xref: /linux/drivers/acpi/scan.c (revision 83439a0f1ce6a592f95e41338320b5f01b98a356)
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 
27 extern struct acpi_device *acpi_root;
28 
29 #define ACPI_BUS_CLASS			"system_bus"
30 #define ACPI_BUS_HID			"LNXSYBUS"
31 #define ACPI_BUS_DEVICE_NAME		"System Bus"
32 
33 #define INVALID_ACPI_HANDLE	((acpi_handle)empty_zero_page)
34 
35 static const char *dummy_hid = "device";
36 
37 static LIST_HEAD(acpi_dep_list);
38 static DEFINE_MUTEX(acpi_dep_list_lock);
39 LIST_HEAD(acpi_bus_id_list);
40 static DEFINE_MUTEX(acpi_scan_lock);
41 static LIST_HEAD(acpi_scan_handlers_list);
42 DEFINE_MUTEX(acpi_device_lock);
43 LIST_HEAD(acpi_wakeup_device_list);
44 static DEFINE_MUTEX(acpi_hp_context_lock);
45 
46 /*
47  * The UART device described by the SPCR table is the only object which needs
48  * special-casing. Everything else is covered by ACPI namespace paths in STAO
49  * table.
50  */
51 static u64 spcr_uart_addr;
52 
53 void acpi_scan_lock_acquire(void)
54 {
55 	mutex_lock(&acpi_scan_lock);
56 }
57 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
58 
59 void acpi_scan_lock_release(void)
60 {
61 	mutex_unlock(&acpi_scan_lock);
62 }
63 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
64 
65 void acpi_lock_hp_context(void)
66 {
67 	mutex_lock(&acpi_hp_context_lock);
68 }
69 
70 void acpi_unlock_hp_context(void)
71 {
72 	mutex_unlock(&acpi_hp_context_lock);
73 }
74 
75 void acpi_initialize_hp_context(struct acpi_device *adev,
76 				struct acpi_hotplug_context *hp,
77 				int (*notify)(struct acpi_device *, u32),
78 				void (*uevent)(struct acpi_device *, u32))
79 {
80 	acpi_lock_hp_context();
81 	hp->notify = notify;
82 	hp->uevent = uevent;
83 	acpi_set_hp_context(adev, hp);
84 	acpi_unlock_hp_context();
85 }
86 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
87 
88 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
89 {
90 	if (!handler)
91 		return -EINVAL;
92 
93 	list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
94 	return 0;
95 }
96 
97 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
98 				       const char *hotplug_profile_name)
99 {
100 	int error;
101 
102 	error = acpi_scan_add_handler(handler);
103 	if (error)
104 		return error;
105 
106 	acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
107 	return 0;
108 }
109 
110 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
111 {
112 	struct acpi_device_physical_node *pn;
113 	bool offline = true;
114 	char *envp[] = { "EVENT=offline", NULL };
115 
116 	/*
117 	 * acpi_container_offline() calls this for all of the container's
118 	 * children under the container's physical_node_lock lock.
119 	 */
120 	mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
121 
122 	list_for_each_entry(pn, &adev->physical_node_list, node)
123 		if (device_supports_offline(pn->dev) && !pn->dev->offline) {
124 			if (uevent)
125 				kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
126 
127 			offline = false;
128 			break;
129 		}
130 
131 	mutex_unlock(&adev->physical_node_lock);
132 	return offline;
133 }
134 
135 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
136 				    void **ret_p)
137 {
138 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
139 	struct acpi_device_physical_node *pn;
140 	bool second_pass = (bool)data;
141 	acpi_status status = AE_OK;
142 
143 	if (!device)
144 		return AE_OK;
145 
146 	if (device->handler && !device->handler->hotplug.enabled) {
147 		*ret_p = &device->dev;
148 		return AE_SUPPORT;
149 	}
150 
151 	mutex_lock(&device->physical_node_lock);
152 
153 	list_for_each_entry(pn, &device->physical_node_list, node) {
154 		int ret;
155 
156 		if (second_pass) {
157 			/* Skip devices offlined by the first pass. */
158 			if (pn->put_online)
159 				continue;
160 		} else {
161 			pn->put_online = false;
162 		}
163 		ret = device_offline(pn->dev);
164 		if (ret >= 0) {
165 			pn->put_online = !ret;
166 		} else {
167 			*ret_p = pn->dev;
168 			if (second_pass) {
169 				status = AE_ERROR;
170 				break;
171 			}
172 		}
173 	}
174 
175 	mutex_unlock(&device->physical_node_lock);
176 
177 	return status;
178 }
179 
180 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
181 				   void **ret_p)
182 {
183 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
184 	struct acpi_device_physical_node *pn;
185 
186 	if (!device)
187 		return AE_OK;
188 
189 	mutex_lock(&device->physical_node_lock);
190 
191 	list_for_each_entry(pn, &device->physical_node_list, node)
192 		if (pn->put_online) {
193 			device_online(pn->dev);
194 			pn->put_online = false;
195 		}
196 
197 	mutex_unlock(&device->physical_node_lock);
198 
199 	return AE_OK;
200 }
201 
202 static int acpi_scan_try_to_offline(struct acpi_device *device)
203 {
204 	acpi_handle handle = device->handle;
205 	struct device *errdev = NULL;
206 	acpi_status status;
207 
208 	/*
209 	 * Carry out two passes here and ignore errors in the first pass,
210 	 * because if the devices in question are memory blocks and
211 	 * CONFIG_MEMCG is set, one of the blocks may hold data structures
212 	 * that the other blocks depend on, but it is not known in advance which
213 	 * block holds them.
214 	 *
215 	 * If the first pass is successful, the second one isn't needed, though.
216 	 */
217 	status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
218 				     NULL, acpi_bus_offline, (void *)false,
219 				     (void **)&errdev);
220 	if (status == AE_SUPPORT) {
221 		dev_warn(errdev, "Offline disabled.\n");
222 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
223 				    acpi_bus_online, NULL, NULL, NULL);
224 		return -EPERM;
225 	}
226 	acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
227 	if (errdev) {
228 		errdev = NULL;
229 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
230 				    NULL, acpi_bus_offline, (void *)true,
231 				    (void **)&errdev);
232 		if (!errdev)
233 			acpi_bus_offline(handle, 0, (void *)true,
234 					 (void **)&errdev);
235 
236 		if (errdev) {
237 			dev_warn(errdev, "Offline failed.\n");
238 			acpi_bus_online(handle, 0, NULL, NULL);
239 			acpi_walk_namespace(ACPI_TYPE_ANY, handle,
240 					    ACPI_UINT32_MAX, acpi_bus_online,
241 					    NULL, NULL, NULL);
242 			return -EBUSY;
243 		}
244 	}
245 	return 0;
246 }
247 
248 static int acpi_scan_hot_remove(struct acpi_device *device)
249 {
250 	acpi_handle handle = device->handle;
251 	unsigned long long sta;
252 	acpi_status status;
253 
254 	if (device->handler && device->handler->hotplug.demand_offline) {
255 		if (!acpi_scan_is_offline(device, true))
256 			return -EBUSY;
257 	} else {
258 		int error = acpi_scan_try_to_offline(device);
259 		if (error)
260 			return error;
261 	}
262 
263 	acpi_handle_debug(handle, "Ejecting\n");
264 
265 	acpi_bus_trim(device);
266 
267 	acpi_evaluate_lck(handle, 0);
268 	/*
269 	 * TBD: _EJD support.
270 	 */
271 	status = acpi_evaluate_ej0(handle);
272 	if (status == AE_NOT_FOUND)
273 		return -ENODEV;
274 	else if (ACPI_FAILURE(status))
275 		return -EIO;
276 
277 	/*
278 	 * Verify if eject was indeed successful.  If not, log an error
279 	 * message.  No need to call _OST since _EJ0 call was made OK.
280 	 */
281 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
282 	if (ACPI_FAILURE(status)) {
283 		acpi_handle_warn(handle,
284 			"Status check after eject failed (0x%x)\n", status);
285 	} else if (sta & ACPI_STA_DEVICE_ENABLED) {
286 		acpi_handle_warn(handle,
287 			"Eject incomplete - status 0x%llx\n", sta);
288 	}
289 
290 	return 0;
291 }
292 
293 static int acpi_scan_device_not_present(struct acpi_device *adev)
294 {
295 	if (!acpi_device_enumerated(adev)) {
296 		dev_warn(&adev->dev, "Still not present\n");
297 		return -EALREADY;
298 	}
299 	acpi_bus_trim(adev);
300 	return 0;
301 }
302 
303 static int acpi_scan_device_check(struct acpi_device *adev)
304 {
305 	int error;
306 
307 	acpi_bus_get_status(adev);
308 	if (adev->status.present || adev->status.functional) {
309 		/*
310 		 * This function is only called for device objects for which
311 		 * matching scan handlers exist.  The only situation in which
312 		 * the scan handler is not attached to this device object yet
313 		 * is when the device has just appeared (either it wasn't
314 		 * present at all before or it was removed and then added
315 		 * again).
316 		 */
317 		if (adev->handler) {
318 			dev_warn(&adev->dev, "Already enumerated\n");
319 			return -EALREADY;
320 		}
321 		error = acpi_bus_scan(adev->handle);
322 		if (error) {
323 			dev_warn(&adev->dev, "Namespace scan failure\n");
324 			return error;
325 		}
326 		if (!adev->handler) {
327 			dev_warn(&adev->dev, "Enumeration failure\n");
328 			error = -ENODEV;
329 		}
330 	} else {
331 		error = acpi_scan_device_not_present(adev);
332 	}
333 	return error;
334 }
335 
336 static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used)
337 {
338 	struct acpi_scan_handler *handler = adev->handler;
339 	int error;
340 
341 	acpi_bus_get_status(adev);
342 	if (!(adev->status.present || adev->status.functional)) {
343 		acpi_scan_device_not_present(adev);
344 		return 0;
345 	}
346 	if (handler && handler->hotplug.scan_dependent)
347 		return handler->hotplug.scan_dependent(adev);
348 
349 	error = acpi_bus_scan(adev->handle);
350 	if (error) {
351 		dev_warn(&adev->dev, "Namespace scan failure\n");
352 		return error;
353 	}
354 	return acpi_dev_for_each_child(adev, acpi_scan_bus_check, NULL);
355 }
356 
357 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
358 {
359 	switch (type) {
360 	case ACPI_NOTIFY_BUS_CHECK:
361 		return acpi_scan_bus_check(adev, NULL);
362 	case ACPI_NOTIFY_DEVICE_CHECK:
363 		return acpi_scan_device_check(adev);
364 	case ACPI_NOTIFY_EJECT_REQUEST:
365 	case ACPI_OST_EC_OSPM_EJECT:
366 		if (adev->handler && !adev->handler->hotplug.enabled) {
367 			dev_info(&adev->dev, "Eject disabled\n");
368 			return -EPERM;
369 		}
370 		acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
371 				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
372 		return acpi_scan_hot_remove(adev);
373 	}
374 	return -EINVAL;
375 }
376 
377 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
378 {
379 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
380 	int error = -ENODEV;
381 
382 	lock_device_hotplug();
383 	mutex_lock(&acpi_scan_lock);
384 
385 	/*
386 	 * The device object's ACPI handle cannot become invalid as long as we
387 	 * are holding acpi_scan_lock, but it might have become invalid before
388 	 * that lock was acquired.
389 	 */
390 	if (adev->handle == INVALID_ACPI_HANDLE)
391 		goto err_out;
392 
393 	if (adev->flags.is_dock_station) {
394 		error = dock_notify(adev, src);
395 	} else if (adev->flags.hotplug_notify) {
396 		error = acpi_generic_hotplug_event(adev, src);
397 	} else {
398 		int (*notify)(struct acpi_device *, u32);
399 
400 		acpi_lock_hp_context();
401 		notify = adev->hp ? adev->hp->notify : NULL;
402 		acpi_unlock_hp_context();
403 		/*
404 		 * There may be additional notify handlers for device objects
405 		 * without the .event() callback, so ignore them here.
406 		 */
407 		if (notify)
408 			error = notify(adev, src);
409 		else
410 			goto out;
411 	}
412 	switch (error) {
413 	case 0:
414 		ost_code = ACPI_OST_SC_SUCCESS;
415 		break;
416 	case -EPERM:
417 		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
418 		break;
419 	case -EBUSY:
420 		ost_code = ACPI_OST_SC_DEVICE_BUSY;
421 		break;
422 	default:
423 		ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
424 		break;
425 	}
426 
427  err_out:
428 	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
429 
430  out:
431 	acpi_put_acpi_dev(adev);
432 	mutex_unlock(&acpi_scan_lock);
433 	unlock_device_hotplug();
434 }
435 
436 static void acpi_free_power_resources_lists(struct acpi_device *device)
437 {
438 	int i;
439 
440 	if (device->wakeup.flags.valid)
441 		acpi_power_resources_list_free(&device->wakeup.resources);
442 
443 	if (!device->power.flags.power_resources)
444 		return;
445 
446 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
447 		struct acpi_device_power_state *ps = &device->power.states[i];
448 		acpi_power_resources_list_free(&ps->resources);
449 	}
450 }
451 
452 static void acpi_device_release(struct device *dev)
453 {
454 	struct acpi_device *acpi_dev = to_acpi_device(dev);
455 
456 	acpi_free_properties(acpi_dev);
457 	acpi_free_pnp_ids(&acpi_dev->pnp);
458 	acpi_free_power_resources_lists(acpi_dev);
459 	kfree(acpi_dev);
460 }
461 
462 static void acpi_device_del(struct acpi_device *device)
463 {
464 	struct acpi_device_bus_id *acpi_device_bus_id;
465 
466 	mutex_lock(&acpi_device_lock);
467 
468 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
469 		if (!strcmp(acpi_device_bus_id->bus_id,
470 			    acpi_device_hid(device))) {
471 			ida_free(&acpi_device_bus_id->instance_ida,
472 				 device->pnp.instance_no);
473 			if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
474 				list_del(&acpi_device_bus_id->node);
475 				kfree_const(acpi_device_bus_id->bus_id);
476 				kfree(acpi_device_bus_id);
477 			}
478 			break;
479 		}
480 
481 	list_del(&device->wakeup_list);
482 
483 	mutex_unlock(&acpi_device_lock);
484 
485 	acpi_power_add_remove_device(device, false);
486 	acpi_device_remove_files(device);
487 	if (device->remove)
488 		device->remove(device);
489 
490 	device_del(&device->dev);
491 }
492 
493 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
494 
495 static LIST_HEAD(acpi_device_del_list);
496 static DEFINE_MUTEX(acpi_device_del_lock);
497 
498 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
499 {
500 	for (;;) {
501 		struct acpi_device *adev;
502 
503 		mutex_lock(&acpi_device_del_lock);
504 
505 		if (list_empty(&acpi_device_del_list)) {
506 			mutex_unlock(&acpi_device_del_lock);
507 			break;
508 		}
509 		adev = list_first_entry(&acpi_device_del_list,
510 					struct acpi_device, del_list);
511 		list_del(&adev->del_list);
512 
513 		mutex_unlock(&acpi_device_del_lock);
514 
515 		blocking_notifier_call_chain(&acpi_reconfig_chain,
516 					     ACPI_RECONFIG_DEVICE_REMOVE, adev);
517 
518 		acpi_device_del(adev);
519 		/*
520 		 * Drop references to all power resources that might have been
521 		 * used by the device.
522 		 */
523 		acpi_power_transition(adev, ACPI_STATE_D3_COLD);
524 		acpi_dev_put(adev);
525 	}
526 }
527 
528 /**
529  * acpi_scan_drop_device - Drop an ACPI device object.
530  * @handle: Handle of an ACPI namespace node, not used.
531  * @context: Address of the ACPI device object to drop.
532  *
533  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
534  * namespace node the device object pointed to by @context is attached to.
535  *
536  * The unregistration is carried out asynchronously to avoid running
537  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
538  * ensure the correct ordering (the device objects must be unregistered in the
539  * same order in which the corresponding namespace nodes are deleted).
540  */
541 static void acpi_scan_drop_device(acpi_handle handle, void *context)
542 {
543 	static DECLARE_WORK(work, acpi_device_del_work_fn);
544 	struct acpi_device *adev = context;
545 
546 	mutex_lock(&acpi_device_del_lock);
547 
548 	/*
549 	 * Use the ACPI hotplug workqueue which is ordered, so this work item
550 	 * won't run after any hotplug work items submitted subsequently.  That
551 	 * prevents attempts to register device objects identical to those being
552 	 * deleted from happening concurrently (such attempts result from
553 	 * hotplug events handled via the ACPI hotplug workqueue).  It also will
554 	 * run after all of the work items submitted previously, which helps
555 	 * those work items to ensure that they are not accessing stale device
556 	 * objects.
557 	 */
558 	if (list_empty(&acpi_device_del_list))
559 		acpi_queue_hotplug_work(&work);
560 
561 	list_add_tail(&adev->del_list, &acpi_device_del_list);
562 	/* Make acpi_ns_validate_handle() return NULL for this handle. */
563 	adev->handle = INVALID_ACPI_HANDLE;
564 
565 	mutex_unlock(&acpi_device_del_lock);
566 }
567 
568 static struct acpi_device *handle_to_device(acpi_handle handle,
569 					    void (*callback)(void *))
570 {
571 	struct acpi_device *adev = NULL;
572 	acpi_status status;
573 
574 	status = acpi_get_data_full(handle, acpi_scan_drop_device,
575 				    (void **)&adev, callback);
576 	if (ACPI_FAILURE(status) || !adev) {
577 		acpi_handle_debug(handle, "No context!\n");
578 		return NULL;
579 	}
580 	return adev;
581 }
582 
583 /**
584  * acpi_fetch_acpi_dev - Retrieve ACPI device object.
585  * @handle: ACPI handle associated with the requested ACPI device object.
586  *
587  * Return a pointer to the ACPI device object associated with @handle, if
588  * present, or NULL otherwise.
589  */
590 struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
591 {
592 	return handle_to_device(handle, NULL);
593 }
594 EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);
595 
596 static void get_acpi_device(void *dev)
597 {
598 	acpi_dev_get(dev);
599 }
600 
601 /**
602  * acpi_get_acpi_dev - Retrieve ACPI device object and reference count it.
603  * @handle: ACPI handle associated with the requested ACPI device object.
604  *
605  * Return a pointer to the ACPI device object associated with @handle and bump
606  * up that object's reference counter (under the ACPI Namespace lock), if
607  * present, or return NULL otherwise.
608  *
609  * The ACPI device object reference acquired by this function needs to be
610  * dropped via acpi_dev_put().
611  */
612 struct acpi_device *acpi_get_acpi_dev(acpi_handle handle)
613 {
614 	return handle_to_device(handle, get_acpi_device);
615 }
616 EXPORT_SYMBOL_GPL(acpi_get_acpi_dev);
617 
618 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
619 {
620 	struct acpi_device_bus_id *acpi_device_bus_id;
621 
622 	/* Find suitable bus_id and instance number in acpi_bus_id_list. */
623 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
624 		if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
625 			return acpi_device_bus_id;
626 	}
627 	return NULL;
628 }
629 
630 static int acpi_device_set_name(struct acpi_device *device,
631 				struct acpi_device_bus_id *acpi_device_bus_id)
632 {
633 	struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
634 	int result;
635 
636 	result = ida_alloc(instance_ida, GFP_KERNEL);
637 	if (result < 0)
638 		return result;
639 
640 	device->pnp.instance_no = result;
641 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
642 	return 0;
643 }
644 
645 int acpi_tie_acpi_dev(struct acpi_device *adev)
646 {
647 	acpi_handle handle = adev->handle;
648 	acpi_status status;
649 
650 	if (!handle)
651 		return 0;
652 
653 	status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
654 	if (ACPI_FAILURE(status)) {
655 		acpi_handle_err(handle, "Unable to attach device data\n");
656 		return -ENODEV;
657 	}
658 
659 	return 0;
660 }
661 
662 static void acpi_store_pld_crc(struct acpi_device *adev)
663 {
664 	struct acpi_pld_info *pld;
665 	acpi_status status;
666 
667 	status = acpi_get_physical_device_location(adev->handle, &pld);
668 	if (ACPI_FAILURE(status))
669 		return;
670 
671 	adev->pld_crc = crc32(~0, pld, sizeof(*pld));
672 	ACPI_FREE(pld);
673 }
674 
675 int acpi_device_add(struct acpi_device *device)
676 {
677 	struct acpi_device_bus_id *acpi_device_bus_id;
678 	int result;
679 
680 	/*
681 	 * Linkage
682 	 * -------
683 	 * Link this device to its parent and siblings.
684 	 */
685 	INIT_LIST_HEAD(&device->wakeup_list);
686 	INIT_LIST_HEAD(&device->physical_node_list);
687 	INIT_LIST_HEAD(&device->del_list);
688 	mutex_init(&device->physical_node_lock);
689 
690 	mutex_lock(&acpi_device_lock);
691 
692 	acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
693 	if (acpi_device_bus_id) {
694 		result = acpi_device_set_name(device, acpi_device_bus_id);
695 		if (result)
696 			goto err_unlock;
697 	} else {
698 		acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
699 					     GFP_KERNEL);
700 		if (!acpi_device_bus_id) {
701 			result = -ENOMEM;
702 			goto err_unlock;
703 		}
704 		acpi_device_bus_id->bus_id =
705 			kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
706 		if (!acpi_device_bus_id->bus_id) {
707 			kfree(acpi_device_bus_id);
708 			result = -ENOMEM;
709 			goto err_unlock;
710 		}
711 
712 		ida_init(&acpi_device_bus_id->instance_ida);
713 
714 		result = acpi_device_set_name(device, acpi_device_bus_id);
715 		if (result) {
716 			kfree_const(acpi_device_bus_id->bus_id);
717 			kfree(acpi_device_bus_id);
718 			goto err_unlock;
719 		}
720 
721 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
722 	}
723 
724 	if (device->wakeup.flags.valid)
725 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
726 
727 	acpi_store_pld_crc(device);
728 
729 	mutex_unlock(&acpi_device_lock);
730 
731 	result = device_add(&device->dev);
732 	if (result) {
733 		dev_err(&device->dev, "Error registering device\n");
734 		goto err;
735 	}
736 
737 	result = acpi_device_setup_files(device);
738 	if (result)
739 		pr_err("Error creating sysfs interface for device %s\n",
740 		       dev_name(&device->dev));
741 
742 	return 0;
743 
744 err:
745 	mutex_lock(&acpi_device_lock);
746 
747 	list_del(&device->wakeup_list);
748 
749 err_unlock:
750 	mutex_unlock(&acpi_device_lock);
751 
752 	acpi_detach_data(device->handle, acpi_scan_drop_device);
753 
754 	return result;
755 }
756 
757 /* --------------------------------------------------------------------------
758                                  Device Enumeration
759    -------------------------------------------------------------------------- */
760 static bool acpi_info_matches_ids(struct acpi_device_info *info,
761 				  const char * const ids[])
762 {
763 	struct acpi_pnp_device_id_list *cid_list = NULL;
764 	int i, index;
765 
766 	if (!(info->valid & ACPI_VALID_HID))
767 		return false;
768 
769 	index = match_string(ids, -1, info->hardware_id.string);
770 	if (index >= 0)
771 		return true;
772 
773 	if (info->valid & ACPI_VALID_CID)
774 		cid_list = &info->compatible_id_list;
775 
776 	if (!cid_list)
777 		return false;
778 
779 	for (i = 0; i < cid_list->count; i++) {
780 		index = match_string(ids, -1, cid_list->ids[i].string);
781 		if (index >= 0)
782 			return true;
783 	}
784 
785 	return false;
786 }
787 
788 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
789 static const char * const acpi_ignore_dep_ids[] = {
790 	"PNP0D80", /* Windows-compatible System Power Management Controller */
791 	"INT33BD", /* Intel Baytrail Mailbox Device */
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 	NULL
799 };
800 
801 static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
802 {
803 	struct acpi_device *adev;
804 
805 	/*
806 	 * Fixed hardware devices do not appear in the namespace and do not
807 	 * have handles, but we fabricate acpi_devices for them, so we have
808 	 * to deal with them specially.
809 	 */
810 	if (!handle)
811 		return acpi_root;
812 
813 	do {
814 		acpi_status status;
815 
816 		status = acpi_get_parent(handle, &handle);
817 		if (ACPI_FAILURE(status)) {
818 			if (status != AE_NULL_ENTRY)
819 				return acpi_root;
820 
821 			return NULL;
822 		}
823 		adev = acpi_fetch_acpi_dev(handle);
824 	} while (!adev);
825 	return adev;
826 }
827 
828 acpi_status
829 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
830 {
831 	acpi_status status;
832 	acpi_handle tmp;
833 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
834 	union acpi_object *obj;
835 
836 	status = acpi_get_handle(handle, "_EJD", &tmp);
837 	if (ACPI_FAILURE(status))
838 		return status;
839 
840 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
841 	if (ACPI_SUCCESS(status)) {
842 		obj = buffer.pointer;
843 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
844 					 ejd);
845 		kfree(buffer.pointer);
846 	}
847 	return status;
848 }
849 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
850 
851 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
852 {
853 	acpi_handle handle = dev->handle;
854 	struct acpi_device_wakeup *wakeup = &dev->wakeup;
855 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
856 	union acpi_object *package = NULL;
857 	union acpi_object *element = NULL;
858 	acpi_status status;
859 	int err = -ENODATA;
860 
861 	INIT_LIST_HEAD(&wakeup->resources);
862 
863 	/* _PRW */
864 	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
865 	if (ACPI_FAILURE(status)) {
866 		acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
867 				 acpi_format_exception(status));
868 		return err;
869 	}
870 
871 	package = (union acpi_object *)buffer.pointer;
872 
873 	if (!package || package->package.count < 2)
874 		goto out;
875 
876 	element = &(package->package.elements[0]);
877 	if (!element)
878 		goto out;
879 
880 	if (element->type == ACPI_TYPE_PACKAGE) {
881 		if ((element->package.count < 2) ||
882 		    (element->package.elements[0].type !=
883 		     ACPI_TYPE_LOCAL_REFERENCE)
884 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
885 			goto out;
886 
887 		wakeup->gpe_device =
888 		    element->package.elements[0].reference.handle;
889 		wakeup->gpe_number =
890 		    (u32) element->package.elements[1].integer.value;
891 	} else if (element->type == ACPI_TYPE_INTEGER) {
892 		wakeup->gpe_device = NULL;
893 		wakeup->gpe_number = element->integer.value;
894 	} else {
895 		goto out;
896 	}
897 
898 	element = &(package->package.elements[1]);
899 	if (element->type != ACPI_TYPE_INTEGER)
900 		goto out;
901 
902 	wakeup->sleep_state = element->integer.value;
903 
904 	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
905 	if (err)
906 		goto out;
907 
908 	if (!list_empty(&wakeup->resources)) {
909 		int sleep_state;
910 
911 		err = acpi_power_wakeup_list_init(&wakeup->resources,
912 						  &sleep_state);
913 		if (err) {
914 			acpi_handle_warn(handle, "Retrieving current states "
915 					 "of wakeup power resources failed\n");
916 			acpi_power_resources_list_free(&wakeup->resources);
917 			goto out;
918 		}
919 		if (sleep_state < wakeup->sleep_state) {
920 			acpi_handle_warn(handle, "Overriding _PRW sleep state "
921 					 "(S%d) by S%d from power resources\n",
922 					 (int)wakeup->sleep_state, sleep_state);
923 			wakeup->sleep_state = sleep_state;
924 		}
925 	}
926 
927  out:
928 	kfree(buffer.pointer);
929 	return err;
930 }
931 
932 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
933 {
934 	static const struct acpi_device_id button_device_ids[] = {
935 		{"PNP0C0C", 0},		/* Power button */
936 		{"PNP0C0D", 0},		/* Lid */
937 		{"PNP0C0E", 0},		/* Sleep button */
938 		{"", 0},
939 	};
940 	struct acpi_device_wakeup *wakeup = &device->wakeup;
941 	acpi_status status;
942 
943 	wakeup->flags.notifier_present = 0;
944 
945 	/* Power button, Lid switch always enable wakeup */
946 	if (!acpi_match_device_ids(device, button_device_ids)) {
947 		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
948 			/* Do not use Lid/sleep button for S5 wakeup */
949 			if (wakeup->sleep_state == ACPI_STATE_S5)
950 				wakeup->sleep_state = ACPI_STATE_S4;
951 		}
952 		acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
953 		device_set_wakeup_capable(&device->dev, true);
954 		return true;
955 	}
956 
957 	status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
958 					 wakeup->gpe_number);
959 	return ACPI_SUCCESS(status);
960 }
961 
962 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
963 {
964 	int err;
965 
966 	/* Presence of _PRW indicates wake capable */
967 	if (!acpi_has_method(device->handle, "_PRW"))
968 		return;
969 
970 	err = acpi_bus_extract_wakeup_device_power_package(device);
971 	if (err) {
972 		dev_err(&device->dev, "Unable to extract wakeup power resources");
973 		return;
974 	}
975 
976 	device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
977 	device->wakeup.prepare_count = 0;
978 	/*
979 	 * Call _PSW/_DSW object to disable its ability to wake the sleeping
980 	 * system for the ACPI device with the _PRW object.
981 	 * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
982 	 * So it is necessary to call _DSW object first. Only when it is not
983 	 * present will the _PSW object used.
984 	 */
985 	err = acpi_device_sleep_wake(device, 0, 0, 0);
986 	if (err)
987 		pr_debug("error in _DSW or _PSW evaluation\n");
988 }
989 
990 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
991 {
992 	struct acpi_device_power_state *ps = &device->power.states[state];
993 	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
994 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
995 	acpi_status status;
996 
997 	INIT_LIST_HEAD(&ps->resources);
998 
999 	/* Evaluate "_PRx" to get referenced power resources */
1000 	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1001 	if (ACPI_SUCCESS(status)) {
1002 		union acpi_object *package = buffer.pointer;
1003 
1004 		if (buffer.length && package
1005 		    && package->type == ACPI_TYPE_PACKAGE
1006 		    && package->package.count)
1007 			acpi_extract_power_resources(package, 0, &ps->resources);
1008 
1009 		ACPI_FREE(buffer.pointer);
1010 	}
1011 
1012 	/* Evaluate "_PSx" to see if we can do explicit sets */
1013 	pathname[2] = 'S';
1014 	if (acpi_has_method(device->handle, pathname))
1015 		ps->flags.explicit_set = 1;
1016 
1017 	/* State is valid if there are means to put the device into it. */
1018 	if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1019 		ps->flags.valid = 1;
1020 
1021 	ps->power = -1;		/* Unknown - driver assigned */
1022 	ps->latency = -1;	/* Unknown - driver assigned */
1023 }
1024 
1025 static void acpi_bus_get_power_flags(struct acpi_device *device)
1026 {
1027 	unsigned long long dsc = ACPI_STATE_D0;
1028 	u32 i;
1029 
1030 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
1031 	if (!acpi_has_method(device->handle, "_PS0") &&
1032 	    !acpi_has_method(device->handle, "_PR0"))
1033 		return;
1034 
1035 	device->flags.power_manageable = 1;
1036 
1037 	/*
1038 	 * Power Management Flags
1039 	 */
1040 	if (acpi_has_method(device->handle, "_PSC"))
1041 		device->power.flags.explicit_get = 1;
1042 
1043 	if (acpi_has_method(device->handle, "_IRC"))
1044 		device->power.flags.inrush_current = 1;
1045 
1046 	if (acpi_has_method(device->handle, "_DSW"))
1047 		device->power.flags.dsw_present = 1;
1048 
1049 	acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1050 	device->power.state_for_enumeration = dsc;
1051 
1052 	/*
1053 	 * Enumerate supported power management states
1054 	 */
1055 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1056 		acpi_bus_init_power_state(device, i);
1057 
1058 	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1059 
1060 	/* Set the defaults for D0 and D3hot (always supported). */
1061 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
1062 	device->power.states[ACPI_STATE_D0].power = 100;
1063 	device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1064 
1065 	/*
1066 	 * Use power resources only if the D0 list of them is populated, because
1067 	 * some platforms may provide _PR3 only to indicate D3cold support and
1068 	 * in those cases the power resources list returned by it may be bogus.
1069 	 */
1070 	if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1071 		device->power.flags.power_resources = 1;
1072 		/*
1073 		 * D3cold is supported if the D3hot list of power resources is
1074 		 * not empty.
1075 		 */
1076 		if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1077 			device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1078 	}
1079 
1080 	if (acpi_bus_init_power(device))
1081 		device->flags.power_manageable = 0;
1082 }
1083 
1084 static void acpi_bus_get_flags(struct acpi_device *device)
1085 {
1086 	/* Presence of _STA indicates 'dynamic_status' */
1087 	if (acpi_has_method(device->handle, "_STA"))
1088 		device->flags.dynamic_status = 1;
1089 
1090 	/* Presence of _RMV indicates 'removable' */
1091 	if (acpi_has_method(device->handle, "_RMV"))
1092 		device->flags.removable = 1;
1093 
1094 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
1095 	if (acpi_has_method(device->handle, "_EJD") ||
1096 	    acpi_has_method(device->handle, "_EJ0"))
1097 		device->flags.ejectable = 1;
1098 }
1099 
1100 static void acpi_device_get_busid(struct acpi_device *device)
1101 {
1102 	char bus_id[5] = { '?', 0 };
1103 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1104 	int i = 0;
1105 
1106 	/*
1107 	 * Bus ID
1108 	 * ------
1109 	 * The device's Bus ID is simply the object name.
1110 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1111 	 */
1112 	if (!acpi_dev_parent(device)) {
1113 		strcpy(device->pnp.bus_id, "ACPI");
1114 		return;
1115 	}
1116 
1117 	switch (device->device_type) {
1118 	case ACPI_BUS_TYPE_POWER_BUTTON:
1119 		strcpy(device->pnp.bus_id, "PWRF");
1120 		break;
1121 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1122 		strcpy(device->pnp.bus_id, "SLPF");
1123 		break;
1124 	case ACPI_BUS_TYPE_ECDT_EC:
1125 		strcpy(device->pnp.bus_id, "ECDT");
1126 		break;
1127 	default:
1128 		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1129 		/* Clean up trailing underscores (if any) */
1130 		for (i = 3; i > 1; i--) {
1131 			if (bus_id[i] == '_')
1132 				bus_id[i] = '\0';
1133 			else
1134 				break;
1135 		}
1136 		strcpy(device->pnp.bus_id, bus_id);
1137 		break;
1138 	}
1139 }
1140 
1141 /*
1142  * acpi_ata_match - see if an acpi object is an ATA device
1143  *
1144  * If an acpi object has one of the ACPI ATA methods defined,
1145  * then we can safely call it an ATA device.
1146  */
1147 bool acpi_ata_match(acpi_handle handle)
1148 {
1149 	return acpi_has_method(handle, "_GTF") ||
1150 	       acpi_has_method(handle, "_GTM") ||
1151 	       acpi_has_method(handle, "_STM") ||
1152 	       acpi_has_method(handle, "_SDD");
1153 }
1154 
1155 /*
1156  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1157  *
1158  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1159  * then we can safely call it an ejectable drive bay
1160  */
1161 bool acpi_bay_match(acpi_handle handle)
1162 {
1163 	acpi_handle phandle;
1164 
1165 	if (!acpi_has_method(handle, "_EJ0"))
1166 		return false;
1167 	if (acpi_ata_match(handle))
1168 		return true;
1169 	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1170 		return false;
1171 
1172 	return acpi_ata_match(phandle);
1173 }
1174 
1175 bool acpi_device_is_battery(struct acpi_device *adev)
1176 {
1177 	struct acpi_hardware_id *hwid;
1178 
1179 	list_for_each_entry(hwid, &adev->pnp.ids, list)
1180 		if (!strcmp("PNP0C0A", hwid->id))
1181 			return true;
1182 
1183 	return false;
1184 }
1185 
1186 static bool is_ejectable_bay(struct acpi_device *adev)
1187 {
1188 	acpi_handle handle = adev->handle;
1189 
1190 	if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1191 		return true;
1192 
1193 	return acpi_bay_match(handle);
1194 }
1195 
1196 /*
1197  * acpi_dock_match - see if an acpi object has a _DCK method
1198  */
1199 bool acpi_dock_match(acpi_handle handle)
1200 {
1201 	return acpi_has_method(handle, "_DCK");
1202 }
1203 
1204 static acpi_status
1205 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1206 			  void **return_value)
1207 {
1208 	long *cap = context;
1209 
1210 	if (acpi_has_method(handle, "_BCM") &&
1211 	    acpi_has_method(handle, "_BCL")) {
1212 		acpi_handle_debug(handle, "Found generic backlight support\n");
1213 		*cap |= ACPI_VIDEO_BACKLIGHT;
1214 		/* We have backlight support, no need to scan further */
1215 		return AE_CTRL_TERMINATE;
1216 	}
1217 	return 0;
1218 }
1219 
1220 /* Returns true if the ACPI object is a video device which can be
1221  * handled by video.ko.
1222  * The device will get a Linux specific CID added in scan.c to
1223  * identify the device as an ACPI graphics device
1224  * Be aware that the graphics device may not be physically present
1225  * Use acpi_video_get_capabilities() to detect general ACPI video
1226  * capabilities of present cards
1227  */
1228 long acpi_is_video_device(acpi_handle handle)
1229 {
1230 	long video_caps = 0;
1231 
1232 	/* Is this device able to support video switching ? */
1233 	if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1234 		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1235 
1236 	/* Is this device able to retrieve a video ROM ? */
1237 	if (acpi_has_method(handle, "_ROM"))
1238 		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1239 
1240 	/* Is this device able to configure which video head to be POSTed ? */
1241 	if (acpi_has_method(handle, "_VPO") &&
1242 	    acpi_has_method(handle, "_GPD") &&
1243 	    acpi_has_method(handle, "_SPD"))
1244 		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1245 
1246 	/* Only check for backlight functionality if one of the above hit. */
1247 	if (video_caps)
1248 		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1249 				    ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1250 				    &video_caps, NULL);
1251 
1252 	return video_caps;
1253 }
1254 EXPORT_SYMBOL(acpi_is_video_device);
1255 
1256 const char *acpi_device_hid(struct acpi_device *device)
1257 {
1258 	struct acpi_hardware_id *hid;
1259 
1260 	if (list_empty(&device->pnp.ids))
1261 		return dummy_hid;
1262 
1263 	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1264 	return hid->id;
1265 }
1266 EXPORT_SYMBOL(acpi_device_hid);
1267 
1268 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1269 {
1270 	struct acpi_hardware_id *id;
1271 
1272 	id = kmalloc(sizeof(*id), GFP_KERNEL);
1273 	if (!id)
1274 		return;
1275 
1276 	id->id = kstrdup_const(dev_id, GFP_KERNEL);
1277 	if (!id->id) {
1278 		kfree(id);
1279 		return;
1280 	}
1281 
1282 	list_add_tail(&id->list, &pnp->ids);
1283 	pnp->type.hardware_id = 1;
1284 }
1285 
1286 /*
1287  * Old IBM workstations have a DSDT bug wherein the SMBus object
1288  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1289  * prefix.  Work around this.
1290  */
1291 static bool acpi_ibm_smbus_match(acpi_handle handle)
1292 {
1293 	char node_name[ACPI_PATH_SEGMENT_LENGTH];
1294 	struct acpi_buffer path = { sizeof(node_name), node_name };
1295 
1296 	if (!dmi_name_in_vendors("IBM"))
1297 		return false;
1298 
1299 	/* Look for SMBS object */
1300 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1301 	    strcmp("SMBS", path.pointer))
1302 		return false;
1303 
1304 	/* Does it have the necessary (but misnamed) methods? */
1305 	if (acpi_has_method(handle, "SBI") &&
1306 	    acpi_has_method(handle, "SBR") &&
1307 	    acpi_has_method(handle, "SBW"))
1308 		return true;
1309 
1310 	return false;
1311 }
1312 
1313 static bool acpi_object_is_system_bus(acpi_handle handle)
1314 {
1315 	acpi_handle tmp;
1316 
1317 	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1318 	    tmp == handle)
1319 		return true;
1320 	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1321 	    tmp == handle)
1322 		return true;
1323 
1324 	return false;
1325 }
1326 
1327 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1328 			     int device_type)
1329 {
1330 	struct acpi_device_info *info = NULL;
1331 	struct acpi_pnp_device_id_list *cid_list;
1332 	int i;
1333 
1334 	switch (device_type) {
1335 	case ACPI_BUS_TYPE_DEVICE:
1336 		if (handle == ACPI_ROOT_OBJECT) {
1337 			acpi_add_id(pnp, ACPI_SYSTEM_HID);
1338 			break;
1339 		}
1340 
1341 		acpi_get_object_info(handle, &info);
1342 		if (!info) {
1343 			pr_err("%s: Error reading device info\n", __func__);
1344 			return;
1345 		}
1346 
1347 		if (info->valid & ACPI_VALID_HID) {
1348 			acpi_add_id(pnp, info->hardware_id.string);
1349 			pnp->type.platform_id = 1;
1350 		}
1351 		if (info->valid & ACPI_VALID_CID) {
1352 			cid_list = &info->compatible_id_list;
1353 			for (i = 0; i < cid_list->count; i++)
1354 				acpi_add_id(pnp, cid_list->ids[i].string);
1355 		}
1356 		if (info->valid & ACPI_VALID_ADR) {
1357 			pnp->bus_address = info->address;
1358 			pnp->type.bus_address = 1;
1359 		}
1360 		if (info->valid & ACPI_VALID_UID)
1361 			pnp->unique_id = kstrdup(info->unique_id.string,
1362 							GFP_KERNEL);
1363 		if (info->valid & ACPI_VALID_CLS)
1364 			acpi_add_id(pnp, info->class_code.string);
1365 
1366 		kfree(info);
1367 
1368 		/*
1369 		 * Some devices don't reliably have _HIDs & _CIDs, so add
1370 		 * synthetic HIDs to make sure drivers can find them.
1371 		 */
1372 		if (acpi_is_video_device(handle))
1373 			acpi_add_id(pnp, ACPI_VIDEO_HID);
1374 		else if (acpi_bay_match(handle))
1375 			acpi_add_id(pnp, ACPI_BAY_HID);
1376 		else if (acpi_dock_match(handle))
1377 			acpi_add_id(pnp, ACPI_DOCK_HID);
1378 		else if (acpi_ibm_smbus_match(handle))
1379 			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1380 		else if (list_empty(&pnp->ids) &&
1381 			 acpi_object_is_system_bus(handle)) {
1382 			/* \_SB, \_TZ, LNXSYBUS */
1383 			acpi_add_id(pnp, ACPI_BUS_HID);
1384 			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1385 			strcpy(pnp->device_class, ACPI_BUS_CLASS);
1386 		}
1387 
1388 		break;
1389 	case ACPI_BUS_TYPE_POWER:
1390 		acpi_add_id(pnp, ACPI_POWER_HID);
1391 		break;
1392 	case ACPI_BUS_TYPE_PROCESSOR:
1393 		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1394 		break;
1395 	case ACPI_BUS_TYPE_THERMAL:
1396 		acpi_add_id(pnp, ACPI_THERMAL_HID);
1397 		break;
1398 	case ACPI_BUS_TYPE_POWER_BUTTON:
1399 		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1400 		break;
1401 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1402 		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1403 		break;
1404 	case ACPI_BUS_TYPE_ECDT_EC:
1405 		acpi_add_id(pnp, ACPI_ECDT_HID);
1406 		break;
1407 	}
1408 }
1409 
1410 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1411 {
1412 	struct acpi_hardware_id *id, *tmp;
1413 
1414 	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1415 		kfree_const(id->id);
1416 		kfree(id);
1417 	}
1418 	kfree(pnp->unique_id);
1419 }
1420 
1421 /**
1422  * acpi_dma_supported - Check DMA support for the specified device.
1423  * @adev: The pointer to acpi device
1424  *
1425  * Return false if DMA is not supported. Otherwise, return true
1426  */
1427 bool acpi_dma_supported(const struct acpi_device *adev)
1428 {
1429 	if (!adev)
1430 		return false;
1431 
1432 	if (adev->flags.cca_seen)
1433 		return true;
1434 
1435 	/*
1436 	* Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1437 	* DMA on "Intel platforms".  Presumably that includes all x86 and
1438 	* ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1439 	*/
1440 	if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1441 		return true;
1442 
1443 	return false;
1444 }
1445 
1446 /**
1447  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1448  * @adev: The pointer to acpi device
1449  *
1450  * Return enum dev_dma_attr.
1451  */
1452 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1453 {
1454 	if (!acpi_dma_supported(adev))
1455 		return DEV_DMA_NOT_SUPPORTED;
1456 
1457 	if (adev->flags.coherent_dma)
1458 		return DEV_DMA_COHERENT;
1459 	else
1460 		return DEV_DMA_NON_COHERENT;
1461 }
1462 
1463 /**
1464  * acpi_dma_get_range() - Get device DMA parameters.
1465  *
1466  * @dev: device to configure
1467  * @map: pointer to DMA ranges result
1468  *
1469  * Evaluate DMA regions and return pointer to DMA regions on
1470  * parsing success; it does not update the passed in values on failure.
1471  *
1472  * Return 0 on success, < 0 on failure.
1473  */
1474 int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
1475 {
1476 	struct acpi_device *adev;
1477 	LIST_HEAD(list);
1478 	struct resource_entry *rentry;
1479 	int ret;
1480 	struct device *dma_dev = dev;
1481 	struct bus_dma_region *r;
1482 
1483 	/*
1484 	 * Walk the device tree chasing an ACPI companion with a _DMA
1485 	 * object while we go. Stop if we find a device with an ACPI
1486 	 * companion containing a _DMA method.
1487 	 */
1488 	do {
1489 		adev = ACPI_COMPANION(dma_dev);
1490 		if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1491 			break;
1492 
1493 		dma_dev = dma_dev->parent;
1494 	} while (dma_dev);
1495 
1496 	if (!dma_dev)
1497 		return -ENODEV;
1498 
1499 	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1500 		acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1501 		return -EINVAL;
1502 	}
1503 
1504 	ret = acpi_dev_get_dma_resources(adev, &list);
1505 	if (ret > 0) {
1506 		r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
1507 		if (!r) {
1508 			ret = -ENOMEM;
1509 			goto out;
1510 		}
1511 
1512 		list_for_each_entry(rentry, &list, node) {
1513 			if (rentry->res->start >= rentry->res->end) {
1514 				kfree(r);
1515 				ret = -EINVAL;
1516 				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1517 				goto out;
1518 			}
1519 
1520 			r->cpu_start = rentry->res->start;
1521 			r->dma_start = rentry->res->start - rentry->offset;
1522 			r->size = resource_size(rentry->res);
1523 			r->offset = rentry->offset;
1524 			r++;
1525 		}
1526 
1527 		*map = r;
1528 	}
1529  out:
1530 	acpi_dev_free_resource_list(&list);
1531 
1532 	return ret >= 0 ? 0 : ret;
1533 }
1534 
1535 #ifdef CONFIG_IOMMU_API
1536 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1537 			   struct fwnode_handle *fwnode,
1538 			   const struct iommu_ops *ops)
1539 {
1540 	int ret = iommu_fwspec_init(dev, fwnode, ops);
1541 
1542 	if (!ret)
1543 		ret = iommu_fwspec_add_ids(dev, &id, 1);
1544 
1545 	return ret;
1546 }
1547 
1548 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1549 {
1550 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1551 
1552 	return fwspec ? fwspec->ops : NULL;
1553 }
1554 
1555 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1556 						       const u32 *id_in)
1557 {
1558 	int err;
1559 	const struct iommu_ops *ops;
1560 
1561 	/*
1562 	 * If we already translated the fwspec there is nothing left to do,
1563 	 * return the iommu_ops.
1564 	 */
1565 	ops = acpi_iommu_fwspec_ops(dev);
1566 	if (ops)
1567 		return ops;
1568 
1569 	err = iort_iommu_configure_id(dev, id_in);
1570 	if (err && err != -EPROBE_DEFER)
1571 		err = viot_iommu_configure(dev);
1572 
1573 	/*
1574 	 * If we have reason to believe the IOMMU driver missed the initial
1575 	 * iommu_probe_device() call for dev, replay it to get things in order.
1576 	 */
1577 	if (!err && dev->bus && !device_iommu_mapped(dev))
1578 		err = iommu_probe_device(dev);
1579 
1580 	/* Ignore all other errors apart from EPROBE_DEFER */
1581 	if (err == -EPROBE_DEFER) {
1582 		return ERR_PTR(err);
1583 	} else if (err) {
1584 		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1585 		return NULL;
1586 	}
1587 	return acpi_iommu_fwspec_ops(dev);
1588 }
1589 
1590 #else /* !CONFIG_IOMMU_API */
1591 
1592 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1593 			   struct fwnode_handle *fwnode,
1594 			   const struct iommu_ops *ops)
1595 {
1596 	return -ENODEV;
1597 }
1598 
1599 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1600 						       const u32 *id_in)
1601 {
1602 	return NULL;
1603 }
1604 
1605 #endif /* !CONFIG_IOMMU_API */
1606 
1607 /**
1608  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1609  * @dev: The pointer to the device
1610  * @attr: device dma attributes
1611  * @input_id: input device id const value pointer
1612  */
1613 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1614 			  const u32 *input_id)
1615 {
1616 	const struct iommu_ops *iommu;
1617 
1618 	if (attr == DEV_DMA_NOT_SUPPORTED) {
1619 		set_dma_ops(dev, &dma_dummy_ops);
1620 		return 0;
1621 	}
1622 
1623 	acpi_arch_dma_setup(dev);
1624 
1625 	iommu = acpi_iommu_configure_id(dev, input_id);
1626 	if (PTR_ERR(iommu) == -EPROBE_DEFER)
1627 		return -EPROBE_DEFER;
1628 
1629 	arch_setup_dma_ops(dev, 0, U64_MAX,
1630 				iommu, attr == DEV_DMA_COHERENT);
1631 
1632 	return 0;
1633 }
1634 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1635 
1636 static void acpi_init_coherency(struct acpi_device *adev)
1637 {
1638 	unsigned long long cca = 0;
1639 	acpi_status status;
1640 	struct acpi_device *parent = acpi_dev_parent(adev);
1641 
1642 	if (parent && parent->flags.cca_seen) {
1643 		/*
1644 		 * From ACPI spec, OSPM will ignore _CCA if an ancestor
1645 		 * already saw one.
1646 		 */
1647 		adev->flags.cca_seen = 1;
1648 		cca = parent->flags.coherent_dma;
1649 	} else {
1650 		status = acpi_evaluate_integer(adev->handle, "_CCA",
1651 					       NULL, &cca);
1652 		if (ACPI_SUCCESS(status))
1653 			adev->flags.cca_seen = 1;
1654 		else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1655 			/*
1656 			 * If architecture does not specify that _CCA is
1657 			 * required for DMA-able devices (e.g. x86),
1658 			 * we default to _CCA=1.
1659 			 */
1660 			cca = 1;
1661 		else
1662 			acpi_handle_debug(adev->handle,
1663 					  "ACPI device is missing _CCA.\n");
1664 	}
1665 
1666 	adev->flags.coherent_dma = cca;
1667 }
1668 
1669 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1670 {
1671 	bool *is_serial_bus_slave_p = data;
1672 
1673 	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1674 		return 1;
1675 
1676 	*is_serial_bus_slave_p = true;
1677 
1678 	 /* no need to do more checking */
1679 	return -1;
1680 }
1681 
1682 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1683 {
1684 	struct acpi_device *parent = acpi_dev_parent(device);
1685 	static const struct acpi_device_id indirect_io_hosts[] = {
1686 		{"HISI0191", 0},
1687 		{}
1688 	};
1689 
1690 	return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1691 }
1692 
1693 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1694 {
1695 	struct list_head resource_list;
1696 	bool is_serial_bus_slave = false;
1697 	static const struct acpi_device_id ignore_serial_bus_ids[] = {
1698 	/*
1699 	 * These devices have multiple SerialBus resources and a client
1700 	 * device must be instantiated for each of them, each with
1701 	 * its own device id.
1702 	 * Normally we only instantiate one client device for the first
1703 	 * resource, using the ACPI HID as id. These special cases are handled
1704 	 * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
1705 	 * knows which client device id to use for each resource.
1706 	 */
1707 		{"BSG1160", },
1708 		{"BSG2150", },
1709 		{"CSC3551", },
1710 		{"INT33FE", },
1711 		{"INT3515", },
1712 		/* Non-conforming _HID for Cirrus Logic already released */
1713 		{"CLSA0100", },
1714 		{"CLSA0101", },
1715 	/*
1716 	 * Some ACPI devs contain SerialBus resources even though they are not
1717 	 * attached to a serial bus at all.
1718 	 */
1719 		{"MSHW0028", },
1720 	/*
1721 	 * HIDs of device with an UartSerialBusV2 resource for which userspace
1722 	 * expects a regular tty cdev to be created (instead of the in kernel
1723 	 * serdev) and which have a kernel driver which expects a platform_dev
1724 	 * such as the rfkill-gpio driver.
1725 	 */
1726 		{"BCM4752", },
1727 		{"LNV4752", },
1728 		{}
1729 	};
1730 
1731 	if (acpi_is_indirect_io_slave(device))
1732 		return true;
1733 
1734 	/* Macs use device properties in lieu of _CRS resources */
1735 	if (x86_apple_machine &&
1736 	    (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1737 	     fwnode_property_present(&device->fwnode, "i2cAddress") ||
1738 	     fwnode_property_present(&device->fwnode, "baud")))
1739 		return true;
1740 
1741 	if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1742 		return false;
1743 
1744 	INIT_LIST_HEAD(&resource_list);
1745 	acpi_dev_get_resources(device, &resource_list,
1746 			       acpi_check_serial_bus_slave,
1747 			       &is_serial_bus_slave);
1748 	acpi_dev_free_resource_list(&resource_list);
1749 
1750 	return is_serial_bus_slave;
1751 }
1752 
1753 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1754 			     int type, void (*release)(struct device *))
1755 {
1756 	struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);
1757 
1758 	INIT_LIST_HEAD(&device->pnp.ids);
1759 	device->device_type = type;
1760 	device->handle = handle;
1761 	device->dev.parent = parent ? &parent->dev : NULL;
1762 	device->dev.release = release;
1763 	device->dev.bus = &acpi_bus_type;
1764 	fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1765 	acpi_set_device_status(device, ACPI_STA_DEFAULT);
1766 	acpi_device_get_busid(device);
1767 	acpi_set_pnp_ids(handle, &device->pnp, type);
1768 	acpi_init_properties(device);
1769 	acpi_bus_get_flags(device);
1770 	device->flags.match_driver = false;
1771 	device->flags.initialized = true;
1772 	device->flags.enumeration_by_parent =
1773 		acpi_device_enumeration_by_parent(device);
1774 	acpi_device_clear_enumerated(device);
1775 	device_initialize(&device->dev);
1776 	dev_set_uevent_suppress(&device->dev, true);
1777 	acpi_init_coherency(device);
1778 }
1779 
1780 static void acpi_scan_dep_init(struct acpi_device *adev)
1781 {
1782 	struct acpi_dep_data *dep;
1783 
1784 	list_for_each_entry(dep, &acpi_dep_list, node) {
1785 		if (dep->consumer == adev->handle) {
1786 			if (dep->honor_dep)
1787 				adev->flags.honor_deps = 1;
1788 
1789 			adev->dep_unmet++;
1790 		}
1791 	}
1792 }
1793 
1794 void acpi_device_add_finalize(struct acpi_device *device)
1795 {
1796 	dev_set_uevent_suppress(&device->dev, false);
1797 	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1798 }
1799 
1800 static void acpi_scan_init_status(struct acpi_device *adev)
1801 {
1802 	if (acpi_bus_get_status(adev))
1803 		acpi_set_device_status(adev, 0);
1804 }
1805 
1806 static int acpi_add_single_object(struct acpi_device **child,
1807 				  acpi_handle handle, int type, bool dep_init)
1808 {
1809 	struct acpi_device *device;
1810 	bool release_dep_lock = false;
1811 	int result;
1812 
1813 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1814 	if (!device)
1815 		return -ENOMEM;
1816 
1817 	acpi_init_device_object(device, handle, type, acpi_device_release);
1818 	/*
1819 	 * Getting the status is delayed till here so that we can call
1820 	 * acpi_bus_get_status() and use its quirk handling.  Note that
1821 	 * this must be done before the get power-/wakeup_dev-flags calls.
1822 	 */
1823 	if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1824 		if (dep_init) {
1825 			mutex_lock(&acpi_dep_list_lock);
1826 			/*
1827 			 * Hold the lock until the acpi_tie_acpi_dev() call
1828 			 * below to prevent concurrent acpi_scan_clear_dep()
1829 			 * from deleting a dependency list entry without
1830 			 * updating dep_unmet for the device.
1831 			 */
1832 			release_dep_lock = true;
1833 			acpi_scan_dep_init(device);
1834 		}
1835 		acpi_scan_init_status(device);
1836 	}
1837 
1838 	acpi_bus_get_power_flags(device);
1839 	acpi_bus_get_wakeup_device_flags(device);
1840 
1841 	result = acpi_tie_acpi_dev(device);
1842 
1843 	if (release_dep_lock)
1844 		mutex_unlock(&acpi_dep_list_lock);
1845 
1846 	if (!result)
1847 		result = acpi_device_add(device);
1848 
1849 	if (result) {
1850 		acpi_device_release(&device->dev);
1851 		return result;
1852 	}
1853 
1854 	acpi_power_add_remove_device(device, true);
1855 	acpi_device_add_finalize(device);
1856 
1857 	acpi_handle_debug(handle, "Added as %s, parent %s\n",
1858 			  dev_name(&device->dev), device->dev.parent ?
1859 				dev_name(device->dev.parent) : "(null)");
1860 
1861 	*child = device;
1862 	return 0;
1863 }
1864 
1865 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1866 					    void *context)
1867 {
1868 	struct resource *res = context;
1869 
1870 	if (acpi_dev_resource_memory(ares, res))
1871 		return AE_CTRL_TERMINATE;
1872 
1873 	return AE_OK;
1874 }
1875 
1876 static bool acpi_device_should_be_hidden(acpi_handle handle)
1877 {
1878 	acpi_status status;
1879 	struct resource res;
1880 
1881 	/* Check if it should ignore the UART device */
1882 	if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1883 		return false;
1884 
1885 	/*
1886 	 * The UART device described in SPCR table is assumed to have only one
1887 	 * memory resource present. So we only look for the first one here.
1888 	 */
1889 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1890 				     acpi_get_resource_memory, &res);
1891 	if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1892 		return false;
1893 
1894 	acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1895 			 &res.start);
1896 
1897 	return true;
1898 }
1899 
1900 bool acpi_device_is_present(const struct acpi_device *adev)
1901 {
1902 	return adev->status.present || adev->status.functional;
1903 }
1904 
1905 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1906 				       const char *idstr,
1907 				       const struct acpi_device_id **matchid)
1908 {
1909 	const struct acpi_device_id *devid;
1910 
1911 	if (handler->match)
1912 		return handler->match(idstr, matchid);
1913 
1914 	for (devid = handler->ids; devid->id[0]; devid++)
1915 		if (!strcmp((char *)devid->id, idstr)) {
1916 			if (matchid)
1917 				*matchid = devid;
1918 
1919 			return true;
1920 		}
1921 
1922 	return false;
1923 }
1924 
1925 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1926 					const struct acpi_device_id **matchid)
1927 {
1928 	struct acpi_scan_handler *handler;
1929 
1930 	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1931 		if (acpi_scan_handler_matching(handler, idstr, matchid))
1932 			return handler;
1933 
1934 	return NULL;
1935 }
1936 
1937 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1938 {
1939 	if (!!hotplug->enabled == !!val)
1940 		return;
1941 
1942 	mutex_lock(&acpi_scan_lock);
1943 
1944 	hotplug->enabled = val;
1945 
1946 	mutex_unlock(&acpi_scan_lock);
1947 }
1948 
1949 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1950 {
1951 	struct acpi_hardware_id *hwid;
1952 
1953 	if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1954 		acpi_dock_add(adev);
1955 		return;
1956 	}
1957 	list_for_each_entry(hwid, &adev->pnp.ids, list) {
1958 		struct acpi_scan_handler *handler;
1959 
1960 		handler = acpi_scan_match_handler(hwid->id, NULL);
1961 		if (handler) {
1962 			adev->flags.hotplug_notify = true;
1963 			break;
1964 		}
1965 	}
1966 }
1967 
1968 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1969 {
1970 	struct acpi_handle_list dep_devices;
1971 	acpi_status status;
1972 	u32 count;
1973 	int i;
1974 
1975 	/*
1976 	 * Check for _HID here to avoid deferring the enumeration of:
1977 	 * 1. PCI devices.
1978 	 * 2. ACPI nodes describing USB ports.
1979 	 * Still, checking for _HID catches more then just these cases ...
1980 	 */
1981 	if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1982 	    !acpi_has_method(handle, "_HID"))
1983 		return 0;
1984 
1985 	status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1986 	if (ACPI_FAILURE(status)) {
1987 		acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1988 		return 0;
1989 	}
1990 
1991 	for (count = 0, i = 0; i < dep_devices.count; i++) {
1992 		struct acpi_device_info *info;
1993 		struct acpi_dep_data *dep;
1994 		bool skip, honor_dep;
1995 
1996 		status = acpi_get_object_info(dep_devices.handles[i], &info);
1997 		if (ACPI_FAILURE(status)) {
1998 			acpi_handle_debug(handle, "Error reading _DEP device info\n");
1999 			continue;
2000 		}
2001 
2002 		skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
2003 		honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
2004 		kfree(info);
2005 
2006 		if (skip)
2007 			continue;
2008 
2009 		dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2010 		if (!dep)
2011 			continue;
2012 
2013 		count++;
2014 
2015 		dep->supplier = dep_devices.handles[i];
2016 		dep->consumer = handle;
2017 		dep->honor_dep = honor_dep;
2018 
2019 		mutex_lock(&acpi_dep_list_lock);
2020 		list_add_tail(&dep->node , &acpi_dep_list);
2021 		mutex_unlock(&acpi_dep_list_lock);
2022 	}
2023 
2024 	return count;
2025 }
2026 
2027 static bool acpi_bus_scan_second_pass;
2028 
2029 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2030 				      struct acpi_device **adev_p)
2031 {
2032 	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
2033 	acpi_object_type acpi_type;
2034 	int type;
2035 
2036 	if (device)
2037 		goto out;
2038 
2039 	if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2040 		return AE_OK;
2041 
2042 	switch (acpi_type) {
2043 	case ACPI_TYPE_DEVICE:
2044 		if (acpi_device_should_be_hidden(handle))
2045 			return AE_OK;
2046 
2047 		/* Bail out if there are dependencies. */
2048 		if (acpi_scan_check_dep(handle, check_dep) > 0) {
2049 			acpi_bus_scan_second_pass = true;
2050 			return AE_CTRL_DEPTH;
2051 		}
2052 
2053 		fallthrough;
2054 	case ACPI_TYPE_ANY:	/* for ACPI_ROOT_OBJECT */
2055 		type = ACPI_BUS_TYPE_DEVICE;
2056 		break;
2057 
2058 	case ACPI_TYPE_PROCESSOR:
2059 		type = ACPI_BUS_TYPE_PROCESSOR;
2060 		break;
2061 
2062 	case ACPI_TYPE_THERMAL:
2063 		type = ACPI_BUS_TYPE_THERMAL;
2064 		break;
2065 
2066 	case ACPI_TYPE_POWER:
2067 		acpi_add_power_resource(handle);
2068 		fallthrough;
2069 	default:
2070 		return AE_OK;
2071 	}
2072 
2073 	/*
2074 	 * If check_dep is true at this point, the device has no dependencies,
2075 	 * or the creation of the device object would have been postponed above.
2076 	 */
2077 	acpi_add_single_object(&device, handle, type, !check_dep);
2078 	if (!device)
2079 		return AE_CTRL_DEPTH;
2080 
2081 	acpi_scan_init_hotplug(device);
2082 
2083 out:
2084 	if (!*adev_p)
2085 		*adev_p = device;
2086 
2087 	return AE_OK;
2088 }
2089 
2090 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2091 					void *not_used, void **ret_p)
2092 {
2093 	return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2094 }
2095 
2096 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2097 					void *not_used, void **ret_p)
2098 {
2099 	return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2100 }
2101 
2102 static void acpi_default_enumeration(struct acpi_device *device)
2103 {
2104 	/*
2105 	 * Do not enumerate devices with enumeration_by_parent flag set as
2106 	 * they will be enumerated by their respective parents.
2107 	 */
2108 	if (!device->flags.enumeration_by_parent) {
2109 		acpi_create_platform_device(device, NULL);
2110 		acpi_device_set_enumerated(device);
2111 	} else {
2112 		blocking_notifier_call_chain(&acpi_reconfig_chain,
2113 					     ACPI_RECONFIG_DEVICE_ADD, device);
2114 	}
2115 }
2116 
2117 static const struct acpi_device_id generic_device_ids[] = {
2118 	{ACPI_DT_NAMESPACE_HID, },
2119 	{"", },
2120 };
2121 
2122 static int acpi_generic_device_attach(struct acpi_device *adev,
2123 				      const struct acpi_device_id *not_used)
2124 {
2125 	/*
2126 	 * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2127 	 * below can be unconditional.
2128 	 */
2129 	if (adev->data.of_compatible)
2130 		acpi_default_enumeration(adev);
2131 
2132 	return 1;
2133 }
2134 
2135 static struct acpi_scan_handler generic_device_handler = {
2136 	.ids = generic_device_ids,
2137 	.attach = acpi_generic_device_attach,
2138 };
2139 
2140 static int acpi_scan_attach_handler(struct acpi_device *device)
2141 {
2142 	struct acpi_hardware_id *hwid;
2143 	int ret = 0;
2144 
2145 	list_for_each_entry(hwid, &device->pnp.ids, list) {
2146 		const struct acpi_device_id *devid;
2147 		struct acpi_scan_handler *handler;
2148 
2149 		handler = acpi_scan_match_handler(hwid->id, &devid);
2150 		if (handler) {
2151 			if (!handler->attach) {
2152 				device->pnp.type.platform_id = 0;
2153 				continue;
2154 			}
2155 			device->handler = handler;
2156 			ret = handler->attach(device, devid);
2157 			if (ret > 0)
2158 				break;
2159 
2160 			device->handler = NULL;
2161 			if (ret < 0)
2162 				break;
2163 		}
2164 	}
2165 
2166 	return ret;
2167 }
2168 
2169 static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
2170 {
2171 	bool skip = !first_pass && device->flags.visited;
2172 	acpi_handle ejd;
2173 	int ret;
2174 
2175 	if (skip)
2176 		goto ok;
2177 
2178 	if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2179 		register_dock_dependent_device(device, ejd);
2180 
2181 	acpi_bus_get_status(device);
2182 	/* Skip devices that are not ready for enumeration (e.g. not present) */
2183 	if (!acpi_dev_ready_for_enumeration(device)) {
2184 		device->flags.initialized = false;
2185 		acpi_device_clear_enumerated(device);
2186 		device->flags.power_manageable = 0;
2187 		return 0;
2188 	}
2189 	if (device->handler)
2190 		goto ok;
2191 
2192 	if (!device->flags.initialized) {
2193 		device->flags.power_manageable =
2194 			device->power.states[ACPI_STATE_D0].flags.valid;
2195 		if (acpi_bus_init_power(device))
2196 			device->flags.power_manageable = 0;
2197 
2198 		device->flags.initialized = true;
2199 	} else if (device->flags.visited) {
2200 		goto ok;
2201 	}
2202 
2203 	ret = acpi_scan_attach_handler(device);
2204 	if (ret < 0)
2205 		return 0;
2206 
2207 	device->flags.match_driver = true;
2208 	if (ret > 0 && !device->flags.enumeration_by_parent) {
2209 		acpi_device_set_enumerated(device);
2210 		goto ok;
2211 	}
2212 
2213 	ret = device_attach(&device->dev);
2214 	if (ret < 0)
2215 		return 0;
2216 
2217 	if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2218 		acpi_default_enumeration(device);
2219 	else
2220 		acpi_device_set_enumerated(device);
2221 
2222 ok:
2223 	acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);
2224 
2225 	if (!skip && device->handler && device->handler->hotplug.notify_online)
2226 		device->handler->hotplug.notify_online(device);
2227 
2228 	return 0;
2229 }
2230 
2231 static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2232 {
2233 	struct acpi_device **adev_p = data;
2234 	struct acpi_device *adev = *adev_p;
2235 
2236 	/*
2237 	 * If we're passed a 'previous' consumer device then we need to skip
2238 	 * any consumers until we meet the previous one, and then NULL @data
2239 	 * so the next one can be returned.
2240 	 */
2241 	if (adev) {
2242 		if (dep->consumer == adev->handle)
2243 			*adev_p = NULL;
2244 
2245 		return 0;
2246 	}
2247 
2248 	adev = acpi_get_acpi_dev(dep->consumer);
2249 	if (adev) {
2250 		*(struct acpi_device **)data = adev;
2251 		return 1;
2252 	}
2253 	/* Continue parsing if the device object is not present. */
2254 	return 0;
2255 }
2256 
2257 struct acpi_scan_clear_dep_work {
2258 	struct work_struct work;
2259 	struct acpi_device *adev;
2260 };
2261 
2262 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2263 {
2264 	struct acpi_scan_clear_dep_work *cdw;
2265 
2266 	cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2267 
2268 	acpi_scan_lock_acquire();
2269 	acpi_bus_attach(cdw->adev, (void *)true);
2270 	acpi_scan_lock_release();
2271 
2272 	acpi_dev_put(cdw->adev);
2273 	kfree(cdw);
2274 }
2275 
2276 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2277 {
2278 	struct acpi_scan_clear_dep_work *cdw;
2279 
2280 	if (adev->dep_unmet)
2281 		return false;
2282 
2283 	cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2284 	if (!cdw)
2285 		return false;
2286 
2287 	cdw->adev = adev;
2288 	INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2289 	/*
2290 	 * Since the work function may block on the lock until the entire
2291 	 * initial enumeration of devices is complete, put it into the unbound
2292 	 * workqueue.
2293 	 */
2294 	queue_work(system_unbound_wq, &cdw->work);
2295 
2296 	return true;
2297 }
2298 
2299 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2300 {
2301 	struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);
2302 
2303 	if (adev) {
2304 		adev->dep_unmet--;
2305 		if (!acpi_scan_clear_dep_queue(adev))
2306 			acpi_dev_put(adev);
2307 	}
2308 
2309 	list_del(&dep->node);
2310 	kfree(dep);
2311 
2312 	return 0;
2313 }
2314 
2315 /**
2316  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2317  * @handle:	The ACPI handle of the supplier device
2318  * @callback:	Pointer to the callback function to apply
2319  * @data:	Pointer to some data to pass to the callback
2320  *
2321  * The return value of the callback determines this function's behaviour. If 0
2322  * is returned we continue to iterate over acpi_dep_list. If a positive value
2323  * is returned then the loop is broken but this function returns 0. If a
2324  * negative value is returned by the callback then the loop is broken and that
2325  * value is returned as the final error.
2326  */
2327 static int acpi_walk_dep_device_list(acpi_handle handle,
2328 				int (*callback)(struct acpi_dep_data *, void *),
2329 				void *data)
2330 {
2331 	struct acpi_dep_data *dep, *tmp;
2332 	int ret = 0;
2333 
2334 	mutex_lock(&acpi_dep_list_lock);
2335 	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2336 		if (dep->supplier == handle) {
2337 			ret = callback(dep, data);
2338 			if (ret)
2339 				break;
2340 		}
2341 	}
2342 	mutex_unlock(&acpi_dep_list_lock);
2343 
2344 	return ret > 0 ? 0 : ret;
2345 }
2346 
2347 /**
2348  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2349  * @supplier: Pointer to the supplier &struct acpi_device
2350  *
2351  * Clear dependencies on the given device.
2352  */
2353 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2354 {
2355 	acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2356 }
2357 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2358 
2359 /**
2360  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2361  * @device: Pointer to the &struct acpi_device to check
2362  *
2363  * Check if the device is present and has no unmet dependencies.
2364  *
2365  * Return true if the device is ready for enumeratino. Otherwise, return false.
2366  */
2367 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2368 {
2369 	if (device->flags.honor_deps && device->dep_unmet)
2370 		return false;
2371 
2372 	return acpi_device_is_present(device);
2373 }
2374 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2375 
2376 /**
2377  * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
2378  * @supplier: Pointer to the dependee device
2379  * @start: Pointer to the current dependent device
2380  *
2381  * Returns the next &struct acpi_device which declares itself dependent on
2382  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2383  *
2384  * If the returned adev is not passed as @start to this function, the caller is
2385  * responsible for putting the reference to adev when it is no longer needed.
2386  */
2387 struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
2388 						   struct acpi_device *start)
2389 {
2390 	struct acpi_device *adev = start;
2391 
2392 	acpi_walk_dep_device_list(supplier->handle,
2393 				  acpi_dev_get_next_consumer_dev_cb, &adev);
2394 
2395 	acpi_dev_put(start);
2396 
2397 	if (adev == start)
2398 		return NULL;
2399 
2400 	return adev;
2401 }
2402 EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);
2403 
2404 /**
2405  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2406  * @handle: Root of the namespace scope to scan.
2407  *
2408  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2409  * found devices.
2410  *
2411  * If no devices were found, -ENODEV is returned, but it does not mean that
2412  * there has been a real error.  There just have been no suitable ACPI objects
2413  * in the table trunk from which the kernel could create a device and add an
2414  * appropriate driver.
2415  *
2416  * Must be called under acpi_scan_lock.
2417  */
2418 int acpi_bus_scan(acpi_handle handle)
2419 {
2420 	struct acpi_device *device = NULL;
2421 
2422 	acpi_bus_scan_second_pass = false;
2423 
2424 	/* Pass 1: Avoid enumerating devices with missing dependencies. */
2425 
2426 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2427 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2428 				    acpi_bus_check_add_1, NULL, NULL,
2429 				    (void **)&device);
2430 
2431 	if (!device)
2432 		return -ENODEV;
2433 
2434 	acpi_bus_attach(device, (void *)true);
2435 
2436 	if (!acpi_bus_scan_second_pass)
2437 		return 0;
2438 
2439 	/* Pass 2: Enumerate all of the remaining devices. */
2440 
2441 	device = NULL;
2442 
2443 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2444 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2445 				    acpi_bus_check_add_2, NULL, NULL,
2446 				    (void **)&device);
2447 
2448 	acpi_bus_attach(device, NULL);
2449 
2450 	return 0;
2451 }
2452 EXPORT_SYMBOL(acpi_bus_scan);
2453 
2454 static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used)
2455 {
2456 	struct acpi_scan_handler *handler = adev->handler;
2457 
2458 	acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL);
2459 
2460 	adev->flags.match_driver = false;
2461 	if (handler) {
2462 		if (handler->detach)
2463 			handler->detach(adev);
2464 
2465 		adev->handler = NULL;
2466 	} else {
2467 		device_release_driver(&adev->dev);
2468 	}
2469 	/*
2470 	 * Most likely, the device is going away, so put it into D3cold before
2471 	 * that.
2472 	 */
2473 	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2474 	adev->flags.initialized = false;
2475 	acpi_device_clear_enumerated(adev);
2476 
2477 	return 0;
2478 }
2479 
2480 /**
2481  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2482  * @adev: Root of the ACPI namespace scope to walk.
2483  *
2484  * Must be called under acpi_scan_lock.
2485  */
2486 void acpi_bus_trim(struct acpi_device *adev)
2487 {
2488 	acpi_bus_trim_one(adev, NULL);
2489 }
2490 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2491 
2492 int acpi_bus_register_early_device(int type)
2493 {
2494 	struct acpi_device *device = NULL;
2495 	int result;
2496 
2497 	result = acpi_add_single_object(&device, NULL, type, false);
2498 	if (result)
2499 		return result;
2500 
2501 	device->flags.match_driver = true;
2502 	return device_attach(&device->dev);
2503 }
2504 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2505 
2506 static void acpi_bus_scan_fixed(void)
2507 {
2508 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2509 		struct acpi_device *adev = NULL;
2510 
2511 		acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
2512 				       false);
2513 		if (adev) {
2514 			adev->flags.match_driver = true;
2515 			if (device_attach(&adev->dev) >= 0)
2516 				device_init_wakeup(&adev->dev, true);
2517 			else
2518 				dev_dbg(&adev->dev, "No driver\n");
2519 		}
2520 	}
2521 
2522 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2523 		struct acpi_device *adev = NULL;
2524 
2525 		acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
2526 				       false);
2527 		if (adev) {
2528 			adev->flags.match_driver = true;
2529 			if (device_attach(&adev->dev) < 0)
2530 				dev_dbg(&adev->dev, "No driver\n");
2531 		}
2532 	}
2533 }
2534 
2535 static void __init acpi_get_spcr_uart_addr(void)
2536 {
2537 	acpi_status status;
2538 	struct acpi_table_spcr *spcr_ptr;
2539 
2540 	status = acpi_get_table(ACPI_SIG_SPCR, 0,
2541 				(struct acpi_table_header **)&spcr_ptr);
2542 	if (ACPI_FAILURE(status)) {
2543 		pr_warn("STAO table present, but SPCR is missing\n");
2544 		return;
2545 	}
2546 
2547 	spcr_uart_addr = spcr_ptr->serial_port.address;
2548 	acpi_put_table((struct acpi_table_header *)spcr_ptr);
2549 }
2550 
2551 static bool acpi_scan_initialized;
2552 
2553 void __init acpi_scan_init(void)
2554 {
2555 	acpi_status status;
2556 	struct acpi_table_stao *stao_ptr;
2557 
2558 	acpi_pci_root_init();
2559 	acpi_pci_link_init();
2560 	acpi_processor_init();
2561 	acpi_platform_init();
2562 	acpi_lpss_init();
2563 	acpi_apd_init();
2564 	acpi_cmos_rtc_init();
2565 	acpi_container_init();
2566 	acpi_memory_hotplug_init();
2567 	acpi_watchdog_init();
2568 	acpi_pnp_init();
2569 	acpi_int340x_thermal_init();
2570 	acpi_amba_init();
2571 	acpi_init_lpit();
2572 
2573 	acpi_scan_add_handler(&generic_device_handler);
2574 
2575 	/*
2576 	 * If there is STAO table, check whether it needs to ignore the UART
2577 	 * device in SPCR table.
2578 	 */
2579 	status = acpi_get_table(ACPI_SIG_STAO, 0,
2580 				(struct acpi_table_header **)&stao_ptr);
2581 	if (ACPI_SUCCESS(status)) {
2582 		if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2583 			pr_info("STAO Name List not yet supported.\n");
2584 
2585 		if (stao_ptr->ignore_uart)
2586 			acpi_get_spcr_uart_addr();
2587 
2588 		acpi_put_table((struct acpi_table_header *)stao_ptr);
2589 	}
2590 
2591 	acpi_gpe_apply_masked_gpes();
2592 	acpi_update_all_gpes();
2593 
2594 	/*
2595 	 * Although we call __add_memory() that is documented to require the
2596 	 * device_hotplug_lock, it is not necessary here because this is an
2597 	 * early code when userspace or any other code path cannot trigger
2598 	 * hotplug/hotunplug operations.
2599 	 */
2600 	mutex_lock(&acpi_scan_lock);
2601 	/*
2602 	 * Enumerate devices in the ACPI namespace.
2603 	 */
2604 	if (acpi_bus_scan(ACPI_ROOT_OBJECT))
2605 		goto unlock;
2606 
2607 	acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
2608 	if (!acpi_root)
2609 		goto unlock;
2610 
2611 	/* Fixed feature devices do not exist on HW-reduced platform */
2612 	if (!acpi_gbl_reduced_hardware)
2613 		acpi_bus_scan_fixed();
2614 
2615 	acpi_turn_off_unused_power_resources();
2616 
2617 	acpi_scan_initialized = true;
2618 
2619 unlock:
2620 	mutex_unlock(&acpi_scan_lock);
2621 }
2622 
2623 static struct acpi_probe_entry *ape;
2624 static int acpi_probe_count;
2625 static DEFINE_MUTEX(acpi_probe_mutex);
2626 
2627 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2628 				  const unsigned long end)
2629 {
2630 	if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2631 		if (!ape->probe_subtbl(header, end))
2632 			acpi_probe_count++;
2633 
2634 	return 0;
2635 }
2636 
2637 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2638 {
2639 	int count = 0;
2640 
2641 	if (acpi_disabled)
2642 		return 0;
2643 
2644 	mutex_lock(&acpi_probe_mutex);
2645 	for (ape = ap_head; nr; ape++, nr--) {
2646 		if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2647 			acpi_probe_count = 0;
2648 			acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2649 			count += acpi_probe_count;
2650 		} else {
2651 			int res;
2652 			res = acpi_table_parse(ape->id, ape->probe_table);
2653 			if (!res)
2654 				count++;
2655 		}
2656 	}
2657 	mutex_unlock(&acpi_probe_mutex);
2658 
2659 	return count;
2660 }
2661 
2662 static void acpi_table_events_fn(struct work_struct *work)
2663 {
2664 	acpi_scan_lock_acquire();
2665 	acpi_bus_scan(ACPI_ROOT_OBJECT);
2666 	acpi_scan_lock_release();
2667 
2668 	kfree(work);
2669 }
2670 
2671 void acpi_scan_table_notify(void)
2672 {
2673 	struct work_struct *work;
2674 
2675 	if (!acpi_scan_initialized)
2676 		return;
2677 
2678 	work = kmalloc(sizeof(*work), GFP_KERNEL);
2679 	if (!work)
2680 		return;
2681 
2682 	INIT_WORK(work, acpi_table_events_fn);
2683 	schedule_work(work);
2684 }
2685 
2686 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2687 {
2688 	return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2689 }
2690 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2691 
2692 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2693 {
2694 	return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2695 }
2696 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);
2697