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Commit | Line | Data |
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07e4a3e2 | 1 | /* |
4a3ad20c | 2 | * drivers/base/dd.c - The core device/driver interactions. |
07e4a3e2 | 3 | * |
4a3ad20c GKH |
4 | * This file contains the (sometimes tricky) code that controls the |
5 | * interactions between devices and drivers, which primarily includes | |
6 | * driver binding and unbinding. | |
07e4a3e2 | 7 | * |
4a3ad20c GKH |
8 | * All of this code used to exist in drivers/base/bus.c, but was |
9 | * relocated to here in the name of compartmentalization (since it wasn't | |
10 | * strictly code just for the 'struct bus_type'. | |
07e4a3e2 | 11 | * |
4a3ad20c GKH |
12 | * Copyright (c) 2002-5 Patrick Mochel |
13 | * Copyright (c) 2002-3 Open Source Development Labs | |
b4028437 GKH |
14 | * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de> |
15 | * Copyright (c) 2007-2009 Novell Inc. | |
07e4a3e2 | 16 | * |
4a3ad20c | 17 | * This file is released under the GPLv2 |
07e4a3e2 PM |
18 | */ |
19 | ||
20 | #include <linux/device.h> | |
216773a7 | 21 | #include <linux/delay.h> |
09515ef5 | 22 | #include <linux/dma-mapping.h> |
07e4a3e2 | 23 | #include <linux/module.h> |
d779249e | 24 | #include <linux/kthread.h> |
735a7ffb | 25 | #include <linux/wait.h> |
216773a7 | 26 | #include <linux/async.h> |
5e928f77 | 27 | #include <linux/pm_runtime.h> |
ab78029e | 28 | #include <linux/pinctrl/devinfo.h> |
07e4a3e2 PM |
29 | |
30 | #include "base.h" | |
31 | #include "power/power.h" | |
32 | ||
d1c3414c GL |
33 | /* |
34 | * Deferred Probe infrastructure. | |
35 | * | |
36 | * Sometimes driver probe order matters, but the kernel doesn't always have | |
37 | * dependency information which means some drivers will get probed before a | |
38 | * resource it depends on is available. For example, an SDHCI driver may | |
39 | * first need a GPIO line from an i2c GPIO controller before it can be | |
40 | * initialized. If a required resource is not available yet, a driver can | |
41 | * request probing to be deferred by returning -EPROBE_DEFER from its probe hook | |
42 | * | |
43 | * Deferred probe maintains two lists of devices, a pending list and an active | |
44 | * list. A driver returning -EPROBE_DEFER causes the device to be added to the | |
45 | * pending list. A successful driver probe will trigger moving all devices | |
46 | * from the pending to the active list so that the workqueue will eventually | |
47 | * retry them. | |
48 | * | |
49 | * The deferred_probe_mutex must be held any time the deferred_probe_*_list | |
ef8a3fd6 | 50 | * of the (struct device*)->p->deferred_probe pointers are manipulated |
d1c3414c GL |
51 | */ |
52 | static DEFINE_MUTEX(deferred_probe_mutex); | |
53 | static LIST_HEAD(deferred_probe_pending_list); | |
54 | static LIST_HEAD(deferred_probe_active_list); | |
58b116bc | 55 | static atomic_t deferred_trigger_count = ATOMIC_INIT(0); |
d1c3414c | 56 | |
013c074f SG |
57 | /* |
58 | * In some cases, like suspend to RAM or hibernation, It might be reasonable | |
59 | * to prohibit probing of devices as it could be unsafe. | |
60 | * Once defer_all_probes is true all drivers probes will be forcibly deferred. | |
61 | */ | |
62 | static bool defer_all_probes; | |
63 | ||
41575335 | 64 | /* |
d1c3414c GL |
65 | * deferred_probe_work_func() - Retry probing devices in the active list. |
66 | */ | |
67 | static void deferred_probe_work_func(struct work_struct *work) | |
68 | { | |
69 | struct device *dev; | |
ef8a3fd6 | 70 | struct device_private *private; |
d1c3414c GL |
71 | /* |
72 | * This block processes every device in the deferred 'active' list. | |
73 | * Each device is removed from the active list and passed to | |
74 | * bus_probe_device() to re-attempt the probe. The loop continues | |
75 | * until every device in the active list is removed and retried. | |
76 | * | |
77 | * Note: Once the device is removed from the list and the mutex is | |
78 | * released, it is possible for the device get freed by another thread | |
79 | * and cause a illegal pointer dereference. This code uses | |
80 | * get/put_device() to ensure the device structure cannot disappear | |
81 | * from under our feet. | |
82 | */ | |
83 | mutex_lock(&deferred_probe_mutex); | |
84 | while (!list_empty(&deferred_probe_active_list)) { | |
ef8a3fd6 GKH |
85 | private = list_first_entry(&deferred_probe_active_list, |
86 | typeof(*dev->p), deferred_probe); | |
87 | dev = private->device; | |
88 | list_del_init(&private->deferred_probe); | |
d1c3414c GL |
89 | |
90 | get_device(dev); | |
91 | ||
8b0372a2 GKH |
92 | /* |
93 | * Drop the mutex while probing each device; the probe path may | |
94 | * manipulate the deferred list | |
95 | */ | |
d1c3414c | 96 | mutex_unlock(&deferred_probe_mutex); |
8153584e MB |
97 | |
98 | /* | |
99 | * Force the device to the end of the dpm_list since | |
100 | * the PM code assumes that the order we add things to | |
101 | * the list is a good order for suspend but deferred | |
102 | * probe makes that very unsafe. | |
103 | */ | |
104 | device_pm_lock(); | |
105 | device_pm_move_last(dev); | |
106 | device_pm_unlock(); | |
107 | ||
d1c3414c GL |
108 | dev_dbg(dev, "Retrying from deferred list\n"); |
109 | bus_probe_device(dev); | |
8153584e | 110 | |
d1c3414c GL |
111 | mutex_lock(&deferred_probe_mutex); |
112 | ||
113 | put_device(dev); | |
114 | } | |
115 | mutex_unlock(&deferred_probe_mutex); | |
116 | } | |
117 | static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func); | |
118 | ||
119 | static void driver_deferred_probe_add(struct device *dev) | |
120 | { | |
121 | mutex_lock(&deferred_probe_mutex); | |
ef8a3fd6 | 122 | if (list_empty(&dev->p->deferred_probe)) { |
d1c3414c | 123 | dev_dbg(dev, "Added to deferred list\n"); |
1d29cfa5 | 124 | list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list); |
d1c3414c GL |
125 | } |
126 | mutex_unlock(&deferred_probe_mutex); | |
127 | } | |
128 | ||
129 | void driver_deferred_probe_del(struct device *dev) | |
130 | { | |
131 | mutex_lock(&deferred_probe_mutex); | |
ef8a3fd6 | 132 | if (!list_empty(&dev->p->deferred_probe)) { |
d1c3414c | 133 | dev_dbg(dev, "Removed from deferred list\n"); |
ef8a3fd6 | 134 | list_del_init(&dev->p->deferred_probe); |
d1c3414c GL |
135 | } |
136 | mutex_unlock(&deferred_probe_mutex); | |
137 | } | |
138 | ||
139 | static bool driver_deferred_probe_enable = false; | |
140 | /** | |
141 | * driver_deferred_probe_trigger() - Kick off re-probing deferred devices | |
142 | * | |
143 | * This functions moves all devices from the pending list to the active | |
144 | * list and schedules the deferred probe workqueue to process them. It | |
145 | * should be called anytime a driver is successfully bound to a device. | |
58b116bc GL |
146 | * |
147 | * Note, there is a race condition in multi-threaded probe. In the case where | |
148 | * more than one device is probing at the same time, it is possible for one | |
149 | * probe to complete successfully while another is about to defer. If the second | |
150 | * depends on the first, then it will get put on the pending list after the | |
9ba8af66 | 151 | * trigger event has already occurred and will be stuck there. |
58b116bc GL |
152 | * |
153 | * The atomic 'deferred_trigger_count' is used to determine if a successful | |
154 | * trigger has occurred in the midst of probing a driver. If the trigger count | |
155 | * changes in the midst of a probe, then deferred processing should be triggered | |
156 | * again. | |
d1c3414c GL |
157 | */ |
158 | static void driver_deferred_probe_trigger(void) | |
159 | { | |
160 | if (!driver_deferred_probe_enable) | |
161 | return; | |
162 | ||
8b0372a2 GKH |
163 | /* |
164 | * A successful probe means that all the devices in the pending list | |
d1c3414c | 165 | * should be triggered to be reprobed. Move all the deferred devices |
8b0372a2 GKH |
166 | * into the active list so they can be retried by the workqueue |
167 | */ | |
d1c3414c | 168 | mutex_lock(&deferred_probe_mutex); |
58b116bc | 169 | atomic_inc(&deferred_trigger_count); |
d1c3414c GL |
170 | list_splice_tail_init(&deferred_probe_pending_list, |
171 | &deferred_probe_active_list); | |
172 | mutex_unlock(&deferred_probe_mutex); | |
173 | ||
8b0372a2 GKH |
174 | /* |
175 | * Kick the re-probe thread. It may already be scheduled, but it is | |
176 | * safe to kick it again. | |
177 | */ | |
2c507e46 | 178 | schedule_work(&deferred_probe_work); |
d1c3414c GL |
179 | } |
180 | ||
013c074f SG |
181 | /** |
182 | * device_block_probing() - Block/defere device's probes | |
183 | * | |
184 | * It will disable probing of devices and defer their probes instead. | |
185 | */ | |
186 | void device_block_probing(void) | |
187 | { | |
188 | defer_all_probes = true; | |
189 | /* sync with probes to avoid races. */ | |
190 | wait_for_device_probe(); | |
191 | } | |
192 | ||
193 | /** | |
194 | * device_unblock_probing() - Unblock/enable device's probes | |
195 | * | |
196 | * It will restore normal behavior and trigger re-probing of deferred | |
197 | * devices. | |
198 | */ | |
199 | void device_unblock_probing(void) | |
200 | { | |
201 | defer_all_probes = false; | |
202 | driver_deferred_probe_trigger(); | |
203 | } | |
204 | ||
d1c3414c GL |
205 | /** |
206 | * deferred_probe_initcall() - Enable probing of deferred devices | |
207 | * | |
208 | * We don't want to get in the way when the bulk of drivers are getting probed. | |
209 | * Instead, this initcall makes sure that deferred probing is delayed until | |
210 | * late_initcall time. | |
211 | */ | |
212 | static int deferred_probe_initcall(void) | |
213 | { | |
d1c3414c GL |
214 | driver_deferred_probe_enable = true; |
215 | driver_deferred_probe_trigger(); | |
d72cca1e | 216 | /* Sort as many dependencies as possible before exiting initcalls */ |
2c507e46 | 217 | flush_work(&deferred_probe_work); |
d1c3414c GL |
218 | return 0; |
219 | } | |
220 | late_initcall(deferred_probe_initcall); | |
07e4a3e2 | 221 | |
6b9cb427 TV |
222 | /** |
223 | * device_is_bound() - Check if device is bound to a driver | |
224 | * @dev: device to check | |
225 | * | |
226 | * Returns true if passed device has already finished probing successfully | |
227 | * against a driver. | |
228 | * | |
229 | * This function must be called with the device lock held. | |
230 | */ | |
231 | bool device_is_bound(struct device *dev) | |
232 | { | |
3ded9104 | 233 | return dev->p && klist_node_attached(&dev->p->knode_driver); |
6b9cb427 TV |
234 | } |
235 | ||
1901fb26 | 236 | static void driver_bound(struct device *dev) |
07e4a3e2 | 237 | { |
6b9cb427 | 238 | if (device_is_bound(dev)) { |
f86db396 | 239 | printk(KERN_WARNING "%s: device %s already bound\n", |
2b3a302a | 240 | __func__, kobject_name(&dev->kobj)); |
1901fb26 | 241 | return; |
f86db396 | 242 | } |
4c898c7f | 243 | |
94f8cc0e FR |
244 | pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name, |
245 | __func__, dev_name(dev)); | |
116af378 | 246 | |
fbb88fad | 247 | klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices); |
9ed98953 | 248 | device_links_driver_bound(dev); |
fbb88fad | 249 | |
aa8e54b5 TV |
250 | device_pm_check_callbacks(dev); |
251 | ||
8b0372a2 GKH |
252 | /* |
253 | * Make sure the device is no longer in one of the deferred lists and | |
254 | * kick off retrying all pending devices | |
255 | */ | |
d1c3414c GL |
256 | driver_deferred_probe_del(dev); |
257 | driver_deferred_probe_trigger(); | |
258 | ||
116af378 | 259 | if (dev->bus) |
c6f7e72a | 260 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 | 261 | BUS_NOTIFY_BOUND_DRIVER, dev); |
1901fb26 KS |
262 | } |
263 | ||
264 | static int driver_sysfs_add(struct device *dev) | |
265 | { | |
266 | int ret; | |
267 | ||
45daef0f MD |
268 | if (dev->bus) |
269 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
270 | BUS_NOTIFY_BIND_DRIVER, dev); | |
271 | ||
e5dd1278 | 272 | ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj, |
07e4a3e2 | 273 | kobject_name(&dev->kobj)); |
f86db396 | 274 | if (ret == 0) { |
e5dd1278 | 275 | ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj, |
f86db396 AM |
276 | "driver"); |
277 | if (ret) | |
e5dd1278 | 278 | sysfs_remove_link(&dev->driver->p->kobj, |
f86db396 AM |
279 | kobject_name(&dev->kobj)); |
280 | } | |
281 | return ret; | |
07e4a3e2 PM |
282 | } |
283 | ||
1901fb26 KS |
284 | static void driver_sysfs_remove(struct device *dev) |
285 | { | |
286 | struct device_driver *drv = dev->driver; | |
287 | ||
288 | if (drv) { | |
e5dd1278 | 289 | sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); |
1901fb26 KS |
290 | sysfs_remove_link(&dev->kobj, "driver"); |
291 | } | |
292 | } | |
293 | ||
294 | /** | |
4a3ad20c GKH |
295 | * device_bind_driver - bind a driver to one device. |
296 | * @dev: device. | |
1901fb26 | 297 | * |
4a3ad20c GKH |
298 | * Allow manual attachment of a driver to a device. |
299 | * Caller must have already set @dev->driver. | |
1901fb26 | 300 | * |
4a3ad20c GKH |
301 | * Note that this does not modify the bus reference count |
302 | * nor take the bus's rwsem. Please verify those are accounted | |
303 | * for before calling this. (It is ok to call with no other effort | |
304 | * from a driver's probe() method.) | |
1901fb26 | 305 | * |
8e9394ce | 306 | * This function must be called with the device lock held. |
1901fb26 KS |
307 | */ |
308 | int device_bind_driver(struct device *dev) | |
309 | { | |
cb986b74 CH |
310 | int ret; |
311 | ||
312 | ret = driver_sysfs_add(dev); | |
313 | if (!ret) | |
314 | driver_bound(dev); | |
14b6257a AS |
315 | else if (dev->bus) |
316 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
317 | BUS_NOTIFY_DRIVER_NOT_BOUND, dev); | |
cb986b74 | 318 | return ret; |
1901fb26 | 319 | } |
4a3ad20c | 320 | EXPORT_SYMBOL_GPL(device_bind_driver); |
1901fb26 | 321 | |
d779249e | 322 | static atomic_t probe_count = ATOMIC_INIT(0); |
735a7ffb AM |
323 | static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); |
324 | ||
21c7f30b | 325 | static int really_probe(struct device *dev, struct device_driver *drv) |
07e4a3e2 | 326 | { |
013c074f | 327 | int ret = -EPROBE_DEFER; |
58b116bc | 328 | int local_trigger_count = atomic_read(&deferred_trigger_count); |
c5f06274 RH |
329 | bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) && |
330 | !drv->suppress_bind_attrs; | |
07e4a3e2 | 331 | |
013c074f SG |
332 | if (defer_all_probes) { |
333 | /* | |
334 | * Value of defer_all_probes can be set only by | |
335 | * device_defer_all_probes_enable() which, in turn, will call | |
336 | * wait_for_device_probe() right after that to avoid any races. | |
337 | */ | |
338 | dev_dbg(dev, "Driver %s force probe deferral\n", drv->name); | |
339 | driver_deferred_probe_add(dev); | |
340 | return ret; | |
341 | } | |
342 | ||
9ed98953 RW |
343 | ret = device_links_check_suppliers(dev); |
344 | if (ret) | |
345 | return ret; | |
346 | ||
d779249e | 347 | atomic_inc(&probe_count); |
7dc72b28 | 348 | pr_debug("bus: '%s': %s: probing driver %s with device %s\n", |
1e0b2cf9 | 349 | drv->bus->name, __func__, drv->name, dev_name(dev)); |
9ac7849e | 350 | WARN_ON(!list_empty(&dev->devres_head)); |
07e4a3e2 | 351 | |
bea5b158 | 352 | re_probe: |
07e4a3e2 | 353 | dev->driver = drv; |
ab78029e LW |
354 | |
355 | /* If using pinctrl, bind pins now before probing */ | |
356 | ret = pinctrl_bind_pins(dev); | |
357 | if (ret) | |
14b6257a | 358 | goto pinctrl_bind_failed; |
ab78029e | 359 | |
09515ef5 S |
360 | ret = dma_configure(dev); |
361 | if (ret) | |
362 | goto dma_failed; | |
363 | ||
1901fb26 KS |
364 | if (driver_sysfs_add(dev)) { |
365 | printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n", | |
1e0b2cf9 | 366 | __func__, dev_name(dev)); |
1901fb26 KS |
367 | goto probe_failed; |
368 | } | |
369 | ||
e90d5532 RW |
370 | if (dev->pm_domain && dev->pm_domain->activate) { |
371 | ret = dev->pm_domain->activate(dev); | |
372 | if (ret) | |
373 | goto probe_failed; | |
374 | } | |
375 | ||
52cdbdd4 GS |
376 | /* |
377 | * Ensure devices are listed in devices_kset in correct order | |
378 | * It's important to move Dev to the end of devices_kset before | |
379 | * calling .probe, because it could be recursive and parent Dev | |
380 | * should always go first | |
381 | */ | |
382 | devices_kset_move_last(dev); | |
383 | ||
594c8281 RK |
384 | if (dev->bus->probe) { |
385 | ret = dev->bus->probe(dev); | |
1901fb26 | 386 | if (ret) |
d779249e | 387 | goto probe_failed; |
594c8281 | 388 | } else if (drv->probe) { |
0d3e5a2e | 389 | ret = drv->probe(dev); |
1901fb26 | 390 | if (ret) |
d779249e | 391 | goto probe_failed; |
f86db396 | 392 | } |
1901fb26 | 393 | |
bea5b158 RH |
394 | if (test_remove) { |
395 | test_remove = false; | |
396 | ||
bdacd1b4 | 397 | if (dev->bus->remove) |
bea5b158 RH |
398 | dev->bus->remove(dev); |
399 | else if (drv->remove) | |
400 | drv->remove(dev); | |
401 | ||
402 | devres_release_all(dev); | |
403 | driver_sysfs_remove(dev); | |
404 | dev->driver = NULL; | |
405 | dev_set_drvdata(dev, NULL); | |
406 | if (dev->pm_domain && dev->pm_domain->dismiss) | |
407 | dev->pm_domain->dismiss(dev); | |
408 | pm_runtime_reinit(dev); | |
409 | ||
410 | goto re_probe; | |
411 | } | |
412 | ||
ef0eebc0 DA |
413 | pinctrl_init_done(dev); |
414 | ||
e90d5532 RW |
415 | if (dev->pm_domain && dev->pm_domain->sync) |
416 | dev->pm_domain->sync(dev); | |
417 | ||
1901fb26 | 418 | driver_bound(dev); |
0d3e5a2e | 419 | ret = 1; |
7dc72b28 | 420 | pr_debug("bus: '%s': %s: bound device %s to driver %s\n", |
1e0b2cf9 | 421 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 422 | goto done; |
0d3e5a2e | 423 | |
d779249e | 424 | probe_failed: |
09515ef5 S |
425 | dma_deconfigure(dev); |
426 | dma_failed: | |
14b6257a AS |
427 | if (dev->bus) |
428 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
429 | BUS_NOTIFY_DRIVER_NOT_BOUND, dev); | |
430 | pinctrl_bind_failed: | |
9ed98953 | 431 | device_links_no_driver(dev); |
9ac7849e | 432 | devres_release_all(dev); |
1901fb26 KS |
433 | driver_sysfs_remove(dev); |
434 | dev->driver = NULL; | |
0998d063 | 435 | dev_set_drvdata(dev, NULL); |
e90d5532 RW |
436 | if (dev->pm_domain && dev->pm_domain->dismiss) |
437 | dev->pm_domain->dismiss(dev); | |
5de85b9d | 438 | pm_runtime_reinit(dev); |
1901fb26 | 439 | |
bb2b4075 SS |
440 | switch (ret) { |
441 | case -EPROBE_DEFER: | |
d1c3414c | 442 | /* Driver requested deferred probing */ |
13fcffbb | 443 | dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name); |
d1c3414c | 444 | driver_deferred_probe_add(dev); |
58b116bc GL |
445 | /* Did a trigger occur while probing? Need to re-trigger if yes */ |
446 | if (local_trigger_count != atomic_read(&deferred_trigger_count)) | |
447 | driver_deferred_probe_trigger(); | |
bb2b4075 SS |
448 | break; |
449 | case -ENODEV: | |
450 | case -ENXIO: | |
451 | pr_debug("%s: probe of %s rejects match %d\n", | |
452 | drv->name, dev_name(dev), ret); | |
453 | break; | |
454 | default: | |
0d3e5a2e PM |
455 | /* driver matched but the probe failed */ |
456 | printk(KERN_WARNING | |
457 | "%s: probe of %s failed with error %d\n", | |
1e0b2cf9 | 458 | drv->name, dev_name(dev), ret); |
0d3e5a2e | 459 | } |
c578abbc CH |
460 | /* |
461 | * Ignore errors returned by ->probe so that the next driver can try | |
462 | * its luck. | |
463 | */ | |
464 | ret = 0; | |
d779249e | 465 | done: |
d779249e | 466 | atomic_dec(&probe_count); |
735a7ffb | 467 | wake_up(&probe_waitqueue); |
d779249e GKH |
468 | return ret; |
469 | } | |
470 | ||
471 | /** | |
472 | * driver_probe_done | |
473 | * Determine if the probe sequence is finished or not. | |
474 | * | |
475 | * Should somehow figure out how to use a semaphore, not an atomic variable... | |
476 | */ | |
477 | int driver_probe_done(void) | |
478 | { | |
2b3a302a | 479 | pr_debug("%s: probe_count = %d\n", __func__, |
d779249e GKH |
480 | atomic_read(&probe_count)); |
481 | if (atomic_read(&probe_count)) | |
482 | return -EBUSY; | |
483 | return 0; | |
484 | } | |
485 | ||
216773a7 AV |
486 | /** |
487 | * wait_for_device_probe | |
488 | * Wait for device probing to be completed. | |
216773a7 | 489 | */ |
b23530eb | 490 | void wait_for_device_probe(void) |
216773a7 | 491 | { |
013c074f | 492 | /* wait for the deferred probe workqueue to finish */ |
2c507e46 | 493 | flush_work(&deferred_probe_work); |
013c074f | 494 | |
216773a7 | 495 | /* wait for the known devices to complete their probing */ |
b23530eb | 496 | wait_event(probe_waitqueue, atomic_read(&probe_count) == 0); |
216773a7 | 497 | async_synchronize_full(); |
216773a7 | 498 | } |
d4d5291c | 499 | EXPORT_SYMBOL_GPL(wait_for_device_probe); |
216773a7 | 500 | |
d779249e GKH |
501 | /** |
502 | * driver_probe_device - attempt to bind device & driver together | |
503 | * @drv: driver to bind a device to | |
504 | * @dev: device to try to bind to the driver | |
505 | * | |
49b420a1 | 506 | * This function returns -ENODEV if the device is not registered, |
af901ca1 | 507 | * 1 if the device is bound successfully and 0 otherwise. |
d779249e | 508 | * |
8e9394ce GKH |
509 | * This function must be called with @dev lock held. When called for a |
510 | * USB interface, @dev->parent lock must be held as well. | |
ddef08dd RW |
511 | * |
512 | * If the device has a parent, runtime-resume the parent before driver probing. | |
d779249e | 513 | */ |
4a3ad20c | 514 | int driver_probe_device(struct device_driver *drv, struct device *dev) |
d779249e | 515 | { |
d779249e GKH |
516 | int ret = 0; |
517 | ||
f2eaae19 AS |
518 | if (!device_is_registered(dev)) |
519 | return -ENODEV; | |
d779249e | 520 | |
7dc72b28 | 521 | pr_debug("bus: '%s': %s: matched device %s with driver %s\n", |
1e0b2cf9 | 522 | drv->bus->name, __func__, dev_name(dev), drv->name); |
d779249e | 523 | |
21d5c57b | 524 | pm_runtime_get_suppliers(dev); |
ddef08dd RW |
525 | if (dev->parent) |
526 | pm_runtime_get_sync(dev->parent); | |
527 | ||
5e928f77 | 528 | pm_runtime_barrier(dev); |
21c7f30b | 529 | ret = really_probe(dev, drv); |
fa180eb4 | 530 | pm_request_idle(dev); |
d779249e | 531 | |
ddef08dd RW |
532 | if (dev->parent) |
533 | pm_runtime_put(dev->parent); | |
534 | ||
21d5c57b | 535 | pm_runtime_put_suppliers(dev); |
0d3e5a2e | 536 | return ret; |
07e4a3e2 PM |
537 | } |
538 | ||
765230b5 | 539 | bool driver_allows_async_probing(struct device_driver *drv) |
2287c322 | 540 | { |
d173a137 LR |
541 | switch (drv->probe_type) { |
542 | case PROBE_PREFER_ASYNCHRONOUS: | |
f2411da7 LR |
543 | return true; |
544 | ||
d173a137 LR |
545 | case PROBE_FORCE_SYNCHRONOUS: |
546 | return false; | |
547 | ||
548 | default: | |
80c6e146 | 549 | if (module_requested_async_probing(drv->owner)) |
d173a137 | 550 | return true; |
f2411da7 | 551 | |
d173a137 LR |
552 | return false; |
553 | } | |
765230b5 DT |
554 | } |
555 | ||
556 | struct device_attach_data { | |
557 | struct device *dev; | |
558 | ||
559 | /* | |
560 | * Indicates whether we are are considering asynchronous probing or | |
561 | * not. Only initial binding after device or driver registration | |
562 | * (including deferral processing) may be done asynchronously, the | |
563 | * rest is always synchronous, as we expect it is being done by | |
564 | * request from userspace. | |
565 | */ | |
566 | bool check_async; | |
567 | ||
568 | /* | |
569 | * Indicates if we are binding synchronous or asynchronous drivers. | |
570 | * When asynchronous probing is enabled we'll execute 2 passes | |
571 | * over drivers: first pass doing synchronous probing and second | |
572 | * doing asynchronous probing (if synchronous did not succeed - | |
573 | * most likely because there was no driver requiring synchronous | |
574 | * probing - and we found asynchronous driver during first pass). | |
575 | * The 2 passes are done because we can't shoot asynchronous | |
576 | * probe for given device and driver from bus_for_each_drv() since | |
577 | * driver pointer is not guaranteed to stay valid once | |
578 | * bus_for_each_drv() iterates to the next driver on the bus. | |
579 | */ | |
580 | bool want_async; | |
581 | ||
582 | /* | |
583 | * We'll set have_async to 'true' if, while scanning for matching | |
584 | * driver, we'll encounter one that requests asynchronous probing. | |
585 | */ | |
586 | bool have_async; | |
587 | }; | |
588 | ||
589 | static int __device_attach_driver(struct device_driver *drv, void *_data) | |
590 | { | |
591 | struct device_attach_data *data = _data; | |
592 | struct device *dev = data->dev; | |
593 | bool async_allowed; | |
656b8035 | 594 | int ret; |
765230b5 DT |
595 | |
596 | /* | |
597 | * Check if device has already been claimed. This may | |
598 | * happen with driver loading, device discovery/registration, | |
599 | * and deferred probe processing happens all at once with | |
600 | * multiple threads. | |
601 | */ | |
602 | if (dev->driver) | |
603 | return -EBUSY; | |
49b420a1 | 604 | |
656b8035 TV |
605 | ret = driver_match_device(drv, dev); |
606 | if (ret == 0) { | |
607 | /* no match */ | |
49b420a1 | 608 | return 0; |
656b8035 TV |
609 | } else if (ret == -EPROBE_DEFER) { |
610 | dev_dbg(dev, "Device match requests probe deferral\n"); | |
611 | driver_deferred_probe_add(dev); | |
612 | } else if (ret < 0) { | |
613 | dev_dbg(dev, "Bus failed to match device: %d", ret); | |
614 | return ret; | |
615 | } /* ret > 0 means positive match */ | |
49b420a1 | 616 | |
765230b5 DT |
617 | async_allowed = driver_allows_async_probing(drv); |
618 | ||
619 | if (async_allowed) | |
620 | data->have_async = true; | |
621 | ||
622 | if (data->check_async && async_allowed != data->want_async) | |
623 | return 0; | |
624 | ||
0d3e5a2e | 625 | return driver_probe_device(drv, dev); |
2287c322 PM |
626 | } |
627 | ||
765230b5 DT |
628 | static void __device_attach_async_helper(void *_dev, async_cookie_t cookie) |
629 | { | |
630 | struct device *dev = _dev; | |
631 | struct device_attach_data data = { | |
632 | .dev = dev, | |
633 | .check_async = true, | |
634 | .want_async = true, | |
635 | }; | |
636 | ||
637 | device_lock(dev); | |
638 | ||
ddef08dd RW |
639 | if (dev->parent) |
640 | pm_runtime_get_sync(dev->parent); | |
641 | ||
765230b5 DT |
642 | bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver); |
643 | dev_dbg(dev, "async probe completed\n"); | |
644 | ||
645 | pm_request_idle(dev); | |
646 | ||
ddef08dd RW |
647 | if (dev->parent) |
648 | pm_runtime_put(dev->parent); | |
649 | ||
765230b5 DT |
650 | device_unlock(dev); |
651 | ||
652 | put_device(dev); | |
653 | } | |
654 | ||
802a87fd | 655 | static int __device_attach(struct device *dev, bool allow_async) |
07e4a3e2 | 656 | { |
0d3e5a2e PM |
657 | int ret = 0; |
658 | ||
8e9394ce | 659 | device_lock(dev); |
07e4a3e2 | 660 | if (dev->driver) { |
6b9cb427 | 661 | if (device_is_bound(dev)) { |
8497d6a2 SO |
662 | ret = 1; |
663 | goto out_unlock; | |
664 | } | |
f86db396 AM |
665 | ret = device_bind_driver(dev); |
666 | if (ret == 0) | |
667 | ret = 1; | |
c6a46696 CH |
668 | else { |
669 | dev->driver = NULL; | |
670 | ret = 0; | |
671 | } | |
21c7f30b | 672 | } else { |
765230b5 DT |
673 | struct device_attach_data data = { |
674 | .dev = dev, | |
675 | .check_async = allow_async, | |
676 | .want_async = false, | |
677 | }; | |
678 | ||
ddef08dd RW |
679 | if (dev->parent) |
680 | pm_runtime_get_sync(dev->parent); | |
681 | ||
765230b5 DT |
682 | ret = bus_for_each_drv(dev->bus, NULL, &data, |
683 | __device_attach_driver); | |
684 | if (!ret && allow_async && data.have_async) { | |
685 | /* | |
686 | * If we could not find appropriate driver | |
687 | * synchronously and we are allowed to do | |
688 | * async probes and there are drivers that | |
689 | * want to probe asynchronously, we'll | |
690 | * try them. | |
691 | */ | |
692 | dev_dbg(dev, "scheduling asynchronous probe\n"); | |
693 | get_device(dev); | |
694 | async_schedule(__device_attach_async_helper, dev); | |
695 | } else { | |
696 | pm_request_idle(dev); | |
697 | } | |
ddef08dd RW |
698 | |
699 | if (dev->parent) | |
700 | pm_runtime_put(dev->parent); | |
21c7f30b | 701 | } |
8497d6a2 | 702 | out_unlock: |
8e9394ce | 703 | device_unlock(dev); |
0d3e5a2e | 704 | return ret; |
2287c322 | 705 | } |
765230b5 DT |
706 | |
707 | /** | |
708 | * device_attach - try to attach device to a driver. | |
709 | * @dev: device. | |
710 | * | |
711 | * Walk the list of drivers that the bus has and call | |
712 | * driver_probe_device() for each pair. If a compatible | |
713 | * pair is found, break out and return. | |
714 | * | |
715 | * Returns 1 if the device was bound to a driver; | |
716 | * 0 if no matching driver was found; | |
717 | * -ENODEV if the device is not registered. | |
718 | * | |
719 | * When called for a USB interface, @dev->parent lock must be held. | |
720 | */ | |
721 | int device_attach(struct device *dev) | |
722 | { | |
723 | return __device_attach(dev, false); | |
724 | } | |
4a3ad20c | 725 | EXPORT_SYMBOL_GPL(device_attach); |
2287c322 | 726 | |
765230b5 DT |
727 | void device_initial_probe(struct device *dev) |
728 | { | |
729 | __device_attach(dev, true); | |
730 | } | |
731 | ||
4a3ad20c | 732 | static int __driver_attach(struct device *dev, void *data) |
2287c322 | 733 | { |
4a3ad20c | 734 | struct device_driver *drv = data; |
656b8035 | 735 | int ret; |
0d3e5a2e PM |
736 | |
737 | /* | |
738 | * Lock device and try to bind to it. We drop the error | |
739 | * here and always return 0, because we need to keep trying | |
740 | * to bind to devices and some drivers will return an error | |
741 | * simply if it didn't support the device. | |
742 | * | |
743 | * driver_probe_device() will spit a warning if there | |
744 | * is an error. | |
745 | */ | |
746 | ||
656b8035 TV |
747 | ret = driver_match_device(drv, dev); |
748 | if (ret == 0) { | |
749 | /* no match */ | |
6cd49586 | 750 | return 0; |
656b8035 TV |
751 | } else if (ret == -EPROBE_DEFER) { |
752 | dev_dbg(dev, "Device match requests probe deferral\n"); | |
753 | driver_deferred_probe_add(dev); | |
754 | } else if (ret < 0) { | |
755 | dev_dbg(dev, "Bus failed to match device: %d", ret); | |
756 | return ret; | |
757 | } /* ret > 0 means positive match */ | |
6cd49586 | 758 | |
bf74ad5b | 759 | if (dev->parent) /* Needed for USB */ |
8e9394ce GKH |
760 | device_lock(dev->parent); |
761 | device_lock(dev); | |
0d3e5a2e PM |
762 | if (!dev->driver) |
763 | driver_probe_device(drv, dev); | |
8e9394ce | 764 | device_unlock(dev); |
bf74ad5b | 765 | if (dev->parent) |
8e9394ce | 766 | device_unlock(dev->parent); |
0d3e5a2e | 767 | |
07e4a3e2 PM |
768 | return 0; |
769 | } | |
770 | ||
771 | /** | |
4a3ad20c GKH |
772 | * driver_attach - try to bind driver to devices. |
773 | * @drv: driver. | |
07e4a3e2 | 774 | * |
4a3ad20c GKH |
775 | * Walk the list of devices that the bus has on it and try to |
776 | * match the driver with each one. If driver_probe_device() | |
777 | * returns 0 and the @dev->driver is set, we've found a | |
778 | * compatible pair. | |
07e4a3e2 | 779 | */ |
4a3ad20c | 780 | int driver_attach(struct device_driver *drv) |
07e4a3e2 | 781 | { |
f86db396 | 782 | return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach); |
07e4a3e2 | 783 | } |
4a3ad20c | 784 | EXPORT_SYMBOL_GPL(driver_attach); |
07e4a3e2 | 785 | |
ab71c6f0 | 786 | /* |
8e9394ce GKH |
787 | * __device_release_driver() must be called with @dev lock held. |
788 | * When called for a USB interface, @dev->parent lock must be held as well. | |
07e4a3e2 | 789 | */ |
9ed98953 | 790 | static void __device_release_driver(struct device *dev, struct device *parent) |
07e4a3e2 | 791 | { |
4a3ad20c | 792 | struct device_driver *drv; |
07e4a3e2 | 793 | |
ef2c5174 | 794 | drv = dev->driver; |
c95a6b05 | 795 | if (drv) { |
765230b5 DT |
796 | if (driver_allows_async_probing(drv)) |
797 | async_synchronize_full(); | |
798 | ||
9ed98953 RW |
799 | while (device_links_busy(dev)) { |
800 | device_unlock(dev); | |
801 | if (parent) | |
802 | device_unlock(parent); | |
803 | ||
804 | device_links_unbind_consumers(dev); | |
805 | if (parent) | |
806 | device_lock(parent); | |
807 | ||
808 | device_lock(dev); | |
809 | /* | |
810 | * A concurrent invocation of the same function might | |
811 | * have released the driver successfully while this one | |
812 | * was waiting, so check for that. | |
813 | */ | |
814 | if (dev->driver != drv) | |
815 | return; | |
816 | } | |
817 | ||
e1866b33 | 818 | pm_runtime_get_sync(dev); |
21d5c57b | 819 | pm_runtime_clean_up_links(dev); |
5e928f77 | 820 | |
1901fb26 | 821 | driver_sysfs_remove(dev); |
0d3e5a2e | 822 | |
116af378 | 823 | if (dev->bus) |
c6f7e72a | 824 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
116af378 BH |
825 | BUS_NOTIFY_UNBIND_DRIVER, |
826 | dev); | |
827 | ||
baab52de | 828 | pm_runtime_put_sync(dev); |
e1866b33 | 829 | |
0f836ca4 | 830 | if (dev->bus && dev->bus->remove) |
594c8281 RK |
831 | dev->bus->remove(dev); |
832 | else if (drv->remove) | |
0d3e5a2e | 833 | drv->remove(dev); |
9ed98953 RW |
834 | |
835 | device_links_driver_cleanup(dev); | |
09515ef5 S |
836 | dma_deconfigure(dev); |
837 | ||
9ac7849e | 838 | devres_release_all(dev); |
0d3e5a2e | 839 | dev->driver = NULL; |
0998d063 | 840 | dev_set_drvdata(dev, NULL); |
e90d5532 RW |
841 | if (dev->pm_domain && dev->pm_domain->dismiss) |
842 | dev->pm_domain->dismiss(dev); | |
5de85b9d | 843 | pm_runtime_reinit(dev); |
e90d5532 | 844 | |
8940b4f3 | 845 | klist_remove(&dev->p->knode_driver); |
aa8e54b5 | 846 | device_pm_check_callbacks(dev); |
309b7d60 JR |
847 | if (dev->bus) |
848 | blocking_notifier_call_chain(&dev->bus->p->bus_notifier, | |
849 | BUS_NOTIFY_UNBOUND_DRIVER, | |
850 | dev); | |
0d3e5a2e | 851 | } |
07e4a3e2 PM |
852 | } |
853 | ||
9ed98953 RW |
854 | void device_release_driver_internal(struct device *dev, |
855 | struct device_driver *drv, | |
856 | struct device *parent) | |
4bdb3550 RW |
857 | { |
858 | if (parent) | |
859 | device_lock(parent); | |
860 | ||
861 | device_lock(dev); | |
862 | if (!drv || drv == dev->driver) | |
9ed98953 | 863 | __device_release_driver(dev, parent); |
4bdb3550 RW |
864 | |
865 | device_unlock(dev); | |
866 | if (parent) | |
867 | device_unlock(parent); | |
868 | } | |
869 | ||
ab71c6f0 | 870 | /** |
4a3ad20c GKH |
871 | * device_release_driver - manually detach device from driver. |
872 | * @dev: device. | |
ab71c6f0 | 873 | * |
4a3ad20c | 874 | * Manually detach device from driver. |
8e9394ce | 875 | * When called for a USB interface, @dev->parent lock must be held. |
9ed98953 RW |
876 | * |
877 | * If this function is to be called with @dev->parent lock held, ensure that | |
878 | * the device's consumers are unbound in advance or that their locks can be | |
879 | * acquired under the @dev->parent lock. | |
ab71c6f0 | 880 | */ |
4a3ad20c | 881 | void device_release_driver(struct device *dev) |
94e7b1c5 | 882 | { |
c95a6b05 AS |
883 | /* |
884 | * If anyone calls device_release_driver() recursively from | |
885 | * within their ->remove callback for the same device, they | |
886 | * will deadlock right here. | |
887 | */ | |
4bdb3550 | 888 | device_release_driver_internal(dev, NULL, NULL); |
94e7b1c5 | 889 | } |
4a3ad20c | 890 | EXPORT_SYMBOL_GPL(device_release_driver); |
c95a6b05 | 891 | |
07e4a3e2 PM |
892 | /** |
893 | * driver_detach - detach driver from all devices it controls. | |
894 | * @drv: driver. | |
895 | */ | |
4a3ad20c | 896 | void driver_detach(struct device_driver *drv) |
07e4a3e2 | 897 | { |
8940b4f3 | 898 | struct device_private *dev_prv; |
4a3ad20c | 899 | struct device *dev; |
c95a6b05 AS |
900 | |
901 | for (;;) { | |
e5dd1278 GKH |
902 | spin_lock(&drv->p->klist_devices.k_lock); |
903 | if (list_empty(&drv->p->klist_devices.k_list)) { | |
904 | spin_unlock(&drv->p->klist_devices.k_lock); | |
c95a6b05 AS |
905 | break; |
906 | } | |
8940b4f3 GKH |
907 | dev_prv = list_entry(drv->p->klist_devices.k_list.prev, |
908 | struct device_private, | |
909 | knode_driver.n_node); | |
910 | dev = dev_prv->device; | |
c95a6b05 | 911 | get_device(dev); |
e5dd1278 | 912 | spin_unlock(&drv->p->klist_devices.k_lock); |
4bdb3550 | 913 | device_release_driver_internal(dev, drv, dev->parent); |
c95a6b05 AS |
914 | put_device(dev); |
915 | } | |
07e4a3e2 | 916 | } |