1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/*******************************************************************************
3 *
4 * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
5 * ACPI Object evaluation interfaces
6 *
7 ******************************************************************************/
8
9#define EXPORT_ACPI_INTERFACES
10
11#include <acpi/acpi.h>
12#include "accommon.h"
13#include "acnamesp.h"
14#include "acinterp.h"
15
16#define _COMPONENT ACPI_NAMESPACE
17ACPI_MODULE_NAME("nsxfeval")
18
19/* Local prototypes */
20static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
21
22/*******************************************************************************
23 *
24 * FUNCTION: acpi_evaluate_object_typed
25 *
26 * PARAMETERS: handle - Object handle (optional)
27 * pathname - Object pathname (optional)
28 * external_params - List of parameters to pass to a method,
29 * terminated by NULL. May be NULL
30 * if no parameters are being passed.
31 * return_buffer - Where to put the object's return value (if
32 * any). If NULL, no value is returned.
33 * return_type - Expected type of return object
34 *
35 * RETURN: Status
36 *
37 * DESCRIPTION: Find and evaluate the given object, passing the given
38 * parameters if necessary. One of "Handle" or "Pathname" must
39 * be valid (non-null)
40 *
41 ******************************************************************************/
42
43acpi_status
44acpi_evaluate_object_typed(acpi_handle handle,
45 acpi_string pathname,
46 struct acpi_object_list *external_params,
47 struct acpi_buffer *return_buffer,
48 acpi_object_type return_type)
49{
50 acpi_status status;
51 u8 free_buffer_on_error = FALSE;
52 acpi_handle target_handle;
53 char *full_pathname;
54
55 ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
56
57 /* Return buffer must be valid */
58
59 if (!return_buffer) {
60 return_ACPI_STATUS(AE_BAD_PARAMETER);
61 }
62
63 if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
64 free_buffer_on_error = TRUE;
65 }
66
67 /* Get a handle here, in order to build an error message if needed */
68
69 target_handle = handle;
70 if (pathname) {
71 status = acpi_get_handle(parent: handle, pathname, ret_handle: &target_handle);
72 if (ACPI_FAILURE(status)) {
73 return_ACPI_STATUS(status);
74 }
75 }
76
77 full_pathname = acpi_ns_get_external_pathname(node: target_handle);
78 if (!full_pathname) {
79 return_ACPI_STATUS(AE_NO_MEMORY);
80 }
81
82 /* Evaluate the object */
83
84 status = acpi_evaluate_object(object: target_handle, NULL, parameter_objects: external_params,
85 return_object_buffer: return_buffer);
86 if (ACPI_FAILURE(status)) {
87 goto exit;
88 }
89
90 /* Type ANY means "don't care about return value type" */
91
92 if (return_type == ACPI_TYPE_ANY) {
93 goto exit;
94 }
95
96 if (return_buffer->length == 0) {
97
98 /* Error because caller specifically asked for a return value */
99
100 ACPI_ERROR((AE_INFO, "%s did not return any object",
101 full_pathname));
102 status = AE_NULL_OBJECT;
103 goto exit;
104 }
105
106 /* Examine the object type returned from evaluate_object */
107
108 if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
109 goto exit;
110 }
111
112 /* Return object type does not match requested type */
113
114 ACPI_ERROR((AE_INFO,
115 "Incorrect return type from %s - received [%s], requested [%s]",
116 full_pathname,
117 acpi_ut_get_type_name(((union acpi_object *)return_buffer->
118 pointer)->type),
119 acpi_ut_get_type_name(return_type)));
120
121 if (free_buffer_on_error) {
122 /*
123 * Free a buffer created via ACPI_ALLOCATE_BUFFER.
124 * Note: We use acpi_os_free here because acpi_os_allocate was used
125 * to allocate the buffer. This purposefully bypasses the
126 * (optionally enabled) allocation tracking mechanism since we
127 * only want to track internal allocations.
128 */
129 acpi_os_free(memory: return_buffer->pointer);
130 return_buffer->pointer = NULL;
131 }
132
133 return_buffer->length = 0;
134 status = AE_TYPE;
135
136exit:
137 ACPI_FREE(full_pathname);
138 return_ACPI_STATUS(status);
139}
140
141ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
142
143/*******************************************************************************
144 *
145 * FUNCTION: acpi_evaluate_object
146 *
147 * PARAMETERS: handle - Object handle (optional)
148 * pathname - Object pathname (optional)
149 * external_params - List of parameters to pass to method,
150 * terminated by NULL. May be NULL
151 * if no parameters are being passed.
152 * return_buffer - Where to put method's return value (if
153 * any). If NULL, no value is returned.
154 *
155 * RETURN: Status
156 *
157 * DESCRIPTION: Find and evaluate the given object, passing the given
158 * parameters if necessary. One of "Handle" or "Pathname" must
159 * be valid (non-null)
160 *
161 ******************************************************************************/
162acpi_status
163acpi_evaluate_object(acpi_handle handle,
164 acpi_string pathname,
165 struct acpi_object_list *external_params,
166 struct acpi_buffer *return_buffer)
167{
168 acpi_status status;
169 struct acpi_evaluate_info *info;
170 acpi_size buffer_space_needed;
171 u32 i;
172
173 ACPI_FUNCTION_TRACE(acpi_evaluate_object);
174
175 /* Allocate and initialize the evaluation information block */
176
177 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
178 if (!info) {
179 return_ACPI_STATUS(AE_NO_MEMORY);
180 }
181
182 /* Convert and validate the device handle */
183
184 info->prefix_node = acpi_ns_validate_handle(handle);
185 if (!info->prefix_node) {
186 status = AE_BAD_PARAMETER;
187 goto cleanup;
188 }
189
190 /*
191 * Get the actual namespace node for the target object.
192 * Handles these cases:
193 *
194 * 1) Null node, valid pathname from root (absolute path)
195 * 2) Node and valid pathname (path relative to Node)
196 * 3) Node, Null pathname
197 */
198 if ((pathname) && (ACPI_IS_ROOT_PREFIX(pathname[0]))) {
199
200 /* The path is fully qualified, just evaluate by name */
201
202 info->prefix_node = NULL;
203 } else if (!handle) {
204 /*
205 * A handle is optional iff a fully qualified pathname is specified.
206 * Since we've already handled fully qualified names above, this is
207 * an error.
208 */
209 if (!pathname) {
210 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
211 "Both Handle and Pathname are NULL"));
212 } else {
213 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
214 "Null Handle with relative pathname [%s]",
215 pathname));
216 }
217
218 status = AE_BAD_PARAMETER;
219 goto cleanup;
220 }
221
222 info->relative_pathname = pathname;
223
224 /*
225 * Convert all external objects passed as arguments to the
226 * internal version(s).
227 */
228 if (external_params && external_params->count) {
229 info->param_count = (u16)external_params->count;
230
231 /* Warn on impossible argument count */
232
233 if (info->param_count > ACPI_METHOD_NUM_ARGS) {
234 ACPI_WARN_PREDEFINED((AE_INFO, pathname,
235 ACPI_WARN_ALWAYS,
236 "Excess arguments (%u) - using only %u",
237 info->param_count,
238 ACPI_METHOD_NUM_ARGS));
239
240 info->param_count = ACPI_METHOD_NUM_ARGS;
241 }
242
243 /*
244 * Allocate a new parameter block for the internal objects
245 * Add 1 to count to allow for null terminated internal list
246 */
247 info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)info->
248 param_count +
249 1) * sizeof(void *));
250 if (!info->parameters) {
251 status = AE_NO_MEMORY;
252 goto cleanup;
253 }
254
255 /* Convert each external object in the list to an internal object */
256
257 for (i = 0; i < info->param_count; i++) {
258 status =
259 acpi_ut_copy_eobject_to_iobject(obj: &external_params->
260 pointer[i],
261 internal_obj: &info->
262 parameters[i]);
263 if (ACPI_FAILURE(status)) {
264 goto cleanup;
265 }
266 }
267
268 info->parameters[info->param_count] = NULL;
269 }
270
271#ifdef _FUTURE_FEATURE
272
273 /*
274 * Begin incoming argument count analysis. Check for too few args
275 * and too many args.
276 */
277 switch (acpi_ns_get_type(info->node)) {
278 case ACPI_TYPE_METHOD:
279
280 /* Check incoming argument count against the method definition */
281
282 if (info->obj_desc->method.param_count > info->param_count) {
283 ACPI_ERROR((AE_INFO,
284 "Insufficient arguments (%u) - %u are required",
285 info->param_count,
286 info->obj_desc->method.param_count));
287
288 status = AE_MISSING_ARGUMENTS;
289 goto cleanup;
290 }
291
292 else if (info->obj_desc->method.param_count < info->param_count) {
293 ACPI_WARNING((AE_INFO,
294 "Excess arguments (%u) - only %u are required",
295 info->param_count,
296 info->obj_desc->method.param_count));
297
298 /* Just pass the required number of arguments */
299
300 info->param_count = info->obj_desc->method.param_count;
301 }
302
303 /*
304 * Any incoming external objects to be passed as arguments to the
305 * method must be converted to internal objects
306 */
307 if (info->param_count) {
308 /*
309 * Allocate a new parameter block for the internal objects
310 * Add 1 to count to allow for null terminated internal list
311 */
312 info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)
313 info->
314 param_count +
315 1) *
316 sizeof(void *));
317 if (!info->parameters) {
318 status = AE_NO_MEMORY;
319 goto cleanup;
320 }
321
322 /* Convert each external object in the list to an internal object */
323
324 for (i = 0; i < info->param_count; i++) {
325 status =
326 acpi_ut_copy_eobject_to_iobject
327 (&external_params->pointer[i],
328 &info->parameters[i]);
329 if (ACPI_FAILURE(status)) {
330 goto cleanup;
331 }
332 }
333
334 info->parameters[info->param_count] = NULL;
335 }
336 break;
337
338 default:
339
340 /* Warn if arguments passed to an object that is not a method */
341
342 if (info->param_count) {
343 ACPI_WARNING((AE_INFO,
344 "%u arguments were passed to a non-method ACPI object",
345 info->param_count));
346 }
347 break;
348 }
349
350#endif
351
352 /* Now we can evaluate the object */
353
354 status = acpi_ns_evaluate(info);
355
356 /*
357 * If we are expecting a return value, and all went well above,
358 * copy the return value to an external object.
359 */
360 if (!return_buffer) {
361 goto cleanup_return_object;
362 }
363
364 if (!info->return_object) {
365 return_buffer->length = 0;
366 goto cleanup;
367 }
368
369 if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
370 ACPI_DESC_TYPE_NAMED) {
371 /*
372 * If we received a NS Node as a return object, this means that
373 * the object we are evaluating has nothing interesting to
374 * return (such as a mutex, etc.) We return an error because
375 * these types are essentially unsupported by this interface.
376 * We don't check up front because this makes it easier to add
377 * support for various types at a later date if necessary.
378 */
379 status = AE_TYPE;
380 info->return_object = NULL; /* No need to delete a NS Node */
381 return_buffer->length = 0;
382 }
383
384 if (ACPI_FAILURE(status)) {
385 goto cleanup_return_object;
386 }
387
388 /* Dereference Index and ref_of references */
389
390 acpi_ns_resolve_references(info);
391
392 /* Get the size of the returned object */
393
394 status = acpi_ut_get_object_size(obj: info->return_object,
395 obj_length: &buffer_space_needed);
396 if (ACPI_SUCCESS(status)) {
397
398 /* Validate/Allocate/Clear caller buffer */
399
400 status = acpi_ut_initialize_buffer(buffer: return_buffer,
401 required_length: buffer_space_needed);
402 if (ACPI_FAILURE(status)) {
403 /*
404 * Caller's buffer is too small or a new one can't
405 * be allocated
406 */
407 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
408 "Needed buffer size %X, %s\n",
409 (u32)buffer_space_needed,
410 acpi_format_exception(status)));
411 } else {
412 /* We have enough space for the object, build it */
413
414 status =
415 acpi_ut_copy_iobject_to_eobject(obj: info->return_object,
416 ret_buffer: return_buffer);
417 }
418 }
419
420cleanup_return_object:
421
422 if (info->return_object) {
423 /*
424 * Delete the internal return object. NOTE: Interpreter must be
425 * locked to avoid race condition.
426 */
427 acpi_ex_enter_interpreter();
428
429 /* Remove one reference on the return object (should delete it) */
430
431 acpi_ut_remove_reference(object: info->return_object);
432 acpi_ex_exit_interpreter();
433 }
434
435cleanup:
436
437 /* Free the input parameter list (if we created one) */
438
439 if (info->parameters) {
440
441 /* Free the allocated parameter block */
442
443 acpi_ut_delete_internal_object_list(obj_list: info->parameters);
444 }
445
446 ACPI_FREE(info);
447 return_ACPI_STATUS(status);
448}
449
450ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
451
452/*******************************************************************************
453 *
454 * FUNCTION: acpi_ns_resolve_references
455 *
456 * PARAMETERS: info - Evaluation info block
457 *
458 * RETURN: Info->return_object is replaced with the dereferenced object
459 *
460 * DESCRIPTION: Dereference certain reference objects. Called before an
461 * internal return object is converted to an external union acpi_object.
462 *
463 * Performs an automatic dereference of Index and ref_of reference objects.
464 * These reference objects are not supported by the union acpi_object, so this is a
465 * last resort effort to return something useful. Also, provides compatibility
466 * with other ACPI implementations.
467 *
468 * NOTE: does not handle references within returned package objects or nested
469 * references, but this support could be added later if found to be necessary.
470 *
471 ******************************************************************************/
472static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
473{
474 union acpi_operand_object *obj_desc = NULL;
475 struct acpi_namespace_node *node;
476
477 /* We are interested in reference objects only */
478
479 if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
480 return;
481 }
482
483 /*
484 * Two types of references are supported - those created by Index and
485 * ref_of operators. A name reference (AML_NAMEPATH_OP) can be converted
486 * to a union acpi_object, so it is not dereferenced here. A ddb_handle
487 * (AML_LOAD_OP) cannot be dereferenced, nor can it be converted to
488 * a union acpi_object.
489 */
490 switch (info->return_object->reference.class) {
491 case ACPI_REFCLASS_INDEX:
492
493 obj_desc = *(info->return_object->reference.where);
494 break;
495
496 case ACPI_REFCLASS_REFOF:
497
498 node = info->return_object->reference.object;
499 if (node) {
500 obj_desc = node->object;
501 }
502 break;
503
504 default:
505
506 return;
507 }
508
509 /* Replace the existing reference object */
510
511 if (obj_desc) {
512 acpi_ut_add_reference(object: obj_desc);
513 acpi_ut_remove_reference(object: info->return_object);
514 info->return_object = obj_desc;
515 }
516
517 return;
518}
519
520/*******************************************************************************
521 *
522 * FUNCTION: acpi_walk_namespace
523 *
524 * PARAMETERS: type - acpi_object_type to search for
525 * start_object - Handle in namespace where search begins
526 * max_depth - Depth to which search is to reach
527 * descending_callback - Called during tree descent
528 * when an object of "Type" is found
529 * ascending_callback - Called during tree ascent
530 * when an object of "Type" is found
531 * context - Passed to user function(s) above
532 * return_value - Location where return value of
533 * user_function is put if terminated early
534 *
535 * RETURNS Return value from the user_function if terminated early.
536 * Otherwise, returns NULL.
537 *
538 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
539 * starting (and ending) at the object specified by start_handle.
540 * The callback function is called whenever an object that matches
541 * the type parameter is found. If the callback function returns
542 * a non-zero value, the search is terminated immediately and this
543 * value is returned to the caller.
544 *
545 * The point of this procedure is to provide a generic namespace
546 * walk routine that can be called from multiple places to
547 * provide multiple services; the callback function(s) can be
548 * tailored to each task, whether it is a print function,
549 * a compare function, etc.
550 *
551 ******************************************************************************/
552
553acpi_status
554acpi_walk_namespace(acpi_object_type type,
555 acpi_handle start_object,
556 u32 max_depth,
557 acpi_walk_callback descending_callback,
558 acpi_walk_callback ascending_callback,
559 void *context, void **return_value)
560{
561 acpi_status status;
562
563 ACPI_FUNCTION_TRACE(acpi_walk_namespace);
564
565 /* Parameter validation */
566
567 if ((type > ACPI_TYPE_LOCAL_MAX) ||
568 (!max_depth) || (!descending_callback && !ascending_callback)) {
569 return_ACPI_STATUS(AE_BAD_PARAMETER);
570 }
571
572 /*
573 * Need to acquire the namespace reader lock to prevent interference
574 * with any concurrent table unloads (which causes the deletion of
575 * namespace objects). We cannot allow the deletion of a namespace node
576 * while the user function is using it. The exception to this are the
577 * nodes created and deleted during control method execution -- these
578 * nodes are marked as temporary nodes and are ignored by the namespace
579 * walk. Thus, control methods can be executed while holding the
580 * namespace deletion lock (and the user function can execute control
581 * methods.)
582 */
583 status = acpi_ut_acquire_read_lock(lock: &acpi_gbl_namespace_rw_lock);
584 if (ACPI_FAILURE(status)) {
585 return_ACPI_STATUS(status);
586 }
587
588 /*
589 * Lock the namespace around the walk. The namespace will be
590 * unlocked/locked around each call to the user function - since the user
591 * function must be allowed to make ACPICA calls itself (for example, it
592 * will typically execute control methods during device enumeration.)
593 */
594 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
595 if (ACPI_FAILURE(status)) {
596 goto unlock_and_exit;
597 }
598
599 /* Now we can validate the starting node */
600
601 if (!acpi_ns_validate_handle(handle: start_object)) {
602 status = AE_BAD_PARAMETER;
603 goto unlock_and_exit2;
604 }
605
606 status = acpi_ns_walk_namespace(type, start_object, max_depth,
607 ACPI_NS_WALK_UNLOCK,
608 descending_callback, ascending_callback,
609 context, return_value);
610
611unlock_and_exit2:
612 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
613
614unlock_and_exit:
615 (void)acpi_ut_release_read_lock(lock: &acpi_gbl_namespace_rw_lock);
616 return_ACPI_STATUS(status);
617}
618
619ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
620
621/*******************************************************************************
622 *
623 * FUNCTION: acpi_ns_get_device_callback
624 *
625 * PARAMETERS: Callback from acpi_get_device
626 *
627 * RETURN: Status
628 *
629 * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
630 * present devices, or if they specified a HID, it filters based
631 * on that.
632 *
633 ******************************************************************************/
634static acpi_status
635acpi_ns_get_device_callback(acpi_handle obj_handle,
636 u32 nesting_level,
637 void *context, void **return_value)
638{
639 struct acpi_get_devices_info *info = context;
640 acpi_status status;
641 struct acpi_namespace_node *node;
642 u32 flags;
643 struct acpi_pnp_device_id *hid;
644 struct acpi_pnp_device_id_list *cid;
645 u32 i;
646 u8 found;
647 int no_match;
648
649 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
650 if (ACPI_FAILURE(status)) {
651 return (status);
652 }
653
654 node = acpi_ns_validate_handle(handle: obj_handle);
655 status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
656 if (ACPI_FAILURE(status)) {
657 return (status);
658 }
659
660 if (!node) {
661 return (AE_BAD_PARAMETER);
662 }
663
664 /*
665 * First, filter based on the device HID and CID.
666 *
667 * 01/2010: For this case where a specific HID is requested, we don't
668 * want to run _STA until we have an actual HID match. Thus, we will
669 * not unnecessarily execute _STA on devices for which the caller
670 * doesn't care about. Previously, _STA was executed unconditionally
671 * on all devices found here.
672 *
673 * A side-effect of this change is that now we will continue to search
674 * for a matching HID even under device trees where the parent device
675 * would have returned a _STA that indicates it is not present or
676 * not functioning (thus aborting the search on that branch).
677 */
678 if (info->hid != NULL) {
679 status = acpi_ut_execute_HID(device_node: node, return_id: &hid);
680 if (status == AE_NOT_FOUND) {
681 return (AE_OK);
682 } else if (ACPI_FAILURE(status)) {
683 return (AE_CTRL_DEPTH);
684 }
685
686 no_match = strcmp(hid->string, info->hid);
687 ACPI_FREE(hid);
688
689 if (no_match) {
690 /*
691 * HID does not match, attempt match within the
692 * list of Compatible IDs (CIDs)
693 */
694 status = acpi_ut_execute_CID(device_node: node, return_cid_list: &cid);
695 if (status == AE_NOT_FOUND) {
696 return (AE_OK);
697 } else if (ACPI_FAILURE(status)) {
698 return (AE_CTRL_DEPTH);
699 }
700
701 /* Walk the CID list */
702
703 found = FALSE;
704 for (i = 0; i < cid->count; i++) {
705 if (strcmp(cid->ids[i].string, info->hid) == 0) {
706
707 /* Found a matching CID */
708
709 found = TRUE;
710 break;
711 }
712 }
713
714 ACPI_FREE(cid);
715 if (!found) {
716 return (AE_OK);
717 }
718 }
719 }
720
721 /* Run _STA to determine if device is present */
722
723 status = acpi_ut_execute_STA(device_node: node, status_flags: &flags);
724 if (ACPI_FAILURE(status)) {
725 return (AE_CTRL_DEPTH);
726 }
727
728 if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
729 !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
730 /*
731 * Don't examine the children of the device only when the
732 * device is neither present nor functional. See ACPI spec,
733 * description of _STA for more information.
734 */
735 return (AE_CTRL_DEPTH);
736 }
737
738 /* We have a valid device, invoke the user function */
739
740 status = info->user_function(obj_handle, nesting_level,
741 info->context, return_value);
742 return (status);
743}
744
745/*******************************************************************************
746 *
747 * FUNCTION: acpi_get_devices
748 *
749 * PARAMETERS: HID - HID to search for. Can be NULL.
750 * user_function - Called when a matching object is found
751 * context - Passed to user function
752 * return_value - Location where return value of
753 * user_function is put if terminated early
754 *
755 * RETURNS Return value from the user_function if terminated early.
756 * Otherwise, returns NULL.
757 *
758 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
759 * starting (and ending) at the object specified by start_handle.
760 * The user_function is called whenever an object of type
761 * Device is found. If the user function returns
762 * a non-zero value, the search is terminated immediately and this
763 * value is returned to the caller.
764 *
765 * This is a wrapper for walk_namespace, but the callback performs
766 * additional filtering. Please see acpi_ns_get_device_callback.
767 *
768 ******************************************************************************/
769
770acpi_status
771acpi_get_devices(const char *HID,
772 acpi_walk_callback user_function,
773 void *context, void **return_value)
774{
775 acpi_status status;
776 struct acpi_get_devices_info info;
777
778 ACPI_FUNCTION_TRACE(acpi_get_devices);
779
780 /* Parameter validation */
781
782 if (!user_function) {
783 return_ACPI_STATUS(AE_BAD_PARAMETER);
784 }
785
786 /*
787 * We're going to call their callback from OUR callback, so we need
788 * to know what it is, and their context parameter.
789 */
790 info.hid = HID;
791 info.context = context;
792 info.user_function = user_function;
793
794 /*
795 * Lock the namespace around the walk.
796 * The namespace will be unlocked/locked around each call
797 * to the user function - since this function
798 * must be allowed to make Acpi calls itself.
799 */
800 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
801 if (ACPI_FAILURE(status)) {
802 return_ACPI_STATUS(status);
803 }
804
805 status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
806 ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
807 descending_callback: acpi_ns_get_device_callback, NULL,
808 context: &info, return_value);
809
810 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
811 return_ACPI_STATUS(status);
812}
813
814ACPI_EXPORT_SYMBOL(acpi_get_devices)
815
816/*******************************************************************************
817 *
818 * FUNCTION: acpi_attach_data
819 *
820 * PARAMETERS: obj_handle - Namespace node
821 * handler - Handler for this attachment
822 * data - Pointer to data to be attached
823 *
824 * RETURN: Status
825 *
826 * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
827 *
828 ******************************************************************************/
829acpi_status
830acpi_attach_data(acpi_handle obj_handle,
831 acpi_object_handler handler, void *data)
832{
833 struct acpi_namespace_node *node;
834 acpi_status status;
835
836 /* Parameter validation */
837
838 if (!obj_handle || !handler || !data) {
839 return (AE_BAD_PARAMETER);
840 }
841
842 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
843 if (ACPI_FAILURE(status)) {
844 return (status);
845 }
846
847 /* Convert and validate the handle */
848
849 node = acpi_ns_validate_handle(handle: obj_handle);
850 if (!node) {
851 status = AE_BAD_PARAMETER;
852 goto unlock_and_exit;
853 }
854
855 status = acpi_ns_attach_data(node, handler, data);
856
857unlock_and_exit:
858 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
859 return (status);
860}
861
862ACPI_EXPORT_SYMBOL(acpi_attach_data)
863
864/*******************************************************************************
865 *
866 * FUNCTION: acpi_detach_data
867 *
868 * PARAMETERS: obj_handle - Namespace node handle
869 * handler - Handler used in call to acpi_attach_data
870 *
871 * RETURN: Status
872 *
873 * DESCRIPTION: Remove data that was previously attached to a node.
874 *
875 ******************************************************************************/
876acpi_status
877acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
878{
879 struct acpi_namespace_node *node;
880 acpi_status status;
881
882 /* Parameter validation */
883
884 if (!obj_handle || !handler) {
885 return (AE_BAD_PARAMETER);
886 }
887
888 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
889 if (ACPI_FAILURE(status)) {
890 return (status);
891 }
892
893 /* Convert and validate the handle */
894
895 node = acpi_ns_validate_handle(handle: obj_handle);
896 if (!node) {
897 status = AE_BAD_PARAMETER;
898 goto unlock_and_exit;
899 }
900
901 status = acpi_ns_detach_data(node, handler);
902
903unlock_and_exit:
904 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
905 return (status);
906}
907
908ACPI_EXPORT_SYMBOL(acpi_detach_data)
909
910/*******************************************************************************
911 *
912 * FUNCTION: acpi_get_data_full
913 *
914 * PARAMETERS: obj_handle - Namespace node
915 * handler - Handler used in call to attach_data
916 * data - Where the data is returned
917 * callback - function to execute before returning
918 *
919 * RETURN: Status
920 *
921 * DESCRIPTION: Retrieve data that was previously attached to a namespace node
922 * and execute a callback before returning.
923 *
924 ******************************************************************************/
925acpi_status
926acpi_get_data_full(acpi_handle obj_handle, acpi_object_handler handler,
927 void **data, void (*callback)(void *))
928{
929 struct acpi_namespace_node *node;
930 acpi_status status;
931
932 /* Parameter validation */
933
934 if (!obj_handle || !handler || !data) {
935 return (AE_BAD_PARAMETER);
936 }
937
938 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
939 if (ACPI_FAILURE(status)) {
940 return (status);
941 }
942
943 /* Convert and validate the handle */
944
945 node = acpi_ns_validate_handle(handle: obj_handle);
946 if (!node) {
947 status = AE_BAD_PARAMETER;
948 goto unlock_and_exit;
949 }
950
951 status = acpi_ns_get_attached_data(node, handler, data);
952 if (ACPI_SUCCESS(status) && callback) {
953 callback(*data);
954 }
955
956unlock_and_exit:
957 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
958 return (status);
959}
960
961ACPI_EXPORT_SYMBOL(acpi_get_data_full)
962
963/*******************************************************************************
964 *
965 * FUNCTION: acpi_get_data
966 *
967 * PARAMETERS: obj_handle - Namespace node
968 * handler - Handler used in call to attach_data
969 * data - Where the data is returned
970 *
971 * RETURN: Status
972 *
973 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
974 *
975 ******************************************************************************/
976acpi_status
977acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
978{
979 return acpi_get_data_full(obj_handle, handler, data, NULL);
980}
981
982ACPI_EXPORT_SYMBOL(acpi_get_data)
983