xref: /kernel/linux/linux-5.10/drivers/acpi/scan.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * scan.c - support for transforming the ACPI namespace into individual objects
4 */
5
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/slab.h>
9#include <linux/kernel.h>
10#include <linux/acpi.h>
11#include <linux/acpi_iort.h>
12#include <linux/signal.h>
13#include <linux/kthread.h>
14#include <linux/dmi.h>
15#include <linux/nls.h>
16#include <linux/dma-map-ops.h>
17#include <linux/platform_data/x86/apple.h>
18#include <linux/pgtable.h>
19#include <linux/dma-direct.h>
20
21#include "internal.h"
22
23#define _COMPONENT		ACPI_BUS_COMPONENT
24ACPI_MODULE_NAME("scan");
25extern 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
35static const char *dummy_hid = "device";
36
37static LIST_HEAD(acpi_dep_list);
38static DEFINE_MUTEX(acpi_dep_list_lock);
39LIST_HEAD(acpi_bus_id_list);
40static DEFINE_MUTEX(acpi_scan_lock);
41static LIST_HEAD(acpi_scan_handlers_list);
42DEFINE_MUTEX(acpi_device_lock);
43LIST_HEAD(acpi_wakeup_device_list);
44static 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 */
51static u64 spcr_uart_addr;
52
53struct acpi_dep_data {
54	struct list_head node;
55	acpi_handle master;
56	acpi_handle slave;
57};
58
59void acpi_scan_lock_acquire(void)
60{
61	mutex_lock(&acpi_scan_lock);
62}
63EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
64
65void acpi_scan_lock_release(void)
66{
67	mutex_unlock(&acpi_scan_lock);
68}
69EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
70
71void acpi_lock_hp_context(void)
72{
73	mutex_lock(&acpi_hp_context_lock);
74}
75
76void acpi_unlock_hp_context(void)
77{
78	mutex_unlock(&acpi_hp_context_lock);
79}
80
81void acpi_initialize_hp_context(struct acpi_device *adev,
82				struct acpi_hotplug_context *hp,
83				int (*notify)(struct acpi_device *, u32),
84				void (*uevent)(struct acpi_device *, u32))
85{
86	acpi_lock_hp_context();
87	hp->notify = notify;
88	hp->uevent = uevent;
89	acpi_set_hp_context(adev, hp);
90	acpi_unlock_hp_context();
91}
92EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
93
94int acpi_scan_add_handler(struct acpi_scan_handler *handler)
95{
96	if (!handler)
97		return -EINVAL;
98
99	list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
100	return 0;
101}
102
103int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
104				       const char *hotplug_profile_name)
105{
106	int error;
107
108	error = acpi_scan_add_handler(handler);
109	if (error)
110		return error;
111
112	acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
113	return 0;
114}
115
116bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
117{
118	struct acpi_device_physical_node *pn;
119	bool offline = true;
120	char *envp[] = { "EVENT=offline", NULL };
121
122	/*
123	 * acpi_container_offline() calls this for all of the container's
124	 * children under the container's physical_node_lock lock.
125	 */
126	mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
127
128	list_for_each_entry(pn, &adev->physical_node_list, node)
129		if (device_supports_offline(pn->dev) && !pn->dev->offline) {
130			if (uevent)
131				kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
132
133			offline = false;
134			break;
135		}
136
137	mutex_unlock(&adev->physical_node_lock);
138	return offline;
139}
140
141static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
142				    void **ret_p)
143{
144	struct acpi_device *device = NULL;
145	struct acpi_device_physical_node *pn;
146	bool second_pass = (bool)data;
147	acpi_status status = AE_OK;
148
149	if (acpi_bus_get_device(handle, &device))
150		return AE_OK;
151
152	if (device->handler && !device->handler->hotplug.enabled) {
153		*ret_p = &device->dev;
154		return AE_SUPPORT;
155	}
156
157	mutex_lock(&device->physical_node_lock);
158
159	list_for_each_entry(pn, &device->physical_node_list, node) {
160		int ret;
161
162		if (second_pass) {
163			/* Skip devices offlined by the first pass. */
164			if (pn->put_online)
165				continue;
166		} else {
167			pn->put_online = false;
168		}
169		ret = device_offline(pn->dev);
170		if (ret >= 0) {
171			pn->put_online = !ret;
172		} else {
173			*ret_p = pn->dev;
174			if (second_pass) {
175				status = AE_ERROR;
176				break;
177			}
178		}
179	}
180
181	mutex_unlock(&device->physical_node_lock);
182
183	return status;
184}
185
186static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
187				   void **ret_p)
188{
189	struct acpi_device *device = NULL;
190	struct acpi_device_physical_node *pn;
191
192	if (acpi_bus_get_device(handle, &device))
193		return AE_OK;
194
195	mutex_lock(&device->physical_node_lock);
196
197	list_for_each_entry(pn, &device->physical_node_list, node)
198		if (pn->put_online) {
199			device_online(pn->dev);
200			pn->put_online = false;
201		}
202
203	mutex_unlock(&device->physical_node_lock);
204
205	return AE_OK;
206}
207
208static int acpi_scan_try_to_offline(struct acpi_device *device)
209{
210	acpi_handle handle = device->handle;
211	struct device *errdev = NULL;
212	acpi_status status;
213
214	/*
215	 * Carry out two passes here and ignore errors in the first pass,
216	 * because if the devices in question are memory blocks and
217	 * CONFIG_MEMCG is set, one of the blocks may hold data structures
218	 * that the other blocks depend on, but it is not known in advance which
219	 * block holds them.
220	 *
221	 * If the first pass is successful, the second one isn't needed, though.
222	 */
223	status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
224				     NULL, acpi_bus_offline, (void *)false,
225				     (void **)&errdev);
226	if (status == AE_SUPPORT) {
227		dev_warn(errdev, "Offline disabled.\n");
228		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
229				    acpi_bus_online, NULL, NULL, NULL);
230		return -EPERM;
231	}
232	acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
233	if (errdev) {
234		errdev = NULL;
235		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
236				    NULL, acpi_bus_offline, (void *)true,
237				    (void **)&errdev);
238		if (!errdev)
239			acpi_bus_offline(handle, 0, (void *)true,
240					 (void **)&errdev);
241
242		if (errdev) {
243			dev_warn(errdev, "Offline failed.\n");
244			acpi_bus_online(handle, 0, NULL, NULL);
245			acpi_walk_namespace(ACPI_TYPE_ANY, handle,
246					    ACPI_UINT32_MAX, acpi_bus_online,
247					    NULL, NULL, NULL);
248			return -EBUSY;
249		}
250	}
251	return 0;
252}
253
254static int acpi_scan_hot_remove(struct acpi_device *device)
255{
256	acpi_handle handle = device->handle;
257	unsigned long long sta;
258	acpi_status status;
259
260	if (device->handler && device->handler->hotplug.demand_offline) {
261		if (!acpi_scan_is_offline(device, true))
262			return -EBUSY;
263	} else {
264		int error = acpi_scan_try_to_offline(device);
265		if (error)
266			return error;
267	}
268
269	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
270		"Hot-removing device %s...\n", dev_name(&device->dev)));
271
272	acpi_bus_trim(device);
273
274	acpi_evaluate_lck(handle, 0);
275	/*
276	 * TBD: _EJD support.
277	 */
278	status = acpi_evaluate_ej0(handle);
279	if (status == AE_NOT_FOUND)
280		return -ENODEV;
281	else if (ACPI_FAILURE(status))
282		return -EIO;
283
284	/*
285	 * Verify if eject was indeed successful.  If not, log an error
286	 * message.  No need to call _OST since _EJ0 call was made OK.
287	 */
288	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
289	if (ACPI_FAILURE(status)) {
290		acpi_handle_warn(handle,
291			"Status check after eject failed (0x%x)\n", status);
292	} else if (sta & ACPI_STA_DEVICE_ENABLED) {
293		acpi_handle_warn(handle,
294			"Eject incomplete - status 0x%llx\n", sta);
295	}
296
297	return 0;
298}
299
300static int acpi_scan_device_not_present(struct acpi_device *adev)
301{
302	if (!acpi_device_enumerated(adev)) {
303		dev_warn(&adev->dev, "Still not present\n");
304		return -EALREADY;
305	}
306	acpi_bus_trim(adev);
307	return 0;
308}
309
310static int acpi_scan_device_check(struct acpi_device *adev)
311{
312	int error;
313
314	acpi_bus_get_status(adev);
315	if (adev->status.present || adev->status.functional) {
316		/*
317		 * This function is only called for device objects for which
318		 * matching scan handlers exist.  The only situation in which
319		 * the scan handler is not attached to this device object yet
320		 * is when the device has just appeared (either it wasn't
321		 * present at all before or it was removed and then added
322		 * again).
323		 */
324		if (adev->handler) {
325			dev_warn(&adev->dev, "Already enumerated\n");
326			return -EALREADY;
327		}
328		error = acpi_bus_scan(adev->handle);
329		if (error) {
330			dev_warn(&adev->dev, "Namespace scan failure\n");
331			return error;
332		}
333		if (!adev->handler) {
334			dev_warn(&adev->dev, "Enumeration failure\n");
335			error = -ENODEV;
336		}
337	} else {
338		error = acpi_scan_device_not_present(adev);
339	}
340	return error;
341}
342
343static int acpi_scan_bus_check(struct acpi_device *adev)
344{
345	struct acpi_scan_handler *handler = adev->handler;
346	struct acpi_device *child;
347	int error;
348
349	acpi_bus_get_status(adev);
350	if (!(adev->status.present || adev->status.functional)) {
351		acpi_scan_device_not_present(adev);
352		return 0;
353	}
354	if (handler && handler->hotplug.scan_dependent)
355		return handler->hotplug.scan_dependent(adev);
356
357	error = acpi_bus_scan(adev->handle);
358	if (error) {
359		dev_warn(&adev->dev, "Namespace scan failure\n");
360		return error;
361	}
362	list_for_each_entry(child, &adev->children, node) {
363		error = acpi_scan_bus_check(child);
364		if (error)
365			return error;
366	}
367	return 0;
368}
369
370static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
371{
372	switch (type) {
373	case ACPI_NOTIFY_BUS_CHECK:
374		return acpi_scan_bus_check(adev);
375	case ACPI_NOTIFY_DEVICE_CHECK:
376		return acpi_scan_device_check(adev);
377	case ACPI_NOTIFY_EJECT_REQUEST:
378	case ACPI_OST_EC_OSPM_EJECT:
379		if (adev->handler && !adev->handler->hotplug.enabled) {
380			dev_info(&adev->dev, "Eject disabled\n");
381			return -EPERM;
382		}
383		acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
384				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
385		return acpi_scan_hot_remove(adev);
386	}
387	return -EINVAL;
388}
389
390void acpi_device_hotplug(struct acpi_device *adev, u32 src)
391{
392	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
393	int error = -ENODEV;
394
395	lock_device_hotplug();
396	mutex_lock(&acpi_scan_lock);
397
398	/*
399	 * The device object's ACPI handle cannot become invalid as long as we
400	 * are holding acpi_scan_lock, but it might have become invalid before
401	 * that lock was acquired.
402	 */
403	if (adev->handle == INVALID_ACPI_HANDLE)
404		goto err_out;
405
406	if (adev->flags.is_dock_station) {
407		error = dock_notify(adev, src);
408	} else if (adev->flags.hotplug_notify) {
409		error = acpi_generic_hotplug_event(adev, src);
410	} else {
411		int (*notify)(struct acpi_device *, u32);
412
413		acpi_lock_hp_context();
414		notify = adev->hp ? adev->hp->notify : NULL;
415		acpi_unlock_hp_context();
416		/*
417		 * There may be additional notify handlers for device objects
418		 * without the .event() callback, so ignore them here.
419		 */
420		if (notify)
421			error = notify(adev, src);
422		else
423			goto out;
424	}
425	switch (error) {
426	case 0:
427		ost_code = ACPI_OST_SC_SUCCESS;
428		break;
429	case -EPERM:
430		ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
431		break;
432	case -EBUSY:
433		ost_code = ACPI_OST_SC_DEVICE_BUSY;
434		break;
435	default:
436		ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
437		break;
438	}
439
440 err_out:
441	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
442
443 out:
444	acpi_bus_put_acpi_device(adev);
445	mutex_unlock(&acpi_scan_lock);
446	unlock_device_hotplug();
447}
448
449static void acpi_free_power_resources_lists(struct acpi_device *device)
450{
451	int i;
452
453	if (device->wakeup.flags.valid)
454		acpi_power_resources_list_free(&device->wakeup.resources);
455
456	if (!device->power.flags.power_resources)
457		return;
458
459	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
460		struct acpi_device_power_state *ps = &device->power.states[i];
461		acpi_power_resources_list_free(&ps->resources);
462	}
463}
464
465static void acpi_device_release(struct device *dev)
466{
467	struct acpi_device *acpi_dev = to_acpi_device(dev);
468
469	acpi_free_properties(acpi_dev);
470	acpi_free_pnp_ids(&acpi_dev->pnp);
471	acpi_free_power_resources_lists(acpi_dev);
472	kfree(acpi_dev);
473}
474
475static void acpi_device_del(struct acpi_device *device)
476{
477	struct acpi_device_bus_id *acpi_device_bus_id;
478
479	mutex_lock(&acpi_device_lock);
480	if (device->parent)
481		list_del(&device->node);
482
483	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
484		if (!strcmp(acpi_device_bus_id->bus_id,
485			    acpi_device_hid(device))) {
486			ida_simple_remove(&acpi_device_bus_id->instance_ida, device->pnp.instance_no);
487			if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
488				list_del(&acpi_device_bus_id->node);
489				kfree_const(acpi_device_bus_id->bus_id);
490				kfree(acpi_device_bus_id);
491			}
492			break;
493		}
494
495	list_del(&device->wakeup_list);
496	mutex_unlock(&acpi_device_lock);
497
498	acpi_power_add_remove_device(device, false);
499	acpi_device_remove_files(device);
500	if (device->remove)
501		device->remove(device);
502
503	device_del(&device->dev);
504}
505
506static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
507
508static LIST_HEAD(acpi_device_del_list);
509static DEFINE_MUTEX(acpi_device_del_lock);
510
511static void acpi_device_del_work_fn(struct work_struct *work_not_used)
512{
513	for (;;) {
514		struct acpi_device *adev;
515
516		mutex_lock(&acpi_device_del_lock);
517
518		if (list_empty(&acpi_device_del_list)) {
519			mutex_unlock(&acpi_device_del_lock);
520			break;
521		}
522		adev = list_first_entry(&acpi_device_del_list,
523					struct acpi_device, del_list);
524		list_del(&adev->del_list);
525
526		mutex_unlock(&acpi_device_del_lock);
527
528		blocking_notifier_call_chain(&acpi_reconfig_chain,
529					     ACPI_RECONFIG_DEVICE_REMOVE, adev);
530
531		acpi_device_del(adev);
532		/*
533		 * Drop references to all power resources that might have been
534		 * used by the device.
535		 */
536		acpi_power_transition(adev, ACPI_STATE_D3_COLD);
537		put_device(&adev->dev);
538	}
539}
540
541/**
542 * acpi_scan_drop_device - Drop an ACPI device object.
543 * @handle: Handle of an ACPI namespace node, not used.
544 * @context: Address of the ACPI device object to drop.
545 *
546 * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
547 * namespace node the device object pointed to by @context is attached to.
548 *
549 * The unregistration is carried out asynchronously to avoid running
550 * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
551 * ensure the correct ordering (the device objects must be unregistered in the
552 * same order in which the corresponding namespace nodes are deleted).
553 */
554static void acpi_scan_drop_device(acpi_handle handle, void *context)
555{
556	static DECLARE_WORK(work, acpi_device_del_work_fn);
557	struct acpi_device *adev = context;
558
559	mutex_lock(&acpi_device_del_lock);
560
561	/*
562	 * Use the ACPI hotplug workqueue which is ordered, so this work item
563	 * won't run after any hotplug work items submitted subsequently.  That
564	 * prevents attempts to register device objects identical to those being
565	 * deleted from happening concurrently (such attempts result from
566	 * hotplug events handled via the ACPI hotplug workqueue).  It also will
567	 * run after all of the work items submitted previosuly, which helps
568	 * those work items to ensure that they are not accessing stale device
569	 * objects.
570	 */
571	if (list_empty(&acpi_device_del_list))
572		acpi_queue_hotplug_work(&work);
573
574	list_add_tail(&adev->del_list, &acpi_device_del_list);
575	/* Make acpi_ns_validate_handle() return NULL for this handle. */
576	adev->handle = INVALID_ACPI_HANDLE;
577
578	mutex_unlock(&acpi_device_del_lock);
579}
580
581static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
582				void (*callback)(void *))
583{
584	acpi_status status;
585
586	if (!device)
587		return -EINVAL;
588
589	*device = NULL;
590
591	status = acpi_get_data_full(handle, acpi_scan_drop_device,
592				    (void **)device, callback);
593	if (ACPI_FAILURE(status) || !*device) {
594		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
595				  handle));
596		return -ENODEV;
597	}
598	return 0;
599}
600
601int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
602{
603	return acpi_get_device_data(handle, device, NULL);
604}
605EXPORT_SYMBOL(acpi_bus_get_device);
606
607static void get_acpi_device(void *dev)
608{
609	if (dev)
610		get_device(&((struct acpi_device *)dev)->dev);
611}
612
613struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
614{
615	struct acpi_device *adev = NULL;
616
617	acpi_get_device_data(handle, &adev, get_acpi_device);
618	return adev;
619}
620
621void acpi_bus_put_acpi_device(struct acpi_device *adev)
622{
623	put_device(&adev->dev);
624}
625
626static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
627{
628	struct acpi_device_bus_id *acpi_device_bus_id;
629
630	/* Find suitable bus_id and instance number in acpi_bus_id_list. */
631	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
632		if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
633			return acpi_device_bus_id;
634	}
635	return NULL;
636}
637
638static int acpi_device_set_name(struct acpi_device *device,
639				struct acpi_device_bus_id *acpi_device_bus_id)
640{
641	struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
642	int result;
643
644	result = ida_simple_get(instance_ida, 0, ACPI_MAX_DEVICE_INSTANCES, GFP_KERNEL);
645	if (result < 0)
646		return result;
647
648	device->pnp.instance_no = result;
649	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
650	return 0;
651}
652
653int acpi_device_add(struct acpi_device *device,
654		    void (*release)(struct device *))
655{
656	struct acpi_device_bus_id *acpi_device_bus_id;
657	int result;
658
659	if (device->handle) {
660		acpi_status status;
661
662		status = acpi_attach_data(device->handle, acpi_scan_drop_device,
663					  device);
664		if (ACPI_FAILURE(status)) {
665			acpi_handle_err(device->handle,
666					"Unable to attach device data\n");
667			return -ENODEV;
668		}
669	}
670
671	/*
672	 * Linkage
673	 * -------
674	 * Link this device to its parent and siblings.
675	 */
676	INIT_LIST_HEAD(&device->children);
677	INIT_LIST_HEAD(&device->node);
678	INIT_LIST_HEAD(&device->wakeup_list);
679	INIT_LIST_HEAD(&device->physical_node_list);
680	INIT_LIST_HEAD(&device->del_list);
681	mutex_init(&device->physical_node_lock);
682
683	mutex_lock(&acpi_device_lock);
684
685	acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
686	if (acpi_device_bus_id) {
687		result = acpi_device_set_name(device, acpi_device_bus_id);
688		if (result)
689			goto err_unlock;
690	} else {
691		acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
692					     GFP_KERNEL);
693		if (!acpi_device_bus_id) {
694			result = -ENOMEM;
695			goto err_unlock;
696		}
697		acpi_device_bus_id->bus_id =
698			kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
699		if (!acpi_device_bus_id->bus_id) {
700			kfree(acpi_device_bus_id);
701			result = -ENOMEM;
702			goto err_unlock;
703		}
704
705		ida_init(&acpi_device_bus_id->instance_ida);
706
707		result = acpi_device_set_name(device, acpi_device_bus_id);
708		if (result) {
709			kfree_const(acpi_device_bus_id->bus_id);
710			kfree(acpi_device_bus_id);
711			goto err_unlock;
712		}
713
714		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
715	}
716
717	if (device->parent)
718		list_add_tail(&device->node, &device->parent->children);
719
720	if (device->wakeup.flags.valid)
721		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
722	mutex_unlock(&acpi_device_lock);
723
724	if (device->parent)
725		device->dev.parent = &device->parent->dev;
726	device->dev.bus = &acpi_bus_type;
727	device->dev.release = release;
728	result = device_add(&device->dev);
729	if (result) {
730		dev_err(&device->dev, "Error registering device\n");
731		goto err;
732	}
733
734	result = acpi_device_setup_files(device);
735	if (result)
736		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
737		       dev_name(&device->dev));
738
739	return 0;
740
741 err:
742	mutex_lock(&acpi_device_lock);
743	if (device->parent)
744		list_del(&device->node);
745	list_del(&device->wakeup_list);
746
747 err_unlock:
748	mutex_unlock(&acpi_device_lock);
749
750	acpi_detach_data(device->handle, acpi_scan_drop_device);
751	return result;
752}
753
754/* --------------------------------------------------------------------------
755                                 Device Enumeration
756   -------------------------------------------------------------------------- */
757static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
758{
759	struct acpi_device *device = NULL;
760	acpi_status status;
761
762	/*
763	 * Fixed hardware devices do not appear in the namespace and do not
764	 * have handles, but we fabricate acpi_devices for them, so we have
765	 * to deal with them specially.
766	 */
767	if (!handle)
768		return acpi_root;
769
770	do {
771		status = acpi_get_parent(handle, &handle);
772		if (ACPI_FAILURE(status))
773			return status == AE_NULL_ENTRY ? NULL : acpi_root;
774	} while (acpi_bus_get_device(handle, &device));
775	return device;
776}
777
778acpi_status
779acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
780{
781	acpi_status status;
782	acpi_handle tmp;
783	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
784	union acpi_object *obj;
785
786	status = acpi_get_handle(handle, "_EJD", &tmp);
787	if (ACPI_FAILURE(status))
788		return status;
789
790	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
791	if (ACPI_SUCCESS(status)) {
792		obj = buffer.pointer;
793		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
794					 ejd);
795		kfree(buffer.pointer);
796	}
797	return status;
798}
799EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
800
801static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
802{
803	acpi_handle handle = dev->handle;
804	struct acpi_device_wakeup *wakeup = &dev->wakeup;
805	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
806	union acpi_object *package = NULL;
807	union acpi_object *element = NULL;
808	acpi_status status;
809	int err = -ENODATA;
810
811	INIT_LIST_HEAD(&wakeup->resources);
812
813	/* _PRW */
814	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
815	if (ACPI_FAILURE(status)) {
816		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
817		return err;
818	}
819
820	package = (union acpi_object *)buffer.pointer;
821
822	if (!package || package->package.count < 2)
823		goto out;
824
825	element = &(package->package.elements[0]);
826	if (!element)
827		goto out;
828
829	if (element->type == ACPI_TYPE_PACKAGE) {
830		if ((element->package.count < 2) ||
831		    (element->package.elements[0].type !=
832		     ACPI_TYPE_LOCAL_REFERENCE)
833		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
834			goto out;
835
836		wakeup->gpe_device =
837		    element->package.elements[0].reference.handle;
838		wakeup->gpe_number =
839		    (u32) element->package.elements[1].integer.value;
840	} else if (element->type == ACPI_TYPE_INTEGER) {
841		wakeup->gpe_device = NULL;
842		wakeup->gpe_number = element->integer.value;
843	} else {
844		goto out;
845	}
846
847	element = &(package->package.elements[1]);
848	if (element->type != ACPI_TYPE_INTEGER)
849		goto out;
850
851	wakeup->sleep_state = element->integer.value;
852
853	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
854	if (err)
855		goto out;
856
857	if (!list_empty(&wakeup->resources)) {
858		int sleep_state;
859
860		err = acpi_power_wakeup_list_init(&wakeup->resources,
861						  &sleep_state);
862		if (err) {
863			acpi_handle_warn(handle, "Retrieving current states "
864					 "of wakeup power resources failed\n");
865			acpi_power_resources_list_free(&wakeup->resources);
866			goto out;
867		}
868		if (sleep_state < wakeup->sleep_state) {
869			acpi_handle_warn(handle, "Overriding _PRW sleep state "
870					 "(S%d) by S%d from power resources\n",
871					 (int)wakeup->sleep_state, sleep_state);
872			wakeup->sleep_state = sleep_state;
873		}
874	}
875
876 out:
877	kfree(buffer.pointer);
878	return err;
879}
880
881static bool acpi_wakeup_gpe_init(struct acpi_device *device)
882{
883	static const struct acpi_device_id button_device_ids[] = {
884		{"PNP0C0C", 0},		/* Power button */
885		{"PNP0C0D", 0},		/* Lid */
886		{"PNP0C0E", 0},		/* Sleep button */
887		{"", 0},
888	};
889	struct acpi_device_wakeup *wakeup = &device->wakeup;
890	acpi_status status;
891
892	wakeup->flags.notifier_present = 0;
893
894	/* Power button, Lid switch always enable wakeup */
895	if (!acpi_match_device_ids(device, button_device_ids)) {
896		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
897			/* Do not use Lid/sleep button for S5 wakeup */
898			if (wakeup->sleep_state == ACPI_STATE_S5)
899				wakeup->sleep_state = ACPI_STATE_S4;
900		}
901		acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
902		device_set_wakeup_capable(&device->dev, true);
903		return true;
904	}
905
906	status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
907					 wakeup->gpe_number);
908	return ACPI_SUCCESS(status);
909}
910
911static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
912{
913	int err;
914
915	/* Presence of _PRW indicates wake capable */
916	if (!acpi_has_method(device->handle, "_PRW"))
917		return;
918
919	err = acpi_bus_extract_wakeup_device_power_package(device);
920	if (err) {
921		dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
922		return;
923	}
924
925	device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
926	device->wakeup.prepare_count = 0;
927	/*
928	 * Call _PSW/_DSW object to disable its ability to wake the sleeping
929	 * system for the ACPI device with the _PRW object.
930	 * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
931	 * So it is necessary to call _DSW object first. Only when it is not
932	 * present will the _PSW object used.
933	 */
934	err = acpi_device_sleep_wake(device, 0, 0, 0);
935	if (err)
936		pr_debug("error in _DSW or _PSW evaluation\n");
937}
938
939static void acpi_bus_init_power_state(struct acpi_device *device, int state)
940{
941	struct acpi_device_power_state *ps = &device->power.states[state];
942	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
943	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
944	acpi_status status;
945
946	INIT_LIST_HEAD(&ps->resources);
947
948	/* Evaluate "_PRx" to get referenced power resources */
949	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
950	if (ACPI_SUCCESS(status)) {
951		union acpi_object *package = buffer.pointer;
952
953		if (buffer.length && package
954		    && package->type == ACPI_TYPE_PACKAGE
955		    && package->package.count)
956			acpi_extract_power_resources(package, 0, &ps->resources);
957
958		ACPI_FREE(buffer.pointer);
959	}
960
961	/* Evaluate "_PSx" to see if we can do explicit sets */
962	pathname[2] = 'S';
963	if (acpi_has_method(device->handle, pathname))
964		ps->flags.explicit_set = 1;
965
966	/* State is valid if there are means to put the device into it. */
967	if (!list_empty(&ps->resources) || ps->flags.explicit_set)
968		ps->flags.valid = 1;
969
970	ps->power = -1;		/* Unknown - driver assigned */
971	ps->latency = -1;	/* Unknown - driver assigned */
972}
973
974static void acpi_bus_get_power_flags(struct acpi_device *device)
975{
976	u32 i;
977
978	/* Presence of _PS0|_PR0 indicates 'power manageable' */
979	if (!acpi_has_method(device->handle, "_PS0") &&
980	    !acpi_has_method(device->handle, "_PR0"))
981		return;
982
983	device->flags.power_manageable = 1;
984
985	/*
986	 * Power Management Flags
987	 */
988	if (acpi_has_method(device->handle, "_PSC"))
989		device->power.flags.explicit_get = 1;
990
991	if (acpi_has_method(device->handle, "_IRC"))
992		device->power.flags.inrush_current = 1;
993
994	if (acpi_has_method(device->handle, "_DSW"))
995		device->power.flags.dsw_present = 1;
996
997	/*
998	 * Enumerate supported power management states
999	 */
1000	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1001		acpi_bus_init_power_state(device, i);
1002
1003	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1004
1005	/* Set the defaults for D0 and D3hot (always supported). */
1006	device->power.states[ACPI_STATE_D0].flags.valid = 1;
1007	device->power.states[ACPI_STATE_D0].power = 100;
1008	device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1009
1010	/*
1011	 * Use power resources only if the D0 list of them is populated, because
1012	 * some platforms may provide _PR3 only to indicate D3cold support and
1013	 * in those cases the power resources list returned by it may be bogus.
1014	 */
1015	if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
1016		device->power.flags.power_resources = 1;
1017		/*
1018		 * D3cold is supported if the D3hot list of power resources is
1019		 * not empty.
1020		 */
1021		if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1022			device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1023	}
1024
1025	if (acpi_bus_init_power(device))
1026		device->flags.power_manageable = 0;
1027}
1028
1029static void acpi_bus_get_flags(struct acpi_device *device)
1030{
1031	/* Presence of _STA indicates 'dynamic_status' */
1032	if (acpi_has_method(device->handle, "_STA"))
1033		device->flags.dynamic_status = 1;
1034
1035	/* Presence of _RMV indicates 'removable' */
1036	if (acpi_has_method(device->handle, "_RMV"))
1037		device->flags.removable = 1;
1038
1039	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
1040	if (acpi_has_method(device->handle, "_EJD") ||
1041	    acpi_has_method(device->handle, "_EJ0"))
1042		device->flags.ejectable = 1;
1043}
1044
1045static void acpi_device_get_busid(struct acpi_device *device)
1046{
1047	char bus_id[5] = { '?', 0 };
1048	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1049	int i = 0;
1050
1051	/*
1052	 * Bus ID
1053	 * ------
1054	 * The device's Bus ID is simply the object name.
1055	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1056	 */
1057	if (ACPI_IS_ROOT_DEVICE(device)) {
1058		strcpy(device->pnp.bus_id, "ACPI");
1059		return;
1060	}
1061
1062	switch (device->device_type) {
1063	case ACPI_BUS_TYPE_POWER_BUTTON:
1064		strcpy(device->pnp.bus_id, "PWRF");
1065		break;
1066	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1067		strcpy(device->pnp.bus_id, "SLPF");
1068		break;
1069	case ACPI_BUS_TYPE_ECDT_EC:
1070		strcpy(device->pnp.bus_id, "ECDT");
1071		break;
1072	default:
1073		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1074		/* Clean up trailing underscores (if any) */
1075		for (i = 3; i > 1; i--) {
1076			if (bus_id[i] == '_')
1077				bus_id[i] = '\0';
1078			else
1079				break;
1080		}
1081		strcpy(device->pnp.bus_id, bus_id);
1082		break;
1083	}
1084}
1085
1086/*
1087 * acpi_ata_match - see if an acpi object is an ATA device
1088 *
1089 * If an acpi object has one of the ACPI ATA methods defined,
1090 * then we can safely call it an ATA device.
1091 */
1092bool acpi_ata_match(acpi_handle handle)
1093{
1094	return acpi_has_method(handle, "_GTF") ||
1095	       acpi_has_method(handle, "_GTM") ||
1096	       acpi_has_method(handle, "_STM") ||
1097	       acpi_has_method(handle, "_SDD");
1098}
1099
1100/*
1101 * acpi_bay_match - see if an acpi object is an ejectable driver bay
1102 *
1103 * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1104 * then we can safely call it an ejectable drive bay
1105 */
1106bool acpi_bay_match(acpi_handle handle)
1107{
1108	acpi_handle phandle;
1109
1110	if (!acpi_has_method(handle, "_EJ0"))
1111		return false;
1112	if (acpi_ata_match(handle))
1113		return true;
1114	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1115		return false;
1116
1117	return acpi_ata_match(phandle);
1118}
1119
1120bool acpi_device_is_battery(struct acpi_device *adev)
1121{
1122	struct acpi_hardware_id *hwid;
1123
1124	list_for_each_entry(hwid, &adev->pnp.ids, list)
1125		if (!strcmp("PNP0C0A", hwid->id))
1126			return true;
1127
1128	return false;
1129}
1130
1131static bool is_ejectable_bay(struct acpi_device *adev)
1132{
1133	acpi_handle handle = adev->handle;
1134
1135	if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1136		return true;
1137
1138	return acpi_bay_match(handle);
1139}
1140
1141/*
1142 * acpi_dock_match - see if an acpi object has a _DCK method
1143 */
1144bool acpi_dock_match(acpi_handle handle)
1145{
1146	return acpi_has_method(handle, "_DCK");
1147}
1148
1149static acpi_status
1150acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1151			  void **return_value)
1152{
1153	long *cap = context;
1154
1155	if (acpi_has_method(handle, "_BCM") &&
1156	    acpi_has_method(handle, "_BCL")) {
1157		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1158				  "support\n"));
1159		*cap |= ACPI_VIDEO_BACKLIGHT;
1160		/* We have backlight support, no need to scan further */
1161		return AE_CTRL_TERMINATE;
1162	}
1163	return 0;
1164}
1165
1166/* Returns true if the ACPI object is a video device which can be
1167 * handled by video.ko.
1168 * The device will get a Linux specific CID added in scan.c to
1169 * identify the device as an ACPI graphics device
1170 * Be aware that the graphics device may not be physically present
1171 * Use acpi_video_get_capabilities() to detect general ACPI video
1172 * capabilities of present cards
1173 */
1174long acpi_is_video_device(acpi_handle handle)
1175{
1176	long video_caps = 0;
1177
1178	/* Is this device able to support video switching ? */
1179	if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1180		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1181
1182	/* Is this device able to retrieve a video ROM ? */
1183	if (acpi_has_method(handle, "_ROM"))
1184		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1185
1186	/* Is this device able to configure which video head to be POSTed ? */
1187	if (acpi_has_method(handle, "_VPO") &&
1188	    acpi_has_method(handle, "_GPD") &&
1189	    acpi_has_method(handle, "_SPD"))
1190		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1191
1192	/* Only check for backlight functionality if one of the above hit. */
1193	if (video_caps)
1194		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1195				    ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1196				    &video_caps, NULL);
1197
1198	return video_caps;
1199}
1200EXPORT_SYMBOL(acpi_is_video_device);
1201
1202const char *acpi_device_hid(struct acpi_device *device)
1203{
1204	struct acpi_hardware_id *hid;
1205
1206	if (list_empty(&device->pnp.ids))
1207		return dummy_hid;
1208
1209	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1210	return hid->id;
1211}
1212EXPORT_SYMBOL(acpi_device_hid);
1213
1214static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1215{
1216	struct acpi_hardware_id *id;
1217
1218	id = kmalloc(sizeof(*id), GFP_KERNEL);
1219	if (!id)
1220		return;
1221
1222	id->id = kstrdup_const(dev_id, GFP_KERNEL);
1223	if (!id->id) {
1224		kfree(id);
1225		return;
1226	}
1227
1228	list_add_tail(&id->list, &pnp->ids);
1229	pnp->type.hardware_id = 1;
1230}
1231
1232/*
1233 * Old IBM workstations have a DSDT bug wherein the SMBus object
1234 * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1235 * prefix.  Work around this.
1236 */
1237static bool acpi_ibm_smbus_match(acpi_handle handle)
1238{
1239	char node_name[ACPI_PATH_SEGMENT_LENGTH];
1240	struct acpi_buffer path = { sizeof(node_name), node_name };
1241
1242	if (!dmi_name_in_vendors("IBM"))
1243		return false;
1244
1245	/* Look for SMBS object */
1246	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1247	    strcmp("SMBS", path.pointer))
1248		return false;
1249
1250	/* Does it have the necessary (but misnamed) methods? */
1251	if (acpi_has_method(handle, "SBI") &&
1252	    acpi_has_method(handle, "SBR") &&
1253	    acpi_has_method(handle, "SBW"))
1254		return true;
1255
1256	return false;
1257}
1258
1259static bool acpi_object_is_system_bus(acpi_handle handle)
1260{
1261	acpi_handle tmp;
1262
1263	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1264	    tmp == handle)
1265		return true;
1266	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1267	    tmp == handle)
1268		return true;
1269
1270	return false;
1271}
1272
1273static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1274				int device_type)
1275{
1276	acpi_status status;
1277	struct acpi_device_info *info;
1278	struct acpi_pnp_device_id_list *cid_list;
1279	int i;
1280
1281	switch (device_type) {
1282	case ACPI_BUS_TYPE_DEVICE:
1283		if (handle == ACPI_ROOT_OBJECT) {
1284			acpi_add_id(pnp, ACPI_SYSTEM_HID);
1285			break;
1286		}
1287
1288		status = acpi_get_object_info(handle, &info);
1289		if (ACPI_FAILURE(status)) {
1290			pr_err(PREFIX "%s: Error reading device info\n",
1291					__func__);
1292			return;
1293		}
1294
1295		if (info->valid & ACPI_VALID_HID) {
1296			acpi_add_id(pnp, info->hardware_id.string);
1297			pnp->type.platform_id = 1;
1298		}
1299		if (info->valid & ACPI_VALID_CID) {
1300			cid_list = &info->compatible_id_list;
1301			for (i = 0; i < cid_list->count; i++)
1302				acpi_add_id(pnp, cid_list->ids[i].string);
1303		}
1304		if (info->valid & ACPI_VALID_ADR) {
1305			pnp->bus_address = info->address;
1306			pnp->type.bus_address = 1;
1307		}
1308		if (info->valid & ACPI_VALID_UID)
1309			pnp->unique_id = kstrdup(info->unique_id.string,
1310							GFP_KERNEL);
1311		if (info->valid & ACPI_VALID_CLS)
1312			acpi_add_id(pnp, info->class_code.string);
1313
1314		kfree(info);
1315
1316		/*
1317		 * Some devices don't reliably have _HIDs & _CIDs, so add
1318		 * synthetic HIDs to make sure drivers can find them.
1319		 */
1320		if (acpi_is_video_device(handle))
1321			acpi_add_id(pnp, ACPI_VIDEO_HID);
1322		else if (acpi_bay_match(handle))
1323			acpi_add_id(pnp, ACPI_BAY_HID);
1324		else if (acpi_dock_match(handle))
1325			acpi_add_id(pnp, ACPI_DOCK_HID);
1326		else if (acpi_ibm_smbus_match(handle))
1327			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1328		else if (list_empty(&pnp->ids) &&
1329			 acpi_object_is_system_bus(handle)) {
1330			/* \_SB, \_TZ, LNXSYBUS */
1331			acpi_add_id(pnp, ACPI_BUS_HID);
1332			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1333			strcpy(pnp->device_class, ACPI_BUS_CLASS);
1334		}
1335
1336		break;
1337	case ACPI_BUS_TYPE_POWER:
1338		acpi_add_id(pnp, ACPI_POWER_HID);
1339		break;
1340	case ACPI_BUS_TYPE_PROCESSOR:
1341		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1342		break;
1343	case ACPI_BUS_TYPE_THERMAL:
1344		acpi_add_id(pnp, ACPI_THERMAL_HID);
1345		break;
1346	case ACPI_BUS_TYPE_POWER_BUTTON:
1347		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1348		break;
1349	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1350		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1351		break;
1352	case ACPI_BUS_TYPE_ECDT_EC:
1353		acpi_add_id(pnp, ACPI_ECDT_HID);
1354		break;
1355	}
1356}
1357
1358void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1359{
1360	struct acpi_hardware_id *id, *tmp;
1361
1362	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1363		kfree_const(id->id);
1364		kfree(id);
1365	}
1366	kfree(pnp->unique_id);
1367}
1368
1369/**
1370 * acpi_dma_supported - Check DMA support for the specified device.
1371 * @adev: The pointer to acpi device
1372 *
1373 * Return false if DMA is not supported. Otherwise, return true
1374 */
1375bool acpi_dma_supported(struct acpi_device *adev)
1376{
1377	if (!adev)
1378		return false;
1379
1380	if (adev->flags.cca_seen)
1381		return true;
1382
1383	/*
1384	* Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1385	* DMA on "Intel platforms".  Presumably that includes all x86 and
1386	* ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1387	*/
1388	if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1389		return true;
1390
1391	return false;
1392}
1393
1394/**
1395 * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1396 * @adev: The pointer to acpi device
1397 *
1398 * Return enum dev_dma_attr.
1399 */
1400enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1401{
1402	if (!acpi_dma_supported(adev))
1403		return DEV_DMA_NOT_SUPPORTED;
1404
1405	if (adev->flags.coherent_dma)
1406		return DEV_DMA_COHERENT;
1407	else
1408		return DEV_DMA_NON_COHERENT;
1409}
1410
1411/**
1412 * acpi_dma_get_range() - Get device DMA parameters.
1413 *
1414 * @dev: device to configure
1415 * @map: pointer to DMA ranges result
1416 *
1417 * Evaluate DMA regions and return pointer to DMA regions on
1418 * parsing success; it does not update the passed in values on failure.
1419 *
1420 * Return 0 on success, < 0 on failure.
1421 */
1422int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
1423{
1424	struct acpi_device *adev;
1425	LIST_HEAD(list);
1426	struct resource_entry *rentry;
1427	int ret;
1428	struct device *dma_dev = dev;
1429	struct bus_dma_region *r;
1430
1431	/*
1432	 * Walk the device tree chasing an ACPI companion with a _DMA
1433	 * object while we go. Stop if we find a device with an ACPI
1434	 * companion containing a _DMA method.
1435	 */
1436	do {
1437		adev = ACPI_COMPANION(dma_dev);
1438		if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1439			break;
1440
1441		dma_dev = dma_dev->parent;
1442	} while (dma_dev);
1443
1444	if (!dma_dev)
1445		return -ENODEV;
1446
1447	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1448		acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1449		return -EINVAL;
1450	}
1451
1452	ret = acpi_dev_get_dma_resources(adev, &list);
1453	if (ret > 0) {
1454		r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
1455		if (!r) {
1456			ret = -ENOMEM;
1457			goto out;
1458		}
1459
1460		list_for_each_entry(rentry, &list, node) {
1461			if (rentry->res->start >= rentry->res->end) {
1462				kfree(r);
1463				ret = -EINVAL;
1464				dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1465				goto out;
1466			}
1467
1468			r->cpu_start = rentry->res->start;
1469			r->dma_start = rentry->res->start - rentry->offset;
1470			r->size = resource_size(rentry->res);
1471			r->offset = rentry->offset;
1472			r++;
1473		}
1474
1475		*map = r;
1476	}
1477 out:
1478	acpi_dev_free_resource_list(&list);
1479
1480	return ret >= 0 ? 0 : ret;
1481}
1482
1483/**
1484 * acpi_dma_configure_id - Set-up DMA configuration for the device.
1485 * @dev: The pointer to the device
1486 * @attr: device dma attributes
1487 * @input_id: input device id const value pointer
1488 */
1489int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
1490			  const u32 *input_id)
1491{
1492	const struct iommu_ops *iommu;
1493
1494	if (attr == DEV_DMA_NOT_SUPPORTED) {
1495		set_dma_ops(dev, &dma_dummy_ops);
1496		return 0;
1497	}
1498
1499	acpi_arch_dma_setup(dev);
1500
1501	iommu = iort_iommu_configure_id(dev, input_id);
1502	if (PTR_ERR(iommu) == -EPROBE_DEFER)
1503		return -EPROBE_DEFER;
1504
1505	arch_setup_dma_ops(dev, 0, U64_MAX,
1506				iommu, attr == DEV_DMA_COHERENT);
1507
1508	return 0;
1509}
1510EXPORT_SYMBOL_GPL(acpi_dma_configure_id);
1511
1512static void acpi_init_coherency(struct acpi_device *adev)
1513{
1514	unsigned long long cca = 0;
1515	acpi_status status;
1516	struct acpi_device *parent = adev->parent;
1517
1518	if (parent && parent->flags.cca_seen) {
1519		/*
1520		 * From ACPI spec, OSPM will ignore _CCA if an ancestor
1521		 * already saw one.
1522		 */
1523		adev->flags.cca_seen = 1;
1524		cca = parent->flags.coherent_dma;
1525	} else {
1526		status = acpi_evaluate_integer(adev->handle, "_CCA",
1527					       NULL, &cca);
1528		if (ACPI_SUCCESS(status))
1529			adev->flags.cca_seen = 1;
1530		else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1531			/*
1532			 * If architecture does not specify that _CCA is
1533			 * required for DMA-able devices (e.g. x86),
1534			 * we default to _CCA=1.
1535			 */
1536			cca = 1;
1537		else
1538			acpi_handle_debug(adev->handle,
1539					  "ACPI device is missing _CCA.\n");
1540	}
1541
1542	adev->flags.coherent_dma = cca;
1543}
1544
1545static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1546{
1547	bool *is_serial_bus_slave_p = data;
1548
1549	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1550		return 1;
1551
1552	*is_serial_bus_slave_p = true;
1553
1554	 /* no need to do more checking */
1555	return -1;
1556}
1557
1558static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1559{
1560	struct acpi_device *parent = device->parent;
1561	static const struct acpi_device_id indirect_io_hosts[] = {
1562		{"HISI0191", 0},
1563		{}
1564	};
1565
1566	return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1567}
1568
1569static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1570{
1571	struct list_head resource_list;
1572	bool is_serial_bus_slave = false;
1573	static const struct acpi_device_id ignore_serial_bus_ids[] = {
1574	/*
1575	 * These devices have multiple I2cSerialBus resources and an i2c-client
1576	 * must be instantiated for each, each with its own i2c_device_id.
1577	 * Normally we only instantiate an i2c-client for the first resource,
1578	 * using the ACPI HID as id. These special cases are handled by the
1579	 * drivers/platform/x86/i2c-multi-instantiate.c driver, which knows
1580	 * which i2c_device_id to use for each resource.
1581	 */
1582		{"BSG1160", },
1583		{"BSG2150", },
1584		{"INT33FE", },
1585		{"INT3515", },
1586	/*
1587	 * HIDs of device with an UartSerialBusV2 resource for which userspace
1588	 * expects a regular tty cdev to be created (instead of the in kernel
1589	 * serdev) and which have a kernel driver which expects a platform_dev
1590	 * such as the rfkill-gpio driver.
1591	 */
1592		{"BCM4752", },
1593		{"LNV4752", },
1594		{}
1595	};
1596
1597	if (acpi_is_indirect_io_slave(device))
1598		return true;
1599
1600	/* Macs use device properties in lieu of _CRS resources */
1601	if (x86_apple_machine &&
1602	    (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1603	     fwnode_property_present(&device->fwnode, "i2cAddress") ||
1604	     fwnode_property_present(&device->fwnode, "baud")))
1605		return true;
1606
1607	if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
1608		return false;
1609
1610	INIT_LIST_HEAD(&resource_list);
1611	acpi_dev_get_resources(device, &resource_list,
1612			       acpi_check_serial_bus_slave,
1613			       &is_serial_bus_slave);
1614	acpi_dev_free_resource_list(&resource_list);
1615
1616	return is_serial_bus_slave;
1617}
1618
1619void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1620			     int type, unsigned long long sta)
1621{
1622	INIT_LIST_HEAD(&device->pnp.ids);
1623	device->device_type = type;
1624	device->handle = handle;
1625	device->parent = acpi_bus_get_parent(handle);
1626	device->fwnode.ops = &acpi_device_fwnode_ops;
1627	acpi_set_device_status(device, sta);
1628	acpi_device_get_busid(device);
1629	acpi_set_pnp_ids(handle, &device->pnp, type);
1630	acpi_init_properties(device);
1631	acpi_bus_get_flags(device);
1632	device->flags.match_driver = false;
1633	device->flags.initialized = true;
1634	device->flags.enumeration_by_parent =
1635		acpi_device_enumeration_by_parent(device);
1636	acpi_device_clear_enumerated(device);
1637	device_initialize(&device->dev);
1638	dev_set_uevent_suppress(&device->dev, true);
1639	acpi_init_coherency(device);
1640	/* Assume there are unmet deps until acpi_device_dep_initialize() runs */
1641	device->dep_unmet = 1;
1642}
1643
1644void acpi_device_add_finalize(struct acpi_device *device)
1645{
1646	dev_set_uevent_suppress(&device->dev, false);
1647	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1648}
1649
1650static int acpi_add_single_object(struct acpi_device **child,
1651				  acpi_handle handle, int type,
1652				  unsigned long long sta)
1653{
1654	int result;
1655	struct acpi_device *device;
1656	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1657
1658	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1659	if (!device) {
1660		printk(KERN_ERR PREFIX "Memory allocation error\n");
1661		return -ENOMEM;
1662	}
1663
1664	acpi_init_device_object(device, handle, type, sta);
1665	/*
1666	 * For ACPI_BUS_TYPE_DEVICE getting the status is delayed till here so
1667	 * that we can call acpi_bus_get_status() and use its quirk handling.
1668	 * Note this must be done before the get power-/wakeup_dev-flags calls.
1669	 */
1670	if (type == ACPI_BUS_TYPE_DEVICE)
1671		if (acpi_bus_get_status(device) < 0)
1672			acpi_set_device_status(device, 0);
1673
1674	acpi_bus_get_power_flags(device);
1675	acpi_bus_get_wakeup_device_flags(device);
1676
1677	result = acpi_device_add(device, acpi_device_release);
1678	if (result) {
1679		acpi_device_release(&device->dev);
1680		return result;
1681	}
1682
1683	acpi_power_add_remove_device(device, true);
1684	acpi_device_add_finalize(device);
1685	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1686	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1687		dev_name(&device->dev), (char *) buffer.pointer,
1688		device->parent ? dev_name(&device->parent->dev) : "(null)"));
1689	kfree(buffer.pointer);
1690	*child = device;
1691	return 0;
1692}
1693
1694static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1695					    void *context)
1696{
1697	struct resource *res = context;
1698
1699	if (acpi_dev_resource_memory(ares, res))
1700		return AE_CTRL_TERMINATE;
1701
1702	return AE_OK;
1703}
1704
1705static bool acpi_device_should_be_hidden(acpi_handle handle)
1706{
1707	acpi_status status;
1708	struct resource res;
1709
1710	/* Check if it should ignore the UART device */
1711	if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1712		return false;
1713
1714	/*
1715	 * The UART device described in SPCR table is assumed to have only one
1716	 * memory resource present. So we only look for the first one here.
1717	 */
1718	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1719				     acpi_get_resource_memory, &res);
1720	if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1721		return false;
1722
1723	acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1724			 &res.start);
1725
1726	return true;
1727}
1728
1729static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1730				    unsigned long long *sta)
1731{
1732	acpi_status status;
1733	acpi_object_type acpi_type;
1734
1735	status = acpi_get_type(handle, &acpi_type);
1736	if (ACPI_FAILURE(status))
1737		return -ENODEV;
1738
1739	switch (acpi_type) {
1740	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
1741	case ACPI_TYPE_DEVICE:
1742		if (acpi_device_should_be_hidden(handle))
1743			return -ENODEV;
1744
1745		*type = ACPI_BUS_TYPE_DEVICE;
1746		/*
1747		 * acpi_add_single_object updates this once we've an acpi_device
1748		 * so that acpi_bus_get_status' quirk handling can be used.
1749		 */
1750		*sta = ACPI_STA_DEFAULT;
1751		break;
1752	case ACPI_TYPE_PROCESSOR:
1753		*type = ACPI_BUS_TYPE_PROCESSOR;
1754		status = acpi_bus_get_status_handle(handle, sta);
1755		if (ACPI_FAILURE(status))
1756			return -ENODEV;
1757		break;
1758	case ACPI_TYPE_THERMAL:
1759		*type = ACPI_BUS_TYPE_THERMAL;
1760		*sta = ACPI_STA_DEFAULT;
1761		break;
1762	case ACPI_TYPE_POWER:
1763		*type = ACPI_BUS_TYPE_POWER;
1764		*sta = ACPI_STA_DEFAULT;
1765		break;
1766	default:
1767		return -ENODEV;
1768	}
1769
1770	return 0;
1771}
1772
1773bool acpi_device_is_present(const struct acpi_device *adev)
1774{
1775	return adev->status.present || adev->status.functional;
1776}
1777
1778static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1779				       const char *idstr,
1780				       const struct acpi_device_id **matchid)
1781{
1782	const struct acpi_device_id *devid;
1783
1784	if (handler->match)
1785		return handler->match(idstr, matchid);
1786
1787	for (devid = handler->ids; devid->id[0]; devid++)
1788		if (!strcmp((char *)devid->id, idstr)) {
1789			if (matchid)
1790				*matchid = devid;
1791
1792			return true;
1793		}
1794
1795	return false;
1796}
1797
1798static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1799					const struct acpi_device_id **matchid)
1800{
1801	struct acpi_scan_handler *handler;
1802
1803	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1804		if (acpi_scan_handler_matching(handler, idstr, matchid))
1805			return handler;
1806
1807	return NULL;
1808}
1809
1810void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1811{
1812	if (!!hotplug->enabled == !!val)
1813		return;
1814
1815	mutex_lock(&acpi_scan_lock);
1816
1817	hotplug->enabled = val;
1818
1819	mutex_unlock(&acpi_scan_lock);
1820}
1821
1822static void acpi_scan_init_hotplug(struct acpi_device *adev)
1823{
1824	struct acpi_hardware_id *hwid;
1825
1826	if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1827		acpi_dock_add(adev);
1828		return;
1829	}
1830	list_for_each_entry(hwid, &adev->pnp.ids, list) {
1831		struct acpi_scan_handler *handler;
1832
1833		handler = acpi_scan_match_handler(hwid->id, NULL);
1834		if (handler) {
1835			adev->flags.hotplug_notify = true;
1836			break;
1837		}
1838	}
1839}
1840
1841static void acpi_device_dep_initialize(struct acpi_device *adev)
1842{
1843	struct acpi_dep_data *dep;
1844	struct acpi_handle_list dep_devices;
1845	acpi_status status;
1846	int i;
1847
1848	adev->dep_unmet = 0;
1849
1850	if (!acpi_has_method(adev->handle, "_DEP"))
1851		return;
1852
1853	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
1854					&dep_devices);
1855	if (ACPI_FAILURE(status)) {
1856		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
1857		return;
1858	}
1859
1860	for (i = 0; i < dep_devices.count; i++) {
1861		struct acpi_device_info *info;
1862		int skip;
1863
1864		status = acpi_get_object_info(dep_devices.handles[i], &info);
1865		if (ACPI_FAILURE(status)) {
1866			dev_dbg(&adev->dev, "Error reading _DEP device info\n");
1867			continue;
1868		}
1869
1870		/*
1871		 * Skip the dependency of Windows System Power
1872		 * Management Controller
1873		 */
1874		skip = info->valid & ACPI_VALID_HID &&
1875			!strcmp(info->hardware_id.string, "INT3396");
1876
1877		kfree(info);
1878
1879		if (skip)
1880			continue;
1881
1882		dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
1883		if (!dep)
1884			return;
1885
1886		dep->master = dep_devices.handles[i];
1887		dep->slave  = adev->handle;
1888		adev->dep_unmet++;
1889
1890		mutex_lock(&acpi_dep_list_lock);
1891		list_add_tail(&dep->node , &acpi_dep_list);
1892		mutex_unlock(&acpi_dep_list_lock);
1893	}
1894}
1895
1896static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1897				      void *not_used, void **return_value)
1898{
1899	struct acpi_device *device = NULL;
1900	int type;
1901	unsigned long long sta;
1902	int result;
1903
1904	acpi_bus_get_device(handle, &device);
1905	if (device)
1906		goto out;
1907
1908	result = acpi_bus_type_and_status(handle, &type, &sta);
1909	if (result)
1910		return AE_OK;
1911
1912	if (type == ACPI_BUS_TYPE_POWER) {
1913		acpi_add_power_resource(handle);
1914		return AE_OK;
1915	}
1916
1917	acpi_add_single_object(&device, handle, type, sta);
1918	if (!device)
1919		return AE_CTRL_DEPTH;
1920
1921	acpi_scan_init_hotplug(device);
1922	acpi_device_dep_initialize(device);
1923
1924 out:
1925	if (!*return_value)
1926		*return_value = device;
1927
1928	return AE_OK;
1929}
1930
1931static void acpi_default_enumeration(struct acpi_device *device)
1932{
1933	/*
1934	 * Do not enumerate devices with enumeration_by_parent flag set as
1935	 * they will be enumerated by their respective parents.
1936	 */
1937	if (!device->flags.enumeration_by_parent) {
1938		acpi_create_platform_device(device, NULL);
1939		acpi_device_set_enumerated(device);
1940	} else {
1941		blocking_notifier_call_chain(&acpi_reconfig_chain,
1942					     ACPI_RECONFIG_DEVICE_ADD, device);
1943	}
1944}
1945
1946static const struct acpi_device_id generic_device_ids[] = {
1947	{ACPI_DT_NAMESPACE_HID, },
1948	{"", },
1949};
1950
1951static int acpi_generic_device_attach(struct acpi_device *adev,
1952				      const struct acpi_device_id *not_used)
1953{
1954	/*
1955	 * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
1956	 * below can be unconditional.
1957	 */
1958	if (adev->data.of_compatible)
1959		acpi_default_enumeration(adev);
1960
1961	return 1;
1962}
1963
1964static struct acpi_scan_handler generic_device_handler = {
1965	.ids = generic_device_ids,
1966	.attach = acpi_generic_device_attach,
1967};
1968
1969static int acpi_scan_attach_handler(struct acpi_device *device)
1970{
1971	struct acpi_hardware_id *hwid;
1972	int ret = 0;
1973
1974	list_for_each_entry(hwid, &device->pnp.ids, list) {
1975		const struct acpi_device_id *devid;
1976		struct acpi_scan_handler *handler;
1977
1978		handler = acpi_scan_match_handler(hwid->id, &devid);
1979		if (handler) {
1980			if (!handler->attach) {
1981				device->pnp.type.platform_id = 0;
1982				continue;
1983			}
1984			device->handler = handler;
1985			ret = handler->attach(device, devid);
1986			if (ret > 0)
1987				break;
1988
1989			device->handler = NULL;
1990			if (ret < 0)
1991				break;
1992		}
1993	}
1994
1995	return ret;
1996}
1997
1998static void acpi_bus_attach(struct acpi_device *device)
1999{
2000	struct acpi_device *child;
2001	acpi_handle ejd;
2002	int ret;
2003
2004	if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2005		register_dock_dependent_device(device, ejd);
2006
2007	acpi_bus_get_status(device);
2008	/* Skip devices that are not present. */
2009	if (!acpi_device_is_present(device)) {
2010		device->flags.initialized = false;
2011		acpi_device_clear_enumerated(device);
2012		device->flags.power_manageable = 0;
2013		return;
2014	}
2015	if (device->handler)
2016		goto ok;
2017
2018	if (!device->flags.initialized) {
2019		device->flags.power_manageable =
2020			device->power.states[ACPI_STATE_D0].flags.valid;
2021		if (acpi_bus_init_power(device))
2022			device->flags.power_manageable = 0;
2023
2024		device->flags.initialized = true;
2025	} else if (device->flags.visited) {
2026		goto ok;
2027	}
2028
2029	ret = acpi_scan_attach_handler(device);
2030	if (ret < 0)
2031		return;
2032
2033	device->flags.match_driver = true;
2034	if (ret > 0 && !device->flags.enumeration_by_parent) {
2035		acpi_device_set_enumerated(device);
2036		goto ok;
2037	}
2038
2039	ret = device_attach(&device->dev);
2040	if (ret < 0)
2041		return;
2042
2043	if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
2044		acpi_default_enumeration(device);
2045	else
2046		acpi_device_set_enumerated(device);
2047
2048 ok:
2049	list_for_each_entry(child, &device->children, node)
2050		acpi_bus_attach(child);
2051
2052	if (device->handler && device->handler->hotplug.notify_online)
2053		device->handler->hotplug.notify_online(device);
2054}
2055
2056void acpi_walk_dep_device_list(acpi_handle handle)
2057{
2058	struct acpi_dep_data *dep, *tmp;
2059	struct acpi_device *adev;
2060
2061	mutex_lock(&acpi_dep_list_lock);
2062	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2063		if (dep->master == handle) {
2064			acpi_bus_get_device(dep->slave, &adev);
2065			if (!adev)
2066				continue;
2067
2068			adev->dep_unmet--;
2069			if (!adev->dep_unmet)
2070				acpi_bus_attach(adev);
2071			list_del(&dep->node);
2072			kfree(dep);
2073		}
2074	}
2075	mutex_unlock(&acpi_dep_list_lock);
2076}
2077EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2078
2079/**
2080 * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2081 * @handle: Root of the namespace scope to scan.
2082 *
2083 * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2084 * found devices.
2085 *
2086 * If no devices were found, -ENODEV is returned, but it does not mean that
2087 * there has been a real error.  There just have been no suitable ACPI objects
2088 * in the table trunk from which the kernel could create a device and add an
2089 * appropriate driver.
2090 *
2091 * Must be called under acpi_scan_lock.
2092 */
2093int acpi_bus_scan(acpi_handle handle)
2094{
2095	void *device = NULL;
2096
2097	if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2098		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2099				    acpi_bus_check_add, NULL, NULL, &device);
2100
2101	if (device) {
2102		acpi_bus_attach(device);
2103		return 0;
2104	}
2105	return -ENODEV;
2106}
2107EXPORT_SYMBOL(acpi_bus_scan);
2108
2109/**
2110 * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2111 * @adev: Root of the ACPI namespace scope to walk.
2112 *
2113 * Must be called under acpi_scan_lock.
2114 */
2115void acpi_bus_trim(struct acpi_device *adev)
2116{
2117	struct acpi_scan_handler *handler = adev->handler;
2118	struct acpi_device *child;
2119
2120	list_for_each_entry_reverse(child, &adev->children, node)
2121		acpi_bus_trim(child);
2122
2123	adev->flags.match_driver = false;
2124	if (handler) {
2125		if (handler->detach)
2126			handler->detach(adev);
2127
2128		adev->handler = NULL;
2129	} else {
2130		device_release_driver(&adev->dev);
2131	}
2132	/*
2133	 * Most likely, the device is going away, so put it into D3cold before
2134	 * that.
2135	 */
2136	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2137	adev->flags.initialized = false;
2138	acpi_device_clear_enumerated(adev);
2139}
2140EXPORT_SYMBOL_GPL(acpi_bus_trim);
2141
2142int acpi_bus_register_early_device(int type)
2143{
2144	struct acpi_device *device = NULL;
2145	int result;
2146
2147	result = acpi_add_single_object(&device, NULL,
2148					type, ACPI_STA_DEFAULT);
2149	if (result)
2150		return result;
2151
2152	device->flags.match_driver = true;
2153	return device_attach(&device->dev);
2154}
2155EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2156
2157static int acpi_bus_scan_fixed(void)
2158{
2159	int result = 0;
2160
2161	/*
2162	 * Enumerate all fixed-feature devices.
2163	 */
2164	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2165		struct acpi_device *device = NULL;
2166
2167		result = acpi_add_single_object(&device, NULL,
2168						ACPI_BUS_TYPE_POWER_BUTTON,
2169						ACPI_STA_DEFAULT);
2170		if (result)
2171			return result;
2172
2173		device->flags.match_driver = true;
2174		result = device_attach(&device->dev);
2175		if (result < 0)
2176			return result;
2177
2178		device_init_wakeup(&device->dev, true);
2179	}
2180
2181	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2182		struct acpi_device *device = NULL;
2183
2184		result = acpi_add_single_object(&device, NULL,
2185						ACPI_BUS_TYPE_SLEEP_BUTTON,
2186						ACPI_STA_DEFAULT);
2187		if (result)
2188			return result;
2189
2190		device->flags.match_driver = true;
2191		result = device_attach(&device->dev);
2192	}
2193
2194	return result < 0 ? result : 0;
2195}
2196
2197static void __init acpi_get_spcr_uart_addr(void)
2198{
2199	acpi_status status;
2200	struct acpi_table_spcr *spcr_ptr;
2201
2202	status = acpi_get_table(ACPI_SIG_SPCR, 0,
2203				(struct acpi_table_header **)&spcr_ptr);
2204	if (ACPI_FAILURE(status)) {
2205		pr_warn(PREFIX "STAO table present, but SPCR is missing\n");
2206		return;
2207	}
2208
2209	spcr_uart_addr = spcr_ptr->serial_port.address;
2210	acpi_put_table((struct acpi_table_header *)spcr_ptr);
2211}
2212
2213static bool acpi_scan_initialized;
2214
2215int __init acpi_scan_init(void)
2216{
2217	int result;
2218	acpi_status status;
2219	struct acpi_table_stao *stao_ptr;
2220
2221	acpi_pci_root_init();
2222	acpi_pci_link_init();
2223	acpi_processor_init();
2224	acpi_platform_init();
2225	acpi_lpss_init();
2226	acpi_apd_init();
2227	acpi_cmos_rtc_init();
2228	acpi_container_init();
2229	acpi_memory_hotplug_init();
2230	acpi_watchdog_init();
2231	acpi_pnp_init();
2232	acpi_int340x_thermal_init();
2233	acpi_amba_init();
2234	acpi_init_lpit();
2235
2236	acpi_scan_add_handler(&generic_device_handler);
2237
2238	/*
2239	 * If there is STAO table, check whether it needs to ignore the UART
2240	 * device in SPCR table.
2241	 */
2242	status = acpi_get_table(ACPI_SIG_STAO, 0,
2243				(struct acpi_table_header **)&stao_ptr);
2244	if (ACPI_SUCCESS(status)) {
2245		if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2246			pr_info(PREFIX "STAO Name List not yet supported.\n");
2247
2248		if (stao_ptr->ignore_uart)
2249			acpi_get_spcr_uart_addr();
2250
2251		acpi_put_table((struct acpi_table_header *)stao_ptr);
2252	}
2253
2254	acpi_gpe_apply_masked_gpes();
2255	acpi_update_all_gpes();
2256
2257	/*
2258	 * Although we call __add_memory() that is documented to require the
2259	 * device_hotplug_lock, it is not necessary here because this is an
2260	 * early code when userspace or any other code path cannot trigger
2261	 * hotplug/hotunplug operations.
2262	 */
2263	mutex_lock(&acpi_scan_lock);
2264	/*
2265	 * Enumerate devices in the ACPI namespace.
2266	 */
2267	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2268	if (result)
2269		goto out;
2270
2271	result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2272	if (result)
2273		goto out;
2274
2275	/* Fixed feature devices do not exist on HW-reduced platform */
2276	if (!acpi_gbl_reduced_hardware) {
2277		result = acpi_bus_scan_fixed();
2278		if (result) {
2279			acpi_detach_data(acpi_root->handle,
2280					 acpi_scan_drop_device);
2281			acpi_device_del(acpi_root);
2282			put_device(&acpi_root->dev);
2283			goto out;
2284		}
2285	}
2286
2287	acpi_scan_initialized = true;
2288
2289 out:
2290	mutex_unlock(&acpi_scan_lock);
2291	return result;
2292}
2293
2294static struct acpi_probe_entry *ape;
2295static int acpi_probe_count;
2296static DEFINE_MUTEX(acpi_probe_mutex);
2297
2298static int __init acpi_match_madt(union acpi_subtable_headers *header,
2299				  const unsigned long end)
2300{
2301	if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
2302		if (!ape->probe_subtbl(header, end))
2303			acpi_probe_count++;
2304
2305	return 0;
2306}
2307
2308int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2309{
2310	int count = 0;
2311
2312	if (acpi_disabled)
2313		return 0;
2314
2315	mutex_lock(&acpi_probe_mutex);
2316	for (ape = ap_head; nr; ape++, nr--) {
2317		if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
2318			acpi_probe_count = 0;
2319			acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2320			count += acpi_probe_count;
2321		} else {
2322			int res;
2323			res = acpi_table_parse(ape->id, ape->probe_table);
2324			if (!res)
2325				count++;
2326		}
2327	}
2328	mutex_unlock(&acpi_probe_mutex);
2329
2330	return count;
2331}
2332
2333struct acpi_table_events_work {
2334	struct work_struct work;
2335	void *table;
2336	u32 event;
2337};
2338
2339static void acpi_table_events_fn(struct work_struct *work)
2340{
2341	struct acpi_table_events_work *tew;
2342
2343	tew = container_of(work, struct acpi_table_events_work, work);
2344
2345	if (tew->event == ACPI_TABLE_EVENT_LOAD) {
2346		acpi_scan_lock_acquire();
2347		acpi_bus_scan(ACPI_ROOT_OBJECT);
2348		acpi_scan_lock_release();
2349	}
2350
2351	kfree(tew);
2352}
2353
2354void acpi_scan_table_handler(u32 event, void *table, void *context)
2355{
2356	struct acpi_table_events_work *tew;
2357
2358	if (!acpi_scan_initialized)
2359		return;
2360
2361	if (event != ACPI_TABLE_EVENT_LOAD)
2362		return;
2363
2364	tew = kmalloc(sizeof(*tew), GFP_KERNEL);
2365	if (!tew)
2366		return;
2367
2368	INIT_WORK(&tew->work, acpi_table_events_fn);
2369	tew->table = table;
2370	tew->event = event;
2371
2372	schedule_work(&tew->work);
2373}
2374
2375int acpi_reconfig_notifier_register(struct notifier_block *nb)
2376{
2377	return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2378}
2379EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2380
2381int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2382{
2383	return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2384}
2385EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);
2386