xref: /openbmc/linux/drivers/acpi/scan.c (revision 6ab70300)
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 
23 #include "internal.h"
24 
25 extern struct acpi_device *acpi_root;
26 
27 #define ACPI_BUS_CLASS			"system_bus"
28 #define ACPI_BUS_HID			"LNXSYBUS"
29 #define ACPI_BUS_DEVICE_NAME		"System Bus"
30 
31 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
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 = NULL;
139 	struct acpi_device_physical_node *pn;
140 	bool second_pass = (bool)data;
141 	acpi_status status = AE_OK;
142 
143 	if (acpi_bus_get_device(handle, &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 = NULL;
184 	struct acpi_device_physical_node *pn;
185 
186 	if (acpi_bus_get_device(handle, &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)
337 {
338 	struct acpi_scan_handler *handler = adev->handler;
339 	struct acpi_device *child;
340 	int error;
341 
342 	acpi_bus_get_status(adev);
343 	if (!(adev->status.present || adev->status.functional)) {
344 		acpi_scan_device_not_present(adev);
345 		return 0;
346 	}
347 	if (handler && handler->hotplug.scan_dependent)
348 		return handler->hotplug.scan_dependent(adev);
349 
350 	error = acpi_bus_scan(adev->handle);
351 	if (error) {
352 		dev_warn(&adev->dev, "Namespace scan failure\n");
353 		return error;
354 	}
355 	list_for_each_entry(child, &adev->children, node) {
356 		error = acpi_scan_bus_check(child);
357 		if (error)
358 			return error;
359 	}
360 	return 0;
361 }
362 
363 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
364 {
365 	switch (type) {
366 	case ACPI_NOTIFY_BUS_CHECK:
367 		return acpi_scan_bus_check(adev);
368 	case ACPI_NOTIFY_DEVICE_CHECK:
369 		return acpi_scan_device_check(adev);
370 	case ACPI_NOTIFY_EJECT_REQUEST:
371 	case ACPI_OST_EC_OSPM_EJECT:
372 		if (adev->handler && !adev->handler->hotplug.enabled) {
373 			dev_info(&adev->dev, "Eject disabled\n");
374 			return -EPERM;
375 		}
376 		acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
377 				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
378 		return acpi_scan_hot_remove(adev);
379 	}
380 	return -EINVAL;
381 }
382 
383 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
384 {
385 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
386 	int error = -ENODEV;
387 
388 	lock_device_hotplug();
389 	mutex_lock(&acpi_scan_lock);
390 
391 	/*
392 	 * The device object's ACPI handle cannot become invalid as long as we
393 	 * are holding acpi_scan_lock, but it might have become invalid before
394 	 * that lock was acquired.
395 	 */
396 	if (adev->handle == INVALID_ACPI_HANDLE)
397 		goto err_out;
398 
399 	if (adev->flags.is_dock_station) {
400 		error = dock_notify(adev, src);
401 	} else if (adev->flags.hotplug_notify) {
402 		error = acpi_generic_hotplug_event(adev, src);
403 	} else {
404 		int (*notify)(struct acpi_device *, u32);
405 
406 		acpi_lock_hp_context();
407 		notify = adev->hp ? adev->hp->notify : NULL;
408 		acpi_unlock_hp_context();
409 		/*
410 		 * There may be additional notify handlers for device objects
411 		 * without the .event() callback, so ignore them here.
412 		 */
413 		if (notify)
414 			error = notify(adev, src);
415 		else
416 			goto out;
417 	}
418 	switch (error) {
419 	case 0:
420 		ost_code = ACPI_OST_SC_SUCCESS;
421 		break;
422 	case -EPERM:
423 		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
424 		break;
425 	case -EBUSY:
426 		ost_code = ACPI_OST_SC_DEVICE_BUSY;
427 		break;
428 	default:
429 		ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
430 		break;
431 	}
432 
433  err_out:
434 	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
435 
436  out:
437 	acpi_bus_put_acpi_device(adev);
438 	mutex_unlock(&acpi_scan_lock);
439 	unlock_device_hotplug();
440 }
441 
442 static void acpi_free_power_resources_lists(struct acpi_device *device)
443 {
444 	int i;
445 
446 	if (device->wakeup.flags.valid)
447 		acpi_power_resources_list_free(&device->wakeup.resources);
448 
449 	if (!device->power.flags.power_resources)
450 		return;
451 
452 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
453 		struct acpi_device_power_state *ps = &device->power.states[i];
454 		acpi_power_resources_list_free(&ps->resources);
455 	}
456 }
457 
458 static void acpi_device_release(struct device *dev)
459 {
460 	struct acpi_device *acpi_dev = to_acpi_device(dev);
461 
462 	acpi_free_properties(acpi_dev);
463 	acpi_free_pnp_ids(&acpi_dev->pnp);
464 	acpi_free_power_resources_lists(acpi_dev);
465 	kfree(acpi_dev);
466 }
467 
468 static void acpi_device_del(struct acpi_device *device)
469 {
470 	struct acpi_device_bus_id *acpi_device_bus_id;
471 
472 	mutex_lock(&acpi_device_lock);
473 	if (device->parent)
474 		list_del(&device->node);
475 
476 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
477 		if (!strcmp(acpi_device_bus_id->bus_id,
478 			    acpi_device_hid(device))) {
479 			ida_simple_remove(&acpi_device_bus_id->instance_ida, device->pnp.instance_no);
480 			if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
481 				list_del(&acpi_device_bus_id->node);
482 				kfree_const(acpi_device_bus_id->bus_id);
483 				kfree(acpi_device_bus_id);
484 			}
485 			break;
486 		}
487 
488 	list_del(&device->wakeup_list);
489 	mutex_unlock(&acpi_device_lock);
490 
491 	acpi_power_add_remove_device(device, false);
492 	acpi_device_remove_files(device);
493 	if (device->remove)
494 		device->remove(device);
495 
496 	device_del(&device->dev);
497 }
498 
499 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
500 
501 static LIST_HEAD(acpi_device_del_list);
502 static DEFINE_MUTEX(acpi_device_del_lock);
503 
504 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
505 {
506 	for (;;) {
507 		struct acpi_device *adev;
508 
509 		mutex_lock(&acpi_device_del_lock);
510 
511 		if (list_empty(&acpi_device_del_list)) {
512 			mutex_unlock(&acpi_device_del_lock);
513 			break;
514 		}
515 		adev = list_first_entry(&acpi_device_del_list,
516 					struct acpi_device, del_list);
517 		list_del(&adev->del_list);
518 
519 		mutex_unlock(&acpi_device_del_lock);
520 
521 		blocking_notifier_call_chain(&acpi_reconfig_chain,
522 					     ACPI_RECONFIG_DEVICE_REMOVE, adev);
523 
524 		acpi_device_del(adev);
525 		/*
526 		 * Drop references to all power resources that might have been
527 		 * used by the device.
528 		 */
529 		acpi_power_transition(adev, ACPI_STATE_D3_COLD);
530 		acpi_dev_put(adev);
531 	}
532 }
533 
534 /**
535  * acpi_scan_drop_device - Drop an ACPI device object.
536  * @handle: Handle of an ACPI namespace node, not used.
537  * @context: Address of the ACPI device object to drop.
538  *
539  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
540  * namespace node the device object pointed to by @context is attached to.
541  *
542  * The unregistration is carried out asynchronously to avoid running
543  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
544  * ensure the correct ordering (the device objects must be unregistered in the
545  * same order in which the corresponding namespace nodes are deleted).
546  */
547 static void acpi_scan_drop_device(acpi_handle handle, void *context)
548 {
549 	static DECLARE_WORK(work, acpi_device_del_work_fn);
550 	struct acpi_device *adev = context;
551 
552 	mutex_lock(&acpi_device_del_lock);
553 
554 	/*
555 	 * Use the ACPI hotplug workqueue which is ordered, so this work item
556 	 * won't run after any hotplug work items submitted subsequently.  That
557 	 * prevents attempts to register device objects identical to those being
558 	 * deleted from happening concurrently (such attempts result from
559 	 * hotplug events handled via the ACPI hotplug workqueue).  It also will
560 	 * run after all of the work items submitted previously, which helps
561 	 * those work items to ensure that they are not accessing stale device
562 	 * objects.
563 	 */
564 	if (list_empty(&acpi_device_del_list))
565 		acpi_queue_hotplug_work(&work);
566 
567 	list_add_tail(&adev->del_list, &acpi_device_del_list);
568 	/* Make acpi_ns_validate_handle() return NULL for this handle. */
569 	adev->handle = INVALID_ACPI_HANDLE;
570 
571 	mutex_unlock(&acpi_device_del_lock);
572 }
573 
574 static struct acpi_device *handle_to_device(acpi_handle handle,
575 					    void (*callback)(void *))
576 {
577 	struct acpi_device *adev = NULL;
578 	acpi_status status;
579 
580 	status = acpi_get_data_full(handle, acpi_scan_drop_device,
581 				    (void **)&adev, callback);
582 	if (ACPI_FAILURE(status) || !adev) {
583 		acpi_handle_debug(handle, "No context!\n");
584 		return NULL;
585 	}
586 	return adev;
587 }
588 
589 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
590 {
591 	if (!device)
592 		return -EINVAL;
593 
594 	*device = handle_to_device(handle, NULL);
595 	if (!*device)
596 		return -ENODEV;
597 
598 	return 0;
599 }
600 EXPORT_SYMBOL(acpi_bus_get_device);
601 
602 static void get_acpi_device(void *dev)
603 {
604 	acpi_dev_get(dev);
605 }
606 
607 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
608 {
609 	return handle_to_device(handle, get_acpi_device);
610 }
611 EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device);
612 
613 static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
614 {
615 	struct acpi_device_bus_id *acpi_device_bus_id;
616 
617 	/* Find suitable bus_id and instance number in acpi_bus_id_list. */
618 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
619 		if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
620 			return acpi_device_bus_id;
621 	}
622 	return NULL;
623 }
624 
625 static int acpi_device_set_name(struct acpi_device *device,
626 				struct acpi_device_bus_id *acpi_device_bus_id)
627 {
628 	struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
629 	int result;
630 
631 	result = ida_simple_get(instance_ida, 0, ACPI_MAX_DEVICE_INSTANCES, GFP_KERNEL);
632 	if (result < 0)
633 		return result;
634 
635 	device->pnp.instance_no = result;
636 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
637 	return 0;
638 }
639 
640 static int acpi_tie_acpi_dev(struct acpi_device *adev)
641 {
642 	acpi_handle handle = adev->handle;
643 	acpi_status status;
644 
645 	if (!handle)
646 		return 0;
647 
648 	status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
649 	if (ACPI_FAILURE(status)) {
650 		acpi_handle_err(handle, "Unable to attach device data\n");
651 		return -ENODEV;
652 	}
653 
654 	return 0;
655 }
656 
657 static int __acpi_device_add(struct acpi_device *device,
658 			     void (*release)(struct device *))
659 {
660 	struct acpi_device_bus_id *acpi_device_bus_id;
661 	int result;
662 
663 	/*
664 	 * Linkage
665 	 * -------
666 	 * Link this device to its parent and siblings.
667 	 */
668 	INIT_LIST_HEAD(&device->children);
669 	INIT_LIST_HEAD(&device->node);
670 	INIT_LIST_HEAD(&device->wakeup_list);
671 	INIT_LIST_HEAD(&device->physical_node_list);
672 	INIT_LIST_HEAD(&device->del_list);
673 	mutex_init(&device->physical_node_lock);
674 
675 	mutex_lock(&acpi_device_lock);
676 
677 	acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
678 	if (acpi_device_bus_id) {
679 		result = acpi_device_set_name(device, acpi_device_bus_id);
680 		if (result)
681 			goto err_unlock;
682 	} else {
683 		acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
684 					     GFP_KERNEL);
685 		if (!acpi_device_bus_id) {
686 			result = -ENOMEM;
687 			goto err_unlock;
688 		}
689 		acpi_device_bus_id->bus_id =
690 			kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
691 		if (!acpi_device_bus_id->bus_id) {
692 			kfree(acpi_device_bus_id);
693 			result = -ENOMEM;
694 			goto err_unlock;
695 		}
696 
697 		ida_init(&acpi_device_bus_id->instance_ida);
698 
699 		result = acpi_device_set_name(device, acpi_device_bus_id);
700 		if (result) {
701 			kfree_const(acpi_device_bus_id->bus_id);
702 			kfree(acpi_device_bus_id);
703 			goto err_unlock;
704 		}
705 
706 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
707 	}
708 
709 	if (device->parent)
710 		list_add_tail(&device->node, &device->parent->children);
711 
712 	if (device->wakeup.flags.valid)
713 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
714 
715 	mutex_unlock(&acpi_device_lock);
716 
717 	if (device->parent)
718 		device->dev.parent = &device->parent->dev;
719 
720 	device->dev.bus = &acpi_bus_type;
721 	device->dev.release = release;
722 	result = device_add(&device->dev);
723 	if (result) {
724 		dev_err(&device->dev, "Error registering device\n");
725 		goto err;
726 	}
727 
728 	result = acpi_device_setup_files(device);
729 	if (result)
730 		pr_err("Error creating sysfs interface for device %s\n",
731 		       dev_name(&device->dev));
732 
733 	return 0;
734 
735 err:
736 	mutex_lock(&acpi_device_lock);
737 
738 	if (device->parent)
739 		list_del(&device->node);
740 
741 	list_del(&device->wakeup_list);
742 
743 err_unlock:
744 	mutex_unlock(&acpi_device_lock);
745 
746 	acpi_detach_data(device->handle, acpi_scan_drop_device);
747 
748 	return result;
749 }
750 
751 int acpi_device_add(struct acpi_device *adev, void (*release)(struct device *))
752 {
753 	int ret;
754 
755 	ret = acpi_tie_acpi_dev(adev);
756 	if (ret)
757 		return ret;
758 
759 	return __acpi_device_add(adev, release);
760 }
761 
762 /* --------------------------------------------------------------------------
763                                  Device Enumeration
764    -------------------------------------------------------------------------- */
765 static bool acpi_info_matches_ids(struct acpi_device_info *info,
766 				  const char * const ids[])
767 {
768 	struct acpi_pnp_device_id_list *cid_list = NULL;
769 	int i, index;
770 
771 	if (!(info->valid & ACPI_VALID_HID))
772 		return false;
773 
774 	index = match_string(ids, -1, info->hardware_id.string);
775 	if (index >= 0)
776 		return true;
777 
778 	if (info->valid & ACPI_VALID_CID)
779 		cid_list = &info->compatible_id_list;
780 
781 	if (!cid_list)
782 		return false;
783 
784 	for (i = 0; i < cid_list->count; i++) {
785 		index = match_string(ids, -1, cid_list->ids[i].string);
786 		if (index >= 0)
787 			return true;
788 	}
789 
790 	return false;
791 }
792 
793 /* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
794 static const char * const acpi_ignore_dep_ids[] = {
795 	"PNP0D80", /* Windows-compatible System Power Management Controller */
796 	"INT33BD", /* Intel Baytrail Mailbox Device */
797 	NULL
798 };
799 
800 /* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
801 static const char * const acpi_honor_dep_ids[] = {
802 	"INT3472", /* Camera sensor PMIC / clk and regulator info */
803 	NULL
804 };
805 
806 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
807 {
808 	struct acpi_device *device = NULL;
809 	acpi_status status;
810 
811 	/*
812 	 * Fixed hardware devices do not appear in the namespace and do not
813 	 * have handles, but we fabricate acpi_devices for them, so we have
814 	 * to deal with them specially.
815 	 */
816 	if (!handle)
817 		return acpi_root;
818 
819 	do {
820 		status = acpi_get_parent(handle, &handle);
821 		if (ACPI_FAILURE(status))
822 			return status == AE_NULL_ENTRY ? NULL : acpi_root;
823 	} while (acpi_bus_get_device(handle, &device));
824 	return device;
825 }
826 
827 acpi_status
828 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
829 {
830 	acpi_status status;
831 	acpi_handle tmp;
832 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
833 	union acpi_object *obj;
834 
835 	status = acpi_get_handle(handle, "_EJD", &tmp);
836 	if (ACPI_FAILURE(status))
837 		return status;
838 
839 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
840 	if (ACPI_SUCCESS(status)) {
841 		obj = buffer.pointer;
842 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
843 					 ejd);
844 		kfree(buffer.pointer);
845 	}
846 	return status;
847 }
848 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
849 
850 static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
851 {
852 	acpi_handle handle = dev->handle;
853 	struct acpi_device_wakeup *wakeup = &dev->wakeup;
854 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
855 	union acpi_object *package = NULL;
856 	union acpi_object *element = NULL;
857 	acpi_status status;
858 	int err = -ENODATA;
859 
860 	INIT_LIST_HEAD(&wakeup->resources);
861 
862 	/* _PRW */
863 	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
864 	if (ACPI_FAILURE(status)) {
865 		acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
866 				 acpi_format_exception(status));
867 		return err;
868 	}
869 
870 	package = (union acpi_object *)buffer.pointer;
871 
872 	if (!package || package->package.count < 2)
873 		goto out;
874 
875 	element = &(package->package.elements[0]);
876 	if (!element)
877 		goto out;
878 
879 	if (element->type == ACPI_TYPE_PACKAGE) {
880 		if ((element->package.count < 2) ||
881 		    (element->package.elements[0].type !=
882 		     ACPI_TYPE_LOCAL_REFERENCE)
883 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
884 			goto out;
885 
886 		wakeup->gpe_device =
887 		    element->package.elements[0].reference.handle;
888 		wakeup->gpe_number =
889 		    (u32) element->package.elements[1].integer.value;
890 	} else if (element->type == ACPI_TYPE_INTEGER) {
891 		wakeup->gpe_device = NULL;
892 		wakeup->gpe_number = element->integer.value;
893 	} else {
894 		goto out;
895 	}
896 
897 	element = &(package->package.elements[1]);
898 	if (element->type != ACPI_TYPE_INTEGER)
899 		goto out;
900 
901 	wakeup->sleep_state = element->integer.value;
902 
903 	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
904 	if (err)
905 		goto out;
906 
907 	if (!list_empty(&wakeup->resources)) {
908 		int sleep_state;
909 
910 		err = acpi_power_wakeup_list_init(&wakeup->resources,
911 						  &sleep_state);
912 		if (err) {
913 			acpi_handle_warn(handle, "Retrieving current states "
914 					 "of wakeup power resources failed\n");
915 			acpi_power_resources_list_free(&wakeup->resources);
916 			goto out;
917 		}
918 		if (sleep_state < wakeup->sleep_state) {
919 			acpi_handle_warn(handle, "Overriding _PRW sleep state "
920 					 "(S%d) by S%d from power resources\n",
921 					 (int)wakeup->sleep_state, sleep_state);
922 			wakeup->sleep_state = sleep_state;
923 		}
924 	}
925 
926  out:
927 	kfree(buffer.pointer);
928 	return err;
929 }
930 
931 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
932 {
933 	static const struct acpi_device_id button_device_ids[] = {
934 		{"PNP0C0C", 0},		/* Power button */
935 		{"PNP0C0D", 0},		/* Lid */
936 		{"PNP0C0E", 0},		/* Sleep button */
937 		{"", 0},
938 	};
939 	struct acpi_device_wakeup *wakeup = &device->wakeup;
940 	acpi_status status;
941 
942 	wakeup->flags.notifier_present = 0;
943 
944 	/* Power button, Lid switch always enable wakeup */
945 	if (!acpi_match_device_ids(device, button_device_ids)) {
946 		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
947 			/* Do not use Lid/sleep button for S5 wakeup */
948 			if (wakeup->sleep_state == ACPI_STATE_S5)
949 				wakeup->sleep_state = ACPI_STATE_S4;
950 		}
951 		acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
952 		device_set_wakeup_capable(&device->dev, true);
953 		return true;
954 	}
955 
956 	status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
957 					 wakeup->gpe_number);
958 	return ACPI_SUCCESS(status);
959 }
960 
961 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
962 {
963 	int err;
964 
965 	/* Presence of _PRW indicates wake capable */
966 	if (!acpi_has_method(device->handle, "_PRW"))
967 		return;
968 
969 	err = acpi_bus_extract_wakeup_device_power_package(device);
970 	if (err) {
971 		dev_err(&device->dev, "Unable to extract wakeup power resources");
972 		return;
973 	}
974 
975 	device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
976 	device->wakeup.prepare_count = 0;
977 	/*
978 	 * Call _PSW/_DSW object to disable its ability to wake the sleeping
979 	 * system for the ACPI device with the _PRW object.
980 	 * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
981 	 * So it is necessary to call _DSW object first. Only when it is not
982 	 * present will the _PSW object used.
983 	 */
984 	err = acpi_device_sleep_wake(device, 0, 0, 0);
985 	if (err)
986 		pr_debug("error in _DSW or _PSW evaluation\n");
987 }
988 
989 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
990 {
991 	struct acpi_device_power_state *ps = &device->power.states[state];
992 	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
993 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
994 	acpi_status status;
995 
996 	INIT_LIST_HEAD(&ps->resources);
997 
998 	/* Evaluate "_PRx" to get referenced power resources */
999 	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1000 	if (ACPI_SUCCESS(status)) {
1001 		union acpi_object *package = buffer.pointer;
1002 
1003 		if (buffer.length && package
1004 		    && package->type == ACPI_TYPE_PACKAGE
1005 		    && package->package.count)
1006 			acpi_extract_power_resources(package, 0, &ps->resources);
1007 
1008 		ACPI_FREE(buffer.pointer);
1009 	}
1010 
1011 	/* Evaluate "_PSx" to see if we can do explicit sets */
1012 	pathname[2] = 'S';
1013 	if (acpi_has_method(device->handle, pathname))
1014 		ps->flags.explicit_set = 1;
1015 
1016 	/* State is valid if there are means to put the device into it. */
1017 	if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1018 		ps->flags.valid = 1;
1019 
1020 	ps->power = -1;		/* Unknown - driver assigned */
1021 	ps->latency = -1;	/* Unknown - driver assigned */
1022 }
1023 
1024 static void acpi_bus_get_power_flags(struct acpi_device *device)
1025 {
1026 	unsigned long long dsc = ACPI_STATE_D0;
1027 	u32 i;
1028 
1029 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
1030 	if (!acpi_has_method(device->handle, "_PS0") &&
1031 	    !acpi_has_method(device->handle, "_PR0"))
1032 		return;
1033 
1034 	device->flags.power_manageable = 1;
1035 
1036 	/*
1037 	 * Power Management Flags
1038 	 */
1039 	if (acpi_has_method(device->handle, "_PSC"))
1040 		device->power.flags.explicit_get = 1;
1041 
1042 	if (acpi_has_method(device->handle, "_IRC"))
1043 		device->power.flags.inrush_current = 1;
1044 
1045 	if (acpi_has_method(device->handle, "_DSW"))
1046 		device->power.flags.dsw_present = 1;
1047 
1048 	acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
1049 	device->power.state_for_enumeration = dsc;
1050 
1051 	/*
1052 	 * Enumerate supported power management states
1053 	 */
1054 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1055 		acpi_bus_init_power_state(device, i);
1056 
1057 	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1058 
1059 	/* Set the defaults for D0 and D3hot (always supported). */
1060 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
1061 	device->power.states[ACPI_STATE_D0].power = 100;
1062 	device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1063 
1064 	/*
1065 	 * Use power resources only if the D0 list of them is populated, because
1066 	 * some platforms may provide _PR3 only to indicate D3cold support and
1067 	 * in those cases the power resources list returned by it may be bogus.
1068 	 */
1069 	if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1070 		device->power.flags.power_resources = 1;
1071 		/*
1072 		 * D3cold is supported if the D3hot list of power resources is
1073 		 * not empty.
1074 		 */
1075 		if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1076 			device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1077 	}
1078 
1079 	if (acpi_bus_init_power(device))
1080 		device->flags.power_manageable = 0;
1081 }
1082 
1083 static void acpi_bus_get_flags(struct acpi_device *device)
1084 {
1085 	/* Presence of _STA indicates 'dynamic_status' */
1086 	if (acpi_has_method(device->handle, "_STA"))
1087 		device->flags.dynamic_status = 1;
1088 
1089 	/* Presence of _RMV indicates 'removable' */
1090 	if (acpi_has_method(device->handle, "_RMV"))
1091 		device->flags.removable = 1;
1092 
1093 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
1094 	if (acpi_has_method(device->handle, "_EJD") ||
1095 	    acpi_has_method(device->handle, "_EJ0"))
1096 		device->flags.ejectable = 1;
1097 }
1098 
1099 static void acpi_device_get_busid(struct acpi_device *device)
1100 {
1101 	char bus_id[5] = { '?', 0 };
1102 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1103 	int i = 0;
1104 
1105 	/*
1106 	 * Bus ID
1107 	 * ------
1108 	 * The device's Bus ID is simply the object name.
1109 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1110 	 */
1111 	if (ACPI_IS_ROOT_DEVICE(device)) {
1112 		strcpy(device->pnp.bus_id, "ACPI");
1113 		return;
1114 	}
1115 
1116 	switch (device->device_type) {
1117 	case ACPI_BUS_TYPE_POWER_BUTTON:
1118 		strcpy(device->pnp.bus_id, "PWRF");
1119 		break;
1120 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1121 		strcpy(device->pnp.bus_id, "SLPF");
1122 		break;
1123 	case ACPI_BUS_TYPE_ECDT_EC:
1124 		strcpy(device->pnp.bus_id, "ECDT");
1125 		break;
1126 	default:
1127 		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1128 		/* Clean up trailing underscores (if any) */
1129 		for (i = 3; i > 1; i--) {
1130 			if (bus_id[i] == '_')
1131 				bus_id[i] = '\0';
1132 			else
1133 				break;
1134 		}
1135 		strcpy(device->pnp.bus_id, bus_id);
1136 		break;
1137 	}
1138 }
1139 
1140 /*
1141  * acpi_ata_match - see if an acpi object is an ATA device
1142  *
1143  * If an acpi object has one of the ACPI ATA methods defined,
1144  * then we can safely call it an ATA device.
1145  */
1146 bool acpi_ata_match(acpi_handle handle)
1147 {
1148 	return acpi_has_method(handle, "_GTF") ||
1149 	       acpi_has_method(handle, "_GTM") ||
1150 	       acpi_has_method(handle, "_STM") ||
1151 	       acpi_has_method(handle, "_SDD");
1152 }
1153 
1154 /*
1155  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1156  *
1157  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1158  * then we can safely call it an ejectable drive bay
1159  */
1160 bool acpi_bay_match(acpi_handle handle)
1161 {
1162 	acpi_handle phandle;
1163 
1164 	if (!acpi_has_method(handle, "_EJ0"))
1165 		return false;
1166 	if (acpi_ata_match(handle))
1167 		return true;
1168 	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1169 		return false;
1170 
1171 	return acpi_ata_match(phandle);
1172 }
1173 
1174 bool acpi_device_is_battery(struct acpi_device *adev)
1175 {
1176 	struct acpi_hardware_id *hwid;
1177 
1178 	list_for_each_entry(hwid, &adev->pnp.ids, list)
1179 		if (!strcmp("PNP0C0A", hwid->id))
1180 			return true;
1181 
1182 	return false;
1183 }
1184 
1185 static bool is_ejectable_bay(struct acpi_device *adev)
1186 {
1187 	acpi_handle handle = adev->handle;
1188 
1189 	if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1190 		return true;
1191 
1192 	return acpi_bay_match(handle);
1193 }
1194 
1195 /*
1196  * acpi_dock_match - see if an acpi object has a _DCK method
1197  */
1198 bool acpi_dock_match(acpi_handle handle)
1199 {
1200 	return acpi_has_method(handle, "_DCK");
1201 }
1202 
1203 static acpi_status
1204 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1205 			  void **return_value)
1206 {
1207 	long *cap = context;
1208 
1209 	if (acpi_has_method(handle, "_BCM") &&
1210 	    acpi_has_method(handle, "_BCL")) {
1211 		acpi_handle_debug(handle, "Found generic backlight support\n");
1212 		*cap |= ACPI_VIDEO_BACKLIGHT;
1213 		/* We have backlight support, no need to scan further */
1214 		return AE_CTRL_TERMINATE;
1215 	}
1216 	return 0;
1217 }
1218 
1219 /* Returns true if the ACPI object is a video device which can be
1220  * handled by video.ko.
1221  * The device will get a Linux specific CID added in scan.c to
1222  * identify the device as an ACPI graphics device
1223  * Be aware that the graphics device may not be physically present
1224  * Use acpi_video_get_capabilities() to detect general ACPI video
1225  * capabilities of present cards
1226  */
1227 long acpi_is_video_device(acpi_handle handle)
1228 {
1229 	long video_caps = 0;
1230 
1231 	/* Is this device able to support video switching ? */
1232 	if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1233 		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1234 
1235 	/* Is this device able to retrieve a video ROM ? */
1236 	if (acpi_has_method(handle, "_ROM"))
1237 		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1238 
1239 	/* Is this device able to configure which video head to be POSTed ? */
1240 	if (acpi_has_method(handle, "_VPO") &&
1241 	    acpi_has_method(handle, "_GPD") &&
1242 	    acpi_has_method(handle, "_SPD"))
1243 		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1244 
1245 	/* Only check for backlight functionality if one of the above hit. */
1246 	if (video_caps)
1247 		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1248 				    ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1249 				    &video_caps, NULL);
1250 
1251 	return video_caps;
1252 }
1253 EXPORT_SYMBOL(acpi_is_video_device);
1254 
1255 const char *acpi_device_hid(struct acpi_device *device)
1256 {
1257 	struct acpi_hardware_id *hid;
1258 
1259 	if (list_empty(&device->pnp.ids))
1260 		return dummy_hid;
1261 
1262 	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1263 	return hid->id;
1264 }
1265 EXPORT_SYMBOL(acpi_device_hid);
1266 
1267 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1268 {
1269 	struct acpi_hardware_id *id;
1270 
1271 	id = kmalloc(sizeof(*id), GFP_KERNEL);
1272 	if (!id)
1273 		return;
1274 
1275 	id->id = kstrdup_const(dev_id, GFP_KERNEL);
1276 	if (!id->id) {
1277 		kfree(id);
1278 		return;
1279 	}
1280 
1281 	list_add_tail(&id->list, &pnp->ids);
1282 	pnp->type.hardware_id = 1;
1283 }
1284 
1285 /*
1286  * Old IBM workstations have a DSDT bug wherein the SMBus object
1287  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1288  * prefix.  Work around this.
1289  */
1290 static bool acpi_ibm_smbus_match(acpi_handle handle)
1291 {
1292 	char node_name[ACPI_PATH_SEGMENT_LENGTH];
1293 	struct acpi_buffer path = { sizeof(node_name), node_name };
1294 
1295 	if (!dmi_name_in_vendors("IBM"))
1296 		return false;
1297 
1298 	/* Look for SMBS object */
1299 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1300 	    strcmp("SMBS", path.pointer))
1301 		return false;
1302 
1303 	/* Does it have the necessary (but misnamed) methods? */
1304 	if (acpi_has_method(handle, "SBI") &&
1305 	    acpi_has_method(handle, "SBR") &&
1306 	    acpi_has_method(handle, "SBW"))
1307 		return true;
1308 
1309 	return false;
1310 }
1311 
1312 static bool acpi_object_is_system_bus(acpi_handle handle)
1313 {
1314 	acpi_handle tmp;
1315 
1316 	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1317 	    tmp == handle)
1318 		return true;
1319 	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1320 	    tmp == handle)
1321 		return true;
1322 
1323 	return false;
1324 }
1325 
1326 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1327 			     int device_type)
1328 {
1329 	struct acpi_device_info *info = NULL;
1330 	struct acpi_pnp_device_id_list *cid_list;
1331 	int i;
1332 
1333 	switch (device_type) {
1334 	case ACPI_BUS_TYPE_DEVICE:
1335 		if (handle == ACPI_ROOT_OBJECT) {
1336 			acpi_add_id(pnp, ACPI_SYSTEM_HID);
1337 			break;
1338 		}
1339 
1340 		acpi_get_object_info(handle, &info);
1341 		if (!info) {
1342 			pr_err("%s: Error reading device info\n", __func__);
1343 			return;
1344 		}
1345 
1346 		if (info->valid & ACPI_VALID_HID) {
1347 			acpi_add_id(pnp, info->hardware_id.string);
1348 			pnp->type.platform_id = 1;
1349 		}
1350 		if (info->valid & ACPI_VALID_CID) {
1351 			cid_list = &info->compatible_id_list;
1352 			for (i = 0; i < cid_list->count; i++)
1353 				acpi_add_id(pnp, cid_list->ids[i].string);
1354 		}
1355 		if (info->valid & ACPI_VALID_ADR) {
1356 			pnp->bus_address = info->address;
1357 			pnp->type.bus_address = 1;
1358 		}
1359 		if (info->valid & ACPI_VALID_UID)
1360 			pnp->unique_id = kstrdup(info->unique_id.string,
1361 							GFP_KERNEL);
1362 		if (info->valid & ACPI_VALID_CLS)
1363 			acpi_add_id(pnp, info->class_code.string);
1364 
1365 		kfree(info);
1366 
1367 		/*
1368 		 * Some devices don't reliably have _HIDs & _CIDs, so add
1369 		 * synthetic HIDs to make sure drivers can find them.
1370 		 */
1371 		if (acpi_is_video_device(handle))
1372 			acpi_add_id(pnp, ACPI_VIDEO_HID);
1373 		else if (acpi_bay_match(handle))
1374 			acpi_add_id(pnp, ACPI_BAY_HID);
1375 		else if (acpi_dock_match(handle))
1376 			acpi_add_id(pnp, ACPI_DOCK_HID);
1377 		else if (acpi_ibm_smbus_match(handle))
1378 			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1379 		else if (list_empty(&pnp->ids) &&
1380 			 acpi_object_is_system_bus(handle)) {
1381 			/* \_SB, \_TZ, LNXSYBUS */
1382 			acpi_add_id(pnp, ACPI_BUS_HID);
1383 			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1384 			strcpy(pnp->device_class, ACPI_BUS_CLASS);
1385 		}
1386 
1387 		break;
1388 	case ACPI_BUS_TYPE_POWER:
1389 		acpi_add_id(pnp, ACPI_POWER_HID);
1390 		break;
1391 	case ACPI_BUS_TYPE_PROCESSOR:
1392 		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1393 		break;
1394 	case ACPI_BUS_TYPE_THERMAL:
1395 		acpi_add_id(pnp, ACPI_THERMAL_HID);
1396 		break;
1397 	case ACPI_BUS_TYPE_POWER_BUTTON:
1398 		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1399 		break;
1400 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1401 		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1402 		break;
1403 	case ACPI_BUS_TYPE_ECDT_EC:
1404 		acpi_add_id(pnp, ACPI_ECDT_HID);
1405 		break;
1406 	}
1407 }
1408 
1409 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1410 {
1411 	struct acpi_hardware_id *id, *tmp;
1412 
1413 	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1414 		kfree_const(id->id);
1415 		kfree(id);
1416 	}
1417 	kfree(pnp->unique_id);
1418 }
1419 
1420 /**
1421  * acpi_dma_supported - Check DMA support for the specified device.
1422  * @adev: The pointer to acpi device
1423  *
1424  * Return false if DMA is not supported. Otherwise, return true
1425  */
1426 bool acpi_dma_supported(const struct acpi_device *adev)
1427 {
1428 	if (!adev)
1429 		return false;
1430 
1431 	if (adev->flags.cca_seen)
1432 		return true;
1433 
1434 	/*
1435 	* Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1436 	* DMA on "Intel platforms".  Presumably that includes all x86 and
1437 	* ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1438 	*/
1439 	if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1440 		return true;
1441 
1442 	return false;
1443 }
1444 
1445 /**
1446  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1447  * @adev: The pointer to acpi device
1448  *
1449  * Return enum dev_dma_attr.
1450  */
1451 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1452 {
1453 	if (!acpi_dma_supported(adev))
1454 		return DEV_DMA_NOT_SUPPORTED;
1455 
1456 	if (adev->flags.coherent_dma)
1457 		return DEV_DMA_COHERENT;
1458 	else
1459 		return DEV_DMA_NON_COHERENT;
1460 }
1461 
1462 /**
1463  * acpi_dma_get_range() - Get device DMA parameters.
1464  *
1465  * @dev: device to configure
1466  * @dma_addr: pointer device DMA address result
1467  * @offset: pointer to the DMA offset result
1468  * @size: pointer to DMA range size result
1469  *
1470  * Evaluate DMA regions and return respectively DMA region start, offset
1471  * and size in dma_addr, offset and size on parsing success; it does not
1472  * update the passed in values on failure.
1473  *
1474  * Return 0 on success, < 0 on failure.
1475  */
1476 int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
1477 		       u64 *size)
1478 {
1479 	struct acpi_device *adev;
1480 	LIST_HEAD(list);
1481 	struct resource_entry *rentry;
1482 	int ret;
1483 	struct device *dma_dev = dev;
1484 	u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
1485 
1486 	/*
1487 	 * Walk the device tree chasing an ACPI companion with a _DMA
1488 	 * object while we go. Stop if we find a device with an ACPI
1489 	 * companion containing a _DMA method.
1490 	 */
1491 	do {
1492 		adev = ACPI_COMPANION(dma_dev);
1493 		if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1494 			break;
1495 
1496 		dma_dev = dma_dev->parent;
1497 	} while (dma_dev);
1498 
1499 	if (!dma_dev)
1500 		return -ENODEV;
1501 
1502 	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1503 		acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1504 		return -EINVAL;
1505 	}
1506 
1507 	ret = acpi_dev_get_dma_resources(adev, &list);
1508 	if (ret > 0) {
1509 		list_for_each_entry(rentry, &list, node) {
1510 			if (dma_offset && rentry->offset != dma_offset) {
1511 				ret = -EINVAL;
1512 				dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n");
1513 				goto out;
1514 			}
1515 			dma_offset = rentry->offset;
1516 
1517 			/* Take lower and upper limits */
1518 			if (rentry->res->start < dma_start)
1519 				dma_start = rentry->res->start;
1520 			if (rentry->res->end > dma_end)
1521 				dma_end = rentry->res->end;
1522 		}
1523 
1524 		if (dma_start >= dma_end) {
1525 			ret = -EINVAL;
1526 			dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1527 			goto out;
1528 		}
1529 
1530 		*dma_addr = dma_start - dma_offset;
1531 		len = dma_end - dma_start;
1532 		*size = max(len, len + 1);
1533 		*offset = dma_offset;
1534 	}
1535  out:
1536 	acpi_dev_free_resource_list(&list);
1537 
1538 	return ret >= 0 ? 0 : ret;
1539 }
1540 
1541 #ifdef CONFIG_IOMMU_API
1542 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1543 			   struct fwnode_handle *fwnode,
1544 			   const struct iommu_ops *ops)
1545 {
1546 	int ret = iommu_fwspec_init(dev, fwnode, ops);
1547 
1548 	if (!ret)
1549 		ret = iommu_fwspec_add_ids(dev, &id, 1);
1550 
1551 	return ret;
1552 }
1553 
1554 static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
1555 {
1556 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
1557 
1558 	return fwspec ? fwspec->ops : NULL;
1559 }
1560 
1561 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1562 						       const u32 *id_in)
1563 {
1564 	int err;
1565 	const struct iommu_ops *ops;
1566 
1567 	/*
1568 	 * If we already translated the fwspec there is nothing left to do,
1569 	 * return the iommu_ops.
1570 	 */
1571 	ops = acpi_iommu_fwspec_ops(dev);
1572 	if (ops)
1573 		return ops;
1574 
1575 	err = iort_iommu_configure_id(dev, id_in);
1576 	if (err && err != -EPROBE_DEFER)
1577 		err = viot_iommu_configure(dev);
1578 
1579 	/*
1580 	 * If we have reason to believe the IOMMU driver missed the initial
1581 	 * iommu_probe_device() call for dev, replay it to get things in order.
1582 	 */
1583 	if (!err && dev->bus && !device_iommu_mapped(dev))
1584 		err = iommu_probe_device(dev);
1585 
1586 	/* Ignore all other errors apart from EPROBE_DEFER */
1587 	if (err == -EPROBE_DEFER) {
1588 		return ERR_PTR(err);
1589 	} else if (err) {
1590 		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1591 		return NULL;
1592 	}
1593 	return acpi_iommu_fwspec_ops(dev);
1594 }
1595 
1596 #else /* !CONFIG_IOMMU_API */
1597 
1598 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
1599 			   struct fwnode_handle *fwnode,
1600 			   const struct iommu_ops *ops)
1601 {
1602 	return -ENODEV;
1603 }
1604 
1605 static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
1606 						       const u32 *id_in)
1607 {
1608 	return NULL;
1609 }
1610 
1611 #endif /* !CONFIG_IOMMU_API */
1612 
1613 /**
1614  * acpi_dma_configure_id - Set-up DMA configuration for the device.
1615  * @dev: The pointer to the device
1616  * @attr: device dma attributes
1617  * @input_id: input device id const value pointer
1618  */
1619 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1620 			  const u32 *input_id)
1621 {
1622 	const struct iommu_ops *iommu;
1623 	u64 dma_addr = 0, size = 0;
1624 
1625 	if (attr == DEV_DMA_NOT_SUPPORTED) {
1626 		set_dma_ops(dev, &dma_dummy_ops);
1627 		return 0;
1628 	}
1629 
1630 	acpi_arch_dma_setup(dev, &dma_addr, &size);
1631 
1632 	iommu = acpi_iommu_configure_id(dev, input_id);
1633 	if (PTR_ERR(iommu) == -EPROBE_DEFER)
1634 		return -EPROBE_DEFER;
1635 
1636 	arch_setup_dma_ops(dev, dma_addr, size,
1637 				iommu, attr == DEV_DMA_COHERENT);
1638 
1639 	return 0;
1640 }
1641 EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1642 
1643 static void acpi_init_coherency(struct acpi_device *adev)
1644 {
1645 	unsigned long long cca = 0;
1646 	acpi_status status;
1647 	struct acpi_device *parent = adev->parent;
1648 
1649 	if (parent && parent->flags.cca_seen) {
1650 		/*
1651 		 * From ACPI spec, OSPM will ignore _CCA if an ancestor
1652 		 * already saw one.
1653 		 */
1654 		adev->flags.cca_seen = 1;
1655 		cca = parent->flags.coherent_dma;
1656 	} else {
1657 		status = acpi_evaluate_integer(adev->handle, "_CCA",
1658 					       NULL, &cca);
1659 		if (ACPI_SUCCESS(status))
1660 			adev->flags.cca_seen = 1;
1661 		else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1662 			/*
1663 			 * If architecture does not specify that _CCA is
1664 			 * required for DMA-able devices (e.g. x86),
1665 			 * we default to _CCA=1.
1666 			 */
1667 			cca = 1;
1668 		else
1669 			acpi_handle_debug(adev->handle,
1670 					  "ACPI device is missing _CCA.\n");
1671 	}
1672 
1673 	adev->flags.coherent_dma = cca;
1674 }
1675 
1676 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1677 {
1678 	bool *is_serial_bus_slave_p = data;
1679 
1680 	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1681 		return 1;
1682 
1683 	*is_serial_bus_slave_p = true;
1684 
1685 	 /* no need to do more checking */
1686 	return -1;
1687 }
1688 
1689 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1690 {
1691 	struct acpi_device *parent = device->parent;
1692 	static const struct acpi_device_id indirect_io_hosts[] = {
1693 		{"HISI0191", 0},
1694 		{}
1695 	};
1696 
1697 	return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1698 }
1699 
1700 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1701 {
1702 	struct list_head resource_list;
1703 	bool is_serial_bus_slave = false;
1704 	/*
1705 	 * These devices have multiple I2cSerialBus resources and an i2c-client
1706 	 * must be instantiated for each, each with its own i2c_device_id.
1707 	 * Normally we only instantiate an i2c-client for the first resource,
1708 	 * using the ACPI HID as id. These special cases are handled by the
1709 	 * drivers/platform/x86/i2c-multi-instantiate.c driver, which knows
1710 	 * which i2c_device_id to use for each resource.
1711 	 */
1712 	static const struct acpi_device_id i2c_multi_instantiate_ids[] = {
1713 		{"BSG1160", },
1714 		{"BSG2150", },
1715 		{"INT33FE", },
1716 		{"INT3515", },
1717 		{}
1718 	};
1719 
1720 	if (acpi_is_indirect_io_slave(device))
1721 		return true;
1722 
1723 	/* Macs use device properties in lieu of _CRS resources */
1724 	if (x86_apple_machine &&
1725 	    (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1726 	     fwnode_property_present(&device->fwnode, "i2cAddress") ||
1727 	     fwnode_property_present(&device->fwnode, "baud")))
1728 		return true;
1729 
1730 	/* Instantiate a pdev for the i2c-multi-instantiate drv to bind to */
1731 	if (!acpi_match_device_ids(device, i2c_multi_instantiate_ids))
1732 		return false;
1733 
1734 	INIT_LIST_HEAD(&resource_list);
1735 	acpi_dev_get_resources(device, &resource_list,
1736 			       acpi_check_serial_bus_slave,
1737 			       &is_serial_bus_slave);
1738 	acpi_dev_free_resource_list(&resource_list);
1739 
1740 	return is_serial_bus_slave;
1741 }
1742 
1743 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1744 			     int type)
1745 {
1746 	INIT_LIST_HEAD(&device->pnp.ids);
1747 	device->device_type = type;
1748 	device->handle = handle;
1749 	device->parent = acpi_bus_get_parent(handle);
1750 	fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
1751 	acpi_set_device_status(device, ACPI_STA_DEFAULT);
1752 	acpi_device_get_busid(device);
1753 	acpi_set_pnp_ids(handle, &device->pnp, type);
1754 	acpi_init_properties(device);
1755 	acpi_bus_get_flags(device);
1756 	device->flags.match_driver = false;
1757 	device->flags.initialized = true;
1758 	device->flags.enumeration_by_parent =
1759 		acpi_device_enumeration_by_parent(device);
1760 	acpi_device_clear_enumerated(device);
1761 	device_initialize(&device->dev);
1762 	dev_set_uevent_suppress(&device->dev, true);
1763 	acpi_init_coherency(device);
1764 }
1765 
1766 static void acpi_scan_dep_init(struct acpi_device *adev)
1767 {
1768 	struct acpi_dep_data *dep;
1769 
1770 	list_for_each_entry(dep, &acpi_dep_list, node) {
1771 		if (dep->consumer == adev->handle) {
1772 			if (dep->honor_dep)
1773 				adev->flags.honor_deps = 1;
1774 
1775 			adev->dep_unmet++;
1776 		}
1777 	}
1778 }
1779 
1780 void acpi_device_add_finalize(struct acpi_device *device)
1781 {
1782 	dev_set_uevent_suppress(&device->dev, false);
1783 	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1784 }
1785 
1786 static void acpi_scan_init_status(struct acpi_device *adev)
1787 {
1788 	if (acpi_bus_get_status(adev))
1789 		acpi_set_device_status(adev, 0);
1790 }
1791 
1792 static int acpi_add_single_object(struct acpi_device **child,
1793 				  acpi_handle handle, int type, bool dep_init)
1794 {
1795 	struct acpi_device *device;
1796 	bool release_dep_lock = false;
1797 	int result;
1798 
1799 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1800 	if (!device)
1801 		return -ENOMEM;
1802 
1803 	acpi_init_device_object(device, handle, type);
1804 	/*
1805 	 * Getting the status is delayed till here so that we can call
1806 	 * acpi_bus_get_status() and use its quirk handling.  Note that
1807 	 * this must be done before the get power-/wakeup_dev-flags calls.
1808 	 */
1809 	if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
1810 		if (dep_init) {
1811 			mutex_lock(&acpi_dep_list_lock);
1812 			/*
1813 			 * Hold the lock until the acpi_tie_acpi_dev() call
1814 			 * below to prevent concurrent acpi_scan_clear_dep()
1815 			 * from deleting a dependency list entry without
1816 			 * updating dep_unmet for the device.
1817 			 */
1818 			release_dep_lock = true;
1819 			acpi_scan_dep_init(device);
1820 		}
1821 		acpi_scan_init_status(device);
1822 	}
1823 
1824 	acpi_bus_get_power_flags(device);
1825 	acpi_bus_get_wakeup_device_flags(device);
1826 
1827 	result = acpi_tie_acpi_dev(device);
1828 
1829 	if (release_dep_lock)
1830 		mutex_unlock(&acpi_dep_list_lock);
1831 
1832 	if (!result)
1833 		result = __acpi_device_add(device, acpi_device_release);
1834 
1835 	if (result) {
1836 		acpi_device_release(&device->dev);
1837 		return result;
1838 	}
1839 
1840 	acpi_power_add_remove_device(device, true);
1841 	acpi_device_add_finalize(device);
1842 
1843 	acpi_handle_debug(handle, "Added as %s, parent %s\n",
1844 			  dev_name(&device->dev), device->parent ?
1845 				dev_name(&device->parent->dev) : "(null)");
1846 
1847 	*child = device;
1848 	return 0;
1849 }
1850 
1851 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1852 					    void *context)
1853 {
1854 	struct resource *res = context;
1855 
1856 	if (acpi_dev_resource_memory(ares, res))
1857 		return AE_CTRL_TERMINATE;
1858 
1859 	return AE_OK;
1860 }
1861 
1862 static bool acpi_device_should_be_hidden(acpi_handle handle)
1863 {
1864 	acpi_status status;
1865 	struct resource res;
1866 
1867 	/* Check if it should ignore the UART device */
1868 	if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1869 		return false;
1870 
1871 	/*
1872 	 * The UART device described in SPCR table is assumed to have only one
1873 	 * memory resource present. So we only look for the first one here.
1874 	 */
1875 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1876 				     acpi_get_resource_memory, &res);
1877 	if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1878 		return false;
1879 
1880 	acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1881 			 &res.start);
1882 
1883 	return true;
1884 }
1885 
1886 bool acpi_device_is_present(const struct acpi_device *adev)
1887 {
1888 	return adev->status.present || adev->status.functional;
1889 }
1890 
1891 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1892 				       const char *idstr,
1893 				       const struct acpi_device_id **matchid)
1894 {
1895 	const struct acpi_device_id *devid;
1896 
1897 	if (handler->match)
1898 		return handler->match(idstr, matchid);
1899 
1900 	for (devid = handler->ids; devid->id[0]; devid++)
1901 		if (!strcmp((char *)devid->id, idstr)) {
1902 			if (matchid)
1903 				*matchid = devid;
1904 
1905 			return true;
1906 		}
1907 
1908 	return false;
1909 }
1910 
1911 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1912 					const struct acpi_device_id **matchid)
1913 {
1914 	struct acpi_scan_handler *handler;
1915 
1916 	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1917 		if (acpi_scan_handler_matching(handler, idstr, matchid))
1918 			return handler;
1919 
1920 	return NULL;
1921 }
1922 
1923 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1924 {
1925 	if (!!hotplug->enabled == !!val)
1926 		return;
1927 
1928 	mutex_lock(&acpi_scan_lock);
1929 
1930 	hotplug->enabled = val;
1931 
1932 	mutex_unlock(&acpi_scan_lock);
1933 }
1934 
1935 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1936 {
1937 	struct acpi_hardware_id *hwid;
1938 
1939 	if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1940 		acpi_dock_add(adev);
1941 		return;
1942 	}
1943 	list_for_each_entry(hwid, &adev->pnp.ids, list) {
1944 		struct acpi_scan_handler *handler;
1945 
1946 		handler = acpi_scan_match_handler(hwid->id, NULL);
1947 		if (handler) {
1948 			adev->flags.hotplug_notify = true;
1949 			break;
1950 		}
1951 	}
1952 }
1953 
1954 static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
1955 {
1956 	struct acpi_handle_list dep_devices;
1957 	acpi_status status;
1958 	u32 count;
1959 	int i;
1960 
1961 	/*
1962 	 * Check for _HID here to avoid deferring the enumeration of:
1963 	 * 1. PCI devices.
1964 	 * 2. ACPI nodes describing USB ports.
1965 	 * Still, checking for _HID catches more then just these cases ...
1966 	 */
1967 	if (!check_dep || !acpi_has_method(handle, "_DEP") ||
1968 	    !acpi_has_method(handle, "_HID"))
1969 		return 0;
1970 
1971 	status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
1972 	if (ACPI_FAILURE(status)) {
1973 		acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
1974 		return 0;
1975 	}
1976 
1977 	for (count = 0, i = 0; i < dep_devices.count; i++) {
1978 		struct acpi_device_info *info;
1979 		struct acpi_dep_data *dep;
1980 		bool skip, honor_dep;
1981 
1982 		status = acpi_get_object_info(dep_devices.handles[i], &info);
1983 		if (ACPI_FAILURE(status)) {
1984 			acpi_handle_debug(handle, "Error reading _DEP device info\n");
1985 			continue;
1986 		}
1987 
1988 		skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
1989 		honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
1990 		kfree(info);
1991 
1992 		if (skip)
1993 			continue;
1994 
1995 		dep = kzalloc(sizeof(*dep), GFP_KERNEL);
1996 		if (!dep)
1997 			continue;
1998 
1999 		count++;
2000 
2001 		dep->supplier = dep_devices.handles[i];
2002 		dep->consumer = handle;
2003 		dep->honor_dep = honor_dep;
2004 
2005 		mutex_lock(&acpi_dep_list_lock);
2006 		list_add_tail(&dep->node , &acpi_dep_list);
2007 		mutex_unlock(&acpi_dep_list_lock);
2008 	}
2009 
2010 	return count;
2011 }
2012 
2013 static bool acpi_bus_scan_second_pass;
2014 
2015 static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
2016 				      struct acpi_device **adev_p)
2017 {
2018 	struct acpi_device *device = NULL;
2019 	acpi_object_type acpi_type;
2020 	int type;
2021 
2022 	acpi_bus_get_device(handle, &device);
2023 	if (device)
2024 		goto out;
2025 
2026 	if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
2027 		return AE_OK;
2028 
2029 	switch (acpi_type) {
2030 	case ACPI_TYPE_DEVICE:
2031 		if (acpi_device_should_be_hidden(handle))
2032 			return AE_OK;
2033 
2034 		/* Bail out if there are dependencies. */
2035 		if (acpi_scan_check_dep(handle, check_dep) > 0) {
2036 			acpi_bus_scan_second_pass = true;
2037 			return AE_CTRL_DEPTH;
2038 		}
2039 
2040 		fallthrough;
2041 	case ACPI_TYPE_ANY:	/* for ACPI_ROOT_OBJECT */
2042 		type = ACPI_BUS_TYPE_DEVICE;
2043 		break;
2044 
2045 	case ACPI_TYPE_PROCESSOR:
2046 		type = ACPI_BUS_TYPE_PROCESSOR;
2047 		break;
2048 
2049 	case ACPI_TYPE_THERMAL:
2050 		type = ACPI_BUS_TYPE_THERMAL;
2051 		break;
2052 
2053 	case ACPI_TYPE_POWER:
2054 		acpi_add_power_resource(handle);
2055 		fallthrough;
2056 	default:
2057 		return AE_OK;
2058 	}
2059 
2060 	/*
2061 	 * If check_dep is true at this point, the device has no dependencies,
2062 	 * or the creation of the device object would have been postponed above.
2063 	 */
2064 	acpi_add_single_object(&device, handle, type, !check_dep);
2065 	if (!device)
2066 		return AE_CTRL_DEPTH;
2067 
2068 	acpi_scan_init_hotplug(device);
2069 
2070 out:
2071 	if (!*adev_p)
2072 		*adev_p = device;
2073 
2074 	return AE_OK;
2075 }
2076 
2077 static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
2078 					void *not_used, void **ret_p)
2079 {
2080 	return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
2081 }
2082 
2083 static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
2084 					void *not_used, void **ret_p)
2085 {
2086 	return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
2087 }
2088 
2089 static void acpi_default_enumeration(struct acpi_device *device)
2090 {
2091 	/*
2092 	 * Do not enumerate devices with enumeration_by_parent flag set as
2093 	 * they will be enumerated by their respective parents.
2094 	 */
2095 	if (!device->flags.enumeration_by_parent) {
2096 		acpi_create_platform_device(device, NULL);
2097 		acpi_device_set_enumerated(device);
2098 	} else {
2099 		blocking_notifier_call_chain(&acpi_reconfig_chain,
2100 					     ACPI_RECONFIG_DEVICE_ADD, device);
2101 	}
2102 }
2103 
2104 static const struct acpi_device_id generic_device_ids[] = {
2105 	{ACPI_DT_NAMESPACE_HID, },
2106 	{"", },
2107 };
2108 
2109 static int acpi_generic_device_attach(struct acpi_device *adev,
2110 				      const struct acpi_device_id *not_used)
2111 {
2112 	/*
2113 	 * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2114 	 * below can be unconditional.
2115 	 */
2116 	if (adev->data.of_compatible)
2117 		acpi_default_enumeration(adev);
2118 
2119 	return 1;
2120 }
2121 
2122 static struct acpi_scan_handler generic_device_handler = {
2123 	.ids = generic_device_ids,
2124 	.attach = acpi_generic_device_attach,
2125 };
2126 
2127 static int acpi_scan_attach_handler(struct acpi_device *device)
2128 {
2129 	struct acpi_hardware_id *hwid;
2130 	int ret = 0;
2131 
2132 	list_for_each_entry(hwid, &device->pnp.ids, list) {
2133 		const struct acpi_device_id *devid;
2134 		struct acpi_scan_handler *handler;
2135 
2136 		handler = acpi_scan_match_handler(hwid->id, &devid);
2137 		if (handler) {
2138 			if (!handler->attach) {
2139 				device->pnp.type.platform_id = 0;
2140 				continue;
2141 			}
2142 			device->handler = handler;
2143 			ret = handler->attach(device, devid);
2144 			if (ret > 0)
2145 				break;
2146 
2147 			device->handler = NULL;
2148 			if (ret < 0)
2149 				break;
2150 		}
2151 	}
2152 
2153 	return ret;
2154 }
2155 
2156 static void acpi_bus_attach(struct acpi_device *device, bool first_pass)
2157 {
2158 	struct acpi_device *child;
2159 	bool skip = !first_pass && device->flags.visited;
2160 	acpi_handle ejd;
2161 	int ret;
2162 
2163 	if (skip)
2164 		goto ok;
2165 
2166 	if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2167 		register_dock_dependent_device(device, ejd);
2168 
2169 	acpi_bus_get_status(device);
2170 	/* Skip devices that are not ready for enumeration (e.g. not present) */
2171 	if (!acpi_dev_ready_for_enumeration(device)) {
2172 		device->flags.initialized = false;
2173 		acpi_device_clear_enumerated(device);
2174 		device->flags.power_manageable = 0;
2175 		return;
2176 	}
2177 	if (device->handler)
2178 		goto ok;
2179 
2180 	if (!device->flags.initialized) {
2181 		device->flags.power_manageable =
2182 			device->power.states[ACPI_STATE_D0].flags.valid;
2183 		if (acpi_bus_init_power(device))
2184 			device->flags.power_manageable = 0;
2185 
2186 		device->flags.initialized = true;
2187 	} else if (device->flags.visited) {
2188 		goto ok;
2189 	}
2190 
2191 	ret = acpi_scan_attach_handler(device);
2192 	if (ret < 0)
2193 		return;
2194 
2195 	device->flags.match_driver = true;
2196 	if (ret > 0 && !device->flags.enumeration_by_parent) {
2197 		acpi_device_set_enumerated(device);
2198 		goto ok;
2199 	}
2200 
2201 	ret = device_attach(&device->dev);
2202 	if (ret < 0)
2203 		return;
2204 
2205 	if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2206 		acpi_default_enumeration(device);
2207 	else
2208 		acpi_device_set_enumerated(device);
2209 
2210  ok:
2211 	list_for_each_entry(child, &device->children, node)
2212 		acpi_bus_attach(child, first_pass);
2213 
2214 	if (!skip && device->handler && device->handler->hotplug.notify_online)
2215 		device->handler->hotplug.notify_online(device);
2216 }
2217 
2218 static int acpi_dev_get_first_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
2219 {
2220 	struct acpi_device *adev;
2221 
2222 	adev = acpi_bus_get_acpi_device(dep->consumer);
2223 	if (adev) {
2224 		*(struct acpi_device **)data = adev;
2225 		return 1;
2226 	}
2227 	/* Continue parsing if the device object is not present. */
2228 	return 0;
2229 }
2230 
2231 struct acpi_scan_clear_dep_work {
2232 	struct work_struct work;
2233 	struct acpi_device *adev;
2234 };
2235 
2236 static void acpi_scan_clear_dep_fn(struct work_struct *work)
2237 {
2238 	struct acpi_scan_clear_dep_work *cdw;
2239 
2240 	cdw = container_of(work, struct acpi_scan_clear_dep_work, work);
2241 
2242 	acpi_scan_lock_acquire();
2243 	acpi_bus_attach(cdw->adev, true);
2244 	acpi_scan_lock_release();
2245 
2246 	acpi_dev_put(cdw->adev);
2247 	kfree(cdw);
2248 }
2249 
2250 static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
2251 {
2252 	struct acpi_scan_clear_dep_work *cdw;
2253 
2254 	if (adev->dep_unmet)
2255 		return false;
2256 
2257 	cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
2258 	if (!cdw)
2259 		return false;
2260 
2261 	cdw->adev = adev;
2262 	INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
2263 	/*
2264 	 * Since the work function may block on the lock until the entire
2265 	 * initial enumeration of devices is complete, put it into the unbound
2266 	 * workqueue.
2267 	 */
2268 	queue_work(system_unbound_wq, &cdw->work);
2269 
2270 	return true;
2271 }
2272 
2273 static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
2274 {
2275 	struct acpi_device *adev = acpi_bus_get_acpi_device(dep->consumer);
2276 
2277 	if (adev) {
2278 		adev->dep_unmet--;
2279 		if (!acpi_scan_clear_dep_queue(adev))
2280 			acpi_dev_put(adev);
2281 	}
2282 
2283 	list_del(&dep->node);
2284 	kfree(dep);
2285 
2286 	return 0;
2287 }
2288 
2289 /**
2290  * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
2291  * @handle:	The ACPI handle of the supplier device
2292  * @callback:	Pointer to the callback function to apply
2293  * @data:	Pointer to some data to pass to the callback
2294  *
2295  * The return value of the callback determines this function's behaviour. If 0
2296  * is returned we continue to iterate over acpi_dep_list. If a positive value
2297  * is returned then the loop is broken but this function returns 0. If a
2298  * negative value is returned by the callback then the loop is broken and that
2299  * value is returned as the final error.
2300  */
2301 static int acpi_walk_dep_device_list(acpi_handle handle,
2302 				int (*callback)(struct acpi_dep_data *, void *),
2303 				void *data)
2304 {
2305 	struct acpi_dep_data *dep, *tmp;
2306 	int ret = 0;
2307 
2308 	mutex_lock(&acpi_dep_list_lock);
2309 	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2310 		if (dep->supplier == handle) {
2311 			ret = callback(dep, data);
2312 			if (ret)
2313 				break;
2314 		}
2315 	}
2316 	mutex_unlock(&acpi_dep_list_lock);
2317 
2318 	return ret > 0 ? 0 : ret;
2319 }
2320 
2321 /**
2322  * acpi_dev_clear_dependencies - Inform consumers that the device is now active
2323  * @supplier: Pointer to the supplier &struct acpi_device
2324  *
2325  * Clear dependencies on the given device.
2326  */
2327 void acpi_dev_clear_dependencies(struct acpi_device *supplier)
2328 {
2329 	acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
2330 }
2331 EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
2332 
2333 /**
2334  * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
2335  * @device: Pointer to the &struct acpi_device to check
2336  *
2337  * Check if the device is present and has no unmet dependencies.
2338  *
2339  * Return true if the device is ready for enumeratino. Otherwise, return false.
2340  */
2341 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
2342 {
2343 	if (device->flags.honor_deps && device->dep_unmet)
2344 		return false;
2345 
2346 	return acpi_device_is_present(device);
2347 }
2348 EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
2349 
2350 /**
2351  * acpi_dev_get_first_consumer_dev - Return ACPI device dependent on @supplier
2352  * @supplier: Pointer to the dependee device
2353  *
2354  * Returns the first &struct acpi_device which declares itself dependent on
2355  * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
2356  *
2357  * The caller is responsible for putting the reference to adev when it is no
2358  * longer needed.
2359  */
2360 struct acpi_device *acpi_dev_get_first_consumer_dev(struct acpi_device *supplier)
2361 {
2362 	struct acpi_device *adev = NULL;
2363 
2364 	acpi_walk_dep_device_list(supplier->handle,
2365 				  acpi_dev_get_first_consumer_dev_cb, &adev);
2366 
2367 	return adev;
2368 }
2369 EXPORT_SYMBOL_GPL(acpi_dev_get_first_consumer_dev);
2370 
2371 /**
2372  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2373  * @handle: Root of the namespace scope to scan.
2374  *
2375  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2376  * found devices.
2377  *
2378  * If no devices were found, -ENODEV is returned, but it does not mean that
2379  * there has been a real error.  There just have been no suitable ACPI objects
2380  * in the table trunk from which the kernel could create a device and add an
2381  * appropriate driver.
2382  *
2383  * Must be called under acpi_scan_lock.
2384  */
2385 int acpi_bus_scan(acpi_handle handle)
2386 {
2387 	struct acpi_device *device = NULL;
2388 
2389 	acpi_bus_scan_second_pass = false;
2390 
2391 	/* Pass 1: Avoid enumerating devices with missing dependencies. */
2392 
2393 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
2394 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2395 				    acpi_bus_check_add_1, NULL, NULL,
2396 				    (void **)&device);
2397 
2398 	if (!device)
2399 		return -ENODEV;
2400 
2401 	acpi_bus_attach(device, true);
2402 
2403 	if (!acpi_bus_scan_second_pass)
2404 		return 0;
2405 
2406 	/* Pass 2: Enumerate all of the remaining devices. */
2407 
2408 	device = NULL;
2409 
2410 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, false, &device)))
2411 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2412 				    acpi_bus_check_add_2, NULL, NULL,
2413 				    (void **)&device);
2414 
2415 	acpi_bus_attach(device, false);
2416 
2417 	return 0;
2418 }
2419 EXPORT_SYMBOL(acpi_bus_scan);
2420 
2421 /**
2422  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2423  * @adev: Root of the ACPI namespace scope to walk.
2424  *
2425  * Must be called under acpi_scan_lock.
2426  */
2427 void acpi_bus_trim(struct acpi_device *adev)
2428 {
2429 	struct acpi_scan_handler *handler = adev->handler;
2430 	struct acpi_device *child;
2431 
2432 	list_for_each_entry_reverse(child, &adev->children, node)
2433 		acpi_bus_trim(child);
2434 
2435 	adev->flags.match_driver = false;
2436 	if (handler) {
2437 		if (handler->detach)
2438 			handler->detach(adev);
2439 
2440 		adev->handler = NULL;
2441 	} else {
2442 		device_release_driver(&adev->dev);
2443 	}
2444 	/*
2445 	 * Most likely, the device is going away, so put it into D3cold before
2446 	 * that.
2447 	 */
2448 	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2449 	adev->flags.initialized = false;
2450 	acpi_device_clear_enumerated(adev);
2451 }
2452 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2453 
2454 int acpi_bus_register_early_device(int type)
2455 {
2456 	struct acpi_device *device = NULL;
2457 	int result;
2458 
2459 	result = acpi_add_single_object(&device, NULL, type, false);
2460 	if (result)
2461 		return result;
2462 
2463 	device->flags.match_driver = true;
2464 	return device_attach(&device->dev);
2465 }
2466 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2467 
2468 static int acpi_bus_scan_fixed(void)
2469 {
2470 	int result = 0;
2471 
2472 	/*
2473 	 * Enumerate all fixed-feature devices.
2474 	 */
2475 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2476 		struct acpi_device *device = NULL;
2477 
2478 		result = acpi_add_single_object(&device, NULL,
2479 						ACPI_BUS_TYPE_POWER_BUTTON, false);
2480 		if (result)
2481 			return result;
2482 
2483 		device->flags.match_driver = true;
2484 		result = device_attach(&device->dev);
2485 		if (result < 0)
2486 			return result;
2487 
2488 		device_init_wakeup(&device->dev, true);
2489 	}
2490 
2491 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2492 		struct acpi_device *device = NULL;
2493 
2494 		result = acpi_add_single_object(&device, NULL,
2495 						ACPI_BUS_TYPE_SLEEP_BUTTON, false);
2496 		if (result)
2497 			return result;
2498 
2499 		device->flags.match_driver = true;
2500 		result = device_attach(&device->dev);
2501 	}
2502 
2503 	return result < 0 ? result : 0;
2504 }
2505 
2506 static void __init acpi_get_spcr_uart_addr(void)
2507 {
2508 	acpi_status status;
2509 	struct acpi_table_spcr *spcr_ptr;
2510 
2511 	status = acpi_get_table(ACPI_SIG_SPCR, 0,
2512 				(struct acpi_table_header **)&spcr_ptr);
2513 	if (ACPI_FAILURE(status)) {
2514 		pr_warn("STAO table present, but SPCR is missing\n");
2515 		return;
2516 	}
2517 
2518 	spcr_uart_addr = spcr_ptr->serial_port.address;
2519 	acpi_put_table((struct acpi_table_header *)spcr_ptr);
2520 }
2521 
2522 static bool acpi_scan_initialized;
2523 
2524 int __init acpi_scan_init(void)
2525 {
2526 	int result;
2527 	acpi_status status;
2528 	struct acpi_table_stao *stao_ptr;
2529 
2530 	acpi_pci_root_init();
2531 	acpi_pci_link_init();
2532 	acpi_processor_init();
2533 	acpi_platform_init();
2534 	acpi_lpss_init();
2535 	acpi_apd_init();
2536 	acpi_cmos_rtc_init();
2537 	acpi_container_init();
2538 	acpi_memory_hotplug_init();
2539 	acpi_watchdog_init();
2540 	acpi_pnp_init();
2541 	acpi_int340x_thermal_init();
2542 	acpi_amba_init();
2543 	acpi_init_lpit();
2544 
2545 	acpi_scan_add_handler(&generic_device_handler);
2546 
2547 	/*
2548 	 * If there is STAO table, check whether it needs to ignore the UART
2549 	 * device in SPCR table.
2550 	 */
2551 	status = acpi_get_table(ACPI_SIG_STAO, 0,
2552 				(struct acpi_table_header **)&stao_ptr);
2553 	if (ACPI_SUCCESS(status)) {
2554 		if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2555 			pr_info("STAO Name List not yet supported.\n");
2556 
2557 		if (stao_ptr->ignore_uart)
2558 			acpi_get_spcr_uart_addr();
2559 
2560 		acpi_put_table((struct acpi_table_header *)stao_ptr);
2561 	}
2562 
2563 	acpi_gpe_apply_masked_gpes();
2564 	acpi_update_all_gpes();
2565 
2566 	/*
2567 	 * Although we call __add_memory() that is documented to require the
2568 	 * device_hotplug_lock, it is not necessary here because this is an
2569 	 * early code when userspace or any other code path cannot trigger
2570 	 * hotplug/hotunplug operations.
2571 	 */
2572 	mutex_lock(&acpi_scan_lock);
2573 	/*
2574 	 * Enumerate devices in the ACPI namespace.
2575 	 */
2576 	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2577 	if (result)
2578 		goto out;
2579 
2580 	result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2581 	if (result)
2582 		goto out;
2583 
2584 	/* Fixed feature devices do not exist on HW-reduced platform */
2585 	if (!acpi_gbl_reduced_hardware) {
2586 		result = acpi_bus_scan_fixed();
2587 		if (result) {
2588 			acpi_detach_data(acpi_root->handle,
2589 					 acpi_scan_drop_device);
2590 			acpi_device_del(acpi_root);
2591 			acpi_bus_put_acpi_device(acpi_root);
2592 			goto out;
2593 		}
2594 	}
2595 
2596 	acpi_turn_off_unused_power_resources();
2597 
2598 	acpi_scan_initialized = true;
2599 
2600  out:
2601 	mutex_unlock(&acpi_scan_lock);
2602 	return result;
2603 }
2604 
2605 static struct acpi_probe_entry *ape;
2606 static int acpi_probe_count;
2607 static DEFINE_MUTEX(acpi_probe_mutex);
2608 
2609 static int __init acpi_match_madt(union acpi_subtable_headers *header,
2610 				  const unsigned long end)
2611 {
2612 	if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2613 		if (!ape->probe_subtbl(header, end))
2614 			acpi_probe_count++;
2615 
2616 	return 0;
2617 }
2618 
2619 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2620 {
2621 	int count = 0;
2622 
2623 	if (acpi_disabled)
2624 		return 0;
2625 
2626 	mutex_lock(&acpi_probe_mutex);
2627 	for (ape = ap_head; nr; ape++, nr--) {
2628 		if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2629 			acpi_probe_count = 0;
2630 			acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2631 			count += acpi_probe_count;
2632 		} else {
2633 			int res;
2634 			res = acpi_table_parse(ape->id, ape->probe_table);
2635 			if (!res)
2636 				count++;
2637 		}
2638 	}
2639 	mutex_unlock(&acpi_probe_mutex);
2640 
2641 	return count;
2642 }
2643 
2644 static void acpi_table_events_fn(struct work_struct *work)
2645 {
2646 	acpi_scan_lock_acquire();
2647 	acpi_bus_scan(ACPI_ROOT_OBJECT);
2648 	acpi_scan_lock_release();
2649 
2650 	kfree(work);
2651 }
2652 
2653 void acpi_scan_table_notify(void)
2654 {
2655 	struct work_struct *work;
2656 
2657 	if (!acpi_scan_initialized)
2658 		return;
2659 
2660 	work = kmalloc(sizeof(*work), GFP_KERNEL);
2661 	if (!work)
2662 		return;
2663 
2664 	INIT_WORK(work, acpi_table_events_fn);
2665 	schedule_work(work);
2666 }
2667 
2668 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2669 {
2670 	return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2671 }
2672 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2673 
2674 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2675 {
2676 	return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2677 }
2678 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);
2679