Version:  2.0.40 2.2.26 2.4.37 3.6 3.7 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

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 static 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 struct acpi_device_bus_id{
 56         char bus_id[15];
 57         unsigned int instance_no;
 58         struct list_head node;
 59 };
 60 
 61 void acpi_scan_lock_acquire(void)
 62 {
 63         mutex_lock(&acpi_scan_lock);
 64 }
 65 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
 66 
 67 void acpi_scan_lock_release(void)
 68 {
 69         mutex_unlock(&acpi_scan_lock);
 70 }
 71 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
 72 
 73 void acpi_lock_hp_context(void)
 74 {
 75         mutex_lock(&acpi_hp_context_lock);
 76 }
 77 
 78 void acpi_unlock_hp_context(void)
 79 {
 80         mutex_unlock(&acpi_hp_context_lock);
 81 }
 82 
 83 void acpi_initialize_hp_context(struct acpi_device *adev,
 84                                 struct acpi_hotplug_context *hp,
 85                                 int (*notify)(struct acpi_device *, u32),
 86                                 void (*uevent)(struct acpi_device *, u32))
 87 {
 88         acpi_lock_hp_context();
 89         hp->notify = notify;
 90         hp->uevent = uevent;
 91         acpi_set_hp_context(adev, hp);
 92         acpi_unlock_hp_context();
 93 }
 94 EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);
 95 
 96 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
 97 {
 98         if (!handler)
 99                 return -EINVAL;
100 
101         list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
102         return 0;
103 }
104 
105 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
106                                        const char *hotplug_profile_name)
107 {
108         int error;
109 
110         error = acpi_scan_add_handler(handler);
111         if (error)
112                 return error;
113 
114         acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
115         return 0;
116 }
117 
118 /**
119  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
120  * @acpi_dev: ACPI device object.
121  * @modalias: Buffer to print into.
122  * @size: Size of the buffer.
123  *
124  * Creates hid/cid(s) string needed for modalias and uevent
125  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
126  * char *modalias: "acpi:IBM0001:ACPI0001"
127  * Return: 0: no _HID and no _CID
128  *         -EINVAL: output error
129  *         -ENOMEM: output is truncated
130 */
131 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
132                                int size)
133 {
134         int len;
135         int count;
136         struct acpi_hardware_id *id;
137 
138         /*
139          * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
140          * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
141          * device's list.
142          */
143         count = 0;
144         list_for_each_entry(id, &acpi_dev->pnp.ids, list)
145                 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
146                         count++;
147 
148         if (!count)
149                 return 0;
150 
151         len = snprintf(modalias, size, "acpi:");
152         if (len <= 0)
153                 return len;
154 
155         size -= len;
156 
157         list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
158                 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
159                         continue;
160 
161                 count = snprintf(&modalias[len], size, "%s:", id->id);
162                 if (count < 0)
163                         return -EINVAL;
164 
165                 if (count >= size)
166                         return -ENOMEM;
167 
168                 len += count;
169                 size -= count;
170         }
171         modalias[len] = '\0';
172         return len;
173 }
174 
175 /**
176  * create_of_modalias - Creates DT compatible string for modalias and uevent
177  * @acpi_dev: ACPI device object.
178  * @modalias: Buffer to print into.
179  * @size: Size of the buffer.
180  *
181  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
182  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
183  * ACPI/PNP IDs.
184  */
185 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
186                               int size)
187 {
188         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
189         const union acpi_object *of_compatible, *obj;
190         int len, count;
191         int i, nval;
192         char *c;
193 
194         acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
195         /* DT strings are all in lower case */
196         for (c = buf.pointer; *c != '\0'; c++)
197                 *c = tolower(*c);
198 
199         len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
200         ACPI_FREE(buf.pointer);
201 
202         if (len <= 0)
203                 return len;
204 
205         of_compatible = acpi_dev->data.of_compatible;
206         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
207                 nval = of_compatible->package.count;
208                 obj = of_compatible->package.elements;
209         } else { /* Must be ACPI_TYPE_STRING. */
210                 nval = 1;
211                 obj = of_compatible;
212         }
213         for (i = 0; i < nval; i++, obj++) {
214                 count = snprintf(&modalias[len], size, "C%s",
215                                  obj->string.pointer);
216                 if (count < 0)
217                         return -EINVAL;
218 
219                 if (count >= size)
220                         return -ENOMEM;
221 
222                 len += count;
223                 size -= count;
224         }
225         modalias[len] = '\0';
226         return len;
227 }
228 
229 /*
230  * acpi_companion_match() - Can we match via ACPI companion device
231  * @dev: Device in question
232  *
233  * Check if the given device has an ACPI companion and if that companion has
234  * a valid list of PNP IDs, and if the device is the first (primary) physical
235  * device associated with it.  Return the companion pointer if that's the case
236  * or NULL otherwise.
237  *
238  * If multiple physical devices are attached to a single ACPI companion, we need
239  * to be careful.  The usage scenario for this kind of relationship is that all
240  * of the physical devices in question use resources provided by the ACPI
241  * companion.  A typical case is an MFD device where all the sub-devices share
242  * the parent's ACPI companion.  In such cases we can only allow the primary
243  * (first) physical device to be matched with the help of the companion's PNP
244  * IDs.
245  *
246  * Additional physical devices sharing the ACPI companion can still use
247  * resources available from it but they will be matched normally using functions
248  * provided by their bus types (and analogously for their modalias).
249  */
250 static struct acpi_device *acpi_companion_match(const struct device *dev)
251 {
252         struct acpi_device *adev;
253         struct mutex *physical_node_lock;
254 
255         adev = ACPI_COMPANION(dev);
256         if (!adev)
257                 return NULL;
258 
259         if (list_empty(&adev->pnp.ids))
260                 return NULL;
261 
262         physical_node_lock = &adev->physical_node_lock;
263         mutex_lock(physical_node_lock);
264         if (list_empty(&adev->physical_node_list)) {
265                 adev = NULL;
266         } else {
267                 const struct acpi_device_physical_node *node;
268 
269                 node = list_first_entry(&adev->physical_node_list,
270                                         struct acpi_device_physical_node, node);
271                 if (node->dev != dev)
272                         adev = NULL;
273         }
274         mutex_unlock(physical_node_lock);
275 
276         return adev;
277 }
278 
279 static int __acpi_device_uevent_modalias(struct acpi_device *adev,
280                                          struct kobj_uevent_env *env)
281 {
282         int len;
283 
284         if (!adev)
285                 return -ENODEV;
286 
287         if (list_empty(&adev->pnp.ids))
288                 return 0;
289 
290         if (add_uevent_var(env, "MODALIAS="))
291                 return -ENOMEM;
292 
293         len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
294                                   sizeof(env->buf) - env->buflen);
295         if (len < 0)
296                 return len;
297 
298         env->buflen += len;
299         if (!adev->data.of_compatible)
300                 return 0;
301 
302         if (len > 0 && add_uevent_var(env, "MODALIAS="))
303                 return -ENOMEM;
304 
305         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
306                                  sizeof(env->buf) - env->buflen);
307         if (len < 0)
308                 return len;
309 
310         env->buflen += len;
311 
312         return 0;
313 }
314 
315 /*
316  * Creates uevent modalias field for ACPI enumerated devices.
317  * Because the other buses does not support ACPI HIDs & CIDs.
318  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
319  * "acpi:IBM0001:ACPI0001"
320  */
321 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
322 {
323         return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
324 }
325 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
326 
327 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
328 {
329         int len, count;
330 
331         if (!adev)
332                 return -ENODEV;
333 
334         if (list_empty(&adev->pnp.ids))
335                 return 0;
336 
337         len = create_pnp_modalias(adev, buf, size - 1);
338         if (len < 0) {
339                 return len;
340         } else if (len > 0) {
341                 buf[len++] = '\n';
342                 size -= len;
343         }
344         if (!adev->data.of_compatible)
345                 return len;
346 
347         count = create_of_modalias(adev, buf + len, size - 1);
348         if (count < 0) {
349                 return count;
350         } else if (count > 0) {
351                 len += count;
352                 buf[len++] = '\n';
353         }
354 
355         return len;
356 }
357 
358 /*
359  * Creates modalias sysfs attribute for ACPI enumerated devices.
360  * Because the other buses does not support ACPI HIDs & CIDs.
361  * e.g. for a device with hid:IBM0001 and cid:ACPI0001 you get:
362  * "acpi:IBM0001:ACPI0001"
363  */
364 int acpi_device_modalias(struct device *dev, char *buf, int size)
365 {
366         return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
367 }
368 EXPORT_SYMBOL_GPL(acpi_device_modalias);
369 
370 static ssize_t
371 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
372         return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
373 }
374 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
375 
376 bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
377 {
378         struct acpi_device_physical_node *pn;
379         bool offline = true;
380 
381         /*
382          * acpi_container_offline() calls this for all of the container's
383          * children under the container's physical_node_lock lock.
384          */
385         mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
386 
387         list_for_each_entry(pn, &adev->physical_node_list, node)
388                 if (device_supports_offline(pn->dev) && !pn->dev->offline) {
389                         if (uevent)
390                                 kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
391 
392                         offline = false;
393                         break;
394                 }
395 
396         mutex_unlock(&adev->physical_node_lock);
397         return offline;
398 }
399 
400 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
401                                     void **ret_p)
402 {
403         struct acpi_device *device = NULL;
404         struct acpi_device_physical_node *pn;
405         bool second_pass = (bool)data;
406         acpi_status status = AE_OK;
407 
408         if (acpi_bus_get_device(handle, &device))
409                 return AE_OK;
410 
411         if (device->handler && !device->handler->hotplug.enabled) {
412                 *ret_p = &device->dev;
413                 return AE_SUPPORT;
414         }
415 
416         mutex_lock(&device->physical_node_lock);
417 
418         list_for_each_entry(pn, &device->physical_node_list, node) {
419                 int ret;
420 
421                 if (second_pass) {
422                         /* Skip devices offlined by the first pass. */
423                         if (pn->put_online)
424                                 continue;
425                 } else {
426                         pn->put_online = false;
427                 }
428                 ret = device_offline(pn->dev);
429                 if (acpi_force_hot_remove)
430                         continue;
431 
432                 if (ret >= 0) {
433                         pn->put_online = !ret;
434                 } else {
435                         *ret_p = pn->dev;
436                         if (second_pass) {
437                                 status = AE_ERROR;
438                                 break;
439                         }
440                 }
441         }
442 
443         mutex_unlock(&device->physical_node_lock);
444 
445         return status;
446 }
447 
448 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
449                                    void **ret_p)
450 {
451         struct acpi_device *device = NULL;
452         struct acpi_device_physical_node *pn;
453 
454         if (acpi_bus_get_device(handle, &device))
455                 return AE_OK;
456 
457         mutex_lock(&device->physical_node_lock);
458 
459         list_for_each_entry(pn, &device->physical_node_list, node)
460                 if (pn->put_online) {
461                         device_online(pn->dev);
462                         pn->put_online = false;
463                 }
464 
465         mutex_unlock(&device->physical_node_lock);
466 
467         return AE_OK;
468 }
469 
470 static int acpi_scan_try_to_offline(struct acpi_device *device)
471 {
472         acpi_handle handle = device->handle;
473         struct device *errdev = NULL;
474         acpi_status status;
475 
476         /*
477          * Carry out two passes here and ignore errors in the first pass,
478          * because if the devices in question are memory blocks and
479          * CONFIG_MEMCG is set, one of the blocks may hold data structures
480          * that the other blocks depend on, but it is not known in advance which
481          * block holds them.
482          *
483          * If the first pass is successful, the second one isn't needed, though.
484          */
485         status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
486                                      NULL, acpi_bus_offline, (void *)false,
487                                      (void **)&errdev);
488         if (status == AE_SUPPORT) {
489                 dev_warn(errdev, "Offline disabled.\n");
490                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
491                                     acpi_bus_online, NULL, NULL, NULL);
492                 return -EPERM;
493         }
494         acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
495         if (errdev) {
496                 errdev = NULL;
497                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
498                                     NULL, acpi_bus_offline, (void *)true,
499                                     (void **)&errdev);
500                 if (!errdev || acpi_force_hot_remove)
501                         acpi_bus_offline(handle, 0, (void *)true,
502                                          (void **)&errdev);
503 
504                 if (errdev && !acpi_force_hot_remove) {
505                         dev_warn(errdev, "Offline failed.\n");
506                         acpi_bus_online(handle, 0, NULL, NULL);
507                         acpi_walk_namespace(ACPI_TYPE_ANY, handle,
508                                             ACPI_UINT32_MAX, acpi_bus_online,
509                                             NULL, NULL, NULL);
510                         return -EBUSY;
511                 }
512         }
513         return 0;
514 }
515 
516 static int acpi_scan_hot_remove(struct acpi_device *device)
517 {
518         acpi_handle handle = device->handle;
519         unsigned long long sta;
520         acpi_status status;
521 
522         if (device->handler && device->handler->hotplug.demand_offline
523             && !acpi_force_hot_remove) {
524                 if (!acpi_scan_is_offline(device, true))
525                         return -EBUSY;
526         } else {
527                 int error = acpi_scan_try_to_offline(device);
528                 if (error)
529                         return error;
530         }
531 
532         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
533                 "Hot-removing device %s...\n", dev_name(&device->dev)));
534 
535         acpi_bus_trim(device);
536 
537         acpi_evaluate_lck(handle, 0);
538         /*
539          * TBD: _EJD support.
540          */
541         status = acpi_evaluate_ej0(handle);
542         if (status == AE_NOT_FOUND)
543                 return -ENODEV;
544         else if (ACPI_FAILURE(status))
545                 return -EIO;
546 
547         /*
548          * Verify if eject was indeed successful.  If not, log an error
549          * message.  No need to call _OST since _EJ0 call was made OK.
550          */
551         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
552         if (ACPI_FAILURE(status)) {
553                 acpi_handle_warn(handle,
554                         "Status check after eject failed (0x%x)\n", status);
555         } else if (sta & ACPI_STA_DEVICE_ENABLED) {
556                 acpi_handle_warn(handle,
557                         "Eject incomplete - status 0x%llx\n", sta);
558         }
559 
560         return 0;
561 }
562 
563 static int acpi_scan_device_not_present(struct acpi_device *adev)
564 {
565         if (!acpi_device_enumerated(adev)) {
566                 dev_warn(&adev->dev, "Still not present\n");
567                 return -EALREADY;
568         }
569         acpi_bus_trim(adev);
570         return 0;
571 }
572 
573 static int acpi_scan_device_check(struct acpi_device *adev)
574 {
575         int error;
576 
577         acpi_bus_get_status(adev);
578         if (adev->status.present || adev->status.functional) {
579                 /*
580                  * This function is only called for device objects for which
581                  * matching scan handlers exist.  The only situation in which
582                  * the scan handler is not attached to this device object yet
583                  * is when the device has just appeared (either it wasn't
584                  * present at all before or it was removed and then added
585                  * again).
586                  */
587                 if (adev->handler) {
588                         dev_warn(&adev->dev, "Already enumerated\n");
589                         return -EALREADY;
590                 }
591                 error = acpi_bus_scan(adev->handle);
592                 if (error) {
593                         dev_warn(&adev->dev, "Namespace scan failure\n");
594                         return error;
595                 }
596                 if (!adev->handler) {
597                         dev_warn(&adev->dev, "Enumeration failure\n");
598                         error = -ENODEV;
599                 }
600         } else {
601                 error = acpi_scan_device_not_present(adev);
602         }
603         return error;
604 }
605 
606 static int acpi_scan_bus_check(struct acpi_device *adev)
607 {
608         struct acpi_scan_handler *handler = adev->handler;
609         struct acpi_device *child;
610         int error;
611 
612         acpi_bus_get_status(adev);
613         if (!(adev->status.present || adev->status.functional)) {
614                 acpi_scan_device_not_present(adev);
615                 return 0;
616         }
617         if (handler && handler->hotplug.scan_dependent)
618                 return handler->hotplug.scan_dependent(adev);
619 
620         error = acpi_bus_scan(adev->handle);
621         if (error) {
622                 dev_warn(&adev->dev, "Namespace scan failure\n");
623                 return error;
624         }
625         list_for_each_entry(child, &adev->children, node) {
626                 error = acpi_scan_bus_check(child);
627                 if (error)
628                         return error;
629         }
630         return 0;
631 }
632 
633 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
634 {
635         switch (type) {
636         case ACPI_NOTIFY_BUS_CHECK:
637                 return acpi_scan_bus_check(adev);
638         case ACPI_NOTIFY_DEVICE_CHECK:
639                 return acpi_scan_device_check(adev);
640         case ACPI_NOTIFY_EJECT_REQUEST:
641         case ACPI_OST_EC_OSPM_EJECT:
642                 if (adev->handler && !adev->handler->hotplug.enabled) {
643                         dev_info(&adev->dev, "Eject disabled\n");
644                         return -EPERM;
645                 }
646                 acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
647                                   ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
648                 return acpi_scan_hot_remove(adev);
649         }
650         return -EINVAL;
651 }
652 
653 void acpi_device_hotplug(struct acpi_device *adev, u32 src)
654 {
655         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
656         int error = -ENODEV;
657 
658         lock_device_hotplug();
659         mutex_lock(&acpi_scan_lock);
660 
661         /*
662          * The device object's ACPI handle cannot become invalid as long as we
663          * are holding acpi_scan_lock, but it might have become invalid before
664          * that lock was acquired.
665          */
666         if (adev->handle == INVALID_ACPI_HANDLE)
667                 goto err_out;
668 
669         if (adev->flags.is_dock_station) {
670                 error = dock_notify(adev, src);
671         } else if (adev->flags.hotplug_notify) {
672                 error = acpi_generic_hotplug_event(adev, src);
673                 if (error == -EPERM) {
674                         ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
675                         goto err_out;
676                 }
677         } else {
678                 int (*notify)(struct acpi_device *, u32);
679 
680                 acpi_lock_hp_context();
681                 notify = adev->hp ? adev->hp->notify : NULL;
682                 acpi_unlock_hp_context();
683                 /*
684                  * There may be additional notify handlers for device objects
685                  * without the .event() callback, so ignore them here.
686                  */
687                 if (notify)
688                         error = notify(adev, src);
689                 else
690                         goto out;
691         }
692         if (!error)
693                 ost_code = ACPI_OST_SC_SUCCESS;
694 
695  err_out:
696         acpi_evaluate_ost(adev->handle, src, ost_code, NULL);
697 
698  out:
699         acpi_bus_put_acpi_device(adev);
700         mutex_unlock(&acpi_scan_lock);
701         unlock_device_hotplug();
702 }
703 
704 static ssize_t real_power_state_show(struct device *dev,
705                                      struct device_attribute *attr, char *buf)
706 {
707         struct acpi_device *adev = to_acpi_device(dev);
708         int state;
709         int ret;
710 
711         ret = acpi_device_get_power(adev, &state);
712         if (ret)
713                 return ret;
714 
715         return sprintf(buf, "%s\n", acpi_power_state_string(state));
716 }
717 
718 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
719 
720 static ssize_t power_state_show(struct device *dev,
721                                 struct device_attribute *attr, char *buf)
722 {
723         struct acpi_device *adev = to_acpi_device(dev);
724 
725         return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
726 }
727 
728 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
729 
730 static ssize_t
731 acpi_eject_store(struct device *d, struct device_attribute *attr,
732                 const char *buf, size_t count)
733 {
734         struct acpi_device *acpi_device = to_acpi_device(d);
735         acpi_object_type not_used;
736         acpi_status status;
737 
738         if (!count || buf[0] != '1')
739                 return -EINVAL;
740 
741         if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
742             && !acpi_device->driver)
743                 return -ENODEV;
744 
745         status = acpi_get_type(acpi_device->handle, &not_used);
746         if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
747                 return -ENODEV;
748 
749         get_device(&acpi_device->dev);
750         status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
751         if (ACPI_SUCCESS(status))
752                 return count;
753 
754         put_device(&acpi_device->dev);
755         acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
756                           ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
757         return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
758 }
759 
760 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
761 
762 static ssize_t
763 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
764         struct acpi_device *acpi_dev = to_acpi_device(dev);
765 
766         return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
767 }
768 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
769 
770 static ssize_t acpi_device_uid_show(struct device *dev,
771                                     struct device_attribute *attr, char *buf)
772 {
773         struct acpi_device *acpi_dev = to_acpi_device(dev);
774 
775         return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
776 }
777 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
778 
779 static ssize_t acpi_device_adr_show(struct device *dev,
780                                     struct device_attribute *attr, char *buf)
781 {
782         struct acpi_device *acpi_dev = to_acpi_device(dev);
783 
784         return sprintf(buf, "0x%08x\n",
785                        (unsigned int)(acpi_dev->pnp.bus_address));
786 }
787 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
788 
789 static ssize_t
790 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
791         struct acpi_device *acpi_dev = to_acpi_device(dev);
792         struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
793         int result;
794 
795         result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
796         if (result)
797                 goto end;
798 
799         result = sprintf(buf, "%s\n", (char*)path.pointer);
800         kfree(path.pointer);
801 end:
802         return result;
803 }
804 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
805 
806 /* sysfs file that shows description text from the ACPI _STR method */
807 static ssize_t description_show(struct device *dev,
808                                 struct device_attribute *attr,
809                                 char *buf) {
810         struct acpi_device *acpi_dev = to_acpi_device(dev);
811         int result;
812 
813         if (acpi_dev->pnp.str_obj == NULL)
814                 return 0;
815 
816         /*
817          * The _STR object contains a Unicode identifier for a device.
818          * We need to convert to utf-8 so it can be displayed.
819          */
820         result = utf16s_to_utf8s(
821                 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
822                 acpi_dev->pnp.str_obj->buffer.length,
823                 UTF16_LITTLE_ENDIAN, buf,
824                 PAGE_SIZE);
825 
826         buf[result++] = '\n';
827 
828         return result;
829 }
830 static DEVICE_ATTR(description, 0444, description_show, NULL);
831 
832 static ssize_t
833 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
834                      char *buf) {
835         struct acpi_device *acpi_dev = to_acpi_device(dev);
836         acpi_status status;
837         unsigned long long sun;
838 
839         status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
840         if (ACPI_FAILURE(status))
841                 return -ENODEV;
842 
843         return sprintf(buf, "%llu\n", sun);
844 }
845 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
846 
847 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
848                                 char *buf) {
849         struct acpi_device *acpi_dev = to_acpi_device(dev);
850         acpi_status status;
851         unsigned long long sta;
852 
853         status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
854         if (ACPI_FAILURE(status))
855                 return -ENODEV;
856 
857         return sprintf(buf, "%llu\n", sta);
858 }
859 static DEVICE_ATTR_RO(status);
860 
861 static int acpi_device_setup_files(struct acpi_device *dev)
862 {
863         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
864         acpi_status status;
865         int result = 0;
866 
867         /*
868          * Devices gotten from FADT don't have a "path" attribute
869          */
870         if (dev->handle) {
871                 result = device_create_file(&dev->dev, &dev_attr_path);
872                 if (result)
873                         goto end;
874         }
875 
876         if (!list_empty(&dev->pnp.ids)) {
877                 result = device_create_file(&dev->dev, &dev_attr_hid);
878                 if (result)
879                         goto end;
880 
881                 result = device_create_file(&dev->dev, &dev_attr_modalias);
882                 if (result)
883                         goto end;
884         }
885 
886         /*
887          * If device has _STR, 'description' file is created
888          */
889         if (acpi_has_method(dev->handle, "_STR")) {
890                 status = acpi_evaluate_object(dev->handle, "_STR",
891                                         NULL, &buffer);
892                 if (ACPI_FAILURE(status))
893                         buffer.pointer = NULL;
894                 dev->pnp.str_obj = buffer.pointer;
895                 result = device_create_file(&dev->dev, &dev_attr_description);
896                 if (result)
897                         goto end;
898         }
899 
900         if (dev->pnp.type.bus_address)
901                 result = device_create_file(&dev->dev, &dev_attr_adr);
902         if (dev->pnp.unique_id)
903                 result = device_create_file(&dev->dev, &dev_attr_uid);
904 
905         if (acpi_has_method(dev->handle, "_SUN")) {
906                 result = device_create_file(&dev->dev, &dev_attr_sun);
907                 if (result)
908                         goto end;
909         }
910 
911         if (acpi_has_method(dev->handle, "_STA")) {
912                 result = device_create_file(&dev->dev, &dev_attr_status);
913                 if (result)
914                         goto end;
915         }
916 
917         /*
918          * If device has _EJ0, 'eject' file is created that is used to trigger
919          * hot-removal function from userland.
920          */
921         if (acpi_has_method(dev->handle, "_EJ0")) {
922                 result = device_create_file(&dev->dev, &dev_attr_eject);
923                 if (result)
924                         return result;
925         }
926 
927         if (dev->flags.power_manageable) {
928                 result = device_create_file(&dev->dev, &dev_attr_power_state);
929                 if (result)
930                         return result;
931 
932                 if (dev->power.flags.power_resources)
933                         result = device_create_file(&dev->dev,
934                                                     &dev_attr_real_power_state);
935         }
936 
937 end:
938         return result;
939 }
940 
941 static void acpi_device_remove_files(struct acpi_device *dev)
942 {
943         if (dev->flags.power_manageable) {
944                 device_remove_file(&dev->dev, &dev_attr_power_state);
945                 if (dev->power.flags.power_resources)
946                         device_remove_file(&dev->dev,
947                                            &dev_attr_real_power_state);
948         }
949 
950         /*
951          * If device has _STR, remove 'description' file
952          */
953         if (acpi_has_method(dev->handle, "_STR")) {
954                 kfree(dev->pnp.str_obj);
955                 device_remove_file(&dev->dev, &dev_attr_description);
956         }
957         /*
958          * If device has _EJ0, remove 'eject' file.
959          */
960         if (acpi_has_method(dev->handle, "_EJ0"))
961                 device_remove_file(&dev->dev, &dev_attr_eject);
962 
963         if (acpi_has_method(dev->handle, "_SUN"))
964                 device_remove_file(&dev->dev, &dev_attr_sun);
965 
966         if (dev->pnp.unique_id)
967                 device_remove_file(&dev->dev, &dev_attr_uid);
968         if (dev->pnp.type.bus_address)
969                 device_remove_file(&dev->dev, &dev_attr_adr);
970         device_remove_file(&dev->dev, &dev_attr_modalias);
971         device_remove_file(&dev->dev, &dev_attr_hid);
972         if (acpi_has_method(dev->handle, "_STA"))
973                 device_remove_file(&dev->dev, &dev_attr_status);
974         if (dev->handle)
975                 device_remove_file(&dev->dev, &dev_attr_path);
976 }
977 /* --------------------------------------------------------------------------
978                         ACPI Bus operations
979    -------------------------------------------------------------------------- */
980 
981 /**
982  * acpi_of_match_device - Match device object using the "compatible" property.
983  * @adev: ACPI device object to match.
984  * @of_match_table: List of device IDs to match against.
985  *
986  * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
987  * identifiers and a _DSD object with the "compatible" property, use that
988  * property to match against the given list of identifiers.
989  */
990 static bool acpi_of_match_device(struct acpi_device *adev,
991                                  const struct of_device_id *of_match_table)
992 {
993         const union acpi_object *of_compatible, *obj;
994         int i, nval;
995 
996         if (!adev)
997                 return false;
998 
999         of_compatible = adev->data.of_compatible;
1000         if (!of_match_table || !of_compatible)
1001                 return false;
1002 
1003         if (of_compatible->type == ACPI_TYPE_PACKAGE) {
1004                 nval = of_compatible->package.count;
1005                 obj = of_compatible->package.elements;
1006         } else { /* Must be ACPI_TYPE_STRING. */
1007                 nval = 1;
1008                 obj = of_compatible;
1009         }
1010         /* Now we can look for the driver DT compatible strings */
1011         for (i = 0; i < nval; i++, obj++) {
1012                 const struct of_device_id *id;
1013 
1014                 for (id = of_match_table; id->compatible[0]; id++)
1015                         if (!strcasecmp(obj->string.pointer, id->compatible))
1016                                 return true;
1017         }
1018 
1019         return false;
1020 }
1021 
1022 static bool __acpi_match_device_cls(const struct acpi_device_id *id,
1023                                     struct acpi_hardware_id *hwid)
1024 {
1025         int i, msk, byte_shift;
1026         char buf[3];
1027 
1028         if (!id->cls)
1029                 return false;
1030 
1031         /* Apply class-code bitmask, before checking each class-code byte */
1032         for (i = 1; i <= 3; i++) {
1033                 byte_shift = 8 * (3 - i);
1034                 msk = (id->cls_msk >> byte_shift) & 0xFF;
1035                 if (!msk)
1036                         continue;
1037 
1038                 sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
1039                 if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
1040                         return false;
1041         }
1042         return true;
1043 }
1044 
1045 static const struct acpi_device_id *__acpi_match_device(
1046         struct acpi_device *device,
1047         const struct acpi_device_id *ids,
1048         const struct of_device_id *of_ids)
1049 {
1050         const struct acpi_device_id *id;
1051         struct acpi_hardware_id *hwid;
1052 
1053         /*
1054          * If the device is not present, it is unnecessary to load device
1055          * driver for it.
1056          */
1057         if (!device || !device->status.present)
1058                 return NULL;
1059 
1060         list_for_each_entry(hwid, &device->pnp.ids, list) {
1061                 /* First, check the ACPI/PNP IDs provided by the caller. */
1062                 for (id = ids; id->id[0] || id->cls; id++) {
1063                         if (id->id[0] && !strcmp((char *) id->id, hwid->id))
1064                                 return id;
1065                         else if (id->cls && __acpi_match_device_cls(id, hwid))
1066                                 return id;
1067                 }
1068 
1069                 /*
1070                  * Next, check ACPI_DT_NAMESPACE_HID and try to match the
1071                  * "compatible" property if found.
1072                  *
1073                  * The id returned by the below is not valid, but the only
1074                  * caller passing non-NULL of_ids here is only interested in
1075                  * whether or not the return value is NULL.
1076                  */
1077                 if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
1078                     && acpi_of_match_device(device, of_ids))
1079                         return id;
1080         }
1081         return NULL;
1082 }
1083 
1084 /**
1085  * acpi_match_device - Match a struct device against a given list of ACPI IDs
1086  * @ids: Array of struct acpi_device_id object to match against.
1087  * @dev: The device structure to match.
1088  *
1089  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
1090  * object for that handle and use that object to match against a given list of
1091  * device IDs.
1092  *
1093  * Return a pointer to the first matching ID on success or %NULL on failure.
1094  */
1095 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
1096                                                const struct device *dev)
1097 {
1098         return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
1099 }
1100 EXPORT_SYMBOL_GPL(acpi_match_device);
1101 
1102 int acpi_match_device_ids(struct acpi_device *device,
1103                           const struct acpi_device_id *ids)
1104 {
1105         return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
1106 }
1107 EXPORT_SYMBOL(acpi_match_device_ids);
1108 
1109 bool acpi_driver_match_device(struct device *dev,
1110                               const struct device_driver *drv)
1111 {
1112         if (!drv->acpi_match_table)
1113                 return acpi_of_match_device(ACPI_COMPANION(dev),
1114                                             drv->of_match_table);
1115 
1116         return !!__acpi_match_device(acpi_companion_match(dev),
1117                                      drv->acpi_match_table, drv->of_match_table);
1118 }
1119 EXPORT_SYMBOL_GPL(acpi_driver_match_device);
1120 
1121 static void acpi_free_power_resources_lists(struct acpi_device *device)
1122 {
1123         int i;
1124 
1125         if (device->wakeup.flags.valid)
1126                 acpi_power_resources_list_free(&device->wakeup.resources);
1127 
1128         if (!device->power.flags.power_resources)
1129                 return;
1130 
1131         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
1132                 struct acpi_device_power_state *ps = &device->power.states[i];
1133                 acpi_power_resources_list_free(&ps->resources);
1134         }
1135 }
1136 
1137 static void acpi_device_release(struct device *dev)
1138 {
1139         struct acpi_device *acpi_dev = to_acpi_device(dev);
1140 
1141         acpi_free_properties(acpi_dev);
1142         acpi_free_pnp_ids(&acpi_dev->pnp);
1143         acpi_free_power_resources_lists(acpi_dev);
1144         kfree(acpi_dev);
1145 }
1146 
1147 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
1148 {
1149         struct acpi_device *acpi_dev = to_acpi_device(dev);
1150         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
1151 
1152         return acpi_dev->flags.match_driver
1153                 && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
1154 }
1155 
1156 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
1157 {
1158         return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
1159 }
1160 
1161 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
1162 {
1163         struct acpi_device *device = data;
1164 
1165         device->driver->ops.notify(device, event);
1166 }
1167 
1168 static void acpi_device_notify_fixed(void *data)
1169 {
1170         struct acpi_device *device = data;
1171 
1172         /* Fixed hardware devices have no handles */
1173         acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
1174 }
1175 
1176 static u32 acpi_device_fixed_event(void *data)
1177 {
1178         acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
1179         return ACPI_INTERRUPT_HANDLED;
1180 }
1181 
1182 static int acpi_device_install_notify_handler(struct acpi_device *device)
1183 {
1184         acpi_status status;
1185 
1186         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1187                 status =
1188                     acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1189                                                      acpi_device_fixed_event,
1190                                                      device);
1191         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1192                 status =
1193                     acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1194                                                      acpi_device_fixed_event,
1195                                                      device);
1196         else
1197                 status = acpi_install_notify_handler(device->handle,
1198                                                      ACPI_DEVICE_NOTIFY,
1199                                                      acpi_device_notify,
1200                                                      device);
1201 
1202         if (ACPI_FAILURE(status))
1203                 return -EINVAL;
1204         return 0;
1205 }
1206 
1207 static void acpi_device_remove_notify_handler(struct acpi_device *device)
1208 {
1209         if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
1210                 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
1211                                                 acpi_device_fixed_event);
1212         else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
1213                 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
1214                                                 acpi_device_fixed_event);
1215         else
1216                 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
1217                                            acpi_device_notify);
1218 }
1219 
1220 static int acpi_device_probe(struct device *dev)
1221 {
1222         struct acpi_device *acpi_dev = to_acpi_device(dev);
1223         struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
1224         int ret;
1225 
1226         if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
1227                 return -EINVAL;
1228 
1229         if (!acpi_drv->ops.add)
1230                 return -ENOSYS;
1231 
1232         ret = acpi_drv->ops.add(acpi_dev);
1233         if (ret)
1234                 return ret;
1235 
1236         acpi_dev->driver = acpi_drv;
1237         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1238                           "Driver [%s] successfully bound to device [%s]\n",
1239                           acpi_drv->name, acpi_dev->pnp.bus_id));
1240 
1241         if (acpi_drv->ops.notify) {
1242                 ret = acpi_device_install_notify_handler(acpi_dev);
1243                 if (ret) {
1244                         if (acpi_drv->ops.remove)
1245                                 acpi_drv->ops.remove(acpi_dev);
1246 
1247                         acpi_dev->driver = NULL;
1248                         acpi_dev->driver_data = NULL;
1249                         return ret;
1250                 }
1251         }
1252 
1253         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
1254                           acpi_drv->name, acpi_dev->pnp.bus_id));
1255         get_device(dev);
1256         return 0;
1257 }
1258 
1259 static int acpi_device_remove(struct device * dev)
1260 {
1261         struct acpi_device *acpi_dev = to_acpi_device(dev);
1262         struct acpi_driver *acpi_drv = acpi_dev->driver;
1263 
1264         if (acpi_drv) {
1265                 if (acpi_drv->ops.notify)
1266                         acpi_device_remove_notify_handler(acpi_dev);
1267                 if (acpi_drv->ops.remove)
1268                         acpi_drv->ops.remove(acpi_dev);
1269         }
1270         acpi_dev->driver = NULL;
1271         acpi_dev->driver_data = NULL;
1272 
1273         put_device(dev);
1274         return 0;
1275 }
1276 
1277 struct bus_type acpi_bus_type = {
1278         .name           = "acpi",
1279         .match          = acpi_bus_match,
1280         .probe          = acpi_device_probe,
1281         .remove         = acpi_device_remove,
1282         .uevent         = acpi_device_uevent,
1283 };
1284 
1285 static void acpi_device_del(struct acpi_device *device)
1286 {
1287         mutex_lock(&acpi_device_lock);
1288         if (device->parent)
1289                 list_del(&device->node);
1290 
1291         list_del(&device->wakeup_list);
1292         mutex_unlock(&acpi_device_lock);
1293 
1294         acpi_power_add_remove_device(device, false);
1295         acpi_device_remove_files(device);
1296         if (device->remove)
1297                 device->remove(device);
1298 
1299         device_del(&device->dev);
1300 }
1301 
1302 static LIST_HEAD(acpi_device_del_list);
1303 static DEFINE_MUTEX(acpi_device_del_lock);
1304 
1305 static void acpi_device_del_work_fn(struct work_struct *work_not_used)
1306 {
1307         for (;;) {
1308                 struct acpi_device *adev;
1309 
1310                 mutex_lock(&acpi_device_del_lock);
1311 
1312                 if (list_empty(&acpi_device_del_list)) {
1313                         mutex_unlock(&acpi_device_del_lock);
1314                         break;
1315                 }
1316                 adev = list_first_entry(&acpi_device_del_list,
1317                                         struct acpi_device, del_list);
1318                 list_del(&adev->del_list);
1319 
1320                 mutex_unlock(&acpi_device_del_lock);
1321 
1322                 acpi_device_del(adev);
1323                 /*
1324                  * Drop references to all power resources that might have been
1325                  * used by the device.
1326                  */
1327                 acpi_power_transition(adev, ACPI_STATE_D3_COLD);
1328                 put_device(&adev->dev);
1329         }
1330 }
1331 
1332 /**
1333  * acpi_scan_drop_device - Drop an ACPI device object.
1334  * @handle: Handle of an ACPI namespace node, not used.
1335  * @context: Address of the ACPI device object to drop.
1336  *
1337  * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
1338  * namespace node the device object pointed to by @context is attached to.
1339  *
1340  * The unregistration is carried out asynchronously to avoid running
1341  * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
1342  * ensure the correct ordering (the device objects must be unregistered in the
1343  * same order in which the corresponding namespace nodes are deleted).
1344  */
1345 static void acpi_scan_drop_device(acpi_handle handle, void *context)
1346 {
1347         static DECLARE_WORK(work, acpi_device_del_work_fn);
1348         struct acpi_device *adev = context;
1349 
1350         mutex_lock(&acpi_device_del_lock);
1351 
1352         /*
1353          * Use the ACPI hotplug workqueue which is ordered, so this work item
1354          * won't run after any hotplug work items submitted subsequently.  That
1355          * prevents attempts to register device objects identical to those being
1356          * deleted from happening concurrently (such attempts result from
1357          * hotplug events handled via the ACPI hotplug workqueue).  It also will
1358          * run after all of the work items submitted previosuly, which helps
1359          * those work items to ensure that they are not accessing stale device
1360          * objects.
1361          */
1362         if (list_empty(&acpi_device_del_list))
1363                 acpi_queue_hotplug_work(&work);
1364 
1365         list_add_tail(&adev->del_list, &acpi_device_del_list);
1366         /* Make acpi_ns_validate_handle() return NULL for this handle. */
1367         adev->handle = INVALID_ACPI_HANDLE;
1368 
1369         mutex_unlock(&acpi_device_del_lock);
1370 }
1371 
1372 static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
1373                                 void (*callback)(void *))
1374 {
1375         acpi_status status;
1376 
1377         if (!device)
1378                 return -EINVAL;
1379 
1380         status = acpi_get_data_full(handle, acpi_scan_drop_device,
1381                                     (void **)device, callback);
1382         if (ACPI_FAILURE(status) || !*device) {
1383                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
1384                                   handle));
1385                 return -ENODEV;
1386         }
1387         return 0;
1388 }
1389 
1390 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
1391 {
1392         return acpi_get_device_data(handle, device, NULL);
1393 }
1394 EXPORT_SYMBOL(acpi_bus_get_device);
1395 
1396 static void get_acpi_device(void *dev)
1397 {
1398         if (dev)
1399                 get_device(&((struct acpi_device *)dev)->dev);
1400 }
1401 
1402 struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
1403 {
1404         struct acpi_device *adev = NULL;
1405 
1406         acpi_get_device_data(handle, &adev, get_acpi_device);
1407         return adev;
1408 }
1409 
1410 void acpi_bus_put_acpi_device(struct acpi_device *adev)
1411 {
1412         put_device(&adev->dev);
1413 }
1414 
1415 int acpi_device_add(struct acpi_device *device,
1416                     void (*release)(struct device *))
1417 {
1418         int result;
1419         struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
1420         int found = 0;
1421 
1422         if (device->handle) {
1423                 acpi_status status;
1424 
1425                 status = acpi_attach_data(device->handle, acpi_scan_drop_device,
1426                                           device);
1427                 if (ACPI_FAILURE(status)) {
1428                         acpi_handle_err(device->handle,
1429                                         "Unable to attach device data\n");
1430                         return -ENODEV;
1431                 }
1432         }
1433 
1434         /*
1435          * Linkage
1436          * -------
1437          * Link this device to its parent and siblings.
1438          */
1439         INIT_LIST_HEAD(&device->children);
1440         INIT_LIST_HEAD(&device->node);
1441         INIT_LIST_HEAD(&device->wakeup_list);
1442         INIT_LIST_HEAD(&device->physical_node_list);
1443         INIT_LIST_HEAD(&device->del_list);
1444         mutex_init(&device->physical_node_lock);
1445 
1446         new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
1447         if (!new_bus_id) {
1448                 pr_err(PREFIX "Memory allocation error\n");
1449                 result = -ENOMEM;
1450                 goto err_detach;
1451         }
1452 
1453         mutex_lock(&acpi_device_lock);
1454         /*
1455          * Find suitable bus_id and instance number in acpi_bus_id_list
1456          * If failed, create one and link it into acpi_bus_id_list
1457          */
1458         list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
1459                 if (!strcmp(acpi_device_bus_id->bus_id,
1460                             acpi_device_hid(device))) {
1461                         acpi_device_bus_id->instance_no++;
1462                         found = 1;
1463                         kfree(new_bus_id);
1464                         break;
1465                 }
1466         }
1467         if (!found) {
1468                 acpi_device_bus_id = new_bus_id;
1469                 strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
1470                 acpi_device_bus_id->instance_no = 0;
1471                 list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
1472         }
1473         dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
1474 
1475         if (device->parent)
1476                 list_add_tail(&device->node, &device->parent->children);
1477 
1478         if (device->wakeup.flags.valid)
1479                 list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1480         mutex_unlock(&acpi_device_lock);
1481 
1482         if (device->parent)
1483                 device->dev.parent = &device->parent->dev;
1484         device->dev.bus = &acpi_bus_type;
1485         device->dev.release = release;
1486         result = device_add(&device->dev);
1487         if (result) {
1488                 dev_err(&device->dev, "Error registering device\n");
1489                 goto err;
1490         }
1491 
1492         result = acpi_device_setup_files(device);
1493         if (result)
1494                 printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1495                        dev_name(&device->dev));
1496 
1497         return 0;
1498 
1499  err:
1500         mutex_lock(&acpi_device_lock);
1501         if (device->parent)
1502                 list_del(&device->node);
1503         list_del(&device->wakeup_list);
1504         mutex_unlock(&acpi_device_lock);
1505 
1506  err_detach:
1507         acpi_detach_data(device->handle, acpi_scan_drop_device);
1508         return result;
1509 }
1510 
1511 struct acpi_device *acpi_get_next_child(struct device *dev,
1512                                         struct acpi_device *child)
1513 {
1514         struct acpi_device *adev = ACPI_COMPANION(dev);
1515         struct list_head *head, *next;
1516 
1517         if (!adev)
1518                 return NULL;
1519 
1520         head = &adev->children;
1521         if (list_empty(head))
1522                 return NULL;
1523 
1524         if (!child)
1525                 return list_first_entry(head, struct acpi_device, node);
1526 
1527         next = child->node.next;
1528         return next == head ? NULL : list_entry(next, struct acpi_device, node);
1529 }
1530 
1531 /* --------------------------------------------------------------------------
1532                                  Driver Management
1533    -------------------------------------------------------------------------- */
1534 /**
1535  * acpi_bus_register_driver - register a driver with the ACPI bus
1536  * @driver: driver being registered
1537  *
1538  * Registers a driver with the ACPI bus.  Searches the namespace for all
1539  * devices that match the driver's criteria and binds.  Returns zero for
1540  * success or a negative error status for failure.
1541  */
1542 int acpi_bus_register_driver(struct acpi_driver *driver)
1543 {
1544         int ret;
1545 
1546         if (acpi_disabled)
1547                 return -ENODEV;
1548         driver->drv.name = driver->name;
1549         driver->drv.bus = &acpi_bus_type;
1550         driver->drv.owner = driver->owner;
1551 
1552         ret = driver_register(&driver->drv);
1553         return ret;
1554 }
1555 
1556 EXPORT_SYMBOL(acpi_bus_register_driver);
1557 
1558 /**
1559  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1560  * @driver: driver to unregister
1561  *
1562  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1563  * devices that match the driver's criteria and unbinds.
1564  */
1565 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1566 {
1567         driver_unregister(&driver->drv);
1568 }
1569 
1570 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1571 
1572 /* --------------------------------------------------------------------------
1573                                  Device Enumeration
1574    -------------------------------------------------------------------------- */
1575 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1576 {
1577         struct acpi_device *device = NULL;
1578         acpi_status status;
1579 
1580         /*
1581          * Fixed hardware devices do not appear in the namespace and do not
1582          * have handles, but we fabricate acpi_devices for them, so we have
1583          * to deal with them specially.
1584          */
1585         if (!handle)
1586                 return acpi_root;
1587 
1588         do {
1589                 status = acpi_get_parent(handle, &handle);
1590                 if (ACPI_FAILURE(status))
1591                         return status == AE_NULL_ENTRY ? NULL : acpi_root;
1592         } while (acpi_bus_get_device(handle, &device));
1593         return device;
1594 }
1595 
1596 acpi_status
1597 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1598 {
1599         acpi_status status;
1600         acpi_handle tmp;
1601         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1602         union acpi_object *obj;
1603 
1604         status = acpi_get_handle(handle, "_EJD", &tmp);
1605         if (ACPI_FAILURE(status))
1606                 return status;
1607 
1608         status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1609         if (ACPI_SUCCESS(status)) {
1610                 obj = buffer.pointer;
1611                 status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1612                                          ejd);
1613                 kfree(buffer.pointer);
1614         }
1615         return status;
1616 }
1617 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1618 
1619 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1620                                         struct acpi_device_wakeup *wakeup)
1621 {
1622         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1623         union acpi_object *package = NULL;
1624         union acpi_object *element = NULL;
1625         acpi_status status;
1626         int err = -ENODATA;
1627 
1628         if (!wakeup)
1629                 return -EINVAL;
1630 
1631         INIT_LIST_HEAD(&wakeup->resources);
1632 
1633         /* _PRW */
1634         status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1635         if (ACPI_FAILURE(status)) {
1636                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1637                 return err;
1638         }
1639 
1640         package = (union acpi_object *)buffer.pointer;
1641 
1642         if (!package || package->package.count < 2)
1643                 goto out;
1644 
1645         element = &(package->package.elements[0]);
1646         if (!element)
1647                 goto out;
1648 
1649         if (element->type == ACPI_TYPE_PACKAGE) {
1650                 if ((element->package.count < 2) ||
1651                     (element->package.elements[0].type !=
1652                      ACPI_TYPE_LOCAL_REFERENCE)
1653                     || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1654                         goto out;
1655 
1656                 wakeup->gpe_device =
1657                     element->package.elements[0].reference.handle;
1658                 wakeup->gpe_number =
1659                     (u32) element->package.elements[1].integer.value;
1660         } else if (element->type == ACPI_TYPE_INTEGER) {
1661                 wakeup->gpe_device = NULL;
1662                 wakeup->gpe_number = element->integer.value;
1663         } else {
1664                 goto out;
1665         }
1666 
1667         element = &(package->package.elements[1]);
1668         if (element->type != ACPI_TYPE_INTEGER)
1669                 goto out;
1670 
1671         wakeup->sleep_state = element->integer.value;
1672 
1673         err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1674         if (err)
1675                 goto out;
1676 
1677         if (!list_empty(&wakeup->resources)) {
1678                 int sleep_state;
1679 
1680                 err = acpi_power_wakeup_list_init(&wakeup->resources,
1681                                                   &sleep_state);
1682                 if (err) {
1683                         acpi_handle_warn(handle, "Retrieving current states "
1684                                          "of wakeup power resources failed\n");
1685                         acpi_power_resources_list_free(&wakeup->resources);
1686                         goto out;
1687                 }
1688                 if (sleep_state < wakeup->sleep_state) {
1689                         acpi_handle_warn(handle, "Overriding _PRW sleep state "
1690                                          "(S%d) by S%d from power resources\n",
1691                                          (int)wakeup->sleep_state, sleep_state);
1692                         wakeup->sleep_state = sleep_state;
1693                 }
1694         }
1695 
1696  out:
1697         kfree(buffer.pointer);
1698         return err;
1699 }
1700 
1701 static void acpi_wakeup_gpe_init(struct acpi_device *device)
1702 {
1703         static const struct acpi_device_id button_device_ids[] = {
1704                 {"PNP0C0C", 0},
1705                 {"PNP0C0D", 0},
1706                 {"PNP0C0E", 0},
1707                 {"", 0},
1708         };
1709         struct acpi_device_wakeup *wakeup = &device->wakeup;
1710         acpi_status status;
1711         acpi_event_status event_status;
1712 
1713         wakeup->flags.notifier_present = 0;
1714 
1715         /* Power button, Lid switch always enable wakeup */
1716         if (!acpi_match_device_ids(device, button_device_ids)) {
1717                 wakeup->flags.run_wake = 1;
1718                 if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1719                         /* Do not use Lid/sleep button for S5 wakeup */
1720                         if (wakeup->sleep_state == ACPI_STATE_S5)
1721                                 wakeup->sleep_state = ACPI_STATE_S4;
1722                 }
1723                 acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
1724                 device_set_wakeup_capable(&device->dev, true);
1725                 return;
1726         }
1727 
1728         acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
1729                                 wakeup->gpe_number);
1730         status = acpi_get_gpe_status(wakeup->gpe_device, wakeup->gpe_number,
1731                                      &event_status);
1732         if (ACPI_FAILURE(status))
1733                 return;
1734 
1735         wakeup->flags.run_wake = !!(event_status & ACPI_EVENT_FLAG_HAS_HANDLER);
1736 }
1737 
1738 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1739 {
1740         int err;
1741 
1742         /* Presence of _PRW indicates wake capable */
1743         if (!acpi_has_method(device->handle, "_PRW"))
1744                 return;
1745 
1746         err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1747                                                            &device->wakeup);
1748         if (err) {
1749                 dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1750                 return;
1751         }
1752 
1753         device->wakeup.flags.valid = 1;
1754         device->wakeup.prepare_count = 0;
1755         acpi_wakeup_gpe_init(device);
1756         /* Call _PSW/_DSW object to disable its ability to wake the sleeping
1757          * system for the ACPI device with the _PRW object.
1758          * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1759          * So it is necessary to call _DSW object first. Only when it is not
1760          * present will the _PSW object used.
1761          */
1762         err = acpi_device_sleep_wake(device, 0, 0, 0);
1763         if (err)
1764                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1765                                 "error in _DSW or _PSW evaluation\n"));
1766 }
1767 
1768 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1769 {
1770         struct acpi_device_power_state *ps = &device->power.states[state];
1771         char pathname[5] = { '_', 'P', 'R', '' + state, '\0' };
1772         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1773         acpi_status status;
1774 
1775         INIT_LIST_HEAD(&ps->resources);
1776 
1777         /* Evaluate "_PRx" to get referenced power resources */
1778         status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1779         if (ACPI_SUCCESS(status)) {
1780                 union acpi_object *package = buffer.pointer;
1781 
1782                 if (buffer.length && package
1783                     && package->type == ACPI_TYPE_PACKAGE
1784                     && package->package.count) {
1785                         int err = acpi_extract_power_resources(package, 0,
1786                                                                &ps->resources);
1787                         if (!err)
1788                                 device->power.flags.power_resources = 1;
1789                 }
1790                 ACPI_FREE(buffer.pointer);
1791         }
1792 
1793         /* Evaluate "_PSx" to see if we can do explicit sets */
1794         pathname[2] = 'S';
1795         if (acpi_has_method(device->handle, pathname))
1796                 ps->flags.explicit_set = 1;
1797 
1798         /* State is valid if there are means to put the device into it. */
1799         if (!list_empty(&ps->resources) || ps->flags.explicit_set)
1800                 ps->flags.valid = 1;
1801 
1802         ps->power = -1;         /* Unknown - driver assigned */
1803         ps->latency = -1;       /* Unknown - driver assigned */
1804 }
1805 
1806 static void acpi_bus_get_power_flags(struct acpi_device *device)
1807 {
1808         u32 i;
1809 
1810         /* Presence of _PS0|_PR0 indicates 'power manageable' */
1811         if (!acpi_has_method(device->handle, "_PS0") &&
1812             !acpi_has_method(device->handle, "_PR0"))
1813                 return;
1814 
1815         device->flags.power_manageable = 1;
1816 
1817         /*
1818          * Power Management Flags
1819          */
1820         if (acpi_has_method(device->handle, "_PSC"))
1821                 device->power.flags.explicit_get = 1;
1822 
1823         if (acpi_has_method(device->handle, "_IRC"))
1824                 device->power.flags.inrush_current = 1;
1825 
1826         if (acpi_has_method(device->handle, "_DSW"))
1827                 device->power.flags.dsw_present = 1;
1828 
1829         /*
1830          * Enumerate supported power management states
1831          */
1832         for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1833                 acpi_bus_init_power_state(device, i);
1834 
1835         INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1836         if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
1837                 device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1838 
1839         /* Set defaults for D0 and D3hot states (always valid) */
1840         device->power.states[ACPI_STATE_D0].flags.valid = 1;
1841         device->power.states[ACPI_STATE_D0].power = 100;
1842         device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;
1843 
1844         if (acpi_bus_init_power(device))
1845                 device->flags.power_manageable = 0;
1846 }
1847 
1848 static void acpi_bus_get_flags(struct acpi_device *device)
1849 {
1850         /* Presence of _STA indicates 'dynamic_status' */
1851         if (acpi_has_method(device->handle, "_STA"))
1852                 device->flags.dynamic_status = 1;
1853 
1854         /* Presence of _RMV indicates 'removable' */
1855         if (acpi_has_method(device->handle, "_RMV"))
1856                 device->flags.removable = 1;
1857 
1858         /* Presence of _EJD|_EJ0 indicates 'ejectable' */
1859         if (acpi_has_method(device->handle, "_EJD") ||
1860             acpi_has_method(device->handle, "_EJ0"))
1861                 device->flags.ejectable = 1;
1862 }
1863 
1864 static void acpi_device_get_busid(struct acpi_device *device)
1865 {
1866         char bus_id[5] = { '?', 0 };
1867         struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1868         int i = 0;
1869 
1870         /*
1871          * Bus ID
1872          * ------
1873          * The device's Bus ID is simply the object name.
1874          * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1875          */
1876         if (ACPI_IS_ROOT_DEVICE(device)) {
1877                 strcpy(device->pnp.bus_id, "ACPI");
1878                 return;
1879         }
1880 
1881         switch (device->device_type) {
1882         case ACPI_BUS_TYPE_POWER_BUTTON:
1883                 strcpy(device->pnp.bus_id, "PWRF");
1884                 break;
1885         case ACPI_BUS_TYPE_SLEEP_BUTTON:
1886                 strcpy(device->pnp.bus_id, "SLPF");
1887                 break;
1888         default:
1889                 acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1890                 /* Clean up trailing underscores (if any) */
1891                 for (i = 3; i > 1; i--) {
1892                         if (bus_id[i] == '_')
1893                                 bus_id[i] = '\0';
1894                         else
1895                                 break;
1896                 }
1897                 strcpy(device->pnp.bus_id, bus_id);
1898                 break;
1899         }
1900 }
1901 
1902 /*
1903  * acpi_ata_match - see if an acpi object is an ATA device
1904  *
1905  * If an acpi object has one of the ACPI ATA methods defined,
1906  * then we can safely call it an ATA device.
1907  */
1908 bool acpi_ata_match(acpi_handle handle)
1909 {
1910         return acpi_has_method(handle, "_GTF") ||
1911                acpi_has_method(handle, "_GTM") ||
1912                acpi_has_method(handle, "_STM") ||
1913                acpi_has_method(handle, "_SDD");
1914 }
1915 
1916 /*
1917  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1918  *
1919  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1920  * then we can safely call it an ejectable drive bay
1921  */
1922 bool acpi_bay_match(acpi_handle handle)
1923 {
1924         acpi_handle phandle;
1925 
1926         if (!acpi_has_method(handle, "_EJ0"))
1927                 return false;
1928         if (acpi_ata_match(handle))
1929                 return true;
1930         if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1931                 return false;
1932 
1933         return acpi_ata_match(phandle);
1934 }
1935 
1936 bool acpi_device_is_battery(struct acpi_device *adev)
1937 {
1938         struct acpi_hardware_id *hwid;
1939 
1940         list_for_each_entry(hwid, &adev->pnp.ids, list)
1941                 if (!strcmp("PNP0C0A", hwid->id))
1942                         return true;
1943 
1944         return false;
1945 }
1946 
1947 static bool is_ejectable_bay(struct acpi_device *adev)
1948 {
1949         acpi_handle handle = adev->handle;
1950 
1951         if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
1952                 return true;
1953 
1954         return acpi_bay_match(handle);
1955 }
1956 
1957 /*
1958  * acpi_dock_match - see if an acpi object has a _DCK method
1959  */
1960 bool acpi_dock_match(acpi_handle handle)
1961 {
1962         return acpi_has_method(handle, "_DCK");
1963 }
1964 
1965 static acpi_status
1966 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
1967                           void **return_value)
1968 {
1969         long *cap = context;
1970 
1971         if (acpi_has_method(handle, "_BCM") &&
1972             acpi_has_method(handle, "_BCL")) {
1973                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
1974                                   "support\n"));
1975                 *cap |= ACPI_VIDEO_BACKLIGHT;
1976                 if (!acpi_has_method(handle, "_BQC"))
1977                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
1978                                 "cannot determine initial brightness\n");
1979                 /* We have backlight support, no need to scan further */
1980                 return AE_CTRL_TERMINATE;
1981         }
1982         return 0;
1983 }
1984 
1985 /* Returns true if the ACPI object is a video device which can be
1986  * handled by video.ko.
1987  * The device will get a Linux specific CID added in scan.c to
1988  * identify the device as an ACPI graphics device
1989  * Be aware that the graphics device may not be physically present
1990  * Use acpi_video_get_capabilities() to detect general ACPI video
1991  * capabilities of present cards
1992  */
1993 long acpi_is_video_device(acpi_handle handle)
1994 {
1995         long video_caps = 0;
1996 
1997         /* Is this device able to support video switching ? */
1998         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
1999                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
2000 
2001         /* Is this device able to retrieve a video ROM ? */
2002         if (acpi_has_method(handle, "_ROM"))
2003                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
2004 
2005         /* Is this device able to configure which video head to be POSTed ? */
2006         if (acpi_has_method(handle, "_VPO") &&
2007             acpi_has_method(handle, "_GPD") &&
2008             acpi_has_method(handle, "_SPD"))
2009                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
2010 
2011         /* Only check for backlight functionality if one of the above hit. */
2012         if (video_caps)
2013                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
2014                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
2015                                     &video_caps, NULL);
2016 
2017         return video_caps;
2018 }
2019 EXPORT_SYMBOL(acpi_is_video_device);
2020 
2021 const char *acpi_device_hid(struct acpi_device *device)
2022 {
2023         struct acpi_hardware_id *hid;
2024 
2025         if (list_empty(&device->pnp.ids))
2026                 return dummy_hid;
2027 
2028         hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
2029         return hid->id;
2030 }
2031 EXPORT_SYMBOL(acpi_device_hid);
2032 
2033 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
2034 {
2035         struct acpi_hardware_id *id;
2036 
2037         id = kmalloc(sizeof(*id), GFP_KERNEL);
2038         if (!id)
2039                 return;
2040 
2041         id->id = kstrdup(dev_id, GFP_KERNEL);
2042         if (!id->id) {
2043                 kfree(id);
2044                 return;
2045         }
2046 
2047         list_add_tail(&id->list, &pnp->ids);
2048         pnp->type.hardware_id = 1;
2049 }
2050 
2051 /*
2052  * Old IBM workstations have a DSDT bug wherein the SMBus object
2053  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
2054  * prefix.  Work around this.
2055  */
2056 static bool acpi_ibm_smbus_match(acpi_handle handle)
2057 {
2058         char node_name[ACPI_PATH_SEGMENT_LENGTH];
2059         struct acpi_buffer path = { sizeof(node_name), node_name };
2060 
2061         if (!dmi_name_in_vendors("IBM"))
2062                 return false;
2063 
2064         /* Look for SMBS object */
2065         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
2066             strcmp("SMBS", path.pointer))
2067                 return false;
2068 
2069         /* Does it have the necessary (but misnamed) methods? */
2070         if (acpi_has_method(handle, "SBI") &&
2071             acpi_has_method(handle, "SBR") &&
2072             acpi_has_method(handle, "SBW"))
2073                 return true;
2074 
2075         return false;
2076 }
2077 
2078 static bool acpi_object_is_system_bus(acpi_handle handle)
2079 {
2080         acpi_handle tmp;
2081 
2082         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
2083             tmp == handle)
2084                 return true;
2085         if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
2086             tmp == handle)
2087                 return true;
2088 
2089         return false;
2090 }
2091 
2092 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
2093                                 int device_type)
2094 {
2095         acpi_status status;
2096         struct acpi_device_info *info;
2097         struct acpi_pnp_device_id_list *cid_list;
2098         int i;
2099 
2100         switch (device_type) {
2101         case ACPI_BUS_TYPE_DEVICE:
2102                 if (handle == ACPI_ROOT_OBJECT) {
2103                         acpi_add_id(pnp, ACPI_SYSTEM_HID);
2104                         break;
2105                 }
2106 
2107                 status = acpi_get_object_info(handle, &info);
2108                 if (ACPI_FAILURE(status)) {
2109                         pr_err(PREFIX "%s: Error reading device info\n",
2110                                         __func__);
2111                         return;
2112                 }
2113 
2114                 if (info->valid & ACPI_VALID_HID) {
2115                         acpi_add_id(pnp, info->hardware_id.string);
2116                         pnp->type.platform_id = 1;
2117                 }
2118                 if (info->valid & ACPI_VALID_CID) {
2119                         cid_list = &info->compatible_id_list;
2120                         for (i = 0; i < cid_list->count; i++)
2121                                 acpi_add_id(pnp, cid_list->ids[i].string);
2122                 }
2123                 if (info->valid & ACPI_VALID_ADR) {
2124                         pnp->bus_address = info->address;
2125                         pnp->type.bus_address = 1;
2126                 }
2127                 if (info->valid & ACPI_VALID_UID)
2128                         pnp->unique_id = kstrdup(info->unique_id.string,
2129                                                         GFP_KERNEL);
2130                 if (info->valid & ACPI_VALID_CLS)
2131                         acpi_add_id(pnp, info->class_code.string);
2132 
2133                 kfree(info);
2134 
2135                 /*
2136                  * Some devices don't reliably have _HIDs & _CIDs, so add
2137                  * synthetic HIDs to make sure drivers can find them.
2138                  */
2139                 if (acpi_is_video_device(handle))
2140                         acpi_add_id(pnp, ACPI_VIDEO_HID);
2141                 else if (acpi_bay_match(handle))
2142                         acpi_add_id(pnp, ACPI_BAY_HID);
2143                 else if (acpi_dock_match(handle))
2144                         acpi_add_id(pnp, ACPI_DOCK_HID);
2145                 else if (acpi_ibm_smbus_match(handle))
2146                         acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
2147                 else if (list_empty(&pnp->ids) &&
2148                          acpi_object_is_system_bus(handle)) {
2149                         /* \_SB, \_TZ, LNXSYBUS */
2150                         acpi_add_id(pnp, ACPI_BUS_HID);
2151                         strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
2152                         strcpy(pnp->device_class, ACPI_BUS_CLASS);
2153                 }
2154 
2155                 break;
2156         case ACPI_BUS_TYPE_POWER:
2157                 acpi_add_id(pnp, ACPI_POWER_HID);
2158                 break;
2159         case ACPI_BUS_TYPE_PROCESSOR:
2160                 acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
2161                 break;
2162         case ACPI_BUS_TYPE_THERMAL:
2163                 acpi_add_id(pnp, ACPI_THERMAL_HID);
2164                 break;
2165         case ACPI_BUS_TYPE_POWER_BUTTON:
2166                 acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
2167                 break;
2168         case ACPI_BUS_TYPE_SLEEP_BUTTON:
2169                 acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
2170                 break;
2171         }
2172 }
2173 
2174 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
2175 {
2176         struct acpi_hardware_id *id, *tmp;
2177 
2178         list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
2179                 kfree(id->id);
2180                 kfree(id);
2181         }
2182         kfree(pnp->unique_id);
2183 }
2184 
2185 static void acpi_init_coherency(struct acpi_device *adev)
2186 {
2187         unsigned long long cca = 0;
2188         acpi_status status;
2189         struct acpi_device *parent = adev->parent;
2190 
2191         if (parent && parent->flags.cca_seen) {
2192                 /*
2193                  * From ACPI spec, OSPM will ignore _CCA if an ancestor
2194                  * already saw one.
2195                  */
2196                 adev->flags.cca_seen = 1;
2197                 cca = parent->flags.coherent_dma;
2198         } else {
2199                 status = acpi_evaluate_integer(adev->handle, "_CCA",
2200                                                NULL, &cca);
2201                 if (ACPI_SUCCESS(status))
2202                         adev->flags.cca_seen = 1;
2203                 else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
2204                         /*
2205                          * If architecture does not specify that _CCA is
2206                          * required for DMA-able devices (e.g. x86),
2207                          * we default to _CCA=1.
2208                          */
2209                         cca = 1;
2210                 else
2211                         acpi_handle_debug(adev->handle,
2212                                           "ACPI device is missing _CCA.\n");
2213         }
2214 
2215         adev->flags.coherent_dma = cca;
2216 }
2217 
2218 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
2219                              int type, unsigned long long sta)
2220 {
2221         INIT_LIST_HEAD(&device->pnp.ids);
2222         device->device_type = type;
2223         device->handle = handle;
2224         device->parent = acpi_bus_get_parent(handle);
2225         device->fwnode.type = FWNODE_ACPI;
2226         acpi_set_device_status(device, sta);
2227         acpi_device_get_busid(device);
2228         acpi_set_pnp_ids(handle, &device->pnp, type);
2229         acpi_init_properties(device);
2230         acpi_bus_get_flags(device);
2231         device->flags.match_driver = false;
2232         device->flags.initialized = true;
2233         device->flags.visited = false;
2234         device_initialize(&device->dev);
2235         dev_set_uevent_suppress(&device->dev, true);
2236         acpi_init_coherency(device);
2237 }
2238 
2239 void acpi_device_add_finalize(struct acpi_device *device)
2240 {
2241         dev_set_uevent_suppress(&device->dev, false);
2242         kobject_uevent(&device->dev.kobj, KOBJ_ADD);
2243 }
2244 
2245 static int acpi_add_single_object(struct acpi_device **child,
2246                                   acpi_handle handle, int type,
2247                                   unsigned long long sta)
2248 {
2249         int result;
2250         struct acpi_device *device;
2251         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
2252 
2253         device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
2254         if (!device) {
2255                 printk(KERN_ERR PREFIX "Memory allocation error\n");
2256                 return -ENOMEM;
2257         }
2258 
2259         acpi_init_device_object(device, handle, type, sta);
2260         acpi_bus_get_power_flags(device);
2261         acpi_bus_get_wakeup_device_flags(device);
2262 
2263         result = acpi_device_add(device, acpi_device_release);
2264         if (result) {
2265                 acpi_device_release(&device->dev);
2266                 return result;
2267         }
2268 
2269         acpi_power_add_remove_device(device, true);
2270         acpi_device_add_finalize(device);
2271         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
2272         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
2273                 dev_name(&device->dev), (char *) buffer.pointer,
2274                 device->parent ? dev_name(&device->parent->dev) : "(null)"));
2275         kfree(buffer.pointer);
2276         *child = device;
2277         return 0;
2278 }
2279 
2280 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
2281                                     unsigned long long *sta)
2282 {
2283         acpi_status status;
2284         acpi_object_type acpi_type;
2285 
2286         status = acpi_get_type(handle, &acpi_type);
2287         if (ACPI_FAILURE(status))
2288                 return -ENODEV;
2289 
2290         switch (acpi_type) {
2291         case ACPI_TYPE_ANY:             /* for ACPI_ROOT_OBJECT */
2292         case ACPI_TYPE_DEVICE:
2293                 *type = ACPI_BUS_TYPE_DEVICE;
2294                 status = acpi_bus_get_status_handle(handle, sta);
2295                 if (ACPI_FAILURE(status))
2296                         return -ENODEV;
2297                 break;
2298         case ACPI_TYPE_PROCESSOR:
2299                 *type = ACPI_BUS_TYPE_PROCESSOR;
2300                 status = acpi_bus_get_status_handle(handle, sta);
2301                 if (ACPI_FAILURE(status))
2302                         return -ENODEV;
2303                 break;
2304         case ACPI_TYPE_THERMAL:
2305                 *type = ACPI_BUS_TYPE_THERMAL;
2306                 *sta = ACPI_STA_DEFAULT;
2307                 break;
2308         case ACPI_TYPE_POWER:
2309                 *type = ACPI_BUS_TYPE_POWER;
2310                 *sta = ACPI_STA_DEFAULT;
2311                 break;
2312         default:
2313                 return -ENODEV;
2314         }
2315 
2316         return 0;
2317 }
2318 
2319 bool acpi_device_is_present(struct acpi_device *adev)
2320 {
2321         if (adev->status.present || adev->status.functional)
2322                 return true;
2323 
2324         adev->flags.initialized = false;
2325         return false;
2326 }
2327 
2328 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
2329                                        char *idstr,
2330                                        const struct acpi_device_id **matchid)
2331 {
2332         const struct acpi_device_id *devid;
2333 
2334         if (handler->match)
2335                 return handler->match(idstr, matchid);
2336 
2337         for (devid = handler->ids; devid->id[0]; devid++)
2338                 if (!strcmp((char *)devid->id, idstr)) {
2339                         if (matchid)
2340                                 *matchid = devid;
2341 
2342                         return true;
2343                 }
2344 
2345         return false;
2346 }
2347 
2348 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
2349                                         const struct acpi_device_id **matchid)
2350 {
2351         struct acpi_scan_handler *handler;
2352 
2353         list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
2354                 if (acpi_scan_handler_matching(handler, idstr, matchid))
2355                         return handler;
2356 
2357         return NULL;
2358 }
2359 
2360 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
2361 {
2362         if (!!hotplug->enabled == !!val)
2363                 return;
2364 
2365         mutex_lock(&acpi_scan_lock);
2366 
2367         hotplug->enabled = val;
2368 
2369         mutex_unlock(&acpi_scan_lock);
2370 }
2371 
2372 static void acpi_scan_init_hotplug(struct acpi_device *adev)
2373 {
2374         struct acpi_hardware_id *hwid;
2375 
2376         if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
2377                 acpi_dock_add(adev);
2378                 return;
2379         }
2380         list_for_each_entry(hwid, &adev->pnp.ids, list) {
2381                 struct acpi_scan_handler *handler;
2382 
2383                 handler = acpi_scan_match_handler(hwid->id, NULL);
2384                 if (handler) {
2385                         adev->flags.hotplug_notify = true;
2386                         break;
2387                 }
2388         }
2389 }
2390 
2391 static void acpi_device_dep_initialize(struct acpi_device *adev)
2392 {
2393         struct acpi_dep_data *dep;
2394         struct acpi_handle_list dep_devices;
2395         acpi_status status;
2396         int i;
2397 
2398         if (!acpi_has_method(adev->handle, "_DEP"))
2399                 return;
2400 
2401         status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
2402                                         &dep_devices);
2403         if (ACPI_FAILURE(status)) {
2404                 dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n");
2405                 return;
2406         }
2407 
2408         for (i = 0; i < dep_devices.count; i++) {
2409                 struct acpi_device_info *info;
2410                 int skip;
2411 
2412                 status = acpi_get_object_info(dep_devices.handles[i], &info);
2413                 if (ACPI_FAILURE(status)) {
2414                         dev_dbg(&adev->dev, "Error reading _DEP device info\n");
2415                         continue;
2416                 }
2417 
2418                 /*
2419                  * Skip the dependency of Windows System Power
2420                  * Management Controller
2421                  */
2422                 skip = info->valid & ACPI_VALID_HID &&
2423                         !strcmp(info->hardware_id.string, "INT3396");
2424 
2425                 kfree(info);
2426 
2427                 if (skip)
2428                         continue;
2429 
2430                 dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
2431                 if (!dep)
2432                         return;
2433 
2434                 dep->master = dep_devices.handles[i];
2435                 dep->slave  = adev->handle;
2436                 adev->dep_unmet++;
2437 
2438                 mutex_lock(&acpi_dep_list_lock);
2439                 list_add_tail(&dep->node , &acpi_dep_list);
2440                 mutex_unlock(&acpi_dep_list_lock);
2441         }
2442 }
2443 
2444 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
2445                                       void *not_used, void **return_value)
2446 {
2447         struct acpi_device *device = NULL;
2448         int type;
2449         unsigned long long sta;
2450         int result;
2451 
2452         acpi_bus_get_device(handle, &device);
2453         if (device)
2454                 goto out;
2455 
2456         result = acpi_bus_type_and_status(handle, &type, &sta);
2457         if (result)
2458                 return AE_OK;
2459 
2460         if (type == ACPI_BUS_TYPE_POWER) {
2461                 acpi_add_power_resource(handle);
2462                 return AE_OK;
2463         }
2464 
2465         acpi_add_single_object(&device, handle, type, sta);
2466         if (!device)
2467                 return AE_CTRL_DEPTH;
2468 
2469         acpi_scan_init_hotplug(device);
2470         acpi_device_dep_initialize(device);
2471 
2472  out:
2473         if (!*return_value)
2474                 *return_value = device;
2475 
2476         return AE_OK;
2477 }
2478 
2479 static int acpi_check_spi_i2c_slave(struct acpi_resource *ares, void *data)
2480 {
2481         bool *is_spi_i2c_slave_p = data;
2482 
2483         if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2484                 return 1;
2485 
2486         /*
2487          * devices that are connected to UART still need to be enumerated to
2488          * platform bus
2489          */
2490         if (ares->data.common_serial_bus.type != ACPI_RESOURCE_SERIAL_TYPE_UART)
2491                 *is_spi_i2c_slave_p = true;
2492 
2493          /* no need to do more checking */
2494         return -1;
2495 }
2496 
2497 static void acpi_default_enumeration(struct acpi_device *device)
2498 {
2499         struct list_head resource_list;
2500         bool is_spi_i2c_slave = false;
2501 
2502         /*
2503          * Do not enemerate SPI/I2C slaves as they will be enuerated by their
2504          * respective parents.
2505          */
2506         INIT_LIST_HEAD(&resource_list);
2507         acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
2508                                &is_spi_i2c_slave);
2509         acpi_dev_free_resource_list(&resource_list);
2510         if (!is_spi_i2c_slave)
2511                 acpi_create_platform_device(device);
2512 }
2513 
2514 static const struct acpi_device_id generic_device_ids[] = {
2515         {ACPI_DT_NAMESPACE_HID, },
2516         {"", },
2517 };
2518 
2519 static int acpi_generic_device_attach(struct acpi_device *adev,
2520                                       const struct acpi_device_id *not_used)
2521 {
2522         /*
2523          * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
2524          * below can be unconditional.
2525          */
2526         if (adev->data.of_compatible)
2527                 acpi_default_enumeration(adev);
2528 
2529         return 1;
2530 }
2531 
2532 static struct acpi_scan_handler generic_device_handler = {
2533         .ids = generic_device_ids,
2534         .attach = acpi_generic_device_attach,
2535 };
2536 
2537 static int acpi_scan_attach_handler(struct acpi_device *device)
2538 {
2539         struct acpi_hardware_id *hwid;
2540         int ret = 0;
2541 
2542         list_for_each_entry(hwid, &device->pnp.ids, list) {
2543                 const struct acpi_device_id *devid;
2544                 struct acpi_scan_handler *handler;
2545 
2546                 handler = acpi_scan_match_handler(hwid->id, &devid);
2547                 if (handler) {
2548                         if (!handler->attach) {
2549                                 device->pnp.type.platform_id = 0;
2550                                 continue;
2551                         }
2552                         device->handler = handler;
2553                         ret = handler->attach(device, devid);
2554                         if (ret > 0)
2555                                 break;
2556 
2557                         device->handler = NULL;
2558                         if (ret < 0)
2559                                 break;
2560                 }
2561         }
2562 
2563         return ret;
2564 }
2565 
2566 static void acpi_bus_attach(struct acpi_device *device)
2567 {
2568         struct acpi_device *child;
2569         acpi_handle ejd;
2570         int ret;
2571 
2572         if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
2573                 register_dock_dependent_device(device, ejd);
2574 
2575         acpi_bus_get_status(device);
2576         /* Skip devices that are not present. */
2577         if (!acpi_device_is_present(device)) {
2578                 device->flags.visited = false;
2579                 device->flags.power_manageable = 0;
2580                 return;
2581         }
2582         if (device->handler)
2583                 goto ok;
2584 
2585         if (!device->flags.initialized) {
2586                 device->flags.power_manageable =
2587                         device->power.states[ACPI_STATE_D0].flags.valid;
2588                 if (acpi_bus_init_power(device))
2589                         device->flags.power_manageable = 0;
2590 
2591                 device->flags.initialized = true;
2592         }
2593         device->flags.visited = false;
2594         ret = acpi_scan_attach_handler(device);
2595         if (ret < 0)
2596                 return;
2597 
2598         device->flags.match_driver = true;
2599         if (!ret) {
2600                 ret = device_attach(&device->dev);
2601                 if (ret < 0)
2602                         return;
2603 
2604                 if (!ret && device->pnp.type.platform_id)
2605                         acpi_default_enumeration(device);
2606         }
2607         device->flags.visited = true;
2608 
2609  ok:
2610         list_for_each_entry(child, &device->children, node)
2611                 acpi_bus_attach(child);
2612 
2613         if (device->handler && device->handler->hotplug.notify_online)
2614                 device->handler->hotplug.notify_online(device);
2615 }
2616 
2617 void acpi_walk_dep_device_list(acpi_handle handle)
2618 {
2619         struct acpi_dep_data *dep, *tmp;
2620         struct acpi_device *adev;
2621 
2622         mutex_lock(&acpi_dep_list_lock);
2623         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
2624                 if (dep->master == handle) {
2625                         acpi_bus_get_device(dep->slave, &adev);
2626                         if (!adev)
2627                                 continue;
2628 
2629                         adev->dep_unmet--;
2630                         if (!adev->dep_unmet)
2631                                 acpi_bus_attach(adev);
2632                         list_del(&dep->node);
2633                         kfree(dep);
2634                 }
2635         }
2636         mutex_unlock(&acpi_dep_list_lock);
2637 }
2638 EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
2639 
2640 /**
2641  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
2642  * @handle: Root of the namespace scope to scan.
2643  *
2644  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
2645  * found devices.
2646  *
2647  * If no devices were found, -ENODEV is returned, but it does not mean that
2648  * there has been a real error.  There just have been no suitable ACPI objects
2649  * in the table trunk from which the kernel could create a device and add an
2650  * appropriate driver.
2651  *
2652  * Must be called under acpi_scan_lock.
2653  */
2654 int acpi_bus_scan(acpi_handle handle)
2655 {
2656         void *device = NULL;
2657 
2658         if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
2659                 acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
2660                                     acpi_bus_check_add, NULL, NULL, &device);
2661 
2662         if (device) {
2663                 acpi_bus_attach(device);
2664                 return 0;
2665         }
2666         return -ENODEV;
2667 }
2668 EXPORT_SYMBOL(acpi_bus_scan);
2669 
2670 /**
2671  * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
2672  * @adev: Root of the ACPI namespace scope to walk.
2673  *
2674  * Must be called under acpi_scan_lock.
2675  */
2676 void acpi_bus_trim(struct acpi_device *adev)
2677 {
2678         struct acpi_scan_handler *handler = adev->handler;
2679         struct acpi_device *child;
2680 
2681         list_for_each_entry_reverse(child, &adev->children, node)
2682                 acpi_bus_trim(child);
2683 
2684         adev->flags.match_driver = false;
2685         if (handler) {
2686                 if (handler->detach)
2687                         handler->detach(adev);
2688 
2689                 adev->handler = NULL;
2690         } else {
2691                 device_release_driver(&adev->dev);
2692         }
2693         /*
2694          * Most likely, the device is going away, so put it into D3cold before
2695          * that.
2696          */
2697         acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
2698         adev->flags.initialized = false;
2699         adev->flags.visited = false;
2700 }
2701 EXPORT_SYMBOL_GPL(acpi_bus_trim);
2702 
2703 static int acpi_bus_scan_fixed(void)
2704 {
2705         int result = 0;
2706 
2707         /*
2708          * Enumerate all fixed-feature devices.
2709          */
2710         if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
2711                 struct acpi_device *device = NULL;
2712 
2713                 result = acpi_add_single_object(&device, NULL,
2714                                                 ACPI_BUS_TYPE_POWER_BUTTON,
2715                                                 ACPI_STA_DEFAULT);
2716                 if (result)
2717                         return result;
2718 
2719                 device->flags.match_driver = true;
2720                 result = device_attach(&device->dev);
2721                 if (result < 0)
2722                         return result;
2723 
2724                 device_init_wakeup(&device->dev, true);
2725         }
2726 
2727         if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2728                 struct acpi_device *device = NULL;
2729 
2730                 result = acpi_add_single_object(&device, NULL,
2731                                                 ACPI_BUS_TYPE_SLEEP_BUTTON,
2732                                                 ACPI_STA_DEFAULT);
2733                 if (result)
2734                         return result;
2735 
2736                 device->flags.match_driver = true;
2737                 result = device_attach(&device->dev);
2738         }
2739 
2740         return result < 0 ? result : 0;
2741 }
2742 
2743 int __init acpi_scan_init(void)
2744 {
2745         int result;
2746 
2747         result = bus_register(&acpi_bus_type);
2748         if (result) {
2749                 /* We don't want to quit even if we failed to add suspend/resume */
2750                 printk(KERN_ERR PREFIX "Could not register bus type\n");
2751         }
2752 
2753         acpi_pci_root_init();
2754         acpi_pci_link_init();
2755         acpi_processor_init();
2756         acpi_lpss_init();
2757         acpi_apd_init();
2758         acpi_cmos_rtc_init();
2759         acpi_container_init();
2760         acpi_memory_hotplug_init();
2761         acpi_pnp_init();
2762         acpi_int340x_thermal_init();
2763 
2764         acpi_scan_add_handler(&generic_device_handler);
2765 
2766         mutex_lock(&acpi_scan_lock);
2767         /*
2768          * Enumerate devices in the ACPI namespace.
2769          */
2770         result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2771         if (result)
2772                 goto out;
2773 
2774         result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2775         if (result)
2776                 goto out;
2777 
2778         /* Fixed feature devices do not exist on HW-reduced platform */
2779         if (!acpi_gbl_reduced_hardware) {
2780                 result = acpi_bus_scan_fixed();
2781                 if (result) {
2782                         acpi_detach_data(acpi_root->handle,
2783                                          acpi_scan_drop_device);
2784                         acpi_device_del(acpi_root);
2785                         put_device(&acpi_root->dev);
2786                         goto out;
2787                 }
2788         }
2789 
2790         acpi_update_all_gpes();
2791 
2792  out:
2793         mutex_unlock(&acpi_scan_lock);
2794         return result;
2795 }
2796 

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