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19#include <linux/debugfs.h>
20#include <linux/device.h>
21#include <linux/delay.h>
22#include <linux/dma-map-ops.h>
23#include <linux/init.h>
24#include <linux/module.h>
25#include <linux/kthread.h>
26#include <linux/wait.h>
27#include <linux/async.h>
28#include <linux/pm_runtime.h>
29#include <linux/pinctrl/devinfo.h>
30#include <linux/slab.h>
31
32#include "base.h"
33#include "power/power.h"
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54static DEFINE_MUTEX(deferred_probe_mutex);
55static LIST_HEAD(deferred_probe_pending_list);
56static LIST_HEAD(deferred_probe_active_list);
57static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
58static bool initcalls_done;
59
60
61#define ASYNC_DRV_NAMES_MAX_LEN 256
62static char async_probe_drv_names[ASYNC_DRV_NAMES_MAX_LEN];
63
64
65
66
67
68
69static bool defer_all_probes;
70
71static 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
77
78
79
80static void deferred_probe_work_func(struct work_struct *work)
81{
82 struct device *dev;
83 struct device_private *private;
84
85
86
87
88
89
90
91
92
93
94
95
96 mutex_lock(&deferred_probe_mutex);
97 while (!list_empty(&deferred_probe_active_list)) {
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);
102
103 get_device(dev);
104
105 __device_set_deferred_probe_reason(dev, NULL);
106
107
108
109
110
111 mutex_unlock(&deferred_probe_mutex);
112
113
114
115
116
117
118
119 device_pm_move_to_tail(dev);
120
121 dev_dbg(dev, "Retrying from deferred list\n");
122 bus_probe_device(dev);
123 mutex_lock(&deferred_probe_mutex);
124
125 put_device(dev);
126 }
127 mutex_unlock(&deferred_probe_mutex);
128}
129static DECLARE_WORK(deferred_probe_work, deferred_probe_work_func);
130
131void driver_deferred_probe_add(struct device *dev)
132{
133 if (!dev->can_match)
134 return;
135
136 mutex_lock(&deferred_probe_mutex);
137 if (list_empty(&dev->p->deferred_probe)) {
138 dev_dbg(dev, "Added to deferred list\n");
139 list_add_tail(&dev->p->deferred_probe, &deferred_probe_pending_list);
140 }
141 mutex_unlock(&deferred_probe_mutex);
142}
143
144void driver_deferred_probe_del(struct device *dev)
145{
146 mutex_lock(&deferred_probe_mutex);
147 if (!list_empty(&dev->p->deferred_probe)) {
148 dev_dbg(dev, "Removed from deferred list\n");
149 list_del_init(&dev->p->deferred_probe);
150 __device_set_deferred_probe_reason(dev, NULL);
151 }
152 mutex_unlock(&deferred_probe_mutex);
153}
154
155static bool driver_deferred_probe_enable = false;
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174static void driver_deferred_probe_trigger(void)
175{
176 if (!driver_deferred_probe_enable)
177 return;
178
179
180
181
182
183
184 mutex_lock(&deferred_probe_mutex);
185 atomic_inc(&deferred_trigger_count);
186 list_splice_tail_init(&deferred_probe_pending_list,
187 &deferred_probe_active_list);
188 mutex_unlock(&deferred_probe_mutex);
189
190
191
192
193
194 queue_work(system_unbound_wq, &deferred_probe_work);
195}
196
197
198
199
200
201
202void device_block_probing(void)
203{
204 defer_all_probes = true;
205
206 wait_for_device_probe();
207}
208
209
210
211
212
213
214
215void device_unblock_probing(void)
216{
217 defer_all_probes = false;
218 driver_deferred_probe_trigger();
219}
220
221
222
223
224
225
226void device_set_deferred_probe_reason(const struct device *dev, struct va_format *vaf)
227{
228 const char *drv = dev_driver_string(dev);
229 char *reason;
230
231 mutex_lock(&deferred_probe_mutex);
232
233 reason = kasprintf(GFP_KERNEL, "%s: %pV", drv, vaf);
234 __device_set_deferred_probe_reason(dev, reason);
235
236 mutex_unlock(&deferred_probe_mutex);
237}
238
239
240
241
242static 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)
249 seq_printf(s, "%s\t%s", dev_name(curr->device),
250 curr->device->p->deferred_probe_reason ?: "\n");
251
252 mutex_unlock(&deferred_probe_mutex);
253
254 return 0;
255}
256DEFINE_SHOW_ATTRIBUTE(deferred_devs);
257
258int driver_deferred_probe_timeout;
259EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout);
260static DECLARE_WAIT_QUEUE_HEAD(probe_timeout_waitqueue);
261
262static int __init deferred_probe_timeout_setup(char *str)
263{
264 int timeout;
265
266 if (!kstrtoint(str, 10, &timeout))
267 driver_deferred_probe_timeout = timeout;
268 return 1;
269}
270__setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285int driver_deferred_probe_check_state(struct device *dev)
286{
287 if (!IS_ENABLED(CONFIG_MODULES) && initcalls_done) {
288 dev_warn(dev, "ignoring dependency for device, assuming no driver\n");
289 return -ENODEV;
290 }
291
292 if (!driver_deferred_probe_timeout && initcalls_done) {
293 dev_warn(dev, "deferred probe timeout, ignoring dependency\n");
294 return -ETIMEDOUT;
295 }
296
297 return -EPROBE_DEFER;
298}
299
300static void deferred_probe_timeout_work_func(struct work_struct *work)
301{
302 struct device_private *p;
303
304 fw_devlink_drivers_done();
305
306 driver_deferred_probe_timeout = 0;
307 driver_deferred_probe_trigger();
308 flush_work(&deferred_probe_work);
309
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);
314 wake_up_all(&probe_timeout_waitqueue);
315}
316static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);
317
318
319
320
321
322
323
324
325static int deferred_probe_initcall(void)
326{
327 debugfs_create_file("devices_deferred", 0444, NULL, NULL,
328 &deferred_devs_fops);
329
330 driver_deferred_probe_enable = true;
331 driver_deferred_probe_trigger();
332
333 flush_work(&deferred_probe_work);
334 initcalls_done = true;
335
336 if (!IS_ENABLED(CONFIG_MODULES))
337 fw_devlink_drivers_done();
338
339
340
341
342
343 driver_deferred_probe_trigger();
344 flush_work(&deferred_probe_work);
345
346 if (driver_deferred_probe_timeout > 0) {
347 schedule_delayed_work(&deferred_probe_timeout_work,
348 driver_deferred_probe_timeout * HZ);
349 }
350 return 0;
351}
352late_initcall(deferred_probe_initcall);
353
354static void __exit deferred_probe_exit(void)
355{
356 debugfs_remove_recursive(debugfs_lookup("devices_deferred", NULL));
357}
358__exitcall(deferred_probe_exit);
359
360
361
362
363
364
365
366
367
368
369bool device_is_bound(struct device *dev)
370{
371 return dev->p && klist_node_attached(&dev->p->knode_driver);
372}
373
374static void driver_bound(struct device *dev)
375{
376 if (device_is_bound(dev)) {
377 pr_warn("%s: device %s already bound\n",
378 __func__, kobject_name(&dev->kobj));
379 return;
380 }
381
382 pr_debug("driver: '%s': %s: bound to device '%s'\n", dev->driver->name,
383 __func__, dev_name(dev));
384
385 klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
386 device_links_driver_bound(dev);
387
388 device_pm_check_callbacks(dev);
389
390
391
392
393
394 driver_deferred_probe_del(dev);
395 driver_deferred_probe_trigger();
396
397 if (dev->bus)
398 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
399 BUS_NOTIFY_BOUND_DRIVER, dev);
400
401 kobject_uevent(&dev->kobj, KOBJ_BIND);
402}
403
404static ssize_t coredump_store(struct device *dev, struct device_attribute *attr,
405 const char *buf, size_t count)
406{
407 device_lock(dev);
408 dev->driver->coredump(dev);
409 device_unlock(dev);
410
411 return count;
412}
413static DEVICE_ATTR_WO(coredump);
414
415static int driver_sysfs_add(struct device *dev)
416{
417 int ret;
418
419 if (dev->bus)
420 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
421 BUS_NOTIFY_BIND_DRIVER, dev);
422
423 ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj,
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
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)
438 return 0;
439
440 sysfs_remove_link(&dev->kobj, "driver");
441
442rm_dev:
443 sysfs_remove_link(&dev->driver->p->kobj,
444 kobject_name(&dev->kobj));
445
446fail:
447 return ret;
448}
449
450static void driver_sysfs_remove(struct device *dev)
451{
452 struct device_driver *drv = dev->driver;
453
454 if (drv) {
455 if (drv->coredump)
456 device_remove_file(dev, &dev_attr_coredump);
457 sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj));
458 sysfs_remove_link(&dev->kobj, "driver");
459 }
460}
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477int device_bind_driver(struct device *dev)
478{
479 int ret;
480
481 ret = driver_sysfs_add(dev);
482 if (!ret) {
483 device_links_force_bind(dev);
484 driver_bound(dev);
485 }
486 else if (dev->bus)
487 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
488 BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
489 return ret;
490}
491EXPORT_SYMBOL_GPL(device_bind_driver);
492
493static atomic_t probe_count = ATOMIC_INIT(0);
494static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
495
496static ssize_t state_synced_show(struct device *dev,
497 struct device_attribute *attr, char *buf)
498{
499 bool val;
500
501 device_lock(dev);
502 val = dev->state_synced;
503 device_unlock(dev);
504
505 return sysfs_emit(buf, "%u\n", val);
506}
507static DEVICE_ATTR_RO(state_synced);
508
509
510static int call_driver_probe(struct device *dev, struct device_driver *drv)
511{
512 int ret = 0;
513
514 if (dev->bus->probe)
515 ret = dev->bus->probe(dev);
516 else if (drv->probe)
517 ret = drv->probe(dev);
518
519 switch (ret) {
520 case 0:
521 break;
522 case -EPROBE_DEFER:
523
524 dev_dbg(dev, "Driver %s requests probe deferral\n", drv->name);
525 break;
526 case -ENODEV:
527 case -ENXIO:
528 pr_debug("%s: probe of %s rejects match %d\n",
529 drv->name, dev_name(dev), ret);
530 break;
531 default:
532
533 pr_warn("%s: probe of %s failed with error %d\n",
534 drv->name, dev_name(dev), ret);
535 break;
536 }
537
538 return ret;
539}
540
541static int really_probe(struct device *dev, struct device_driver *drv)
542{
543 bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
544 !drv->suppress_bind_attrs;
545 int ret;
546
547 if (defer_all_probes) {
548
549
550
551
552
553 dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
554 return -EPROBE_DEFER;
555 }
556
557 ret = device_links_check_suppliers(dev);
558 if (ret)
559 return ret;
560
561 pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
562 drv->bus->name, __func__, drv->name, dev_name(dev));
563 if (!list_empty(&dev->devres_head)) {
564 dev_crit(dev, "Resources present before probing\n");
565 ret = -EBUSY;
566 goto done;
567 }
568
569re_probe:
570 dev->driver = drv;
571
572
573 ret = pinctrl_bind_pins(dev);
574 if (ret)
575 goto pinctrl_bind_failed;
576
577 if (dev->bus->dma_configure) {
578 ret = dev->bus->dma_configure(dev);
579 if (ret)
580 goto probe_failed;
581 }
582
583 ret = driver_sysfs_add(dev);
584 if (ret) {
585 pr_err("%s: driver_sysfs_add(%s) failed\n",
586 __func__, dev_name(dev));
587 goto probe_failed;
588 }
589
590 if (dev->pm_domain && dev->pm_domain->activate) {
591 ret = dev->pm_domain->activate(dev);
592 if (ret)
593 goto probe_failed;
594 }
595
596 ret = call_driver_probe(dev, drv);
597 if (ret) {
598
599
600
601
602 ret = -ret;
603 goto probe_failed;
604 }
605
606 ret = device_add_groups(dev, drv->dev_groups);
607 if (ret) {
608 dev_err(dev, "device_add_groups() failed\n");
609 goto dev_groups_failed;
610 }
611
612 if (dev_has_sync_state(dev)) {
613 ret = device_create_file(dev, &dev_attr_state_synced);
614 if (ret) {
615 dev_err(dev, "state_synced sysfs add failed\n");
616 goto dev_sysfs_state_synced_failed;
617 }
618 }
619
620 if (test_remove) {
621 test_remove = false;
622
623 device_remove_file(dev, &dev_attr_state_synced);
624 device_remove_groups(dev, drv->dev_groups);
625
626 if (dev->bus->remove)
627 dev->bus->remove(dev);
628 else if (drv->remove)
629 drv->remove(dev);
630
631 devres_release_all(dev);
632 driver_sysfs_remove(dev);
633 dev->driver = NULL;
634 dev_set_drvdata(dev, NULL);
635 if (dev->pm_domain && dev->pm_domain->dismiss)
636 dev->pm_domain->dismiss(dev);
637 pm_runtime_reinit(dev);
638
639 goto re_probe;
640 }
641
642 pinctrl_init_done(dev);
643
644 if (dev->pm_domain && dev->pm_domain->sync)
645 dev->pm_domain->sync(dev);
646
647 driver_bound(dev);
648 pr_debug("bus: '%s': %s: bound device %s to driver %s\n",
649 drv->bus->name, __func__, dev_name(dev), drv->name);
650 goto done;
651
652dev_sysfs_state_synced_failed:
653 device_remove_groups(dev, drv->dev_groups);
654dev_groups_failed:
655 if (dev->bus->remove)
656 dev->bus->remove(dev);
657 else if (drv->remove)
658 drv->remove(dev);
659probe_failed:
660 if (dev->bus)
661 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
662 BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
663pinctrl_bind_failed:
664 device_links_no_driver(dev);
665 devres_release_all(dev);
666 arch_teardown_dma_ops(dev);
667 kfree(dev->dma_range_map);
668 dev->dma_range_map = NULL;
669 driver_sysfs_remove(dev);
670 dev->driver = NULL;
671 dev_set_drvdata(dev, NULL);
672 if (dev->pm_domain && dev->pm_domain->dismiss)
673 dev->pm_domain->dismiss(dev);
674 pm_runtime_reinit(dev);
675 dev_pm_set_driver_flags(dev, 0);
676done:
677 return ret;
678}
679
680
681
682
683static int really_probe_debug(struct device *dev, struct device_driver *drv)
684{
685 ktime_t calltime, rettime;
686 int ret;
687
688 calltime = ktime_get();
689 ret = really_probe(dev, drv);
690 rettime = ktime_get();
691 pr_debug("probe of %s returned %d after %lld usecs\n",
692 dev_name(dev), ret, ktime_us_delta(rettime, calltime));
693 return ret;
694}
695
696
697
698
699
700
701
702int driver_probe_done(void)
703{
704 int local_probe_count = atomic_read(&probe_count);
705
706 pr_debug("%s: probe_count = %d\n", __func__, local_probe_count);
707 if (local_probe_count)
708 return -EBUSY;
709 return 0;
710}
711
712
713
714
715
716void wait_for_device_probe(void)
717{
718
719 wait_event(probe_timeout_waitqueue, !driver_deferred_probe_timeout);
720
721
722 flush_work(&deferred_probe_work);
723
724
725 wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
726 async_synchronize_full();
727}
728EXPORT_SYMBOL_GPL(wait_for_device_probe);
729
730static int __driver_probe_device(struct device_driver *drv, struct device *dev)
731{
732 int ret = 0;
733
734 if (dev->p->dead || !device_is_registered(dev))
735 return -ENODEV;
736 if (dev->driver)
737 return -EBUSY;
738
739 dev->can_match = true;
740 pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
741 drv->bus->name, __func__, dev_name(dev), drv->name);
742
743 pm_runtime_get_suppliers(dev);
744 if (dev->parent)
745 pm_runtime_get_sync(dev->parent);
746
747 pm_runtime_barrier(dev);
748 if (initcall_debug)
749 ret = really_probe_debug(dev, drv);
750 else
751 ret = really_probe(dev, drv);
752 pm_request_idle(dev);
753
754 if (dev->parent)
755 pm_runtime_put(dev->parent);
756
757 pm_runtime_put_suppliers(dev);
758 return ret;
759}
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775static int driver_probe_device(struct device_driver *drv, struct device *dev)
776{
777 int trigger_count = atomic_read(&deferred_trigger_count);
778 int ret;
779
780 atomic_inc(&probe_count);
781 ret = __driver_probe_device(drv, dev);
782 if (ret == -EPROBE_DEFER || ret == EPROBE_DEFER) {
783 driver_deferred_probe_add(dev);
784
785
786
787
788 if (trigger_count != atomic_read(&deferred_trigger_count) &&
789 !defer_all_probes)
790 driver_deferred_probe_trigger();
791 }
792 atomic_dec(&probe_count);
793 wake_up_all(&probe_waitqueue);
794 return ret;
795}
796
797static inline bool cmdline_requested_async_probing(const char *drv_name)
798{
799 return parse_option_str(async_probe_drv_names, drv_name);
800}
801
802
803static int __init save_async_options(char *buf)
804{
805 if (strlen(buf) >= ASYNC_DRV_NAMES_MAX_LEN)
806 pr_warn("Too long list of driver names for 'driver_async_probe'!\n");
807
808 strlcpy(async_probe_drv_names, buf, ASYNC_DRV_NAMES_MAX_LEN);
809 return 0;
810}
811__setup("driver_async_probe=", save_async_options);
812
813bool driver_allows_async_probing(struct device_driver *drv)
814{
815 switch (drv->probe_type) {
816 case PROBE_PREFER_ASYNCHRONOUS:
817 return true;
818
819 case PROBE_FORCE_SYNCHRONOUS:
820 return false;
821
822 default:
823 if (cmdline_requested_async_probing(drv->name))
824 return true;
825
826 if (module_requested_async_probing(drv->owner))
827 return true;
828
829 return false;
830 }
831}
832
833struct device_attach_data {
834 struct device *dev;
835
836
837
838
839
840
841
842
843 bool check_async;
844
845
846
847
848
849
850
851
852
853
854
855
856
857 bool want_async;
858
859
860
861
862
863 bool have_async;
864};
865
866static int __device_attach_driver(struct device_driver *drv, void *_data)
867{
868 struct device_attach_data *data = _data;
869 struct device *dev = data->dev;
870 bool async_allowed;
871 int ret;
872
873 ret = driver_match_device(drv, dev);
874 if (ret == 0) {
875
876 return 0;
877 } else if (ret == -EPROBE_DEFER) {
878 dev_dbg(dev, "Device match requests probe deferral\n");
879 dev->can_match = true;
880 driver_deferred_probe_add(dev);
881 } else if (ret < 0) {
882 dev_dbg(dev, "Bus failed to match device: %d\n", ret);
883 return ret;
884 }
885
886 async_allowed = driver_allows_async_probing(drv);
887
888 if (async_allowed)
889 data->have_async = true;
890
891 if (data->check_async && async_allowed != data->want_async)
892 return 0;
893
894
895
896
897
898 ret = driver_probe_device(drv, dev);
899 if (ret < 0)
900 return ret;
901 return ret == 0;
902}
903
904static void __device_attach_async_helper(void *_dev, async_cookie_t cookie)
905{
906 struct device *dev = _dev;
907 struct device_attach_data data = {
908 .dev = dev,
909 .check_async = true,
910 .want_async = true,
911 };
912
913 device_lock(dev);
914
915
916
917
918
919
920
921 if (dev->p->dead || dev->driver)
922 goto out_unlock;
923
924 if (dev->parent)
925 pm_runtime_get_sync(dev->parent);
926
927 bus_for_each_drv(dev->bus, NULL, &data, __device_attach_driver);
928 dev_dbg(dev, "async probe completed\n");
929
930 pm_request_idle(dev);
931
932 if (dev->parent)
933 pm_runtime_put(dev->parent);
934out_unlock:
935 device_unlock(dev);
936
937 put_device(dev);
938}
939
940static int __device_attach(struct device *dev, bool allow_async)
941{
942 int ret = 0;
943
944 device_lock(dev);
945 if (dev->p->dead) {
946 goto out_unlock;
947 } else if (dev->driver) {
948 if (device_is_bound(dev)) {
949 ret = 1;
950 goto out_unlock;
951 }
952 ret = device_bind_driver(dev);
953 if (ret == 0)
954 ret = 1;
955 else {
956 dev->driver = NULL;
957 ret = 0;
958 }
959 } else {
960 struct device_attach_data data = {
961 .dev = dev,
962 .check_async = allow_async,
963 .want_async = false,
964 };
965
966 if (dev->parent)
967 pm_runtime_get_sync(dev->parent);
968
969 ret = bus_for_each_drv(dev->bus, NULL, &data,
970 __device_attach_driver);
971 if (!ret && allow_async && data.have_async) {
972
973
974
975
976
977
978
979 dev_dbg(dev, "scheduling asynchronous probe\n");
980 get_device(dev);
981 async_schedule_dev(__device_attach_async_helper, dev);
982 } else {
983 pm_request_idle(dev);
984 }
985
986 if (dev->parent)
987 pm_runtime_put(dev->parent);
988 }
989out_unlock:
990 device_unlock(dev);
991 return ret;
992}
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008int device_attach(struct device *dev)
1009{
1010 return __device_attach(dev, false);
1011}
1012EXPORT_SYMBOL_GPL(device_attach);
1013
1014void device_initial_probe(struct device *dev)
1015{
1016 __device_attach(dev, true);
1017}
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028static void __device_driver_lock(struct device *dev, struct device *parent)
1029{
1030 if (parent && dev->bus->need_parent_lock)
1031 device_lock(parent);
1032 device_lock(dev);
1033}
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044static void __device_driver_unlock(struct device *dev, struct device *parent)
1045{
1046 device_unlock(dev);
1047 if (parent && dev->bus->need_parent_lock)
1048 device_unlock(parent);
1049}
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059int device_driver_attach(struct device_driver *drv, struct device *dev)
1060{
1061 int ret;
1062
1063 __device_driver_lock(dev, dev->parent);
1064 ret = __driver_probe_device(drv, dev);
1065 __device_driver_unlock(dev, dev->parent);
1066
1067
1068 if (ret > 0)
1069 ret = -ret;
1070 if (ret == -EPROBE_DEFER)
1071 return -EAGAIN;
1072 return ret;
1073}
1074EXPORT_SYMBOL_GPL(device_driver_attach);
1075
1076static void __driver_attach_async_helper(void *_dev, async_cookie_t cookie)
1077{
1078 struct device *dev = _dev;
1079 struct device_driver *drv;
1080 int ret;
1081
1082 __device_driver_lock(dev, dev->parent);
1083 drv = dev->p->async_driver;
1084 ret = driver_probe_device(drv, dev);
1085 __device_driver_unlock(dev, dev->parent);
1086
1087 dev_dbg(dev, "driver %s async attach completed: %d\n", drv->name, ret);
1088
1089 put_device(dev);
1090}
1091
1092static int __driver_attach(struct device *dev, void *data)
1093{
1094 struct device_driver *drv = data;
1095 int ret;
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107 ret = driver_match_device(drv, dev);
1108 if (ret == 0) {
1109
1110 return 0;
1111 } else if (ret == -EPROBE_DEFER) {
1112 dev_dbg(dev, "Device match requests probe deferral\n");
1113 dev->can_match = true;
1114 driver_deferred_probe_add(dev);
1115 } else if (ret < 0) {
1116 dev_dbg(dev, "Bus failed to match device: %d\n", ret);
1117 return ret;
1118 }
1119
1120 if (driver_allows_async_probing(drv)) {
1121
1122
1123
1124
1125
1126
1127
1128 dev_dbg(dev, "probing driver %s asynchronously\n", drv->name);
1129 device_lock(dev);
1130 if (!dev->driver) {
1131 get_device(dev);
1132 dev->p->async_driver = drv;
1133 async_schedule_dev(__driver_attach_async_helper, dev);
1134 }
1135 device_unlock(dev);
1136 return 0;
1137 }
1138
1139 __device_driver_lock(dev, dev->parent);
1140 driver_probe_device(drv, dev);
1141 __device_driver_unlock(dev, dev->parent);
1142
1143 return 0;
1144}
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155int driver_attach(struct device_driver *drv)
1156{
1157 return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
1158}
1159EXPORT_SYMBOL_GPL(driver_attach);
1160
1161
1162
1163
1164
1165static void __device_release_driver(struct device *dev, struct device *parent)
1166{
1167 struct device_driver *drv;
1168
1169 drv = dev->driver;
1170 if (drv) {
1171 pm_runtime_get_sync(dev);
1172
1173 while (device_links_busy(dev)) {
1174 __device_driver_unlock(dev, parent);
1175
1176 device_links_unbind_consumers(dev);
1177
1178 __device_driver_lock(dev, parent);
1179
1180
1181
1182
1183
1184 if (dev->driver != drv) {
1185 pm_runtime_put(dev);
1186 return;
1187 }
1188 }
1189
1190 driver_sysfs_remove(dev);
1191
1192 if (dev->bus)
1193 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1194 BUS_NOTIFY_UNBIND_DRIVER,
1195 dev);
1196
1197 pm_runtime_put_sync(dev);
1198
1199 device_remove_file(dev, &dev_attr_state_synced);
1200 device_remove_groups(dev, drv->dev_groups);
1201
1202 if (dev->bus && dev->bus->remove)
1203 dev->bus->remove(dev);
1204 else if (drv->remove)
1205 drv->remove(dev);
1206
1207 device_links_driver_cleanup(dev);
1208
1209 devres_release_all(dev);
1210 arch_teardown_dma_ops(dev);
1211 dev->driver = NULL;
1212 dev_set_drvdata(dev, NULL);
1213 if (dev->pm_domain && dev->pm_domain->dismiss)
1214 dev->pm_domain->dismiss(dev);
1215 pm_runtime_reinit(dev);
1216 dev_pm_set_driver_flags(dev, 0);
1217
1218 klist_remove(&dev->p->knode_driver);
1219 device_pm_check_callbacks(dev);
1220 if (dev->bus)
1221 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1222 BUS_NOTIFY_UNBOUND_DRIVER,
1223 dev);
1224
1225 kobject_uevent(&dev->kobj, KOBJ_UNBIND);
1226 }
1227}
1228
1229void device_release_driver_internal(struct device *dev,
1230 struct device_driver *drv,
1231 struct device *parent)
1232{
1233 __device_driver_lock(dev, parent);
1234
1235 if (!drv || drv == dev->driver)
1236 __device_release_driver(dev, parent);
1237
1238 __device_driver_unlock(dev, parent);
1239}
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252void device_release_driver(struct device *dev)
1253{
1254
1255
1256
1257
1258
1259 device_release_driver_internal(dev, NULL, NULL);
1260}
1261EXPORT_SYMBOL_GPL(device_release_driver);
1262
1263
1264
1265
1266
1267
1268
1269
1270void device_driver_detach(struct device *dev)
1271{
1272 device_release_driver_internal(dev, NULL, dev->parent);
1273}
1274
1275
1276
1277
1278
1279void driver_detach(struct device_driver *drv)
1280{
1281 struct device_private *dev_prv;
1282 struct device *dev;
1283
1284 if (driver_allows_async_probing(drv))
1285 async_synchronize_full();
1286
1287 for (;;) {
1288 spin_lock(&drv->p->klist_devices.k_lock);
1289 if (list_empty(&drv->p->klist_devices.k_list)) {
1290 spin_unlock(&drv->p->klist_devices.k_lock);
1291 break;
1292 }
1293 dev_prv = list_last_entry(&drv->p->klist_devices.k_list,
1294 struct device_private,
1295 knode_driver.n_node);
1296 dev = dev_prv->device;
1297 get_device(dev);
1298 spin_unlock(&drv->p->klist_devices.k_lock);
1299 device_release_driver_internal(dev, drv, dev->parent);
1300 put_device(dev);
1301 }
1302}
1303