Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/drivers/acpi/scan.c

  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/signal.h>
 11 #include <linux/kthread.h>
 12 #include <linux/dmi.h>
 13 #include <linux/nls.h>
 14 #include <linux/dma-mapping.h>
 15 
 16 #include <asm/pgtable.h>
 17 
 18 #include "internal.h"
 19 
 20 #define _COMPONENT              ACPI_BUS_COMPONENT
 21 ACPI_MODULE_NAME("scan");
 22 extern struct acpi_device *acpi_root;
 23 
 24 #define ACPI_BUS_CLASS                  "system_bus"
 25 #define ACPI_BUS_HID                    "LNXSYBUS"
 26 #define ACPI_BUS_DEVICE_NAME            "System Bus"
 27 
 28 #define ACPI_IS_ROOT_DEVICE(device)    (!(device)->parent)
 29 
 30 #define INVALID_ACPI_HANDLE     ((acpi_handle)empty_zero_page)
 31 
 32 /*
 33  * If set, devices will be hot-removed even if they cannot be put offline
 34  * gracefully (from the kernel's standpoint).
 35  */
 36 bool acpi_force_hot_remove;
 37 
 38 static const char *dummy_hid = "device";
 39 
 40 static LIST_HEAD(acpi_dep_list);
 41 static DEFINE_MUTEX(acpi_dep_list_lock);
 42 LIST_HEAD(acpi_bus_id_list);
 43 static DEFINE_MUTEX(acpi_scan_lock);
 44 static LIST_HEAD(acpi_scan_handlers_list);
 45 DEFINE_MUTEX(acpi_device_lock);
 46 LIST_HEAD(acpi_wakeup_device_list);
 47 static DEFINE_MUTEX(acpi_hp_context_lock);
 48 
 49 struct acpi_dep_data {
 50         struct list_head node;
 51         acpi_handle master;
 52         acpi_handle slave;
 53 };
 54 
 55 void acpi_scan_lock_acquire(void)
 56 {
 57         mutex_lock(&acpi_scan_lock);
 58 }
 59 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
 60 
 61 void acpi_scan_lock_release(void)
 62 {
 63         mutex_unlock(&acpi_scan_lock);
 64 }
 65 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
 66 
 67 void acpi_lock_hp_context(void)
 68 {
 69         mutex_lock(&acpi_hp_context_lock);
 70 }
 71 
 72 void acpi_unlock_hp_context(void)
 73 {
 74         mutex_unlock(&acpi_hp_context_lock);
 75 }
 76 
 77 void acpi_initialize_hp_context(struct acpi_device *adev,
 78                                 struct acpi_hotplug_context *hp,
 79                                 int (*notify)(struct acpi_device *, u32),
 80                                 void (*uevent)(struct acpi_device *, u32))
 81 {
 82         acpi_lock_hp_context();
 83         hp->notify = notify;
 84         hp->uevent = uevent;
 85         acpi_set_hp_context(adev, hp);
 86         acpi_unlock_hp_context();
 87 }
 88 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
 89 
 90 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
 91 {
 92         if (!handler)
 93                 return -EINVAL;
 94 
 95         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
 96         return 0;
 97 }
 98 
 99 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
100                                        const char *hotplug_profile_name)
101 {
102         int error;
103 
104         error = acpi_scan_add_handler(handler);
105         if (error)
106                 return error;
107 
108         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
109         return 0;
110 }
111 
112 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
113 {
114         struct acpi_device_physical_node *pn;
115         bool offline = true;
116 
117         /*
118          * acpi_container_offline() calls this for all of the container's
119          * children under the container's physical_node_lock lock.
120          */
121         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
122 
123         list_for_each_entry(pn, &adev->physical_node_list, node)
124                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
125                         if (uevent)
126                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
127 
128                         offline = false;
129                         break;
130                 }
131 
132         mutex_unlock(&adev->physical_node_lock);
133         return offline;
134 }
135 
136 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
137                                     void **ret_p)
138 {
139         struct acpi_device *device = NULL;
140         struct acpi_device_physical_node *pn;
141         bool second_pass = (bool)data;
142         acpi_status status = AE_OK;
143 
144         if (acpi_bus_get_device(handle, &device))
145                 return AE_OK;
146 
147         if (device->handler && !device->handler->hotplug.enabled) {
148                 *ret_p = &device->dev;
149                 return AE_SUPPORT;
150         }
151 
152         mutex_lock(&device->physical_node_lock);
153 
154         list_for_each_entry(pn, &device->physical_node_list, node) {
155                 int ret;
156 
157                 if (second_pass) {
158                         /* Skip devices offlined by the first pass. */
159                         if (pn->put_online)
160                                 continue;
161                 } else {
162                         pn->put_online = false;
163                 }
164                 ret = device_offline(pn->dev);
165                 if (acpi_force_hot_remove)
166                         continue;
167 
168                 if (ret >= 0) {
169                         pn->put_online = !ret;
170                 } else {
171                         *ret_p = pn->dev;
172                         if (second_pass) {
173                                 status = AE_ERROR;
174                                 break;
175                         }
176                 }
177         }
178 
179         mutex_unlock(&device->physical_node_lock);
180 
181         return status;
182 }
183 
184 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
185                                    void **ret_p)
186 {
187         struct acpi_device *device = NULL;
188         struct acpi_device_physical_node *pn;
189 
190         if (acpi_bus_get_device(handle, &device))
191                 return AE_OK;
192 
193         mutex_lock(&device->physical_node_lock);
194 
195         list_for_each_entry(pn, &device->physical_node_list, node)
196                 if (pn->put_online) {
197                         device_online(pn->dev);
198                         pn->put_online = false;
199                 }
200 
201         mutex_unlock(&device->physical_node_lock);
202 
203         return AE_OK;
204 }
205 
206 static int acpi_scan_try_to_offline(struct acpi_device *device)
207 {
208         acpi_handle handle = device->handle;
209         struct device *errdev = NULL;
210         acpi_status status;
211 
212         /*
213          * Carry out two passes here and ignore errors in the first pass,
214          * because if the devices in question are memory blocks and
215          * CONFIG_MEMCG is set, one of the blocks may hold data structures
216          * that the other blocks depend on, but it is not known in advance which
217          * block holds them.
218          *
219          * If the first pass is successful, the second one isn't needed, though.
220          */
221         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
222                                      NULL, acpi_bus_offline, (void *)false,
223                                      (void **)&errdev);
224         if (status == AE_SUPPORT) {
225                 dev_warn(errdev, "Offline disabled.\n");
226                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
227                                     acpi_bus_online, NULL, NULL, NULL);
228                 return -EPERM;
229         }
230         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
231         if (errdev) {
232                 errdev = NULL;
233                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
234                                     NULL, acpi_bus_offline, (void *)true,
235                                     (void **)&errdev);
236                 if (!errdev || acpi_force_hot_remove)
237                         acpi_bus_offline(handle, 0, (void *)true,
238                                          (void **)&errdev);
239 
240                 if (errdev && !acpi_force_hot_remove) {
241                         dev_warn(errdev, "Offline failed.\n");
242                         acpi_bus_online(handle, 0, NULL, NULL);
243                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
244                                             ACPI_UINT32_MAX, acpi_bus_online,
245                                             NULL, NULL, NULL);
246                         return -EBUSY;
247                 }
248         }
249         return 0;
250 }
251 
252 static int acpi_scan_hot_remove(struct acpi_device *device)
253 {
254         acpi_handle handle = device->handle;
255         unsigned long long sta;
256         acpi_status status;
257 
258         if (device->handler && device->handler->hotplug.demand_offline
259             && !acpi_force_hot_remove) {
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;
266         }
267 
268         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
269                 "Hot-removing device %s...\n", dev_name(&device->dev)));
270 
271         acpi_bus_trim(device);
272 
273         acpi_evaluate_lck(handle, 0);
274         /*
275          * TBD: _EJD support.
276          */
277         status = acpi_evaluate_ej0(handle);
278         if (status == AE_NOT_FOUND)
279                 return -ENODEV;
280         else if (ACPI_FAILURE(status))
281                 return -EIO;
282 
283         /*
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.
286          */
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);
294         }
295 
296         return 0;
297 }
298 
299 static int acpi_scan_device_not_present(struct acpi_device *adev)
300 {
301         if (!acpi_device_enumerated(adev)) {
302                 dev_warn(&adev->dev, "Still not present\n");
303                 return -EALREADY;
304         }
305         acpi_bus_trim(adev);
306         return 0;
307 }
308 
309 static int acpi_scan_device_check(struct acpi_device *adev)
310 {
311         int error;
312 
313         acpi_bus_get_status(adev);
314         if (adev->status.present || adev->status.functional) {
315                 /*
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).
322                  */
323                 if (adev->handler) {
324                         dev_warn(&adev->dev, "Already enumerated\n");
325                         return -EALREADY;
326                 }
327                 error = acpi_bus_scan(adev->handle);
328                 if (error) {
329                         dev_warn(&adev->dev, "Namespace scan failure\n");
330                         return error;
331                 }
332                 if (!adev->handler) {
333                         dev_warn(&adev->dev, "Enumeration failure\n");
334                         error = -ENODEV;
335                 }
336         } else {
337                 error = acpi_scan_device_not_present(adev);
338         }
339         return error;
340 }
341 
342 static int acpi_scan_bus_check(struct acpi_device *adev)
343 {
344         struct acpi_scan_handler *handler = adev->handler;
345         struct acpi_device *child;
346         int error;
347 
348         acpi_bus_get_status(adev);
349         if (!(adev->status.present || adev->status.functional)) {
350                 acpi_scan_device_not_present(adev);
351                 return 0;
352         }
353         if (handler && handler->hotplug.scan_dependent)
354                 return handler->hotplug.scan_dependent(adev);
355 
356         error = acpi_bus_scan(adev->handle);
357         if (error) {
358                 dev_warn(&adev->dev, "Namespace scan failure\n");
359                 return error;
360         }
361         list_for_each_entry(child, &adev->children, node) {
362                 error = acpi_scan_bus_check(child);
363                 if (error)
364                         return error;
365         }
366         return 0;
367 }
368 
369 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
370 {
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;
381                 }
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);
385         }
386         return -EINVAL;
387 }
388 
389 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
390 {
391         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
392         int error = -ENODEV;
393 
394         lock_device_hotplug();
395         mutex_lock(&acpi_scan_lock);
396 
397         /*
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.
401          */
402         if (adev->handle == INVALID_ACPI_HANDLE)
403                 goto err_out;
404 
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                 if (error == -EPERM) {
410                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
411                         goto err_out;
412                 }
413         } else {
414                 int (*notify)(struct acpi_device *, u32);
415 
416                 acpi_lock_hp_context();
417                 notify = adev->hp ? adev->hp->notify : NULL;
418                 acpi_unlock_hp_context();
419                 /*
420                  * There may be additional notify handlers for device objects
421                  * without the .event() callback, so ignore them here.
422                  */
423                 if (notify)
424                         error = notify(adev, src);
425                 else
426                         goto out;
427         }
428         if (!error)
429                 ost_code = ACPI_OST_SC_SUCCESS;
430 
431  err_out:
432         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
433 
434  out:
435         acpi_bus_put_acpi_device(adev);
436         mutex_unlock(&acpi_scan_lock);
437         unlock_device_hotplug();
438 }
439 
440 static void acpi_free_power_resources_lists(struct acpi_device *device)
441 {
442         int i;
443 
444         if (device->wakeup.flags.valid)
445                 acpi_power_resources_list_free(&device->wakeup.resources);
446 
447         if (!device->power.flags.power_resources)
448                 return;
449 
450         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
451                 struct acpi_device_power_state *ps = &device->power.states[i];
452                 acpi_power_resources_list_free(&ps->resources);
453         }
454 }
455 
456 static void acpi_device_release(struct device *dev)
457 {
458         struct acpi_device *acpi_dev = to_acpi_device(dev);
459 
460         acpi_free_properties(acpi_dev);
461         acpi_free_pnp_ids(&acpi_dev->pnp);
462         acpi_free_power_resources_lists(acpi_dev);
463         kfree(acpi_dev);
464 }
465 
466 static void acpi_device_del(struct acpi_device *device)
467 {
468         struct acpi_device_bus_id *acpi_device_bus_id;
469 
470         mutex_lock(&acpi_device_lock);
471         if (device->parent)
472                 list_del(&device->node);
473 
474         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
475                 if (!strcmp(acpi_device_bus_id->bus_id,
476                             acpi_device_hid(device))) {
477                         if (acpi_device_bus_id->instance_no > 0)
478                                 acpi_device_bus_id->instance_no--;
479                         else {
480                                 list_del(&acpi_device_bus_id->node);
481                                 kfree(acpi_device_bus_id);
482                         }
483                         break;
484                 }
485 
486         list_del(&device->wakeup_list);
487         mutex_unlock(&acpi_device_lock);
488 
489         acpi_power_add_remove_device(device, false);
490         acpi_device_remove_files(device);
491         if (device->remove)
492                 device->remove(device);
493 
494         device_del(&device->dev);
495 }
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                 acpi_device_del(adev);
518                 /*
519                  * Drop references to all power resources that might have been
520                  * used by the device.
521                  */
522                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
523                 put_device(&adev->dev);
524         }
525 }
526 
527 /**
528  * acpi_scan_drop_device - Drop an ACPI device object.
529  * @handle: Handle of an ACPI namespace node, not used.
530  * @context: Address of the ACPI device object to drop.
531  *
532  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
533  * namespace node the device object pointed to by @context is attached to.
534  *
535  * The unregistration is carried out asynchronously to avoid running
536  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
537  * ensure the correct ordering (the device objects must be unregistered in the
538  * same order in which the corresponding namespace nodes are deleted).
539  */
540 static void acpi_scan_drop_device(acpi_handle handle, void *context)
541 {
542         static DECLARE_WORK(work, acpi_device_del_work_fn);
543         struct acpi_device *adev = context;
544 
545         mutex_lock(&acpi_device_del_lock);
546 
547         /*
548          * Use the ACPI hotplug workqueue which is ordered, so this work item
549          * won't run after any hotplug work items submitted subsequently.  That
550          * prevents attempts to register device objects identical to those being
551          * deleted from happening concurrently (such attempts result from
552          * hotplug events handled via the ACPI hotplug workqueue).  It also will
553          * run after all of the work items submitted previosuly, which helps
554          * those work items to ensure that they are not accessing stale device
555          * objects.
556          */
557         if (list_empty(&acpi_device_del_list))
558                 acpi_queue_hotplug_work(&work);
559 
560         list_add_tail(&adev->del_list, &acpi_device_del_list);
561         /* Make acpi_ns_validate_handle() return NULL for this handle. */
562         adev->handle = INVALID_ACPI_HANDLE;
563 
564         mutex_unlock(&acpi_device_del_lock);
565 }
566 
567 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
568                                 void (*callback)(void *))
569 {
570         acpi_status status;
571 
572         if (!device)
573                 return -EINVAL;
574 
575         status = acpi_get_data_full(handle, acpi_scan_drop_device,
576                                     (void **)device, callback);
577         if (ACPI_FAILURE(status) || !*device) {
578                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
579                                   handle));
580                 return -ENODEV;
581         }
582         return 0;
583 }
584 
585 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
586 {
587         return acpi_get_device_data(handle, device, NULL);
588 }
589 EXPORT_SYMBOL(acpi_bus_get_device);
590 
591 static void get_acpi_device(void *dev)
592 {
593         if (dev)
594                 get_device(&((struct acpi_device *)dev)->dev);
595 }
596 
597 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
598 {
599         struct acpi_device *adev = NULL;
600 
601         acpi_get_device_data(handle, &adev, get_acpi_device);
602         return adev;
603 }
604 
605 void acpi_bus_put_acpi_device(struct acpi_device *adev)
606 {
607         put_device(&adev->dev);
608 }
609 
610 int acpi_device_add(struct acpi_device *device,
611                     void (*release)(struct device *))
612 {
613         int result;
614         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
615         int found = 0;
616 
617         if (device->handle) {
618                 acpi_status status;
619 
620                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
621                                           device);
622                 if (ACPI_FAILURE(status)) {
623                         acpi_handle_err(device->handle,
624                                         "Unable to attach device data\n");
625                         return -ENODEV;
626                 }
627         }
628 
629         /*
630          * Linkage
631          * -------
632          * Link this device to its parent and siblings.
633          */
634         INIT_LIST_HEAD(&device->children);
635         INIT_LIST_HEAD(&device->node);
636         INIT_LIST_HEAD(&device->wakeup_list);
637         INIT_LIST_HEAD(&device->physical_node_list);
638         INIT_LIST_HEAD(&device->del_list);
639         mutex_init(&device->physical_node_lock);
640 
641         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
642         if (!new_bus_id) {
643                 pr_err(PREFIX "Memory allocation error\n");
644                 result = -ENOMEM;
645                 goto err_detach;
646         }
647 
648         mutex_lock(&acpi_device_lock);
649         /*
650          * Find suitable bus_id and instance number in acpi_bus_id_list
651          * If failed, create one and link it into acpi_bus_id_list
652          */
653         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
654                 if (!strcmp(acpi_device_bus_id->bus_id,
655                             acpi_device_hid(device))) {
656                         acpi_device_bus_id->instance_no++;
657                         found = 1;
658                         kfree(new_bus_id);
659                         break;
660                 }
661         }
662         if (!found) {
663                 acpi_device_bus_id = new_bus_id;
664                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
665                 acpi_device_bus_id->instance_no = 0;
666                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
667         }
668         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
669 
670         if (device->parent)
671                 list_add_tail(&device->node, &device->parent->children);
672 
673         if (device->wakeup.flags.valid)
674                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
675         mutex_unlock(&acpi_device_lock);
676 
677         if (device->parent)
678                 device->dev.parent = &device->parent->dev;
679         device->dev.bus = &acpi_bus_type;
680         device->dev.release = release;
681         result = device_add(&device->dev);
682         if (result) {
683                 dev_err(&device->dev, "Error registering device\n");
684                 goto err;
685         }
686 
687         result = acpi_device_setup_files(device);
688         if (result)
689                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
690                        dev_name(&device->dev));
691 
692         return 0;
693 
694  err:
695         mutex_lock(&acpi_device_lock);
696         if (device->parent)
697                 list_del(&device->node);
698         list_del(&device->wakeup_list);
699         mutex_unlock(&acpi_device_lock);
700 
701  err_detach:
702         acpi_detach_data(device->handle, acpi_scan_drop_device);
703         return result;
704 }
705 
706 /* --------------------------------------------------------------------------
707                                  Device Enumeration
708    -------------------------------------------------------------------------- */
709 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
710 {
711         struct acpi_device *device = NULL;
712         acpi_status status;
713 
714         /*
715          * Fixed hardware devices do not appear in the namespace and do not
716          * have handles, but we fabricate acpi_devices for them, so we have
717          * to deal with them specially.
718          */
719         if (!handle)
720                 return acpi_root;
721 
722         do {
723                 status = acpi_get_parent(handle, &handle);
724                 if (ACPI_FAILURE(status))
725                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
726         } while (acpi_bus_get_device(handle, &device));
727         return device;
728 }
729 
730 acpi_status
731 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
732 {
733         acpi_status status;
734         acpi_handle tmp;
735         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
736         union acpi_object *obj;
737 
738         status = acpi_get_handle(handle, "_EJD", &tmp);
739         if (ACPI_FAILURE(status))
740                 return status;
741 
742         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
743         if (ACPI_SUCCESS(status)) {
744                 obj = buffer.pointer;
745                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
746                                          ejd);
747                 kfree(buffer.pointer);
748         }
749         return status;
750 }
751 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
752 
753 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
754                                         struct acpi_device_wakeup *wakeup)
755 {
756         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
757         union acpi_object *package = NULL;
758         union acpi_object *element = NULL;
759         acpi_status status;
760         int err = -ENODATA;
761 
762         if (!wakeup)
763                 return -EINVAL;
764 
765         INIT_LIST_HEAD(&wakeup->resources);
766 
767         /* _PRW */
768         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
769         if (ACPI_FAILURE(status)) {
770                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
771                 return err;
772         }
773 
774         package = (union acpi_object *)buffer.pointer;
775 
776         if (!package || package->package.count < 2)
777                 goto out;
778 
779         element = &(package->package.elements[0]);
780         if (!element)
781                 goto out;
782 
783         if (element->type == ACPI_TYPE_PACKAGE) {
784                 if ((element->package.count < 2) ||
785                     (element->package.elements[0].type !=
786                      ACPI_TYPE_LOCAL_REFERENCE)
787                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
788                         goto out;
789 
790                 wakeup->gpe_device =
791                     element->package.elements[0].reference.handle;
792                 wakeup->gpe_number =
793                     (u32) element->package.elements[1].integer.value;
794         } else if (element->type == ACPI_TYPE_INTEGER) {
795                 wakeup->gpe_device = NULL;
796                 wakeup->gpe_number = element->integer.value;
797         } else {
798                 goto out;
799         }
800 
801         element = &(package->package.elements[1]);
802         if (element->type != ACPI_TYPE_INTEGER)
803                 goto out;
804 
805         wakeup->sleep_state = element->integer.value;
806 
807         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
808         if (err)
809                 goto out;
810 
811         if (!list_empty(&wakeup->resources)) {
812                 int sleep_state;
813 
814                 err = acpi_power_wakeup_list_init(&wakeup->resources,
815                                                   &sleep_state);
816                 if (err) {
817                         acpi_handle_warn(handle, "Retrieving current states "
818                                          "of wakeup power resources failed\n");
819                         acpi_power_resources_list_free(&wakeup->resources);
820                         goto out;
821                 }
822                 if (sleep_state < wakeup->sleep_state) {
823                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
824                                          "(S%d) by S%d from power resources\n",
825                                          (int)wakeup->sleep_state, sleep_state);
826                         wakeup->sleep_state = sleep_state;
827                 }
828         }
829 
830  out:
831         kfree(buffer.pointer);
832         return err;
833 }
834 
835 static void acpi_wakeup_gpe_init(struct acpi_device *device)
836 {
837         static const struct acpi_device_id button_device_ids[] = {
838                 {"PNP0C0C", 0},
839                 {"PNP0C0D", 0},
840                 {"PNP0C0E", 0},
841                 {"", 0},
842         };
843         struct acpi_device_wakeup *wakeup = &device->wakeup;
844         acpi_status status;
845         acpi_event_status event_status;
846 
847         wakeup->flags.notifier_present = 0;
848 
849         /* Power button, Lid switch always enable wakeup */
850         if (!acpi_match_device_ids(device, button_device_ids)) {
851                 wakeup->flags.run_wake = 1;
852                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
853                         /* Do not use Lid/sleep button for S5 wakeup */
854                         if (wakeup->sleep_state == ACPI_STATE_S5)
855                                 wakeup->sleep_state = ACPI_STATE_S4;
856                 }
857                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
858                 device_set_wakeup_capable(&device->dev, true);
859                 return;
860         }
861 
862         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
863                                 wakeup->gpe_number);
864         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
865                                      &event_status);
866         if (ACPI_FAILURE(status))
867                 return;
868 
869         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
870 }
871 
872 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
873 {
874         int err;
875 
876         /* Presence of _PRW indicates wake capable */
877         if (!acpi_has_method(device->handle, "_PRW"))
878                 return;
879 
880         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
881                                                            &device->wakeup);
882         if (err) {
883                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
884                 return;
885         }
886 
887         device->wakeup.flags.valid = 1;
888         device->wakeup.prepare_count = 0;
889         acpi_wakeup_gpe_init(device);
890         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
891          * system for the ACPI device with the _PRW object.
892          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
893          * So it is necessary to call _DSW object first. Only when it is not
894          * present will the _PSW object used.
895          */
896         err = acpi_device_sleep_wake(device, 0, 0, 0);
897         if (err)
898                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
899                                 "error in _DSW or _PSW evaluation\n"));
900 }
901 
902 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
903 {
904         struct acpi_device_power_state *ps = &device->power.states[state];
905         char pathname[5] = { '_', 'P', 'R', '' + state, '\0' };
906         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
907         acpi_status status;
908 
909         INIT_LIST_HEAD(&ps->resources);
910 
911         /* Evaluate "_PRx" to get referenced power resources */
912         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
913         if (ACPI_SUCCESS(status)) {
914                 union acpi_object *package = buffer.pointer;
915 
916                 if (buffer.length && package
917                     && package->type == ACPI_TYPE_PACKAGE
918                     && package->package.count) {
919                         int err = acpi_extract_power_resources(package, 0,
920                                                                &ps->resources);
921                         if (!err)
922                                 device->power.flags.power_resources = 1;
923                 }
924                 ACPI_FREE(buffer.pointer);
925         }
926 
927         /* Evaluate "_PSx" to see if we can do explicit sets */
928         pathname[2] = 'S';
929         if (acpi_has_method(device->handle, pathname))
930                 ps->flags.explicit_set = 1;
931 
932         /* State is valid if there are means to put the device into it. */
933         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
934                 ps->flags.valid = 1;
935 
936         ps->power = -1;         /* Unknown - driver assigned */
937         ps->latency = -1;       /* Unknown - driver assigned */
938 }
939 
940 static void acpi_bus_get_power_flags(struct acpi_device *device)
941 {
942         u32 i;
943 
944         /* Presence of _PS0|_PR0 indicates 'power manageable' */
945         if (!acpi_has_method(device->handle, "_PS0") &&
946             !acpi_has_method(device->handle, "_PR0"))
947                 return;
948 
949         device->flags.power_manageable = 1;
950 
951         /*
952          * Power Management Flags
953          */
954         if (acpi_has_method(device->handle, "_PSC"))
955                 device->power.flags.explicit_get = 1;
956 
957         if (acpi_has_method(device->handle, "_IRC"))
958                 device->power.flags.inrush_current = 1;
959 
960         if (acpi_has_method(device->handle, "_DSW"))
961                 device->power.flags.dsw_present = 1;
962 
963         /*
964          * Enumerate supported power management states
965          */
966         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
967                 acpi_bus_init_power_state(device, i);
968 
969         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
970         if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
971                 device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
972 
973         /* Set defaults for D0 and D3hot states (always valid) */
974         device->power.states[ACPI_STATE_D0].flags.valid = 1;
975         device->power.states[ACPI_STATE_D0].power = 100;
976         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
977 
978         if (acpi_bus_init_power(device))
979                 device->flags.power_manageable = 0;
980 }
981 
982 static void acpi_bus_get_flags(struct acpi_device *device)
983 {
984         /* Presence of _STA indicates 'dynamic_status' */
985         if (acpi_has_method(device->handle, "_STA"))
986                 device->flags.dynamic_status = 1;
987 
988         /* Presence of _RMV indicates 'removable' */
989         if (acpi_has_method(device->handle, "_RMV"))
990                 device->flags.removable = 1;
991 
992         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
993         if (acpi_has_method(device->handle, "_EJD") ||
994             acpi_has_method(device->handle, "_EJ0"))
995                 device->flags.ejectable = 1;
996 }
997 
998 static void acpi_device_get_busid(struct acpi_device *device)
999 {
1000         char bus_id[5] = { '?', 0 };
1001         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1002         int i = 0;
1003 
1004         /*
1005          * Bus ID
1006          * ------
1007          * The device's Bus ID is simply the object name.
1008          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1009          */
1010         if (ACPI_IS_ROOT_DEVICE(device)) {
1011                 strcpy(device->pnp.bus_id, "ACPI");
1012                 return;
1013         }
1014 
1015         switch (device->device_type) {
1016         case ACPI_BUS_TYPE_POWER_BUTTON:
1017                 strcpy(device->pnp.bus_id, "PWRF");
1018                 break;
1019         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1020                 strcpy(device->pnp.bus_id, "SLPF");
1021                 break;
1022         default:
1023                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1024                 /* Clean up trailing underscores (if any) */
1025                 for (i = 3; i > 1; i--) {
1026                         if (bus_id[i] == '_')
1027                                 bus_id[i] = '\0';
1028                         else
1029                                 break;
1030                 }
1031                 strcpy(device->pnp.bus_id, bus_id);
1032                 break;
1033         }
1034 }
1035 
1036 /*
1037  * acpi_ata_match - see if an acpi object is an ATA device
1038  *
1039  * If an acpi object has one of the ACPI ATA methods defined,
1040  * then we can safely call it an ATA device.
1041  */
1042 bool acpi_ata_match(acpi_handle handle)
1043 {
1044         return acpi_has_method(handle, "_GTF") ||
1045                acpi_has_method(handle, "_GTM") ||
1046                acpi_has_method(handle, "_STM") ||
1047                acpi_has_method(handle, "_SDD");
1048 }
1049 
1050 /*
1051  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1052  *
1053  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1054  * then we can safely call it an ejectable drive bay
1055  */
1056 bool acpi_bay_match(acpi_handle handle)
1057 {
1058         acpi_handle phandle;
1059 
1060         if (!acpi_has_method(handle, "_EJ0"))
1061                 return false;
1062         if (acpi_ata_match(handle))
1063                 return true;
1064         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1065                 return false;
1066 
1067         return acpi_ata_match(phandle);
1068 }
1069 
1070 bool acpi_device_is_battery(struct acpi_device *adev)
1071 {
1072         struct acpi_hardware_id *hwid;
1073 
1074         list_for_each_entry(hwid, &adev->pnp.ids, list)
1075                 if (!strcmp("PNP0C0A", hwid->id))
1076                         return true;
1077 
1078         return false;
1079 }
1080 
1081 static bool is_ejectable_bay(struct acpi_device *adev)
1082 {
1083         acpi_handle handle = adev->handle;
1084 
1085         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1086                 return true;
1087 
1088         return acpi_bay_match(handle);
1089 }
1090 
1091 /*
1092  * acpi_dock_match - see if an acpi object has a _DCK method
1093  */
1094 bool acpi_dock_match(acpi_handle handle)
1095 {
1096         return acpi_has_method(handle, "_DCK");
1097 }
1098 
1099 static acpi_status
1100 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1101                           void **return_value)
1102 {
1103         long *cap = context;
1104 
1105         if (acpi_has_method(handle, "_BCM") &&
1106             acpi_has_method(handle, "_BCL")) {
1107                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1108                                   "support\n"));
1109                 *cap |= ACPI_VIDEO_BACKLIGHT;
1110                 if (!acpi_has_method(handle, "_BQC"))
1111                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
1112                                 "cannot determine initial brightness\n");
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 static void acpi_init_coherency(struct acpi_device *adev)
1362 {
1363         unsigned long long cca = 0;
1364         acpi_status status;
1365         struct acpi_device *parent = adev->parent;
1366 
1367         if (parent && parent->flags.cca_seen) {
1368                 /*
1369                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
1370                  * already saw one.
1371                  */
1372                 adev->flags.cca_seen = 1;
1373                 cca = parent->flags.coherent_dma;
1374         } else {
1375                 status = acpi_evaluate_integer(adev->handle, "_CCA",
1376                                                NULL, &cca);
1377                 if (ACPI_SUCCESS(status))
1378                         adev->flags.cca_seen = 1;
1379                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
1380                         /*
1381                          * If architecture does not specify that _CCA is
1382                          * required for DMA-able devices (e.g. x86),
1383                          * we default to _CCA=1.
1384                          */
1385                         cca = 1;
1386                 else
1387                         acpi_handle_debug(adev->handle,
1388                                           "ACPI device is missing _CCA.\n");
1389         }
1390 
1391         adev->flags.coherent_dma = cca;
1392 }
1393 
1394 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1395                              int type, unsigned long long sta)
1396 {
1397         INIT_LIST_HEAD(&device->pnp.ids);
1398         device->device_type = type;
1399         device->handle = handle;
1400         device->parent = acpi_bus_get_parent(handle);
1401         device->fwnode.type = FWNODE_ACPI;
1402         acpi_set_device_status(device, sta);
1403         acpi_device_get_busid(device);
1404         acpi_set_pnp_ids(handle, &device->pnp, type);
1405         acpi_init_properties(device);
1406         acpi_bus_get_flags(device);
1407         device->flags.match_driver = false;
1408         device->flags.initialized = true;
1409         device->flags.visited = false;
1410         device_initialize(&device->dev);
1411         dev_set_uevent_suppress(&device->dev, true);
1412         acpi_init_coherency(device);
1413 }
1414 
1415 void acpi_device_add_finalize(struct acpi_device *device)
1416 {
1417         dev_set_uevent_suppress(&device->dev, false);
1418         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1419 }
1420 
1421 static int acpi_add_single_object(struct acpi_device **child,
1422                                   acpi_handle handle, int type,
1423                                   unsigned long long sta)
1424 {
1425         int result;
1426         struct acpi_device *device;
1427         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1428 
1429         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1430         if (!device) {
1431                 printk(KERN_ERR PREFIX "Memory allocation error\n");
1432                 return -ENOMEM;
1433         }
1434 
1435         acpi_init_device_object(device, handle, type, sta);
1436         acpi_bus_get_power_flags(device);
1437         acpi_bus_get_wakeup_device_flags(device);
1438 
1439         result = acpi_device_add(device, acpi_device_release);
1440         if (result) {
1441                 acpi_device_release(&device->dev);
1442                 return result;
1443         }
1444 
1445         acpi_power_add_remove_device(device, true);
1446         acpi_device_add_finalize(device);
1447         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1448         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1449                 dev_name(&device->dev), (char *) buffer.pointer,
1450                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
1451         kfree(buffer.pointer);
1452         *child = device;
1453         return 0;
1454 }
1455 
1456 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1457                                     unsigned long long *sta)
1458 {
1459         acpi_status status;
1460         acpi_object_type acpi_type;
1461 
1462         status = acpi_get_type(handle, &acpi_type);
1463         if (ACPI_FAILURE(status))
1464                 return -ENODEV;
1465 
1466         switch (acpi_type) {
1467         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
1468         case ACPI_TYPE_DEVICE:
1469                 *type = ACPI_BUS_TYPE_DEVICE;
1470                 status = acpi_bus_get_status_handle(handle, sta);
1471                 if (ACPI_FAILURE(status))
1472                         *sta = 0;
1473                 break;
1474         case ACPI_TYPE_PROCESSOR:
1475                 *type = ACPI_BUS_TYPE_PROCESSOR;
1476                 status = acpi_bus_get_status_handle(handle, sta);
1477                 if (ACPI_FAILURE(status))
1478                         return -ENODEV;
1479                 break;
1480         case ACPI_TYPE_THERMAL:
1481                 *type = ACPI_BUS_TYPE_THERMAL;
1482                 *sta = ACPI_STA_DEFAULT;
1483                 break;
1484         case ACPI_TYPE_POWER:
1485                 *type = ACPI_BUS_TYPE_POWER;
1486                 *sta = ACPI_STA_DEFAULT;
1487                 break;
1488         default:
1489                 return -ENODEV;
1490         }
1491 
1492         return 0;
1493 }
1494 
1495 bool acpi_device_is_present(struct acpi_device *adev)
1496 {
1497         if (adev->status.present || adev->status.functional)
1498                 return true;
1499 
1500         adev->flags.initialized = false;
1501         return false;
1502 }
1503 
1504 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1505                                        const char *idstr,
1506                                        const struct acpi_device_id **matchid)
1507 {
1508         const struct acpi_device_id *devid;
1509 
1510         if (handler->match)
1511                 return handler->match(idstr, matchid);
1512 
1513         for (devid = handler->ids; devid->id[0]; devid++)
1514                 if (!strcmp((char *)devid->id, idstr)) {
1515                         if (matchid)
1516                                 *matchid = devid;
1517 
1518                         return true;
1519                 }
1520 
1521         return false;
1522 }
1523 
1524 static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
1525                                         const struct acpi_device_id **matchid)
1526 {
1527         struct acpi_scan_handler *handler;
1528 
1529         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1530                 if (acpi_scan_handler_matching(handler, idstr, matchid))
1531                         return handler;
1532 
1533         return NULL;
1534 }
1535 
1536 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1537 {
1538         if (!!hotplug->enabled == !!val)
1539                 return;
1540 
1541         mutex_lock(&acpi_scan_lock);
1542 
1543         hotplug->enabled = val;
1544 
1545         mutex_unlock(&acpi_scan_lock);
1546 }
1547 
1548 static void acpi_scan_init_hotplug(struct acpi_device *adev)
1549 {
1550         struct acpi_hardware_id *hwid;
1551 
1552         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
1553                 acpi_dock_add(adev);
1554                 return;
1555         }
1556         list_for_each_entry(hwid, &adev->pnp.ids, list) {
1557                 struct acpi_scan_handler *handler;
1558 
1559                 handler = acpi_scan_match_handler(hwid->id, NULL);
1560                 if (handler) {
1561                         adev->flags.hotplug_notify = true;
1562                         break;
1563                 }
1564         }
1565 }
1566 
1567 static void acpi_device_dep_initialize(struct acpi_device *adev)
1568 {
1569         struct acpi_dep_data *dep;
1570         struct acpi_handle_list dep_devices;
1571         acpi_status status;
1572         int i;
1573 
1574         if (!acpi_has_method(adev->handle, "_DEP"))
1575                 return;
1576 
1577         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
1578                                         &dep_devices);
1579         if (ACPI_FAILURE(status)) {
1580                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
1581                 return;
1582         }
1583 
1584         for (i = 0; i < dep_devices.count; i++) {
1585                 struct acpi_device_info *info;
1586                 int skip;
1587 
1588                 status = acpi_get_object_info(dep_devices.handles[i], &info);
1589                 if (ACPI_FAILURE(status)) {
1590                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
1591                         continue;
1592                 }
1593 
1594                 /*
1595                  * Skip the dependency of Windows System Power
1596                  * Management Controller
1597                  */
1598                 skip = info->valid & ACPI_VALID_HID &&
1599                         !strcmp(info->hardware_id.string, "INT3396");
1600 
1601                 kfree(info);
1602 
1603                 if (skip)
1604                         continue;
1605 
1606                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
1607                 if (!dep)
1608                         return;
1609 
1610                 dep->master = dep_devices.handles[i];
1611                 dep->slave  = adev->handle;
1612                 adev->dep_unmet++;
1613 
1614                 mutex_lock(&acpi_dep_list_lock);
1615                 list_add_tail(&dep->node , &acpi_dep_list);
1616                 mutex_unlock(&acpi_dep_list_lock);
1617         }
1618 }
1619 
1620 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1621                                       void *not_used, void **return_value)
1622 {
1623         struct acpi_device *device = NULL;
1624         int type;
1625         unsigned long long sta;
1626         int result;
1627 
1628         acpi_bus_get_device(handle, &device);
1629         if (device)
1630                 goto out;
1631 
1632         result = acpi_bus_type_and_status(handle, &type, &sta);
1633         if (result)
1634                 return AE_OK;
1635 
1636         if (type == ACPI_BUS_TYPE_POWER) {
1637                 acpi_add_power_resource(handle);
1638                 return AE_OK;
1639         }
1640 
1641         acpi_add_single_object(&device, handle, type, sta);
1642         if (!device)
1643                 return AE_CTRL_DEPTH;
1644 
1645         acpi_scan_init_hotplug(device);
1646         acpi_device_dep_initialize(device);
1647 
1648  out:
1649         if (!*return_value)
1650                 *return_value = device;
1651 
1652         return AE_OK;
1653 }
1654 
1655 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
1656 {
1657         bool *is_spi_i2c_slave_p = data;
1658 
1659         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
1660                 return 1;
1661 
1662         /*
1663          * devices that are connected to UART still need to be enumerated to
1664          * platform bus
1665          */
1666         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
1667                 *is_spi_i2c_slave_p = true;
1668 
1669          /* no need to do more checking */
1670         return -1;
1671 }
1672 
1673 static void acpi_default_enumeration(struct acpi_device *device)
1674 {
1675         struct list_head resource_list;
1676         bool is_spi_i2c_slave = false;
1677 
1678         /*
1679          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
1680          * respective parents.
1681          */
1682         INIT_LIST_HEAD(&resource_list);
1683         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
1684                                &is_spi_i2c_slave);
1685         acpi_dev_free_resource_list(&resource_list);
1686         if (!is_spi_i2c_slave)
1687                 acpi_create_platform_device(device);
1688 }
1689 
1690 static const struct acpi_device_id generic_device_ids[] = {
1691         {ACPI_DT_NAMESPACE_HID, },
1692         {"", },
1693 };
1694 
1695 static int acpi_generic_device_attach(struct acpi_device *adev,
1696                                       const struct acpi_device_id *not_used)
1697 {
1698         /*
1699          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
1700          * below can be unconditional.
1701          */
1702         if (adev->data.of_compatible)
1703                 acpi_default_enumeration(adev);
1704 
1705         return 1;
1706 }
1707 
1708 static struct acpi_scan_handler generic_device_handler = {
1709         .ids = generic_device_ids,
1710         .attach = acpi_generic_device_attach,
1711 };
1712 
1713 static int acpi_scan_attach_handler(struct acpi_device *device)
1714 {
1715         struct acpi_hardware_id *hwid;
1716         int ret = 0;
1717 
1718         list_for_each_entry(hwid, &device->pnp.ids, list) {
1719                 const struct acpi_device_id *devid;
1720                 struct acpi_scan_handler *handler;
1721 
1722                 handler = acpi_scan_match_handler(hwid->id, &devid);
1723                 if (handler) {
1724                         if (!handler->attach) {
1725                                 device->pnp.type.platform_id = 0;
1726                                 continue;
1727                         }
1728                         device->handler = handler;
1729                         ret = handler->attach(device, devid);
1730                         if (ret > 0)
1731                                 break;
1732 
1733                         device->handler = NULL;
1734                         if (ret < 0)
1735                                 break;
1736                 }
1737         }
1738 
1739         return ret;
1740 }
1741 
1742 static void acpi_bus_attach(struct acpi_device *device)
1743 {
1744         struct acpi_device *child;
1745         acpi_handle ejd;
1746         int ret;
1747 
1748         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
1749                 register_dock_dependent_device(device, ejd);
1750 
1751         acpi_bus_get_status(device);
1752         /* Skip devices that are not present. */
1753         if (!acpi_device_is_present(device)) {
1754                 device->flags.visited = false;
1755                 device->flags.power_manageable = 0;
1756                 return;
1757         }
1758         if (device->handler)
1759                 goto ok;
1760 
1761         if (!device->flags.initialized) {
1762                 device->flags.power_manageable =
1763                         device->power.states[ACPI_STATE_D0].flags.valid;
1764                 if (acpi_bus_init_power(device))
1765                         device->flags.power_manageable = 0;
1766 
1767                 device->flags.initialized = true;
1768         }
1769         device->flags.visited = false;
1770         ret = acpi_scan_attach_handler(device);
1771         if (ret < 0)
1772                 return;
1773 
1774         device->flags.match_driver = true;
1775         if (!ret) {
1776                 ret = device_attach(&device->dev);
1777                 if (ret < 0)
1778                         return;
1779 
1780                 if (!ret && device->pnp.type.platform_id)
1781                         acpi_default_enumeration(device);
1782         }
1783         device->flags.visited = true;
1784 
1785  ok:
1786         list_for_each_entry(child, &device->children, node)
1787                 acpi_bus_attach(child);
1788 
1789         if (device->handler && device->handler->hotplug.notify_online)
1790                 device->handler->hotplug.notify_online(device);
1791 }
1792 
1793 void acpi_walk_dep_device_list(acpi_handle handle)
1794 {
1795         struct acpi_dep_data *dep, *tmp;
1796         struct acpi_device *adev;
1797 
1798         mutex_lock(&acpi_dep_list_lock);
1799         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
1800                 if (dep->master == handle) {
1801                         acpi_bus_get_device(dep->slave, &adev);
1802                         if (!adev)
1803                                 continue;
1804 
1805                         adev->dep_unmet--;
1806                         if (!adev->dep_unmet)
1807                                 acpi_bus_attach(adev);
1808                         list_del(&dep->node);
1809                         kfree(dep);
1810                 }
1811         }
1812         mutex_unlock(&acpi_dep_list_lock);
1813 }
1814 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
1815 
1816 /**
1817  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1818  * @handle: Root of the namespace scope to scan.
1819  *
1820  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1821  * found devices.
1822  *
1823  * If no devices were found, -ENODEV is returned, but it does not mean that
1824  * there has been a real error.  There just have been no suitable ACPI objects
1825  * in the table trunk from which the kernel could create a device and add an
1826  * appropriate driver.
1827  *
1828  * Must be called under acpi_scan_lock.
1829  */
1830 int acpi_bus_scan(acpi_handle handle)
1831 {
1832         void *device = NULL;
1833 
1834         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1835                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1836                                     acpi_bus_check_add, NULL, NULL, &device);
1837 
1838         if (device) {
1839                 acpi_bus_attach(device);
1840                 return 0;
1841         }
1842         return -ENODEV;
1843 }
1844 EXPORT_SYMBOL(acpi_bus_scan);
1845 
1846 /**
1847  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
1848  * @adev: Root of the ACPI namespace scope to walk.
1849  *
1850  * Must be called under acpi_scan_lock.
1851  */
1852 void acpi_bus_trim(struct acpi_device *adev)
1853 {
1854         struct acpi_scan_handler *handler = adev->handler;
1855         struct acpi_device *child;
1856 
1857         list_for_each_entry_reverse(child, &adev->children, node)
1858                 acpi_bus_trim(child);
1859 
1860         adev->flags.match_driver = false;
1861         if (handler) {
1862                 if (handler->detach)
1863                         handler->detach(adev);
1864 
1865                 adev->handler = NULL;
1866         } else {
1867                 device_release_driver(&adev->dev);
1868         }
1869         /*
1870          * Most likely, the device is going away, so put it into D3cold before
1871          * that.
1872          */
1873         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
1874         adev->flags.initialized = false;
1875         adev->flags.visited = false;
1876 }
1877 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1878 
1879 static int acpi_bus_scan_fixed(void)
1880 {
1881         int result = 0;
1882 
1883         /*
1884          * Enumerate all fixed-feature devices.
1885          */
1886         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1887                 struct acpi_device *device = NULL;
1888 
1889                 result = acpi_add_single_object(&device, NULL,
1890                                                 ACPI_BUS_TYPE_POWER_BUTTON,
1891                                                 ACPI_STA_DEFAULT);
1892                 if (result)
1893                         return result;
1894 
1895                 device->flags.match_driver = true;
1896                 result = device_attach(&device->dev);
1897                 if (result < 0)
1898                         return result;
1899 
1900                 device_init_wakeup(&device->dev, true);
1901         }
1902 
1903         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
1904                 struct acpi_device *device = NULL;
1905 
1906                 result = acpi_add_single_object(&device, NULL,
1907                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
1908                                                 ACPI_STA_DEFAULT);
1909                 if (result)
1910                         return result;
1911 
1912                 device->flags.match_driver = true;
1913                 result = device_attach(&device->dev);
1914         }
1915 
1916         return result < 0 ? result : 0;
1917 }
1918 
1919 int __init acpi_scan_init(void)
1920 {
1921         int result;
1922 
1923         acpi_pci_root_init();
1924         acpi_pci_link_init();
1925         acpi_processor_init();
1926         acpi_lpss_init();
1927         acpi_apd_init();
1928         acpi_cmos_rtc_init();
1929         acpi_container_init();
1930         acpi_memory_hotplug_init();
1931         acpi_pnp_init();
1932         acpi_int340x_thermal_init();
1933 
1934         acpi_scan_add_handler(&generic_device_handler);
1935 
1936         mutex_lock(&acpi_scan_lock);
1937         /*
1938          * Enumerate devices in the ACPI namespace.
1939          */
1940         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
1941         if (result)
1942                 goto out;
1943 
1944         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
1945         if (result)
1946                 goto out;
1947 
1948         /* Fixed feature devices do not exist on HW-reduced platform */
1949         if (!acpi_gbl_reduced_hardware) {
1950                 result = acpi_bus_scan_fixed();
1951                 if (result) {
1952                         acpi_detach_data(acpi_root->handle,
1953                                          acpi_scan_drop_device);
1954                         acpi_device_del(acpi_root);
1955                         put_device(&acpi_root->dev);
1956                         goto out;
1957                 }
1958         }
1959 
1960         acpi_update_all_gpes();
1961 
1962  out:
1963         mutex_unlock(&acpi_scan_lock);
1964         return result;
1965 }
1966 
1967 static struct acpi_probe_entry *ape;
1968 static int acpi_probe_count;
1969 static DEFINE_SPINLOCK(acpi_probe_lock);
1970 
1971 static int __init acpi_match_madt(struct acpi_subtable_header *header,
1972                                   const unsigned long end)
1973 {
1974         if (!ape->subtable_valid || ape->subtable_valid(header, ape))
1975                 if (!ape->probe_subtbl(header, end))
1976                         acpi_probe_count++;
1977 
1978         return 0;
1979 }
1980 
1981 int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
1982 {
1983         int count = 0;
1984 
1985         if (acpi_disabled)
1986                 return 0;
1987 
1988         spin_lock(&acpi_probe_lock);
1989         for (ape = ap_head; nr; ape++, nr--) {
1990                 if (ACPI_COMPARE_NAME(ACPI_SIG_MADT, ape->id)) {
1991                         acpi_probe_count = 0;
1992                         acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
1993                         count += acpi_probe_count;
1994                 } else {
1995                         int res;
1996                         res = acpi_table_parse(ape->id, ape->probe_table);
1997                         if (!res)
1998                                 count++;
1999                 }
2000         }
2001         spin_unlock(&acpi_probe_lock);
2002 
2003         return count;
2004 }
2005 

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