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989d42e8 | 1 | // SPDX-License-Identifier: GPL-2.0 |
07e4a3e2 | 2 | /* |
4a3ad20c | 3 | * drivers/base/dd.c - The core device/driver interactions. |
07e4a3e2 | 4 | * |
4a3ad20c GKH |
5 | * This file contains the (sometimes tricky) code that controls the |
6 | * interactions between devices and drivers, which primarily includes | |
7 | * driver binding and unbinding. | |
07e4a3e2 | 8 | * |
4a3ad20c GKH |
9 | * All of this code used to exist in drivers/base/bus.c, but was |
10 | * relocated to here in the name of compartmentalization (since it wasn't | |
11 | * strictly code just for the 'struct bus_type'. | |
07e4a3e2 | 12 | * |
4a3ad20c GKH |
13 | * Copyright (c) 2002-5 Patrick Mochel |
14 | * Copyright (c) 2002-3 Open Source Development Labs | |
b4028437 GKH |
15 | * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de> |
16 | * Copyright (c) 2007-2009 Novell Inc. | |
07e4a3e2 PM |
17 | */ |
18 | ||
28af109a | 19 | #include <linux/debugfs.h> |
07e4a3e2 | 20 | #include <linux/device.h> |
216773a7 | 21 | #include <linux/delay.h> |
0a0f0d8b | 22 | #include <linux/dma-map-ops.h> |
1f5000bd | 23 | #include <linux/init.h> |
07e4a3e2 | 24 | #include <linux/module.h> |
d779249e | 25 | #include <linux/kthread.h> |
735a7ffb | 26 | #include <linux/wait.h> |
216773a7 | 27 | #include <linux/async.h> |
5e928f77 | 28 | #include <linux/pm_runtime.h> |
ab78029e | 29 | #include <linux/pinctrl/devinfo.h> |
d090b70e | 30 | #include <linux/slab.h> |
07e4a3e2 PM |
31 | |
32 | #include "base.h" | |
33 | #include "power/power.h" | |
34 | ||
d1c3414c GL |
35 | /* |
36 | * Deferred Probe infrastructure. | |
37 | * | |
38 | * Sometimes driver probe order matters, but the kernel doesn't always have | |
39 | * dependency information which means some drivers will get probed before a | |
40 | * resource it depends on is available. For example, an SDHCI driver may | |
41 | * first need a GPIO line from an i2c GPIO controller before it can be | |
42 | * initialized. If a required resource is not available yet, a driver can | |
43 | * request probing to be deferred by returning -EPROBE_DEFER from its probe hook | |
44 | * | |
45 | * Deferred probe maintains two lists of devices, a pending list and an active | |
46 | * list. A driver returning -EPROBE_DEFER causes the device to be added to the | |
47 | * pending list. A successful driver probe will trigger moving all devices | |
48 | * from the pending to the active list so that the workqueue will eventually | |
49 | * retry them. | |
50 | * | |
51 | * The deferred_probe_mutex must be held any time the deferred_probe_*_list | |
ef8a3fd6 | 52 | * of the (struct device*)->p->deferred_probe pointers are manipulated |
d1c3414c GL |
53 | */ |
54 | static DEFINE_MUTEX(deferred_probe_mutex); | |
55 | static LIST_HEAD(deferred_probe_pending_list); | |
56 | static LIST_HEAD(deferred_probe_active_list); | |
58b116bc | 57 | static atomic_t deferred_trigger_count = ATOMIC_INIT(0); |
25b4e70d | 58 | static bool initcalls_done; |
d1c3414c | 59 | |
1ea61b68 FT |
60 | /* Save the async probe drivers' name from kernel cmdline */ |
61 | #define ASYNC_DRV_NAMES_MAX_LEN 256 | |
62 | static char async_probe_drv_names[ASYNC_DRV_NAMES_MAX_LEN]; | |
63 | ||
013c074f SG |
64 | /* |
65 | * In some cases, like suspend to RAM or hibernation, It might be reasonable | |
66 | * to prohibit probing of devices as it could be unsafe. | |
67 | * Once defer_all_probes is true all drivers probes will be forcibly deferred. | |
68 | */ | |
69 | static bool defer_all_probes; | |
70 | ||
72a91f19 AF |
71 | static void __device_set_deferred_probe_reason(const struct device *dev, char *reason) |
72 | { | |
73 | kfree(dev->p->deferred_probe_reason); | |
74 | dev->p->deferred_probe_reason = reason; | |
75 | } | |
76 | ||
41575335 | 77 | /* |
d1c3414c GL |
78 | * deferred_probe_work_func() - Retry probing devices in the active list. |
79 | */ | |
80 | static void deferred_probe_work_func(struct work_struct *work) | |
81 | { | |
82 | struct device *dev; | |
ef8a3fd6 | 83 | struct device_private *private; |
d1c3414c GL |
84 | /* |
85 | * This block processes every device in the deferred 'active' list. | |
86 | * Each device is removed from the active list and passed to | |
87 | * bus_probe_device() to re-attempt the probe. The loop continues | |
88 | * until every device in the active list is removed and retried. | |
89 | * | |
90 | * Note: Once the device is removed from the list and the mutex is | |
91 | * released, it is possible for the device get freed by another thread | |
92 | * and cause a illegal pointer dereference. This code uses | |
93 | * get/put_device() to ensure the device structure cannot disappear | |
94 | * from under our feet. | |
95 | */ | |
96 | mutex_lock(&deferred_probe_mutex); | |
97 | while (!list_empty(&deferred_probe_active_list)) { | |
ef8a3fd6 GKH |
98 | private = list_first_entry(&deferred_probe_active_list, |
99 | typeof(*dev->p), deferred_probe); | |
100 | dev = private->device; | |
101 | list_del_init(&private->deferred_probe); | |
d1c3414c GL |
102 | |
103 | get_device(dev); | |
104 | ||
72a91f19 | 105 | __device_set_deferred_probe_reason(dev, NULL); |
f0acf637 | 106 | |
8b0372a2 GKH |
107 | /* |
108 | * Drop the mutex while probing each device; the probe path may | |
109 | * manipulate the deferred list | |
110 | */ | |
d1c3414c | 111 | mutex_unlock(&deferred_probe_mutex); |
8153584e MB |
112 | |
113 | /* | |
114 | * Force the device to the end of the dpm_list since | |
115 | * the PM code assumes that the order we add things to | |
116 | * the list is a good order for suspend but deferred | |
117 | * probe makes that very unsafe. | |
118 | */ | |
494fd7b7 | 119 | device_pm_move_to_tail(dev); |
8153584e | 120 | |
d1c3414c | 121 | dev_dbg(dev, "Retrying from deferred list\n"); |
0a50f61c | 122 | bus_probe_device(dev); |
d1c3414c GL |
123 | mutex_lock(&deferred_probe_mutex); |
124 | ||
125 | put_device(dev); | |
126 | } | |
127 | mutex_unlock(&deferred_probe_mutex); | |
128 | } | |
129 | static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func); | |
130 | ||
e7dd4010 | 131 | void driver_deferred_probe_add(struct device *dev) |
d1c3414c | 132 | { |
f2db85b6 SK |
133 | if (!dev->can_match) |
134 | return; | |
135 | ||
d1c3414c | 136 | mutex_lock(&deferred_probe_mutex); |
ef8a3fd6 | 137 | if (list_empty(&dev->p->deferred_probe)) { |
d1c3414c | 138 | dev_dbg(dev, "Added to deferred list\n"); |
1d29cfa5 | 139 | list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list); |
d1c3414c GL |
140 | } |
141 | mutex_unlock(&deferred_probe_mutex); | |
142 | } | |
143 | ||
144 | void driver_deferred_probe_del(struct device *dev) | |
145 | { | |
146 | mutex_lock(&deferred_probe_mutex); | |
ef8a3fd6 | 147 | if (!list_empty(&dev->p->deferred_probe)) { |
d1c3414c | 148 | dev_dbg(dev, "Removed from deferred list\n"); |
ef8a3fd6 | 149 | list_del_init(&dev->p->deferred_probe); |
72a91f19 | 150 | __device_set_deferred_probe_reason(dev, NULL); |
d1c3414c GL |
151 | } |
152 | mutex_unlock(&deferred_probe_mutex); | |
153 | } | |
154 | ||
155 | static bool driver_deferred_probe_enable = false; | |
156 | /** | |
157 | * driver_deferred_probe_trigger() - Kick off re-probing deferred devices | |
158 | * | |
159 | * This functions moves all devices from the pending list to the active | |
160 | * list and schedules the deferred probe workqueue to process them. It | |
161 | * should be called anytime a driver is successfully bound to a device. | |
58b116bc GL |
162 | * |
163 | * Note, there is a race condition in multi-threaded probe. In the case where | |
164 | * more than one device is probing at the same time, it is possible for one | |
165 | * probe to complete successfully while another is about to defer. If the second | |
166 | * depends on the first, then it will get put on the pending list after the | |
9ba8af66 | 167 | * trigger event has already occurred and will be stuck there. |
58b116bc GL |
168 | * |
169 | * The atomic 'deferred_trigger_count' is used to determine if a successful | |
170 | * trigger has occurred in the midst of probing a driver. If the trigger count | |
171 | * changes in the midst of a probe, then deferred processing should be triggered | |
172 | * again. | |
d1c3414c GL |
173 | */ |
174 | static void driver_deferred_probe_trigger(void) | |
96d8a916 | 175 | { |
999032ec SK |
176 | if (!driver_deferred_probe_enable) |
177 | return; | |
178 | ||
8b0372a2 GKH |
179 | /* |
180 | * A successful probe means that all the devices in the pending list | |
d1c3414c | 181 | * should be triggered to be reprobed. Move all the deferred devices |
8b0372a2 GKH |
182 | * into the active list so they can be retried by the workqueue |
183 | */ | |
d1c3414c | 184 | mutex_lock(&deferred_probe_mutex); |
58b116bc | 185 | atomic_inc(&deferred_trigger_count); |
d1c3414c GL |
186 | list_splice_tail_init(&deferred_probe_pending_list, |
187 | &deferred_probe_active_list); | |
188 | mutex_unlock(&deferred_probe_mutex); | |
189 | ||
8b0372a2 GKH |
190 | /* |
191 | * Kick the re-probe thread. It may already be scheduled, but it is | |
192 | * safe to kick it again. | |
193 | */ | |
e611f8cd | 194 | queue_work(system_unbound_wq, &deferred_probe_work); |
d1c3414c GL |
195 | } |
196 | ||
013c074f | 197 | /** |
dbf03d65 | 198 | * device_block_probing() - Block/defer device's probes |
013c074f SG |
199 | * |
200 | * It will disable probing of devices and defer their probes instead. | |
201 | */ | |
202 | void device_block_probing(void) | |
203 | { | |
204 | defer_all_probes = true; | |
205 | /* sync with probes to avoid races. */ | |
206 | wait_for_device_probe(); | |
207 | } | |
208 | ||
209 | /** | |
210 | * device_unblock_probing() - Unblock/enable device's probes | |
211 | * | |
212 | * It will restore normal behavior and trigger re-probing of deferred | |
213 | * devices. | |
214 | */ | |
215 | void device_unblock_probing(void) | |
216 | { | |
217 | defer_all_probes = false; | |
218 | driver_deferred_probe_trigger(); | |
219 | } | |
220 | ||
d090b70e AH |
221 | /** |
222 | * device_set_deferred_probe_reason() - Set defer probe reason message for device | |
223 | * @dev: the pointer to the struct device | |
224 | * @vaf: the pointer to va_format structure with message | |
225 | */ | |
226 | void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf) | |
227 | { | |
228 | const char *drv = dev_driver_string(dev); | |
72a91f19 | 229 | char *reason; |
d090b70e AH |
230 | |
231 | mutex_lock(&deferred_probe_mutex); | |
232 | ||
72a91f19 AF |
233 | reason = kasprintf(GFP_KERNEL, "%s: %pV", drv, vaf); |
234 | __device_set_deferred_probe_reason(dev, reason); | |
d090b70e AH |
235 | |
236 | mutex_unlock(&deferred_probe_mutex); | |
237 | } | |
238 | ||
28af109a JMC |
239 | /* |
240 | * deferred_devs_show() - Show the devices in the deferred probe pending list. | |
241 | */ | |
242 | static int deferred_devs_show(struct seq_file *s, void *data) | |
243 | { | |
244 | struct device_private *curr; | |
245 | ||
246 | mutex_lock(&deferred_probe_mutex); | |
247 | ||
248 | list_for_each_entry(curr, &deferred_probe_pending_list, deferred_probe) | |
d090b70e AH |
249 | seq_printf(s, "%s\t%s", dev_name(curr->device), |
250 | curr->device->p->deferred_probe_reason ?: "\n"); | |
28af109a JMC |
251 | |
252 | mutex_unlock(&deferred_probe_mutex); | |
253 | ||
254 | return 0; | |
255 | } | |
256 | DEFINE_SHOW_ATTRIBUTE(deferred_devs); | |
257 | ||
ce68929f | 258 | int driver_deferred_probe_timeout; |
64c775fb | 259 | EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout); |
35a67236 | 260 | static DECLARE_WAIT_QUEUE_HEAD(probe_timeout_waitqueue); |
64c775fb | 261 | |
25b4e70d RH |
262 | static int __init deferred_probe_timeout_setup(char *str) |
263 | { | |
63c98047 MS |
264 | int timeout; |
265 | ||
266 | if (!kstrtoint(str, 10, &timeout)) | |
64c775fb | 267 | driver_deferred_probe_timeout = timeout; |
25b4e70d RH |
268 | return 1; |
269 | } | |
270 | __setup("deferred_probe_timeout=", deferred_probe_timeout_setup); | |
271 | ||
272 | /** | |
273 | * driver_deferred_probe_check_state() - Check deferred probe state | |
274 | * @dev: device to check | |
275 | * | |
c8c43cee JS |
276 | * Return: |
277 | * -ENODEV if initcalls have completed and modules are disabled. | |
278 | * -ETIMEDOUT if the deferred probe timeout was set and has expired | |
279 | * and modules are enabled. | |
280 | * -EPROBE_DEFER in other cases. | |
25b4e70d RH |
281 | * |
282 | * Drivers or subsystems can opt-in to calling this function instead of directly | |
283 | * returning -EPROBE_DEFER. | |
284 | */ | |
285 | int driver_deferred_probe_check_state(struct device *dev) | |
286 | { | |
0e9f8d09 | 287 | if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) { |
eb7fbc9f | 288 | dev_warn(dev, "ignoring dependency for device, assuming no driver\n"); |
0e9f8d09 JS |
289 | return -ENODEV; |
290 | } | |
62a6bc3a | 291 | |
ce68929f | 292 | if (!driver_deferred_probe_timeout && initcalls_done) { |
c8be6af9 | 293 | dev_warn(dev, "deferred probe timeout, ignoring dependency\n"); |
0e9f8d09 JS |
294 | return -ETIMEDOUT; |
295 | } | |
62a6bc3a | 296 | |
25b4e70d RH |
297 | return -EPROBE_DEFER; |
298 | } | |
299 | ||
300 | static void deferred_probe_timeout_work_func(struct work_struct *work) | |
301 | { | |
eed6e418 | 302 | struct device_private *p; |
25b4e70d | 303 | |
d46f3e3e SK |
304 | fw_devlink_drivers_done(); |
305 | ||
64c775fb | 306 | driver_deferred_probe_timeout = 0; |
25b4e70d RH |
307 | driver_deferred_probe_trigger(); |
308 | flush_work(&deferred_probe_work); | |
309 | ||
eed6e418 SK |
310 | mutex_lock(&deferred_probe_mutex); |
311 | list_for_each_entry(p, &deferred_probe_pending_list, deferred_probe) | |
312 | dev_info(p->device, "deferred probe pending\n"); | |
313 | mutex_unlock(&deferred_probe_mutex); | |
b292b50b | 314 | wake_up_all(&probe_timeout_waitqueue); |
25b4e70d RH |
315 | } |
316 | static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func); | |
317 | ||
d1c3414c GL |
318 | /** |
319 | * deferred_probe_initcall() - Enable probing of deferred devices | |
320 | * | |
321 | * We don't want to get in the way when the bulk of drivers are getting probed. | |
322 | * Instead, this initcall makes sure that deferred probing is delayed until | |
323 | * late_initcall time. | |
324 | */ | |
325 | static int deferred_probe_initcall(void) | |
326 | { | |
2942df67 GKH |
327 | debugfs_create_file("devices_deferred", 0444, NULL, NULL, |
328 | &deferred_devs_fops); | |
28af109a | 329 | |
d1c3414c GL |
330 | driver_deferred_probe_enable = true; |
331 | driver_deferred_probe_trigger(); | |
d72cca1e | 332 | /* Sort as many dependencies as possible before exiting initcalls */ |
2c507e46 | 333 | flush_work(&deferred_probe_work); |
25b4e70d RH |
334 | initcalls_done = true; |
335 | ||
d46f3e3e SK |
336 | if (!IS_ENABLED(CONFIG_MODULES)) |
337 | fw_devlink_drivers_done(); | |
338 | ||
25b4e70d RH |
339 | /* |
340 | * Trigger deferred probe again, this time we won't defer anything | |
341 | * that is optional | |
342 | */ | |
343 | driver_deferred_probe_trigger(); | |
344 | flush_work(&deferred_probe_work); | |
345 | ||
64c775fb | 346 | if (driver_deferred_probe_timeout > 0) { |
25b4e70d | 347 | schedule_delayed_work(&deferred_probe_timeout_work, |
64c775fb | 348 | driver_deferred_probe_timeout * HZ); |
25b4e70d | 349 | } |
d1c3414c GL |
350 | return 0; |
351 | } | |
352 | late_initcall(deferred_probe_initcall); | |
07e4a3e2 | 353 | |
28af109a JMC |
354 | static void __exit deferred_probe_exit(void) |
355 | { | |
2942df67 | 356 | debugfs_remove_recursive(debugfs_lookup("devices_deferred", NULL)); |
28af109a JMC |
357 | } |
358 | __exitcall(deferred_probe_exit); | |
359 | ||
6b9cb427 TV |
360 | /** |
361 | * device_is_bound() - Check if device is bound to a driver | |
362 | * @dev: device to check | |
363 | * | |
364 | * Returns true if passed device has already finished probing successfully | |
365 | * against a driver. | |
366 | * | |
367 | * This function must be called with the device lock held. | |
368 | */ | |
369 | bool device_is_bound(struct device *dev) | |
370 | { | |
3ded9104 | 371 | return dev->p && klist_node_attached(&dev->p->knode_driver); |
6b9cb427 TV |
372 | } |
373 | ||
1901fb26 | 374 | static void driver_bound(struct device *dev) |
07e4a3e2 | 375 | { |
6b9cb427 | 376 | if (device_is_bound(dev)) { |
eb7fbc9f | 377 | pr_warn("%s: device %s already bound\n", |
2b3a302a | 378 | __func__, kobject_name(&dev->kobj)); |
1901fb26 | 379 | return; |
f86db396 | 380 | } |
4c898c7f | 381 | |
94f8cc0e FR |
382 | pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name, |
383 | __func__, dev_name(dev)); | |
116af378 | 384 | |
fbb88fad | 385 | klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); |
9ed98953 | 386 | device_links_driver_bound(dev); |
fbb88fad | 387 | |
aa8e54b5 TV |
388 | device_pm_check_callbacks(dev); |
389 | ||
8b0372a2 GKH |
390 | /* |
391 | * Make sure the device is no longer in one of the deferred lists and | |
392 | * kick off retrying all pending devices | |
393 | */ | |
d1c3414c GL |
394 | driver_deferred_probe_del(dev); |
395 | driver_deferred_probe_trigger(); | |
396 | ||
116af378 | 397 | if (dev->bus) |
c6f7e72a | 398 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 | 399 | BUS_NOTIFY_BOUND_DRIVER, dev); |
1455cf8d DT |
400 | |
401 | kobject_uevent(&dev->kobj, KOBJ_BIND); | |
1901fb26 KS |
402 | } |
403 | ||
3c47d19f AS |
404 | static ssize_t coredump_store(struct device *dev, struct device_attribute *attr, |
405 | const char *buf, size_t count) | |
406 | { | |
407 | device_lock(dev); | |
1fe56e0c | 408 | dev->driver->coredump(dev); |
3c47d19f AS |
409 | device_unlock(dev); |
410 | ||
411 | return count; | |
412 | } | |
413 | static DEVICE_ATTR_WO(coredump); | |
414 | ||
1901fb26 KS |
415 | static int driver_sysfs_add(struct device *dev) |
416 | { | |
417 | int ret; | |
418 | ||
45daef0f MD |
419 | if (dev->bus) |
420 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
421 | BUS_NOTIFY_BIND_DRIVER, dev); | |
422 | ||
e5dd1278 | 423 | ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj, |
3c47d19f AS |
424 | kobject_name(&dev->kobj)); |
425 | if (ret) | |
426 | goto fail; | |
427 | ||
428 | ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj, | |
429 | "driver"); | |
430 | if (ret) | |
431 | goto rm_dev; | |
432 | ||
d225ef6f JJB |
433 | if (!IS_ENABLED(CONFIG_DEV_COREDUMP) || !dev->driver->coredump) |
434 | return 0; | |
435 | ||
436 | ret = device_create_file(dev, &dev_attr_coredump); | |
437 | if (!ret) | |
3c47d19f AS |
438 | return 0; |
439 | ||
440 | sysfs_remove_link(&dev->kobj, "driver"); | |
441 | ||
442 | rm_dev: | |
443 | sysfs_remove_link(&dev->driver->p->kobj, | |
07e4a3e2 | 444 | kobject_name(&dev->kobj)); |
3c47d19f AS |
445 | |
446 | fail: | |
f86db396 | 447 | return ret; |
07e4a3e2 PM |
448 | } |
449 | ||
1901fb26 KS |
450 | static void driver_sysfs_remove(struct device *dev) |
451 | { | |
452 | struct device_driver *drv = dev->driver; | |
453 | ||
454 | if (drv) { | |
3c47d19f AS |
455 | if (drv->coredump) |
456 | device_remove_file(dev, &dev_attr_coredump); | |
e5dd1278 | 457 | sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); |
1901fb26 KS |
458 | sysfs_remove_link(&dev->kobj, "driver"); |
459 | } | |
460 | } | |
461 | ||
462 | /** | |
4a3ad20c GKH |
463 | * device_bind_driver - bind a driver to one device. |
464 | * @dev: device. | |
1901fb26 | 465 | * |
4a3ad20c GKH |
466 | * Allow manual attachment of a driver to a device. |
467 | * Caller must have already set @dev->driver. | |
1901fb26 | 468 | * |
fe940d73 LW |
469 | * Note that this does not modify the bus reference count. |
470 | * Please verify that is accounted for before calling this. | |
471 | * (It is ok to call with no other effort from a driver's probe() method.) | |
1901fb26 | 472 | * |
8e9394ce | 473 | * This function must be called with the device lock held. |
1901fb26 KS |
474 | */ |
475 | int device_bind_driver(struct device *dev) | |
476 | { | |
cb986b74 CH |
477 | int ret; |
478 | ||
479 | ret = driver_sysfs_add(dev); | |
b6f617df SK |
480 | if (!ret) { |
481 | device_links_force_bind(dev); | |
cb986b74 | 482 | driver_bound(dev); |
b6f617df | 483 | } |
14b6257a AS |
484 | else if (dev->bus) |
485 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
486 | BUS_NOTIFY_DRIVER_NOT_BOUND, dev); | |
cb986b74 | 487 | return ret; |
1901fb26 | 488 | } |
4a3ad20c | 489 | EXPORT_SYMBOL_GPL(device_bind_driver); |
1901fb26 | 490 | |
d779249e | 491 | static atomic_t probe_count = ATOMIC_INIT(0); |
735a7ffb AM |
492 | static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); |
493 | ||
0ff26c66 AH |
494 | static void driver_deferred_probe_add_trigger(struct device *dev, |
495 | int local_trigger_count) | |
496 | { | |
497 | driver_deferred_probe_add(dev); | |
498 | /* Did a trigger occur while probing? Need to re-trigger if yes */ | |
499 | if (local_trigger_count != atomic_read(&deferred_trigger_count)) | |
500 | driver_deferred_probe_trigger(); | |
501 | } | |
502 | ||
8fd456ec SK |
503 | static ssize_t state_synced_show(struct device *dev, |
504 | struct device_attribute *attr, char *buf) | |
505 | { | |
506 | bool val; | |
507 | ||
508 | device_lock(dev); | |
509 | val = dev->state_synced; | |
510 | device_unlock(dev); | |
948b3edb | 511 | |
aa838896 | 512 | return sysfs_emit(buf, "%u\n", val); |
8fd456ec SK |
513 | } |
514 | static DEVICE_ATTR_RO(state_synced); | |
515 | ||
21c7f30b | 516 | static int really_probe(struct device *dev, struct device_driver *drv) |
07e4a3e2 | 517 | { |
013c074f | 518 | int ret = -EPROBE_DEFER; |
58b116bc | 519 | int local_trigger_count = atomic_read(&deferred_trigger_count); |
c5f06274 RH |
520 | bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) && |
521 | !drv->suppress_bind_attrs; | |
07e4a3e2 | 522 | |
013c074f SG |
523 | if (defer_all_probes) { |
524 | /* | |
525 | * Value of defer_all_probes can be set only by | |
dbf03d65 | 526 | * device_block_probing() which, in turn, will call |
013c074f SG |
527 | * wait_for_device_probe() right after that to avoid any races. |
528 | */ | |
529 | dev_dbg(dev, "Driver %s force probe deferral\n", drv->name); | |
530 | driver_deferred_probe_add(dev); | |
531 | return ret; | |
532 | } | |
533 | ||
9ed98953 | 534 | ret = device_links_check_suppliers(dev); |
0ff26c66 AH |
535 | if (ret == -EPROBE_DEFER) |
536 | driver_deferred_probe_add_trigger(dev, local_trigger_count); | |
9ed98953 RW |
537 | if (ret) |
538 | return ret; | |
539 | ||
d779249e | 540 | atomic_inc(&probe_count); |
7dc72b28 | 541 | pr_debug("bus: '%s': %s: probing driver %s with device %s\n", |
1e0b2cf9 | 542 | drv->bus->name, __func__, drv->name, dev_name(dev)); |
7c35e699 GU |
543 | if (!list_empty(&dev->devres_head)) { |
544 | dev_crit(dev, "Resources present before probing\n"); | |
b292b50b TH |
545 | ret = -EBUSY; |
546 | goto done; | |
7c35e699 | 547 | } |
07e4a3e2 | 548 | |
bea5b158 | 549 | re_probe: |
07e4a3e2 | 550 | dev->driver = drv; |
ab78029e LW |
551 | |
552 | /* If using pinctrl, bind pins now before probing */ | |
553 | ret = pinctrl_bind_pins(dev); | |
554 | if (ret) | |
14b6257a | 555 | goto pinctrl_bind_failed; |
ab78029e | 556 | |
ccf640f4 CH |
557 | if (dev->bus->dma_configure) { |
558 | ret = dev->bus->dma_configure(dev); | |
559 | if (ret) | |
0b777eee | 560 | goto probe_failed; |
ccf640f4 | 561 | } |
09515ef5 | 562 | |
1901fb26 | 563 | if (driver_sysfs_add(dev)) { |
eb7fbc9f CJ |
564 | pr_err("%s: driver_sysfs_add(%s) failed\n", |
565 | __func__, dev_name(dev)); | |
1901fb26 KS |
566 | goto probe_failed; |
567 | } | |
568 | ||
e90d5532 RW |
569 | if (dev->pm_domain && dev->pm_domain->activate) { |
570 | ret = dev->pm_domain->activate(dev); | |
571 | if (ret) | |
572 | goto probe_failed; | |
573 | } | |
574 | ||
594c8281 RK |
575 | if (dev->bus->probe) { |
576 | ret = dev->bus->probe(dev); | |
1901fb26 | 577 | if (ret) |
d779249e | 578 | goto probe_failed; |
594c8281 | 579 | } else if (drv->probe) { |
0d3e5a2e | 580 | ret = drv->probe(dev); |
1901fb26 | 581 | if (ret) |
d779249e | 582 | goto probe_failed; |
f86db396 | 583 | } |
1901fb26 | 584 | |
23b69044 DT |
585 | if (device_add_groups(dev, drv->dev_groups)) { |
586 | dev_err(dev, "device_add_groups() failed\n"); | |
587 | goto dev_groups_failed; | |
588 | } | |
589 | ||
8fd456ec SK |
590 | if (dev_has_sync_state(dev) && |
591 | device_create_file(dev, &dev_attr_state_synced)) { | |
592 | dev_err(dev, "state_synced sysfs add failed\n"); | |
593 | goto dev_sysfs_state_synced_failed; | |
594 | } | |
595 | ||
bea5b158 RH |
596 | if (test_remove) { |
597 | test_remove = false; | |
598 | ||
8fd456ec | 599 | device_remove_file(dev, &dev_attr_state_synced); |
23b69044 DT |
600 | device_remove_groups(dev, drv->dev_groups); |
601 | ||
bdacd1b4 | 602 | if (dev->bus->remove) |
bea5b158 RH |
603 | dev->bus->remove(dev); |
604 | else if (drv->remove) | |
605 | drv->remove(dev); | |
606 | ||
607 | devres_release_all(dev); | |
608 | driver_sysfs_remove(dev); | |
609 | dev->driver = NULL; | |
610 | dev_set_drvdata(dev, NULL); | |
611 | if (dev->pm_domain && dev->pm_domain->dismiss) | |
612 | dev->pm_domain->dismiss(dev); | |
613 | pm_runtime_reinit(dev); | |
614 | ||
615 | goto re_probe; | |
616 | } | |
617 | ||
ef0eebc0 DA |
618 | pinctrl_init_done(dev); |
619 | ||
e90d5532 RW |
620 | if (dev->pm_domain && dev->pm_domain->sync) |
621 | dev->pm_domain->sync(dev); | |
622 | ||
1901fb26 | 623 | driver_bound(dev); |
0d3e5a2e | 624 | ret = 1; |
7dc72b28 | 625 | pr_debug("bus: '%s': %s: bound device %s to driver %s\n", |
1e0b2cf9 | 626 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 627 | goto done; |
0d3e5a2e | 628 | |
8fd456ec SK |
629 | dev_sysfs_state_synced_failed: |
630 | device_remove_groups(dev, drv->dev_groups); | |
23b69044 DT |
631 | dev_groups_failed: |
632 | if (dev->bus->remove) | |
633 | dev->bus->remove(dev); | |
634 | else if (drv->remove) | |
635 | drv->remove(dev); | |
d779249e | 636 | probe_failed: |
d0243bbd ML |
637 | kfree(dev->dma_range_map); |
638 | dev->dma_range_map = NULL; | |
14b6257a AS |
639 | if (dev->bus) |
640 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
641 | BUS_NOTIFY_DRIVER_NOT_BOUND, dev); | |
642 | pinctrl_bind_failed: | |
9ed98953 | 643 | device_links_no_driver(dev); |
9ac7849e | 644 | devres_release_all(dev); |
0b777eee | 645 | arch_teardown_dma_ops(dev); |
1901fb26 KS |
646 | driver_sysfs_remove(dev); |
647 | dev->driver = NULL; | |
0998d063 | 648 | dev_set_drvdata(dev, NULL); |
e90d5532 RW |
649 | if (dev->pm_domain && dev->pm_domain->dismiss) |
650 | dev->pm_domain->dismiss(dev); | |
5de85b9d | 651 | pm_runtime_reinit(dev); |
08810a41 | 652 | dev_pm_set_driver_flags(dev, 0); |
1901fb26 | 653 | |
bb2b4075 SS |
654 | switch (ret) { |
655 | case -EPROBE_DEFER: | |
d1c3414c | 656 | /* Driver requested deferred probing */ |
13fcffbb | 657 | dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name); |
0ff26c66 | 658 | driver_deferred_probe_add_trigger(dev, local_trigger_count); |
bb2b4075 SS |
659 | break; |
660 | case -ENODEV: | |
661 | case -ENXIO: | |
662 | pr_debug("%s: probe of %s rejects match %d\n", | |
663 | drv->name, dev_name(dev), ret); | |
664 | break; | |
665 | default: | |
0d3e5a2e | 666 | /* driver matched but the probe failed */ |
eb7fbc9f CJ |
667 | pr_warn("%s: probe of %s failed with error %d\n", |
668 | drv->name, dev_name(dev), ret); | |
0d3e5a2e | 669 | } |
c578abbc CH |
670 | /* |
671 | * Ignore errors returned by ->probe so that the next driver can try | |
672 | * its luck. | |
673 | */ | |
674 | ret = 0; | |
d779249e | 675 | done: |
d779249e | 676 | atomic_dec(&probe_count); |
b292b50b | 677 | wake_up_all(&probe_waitqueue); |
d779249e GKH |
678 | return ret; |
679 | } | |
680 | ||
0a50f61c TP |
681 | /* |
682 | * For initcall_debug, show the driver probe time. | |
683 | */ | |
684 | static int really_probe_debug(struct device *dev, struct device_driver *drv) | |
685 | { | |
e3aa745f | 686 | ktime_t calltime, rettime; |
0a50f61c TP |
687 | int ret; |
688 | ||
689 | calltime = ktime_get(); | |
690 | ret = really_probe(dev, drv); | |
691 | rettime = ktime_get(); | |
eb7fbc9f | 692 | pr_debug("probe of %s returned %d after %lld usecs\n", |
e3aa745f | 693 | dev_name(dev), ret, ktime_us_delta(rettime, calltime)); |
0a50f61c TP |
694 | return ret; |
695 | } | |
696 | ||
d779249e GKH |
697 | /** |
698 | * driver_probe_done | |
699 | * Determine if the probe sequence is finished or not. | |
700 | * | |
701 | * Should somehow figure out how to use a semaphore, not an atomic variable... | |
702 | */ | |
703 | int driver_probe_done(void) | |
704 | { | |
927f8287 AS |
705 | int local_probe_count = atomic_read(&probe_count); |
706 | ||
707 | pr_debug("%s: probe_count = %d\n", __func__, local_probe_count); | |
708 | if (local_probe_count) | |
d779249e GKH |
709 | return -EBUSY; |
710 | return 0; | |
711 | } | |
712 | ||
216773a7 AV |
713 | /** |
714 | * wait_for_device_probe | |
715 | * Wait for device probing to be completed. | |
216773a7 | 716 | */ |
b23530eb | 717 | void wait_for_device_probe(void) |
216773a7 | 718 | { |
35a67236 JS |
719 | /* wait for probe timeout */ |
720 | wait_event(probe_timeout_waitqueue, !driver_deferred_probe_timeout); | |
721 | ||
013c074f | 722 | /* wait for the deferred probe workqueue to finish */ |
2c507e46 | 723 | flush_work(&deferred_probe_work); |
013c074f | 724 | |
216773a7 | 725 | /* wait for the known devices to complete their probing */ |
b23530eb | 726 | wait_event(probe_waitqueue, atomic_read(&probe_count) == 0); |
216773a7 | 727 | async_synchronize_full(); |
216773a7 | 728 | } |
d4d5291c | 729 | EXPORT_SYMBOL_GPL(wait_for_device_probe); |
216773a7 | 730 | |
d779249e GKH |
731 | /** |
732 | * driver_probe_device - attempt to bind device & driver together | |
733 | * @drv: driver to bind a device to | |
734 | * @dev: device to try to bind to the driver | |
735 | * | |
204db60c JG |
736 | * This function returns -ENODEV if the device is not registered, -EBUSY if it |
737 | * already has a driver, and 1 if the device is bound successfully and 0 | |
738 | * otherwise. | |
d779249e | 739 | * |
8e9394ce GKH |
740 | * This function must be called with @dev lock held. When called for a |
741 | * USB interface, @dev->parent lock must be held as well. | |
ddef08dd RW |
742 | * |
743 | * If the device has a parent, runtime-resume the parent before driver probing. | |
d779249e | 744 | */ |
2c3dc643 | 745 | static int driver_probe_device(struct device_driver *drv, struct device *dev) |
d779249e | 746 | { |
d779249e GKH |
747 | int ret = 0; |
748 | ||
204db60c | 749 | if (dev->p->dead || !device_is_registered(dev)) |
f2eaae19 | 750 | return -ENODEV; |
204db60c JG |
751 | if (dev->driver) |
752 | return -EBUSY; | |
d779249e | 753 | |
f2db85b6 | 754 | dev->can_match = true; |
7dc72b28 | 755 | pr_debug("bus: '%s': %s: matched device %s with driver %s\n", |
1e0b2cf9 | 756 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 757 | |
b06c0b2f | 758 | pm_runtime_get_suppliers(dev); |
ddef08dd RW |
759 | if (dev->parent) |
760 | pm_runtime_get_sync(dev->parent); | |
761 | ||
5e928f77 | 762 | pm_runtime_barrier(dev); |
0a50f61c TP |
763 | if (initcall_debug) |
764 | ret = really_probe_debug(dev, drv); | |
765 | else | |
766 | ret = really_probe(dev, drv); | |
fa180eb4 | 767 | pm_request_idle(dev); |
d779249e | 768 | |
ddef08dd RW |
769 | if (dev->parent) |
770 | pm_runtime_put(dev->parent); | |
771 | ||
b06c0b2f | 772 | pm_runtime_put_suppliers(dev); |
0d3e5a2e | 773 | return ret; |
07e4a3e2 PM |
774 | } |
775 | ||
1ea61b68 FT |
776 | static inline bool cmdline_requested_async_probing(const char *drv_name) |
777 | { | |
778 | return parse_option_str(async_probe_drv_names, drv_name); | |
779 | } | |
780 | ||
781 | /* The option format is "driver_async_probe=drv_name1,drv_name2,..." */ | |
782 | static int __init save_async_options(char *buf) | |
783 | { | |
784 | if (strlen(buf) >= ASYNC_DRV_NAMES_MAX_LEN) | |
eb7fbc9f | 785 | pr_warn("Too long list of driver names for 'driver_async_probe'!\n"); |
1ea61b68 FT |
786 | |
787 | strlcpy(async_probe_drv_names, buf, ASYNC_DRV_NAMES_MAX_LEN); | |
788 | return 0; | |
789 | } | |
790 | __setup("driver_async_probe=", save_async_options); | |
791 | ||
765230b5 | 792 | bool driver_allows_async_probing(struct device_driver *drv) |
2287c322 | 793 | { |
d173a137 LR |
794 | switch (drv->probe_type) { |
795 | case PROBE_PREFER_ASYNCHRONOUS: | |
f2411da7 LR |
796 | return true; |
797 | ||
d173a137 LR |
798 | case PROBE_FORCE_SYNCHRONOUS: |
799 | return false; | |
800 | ||
801 | default: | |
1ea61b68 FT |
802 | if (cmdline_requested_async_probing(drv->name)) |
803 | return true; | |
804 | ||
80c6e146 | 805 | if (module_requested_async_probing(drv->owner)) |
d173a137 | 806 | return true; |
f2411da7 | 807 | |
d173a137 LR |
808 | return false; |
809 | } | |
765230b5 DT |
810 | } |
811 | ||
812 | struct device_attach_data { | |
813 | struct device *dev; | |
814 | ||
815 | /* | |
816 | * Indicates whether we are are considering asynchronous probing or | |
817 | * not. Only initial binding after device or driver registration | |
818 | * (including deferral processing) may be done asynchronously, the | |
819 | * rest is always synchronous, as we expect it is being done by | |
820 | * request from userspace. | |
821 | */ | |
822 | bool check_async; | |
823 | ||
824 | /* | |
825 | * Indicates if we are binding synchronous or asynchronous drivers. | |
826 | * When asynchronous probing is enabled we'll execute 2 passes | |
827 | * over drivers: first pass doing synchronous probing and second | |
828 | * doing asynchronous probing (if synchronous did not succeed - | |
829 | * most likely because there was no driver requiring synchronous | |
830 | * probing - and we found asynchronous driver during first pass). | |
831 | * The 2 passes are done because we can't shoot asynchronous | |
832 | * probe for given device and driver from bus_for_each_drv() since | |
833 | * driver pointer is not guaranteed to stay valid once | |
834 | * bus_for_each_drv() iterates to the next driver on the bus. | |
835 | */ | |
836 | bool want_async; | |
837 | ||
838 | /* | |
839 | * We'll set have_async to 'true' if, while scanning for matching | |
840 | * driver, we'll encounter one that requests asynchronous probing. | |
841 | */ | |
842 | bool have_async; | |
843 | }; | |
844 | ||
845 | static int __device_attach_driver(struct device_driver *drv, void *_data) | |
846 | { | |
847 | struct device_attach_data *data = _data; | |
848 | struct device *dev = data->dev; | |
849 | bool async_allowed; | |
656b8035 | 850 | int ret; |
765230b5 | 851 | |
656b8035 TV |
852 | ret = driver_match_device(drv, dev); |
853 | if (ret == 0) { | |
854 | /* no match */ | |
49b420a1 | 855 | return 0; |
656b8035 TV |
856 | } else if (ret == -EPROBE_DEFER) { |
857 | dev_dbg(dev, "Device match requests probe deferral\n"); | |
f2db85b6 | 858 | dev->can_match = true; |
656b8035 TV |
859 | driver_deferred_probe_add(dev); |
860 | } else if (ret < 0) { | |
eb7fbc9f | 861 | dev_dbg(dev, "Bus failed to match device: %d\n", ret); |
656b8035 TV |
862 | return ret; |
863 | } /* ret > 0 means positive match */ | |
49b420a1 | 864 | |
765230b5 DT |
865 | async_allowed = driver_allows_async_probing(drv); |
866 | ||
867 | if (async_allowed) | |
868 | data->have_async = true; | |
869 | ||
870 | if (data->check_async && async_allowed != data->want_async) | |
871 | return 0; | |
872 | ||
0d3e5a2e | 873 | return driver_probe_device(drv, dev); |
2287c322 PM |
874 | } |
875 | ||
765230b5 DT |
876 | static void __device_attach_async_helper(void *_dev, async_cookie_t cookie) |
877 | { | |
878 | struct device *dev = _dev; | |
879 | struct device_attach_data data = { | |
880 | .dev = dev, | |
881 | .check_async = true, | |
882 | .want_async = true, | |
883 | }; | |
884 | ||
885 | device_lock(dev); | |
886 | ||
3451a495 AD |
887 | /* |
888 | * Check if device has already been removed or claimed. This may | |
889 | * happen with driver loading, device discovery/registration, | |
890 | * and deferred probe processing happens all at once with | |
891 | * multiple threads. | |
892 | */ | |
893 | if (dev->p->dead || dev->driver) | |
894 | goto out_unlock; | |
895 | ||
ddef08dd RW |
896 | if (dev->parent) |
897 | pm_runtime_get_sync(dev->parent); | |
898 | ||
765230b5 DT |
899 | bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver); |
900 | dev_dbg(dev, "async probe completed\n"); | |
901 | ||
902 | pm_request_idle(dev); | |
903 | ||
ddef08dd RW |
904 | if (dev->parent) |
905 | pm_runtime_put(dev->parent); | |
3451a495 | 906 | out_unlock: |
765230b5 DT |
907 | device_unlock(dev); |
908 | ||
909 | put_device(dev); | |
910 | } | |
911 | ||
802a87fd | 912 | static int __device_attach(struct device *dev, bool allow_async) |
07e4a3e2 | 913 | { |
0d3e5a2e PM |
914 | int ret = 0; |
915 | ||
8e9394ce | 916 | device_lock(dev); |
65488832 LW |
917 | if (dev->p->dead) { |
918 | goto out_unlock; | |
919 | } else if (dev->driver) { | |
6b9cb427 | 920 | if (device_is_bound(dev)) { |
8497d6a2 SO |
921 | ret = 1; |
922 | goto out_unlock; | |
923 | } | |
f86db396 AM |
924 | ret = device_bind_driver(dev); |
925 | if (ret == 0) | |
926 | ret = 1; | |
c6a46696 CH |
927 | else { |
928 | dev->driver = NULL; | |
929 | ret = 0; | |
930 | } | |
21c7f30b | 931 | } else { |
765230b5 DT |
932 | struct device_attach_data data = { |
933 | .dev = dev, | |
934 | .check_async = allow_async, | |
935 | .want_async = false, | |
936 | }; | |
937 | ||
ddef08dd RW |
938 | if (dev->parent) |
939 | pm_runtime_get_sync(dev->parent); | |
940 | ||
765230b5 DT |
941 | ret = bus_for_each_drv(dev->bus, NULL, &data, |
942 | __device_attach_driver); | |
943 | if (!ret && allow_async && data.have_async) { | |
944 | /* | |
945 | * If we could not find appropriate driver | |
946 | * synchronously and we are allowed to do | |
947 | * async probes and there are drivers that | |
948 | * want to probe asynchronously, we'll | |
949 | * try them. | |
950 | */ | |
951 | dev_dbg(dev, "scheduling asynchronous probe\n"); | |
952 | get_device(dev); | |
c37e20ea | 953 | async_schedule_dev(__device_attach_async_helper, dev); |
765230b5 DT |
954 | } else { |
955 | pm_request_idle(dev); | |
956 | } | |
ddef08dd RW |
957 | |
958 | if (dev->parent) | |
959 | pm_runtime_put(dev->parent); | |
21c7f30b | 960 | } |
8497d6a2 | 961 | out_unlock: |
8e9394ce | 962 | device_unlock(dev); |
0d3e5a2e | 963 | return ret; |
2287c322 | 964 | } |
765230b5 DT |
965 | |
966 | /** | |
967 | * device_attach - try to attach device to a driver. | |
968 | * @dev: device. | |
969 | * | |
970 | * Walk the list of drivers that the bus has and call | |
971 | * driver_probe_device() for each pair. If a compatible | |
972 | * pair is found, break out and return. | |
973 | * | |
974 | * Returns 1 if the device was bound to a driver; | |
975 | * 0 if no matching driver was found; | |
976 | * -ENODEV if the device is not registered. | |
977 | * | |
978 | * When called for a USB interface, @dev->parent lock must be held. | |
979 | */ | |
980 | int device_attach(struct device *dev) | |
981 | { | |
982 | return __device_attach(dev, false); | |
983 | } | |
4a3ad20c | 984 | EXPORT_SYMBOL_GPL(device_attach); |
2287c322 | 985 | |
765230b5 DT |
986 | void device_initial_probe(struct device *dev) |
987 | { | |
988 | __device_attach(dev, true); | |
989 | } | |
990 | ||
ed88747c AD |
991 | /* |
992 | * __device_driver_lock - acquire locks needed to manipulate dev->drv | |
993 | * @dev: Device we will update driver info for | |
994 | * @parent: Parent device. Needed if the bus requires parent lock | |
995 | * | |
996 | * This function will take the required locks for manipulating dev->drv. | |
997 | * Normally this will just be the @dev lock, but when called for a USB | |
998 | * interface, @parent lock will be held as well. | |
999 | */ | |
1000 | static void __device_driver_lock(struct device *dev, struct device *parent) | |
1001 | { | |
1002 | if (parent && dev->bus->need_parent_lock) | |
1003 | device_lock(parent); | |
1004 | device_lock(dev); | |
1005 | } | |
1006 | ||
1007 | /* | |
1008 | * __device_driver_unlock - release locks needed to manipulate dev->drv | |
1009 | * @dev: Device we will update driver info for | |
1010 | * @parent: Parent device. Needed if the bus requires parent lock | |
1011 | * | |
1012 | * This function will release the required locks for manipulating dev->drv. | |
1013 | * Normally this will just be the the @dev lock, but when called for a | |
1014 | * USB interface, @parent lock will be released as well. | |
1015 | */ | |
1016 | static void __device_driver_unlock(struct device *dev, struct device *parent) | |
1017 | { | |
1018 | device_unlock(dev); | |
1019 | if (parent && dev->bus->need_parent_lock) | |
1020 | device_unlock(parent); | |
1021 | } | |
1022 | ||
1023 | /** | |
1024 | * device_driver_attach - attach a specific driver to a specific device | |
1025 | * @drv: Driver to attach | |
1026 | * @dev: Device to attach it to | |
1027 | * | |
1028 | * Manually attach driver to a device. Will acquire both @dev lock and | |
1029 | * @dev->parent lock if needed. | |
1030 | */ | |
1031 | int device_driver_attach(struct device_driver *drv, struct device *dev) | |
1032 | { | |
204db60c | 1033 | int ret; |
ed88747c AD |
1034 | |
1035 | __device_driver_lock(dev, dev->parent); | |
204db60c | 1036 | ret = driver_probe_device(drv, dev); |
ed88747c AD |
1037 | __device_driver_unlock(dev, dev->parent); |
1038 | ||
1039 | return ret; | |
1040 | } | |
1041 | ||
ef0ff683 AD |
1042 | static void __driver_attach_async_helper(void *_dev, async_cookie_t cookie) |
1043 | { | |
1044 | struct device *dev = _dev; | |
1045 | struct device_driver *drv; | |
204db60c | 1046 | int ret; |
ef0ff683 AD |
1047 | |
1048 | __device_driver_lock(dev, dev->parent); | |
ef0ff683 | 1049 | drv = dev->p->async_driver; |
204db60c | 1050 | ret = driver_probe_device(drv, dev); |
ef0ff683 AD |
1051 | __device_driver_unlock(dev, dev->parent); |
1052 | ||
1053 | dev_dbg(dev, "driver %s async attach completed: %d\n", drv->name, ret); | |
1054 | ||
1055 | put_device(dev); | |
1056 | } | |
1057 | ||
4a3ad20c | 1058 | static int __driver_attach(struct device *dev, void *data) |
2287c322 | 1059 | { |
4a3ad20c | 1060 | struct device_driver *drv = data; |
656b8035 | 1061 | int ret; |
0d3e5a2e PM |
1062 | |
1063 | /* | |
1064 | * Lock device and try to bind to it. We drop the error | |
1065 | * here and always return 0, because we need to keep trying | |
1066 | * to bind to devices and some drivers will return an error | |
1067 | * simply if it didn't support the device. | |
1068 | * | |
1069 | * driver_probe_device() will spit a warning if there | |
1070 | * is an error. | |
1071 | */ | |
1072 | ||
656b8035 TV |
1073 | ret = driver_match_device(drv, dev); |
1074 | if (ret == 0) { | |
1075 | /* no match */ | |
6cd49586 | 1076 | return 0; |
656b8035 TV |
1077 | } else if (ret == -EPROBE_DEFER) { |
1078 | dev_dbg(dev, "Device match requests probe deferral\n"); | |
f2db85b6 | 1079 | dev->can_match = true; |
656b8035 TV |
1080 | driver_deferred_probe_add(dev); |
1081 | } else if (ret < 0) { | |
eb7fbc9f | 1082 | dev_dbg(dev, "Bus failed to match device: %d\n", ret); |
656b8035 TV |
1083 | return ret; |
1084 | } /* ret > 0 means positive match */ | |
6cd49586 | 1085 | |
ef0ff683 AD |
1086 | if (driver_allows_async_probing(drv)) { |
1087 | /* | |
1088 | * Instead of probing the device synchronously we will | |
1089 | * probe it asynchronously to allow for more parallelism. | |
1090 | * | |
1091 | * We only take the device lock here in order to guarantee | |
1092 | * that the dev->driver and async_driver fields are protected | |
1093 | */ | |
1094 | dev_dbg(dev, "probing driver %s asynchronously\n", drv->name); | |
1095 | device_lock(dev); | |
1096 | if (!dev->driver) { | |
1097 | get_device(dev); | |
1098 | dev->p->async_driver = drv; | |
c37e20ea | 1099 | async_schedule_dev(__driver_attach_async_helper, dev); |
ef0ff683 AD |
1100 | } |
1101 | device_unlock(dev); | |
1102 | return 0; | |
1103 | } | |
1104 | ||
ed88747c | 1105 | device_driver_attach(drv, dev); |
0d3e5a2e | 1106 | |
07e4a3e2 PM |
1107 | return 0; |
1108 | } | |
1109 | ||
1110 | /** | |
4a3ad20c GKH |
1111 | * driver_attach - try to bind driver to devices. |
1112 | * @drv: driver. | |
07e4a3e2 | 1113 | * |
4a3ad20c GKH |
1114 | * Walk the list of devices that the bus has on it and try to |
1115 | * match the driver with each one. If driver_probe_device() | |
1116 | * returns 0 and the @dev->driver is set, we've found a | |
1117 | * compatible pair. | |
07e4a3e2 | 1118 | */ |
4a3ad20c | 1119 | int driver_attach(struct device_driver *drv) |
07e4a3e2 | 1120 | { |
f86db396 | 1121 | return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach); |
07e4a3e2 | 1122 | } |
4a3ad20c | 1123 | EXPORT_SYMBOL_GPL(driver_attach); |
07e4a3e2 | 1124 | |
ab71c6f0 | 1125 | /* |
8e9394ce GKH |
1126 | * __device_release_driver() must be called with @dev lock held. |
1127 | * When called for a USB interface, @dev->parent lock must be held as well. | |
07e4a3e2 | 1128 | */ |
9ed98953 | 1129 | static void __device_release_driver(struct device *dev, struct device *parent) |
07e4a3e2 | 1130 | { |
4a3ad20c | 1131 | struct device_driver *drv; |
07e4a3e2 | 1132 | |
ef2c5174 | 1133 | drv = dev->driver; |
c95a6b05 | 1134 | if (drv) { |
9226c504 RW |
1135 | pm_runtime_get_sync(dev); |
1136 | ||
9ed98953 | 1137 | while (device_links_busy(dev)) { |
ed88747c | 1138 | __device_driver_unlock(dev, parent); |
9ed98953 RW |
1139 | |
1140 | device_links_unbind_consumers(dev); | |
9ed98953 | 1141 | |
ed88747c | 1142 | __device_driver_lock(dev, parent); |
9ed98953 RW |
1143 | /* |
1144 | * A concurrent invocation of the same function might | |
1145 | * have released the driver successfully while this one | |
1146 | * was waiting, so check for that. | |
1147 | */ | |
9226c504 RW |
1148 | if (dev->driver != drv) { |
1149 | pm_runtime_put(dev); | |
9ed98953 | 1150 | return; |
9226c504 | 1151 | } |
9ed98953 RW |
1152 | } |
1153 | ||
1901fb26 | 1154 | driver_sysfs_remove(dev); |
0d3e5a2e | 1155 | |
116af378 | 1156 | if (dev->bus) |
c6f7e72a | 1157 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 BH |
1158 | BUS_NOTIFY_UNBIND_DRIVER, |
1159 | dev); | |
1160 | ||
baab52de | 1161 | pm_runtime_put_sync(dev); |
e1866b33 | 1162 | |
8fd456ec | 1163 | device_remove_file(dev, &dev_attr_state_synced); |
23b69044 DT |
1164 | device_remove_groups(dev, drv->dev_groups); |
1165 | ||
0f836ca4 | 1166 | if (dev->bus && dev->bus->remove) |
594c8281 RK |
1167 | dev->bus->remove(dev); |
1168 | else if (drv->remove) | |
0d3e5a2e | 1169 | drv->remove(dev); |
9ed98953 RW |
1170 | |
1171 | device_links_driver_cleanup(dev); | |
09515ef5 | 1172 | |
9ac7849e | 1173 | devres_release_all(dev); |
376991db | 1174 | arch_teardown_dma_ops(dev); |
0d3e5a2e | 1175 | dev->driver = NULL; |
0998d063 | 1176 | dev_set_drvdata(dev, NULL); |
e90d5532 RW |
1177 | if (dev->pm_domain && dev->pm_domain->dismiss) |
1178 | dev->pm_domain->dismiss(dev); | |
5de85b9d | 1179 | pm_runtime_reinit(dev); |
08810a41 | 1180 | dev_pm_set_driver_flags(dev, 0); |
e90d5532 | 1181 | |
8940b4f3 | 1182 | klist_remove(&dev->p->knode_driver); |
aa8e54b5 | 1183 | device_pm_check_callbacks(dev); |
309b7d60 JR |
1184 | if (dev->bus) |
1185 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
1186 | BUS_NOTIFY_UNBOUND_DRIVER, | |
1187 | dev); | |
1455cf8d DT |
1188 | |
1189 | kobject_uevent(&dev->kobj, KOBJ_UNBIND); | |
0d3e5a2e | 1190 | } |
07e4a3e2 PM |
1191 | } |
1192 | ||
9ed98953 RW |
1193 | void device_release_driver_internal(struct device *dev, |
1194 | struct device_driver *drv, | |
1195 | struct device *parent) | |
4bdb3550 | 1196 | { |
ed88747c | 1197 | __device_driver_lock(dev, parent); |
4bdb3550 | 1198 | |
4bdb3550 | 1199 | if (!drv || drv == dev->driver) |
9ed98953 | 1200 | __device_release_driver(dev, parent); |
4bdb3550 | 1201 | |
ed88747c | 1202 | __device_driver_unlock(dev, parent); |
4bdb3550 RW |
1203 | } |
1204 | ||
ab71c6f0 | 1205 | /** |
4a3ad20c GKH |
1206 | * device_release_driver - manually detach device from driver. |
1207 | * @dev: device. | |
ab71c6f0 | 1208 | * |
4a3ad20c | 1209 | * Manually detach device from driver. |
8e9394ce | 1210 | * When called for a USB interface, @dev->parent lock must be held. |
9ed98953 RW |
1211 | * |
1212 | * If this function is to be called with @dev->parent lock held, ensure that | |
1213 | * the device's consumers are unbound in advance or that their locks can be | |
1214 | * acquired under the @dev->parent lock. | |
ab71c6f0 | 1215 | */ |
4a3ad20c | 1216 | void device_release_driver(struct device *dev) |
94e7b1c5 | 1217 | { |
c95a6b05 AS |
1218 | /* |
1219 | * If anyone calls device_release_driver() recursively from | |
1220 | * within their ->remove callback for the same device, they | |
1221 | * will deadlock right here. | |
1222 | */ | |
4bdb3550 | 1223 | device_release_driver_internal(dev, NULL, NULL); |
94e7b1c5 | 1224 | } |
4a3ad20c | 1225 | EXPORT_SYMBOL_GPL(device_release_driver); |
c95a6b05 | 1226 | |
ed88747c AD |
1227 | /** |
1228 | * device_driver_detach - detach driver from a specific device | |
1229 | * @dev: device to detach driver from | |
1230 | * | |
1231 | * Detach driver from device. Will acquire both @dev lock and @dev->parent | |
1232 | * lock if needed. | |
1233 | */ | |
1234 | void device_driver_detach(struct device *dev) | |
1235 | { | |
1236 | device_release_driver_internal(dev, NULL, dev->parent); | |
1237 | } | |
1238 | ||
07e4a3e2 PM |
1239 | /** |
1240 | * driver_detach - detach driver from all devices it controls. | |
1241 | * @drv: driver. | |
1242 | */ | |
4a3ad20c | 1243 | void driver_detach(struct device_driver *drv) |
07e4a3e2 | 1244 | { |
8940b4f3 | 1245 | struct device_private *dev_prv; |
4a3ad20c | 1246 | struct device *dev; |
c95a6b05 | 1247 | |
c37d721c AD |
1248 | if (driver_allows_async_probing(drv)) |
1249 | async_synchronize_full(); | |
1250 | ||
c95a6b05 | 1251 | for (;;) { |
e5dd1278 GKH |
1252 | spin_lock(&drv->p->klist_devices.k_lock); |
1253 | if (list_empty(&drv->p->klist_devices.k_list)) { | |
1254 | spin_unlock(&drv->p->klist_devices.k_lock); | |
c95a6b05 AS |
1255 | break; |
1256 | } | |
a3a87d66 | 1257 | dev_prv = list_last_entry(&drv->p->klist_devices.k_list, |
8940b4f3 GKH |
1258 | struct device_private, |
1259 | knode_driver.n_node); | |
1260 | dev = dev_prv->device; | |
c95a6b05 | 1261 | get_device(dev); |
e5dd1278 | 1262 | spin_unlock(&drv->p->klist_devices.k_lock); |
4bdb3550 | 1263 | device_release_driver_internal(dev, drv, dev->parent); |
c95a6b05 AS |
1264 | put_device(dev); |
1265 | } | |
07e4a3e2 | 1266 | } |