTIFY_ADD_DEVICE, dev);
3339
Cornelia Huck83b5fb4c2007-03-29 11:12:11 +02003340 kobject_uevent(&dev->kobj, KOBJ_ADD);
Saravana Kannan372a67c2019-09-04 14:11:20 -07003341
Saravana Kannane2ae9bc2019-09-04 14:11:21 -07003342 /*
3343 * Check if any of the other devices (consumers) have been waiting for
3344 * this device (supplier) to be added so that they can create a device
3345 * link to it.
3346 *
3347 * This needs to happen after device_pm_add() because device_link_add()
3348 * requires the supplier be registered before it's called.
3349 *
Saravana Kannan2cd38fd2020-05-19 20:48:21 -07003350 * But this also needs to happen before bus_probe_device() to make sure
Saravana Kannane2ae9bc2019-09-04 14:11:21 -07003351 * waiting consumers can link to it before the driver is bound to the
3352 * device and the driver sync_state callback is called for this device.
3353 */
Saravana Kannan2cd38fd2020-05-19 20:48:21 -07003354 if (dev->fwnode && !dev->fwnode->dev) {
3355 dev->fwnode->dev = dev;
Saravana Kannan5f5377e2020-05-14 22:34:58 -07003356 fw_devlink_link_device(dev);
Saravana Kannan03324502019-10-28 15:00:24 -07003357 }
Saravana Kannane2ae9bc2019-09-04 14:11:21 -07003358
Alan Stern2023c612009-07-30 15:27:18 -04003359 bus_probe_device(dev);
Saravana Kannand46f3e32021-04-01 21:03:41 -07003360
3361 /*
3362 * If all driver registration is done and a newly added device doesn't
3363 * match with any driver, don't block its consumers from probing in
3364 * case the consumer device is able to operate without this supplier.
3365 */
3366 if (dev->fwnode && fw_devlink_drv_reg_done && !dev->can_match)
3367 fw_devlink_unblock_consumers(dev);
3368
Linus Torvalds1da177e2005-04-16 15:20:36 -07003369 if (parent)
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08003370 klist_add_tail(&dev->p->knode_parent,
3371 &parent->p->klist_children);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003372
Greg Kroah-Hartman5d9fd162006-06-22 17:17:32 -07003373 if (dev->class) {
Kay Sieversca22e562011-12-14 14:29:38 -08003374 mutex_lock(&dev->class->p->mutex);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003375 /* tie the class to the device */
Wei Yang570d0202019-01-18 10:34:59 +08003376 klist_add_tail(&dev->p->knode_class,
Kay Sievers6b6e39a2010-11-15 23:13:18 +01003377 &dev->class->p->klist_devices);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003378
3379 /* notify any interfaces that the device is here */
Greg Kroah-Hartman184f1f72008-05-28 09:28:39 -07003380 list_for_each_entry(class_intf,
Kay Sieversca22e562011-12-14 14:29:38 -08003381 &dev->class->p->interfaces, node)
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003382 if (class_intf->add_dev)
3383 class_intf->add_dev(dev, class_intf);
Kay Sieversca22e562011-12-14 14:29:38 -08003384 mutex_unlock(&dev->class->p->mutex);
Greg Kroah-Hartman5d9fd162006-06-22 17:17:32 -07003385 }
Greg Kroah-Hartmanc906a482008-05-30 10:45:12 -07003386done:
Linus Torvalds1da177e2005-04-16 15:20:36 -07003387 put_device(dev);
3388 return error;
Sergey Klyaus0cd75042014-10-08 11:31:54 +04003389 SysEntryError:
3390 if (MAJOR(dev->devt))
3391 device_remove_file(dev, &dev_attr_dev);
3392 DevAttrError:
3393 device_pm_remove(dev);
3394 dpm_sysfs_remove(dev);
Alan Stern3b98aea2008-08-07 13:06:12 -04003395 DPMError:
Rafael J. Wysocki57eee3d2008-03-12 00:59:38 +01003396 bus_remove_device(dev);
3397 BusError:
James Simmons82f0cf92007-02-21 17:44:51 +00003398 device_remove_attrs(dev);
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07003399 AttrsError:
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07003400 device_remove_class_symlinks(dev);
3401 SymlinkError:
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07003402 device_remove_file(dev, &dev_attr_uevent);
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07003403 attrError:
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02003404 device_platform_notify_remove(dev);
Kay Sievers312c0042005-11-16 09:00:00 +01003405 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
Ming Leicebf8fd2016-07-10 19:27:36 +08003406 glue_dir = get_glue_dir(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003407 kobject_del(&dev->kobj);
3408 Error:
Ming Leicebf8fd2016-07-10 19:27:36 +08003409 cleanup_glue_dir(dev, glue_dir);
Tetsuo Handa84d0c272018-05-07 19:10:31 +09003410parent_error:
Markus Elfring5f0163a2015-02-05 11:48:26 +01003411 put_device(parent);
Kay Sievers5c8563d2009-05-28 14:24:07 -07003412name_error:
3413 kfree(dev->p);
3414 dev->p = NULL;
Greg Kroah-Hartmanc906a482008-05-30 10:45:12 -07003415 goto done;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003416}
David Graham White86df2682013-07-21 20:41:14 -04003417EXPORT_SYMBOL_GPL(device_add);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003418
Linus Torvalds1da177e2005-04-16 15:20:36 -07003419/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003420 * device_register - register a device with the system.
3421 * @dev: pointer to the device structure
Linus Torvalds1da177e2005-04-16 15:20:36 -07003422 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003423 * This happens in two clean steps - initialize the device
3424 * and add it to the system. The two steps can be called
3425 * separately, but this is the easiest and most common.
3426 * I.e. you should only call the two helpers separately if
3427 * have a clearly defined need to use and refcount the device
3428 * before it is added to the hierarchy.
Cornelia Huck57394112008-09-03 18:26:40 +02003429 *
Alan Sternb10d5ef2012-01-17 11:39:00 -05003430 * For more information, see the kerneldoc for device_initialize()
3431 * and device_add().
3432 *
Cornelia Huck57394112008-09-03 18:26:40 +02003433 * NOTE: _Never_ directly free @dev after calling this function, even
3434 * if it returned an error! Always use put_device() to give up the
3435 * reference initialized in this function instead.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003436 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003437int device_register(struct device *dev)
3438{
3439 device_initialize(dev);
3440 return device_add(dev);
3441}
David Graham White86df2682013-07-21 20:41:14 -04003442EXPORT_SYMBOL_GPL(device_register);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003443
Linus Torvalds1da177e2005-04-16 15:20:36 -07003444/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003445 * get_device - increment reference count for device.
3446 * @dev: device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003447 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003448 * This simply forwards the call to kobject_get(), though
3449 * we do take care to provide for the case that we get a NULL
3450 * pointer passed in.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003451 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003452struct device *get_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003453{
Lars-Peter Clausenb0d1f802012-07-03 18:49:36 +02003454 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003455}
David Graham White86df2682013-07-21 20:41:14 -04003456EXPORT_SYMBOL_GPL(get_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003457
Linus Torvalds1da177e2005-04-16 15:20:36 -07003458/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003459 * put_device - decrement reference count.
3460 * @dev: device in question.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003461 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003462void put_device(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003463{
Kay Sieversedfaa7c2007-05-21 22:08:01 +02003464 /* might_sleep(); */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003465 if (dev)
3466 kobject_put(&dev->kobj);
3467}
David Graham White86df2682013-07-21 20:41:14 -04003468EXPORT_SYMBOL_GPL(put_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003469
Dan Williams00289cd2019-07-17 18:07:53 -07003470bool kill_device(struct device *dev)
3471{
3472 /*
3473 * Require the device lock and set the "dead" flag to guarantee that
3474 * the update behavior is consistent with the other bitfields near
3475 * it and that we cannot have an asynchronous probe routine trying
3476 * to run while we are tearing out the bus/class/sysfs from
3477 * underneath the device.
3478 */
Julian Wiedmann8c60a142021-05-12 16:10:54 +02003479 device_lock_assert(dev);
Dan Williams00289cd2019-07-17 18:07:53 -07003480
3481 if (dev->p->dead)
3482 return false;
3483 dev->p->dead = true;
3484 return true;
3485}
3486EXPORT_SYMBOL_GPL(kill_device);
3487
Linus Torvalds1da177e2005-04-16 15:20:36 -07003488/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003489 * device_del - delete device from system.
3490 * @dev: device.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003491 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003492 * This is the first part of the device unregistration
3493 * sequence. This removes the device from the lists we control
3494 * from here, has it removed from the other driver model
3495 * subsystems it was added to in device_add(), and removes it
3496 * from the kobject hierarchy.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003497 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003498 * NOTE: this should be called manually _iff_ device_add() was
3499 * also called manually.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003500 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003501void device_del(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003502{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003503 struct device *parent = dev->parent;
Ming Leicebf8fd2016-07-10 19:27:36 +08003504 struct kobject *glue_dir = NULL;
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003505 struct class_interface *class_intf;
Oliver Neukumb8530012020-09-16 21:15:44 +02003506 unsigned int noio_flag;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003507
Alexander Duyck3451a492019-01-22 10:39:10 -08003508 device_lock(dev);
Dan Williams00289cd2019-07-17 18:07:53 -07003509 kill_device(dev);
Alexander Duyck3451a492019-01-22 10:39:10 -08003510 device_unlock(dev);
3511
Saravana Kannan372a67c2019-09-04 14:11:20 -07003512 if (dev->fwnode && dev->fwnode->dev == dev)
3513 dev->fwnode->dev = NULL;
3514
Alan Sternec0676ee2008-12-05 14:10:31 -05003515 /* Notify clients of device removal. This call must come
3516 * before dpm_sysfs_remove().
3517 */
Oliver Neukumb8530012020-09-16 21:15:44 +02003518 noio_flag = memalloc_noio_save();
Alan Sternec0676ee2008-12-05 14:10:31 -05003519 if (dev->bus)
3520 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
3521 BUS_NOTIFY_DEL_DEVICE, dev);
Rafael J. Wysocki9ed98952016-10-30 17:32:16 +01003522
Alan Stern3b98aea2008-08-07 13:06:12 -04003523 dpm_sysfs_remove(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003524 if (parent)
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08003525 klist_del(&dev->p->knode_parent);
Dan Williamse105b8b2008-04-21 10:51:07 -07003526 if (MAJOR(dev->devt)) {
Kay Sievers2b2af542009-04-30 15:23:42 +02003527 devtmpfs_delete_node(dev);
Dan Williamse105b8b2008-04-21 10:51:07 -07003528 device_remove_sys_dev_entry(dev);
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07003529 device_remove_file(dev, &dev_attr_dev);
Dan Williamse105b8b2008-04-21 10:51:07 -07003530 }
Kay Sieversb9d9c822006-06-15 15:31:56 +02003531 if (dev->class) {
Kay Sieversda231fd2007-11-21 17:29:15 +01003532 device_remove_class_symlinks(dev);
Kay Sievers99ef3ef2006-09-14 11:23:28 +02003533
Kay Sieversca22e562011-12-14 14:29:38 -08003534 mutex_lock(&dev->class->p->mutex);
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003535 /* notify any interfaces that the device is now gone */
Greg Kroah-Hartman184f1f72008-05-28 09:28:39 -07003536 list_for_each_entry(class_intf,
Kay Sieversca22e562011-12-14 14:29:38 -08003537 &dev->class->p->interfaces, node)
Greg Kroah-Hartmanc47ed212006-09-13 15:34:05 +02003538 if (class_intf->remove_dev)
3539 class_intf->remove_dev(dev, class_intf);
3540 /* remove the device from the class list */
Wei Yang570d0202019-01-18 10:34:59 +08003541 klist_del(&dev->p->knode_class);
Kay Sieversca22e562011-12-14 14:29:38 -08003542 mutex_unlock(&dev->class->p->mutex);
Kay Sieversb9d9c822006-06-15 15:31:56 +02003543 }
Greg Kroah-Hartmanc5e064a2013-08-23 17:07:26 -07003544 device_remove_file(dev, &dev_attr_uevent);
Greg Kroah-Hartman2620efe2006-06-28 16:19:58 -07003545 device_remove_attrs(dev);
Benjamin Herrenschmidt28953532006-11-08 19:46:14 -08003546 bus_remove_device(dev);
LongX Zhang4b6d1f122012-10-25 00:21:28 +02003547 device_pm_remove(dev);
Grant Likelyd1c34142012-03-05 08:47:41 -07003548 driver_deferred_probe_del(dev);
Rafael J. Wysockib2ebd9d2021-07-12 19:28:16 +02003549 device_platform_notify_remove(dev);
Lukas Wunner478573c2016-07-28 02:25:41 +02003550 device_remove_properties(dev);
Jeffy Chen2ec16152017-10-20 20:01:01 +08003551 device_links_purge(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003552
Joerg Roedel599bad32014-09-30 13:02:02 +02003553 if (dev->bus)
3554 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
3555 BUS_NOTIFY_REMOVED_DEVICE, dev);
Kay Sievers312c0042005-11-16 09:00:00 +01003556 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
Ming Leicebf8fd2016-07-10 19:27:36 +08003557 glue_dir = get_glue_dir(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003558 kobject_del(&dev->kobj);
Ming Leicebf8fd2016-07-10 19:27:36 +08003559 cleanup_glue_dir(dev, glue_dir);
Oliver Neukumb8530012020-09-16 21:15:44 +02003560 memalloc_noio_restore(noio_flag);
Kay Sieversda231fd2007-11-21 17:29:15 +01003561 put_device(parent);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003562}
David Graham White86df2682013-07-21 20:41:14 -04003563EXPORT_SYMBOL_GPL(device_del);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003564
3565/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003566 * device_unregister - unregister device from system.
3567 * @dev: device going away.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003568 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003569 * We do this in two parts, like we do device_register(). First,
3570 * we remove it from all the subsystems with device_del(), then
3571 * we decrement the reference count via put_device(). If that
3572 * is the final reference count, the device will be cleaned up
3573 * via device_release() above. Otherwise, the structure will
3574 * stick around until the final reference to the device is dropped.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003575 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003576void device_unregister(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003577{
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01003578 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003579 device_del(dev);
3580 put_device(dev);
3581}
David Graham White86df2682013-07-21 20:41:14 -04003582EXPORT_SYMBOL_GPL(device_unregister);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003583
Andy Shevchenko3d060ae2015-07-27 18:04:00 +03003584static struct device *prev_device(struct klist_iter *i)
3585{
3586 struct klist_node *n = klist_prev(i);
3587 struct device *dev = NULL;
3588 struct device_private *p;
3589
3590 if (n) {
3591 p = to_device_private_parent(n);
3592 dev = p->device;
3593 }
3594 return dev;
3595}
3596
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003597static struct device *next_device(struct klist_iter *i)
mochel@digitalimplant.org36239572005-03-24 19:08:30 -08003598{
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003599 struct klist_node *n = klist_next(i);
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08003600 struct device *dev = NULL;
3601 struct device_private *p;
3602
3603 if (n) {
3604 p = to_device_private_parent(n);
3605 dev = p->device;
3606 }
3607 return dev;
mochel@digitalimplant.org36239572005-03-24 19:08:30 -08003608}
3609
Linus Torvalds1da177e2005-04-16 15:20:36 -07003610/**
Kay Sieverse454cea2009-09-18 23:01:12 +02003611 * device_get_devnode - path of device node file
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003612 * @dev: device
Kay Sieverse454cea2009-09-18 23:01:12 +02003613 * @mode: returned file access mode
Kay Sievers3c2670e2013-04-06 09:56:00 -07003614 * @uid: returned file owner
3615 * @gid: returned file group
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003616 * @tmp: possibly allocated string
3617 *
3618 * Return the relative path of a possible device node.
3619 * Non-default names may need to allocate a memory to compose
3620 * a name. This memory is returned in tmp and needs to be
3621 * freed by the caller.
3622 */
Kay Sieverse454cea2009-09-18 23:01:12 +02003623const char *device_get_devnode(struct device *dev,
Greg Kroah-Hartman4e4098a2013-04-11 11:43:29 -07003624 umode_t *mode, kuid_t *uid, kgid_t *gid,
Kay Sievers3c2670e2013-04-06 09:56:00 -07003625 const char **tmp)
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003626{
3627 char *s;
3628
3629 *tmp = NULL;
3630
3631 /* the device type may provide a specific name */
Kay Sieverse454cea2009-09-18 23:01:12 +02003632 if (dev->type && dev->type->devnode)
Kay Sievers3c2670e2013-04-06 09:56:00 -07003633 *tmp = dev->type->devnode(dev, mode, uid, gid);
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003634 if (*tmp)
3635 return *tmp;
3636
3637 /* the class may provide a specific name */
Kay Sieverse454cea2009-09-18 23:01:12 +02003638 if (dev->class && dev->class->devnode)
3639 *tmp = dev->class->devnode(dev, mode);
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003640 if (*tmp)
3641 return *tmp;
3642
3643 /* return name without allocation, tmp == NULL */
3644 if (strchr(dev_name(dev), '!') == NULL)
3645 return dev_name(dev);
3646
3647 /* replace '!' in the name with '/' */
Rasmus Villemoesa29fd612015-06-25 15:02:33 -07003648 s = kstrdup(dev_name(dev), GFP_KERNEL);
3649 if (!s)
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003650 return NULL;
Rasmus Villemoesa29fd612015-06-25 15:02:33 -07003651 strreplace(s, '!', '/');
3652 return *tmp = s;
Kay Sievers6fcf53a2009-04-30 15:23:42 +02003653}
3654
3655/**
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003656 * device_for_each_child - device child iterator.
3657 * @parent: parent struct device.
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003658 * @fn: function to be called for each device.
Robert P. J. Dayf8878dc2013-06-01 20:17:34 -04003659 * @data: data for the callback.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003660 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003661 * Iterate over @parent's child devices, and call @fn for each,
3662 * passing it @data.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003663 *
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003664 * We check the return of @fn each time. If it returns anything
3665 * other than 0, we break out and return that value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003666 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003667int device_for_each_child(struct device *parent, void *data,
3668 int (*fn)(struct device *dev, void *data))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003669{
mochel@digitalimplant.org36239572005-03-24 19:08:30 -08003670 struct klist_iter i;
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003671 struct device *child;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003672 int error = 0;
3673
Greg Kroah-Hartman014c90db2009-04-15 16:00:12 -07003674 if (!parent->p)
3675 return 0;
3676
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08003677 klist_iter_init(&parent->p->klist_children, &i);
Gimcuan Hui93ead7c2017-11-11 05:52:54 +00003678 while (!error && (child = next_device(&i)))
mochel@digitalimplant.org36239572005-03-24 19:08:30 -08003679 error = fn(child, data);
3680 klist_iter_exit(&i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003681 return error;
3682}
David Graham White86df2682013-07-21 20:41:14 -04003683EXPORT_SYMBOL_GPL(device_for_each_child);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003684
Cornelia Huck5ab69982006-11-16 15:42:07 +01003685/**
Andy Shevchenko3d060ae2015-07-27 18:04:00 +03003686 * device_for_each_child_reverse - device child iterator in reversed order.
3687 * @parent: parent struct device.
3688 * @fn: function to be called for each device.
3689 * @data: data for the callback.
3690 *
3691 * Iterate over @parent's child devices, and call @fn for each,
3692 * passing it @data.
3693 *
3694 * We check the return of @fn each time. If it returns anything
3695 * other than 0, we break out and return that value.
3696 */
3697int device_for_each_child_reverse(struct device *parent, void *data,
3698 int (*fn)(struct device *dev, void *data))
3699{
3700 struct klist_iter i;
3701 struct device *child;
3702 int error = 0;
3703
3704 if (!parent->p)
3705 return 0;
3706
3707 klist_iter_init(&parent->p->klist_children, &i);
3708 while ((child = prev_device(&i)) && !error)
3709 error = fn(child, data);
3710 klist_iter_exit(&i);
3711 return error;
3712}
3713EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
3714
3715/**
Cornelia Huck5ab69982006-11-16 15:42:07 +01003716 * device_find_child - device iterator for locating a particular device.
3717 * @parent: parent struct device
Cornelia Huck5ab69982006-11-16 15:42:07 +01003718 * @match: Callback function to check device
Robert P. J. Dayf8878dc2013-06-01 20:17:34 -04003719 * @data: Data to pass to match function
Cornelia Huck5ab69982006-11-16 15:42:07 +01003720 *
3721 * This is similar to the device_for_each_child() function above, but it
3722 * returns a reference to a device that is 'found' for later use, as
3723 * determined by the @match callback.
3724 *
3725 * The callback should return 0 if the device doesn't match and non-zero
3726 * if it does. If the callback returns non-zero and a reference to the
3727 * current device can be obtained, this function will return to the caller
3728 * and not iterate over any more devices.
Federico Vagaa4e24002013-04-15 11:18:11 +02003729 *
3730 * NOTE: you will need to drop the reference with put_device() after use.
Cornelia Huck5ab69982006-11-16 15:42:07 +01003731 */
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08003732struct device *device_find_child(struct device *parent, void *data,
3733 int (*match)(struct device *dev, void *data))
Cornelia Huck5ab69982006-11-16 15:42:07 +01003734{
3735 struct klist_iter i;
3736 struct device *child;
3737
3738 if (!parent)
3739 return NULL;
3740
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08003741 klist_iter_init(&parent->p->klist_children, &i);
Cornelia Huck5ab69982006-11-16 15:42:07 +01003742 while ((child = next_device(&i)))
3743 if (match(child, data) && get_device(child))
3744 break;
3745 klist_iter_exit(&i);
3746 return child;
3747}
David Graham White86df2682013-07-21 20:41:14 -04003748EXPORT_SYMBOL_GPL(device_find_child);
Cornelia Huck5ab69982006-11-16 15:42:07 +01003749
Heikki Krogerusdad9bb02019-05-31 17:15:37 +03003750/**
3751 * device_find_child_by_name - device iterator for locating a child device.
3752 * @parent: parent struct device
3753 * @name: name of the child device
3754 *
3755 * This is similar to the device_find_child() function above, but it
3756 * returns a reference to a device that has the name @name.
3757 *
3758 * NOTE: you will need to drop the reference with put_device() after use.
3759 */
3760struct device *device_find_child_by_name(struct device *parent,
3761 const char *name)
3762{
3763 struct klist_iter i;
3764 struct device *child;
3765
3766 if (!parent)
3767 return NULL;
3768
3769 klist_iter_init(&parent->p->klist_children, &i);
3770 while ((child = next_device(&i)))
Dan Williamsc77f5202020-10-13 16:50:18 -07003771 if (sysfs_streq(dev_name(child), name) && get_device(child))
Heikki Krogerusdad9bb02019-05-31 17:15:37 +03003772 break;
3773 klist_iter_exit(&i);
3774 return child;
3775}
3776EXPORT_SYMBOL_GPL(device_find_child_by_name);
3777
Linus Torvalds1da177e2005-04-16 15:20:36 -07003778int __init devices_init(void)
3779{
Greg Kroah-Hartman881c6cfd2007-11-01 09:29:06 -06003780 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
3781 if (!devices_kset)
3782 return -ENOMEM;
Dan Williamse105b8b2008-04-21 10:51:07 -07003783 dev_kobj = kobject_create_and_add("dev", NULL);
3784 if (!dev_kobj)
3785 goto dev_kobj_err;
3786 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
3787 if (!sysfs_dev_block_kobj)
3788 goto block_kobj_err;
3789 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
3790 if (!sysfs_dev_char_kobj)
3791 goto char_kobj_err;
3792
Greg Kroah-Hartman881c6cfd2007-11-01 09:29:06 -06003793 return 0;
Dan Williamse105b8b2008-04-21 10:51:07 -07003794
3795 char_kobj_err:
3796 kobject_put(sysfs_dev_block_kobj);
3797 block_kobj_err:
3798 kobject_put(dev_kobj);
3799 dev_kobj_err:
3800 kset_unregister(devices_kset);
3801 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003802}
3803
Rafael J. Wysocki4f3549d2013-05-02 22:15:29 +02003804static int device_check_offline(struct device *dev, void *not_used)
3805{
3806 int ret;
3807
3808 ret = device_for_each_child(dev, NULL, device_check_offline);
3809 if (ret)
3810 return ret;
3811
3812 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
3813}
3814
3815/**
3816 * device_offline - Prepare the device for hot-removal.
3817 * @dev: Device to be put offline.
3818 *
3819 * Execute the device bus type's .offline() callback, if present, to prepare
3820 * the device for a subsequent hot-removal. If that succeeds, the device must
3821 * not be used until either it is removed or its bus type's .online() callback
3822 * is executed.
3823 *
3824 * Call under device_hotplug_lock.
3825 */
3826int device_offline(struct device *dev)
3827{
3828 int ret;
3829
3830 if (dev->offline_disabled)
3831 return -EPERM;
3832
3833 ret = device_for_each_child(dev, NULL, device_check_offline);
3834 if (ret)
3835 return ret;
3836
3837 device_lock(dev);
3838 if (device_supports_offline(dev)) {
3839 if (dev->offline) {
3840 ret = 1;
3841 } else {
3842 ret = dev->bus->offline(dev);
3843 if (!ret) {
3844 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
3845 dev->offline = true;
3846 }
3847 }
3848 }
3849 device_unlock(dev);
3850
3851 return ret;
3852}
3853
3854/**
3855 * device_online - Put the device back online after successful device_offline().
3856 * @dev: Device to be put back online.
3857 *
3858 * If device_offline() has been successfully executed for @dev, but the device
3859 * has not been removed subsequently, execute its bus type's .online() callback
3860 * to indicate that the device can be used again.
3861 *
3862 * Call under device_hotplug_lock.
3863 */
3864int device_online(struct device *dev)
3865{
3866 int ret = 0;
3867
3868 device_lock(dev);
3869 if (device_supports_offline(dev)) {
3870 if (dev->offline) {
3871 ret = dev->bus->online(dev);
3872 if (!ret) {
3873 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
3874 dev->offline = false;
3875 }
3876 } else {
3877 ret = 1;
3878 }
3879 }
3880 device_unlock(dev);
3881
3882 return ret;
3883}
3884
Karthigan Srinivasan7f100d12011-04-18 16:16:52 -05003885struct root_device {
Mark McLoughlin0aa0dc42008-12-15 12:58:26 +00003886 struct device dev;
3887 struct module *owner;
3888};
3889
Josh Triplett93058422012-11-18 21:27:55 -08003890static inline struct root_device *to_root_device(struct device *d)
Ferenc Wagner481e2072011-01-07 15:17:47 +01003891{
3892 return container_of(d, struct root_device, dev);
3893}
Mark McLoughlin0aa0dc42008-12-15 12:58:26 +00003894
3895static void root_device_release(struct device *dev)
3896{
3897 kfree(to_root_device(dev));
3898}
3899
3900/**
3901 * __root_device_register - allocate and register a root device
3902 * @name: root device name
3903 * @owner: owner module of the root device, usually THIS_MODULE
3904 *
3905 * This function allocates a root device and registers it
3906 * using device_register(). In order to free the returned
3907 * device, use root_device_unregister().
3908 *
3909 * Root devices are dummy devices which allow other devices
3910 * to be grouped under /sys/devices. Use this function to
3911 * allocate a root device and then use it as the parent of
3912 * any device which should appear under /sys/devices/{name}
3913 *
3914 * The /sys/devices/{name} directory will also contain a
3915 * 'module' symlink which points to the @owner directory
3916 * in sysfs.
3917 *
Jani Nikulaf0eae0e2010-03-11 18:11:45 +02003918 * Returns &struct device pointer on success, or ERR_PTR() on error.
3919 *
Mark McLoughlin0aa0dc42008-12-15 12:58:26 +00003920 * Note: You probably want to use root_device_register().
3921 */
3922struct device *__root_device_register(const char *name, struct module *owner)
3923{
3924 struct root_device *root;
3925 int err = -ENOMEM;
3926
3927 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
3928 if (!root)
3929 return ERR_PTR(err);
3930
Greg Kroah-Hartmanacc0e902009-06-02 15:39:55 -07003931 err = dev_set_name(&root->dev, "%s", name);
Mark McLoughlin0aa0dc42008-12-15 12:58:26 +00003932 if (err) {
3933 kfree(root);
3934 return ERR_PTR(err);
3935 }
3936
3937 root->dev.release = root_device_release;
3938
3939 err = device_register(&root->dev);
3940 if (err) {
3941 put_device(&root->dev);
3942 return ERR_PTR(err);
3943 }
3944
Christoph Egger1d9e8822010-05-17 16:57:58 +02003945#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
Mark McLoughlin0aa0dc42008-12-15 12:58:26 +00003946 if (owner) {
3947 struct module_kobject *mk = &owner->mkobj;
3948
3949 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
3950 if (err) {
3951 device_unregister(&root->dev);
3952 return ERR_PTR(err);
3953 }
3954 root->owner = owner;
3955 }
3956#endif
3957
3958 return &root->dev;
3959}
3960EXPORT_SYMBOL_GPL(__root_device_register);
3961
3962/**
3963 * root_device_unregister - unregister and free a root device
Randy Dunlap7cbcf222009-01-20 16:29:13 -08003964 * @dev: device going away
Mark McLoughlin0aa0dc42008-12-15 12:58:26 +00003965 *
3966 * This function unregisters and cleans up a device that was created by
3967 * root_device_register().
3968 */
3969void root_device_unregister(struct device *dev)
3970{
3971 struct root_device *root = to_root_device(dev);
3972
3973 if (root->owner)
3974 sysfs_remove_link(&root->dev.kobj, "module");
3975
3976 device_unregister(dev);
3977}
3978EXPORT_SYMBOL_GPL(root_device_unregister);
3979
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07003980
3981static void device_create_release(struct device *dev)
3982{
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01003983 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07003984 kfree(dev);
3985}
3986
Mathieu Malaterre6a8b55d2018-05-05 21:57:41 +02003987static __printf(6, 0) struct device *
Guenter Roeck39ef3112013-07-14 16:05:57 -07003988device_create_groups_vargs(struct class *class, struct device *parent,
3989 dev_t devt, void *drvdata,
3990 const struct attribute_group **groups,
3991 const char *fmt, va_list args)
3992{
3993 struct device *dev = NULL;
3994 int retval = -ENODEV;
3995
3996 if (class == NULL || IS_ERR(class))
3997 goto error;
3998
3999 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
4000 if (!dev) {
4001 retval = -ENOMEM;
4002 goto error;
4003 }
4004
David Herrmannbbc780f2013-11-21 20:15:48 +01004005 device_initialize(dev);
Guenter Roeck39ef3112013-07-14 16:05:57 -07004006 dev->devt = devt;
4007 dev->class = class;
4008 dev->parent = parent;
4009 dev->groups = groups;
4010 dev->release = device_create_release;
4011 dev_set_drvdata(dev, drvdata);
4012
4013 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
4014 if (retval)
4015 goto error;
4016
David Herrmannbbc780f2013-11-21 20:15:48 +01004017 retval = device_add(dev);
Guenter Roeck39ef3112013-07-14 16:05:57 -07004018 if (retval)
4019 goto error;
4020
4021 return dev;
4022
4023error:
4024 put_device(dev);
4025 return ERR_PTR(retval);
4026}
4027
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07004028/**
Greg Kroah-Hartman4e106732008-07-21 20:03:34 -07004029 * device_create - creates a device and registers it with sysfs
Greg Kroah-Hartman8882b392008-05-15 13:44:08 -07004030 * @class: pointer to the struct class that this device should be registered to
4031 * @parent: pointer to the parent struct device of this new device, if any
4032 * @devt: the dev_t for the char device to be added
4033 * @drvdata: the data to be added to the device for callbacks
4034 * @fmt: string for the device's name
4035 *
4036 * This function can be used by char device classes. A struct device
4037 * will be created in sysfs, registered to the specified class.
4038 *
4039 * A "dev" file will be created, showing the dev_t for the device, if
4040 * the dev_t is not 0,0.
4041 * If a pointer to a parent struct device is passed in, the newly created
4042 * struct device will be a child of that device in sysfs.
4043 * The pointer to the struct device will be returned from the call.
4044 * Any further sysfs files that might be required can be created using this
4045 * pointer.
4046 *
Jani Nikulaf0eae0e2010-03-11 18:11:45 +02004047 * Returns &struct device pointer on success, or ERR_PTR() on error.
4048 *
Greg Kroah-Hartman8882b392008-05-15 13:44:08 -07004049 * Note: the struct class passed to this function must have previously
4050 * been created with a call to class_create().
4051 */
Greg Kroah-Hartman4e106732008-07-21 20:03:34 -07004052struct device *device_create(struct class *class, struct device *parent,
4053 dev_t devt, void *drvdata, const char *fmt, ...)
Greg Kroah-Hartman8882b392008-05-15 13:44:08 -07004054{
4055 va_list vargs;
4056 struct device *dev;
4057
4058 va_start(vargs, fmt);
Christoph Hellwig4c747462020-05-04 14:47:57 +02004059 dev = device_create_groups_vargs(class, parent, devt, drvdata, NULL,
4060 fmt, vargs);
Greg Kroah-Hartman8882b392008-05-15 13:44:08 -07004061 va_end(vargs);
4062 return dev;
4063}
Greg Kroah-Hartman4e106732008-07-21 20:03:34 -07004064EXPORT_SYMBOL_GPL(device_create);
Greg Kroah-Hartman8882b392008-05-15 13:44:08 -07004065
Guenter Roeck39ef3112013-07-14 16:05:57 -07004066/**
4067 * device_create_with_groups - creates a device and registers it with sysfs
4068 * @class: pointer to the struct class that this device should be registered to
4069 * @parent: pointer to the parent struct device of this new device, if any
4070 * @devt: the dev_t for the char device to be added
4071 * @drvdata: the data to be added to the device for callbacks
4072 * @groups: NULL-terminated list of attribute groups to be created
4073 * @fmt: string for the device's name
4074 *
4075 * This function can be used by char device classes. A struct device
4076 * will be created in sysfs, registered to the specified class.
4077 * Additional attributes specified in the groups parameter will also
4078 * be created automatically.
4079 *
4080 * A "dev" file will be created, showing the dev_t for the device, if
4081 * the dev_t is not 0,0.
4082 * If a pointer to a parent struct device is passed in, the newly created
4083 * struct device will be a child of that device in sysfs.
4084 * The pointer to the struct device will be returned from the call.
4085 * Any further sysfs files that might be required can be created using this
4086 * pointer.
4087 *
4088 * Returns &struct device pointer on success, or ERR_PTR() on error.
4089 *
4090 * Note: the struct class passed to this function must have previously
4091 * been created with a call to class_create().
4092 */
4093struct device *device_create_with_groups(struct class *class,
4094 struct device *parent, dev_t devt,
4095 void *drvdata,
4096 const struct attribute_group **groups,
4097 const char *fmt, ...)
4098{
4099 va_list vargs;
4100 struct device *dev;
4101
4102 va_start(vargs, fmt);
4103 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
4104 fmt, vargs);
4105 va_end(vargs);
4106 return dev;
4107}
4108EXPORT_SYMBOL_GPL(device_create_with_groups);
4109
Rafael J. Wysocki775b64d2008-01-12 20:40:46 +01004110/**
4111 * device_destroy - removes a device that was created with device_create()
4112 * @class: pointer to the struct class that this device was registered with
4113 * @devt: the dev_t of the device that was previously registered
4114 *
4115 * This call unregisters and cleans up a device that was created with a
4116 * call to device_create().
4117 */
4118void device_destroy(struct class *class, dev_t devt)
4119{
4120 struct device *dev;
4121
Suzuki K Poulose4495dfd2019-07-23 23:18:35 +01004122 dev = class_find_device_by_devt(class, devt);
Dave Youngcd354492008-01-28 16:56:11 +08004123 if (dev) {
4124 put_device(dev);
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07004125 device_unregister(dev);
Dave Youngcd354492008-01-28 16:56:11 +08004126 }
Greg Kroah-Hartman23681e42006-06-14 12:14:34 -07004127}
4128EXPORT_SYMBOL_GPL(device_destroy);
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004129
4130/**
4131 * device_rename - renames a device
4132 * @dev: the pointer to the struct device to be renamed
4133 * @new_name: the new name of the device
Eric W. Biederman030c1d22008-05-08 14:41:00 -07004134 *
4135 * It is the responsibility of the caller to provide mutual
4136 * exclusion between two different calls of device_rename
4137 * on the same device to ensure that new_name is valid and
4138 * won't conflict with other devices.
Michael Ellermanc6c0ac62010-11-25 09:44:07 +11004139 *
Timur Tabia5462512010-12-13 14:08:52 -06004140 * Note: Don't call this function. Currently, the networking layer calls this
4141 * function, but that will change. The following text from Kay Sievers offers
4142 * some insight:
4143 *
4144 * Renaming devices is racy at many levels, symlinks and other stuff are not
4145 * replaced atomically, and you get a "move" uevent, but it's not easy to
4146 * connect the event to the old and new device. Device nodes are not renamed at
4147 * all, there isn't even support for that in the kernel now.
4148 *
4149 * In the meantime, during renaming, your target name might be taken by another
4150 * driver, creating conflicts. Or the old name is taken directly after you
4151 * renamed it -- then you get events for the same DEVPATH, before you even see
4152 * the "move" event. It's just a mess, and nothing new should ever rely on
4153 * kernel device renaming. Besides that, it's not even implemented now for
4154 * other things than (driver-core wise very simple) network devices.
4155 *
4156 * We are currently about to change network renaming in udev to completely
4157 * disallow renaming of devices in the same namespace as the kernel uses,
4158 * because we can't solve the problems properly, that arise with swapping names
4159 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
4160 * be allowed to some other name than eth[0-9]*, for the aforementioned
4161 * reasons.
4162 *
4163 * Make up a "real" name in the driver before you register anything, or add
4164 * some other attributes for userspace to find the device, or use udev to add
4165 * symlinks -- but never rename kernel devices later, it's a complete mess. We
4166 * don't even want to get into that and try to implement the missing pieces in
4167 * the core. We really have other pieces to fix in the driver core mess. :)
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004168 */
Johannes Berg6937e8f2010-08-05 17:38:18 +02004169int device_rename(struct device *dev, const char *new_name)
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004170{
Tejun Heo4b30ee52013-09-11 22:29:06 -04004171 struct kobject *kobj = &dev->kobj;
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07004172 char *old_device_name = NULL;
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004173 int error;
4174
4175 dev = get_device(dev);
4176 if (!dev)
4177 return -EINVAL;
4178
ethan.zhao69df7532013-10-13 22:12:35 +08004179 dev_dbg(dev, "renaming to %s\n", new_name);
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004180
Kay Sievers1fa5ae82009-01-25 15:17:37 +01004181 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07004182 if (!old_device_name) {
4183 error = -ENOMEM;
4184 goto out;
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004185 }
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004186
Eric W. Biedermanf349cf32010-03-30 11:31:29 -07004187 if (dev->class) {
Tejun Heo4b30ee52013-09-11 22:29:06 -04004188 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
4189 kobj, old_device_name,
4190 new_name, kobject_namespace(kobj));
Eric W. Biedermanf349cf32010-03-30 11:31:29 -07004191 if (error)
4192 goto out;
4193 }
Kay Sievers39aba962010-09-04 22:33:14 -07004194
Tejun Heo4b30ee52013-09-11 22:29:06 -04004195 error = kobject_rename(kobj, new_name);
Kay Sievers1fa5ae82009-01-25 15:17:37 +01004196 if (error)
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07004197 goto out;
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004198
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07004199out:
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004200 put_device(dev);
4201
Cornelia Huck2ee97ca2007-07-18 01:43:47 -07004202 kfree(old_device_name);
Greg Kroah-Hartmana2de48c2006-07-03 14:31:12 -07004203
4204 return error;
4205}
Johannes Berga2807db2007-02-28 12:38:31 +01004206EXPORT_SYMBOL_GPL(device_rename);
Cornelia Huck8a824722006-11-20 17:07:51 +01004207
4208static int device_move_class_links(struct device *dev,
4209 struct device *old_parent,
4210 struct device *new_parent)
4211{
Greg Kroah-Hartmanf7f34612007-03-06 12:55:53 -08004212 int error = 0;
Cornelia Huck8a824722006-11-20 17:07:51 +01004213
Greg Kroah-Hartmanf7f34612007-03-06 12:55:53 -08004214 if (old_parent)
4215 sysfs_remove_link(&dev->kobj, "device");
4216 if (new_parent)
4217 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
4218 "device");
4219 return error;
Cornelia Huck8a824722006-11-20 17:07:51 +01004220}
4221
4222/**
4223 * device_move - moves a device to a new parent
4224 * @dev: the pointer to the struct device to be moved
Wolfram Sang13509862018-05-06 13:23:47 +02004225 * @new_parent: the new parent of the device (can be NULL)
Cornelia Huckffa6a702009-03-04 12:44:00 +01004226 * @dpm_order: how to reorder the dpm_list
Cornelia Huck8a824722006-11-20 17:07:51 +01004227 */
Cornelia Huckffa6a702009-03-04 12:44:00 +01004228int device_move(struct device *dev, struct device *new_parent,
4229 enum dpm_order dpm_order)
Cornelia Huck8a824722006-11-20 17:07:51 +01004230{
4231 int error;
4232 struct device *old_parent;
Cornelia Huckc744aeae2007-01-08 20:16:44 +01004233 struct kobject *new_parent_kobj;
Cornelia Huck8a824722006-11-20 17:07:51 +01004234
4235 dev = get_device(dev);
4236 if (!dev)
4237 return -EINVAL;
4238
Cornelia Huckffa6a702009-03-04 12:44:00 +01004239 device_pm_lock();
Cornelia Huck8a824722006-11-20 17:07:51 +01004240 new_parent = get_device(new_parent);
Greg Kroah-Hartman4a3ad202008-01-24 22:50:12 -08004241 new_parent_kobj = get_device_parent(dev, new_parent);
Tetsuo Handa84d0c272018-05-07 19:10:31 +09004242 if (IS_ERR(new_parent_kobj)) {
4243 error = PTR_ERR(new_parent_kobj);
4244 put_device(new_parent);
4245 goto out;
4246 }
Cornelia Huck63b69712008-01-21 16:09:44 +01004247
Kay Sievers1e0b2cf2008-10-30 01:36:48 +01004248 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
4249 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
Cornelia Huckc744aeae2007-01-08 20:16:44 +01004250 error = kobject_move(&dev->kobj, new_parent_kobj);
Cornelia Huck8a824722006-11-20 17:07:51 +01004251 if (error) {
Cornelia Huck63b69712008-01-21 16:09:44 +01004252 cleanup_glue_dir(dev, new_parent_kobj);
Cornelia Huck8a824722006-11-20 17:07:51 +01004253 put_device(new_parent);
4254 goto out;
4255 }
4256 old_parent = dev->parent;
4257 dev->parent = new_parent;
4258 if (old_parent)
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08004259 klist_remove(&dev->p->knode_parent);
Yinghai Lu0d358f22008-02-19 03:20:41 -08004260 if (new_parent) {
Greg Kroah-Hartmanf791b8c2008-12-16 12:24:56 -08004261 klist_add_tail(&dev->p->knode_parent,
4262 &new_parent->p->klist_children);
Yinghai Lu0d358f22008-02-19 03:20:41 -08004263 set_dev_node(dev, dev_to_node(new_parent));
4264 }
4265
Rabin Vincentbdd40342012-04-23 09:16:36 +02004266 if (dev->class) {
4267 error = device_move_class_links(dev, old_parent, new_parent);
4268 if (error) {
4269 /* We ignore errors on cleanup since we're hosed anyway... */
4270 device_move_class_links(dev, new_parent, old_parent);
4271 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
4272 if (new_parent)
4273 klist_remove(&dev->p->knode_parent);
4274 dev->parent = old_parent;
4275 if (old_parent) {
4276 klist_add_tail(&dev->p->knode_parent,
4277 &old_parent->p->klist_children);
4278 set_dev_node(dev, dev_to_node(old_parent));
4279 }
Yinghai Lu0d358f22008-02-19 03:20:41 -08004280 }
Rabin Vincentbdd40342012-04-23 09:16:36 +02004281 cleanup_glue_dir(dev, new_parent_kobj);
4282 put_device(new_parent);
4283 goto out;
Cornelia Huck8a824722006-11-20 17:07:51 +01004284 }
Cornelia Huck8a824722006-11-20 17:07:51 +01004285 }
Cornelia Huckffa6a702009-03-04 12:44:00 +01004286 switch (dpm_order) {
4287 case DPM_ORDER_NONE:
4288 break;
4289 case DPM_ORDER_DEV_AFTER_PARENT:
4290 device_pm_move_after(dev, new_parent);
Grygorii Strashko52cdbdd2015-07-27 20:43:01 +03004291 devices_kset_move_after(dev, new_parent);
Cornelia Huckffa6a702009-03-04 12:44:00 +01004292 break;
4293 case DPM_ORDER_PARENT_BEFORE_DEV:
4294 device_pm_move_before(new_parent, dev);
Grygorii Strashko52cdbdd2015-07-27 20:43:01 +03004295 devices_kset_move_before(new_parent, dev);
Cornelia Huckffa6a702009-03-04 12:44:00 +01004296 break;
4297 case DPM_ORDER_DEV_LAST:
4298 device_pm_move_last(dev);
Grygorii Strashko52cdbdd2015-07-27 20:43:01 +03004299 devices_kset_move_last(dev);
Cornelia Huckffa6a702009-03-04 12:44:00 +01004300 break;
4301 }
Rabin Vincentbdd40342012-04-23 09:16:36 +02004302
Cornelia Huck8a824722006-11-20 17:07:51 +01004303 put_device(old_parent);
4304out:
Cornelia Huckffa6a702009-03-04 12:44:00 +01004305 device_pm_unlock();
Cornelia Huck8a824722006-11-20 17:07:51 +01004306 put_device(dev);
4307 return error;
4308}
Cornelia Huck8a824722006-11-20 17:07:51 +01004309EXPORT_SYMBOL_GPL(device_move);
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004310
Christian Braunerb8f33e52020-02-27 04:37:15 +01004311static int device_attrs_change_owner(struct device *dev, kuid_t kuid,
4312 kgid_t kgid)
4313{
4314 struct kobject *kobj = &dev->kobj;
4315 struct class *class = dev->class;
4316 const struct device_type *type = dev->type;
4317 int error;
4318
4319 if (class) {
4320 /*
4321 * Change the device groups of the device class for @dev to
4322 * @kuid/@kgid.
4323 */
4324 error = sysfs_groups_change_owner(kobj, class->dev_groups, kuid,
4325 kgid);
4326 if (error)
4327 return error;
4328 }
4329
4330 if (type) {
4331 /*
4332 * Change the device groups of the device type for @dev to
4333 * @kuid/@kgid.
4334 */
4335 error = sysfs_groups_change_owner(kobj, type->groups, kuid,
4336 kgid);
4337 if (error)
4338 return error;
4339 }
4340
4341 /* Change the device groups of @dev to @kuid/@kgid. */
4342 error = sysfs_groups_change_owner(kobj, dev->groups, kuid, kgid);
4343 if (error)
4344 return error;
4345
4346 if (device_supports_offline(dev) && !dev->offline_disabled) {
4347 /* Change online device attributes of @dev to @kuid/@kgid. */
4348 error = sysfs_file_change_owner(kobj, dev_attr_online.attr.name,
4349 kuid, kgid);
4350 if (error)
4351 return error;
4352 }
4353
4354 return 0;
4355}
4356
4357/**
4358 * device_change_owner - change the owner of an existing device.
4359 * @dev: device.
4360 * @kuid: new owner's kuid
4361 * @kgid: new owner's kgid
4362 *
4363 * This changes the owner of @dev and its corresponding sysfs entries to
4364 * @kuid/@kgid. This function closely mirrors how @dev was added via driver
4365 * core.
4366 *
4367 * Returns 0 on success or error code on failure.
4368 */
4369int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
4370{
4371 int error;
4372 struct kobject *kobj = &dev->kobj;
4373
4374 dev = get_device(dev);
4375 if (!dev)
4376 return -EINVAL;
4377
4378 /*
4379 * Change the kobject and the default attributes and groups of the
4380 * ktype associated with it to @kuid/@kgid.
4381 */
4382 error = sysfs_change_owner(kobj, kuid, kgid);
4383 if (error)
4384 goto out;
4385
4386 /*
4387 * Change the uevent file for @dev to the new owner. The uevent file
4388 * was created in a separate step when @dev got added and we mirror
4389 * that step here.
4390 */
4391 error = sysfs_file_change_owner(kobj, dev_attr_uevent.attr.name, kuid,
4392 kgid);
4393 if (error)
4394 goto out;
4395
4396 /*
4397 * Change the device groups, the device groups associated with the
4398 * device class, and the groups associated with the device type of @dev
4399 * to @kuid/@kgid.
4400 */
4401 error = device_attrs_change_owner(dev, kuid, kgid);
4402 if (error)
4403 goto out;
4404
Christian Brauner3b52fc52020-02-27 04:37:16 +01004405 error = dpm_sysfs_change_owner(dev, kuid, kgid);
4406 if (error)
4407 goto out;
4408
Christian Braunerb8f33e52020-02-27 04:37:15 +01004409#ifdef CONFIG_BLOCK
4410 if (sysfs_deprecated && dev->class == &block_class)
4411 goto out;
4412#endif
4413
4414 /*
4415 * Change the owner of the symlink located in the class directory of
4416 * the device class associated with @dev which points to the actual
4417 * directory entry for @dev to @kuid/@kgid. This ensures that the
4418 * symlink shows the same permissions as its target.
4419 */
4420 error = sysfs_link_change_owner(&dev->class->p->subsys.kobj, &dev->kobj,
4421 dev_name(dev), kuid, kgid);
4422 if (error)
4423 goto out;
4424
4425out:
4426 put_device(dev);
4427 return error;
4428}
4429EXPORT_SYMBOL_GPL(device_change_owner);
4430
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004431/**
4432 * device_shutdown - call ->shutdown() on each device to shutdown.
4433 */
4434void device_shutdown(void)
4435{
Benson Leungf123db82013-09-24 20:05:11 -07004436 struct device *dev, *parent;
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004437
Pingfan Liu3297c8f2018-07-19 13:14:58 +08004438 wait_for_device_probe();
4439 device_block_probing();
4440
Rafael J. Wysocki65650b32019-10-09 01:29:10 +02004441 cpufreq_suspend();
4442
Hugh Daschbach62458382010-03-22 10:36:37 -07004443 spin_lock(&devices_kset->list_lock);
4444 /*
4445 * Walk the devices list backward, shutting down each in turn.
4446 * Beware that device unplug events may also start pulling
4447 * devices offline, even as the system is shutting down.
4448 */
4449 while (!list_empty(&devices_kset->list)) {
4450 dev = list_entry(devices_kset->list.prev, struct device,
4451 kobj.entry);
Ming Leid1c6c032012-06-22 18:01:40 +08004452
4453 /*
4454 * hold reference count of device's parent to
4455 * prevent it from being freed because parent's
4456 * lock is to be held
4457 */
Benson Leungf123db82013-09-24 20:05:11 -07004458 parent = get_device(dev->parent);
Hugh Daschbach62458382010-03-22 10:36:37 -07004459 get_device(dev);
4460 /*
4461 * Make sure the device is off the kset list, in the
4462 * event that dev->*->shutdown() doesn't remove it.
4463 */
4464 list_del_init(&dev->kobj.entry);
4465 spin_unlock(&devices_kset->list_lock);
Alan Sternfe6b91f2011-12-06 23:24:52 +01004466
Ming Leid1c6c032012-06-22 18:01:40 +08004467 /* hold lock to avoid race with probe/release */
Benson Leungf123db82013-09-24 20:05:11 -07004468 if (parent)
4469 device_lock(parent);
Ming Leid1c6c032012-06-22 18:01:40 +08004470 device_lock(dev);
4471
Alan Sternfe6b91f2011-12-06 23:24:52 +01004472 /* Don't allow any more runtime suspends */
4473 pm_runtime_get_noresume(dev);
4474 pm_runtime_barrier(dev);
Hugh Daschbach62458382010-03-22 10:36:37 -07004475
Michal Suchanek75216212017-08-11 15:44:43 +02004476 if (dev->class && dev->class->shutdown_pre) {
Josh Zimmermanf77af152017-06-25 14:53:23 -07004477 if (initcall_debug)
Michal Suchanek75216212017-08-11 15:44:43 +02004478 dev_info(dev, "shutdown_pre\n");
4479 dev->class->shutdown_pre(dev);
4480 }
4481 if (dev->bus && dev->bus->shutdown) {
ShuoX Liu0246c4f2012-11-23 15:14:12 +08004482 if (initcall_debug)
4483 dev_info(dev, "shutdown\n");
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004484 dev->bus->shutdown(dev);
4485 } else if (dev->driver && dev->driver->shutdown) {
ShuoX Liu0246c4f2012-11-23 15:14:12 +08004486 if (initcall_debug)
4487 dev_info(dev, "shutdown\n");
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004488 dev->driver->shutdown(dev);
4489 }
Ming Leid1c6c032012-06-22 18:01:40 +08004490
4491 device_unlock(dev);
Benson Leungf123db82013-09-24 20:05:11 -07004492 if (parent)
4493 device_unlock(parent);
Ming Leid1c6c032012-06-22 18:01:40 +08004494
Hugh Daschbach62458382010-03-22 10:36:37 -07004495 put_device(dev);
Benson Leungf123db82013-09-24 20:05:11 -07004496 put_device(parent);
Hugh Daschbach62458382010-03-22 10:36:37 -07004497
4498 spin_lock(&devices_kset->list_lock);
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004499 }
Hugh Daschbach62458382010-03-22 10:36:37 -07004500 spin_unlock(&devices_kset->list_lock);
Greg Kroah-Hartman37b0c022007-11-26 22:11:55 -08004501}
Joe Perches99bcf212010-06-27 01:02:34 +00004502
4503/*
4504 * Device logging functions
4505 */
4506
4507#ifdef CONFIG_PRINTK
John Ogness74caba72020-09-21 13:24:45 +02064508static void
4509set_dev_info(const struct device *dev, struct dev_printk_info *dev_info)
Joe Perches99bcf212010-06-27 01:02:34 +00004510{
Kay Sieversc4e00da2012-05-03 02:29:59 +02004511 const char *subsys;
John Ogness74caba72020-09-21 13:24:45 +02064512
4513 memset(dev_info, 0, sizeof(*dev_info));
Joe Perches99bcf212010-06-27 01:02:34 +00004514
Kay Sieversc4e00da2012-05-03 02:29:59 +02004515 if (dev->class)
4516 subsys = dev->class->name;
4517 else if (dev->bus)
4518 subsys = dev->bus->name;
4519 else
John Ogness74caba72020-09-21 13:24:45 +02064520 return;
Kay Sieversc4e00da2012-05-03 02:29:59 +02004521
John Ogness74caba72020-09-21 13:24:45 +02064522 strscpy(dev_info->subsystem, subsys, sizeof(dev_info->subsystem));
Kay Sieversc4e00da2012-05-03 02:29:59 +02004523
4524 /*
4525 * Add device identifier DEVICE=:
4526 * b12:8 block dev_t
4527 * c127:3 char dev_t
4528 * n8 netdev ifindex
4529 * +sound:card0 subsystem:devname
4530 */
4531 if (MAJOR(dev->devt)) {
4532 char c;
4533
4534 if (strcmp(subsys, "block") == 0)
4535 c = 'b';
4536 else
4537 c = 'c';
John Ogness74caba72020-09-21 13:24:45 +02064538
4539 snprintf(dev_info->device, sizeof(dev_info->device),
4540 "%c%u:%u", c, MAJOR(dev->devt), MINOR(dev->devt));
Kay Sieversc4e00da2012-05-03 02:29:59 +02004541 } else if (strcmp(subsys, "net") == 0) {
4542 struct net_device *net = to_net_dev(dev);
4543
John Ogness74caba72020-09-21 13:24:45 +02064544 snprintf(dev_info->device, sizeof(dev_info->device),
4545 "n%u", net->ifindex);
Kay Sieversc4e00da2012-05-03 02:29:59 +02004546 } else {
John Ogness74caba72020-09-21 13:24:45 +02064547 snprintf(dev_info->device, sizeof(dev_info->device),
4548 "+%s:%s", subsys, dev_name(dev));
Kay Sieversc4e00da2012-05-03 02:29:59 +02004549 }
Joe Perches99bcf212010-06-27 01:02:34 +00004550}
Joe Perches798efc62012-09-12 20:11:29 -07004551
Joe Perches05e4e5b2012-09-12 20:13:37 -07004552int dev_vprintk_emit(int level, const struct device *dev,
4553 const char *fmt, va_list args)
4554{
John Ogness74caba72020-09-21 13:24:45 +02064555 struct dev_printk_info dev_info;
Joe Perches05e4e5b2012-09-12 20:13:37 -07004556
John Ogness74caba72020-09-21 13:24:45 +02064557 set_dev_info(dev, &dev_info);
Joe Perches05e4e5b2012-09-12 20:13:37 -07004558
John Ogness74caba72020-09-21 13:24:45 +02064559 return vprintk_emit(0, level, &dev_info, fmt, args);
Joe Perches05e4e5b2012-09-12 20:13:37 -07004560}
4561EXPORT_SYMBOL(dev_vprintk_emit);
4562
4563int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
4564{
4565 va_list args;
4566 int r;
4567
4568 va_start(args, fmt);
4569
4570 r = dev_vprintk_emit(level, dev, fmt, args);
4571
4572 va_end(args);
4573
4574 return r;
4575}
4576EXPORT_SYMBOL(dev_printk_emit);
4577
Joe Perchesd1f10522014-12-25 15:07:04 -08004578static void __dev_printk(const char *level, const struct device *dev,
Joe Perches798efc62012-09-12 20:11:29 -07004579 struct va_format *vaf)
4580{
Joe Perchesd1f10522014-12-25 15:07:04 -08004581 if (dev)
4582 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
4583 dev_driver_string(dev), dev_name(dev), vaf);
4584 else
4585 printk("%s(NULL device *): %pV", level, vaf);
Joe Perches798efc62012-09-12 20:11:29 -07004586}
Joe Perches99bcf212010-06-27 01:02:34 +00004587
Chris Downad7d61f2021-06-15 17:52:56 +01004588void _dev_printk(const char *level, const struct device *dev,
4589 const char *fmt, ...)
Joe Perches99bcf212010-06-27 01:02:34 +00004590{
4591 struct va_format vaf;
4592 va_list args;
Joe Perches99bcf212010-06-27 01:02:34 +00004593
4594 va_start(args, fmt);
4595
4596 vaf.fmt = fmt;
4597 vaf.va = &args;
4598
Joe Perchesd1f10522014-12-25 15:07:04 -08004599 __dev_printk(level, dev, &vaf);
Joe Perches798efc62012-09-12 20:11:29 -07004600
Joe Perches99bcf212010-06-27 01:02:34 +00004601 va_end(args);
Joe Perches99bcf212010-06-27 01:02:34 +00004602}
Chris Downad7d61f2021-06-15 17:52:56 +01004603EXPORT_SYMBOL(_dev_printk);
Joe Perches99bcf212010-06-27 01:02:34 +00004604
4605#define define_dev_printk_level(func, kern_level) \
Joe Perchesd1f10522014-12-25 15:07:04 -08004606void func(const struct device *dev, const char *fmt, ...) \
Joe Perches99bcf212010-06-27 01:02:34 +00004607{ \
4608 struct va_format vaf; \
4609 va_list args; \
Joe Perches99bcf212010-06-27 01:02:34 +00004610 \
4611 va_start(args, fmt); \
4612 \
4613 vaf.fmt = fmt; \
4614 vaf.va = &args; \
4615 \
Joe Perchesd1f10522014-12-25 15:07:04 -08004616 __dev_printk(kern_level, dev, &vaf); \
Joe Perches798efc62012-09-12 20:11:29 -07004617 \
Joe Perches99bcf212010-06-27 01:02:34 +00004618 va_end(args); \
Joe Perches99bcf212010-06-27 01:02:34 +00004619} \
4620EXPORT_SYMBOL(func);
4621
Joe Perches663336e2018-05-09 08:15:46 -07004622define_dev_printk_level(_dev_emerg, KERN_EMERG);
4623define_dev_printk_level(_dev_alert, KERN_ALERT);
4624define_dev_printk_level(_dev_crit, KERN_CRIT);
4625define_dev_printk_level(_dev_err, KERN_ERR);
4626define_dev_printk_level(_dev_warn, KERN_WARNING);
4627define_dev_printk_level(_dev_notice, KERN_NOTICE);
Joe Perches99bcf212010-06-27 01:02:34 +00004628define_dev_printk_level(_dev_info, KERN_INFO);
4629
4630#endif
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004631
Andrzej Hajdaa787e542020-07-13 16:43:21 +02004632/**
4633 * dev_err_probe - probe error check and log helper
4634 * @dev: the pointer to the struct device
4635 * @err: error value to test
4636 * @fmt: printf-style format string
4637 * @...: arguments as specified in the format string
4638 *
4639 * This helper implements common pattern present in probe functions for error
4640 * checking: print debug or error message depending if the error value is
4641 * -EPROBE_DEFER and propagate error upwards.
Andrzej Hajdad090b702020-07-13 16:43:22 +02004642 * In case of -EPROBE_DEFER it sets also defer probe reason, which can be
4643 * checked later by reading devices_deferred debugfs attribute.
Mauro Carvalho Chehab074b3aa2020-09-09 11:53:43 +02004644 * It replaces code sequence::
4645 *
Andrzej Hajdaa787e542020-07-13 16:43:21 +02004646 * if (err != -EPROBE_DEFER)
4647 * dev_err(dev, ...);
4648 * else
4649 * dev_dbg(dev, ...);
4650 * return err;
Mauro Carvalho Chehab074b3aa2020-09-09 11:53:43 +02004651 *
4652 * with::
4653 *
Andrzej Hajdaa787e542020-07-13 16:43:21 +02004654 * return dev_err_probe(dev, err, ...);
4655 *
Douglas Anderson7065f922021-09-16 16:19:40 -07004656 * Note that it is deemed acceptable to use this function for error
4657 * prints during probe even if the @err is known to never be -EPROBE_DEFER.
4658 * The benefit compared to a normal dev_err() is the standardized format
4659 * of the error code and the fact that the error code is returned.
4660 *
Andrzej Hajdaa787e542020-07-13 16:43:21 +02004661 * Returns @err.
4662 *
4663 */
4664int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
4665{
4666 struct va_format vaf;
4667 va_list args;
4668
4669 va_start(args, fmt);
4670 vaf.fmt = fmt;
4671 vaf.va = &args;
4672
Andrzej Hajdad090b702020-07-13 16:43:22 +02004673 if (err != -EPROBE_DEFER) {
Michał Mirosław693a8e92020-08-28 18:14:35 +02004674 dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
Andrzej Hajdad090b702020-07-13 16:43:22 +02004675 } else {
4676 device_set_deferred_probe_reason(dev, &vaf);
Michał Mirosław693a8e92020-08-28 18:14:35 +02004677 dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
Andrzej Hajdad090b702020-07-13 16:43:22 +02004678 }
Andrzej Hajdaa787e542020-07-13 16:43:21 +02004679
4680 va_end(args);
4681
4682 return err;
4683}
4684EXPORT_SYMBOL_GPL(dev_err_probe);
4685
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004686static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
4687{
4688 return fwnode && !IS_ERR(fwnode->secondary);
4689}
4690
4691/**
4692 * set_primary_fwnode - Change the primary firmware node of a given device.
4693 * @dev: Device to handle.
4694 * @fwnode: New primary firmware node of the device.
4695 *
4696 * Set the device's firmware node pointer to @fwnode, but if a secondary
4697 * firmware node of the device is present, preserve it.
Bard Liao3f7bdda2021-01-05 17:11:46 +08004698 *
4699 * Valid fwnode cases are:
4700 * - primary --> secondary --> -ENODEV
4701 * - primary --> NULL
4702 * - secondary --> -ENODEV
4703 * - NULL
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004704 */
4705void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
4706{
Andy Shevchenko99aed922020-10-22 21:41:00 +03004707 struct device *parent = dev->parent;
Heikki Krogerusc15e1bd2020-08-21 13:53:42 +03004708 struct fwnode_handle *fn = dev->fwnode;
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004709
Heikki Krogerusc15e1bd2020-08-21 13:53:42 +03004710 if (fwnode) {
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004711 if (fwnode_is_primary(fn))
4712 fn = fn->secondary;
4713
Mika Westerberg55f89a82015-11-30 17:11:39 +02004714 if (fn) {
4715 WARN_ON(fwnode->secondary);
4716 fwnode->secondary = fn;
4717 }
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004718 dev->fwnode = fwnode;
4719 } else {
Heikki Krogerusc15e1bd2020-08-21 13:53:42 +03004720 if (fwnode_is_primary(fn)) {
4721 dev->fwnode = fn->secondary;
Bard Liao3f7bdda2021-01-05 17:11:46 +08004722 /* Set fn->secondary = NULL, so fn remains the primary fwnode */
Andy Shevchenko99aed922020-10-22 21:41:00 +03004723 if (!(parent && fn == parent->fwnode))
Bard Liao47f44692021-01-05 17:11:45 +08004724 fn->secondary = NULL;
Heikki Krogerusc15e1bd2020-08-21 13:53:42 +03004725 } else {
4726 dev->fwnode = NULL;
4727 }
Rafael J. Wysocki97badf82015-04-03 23:23:37 +02004728 }
4729}
4730EXPORT_SYMBOL_GPL(set_primary_fwnode);
4731
4732/**
4733 * set_secondary_fwnode - Change the secondary firmware node of a given device.
4734 * @dev: Device to handle.
4735 * @fwnode: New secondary firmware node of the device.
4736 *
4737 * If a primary firmware node of the device is present, set its secondary
4738 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
4739 * @fwnode.
4740 */
4741void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
4742{
4743 if (fwnode)
4744 fwnode->secondary = ERR_PTR(-ENODEV);
4745
4746 if (fwnode_is_primary(dev->fwnode))
4747 dev->fwnode->secondary = fwnode;
4748 else
4749 dev->fwnode = fwnode;
4750}
Andy Shevchenko96489ae2020-04-08 19:09:01 +03004751EXPORT_SYMBOL_GPL(set_secondary_fwnode);
Johan Hovold4e75e1d2017-06-06 17:59:00 +02004752
4753/**
4754 * device_set_of_node_from_dev - reuse device-tree node of another device
4755 * @dev: device whose device-tree node is being set
4756 * @dev2: device whose device-tree node is being reused
4757 *
4758 * Takes another reference to the new device-tree node after first dropping
4759 * any reference held to the old node.
4760 */
4761void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
4762{
4763 of_node_put(dev->of_node);
4764 dev->of_node = of_node_get(dev2->of_node);
4765 dev->of_node_reused = true;
4766}
4767EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
Suzuki K Poulose65b66682019-06-14 18:54:01 +01004768
Ioana Ciornei43e76d42021-06-17 15:29:04 +03004769void device_set_node(struct device *dev, struct fwnode_handle *fwnode)
4770{
4771 dev->fwnode = fwnode;
4772 dev->of_node = to_of_node(fwnode);
4773}
4774EXPORT_SYMBOL_GPL(device_set_node);
4775
Suzuki K Poulose6cda08a2019-07-23 23:18:32 +01004776int device_match_name(struct device *dev, const void *name)
4777{
4778 return sysfs_streq(dev_name(dev), name);
4779}
4780EXPORT_SYMBOL_GPL(device_match_name);
4781
Suzuki K Poulose65b66682019-06-14 18:54:01 +01004782int device_match_of_node(struct device *dev, const void *np)
4783{
4784 return dev->of_node == np;
4785}
4786EXPORT_SYMBOL_GPL(device_match_of_node);
Suzuki K Poulose67843bb2019-07-23 23:18:34 +01004787
4788int device_match_fwnode(struct device *dev, const void *fwnode)
4789{
4790 return dev_fwnode(dev) == fwnode;
4791}
4792EXPORT_SYMBOL_GPL(device_match_fwnode);
Suzuki K Poulose4495dfd2019-07-23 23:18:35 +01004793
4794int device_match_devt(struct device *dev, const void *pdevt)
4795{
4796 return dev->devt == *(dev_t *)pdevt;
4797}
4798EXPORT_SYMBOL_GPL(device_match_devt);
Suzuki K Poulose00500142019-07-23 23:18:36 +01004799
4800int device_match_acpi_dev(struct device *dev, const void *adev)
4801{
4802 return ACPI_COMPANION(dev) == adev;
4803}
4804EXPORT_SYMBOL(device_match_acpi_dev);
Suzuki K Poulose6bf85ba2019-07-23 23:18:37 +01004805
4806int device_match_any(struct device *dev, const void *unused)
4807{
4808 return 1;
4809}
4810EXPORT_SYMBOL_GPL(device_match_any);