mm/hmm.c: remove superfluous RCU protection around radix tree lookup
[linux/fpc-iii.git] / drivers / acpi / scan.c
blobcc234e6a6297586a5c64b8252fb827474ae1e348
1 /*
2 * scan.c - support for transforming the ACPI namespace into individual objects
3 */
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 #include <linux/platform_data/x86/apple.h>
18 #include <asm/pgtable.h>
20 #include "internal.h"
22 #define _COMPONENT ACPI_BUS_COMPONENT
23 ACPI_MODULE_NAME("scan");
24 extern struct acpi_device *acpi_root;
26 #define ACPI_BUS_CLASS "system_bus"
27 #define ACPI_BUS_HID "LNXSYBUS"
28 #define ACPI_BUS_DEVICE_NAME "System Bus"
30 #define ACPI_IS_ROOT_DEVICE(device) (!(device)->parent)
32 #define INVALID_ACPI_HANDLE ((acpi_handle)empty_zero_page)
34 static const char *dummy_hid = "device";
36 static LIST_HEAD(acpi_dep_list);
37 static DEFINE_MUTEX(acpi_dep_list_lock);
38 LIST_HEAD(acpi_bus_id_list);
39 static DEFINE_MUTEX(acpi_scan_lock);
40 static LIST_HEAD(acpi_scan_handlers_list);
41 DEFINE_MUTEX(acpi_device_lock);
42 LIST_HEAD(acpi_wakeup_device_list);
43 static DEFINE_MUTEX(acpi_hp_context_lock);
46 * The UART device described by the SPCR table is the only object which needs
47 * special-casing. Everything else is covered by ACPI namespace paths in STAO
48 * table.
50 static u64 spcr_uart_addr;
52 struct acpi_dep_data {
53 struct list_head node;
54 acpi_handle master;
55 acpi_handle slave;
58 void acpi_scan_lock_acquire(void)
60 mutex_lock(&acpi_scan_lock);
62 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
64 void acpi_scan_lock_release(void)
66 mutex_unlock(&acpi_scan_lock);
68 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
70 void acpi_lock_hp_context(void)
72 mutex_lock(&acpi_hp_context_lock);
75 void acpi_unlock_hp_context(void)
77 mutex_unlock(&acpi_hp_context_lock);
80 void acpi_initialize_hp_context(struct acpi_device *adev,
81 struct acpi_hotplug_context *hp,
82 int (*notify)(struct acpi_device *, u32),
83 void (*uevent)(struct acpi_device *, u32))
85 acpi_lock_hp_context();
86 hp->notify = notify;
87 hp->uevent = uevent;
88 acpi_set_hp_context(adev, hp);
89 acpi_unlock_hp_context();
91 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
93 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
95 if (!handler)
96 return -EINVAL;
98 list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
99 return 0;
102 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
103 const char *hotplug_profile_name)
105 int error;
107 error = acpi_scan_add_handler(handler);
108 if (error)
109 return error;
111 acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
112 return 0;
115 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
117 struct acpi_device_physical_node *pn;
118 bool offline = true;
119 char *envp[] = { "EVENT=offline", NULL };
122 * acpi_container_offline() calls this for all of the container's
123 * children under the container's physical_node_lock lock.
125 mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
127 list_for_each_entry(pn, &adev->physical_node_list, node)
128 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
129 if (uevent)
130 kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);
132 offline = false;
133 break;
136 mutex_unlock(&adev->physical_node_lock);
137 return offline;
140 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
141 void **ret_p)
143 struct acpi_device *device = NULL;
144 struct acpi_device_physical_node *pn;
145 bool second_pass = (bool)data;
146 acpi_status status = AE_OK;
148 if (acpi_bus_get_device(handle, &device))
149 return AE_OK;
151 if (device->handler && !device->handler->hotplug.enabled) {
152 *ret_p = &device->dev;
153 return AE_SUPPORT;
156 mutex_lock(&device->physical_node_lock);
158 list_for_each_entry(pn, &device->physical_node_list, node) {
159 int ret;
161 if (second_pass) {
162 /* Skip devices offlined by the first pass. */
163 if (pn->put_online)
164 continue;
165 } else {
166 pn->put_online = false;
168 ret = device_offline(pn->dev);
169 if (ret >= 0) {
170 pn->put_online = !ret;
171 } else {
172 *ret_p = pn->dev;
173 if (second_pass) {
174 status = AE_ERROR;
175 break;
180 mutex_unlock(&device->physical_node_lock);
182 return status;
185 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
186 void **ret_p)
188 struct acpi_device *device = NULL;
189 struct acpi_device_physical_node *pn;
191 if (acpi_bus_get_device(handle, &device))
192 return AE_OK;
194 mutex_lock(&device->physical_node_lock);
196 list_for_each_entry(pn, &device->physical_node_list, node)
197 if (pn->put_online) {
198 device_online(pn->dev);
199 pn->put_online = false;
202 mutex_unlock(&device->physical_node_lock);
204 return AE_OK;
207 static int acpi_scan_try_to_offline(struct acpi_device *device)
209 acpi_handle handle = device->handle;
210 struct device *errdev = NULL;
211 acpi_status status;
214 * Carry out two passes here and ignore errors in the first pass,
215 * because if the devices in question are memory blocks and
216 * CONFIG_MEMCG is set, one of the blocks may hold data structures
217 * that the other blocks depend on, but it is not known in advance which
218 * block holds them.
220 * If the first pass is successful, the second one isn't needed, though.
222 status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
223 NULL, acpi_bus_offline, (void *)false,
224 (void **)&errdev);
225 if (status == AE_SUPPORT) {
226 dev_warn(errdev, "Offline disabled.\n");
227 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
228 acpi_bus_online, NULL, NULL, NULL);
229 return -EPERM;
231 acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
232 if (errdev) {
233 errdev = NULL;
234 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
235 NULL, acpi_bus_offline, (void *)true,
236 (void **)&errdev);
237 if (!errdev)
238 acpi_bus_offline(handle, 0, (void *)true,
239 (void **)&errdev);
241 if (errdev) {
242 dev_warn(errdev, "Offline failed.\n");
243 acpi_bus_online(handle, 0, NULL, NULL);
244 acpi_walk_namespace(ACPI_TYPE_ANY, handle,
245 ACPI_UINT32_MAX, acpi_bus_online,
246 NULL, NULL, NULL);
247 return -EBUSY;
250 return 0;
253 static int acpi_scan_hot_remove(struct acpi_device *device)
255 acpi_handle handle = device->handle;
256 unsigned long long sta;
257 acpi_status status;
259 if (device->handler && device->handler->hotplug.demand_offline) {
260 if (!acpi_scan_is_offline(device, true))
261 return -EBUSY;
262 } else {
263 int error = acpi_scan_try_to_offline(device);
264 if (error)
265 return error;
268 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
269 "Hot-removing device %s...\n", dev_name(&device->dev)));
271 acpi_bus_trim(device);
273 acpi_evaluate_lck(handle, 0);
275 * TBD: _EJD support.
277 status = acpi_evaluate_ej0(handle);
278 if (status == AE_NOT_FOUND)
279 return -ENODEV;
280 else if (ACPI_FAILURE(status))
281 return -EIO;
284 * Verify if eject was indeed successful. If not, log an error
285 * message. No need to call _OST since _EJ0 call was made OK.
287 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
288 if (ACPI_FAILURE(status)) {
289 acpi_handle_warn(handle,
290 "Status check after eject failed (0x%x)\n", status);
291 } else if (sta & ACPI_STA_DEVICE_ENABLED) {
292 acpi_handle_warn(handle,
293 "Eject incomplete - status 0x%llx\n", sta);
296 return 0;
299 static int acpi_scan_device_not_present(struct acpi_device *adev)
301 if (!acpi_device_enumerated(adev)) {
302 dev_warn(&adev->dev, "Still not present\n");
303 return -EALREADY;
305 acpi_bus_trim(adev);
306 return 0;
309 static int acpi_scan_device_check(struct acpi_device *adev)
311 int error;
313 acpi_bus_get_status(adev);
314 if (adev->status.present || adev->status.functional) {
316 * This function is only called for device objects for which
317 * matching scan handlers exist. The only situation in which
318 * the scan handler is not attached to this device object yet
319 * is when the device has just appeared (either it wasn't
320 * present at all before or it was removed and then added
321 * again).
323 if (adev->handler) {
324 dev_warn(&adev->dev, "Already enumerated\n");
325 return -EALREADY;
327 error = acpi_bus_scan(adev->handle);
328 if (error) {
329 dev_warn(&adev->dev, "Namespace scan failure\n");
330 return error;
332 if (!adev->handler) {
333 dev_warn(&adev->dev, "Enumeration failure\n");
334 error = -ENODEV;
336 } else {
337 error = acpi_scan_device_not_present(adev);
339 return error;
342 static int acpi_scan_bus_check(struct acpi_device *adev)
344 struct acpi_scan_handler *handler = adev->handler;
345 struct acpi_device *child;
346 int error;
348 acpi_bus_get_status(adev);
349 if (!(adev->status.present || adev->status.functional)) {
350 acpi_scan_device_not_present(adev);
351 return 0;
353 if (handler && handler->hotplug.scan_dependent)
354 return handler->hotplug.scan_dependent(adev);
356 error = acpi_bus_scan(adev->handle);
357 if (error) {
358 dev_warn(&adev->dev, "Namespace scan failure\n");
359 return error;
361 list_for_each_entry(child, &adev->children, node) {
362 error = acpi_scan_bus_check(child);
363 if (error)
364 return error;
366 return 0;
369 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
371 switch (type) {
372 case ACPI_NOTIFY_BUS_CHECK:
373 return acpi_scan_bus_check(adev);
374 case ACPI_NOTIFY_DEVICE_CHECK:
375 return acpi_scan_device_check(adev);
376 case ACPI_NOTIFY_EJECT_REQUEST:
377 case ACPI_OST_EC_OSPM_EJECT:
378 if (adev->handler && !adev->handler->hotplug.enabled) {
379 dev_info(&adev->dev, "Eject disabled\n");
380 return -EPERM;
382 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
383 ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
384 return acpi_scan_hot_remove(adev);
386 return -EINVAL;
389 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
391 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
392 int error = -ENODEV;
394 lock_device_hotplug();
395 mutex_lock(&acpi_scan_lock);
398 * The device object's ACPI handle cannot become invalid as long as we
399 * are holding acpi_scan_lock, but it might have become invalid before
400 * that lock was acquired.
402 if (adev->handle == INVALID_ACPI_HANDLE)
403 goto err_out;
405 if (adev->flags.is_dock_station) {
406 error = dock_notify(adev, src);
407 } else if (adev->flags.hotplug_notify) {
408 error = acpi_generic_hotplug_event(adev, src);
409 } else {
410 int (*notify)(struct acpi_device *, u32);
412 acpi_lock_hp_context();
413 notify = adev->hp ? adev->hp->notify : NULL;
414 acpi_unlock_hp_context();
416 * There may be additional notify handlers for device objects
417 * without the .event() callback, so ignore them here.
419 if (notify)
420 error = notify(adev, src);
421 else
422 goto out;
424 switch (error) {
425 case 0:
426 ost_code = ACPI_OST_SC_SUCCESS;
427 break;
428 case -EPERM:
429 ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
430 break;
431 case -EBUSY:
432 ost_code = ACPI_OST_SC_DEVICE_BUSY;
433 break;
434 default:
435 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
436 break;
439 err_out:
440 acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
442 out:
443 acpi_bus_put_acpi_device(adev);
444 mutex_unlock(&acpi_scan_lock);
445 unlock_device_hotplug();
448 static void acpi_free_power_resources_lists(struct acpi_device *device)
450 int i;
452 if (device->wakeup.flags.valid)
453 acpi_power_resources_list_free(&device->wakeup.resources);
455 if (!device->power.flags.power_resources)
456 return;
458 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
459 struct acpi_device_power_state *ps = &device->power.states[i];
460 acpi_power_resources_list_free(&ps->resources);
464 static void acpi_device_release(struct device *dev)
466 struct acpi_device *acpi_dev = to_acpi_device(dev);
468 acpi_free_properties(acpi_dev);
469 acpi_free_pnp_ids(&acpi_dev->pnp);
470 acpi_free_power_resources_lists(acpi_dev);
471 kfree(acpi_dev);
474 static void acpi_device_del(struct acpi_device *device)
476 struct acpi_device_bus_id *acpi_device_bus_id;
478 mutex_lock(&acpi_device_lock);
479 if (device->parent)
480 list_del(&device->node);
482 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
483 if (!strcmp(acpi_device_bus_id->bus_id,
484 acpi_device_hid(device))) {
485 if (acpi_device_bus_id->instance_no > 0)
486 acpi_device_bus_id->instance_no--;
487 else {
488 list_del(&acpi_device_bus_id->node);
489 kfree(acpi_device_bus_id);
491 break;
494 list_del(&device->wakeup_list);
495 mutex_unlock(&acpi_device_lock);
497 acpi_power_add_remove_device(device, false);
498 acpi_device_remove_files(device);
499 if (device->remove)
500 device->remove(device);
502 device_del(&device->dev);
505 static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);
507 static LIST_HEAD(acpi_device_del_list);
508 static DEFINE_MUTEX(acpi_device_del_lock);
510 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
512 for (;;) {
513 struct acpi_device *adev;
515 mutex_lock(&acpi_device_del_lock);
517 if (list_empty(&acpi_device_del_list)) {
518 mutex_unlock(&acpi_device_del_lock);
519 break;
521 adev = list_first_entry(&acpi_device_del_list,
522 struct acpi_device, del_list);
523 list_del(&adev->del_list);
525 mutex_unlock(&acpi_device_del_lock);
527 blocking_notifier_call_chain(&acpi_reconfig_chain,
528 ACPI_RECONFIG_DEVICE_REMOVE, adev);
530 acpi_device_del(adev);
532 * Drop references to all power resources that might have been
533 * used by the device.
535 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
536 put_device(&adev->dev);
541 * acpi_scan_drop_device - Drop an ACPI device object.
542 * @handle: Handle of an ACPI namespace node, not used.
543 * @context: Address of the ACPI device object to drop.
545 * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
546 * namespace node the device object pointed to by @context is attached to.
548 * The unregistration is carried out asynchronously to avoid running
549 * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
550 * ensure the correct ordering (the device objects must be unregistered in the
551 * same order in which the corresponding namespace nodes are deleted).
553 static void acpi_scan_drop_device(acpi_handle handle, void *context)
555 static DECLARE_WORK(work, acpi_device_del_work_fn);
556 struct acpi_device *adev = context;
558 mutex_lock(&acpi_device_del_lock);
561 * Use the ACPI hotplug workqueue which is ordered, so this work item
562 * won't run after any hotplug work items submitted subsequently. That
563 * prevents attempts to register device objects identical to those being
564 * deleted from happening concurrently (such attempts result from
565 * hotplug events handled via the ACPI hotplug workqueue). It also will
566 * run after all of the work items submitted previosuly, which helps
567 * those work items to ensure that they are not accessing stale device
568 * objects.
570 if (list_empty(&acpi_device_del_list))
571 acpi_queue_hotplug_work(&work);
573 list_add_tail(&adev->del_list, &acpi_device_del_list);
574 /* Make acpi_ns_validate_handle() return NULL for this handle. */
575 adev->handle = INVALID_ACPI_HANDLE;
577 mutex_unlock(&acpi_device_del_lock);
580 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
581 void (*callback)(void *))
583 acpi_status status;
585 if (!device)
586 return -EINVAL;
588 status = acpi_get_data_full(handle, acpi_scan_drop_device,
589 (void **)device, callback);
590 if (ACPI_FAILURE(status) || !*device) {
591 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
592 handle));
593 return -ENODEV;
595 return 0;
598 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
600 return acpi_get_device_data(handle, device, NULL);
602 EXPORT_SYMBOL(acpi_bus_get_device);
604 static void get_acpi_device(void *dev)
606 if (dev)
607 get_device(&((struct acpi_device *)dev)->dev);
610 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
612 struct acpi_device *adev = NULL;
614 acpi_get_device_data(handle, &adev, get_acpi_device);
615 return adev;
618 void acpi_bus_put_acpi_device(struct acpi_device *adev)
620 put_device(&adev->dev);
623 int acpi_device_add(struct acpi_device *device,
624 void (*release)(struct device *))
626 int result;
627 struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
628 int found = 0;
630 if (device->handle) {
631 acpi_status status;
633 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
634 device);
635 if (ACPI_FAILURE(status)) {
636 acpi_handle_err(device->handle,
637 "Unable to attach device data\n");
638 return -ENODEV;
643 * Linkage
644 * -------
645 * Link this device to its parent and siblings.
647 INIT_LIST_HEAD(&device->children);
648 INIT_LIST_HEAD(&device->node);
649 INIT_LIST_HEAD(&device->wakeup_list);
650 INIT_LIST_HEAD(&device->physical_node_list);
651 INIT_LIST_HEAD(&device->del_list);
652 mutex_init(&device->physical_node_lock);
654 new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
655 if (!new_bus_id) {
656 pr_err(PREFIX "Memory allocation error\n");
657 result = -ENOMEM;
658 goto err_detach;
661 mutex_lock(&acpi_device_lock);
663 * Find suitable bus_id and instance number in acpi_bus_id_list
664 * If failed, create one and link it into acpi_bus_id_list
666 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
667 if (!strcmp(acpi_device_bus_id->bus_id,
668 acpi_device_hid(device))) {
669 acpi_device_bus_id->instance_no++;
670 found = 1;
671 kfree(new_bus_id);
672 break;
675 if (!found) {
676 acpi_device_bus_id = new_bus_id;
677 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
678 acpi_device_bus_id->instance_no = 0;
679 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
681 dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
683 if (device->parent)
684 list_add_tail(&device->node, &device->parent->children);
686 if (device->wakeup.flags.valid)
687 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
688 mutex_unlock(&acpi_device_lock);
690 if (device->parent)
691 device->dev.parent = &device->parent->dev;
692 device->dev.bus = &acpi_bus_type;
693 device->dev.release = release;
694 result = device_add(&device->dev);
695 if (result) {
696 dev_err(&device->dev, "Error registering device\n");
697 goto err;
700 result = acpi_device_setup_files(device);
701 if (result)
702 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
703 dev_name(&device->dev));
705 return 0;
707 err:
708 mutex_lock(&acpi_device_lock);
709 if (device->parent)
710 list_del(&device->node);
711 list_del(&device->wakeup_list);
712 mutex_unlock(&acpi_device_lock);
714 err_detach:
715 acpi_detach_data(device->handle, acpi_scan_drop_device);
716 return result;
719 /* --------------------------------------------------------------------------
720 Device Enumeration
721 -------------------------------------------------------------------------- */
722 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
724 struct acpi_device *device = NULL;
725 acpi_status status;
728 * Fixed hardware devices do not appear in the namespace and do not
729 * have handles, but we fabricate acpi_devices for them, so we have
730 * to deal with them specially.
732 if (!handle)
733 return acpi_root;
735 do {
736 status = acpi_get_parent(handle, &handle);
737 if (ACPI_FAILURE(status))
738 return status == AE_NULL_ENTRY ? NULL : acpi_root;
739 } while (acpi_bus_get_device(handle, &device));
740 return device;
743 acpi_status
744 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
746 acpi_status status;
747 acpi_handle tmp;
748 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
749 union acpi_object *obj;
751 status = acpi_get_handle(handle, "_EJD", &tmp);
752 if (ACPI_FAILURE(status))
753 return status;
755 status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
756 if (ACPI_SUCCESS(status)) {
757 obj = buffer.pointer;
758 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
759 ejd);
760 kfree(buffer.pointer);
762 return status;
764 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
766 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
767 struct acpi_device_wakeup *wakeup)
769 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
770 union acpi_object *package = NULL;
771 union acpi_object *element = NULL;
772 acpi_status status;
773 int err = -ENODATA;
775 if (!wakeup)
776 return -EINVAL;
778 INIT_LIST_HEAD(&wakeup->resources);
780 /* _PRW */
781 status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
782 if (ACPI_FAILURE(status)) {
783 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
784 return err;
787 package = (union acpi_object *)buffer.pointer;
789 if (!package || package->package.count < 2)
790 goto out;
792 element = &(package->package.elements[0]);
793 if (!element)
794 goto out;
796 if (element->type == ACPI_TYPE_PACKAGE) {
797 if ((element->package.count < 2) ||
798 (element->package.elements[0].type !=
799 ACPI_TYPE_LOCAL_REFERENCE)
800 || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
801 goto out;
803 wakeup->gpe_device =
804 element->package.elements[0].reference.handle;
805 wakeup->gpe_number =
806 (u32) element->package.elements[1].integer.value;
807 } else if (element->type == ACPI_TYPE_INTEGER) {
808 wakeup->gpe_device = NULL;
809 wakeup->gpe_number = element->integer.value;
810 } else {
811 goto out;
814 element = &(package->package.elements[1]);
815 if (element->type != ACPI_TYPE_INTEGER)
816 goto out;
818 wakeup->sleep_state = element->integer.value;
820 err = acpi_extract_power_resources(package, 2, &wakeup->resources);
821 if (err)
822 goto out;
824 if (!list_empty(&wakeup->resources)) {
825 int sleep_state;
827 err = acpi_power_wakeup_list_init(&wakeup->resources,
828 &sleep_state);
829 if (err) {
830 acpi_handle_warn(handle, "Retrieving current states "
831 "of wakeup power resources failed\n");
832 acpi_power_resources_list_free(&wakeup->resources);
833 goto out;
835 if (sleep_state < wakeup->sleep_state) {
836 acpi_handle_warn(handle, "Overriding _PRW sleep state "
837 "(S%d) by S%d from power resources\n",
838 (int)wakeup->sleep_state, sleep_state);
839 wakeup->sleep_state = sleep_state;
843 out:
844 kfree(buffer.pointer);
845 return err;
848 static bool acpi_wakeup_gpe_init(struct acpi_device *device)
850 static const struct acpi_device_id button_device_ids[] = {
851 {"PNP0C0C", 0},
852 {"PNP0C0D", 0},
853 {"PNP0C0E", 0},
854 {"", 0},
856 struct acpi_device_wakeup *wakeup = &device->wakeup;
857 acpi_status status;
859 wakeup->flags.notifier_present = 0;
861 /* Power button, Lid switch always enable wakeup */
862 if (!acpi_match_device_ids(device, button_device_ids)) {
863 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
864 /* Do not use Lid/sleep button for S5 wakeup */
865 if (wakeup->sleep_state == ACPI_STATE_S5)
866 wakeup->sleep_state = ACPI_STATE_S4;
868 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
869 device_set_wakeup_capable(&device->dev, true);
870 return true;
873 status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
874 wakeup->gpe_number);
875 return ACPI_SUCCESS(status);
878 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
880 int err;
882 /* Presence of _PRW indicates wake capable */
883 if (!acpi_has_method(device->handle, "_PRW"))
884 return;
886 err = acpi_bus_extract_wakeup_device_power_package(device->handle,
887 &device->wakeup);
888 if (err) {
889 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
890 return;
893 device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
894 device->wakeup.prepare_count = 0;
896 * Call _PSW/_DSW object to disable its ability to wake the sleeping
897 * system for the ACPI device with the _PRW object.
898 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
899 * So it is necessary to call _DSW object first. Only when it is not
900 * present will the _PSW object used.
902 err = acpi_device_sleep_wake(device, 0, 0, 0);
903 if (err)
904 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
905 "error in _DSW or _PSW evaluation\n"));
908 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
910 struct acpi_device_power_state *ps = &device->power.states[state];
911 char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
912 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
913 acpi_status status;
915 INIT_LIST_HEAD(&ps->resources);
917 /* Evaluate "_PRx" to get referenced power resources */
918 status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
919 if (ACPI_SUCCESS(status)) {
920 union acpi_object *package = buffer.pointer;
922 if (buffer.length && package
923 && package->type == ACPI_TYPE_PACKAGE
924 && package->package.count) {
925 int err = acpi_extract_power_resources(package, 0,
926 &ps->resources);
927 if (!err)
928 device->power.flags.power_resources = 1;
930 ACPI_FREE(buffer.pointer);
933 /* Evaluate "_PSx" to see if we can do explicit sets */
934 pathname[2] = 'S';
935 if (acpi_has_method(device->handle, pathname))
936 ps->flags.explicit_set = 1;
938 /* State is valid if there are means to put the device into it. */
939 if (!list_empty(&ps->resources) || ps->flags.explicit_set)
940 ps->flags.valid = 1;
942 ps->power = -1; /* Unknown - driver assigned */
943 ps->latency = -1; /* Unknown - driver assigned */
946 static void acpi_bus_get_power_flags(struct acpi_device *device)
948 u32 i;
950 /* Presence of _PS0|_PR0 indicates 'power manageable' */
951 if (!acpi_has_method(device->handle, "_PS0") &&
952 !acpi_has_method(device->handle, "_PR0"))
953 return;
955 device->flags.power_manageable = 1;
958 * Power Management Flags
960 if (acpi_has_method(device->handle, "_PSC"))
961 device->power.flags.explicit_get = 1;
963 if (acpi_has_method(device->handle, "_IRC"))
964 device->power.flags.inrush_current = 1;
966 if (acpi_has_method(device->handle, "_DSW"))
967 device->power.flags.dsw_present = 1;
970 * Enumerate supported power management states
972 for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
973 acpi_bus_init_power_state(device, i);
975 INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
976 if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
977 device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
979 /* Set defaults for D0 and D3hot states (always valid) */
980 device->power.states[ACPI_STATE_D0].flags.valid = 1;
981 device->power.states[ACPI_STATE_D0].power = 100;
982 device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
984 if (acpi_bus_init_power(device))
985 device->flags.power_manageable = 0;
988 static void acpi_bus_get_flags(struct acpi_device *device)
990 /* Presence of _STA indicates 'dynamic_status' */
991 if (acpi_has_method(device->handle, "_STA"))
992 device->flags.dynamic_status = 1;
994 /* Presence of _RMV indicates 'removable' */
995 if (acpi_has_method(device->handle, "_RMV"))
996 device->flags.removable = 1;
998 /* Presence of _EJD|_EJ0 indicates 'ejectable' */
999 if (acpi_has_method(device->handle, "_EJD") ||
1000 acpi_has_method(device->handle, "_EJ0"))
1001 device->flags.ejectable = 1;
1004 static void acpi_device_get_busid(struct acpi_device *device)
1006 char bus_id[5] = { '?', 0 };
1007 struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1008 int i = 0;
1011 * Bus ID
1012 * ------
1013 * The device's Bus ID is simply the object name.
1014 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1016 if (ACPI_IS_ROOT_DEVICE(device)) {
1017 strcpy(device->pnp.bus_id, "ACPI");
1018 return;
1021 switch (device->device_type) {
1022 case ACPI_BUS_TYPE_POWER_BUTTON:
1023 strcpy(device->pnp.bus_id, "PWRF");
1024 break;
1025 case ACPI_BUS_TYPE_SLEEP_BUTTON:
1026 strcpy(device->pnp.bus_id, "SLPF");
1027 break;
1028 case ACPI_BUS_TYPE_ECDT_EC:
1029 strcpy(device->pnp.bus_id, "ECDT");
1030 break;
1031 default:
1032 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1033 /* Clean up trailing underscores (if any) */
1034 for (i = 3; i > 1; i--) {
1035 if (bus_id[i] == '_')
1036 bus_id[i] = '\0';
1037 else
1038 break;
1040 strcpy(device->pnp.bus_id, bus_id);
1041 break;
1046 * acpi_ata_match - see if an acpi object is an ATA device
1048 * If an acpi object has one of the ACPI ATA methods defined,
1049 * then we can safely call it an ATA device.
1051 bool acpi_ata_match(acpi_handle handle)
1053 return acpi_has_method(handle, "_GTF") ||
1054 acpi_has_method(handle, "_GTM") ||
1055 acpi_has_method(handle, "_STM") ||
1056 acpi_has_method(handle, "_SDD");
1060 * acpi_bay_match - see if an acpi object is an ejectable driver bay
1062 * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1063 * then we can safely call it an ejectable drive bay
1065 bool acpi_bay_match(acpi_handle handle)
1067 acpi_handle phandle;
1069 if (!acpi_has_method(handle, "_EJ0"))
1070 return false;
1071 if (acpi_ata_match(handle))
1072 return true;
1073 if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1074 return false;
1076 return acpi_ata_match(phandle);
1079 bool acpi_device_is_battery(struct acpi_device *adev)
1081 struct acpi_hardware_id *hwid;
1083 list_for_each_entry(hwid, &adev->pnp.ids, list)
1084 if (!strcmp("PNP0C0A", hwid->id))
1085 return true;
1087 return false;
1090 static bool is_ejectable_bay(struct acpi_device *adev)
1092 acpi_handle handle = adev->handle;
1094 if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1095 return true;
1097 return acpi_bay_match(handle);
1101 * acpi_dock_match - see if an acpi object has a _DCK method
1103 bool acpi_dock_match(acpi_handle handle)
1105 return acpi_has_method(handle, "_DCK");
1108 static acpi_status
1109 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1110 void **return_value)
1112 long *cap = context;
1114 if (acpi_has_method(handle, "_BCM") &&
1115 acpi_has_method(handle, "_BCL")) {
1116 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1117 "support\n"));
1118 *cap |= ACPI_VIDEO_BACKLIGHT;
1119 /* We have backlight support, no need to scan further */
1120 return AE_CTRL_TERMINATE;
1122 return 0;
1125 /* Returns true if the ACPI object is a video device which can be
1126 * handled by video.ko.
1127 * The device will get a Linux specific CID added in scan.c to
1128 * identify the device as an ACPI graphics device
1129 * Be aware that the graphics device may not be physically present
1130 * Use acpi_video_get_capabilities() to detect general ACPI video
1131 * capabilities of present cards
1133 long acpi_is_video_device(acpi_handle handle)
1135 long video_caps = 0;
1137 /* Is this device able to support video switching ? */
1138 if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1139 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
1141 /* Is this device able to retrieve a video ROM ? */
1142 if (acpi_has_method(handle, "_ROM"))
1143 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
1145 /* Is this device able to configure which video head to be POSTed ? */
1146 if (acpi_has_method(handle, "_VPO") &&
1147 acpi_has_method(handle, "_GPD") &&
1148 acpi_has_method(handle, "_SPD"))
1149 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
1151 /* Only check for backlight functionality if one of the above hit. */
1152 if (video_caps)
1153 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
1154 ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
1155 &video_caps, NULL);
1157 return video_caps;
1159 EXPORT_SYMBOL(acpi_is_video_device);
1161 const char *acpi_device_hid(struct acpi_device *device)
1163 struct acpi_hardware_id *hid;
1165 if (list_empty(&device->pnp.ids))
1166 return dummy_hid;
1168 hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1169 return hid->id;
1171 EXPORT_SYMBOL(acpi_device_hid);
1173 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1175 struct acpi_hardware_id *id;
1177 id = kmalloc(sizeof(*id), GFP_KERNEL);
1178 if (!id)
1179 return;
1181 id->id = kstrdup_const(dev_id, GFP_KERNEL);
1182 if (!id->id) {
1183 kfree(id);
1184 return;
1187 list_add_tail(&id->list, &pnp->ids);
1188 pnp->type.hardware_id = 1;
1192 * Old IBM workstations have a DSDT bug wherein the SMBus object
1193 * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1194 * prefix. Work around this.
1196 static bool acpi_ibm_smbus_match(acpi_handle handle)
1198 char node_name[ACPI_PATH_SEGMENT_LENGTH];
1199 struct acpi_buffer path = { sizeof(node_name), node_name };
1201 if (!dmi_name_in_vendors("IBM"))
1202 return false;
1204 /* Look for SMBS object */
1205 if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1206 strcmp("SMBS", path.pointer))
1207 return false;
1209 /* Does it have the necessary (but misnamed) methods? */
1210 if (acpi_has_method(handle, "SBI") &&
1211 acpi_has_method(handle, "SBR") &&
1212 acpi_has_method(handle, "SBW"))
1213 return true;
1215 return false;
1218 static bool acpi_object_is_system_bus(acpi_handle handle)
1220 acpi_handle tmp;
1222 if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
1223 tmp == handle)
1224 return true;
1225 if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
1226 tmp == handle)
1227 return true;
1229 return false;
1232 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1233 int device_type)
1235 acpi_status status;
1236 struct acpi_device_info *info;
1237 struct acpi_pnp_device_id_list *cid_list;
1238 int i;
1240 switch (device_type) {
1241 case ACPI_BUS_TYPE_DEVICE:
1242 if (handle == ACPI_ROOT_OBJECT) {
1243 acpi_add_id(pnp, ACPI_SYSTEM_HID);
1244 break;
1247 status = acpi_get_object_info(handle, &info);
1248 if (ACPI_FAILURE(status)) {
1249 pr_err(PREFIX "%s: Error reading device info\n",
1250 __func__);
1251 return;
1254 if (info->valid & ACPI_VALID_HID) {
1255 acpi_add_id(pnp, info->hardware_id.string);
1256 pnp->type.platform_id = 1;
1258 if (info->valid & ACPI_VALID_CID) {
1259 cid_list = &info->compatible_id_list;
1260 for (i = 0; i < cid_list->count; i++)
1261 acpi_add_id(pnp, cid_list->ids[i].string);
1263 if (info->valid & ACPI_VALID_ADR) {
1264 pnp->bus_address = info->address;
1265 pnp->type.bus_address = 1;
1267 if (info->valid & ACPI_VALID_UID)
1268 pnp->unique_id = kstrdup(info->unique_id.string,
1269 GFP_KERNEL);
1270 if (info->valid & ACPI_VALID_CLS)
1271 acpi_add_id(pnp, info->class_code.string);
1273 kfree(info);
1276 * Some devices don't reliably have _HIDs & _CIDs, so add
1277 * synthetic HIDs to make sure drivers can find them.
1279 if (acpi_is_video_device(handle))
1280 acpi_add_id(pnp, ACPI_VIDEO_HID);
1281 else if (acpi_bay_match(handle))
1282 acpi_add_id(pnp, ACPI_BAY_HID);
1283 else if (acpi_dock_match(handle))
1284 acpi_add_id(pnp, ACPI_DOCK_HID);
1285 else if (acpi_ibm_smbus_match(handle))
1286 acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1287 else if (list_empty(&pnp->ids) &&
1288 acpi_object_is_system_bus(handle)) {
1289 /* \_SB, \_TZ, LNXSYBUS */
1290 acpi_add_id(pnp, ACPI_BUS_HID);
1291 strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1292 strcpy(pnp->device_class, ACPI_BUS_CLASS);
1295 break;
1296 case ACPI_BUS_TYPE_POWER:
1297 acpi_add_id(pnp, ACPI_POWER_HID);
1298 break;
1299 case ACPI_BUS_TYPE_PROCESSOR:
1300 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1301 break;
1302 case ACPI_BUS_TYPE_THERMAL:
1303 acpi_add_id(pnp, ACPI_THERMAL_HID);
1304 break;
1305 case ACPI_BUS_TYPE_POWER_BUTTON:
1306 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1307 break;
1308 case ACPI_BUS_TYPE_SLEEP_BUTTON:
1309 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1310 break;
1311 case ACPI_BUS_TYPE_ECDT_EC:
1312 acpi_add_id(pnp, ACPI_ECDT_HID);
1313 break;
1317 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1319 struct acpi_hardware_id *id, *tmp;
1321 list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1322 kfree_const(id->id);
1323 kfree(id);
1325 kfree(pnp->unique_id);
1329 * acpi_dma_supported - Check DMA support for the specified device.
1330 * @adev: The pointer to acpi device
1332 * Return false if DMA is not supported. Otherwise, return true
1334 bool acpi_dma_supported(struct acpi_device *adev)
1336 if (!adev)
1337 return false;
1339 if (adev->flags.cca_seen)
1340 return true;
1343 * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
1344 * DMA on "Intel platforms". Presumably that includes all x86 and
1345 * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
1347 if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1348 return true;
1350 return false;
1354 * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
1355 * @adev: The pointer to acpi device
1357 * Return enum dev_dma_attr.
1359 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
1361 if (!acpi_dma_supported(adev))
1362 return DEV_DMA_NOT_SUPPORTED;
1364 if (adev->flags.coherent_dma)
1365 return DEV_DMA_COHERENT;
1366 else
1367 return DEV_DMA_NON_COHERENT;
1371 * acpi_dma_get_range() - Get device DMA parameters.
1373 * @dev: device to configure
1374 * @dma_addr: pointer device DMA address result
1375 * @offset: pointer to the DMA offset result
1376 * @size: pointer to DMA range size result
1378 * Evaluate DMA regions and return respectively DMA region start, offset
1379 * and size in dma_addr, offset and size on parsing success; it does not
1380 * update the passed in values on failure.
1382 * Return 0 on success, < 0 on failure.
1384 int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
1385 u64 *size)
1387 struct acpi_device *adev;
1388 LIST_HEAD(list);
1389 struct resource_entry *rentry;
1390 int ret;
1391 struct device *dma_dev = dev;
1392 u64 len, dma_start = U64_MAX, dma_end = 0, dma_offset = 0;
1395 * Walk the device tree chasing an ACPI companion with a _DMA
1396 * object while we go. Stop if we find a device with an ACPI
1397 * companion containing a _DMA method.
1399 do {
1400 adev = ACPI_COMPANION(dma_dev);
1401 if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
1402 break;
1404 dma_dev = dma_dev->parent;
1405 } while (dma_dev);
1407 if (!dma_dev)
1408 return -ENODEV;
1410 if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
1411 acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
1412 return -EINVAL;
1415 ret = acpi_dev_get_dma_resources(adev, &list);
1416 if (ret > 0) {
1417 list_for_each_entry(rentry, &list, node) {
1418 if (dma_offset && rentry->offset != dma_offset) {
1419 ret = -EINVAL;
1420 dev_warn(dma_dev, "Can't handle multiple windows with different offsets\n");
1421 goto out;
1423 dma_offset = rentry->offset;
1425 /* Take lower and upper limits */
1426 if (rentry->res->start < dma_start)
1427 dma_start = rentry->res->start;
1428 if (rentry->res->end > dma_end)
1429 dma_end = rentry->res->end;
1432 if (dma_start >= dma_end) {
1433 ret = -EINVAL;
1434 dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
1435 goto out;
1438 *dma_addr = dma_start - dma_offset;
1439 len = dma_end - dma_start;
1440 *size = max(len, len + 1);
1441 *offset = dma_offset;
1443 out:
1444 acpi_dev_free_resource_list(&list);
1446 return ret >= 0 ? 0 : ret;
1450 * acpi_dma_configure - Set-up DMA configuration for the device.
1451 * @dev: The pointer to the device
1452 * @attr: device dma attributes
1454 int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
1456 const struct iommu_ops *iommu;
1457 u64 dma_addr = 0, size = 0;
1459 iort_dma_setup(dev, &dma_addr, &size);
1461 iommu = iort_iommu_configure(dev);
1462 if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
1463 return -EPROBE_DEFER;
1465 arch_setup_dma_ops(dev, dma_addr, size,
1466 iommu, attr == DEV_DMA_COHERENT);
1468 return 0;
1470 EXPORT_SYMBOL_GPL(acpi_dma_configure);
1473 * acpi_dma_deconfigure - Tear-down DMA configuration for the device.
1474 * @dev: The pointer to the device
1476 void acpi_dma_deconfigure(struct device *dev)
1478 arch_teardown_dma_ops(dev);
1480 EXPORT_SYMBOL_GPL(acpi_dma_deconfigure);
1482 static void acpi_init_coherency(struct acpi_device *adev)
1484 unsigned long long cca = 0;
1485 acpi_status status;
1486 struct acpi_device *parent = adev->parent;
1488 if (parent && parent->flags.cca_seen) {
1490 * From ACPI spec, OSPM will ignore _CCA if an ancestor
1491 * already saw one.
1493 adev->flags.cca_seen = 1;
1494 cca = parent->flags.coherent_dma;
1495 } else {
1496 status = acpi_evaluate_integer(adev->handle, "_CCA",
1497 NULL, &cca);
1498 if (ACPI_SUCCESS(status))
1499 adev->flags.cca_seen = 1;
1500 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1502 * If architecture does not specify that _CCA is
1503 * required for DMA-able devices (e.g. x86),
1504 * we default to _CCA=1.
1506 cca = 1;
1507 else
1508 acpi_handle_debug(adev->handle,
1509 "ACPI device is missing _CCA.\n");
1512 adev->flags.coherent_dma = cca;
1515 static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
1517 bool *is_serial_bus_slave_p = data;
1519 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1520 return 1;
1522 *is_serial_bus_slave_p = true;
1524 /* no need to do more checking */
1525 return -1;
1528 static bool acpi_is_indirect_io_slave(struct acpi_device *device)
1530 struct acpi_device *parent = device->parent;
1531 const struct acpi_device_id indirect_io_hosts[] = {
1532 {"HISI0191", 0},
1536 return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
1539 static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
1541 struct list_head resource_list;
1542 bool is_serial_bus_slave = false;
1544 if (acpi_is_indirect_io_slave(device))
1545 return true;
1547 /* Macs use device properties in lieu of _CRS resources */
1548 if (x86_apple_machine &&
1549 (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
1550 fwnode_property_present(&device->fwnode, "i2cAddress") ||
1551 fwnode_property_present(&device->fwnode, "baud")))
1552 return true;
1554 INIT_LIST_HEAD(&resource_list);
1555 acpi_dev_get_resources(device, &resource_list,
1556 acpi_check_serial_bus_slave,
1557 &is_serial_bus_slave);
1558 acpi_dev_free_resource_list(&resource_list);
1560 return is_serial_bus_slave;
1563 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1564 int type, unsigned long long sta)
1566 INIT_LIST_HEAD(&device->pnp.ids);
1567 device->device_type = type;
1568 device->handle = handle;
1569 device->parent = acpi_bus_get_parent(handle);
1570 device->fwnode.ops = &acpi_device_fwnode_ops;
1571 acpi_set_device_status(device, sta);
1572 acpi_device_get_busid(device);
1573 acpi_set_pnp_ids(handle, &device->pnp, type);
1574 acpi_init_properties(device);
1575 acpi_bus_get_flags(device);
1576 device->flags.match_driver = false;
1577 device->flags.initialized = true;
1578 device->flags.enumeration_by_parent =
1579 acpi_device_enumeration_by_parent(device);
1580 acpi_device_clear_enumerated(device);
1581 device_initialize(&device->dev);
1582 dev_set_uevent_suppress(&device->dev, true);
1583 acpi_init_coherency(device);
1584 /* Assume there are unmet deps until acpi_device_dep_initialize() runs */
1585 device->dep_unmet = 1;
1588 void acpi_device_add_finalize(struct acpi_device *device)
1590 dev_set_uevent_suppress(&device->dev, false);
1591 kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1594 static int acpi_add_single_object(struct acpi_device **child,
1595 acpi_handle handle, int type,
1596 unsigned long long sta)
1598 int result;
1599 struct acpi_device *device;
1600 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1602 device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1603 if (!device) {
1604 printk(KERN_ERR PREFIX "Memory allocation error\n");
1605 return -ENOMEM;
1608 acpi_init_device_object(device, handle, type, sta);
1610 * For ACPI_BUS_TYPE_DEVICE getting the status is delayed till here so
1611 * that we can call acpi_bus_get_status() and use its quirk handling.
1612 * Note this must be done before the get power-/wakeup_dev-flags calls.
1614 if (type == ACPI_BUS_TYPE_DEVICE)
1615 acpi_bus_get_status(device);
1617 acpi_bus_get_power_flags(device);
1618 acpi_bus_get_wakeup_device_flags(device);
1620 result = acpi_device_add(device, acpi_device_release);
1621 if (result) {
1622 acpi_device_release(&device->dev);
1623 return result;
1626 acpi_power_add_remove_device(device, true);
1627 acpi_device_add_finalize(device);
1628 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1629 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1630 dev_name(&device->dev), (char *) buffer.pointer,
1631 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1632 kfree(buffer.pointer);
1633 *child = device;
1634 return 0;
1637 static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
1638 void *context)
1640 struct resource *res = context;
1642 if (acpi_dev_resource_memory(ares, res))
1643 return AE_CTRL_TERMINATE;
1645 return AE_OK;
1648 static bool acpi_device_should_be_hidden(acpi_handle handle)
1650 acpi_status status;
1651 struct resource res;
1653 /* Check if it should ignore the UART device */
1654 if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
1655 return false;
1658 * The UART device described in SPCR table is assumed to have only one
1659 * memory resource present. So we only look for the first one here.
1661 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1662 acpi_get_resource_memory, &res);
1663 if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
1664 return false;
1666 acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
1667 &res.start);
1669 return true;
1672 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1673 unsigned long long *sta)
1675 acpi_status status;
1676 acpi_object_type acpi_type;
1678 status = acpi_get_type(handle, &acpi_type);
1679 if (ACPI_FAILURE(status))
1680 return -ENODEV;
1682 switch (acpi_type) {
1683 case ACPI_TYPE_ANY: /* for ACPI_ROOT_OBJECT */
1684 case ACPI_TYPE_DEVICE:
1685 if (acpi_device_should_be_hidden(handle))
1686 return -ENODEV;
1688 *type = ACPI_BUS_TYPE_DEVICE;
1690 * acpi_add_single_object updates this once we've an acpi_device
1691 * so that acpi_bus_get_status' quirk handling can be used.
1693 *sta = 0;
1694 break;
1695 case ACPI_TYPE_PROCESSOR:
1696 *type = ACPI_BUS_TYPE_PROCESSOR;
1697 status = acpi_bus_get_status_handle(handle, sta);
1698 if (ACPI_FAILURE(status))
1699 return -ENODEV;
1700 break;
1701 case ACPI_TYPE_THERMAL:
1702 *type = ACPI_BUS_TYPE_THERMAL;
1703 *sta = ACPI_STA_DEFAULT;
1704 break;
1705 case ACPI_TYPE_POWER:
1706 *type = ACPI_BUS_TYPE_POWER;
1707 *sta = ACPI_STA_DEFAULT;
1708 break;
1709 default:
1710 return -ENODEV;
1713 return 0;
1716 bool acpi_device_is_present(const struct acpi_device *adev)
1718 return adev->status.present || adev->status.functional;
1721 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1722 const char *idstr,
1723 const struct acpi_device_id **matchid)
1725 const struct acpi_device_id *devid;
1727 if (handler->match)
1728 return handler->match(idstr, matchid);
1730 for (devid = handler->ids; devid->id[0]; devid++)
1731 if (!strcmp((char *)devid->id, idstr)) {
1732 if (matchid)
1733 *matchid = devid;
1735 return true;
1738 return false;
1741 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1742 const struct acpi_device_id **matchid)
1744 struct acpi_scan_handler *handler;
1746 list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1747 if (acpi_scan_handler_matching(handler, idstr, matchid))
1748 return handler;
1750 return NULL;
1753 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1755 if (!!hotplug->enabled == !!val)
1756 return;
1758 mutex_lock(&acpi_scan_lock);
1760 hotplug->enabled = val;
1762 mutex_unlock(&acpi_scan_lock);
1765 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1767 struct acpi_hardware_id *hwid;
1769 if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1770 acpi_dock_add(adev);
1771 return;
1773 list_for_each_entry(hwid, &adev->pnp.ids, list) {
1774 struct acpi_scan_handler *handler;
1776 handler = acpi_scan_match_handler(hwid->id, NULL);
1777 if (handler) {
1778 adev->flags.hotplug_notify = true;
1779 break;
1784 static void acpi_device_dep_initialize(struct acpi_device *adev)
1786 struct acpi_dep_data *dep;
1787 struct acpi_handle_list dep_devices;
1788 acpi_status status;
1789 int i;
1791 adev->dep_unmet = 0;
1793 if (!acpi_has_method(adev->handle, "_DEP"))
1794 return;
1796 status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
1797 &dep_devices);
1798 if (ACPI_FAILURE(status)) {
1799 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
1800 return;
1803 for (i = 0; i < dep_devices.count; i++) {
1804 struct acpi_device_info *info;
1805 int skip;
1807 status = acpi_get_object_info(dep_devices.handles[i], &info);
1808 if (ACPI_FAILURE(status)) {
1809 dev_dbg(&adev->dev, "Error reading _DEP device info\n");
1810 continue;
1814 * Skip the dependency of Windows System Power
1815 * Management Controller
1817 skip = info->valid & ACPI_VALID_HID &&
1818 !strcmp(info->hardware_id.string, "INT3396");
1820 kfree(info);
1822 if (skip)
1823 continue;
1825 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
1826 if (!dep)
1827 return;
1829 dep->master = dep_devices.handles[i];
1830 dep->slave = adev->handle;
1831 adev->dep_unmet++;
1833 mutex_lock(&acpi_dep_list_lock);
1834 list_add_tail(&dep->node , &acpi_dep_list);
1835 mutex_unlock(&acpi_dep_list_lock);
1839 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1840 void *not_used, void **return_value)
1842 struct acpi_device *device = NULL;
1843 int type;
1844 unsigned long long sta;
1845 int result;
1847 acpi_bus_get_device(handle, &device);
1848 if (device)
1849 goto out;
1851 result = acpi_bus_type_and_status(handle, &type, &sta);
1852 if (result)
1853 return AE_OK;
1855 if (type == ACPI_BUS_TYPE_POWER) {
1856 acpi_add_power_resource(handle);
1857 return AE_OK;
1860 acpi_add_single_object(&device, handle, type, sta);
1861 if (!device)
1862 return AE_CTRL_DEPTH;
1864 acpi_scan_init_hotplug(device);
1865 acpi_device_dep_initialize(device);
1867 out:
1868 if (!*return_value)
1869 *return_value = device;
1871 return AE_OK;
1874 static void acpi_default_enumeration(struct acpi_device *device)
1877 * Do not enumerate devices with enumeration_by_parent flag set as
1878 * they will be enumerated by their respective parents.
1880 if (!device->flags.enumeration_by_parent) {
1881 acpi_create_platform_device(device, NULL);
1882 acpi_device_set_enumerated(device);
1883 } else {
1884 blocking_notifier_call_chain(&acpi_reconfig_chain,
1885 ACPI_RECONFIG_DEVICE_ADD, device);
1889 static const struct acpi_device_id generic_device_ids[] = {
1890 {ACPI_DT_NAMESPACE_HID, },
1891 {"", },
1894 static int acpi_generic_device_attach(struct acpi_device *adev,
1895 const struct acpi_device_id *not_used)
1898 * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
1899 * below can be unconditional.
1901 if (adev->data.of_compatible)
1902 acpi_default_enumeration(adev);
1904 return 1;
1907 static struct acpi_scan_handler generic_device_handler = {
1908 .ids = generic_device_ids,
1909 .attach = acpi_generic_device_attach,
1912 static int acpi_scan_attach_handler(struct acpi_device *device)
1914 struct acpi_hardware_id *hwid;
1915 int ret = 0;
1917 list_for_each_entry(hwid, &device->pnp.ids, list) {
1918 const struct acpi_device_id *devid;
1919 struct acpi_scan_handler *handler;
1921 handler = acpi_scan_match_handler(hwid->id, &devid);
1922 if (handler) {
1923 if (!handler->attach) {
1924 device->pnp.type.platform_id = 0;
1925 continue;
1927 device->handler = handler;
1928 ret = handler->attach(device, devid);
1929 if (ret > 0)
1930 break;
1932 device->handler = NULL;
1933 if (ret < 0)
1934 break;
1938 return ret;
1941 static void acpi_bus_attach(struct acpi_device *device)
1943 struct acpi_device *child;
1944 acpi_handle ejd;
1945 int ret;
1947 if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
1948 register_dock_dependent_device(device, ejd);
1950 acpi_bus_get_status(device);
1951 /* Skip devices that are not present. */
1952 if (!acpi_device_is_present(device)) {
1953 device->flags.initialized = false;
1954 acpi_device_clear_enumerated(device);
1955 device->flags.power_manageable = 0;
1956 return;
1958 if (device->handler)
1959 goto ok;
1961 if (!device->flags.initialized) {
1962 device->flags.power_manageable =
1963 device->power.states[ACPI_STATE_D0].flags.valid;
1964 if (acpi_bus_init_power(device))
1965 device->flags.power_manageable = 0;
1967 device->flags.initialized = true;
1968 } else if (device->flags.visited) {
1969 goto ok;
1972 ret = acpi_scan_attach_handler(device);
1973 if (ret < 0)
1974 return;
1976 device->flags.match_driver = true;
1977 if (ret > 0 && !device->flags.enumeration_by_parent) {
1978 acpi_device_set_enumerated(device);
1979 goto ok;
1982 ret = device_attach(&device->dev);
1983 if (ret < 0)
1984 return;
1986 if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
1987 acpi_default_enumeration(device);
1988 else
1989 acpi_device_set_enumerated(device);
1992 list_for_each_entry(child, &device->children, node)
1993 acpi_bus_attach(child);
1995 if (device->handler && device->handler->hotplug.notify_online)
1996 device->handler->hotplug.notify_online(device);
1999 void acpi_walk_dep_device_list(acpi_handle handle)
2001 struct acpi_dep_data *dep, *tmp;
2002 struct acpi_device *adev;
2004 mutex_lock(&acpi_dep_list_lock);
2005 list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2006 if (dep->master == handle) {
2007 acpi_bus_get_device(dep->slave, &adev);
2008 if (!adev)
2009 continue;
2011 adev->dep_unmet--;
2012 if (!adev->dep_unmet)
2013 acpi_bus_attach(adev);
2014 list_del(&dep->node);
2015 kfree(dep);
2018 mutex_unlock(&acpi_dep_list_lock);
2020 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2023 * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2024 * @handle: Root of the namespace scope to scan.
2026 * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2027 * found devices.
2029 * If no devices were found, -ENODEV is returned, but it does not mean that
2030 * there has been a real error. There just have been no suitable ACPI objects
2031 * in the table trunk from which the kernel could create a device and add an
2032 * appropriate driver.
2034 * Must be called under acpi_scan_lock.
2036 int acpi_bus_scan(acpi_handle handle)
2038 void *device = NULL;
2040 if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2041 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2042 acpi_bus_check_add, NULL, NULL, &device);
2044 if (device) {
2045 acpi_bus_attach(device);
2046 return 0;
2048 return -ENODEV;
2050 EXPORT_SYMBOL(acpi_bus_scan);
2053 * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2054 * @adev: Root of the ACPI namespace scope to walk.
2056 * Must be called under acpi_scan_lock.
2058 void acpi_bus_trim(struct acpi_device *adev)
2060 struct acpi_scan_handler *handler = adev->handler;
2061 struct acpi_device *child;
2063 list_for_each_entry_reverse(child, &adev->children, node)
2064 acpi_bus_trim(child);
2066 adev->flags.match_driver = false;
2067 if (handler) {
2068 if (handler->detach)
2069 handler->detach(adev);
2071 adev->handler = NULL;
2072 } else {
2073 device_release_driver(&adev->dev);
2076 * Most likely, the device is going away, so put it into D3cold before
2077 * that.
2079 acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2080 adev->flags.initialized = false;
2081 acpi_device_clear_enumerated(adev);
2083 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2085 int acpi_bus_register_early_device(int type)
2087 struct acpi_device *device = NULL;
2088 int result;
2090 result = acpi_add_single_object(&device, NULL,
2091 type, ACPI_STA_DEFAULT);
2092 if (result)
2093 return result;
2095 device->flags.match_driver = true;
2096 return device_attach(&device->dev);
2098 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
2100 static int acpi_bus_scan_fixed(void)
2102 int result = 0;
2105 * Enumerate all fixed-feature devices.
2107 if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2108 struct acpi_device *device = NULL;
2110 result = acpi_add_single_object(&device, NULL,
2111 ACPI_BUS_TYPE_POWER_BUTTON,
2112 ACPI_STA_DEFAULT);
2113 if (result)
2114 return result;
2116 device->flags.match_driver = true;
2117 result = device_attach(&device->dev);
2118 if (result < 0)
2119 return result;
2121 device_init_wakeup(&device->dev, true);
2124 if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2125 struct acpi_device *device = NULL;
2127 result = acpi_add_single_object(&device, NULL,
2128 ACPI_BUS_TYPE_SLEEP_BUTTON,
2129 ACPI_STA_DEFAULT);
2130 if (result)
2131 return result;
2133 device->flags.match_driver = true;
2134 result = device_attach(&device->dev);
2137 return result < 0 ? result : 0;
2140 static void __init acpi_get_spcr_uart_addr(void)
2142 acpi_status status;
2143 struct acpi_table_spcr *spcr_ptr;
2145 status = acpi_get_table(ACPI_SIG_SPCR, 0,
2146 (struct acpi_table_header **)&spcr_ptr);
2147 if (ACPI_SUCCESS(status))
2148 spcr_uart_addr = spcr_ptr->serial_port.address;
2149 else
2150 printk(KERN_WARNING PREFIX "STAO table present, but SPCR is missing\n");
2153 static bool acpi_scan_initialized;
2155 int __init acpi_scan_init(void)
2157 int result;
2158 acpi_status status;
2159 struct acpi_table_stao *stao_ptr;
2161 acpi_pci_root_init();
2162 acpi_pci_link_init();
2163 acpi_processor_init();
2164 acpi_lpss_init();
2165 acpi_apd_init();
2166 acpi_cmos_rtc_init();
2167 acpi_container_init();
2168 acpi_memory_hotplug_init();
2169 acpi_pnp_init();
2170 acpi_int340x_thermal_init();
2171 acpi_amba_init();
2172 acpi_watchdog_init();
2173 acpi_init_lpit();
2175 acpi_scan_add_handler(&generic_device_handler);
2178 * If there is STAO table, check whether it needs to ignore the UART
2179 * device in SPCR table.
2181 status = acpi_get_table(ACPI_SIG_STAO, 0,
2182 (struct acpi_table_header **)&stao_ptr);
2183 if (ACPI_SUCCESS(status)) {
2184 if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
2185 printk(KERN_INFO PREFIX "STAO Name List not yet supported.");
2187 if (stao_ptr->ignore_uart)
2188 acpi_get_spcr_uart_addr();
2191 acpi_gpe_apply_masked_gpes();
2192 acpi_update_all_gpes();
2194 mutex_lock(&acpi_scan_lock);
2196 * Enumerate devices in the ACPI namespace.
2198 result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2199 if (result)
2200 goto out;
2202 result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2203 if (result)
2204 goto out;
2206 /* Fixed feature devices do not exist on HW-reduced platform */
2207 if (!acpi_gbl_reduced_hardware) {
2208 result = acpi_bus_scan_fixed();
2209 if (result) {
2210 acpi_detach_data(acpi_root->handle,
2211 acpi_scan_drop_device);
2212 acpi_device_del(acpi_root);
2213 put_device(&acpi_root->dev);
2214 goto out;
2218 acpi_scan_initialized = true;
2220 out:
2221 mutex_unlock(&acpi_scan_lock);
2222 return result;
2225 static struct acpi_probe_entry *ape;
2226 static int acpi_probe_count;
2227 static DEFINE_MUTEX(acpi_probe_mutex);
2229 static int __init acpi_match_madt(struct acpi_subtable_header *header,
2230 const unsigned long end)
2232 if (!ape->subtable_valid || ape->subtable_valid(header, ape))
2233 if (!ape->probe_subtbl(header, end))
2234 acpi_probe_count++;
2236 return 0;
2239 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
2241 int count = 0;
2243 if (acpi_disabled)
2244 return 0;
2246 mutex_lock(&acpi_probe_mutex);
2247 for (ape = ap_head; nr; ape++, nr--) {
2248 if (ACPI_COMPARE_NAME(ACPI_SIG_MADT, ape->id)) {
2249 acpi_probe_count = 0;
2250 acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
2251 count += acpi_probe_count;
2252 } else {
2253 int res;
2254 res = acpi_table_parse(ape->id, ape->probe_table);
2255 if (!res)
2256 count++;
2259 mutex_unlock(&acpi_probe_mutex);
2261 return count;
2264 struct acpi_table_events_work {
2265 struct work_struct work;
2266 void *table;
2267 u32 event;
2270 static void acpi_table_events_fn(struct work_struct *work)
2272 struct acpi_table_events_work *tew;
2274 tew = container_of(work, struct acpi_table_events_work, work);
2276 if (tew->event == ACPI_TABLE_EVENT_LOAD) {
2277 acpi_scan_lock_acquire();
2278 acpi_bus_scan(ACPI_ROOT_OBJECT);
2279 acpi_scan_lock_release();
2282 kfree(tew);
2285 void acpi_scan_table_handler(u32 event, void *table, void *context)
2287 struct acpi_table_events_work *tew;
2289 if (!acpi_scan_initialized)
2290 return;
2292 if (event != ACPI_TABLE_EVENT_LOAD)
2293 return;
2295 tew = kmalloc(sizeof(*tew), GFP_KERNEL);
2296 if (!tew)
2297 return;
2299 INIT_WORK(&tew->work, acpi_table_events_fn);
2300 tew->table = table;
2301 tew->event = event;
2303 schedule_work(&tew->work);
2306 int acpi_reconfig_notifier_register(struct notifier_block *nb)
2308 return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
2310 EXPORT_SYMBOL(acpi_reconfig_notifier_register);
2312 int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
2314 return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
2316 EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);