Merge branch 'topic/convert-bint' into topic/hda
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / acpi / acpica / rsxface.c
CommitLineData
1da177e4
LT
1/*******************************************************************************
2 *
3 * Module Name: rsxface - Public interfaces to the resource manager
4 *
5 ******************************************************************************/
6
7/*
77848130 8 * Copyright (C) 2000 - 2012, Intel Corp.
1da177e4
LT
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions, and the following disclaimer,
16 * without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 * substantially similar to the "NO WARRANTY" disclaimer below
19 * ("Disclaimer") and any redistribution must be conditioned upon
20 * including a substantially similar Disclaimer requirement for further
21 * binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 * of any contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
214f2c90 44#include <linux/export.h>
1da177e4 45#include <acpi/acpi.h>
e2f7a777
LB
46#include "accommon.h"
47#include "acresrc.h"
48#include "acnamesp.h"
1da177e4
LT
49
50#define _COMPONENT ACPI_RESOURCES
4be44fcd 51ACPI_MODULE_NAME("rsxface")
1da177e4 52
44f6c012 53/* Local macros for 16,32-bit to 64-bit conversion */
44f6c012
RM
54#define ACPI_COPY_FIELD(out, in, field) ((out)->field = (in)->field)
55#define ACPI_COPY_ADDRESS(out, in) \
56 ACPI_COPY_FIELD(out, in, resource_type); \
57 ACPI_COPY_FIELD(out, in, producer_consumer); \
58 ACPI_COPY_FIELD(out, in, decode); \
59 ACPI_COPY_FIELD(out, in, min_address_fixed); \
60 ACPI_COPY_FIELD(out, in, max_address_fixed); \
0897831b 61 ACPI_COPY_FIELD(out, in, info); \
44f6c012 62 ACPI_COPY_FIELD(out, in, granularity); \
50eca3eb
BM
63 ACPI_COPY_FIELD(out, in, minimum); \
64 ACPI_COPY_FIELD(out, in, maximum); \
65 ACPI_COPY_FIELD(out, in, translation_offset); \
44f6c012
RM
66 ACPI_COPY_FIELD(out, in, address_length); \
67 ACPI_COPY_FIELD(out, in, resource_source);
c51a4de8
BM
68/* Local prototypes */
69static acpi_status
70acpi_rs_match_vendor_resource(struct acpi_resource *resource, void *context);
71
4119532c
BM
72static acpi_status
73acpi_rs_validate_parameters(acpi_handle device_handle,
74 struct acpi_buffer *buffer,
75 struct acpi_namespace_node **return_node);
76
77/*******************************************************************************
78 *
79 * FUNCTION: acpi_rs_validate_parameters
80 *
81 * PARAMETERS: device_handle - Handle to a device
82 * Buffer - Pointer to a data buffer
83 * return_node - Pointer to where the device node is returned
84 *
85 * RETURN: Status
86 *
87 * DESCRIPTION: Common parameter validation for resource interfaces
88 *
89 ******************************************************************************/
90
91static acpi_status
92acpi_rs_validate_parameters(acpi_handle device_handle,
93 struct acpi_buffer *buffer,
94 struct acpi_namespace_node **return_node)
95{
96 acpi_status status;
97 struct acpi_namespace_node *node;
98
99 ACPI_FUNCTION_TRACE(rs_validate_parameters);
100
101 /*
102 * Must have a valid handle to an ACPI device
103 */
104 if (!device_handle) {
105 return_ACPI_STATUS(AE_BAD_PARAMETER);
106 }
107
f24b664d 108 node = acpi_ns_validate_handle(device_handle);
4119532c
BM
109 if (!node) {
110 return_ACPI_STATUS(AE_BAD_PARAMETER);
111 }
112
113 if (node->type != ACPI_TYPE_DEVICE) {
114 return_ACPI_STATUS(AE_TYPE);
115 }
116
117 /*
118 * Validate the user buffer object
119 *
120 * if there is a non-zero buffer length we also need a valid pointer in
121 * the buffer. If it's a zero buffer length, we'll be returning the
122 * needed buffer size (later), so keep going.
123 */
124 status = acpi_ut_validate_buffer(buffer);
125 if (ACPI_FAILURE(status)) {
126 return_ACPI_STATUS(status);
127 }
128
129 *return_node = node;
130 return_ACPI_STATUS(AE_OK);
131}
132
1da177e4
LT
133/*******************************************************************************
134 *
135 * FUNCTION: acpi_get_irq_routing_table
136 *
4119532c
BM
137 * PARAMETERS: device_handle - Handle to the Bus device we are querying
138 * ret_buffer - Pointer to a buffer to receive the
1da177e4
LT
139 * current resources for the device
140 *
141 * RETURN: Status
142 *
143 * DESCRIPTION: This function is called to get the IRQ routing table for a
4119532c
BM
144 * specific bus. The caller must first acquire a handle for the
145 * desired bus. The routine table is placed in the buffer pointed
1da177e4
LT
146 * to by the ret_buffer variable parameter.
147 *
148 * If the function fails an appropriate status will be returned
149 * and the value of ret_buffer is undefined.
150 *
151 * This function attempts to execute the _PRT method contained in
152 * the object indicated by the passed device_handle.
153 *
154 ******************************************************************************/
c51a4de8 155
1da177e4 156acpi_status
4be44fcd
LB
157acpi_get_irq_routing_table(acpi_handle device_handle,
158 struct acpi_buffer *ret_buffer)
1da177e4 159{
4be44fcd 160 acpi_status status;
4119532c 161 struct acpi_namespace_node *node;
1da177e4 162
b229cf92 163 ACPI_FUNCTION_TRACE(acpi_get_irq_routing_table);
1da177e4 164
4119532c 165 /* Validate parameters then dispatch to internal routine */
1da177e4 166
4119532c 167 status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
4be44fcd
LB
168 if (ACPI_FAILURE(status)) {
169 return_ACPI_STATUS(status);
1da177e4
LT
170 }
171
4119532c 172 status = acpi_rs_get_prt_method_data(node, ret_buffer);
4be44fcd 173 return_ACPI_STATUS(status);
1da177e4
LT
174}
175
8313524a
BM
176ACPI_EXPORT_SYMBOL(acpi_get_irq_routing_table)
177
1da177e4
LT
178/*******************************************************************************
179 *
180 * FUNCTION: acpi_get_current_resources
181 *
4119532c 182 * PARAMETERS: device_handle - Handle to the device object for the
1da177e4 183 * device we are querying
4119532c 184 * ret_buffer - Pointer to a buffer to receive the
1da177e4
LT
185 * current resources for the device
186 *
187 * RETURN: Status
188 *
189 * DESCRIPTION: This function is called to get the current resources for a
4119532c
BM
190 * specific device. The caller must first acquire a handle for
191 * the desired device. The resource data is placed in the buffer
1da177e4
LT
192 * pointed to by the ret_buffer variable parameter.
193 *
194 * If the function fails an appropriate status will be returned
195 * and the value of ret_buffer is undefined.
196 *
197 * This function attempts to execute the _CRS method contained in
198 * the object indicated by the passed device_handle.
199 *
200 ******************************************************************************/
1da177e4 201acpi_status
4be44fcd
LB
202acpi_get_current_resources(acpi_handle device_handle,
203 struct acpi_buffer *ret_buffer)
1da177e4 204{
4be44fcd 205 acpi_status status;
4119532c 206 struct acpi_namespace_node *node;
1da177e4 207
b229cf92 208 ACPI_FUNCTION_TRACE(acpi_get_current_resources);
1da177e4 209
4119532c 210 /* Validate parameters then dispatch to internal routine */
1da177e4 211
4119532c 212 status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
4be44fcd
LB
213 if (ACPI_FAILURE(status)) {
214 return_ACPI_STATUS(status);
1da177e4
LT
215 }
216
4119532c 217 status = acpi_rs_get_crs_method_data(node, ret_buffer);
4be44fcd 218 return_ACPI_STATUS(status);
1da177e4 219}
1da177e4 220
8313524a 221ACPI_EXPORT_SYMBOL(acpi_get_current_resources)
8313524a 222#ifdef ACPI_FUTURE_USAGE
1da177e4
LT
223/*******************************************************************************
224 *
225 * FUNCTION: acpi_get_possible_resources
226 *
4119532c 227 * PARAMETERS: device_handle - Handle to the device object for the
1da177e4 228 * device we are querying
4119532c 229 * ret_buffer - Pointer to a buffer to receive the
1da177e4
LT
230 * resources for the device
231 *
232 * RETURN: Status
233 *
234 * DESCRIPTION: This function is called to get a list of the possible resources
4119532c
BM
235 * for a specific device. The caller must first acquire a handle
236 * for the desired device. The resource data is placed in the
1da177e4
LT
237 * buffer pointed to by the ret_buffer variable.
238 *
239 * If the function fails an appropriate status will be returned
240 * and the value of ret_buffer is undefined.
241 *
242 ******************************************************************************/
1da177e4 243acpi_status
4be44fcd
LB
244acpi_get_possible_resources(acpi_handle device_handle,
245 struct acpi_buffer *ret_buffer)
1da177e4 246{
4be44fcd 247 acpi_status status;
4119532c 248 struct acpi_namespace_node *node;
1da177e4 249
b229cf92 250 ACPI_FUNCTION_TRACE(acpi_get_possible_resources);
1da177e4 251
4119532c 252 /* Validate parameters then dispatch to internal routine */
1da177e4 253
4119532c 254 status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
4be44fcd
LB
255 if (ACPI_FAILURE(status)) {
256 return_ACPI_STATUS(status);
1da177e4
LT
257 }
258
4119532c 259 status = acpi_rs_get_prs_method_data(node, ret_buffer);
4be44fcd 260 return_ACPI_STATUS(status);
1da177e4 261}
1da177e4 262
8313524a 263ACPI_EXPORT_SYMBOL(acpi_get_possible_resources)
4be44fcd 264#endif /* ACPI_FUTURE_USAGE */
1da177e4
LT
265/*******************************************************************************
266 *
267 * FUNCTION: acpi_set_current_resources
268 *
4119532c
BM
269 * PARAMETERS: device_handle - Handle to the device object for the
270 * device we are setting resources
271 * in_buffer - Pointer to a buffer containing the
1da177e4
LT
272 * resources to be set for the device
273 *
274 * RETURN: Status
275 *
276 * DESCRIPTION: This function is called to set the current resources for a
4119532c
BM
277 * specific device. The caller must first acquire a handle for
278 * the desired device. The resource data is passed to the routine
1da177e4
LT
279 * the buffer pointed to by the in_buffer variable.
280 *
281 ******************************************************************************/
1da177e4 282acpi_status
4be44fcd
LB
283acpi_set_current_resources(acpi_handle device_handle,
284 struct acpi_buffer *in_buffer)
1da177e4 285{
4be44fcd 286 acpi_status status;
4119532c 287 struct acpi_namespace_node *node;
1da177e4 288
b229cf92 289 ACPI_FUNCTION_TRACE(acpi_set_current_resources);
1da177e4 290
4119532c 291 /* Validate the buffer, don't allow zero length */
44f6c012 292
4119532c 293 if ((!in_buffer) || (!in_buffer->pointer) || (!in_buffer->length)) {
4be44fcd 294 return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4
LT
295 }
296
4119532c
BM
297 /* Validate parameters then dispatch to internal routine */
298
299 status = acpi_rs_validate_parameters(device_handle, in_buffer, &node);
300 if (ACPI_FAILURE(status)) {
301 return_ACPI_STATUS(status);
302 }
303
304 status = acpi_rs_set_srs_method_data(node, in_buffer);
4be44fcd 305 return_ACPI_STATUS(status);
1da177e4 306}
1da177e4 307
8313524a 308ACPI_EXPORT_SYMBOL(acpi_set_current_resources)
1da177e4 309
a91cdde2
BM
310/*******************************************************************************
311 *
312 * FUNCTION: acpi_get_event_resources
313 *
314 * PARAMETERS: device_handle - Handle to the device object for the
315 * device we are getting resources
316 * in_buffer - Pointer to a buffer containing the
317 * resources to be set for the device
318 *
319 * RETURN: Status
320 *
321 * DESCRIPTION: This function is called to get the event resources for a
322 * specific device. The caller must first acquire a handle for
323 * the desired device. The resource data is passed to the routine
324 * the buffer pointed to by the in_buffer variable. Uses the
325 * _AEI method.
326 *
327 ******************************************************************************/
328acpi_status
329acpi_get_event_resources(acpi_handle device_handle,
330 struct acpi_buffer *ret_buffer)
331{
332 acpi_status status;
333 struct acpi_namespace_node *node;
334
335 ACPI_FUNCTION_TRACE(acpi_get_event_resources);
336
337 /* Validate parameters then dispatch to internal routine */
338
339 status = acpi_rs_validate_parameters(device_handle, ret_buffer, &node);
340 if (ACPI_FAILURE(status)) {
341 return_ACPI_STATUS(status);
342 }
343
344 status = acpi_rs_get_aei_method_data(node, ret_buffer);
345 return_ACPI_STATUS(status);
346}
347
348ACPI_EXPORT_SYMBOL(acpi_get_event_resources)
349
1da177e4
LT
350/******************************************************************************
351 *
352 * FUNCTION: acpi_resource_to_address64
353 *
4119532c
BM
354 * PARAMETERS: Resource - Pointer to a resource
355 * Out - Pointer to the users's return buffer
356 * (a struct acpi_resource_address64)
1da177e4
LT
357 *
358 * RETURN: Status
359 *
360 * DESCRIPTION: If the resource is an address16, address32, or address64,
4119532c 361 * copy it to the address64 return buffer. This saves the
1da177e4
LT
362 * caller from having to duplicate code for different-sized
363 * addresses.
364 *
365 ******************************************************************************/
1da177e4 366acpi_status
4be44fcd
LB
367acpi_resource_to_address64(struct acpi_resource *resource,
368 struct acpi_resource_address64 *out)
1da177e4 369{
4be44fcd
LB
370 struct acpi_resource_address16 *address16;
371 struct acpi_resource_address32 *address32;
1da177e4 372
c51a4de8
BM
373 if (!resource || !out) {
374 return (AE_BAD_PARAMETER);
375 }
376
377 /* Convert 16 or 32 address descriptor to 64 */
378
bda663d3 379 switch (resource->type) {
50eca3eb 380 case ACPI_RESOURCE_TYPE_ADDRESS16:
1da177e4 381
ba9c3f55
BM
382 address16 =
383 ACPI_CAST_PTR(struct acpi_resource_address16,
384 &resource->data);
4be44fcd 385 ACPI_COPY_ADDRESS(out, address16);
1da177e4
LT
386 break;
387
50eca3eb 388 case ACPI_RESOURCE_TYPE_ADDRESS32:
1da177e4 389
ba9c3f55
BM
390 address32 =
391 ACPI_CAST_PTR(struct acpi_resource_address32,
392 &resource->data);
4be44fcd 393 ACPI_COPY_ADDRESS(out, address32);
1da177e4
LT
394 break;
395
50eca3eb 396 case ACPI_RESOURCE_TYPE_ADDRESS64:
1da177e4
LT
397
398 /* Simple copy for 64 bit source */
399
4be44fcd
LB
400 ACPI_MEMCPY(out, &resource->data,
401 sizeof(struct acpi_resource_address64));
1da177e4
LT
402 break;
403
1da177e4
LT
404 default:
405 return (AE_BAD_PARAMETER);
406 }
407
408 return (AE_OK);
409}
4be44fcd 410
8313524a 411ACPI_EXPORT_SYMBOL(acpi_resource_to_address64)
c51a4de8
BM
412
413/*******************************************************************************
414 *
415 * FUNCTION: acpi_get_vendor_resource
416 *
4119532c
BM
417 * PARAMETERS: device_handle - Handle for the parent device object
418 * Name - Method name for the parent resource
419 * (METHOD_NAME__CRS or METHOD_NAME__PRS)
420 * Uuid - Pointer to the UUID to be matched.
421 * includes both subtype and 16-byte UUID
422 * ret_buffer - Where the vendor resource is returned
c51a4de8
BM
423 *
424 * RETURN: Status
425 *
426 * DESCRIPTION: Walk a resource template for the specified evice to find a
427 * vendor-defined resource that matches the supplied UUID and
428 * UUID subtype. Returns a struct acpi_resource of type Vendor.
429 *
430 ******************************************************************************/
c51a4de8
BM
431acpi_status
432acpi_get_vendor_resource(acpi_handle device_handle,
433 char *name,
434 struct acpi_vendor_uuid * uuid,
435 struct acpi_buffer * ret_buffer)
436{
437 struct acpi_vendor_walk_info info;
438 acpi_status status;
439
440 /* Other parameters are validated by acpi_walk_resources */
441
442 if (!uuid || !ret_buffer) {
443 return (AE_BAD_PARAMETER);
444 }
445
446 info.uuid = uuid;
447 info.buffer = ret_buffer;
448 info.status = AE_NOT_EXIST;
449
450 /* Walk the _CRS or _PRS resource list for this device */
451
452 status =
453 acpi_walk_resources(device_handle, name,
454 acpi_rs_match_vendor_resource, &info);
455 if (ACPI_FAILURE(status)) {
456 return (status);
457 }
458
459 return (info.status);
460}
461
8313524a
BM
462ACPI_EXPORT_SYMBOL(acpi_get_vendor_resource)
463
c51a4de8
BM
464/*******************************************************************************
465 *
466 * FUNCTION: acpi_rs_match_vendor_resource
467 *
61686124 468 * PARAMETERS: acpi_walk_resource_callback
c51a4de8
BM
469 *
470 * RETURN: Status
471 *
472 * DESCRIPTION: Match a vendor resource via the ACPI 3.0 UUID
473 *
474 ******************************************************************************/
c51a4de8
BM
475static acpi_status
476acpi_rs_match_vendor_resource(struct acpi_resource *resource, void *context)
477{
478 struct acpi_vendor_walk_info *info = context;
479 struct acpi_resource_vendor_typed *vendor;
480 struct acpi_buffer *buffer;
481 acpi_status status;
482
483 /* Ignore all descriptors except Vendor */
484
485 if (resource->type != ACPI_RESOURCE_TYPE_VENDOR) {
486 return (AE_OK);
487 }
488
489 vendor = &resource->data.vendor_typed;
490
491 /*
492 * For a valid match, these conditions must hold:
493 *
494 * 1) Length of descriptor data must be at least as long as a UUID struct
495 * 2) The UUID subtypes must match
496 * 3) The UUID data must match
497 */
498 if ((vendor->byte_length < (ACPI_UUID_LENGTH + 1)) ||
499 (vendor->uuid_subtype != info->uuid->subtype) ||
500 (ACPI_MEMCMP(vendor->uuid, info->uuid->data, ACPI_UUID_LENGTH))) {
501 return (AE_OK);
502 }
503
504 /* Validate/Allocate/Clear caller buffer */
505
506 buffer = info->buffer;
507 status = acpi_ut_initialize_buffer(buffer, resource->length);
508 if (ACPI_FAILURE(status)) {
509 return (status);
510 }
511
512 /* Found the correct resource, copy and return it */
513
514 ACPI_MEMCPY(buffer->pointer, resource, resource->length);
515 buffer->length = resource->length;
516
517 /* Found the desired descriptor, terminate resource walk */
518
519 info->status = AE_OK;
520 return (AE_CTRL_TERMINATE);
521}
8313524a 522
4119532c
BM
523/*******************************************************************************
524 *
525 * FUNCTION: acpi_walk_resources
526 *
527 * PARAMETERS: device_handle - Handle to the device object for the
528 * device we are querying
25169b77
ZR
529 * Name - Method name of the resources we want.
530 * (METHOD_NAME__CRS, METHOD_NAME__PRS, or
531 * METHOD_NAME__AEI)
4119532c
BM
532 * user_function - Called for each resource
533 * Context - Passed to user_function
534 *
535 * RETURN: Status
536 *
537 * DESCRIPTION: Retrieves the current or possible resource list for the
538 * specified device. The user_function is called once for
539 * each resource in the list.
540 *
541 ******************************************************************************/
4119532c
BM
542acpi_status
543acpi_walk_resources(acpi_handle device_handle,
544 char *name,
545 acpi_walk_resource_callback user_function, void *context)
546{
547 acpi_status status;
548 struct acpi_buffer buffer;
549 struct acpi_resource *resource;
550 struct acpi_resource *resource_end;
551
552 ACPI_FUNCTION_TRACE(acpi_walk_resources);
553
554 /* Parameter validation */
555
556 if (!device_handle || !user_function || !name ||
557 (!ACPI_COMPARE_NAME(name, METHOD_NAME__CRS) &&
25169b77
ZR
558 !ACPI_COMPARE_NAME(name, METHOD_NAME__PRS) &&
559 !ACPI_COMPARE_NAME(name, METHOD_NAME__AEI))) {
4119532c
BM
560 return_ACPI_STATUS(AE_BAD_PARAMETER);
561 }
562
25169b77 563 /* Get the _CRS/_PRS/_AEI resource list */
4119532c
BM
564
565 buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
566 status = acpi_rs_get_method_data(device_handle, name, &buffer);
567 if (ACPI_FAILURE(status)) {
568 return_ACPI_STATUS(status);
569 }
570
571 /* Buffer now contains the resource list */
572
573 resource = ACPI_CAST_PTR(struct acpi_resource, buffer.pointer);
574 resource_end =
575 ACPI_ADD_PTR(struct acpi_resource, buffer.pointer, buffer.length);
576
577 /* Walk the resource list until the end_tag is found (or buffer end) */
578
579 while (resource < resource_end) {
580
581 /* Sanity check the resource */
582
583 if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
584 status = AE_AML_INVALID_RESOURCE_TYPE;
585 break;
586 }
587
588 /* Invoke the user function, abort on any error returned */
589
590 status = user_function(resource, context);
591 if (ACPI_FAILURE(status)) {
592 if (status == AE_CTRL_TERMINATE) {
593
594 /* This is an OK termination by the user function */
595
596 status = AE_OK;
597 }
598 break;
599 }
600
601 /* end_tag indicates end-of-list */
602
603 if (resource->type == ACPI_RESOURCE_TYPE_END_TAG) {
604 break;
605 }
606
607 /* Get the next resource descriptor */
608
609 resource =
610 ACPI_ADD_PTR(struct acpi_resource, resource,
611 resource->length);
612 }
613
614 ACPI_FREE(buffer.pointer);
615 return_ACPI_STATUS(status);
616}
617
618ACPI_EXPORT_SYMBOL(acpi_walk_resources)