xref: /openbmc/linux/drivers/acpi/scan.c (revision 12eb4683)
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 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
293 	int error;
294 
295 	lock_device_hotplug();
296 	mutex_lock(&acpi_scan_lock);
297 
298 	if (ost_src == ACPI_NOTIFY_EJECT_REQUEST)
299 		acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
300 					  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
301 
302 	if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
303 		kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
304 
305 	error = acpi_scan_hot_remove(device);
306 	if (error == -EPERM) {
307 		goto err_support;
308 	} else if (error) {
309 		goto err_out;
310 	}
311 
312  out:
313 	mutex_unlock(&acpi_scan_lock);
314 	unlock_device_hotplug();
315 	return;
316 
317  err_support:
318 	ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
319  err_out:
320 	acpi_evaluate_hotplug_ost(handle, ost_src, ost_code, NULL);
321 	goto out;
322 }
323 
324 static void acpi_scan_bus_device_check(void *data, u32 ost_source)
325 {
326 	acpi_handle handle = data;
327 	struct acpi_device *device = NULL;
328 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
329 	int error;
330 
331 	lock_device_hotplug();
332 	mutex_lock(&acpi_scan_lock);
333 
334 	if (ost_source != ACPI_NOTIFY_BUS_CHECK) {
335 		acpi_bus_get_device(handle, &device);
336 		if (device) {
337 			dev_warn(&device->dev, "Attempt to re-insert\n");
338 			goto out;
339 		}
340 	}
341 	error = acpi_bus_scan(handle);
342 	if (error) {
343 		acpi_handle_warn(handle, "Namespace scan failure\n");
344 		goto out;
345 	}
346 	error = acpi_bus_get_device(handle, &device);
347 	if (error) {
348 		acpi_handle_warn(handle, "Missing device node object\n");
349 		goto out;
350 	}
351 	ost_code = ACPI_OST_SC_SUCCESS;
352 	if (device->handler && device->handler->hotplug.mode == AHM_CONTAINER)
353 		kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
354 
355  out:
356 	acpi_evaluate_hotplug_ost(handle, ost_source, ost_code, NULL);
357 	mutex_unlock(&acpi_scan_lock);
358 	unlock_device_hotplug();
359 }
360 
361 static void acpi_hotplug_unsupported(acpi_handle handle, u32 type)
362 {
363 	u32 ost_status;
364 
365 	switch (type) {
366 	case ACPI_NOTIFY_BUS_CHECK:
367 		acpi_handle_debug(handle,
368 			"ACPI_NOTIFY_BUS_CHECK event: unsupported\n");
369 		ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
370 		break;
371 	case ACPI_NOTIFY_DEVICE_CHECK:
372 		acpi_handle_debug(handle,
373 			"ACPI_NOTIFY_DEVICE_CHECK event: unsupported\n");
374 		ost_status = ACPI_OST_SC_INSERT_NOT_SUPPORTED;
375 		break;
376 	case ACPI_NOTIFY_EJECT_REQUEST:
377 		acpi_handle_debug(handle,
378 			"ACPI_NOTIFY_EJECT_REQUEST event: unsupported\n");
379 		ost_status = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
380 		break;
381 	default:
382 		/* non-hotplug event; possibly handled by other handler */
383 		return;
384 	}
385 
386 	acpi_evaluate_hotplug_ost(handle, type, ost_status, NULL);
387 }
388 
389 static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
390 {
391 	struct acpi_scan_handler *handler = data;
392 	struct acpi_device *adev;
393 	acpi_status status;
394 
395 	if (!handler->hotplug.enabled)
396 		return acpi_hotplug_unsupported(handle, type);
397 
398 	switch (type) {
399 	case ACPI_NOTIFY_BUS_CHECK:
400 		acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
401 		break;
402 	case ACPI_NOTIFY_DEVICE_CHECK:
403 		acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
404 		break;
405 	case ACPI_NOTIFY_EJECT_REQUEST:
406 		acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
407 		if (acpi_bus_get_device(handle, &adev))
408 			goto err_out;
409 
410 		get_device(&adev->dev);
411 		status = acpi_hotplug_execute(acpi_bus_device_eject, adev, type);
412 		if (ACPI_SUCCESS(status))
413 			return;
414 
415 		put_device(&adev->dev);
416 		goto err_out;
417 	default:
418 		/* non-hotplug event; possibly handled by other handler */
419 		return;
420 	}
421 	status = acpi_hotplug_execute(acpi_scan_bus_device_check, handle, type);
422 	if (ACPI_SUCCESS(status))
423 		return;
424 
425  err_out:
426 	acpi_evaluate_hotplug_ost(handle, type,
427 				  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
428 }
429 
430 static ssize_t real_power_state_show(struct device *dev,
431 				     struct device_attribute *attr, char *buf)
432 {
433 	struct acpi_device *adev = to_acpi_device(dev);
434 	int state;
435 	int ret;
436 
437 	ret = acpi_device_get_power(adev, &state);
438 	if (ret)
439 		return ret;
440 
441 	return sprintf(buf, "%s\n", acpi_power_state_string(state));
442 }
443 
444 static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
445 
446 static ssize_t power_state_show(struct device *dev,
447 				struct device_attribute *attr, char *buf)
448 {
449 	struct acpi_device *adev = to_acpi_device(dev);
450 
451 	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
452 }
453 
454 static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
455 
456 static ssize_t
457 acpi_eject_store(struct device *d, struct device_attribute *attr,
458 		const char *buf, size_t count)
459 {
460 	struct acpi_device *acpi_device = to_acpi_device(d);
461 	acpi_object_type not_used;
462 	acpi_status status;
463 
464 	if (!count || buf[0] != '1')
465 		return -EINVAL;
466 
467 	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
468 	    && !acpi_device->driver)
469 		return -ENODEV;
470 
471 	status = acpi_get_type(acpi_device->handle, &not_used);
472 	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
473 		return -ENODEV;
474 
475 	acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
476 				  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
477 	get_device(&acpi_device->dev);
478 	status = acpi_hotplug_execute(acpi_bus_device_eject, acpi_device,
479 				      ACPI_OST_EC_OSPM_EJECT);
480 	if (ACPI_SUCCESS(status))
481 		return count;
482 
483 	put_device(&acpi_device->dev);
484 	acpi_evaluate_hotplug_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
485 				  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
486 	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
487 }
488 
489 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
490 
491 static ssize_t
492 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
493 	struct acpi_device *acpi_dev = to_acpi_device(dev);
494 
495 	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
496 }
497 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
498 
499 static ssize_t acpi_device_uid_show(struct device *dev,
500 				    struct device_attribute *attr, char *buf)
501 {
502 	struct acpi_device *acpi_dev = to_acpi_device(dev);
503 
504 	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
505 }
506 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
507 
508 static ssize_t acpi_device_adr_show(struct device *dev,
509 				    struct device_attribute *attr, char *buf)
510 {
511 	struct acpi_device *acpi_dev = to_acpi_device(dev);
512 
513 	return sprintf(buf, "0x%08x\n",
514 		       (unsigned int)(acpi_dev->pnp.bus_address));
515 }
516 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
517 
518 static ssize_t
519 acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
520 	struct acpi_device *acpi_dev = to_acpi_device(dev);
521 	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
522 	int result;
523 
524 	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
525 	if (result)
526 		goto end;
527 
528 	result = sprintf(buf, "%s\n", (char*)path.pointer);
529 	kfree(path.pointer);
530 end:
531 	return result;
532 }
533 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
534 
535 /* sysfs file that shows description text from the ACPI _STR method */
536 static ssize_t description_show(struct device *dev,
537 				struct device_attribute *attr,
538 				char *buf) {
539 	struct acpi_device *acpi_dev = to_acpi_device(dev);
540 	int result;
541 
542 	if (acpi_dev->pnp.str_obj == NULL)
543 		return 0;
544 
545 	/*
546 	 * The _STR object contains a Unicode identifier for a device.
547 	 * We need to convert to utf-8 so it can be displayed.
548 	 */
549 	result = utf16s_to_utf8s(
550 		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
551 		acpi_dev->pnp.str_obj->buffer.length,
552 		UTF16_LITTLE_ENDIAN, buf,
553 		PAGE_SIZE);
554 
555 	buf[result++] = '\n';
556 
557 	return result;
558 }
559 static DEVICE_ATTR(description, 0444, description_show, NULL);
560 
561 static ssize_t
562 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
563 		     char *buf) {
564 	struct acpi_device *acpi_dev = to_acpi_device(dev);
565 
566 	return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
567 }
568 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
569 
570 static int acpi_device_setup_files(struct acpi_device *dev)
571 {
572 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
573 	acpi_status status;
574 	unsigned long long sun;
575 	int result = 0;
576 
577 	/*
578 	 * Devices gotten from FADT don't have a "path" attribute
579 	 */
580 	if (dev->handle) {
581 		result = device_create_file(&dev->dev, &dev_attr_path);
582 		if (result)
583 			goto end;
584 	}
585 
586 	if (!list_empty(&dev->pnp.ids)) {
587 		result = device_create_file(&dev->dev, &dev_attr_hid);
588 		if (result)
589 			goto end;
590 
591 		result = device_create_file(&dev->dev, &dev_attr_modalias);
592 		if (result)
593 			goto end;
594 	}
595 
596 	/*
597 	 * If device has _STR, 'description' file is created
598 	 */
599 	if (acpi_has_method(dev->handle, "_STR")) {
600 		status = acpi_evaluate_object(dev->handle, "_STR",
601 					NULL, &buffer);
602 		if (ACPI_FAILURE(status))
603 			buffer.pointer = NULL;
604 		dev->pnp.str_obj = buffer.pointer;
605 		result = device_create_file(&dev->dev, &dev_attr_description);
606 		if (result)
607 			goto end;
608 	}
609 
610 	if (dev->pnp.type.bus_address)
611 		result = device_create_file(&dev->dev, &dev_attr_adr);
612 	if (dev->pnp.unique_id)
613 		result = device_create_file(&dev->dev, &dev_attr_uid);
614 
615 	status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
616 	if (ACPI_SUCCESS(status)) {
617 		dev->pnp.sun = (unsigned long)sun;
618 		result = device_create_file(&dev->dev, &dev_attr_sun);
619 		if (result)
620 			goto end;
621 	} else {
622 		dev->pnp.sun = (unsigned long)-1;
623 	}
624 
625         /*
626          * If device has _EJ0, 'eject' file is created that is used to trigger
627          * hot-removal function from userland.
628          */
629 	if (acpi_has_method(dev->handle, "_EJ0")) {
630 		result = device_create_file(&dev->dev, &dev_attr_eject);
631 		if (result)
632 			return result;
633 	}
634 
635 	if (dev->flags.power_manageable) {
636 		result = device_create_file(&dev->dev, &dev_attr_power_state);
637 		if (result)
638 			return result;
639 
640 		if (dev->power.flags.power_resources)
641 			result = device_create_file(&dev->dev,
642 						    &dev_attr_real_power_state);
643 	}
644 
645 end:
646 	return result;
647 }
648 
649 static void acpi_device_remove_files(struct acpi_device *dev)
650 {
651 	if (dev->flags.power_manageable) {
652 		device_remove_file(&dev->dev, &dev_attr_power_state);
653 		if (dev->power.flags.power_resources)
654 			device_remove_file(&dev->dev,
655 					   &dev_attr_real_power_state);
656 	}
657 
658 	/*
659 	 * If device has _STR, remove 'description' file
660 	 */
661 	if (acpi_has_method(dev->handle, "_STR")) {
662 		kfree(dev->pnp.str_obj);
663 		device_remove_file(&dev->dev, &dev_attr_description);
664 	}
665 	/*
666 	 * If device has _EJ0, remove 'eject' file.
667 	 */
668 	if (acpi_has_method(dev->handle, "_EJ0"))
669 		device_remove_file(&dev->dev, &dev_attr_eject);
670 
671 	if (acpi_has_method(dev->handle, "_SUN"))
672 		device_remove_file(&dev->dev, &dev_attr_sun);
673 
674 	if (dev->pnp.unique_id)
675 		device_remove_file(&dev->dev, &dev_attr_uid);
676 	if (dev->pnp.type.bus_address)
677 		device_remove_file(&dev->dev, &dev_attr_adr);
678 	device_remove_file(&dev->dev, &dev_attr_modalias);
679 	device_remove_file(&dev->dev, &dev_attr_hid);
680 	if (dev->handle)
681 		device_remove_file(&dev->dev, &dev_attr_path);
682 }
683 /* --------------------------------------------------------------------------
684 			ACPI Bus operations
685    -------------------------------------------------------------------------- */
686 
687 static const struct acpi_device_id *__acpi_match_device(
688 	struct acpi_device *device, const struct acpi_device_id *ids)
689 {
690 	const struct acpi_device_id *id;
691 	struct acpi_hardware_id *hwid;
692 
693 	/*
694 	 * If the device is not present, it is unnecessary to load device
695 	 * driver for it.
696 	 */
697 	if (!device->status.present)
698 		return NULL;
699 
700 	for (id = ids; id->id[0]; id++)
701 		list_for_each_entry(hwid, &device->pnp.ids, list)
702 			if (!strcmp((char *) id->id, hwid->id))
703 				return id;
704 
705 	return NULL;
706 }
707 
708 /**
709  * acpi_match_device - Match a struct device against a given list of ACPI IDs
710  * @ids: Array of struct acpi_device_id object to match against.
711  * @dev: The device structure to match.
712  *
713  * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
714  * object for that handle and use that object to match against a given list of
715  * device IDs.
716  *
717  * Return a pointer to the first matching ID on success or %NULL on failure.
718  */
719 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
720 					       const struct device *dev)
721 {
722 	struct acpi_device *adev;
723 	acpi_handle handle = ACPI_HANDLE(dev);
724 
725 	if (!ids || !handle || acpi_bus_get_device(handle, &adev))
726 		return NULL;
727 
728 	return __acpi_match_device(adev, ids);
729 }
730 EXPORT_SYMBOL_GPL(acpi_match_device);
731 
732 int acpi_match_device_ids(struct acpi_device *device,
733 			  const struct acpi_device_id *ids)
734 {
735 	return __acpi_match_device(device, ids) ? 0 : -ENOENT;
736 }
737 EXPORT_SYMBOL(acpi_match_device_ids);
738 
739 static void acpi_free_power_resources_lists(struct acpi_device *device)
740 {
741 	int i;
742 
743 	if (device->wakeup.flags.valid)
744 		acpi_power_resources_list_free(&device->wakeup.resources);
745 
746 	if (!device->flags.power_manageable)
747 		return;
748 
749 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
750 		struct acpi_device_power_state *ps = &device->power.states[i];
751 		acpi_power_resources_list_free(&ps->resources);
752 	}
753 }
754 
755 static void acpi_device_release(struct device *dev)
756 {
757 	struct acpi_device *acpi_dev = to_acpi_device(dev);
758 
759 	acpi_free_pnp_ids(&acpi_dev->pnp);
760 	acpi_free_power_resources_lists(acpi_dev);
761 	kfree(acpi_dev);
762 }
763 
764 static int acpi_bus_match(struct device *dev, struct device_driver *drv)
765 {
766 	struct acpi_device *acpi_dev = to_acpi_device(dev);
767 	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
768 
769 	return acpi_dev->flags.match_driver
770 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
771 }
772 
773 static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
774 {
775 	struct acpi_device *acpi_dev = to_acpi_device(dev);
776 	int len;
777 
778 	if (list_empty(&acpi_dev->pnp.ids))
779 		return 0;
780 
781 	if (add_uevent_var(env, "MODALIAS="))
782 		return -ENOMEM;
783 	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
784 			      sizeof(env->buf) - env->buflen);
785 	if (len >= (sizeof(env->buf) - env->buflen))
786 		return -ENOMEM;
787 	env->buflen += len;
788 	return 0;
789 }
790 
791 static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
792 {
793 	struct acpi_device *device = data;
794 
795 	device->driver->ops.notify(device, event);
796 }
797 
798 static acpi_status acpi_device_notify_fixed(void *data)
799 {
800 	struct acpi_device *device = data;
801 
802 	/* Fixed hardware devices have no handles */
803 	acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
804 	return AE_OK;
805 }
806 
807 static int acpi_device_install_notify_handler(struct acpi_device *device)
808 {
809 	acpi_status status;
810 
811 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
812 		status =
813 		    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
814 						     acpi_device_notify_fixed,
815 						     device);
816 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
817 		status =
818 		    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
819 						     acpi_device_notify_fixed,
820 						     device);
821 	else
822 		status = acpi_install_notify_handler(device->handle,
823 						     ACPI_DEVICE_NOTIFY,
824 						     acpi_device_notify,
825 						     device);
826 
827 	if (ACPI_FAILURE(status))
828 		return -EINVAL;
829 	return 0;
830 }
831 
832 static void acpi_device_remove_notify_handler(struct acpi_device *device)
833 {
834 	if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
835 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
836 						acpi_device_notify_fixed);
837 	else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
838 		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
839 						acpi_device_notify_fixed);
840 	else
841 		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
842 					   acpi_device_notify);
843 }
844 
845 static int acpi_device_probe(struct device *dev)
846 {
847 	struct acpi_device *acpi_dev = to_acpi_device(dev);
848 	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
849 	int ret;
850 
851 	if (acpi_dev->handler)
852 		return -EINVAL;
853 
854 	if (!acpi_drv->ops.add)
855 		return -ENOSYS;
856 
857 	ret = acpi_drv->ops.add(acpi_dev);
858 	if (ret)
859 		return ret;
860 
861 	acpi_dev->driver = acpi_drv;
862 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
863 			  "Driver [%s] successfully bound to device [%s]\n",
864 			  acpi_drv->name, acpi_dev->pnp.bus_id));
865 
866 	if (acpi_drv->ops.notify) {
867 		ret = acpi_device_install_notify_handler(acpi_dev);
868 		if (ret) {
869 			if (acpi_drv->ops.remove)
870 				acpi_drv->ops.remove(acpi_dev);
871 
872 			acpi_dev->driver = NULL;
873 			acpi_dev->driver_data = NULL;
874 			return ret;
875 		}
876 	}
877 
878 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
879 			  acpi_drv->name, acpi_dev->pnp.bus_id));
880 	get_device(dev);
881 	return 0;
882 }
883 
884 static int acpi_device_remove(struct device * dev)
885 {
886 	struct acpi_device *acpi_dev = to_acpi_device(dev);
887 	struct acpi_driver *acpi_drv = acpi_dev->driver;
888 
889 	if (acpi_drv) {
890 		if (acpi_drv->ops.notify)
891 			acpi_device_remove_notify_handler(acpi_dev);
892 		if (acpi_drv->ops.remove)
893 			acpi_drv->ops.remove(acpi_dev);
894 	}
895 	acpi_dev->driver = NULL;
896 	acpi_dev->driver_data = NULL;
897 
898 	put_device(dev);
899 	return 0;
900 }
901 
902 struct bus_type acpi_bus_type = {
903 	.name		= "acpi",
904 	.match		= acpi_bus_match,
905 	.probe		= acpi_device_probe,
906 	.remove		= acpi_device_remove,
907 	.uevent		= acpi_device_uevent,
908 };
909 
910 static void acpi_bus_data_handler(acpi_handle handle, void *context)
911 {
912 	/* Intentionally empty. */
913 }
914 
915 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
916 {
917 	acpi_status status;
918 
919 	if (!device)
920 		return -EINVAL;
921 
922 	status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
923 	if (ACPI_FAILURE(status) || !*device) {
924 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
925 				  handle));
926 		return -ENODEV;
927 	}
928 	return 0;
929 }
930 EXPORT_SYMBOL(acpi_bus_get_device);
931 
932 int acpi_device_add(struct acpi_device *device,
933 		    void (*release)(struct device *))
934 {
935 	int result;
936 	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
937 	int found = 0;
938 
939 	if (device->handle) {
940 		acpi_status status;
941 
942 		status = acpi_attach_data(device->handle, acpi_bus_data_handler,
943 					  device);
944 		if (ACPI_FAILURE(status)) {
945 			acpi_handle_err(device->handle,
946 					"Unable to attach device data\n");
947 			return -ENODEV;
948 		}
949 	}
950 
951 	/*
952 	 * Linkage
953 	 * -------
954 	 * Link this device to its parent and siblings.
955 	 */
956 	INIT_LIST_HEAD(&device->children);
957 	INIT_LIST_HEAD(&device->node);
958 	INIT_LIST_HEAD(&device->wakeup_list);
959 	INIT_LIST_HEAD(&device->physical_node_list);
960 	mutex_init(&device->physical_node_lock);
961 
962 	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
963 	if (!new_bus_id) {
964 		pr_err(PREFIX "Memory allocation error\n");
965 		result = -ENOMEM;
966 		goto err_detach;
967 	}
968 
969 	mutex_lock(&acpi_device_lock);
970 	/*
971 	 * Find suitable bus_id and instance number in acpi_bus_id_list
972 	 * If failed, create one and link it into acpi_bus_id_list
973 	 */
974 	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
975 		if (!strcmp(acpi_device_bus_id->bus_id,
976 			    acpi_device_hid(device))) {
977 			acpi_device_bus_id->instance_no++;
978 			found = 1;
979 			kfree(new_bus_id);
980 			break;
981 		}
982 	}
983 	if (!found) {
984 		acpi_device_bus_id = new_bus_id;
985 		strcpy(acpi_device_bus_id->bus_id, acpi_device_hid(device));
986 		acpi_device_bus_id->instance_no = 0;
987 		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
988 	}
989 	dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);
990 
991 	if (device->parent)
992 		list_add_tail(&device->node, &device->parent->children);
993 
994 	if (device->wakeup.flags.valid)
995 		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
996 	mutex_unlock(&acpi_device_lock);
997 
998 	if (device->parent)
999 		device->dev.parent = &device->parent->dev;
1000 	device->dev.bus = &acpi_bus_type;
1001 	device->dev.release = release;
1002 	result = device_add(&device->dev);
1003 	if (result) {
1004 		dev_err(&device->dev, "Error registering device\n");
1005 		goto err;
1006 	}
1007 
1008 	result = acpi_device_setup_files(device);
1009 	if (result)
1010 		printk(KERN_ERR PREFIX "Error creating sysfs interface for device %s\n",
1011 		       dev_name(&device->dev));
1012 
1013 	return 0;
1014 
1015  err:
1016 	mutex_lock(&acpi_device_lock);
1017 	if (device->parent)
1018 		list_del(&device->node);
1019 	list_del(&device->wakeup_list);
1020 	mutex_unlock(&acpi_device_lock);
1021 
1022  err_detach:
1023 	acpi_detach_data(device->handle, acpi_bus_data_handler);
1024 	return result;
1025 }
1026 
1027 static void acpi_device_unregister(struct acpi_device *device)
1028 {
1029 	mutex_lock(&acpi_device_lock);
1030 	if (device->parent)
1031 		list_del(&device->node);
1032 
1033 	list_del(&device->wakeup_list);
1034 	mutex_unlock(&acpi_device_lock);
1035 
1036 	acpi_detach_data(device->handle, acpi_bus_data_handler);
1037 
1038 	acpi_power_add_remove_device(device, false);
1039 	acpi_device_remove_files(device);
1040 	if (device->remove)
1041 		device->remove(device);
1042 
1043 	device_del(&device->dev);
1044 	/*
1045 	 * Transition the device to D3cold to drop the reference counts of all
1046 	 * power resources the device depends on and turn off the ones that have
1047 	 * no more references.
1048 	 */
1049 	acpi_device_set_power(device, ACPI_STATE_D3_COLD);
1050 	device->handle = NULL;
1051 	put_device(&device->dev);
1052 }
1053 
1054 /* --------------------------------------------------------------------------
1055                                  Driver Management
1056    -------------------------------------------------------------------------- */
1057 /**
1058  * acpi_bus_register_driver - register a driver with the ACPI bus
1059  * @driver: driver being registered
1060  *
1061  * Registers a driver with the ACPI bus.  Searches the namespace for all
1062  * devices that match the driver's criteria and binds.  Returns zero for
1063  * success or a negative error status for failure.
1064  */
1065 int acpi_bus_register_driver(struct acpi_driver *driver)
1066 {
1067 	int ret;
1068 
1069 	if (acpi_disabled)
1070 		return -ENODEV;
1071 	driver->drv.name = driver->name;
1072 	driver->drv.bus = &acpi_bus_type;
1073 	driver->drv.owner = driver->owner;
1074 
1075 	ret = driver_register(&driver->drv);
1076 	return ret;
1077 }
1078 
1079 EXPORT_SYMBOL(acpi_bus_register_driver);
1080 
1081 /**
1082  * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
1083  * @driver: driver to unregister
1084  *
1085  * Unregisters a driver with the ACPI bus.  Searches the namespace for all
1086  * devices that match the driver's criteria and unbinds.
1087  */
1088 void acpi_bus_unregister_driver(struct acpi_driver *driver)
1089 {
1090 	driver_unregister(&driver->drv);
1091 }
1092 
1093 EXPORT_SYMBOL(acpi_bus_unregister_driver);
1094 
1095 /* --------------------------------------------------------------------------
1096                                  Device Enumeration
1097    -------------------------------------------------------------------------- */
1098 static struct acpi_device *acpi_bus_get_parent(acpi_handle handle)
1099 {
1100 	struct acpi_device *device = NULL;
1101 	acpi_status status;
1102 
1103 	/*
1104 	 * Fixed hardware devices do not appear in the namespace and do not
1105 	 * have handles, but we fabricate acpi_devices for them, so we have
1106 	 * to deal with them specially.
1107 	 */
1108 	if (!handle)
1109 		return acpi_root;
1110 
1111 	do {
1112 		status = acpi_get_parent(handle, &handle);
1113 		if (ACPI_FAILURE(status))
1114 			return status == AE_NULL_ENTRY ? NULL : acpi_root;
1115 	} while (acpi_bus_get_device(handle, &device));
1116 	return device;
1117 }
1118 
1119 acpi_status
1120 acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
1121 {
1122 	acpi_status status;
1123 	acpi_handle tmp;
1124 	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
1125 	union acpi_object *obj;
1126 
1127 	status = acpi_get_handle(handle, "_EJD", &tmp);
1128 	if (ACPI_FAILURE(status))
1129 		return status;
1130 
1131 	status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
1132 	if (ACPI_SUCCESS(status)) {
1133 		obj = buffer.pointer;
1134 		status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
1135 					 ejd);
1136 		kfree(buffer.pointer);
1137 	}
1138 	return status;
1139 }
1140 EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);
1141 
1142 static int acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
1143 					struct acpi_device_wakeup *wakeup)
1144 {
1145 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1146 	union acpi_object *package = NULL;
1147 	union acpi_object *element = NULL;
1148 	acpi_status status;
1149 	int err = -ENODATA;
1150 
1151 	if (!wakeup)
1152 		return -EINVAL;
1153 
1154 	INIT_LIST_HEAD(&wakeup->resources);
1155 
1156 	/* _PRW */
1157 	status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
1158 	if (ACPI_FAILURE(status)) {
1159 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
1160 		return err;
1161 	}
1162 
1163 	package = (union acpi_object *)buffer.pointer;
1164 
1165 	if (!package || package->package.count < 2)
1166 		goto out;
1167 
1168 	element = &(package->package.elements[0]);
1169 	if (!element)
1170 		goto out;
1171 
1172 	if (element->type == ACPI_TYPE_PACKAGE) {
1173 		if ((element->package.count < 2) ||
1174 		    (element->package.elements[0].type !=
1175 		     ACPI_TYPE_LOCAL_REFERENCE)
1176 		    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
1177 			goto out;
1178 
1179 		wakeup->gpe_device =
1180 		    element->package.elements[0].reference.handle;
1181 		wakeup->gpe_number =
1182 		    (u32) element->package.elements[1].integer.value;
1183 	} else if (element->type == ACPI_TYPE_INTEGER) {
1184 		wakeup->gpe_device = NULL;
1185 		wakeup->gpe_number = element->integer.value;
1186 	} else {
1187 		goto out;
1188 	}
1189 
1190 	element = &(package->package.elements[1]);
1191 	if (element->type != ACPI_TYPE_INTEGER)
1192 		goto out;
1193 
1194 	wakeup->sleep_state = element->integer.value;
1195 
1196 	err = acpi_extract_power_resources(package, 2, &wakeup->resources);
1197 	if (err)
1198 		goto out;
1199 
1200 	if (!list_empty(&wakeup->resources)) {
1201 		int sleep_state;
1202 
1203 		err = acpi_power_wakeup_list_init(&wakeup->resources,
1204 						  &sleep_state);
1205 		if (err) {
1206 			acpi_handle_warn(handle, "Retrieving current states "
1207 					 "of wakeup power resources failed\n");
1208 			acpi_power_resources_list_free(&wakeup->resources);
1209 			goto out;
1210 		}
1211 		if (sleep_state < wakeup->sleep_state) {
1212 			acpi_handle_warn(handle, "Overriding _PRW sleep state "
1213 					 "(S%d) by S%d from power resources\n",
1214 					 (int)wakeup->sleep_state, sleep_state);
1215 			wakeup->sleep_state = sleep_state;
1216 		}
1217 	}
1218 	acpi_setup_gpe_for_wake(handle, wakeup->gpe_device, wakeup->gpe_number);
1219 
1220  out:
1221 	kfree(buffer.pointer);
1222 	return err;
1223 }
1224 
1225 static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
1226 {
1227 	struct acpi_device_id button_device_ids[] = {
1228 		{"PNP0C0C", 0},
1229 		{"PNP0C0D", 0},
1230 		{"PNP0C0E", 0},
1231 		{"", 0},
1232 	};
1233 	acpi_status status;
1234 	acpi_event_status event_status;
1235 
1236 	device->wakeup.flags.notifier_present = 0;
1237 
1238 	/* Power button, Lid switch always enable wakeup */
1239 	if (!acpi_match_device_ids(device, button_device_ids)) {
1240 		device->wakeup.flags.run_wake = 1;
1241 		if (!acpi_match_device_ids(device, &button_device_ids[1])) {
1242 			/* Do not use Lid/sleep button for S5 wakeup */
1243 			if (device->wakeup.sleep_state == ACPI_STATE_S5)
1244 				device->wakeup.sleep_state = ACPI_STATE_S4;
1245 		}
1246 		device_set_wakeup_capable(&device->dev, true);
1247 		return;
1248 	}
1249 
1250 	status = acpi_get_gpe_status(device->wakeup.gpe_device,
1251 					device->wakeup.gpe_number,
1252 						&event_status);
1253 	if (status == AE_OK)
1254 		device->wakeup.flags.run_wake =
1255 				!!(event_status & ACPI_EVENT_FLAG_HANDLE);
1256 }
1257 
1258 static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
1259 {
1260 	int err;
1261 
1262 	/* Presence of _PRW indicates wake capable */
1263 	if (!acpi_has_method(device->handle, "_PRW"))
1264 		return;
1265 
1266 	err = acpi_bus_extract_wakeup_device_power_package(device->handle,
1267 							   &device->wakeup);
1268 	if (err) {
1269 		dev_err(&device->dev, "_PRW evaluation error: %d\n", err);
1270 		return;
1271 	}
1272 
1273 	device->wakeup.flags.valid = 1;
1274 	device->wakeup.prepare_count = 0;
1275 	acpi_bus_set_run_wake_flags(device);
1276 	/* Call _PSW/_DSW object to disable its ability to wake the sleeping
1277 	 * system for the ACPI device with the _PRW object.
1278 	 * The _PSW object is depreciated in ACPI 3.0 and is replaced by _DSW.
1279 	 * So it is necessary to call _DSW object first. Only when it is not
1280 	 * present will the _PSW object used.
1281 	 */
1282 	err = acpi_device_sleep_wake(device, 0, 0, 0);
1283 	if (err)
1284 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1285 				"error in _DSW or _PSW evaluation\n"));
1286 }
1287 
1288 static void acpi_bus_init_power_state(struct acpi_device *device, int state)
1289 {
1290 	struct acpi_device_power_state *ps = &device->power.states[state];
1291 	char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
1292 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1293 	acpi_status status;
1294 
1295 	INIT_LIST_HEAD(&ps->resources);
1296 
1297 	/* Evaluate "_PRx" to get referenced power resources */
1298 	status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
1299 	if (ACPI_SUCCESS(status)) {
1300 		union acpi_object *package = buffer.pointer;
1301 
1302 		if (buffer.length && package
1303 		    && package->type == ACPI_TYPE_PACKAGE
1304 		    && package->package.count) {
1305 			int err = acpi_extract_power_resources(package, 0,
1306 							       &ps->resources);
1307 			if (!err)
1308 				device->power.flags.power_resources = 1;
1309 		}
1310 		ACPI_FREE(buffer.pointer);
1311 	}
1312 
1313 	/* Evaluate "_PSx" to see if we can do explicit sets */
1314 	pathname[2] = 'S';
1315 	if (acpi_has_method(device->handle, pathname))
1316 		ps->flags.explicit_set = 1;
1317 
1318 	/*
1319 	 * State is valid if there are means to put the device into it.
1320 	 * D3hot is only valid if _PR3 present.
1321 	 */
1322 	if (!list_empty(&ps->resources)
1323 	    || (ps->flags.explicit_set && state < ACPI_STATE_D3_HOT)) {
1324 		ps->flags.valid = 1;
1325 		ps->flags.os_accessible = 1;
1326 	}
1327 
1328 	ps->power = -1;		/* Unknown - driver assigned */
1329 	ps->latency = -1;	/* Unknown - driver assigned */
1330 }
1331 
1332 static void acpi_bus_get_power_flags(struct acpi_device *device)
1333 {
1334 	u32 i;
1335 
1336 	/* Presence of _PS0|_PR0 indicates 'power manageable' */
1337 	if (!acpi_has_method(device->handle, "_PS0") &&
1338 	    !acpi_has_method(device->handle, "_PR0"))
1339 		return;
1340 
1341 	device->flags.power_manageable = 1;
1342 
1343 	/*
1344 	 * Power Management Flags
1345 	 */
1346 	if (acpi_has_method(device->handle, "_PSC"))
1347 		device->power.flags.explicit_get = 1;
1348 	if (acpi_has_method(device->handle, "_IRC"))
1349 		device->power.flags.inrush_current = 1;
1350 
1351 	/*
1352 	 * Enumerate supported power management states
1353 	 */
1354 	for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
1355 		acpi_bus_init_power_state(device, i);
1356 
1357 	INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);
1358 
1359 	/* Set defaults for D0 and D3 states (always valid) */
1360 	device->power.states[ACPI_STATE_D0].flags.valid = 1;
1361 	device->power.states[ACPI_STATE_D0].power = 100;
1362 	device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
1363 	device->power.states[ACPI_STATE_D3_COLD].power = 0;
1364 
1365 	/* Set D3cold's explicit_set flag if _PS3 exists. */
1366 	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
1367 		device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
1368 
1369 	/* Presence of _PS3 or _PRx means we can put the device into D3 cold */
1370 	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
1371 			device->power.flags.power_resources)
1372 		device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
1373 
1374 	if (acpi_bus_init_power(device)) {
1375 		acpi_free_power_resources_lists(device);
1376 		device->flags.power_manageable = 0;
1377 	}
1378 }
1379 
1380 static void acpi_bus_get_flags(struct acpi_device *device)
1381 {
1382 	/* Presence of _STA indicates 'dynamic_status' */
1383 	if (acpi_has_method(device->handle, "_STA"))
1384 		device->flags.dynamic_status = 1;
1385 
1386 	/* Presence of _RMV indicates 'removable' */
1387 	if (acpi_has_method(device->handle, "_RMV"))
1388 		device->flags.removable = 1;
1389 
1390 	/* Presence of _EJD|_EJ0 indicates 'ejectable' */
1391 	if (acpi_has_method(device->handle, "_EJD") ||
1392 	    acpi_has_method(device->handle, "_EJ0"))
1393 		device->flags.ejectable = 1;
1394 }
1395 
1396 static void acpi_device_get_busid(struct acpi_device *device)
1397 {
1398 	char bus_id[5] = { '?', 0 };
1399 	struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
1400 	int i = 0;
1401 
1402 	/*
1403 	 * Bus ID
1404 	 * ------
1405 	 * The device's Bus ID is simply the object name.
1406 	 * TBD: Shouldn't this value be unique (within the ACPI namespace)?
1407 	 */
1408 	if (ACPI_IS_ROOT_DEVICE(device)) {
1409 		strcpy(device->pnp.bus_id, "ACPI");
1410 		return;
1411 	}
1412 
1413 	switch (device->device_type) {
1414 	case ACPI_BUS_TYPE_POWER_BUTTON:
1415 		strcpy(device->pnp.bus_id, "PWRF");
1416 		break;
1417 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1418 		strcpy(device->pnp.bus_id, "SLPF");
1419 		break;
1420 	default:
1421 		acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
1422 		/* Clean up trailing underscores (if any) */
1423 		for (i = 3; i > 1; i--) {
1424 			if (bus_id[i] == '_')
1425 				bus_id[i] = '\0';
1426 			else
1427 				break;
1428 		}
1429 		strcpy(device->pnp.bus_id, bus_id);
1430 		break;
1431 	}
1432 }
1433 
1434 /*
1435  * acpi_ata_match - see if an acpi object is an ATA device
1436  *
1437  * If an acpi object has one of the ACPI ATA methods defined,
1438  * then we can safely call it an ATA device.
1439  */
1440 bool acpi_ata_match(acpi_handle handle)
1441 {
1442 	return acpi_has_method(handle, "_GTF") ||
1443 	       acpi_has_method(handle, "_GTM") ||
1444 	       acpi_has_method(handle, "_STM") ||
1445 	       acpi_has_method(handle, "_SDD");
1446 }
1447 
1448 /*
1449  * acpi_bay_match - see if an acpi object is an ejectable driver bay
1450  *
1451  * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
1452  * then we can safely call it an ejectable drive bay
1453  */
1454 bool acpi_bay_match(acpi_handle handle)
1455 {
1456 	acpi_handle phandle;
1457 
1458 	if (!acpi_has_method(handle, "_EJ0"))
1459 		return false;
1460 	if (acpi_ata_match(handle))
1461 		return true;
1462 	if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
1463 		return false;
1464 
1465 	return acpi_ata_match(phandle);
1466 }
1467 
1468 /*
1469  * acpi_dock_match - see if an acpi object has a _DCK method
1470  */
1471 bool acpi_dock_match(acpi_handle handle)
1472 {
1473 	return acpi_has_method(handle, "_DCK");
1474 }
1475 
1476 const char *acpi_device_hid(struct acpi_device *device)
1477 {
1478 	struct acpi_hardware_id *hid;
1479 
1480 	if (list_empty(&device->pnp.ids))
1481 		return dummy_hid;
1482 
1483 	hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
1484 	return hid->id;
1485 }
1486 EXPORT_SYMBOL(acpi_device_hid);
1487 
1488 static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
1489 {
1490 	struct acpi_hardware_id *id;
1491 
1492 	id = kmalloc(sizeof(*id), GFP_KERNEL);
1493 	if (!id)
1494 		return;
1495 
1496 	id->id = kstrdup(dev_id, GFP_KERNEL);
1497 	if (!id->id) {
1498 		kfree(id);
1499 		return;
1500 	}
1501 
1502 	list_add_tail(&id->list, &pnp->ids);
1503 	pnp->type.hardware_id = 1;
1504 }
1505 
1506 /*
1507  * Old IBM workstations have a DSDT bug wherein the SMBus object
1508  * lacks the SMBUS01 HID and the methods do not have the necessary "_"
1509  * prefix.  Work around this.
1510  */
1511 static bool acpi_ibm_smbus_match(acpi_handle handle)
1512 {
1513 	char node_name[ACPI_PATH_SEGMENT_LENGTH];
1514 	struct acpi_buffer path = { sizeof(node_name), node_name };
1515 
1516 	if (!dmi_name_in_vendors("IBM"))
1517 		return false;
1518 
1519 	/* Look for SMBS object */
1520 	if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
1521 	    strcmp("SMBS", path.pointer))
1522 		return false;
1523 
1524 	/* Does it have the necessary (but misnamed) methods? */
1525 	if (acpi_has_method(handle, "SBI") &&
1526 	    acpi_has_method(handle, "SBR") &&
1527 	    acpi_has_method(handle, "SBW"))
1528 		return true;
1529 
1530 	return false;
1531 }
1532 
1533 static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
1534 				int device_type)
1535 {
1536 	acpi_status status;
1537 	struct acpi_device_info *info;
1538 	struct acpi_pnp_device_id_list *cid_list;
1539 	int i;
1540 
1541 	switch (device_type) {
1542 	case ACPI_BUS_TYPE_DEVICE:
1543 		if (handle == ACPI_ROOT_OBJECT) {
1544 			acpi_add_id(pnp, ACPI_SYSTEM_HID);
1545 			break;
1546 		}
1547 
1548 		status = acpi_get_object_info(handle, &info);
1549 		if (ACPI_FAILURE(status)) {
1550 			pr_err(PREFIX "%s: Error reading device info\n",
1551 					__func__);
1552 			return;
1553 		}
1554 
1555 		if (info->valid & ACPI_VALID_HID)
1556 			acpi_add_id(pnp, info->hardware_id.string);
1557 		if (info->valid & ACPI_VALID_CID) {
1558 			cid_list = &info->compatible_id_list;
1559 			for (i = 0; i < cid_list->count; i++)
1560 				acpi_add_id(pnp, cid_list->ids[i].string);
1561 		}
1562 		if (info->valid & ACPI_VALID_ADR) {
1563 			pnp->bus_address = info->address;
1564 			pnp->type.bus_address = 1;
1565 		}
1566 		if (info->valid & ACPI_VALID_UID)
1567 			pnp->unique_id = kstrdup(info->unique_id.string,
1568 							GFP_KERNEL);
1569 
1570 		kfree(info);
1571 
1572 		/*
1573 		 * Some devices don't reliably have _HIDs & _CIDs, so add
1574 		 * synthetic HIDs to make sure drivers can find them.
1575 		 */
1576 		if (acpi_is_video_device(handle))
1577 			acpi_add_id(pnp, ACPI_VIDEO_HID);
1578 		else if (acpi_bay_match(handle))
1579 			acpi_add_id(pnp, ACPI_BAY_HID);
1580 		else if (acpi_dock_match(handle))
1581 			acpi_add_id(pnp, ACPI_DOCK_HID);
1582 		else if (acpi_ibm_smbus_match(handle))
1583 			acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
1584 		else if (list_empty(&pnp->ids) && handle == ACPI_ROOT_OBJECT) {
1585 			acpi_add_id(pnp, ACPI_BUS_HID); /* \_SB, LNXSYBUS */
1586 			strcpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
1587 			strcpy(pnp->device_class, ACPI_BUS_CLASS);
1588 		}
1589 
1590 		break;
1591 	case ACPI_BUS_TYPE_POWER:
1592 		acpi_add_id(pnp, ACPI_POWER_HID);
1593 		break;
1594 	case ACPI_BUS_TYPE_PROCESSOR:
1595 		acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
1596 		break;
1597 	case ACPI_BUS_TYPE_THERMAL:
1598 		acpi_add_id(pnp, ACPI_THERMAL_HID);
1599 		break;
1600 	case ACPI_BUS_TYPE_POWER_BUTTON:
1601 		acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
1602 		break;
1603 	case ACPI_BUS_TYPE_SLEEP_BUTTON:
1604 		acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
1605 		break;
1606 	}
1607 }
1608 
1609 void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
1610 {
1611 	struct acpi_hardware_id *id, *tmp;
1612 
1613 	list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
1614 		kfree(id->id);
1615 		kfree(id);
1616 	}
1617 	kfree(pnp->unique_id);
1618 }
1619 
1620 void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
1621 			     int type, unsigned long long sta)
1622 {
1623 	INIT_LIST_HEAD(&device->pnp.ids);
1624 	device->device_type = type;
1625 	device->handle = handle;
1626 	device->parent = acpi_bus_get_parent(handle);
1627 	STRUCT_TO_INT(device->status) = sta;
1628 	acpi_device_get_busid(device);
1629 	acpi_set_pnp_ids(handle, &device->pnp, type);
1630 	acpi_bus_get_flags(device);
1631 	device->flags.match_driver = false;
1632 	device_initialize(&device->dev);
1633 	dev_set_uevent_suppress(&device->dev, true);
1634 }
1635 
1636 void acpi_device_add_finalize(struct acpi_device *device)
1637 {
1638 	dev_set_uevent_suppress(&device->dev, false);
1639 	kobject_uevent(&device->dev.kobj, KOBJ_ADD);
1640 }
1641 
1642 static int acpi_add_single_object(struct acpi_device **child,
1643 				  acpi_handle handle, int type,
1644 				  unsigned long long sta)
1645 {
1646 	int result;
1647 	struct acpi_device *device;
1648 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1649 
1650 	device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
1651 	if (!device) {
1652 		printk(KERN_ERR PREFIX "Memory allocation error\n");
1653 		return -ENOMEM;
1654 	}
1655 
1656 	acpi_init_device_object(device, handle, type, sta);
1657 	acpi_bus_get_power_flags(device);
1658 	acpi_bus_get_wakeup_device_flags(device);
1659 
1660 	result = acpi_device_add(device, acpi_device_release);
1661 	if (result) {
1662 		acpi_device_release(&device->dev);
1663 		return result;
1664 	}
1665 
1666 	acpi_power_add_remove_device(device, true);
1667 	acpi_device_add_finalize(device);
1668 	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
1669 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Added %s [%s] parent %s\n",
1670 		dev_name(&device->dev), (char *) buffer.pointer,
1671 		device->parent ? dev_name(&device->parent->dev) : "(null)"));
1672 	kfree(buffer.pointer);
1673 	*child = device;
1674 	return 0;
1675 }
1676 
1677 static int acpi_bus_type_and_status(acpi_handle handle, int *type,
1678 				    unsigned long long *sta)
1679 {
1680 	acpi_status status;
1681 	acpi_object_type acpi_type;
1682 
1683 	status = acpi_get_type(handle, &acpi_type);
1684 	if (ACPI_FAILURE(status))
1685 		return -ENODEV;
1686 
1687 	switch (acpi_type) {
1688 	case ACPI_TYPE_ANY:		/* for ACPI_ROOT_OBJECT */
1689 	case ACPI_TYPE_DEVICE:
1690 		*type = ACPI_BUS_TYPE_DEVICE;
1691 		status = acpi_bus_get_status_handle(handle, sta);
1692 		if (ACPI_FAILURE(status))
1693 			return -ENODEV;
1694 		break;
1695 	case ACPI_TYPE_PROCESSOR:
1696 		*type = ACPI_BUS_TYPE_PROCESSOR;
1697 		status = acpi_bus_get_status_handle(handle, sta);
1698 		if (ACPI_FAILURE(status))
1699 			return -ENODEV;
1700 		break;
1701 	case ACPI_TYPE_THERMAL:
1702 		*type = ACPI_BUS_TYPE_THERMAL;
1703 		*sta = ACPI_STA_DEFAULT;
1704 		break;
1705 	case ACPI_TYPE_POWER:
1706 		*type = ACPI_BUS_TYPE_POWER;
1707 		*sta = ACPI_STA_DEFAULT;
1708 		break;
1709 	default:
1710 		return -ENODEV;
1711 	}
1712 
1713 	return 0;
1714 }
1715 
1716 static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
1717 				       char *idstr,
1718 				       const struct acpi_device_id **matchid)
1719 {
1720 	const struct acpi_device_id *devid;
1721 
1722 	for (devid = handler->ids; devid->id[0]; devid++)
1723 		if (!strcmp((char *)devid->id, idstr)) {
1724 			if (matchid)
1725 				*matchid = devid;
1726 
1727 			return true;
1728 		}
1729 
1730 	return false;
1731 }
1732 
1733 static struct acpi_scan_handler *acpi_scan_match_handler(char *idstr,
1734 					const struct acpi_device_id **matchid)
1735 {
1736 	struct acpi_scan_handler *handler;
1737 
1738 	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
1739 		if (acpi_scan_handler_matching(handler, idstr, matchid))
1740 			return handler;
1741 
1742 	return NULL;
1743 }
1744 
1745 void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
1746 {
1747 	if (!!hotplug->enabled == !!val)
1748 		return;
1749 
1750 	mutex_lock(&acpi_scan_lock);
1751 
1752 	hotplug->enabled = val;
1753 
1754 	mutex_unlock(&acpi_scan_lock);
1755 }
1756 
1757 static void acpi_scan_init_hotplug(acpi_handle handle, int type)
1758 {
1759 	struct acpi_device_pnp pnp = {};
1760 	struct acpi_hardware_id *hwid;
1761 	struct acpi_scan_handler *handler;
1762 
1763 	INIT_LIST_HEAD(&pnp.ids);
1764 	acpi_set_pnp_ids(handle, &pnp, type);
1765 
1766 	if (!pnp.type.hardware_id)
1767 		goto out;
1768 
1769 	/*
1770 	 * This relies on the fact that acpi_install_notify_handler() will not
1771 	 * install the same notify handler routine twice for the same handle.
1772 	 */
1773 	list_for_each_entry(hwid, &pnp.ids, list) {
1774 		handler = acpi_scan_match_handler(hwid->id, NULL);
1775 		if (handler && !handler->hotplug.ignore) {
1776 			acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
1777 					acpi_hotplug_notify_cb, handler);
1778 			break;
1779 		}
1780 	}
1781 
1782 out:
1783 	acpi_free_pnp_ids(&pnp);
1784 }
1785 
1786 static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
1787 				      void *not_used, void **return_value)
1788 {
1789 	struct acpi_device *device = NULL;
1790 	int type;
1791 	unsigned long long sta;
1792 	int result;
1793 
1794 	acpi_bus_get_device(handle, &device);
1795 	if (device)
1796 		goto out;
1797 
1798 	result = acpi_bus_type_and_status(handle, &type, &sta);
1799 	if (result)
1800 		return AE_OK;
1801 
1802 	if (type == ACPI_BUS_TYPE_POWER) {
1803 		acpi_add_power_resource(handle);
1804 		return AE_OK;
1805 	}
1806 
1807 	acpi_scan_init_hotplug(handle, type);
1808 
1809 	if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
1810 	    !(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
1811 		struct acpi_device_wakeup wakeup;
1812 
1813 		if (acpi_has_method(handle, "_PRW")) {
1814 			acpi_bus_extract_wakeup_device_power_package(handle,
1815 								     &wakeup);
1816 			acpi_power_resources_list_free(&wakeup.resources);
1817 		}
1818 		return AE_CTRL_DEPTH;
1819 	}
1820 
1821 	acpi_add_single_object(&device, handle, type, sta);
1822 	if (!device)
1823 		return AE_CTRL_DEPTH;
1824 
1825  out:
1826 	if (!*return_value)
1827 		*return_value = device;
1828 
1829 	return AE_OK;
1830 }
1831 
1832 static int acpi_scan_attach_handler(struct acpi_device *device)
1833 {
1834 	struct acpi_hardware_id *hwid;
1835 	int ret = 0;
1836 
1837 	list_for_each_entry(hwid, &device->pnp.ids, list) {
1838 		const struct acpi_device_id *devid;
1839 		struct acpi_scan_handler *handler;
1840 
1841 		handler = acpi_scan_match_handler(hwid->id, &devid);
1842 		if (handler) {
1843 			ret = handler->attach(device, devid);
1844 			if (ret > 0) {
1845 				device->handler = handler;
1846 				break;
1847 			} else if (ret < 0) {
1848 				break;
1849 			}
1850 		}
1851 	}
1852 	return ret;
1853 }
1854 
1855 static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
1856 					  void *not_used, void **ret_not_used)
1857 {
1858 	struct acpi_device *device;
1859 	unsigned long long sta_not_used;
1860 	int ret;
1861 
1862 	/*
1863 	 * Ignore errors ignored by acpi_bus_check_add() to avoid terminating
1864 	 * namespace walks prematurely.
1865 	 */
1866 	if (acpi_bus_type_and_status(handle, &ret, &sta_not_used))
1867 		return AE_OK;
1868 
1869 	if (acpi_bus_get_device(handle, &device))
1870 		return AE_CTRL_DEPTH;
1871 
1872 	if (device->handler)
1873 		return AE_OK;
1874 
1875 	ret = acpi_scan_attach_handler(device);
1876 	if (ret < 0)
1877 		return AE_CTRL_DEPTH;
1878 
1879 	device->flags.match_driver = true;
1880 	if (ret > 0)
1881 		return AE_OK;
1882 
1883 	ret = device_attach(&device->dev);
1884 	return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
1885 }
1886 
1887 /**
1888  * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
1889  * @handle: Root of the namespace scope to scan.
1890  *
1891  * Scan a given ACPI tree (probably recently hot-plugged) and create and add
1892  * found devices.
1893  *
1894  * If no devices were found, -ENODEV is returned, but it does not mean that
1895  * there has been a real error.  There just have been no suitable ACPI objects
1896  * in the table trunk from which the kernel could create a device and add an
1897  * appropriate driver.
1898  *
1899  * Must be called under acpi_scan_lock.
1900  */
1901 int acpi_bus_scan(acpi_handle handle)
1902 {
1903 	void *device = NULL;
1904 	int error = 0;
1905 
1906 	if (ACPI_SUCCESS(acpi_bus_check_add(handle, 0, NULL, &device)))
1907 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1908 				    acpi_bus_check_add, NULL, NULL, &device);
1909 
1910 	if (!device)
1911 		error = -ENODEV;
1912 	else if (ACPI_SUCCESS(acpi_bus_device_attach(handle, 0, NULL, NULL)))
1913 		acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
1914 				    acpi_bus_device_attach, NULL, NULL, NULL);
1915 
1916 	return error;
1917 }
1918 EXPORT_SYMBOL(acpi_bus_scan);
1919 
1920 static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
1921 					  void *not_used, void **ret_not_used)
1922 {
1923 	struct acpi_device *device = NULL;
1924 
1925 	if (!acpi_bus_get_device(handle, &device)) {
1926 		struct acpi_scan_handler *dev_handler = device->handler;
1927 
1928 		if (dev_handler) {
1929 			if (dev_handler->detach)
1930 				dev_handler->detach(device);
1931 
1932 			device->handler = NULL;
1933 		} else {
1934 			device_release_driver(&device->dev);
1935 		}
1936 	}
1937 	return AE_OK;
1938 }
1939 
1940 static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
1941 				   void *not_used, void **ret_not_used)
1942 {
1943 	struct acpi_device *device = NULL;
1944 
1945 	if (!acpi_bus_get_device(handle, &device))
1946 		acpi_device_unregister(device);
1947 
1948 	return AE_OK;
1949 }
1950 
1951 /**
1952  * acpi_bus_trim - Remove ACPI device node and all of its descendants
1953  * @start: Root of the ACPI device nodes subtree to remove.
1954  *
1955  * Must be called under acpi_scan_lock.
1956  */
1957 void acpi_bus_trim(struct acpi_device *start)
1958 {
1959 	/*
1960 	 * Execute acpi_bus_device_detach() as a post-order callback to detach
1961 	 * all ACPI drivers from the device nodes being removed.
1962 	 */
1963 	acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1964 			    acpi_bus_device_detach, NULL, NULL);
1965 	acpi_bus_device_detach(start->handle, 0, NULL, NULL);
1966 	/*
1967 	 * Execute acpi_bus_remove() as a post-order callback to remove device
1968 	 * nodes in the given namespace scope.
1969 	 */
1970 	acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
1971 			    acpi_bus_remove, NULL, NULL);
1972 	acpi_bus_remove(start->handle, 0, NULL, NULL);
1973 }
1974 EXPORT_SYMBOL_GPL(acpi_bus_trim);
1975 
1976 static int acpi_bus_scan_fixed(void)
1977 {
1978 	int result = 0;
1979 
1980 	/*
1981 	 * Enumerate all fixed-feature devices.
1982 	 */
1983 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
1984 		struct acpi_device *device = NULL;
1985 
1986 		result = acpi_add_single_object(&device, NULL,
1987 						ACPI_BUS_TYPE_POWER_BUTTON,
1988 						ACPI_STA_DEFAULT);
1989 		if (result)
1990 			return result;
1991 
1992 		device->flags.match_driver = true;
1993 		result = device_attach(&device->dev);
1994 		if (result < 0)
1995 			return result;
1996 
1997 		device_init_wakeup(&device->dev, true);
1998 	}
1999 
2000 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
2001 		struct acpi_device *device = NULL;
2002 
2003 		result = acpi_add_single_object(&device, NULL,
2004 						ACPI_BUS_TYPE_SLEEP_BUTTON,
2005 						ACPI_STA_DEFAULT);
2006 		if (result)
2007 			return result;
2008 
2009 		device->flags.match_driver = true;
2010 		result = device_attach(&device->dev);
2011 	}
2012 
2013 	return result < 0 ? result : 0;
2014 }
2015 
2016 int __init acpi_scan_init(void)
2017 {
2018 	int result;
2019 
2020 	result = bus_register(&acpi_bus_type);
2021 	if (result) {
2022 		/* We don't want to quit even if we failed to add suspend/resume */
2023 		printk(KERN_ERR PREFIX "Could not register bus type\n");
2024 	}
2025 
2026 	acpi_pci_root_init();
2027 	acpi_pci_link_init();
2028 	acpi_processor_init();
2029 	acpi_platform_init();
2030 	acpi_lpss_init();
2031 	acpi_cmos_rtc_init();
2032 	acpi_container_init();
2033 	acpi_memory_hotplug_init();
2034 	acpi_dock_init();
2035 
2036 	mutex_lock(&acpi_scan_lock);
2037 	/*
2038 	 * Enumerate devices in the ACPI namespace.
2039 	 */
2040 	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
2041 	if (result)
2042 		goto out;
2043 
2044 	result = acpi_bus_get_device(ACPI_ROOT_OBJECT, &acpi_root);
2045 	if (result)
2046 		goto out;
2047 
2048 	result = acpi_bus_scan_fixed();
2049 	if (result) {
2050 		acpi_device_unregister(acpi_root);
2051 		goto out;
2052 	}
2053 
2054 	acpi_update_all_gpes();
2055 
2056 	acpi_pci_root_hp_init();
2057 
2058  out:
2059 	mutex_unlock(&acpi_scan_lock);
2060 	return result;
2061 }
2062