xref: /openbmc/linux/drivers/acpi/scan.c (revision 1c2dd16a)
1 /*
2  * scan.c - support for transforming the ACPI namespace into individual objects
3  */
4 
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/kernel.h>
9 #include <linux/acpi.h>
10 #include <linux/acpi_iort.h>
11 #include <linux/signal.h>
12 #include <linux/kthread.h>
13 #include <linux/dmi.h>
14 #include <linux/nls.h>
15 #include <linux/dma-mapping.h>
16 
17 #include <asm/pgtable.h>
18 
19 #include "internal.h"
20 
21 #define _COMPONENT		ACPI_BUS_COMPONENT
22 ACPI_MODULE_NAME("scan");
23 extern struct acpi_device *acpi_root;
24 
25 #define ACPI_BUS_CLASS			"system_bus"
26 #define ACPI_BUS_HID			"LNXSYBUS"
27 #define ACPI_BUS_DEVICE_NAME		"System Bus"
28 
29 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
30 
31 #define INVALID_ACPI_HANDLE	((acpi_handle)empty_zero_page)
32 
33 static const char *dummy_hid = "device";
34 
35 static LIST_HEAD(acpi_dep_list);
36 static DEFINE_MUTEX(acpi_dep_list_lock);
37 LIST_HEAD(acpi_bus_id_list);
38 static DEFINE_MUTEX(acpi_scan_lock);
39 static LIST_HEAD(acpi_scan_handlers_list);
40 DEFINE_MUTEX(acpi_device_lock);
41 LIST_HEAD(acpi_wakeup_device_list);
42 static DEFINE_MUTEX(acpi_hp_context_lock);
43 
44 /*
45  * The UART device described by the SPCR table is the only object which needs
46  * special-casing. Everything else is covered by ACPI namespace paths in STAO
47  * table.
48  */
49 static u64 spcr_uart_addr;
50 
51 struct acpi_dep_data {
52 	struct list_head node;
53 	acpi_handle master;
54 	acpi_handle slave;
55 };
56 
57 void acpi_scan_lock_acquire(void)
58 {
59 	mutex_lock(&acpi_scan_lock);
60 }
61 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
62 
63 void acpi_scan_lock_release(void)
64 {
65 	mutex_unlock(&acpi_scan_lock);
66 }
67 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
68 
69 void acpi_lock_hp_context(void)
70 {
71 	mutex_lock(&acpi_hp_context_lock);
72 }
73 
74 void acpi_unlock_hp_context(void)
75 {
76 	mutex_unlock(&acpi_hp_context_lock);
77 }
78 
79 void acpi_initialize_hp_context(struct acpi_device *adev,
80 				struct acpi_hotplug_context *hp,
81 				int (*notify)(struct acpi_device *, u32),
82 				void (*uevent)(struct acpi_device *, u32))
83 {
84 	acpi_lock_hp_context();
85 	hp->notify = notify;
86 	hp->uevent = uevent;
87 	acpi_set_hp_context(adev, hp);
88 	acpi_unlock_hp_context();
89 }
90 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
91 
92 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
93 {
94 	if (!handler)
95 		return -EINVAL;
96 
97 	list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
98 	return 0;
99 }
100 
101 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
102 				       const char *hotplug_profile_name)
103 {
104 	int error;
105 
106 	error = acpi_scan_add_handler(handler);
107 	if (error)
108 		return error;
109 
110 	acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
111 	return 0;
112 }
113 
114 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
115 {
116 	struct acpi_device_physical_node *pn;
117 	bool offline = true;
118 
119 	/*
120 	 * acpi_container_offline() calls this for all of the container's
121 	 * children under the container's physical_node_lock lock.
122 	 */
123 	mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
124 
125 	list_for_each_entry(pn, &adev->physical_node_list, node)
126 		if (device_supports_offline(pn->dev) && !pn->dev->offline) {
127 			if (uevent)
128 				kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
129 
130 			offline = false;
131 			break;
132 		}
133 
134 	mutex_unlock(&adev->physical_node_lock);
135 	return offline;
136 }
137 
138 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
139 				    void **ret_p)
140 {
141 	struct acpi_device *device = NULL;
142 	struct acpi_device_physical_node *pn;
143 	bool second_pass = (bool)data;
144 	acpi_status status = AE_OK;
145 
146 	if (acpi_bus_get_device(handle, &device))
147 		return AE_OK;
148 
149 	if (device->handler && !device->handler->hotplug.enabled) {
150 		*ret_p = &device->dev;
151 		return AE_SUPPORT;
152 	}
153 
154 	mutex_lock(&device->physical_node_lock);
155 
156 	list_for_each_entry(pn, &device->physical_node_list, node) {
157 		int ret;
158 
159 		if (second_pass) {
160 			/* Skip devices offlined by the first pass. */
161 			if (pn->put_online)
162 				continue;
163 		} else {
164 			pn->put_online = false;
165 		}
166 		ret = device_offline(pn->dev);
167 		if (ret >= 0) {
168 			pn->put_online = !ret;
169 		} else {
170 			*ret_p = pn->dev;
171 			if (second_pass) {
172 				status = AE_ERROR;
173 				break;
174 			}
175 		}
176 	}
177 
178 	mutex_unlock(&device->physical_node_lock);
179 
180 	return status;
181 }
182 
183 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
184 				   void **ret_p)
185 {
186 	struct acpi_device *device = NULL;
187 	struct acpi_device_physical_node *pn;
188 
189 	if (acpi_bus_get_device(handle, &device))
190 		return AE_OK;
191 
192 	mutex_lock(&device->physical_node_lock);
193 
194 	list_for_each_entry(pn, &device->physical_node_list, node)
195 		if (pn->put_online) {
196 			device_online(pn->dev);
197 			pn->put_online = false;
198 		}
199 
200 	mutex_unlock(&device->physical_node_lock);
201 
202 	return AE_OK;
203 }
204 
205 static int acpi_scan_try_to_offline(struct acpi_device *device)
206 {
207 	acpi_handle handle = device->handle;
208 	struct device *errdev = NULL;
209 	acpi_status status;
210 
211 	/*
212 	 * Carry out two passes here and ignore errors in the first pass,
213 	 * because if the devices in question are memory blocks and
214 	 * CONFIG_MEMCG is set, one of the blocks may hold data structures
215 	 * that the other blocks depend on, but it is not known in advance which
216 	 * block holds them.
217 	 *
218 	 * If the first pass is successful, the second one isn't needed, though.
219 	 */
220 	status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
221 				     NULL, acpi_bus_offline, (void *)false,
222 				     (void **)&errdev);
223 	if (status == AE_SUPPORT) {
224 		dev_warn(errdev, "Offline disabled.\n");
225 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
226 				    acpi_bus_online, NULL, NULL, NULL);
227 		return -EPERM;
228 	}
229 	acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
230 	if (errdev) {
231 		errdev = NULL;
232 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
233 				    NULL, acpi_bus_offline, (void *)true,
234 				    (void **)&errdev);
235 		if (!errdev)
236 			acpi_bus_offline(handle, 0, (void *)true,
237 					 (void **)&errdev);
238 
239 		if (errdev) {
240 			dev_warn(errdev, "Offline failed.\n");
241 			acpi_bus_online(handle, 0, NULL, NULL);
242 			acpi_walk_namespace(ACPI_TYPE_ANY, handle,
243 					    ACPI_UINT32_MAX, acpi_bus_online,
244 					    NULL, NULL, NULL);
245 			return -EBUSY;
246 		}
247 	}
248 	return 0;
249 }
250 
251 static int acpi_scan_hot_remove(struct acpi_device *device)
252 {
253 	acpi_handle handle = device->handle;
254 	unsigned long long sta;
255 	acpi_status status;
256 
257 	if (device->handler && device->handler->hotplug.demand_offline) {
258 		if (!acpi_scan_is_offline(device, true))
259 			return -EBUSY;
260 	} else {
261 		int error = acpi_scan_try_to_offline(device);
262 		if (error)
263 			return error;
264 	}
265 
266 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
267 		"Hot-removing device %s...\n", dev_name(&device->dev)));
268 
269 	acpi_bus_trim(device);
270 
271 	acpi_evaluate_lck(handle, 0);
272 	/*
273 	 * TBD: _EJD support.
274 	 */
275 	status = acpi_evaluate_ej0(handle);
276 	if (status == AE_NOT_FOUND)
277 		return -ENODEV;
278 	else if (ACPI_FAILURE(status))
279 		return -EIO;
280 
281 	/*
282 	 * Verify if eject was indeed successful.  If not, log an error
283 	 * message.  No need to call _OST since _EJ0 call was made OK.
284 	 */
285 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
286 	if (ACPI_FAILURE(status)) {
287 		acpi_handle_warn(handle,
288 			"Status check after eject failed (0x%x)\n", status);
289 	} else if (sta & ACPI_STA_DEVICE_ENABLED) {
290 		acpi_handle_warn(handle,
291 			"Eject incomplete - status 0x%llx\n", sta);
292 	}
293 
294 	return 0;
295 }
296 
297 static int acpi_scan_device_not_present(struct acpi_device *adev)
298 {
299 	if (!acpi_device_enumerated(adev)) {
300 		dev_warn(&adev->dev, "Still not present\n");
301 		return -EALREADY;
302 	}
303 	acpi_bus_trim(adev);
304 	return 0;
305 }
306 
307 static int acpi_scan_device_check(struct acpi_device *adev)
308 {
309 	int error;
310 
311 	acpi_bus_get_status(adev);
312 	if (adev->status.present || adev->status.functional) {
313 		/*
314 		 * This function is only called for device objects for which
315 		 * matching scan handlers exist.  The only situation in which
316 		 * the scan handler is not attached to this device object yet
317 		 * is when the device has just appeared (either it wasn't
318 		 * present at all before or it was removed and then added
319 		 * again).
320 		 */
321 		if (adev->handler) {
322 			dev_warn(&adev->dev, "Already enumerated\n");
323 			return -EALREADY;
324 		}
325 		error = acpi_bus_scan(adev->handle);
326 		if (error) {
327 			dev_warn(&adev->dev, "Namespace scan failure\n");
328 			return error;
329 		}
330 		if (!adev->handler) {
331 			dev_warn(&adev->dev, "Enumeration failure\n");
332 			error = -ENODEV;
333 		}
334 	} else {
335 		error = acpi_scan_device_not_present(adev);
336 	}
337 	return error;
338 }
339 
340 static int acpi_scan_bus_check(struct acpi_device *adev)
341 {
342 	struct acpi_scan_handler *handler = adev->handler;
343 	struct acpi_device *child;
344 	int error;
345 
346 	acpi_bus_get_status(adev);
347 	if (!(adev->status.present || adev->status.functional)) {
348 		acpi_scan_device_not_present(adev);
349 		return 0;
350 	}
351 	if (handler && handler->hotplug.scan_dependent)
352 		return handler->hotplug.scan_dependent(adev);
353 
354 	error = acpi_bus_scan(adev->handle);
355 	if (error) {
356 		dev_warn(&adev->dev, "Namespace scan failure\n");
357 		return error;
358 	}
359 	list_for_each_entry(child, &adev->children, node) {
360 		error = acpi_scan_bus_check(child);
361 		if (error)
362 			return error;
363 	}
364 	return 0;
365 }
366 
367 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
368 {
369 	switch (type) {
370 	case ACPI_NOTIFY_BUS_CHECK:
371 		return acpi_scan_bus_check(adev);
372 	case ACPI_NOTIFY_DEVICE_CHECK:
373 		return acpi_scan_device_check(adev);
374 	case ACPI_NOTIFY_EJECT_REQUEST:
375 	case ACPI_OST_EC_OSPM_EJECT:
376 		if (adev->handler && !adev->handler->hotplug.enabled) {
377 			dev_info(&adev->dev, "Eject disabled\n");
378 			return -EPERM;
379 		}
380 		acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
381 				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
382 		return acpi_scan_hot_remove(adev);
383 	}
384 	return -EINVAL;
385 }
386 
387 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
388 {
389 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
390 	int error = -ENODEV;
391 
392 	lock_device_hotplug();
393 	mutex_lock(&acpi_scan_lock);
394 
395 	/*
396 	 * The device object's ACPI handle cannot become invalid as long as we
397 	 * are holding acpi_scan_lock, but it might have become invalid before
398 	 * that lock was acquired.
399 	 */
400 	if (adev->handle == INVALID_ACPI_HANDLE)
401 		goto err_out;
402 
403 	if (adev->flags.is_dock_station) {
404 		error = dock_notify(adev, src);
405 	} else if (adev->flags.hotplug_notify) {
406 		error = acpi_generic_hotplug_event(adev, src);
407 		if (error == -EPERM) {
408 			ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
409 			goto err_out;
410 		}
411 	} else {
412 		int (*notify)(struct acpi_device *, u32);
413 
414 		acpi_lock_hp_context();
415 		notify = adev->hp ? adev->hp->notify : NULL;
416 		acpi_unlock_hp_context();
417 		/*
418 		 * There may be additional notify handlers for device objects
419 		 * without the .event() callback, so ignore them here.
420 		 */
421 		if (notify)
422 			error = notify(adev, src);
423 		else
424 			goto out;
425 	}
426 	if (!error)
427 		ost_code = ACPI_OST_SC_SUCCESS;
428 
429  err_out:
430 	acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
431 
432  out:
433 	acpi_bus_put_acpi_device(adev);
434 	mutex_unlock(&acpi_scan_lock);
435 	unlock_device_hotplug();
436 }
437 
438 static void acpi_free_power_resources_lists(struct acpi_device *device)
439 {
440 	int i;
441 
442 	if (device->wakeup.flags.valid)
443 		acpi_power_resources_list_free(&device->wakeup.resources);
444 
445 	if (!device->power.flags.power_resources)
446 		return;
447 
448 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
449 		struct acpi_device_power_state *ps = &device->power.states[i];
450 		acpi_power_resources_list_free(&ps->resources);
451 	}
452 }
453 
454 static void acpi_device_release(struct device *dev)
455 {
456 	struct acpi_device *acpi_dev = to_acpi_device(dev);
457 
458 	acpi_free_properties(acpi_dev);
459 	acpi_free_pnp_ids(&acpi_dev->pnp);
460 	acpi_free_power_resources_lists(acpi_dev);
461 	kfree(acpi_dev);
462 }
463 
464 static void acpi_device_del(struct acpi_device *device)
465 {
466 	struct acpi_device_bus_id *acpi_device_bus_id;
467 
468 	mutex_lock(&acpi_device_lock);
469 	if (device->parent)
470 		list_del(&device->node);
471 
472 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
473 		if (!strcmp(acpi_device_bus_id->bus_id,
474 			    acpi_device_hid(device))) {
475 			if (acpi_device_bus_id->instance_no > 0)
476 				acpi_device_bus_id->instance_no--;
477 			else {
478 				list_del(&acpi_device_bus_id->node);
479 				kfree(acpi_device_bus_id);
480 			}
481 			break;
482 		}
483 
484 	list_del(&device->wakeup_list);
485 	mutex_unlock(&acpi_device_lock);
486 
487 	acpi_power_add_remove_device(device, false);
488 	acpi_device_remove_files(device);
489 	if (device->remove)
490 		device->remove(device);
491 
492 	device_del(&device->dev);
493 }
494 
495 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
496 
497 static LIST_HEAD(acpi_device_del_list);
498 static DEFINE_MUTEX(acpi_device_del_lock);
499 
500 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
501 {
502 	for (;;) {
503 		struct acpi_device *adev;
504 
505 		mutex_lock(&acpi_device_del_lock);
506 
507 		if (list_empty(&acpi_device_del_list)) {
508 			mutex_unlock(&acpi_device_del_lock);
509 			break;
510 		}
511 		adev = list_first_entry(&acpi_device_del_list,
512 					struct acpi_device, del_list);
513 		list_del(&adev->del_list);
514 
515 		mutex_unlock(&acpi_device_del_lock);
516 
517 		blocking_notifier_call_chain(&acpi_reconfig_chain,
518 					     ACPI_RECONFIG_DEVICE_REMOVE, adev);
519 
520 		acpi_device_del(adev);
521 		/*
522 		 * Drop references to all power resources that might have been
523 		 * used by the device.
524 		 */
525 		acpi_power_transition(adev, ACPI_STATE_D3_COLD);
526 		put_device(&adev->dev);
527 	}
528 }
529 
530 /**
531  * acpi_scan_drop_device - Drop an ACPI device object.
532  * @handle: Handle of an ACPI namespace node, not used.
533  * @context: Address of the ACPI device object to drop.
534  *
535  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
536  * namespace node the device object pointed to by @context is attached to.
537  *
538  * The unregistration is carried out asynchronously to avoid running
539  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
540  * ensure the correct ordering (the device objects must be unregistered in the
541  * same order in which the corresponding namespace nodes are deleted).
542  */
543 static void acpi_scan_drop_device(acpi_handle handle, void *context)
544 {
545 	static DECLARE_WORK(work, acpi_device_del_work_fn);
546 	struct acpi_device *adev = context;
547 
548 	mutex_lock(&acpi_device_del_lock);
549 
550 	/*
551 	 * Use the ACPI hotplug workqueue which is ordered, so this work item
552 	 * won't run after any hotplug work items submitted subsequently.  That
553 	 * prevents attempts to register device objects identical to those being
554 	 * deleted from happening concurrently (such attempts result from
555 	 * hotplug events handled via the ACPI hotplug workqueue).  It also will
556 	 * run after all of the work items submitted previosuly, which helps
557 	 * those work items to ensure that they are not accessing stale device
558 	 * objects.
559 	 */
560 	if (list_empty(&acpi_device_del_list))
561 		acpi_queue_hotplug_work(&work);
562 
563 	list_add_tail(&adev->del_list, &acpi_device_del_list);
564 	/* Make acpi_ns_validate_handle() return NULL for this handle. */
565 	adev->handle = INVALID_ACPI_HANDLE;
566 
567 	mutex_unlock(&acpi_device_del_lock);
568 }
569 
570 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
571 				void (*callback)(void *))
572 {
573 	acpi_status status;
574 
575 	if (!device)
576 		return -EINVAL;
577 
578 	status = acpi_get_data_full(handle, acpi_scan_drop_device,
579 				    (void **)device, callback);
580 	if (ACPI_FAILURE(status) || !*device) {
581 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
582 				  handle));
583 		return -ENODEV;
584 	}
585 	return 0;
586 }
587 
588 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
589 {
590 	return acpi_get_device_data(handle, device, NULL);
591 }
592 EXPORT_SYMBOL(acpi_bus_get_device);
593 
594 static void get_acpi_device(void *dev)
595 {
596 	if (dev)
597 		get_device(&((struct acpi_device *)dev)->dev);
598 }
599 
600 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
601 {
602 	struct acpi_device *adev = NULL;
603 
604 	acpi_get_device_data(handle, &adev, get_acpi_device);
605 	return adev;
606 }
607 
608 void acpi_bus_put_acpi_device(struct acpi_device *adev)
609 {
610 	put_device(&adev->dev);
611 }
612 
613 int acpi_device_add(struct acpi_device *device,
614 		    void (*release)(struct device *))
615 {
616 	int result;
617 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
618 	int found = 0;
619 
620 	if (device->handle) {
621 		acpi_status status;
622 
623 		status = acpi_attach_data(device->handle, acpi_scan_drop_device,
624 					  device);
625 		if (ACPI_FAILURE(status)) {
626 			acpi_handle_err(device->handle,
627 					"Unable to attach device data\n");
628 			return -ENODEV;
629 		}
630 	}
631 
632 	/*
633 	 * Linkage
634 	 * -------
635 	 * Link this device to its parent and siblings.
636 	 */
637 	INIT_LIST_HEAD(&device->children);
638 	INIT_LIST_HEAD(&device->node);
639 	INIT_LIST_HEAD(&device->wakeup_list);
640 	INIT_LIST_HEAD(&device->physical_node_list);
641 	INIT_LIST_HEAD(&device->del_list);
642 	mutex_init(&device->physical_node_lock);
643 
644 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
645 	if (!new_bus_id) {
646 		pr_err(PREFIX "Memory allocation error\n");
647 		result = -ENOMEM;
648 		goto err_detach;
649 	}
650 
651 	mutex_lock(&acpi_device_lock);
652 	/*
653 	 * Find suitable bus_id and instance number in acpi_bus_id_list
654 	 * If failed, create one and link it into acpi_bus_id_list
655 	 */
656 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
657 		if (!strcmp(acpi_device_bus_id->bus_id,
658 			    acpi_device_hid(device))) {
659 			acpi_device_bus_id->instance_no++;
660 			found = 1;
661 			kfree(new_bus_id);
662 			break;
663 		}
664 	}
665 	if (!found) {
666 		acpi_device_bus_id = new_bus_id;
667 		strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
668 		acpi_device_bus_id->instance_no = 0;
669 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
670 	}
671 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
672 
673 	if (device->parent)
674 		list_add_tail(&device->node, &device->parent->children);
675 
676 	if (device->wakeup.flags.valid)
677 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
678 	mutex_unlock(&acpi_device_lock);
679 
680 	if (device->parent)
681 		device->dev.parent = &device->parent->dev;
682 	device->dev.bus = &acpi_bus_type;
683 	device->dev.release = release;
684 	result = device_add(&device->dev);
685 	if (result) {
686 		dev_err(&device->dev, "Error registering device\n");
687 		goto err;
688 	}
689 
690 	result = acpi_device_setup_files(device);
691 	if (result)
692 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
693 		       dev_name(&device->dev));
694 
695 	return 0;
696 
697  err:
698 	mutex_lock(&acpi_device_lock);
699 	if (device->parent)
700 		list_del(&device->node);
701 	list_del(&device->wakeup_list);
702 	mutex_unlock(&acpi_device_lock);
703 
704  err_detach:
705 	acpi_detach_data(device->handle, acpi_scan_drop_device);
706 	return result;
707 }
708 
709 /* --------------------------------------------------------------------------
710                                  Device Enumeration
711    -------------------------------------------------------------------------- */
712 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
713 {
714 	struct acpi_device *device = NULL;
715 	acpi_status status;
716 
717 	/*
718 	 * Fixed hardware devices do not appear in the namespace and do not
719 	 * have handles, but we fabricate acpi_devices for them, so we have
720 	 * to deal with them specially.
721 	 */
722 	if (!handle)
723 		return acpi_root;
724 
725 	do {
726 		status = acpi_get_parent(handle, &handle);
727 		if (ACPI_FAILURE(status))
728 			return status == AE_NULL_ENTRY ? NULL : acpi_root;
729 	} while (acpi_bus_get_device(handle, &device));
730 	return device;
731 }
732 
733 acpi_status
734 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
735 {
736 	acpi_status status;
737 	acpi_handle tmp;
738 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
739 	union acpi_object *obj;
740 
741 	status = acpi_get_handle(handle, "_EJD", &tmp);
742 	if (ACPI_FAILURE(status))
743 		return status;
744 
745 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
746 	if (ACPI_SUCCESS(status)) {
747 		obj = buffer.pointer;
748 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
749 					 ejd);
750 		kfree(buffer.pointer);
751 	}
752 	return status;
753 }
754 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
755 
756 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
757 					struct acpi_device_wakeup *wakeup)
758 {
759 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
760 	union acpi_object *package = NULL;
761 	union acpi_object *element = NULL;
762 	acpi_status status;
763 	int err = -ENODATA;
764 
765 	if (!wakeup)
766 		return -EINVAL;
767 
768 	INIT_LIST_HEAD(&wakeup->resources);
769 
770 	/* _PRW */
771 	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
772 	if (ACPI_FAILURE(status)) {
773 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
774 		return err;
775 	}
776 
777 	package = (union acpi_object *)buffer.pointer;
778 
779 	if (!package || package->package.count < 2)
780 		goto out;
781 
782 	element = &(package->package.elements[0]);
783 	if (!element)
784 		goto out;
785 
786 	if (element->type == ACPI_TYPE_PACKAGE) {
787 		if ((element->package.count < 2) ||
788 		    (element->package.elements[0].type !=
789 		     ACPI_TYPE_LOCAL_REFERENCE)
790 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
791 			goto out;
792 
793 		wakeup->gpe_device =
794 		    element->package.elements[0].reference.handle;
795 		wakeup->gpe_number =
796 		    (u32) element->package.elements[1].integer.value;
797 	} else if (element->type == ACPI_TYPE_INTEGER) {
798 		wakeup->gpe_device = NULL;
799 		wakeup->gpe_number = element->integer.value;
800 	} else {
801 		goto out;
802 	}
803 
804 	element = &(package->package.elements[1]);
805 	if (element->type != ACPI_TYPE_INTEGER)
806 		goto out;
807 
808 	wakeup->sleep_state = element->integer.value;
809 
810 	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
811 	if (err)
812 		goto out;
813 
814 	if (!list_empty(&wakeup->resources)) {
815 		int sleep_state;
816 
817 		err = acpi_power_wakeup_list_init(&wakeup->resources,
818 						  &sleep_state);
819 		if (err) {
820 			acpi_handle_warn(handle, "Retrieving current states "
821 					 "of wakeup power resources failed\n");
822 			acpi_power_resources_list_free(&wakeup->resources);
823 			goto out;
824 		}
825 		if (sleep_state < wakeup->sleep_state) {
826 			acpi_handle_warn(handle, "Overriding _PRW sleep state "
827 					 "(S%d) by S%d from power resources\n",
828 					 (int)wakeup->sleep_state, sleep_state);
829 			wakeup->sleep_state = sleep_state;
830 		}
831 	}
832 
833  out:
834 	kfree(buffer.pointer);
835 	return err;
836 }
837 
838 static void acpi_wakeup_gpe_init(struct acpi_device *device)
839 {
840 	static const struct acpi_device_id button_device_ids[] = {
841 		{"PNP0C0C", 0},
842 		{"PNP0C0D", 0},
843 		{"PNP0C0E", 0},
844 		{"", 0},
845 	};
846 	struct acpi_device_wakeup *wakeup = &device->wakeup;
847 	acpi_status status;
848 	acpi_event_status event_status;
849 
850 	wakeup->flags.notifier_present = 0;
851 
852 	/* Power button, Lid switch always enable wakeup */
853 	if (!acpi_match_device_ids(device, button_device_ids)) {
854 		wakeup->flags.run_wake = 1;
855 		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
856 			/* Do not use Lid/sleep button for S5 wakeup */
857 			if (wakeup->sleep_state == ACPI_STATE_S5)
858 				wakeup->sleep_state = ACPI_STATE_S4;
859 		}
860 		acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
861 		device_set_wakeup_capable(&device->dev, true);
862 		return;
863 	}
864 
865 	acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
866 				wakeup->gpe_number);
867 	status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
868 				     &event_status);
869 	if (ACPI_FAILURE(status))
870 		return;
871 
872 	wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
873 }
874 
875 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
876 {
877 	int err;
878 
879 	/* Presence of _PRW indicates wake capable */
880 	if (!acpi_has_method(device->handle, "_PRW"))
881 		return;
882 
883 	err = acpi_bus_extract_wakeup_device_power_package(device->handle,
884 							   &device->wakeup);
885 	if (err) {
886 		dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
887 		return;
888 	}
889 
890 	device->wakeup.flags.valid = 1;
891 	device->wakeup.prepare_count = 0;
892 	acpi_wakeup_gpe_init(device);
893 	/* Call _PSW/_DSW object to disable its ability to wake the sleeping
894 	 * system for the ACPI device with the _PRW object.
895 	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
896 	 * So it is necessary to call _DSW object first. Only when it is not
897 	 * present will the _PSW object used.
898 	 */
899 	err = acpi_device_sleep_wake(device, 0, 0, 0);
900 	if (err)
901 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
902 				"error in _DSW or _PSW evaluation\n"));
903 }
904 
905 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
906 {
907 	struct acpi_device_power_state *ps = &device->power.states[state];
908 	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
909 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
910 	acpi_status status;
911 
912 	INIT_LIST_HEAD(&ps->resources);
913 
914 	/* Evaluate "_PRx" to get referenced power resources */
915 	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
916 	if (ACPI_SUCCESS(status)) {
917 		union acpi_object *package = buffer.pointer;
918 
919 		if (buffer.length && package
920 		    && package->type == ACPI_TYPE_PACKAGE
921 		    && package->package.count) {
922 			int err = acpi_extract_power_resources(package, 0,
923 							       &ps->resources);
924 			if (!err)
925 				device->power.flags.power_resources = 1;
926 		}
927 		ACPI_FREE(buffer.pointer);
928 	}
929 
930 	/* Evaluate "_PSx" to see if we can do explicit sets */
931 	pathname[2] = 'S';
932 	if (acpi_has_method(device->handle, pathname))
933 		ps->flags.explicit_set = 1;
934 
935 	/* State is valid if there are means to put the device into it. */
936 	if (!list_empty(&ps->resources) || ps->flags.explicit_set)
937 		ps->flags.valid = 1;
938 
939 	ps->power = -1;		/* Unknown - driver assigned */
940 	ps->latency = -1;	/* Unknown - driver assigned */
941 }
942 
943 static void acpi_bus_get_power_flags(struct acpi_device *device)
944 {
945 	u32 i;
946 
947 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
948 	if (!acpi_has_method(device->handle, "_PS0") &&
949 	    !acpi_has_method(device->handle, "_PR0"))
950 		return;
951 
952 	device->flags.power_manageable = 1;
953 
954 	/*
955 	 * Power Management Flags
956 	 */
957 	if (acpi_has_method(device->handle, "_PSC"))
958 		device->power.flags.explicit_get = 1;
959 
960 	if (acpi_has_method(device->handle, "_IRC"))
961 		device->power.flags.inrush_current = 1;
962 
963 	if (acpi_has_method(device->handle, "_DSW"))
964 		device->power.flags.dsw_present = 1;
965 
966 	/*
967 	 * Enumerate supported power management states
968 	 */
969 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
970 		acpi_bus_init_power_state(device, i);
971 
972 	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
973 	if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
974 		device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
975 
976 	/* Set defaults for D0 and D3hot states (always valid) */
977 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
978 	device->power.states[ACPI_STATE_D0].power = 100;
979 	device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
980 
981 	if (acpi_bus_init_power(device))
982 		device->flags.power_manageable = 0;
983 }
984 
985 static void acpi_bus_get_flags(struct acpi_device *device)
986 {
987 	/* Presence of _STA indicates 'dynamic_status' */
988 	if (acpi_has_method(device->handle, "_STA"))
989 		device->flags.dynamic_status = 1;
990 
991 	/* Presence of _RMV indicates 'removable' */
992 	if (acpi_has_method(device->handle, "_RMV"))
993 		device->flags.removable = 1;
994 
995 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
996 	if (acpi_has_method(device->handle, "_EJD") ||
997 	    acpi_has_method(device->handle, "_EJ0"))
998 		device->flags.ejectable = 1;
999 }
1000 
1001 static void acpi_device_get_busid(struct acpi_device *device)
1002 {
1003 	char bus_id[5] = { '?', 0 };
1004 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1005 	int i = 0;
1006 
1007 	/*
1008 	 * Bus ID
1009 	 * ------
1010 	 * The device's Bus ID is simply the object name.
1011 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1012 	 */
1013 	if (ACPI_IS_ROOT_DEVICE(device)) {
1014 		strcpy(device->pnp.bus_id, "ACPI");
1015 		return;
1016 	}
1017 
1018 	switch (device->device_type) {
1019 	case ACPI_BUS_TYPE_POWER_BUTTON:
1020 		strcpy(device->pnp.bus_id, "PWRF");
1021 		break;
1022 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1023 		strcpy(device->pnp.bus_id, "SLPF");
1024 		break;
1025 	default:
1026 		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1027 		/* Clean up trailing underscores (if any) */
1028 		for (i = 3; i > 1; i--) {
1029 			if (bus_id[i] == '_')
1030 				bus_id[i] = '\0';
1031 			else
1032 				break;
1033 		}
1034 		strcpy(device->pnp.bus_id, bus_id);
1035 		break;
1036 	}
1037 }
1038 
1039 /*
1040  * acpi_ata_match - see if an acpi object is an ATA device
1041  *
1042  * If an acpi object has one of the ACPI ATA methods defined,
1043  * then we can safely call it an ATA device.
1044  */
1045 bool acpi_ata_match(acpi_handle handle)
1046 {
1047 	return acpi_has_method(handle, "_GTF") ||
1048 	       acpi_has_method(handle, "_GTM") ||
1049 	       acpi_has_method(handle, "_STM") ||
1050 	       acpi_has_method(handle, "_SDD");
1051 }
1052 
1053 /*
1054  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1055  *
1056  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1057  * then we can safely call it an ejectable drive bay
1058  */
1059 bool acpi_bay_match(acpi_handle handle)
1060 {
1061 	acpi_handle phandle;
1062 
1063 	if (!acpi_has_method(handle, "_EJ0"))
1064 		return false;
1065 	if (acpi_ata_match(handle))
1066 		return true;
1067 	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1068 		return false;
1069 
1070 	return acpi_ata_match(phandle);
1071 }
1072 
1073 bool acpi_device_is_battery(struct acpi_device *adev)
1074 {
1075 	struct acpi_hardware_id *hwid;
1076 
1077 	list_for_each_entry(hwid, &adev->pnp.ids, list)
1078 		if (!strcmp("PNP0C0A", hwid->id))
1079 			return true;
1080 
1081 	return false;
1082 }
1083 
1084 static bool is_ejectable_bay(struct acpi_device *adev)
1085 {
1086 	acpi_handle handle = adev->handle;
1087 
1088 	if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1089 		return true;
1090 
1091 	return acpi_bay_match(handle);
1092 }
1093 
1094 /*
1095  * acpi_dock_match - see if an acpi object has a _DCK method
1096  */
1097 bool acpi_dock_match(acpi_handle handle)
1098 {
1099 	return acpi_has_method(handle, "_DCK");
1100 }
1101 
1102 static acpi_status
1103 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1104 			  void **return_value)
1105 {
1106 	long *cap = context;
1107 
1108 	if (acpi_has_method(handle, "_BCM") &&
1109 	    acpi_has_method(handle, "_BCL")) {
1110 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1111 				  "support\n"));
1112 		*cap |= ACPI_VIDEO_BACKLIGHT;
1113 		/* We have backlight support, no need to scan further */
1114 		return AE_CTRL_TERMINATE;
1115 	}
1116 	return 0;
1117 }
1118 
1119 /* Returns true if the ACPI object is a video device which can be
1120  * handled by video.ko.
1121  * The device will get a Linux specific CID added in scan.c to
1122  * identify the device as an ACPI graphics device
1123  * Be aware that the graphics device may not be physically present
1124  * Use acpi_video_get_capabilities() to detect general ACPI video
1125  * capabilities of present cards
1126  */
1127 long acpi_is_video_device(acpi_handle handle)
1128 {
1129 	long video_caps = 0;
1130 
1131 	/* Is this device able to support video switching ? */
1132 	if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1133 		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1134 
1135 	/* Is this device able to retrieve a video ROM ? */
1136 	if (acpi_has_method(handle, "_ROM"))
1137 		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1138 
1139 	/* Is this device able to configure which video head to be POSTed ? */
1140 	if (acpi_has_method(handle, "_VPO") &&
1141 	    acpi_has_method(handle, "_GPD") &&
1142 	    acpi_has_method(handle, "_SPD"))
1143 		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1144 
1145 	/* Only check for backlight functionality if one of the above hit. */
1146 	if (video_caps)
1147 		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1148 				    ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1149 				    &video_caps, NULL);
1150 
1151 	return video_caps;
1152 }
1153 EXPORT_SYMBOL(acpi_is_video_device);
1154 
1155 const char *acpi_device_hid(struct acpi_device *device)
1156 {
1157 	struct acpi_hardware_id *hid;
1158 
1159 	if (list_empty(&device->pnp.ids))
1160 		return dummy_hid;
1161 
1162 	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1163 	return hid->id;
1164 }
1165 EXPORT_SYMBOL(acpi_device_hid);
1166 
1167 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1168 {
1169 	struct acpi_hardware_id *id;
1170 
1171 	id = kmalloc(sizeof(*id), GFP_KERNEL);
1172 	if (!id)
1173 		return;
1174 
1175 	id->id = kstrdup_const(dev_id, GFP_KERNEL);
1176 	if (!id->id) {
1177 		kfree(id);
1178 		return;
1179 	}
1180 
1181 	list_add_tail(&id->list, &pnp->ids);
1182 	pnp->type.hardware_id = 1;
1183 }
1184 
1185 /*
1186  * Old IBM workstations have a DSDT bug wherein the SMBus object
1187  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1188  * prefix.  Work around this.
1189  */
1190 static bool acpi_ibm_smbus_match(acpi_handle handle)
1191 {
1192 	char node_name[ACPI_PATH_SEGMENT_LENGTH];
1193 	struct acpi_buffer path = { sizeof(node_name), node_name };
1194 
1195 	if (!dmi_name_in_vendors("IBM"))
1196 		return false;
1197 
1198 	/* Look for SMBS object */
1199 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1200 	    strcmp("SMBS", path.pointer))
1201 		return false;
1202 
1203 	/* Does it have the necessary (but misnamed) methods? */
1204 	if (acpi_has_method(handle, "SBI") &&
1205 	    acpi_has_method(handle, "SBR") &&
1206 	    acpi_has_method(handle, "SBW"))
1207 		return true;
1208 
1209 	return false;
1210 }
1211 
1212 static bool acpi_object_is_system_bus(acpi_handle handle)
1213 {
1214 	acpi_handle tmp;
1215 
1216 	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1217 	    tmp == handle)
1218 		return true;
1219 	if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1220 	    tmp == handle)
1221 		return true;
1222 
1223 	return false;
1224 }
1225 
1226 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1227 				int device_type)
1228 {
1229 	acpi_status status;
1230 	struct acpi_device_info *info;
1231 	struct acpi_pnp_device_id_list *cid_list;
1232 	int i;
1233 
1234 	switch (device_type) {
1235 	case ACPI_BUS_TYPE_DEVICE:
1236 		if (handle == ACPI_ROOT_OBJECT) {
1237 			acpi_add_id(pnp, ACPI_SYSTEM_HID);
1238 			break;
1239 		}
1240 
1241 		status = acpi_get_object_info(handle, &info);
1242 		if (ACPI_FAILURE(status)) {
1243 			pr_err(PREFIX "%s: Error reading device info\n",
1244 					__func__);
1245 			return;
1246 		}
1247 
1248 		if (info->valid & ACPI_VALID_HID) {
1249 			acpi_add_id(pnp, info->hardware_id.string);
1250 			pnp->type.platform_id = 1;
1251 		}
1252 		if (info->valid & ACPI_VALID_CID) {
1253 			cid_list = &info->compatible_id_list;
1254 			for (i = 0; i < cid_list->count; i++)
1255 				acpi_add_id(pnp, cid_list->ids[i].string);
1256 		}
1257 		if (info->valid & ACPI_VALID_ADR) {
1258 			pnp->bus_address = info->address;
1259 			pnp->type.bus_address = 1;
1260 		}
1261 		if (info->valid & ACPI_VALID_UID)
1262 			pnp->unique_id = kstrdup(info->unique_id.string,
1263 							GFP_KERNEL);
1264 		if (info->valid & ACPI_VALID_CLS)
1265 			acpi_add_id(pnp, info->class_code.string);
1266 
1267 		kfree(info);
1268 
1269 		/*
1270 		 * Some devices don't reliably have _HIDs & _CIDs, so add
1271 		 * synthetic HIDs to make sure drivers can find them.
1272 		 */
1273 		if (acpi_is_video_device(handle))
1274 			acpi_add_id(pnp, ACPI_VIDEO_HID);
1275 		else if (acpi_bay_match(handle))
1276 			acpi_add_id(pnp, ACPI_BAY_HID);
1277 		else if (acpi_dock_match(handle))
1278 			acpi_add_id(pnp, ACPI_DOCK_HID);
1279 		else if (acpi_ibm_smbus_match(handle))
1280 			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1281 		else if (list_empty(&pnp->ids) &&
1282 			 acpi_object_is_system_bus(handle)) {
1283 			/* \_SB, \_TZ, LNXSYBUS */
1284 			acpi_add_id(pnp, ACPI_BUS_HID);
1285 			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1286 			strcpy(pnp->device_class, ACPI_BUS_CLASS);
1287 		}
1288 
1289 		break;
1290 	case ACPI_BUS_TYPE_POWER:
1291 		acpi_add_id(pnp, ACPI_POWER_HID);
1292 		break;
1293 	case ACPI_BUS_TYPE_PROCESSOR:
1294 		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1295 		break;
1296 	case ACPI_BUS_TYPE_THERMAL:
1297 		acpi_add_id(pnp, ACPI_THERMAL_HID);
1298 		break;
1299 	case ACPI_BUS_TYPE_POWER_BUTTON:
1300 		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1301 		break;
1302 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1303 		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1304 		break;
1305 	}
1306 }
1307 
1308 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1309 {
1310 	struct acpi_hardware_id *id, *tmp;
1311 
1312 	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1313 		kfree_const(id->id);
1314 		kfree(id);
1315 	}
1316 	kfree(pnp->unique_id);
1317 }
1318 
1319 /**
1320  * acpi_dma_supported - Check DMA support for the specified device.
1321  * @adev: The pointer to acpi device
1322  *
1323  * Return false if DMA is not supported. Otherwise, return true
1324  */
1325 bool acpi_dma_supported(struct acpi_device *adev)
1326 {
1327 	if (!adev)
1328 		return false;
1329 
1330 	if (adev->flags.cca_seen)
1331 		return true;
1332 
1333 	/*
1334 	* Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1335 	* DMA on "Intel platforms".  Presumably that includes all x86 and
1336 	* ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1337 	*/
1338 	if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1339 		return true;
1340 
1341 	return false;
1342 }
1343 
1344 /**
1345  * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1346  * @adev: The pointer to acpi device
1347  *
1348  * Return enum dev_dma_attr.
1349  */
1350 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1351 {
1352 	if (!acpi_dma_supported(adev))
1353 		return DEV_DMA_NOT_SUPPORTED;
1354 
1355 	if (adev->flags.coherent_dma)
1356 		return DEV_DMA_COHERENT;
1357 	else
1358 		return DEV_DMA_NON_COHERENT;
1359 }
1360 
1361 /**
1362  * acpi_dma_configure - Set-up DMA configuration for the device.
1363  * @dev: The pointer to the device
1364  * @attr: device dma attributes
1365  */
1366 void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
1367 {
1368 	const struct iommu_ops *iommu;
1369 
1370 	iort_set_dma_mask(dev);
1371 
1372 	iommu = iort_iommu_configure(dev);
1373 
1374 	/*
1375 	 * Assume dma valid range starts at 0 and covers the whole
1376 	 * coherent_dma_mask.
1377 	 */
1378 	arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, iommu,
1379 			   attr == DEV_DMA_COHERENT);
1380 }
1381 EXPORT_SYMBOL_GPL(acpi_dma_configure);
1382 
1383 /**
1384  * acpi_dma_deconfigure - Tear-down DMA configuration for the device.
1385  * @dev: The pointer to the device
1386  */
1387 void acpi_dma_deconfigure(struct device *dev)
1388 {
1389 	arch_teardown_dma_ops(dev);
1390 }
1391 EXPORT_SYMBOL_GPL(acpi_dma_deconfigure);
1392 
1393 static void acpi_init_coherency(struct acpi_device *adev)
1394 {
1395 	unsigned long long cca = 0;
1396 	acpi_status status;
1397 	struct acpi_device *parent = adev->parent;
1398 
1399 	if (parent && parent->flags.cca_seen) {
1400 		/*
1401 		 * From ACPI spec, OSPM will ignore _CCA if an ancestor
1402 		 * already saw one.
1403 		 */
1404 		adev->flags.cca_seen = 1;
1405 		cca = parent->flags.coherent_dma;
1406 	} else {
1407 		status = acpi_evaluate_integer(adev->handle, "_CCA",
1408 					       NULL, &cca);
1409 		if (ACPI_SUCCESS(status))
1410 			adev->flags.cca_seen = 1;
1411 		else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1412 			/*
1413 			 * If architecture does not specify that _CCA is
1414 			 * required for DMA-able devices (e.g. x86),
1415 			 * we default to _CCA=1.
1416 			 */
1417 			cca = 1;
1418 		else
1419 			acpi_handle_debug(adev->handle,
1420 					  "ACPI device is missing _CCA.\n");
1421 	}
1422 
1423 	adev->flags.coherent_dma = cca;
1424 }
1425 
1426 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1427 			     int type, unsigned long long sta)
1428 {
1429 	INIT_LIST_HEAD(&device->pnp.ids);
1430 	device->device_type = type;
1431 	device->handle = handle;
1432 	device->parent = acpi_bus_get_parent(handle);
1433 	device->fwnode.type = FWNODE_ACPI;
1434 	acpi_set_device_status(device, sta);
1435 	acpi_device_get_busid(device);
1436 	acpi_set_pnp_ids(handle, &device->pnp, type);
1437 	acpi_init_properties(device);
1438 	acpi_bus_get_flags(device);
1439 	device->flags.match_driver = false;
1440 	device->flags.initialized = true;
1441 	acpi_device_clear_enumerated(device);
1442 	device_initialize(&device->dev);
1443 	dev_set_uevent_suppress(&device->dev, true);
1444 	acpi_init_coherency(device);
1445 }
1446 
1447 void acpi_device_add_finalize(struct acpi_device *device)
1448 {
1449 	dev_set_uevent_suppress(&device->dev, false);
1450 	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1451 }
1452 
1453 static int acpi_add_single_object(struct acpi_device **child,
1454 				  acpi_handle handle, int type,
1455 				  unsigned long long sta)
1456 {
1457 	int result;
1458 	struct acpi_device *device;
1459 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1460 
1461 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1462 	if (!device) {
1463 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1464 		return -ENOMEM;
1465 	}
1466 
1467 	acpi_init_device_object(device, handle, type, sta);
1468 	acpi_bus_get_power_flags(device);
1469 	acpi_bus_get_wakeup_device_flags(device);
1470 
1471 	result = acpi_device_add(device, acpi_device_release);
1472 	if (result) {
1473 		acpi_device_release(&device->dev);
1474 		return result;
1475 	}
1476 
1477 	acpi_power_add_remove_device(device, true);
1478 	acpi_device_add_finalize(device);
1479 	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1480 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1481 		dev_name(&device->dev), (char *) buffer.pointer,
1482 		device->parent ? dev_name(&device->parent->dev) : "(null)"));
1483 	kfree(buffer.pointer);
1484 	*child = device;
1485 	return 0;
1486 }
1487 
1488 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1489 					    void *context)
1490 {
1491 	struct resource *res = context;
1492 
1493 	if (acpi_dev_resource_memory(ares, res))
1494 		return AE_CTRL_TERMINATE;
1495 
1496 	return AE_OK;
1497 }
1498 
1499 static bool acpi_device_should_be_hidden(acpi_handle handle)
1500 {
1501 	acpi_status status;
1502 	struct resource res;
1503 
1504 	/* Check if it should ignore the UART device */
1505 	if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1506 		return false;
1507 
1508 	/*
1509 	 * The UART device described in SPCR table is assumed to have only one
1510 	 * memory resource present. So we only look for the first one here.
1511 	 */
1512 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1513 				     acpi_get_resource_memory, &res);
1514 	if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1515 		return false;
1516 
1517 	acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1518 			 &res.start);
1519 
1520 	return true;
1521 }
1522 
1523 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1524 				    unsigned long long *sta)
1525 {
1526 	acpi_status status;
1527 	acpi_object_type acpi_type;
1528 
1529 	status = acpi_get_type(handle, &acpi_type);
1530 	if (ACPI_FAILURE(status))
1531 		return -ENODEV;
1532 
1533 	switch (acpi_type) {
1534 	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
1535 	case ACPI_TYPE_DEVICE:
1536 		if (acpi_device_should_be_hidden(handle))
1537 			return -ENODEV;
1538 
1539 		*type = ACPI_BUS_TYPE_DEVICE;
1540 		status = acpi_bus_get_status_handle(handle, sta);
1541 		if (ACPI_FAILURE(status))
1542 			*sta = 0;
1543 		break;
1544 	case ACPI_TYPE_PROCESSOR:
1545 		*type = ACPI_BUS_TYPE_PROCESSOR;
1546 		status = acpi_bus_get_status_handle(handle, sta);
1547 		if (ACPI_FAILURE(status))
1548 			return -ENODEV;
1549 		break;
1550 	case ACPI_TYPE_THERMAL:
1551 		*type = ACPI_BUS_TYPE_THERMAL;
1552 		*sta = ACPI_STA_DEFAULT;
1553 		break;
1554 	case ACPI_TYPE_POWER:
1555 		*type = ACPI_BUS_TYPE_POWER;
1556 		*sta = ACPI_STA_DEFAULT;
1557 		break;
1558 	default:
1559 		return -ENODEV;
1560 	}
1561 
1562 	return 0;
1563 }
1564 
1565 bool acpi_device_is_present(struct acpi_device *adev)
1566 {
1567 	if (adev->status.present || adev->status.functional)
1568 		return true;
1569 
1570 	adev->flags.initialized = false;
1571 	return false;
1572 }
1573 
1574 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1575 				       const char *idstr,
1576 				       const struct acpi_device_id **matchid)
1577 {
1578 	const struct acpi_device_id *devid;
1579 
1580 	if (handler->match)
1581 		return handler->match(idstr, matchid);
1582 
1583 	for (devid = handler->ids; devid->id[0]; devid++)
1584 		if (!strcmp((char *)devid->id, idstr)) {
1585 			if (matchid)
1586 				*matchid = devid;
1587 
1588 			return true;
1589 		}
1590 
1591 	return false;
1592 }
1593 
1594 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1595 					const struct acpi_device_id **matchid)
1596 {
1597 	struct acpi_scan_handler *handler;
1598 
1599 	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1600 		if (acpi_scan_handler_matching(handler, idstr, matchid))
1601 			return handler;
1602 
1603 	return NULL;
1604 }
1605 
1606 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1607 {
1608 	if (!!hotplug->enabled == !!val)
1609 		return;
1610 
1611 	mutex_lock(&acpi_scan_lock);
1612 
1613 	hotplug->enabled = val;
1614 
1615 	mutex_unlock(&acpi_scan_lock);
1616 }
1617 
1618 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1619 {
1620 	struct acpi_hardware_id *hwid;
1621 
1622 	if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1623 		acpi_dock_add(adev);
1624 		return;
1625 	}
1626 	list_for_each_entry(hwid, &adev->pnp.ids, list) {
1627 		struct acpi_scan_handler *handler;
1628 
1629 		handler = acpi_scan_match_handler(hwid->id, NULL);
1630 		if (handler) {
1631 			adev->flags.hotplug_notify = true;
1632 			break;
1633 		}
1634 	}
1635 }
1636 
1637 static void acpi_device_dep_initialize(struct acpi_device *adev)
1638 {
1639 	struct acpi_dep_data *dep;
1640 	struct acpi_handle_list dep_devices;
1641 	acpi_status status;
1642 	int i;
1643 
1644 	if (!acpi_has_method(adev->handle, "_DEP"))
1645 		return;
1646 
1647 	status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
1648 					&dep_devices);
1649 	if (ACPI_FAILURE(status)) {
1650 		dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
1651 		return;
1652 	}
1653 
1654 	for (i = 0; i < dep_devices.count; i++) {
1655 		struct acpi_device_info *info;
1656 		int skip;
1657 
1658 		status = acpi_get_object_info(dep_devices.handles[i], &info);
1659 		if (ACPI_FAILURE(status)) {
1660 			dev_dbg(&adev->dev, "Error reading _DEP device info\n");
1661 			continue;
1662 		}
1663 
1664 		/*
1665 		 * Skip the dependency of Windows System Power
1666 		 * Management Controller
1667 		 */
1668 		skip = info->valid & ACPI_VALID_HID &&
1669 			!strcmp(info->hardware_id.string, "INT3396");
1670 
1671 		kfree(info);
1672 
1673 		if (skip)
1674 			continue;
1675 
1676 		dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
1677 		if (!dep)
1678 			return;
1679 
1680 		dep->master = dep_devices.handles[i];
1681 		dep->slave  = adev->handle;
1682 		adev->dep_unmet++;
1683 
1684 		mutex_lock(&acpi_dep_list_lock);
1685 		list_add_tail(&dep->node , &acpi_dep_list);
1686 		mutex_unlock(&acpi_dep_list_lock);
1687 	}
1688 }
1689 
1690 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1691 				      void *not_used, void **return_value)
1692 {
1693 	struct acpi_device *device = NULL;
1694 	int type;
1695 	unsigned long long sta;
1696 	int result;
1697 
1698 	acpi_bus_get_device(handle, &device);
1699 	if (device)
1700 		goto out;
1701 
1702 	result = acpi_bus_type_and_status(handle, &type, &sta);
1703 	if (result)
1704 		return AE_OK;
1705 
1706 	if (type == ACPI_BUS_TYPE_POWER) {
1707 		acpi_add_power_resource(handle);
1708 		return AE_OK;
1709 	}
1710 
1711 	acpi_add_single_object(&device, handle, type, sta);
1712 	if (!device)
1713 		return AE_CTRL_DEPTH;
1714 
1715 	acpi_scan_init_hotplug(device);
1716 	acpi_device_dep_initialize(device);
1717 
1718  out:
1719 	if (!*return_value)
1720 		*return_value = device;
1721 
1722 	return AE_OK;
1723 }
1724 
1725 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
1726 {
1727 	bool *is_spi_i2c_slave_p = data;
1728 
1729 	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1730 		return 1;
1731 
1732 	/*
1733 	 * devices that are connected to UART still need to be enumerated to
1734 	 * platform bus
1735 	 */
1736 	if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
1737 		*is_spi_i2c_slave_p = true;
1738 
1739 	 /* no need to do more checking */
1740 	return -1;
1741 }
1742 
1743 static void acpi_default_enumeration(struct acpi_device *device)
1744 {
1745 	struct list_head resource_list;
1746 	bool is_spi_i2c_slave = false;
1747 
1748 	/*
1749 	 * Do not enumerate SPI/I2C slaves as they will be enumerated by their
1750 	 * respective parents.
1751 	 */
1752 	INIT_LIST_HEAD(&resource_list);
1753 	acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
1754 			       &is_spi_i2c_slave);
1755 	acpi_dev_free_resource_list(&resource_list);
1756 	if (!is_spi_i2c_slave) {
1757 		acpi_create_platform_device(device, NULL);
1758 		acpi_device_set_enumerated(device);
1759 	} else {
1760 		blocking_notifier_call_chain(&acpi_reconfig_chain,
1761 					     ACPI_RECONFIG_DEVICE_ADD, device);
1762 	}
1763 }
1764 
1765 static const struct acpi_device_id generic_device_ids[] = {
1766 	{ACPI_DT_NAMESPACE_HID, },
1767 	{"", },
1768 };
1769 
1770 static int acpi_generic_device_attach(struct acpi_device *adev,
1771 				      const struct acpi_device_id *not_used)
1772 {
1773 	/*
1774 	 * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
1775 	 * below can be unconditional.
1776 	 */
1777 	if (adev->data.of_compatible)
1778 		acpi_default_enumeration(adev);
1779 
1780 	return 1;
1781 }
1782 
1783 static struct acpi_scan_handler generic_device_handler = {
1784 	.ids = generic_device_ids,
1785 	.attach = acpi_generic_device_attach,
1786 };
1787 
1788 static int acpi_scan_attach_handler(struct acpi_device *device)
1789 {
1790 	struct acpi_hardware_id *hwid;
1791 	int ret = 0;
1792 
1793 	list_for_each_entry(hwid, &device->pnp.ids, list) {
1794 		const struct acpi_device_id *devid;
1795 		struct acpi_scan_handler *handler;
1796 
1797 		handler = acpi_scan_match_handler(hwid->id, &devid);
1798 		if (handler) {
1799 			if (!handler->attach) {
1800 				device->pnp.type.platform_id = 0;
1801 				continue;
1802 			}
1803 			device->handler = handler;
1804 			ret = handler->attach(device, devid);
1805 			if (ret > 0)
1806 				break;
1807 
1808 			device->handler = NULL;
1809 			if (ret < 0)
1810 				break;
1811 		}
1812 	}
1813 
1814 	return ret;
1815 }
1816 
1817 static void acpi_bus_attach(struct acpi_device *device)
1818 {
1819 	struct acpi_device *child;
1820 	acpi_handle ejd;
1821 	int ret;
1822 
1823 	if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
1824 		register_dock_dependent_device(device, ejd);
1825 
1826 	acpi_bus_get_status(device);
1827 	/* Skip devices that are not present. */
1828 	if (!acpi_device_is_present(device)) {
1829 		acpi_device_clear_enumerated(device);
1830 		device->flags.power_manageable = 0;
1831 		return;
1832 	}
1833 	if (device->handler)
1834 		goto ok;
1835 
1836 	if (!device->flags.initialized) {
1837 		device->flags.power_manageable =
1838 			device->power.states[ACPI_STATE_D0].flags.valid;
1839 		if (acpi_bus_init_power(device))
1840 			device->flags.power_manageable = 0;
1841 
1842 		device->flags.initialized = true;
1843 	} else if (device->flags.visited) {
1844 		goto ok;
1845 	}
1846 
1847 	ret = acpi_scan_attach_handler(device);
1848 	if (ret < 0)
1849 		return;
1850 
1851 	device->flags.match_driver = true;
1852 	if (ret > 0) {
1853 		acpi_device_set_enumerated(device);
1854 		goto ok;
1855 	}
1856 
1857 	ret = device_attach(&device->dev);
1858 	if (ret < 0)
1859 		return;
1860 
1861 	if (device->pnp.type.platform_id)
1862 		acpi_default_enumeration(device);
1863 	else
1864 		acpi_device_set_enumerated(device);
1865 
1866  ok:
1867 	list_for_each_entry(child, &device->children, node)
1868 		acpi_bus_attach(child);
1869 
1870 	if (device->handler && device->handler->hotplug.notify_online)
1871 		device->handler->hotplug.notify_online(device);
1872 }
1873 
1874 void acpi_walk_dep_device_list(acpi_handle handle)
1875 {
1876 	struct acpi_dep_data *dep, *tmp;
1877 	struct acpi_device *adev;
1878 
1879 	mutex_lock(&acpi_dep_list_lock);
1880 	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
1881 		if (dep->master == handle) {
1882 			acpi_bus_get_device(dep->slave, &adev);
1883 			if (!adev)
1884 				continue;
1885 
1886 			adev->dep_unmet--;
1887 			if (!adev->dep_unmet)
1888 				acpi_bus_attach(adev);
1889 			list_del(&dep->node);
1890 			kfree(dep);
1891 		}
1892 	}
1893 	mutex_unlock(&acpi_dep_list_lock);
1894 }
1895 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
1896 
1897 /**
1898  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1899  * @handle: Root of the namespace scope to scan.
1900  *
1901  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1902  * found devices.
1903  *
1904  * If no devices were found, -ENODEV is returned, but it does not mean that
1905  * there has been a real error.  There just have been no suitable ACPI objects
1906  * in the table trunk from which the kernel could create a device and add an
1907  * appropriate driver.
1908  *
1909  * Must be called under acpi_scan_lock.
1910  */
1911 int acpi_bus_scan(acpi_handle handle)
1912 {
1913 	void *device = NULL;
1914 
1915 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1916 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1917 				    acpi_bus_check_add, NULL, NULL, &device);
1918 
1919 	if (device) {
1920 		acpi_bus_attach(device);
1921 		return 0;
1922 	}
1923 	return -ENODEV;
1924 }
1925 EXPORT_SYMBOL(acpi_bus_scan);
1926 
1927 /**
1928  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
1929  * @adev: Root of the ACPI namespace scope to walk.
1930  *
1931  * Must be called under acpi_scan_lock.
1932  */
1933 void acpi_bus_trim(struct acpi_device *adev)
1934 {
1935 	struct acpi_scan_handler *handler = adev->handler;
1936 	struct acpi_device *child;
1937 
1938 	list_for_each_entry_reverse(child, &adev->children, node)
1939 		acpi_bus_trim(child);
1940 
1941 	adev->flags.match_driver = false;
1942 	if (handler) {
1943 		if (handler->detach)
1944 			handler->detach(adev);
1945 
1946 		adev->handler = NULL;
1947 	} else {
1948 		device_release_driver(&adev->dev);
1949 	}
1950 	/*
1951 	 * Most likely, the device is going away, so put it into D3cold before
1952 	 * that.
1953 	 */
1954 	acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
1955 	adev->flags.initialized = false;
1956 	acpi_device_clear_enumerated(adev);
1957 }
1958 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1959 
1960 static int acpi_bus_scan_fixed(void)
1961 {
1962 	int result = 0;
1963 
1964 	/*
1965 	 * Enumerate all fixed-feature devices.
1966 	 */
1967 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1968 		struct acpi_device *device = NULL;
1969 
1970 		result = acpi_add_single_object(&device, NULL,
1971 						ACPI_BUS_TYPE_POWER_BUTTON,
1972 						ACPI_STA_DEFAULT);
1973 		if (result)
1974 			return result;
1975 
1976 		device->flags.match_driver = true;
1977 		result = device_attach(&device->dev);
1978 		if (result < 0)
1979 			return result;
1980 
1981 		device_init_wakeup(&device->dev, true);
1982 	}
1983 
1984 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
1985 		struct acpi_device *device = NULL;
1986 
1987 		result = acpi_add_single_object(&device, NULL,
1988 						ACPI_BUS_TYPE_SLEEP_BUTTON,
1989 						ACPI_STA_DEFAULT);
1990 		if (result)
1991 			return result;
1992 
1993 		device->flags.match_driver = true;
1994 		result = device_attach(&device->dev);
1995 	}
1996 
1997 	return result < 0 ? result : 0;
1998 }
1999 
2000 static void __init acpi_get_spcr_uart_addr(void)
2001 {
2002 	acpi_status status;
2003 	struct acpi_table_spcr *spcr_ptr;
2004 
2005 	status = acpi_get_table(ACPI_SIG_SPCR, 0,
2006 				(struct acpi_table_header **)&spcr_ptr);
2007 	if (ACPI_SUCCESS(status))
2008 		spcr_uart_addr = spcr_ptr->serial_port.address;
2009 	else
2010 		printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n");
2011 }
2012 
2013 static bool acpi_scan_initialized;
2014 
2015 int __init acpi_scan_init(void)
2016 {
2017 	int result;
2018 	acpi_status status;
2019 	struct acpi_table_stao *stao_ptr;
2020 
2021 	acpi_pci_root_init();
2022 	acpi_pci_link_init();
2023 	acpi_processor_init();
2024 	acpi_lpss_init();
2025 	acpi_apd_init();
2026 	acpi_cmos_rtc_init();
2027 	acpi_container_init();
2028 	acpi_memory_hotplug_init();
2029 	acpi_pnp_init();
2030 	acpi_int340x_thermal_init();
2031 	acpi_amba_init();
2032 	acpi_watchdog_init();
2033 
2034 	acpi_scan_add_handler(&generic_device_handler);
2035 
2036 	/*
2037 	 * If there is STAO table, check whether it needs to ignore the UART
2038 	 * device in SPCR table.
2039 	 */
2040 	status = acpi_get_table(ACPI_SIG_STAO, 0,
2041 				(struct acpi_table_header **)&stao_ptr);
2042 	if (ACPI_SUCCESS(status)) {
2043 		if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2044 			printk(KERN_INFO PREFIX "STAO Name List not yet supported.");
2045 
2046 		if (stao_ptr->ignore_uart)
2047 			acpi_get_spcr_uart_addr();
2048 	}
2049 
2050 	mutex_lock(&acpi_scan_lock);
2051 	/*
2052 	 * Enumerate devices in the ACPI namespace.
2053 	 */
2054 	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2055 	if (result)
2056 		goto out;
2057 
2058 	result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2059 	if (result)
2060 		goto out;
2061 
2062 	/* Fixed feature devices do not exist on HW-reduced platform */
2063 	if (!acpi_gbl_reduced_hardware) {
2064 		result = acpi_bus_scan_fixed();
2065 		if (result) {
2066 			acpi_detach_data(acpi_root->handle,
2067 					 acpi_scan_drop_device);
2068 			acpi_device_del(acpi_root);
2069 			put_device(&acpi_root->dev);
2070 			goto out;
2071 		}
2072 	}
2073 
2074 	acpi_gpe_apply_masked_gpes();
2075 	acpi_update_all_gpes();
2076 	acpi_ec_ecdt_start();
2077 
2078 	acpi_scan_initialized = true;
2079 
2080  out:
2081 	mutex_unlock(&acpi_scan_lock);
2082 	return result;
2083 }
2084 
2085 static struct acpi_probe_entry *ape;
2086 static int acpi_probe_count;
2087 static DEFINE_MUTEX(acpi_probe_mutex);
2088 
2089 static int __init acpi_match_madt(struct acpi_subtable_header *header,
2090 				  const unsigned long end)
2091 {
2092 	if (!ape->subtable_valid || ape->subtable_valid(header, ape))
2093 		if (!ape->probe_subtbl(header, end))
2094 			acpi_probe_count++;
2095 
2096 	return 0;
2097 }
2098 
2099 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2100 {
2101 	int count = 0;
2102 
2103 	if (acpi_disabled)
2104 		return 0;
2105 
2106 	mutex_lock(&acpi_probe_mutex);
2107 	for (ape = ap_head; nr; ape++, nr--) {
2108 		if (ACPI_COMPARE_NAME(ACPI_SIG_MADT, ape->id)) {
2109 			acpi_probe_count = 0;
2110 			acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2111 			count += acpi_probe_count;
2112 		} else {
2113 			int res;
2114 			res = acpi_table_parse(ape->id, ape->probe_table);
2115 			if (!res)
2116 				count++;
2117 		}
2118 	}
2119 	mutex_unlock(&acpi_probe_mutex);
2120 
2121 	return count;
2122 }
2123 
2124 struct acpi_table_events_work {
2125 	struct work_struct work;
2126 	void *table;
2127 	u32 event;
2128 };
2129 
2130 static void acpi_table_events_fn(struct work_struct *work)
2131 {
2132 	struct acpi_table_events_work *tew;
2133 
2134 	tew = container_of(work, struct acpi_table_events_work, work);
2135 
2136 	if (tew->event == ACPI_TABLE_EVENT_LOAD) {
2137 		acpi_scan_lock_acquire();
2138 		acpi_bus_scan(ACPI_ROOT_OBJECT);
2139 		acpi_scan_lock_release();
2140 	}
2141 
2142 	kfree(tew);
2143 }
2144 
2145 void acpi_scan_table_handler(u32 event, void *table, void *context)
2146 {
2147 	struct acpi_table_events_work *tew;
2148 
2149 	if (!acpi_scan_initialized)
2150 		return;
2151 
2152 	if (event != ACPI_TABLE_EVENT_LOAD)
2153 		return;
2154 
2155 	tew = kmalloc(sizeof(*tew), GFP_KERNEL);
2156 	if (!tew)
2157 		return;
2158 
2159 	INIT_WORK(&tew->work, acpi_table_events_fn);
2160 	tew->table = table;
2161 	tew->event = event;
2162 
2163 	schedule_work(&tew->work);
2164 }
2165 
2166 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2167 {
2168 	return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2169 }
2170 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2171 
2172 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2173 {
2174 	return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2175 }
2176 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);
2177