GNU Linux-libre 6.7.9-gnu
[releases.git] / drivers / acpi / scan.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * scan.c - support for transforming the ACPI namespace into individual objects
4  */
5
6 #define pr_fmt(fmt) "ACPI: " fmt
7
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/slab.h>
11 #include <linux/kernel.h>
12 #include <linux/acpi.h>
13 #include <linux/acpi_iort.h>
14 #include <linux/acpi_viot.h>
15 #include <linux/iommu.h>
16 #include <linux/signal.h>
17 #include <linux/kthread.h>
18 #include <linux/dmi.h>
19 #include <linux/dma-map-ops.h>
20 #include <linux/platform_data/x86/apple.h>
21 #include <linux/pgtable.h>
22 #include <linux/crc32.h>
23 #include <linux/dma-direct.h>
24
25 #include "internal.h"
26 #include "sleep.h"
27
28 #define ACPI_BUS_CLASS                  "system_bus"
29 #define ACPI_BUS_HID                    "LNXSYBUS"
30 #define ACPI_BUS_DEVICE_NAME            "System Bus"
31
32 #define INVALID_ACPI_HANDLE     ((acpi_handle)ZERO_PAGE(0))
33
34 static const char *dummy_hid = "device";
35
36 static LIST_HEAD(acpi_dep_list);
37 static DEFINE_MUTEX(acpi_dep_list_lock);
38 LIST_HEAD(acpi_bus_id_list);
39 static DEFINE_MUTEX(acpi_scan_lock);
40 static LIST_HEAD(acpi_scan_handlers_list);
41 DEFINE_MUTEX(acpi_device_lock);
42 LIST_HEAD(acpi_wakeup_device_list);
43 static DEFINE_MUTEX(acpi_hp_context_lock);
44
45 /*
46  * The UART device described by the SPCR table is the only object which needs
47  * special-casing. Everything else is covered by ACPI namespace paths in STAO
48  * table.
49  */
50 static u64 spcr_uart_addr;
51
52 void acpi_scan_lock_acquire(void)
53 {
54         mutex_lock(&acpi_scan_lock);
55 }
56 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
57
58 void acpi_scan_lock_release(void)
59 {
60         mutex_unlock(&acpi_scan_lock);
61 }
62 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
63
64 void acpi_lock_hp_context(void)
65 {
66         mutex_lock(&acpi_hp_context_lock);
67 }
68
69 void acpi_unlock_hp_context(void)
70 {
71         mutex_unlock(&acpi_hp_context_lock);
72 }
73
74 void acpi_initialize_hp_context(struct acpi_device *adev,
75                                 struct acpi_hotplug_context *hp,
76                                 int (*notify)(struct acpi_device *, u32),
77                                 void (*uevent)(struct acpi_device *, u32))
78 {
79         acpi_lock_hp_context();
80         hp->notify = notify;
81         hp->uevent = uevent;
82         acpi_set_hp_context(adev, hp);
83         acpi_unlock_hp_context();
84 }
85 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
86
87 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
88 {
89         if (!handler)
90                 return -EINVAL;
91
92         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
93         return 0;
94 }
95
96 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
97                                        const char *hotplug_profile_name)
98 {
99         int error;
100
101         error = acpi_scan_add_handler(handler);
102         if (error)
103                 return error;
104
105         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
106         return 0;
107 }
108
109 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
110 {
111         struct acpi_device_physical_node *pn;
112         bool offline = true;
113         char *envp[] = { "EVENT=offline", NULL };
114
115         /*
116          * acpi_container_offline() calls this for all of the container's
117          * children under the container's physical_node_lock lock.
118          */
119         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
120
121         list_for_each_entry(pn, &adev->physical_node_list, node)
122                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
123                         if (uevent)
124                                 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
125
126                         offline = false;
127                         break;
128                 }
129
130         mutex_unlock(&adev->physical_node_lock);
131         return offline;
132 }
133
134 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
135                                     void **ret_p)
136 {
137         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
138         struct acpi_device_physical_node *pn;
139         bool second_pass = (bool)data;
140         acpi_status status = AE_OK;
141
142         if (!device)
143                 return AE_OK;
144
145         if (device->handler && !device->handler->hotplug.enabled) {
146                 *ret_p = &device->dev;
147                 return AE_SUPPORT;
148         }
149
150         mutex_lock(&device->physical_node_lock);
151
152         list_for_each_entry(pn, &device->physical_node_list, node) {
153                 int ret;
154
155                 if (second_pass) {
156                         /* Skip devices offlined by the first pass. */
157                         if (pn->put_online)
158                                 continue;
159                 } else {
160                         pn->put_online = false;
161                 }
162                 ret = device_offline(pn->dev);
163                 if (ret >= 0) {
164                         pn->put_online = !ret;
165                 } else {
166                         *ret_p = pn->dev;
167                         if (second_pass) {
168                                 status = AE_ERROR;
169                                 break;
170                         }
171                 }
172         }
173
174         mutex_unlock(&device->physical_node_lock);
175
176         return status;
177 }
178
179 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
180                                    void **ret_p)
181 {
182         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
183         struct acpi_device_physical_node *pn;
184
185         if (!device)
186                 return AE_OK;
187
188         mutex_lock(&device->physical_node_lock);
189
190         list_for_each_entry(pn, &device->physical_node_list, node)
191                 if (pn->put_online) {
192                         device_online(pn->dev);
193                         pn->put_online = false;
194                 }
195
196         mutex_unlock(&device->physical_node_lock);
197
198         return AE_OK;
199 }
200
201 static int acpi_scan_try_to_offline(struct acpi_device *device)
202 {
203         acpi_handle handle = device->handle;
204         struct device *errdev = NULL;
205         acpi_status status;
206
207         /*
208          * Carry out two passes here and ignore errors in the first pass,
209          * because if the devices in question are memory blocks and
210          * CONFIG_MEMCG is set, one of the blocks may hold data structures
211          * that the other blocks depend on, but it is not known in advance which
212          * block holds them.
213          *
214          * If the first pass is successful, the second one isn't needed, though.
215          */
216         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
217                                      NULL, acpi_bus_offline, (void *)false,
218                                      (void **)&errdev);
219         if (status == AE_SUPPORT) {
220                 dev_warn(errdev, "Offline disabled.\n");
221                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
222                                     acpi_bus_online, NULL, NULL, NULL);
223                 return -EPERM;
224         }
225         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
226         if (errdev) {
227                 errdev = NULL;
228                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
229                                     NULL, acpi_bus_offline, (void *)true,
230                                     (void **)&errdev);
231                 if (!errdev)
232                         acpi_bus_offline(handle, 0, (void *)true,
233                                          (void **)&errdev);
234
235                 if (errdev) {
236                         dev_warn(errdev, "Offline failed.\n");
237                         acpi_bus_online(handle, 0, NULL, NULL);
238                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
239                                             ACPI_UINT32_MAX, acpi_bus_online,
240                                             NULL, NULL, NULL);
241                         return -EBUSY;
242                 }
243         }
244         return 0;
245 }
246
247 static int acpi_scan_hot_remove(struct acpi_device *device)
248 {
249         acpi_handle handle = device->handle;
250         unsigned long long sta;
251         acpi_status status;
252
253         if (device->handler && device->handler->hotplug.demand_offline) {
254                 if (!acpi_scan_is_offline(device, true))
255                         return -EBUSY;
256         } else {
257                 int error = acpi_scan_try_to_offline(device);
258                 if (error)
259                         return error;
260         }
261
262         acpi_handle_debug(handle, "Ejecting\n");
263
264         acpi_bus_trim(device);
265
266         acpi_evaluate_lck(handle, 0);
267         /*
268          * TBD: _EJD support.
269          */
270         status = acpi_evaluate_ej0(handle);
271         if (status == AE_NOT_FOUND)
272                 return -ENODEV;
273         else if (ACPI_FAILURE(status))
274                 return -EIO;
275
276         /*
277          * Verify if eject was indeed successful.  If not, log an error
278          * message.  No need to call _OST since _EJ0 call was made OK.
279          */
280         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
281         if (ACPI_FAILURE(status)) {
282                 acpi_handle_warn(handle,
283                         "Status check after eject failed (0x%x)\n", status);
284         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
285                 acpi_handle_warn(handle,
286                         "Eject incomplete - status 0x%llx\n", sta);
287         }
288
289         return 0;
290 }
291
292 static int acpi_scan_device_not_enumerated(struct acpi_device *adev)
293 {
294         if (!acpi_device_enumerated(adev)) {
295                 dev_warn(&adev->dev, "Still not enumerated\n");
296                 return -EALREADY;
297         }
298         acpi_bus_trim(adev);
299         return 0;
300 }
301
302 static int acpi_scan_device_check(struct acpi_device *adev)
303 {
304         int error;
305
306         acpi_bus_get_status(adev);
307         if (acpi_device_is_present(adev)) {
308                 /*
309                  * This function is only called for device objects for which
310                  * matching scan handlers exist.  The only situation in which
311                  * the scan handler is not attached to this device object yet
312                  * is when the device has just appeared (either it wasn't
313                  * present at all before or it was removed and then added
314                  * again).
315                  */
316                 if (adev->handler) {
317                         dev_warn(&adev->dev, "Already enumerated\n");
318                         return -EALREADY;
319                 }
320                 error = acpi_bus_scan(adev->handle);
321                 if (error) {
322                         dev_warn(&adev->dev, "Namespace scan failure\n");
323                         return error;
324                 }
325                 if (!adev->handler) {
326                         dev_warn(&adev->dev, "Enumeration failure\n");
327                         error = -ENODEV;
328                 }
329         } else {
330                 error = acpi_scan_device_not_enumerated(adev);
331         }
332         return error;
333 }
334
335 static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used)
336 {
337         struct acpi_scan_handler *handler = adev->handler;
338         int error;
339
340         acpi_bus_get_status(adev);
341         if (!acpi_device_is_present(adev)) {
342                 acpi_scan_device_not_enumerated(adev);
343                 return 0;
344         }
345         if (handler && handler->hotplug.scan_dependent)
346                 return handler->hotplug.scan_dependent(adev);
347
348         error = acpi_bus_scan(adev->handle);
349         if (error) {
350                 dev_warn(&adev->dev, "Namespace scan failure\n");
351                 return error;
352         }
353         return acpi_dev_for_each_child(adev, acpi_scan_bus_check, NULL);
354 }
355
356 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
357 {
358         switch (type) {
359         case ACPI_NOTIFY_BUS_CHECK:
360                 return acpi_scan_bus_check(adev, NULL);
361         case ACPI_NOTIFY_DEVICE_CHECK:
362                 return acpi_scan_device_check(adev);
363         case ACPI_NOTIFY_EJECT_REQUEST:
364         case ACPI_OST_EC_OSPM_EJECT:
365                 if (adev->handler && !adev->handler->hotplug.enabled) {
366                         dev_info(&adev->dev, "Eject disabled\n");
367                         return -EPERM;
368                 }
369                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
370                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
371                 return acpi_scan_hot_remove(adev);
372         }
373         return -EINVAL;
374 }
375
376 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
377 {
378         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
379         int error = -ENODEV;
380
381         lock_device_hotplug();
382         mutex_lock(&acpi_scan_lock);
383
384         /*
385          * The device object's ACPI handle cannot become invalid as long as we
386          * are holding acpi_scan_lock, but it might have become invalid before
387          * that lock was acquired.
388          */
389         if (adev->handle == INVALID_ACPI_HANDLE)
390                 goto err_out;
391
392         if (adev->flags.is_dock_station) {
393                 error = dock_notify(adev, src);
394         } else if (adev->flags.hotplug_notify) {
395                 error = acpi_generic_hotplug_event(adev, src);
396         } else {
397                 int (*notify)(struct acpi_device *, u32);
398
399                 acpi_lock_hp_context();
400                 notify = adev->hp ? adev->hp->notify : NULL;
401                 acpi_unlock_hp_context();
402                 /*
403                  * There may be additional notify handlers for device objects
404                  * without the .event() callback, so ignore them here.
405                  */
406                 if (notify)
407                         error = notify(adev, src);
408                 else
409                         goto out;
410         }
411         switch (error) {
412         case 0:
413                 ost_code = ACPI_OST_SC_SUCCESS;
414                 break;
415         case -EPERM:
416                 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
417                 break;
418         case -EBUSY:
419                 ost_code = ACPI_OST_SC_DEVICE_BUSY;
420                 break;
421         default:
422                 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
423                 break;
424         }
425
426  err_out:
427         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
428
429  out:
430         acpi_put_acpi_dev(adev);
431         mutex_unlock(&acpi_scan_lock);
432         unlock_device_hotplug();
433 }
434
435 static void acpi_free_power_resources_lists(struct acpi_device *device)
436 {
437         int i;
438
439         if (device->wakeup.flags.valid)
440                 acpi_power_resources_list_free(&device->wakeup.resources);
441
442         if (!device->power.flags.power_resources)
443                 return;
444
445         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
446                 struct acpi_device_power_state *ps = &device->power.states[i];
447                 acpi_power_resources_list_free(&ps->resources);
448         }
449 }
450
451 static void acpi_device_release(struct device *dev)
452 {
453         struct acpi_device *acpi_dev = to_acpi_device(dev);
454
455         acpi_free_properties(acpi_dev);
456         acpi_free_pnp_ids(&acpi_dev->pnp);
457         acpi_free_power_resources_lists(acpi_dev);
458         kfree(acpi_dev);
459 }
460
461 static void acpi_device_del(struct acpi_device *device)
462 {
463         struct acpi_device_bus_id *acpi_device_bus_id;
464
465         mutex_lock(&acpi_device_lock);
466
467         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
468                 if (!strcmp(acpi_device_bus_id->bus_id,
469                             acpi_device_hid(device))) {
470                         ida_free(&acpi_device_bus_id->instance_ida,
471                                  device->pnp.instance_no);
472                         if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
473                                 list_del(&acpi_device_bus_id->node);
474                                 kfree_const(acpi_device_bus_id->bus_id);
475                                 kfree(acpi_device_bus_id);
476                         }
477                         break;
478                 }
479
480         list_del(&device->wakeup_list);
481
482         mutex_unlock(&acpi_device_lock);
483
484         acpi_power_add_remove_device(device, false);
485         acpi_device_remove_files(device);
486         if (device->remove)
487                 device->remove(device);
488
489         device_del(&device->dev);
490 }
491
492 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
493
494 static LIST_HEAD(acpi_device_del_list);
495 static DEFINE_MUTEX(acpi_device_del_lock);
496
497 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
498 {
499         for (;;) {
500                 struct acpi_device *adev;
501
502                 mutex_lock(&acpi_device_del_lock);
503
504                 if (list_empty(&acpi_device_del_list)) {
505                         mutex_unlock(&acpi_device_del_lock);
506                         break;
507                 }
508                 adev = list_first_entry(&acpi_device_del_list,
509                                         struct acpi_device, del_list);
510                 list_del(&adev->del_list);
511
512                 mutex_unlock(&acpi_device_del_lock);
513
514                 blocking_notifier_call_chain(&acpi_reconfig_chain,
515                                              ACPI_RECONFIG_DEVICE_REMOVE, adev);
516
517                 acpi_device_del(adev);
518                 /*
519                  * Drop references to all power resources that might have been
520                  * used by the device.
521                  */
522                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
523                 acpi_dev_put(adev);
524         }
525 }
526
527 /**
528  * acpi_scan_drop_device - Drop an ACPI device object.
529  * @handle: Handle of an ACPI namespace node, not used.
530  * @context: Address of the ACPI device object to drop.
531  *
532  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
533  * namespace node the device object pointed to by @context is attached to.
534  *
535  * The unregistration is carried out asynchronously to avoid running
536  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
537  * ensure the correct ordering (the device objects must be unregistered in the
538  * same order in which the corresponding namespace nodes are deleted).
539  */
540 static void acpi_scan_drop_device(acpi_handle handle, void *context)
541 {
542         static DECLARE_WORK(work, acpi_device_del_work_fn);
543         struct acpi_device *adev = context;
544
545         mutex_lock(&acpi_device_del_lock);
546
547         /*
548          * Use the ACPI hotplug workqueue which is ordered, so this work item
549          * won't run after any hotplug work items submitted subsequently.  That
550          * prevents attempts to register device objects identical to those being
551          * deleted from happening concurrently (such attempts result from
552          * hotplug events handled via the ACPI hotplug workqueue).  It also will
553          * run after all of the work items submitted previously, which helps
554          * those work items to ensure that they are not accessing stale device
555          * objects.
556          */
557         if (list_empty(&acpi_device_del_list))
558                 acpi_queue_hotplug_work(&work);
559
560         list_add_tail(&adev->del_list, &acpi_device_del_list);
561         /* Make acpi_ns_validate_handle() return NULL for this handle. */
562         adev->handle = INVALID_ACPI_HANDLE;
563
564         mutex_unlock(&acpi_device_del_lock);
565 }
566
567 static struct acpi_device *handle_to_device(acpi_handle handle,
568                                             void (*callback)(void *))
569 {
570         struct acpi_device *adev = NULL;
571         acpi_status status;
572
573         status = acpi_get_data_full(handle, acpi_scan_drop_device,
574                                     (void **)&adev, callback);
575         if (ACPI_FAILURE(status) || !adev) {
576                 acpi_handle_debug(handle, "No context!\n");
577                 return NULL;
578         }
579         return adev;
580 }
581
582 /**
583  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
584  * @handle: ACPI handle associated with the requested ACPI device object.
585  *
586  * Return a pointer to the ACPI device object associated with @handle, if
587  * present, or NULL otherwise.
588  */
589 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
590 {
591         return handle_to_device(handle, NULL);
592 }
593 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
594
595 static void get_acpi_device(void *dev)
596 {
597         acpi_dev_get(dev);
598 }
599
600 /**
601  * acpi_get_acpi_dev - Retrieve ACPI device object and reference count it.
602  * @handle: ACPI handle associated with the requested ACPI device object.
603  *
604  * Return a pointer to the ACPI device object associated with @handle and bump
605  * up that object's reference counter (under the ACPI Namespace lock), if
606  * present, or return NULL otherwise.
607  *
608  * The ACPI device object reference acquired by this function needs to be
609  * dropped via acpi_dev_put().
610  */
611 struct acpi_device *acpi_get_acpi_dev(acpi_handle handle)
612 {
613         return handle_to_device(handle, get_acpi_device);
614 }
615 EXPORT_SYMBOL_GPL(acpi_get_acpi_dev);
616
617 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
618 {
619         struct acpi_device_bus_id *acpi_device_bus_id;
620
621         /* Find suitable bus_id and instance number in acpi_bus_id_list. */
622         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
623                 if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
624                         return acpi_device_bus_id;
625         }
626         return NULL;
627 }
628
629 static int acpi_device_set_name(struct acpi_device *device,
630                                 struct acpi_device_bus_id *acpi_device_bus_id)
631 {
632         struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
633         int result;
634
635         result = ida_alloc(instance_ida, GFP_KERNEL);
636         if (result < 0)
637                 return result;
638
639         device->pnp.instance_no = result;
640         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
641         return 0;
642 }
643
644 int acpi_tie_acpi_dev(struct acpi_device *adev)
645 {
646         acpi_handle handle = adev->handle;
647         acpi_status status;
648
649         if (!handle)
650                 return 0;
651
652         status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
653         if (ACPI_FAILURE(status)) {
654                 acpi_handle_err(handle, "Unable to attach device data\n");
655                 return -ENODEV;
656         }
657
658         return 0;
659 }
660
661 static void acpi_store_pld_crc(struct acpi_device *adev)
662 {
663         struct acpi_pld_info *pld;
664         acpi_status status;
665
666         status = acpi_get_physical_device_location(adev->handle, &pld);
667         if (ACPI_FAILURE(status))
668                 return;
669
670         adev->pld_crc = crc32(~0, pld, sizeof(*pld));
671         ACPI_FREE(pld);
672 }
673
674 int acpi_device_add(struct acpi_device *device)
675 {
676         struct acpi_device_bus_id *acpi_device_bus_id;
677         int result;
678
679         /*
680          * Linkage
681          * -------
682          * Link this device to its parent and siblings.
683          */
684         INIT_LIST_HEAD(&device->wakeup_list);
685         INIT_LIST_HEAD(&device->physical_node_list);
686         INIT_LIST_HEAD(&device->del_list);
687         mutex_init(&device->physical_node_lock);
688
689         mutex_lock(&acpi_device_lock);
690
691         acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
692         if (acpi_device_bus_id) {
693                 result = acpi_device_set_name(device, acpi_device_bus_id);
694                 if (result)
695                         goto err_unlock;
696         } else {
697                 acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
698                                              GFP_KERNEL);
699                 if (!acpi_device_bus_id) {
700                         result = -ENOMEM;
701                         goto err_unlock;
702                 }
703                 acpi_device_bus_id->bus_id =
704                         kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
705                 if (!acpi_device_bus_id->bus_id) {
706                         kfree(acpi_device_bus_id);
707                         result = -ENOMEM;
708                         goto err_unlock;
709                 }
710
711                 ida_init(&acpi_device_bus_id->instance_ida);
712
713                 result = acpi_device_set_name(device, acpi_device_bus_id);
714                 if (result) {
715                         kfree_const(acpi_device_bus_id->bus_id);
716                         kfree(acpi_device_bus_id);
717                         goto err_unlock;
718                 }
719
720                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
721         }
722
723         if (device->wakeup.flags.valid)
724                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
725
726         acpi_store_pld_crc(device);
727
728         mutex_unlock(&acpi_device_lock);
729
730         result = device_add(&device->dev);
731         if (result) {
732                 dev_err(&device->dev, "Error registering device\n");
733                 goto err;
734         }
735
736         result = acpi_device_setup_files(device);
737         if (result)
738                 pr_err("Error creating sysfs interface for device %s\n",
739                        dev_name(&device->dev));
740
741         return 0;
742
743 err:
744         mutex_lock(&acpi_device_lock);
745
746         list_del(&device->wakeup_list);
747
748 err_unlock:
749         mutex_unlock(&acpi_device_lock);
750
751         acpi_detach_data(device->handle, acpi_scan_drop_device);
752
753         return result;
754 }
755
756 /* --------------------------------------------------------------------------
757                                  Device Enumeration
758    -------------------------------------------------------------------------- */
759 static bool acpi_info_matches_ids(struct acpi_device_info *info,
760                                   const char * const ids[])
761 {
762         struct acpi_pnp_device_id_list *cid_list = NULL;
763         int i, index;
764
765         if (!(info->valid & ACPI_VALID_HID))
766                 return false;
767
768         index = match_string(ids, -1, info->hardware_id.string);
769         if (index >= 0)
770                 return true;
771
772         if (info->valid & ACPI_VALID_CID)
773                 cid_list = &info->compatible_id_list;
774
775         if (!cid_list)
776                 return false;
777
778         for (i = 0; i < cid_list->count; i++) {
779                 index = match_string(ids, -1, cid_list->ids[i].string);
780                 if (index >= 0)
781                         return true;
782         }
783
784         return false;
785 }
786
787 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
788 static const char * const acpi_ignore_dep_ids[] = {
789         "PNP0D80", /* Windows-compatible System Power Management Controller */
790         "INT33BD", /* Intel Baytrail Mailbox Device */
791         "LATT2021", /* Lattice FW Update Client Driver */
792         NULL
793 };
794
795 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
796 static const char * const acpi_honor_dep_ids[] = {
797         "INT3472", /* Camera sensor PMIC / clk and regulator info */
798         "INTC1059", /* IVSC (TGL) driver must be loaded to allow i2c access to camera sensors */
799         "INTC1095", /* IVSC (ADL) driver must be loaded to allow i2c access to camera sensors */
800         "INTC100A", /* IVSC (RPL) driver must be loaded to allow i2c access to camera sensors */
801         NULL
802 };
803
804 static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
805 {
806         struct acpi_device *adev;
807
808         /*
809          * Fixed hardware devices do not appear in the namespace and do not
810          * have handles, but we fabricate acpi_devices for them, so we have
811          * to deal with them specially.
812          */
813         if (!handle)
814                 return acpi_root;
815
816         do {
817                 acpi_status status;
818
819                 status = acpi_get_parent(handle, &handle);
820                 if (ACPI_FAILURE(status)) {
821                         if (status != AE_NULL_ENTRY)
822                                 return acpi_root;
823
824                         return NULL;
825                 }
826                 adev = acpi_fetch_acpi_dev(handle);
827         } while (!adev);
828         return adev;
829 }
830
831 acpi_status
832 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
833 {
834         acpi_status status;
835         acpi_handle tmp;
836         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
837         union acpi_object *obj;
838
839         status = acpi_get_handle(handle, "_EJD", &tmp);
840         if (ACPI_FAILURE(status))
841                 return status;
842
843         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
844         if (ACPI_SUCCESS(status)) {
845                 obj = buffer.pointer;
846                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
847                                          ejd);
848                 kfree(buffer.pointer);
849         }
850         return status;
851 }
852 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
853
854 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
855 {
856         acpi_handle handle = dev->handle;
857         struct acpi_device_wakeup *wakeup = &dev->wakeup;
858         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
859         union acpi_object *package = NULL;
860         union acpi_object *element = NULL;
861         acpi_status status;
862         int err = -ENODATA;
863
864         INIT_LIST_HEAD(&wakeup->resources);
865
866         /* _PRW */
867         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
868         if (ACPI_FAILURE(status)) {
869                 acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
870                                  acpi_format_exception(status));
871                 return err;
872         }
873
874         package = (union acpi_object *)buffer.pointer;
875
876         if (!package || package->package.count < 2)
877                 goto out;
878
879         element = &(package->package.elements[0]);
880         if (!element)
881                 goto out;
882
883         if (element->type == ACPI_TYPE_PACKAGE) {
884                 if ((element->package.count < 2) ||
885                     (element->package.elements[0].type !=
886                      ACPI_TYPE_LOCAL_REFERENCE)
887                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
888                         goto out;
889
890                 wakeup->gpe_device =
891                     element->package.elements[0].reference.handle;
892                 wakeup->gpe_number =
893                     (u32) element->package.elements[1].integer.value;
894         } else if (element->type == ACPI_TYPE_INTEGER) {
895                 wakeup->gpe_device = NULL;
896                 wakeup->gpe_number = element->integer.value;
897         } else {
898                 goto out;
899         }
900
901         element = &(package->package.elements[1]);
902         if (element->type != ACPI_TYPE_INTEGER)
903                 goto out;
904
905         wakeup->sleep_state = element->integer.value;
906
907         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
908         if (err)
909                 goto out;
910
911         if (!list_empty(&wakeup->resources)) {
912                 int sleep_state;
913
914                 err = acpi_power_wakeup_list_init(&wakeup->resources,
915                                                   &sleep_state);
916                 if (err) {
917                         acpi_handle_warn(handle, "Retrieving current states "
918                                          "of wakeup power resources failed\n");
919                         acpi_power_resources_list_free(&wakeup->resources);
920                         goto out;
921                 }
922                 if (sleep_state < wakeup->sleep_state) {
923                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
924                                          "(S%d) by S%d from power resources\n",
925                                          (int)wakeup->sleep_state, sleep_state);
926                         wakeup->sleep_state = sleep_state;
927                 }
928         }
929
930  out:
931         kfree(buffer.pointer);
932         return err;
933 }
934
935 /* Do not use a button for S5 wakeup */
936 #define ACPI_AVOID_WAKE_FROM_S5         BIT(0)
937
938 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
939 {
940         static const struct acpi_device_id button_device_ids[] = {
941                 {"PNP0C0C", 0},                         /* Power button */
942                 {"PNP0C0D", ACPI_AVOID_WAKE_FROM_S5},   /* Lid */
943                 {"PNP0C0E", ACPI_AVOID_WAKE_FROM_S5},   /* Sleep button */
944                 {"", 0},
945         };
946         struct acpi_device_wakeup *wakeup = &device->wakeup;
947         const struct acpi_device_id *match;
948         acpi_status status;
949
950         wakeup->flags.notifier_present = 0;
951
952         /* Power button, Lid switch always enable wakeup */
953         match = acpi_match_acpi_device(button_device_ids, device);
954         if (match) {
955                 if ((match->driver_data & ACPI_AVOID_WAKE_FROM_S5) &&
956                     wakeup->sleep_state == ACPI_STATE_S5)
957                         wakeup->sleep_state = ACPI_STATE_S4;
958                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
959                 device_set_wakeup_capable(&device->dev, true);
960                 return true;
961         }
962
963         status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
964                                          wakeup->gpe_number);
965         return ACPI_SUCCESS(status);
966 }
967
968 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
969 {
970         int err;
971
972         /* Presence of _PRW indicates wake capable */
973         if (!acpi_has_method(device->handle, "_PRW"))
974                 return;
975
976         err = acpi_bus_extract_wakeup_device_power_package(device);
977         if (err) {
978                 dev_err(&device->dev, "Unable to extract wakeup power resources");
979                 return;
980         }
981
982         device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
983         device->wakeup.prepare_count = 0;
984         /*
985          * Call _PSW/_DSW object to disable its ability to wake the sleeping
986          * system for the ACPI device with the _PRW object.
987          * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
988          * So it is necessary to call _DSW object first. Only when it is not
989          * present will the _PSW object used.
990          */
991         err = acpi_device_sleep_wake(device, 0, 0, 0);
992         if (err)
993                 pr_debug("error in _DSW or _PSW evaluation\n");
994 }
995
996 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
997 {
998         struct acpi_device_power_state *ps = &device->power.states[state];
999         char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1000         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1001         acpi_status status;
1002
1003         INIT_LIST_HEAD(&ps->resources);
1004
1005         /* Evaluate "_PRx" to get referenced power resources */
1006         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1007         if (ACPI_SUCCESS(status)) {
1008                 union acpi_object *package = buffer.pointer;
1009
1010                 if (buffer.length && package
1011                     && package->type == ACPI_TYPE_PACKAGE
1012                     && package->package.count)
1013                         acpi_extract_power_resources(package, 0, &ps->resources);
1014
1015                 ACPI_FREE(buffer.pointer);
1016         }
1017
1018         /* Evaluate "_PSx" to see if we can do explicit sets */
1019         pathname[2] = 'S';
1020         if (acpi_has_method(device->handle, pathname))
1021                 ps->flags.explicit_set = 1;
1022
1023         /* State is valid if there are means to put the device into it. */
1024         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1025                 ps->flags.valid = 1;
1026
1027         ps->power = -1;         /* Unknown - driver assigned */
1028         ps->latency = -1;       /* Unknown - driver assigned */
1029 }
1030
1031 static void acpi_bus_get_power_flags(struct acpi_device *device)
1032 {
1033         unsigned long long dsc = ACPI_STATE_D0;
1034         u32 i;
1035
1036         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1037         if (!acpi_has_method(device->handle, "_PS0") &&
1038             !acpi_has_method(device->handle, "_PR0"))
1039                 return;
1040
1041         device->flags.power_manageable = 1;
1042
1043         /*
1044          * Power Management Flags
1045          */
1046         if (acpi_has_method(device->handle, "_PSC"))
1047                 device->power.flags.explicit_get = 1;
1048
1049         if (acpi_has_method(device->handle, "_IRC"))
1050                 device->power.flags.inrush_current = 1;
1051
1052         if (acpi_has_method(device->handle, "_DSW"))
1053                 device->power.flags.dsw_present = 1;
1054
1055         acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1056         device->power.state_for_enumeration = dsc;
1057
1058         /*
1059          * Enumerate supported power management states
1060          */
1061         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1062                 acpi_bus_init_power_state(device, i);
1063
1064         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1065
1066         /* Set the defaults for D0 and D3hot (always supported). */
1067         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1068         device->power.states[ACPI_STATE_D0].power = 100;
1069         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1070
1071         /*
1072          * Use power resources only if the D0 list of them is populated, because
1073          * some platforms may provide _PR3 only to indicate D3cold support and
1074          * in those cases the power resources list returned by it may be bogus.
1075          */
1076         if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1077                 device->power.flags.power_resources = 1;
1078                 /*
1079                  * D3cold is supported if the D3hot list of power resources is
1080                  * not empty.
1081                  */
1082                 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1083                         device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1084         }
1085
1086         if (acpi_bus_init_power(device))
1087                 device->flags.power_manageable = 0;
1088 }
1089
1090 static void acpi_bus_get_flags(struct acpi_device *device)
1091 {
1092         /* Presence of _STA indicates 'dynamic_status' */
1093         if (acpi_has_method(device->handle, "_STA"))
1094                 device->flags.dynamic_status = 1;
1095
1096         /* Presence of _RMV indicates 'removable' */
1097         if (acpi_has_method(device->handle, "_RMV"))
1098                 device->flags.removable = 1;
1099
1100         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1101         if (acpi_has_method(device->handle, "_EJD") ||
1102             acpi_has_method(device->handle, "_EJ0"))
1103                 device->flags.ejectable = 1;
1104 }
1105
1106 static void acpi_device_get_busid(struct acpi_device *device)
1107 {
1108         char bus_id[5] = { '?', 0 };
1109         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1110         int i = 0;
1111
1112         /*
1113          * Bus ID
1114          * ------
1115          * The device's Bus ID is simply the object name.
1116          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1117          */
1118         if (!acpi_dev_parent(device)) {
1119                 strcpy(device->pnp.bus_id, "ACPI");
1120                 return;
1121         }
1122
1123         switch (device->device_type) {
1124         case ACPI_BUS_TYPE_POWER_BUTTON:
1125                 strcpy(device->pnp.bus_id, "PWRF");
1126                 break;
1127         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1128                 strcpy(device->pnp.bus_id, "SLPF");
1129                 break;
1130         case ACPI_BUS_TYPE_ECDT_EC:
1131                 strcpy(device->pnp.bus_id, "ECDT");
1132                 break;
1133         default:
1134                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1135                 /* Clean up trailing underscores (if any) */
1136                 for (i = 3; i > 1; i--) {
1137                         if (bus_id[i] == '_')
1138                                 bus_id[i] = '\0';
1139                         else
1140                                 break;
1141                 }
1142                 strcpy(device->pnp.bus_id, bus_id);
1143                 break;
1144         }
1145 }
1146
1147 /*
1148  * acpi_ata_match - see if an acpi object is an ATA device
1149  *
1150  * If an acpi object has one of the ACPI ATA methods defined,
1151  * then we can safely call it an ATA device.
1152  */
1153 bool acpi_ata_match(acpi_handle handle)
1154 {
1155         return acpi_has_method(handle, "_GTF") ||
1156                acpi_has_method(handle, "_GTM") ||
1157                acpi_has_method(handle, "_STM") ||
1158                acpi_has_method(handle, "_SDD");
1159 }
1160
1161 /*
1162  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1163  *
1164  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1165  * then we can safely call it an ejectable drive bay
1166  */
1167 bool acpi_bay_match(acpi_handle handle)
1168 {
1169         acpi_handle phandle;
1170
1171         if (!acpi_has_method(handle, "_EJ0"))
1172                 return false;
1173         if (acpi_ata_match(handle))
1174                 return true;
1175         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1176                 return false;
1177
1178         return acpi_ata_match(phandle);
1179 }
1180
1181 bool acpi_device_is_battery(struct acpi_device *adev)
1182 {
1183         struct acpi_hardware_id *hwid;
1184
1185         list_for_each_entry(hwid, &adev->pnp.ids, list)
1186                 if (!strcmp("PNP0C0A", hwid->id))
1187                         return true;
1188
1189         return false;
1190 }
1191
1192 static bool is_ejectable_bay(struct acpi_device *adev)
1193 {
1194         acpi_handle handle = adev->handle;
1195
1196         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1197                 return true;
1198
1199         return acpi_bay_match(handle);
1200 }
1201
1202 /*
1203  * acpi_dock_match - see if an acpi object has a _DCK method
1204  */
1205 bool acpi_dock_match(acpi_handle handle)
1206 {
1207         return acpi_has_method(handle, "_DCK");
1208 }
1209
1210 static acpi_status
1211 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1212                           void **return_value)
1213 {
1214         long *cap = context;
1215
1216         if (acpi_has_method(handle, "_BCM") &&
1217             acpi_has_method(handle, "_BCL")) {
1218                 acpi_handle_debug(handle, "Found generic backlight support\n");
1219                 *cap |= ACPI_VIDEO_BACKLIGHT;
1220                 /* We have backlight support, no need to scan further */
1221                 return AE_CTRL_TERMINATE;
1222         }
1223         return 0;
1224 }
1225
1226 /* Returns true if the ACPI object is a video device which can be
1227  * handled by video.ko.
1228  * The device will get a Linux specific CID added in scan.c to
1229  * identify the device as an ACPI graphics device
1230  * Be aware that the graphics device may not be physically present
1231  * Use acpi_video_get_capabilities() to detect general ACPI video
1232  * capabilities of present cards
1233  */
1234 long acpi_is_video_device(acpi_handle handle)
1235 {
1236         long video_caps = 0;
1237
1238         /* Is this device able to support video switching ? */
1239         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1240                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1241
1242         /* Is this device able to retrieve a video ROM ? */
1243         if (acpi_has_method(handle, "_ROM"))
1244                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1245
1246         /* Is this device able to configure which video head to be POSTed ? */
1247         if (acpi_has_method(handle, "_VPO") &&
1248             acpi_has_method(handle, "_GPD") &&
1249             acpi_has_method(handle, "_SPD"))
1250                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1251
1252         /* Only check for backlight functionality if one of the above hit. */
1253         if (video_caps)
1254                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1255                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1256                                     &video_caps, NULL);
1257
1258         return video_caps;
1259 }
1260 EXPORT_SYMBOL(acpi_is_video_device);
1261
1262 const char *acpi_device_hid(struct acpi_device *device)
1263 {
1264         struct acpi_hardware_id *hid;
1265
1266         if (list_empty(&device->pnp.ids))
1267                 return dummy_hid;
1268
1269         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1270         return hid->id;
1271 }
1272 EXPORT_SYMBOL(acpi_device_hid);
1273
1274 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1275 {
1276         struct acpi_hardware_id *id;
1277
1278         id = kmalloc(sizeof(*id), GFP_KERNEL);
1279         if (!id)
1280                 return;
1281
1282         id->id = kstrdup_const(dev_id, GFP_KERNEL);
1283         if (!id->id) {
1284                 kfree(id);
1285                 return;
1286         }
1287
1288         list_add_tail(&id->list, &pnp->ids);
1289         pnp->type.hardware_id = 1;
1290 }
1291
1292 /*
1293  * Old IBM workstations have a DSDT bug wherein the SMBus object
1294  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1295  * prefix.  Work around this.
1296  */
1297 static bool acpi_ibm_smbus_match(acpi_handle handle)
1298 {
1299         char node_name[ACPI_PATH_SEGMENT_LENGTH];
1300         struct acpi_buffer path = { sizeof(node_name), node_name };
1301
1302         if (!dmi_name_in_vendors("IBM"))
1303                 return false;
1304
1305         /* Look for SMBS object */
1306         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1307             strcmp("SMBS", path.pointer))
1308                 return false;
1309
1310         /* Does it have the necessary (but misnamed) methods? */
1311         if (acpi_has_method(handle, "SBI") &&
1312             acpi_has_method(handle, "SBR") &&
1313             acpi_has_method(handle, "SBW"))
1314                 return true;
1315
1316         return false;
1317 }
1318
1319 static bool acpi_object_is_system_bus(acpi_handle handle)
1320 {
1321         acpi_handle tmp;
1322
1323         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1324             tmp == handle)
1325                 return true;
1326         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1327             tmp == handle)
1328                 return true;
1329
1330         return false;
1331 }
1332
1333 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1334                              int device_type)
1335 {
1336         struct acpi_device_info *info = NULL;
1337         struct acpi_pnp_device_id_list *cid_list;
1338         int i;
1339
1340         switch (device_type) {
1341         case ACPI_BUS_TYPE_DEVICE:
1342                 if (handle == ACPI_ROOT_OBJECT) {
1343                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
1344                         break;
1345                 }
1346
1347                 acpi_get_object_info(handle, &info);
1348                 if (!info) {
1349                         pr_err("%s: Error reading device info\n", __func__);
1350                         return;
1351                 }
1352
1353                 if (info->valid & ACPI_VALID_HID) {
1354                         acpi_add_id(pnp, info->hardware_id.string);
1355                         pnp->type.platform_id = 1;
1356                 }
1357                 if (info->valid & ACPI_VALID_CID) {
1358                         cid_list = &info->compatible_id_list;
1359                         for (i = 0; i < cid_list->count; i++)
1360                                 acpi_add_id(pnp, cid_list->ids[i].string);
1361                 }
1362                 if (info->valid & ACPI_VALID_ADR) {
1363                         pnp->bus_address = info->address;
1364                         pnp->type.bus_address = 1;
1365                 }
1366                 if (info->valid & ACPI_VALID_UID)
1367                         pnp->unique_id = kstrdup(info->unique_id.string,
1368                                                         GFP_KERNEL);
1369                 if (info->valid & ACPI_VALID_CLS)
1370                         acpi_add_id(pnp, info->class_code.string);
1371
1372                 kfree(info);
1373
1374                 /*
1375                  * Some devices don't reliably have _HIDs & _CIDs, so add
1376                  * synthetic HIDs to make sure drivers can find them.
1377                  */
1378                 if (acpi_is_video_device(handle)) {
1379                         acpi_add_id(pnp, ACPI_VIDEO_HID);
1380                         pnp->type.backlight = 1;
1381                         break;
1382                 }
1383                 if (acpi_bay_match(handle))
1384                         acpi_add_id(pnp, ACPI_BAY_HID);
1385                 else if (acpi_dock_match(handle))
1386                         acpi_add_id(pnp, ACPI_DOCK_HID);
1387                 else if (acpi_ibm_smbus_match(handle))
1388                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1389                 else if (list_empty(&pnp->ids) &&
1390                          acpi_object_is_system_bus(handle)) {
1391                         /* \_SB, \_TZ, LNXSYBUS */
1392                         acpi_add_id(pnp, ACPI_BUS_HID);
1393                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1394                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
1395                 }
1396
1397                 break;
1398         case ACPI_BUS_TYPE_POWER:
1399                 acpi_add_id(pnp, ACPI_POWER_HID);
1400                 break;
1401         case ACPI_BUS_TYPE_PROCESSOR:
1402                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1403                 break;
1404         case ACPI_BUS_TYPE_THERMAL:
1405                 acpi_add_id(pnp, ACPI_THERMAL_HID);
1406                 break;
1407         case ACPI_BUS_TYPE_POWER_BUTTON:
1408                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1409                 break;
1410         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1411                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1412                 break;
1413         case ACPI_BUS_TYPE_ECDT_EC:
1414                 acpi_add_id(pnp, ACPI_ECDT_HID);
1415                 break;
1416         }
1417 }
1418
1419 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1420 {
1421         struct acpi_hardware_id *id, *tmp;
1422
1423         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1424                 kfree_const(id->id);
1425                 kfree(id);
1426         }
1427         kfree(pnp->unique_id);
1428 }
1429
1430 /**
1431  * acpi_dma_supported - Check DMA support for the specified device.
1432  * @adev: The pointer to acpi device
1433  *
1434  * Return false if DMA is not supported. Otherwise, return true
1435  */
1436 bool acpi_dma_supported(const struct acpi_device *adev)
1437 {
1438         if (!adev)
1439                 return false;
1440
1441         if (adev->flags.cca_seen)
1442                 return true;
1443
1444         /*
1445         * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1446         * DMA on "Intel platforms".  Presumably that includes all x86 and
1447         * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1448         */
1449         if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1450                 return true;
1451
1452         return false;
1453 }
1454
1455 /**
1456  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1457  * @adev: The pointer to acpi device
1458  *
1459  * Return enum dev_dma_attr.
1460  */
1461 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1462 {
1463         if (!acpi_dma_supported(adev))
1464                 return DEV_DMA_NOT_SUPPORTED;
1465
1466         if (adev->flags.coherent_dma)
1467                 return DEV_DMA_COHERENT;
1468         else
1469                 return DEV_DMA_NON_COHERENT;
1470 }
1471
1472 /**
1473  * acpi_dma_get_range() - Get device DMA parameters.
1474  *
1475  * @dev: device to configure
1476  * @map: pointer to DMA ranges result
1477  *
1478  * Evaluate DMA regions and return pointer to DMA regions on
1479  * parsing success; it does not update the passed in values on failure.
1480  *
1481  * Return 0 on success, < 0 on failure.
1482  */
1483 int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
1484 {
1485         struct acpi_device *adev;
1486         LIST_HEAD(list);
1487         struct resource_entry *rentry;
1488         int ret;
1489         struct device *dma_dev = dev;
1490         struct bus_dma_region *r;
1491
1492         /*
1493          * Walk the device tree chasing an ACPI companion with a _DMA
1494          * object while we go. Stop if we find a device with an ACPI
1495          * companion containing a _DMA method.
1496          */
1497         do {
1498                 adev = ACPI_COMPANION(dma_dev);
1499                 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1500                         break;
1501
1502                 dma_dev = dma_dev->parent;
1503         } while (dma_dev);
1504
1505         if (!dma_dev)
1506                 return -ENODEV;
1507
1508         if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1509                 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1510                 return -EINVAL;
1511         }
1512
1513         ret = acpi_dev_get_dma_resources(adev, &list);
1514         if (ret > 0) {
1515                 r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
1516                 if (!r) {
1517                         ret = -ENOMEM;
1518                         goto out;
1519                 }
1520
1521                 *map = r;
1522
1523                 list_for_each_entry(rentry, &list, node) {
1524                         if (rentry->res->start >= rentry->res->end) {
1525                                 kfree(*map);
1526                                 *map = NULL;
1527                                 ret = -EINVAL;
1528                                 dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1529                                 goto out;
1530                         }
1531
1532                         r->cpu_start = rentry->res->start;
1533                         r->dma_start = rentry->res->start - rentry->offset;
1534                         r->size = resource_size(rentry->res);
1535                         r->offset = rentry->offset;
1536                         r++;
1537                 }
1538         }
1539  out:
1540         acpi_dev_free_resource_list(&list);
1541
1542         return ret >= 0 ? 0 : ret;
1543 }
1544
1545 #ifdef CONFIG_IOMMU_API
1546 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1547                            struct fwnode_handle *fwnode,
1548                            const struct iommu_ops *ops)
1549 {
1550         int ret = iommu_fwspec_init(dev, fwnode, ops);
1551
1552         if (!ret)
1553                 ret = iommu_fwspec_add_ids(dev, &id, 1);
1554
1555         return ret;
1556 }
1557
1558 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1559 {
1560         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1561
1562         return fwspec ? fwspec->ops : NULL;
1563 }
1564
1565 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1566                                                        const u32 *id_in)
1567 {
1568         int err;
1569         const struct iommu_ops *ops;
1570
1571         /* Serialise to make dev->iommu stable under our potential fwspec */
1572         mutex_lock(&iommu_probe_device_lock);
1573         /*
1574          * If we already translated the fwspec there is nothing left to do,
1575          * return the iommu_ops.
1576          */
1577         ops = acpi_iommu_fwspec_ops(dev);
1578         if (ops) {
1579                 mutex_unlock(&iommu_probe_device_lock);
1580                 return ops;
1581         }
1582
1583         err = iort_iommu_configure_id(dev, id_in);
1584         if (err && err != -EPROBE_DEFER)
1585                 err = viot_iommu_configure(dev);
1586         mutex_unlock(&iommu_probe_device_lock);
1587
1588         /*
1589          * If we have reason to believe the IOMMU driver missed the initial
1590          * iommu_probe_device() call for dev, replay it to get things in order.
1591          */
1592         if (!err && dev->bus)
1593                 err = iommu_probe_device(dev);
1594
1595         /* Ignore all other errors apart from EPROBE_DEFER */
1596         if (err == -EPROBE_DEFER) {
1597                 return ERR_PTR(err);
1598         } else if (err) {
1599                 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1600                 return NULL;
1601         }
1602         return acpi_iommu_fwspec_ops(dev);
1603 }
1604
1605 #else /* !CONFIG_IOMMU_API */
1606
1607 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1608                            struct fwnode_handle *fwnode,
1609                            const struct iommu_ops *ops)
1610 {
1611         return -ENODEV;
1612 }
1613
1614 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1615                                                        const u32 *id_in)
1616 {
1617         return NULL;
1618 }
1619
1620 #endif /* !CONFIG_IOMMU_API */
1621
1622 /**
1623  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1624  * @dev: The pointer to the device
1625  * @attr: device dma attributes
1626  * @input_id: input device id const value pointer
1627  */
1628 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1629                           const u32 *input_id)
1630 {
1631         const struct iommu_ops *iommu;
1632
1633         if (attr == DEV_DMA_NOT_SUPPORTED) {
1634                 set_dma_ops(dev, &dma_dummy_ops);
1635                 return 0;
1636         }
1637
1638         acpi_arch_dma_setup(dev);
1639
1640         iommu = acpi_iommu_configure_id(dev, input_id);
1641         if (PTR_ERR(iommu) == -EPROBE_DEFER)
1642                 return -EPROBE_DEFER;
1643
1644         arch_setup_dma_ops(dev, 0, U64_MAX,
1645                                 iommu, attr == DEV_DMA_COHERENT);
1646
1647         return 0;
1648 }
1649 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1650
1651 static void acpi_init_coherency(struct acpi_device *adev)
1652 {
1653         unsigned long long cca = 0;
1654         acpi_status status;
1655         struct acpi_device *parent = acpi_dev_parent(adev);
1656
1657         if (parent && parent->flags.cca_seen) {
1658                 /*
1659                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1660                  * already saw one.
1661                  */
1662                 adev->flags.cca_seen = 1;
1663                 cca = parent->flags.coherent_dma;
1664         } else {
1665                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1666                                                NULL, &cca);
1667                 if (ACPI_SUCCESS(status))
1668                         adev->flags.cca_seen = 1;
1669                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1670                         /*
1671                          * If architecture does not specify that _CCA is
1672                          * required for DMA-able devices (e.g. x86),
1673                          * we default to _CCA=1.
1674                          */
1675                         cca = 1;
1676                 else
1677                         acpi_handle_debug(adev->handle,
1678                                           "ACPI device is missing _CCA.\n");
1679         }
1680
1681         adev->flags.coherent_dma = cca;
1682 }
1683
1684 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1685 {
1686         bool *is_serial_bus_slave_p = data;
1687
1688         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1689                 return 1;
1690
1691         *is_serial_bus_slave_p = true;
1692
1693          /* no need to do more checking */
1694         return -1;
1695 }
1696
1697 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1698 {
1699         struct acpi_device *parent = acpi_dev_parent(device);
1700         static const struct acpi_device_id indirect_io_hosts[] = {
1701                 {"HISI0191", 0},
1702                 {}
1703         };
1704
1705         return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1706 }
1707
1708 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1709 {
1710         struct list_head resource_list;
1711         bool is_serial_bus_slave = false;
1712         static const struct acpi_device_id ignore_serial_bus_ids[] = {
1713         /*
1714          * These devices have multiple SerialBus resources and a client
1715          * device must be instantiated for each of them, each with
1716          * its own device id.
1717          * Normally we only instantiate one client device for the first
1718          * resource, using the ACPI HID as id. These special cases are handled
1719          * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1720          * knows which client device id to use for each resource.
1721          */
1722                 {"BSG1160", },
1723                 {"BSG2150", },
1724                 {"CSC3551", },
1725                 {"CSC3556", },
1726                 {"INT33FE", },
1727                 {"INT3515", },
1728                 /* Non-conforming _HID for Cirrus Logic already released */
1729                 {"CLSA0100", },
1730                 {"CLSA0101", },
1731         /*
1732          * Some ACPI devs contain SerialBus resources even though they are not
1733          * attached to a serial bus at all.
1734          */
1735                 {"MSHW0028", },
1736         /*
1737          * HIDs of device with an UartSerialBusV2 resource for which userspace
1738          * expects a regular tty cdev to be created (instead of the in kernel
1739          * serdev) and which have a kernel driver which expects a platform_dev
1740          * such as the rfkill-gpio driver.
1741          */
1742                 {"BCM4752", },
1743                 {"LNV4752", },
1744                 {}
1745         };
1746
1747         if (acpi_is_indirect_io_slave(device))
1748                 return true;
1749
1750         /* Macs use device properties in lieu of _CRS resources */
1751         if (x86_apple_machine &&
1752             (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1753              fwnode_property_present(&device->fwnode, "i2cAddress") ||
1754              fwnode_property_present(&device->fwnode, "baud")))
1755                 return true;
1756
1757         if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1758                 return false;
1759
1760         INIT_LIST_HEAD(&resource_list);
1761         acpi_dev_get_resources(device, &resource_list,
1762                                acpi_check_serial_bus_slave,
1763                                &is_serial_bus_slave);
1764         acpi_dev_free_resource_list(&resource_list);
1765
1766         return is_serial_bus_slave;
1767 }
1768
1769 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1770                              int type, void (*release)(struct device *))
1771 {
1772         struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1773
1774         INIT_LIST_HEAD(&device->pnp.ids);
1775         device->device_type = type;
1776         device->handle = handle;
1777         device->dev.parent = parent ? &parent->dev : NULL;
1778         device->dev.release = release;
1779         device->dev.bus = &acpi_bus_type;
1780         fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1781         acpi_set_device_status(device, ACPI_STA_DEFAULT);
1782         acpi_device_get_busid(device);
1783         acpi_set_pnp_ids(handle, &device->pnp, type);
1784         acpi_init_properties(device);
1785         acpi_bus_get_flags(device);
1786         device->flags.match_driver = false;
1787         device->flags.initialized = true;
1788         device->flags.enumeration_by_parent =
1789                 acpi_device_enumeration_by_parent(device);
1790         acpi_device_clear_enumerated(device);
1791         device_initialize(&device->dev);
1792         dev_set_uevent_suppress(&device->dev, true);
1793         acpi_init_coherency(device);
1794 }
1795
1796 static void acpi_scan_dep_init(struct acpi_device *adev)
1797 {
1798         struct acpi_dep_data *dep;
1799
1800         list_for_each_entry(dep, &acpi_dep_list, node) {
1801                 if (dep->consumer == adev->handle) {
1802                         if (dep->honor_dep)
1803                                 adev->flags.honor_deps = 1;
1804
1805                         adev->dep_unmet++;
1806                 }
1807         }
1808 }
1809
1810 void acpi_device_add_finalize(struct acpi_device *device)
1811 {
1812         dev_set_uevent_suppress(&device->dev, false);
1813         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1814 }
1815
1816 static void acpi_scan_init_status(struct acpi_device *adev)
1817 {
1818         if (acpi_bus_get_status(adev))
1819                 acpi_set_device_status(adev, 0);
1820 }
1821
1822 static int acpi_add_single_object(struct acpi_device **child,
1823                                   acpi_handle handle, int type, bool dep_init)
1824 {
1825         struct acpi_device *device;
1826         bool release_dep_lock = false;
1827         int result;
1828
1829         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1830         if (!device)
1831                 return -ENOMEM;
1832
1833         acpi_init_device_object(device, handle, type, acpi_device_release);
1834         /*
1835          * Getting the status is delayed till here so that we can call
1836          * acpi_bus_get_status() and use its quirk handling.  Note that
1837          * this must be done before the get power-/wakeup_dev-flags calls.
1838          */
1839         if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1840                 if (dep_init) {
1841                         mutex_lock(&acpi_dep_list_lock);
1842                         /*
1843                          * Hold the lock until the acpi_tie_acpi_dev() call
1844                          * below to prevent concurrent acpi_scan_clear_dep()
1845                          * from deleting a dependency list entry without
1846                          * updating dep_unmet for the device.
1847                          */
1848                         release_dep_lock = true;
1849                         acpi_scan_dep_init(device);
1850                 }
1851                 acpi_scan_init_status(device);
1852         }
1853
1854         acpi_bus_get_power_flags(device);
1855         acpi_bus_get_wakeup_device_flags(device);
1856
1857         result = acpi_tie_acpi_dev(device);
1858
1859         if (release_dep_lock)
1860                 mutex_unlock(&acpi_dep_list_lock);
1861
1862         if (!result)
1863                 result = acpi_device_add(device);
1864
1865         if (result) {
1866                 acpi_device_release(&device->dev);
1867                 return result;
1868         }
1869
1870         acpi_power_add_remove_device(device, true);
1871         acpi_device_add_finalize(device);
1872
1873         acpi_handle_debug(handle, "Added as %s, parent %s\n",
1874                           dev_name(&device->dev), device->dev.parent ?
1875                                 dev_name(device->dev.parent) : "(null)");
1876
1877         *child = device;
1878         return 0;
1879 }
1880
1881 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1882                                             void *context)
1883 {
1884         struct resource *res = context;
1885
1886         if (acpi_dev_resource_memory(ares, res))
1887                 return AE_CTRL_TERMINATE;
1888
1889         return AE_OK;
1890 }
1891
1892 static bool acpi_device_should_be_hidden(acpi_handle handle)
1893 {
1894         acpi_status status;
1895         struct resource res;
1896
1897         /* Check if it should ignore the UART device */
1898         if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1899                 return false;
1900
1901         /*
1902          * The UART device described in SPCR table is assumed to have only one
1903          * memory resource present. So we only look for the first one here.
1904          */
1905         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1906                                      acpi_get_resource_memory, &res);
1907         if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1908                 return false;
1909
1910         acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1911                          &res.start);
1912
1913         return true;
1914 }
1915
1916 bool acpi_device_is_present(const struct acpi_device *adev)
1917 {
1918         return adev->status.present || adev->status.functional;
1919 }
1920
1921 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1922                                        const char *idstr,
1923                                        const struct acpi_device_id **matchid)
1924 {
1925         const struct acpi_device_id *devid;
1926
1927         if (handler->match)
1928                 return handler->match(idstr, matchid);
1929
1930         for (devid = handler->ids; devid->id[0]; devid++)
1931                 if (!strcmp((char *)devid->id, idstr)) {
1932                         if (matchid)
1933                                 *matchid = devid;
1934
1935                         return true;
1936                 }
1937
1938         return false;
1939 }
1940
1941 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1942                                         const struct acpi_device_id **matchid)
1943 {
1944         struct acpi_scan_handler *handler;
1945
1946         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1947                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1948                         return handler;
1949
1950         return NULL;
1951 }
1952
1953 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1954 {
1955         if (!!hotplug->enabled == !!val)
1956                 return;
1957
1958         mutex_lock(&acpi_scan_lock);
1959
1960         hotplug->enabled = val;
1961
1962         mutex_unlock(&acpi_scan_lock);
1963 }
1964
1965 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1966 {
1967         struct acpi_hardware_id *hwid;
1968
1969         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1970                 acpi_dock_add(adev);
1971                 return;
1972         }
1973         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1974                 struct acpi_scan_handler *handler;
1975
1976                 handler = acpi_scan_match_handler(hwid->id, NULL);
1977                 if (handler) {
1978                         adev->flags.hotplug_notify = true;
1979                         break;
1980                 }
1981         }
1982 }
1983
1984 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1985 {
1986         struct acpi_handle_list dep_devices;
1987         acpi_status status;
1988         u32 count;
1989         int i;
1990
1991         /*
1992          * Check for _HID here to avoid deferring the enumeration of:
1993          * 1. PCI devices.
1994          * 2. ACPI nodes describing USB ports.
1995          * Still, checking for _HID catches more then just these cases ...
1996          */
1997         if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1998             !acpi_has_method(handle, "_HID"))
1999                 return 0;
2000
2001         status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
2002         if (ACPI_FAILURE(status)) {
2003                 acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
2004                 return 0;
2005         }
2006
2007         for (count = 0, i = 0; i < dep_devices.count; i++) {
2008                 struct acpi_device_info *info;
2009                 struct acpi_dep_data *dep;
2010                 bool skip, honor_dep;
2011
2012                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2013                 if (ACPI_FAILURE(status)) {
2014                         acpi_handle_debug(handle, "Error reading _DEP device info\n");
2015                         continue;
2016                 }
2017
2018                 skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2019                 honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2020                 kfree(info);
2021
2022                 if (skip)
2023                         continue;
2024
2025                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2026                 if (!dep)
2027                         continue;
2028
2029                 count++;
2030
2031                 dep->supplier = dep_devices.handles[i];
2032                 dep->consumer = handle;
2033                 dep->honor_dep = honor_dep;
2034
2035                 mutex_lock(&acpi_dep_list_lock);
2036                 list_add_tail(&dep->node , &acpi_dep_list);
2037                 mutex_unlock(&acpi_dep_list_lock);
2038         }
2039
2040         acpi_handle_list_free(&dep_devices);
2041         return count;
2042 }
2043
2044 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2045                                       struct acpi_device **adev_p)
2046 {
2047         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2048         acpi_object_type acpi_type;
2049         int type;
2050
2051         if (device)
2052                 goto out;
2053
2054         if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2055                 return AE_OK;
2056
2057         switch (acpi_type) {
2058         case ACPI_TYPE_DEVICE:
2059                 if (acpi_device_should_be_hidden(handle))
2060                         return AE_OK;
2061
2062                 /* Bail out if there are dependencies. */
2063                 if (acpi_scan_check_dep(handle, check_dep) > 0)
2064                         return AE_CTRL_DEPTH;
2065
2066                 fallthrough;
2067         case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
2068                 type = ACPI_BUS_TYPE_DEVICE;
2069                 break;
2070
2071         case ACPI_TYPE_PROCESSOR:
2072                 type = ACPI_BUS_TYPE_PROCESSOR;
2073                 break;
2074
2075         case ACPI_TYPE_THERMAL:
2076                 type = ACPI_BUS_TYPE_THERMAL;
2077                 break;
2078
2079         case ACPI_TYPE_POWER:
2080                 acpi_add_power_resource(handle);
2081                 fallthrough;
2082         default:
2083                 return AE_OK;
2084         }
2085
2086         /*
2087          * If check_dep is true at this point, the device has no dependencies,
2088          * or the creation of the device object would have been postponed above.
2089          */
2090         acpi_add_single_object(&device, handle, type, !check_dep);
2091         if (!device)
2092                 return AE_CTRL_DEPTH;
2093
2094         acpi_scan_init_hotplug(device);
2095
2096 out:
2097         if (!*adev_p)
2098                 *adev_p = device;
2099
2100         return AE_OK;
2101 }
2102
2103 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2104                                         void *not_used, void **ret_p)
2105 {
2106         return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2107 }
2108
2109 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2110                                         void *not_used, void **ret_p)
2111 {
2112         return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2113 }
2114
2115 static void acpi_default_enumeration(struct acpi_device *device)
2116 {
2117         /*
2118          * Do not enumerate devices with enumeration_by_parent flag set as
2119          * they will be enumerated by their respective parents.
2120          */
2121         if (!device->flags.enumeration_by_parent) {
2122                 acpi_create_platform_device(device, NULL);
2123                 acpi_device_set_enumerated(device);
2124         } else {
2125                 blocking_notifier_call_chain(&acpi_reconfig_chain,
2126                                              ACPI_RECONFIG_DEVICE_ADD, device);
2127         }
2128 }
2129
2130 static const struct acpi_device_id generic_device_ids[] = {
2131         {ACPI_DT_NAMESPACE_HID, },
2132         {"", },
2133 };
2134
2135 static int acpi_generic_device_attach(struct acpi_device *adev,
2136                                       const struct acpi_device_id *not_used)
2137 {
2138         /*
2139          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2140          * below can be unconditional.
2141          */
2142         if (adev->data.of_compatible)
2143                 acpi_default_enumeration(adev);
2144
2145         return 1;
2146 }
2147
2148 static struct acpi_scan_handler generic_device_handler = {
2149         .ids = generic_device_ids,
2150         .attach = acpi_generic_device_attach,
2151 };
2152
2153 static int acpi_scan_attach_handler(struct acpi_device *device)
2154 {
2155         struct acpi_hardware_id *hwid;
2156         int ret = 0;
2157
2158         list_for_each_entry(hwid, &device->pnp.ids, list) {
2159                 const struct acpi_device_id *devid;
2160                 struct acpi_scan_handler *handler;
2161
2162                 handler = acpi_scan_match_handler(hwid->id, &devid);
2163                 if (handler) {
2164                         if (!handler->attach) {
2165                                 device->pnp.type.platform_id = 0;
2166                                 continue;
2167                         }
2168                         device->handler = handler;
2169                         ret = handler->attach(device, devid);
2170                         if (ret > 0)
2171                                 break;
2172
2173                         device->handler = NULL;
2174                         if (ret < 0)
2175                                 break;
2176                 }
2177         }
2178
2179         return ret;
2180 }
2181
2182 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2183 {
2184         bool skip = !first_pass && device->flags.visited;
2185         acpi_handle ejd;
2186         int ret;
2187
2188         if (skip)
2189                 goto ok;
2190
2191         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2192                 register_dock_dependent_device(device, ejd);
2193
2194         acpi_bus_get_status(device);
2195         /* Skip devices that are not ready for enumeration (e.g. not present) */
2196         if (!acpi_dev_ready_for_enumeration(device)) {
2197                 device->flags.initialized = false;
2198                 acpi_device_clear_enumerated(device);
2199                 device->flags.power_manageable = 0;
2200                 return 0;
2201         }
2202         if (device->handler)
2203                 goto ok;
2204
2205         if (!device->flags.initialized) {
2206                 device->flags.power_manageable =
2207                         device->power.states[ACPI_STATE_D0].flags.valid;
2208                 if (acpi_bus_init_power(device))
2209                         device->flags.power_manageable = 0;
2210
2211                 device->flags.initialized = true;
2212         } else if (device->flags.visited) {
2213                 goto ok;
2214         }
2215
2216         ret = acpi_scan_attach_handler(device);
2217         if (ret < 0)
2218                 return 0;
2219
2220         device->flags.match_driver = true;
2221         if (ret > 0 && !device->flags.enumeration_by_parent) {
2222                 acpi_device_set_enumerated(device);
2223                 goto ok;
2224         }
2225
2226         ret = device_attach(&device->dev);
2227         if (ret < 0)
2228                 return 0;
2229
2230         if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2231                 acpi_default_enumeration(device);
2232         else
2233                 acpi_device_set_enumerated(device);
2234
2235 ok:
2236         acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2237
2238         if (!skip && device->handler && device->handler->hotplug.notify_online)
2239                 device->handler->hotplug.notify_online(device);
2240
2241         return 0;
2242 }
2243
2244 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2245 {
2246         struct acpi_device **adev_p = data;
2247         struct acpi_device *adev = *adev_p;
2248
2249         /*
2250          * If we're passed a 'previous' consumer device then we need to skip
2251          * any consumers until we meet the previous one, and then NULL @data
2252          * so the next one can be returned.
2253          */
2254         if (adev) {
2255                 if (dep->consumer == adev->handle)
2256                         *adev_p = NULL;
2257
2258                 return 0;
2259         }
2260
2261         adev = acpi_get_acpi_dev(dep->consumer);
2262         if (adev) {
2263                 *(struct acpi_device **)data = adev;
2264                 return 1;
2265         }
2266         /* Continue parsing if the device object is not present. */
2267         return 0;
2268 }
2269
2270 struct acpi_scan_clear_dep_work {
2271         struct work_struct work;
2272         struct acpi_device *adev;
2273 };
2274
2275 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2276 {
2277         struct acpi_scan_clear_dep_work *cdw;
2278
2279         cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2280
2281         acpi_scan_lock_acquire();
2282         acpi_bus_attach(cdw->adev, (void *)true);
2283         acpi_scan_lock_release();
2284
2285         acpi_dev_put(cdw->adev);
2286         kfree(cdw);
2287 }
2288
2289 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2290 {
2291         struct acpi_scan_clear_dep_work *cdw;
2292
2293         if (adev->dep_unmet)
2294                 return false;
2295
2296         cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2297         if (!cdw)
2298                 return false;
2299
2300         cdw->adev = adev;
2301         INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2302         /*
2303          * Since the work function may block on the lock until the entire
2304          * initial enumeration of devices is complete, put it into the unbound
2305          * workqueue.
2306          */
2307         queue_work(system_unbound_wq, &cdw->work);
2308
2309         return true;
2310 }
2311
2312 static void acpi_scan_delete_dep_data(struct acpi_dep_data *dep)
2313 {
2314         list_del(&dep->node);
2315         kfree(dep);
2316 }
2317
2318 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2319 {
2320         struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2321
2322         if (adev) {
2323                 adev->dep_unmet--;
2324                 if (!acpi_scan_clear_dep_queue(adev))
2325                         acpi_dev_put(adev);
2326         }
2327
2328         if (dep->free_when_met)
2329                 acpi_scan_delete_dep_data(dep);
2330         else
2331                 dep->met = true;
2332
2333         return 0;
2334 }
2335
2336 /**
2337  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2338  * @handle:     The ACPI handle of the supplier device
2339  * @callback:   Pointer to the callback function to apply
2340  * @data:       Pointer to some data to pass to the callback
2341  *
2342  * The return value of the callback determines this function's behaviour. If 0
2343  * is returned we continue to iterate over acpi_dep_list. If a positive value
2344  * is returned then the loop is broken but this function returns 0. If a
2345  * negative value is returned by the callback then the loop is broken and that
2346  * value is returned as the final error.
2347  */
2348 static int acpi_walk_dep_device_list(acpi_handle handle,
2349                                 int (*callback)(struct acpi_dep_data *, void *),
2350                                 void *data)
2351 {
2352         struct acpi_dep_data *dep, *tmp;
2353         int ret = 0;
2354
2355         mutex_lock(&acpi_dep_list_lock);
2356         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2357                 if (dep->supplier == handle) {
2358                         ret = callback(dep, data);
2359                         if (ret)
2360                                 break;
2361                 }
2362         }
2363         mutex_unlock(&acpi_dep_list_lock);
2364
2365         return ret > 0 ? 0 : ret;
2366 }
2367
2368 /**
2369  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2370  * @supplier: Pointer to the supplier &struct acpi_device
2371  *
2372  * Clear dependencies on the given device.
2373  */
2374 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2375 {
2376         acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2377 }
2378 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2379
2380 /**
2381  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2382  * @device: Pointer to the &struct acpi_device to check
2383  *
2384  * Check if the device is present and has no unmet dependencies.
2385  *
2386  * Return true if the device is ready for enumeratino. Otherwise, return false.
2387  */
2388 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2389 {
2390         if (device->flags.honor_deps && device->dep_unmet)
2391                 return false;
2392
2393         return acpi_device_is_present(device);
2394 }
2395 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2396
2397 /**
2398  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2399  * @supplier: Pointer to the dependee device
2400  * @start: Pointer to the current dependent device
2401  *
2402  * Returns the next &struct acpi_device which declares itself dependent on
2403  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2404  *
2405  * If the returned adev is not passed as @start to this function, the caller is
2406  * responsible for putting the reference to adev when it is no longer needed.
2407  */
2408 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2409                                                    struct acpi_device *start)
2410 {
2411         struct acpi_device *adev = start;
2412
2413         acpi_walk_dep_device_list(supplier->handle,
2414                                   acpi_dev_get_next_consumer_dev_cb, &adev);
2415
2416         acpi_dev_put(start);
2417
2418         if (adev == start)
2419                 return NULL;
2420
2421         return adev;
2422 }
2423 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2424
2425 static void acpi_scan_postponed_branch(acpi_handle handle)
2426 {
2427         struct acpi_device *adev = NULL;
2428
2429         if (ACPI_FAILURE(acpi_bus_check_add(handle, false, &adev)))
2430                 return;
2431
2432         acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2433                             acpi_bus_check_add_2, NULL, NULL, (void **)&adev);
2434         acpi_bus_attach(adev, NULL);
2435 }
2436
2437 static void acpi_scan_postponed(void)
2438 {
2439         struct acpi_dep_data *dep, *tmp;
2440
2441         mutex_lock(&acpi_dep_list_lock);
2442
2443         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2444                 acpi_handle handle = dep->consumer;
2445
2446                 /*
2447                  * In case there are multiple acpi_dep_list entries with the
2448                  * same consumer, skip the current entry if the consumer device
2449                  * object corresponding to it is present already.
2450                  */
2451                 if (!acpi_fetch_acpi_dev(handle)) {
2452                         /*
2453                          * Even though the lock is released here, tmp is
2454                          * guaranteed to be valid, because none of the list
2455                          * entries following dep is marked as "free when met"
2456                          * and so they cannot be deleted.
2457                          */
2458                         mutex_unlock(&acpi_dep_list_lock);
2459
2460                         acpi_scan_postponed_branch(handle);
2461
2462                         mutex_lock(&acpi_dep_list_lock);
2463                 }
2464
2465                 if (dep->met)
2466                         acpi_scan_delete_dep_data(dep);
2467                 else
2468                         dep->free_when_met = true;
2469         }
2470
2471         mutex_unlock(&acpi_dep_list_lock);
2472 }
2473
2474 /**
2475  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2476  * @handle: Root of the namespace scope to scan.
2477  *
2478  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2479  * found devices.
2480  *
2481  * If no devices were found, -ENODEV is returned, but it does not mean that
2482  * there has been a real error.  There just have been no suitable ACPI objects
2483  * in the table trunk from which the kernel could create a device and add an
2484  * appropriate driver.
2485  *
2486  * Must be called under acpi_scan_lock.
2487  */
2488 int acpi_bus_scan(acpi_handle handle)
2489 {
2490         struct acpi_device *device = NULL;
2491
2492         /* Pass 1: Avoid enumerating devices with missing dependencies. */
2493
2494         if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2495                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2496                                     acpi_bus_check_add_1, NULL, NULL,
2497                                     (void **)&device);
2498
2499         if (!device)
2500                 return -ENODEV;
2501
2502         acpi_bus_attach(device, (void *)true);
2503
2504         /* Pass 2: Enumerate all of the remaining devices. */
2505
2506         acpi_scan_postponed();
2507
2508         return 0;
2509 }
2510 EXPORT_SYMBOL(acpi_bus_scan);
2511
2512 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2513 {
2514         struct acpi_scan_handler *handler = adev->handler;
2515
2516         acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2517
2518         adev->flags.match_driver = false;
2519         if (handler) {
2520                 if (handler->detach)
2521                         handler->detach(adev);
2522
2523                 adev->handler = NULL;
2524         } else {
2525                 device_release_driver(&adev->dev);
2526         }
2527         /*
2528          * Most likely, the device is going away, so put it into D3cold before
2529          * that.
2530          */
2531         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2532         adev->flags.initialized = false;
2533         acpi_device_clear_enumerated(adev);
2534
2535         return 0;
2536 }
2537
2538 /**
2539  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2540  * @adev: Root of the ACPI namespace scope to walk.
2541  *
2542  * Must be called under acpi_scan_lock.
2543  */
2544 void acpi_bus_trim(struct acpi_device *adev)
2545 {
2546         acpi_bus_trim_one(adev, NULL);
2547 }
2548 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2549
2550 int acpi_bus_register_early_device(int type)
2551 {
2552         struct acpi_device *device = NULL;
2553         int result;
2554
2555         result = acpi_add_single_object(&device, NULL, type, false);
2556         if (result)
2557                 return result;
2558
2559         device->flags.match_driver = true;
2560         return device_attach(&device->dev);
2561 }
2562 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2563
2564 static void acpi_bus_scan_fixed(void)
2565 {
2566         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2567                 struct acpi_device *adev = NULL;
2568
2569                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2570                                        false);
2571                 if (adev) {
2572                         adev->flags.match_driver = true;
2573                         if (device_attach(&adev->dev) >= 0)
2574                                 device_init_wakeup(&adev->dev, true);
2575                         else
2576                                 dev_dbg(&adev->dev, "No driver\n");
2577                 }
2578         }
2579
2580         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2581                 struct acpi_device *adev = NULL;
2582
2583                 acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2584                                        false);
2585                 if (adev) {
2586                         adev->flags.match_driver = true;
2587                         if (device_attach(&adev->dev) < 0)
2588                                 dev_dbg(&adev->dev, "No driver\n");
2589                 }
2590         }
2591 }
2592
2593 static void __init acpi_get_spcr_uart_addr(void)
2594 {
2595         acpi_status status;
2596         struct acpi_table_spcr *spcr_ptr;
2597
2598         status = acpi_get_table(ACPI_SIG_SPCR, 0,
2599                                 (struct acpi_table_header **)&spcr_ptr);
2600         if (ACPI_FAILURE(status)) {
2601                 pr_warn("STAO table present, but SPCR is missing\n");
2602                 return;
2603         }
2604
2605         spcr_uart_addr = spcr_ptr->serial_port.address;
2606         acpi_put_table((struct acpi_table_header *)spcr_ptr);
2607 }
2608
2609 static bool acpi_scan_initialized;
2610
2611 void __init acpi_scan_init(void)
2612 {
2613         acpi_status status;
2614         struct acpi_table_stao *stao_ptr;
2615
2616         acpi_pci_root_init();
2617         acpi_pci_link_init();
2618         acpi_processor_init();
2619         acpi_platform_init();
2620         acpi_lpss_init();
2621         acpi_apd_init();
2622         acpi_cmos_rtc_init();
2623         acpi_container_init();
2624         acpi_memory_hotplug_init();
2625         acpi_watchdog_init();
2626         acpi_pnp_init();
2627         acpi_int340x_thermal_init();
2628         acpi_init_lpit();
2629
2630         acpi_scan_add_handler(&generic_device_handler);
2631
2632         /*
2633          * If there is STAO table, check whether it needs to ignore the UART
2634          * device in SPCR table.
2635          */
2636         status = acpi_get_table(ACPI_SIG_STAO, 0,
2637                                 (struct acpi_table_header **)&stao_ptr);
2638         if (ACPI_SUCCESS(status)) {
2639                 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2640                         pr_info("STAO Name List not yet supported.\n");
2641
2642                 if (stao_ptr->ignore_uart)
2643                         acpi_get_spcr_uart_addr();
2644
2645                 acpi_put_table((struct acpi_table_header *)stao_ptr);
2646         }
2647
2648         acpi_gpe_apply_masked_gpes();
2649         acpi_update_all_gpes();
2650
2651         /*
2652          * Although we call __add_memory() that is documented to require the
2653          * device_hotplug_lock, it is not necessary here because this is an
2654          * early code when userspace or any other code path cannot trigger
2655          * hotplug/hotunplug operations.
2656          */
2657         mutex_lock(&acpi_scan_lock);
2658         /*
2659          * Enumerate devices in the ACPI namespace.
2660          */
2661         if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2662                 goto unlock;
2663
2664         acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2665         if (!acpi_root)
2666                 goto unlock;
2667
2668         /* Fixed feature devices do not exist on HW-reduced platform */
2669         if (!acpi_gbl_reduced_hardware)
2670                 acpi_bus_scan_fixed();
2671
2672         acpi_turn_off_unused_power_resources();
2673
2674         acpi_scan_initialized = true;
2675
2676 unlock:
2677         mutex_unlock(&acpi_scan_lock);
2678 }
2679
2680 static struct acpi_probe_entry *ape;
2681 static int acpi_probe_count;
2682 static DEFINE_MUTEX(acpi_probe_mutex);
2683
2684 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2685                                   const unsigned long end)
2686 {
2687         if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2688                 if (!ape->probe_subtbl(header, end))
2689                         acpi_probe_count++;
2690
2691         return 0;
2692 }
2693
2694 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2695 {
2696         int count = 0;
2697
2698         if (acpi_disabled)
2699                 return 0;
2700
2701         mutex_lock(&acpi_probe_mutex);
2702         for (ape = ap_head; nr; ape++, nr--) {
2703                 if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2704                         acpi_probe_count = 0;
2705                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2706                         count += acpi_probe_count;
2707                 } else {
2708                         int res;
2709                         res = acpi_table_parse(ape->id, ape->probe_table);
2710                         if (!res)
2711                                 count++;
2712                 }
2713         }
2714         mutex_unlock(&acpi_probe_mutex);
2715
2716         return count;
2717 }
2718
2719 static void acpi_table_events_fn(struct work_struct *work)
2720 {
2721         acpi_scan_lock_acquire();
2722         acpi_bus_scan(ACPI_ROOT_OBJECT);
2723         acpi_scan_lock_release();
2724
2725         kfree(work);
2726 }
2727
2728 void acpi_scan_table_notify(void)
2729 {
2730         struct work_struct *work;
2731
2732         if (!acpi_scan_initialized)
2733                 return;
2734
2735         work = kmalloc(sizeof(*work), GFP_KERNEL);
2736         if (!work)
2737                 return;
2738
2739         INIT_WORK(work, acpi_table_events_fn);
2740         schedule_work(work);
2741 }
2742
2743 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2744 {
2745         return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2746 }
2747 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2748
2749 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2750 {
2751         return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2752 }
2753 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);