xref: /linux/drivers/acpi/scan.c (revision 498d319bb512992ef0784c278fa03679f2f5649d)
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 
15 #include <acpi/acpi_drivers.h>
16 
17 #include "internal.h"
18 
19 #define _COMPONENT		ACPI_BUS_COMPONENT
20 ACPI_MODULE_NAME("scan");
21 #define STRUCT_TO_INT(s)	(*((int*)&s))
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 /*
31  * If set, devices will be hot-removed even if they cannot be put offline
32  * gracefully (from the kernel's standpoint).
33  */
34 bool acpi_force_hot_remove;
35 
36 static const char *dummy_hid = "device";
37 
38 static LIST_HEAD(acpi_bus_id_list);
39 static DEFINE_MUTEX(acpi_scan_lock);
40 static LIST_HEAD(acpi_scan_handlers_list);
41 DEFINE_MUTEX(acpi_device_lock);
42 LIST_HEAD(acpi_wakeup_device_list);
43 
44 struct acpi_device_bus_id{
45 	char bus_id[15];
46 	unsigned int instance_no;
47 	struct list_head node;
48 };
49 
50 void acpi_scan_lock_acquire(void)
51 {
52 	mutex_lock(&acpi_scan_lock);
53 }
54 EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);
55 
56 void acpi_scan_lock_release(void)
57 {
58 	mutex_unlock(&acpi_scan_lock);
59 }
60 EXPORT_SYMBOL_GPL(acpi_scan_lock_release);
61 
62 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
63 {
64 	if (!handler || !handler->attach)
65 		return -EINVAL;
66 
67 	list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
68 	return 0;
69 }
70 
71 int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
72 				       const char *hotplug_profile_name)
73 {
74 	int error;
75 
76 	error = acpi_scan_add_handler(handler);
77 	if (error)
78 		return error;
79 
80 	acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
81 	return 0;
82 }
83 
84 /*
85  * Creates hid/cid(s) string needed for modalias and uevent
86  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
87  * char *modalias: "acpi:IBM0001:ACPI0001"
88 */
89 static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
90 			   int size)
91 {
92 	int len;
93 	int count;
94 	struct acpi_hardware_id *id;
95 
96 	if (list_empty(&acpi_dev->pnp.ids))
97 		return 0;
98 
99 	len = snprintf(modalias, size, "acpi:");
100 	size -= len;
101 
102 	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
103 		count = snprintf(&modalias[len], size, "%s:", id->id);
104 		if (count < 0 || count >= size)
105 			return -EINVAL;
106 		len += count;
107 		size -= count;
108 	}
109 
110 	modalias[len] = '\0';
111 	return len;
112 }
113 
114 static ssize_t
115 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
116 	struct acpi_device *acpi_dev = to_acpi_device(dev);
117 	int len;
118 
119 	/* Device has no HID and no CID or string is >1024 */
120 	len = create_modalias(acpi_dev, buf, 1024);
121 	if (len <= 0)
122 		return 0;
123 	buf[len++] = '\n';
124 	return len;
125 }
126 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
127 
128 static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
129 				    void **ret_p)
130 {
131 	struct acpi_device *device = NULL;
132 	struct acpi_device_physical_node *pn;
133 	bool second_pass = (bool)data;
134 	acpi_status status = AE_OK;
135 
136 	if (acpi_bus_get_device(handle, &device))
137 		return AE_OK;
138 
139 	if (device->handler && !device->handler->hotplug.enabled) {
140 		*ret_p = &device->dev;
141 		return AE_SUPPORT;
142 	}
143 
144 	mutex_lock(&device->physical_node_lock);
145 
146 	list_for_each_entry(pn, &device->physical_node_list, node) {
147 		int ret;
148 
149 		if (second_pass) {
150 			/* Skip devices offlined by the first pass. */
151 			if (pn->put_online)
152 				continue;
153 		} else {
154 			pn->put_online = false;
155 		}
156 		ret = device_offline(pn->dev);
157 		if (acpi_force_hot_remove)
158 			continue;
159 
160 		if (ret >= 0) {
161 			pn->put_online = !ret;
162 		} else {
163 			*ret_p = pn->dev;
164 			if (second_pass) {
165 				status = AE_ERROR;
166 				break;
167 			}
168 		}
169 	}
170 
171 	mutex_unlock(&device->physical_node_lock);
172 
173 	return status;
174 }
175 
176 static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
177 				   void **ret_p)
178 {
179 	struct acpi_device *device = NULL;
180 	struct acpi_device_physical_node *pn;
181 
182 	if (acpi_bus_get_device(handle, &device))
183 		return AE_OK;
184 
185 	mutex_lock(&device->physical_node_lock);
186 
187 	list_for_each_entry(pn, &device->physical_node_list, node)
188 		if (pn->put_online) {
189 			device_online(pn->dev);
190 			pn->put_online = false;
191 		}
192 
193 	mutex_unlock(&device->physical_node_lock);
194 
195 	return AE_OK;
196 }
197 
198 static int acpi_scan_hot_remove(struct acpi_device *device)
199 {
200 	acpi_handle handle = device->handle;
201 	struct device *errdev;
202 	acpi_status status;
203 	unsigned long long sta;
204 
205 	/* If there is no handle, the device node has been unregistered. */
206 	if (!handle) {
207 		dev_dbg(&device->dev, "ACPI handle missing\n");
208 		put_device(&device->dev);
209 		return -EINVAL;
210 	}
211 
212 	/*
213 	 * Carry out two passes here and ignore errors in the first pass,
214 	 * because if the devices in question are memory blocks and
215 	 * CONFIG_MEMCG is set, one of the blocks may hold data structures
216 	 * that the other blocks depend on, but it is not known in advance which
217 	 * block holds them.
218 	 *
219 	 * If the first pass is successful, the second one isn't needed, though.
220 	 */
221 	errdev = NULL;
222 	status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
223 				     NULL, acpi_bus_offline, (void *)false,
224 				     (void **)&errdev);
225 	if (status == AE_SUPPORT) {
226 		dev_warn(errdev, "Offline disabled.\n");
227 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
228 				    acpi_bus_online, NULL, NULL, NULL);
229 		put_device(&device->dev);
230 		return -EPERM;
231 	}
232 	acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
233 	if (errdev) {
234 		errdev = NULL;
235 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
236 				    NULL, acpi_bus_offline, (void *)true,
237 				    (void **)&errdev);
238 		if (!errdev || acpi_force_hot_remove)
239 			acpi_bus_offline(handle, 0, (void *)true,
240 					 (void **)&errdev);
241 
242 		if (errdev && !acpi_force_hot_remove) {
243 			dev_warn(errdev, "Offline failed.\n");
244 			acpi_bus_online(handle, 0, NULL, NULL);
245 			acpi_walk_namespace(ACPI_TYPE_ANY, handle,
246 					    ACPI_UINT32_MAX, acpi_bus_online,
247 					    NULL, NULL, NULL);
248 			put_device(&device->dev);
249 			return -EBUSY;
250 		}
251 	}
252 
253 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
254 		"Hot-removing device %s...\n", dev_name(&device->dev)));
255 
256 	acpi_bus_trim(device);
257 
258 	/* Device node has been unregistered. */
259 	put_device(&device->dev);
260 	device = NULL;
261 
262 	acpi_evaluate_lck(handle, 0);
263 	/*
264 	 * TBD: _EJD support.
265 	 */
266 	status = acpi_evaluate_ej0(handle);
267 	if (status == AE_NOT_FOUND)
268 		return -ENODEV;
269 	else if (ACPI_FAILURE(status))
270 		return -EIO;
271 
272 	/*
273 	 * Verify if eject was indeed successful.  If not, log an error
274 	 * message.  No need to call _OST since _EJ0 call was made OK.
275 	 */
276 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
277 	if (ACPI_FAILURE(status)) {
278 		acpi_handle_warn(handle,
279 			"Status check after eject failed (0x%x)\n", status);
280 	} else if (sta & ACPI_STA_DEVICE_ENABLED) {
281 		acpi_handle_warn(handle,
282 			"Eject incomplete - status 0x%llx\n", sta);
283 	}
284 
285 	return 0;
286 }
287 
288 void acpi_bus_device_eject(void *data, u32 ost_src)
289 {
290 	struct acpi_device *device = data;
291 	acpi_handle handle = device->handle;
292 	struct acpi_scan_handler *handler;
293 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
294 	int error;
295 
296 	lock_device_hotplug();
297 	mutex_lock(&acpi_scan_lock);
298 
299 	handler = device->handler;
300 	if (!handler || !handler->hotplug.enabled) {
301 		put_device(&device->dev);
302 		goto err_support;
303 	}
304 
305 	if (ost_src == ACPI_NOTIFY_EJECT_REQUEST)
306 		acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
307 					  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
308 
309 	if (handler->hotplug.mode == AHM_CONTAINER)
310 		kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
311 
312 	error = acpi_scan_hot_remove(device);
313 	if (error == -EPERM) {
314 		goto err_support;
315 	} else if (error) {
316 		goto err_out;
317 	}
318 
319  out:
320 	mutex_unlock(&acpi_scan_lock);
321 	unlock_device_hotplug();
322 	return;
323 
324  err_support:
325 	ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
326  err_out:
327 	acpi_evaluate_hotplug_ost(handle, ost_src, ost_code, NULL);
328 	goto out;
329 }
330 
331 static void acpi_scan_bus_device_check(void *data, u32 ost_source)
332 {
333 	acpi_handle handle = data;
334 	struct acpi_device *device = NULL;
335 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
336 	int error;
337 
338 	lock_device_hotplug();
339 	mutex_lock(&acpi_scan_lock);
340 
341 	if (ost_source != ACPI_NOTIFY_BUS_CHECK) {
342 		acpi_bus_get_device(handle, &device);
343 		if (device) {
344 			dev_warn(&device->dev, "Attempt to re-insert\n");
345 			goto out;
346 		}
347 	}
348 	error = acpi_bus_scan(handle);
349 	if (error) {
350 		acpi_handle_warn(handle, "Namespace scan failure\n");
351 		goto out;
352 	}
353 	error = acpi_bus_get_device(handle, &device);
354 	if (error) {
355 		acpi_handle_warn(handle, "Missing device node object\n");
356 		goto out;
357 	}
358 	ost_code = ACPI_OST_SC_SUCCESS;
359 	if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
360 		kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
361 
362  out:
363 	acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
364 	mutex_unlock(&acpi_scan_lock);
365 	unlock_device_hotplug();
366 }
367 
368 static void acpi_hotplug_unsupported(acpi_handle handle, u32 type)
369 {
370 	u32 ost_status;
371 
372 	switch (type) {
373 	case ACPI_NOTIFY_BUS_CHECK:
374 		acpi_handle_debug(handle,
375 			"ACPI_NOTIFY_BUS_CHECK event: unsupported\n");
376 		ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
377 		break;
378 	case ACPI_NOTIFY_DEVICE_CHECK:
379 		acpi_handle_debug(handle,
380 			"ACPI_NOTIFY_DEVICE_CHECK event: unsupported\n");
381 		ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
382 		break;
383 	case ACPI_NOTIFY_EJECT_REQUEST:
384 		acpi_handle_debug(handle,
385 			"ACPI_NOTIFY_EJECT_REQUEST event: unsupported\n");
386 		ost_status = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
387 		break;
388 	default:
389 		/* non-hotplug event; possibly handled by other handler */
390 		return;
391 	}
392 
393 	acpi_evaluate_hotplug_ost(handle, type, ost_status, NULL);
394 }
395 
396 static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
397 {
398 	struct acpi_scan_handler *handler = data;
399 	struct acpi_device *adev;
400 	acpi_status status;
401 
402 	if (!handler->hotplug.enabled)
403 		return acpi_hotplug_unsupported(handle, type);
404 
405 	switch (type) {
406 	case ACPI_NOTIFY_BUS_CHECK:
407 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
408 		break;
409 	case ACPI_NOTIFY_DEVICE_CHECK:
410 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
411 		break;
412 	case ACPI_NOTIFY_EJECT_REQUEST:
413 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
414 		status = acpi_bus_get_device(handle, &adev);
415 		if (ACPI_FAILURE(status))
416 			goto err_out;
417 
418 		get_device(&adev->dev);
419 		status = acpi_hotplug_execute(acpi_bus_device_eject, adev, type);
420 		if (ACPI_SUCCESS(status))
421 			return;
422 
423 		put_device(&adev->dev);
424 		goto err_out;
425 	default:
426 		/* non-hotplug event; possibly handled by other handler */
427 		return;
428 	}
429 	status = acpi_hotplug_execute(acpi_scan_bus_device_check, handle, type);
430 	if (ACPI_SUCCESS(status))
431 		return;
432 
433  err_out:
434 	acpi_evaluate_hotplug_ost(handle, type,
435 				  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
436 }
437 
438 static ssize_t real_power_state_show(struct device *dev,
439 				     struct device_attribute *attr, char *buf)
440 {
441 	struct acpi_device *adev = to_acpi_device(dev);
442 	int state;
443 	int ret;
444 
445 	ret = acpi_device_get_power(adev, &state);
446 	if (ret)
447 		return ret;
448 
449 	return sprintf(buf, "%s\n", acpi_power_state_string(state));
450 }
451 
452 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
453 
454 static ssize_t power_state_show(struct device *dev,
455 				struct device_attribute *attr, char *buf)
456 {
457 	struct acpi_device *adev = to_acpi_device(dev);
458 
459 	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
460 }
461 
462 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
463 
464 static ssize_t
465 acpi_eject_store(struct device *d, struct device_attribute *attr,
466 		const char *buf, size_t count)
467 {
468 	struct acpi_device *acpi_device = to_acpi_device(d);
469 	acpi_object_type not_used;
470 	acpi_status status;
471 
472 	if (!count || buf[0] != '1')
473 		return -EINVAL;
474 
475 	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
476 	    && !acpi_device->driver)
477 		return -ENODEV;
478 
479 	status = acpi_get_type(acpi_device->handle, &not_used);
480 	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
481 		return -ENODEV;
482 
483 	acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
484 				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
485 	get_device(&acpi_device->dev);
486 	status = acpi_hotplug_execute(acpi_bus_device_eject, acpi_device,
487 				      ACPI_OST_EC_OSPM_EJECT);
488 	if (ACPI_SUCCESS(status))
489 		return count;
490 
491 	put_device(&acpi_device->dev);
492 	acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
493 				  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
494 	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
495 }
496 
497 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
498 
499 static ssize_t
500 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
501 	struct acpi_device *acpi_dev = to_acpi_device(dev);
502 
503 	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
504 }
505 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
506 
507 static ssize_t acpi_device_uid_show(struct device *dev,
508 				    struct device_attribute *attr, char *buf)
509 {
510 	struct acpi_device *acpi_dev = to_acpi_device(dev);
511 
512 	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
513 }
514 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
515 
516 static ssize_t acpi_device_adr_show(struct device *dev,
517 				    struct device_attribute *attr, char *buf)
518 {
519 	struct acpi_device *acpi_dev = to_acpi_device(dev);
520 
521 	return sprintf(buf, "0x%08x\n",
522 		       (unsigned int)(acpi_dev->pnp.bus_address));
523 }
524 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
525 
526 static ssize_t
527 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
528 	struct acpi_device *acpi_dev = to_acpi_device(dev);
529 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
530 	int result;
531 
532 	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
533 	if (result)
534 		goto end;
535 
536 	result = sprintf(buf, "%s\n", (char*)path.pointer);
537 	kfree(path.pointer);
538 end:
539 	return result;
540 }
541 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
542 
543 /* sysfs file that shows description text from the ACPI _STR method */
544 static ssize_t description_show(struct device *dev,
545 				struct device_attribute *attr,
546 				char *buf) {
547 	struct acpi_device *acpi_dev = to_acpi_device(dev);
548 	int result;
549 
550 	if (acpi_dev->pnp.str_obj == NULL)
551 		return 0;
552 
553 	/*
554 	 * The _STR object contains a Unicode identifier for a device.
555 	 * We need to convert to utf-8 so it can be displayed.
556 	 */
557 	result = utf16s_to_utf8s(
558 		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
559 		acpi_dev->pnp.str_obj->buffer.length,
560 		UTF16_LITTLE_ENDIAN, buf,
561 		PAGE_SIZE);
562 
563 	buf[result++] = '\n';
564 
565 	return result;
566 }
567 static DEVICE_ATTR(description, 0444, description_show, NULL);
568 
569 static ssize_t
570 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
571 		     char *buf) {
572 	struct acpi_device *acpi_dev = to_acpi_device(dev);
573 
574 	return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
575 }
576 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
577 
578 static int acpi_device_setup_files(struct acpi_device *dev)
579 {
580 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
581 	acpi_status status;
582 	unsigned long long sun;
583 	int result = 0;
584 
585 	/*
586 	 * Devices gotten from FADT don't have a "path" attribute
587 	 */
588 	if (dev->handle) {
589 		result = device_create_file(&dev->dev, &dev_attr_path);
590 		if (result)
591 			goto end;
592 	}
593 
594 	if (!list_empty(&dev->pnp.ids)) {
595 		result = device_create_file(&dev->dev, &dev_attr_hid);
596 		if (result)
597 			goto end;
598 
599 		result = device_create_file(&dev->dev, &dev_attr_modalias);
600 		if (result)
601 			goto end;
602 	}
603 
604 	/*
605 	 * If device has _STR, 'description' file is created
606 	 */
607 	if (acpi_has_method(dev->handle, "_STR")) {
608 		status = acpi_evaluate_object(dev->handle, "_STR",
609 					NULL, &buffer);
610 		if (ACPI_FAILURE(status))
611 			buffer.pointer = NULL;
612 		dev->pnp.str_obj = buffer.pointer;
613 		result = device_create_file(&dev->dev, &dev_attr_description);
614 		if (result)
615 			goto end;
616 	}
617 
618 	if (dev->pnp.type.bus_address)
619 		result = device_create_file(&dev->dev, &dev_attr_adr);
620 	if (dev->pnp.unique_id)
621 		result = device_create_file(&dev->dev, &dev_attr_uid);
622 
623 	status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
624 	if (ACPI_SUCCESS(status)) {
625 		dev->pnp.sun = (unsigned long)sun;
626 		result = device_create_file(&dev->dev, &dev_attr_sun);
627 		if (result)
628 			goto end;
629 	} else {
630 		dev->pnp.sun = (unsigned long)-1;
631 	}
632 
633         /*
634          * If device has _EJ0, 'eject' file is created that is used to trigger
635          * hot-removal function from userland.
636          */
637 	if (acpi_has_method(dev->handle, "_EJ0")) {
638 		result = device_create_file(&dev->dev, &dev_attr_eject);
639 		if (result)
640 			return result;
641 	}
642 
643 	if (dev->flags.power_manageable) {
644 		result = device_create_file(&dev->dev, &dev_attr_power_state);
645 		if (result)
646 			return result;
647 
648 		if (dev->power.flags.power_resources)
649 			result = device_create_file(&dev->dev,
650 						    &dev_attr_real_power_state);
651 	}
652 
653 end:
654 	return result;
655 }
656 
657 static void acpi_device_remove_files(struct acpi_device *dev)
658 {
659 	if (dev->flags.power_manageable) {
660 		device_remove_file(&dev->dev, &dev_attr_power_state);
661 		if (dev->power.flags.power_resources)
662 			device_remove_file(&dev->dev,
663 					   &dev_attr_real_power_state);
664 	}
665 
666 	/*
667 	 * If device has _STR, remove 'description' file
668 	 */
669 	if (acpi_has_method(dev->handle, "_STR")) {
670 		kfree(dev->pnp.str_obj);
671 		device_remove_file(&dev->dev, &dev_attr_description);
672 	}
673 	/*
674 	 * If device has _EJ0, remove 'eject' file.
675 	 */
676 	if (acpi_has_method(dev->handle, "_EJ0"))
677 		device_remove_file(&dev->dev, &dev_attr_eject);
678 
679 	if (acpi_has_method(dev->handle, "_SUN"))
680 		device_remove_file(&dev->dev, &dev_attr_sun);
681 
682 	if (dev->pnp.unique_id)
683 		device_remove_file(&dev->dev, &dev_attr_uid);
684 	if (dev->pnp.type.bus_address)
685 		device_remove_file(&dev->dev, &dev_attr_adr);
686 	device_remove_file(&dev->dev, &dev_attr_modalias);
687 	device_remove_file(&dev->dev, &dev_attr_hid);
688 	if (dev->handle)
689 		device_remove_file(&dev->dev, &dev_attr_path);
690 }
691 /* --------------------------------------------------------------------------
692 			ACPI Bus operations
693    -------------------------------------------------------------------------- */
694 
695 static const struct acpi_device_id *__acpi_match_device(
696 	struct acpi_device *device, const struct acpi_device_id *ids)
697 {
698 	const struct acpi_device_id *id;
699 	struct acpi_hardware_id *hwid;
700 
701 	/*
702 	 * If the device is not present, it is unnecessary to load device
703 	 * driver for it.
704 	 */
705 	if (!device->status.present)
706 		return NULL;
707 
708 	for (id = ids; id->id[0]; id++)
709 		list_for_each_entry(hwid, &device->pnp.ids, list)
710 			if (!strcmp((char *) id->id, hwid->id))
711 				return id;
712 
713 	return NULL;
714 }
715 
716 /**
717  * acpi_match_device - Match a struct device against a given list of ACPI IDs
718  * @ids: Array of struct acpi_device_id object to match against.
719  * @dev: The device structure to match.
720  *
721  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
722  * object for that handle and use that object to match against a given list of
723  * device IDs.
724  *
725  * Return a pointer to the first matching ID on success or %NULL on failure.
726  */
727 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
728 					       const struct device *dev)
729 {
730 	struct acpi_device *adev;
731 	acpi_handle handle = ACPI_HANDLE(dev);
732 
733 	if (!ids || !handle || acpi_bus_get_device(handle, &adev))
734 		return NULL;
735 
736 	return __acpi_match_device(adev, ids);
737 }
738 EXPORT_SYMBOL_GPL(acpi_match_device);
739 
740 int acpi_match_device_ids(struct acpi_device *device,
741 			  const struct acpi_device_id *ids)
742 {
743 	return __acpi_match_device(device, ids) ? 0 : -ENOENT;
744 }
745 EXPORT_SYMBOL(acpi_match_device_ids);
746 
747 static void acpi_free_power_resources_lists(struct acpi_device *device)
748 {
749 	int i;
750 
751 	if (device->wakeup.flags.valid)
752 		acpi_power_resources_list_free(&device->wakeup.resources);
753 
754 	if (!device->flags.power_manageable)
755 		return;
756 
757 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
758 		struct acpi_device_power_state *ps = &device->power.states[i];
759 		acpi_power_resources_list_free(&ps->resources);
760 	}
761 }
762 
763 static void acpi_device_release(struct device *dev)
764 {
765 	struct acpi_device *acpi_dev = to_acpi_device(dev);
766 
767 	acpi_free_pnp_ids(&acpi_dev->pnp);
768 	acpi_free_power_resources_lists(acpi_dev);
769 	kfree(acpi_dev);
770 }
771 
772 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
773 {
774 	struct acpi_device *acpi_dev = to_acpi_device(dev);
775 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
776 
777 	return acpi_dev->flags.match_driver
778 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
779 }
780 
781 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
782 {
783 	struct acpi_device *acpi_dev = to_acpi_device(dev);
784 	int len;
785 
786 	if (list_empty(&acpi_dev->pnp.ids))
787 		return 0;
788 
789 	if (add_uevent_var(env, "MODALIAS="))
790 		return -ENOMEM;
791 	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
792 			      sizeof(env->buf) - env->buflen);
793 	if (len >= (sizeof(env->buf) - env->buflen))
794 		return -ENOMEM;
795 	env->buflen += len;
796 	return 0;
797 }
798 
799 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
800 {
801 	struct acpi_device *device = data;
802 
803 	device->driver->ops.notify(device, event);
804 }
805 
806 static acpi_status acpi_device_notify_fixed(void *data)
807 {
808 	struct acpi_device *device = data;
809 
810 	/* Fixed hardware devices have no handles */
811 	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
812 	return AE_OK;
813 }
814 
815 static int acpi_device_install_notify_handler(struct acpi_device *device)
816 {
817 	acpi_status status;
818 
819 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
820 		status =
821 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
822 						     acpi_device_notify_fixed,
823 						     device);
824 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
825 		status =
826 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
827 						     acpi_device_notify_fixed,
828 						     device);
829 	else
830 		status = acpi_install_notify_handler(device->handle,
831 						     ACPI_DEVICE_NOTIFY,
832 						     acpi_device_notify,
833 						     device);
834 
835 	if (ACPI_FAILURE(status))
836 		return -EINVAL;
837 	return 0;
838 }
839 
840 static void acpi_device_remove_notify_handler(struct acpi_device *device)
841 {
842 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
843 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
844 						acpi_device_notify_fixed);
845 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
846 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
847 						acpi_device_notify_fixed);
848 	else
849 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
850 					   acpi_device_notify);
851 }
852 
853 static int acpi_device_probe(struct device *dev)
854 {
855 	struct acpi_device *acpi_dev = to_acpi_device(dev);
856 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
857 	int ret;
858 
859 	if (acpi_dev->handler)
860 		return -EINVAL;
861 
862 	if (!acpi_drv->ops.add)
863 		return -ENOSYS;
864 
865 	ret = acpi_drv->ops.add(acpi_dev);
866 	if (ret)
867 		return ret;
868 
869 	acpi_dev->driver = acpi_drv;
870 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
871 			  "Driver [%s] successfully bound to device [%s]\n",
872 			  acpi_drv->name, acpi_dev->pnp.bus_id));
873 
874 	if (acpi_drv->ops.notify) {
875 		ret = acpi_device_install_notify_handler(acpi_dev);
876 		if (ret) {
877 			if (acpi_drv->ops.remove)
878 				acpi_drv->ops.remove(acpi_dev);
879 
880 			acpi_dev->driver = NULL;
881 			acpi_dev->driver_data = NULL;
882 			return ret;
883 		}
884 	}
885 
886 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
887 			  acpi_drv->name, acpi_dev->pnp.bus_id));
888 	get_device(dev);
889 	return 0;
890 }
891 
892 static int acpi_device_remove(struct device * dev)
893 {
894 	struct acpi_device *acpi_dev = to_acpi_device(dev);
895 	struct acpi_driver *acpi_drv = acpi_dev->driver;
896 
897 	if (acpi_drv) {
898 		if (acpi_drv->ops.notify)
899 			acpi_device_remove_notify_handler(acpi_dev);
900 		if (acpi_drv->ops.remove)
901 			acpi_drv->ops.remove(acpi_dev);
902 	}
903 	acpi_dev->driver = NULL;
904 	acpi_dev->driver_data = NULL;
905 
906 	put_device(dev);
907 	return 0;
908 }
909 
910 struct bus_type acpi_bus_type = {
911 	.name		= "acpi",
912 	.match		= acpi_bus_match,
913 	.probe		= acpi_device_probe,
914 	.remove		= acpi_device_remove,
915 	.uevent		= acpi_device_uevent,
916 };
917 
918 static void acpi_bus_data_handler(acpi_handle handle, void *context)
919 {
920 	/* Intentionally empty. */
921 }
922 
923 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
924 {
925 	acpi_status status;
926 
927 	if (!device)
928 		return -EINVAL;
929 
930 	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
931 	if (ACPI_FAILURE(status) || !*device) {
932 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
933 				  handle));
934 		return -ENODEV;
935 	}
936 	return 0;
937 }
938 EXPORT_SYMBOL(acpi_bus_get_device);
939 
940 int acpi_device_add(struct acpi_device *device,
941 		    void (*release)(struct device *))
942 {
943 	int result;
944 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
945 	int found = 0;
946 
947 	if (device->handle) {
948 		acpi_status status;
949 
950 		status = acpi_attach_data(device->handle, acpi_bus_data_handler,
951 					  device);
952 		if (ACPI_FAILURE(status)) {
953 			acpi_handle_err(device->handle,
954 					"Unable to attach device data\n");
955 			return -ENODEV;
956 		}
957 	}
958 
959 	/*
960 	 * Linkage
961 	 * -------
962 	 * Link this device to its parent and siblings.
963 	 */
964 	INIT_LIST_HEAD(&device->children);
965 	INIT_LIST_HEAD(&device->node);
966 	INIT_LIST_HEAD(&device->wakeup_list);
967 	INIT_LIST_HEAD(&device->physical_node_list);
968 	mutex_init(&device->physical_node_lock);
969 
970 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
971 	if (!new_bus_id) {
972 		pr_err(PREFIX "Memory allocation error\n");
973 		result = -ENOMEM;
974 		goto err_detach;
975 	}
976 
977 	mutex_lock(&acpi_device_lock);
978 	/*
979 	 * Find suitable bus_id and instance number in acpi_bus_id_list
980 	 * If failed, create one and link it into acpi_bus_id_list
981 	 */
982 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
983 		if (!strcmp(acpi_device_bus_id->bus_id,
984 			    acpi_device_hid(device))) {
985 			acpi_device_bus_id->instance_no++;
986 			found = 1;
987 			kfree(new_bus_id);
988 			break;
989 		}
990 	}
991 	if (!found) {
992 		acpi_device_bus_id = new_bus_id;
993 		strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
994 		acpi_device_bus_id->instance_no = 0;
995 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
996 	}
997 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
998 
999 	if (device->parent)
1000 		list_add_tail(&device->node, &device->parent->children);
1001 
1002 	if (device->wakeup.flags.valid)
1003 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
1004 	mutex_unlock(&acpi_device_lock);
1005 
1006 	if (device->parent)
1007 		device->dev.parent = &device->parent->dev;
1008 	device->dev.bus = &acpi_bus_type;
1009 	device->dev.release = release;
1010 	result = device_add(&device->dev);
1011 	if (result) {
1012 		dev_err(&device->dev, "Error registering device\n");
1013 		goto err;
1014 	}
1015 
1016 	result = acpi_device_setup_files(device);
1017 	if (result)
1018 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1019 		       dev_name(&device->dev));
1020 
1021 	return 0;
1022 
1023  err:
1024 	mutex_lock(&acpi_device_lock);
1025 	if (device->parent)
1026 		list_del(&device->node);
1027 	list_del(&device->wakeup_list);
1028 	mutex_unlock(&acpi_device_lock);
1029 
1030  err_detach:
1031 	acpi_detach_data(device->handle, acpi_bus_data_handler);
1032 	return result;
1033 }
1034 
1035 static void acpi_device_unregister(struct acpi_device *device)
1036 {
1037 	mutex_lock(&acpi_device_lock);
1038 	if (device->parent)
1039 		list_del(&device->node);
1040 
1041 	list_del(&device->wakeup_list);
1042 	mutex_unlock(&acpi_device_lock);
1043 
1044 	acpi_detach_data(device->handle, acpi_bus_data_handler);
1045 
1046 	acpi_power_add_remove_device(device, false);
1047 	acpi_device_remove_files(device);
1048 	if (device->remove)
1049 		device->remove(device);
1050 
1051 	device_del(&device->dev);
1052 	/*
1053 	 * Transition the device to D3cold to drop the reference counts of all
1054 	 * power resources the device depends on and turn off the ones that have
1055 	 * no more references.
1056 	 */
1057 	acpi_device_set_power(device, ACPI_STATE_D3_COLD);
1058 	device->handle = NULL;
1059 	put_device(&device->dev);
1060 }
1061 
1062 /* --------------------------------------------------------------------------
1063                                  Driver Management
1064    -------------------------------------------------------------------------- */
1065 /**
1066  * acpi_bus_register_driver - register a driver with the ACPI bus
1067  * @driver: driver being registered
1068  *
1069  * Registers a driver with the ACPI bus.  Searches the namespace for all
1070  * devices that match the driver's criteria and binds.  Returns zero for
1071  * success or a negative error status for failure.
1072  */
1073 int acpi_bus_register_driver(struct acpi_driver *driver)
1074 {
1075 	int ret;
1076 
1077 	if (acpi_disabled)
1078 		return -ENODEV;
1079 	driver->drv.name = driver->name;
1080 	driver->drv.bus = &acpi_bus_type;
1081 	driver->drv.owner = driver->owner;
1082 
1083 	ret = driver_register(&driver->drv);
1084 	return ret;
1085 }
1086 
1087 EXPORT_SYMBOL(acpi_bus_register_driver);
1088 
1089 /**
1090  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1091  * @driver: driver to unregister
1092  *
1093  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1094  * devices that match the driver's criteria and unbinds.
1095  */
1096 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1097 {
1098 	driver_unregister(&driver->drv);
1099 }
1100 
1101 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1102 
1103 /* --------------------------------------------------------------------------
1104                                  Device Enumeration
1105    -------------------------------------------------------------------------- */
1106 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1107 {
1108 	struct acpi_device *device = NULL;
1109 	acpi_status status;
1110 
1111 	/*
1112 	 * Fixed hardware devices do not appear in the namespace and do not
1113 	 * have handles, but we fabricate acpi_devices for them, so we have
1114 	 * to deal with them specially.
1115 	 */
1116 	if (!handle)
1117 		return acpi_root;
1118 
1119 	do {
1120 		status = acpi_get_parent(handle, &handle);
1121 		if (ACPI_FAILURE(status))
1122 			return status == AE_NULL_ENTRY ? NULL : acpi_root;
1123 	} while (acpi_bus_get_device(handle, &device));
1124 	return device;
1125 }
1126 
1127 acpi_status
1128 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1129 {
1130 	acpi_status status;
1131 	acpi_handle tmp;
1132 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1133 	union acpi_object *obj;
1134 
1135 	status = acpi_get_handle(handle, "_EJD", &tmp);
1136 	if (ACPI_FAILURE(status))
1137 		return status;
1138 
1139 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1140 	if (ACPI_SUCCESS(status)) {
1141 		obj = buffer.pointer;
1142 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1143 					 ejd);
1144 		kfree(buffer.pointer);
1145 	}
1146 	return status;
1147 }
1148 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1149 
1150 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1151 					struct acpi_device_wakeup *wakeup)
1152 {
1153 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1154 	union acpi_object *package = NULL;
1155 	union acpi_object *element = NULL;
1156 	acpi_status status;
1157 	int err = -ENODATA;
1158 
1159 	if (!wakeup)
1160 		return -EINVAL;
1161 
1162 	INIT_LIST_HEAD(&wakeup->resources);
1163 
1164 	/* _PRW */
1165 	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1166 	if (ACPI_FAILURE(status)) {
1167 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1168 		return err;
1169 	}
1170 
1171 	package = (union acpi_object *)buffer.pointer;
1172 
1173 	if (!package || package->package.count < 2)
1174 		goto out;
1175 
1176 	element = &(package->package.elements[0]);
1177 	if (!element)
1178 		goto out;
1179 
1180 	if (element->type == ACPI_TYPE_PACKAGE) {
1181 		if ((element->package.count < 2) ||
1182 		    (element->package.elements[0].type !=
1183 		     ACPI_TYPE_LOCAL_REFERENCE)
1184 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1185 			goto out;
1186 
1187 		wakeup->gpe_device =
1188 		    element->package.elements[0].reference.handle;
1189 		wakeup->gpe_number =
1190 		    (u32) element->package.elements[1].integer.value;
1191 	} else if (element->type == ACPI_TYPE_INTEGER) {
1192 		wakeup->gpe_device = NULL;
1193 		wakeup->gpe_number = element->integer.value;
1194 	} else {
1195 		goto out;
1196 	}
1197 
1198 	element = &(package->package.elements[1]);
1199 	if (element->type != ACPI_TYPE_INTEGER)
1200 		goto out;
1201 
1202 	wakeup->sleep_state = element->integer.value;
1203 
1204 	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1205 	if (err)
1206 		goto out;
1207 
1208 	if (!list_empty(&wakeup->resources)) {
1209 		int sleep_state;
1210 
1211 		err = acpi_power_wakeup_list_init(&wakeup->resources,
1212 						  &sleep_state);
1213 		if (err) {
1214 			acpi_handle_warn(handle, "Retrieving current states "
1215 					 "of wakeup power resources failed\n");
1216 			acpi_power_resources_list_free(&wakeup->resources);
1217 			goto out;
1218 		}
1219 		if (sleep_state < wakeup->sleep_state) {
1220 			acpi_handle_warn(handle, "Overriding _PRW sleep state "
1221 					 "(S%d) by S%d from power resources\n",
1222 					 (int)wakeup->sleep_state, sleep_state);
1223 			wakeup->sleep_state = sleep_state;
1224 		}
1225 	}
1226 	acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
1227 
1228  out:
1229 	kfree(buffer.pointer);
1230 	return err;
1231 }
1232 
1233 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
1234 {
1235 	struct acpi_device_id button_device_ids[] = {
1236 		{"PNP0C0C", 0},
1237 		{"PNP0C0D", 0},
1238 		{"PNP0C0E", 0},
1239 		{"", 0},
1240 	};
1241 	acpi_status status;
1242 	acpi_event_status event_status;
1243 
1244 	device->wakeup.flags.notifier_present = 0;
1245 
1246 	/* Power button, Lid switch always enable wakeup */
1247 	if (!acpi_match_device_ids(device, button_device_ids)) {
1248 		device->wakeup.flags.run_wake = 1;
1249 		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1250 			/* Do not use Lid/sleep button for S5 wakeup */
1251 			if (device->wakeup.sleep_state == ACPI_STATE_S5)
1252 				device->wakeup.sleep_state = ACPI_STATE_S4;
1253 		}
1254 		device_set_wakeup_capable(&device->dev, true);
1255 		return;
1256 	}
1257 
1258 	status = acpi_get_gpe_status(device->wakeup.gpe_device,
1259 					device->wakeup.gpe_number,
1260 						&event_status);
1261 	if (status == AE_OK)
1262 		device->wakeup.flags.run_wake =
1263 				!!(event_status & ACPI_EVENT_FLAG_HANDLE);
1264 }
1265 
1266 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1267 {
1268 	int err;
1269 
1270 	/* Presence of _PRW indicates wake capable */
1271 	if (!acpi_has_method(device->handle, "_PRW"))
1272 		return;
1273 
1274 	err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1275 							   &device->wakeup);
1276 	if (err) {
1277 		dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1278 		return;
1279 	}
1280 
1281 	device->wakeup.flags.valid = 1;
1282 	device->wakeup.prepare_count = 0;
1283 	acpi_bus_set_run_wake_flags(device);
1284 	/* Call _PSW/_DSW object to disable its ability to wake the sleeping
1285 	 * system for the ACPI device with the _PRW object.
1286 	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1287 	 * So it is necessary to call _DSW object first. Only when it is not
1288 	 * present will the _PSW object used.
1289 	 */
1290 	err = acpi_device_sleep_wake(device, 0, 0, 0);
1291 	if (err)
1292 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1293 				"error in _DSW or _PSW evaluation\n"));
1294 }
1295 
1296 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1297 {
1298 	struct acpi_device_power_state *ps = &device->power.states[state];
1299 	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1300 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1301 	acpi_status status;
1302 
1303 	INIT_LIST_HEAD(&ps->resources);
1304 
1305 	/* Evaluate "_PRx" to get referenced power resources */
1306 	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1307 	if (ACPI_SUCCESS(status)) {
1308 		union acpi_object *package = buffer.pointer;
1309 
1310 		if (buffer.length && package
1311 		    && package->type == ACPI_TYPE_PACKAGE
1312 		    && package->package.count) {
1313 			int err = acpi_extract_power_resources(package, 0,
1314 							       &ps->resources);
1315 			if (!err)
1316 				device->power.flags.power_resources = 1;
1317 		}
1318 		ACPI_FREE(buffer.pointer);
1319 	}
1320 
1321 	/* Evaluate "_PSx" to see if we can do explicit sets */
1322 	pathname[2] = 'S';
1323 	if (acpi_has_method(device->handle, pathname))
1324 		ps->flags.explicit_set = 1;
1325 
1326 	/*
1327 	 * State is valid if there are means to put the device into it.
1328 	 * D3hot is only valid if _PR3 present.
1329 	 */
1330 	if (!list_empty(&ps->resources)
1331 	    || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1332 		ps->flags.valid = 1;
1333 		ps->flags.os_accessible = 1;
1334 	}
1335 
1336 	ps->power = -1;		/* Unknown - driver assigned */
1337 	ps->latency = -1;	/* Unknown - driver assigned */
1338 }
1339 
1340 static void acpi_bus_get_power_flags(struct acpi_device *device)
1341 {
1342 	u32 i;
1343 
1344 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
1345 	if (!acpi_has_method(device->handle, "_PS0") &&
1346 	    !acpi_has_method(device->handle, "_PR0"))
1347 		return;
1348 
1349 	device->flags.power_manageable = 1;
1350 
1351 	/*
1352 	 * Power Management Flags
1353 	 */
1354 	if (acpi_has_method(device->handle, "_PSC"))
1355 		device->power.flags.explicit_get = 1;
1356 	if (acpi_has_method(device->handle, "_IRC"))
1357 		device->power.flags.inrush_current = 1;
1358 
1359 	/*
1360 	 * Enumerate supported power management states
1361 	 */
1362 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1363 		acpi_bus_init_power_state(device, i);
1364 
1365 	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1366 
1367 	/* Set defaults for D0 and D3 states (always valid) */
1368 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
1369 	device->power.states[ACPI_STATE_D0].power = 100;
1370 	device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1371 	device->power.states[ACPI_STATE_D3_COLD].power = 0;
1372 
1373 	/* Set D3cold's explicit_set flag if _PS3 exists. */
1374 	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1375 		device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1376 
1377 	/* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1378 	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1379 			device->power.flags.power_resources)
1380 		device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1381 
1382 	if (acpi_bus_init_power(device)) {
1383 		acpi_free_power_resources_lists(device);
1384 		device->flags.power_manageable = 0;
1385 	}
1386 }
1387 
1388 static void acpi_bus_get_flags(struct acpi_device *device)
1389 {
1390 	/* Presence of _STA indicates 'dynamic_status' */
1391 	if (acpi_has_method(device->handle, "_STA"))
1392 		device->flags.dynamic_status = 1;
1393 
1394 	/* Presence of _RMV indicates 'removable' */
1395 	if (acpi_has_method(device->handle, "_RMV"))
1396 		device->flags.removable = 1;
1397 
1398 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
1399 	if (acpi_has_method(device->handle, "_EJD") ||
1400 	    acpi_has_method(device->handle, "_EJ0"))
1401 		device->flags.ejectable = 1;
1402 }
1403 
1404 static void acpi_device_get_busid(struct acpi_device *device)
1405 {
1406 	char bus_id[5] = { '?', 0 };
1407 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1408 	int i = 0;
1409 
1410 	/*
1411 	 * Bus ID
1412 	 * ------
1413 	 * The device's Bus ID is simply the object name.
1414 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1415 	 */
1416 	if (ACPI_IS_ROOT_DEVICE(device)) {
1417 		strcpy(device->pnp.bus_id, "ACPI");
1418 		return;
1419 	}
1420 
1421 	switch (device->device_type) {
1422 	case ACPI_BUS_TYPE_POWER_BUTTON:
1423 		strcpy(device->pnp.bus_id, "PWRF");
1424 		break;
1425 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1426 		strcpy(device->pnp.bus_id, "SLPF");
1427 		break;
1428 	default:
1429 		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1430 		/* Clean up trailing underscores (if any) */
1431 		for (i = 3; i > 1; i--) {
1432 			if (bus_id[i] == '_')
1433 				bus_id[i] = '\0';
1434 			else
1435 				break;
1436 		}
1437 		strcpy(device->pnp.bus_id, bus_id);
1438 		break;
1439 	}
1440 }
1441 
1442 /*
1443  * acpi_ata_match - see if an acpi object is an ATA device
1444  *
1445  * If an acpi object has one of the ACPI ATA methods defined,
1446  * then we can safely call it an ATA device.
1447  */
1448 bool acpi_ata_match(acpi_handle handle)
1449 {
1450 	return acpi_has_method(handle, "_GTF") ||
1451 	       acpi_has_method(handle, "_GTM") ||
1452 	       acpi_has_method(handle, "_STM") ||
1453 	       acpi_has_method(handle, "_SDD");
1454 }
1455 
1456 /*
1457  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1458  *
1459  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1460  * then we can safely call it an ejectable drive bay
1461  */
1462 bool acpi_bay_match(acpi_handle handle)
1463 {
1464 	acpi_handle phandle;
1465 
1466 	if (!acpi_has_method(handle, "_EJ0"))
1467 		return false;
1468 	if (acpi_ata_match(handle))
1469 		return true;
1470 	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1471 		return false;
1472 
1473 	return acpi_ata_match(phandle);
1474 }
1475 
1476 /*
1477  * acpi_dock_match - see if an acpi object has a _DCK method
1478  */
1479 bool acpi_dock_match(acpi_handle handle)
1480 {
1481 	return acpi_has_method(handle, "_DCK");
1482 }
1483 
1484 const char *acpi_device_hid(struct acpi_device *device)
1485 {
1486 	struct acpi_hardware_id *hid;
1487 
1488 	if (list_empty(&device->pnp.ids))
1489 		return dummy_hid;
1490 
1491 	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1492 	return hid->id;
1493 }
1494 EXPORT_SYMBOL(acpi_device_hid);
1495 
1496 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1497 {
1498 	struct acpi_hardware_id *id;
1499 
1500 	id = kmalloc(sizeof(*id), GFP_KERNEL);
1501 	if (!id)
1502 		return;
1503 
1504 	id->id = kstrdup(dev_id, GFP_KERNEL);
1505 	if (!id->id) {
1506 		kfree(id);
1507 		return;
1508 	}
1509 
1510 	list_add_tail(&id->list, &pnp->ids);
1511 	pnp->type.hardware_id = 1;
1512 }
1513 
1514 /*
1515  * Old IBM workstations have a DSDT bug wherein the SMBus object
1516  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1517  * prefix.  Work around this.
1518  */
1519 static bool acpi_ibm_smbus_match(acpi_handle handle)
1520 {
1521 	char node_name[ACPI_PATH_SEGMENT_LENGTH];
1522 	struct acpi_buffer path = { sizeof(node_name), node_name };
1523 
1524 	if (!dmi_name_in_vendors("IBM"))
1525 		return false;
1526 
1527 	/* Look for SMBS object */
1528 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1529 	    strcmp("SMBS", path.pointer))
1530 		return false;
1531 
1532 	/* Does it have the necessary (but misnamed) methods? */
1533 	if (acpi_has_method(handle, "SBI") &&
1534 	    acpi_has_method(handle, "SBR") &&
1535 	    acpi_has_method(handle, "SBW"))
1536 		return true;
1537 
1538 	return false;
1539 }
1540 
1541 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1542 				int device_type)
1543 {
1544 	acpi_status status;
1545 	struct acpi_device_info *info;
1546 	struct acpi_pnp_device_id_list *cid_list;
1547 	int i;
1548 
1549 	switch (device_type) {
1550 	case ACPI_BUS_TYPE_DEVICE:
1551 		if (handle == ACPI_ROOT_OBJECT) {
1552 			acpi_add_id(pnp, ACPI_SYSTEM_HID);
1553 			break;
1554 		}
1555 
1556 		status = acpi_get_object_info(handle, &info);
1557 		if (ACPI_FAILURE(status)) {
1558 			pr_err(PREFIX "%s: Error reading device info\n",
1559 					__func__);
1560 			return;
1561 		}
1562 
1563 		if (info->valid & ACPI_VALID_HID)
1564 			acpi_add_id(pnp, info->hardware_id.string);
1565 		if (info->valid & ACPI_VALID_CID) {
1566 			cid_list = &info->compatible_id_list;
1567 			for (i = 0; i < cid_list->count; i++)
1568 				acpi_add_id(pnp, cid_list->ids[i].string);
1569 		}
1570 		if (info->valid & ACPI_VALID_ADR) {
1571 			pnp->bus_address = info->address;
1572 			pnp->type.bus_address = 1;
1573 		}
1574 		if (info->valid & ACPI_VALID_UID)
1575 			pnp->unique_id = kstrdup(info->unique_id.string,
1576 							GFP_KERNEL);
1577 
1578 		kfree(info);
1579 
1580 		/*
1581 		 * Some devices don't reliably have _HIDs & _CIDs, so add
1582 		 * synthetic HIDs to make sure drivers can find them.
1583 		 */
1584 		if (acpi_is_video_device(handle))
1585 			acpi_add_id(pnp, ACPI_VIDEO_HID);
1586 		else if (acpi_bay_match(handle))
1587 			acpi_add_id(pnp, ACPI_BAY_HID);
1588 		else if (acpi_dock_match(handle))
1589 			acpi_add_id(pnp, ACPI_DOCK_HID);
1590 		else if (acpi_ibm_smbus_match(handle))
1591 			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1592 		else if (list_empty(&pnp->ids) && handle == ACPI_ROOT_OBJECT) {
1593 			acpi_add_id(pnp, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1594 			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1595 			strcpy(pnp->device_class, ACPI_BUS_CLASS);
1596 		}
1597 
1598 		break;
1599 	case ACPI_BUS_TYPE_POWER:
1600 		acpi_add_id(pnp, ACPI_POWER_HID);
1601 		break;
1602 	case ACPI_BUS_TYPE_PROCESSOR:
1603 		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1604 		break;
1605 	case ACPI_BUS_TYPE_THERMAL:
1606 		acpi_add_id(pnp, ACPI_THERMAL_HID);
1607 		break;
1608 	case ACPI_BUS_TYPE_POWER_BUTTON:
1609 		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1610 		break;
1611 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1612 		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1613 		break;
1614 	}
1615 }
1616 
1617 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1618 {
1619 	struct acpi_hardware_id *id, *tmp;
1620 
1621 	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1622 		kfree(id->id);
1623 		kfree(id);
1624 	}
1625 	kfree(pnp->unique_id);
1626 }
1627 
1628 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1629 			     int type, unsigned long long sta)
1630 {
1631 	INIT_LIST_HEAD(&device->pnp.ids);
1632 	device->device_type = type;
1633 	device->handle = handle;
1634 	device->parent = acpi_bus_get_parent(handle);
1635 	STRUCT_TO_INT(device->status) = sta;
1636 	acpi_device_get_busid(device);
1637 	acpi_set_pnp_ids(handle, &device->pnp, type);
1638 	acpi_bus_get_flags(device);
1639 	device->flags.match_driver = false;
1640 	device_initialize(&device->dev);
1641 	dev_set_uevent_suppress(&device->dev, true);
1642 }
1643 
1644 void acpi_device_add_finalize(struct acpi_device *device)
1645 {
1646 	dev_set_uevent_suppress(&device->dev, false);
1647 	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1648 }
1649 
1650 static int acpi_add_single_object(struct acpi_device **child,
1651 				  acpi_handle handle, int type,
1652 				  unsigned long long sta)
1653 {
1654 	int result;
1655 	struct acpi_device *device;
1656 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1657 
1658 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1659 	if (!device) {
1660 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1661 		return -ENOMEM;
1662 	}
1663 
1664 	acpi_init_device_object(device, handle, type, sta);
1665 	acpi_bus_get_power_flags(device);
1666 	acpi_bus_get_wakeup_device_flags(device);
1667 
1668 	result = acpi_device_add(device, acpi_device_release);
1669 	if (result) {
1670 		acpi_device_release(&device->dev);
1671 		return result;
1672 	}
1673 
1674 	acpi_power_add_remove_device(device, true);
1675 	acpi_device_add_finalize(device);
1676 	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1677 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1678 		dev_name(&device->dev), (char *) buffer.pointer,
1679 		device->parent ? dev_name(&device->parent->dev) : "(null)"));
1680 	kfree(buffer.pointer);
1681 	*child = device;
1682 	return 0;
1683 }
1684 
1685 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1686 				    unsigned long long *sta)
1687 {
1688 	acpi_status status;
1689 	acpi_object_type acpi_type;
1690 
1691 	status = acpi_get_type(handle, &acpi_type);
1692 	if (ACPI_FAILURE(status))
1693 		return -ENODEV;
1694 
1695 	switch (acpi_type) {
1696 	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
1697 	case ACPI_TYPE_DEVICE:
1698 		*type = ACPI_BUS_TYPE_DEVICE;
1699 		status = acpi_bus_get_status_handle(handle, sta);
1700 		if (ACPI_FAILURE(status))
1701 			return -ENODEV;
1702 		break;
1703 	case ACPI_TYPE_PROCESSOR:
1704 		*type = ACPI_BUS_TYPE_PROCESSOR;
1705 		status = acpi_bus_get_status_handle(handle, sta);
1706 		if (ACPI_FAILURE(status))
1707 			return -ENODEV;
1708 		break;
1709 	case ACPI_TYPE_THERMAL:
1710 		*type = ACPI_BUS_TYPE_THERMAL;
1711 		*sta = ACPI_STA_DEFAULT;
1712 		break;
1713 	case ACPI_TYPE_POWER:
1714 		*type = ACPI_BUS_TYPE_POWER;
1715 		*sta = ACPI_STA_DEFAULT;
1716 		break;
1717 	default:
1718 		return -ENODEV;
1719 	}
1720 
1721 	return 0;
1722 }
1723 
1724 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1725 				       char *idstr,
1726 				       const struct acpi_device_id **matchid)
1727 {
1728 	const struct acpi_device_id *devid;
1729 
1730 	for (devid = handler->ids; devid->id[0]; devid++)
1731 		if (!strcmp((char *)devid->id, idstr)) {
1732 			if (matchid)
1733 				*matchid = devid;
1734 
1735 			return true;
1736 		}
1737 
1738 	return false;
1739 }
1740 
1741 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
1742 					const struct acpi_device_id **matchid)
1743 {
1744 	struct acpi_scan_handler *handler;
1745 
1746 	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1747 		if (acpi_scan_handler_matching(handler, idstr, matchid))
1748 			return handler;
1749 
1750 	return NULL;
1751 }
1752 
1753 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1754 {
1755 	if (!!hotplug->enabled == !!val)
1756 		return;
1757 
1758 	mutex_lock(&acpi_scan_lock);
1759 
1760 	hotplug->enabled = val;
1761 
1762 	mutex_unlock(&acpi_scan_lock);
1763 }
1764 
1765 static void acpi_scan_init_hotplug(acpi_handle handle, int type)
1766 {
1767 	struct acpi_device_pnp pnp = {};
1768 	struct acpi_hardware_id *hwid;
1769 	struct acpi_scan_handler *handler;
1770 
1771 	INIT_LIST_HEAD(&pnp.ids);
1772 	acpi_set_pnp_ids(handle, &pnp, type);
1773 
1774 	if (!pnp.type.hardware_id)
1775 		goto out;
1776 
1777 	/*
1778 	 * This relies on the fact that acpi_install_notify_handler() will not
1779 	 * install the same notify handler routine twice for the same handle.
1780 	 */
1781 	list_for_each_entry(hwid, &pnp.ids, list) {
1782 		handler = acpi_scan_match_handler(hwid->id, NULL);
1783 		if (handler) {
1784 			acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1785 					acpi_hotplug_notify_cb, handler);
1786 			break;
1787 		}
1788 	}
1789 
1790 out:
1791 	acpi_free_pnp_ids(&pnp);
1792 }
1793 
1794 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1795 				      void *not_used, void **return_value)
1796 {
1797 	struct acpi_device *device = NULL;
1798 	int type;
1799 	unsigned long long sta;
1800 	int result;
1801 
1802 	acpi_bus_get_device(handle, &device);
1803 	if (device)
1804 		goto out;
1805 
1806 	result = acpi_bus_type_and_status(handle, &type, &sta);
1807 	if (result)
1808 		return AE_OK;
1809 
1810 	if (type == ACPI_BUS_TYPE_POWER) {
1811 		acpi_add_power_resource(handle);
1812 		return AE_OK;
1813 	}
1814 
1815 	acpi_scan_init_hotplug(handle, type);
1816 
1817 	if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1818 	    !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1819 		struct acpi_device_wakeup wakeup;
1820 
1821 		if (acpi_has_method(handle, "_PRW")) {
1822 			acpi_bus_extract_wakeup_device_power_package(handle,
1823 								     &wakeup);
1824 			acpi_power_resources_list_free(&wakeup.resources);
1825 		}
1826 		return AE_CTRL_DEPTH;
1827 	}
1828 
1829 	acpi_add_single_object(&device, handle, type, sta);
1830 	if (!device)
1831 		return AE_CTRL_DEPTH;
1832 
1833  out:
1834 	if (!*return_value)
1835 		*return_value = device;
1836 
1837 	return AE_OK;
1838 }
1839 
1840 static int acpi_scan_attach_handler(struct acpi_device *device)
1841 {
1842 	struct acpi_hardware_id *hwid;
1843 	int ret = 0;
1844 
1845 	list_for_each_entry(hwid, &device->pnp.ids, list) {
1846 		const struct acpi_device_id *devid;
1847 		struct acpi_scan_handler *handler;
1848 
1849 		handler = acpi_scan_match_handler(hwid->id, &devid);
1850 		if (handler) {
1851 			ret = handler->attach(device, devid);
1852 			if (ret > 0) {
1853 				device->handler = handler;
1854 				break;
1855 			} else if (ret < 0) {
1856 				break;
1857 			}
1858 		}
1859 	}
1860 	return ret;
1861 }
1862 
1863 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
1864 					  void *not_used, void **ret_not_used)
1865 {
1866 	struct acpi_device *device;
1867 	unsigned long long sta_not_used;
1868 	int ret;
1869 
1870 	/*
1871 	 * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
1872 	 * namespace walks prematurely.
1873 	 */
1874 	if (acpi_bus_type_and_status(handle, &ret, &sta_not_used))
1875 		return AE_OK;
1876 
1877 	if (acpi_bus_get_device(handle, &device))
1878 		return AE_CTRL_DEPTH;
1879 
1880 	if (device->handler)
1881 		return AE_OK;
1882 
1883 	ret = acpi_scan_attach_handler(device);
1884 	if (ret < 0)
1885 		return AE_CTRL_DEPTH;
1886 
1887 	device->flags.match_driver = true;
1888 	if (ret > 0)
1889 		return AE_OK;
1890 
1891 	ret = device_attach(&device->dev);
1892 	return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
1893 }
1894 
1895 /**
1896  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1897  * @handle: Root of the namespace scope to scan.
1898  *
1899  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1900  * found devices.
1901  *
1902  * If no devices were found, -ENODEV is returned, but it does not mean that
1903  * there has been a real error.  There just have been no suitable ACPI objects
1904  * in the table trunk from which the kernel could create a device and add an
1905  * appropriate driver.
1906  *
1907  * Must be called under acpi_scan_lock.
1908  */
1909 int acpi_bus_scan(acpi_handle handle)
1910 {
1911 	void *device = NULL;
1912 	int error = 0;
1913 
1914 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1915 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1916 				    acpi_bus_check_add, NULL, NULL, &device);
1917 
1918 	if (!device)
1919 		error = -ENODEV;
1920 	else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
1921 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1922 				    acpi_bus_device_attach, NULL, NULL, NULL);
1923 
1924 	return error;
1925 }
1926 EXPORT_SYMBOL(acpi_bus_scan);
1927 
1928 static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
1929 					  void *not_used, void **ret_not_used)
1930 {
1931 	struct acpi_device *device = NULL;
1932 
1933 	if (!acpi_bus_get_device(handle, &device)) {
1934 		struct acpi_scan_handler *dev_handler = device->handler;
1935 
1936 		if (dev_handler) {
1937 			if (dev_handler->detach)
1938 				dev_handler->detach(device);
1939 
1940 			device->handler = NULL;
1941 		} else {
1942 			device_release_driver(&device->dev);
1943 		}
1944 	}
1945 	return AE_OK;
1946 }
1947 
1948 static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
1949 				   void *not_used, void **ret_not_used)
1950 {
1951 	struct acpi_device *device = NULL;
1952 
1953 	if (!acpi_bus_get_device(handle, &device))
1954 		acpi_device_unregister(device);
1955 
1956 	return AE_OK;
1957 }
1958 
1959 /**
1960  * acpi_bus_trim - Remove ACPI device node and all of its descendants
1961  * @start: Root of the ACPI device nodes subtree to remove.
1962  *
1963  * Must be called under acpi_scan_lock.
1964  */
1965 void acpi_bus_trim(struct acpi_device *start)
1966 {
1967 	/*
1968 	 * Execute acpi_bus_device_detach() as a post-order callback to detach
1969 	 * all ACPI drivers from the device nodes being removed.
1970 	 */
1971 	acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1972 			    acpi_bus_device_detach, NULL, NULL);
1973 	acpi_bus_device_detach(start->handle, 0, NULL, NULL);
1974 	/*
1975 	 * Execute acpi_bus_remove() as a post-order callback to remove device
1976 	 * nodes in the given namespace scope.
1977 	 */
1978 	acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1979 			    acpi_bus_remove, NULL, NULL);
1980 	acpi_bus_remove(start->handle, 0, NULL, NULL);
1981 }
1982 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1983 
1984 static int acpi_bus_scan_fixed(void)
1985 {
1986 	int result = 0;
1987 
1988 	/*
1989 	 * Enumerate all fixed-feature devices.
1990 	 */
1991 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1992 		struct acpi_device *device = NULL;
1993 
1994 		result = acpi_add_single_object(&device, NULL,
1995 						ACPI_BUS_TYPE_POWER_BUTTON,
1996 						ACPI_STA_DEFAULT);
1997 		if (result)
1998 			return result;
1999 
2000 		result = device_attach(&device->dev);
2001 		if (result < 0)
2002 			return result;
2003 
2004 		device_init_wakeup(&device->dev, true);
2005 	}
2006 
2007 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2008 		struct acpi_device *device = NULL;
2009 
2010 		result = acpi_add_single_object(&device, NULL,
2011 						ACPI_BUS_TYPE_SLEEP_BUTTON,
2012 						ACPI_STA_DEFAULT);
2013 		if (result)
2014 			return result;
2015 
2016 		result = device_attach(&device->dev);
2017 	}
2018 
2019 	return result < 0 ? result : 0;
2020 }
2021 
2022 int __init acpi_scan_init(void)
2023 {
2024 	int result;
2025 
2026 	result = bus_register(&acpi_bus_type);
2027 	if (result) {
2028 		/* We don't want to quit even if we failed to add suspend/resume */
2029 		printk(KERN_ERR PREFIX "Could not register bus type\n");
2030 	}
2031 
2032 	acpi_pci_root_init();
2033 	acpi_pci_link_init();
2034 	acpi_processor_init();
2035 	acpi_platform_init();
2036 	acpi_lpss_init();
2037 	acpi_cmos_rtc_init();
2038 	acpi_container_init();
2039 	acpi_memory_hotplug_init();
2040 	acpi_dock_init();
2041 
2042 	mutex_lock(&acpi_scan_lock);
2043 	/*
2044 	 * Enumerate devices in the ACPI namespace.
2045 	 */
2046 	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2047 	if (result)
2048 		goto out;
2049 
2050 	result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2051 	if (result)
2052 		goto out;
2053 
2054 	result = acpi_bus_scan_fixed();
2055 	if (result) {
2056 		acpi_device_unregister(acpi_root);
2057 		goto out;
2058 	}
2059 
2060 	acpi_update_all_gpes();
2061 
2062 	acpi_pci_root_hp_init();
2063 
2064  out:
2065 	mutex_unlock(&acpi_scan_lock);
2066 	return result;
2067 }
2068