xref: /titanic_41/usr/src/uts/intel/io/acpica/namespace/nsxfeval.c (revision a970c705050f9e90c4b6d7982a9b3211719353fb)
1 /*******************************************************************************
2  *
3  * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
4  *                         ACPI Object evaluation interfaces
5  *
6  ******************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2011, Intel Corp.
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44 
45 
46 #define __NSXFEVAL_C__
47 
48 #include "acpi.h"
49 #include "accommon.h"
50 #include "acnamesp.h"
51 #include "acinterp.h"
52 
53 
54 #define _COMPONENT          ACPI_NAMESPACE
55         ACPI_MODULE_NAME    ("nsxfeval")
56 
57 /* Local prototypes */
58 
59 static void
60 AcpiNsResolveReferences (
61     ACPI_EVALUATE_INFO      *Info);
62 
63 
64 /*******************************************************************************
65  *
66  * FUNCTION:    AcpiEvaluateObjectTyped
67  *
68  * PARAMETERS:  Handle              - Object handle (optional)
69  *              Pathname            - Object pathname (optional)
70  *              ExternalParams      - List of parameters to pass to method,
71  *                                    terminated by NULL.  May be NULL
72  *                                    if no parameters are being passed.
73  *              ReturnBuffer        - Where to put method's return value (if
74  *                                    any).  If NULL, no value is returned.
75  *              ReturnType          - Expected type of return object
76  *
77  * RETURN:      Status
78  *
79  * DESCRIPTION: Find and evaluate the given object, passing the given
80  *              parameters if necessary.  One of "Handle" or "Pathname" must
81  *              be valid (non-null)
82  *
83  ******************************************************************************/
84 
85 ACPI_STATUS
86 AcpiEvaluateObjectTyped (
87     ACPI_HANDLE             Handle,
88     ACPI_STRING             Pathname,
89     ACPI_OBJECT_LIST        *ExternalParams,
90     ACPI_BUFFER             *ReturnBuffer,
91     ACPI_OBJECT_TYPE        ReturnType)
92 {
93     ACPI_STATUS             Status;
94     BOOLEAN                 MustFree = FALSE;
95 
96 
97     ACPI_FUNCTION_TRACE (AcpiEvaluateObjectTyped);
98 
99 
100     /* Return buffer must be valid */
101 
102     if (!ReturnBuffer)
103     {
104         return_ACPI_STATUS (AE_BAD_PARAMETER);
105     }
106 
107     if (ReturnBuffer->Length == ACPI_ALLOCATE_BUFFER)
108     {
109         MustFree = TRUE;
110     }
111 
112     /* Evaluate the object */
113 
114     Status = AcpiEvaluateObject (Handle, Pathname, ExternalParams, ReturnBuffer);
115     if (ACPI_FAILURE (Status))
116     {
117         return_ACPI_STATUS (Status);
118     }
119 
120     /* Type ANY means "don't care" */
121 
122     if (ReturnType == ACPI_TYPE_ANY)
123     {
124         return_ACPI_STATUS (AE_OK);
125     }
126 
127     if (ReturnBuffer->Length == 0)
128     {
129         /* Error because caller specifically asked for a return value */
130 
131         ACPI_ERROR ((AE_INFO, "No return value"));
132         return_ACPI_STATUS (AE_NULL_OBJECT);
133     }
134 
135     /* Examine the object type returned from EvaluateObject */
136 
137     if (((ACPI_OBJECT *) ReturnBuffer->Pointer)->Type == ReturnType)
138     {
139         return_ACPI_STATUS (AE_OK);
140     }
141 
142     /* Return object type does not match requested type */
143 
144     ACPI_ERROR ((AE_INFO,
145         "Incorrect return type [%s] requested [%s]",
146         AcpiUtGetTypeName (((ACPI_OBJECT *) ReturnBuffer->Pointer)->Type),
147         AcpiUtGetTypeName (ReturnType)));
148 
149     if (MustFree)
150     {
151         /* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */
152 
153         AcpiOsFree (ReturnBuffer->Pointer);
154         ReturnBuffer->Pointer = NULL;
155     }
156 
157     ReturnBuffer->Length = 0;
158     return_ACPI_STATUS (AE_TYPE);
159 }
160 
161 ACPI_EXPORT_SYMBOL (AcpiEvaluateObjectTyped)
162 
163 
164 /*******************************************************************************
165  *
166  * FUNCTION:    AcpiEvaluateObject
167  *
168  * PARAMETERS:  Handle              - Object handle (optional)
169  *              Pathname            - Object pathname (optional)
170  *              ExternalParams      - List of parameters to pass to method,
171  *                                    terminated by NULL.  May be NULL
172  *                                    if no parameters are being passed.
173  *              ReturnBuffer        - Where to put method's return value (if
174  *                                    any).  If NULL, no value is returned.
175  *
176  * RETURN:      Status
177  *
178  * DESCRIPTION: Find and evaluate the given object, passing the given
179  *              parameters if necessary.  One of "Handle" or "Pathname" must
180  *              be valid (non-null)
181  *
182  ******************************************************************************/
183 
184 ACPI_STATUS
185 AcpiEvaluateObject (
186     ACPI_HANDLE             Handle,
187     ACPI_STRING             Pathname,
188     ACPI_OBJECT_LIST        *ExternalParams,
189     ACPI_BUFFER             *ReturnBuffer)
190 {
191     ACPI_STATUS             Status;
192     ACPI_EVALUATE_INFO      *Info;
193     ACPI_SIZE               BufferSpaceNeeded;
194     UINT32                  i;
195 
196 
197     ACPI_FUNCTION_TRACE (AcpiEvaluateObject);
198 
199 
200     /* Allocate and initialize the evaluation information block */
201 
202     Info = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));
203     if (!Info)
204     {
205         return_ACPI_STATUS (AE_NO_MEMORY);
206     }
207 
208     Info->Pathname = Pathname;
209 
210     /* Convert and validate the device handle */
211 
212     Info->PrefixNode = AcpiNsValidateHandle (Handle);
213     if (!Info->PrefixNode)
214     {
215         Status = AE_BAD_PARAMETER;
216         goto Cleanup;
217     }
218 
219     /*
220      * If there are parameters to be passed to a control method, the external
221      * objects must all be converted to internal objects
222      */
223     if (ExternalParams && ExternalParams->Count)
224     {
225         /*
226          * Allocate a new parameter block for the internal objects
227          * Add 1 to count to allow for null terminated internal list
228          */
229         Info->Parameters = ACPI_ALLOCATE_ZEROED (
230             ((ACPI_SIZE) ExternalParams->Count + 1) * sizeof (void *));
231         if (!Info->Parameters)
232         {
233             Status = AE_NO_MEMORY;
234             goto Cleanup;
235         }
236 
237         /* Convert each external object in the list to an internal object */
238 
239         for (i = 0; i < ExternalParams->Count; i++)
240         {
241             Status = AcpiUtCopyEobjectToIobject (
242                         &ExternalParams->Pointer[i], &Info->Parameters[i]);
243             if (ACPI_FAILURE (Status))
244             {
245                 goto Cleanup;
246             }
247         }
248         Info->Parameters[ExternalParams->Count] = NULL;
249     }
250 
251     /*
252      * Three major cases:
253      * 1) Fully qualified pathname
254      * 2) No handle, not fully qualified pathname (error)
255      * 3) Valid handle
256      */
257     if ((Pathname) &&
258         (AcpiNsValidRootPrefix (Pathname[0])))
259     {
260         /* The path is fully qualified, just evaluate by name */
261 
262         Info->PrefixNode = NULL;
263         Status = AcpiNsEvaluate (Info);
264     }
265     else if (!Handle)
266     {
267         /*
268          * A handle is optional iff a fully qualified pathname is specified.
269          * Since we've already handled fully qualified names above, this is
270          * an error
271          */
272         if (!Pathname)
273         {
274             ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
275                 "Both Handle and Pathname are NULL"));
276         }
277         else
278         {
279             ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
280                 "Null Handle with relative pathname [%s]", Pathname));
281         }
282 
283         Status = AE_BAD_PARAMETER;
284     }
285     else
286     {
287         /* We have a namespace a node and a possible relative path */
288 
289         Status = AcpiNsEvaluate (Info);
290     }
291 
292     /*
293      * If we are expecting a return value, and all went well above,
294      * copy the return value to an external object.
295      */
296     if (ReturnBuffer)
297     {
298         if (!Info->ReturnObject)
299         {
300             ReturnBuffer->Length = 0;
301         }
302         else
303         {
304             if (ACPI_GET_DESCRIPTOR_TYPE (Info->ReturnObject) ==
305                 ACPI_DESC_TYPE_NAMED)
306             {
307                 /*
308                  * If we received a NS Node as a return object, this means that
309                  * the object we are evaluating has nothing interesting to
310                  * return (such as a mutex, etc.)  We return an error because
311                  * these types are essentially unsupported by this interface.
312                  * We don't check up front because this makes it easier to add
313                  * support for various types at a later date if necessary.
314                  */
315                 Status = AE_TYPE;
316                 Info->ReturnObject = NULL;   /* No need to delete a NS Node */
317                 ReturnBuffer->Length = 0;
318             }
319 
320             if (ACPI_SUCCESS (Status))
321             {
322                 /* Dereference Index and RefOf references */
323 
324                 AcpiNsResolveReferences (Info);
325 
326                 /* Get the size of the returned object */
327 
328                 Status = AcpiUtGetObjectSize (Info->ReturnObject,
329                             &BufferSpaceNeeded);
330                 if (ACPI_SUCCESS (Status))
331                 {
332                     /* Validate/Allocate/Clear caller buffer */
333 
334                     Status = AcpiUtInitializeBuffer (ReturnBuffer,
335                                 BufferSpaceNeeded);
336                     if (ACPI_FAILURE (Status))
337                     {
338                         /*
339                          * Caller's buffer is too small or a new one can't
340                          * be allocated
341                          */
342                         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
343                             "Needed buffer size %X, %s\n",
344                             (UINT32) BufferSpaceNeeded,
345                             AcpiFormatException (Status)));
346                     }
347                     else
348                     {
349                         /* We have enough space for the object, build it */
350 
351                         Status = AcpiUtCopyIobjectToEobject (Info->ReturnObject,
352                                     ReturnBuffer);
353                     }
354                 }
355             }
356         }
357     }
358 
359     if (Info->ReturnObject)
360     {
361         /*
362          * Delete the internal return object. NOTE: Interpreter must be
363          * locked to avoid race condition.
364          */
365         AcpiExEnterInterpreter ();
366 
367         /* Remove one reference on the return object (should delete it) */
368 
369         AcpiUtRemoveReference (Info->ReturnObject);
370         AcpiExExitInterpreter ();
371     }
372 
373 
374 Cleanup:
375 
376     /* Free the input parameter list (if we created one) */
377 
378     if (Info->Parameters)
379     {
380         /* Free the allocated parameter block */
381 
382         AcpiUtDeleteInternalObjectList (Info->Parameters);
383     }
384 
385     ACPI_FREE (Info);
386     return_ACPI_STATUS (Status);
387 }
388 
389 ACPI_EXPORT_SYMBOL (AcpiEvaluateObject)
390 
391 
392 /*******************************************************************************
393  *
394  * FUNCTION:    AcpiNsResolveReferences
395  *
396  * PARAMETERS:  Info                    - Evaluation info block
397  *
398  * RETURN:      Info->ReturnObject is replaced with the dereferenced object
399  *
400  * DESCRIPTION: Dereference certain reference objects. Called before an
401  *              internal return object is converted to an external ACPI_OBJECT.
402  *
403  * Performs an automatic dereference of Index and RefOf reference objects.
404  * These reference objects are not supported by the ACPI_OBJECT, so this is a
405  * last resort effort to return something useful. Also, provides compatibility
406  * with other ACPI implementations.
407  *
408  * NOTE: does not handle references within returned package objects or nested
409  * references, but this support could be added later if found to be necessary.
410  *
411  ******************************************************************************/
412 
413 static void
414 AcpiNsResolveReferences (
415     ACPI_EVALUATE_INFO      *Info)
416 {
417     ACPI_OPERAND_OBJECT     *ObjDesc = NULL;
418     ACPI_NAMESPACE_NODE     *Node;
419 
420 
421     /* We are interested in reference objects only */
422 
423     if ((Info->ReturnObject)->Common.Type != ACPI_TYPE_LOCAL_REFERENCE)
424     {
425         return;
426     }
427 
428     /*
429      * Two types of references are supported - those created by Index and
430      * RefOf operators. A name reference (AML_NAMEPATH_OP) can be converted
431      * to an ACPI_OBJECT, so it is not dereferenced here. A DdbHandle
432      * (AML_LOAD_OP) cannot be dereferenced, nor can it be converted to
433      * an ACPI_OBJECT.
434      */
435     switch (Info->ReturnObject->Reference.Class)
436     {
437     case ACPI_REFCLASS_INDEX:
438 
439         ObjDesc = *(Info->ReturnObject->Reference.Where);
440         break;
441 
442     case ACPI_REFCLASS_REFOF:
443 
444         Node = Info->ReturnObject->Reference.Object;
445         if (Node)
446         {
447             ObjDesc = Node->Object;
448         }
449         break;
450 
451     default:
452         return;
453     }
454 
455     /* Replace the existing reference object */
456 
457     if (ObjDesc)
458     {
459         AcpiUtAddReference (ObjDesc);
460         AcpiUtRemoveReference (Info->ReturnObject);
461         Info->ReturnObject = ObjDesc;
462     }
463 
464     return;
465 }
466 
467 
468 /*******************************************************************************
469  *
470  * FUNCTION:    AcpiWalkNamespace
471  *
472  * PARAMETERS:  Type                - ACPI_OBJECT_TYPE to search for
473  *              StartObject         - Handle in namespace where search begins
474  *              MaxDepth            - Depth to which search is to reach
475  *              PreOrderVisit       - Called during tree pre-order visit
476  *                                    when an object of "Type" is found
477  *              PostOrderVisit      - Called during tree post-order visit
478  *                                    when an object of "Type" is found
479  *              Context             - Passed to user function(s) above
480  *              ReturnValue         - Location where return value of
481  *                                    UserFunction is put if terminated early
482  *
483  * RETURNS      Return value from the UserFunction if terminated early.
484  *              Otherwise, returns NULL.
485  *
486  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
487  *              starting (and ending) at the object specified by StartHandle.
488  *              The callback function is called whenever an object that matches
489  *              the type parameter is found. If the callback function returns
490  *              a non-zero value, the search is terminated immediately and this
491  *              value is returned to the caller.
492  *
493  *              The point of this procedure is to provide a generic namespace
494  *              walk routine that can be called from multiple places to
495  *              provide multiple services; the callback function(s) can be
496  *              tailored to each task, whether it is a print function,
497  *              a compare function, etc.
498  *
499  ******************************************************************************/
500 
501 ACPI_STATUS
502 AcpiWalkNamespace (
503     ACPI_OBJECT_TYPE        Type,
504     ACPI_HANDLE             StartObject,
505     UINT32                  MaxDepth,
506     ACPI_WALK_CALLBACK      PreOrderVisit,
507     ACPI_WALK_CALLBACK      PostOrderVisit,
508     void                    *Context,
509     void                    **ReturnValue)
510 {
511     ACPI_STATUS             Status;
512 
513 
514     ACPI_FUNCTION_TRACE (AcpiWalkNamespace);
515 
516 
517     /* Parameter validation */
518 
519     if ((Type > ACPI_TYPE_LOCAL_MAX) ||
520         (!MaxDepth)                  ||
521         (!PreOrderVisit && !PostOrderVisit))
522     {
523         return_ACPI_STATUS (AE_BAD_PARAMETER);
524     }
525 
526     /*
527      * Need to acquire the namespace reader lock to prevent interference
528      * with any concurrent table unloads (which causes the deletion of
529      * namespace objects). We cannot allow the deletion of a namespace node
530      * while the user function is using it. The exception to this are the
531      * nodes created and deleted during control method execution -- these
532      * nodes are marked as temporary nodes and are ignored by the namespace
533      * walk. Thus, control methods can be executed while holding the
534      * namespace deletion lock (and the user function can execute control
535      * methods.)
536      */
537     Status = AcpiUtAcquireReadLock (&AcpiGbl_NamespaceRwLock);
538     if (ACPI_FAILURE (Status))
539     {
540         return (Status);
541     }
542 
543     /*
544      * Lock the namespace around the walk. The namespace will be
545      * unlocked/locked around each call to the user function - since the user
546      * function must be allowed to make ACPICA calls itself (for example, it
547      * will typically execute control methods during device enumeration.)
548      */
549     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
550     if (ACPI_FAILURE (Status))
551     {
552         goto UnlockAndExit;
553     }
554 
555     Status = AcpiNsWalkNamespace (Type, StartObject, MaxDepth,
556                 ACPI_NS_WALK_UNLOCK, PreOrderVisit,
557                 PostOrderVisit, Context, ReturnValue);
558 
559     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
560 
561 UnlockAndExit:
562     (void) AcpiUtReleaseReadLock (&AcpiGbl_NamespaceRwLock);
563     return_ACPI_STATUS (Status);
564 }
565 
566 ACPI_EXPORT_SYMBOL (AcpiWalkNamespace)
567 
568 
569 /*******************************************************************************
570  *
571  * FUNCTION:    AcpiNsGetDeviceCallback
572  *
573  * PARAMETERS:  Callback from AcpiGetDevice
574  *
575  * RETURN:      Status
576  *
577  * DESCRIPTION: Takes callbacks from WalkNamespace and filters out all non-
578  *              present devices, or if they specified a HID, it filters based
579  *              on that.
580  *
581  ******************************************************************************/
582 
583 static ACPI_STATUS
584 AcpiNsGetDeviceCallback (
585     ACPI_HANDLE             ObjHandle,
586     UINT32                  NestingLevel,
587     void                    *Context,
588     void                    **ReturnValue)
589 {
590     ACPI_GET_DEVICES_INFO   *Info = Context;
591     ACPI_STATUS             Status;
592     ACPI_NAMESPACE_NODE     *Node;
593     UINT32                  Flags;
594     ACPI_DEVICE_ID          *Hid;
595     ACPI_DEVICE_ID_LIST     *Cid;
596     UINT32                  i;
597     BOOLEAN                 Found;
598     int                     NoMatch;
599 
600 
601     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
602     if (ACPI_FAILURE (Status))
603     {
604         return (Status);
605     }
606 
607     Node = AcpiNsValidateHandle (ObjHandle);
608     Status = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
609     if (ACPI_FAILURE (Status))
610     {
611         return (Status);
612     }
613 
614     if (!Node)
615     {
616         return (AE_BAD_PARAMETER);
617     }
618 
619     /*
620      * First, filter based on the device HID and CID.
621      *
622      * 01/2010: For this case where a specific HID is requested, we don't
623      * want to run _STA until we have an actual HID match. Thus, we will
624      * not unnecessarily execute _STA on devices for which the caller
625      * doesn't care about. Previously, _STA was executed unconditionally
626      * on all devices found here.
627      *
628      * A side-effect of this change is that now we will continue to search
629      * for a matching HID even under device trees where the parent device
630      * would have returned a _STA that indicates it is not present or
631      * not functioning (thus aborting the search on that branch).
632      */
633     if (Info->Hid != NULL)
634     {
635         Status = AcpiUtExecute_HID (Node, &Hid);
636         if (Status == AE_NOT_FOUND)
637         {
638             return (AE_OK);
639         }
640         else if (ACPI_FAILURE (Status))
641         {
642             return (AE_CTRL_DEPTH);
643         }
644 
645         NoMatch = ACPI_STRCMP (Hid->String, Info->Hid);
646         ACPI_FREE (Hid);
647 
648         if (NoMatch)
649         {
650             /*
651              * HID does not match, attempt match within the
652              * list of Compatible IDs (CIDs)
653              */
654             Status = AcpiUtExecute_CID (Node, &Cid);
655             if (Status == AE_NOT_FOUND)
656             {
657                 return (AE_OK);
658             }
659             else if (ACPI_FAILURE (Status))
660             {
661                 return (AE_CTRL_DEPTH);
662             }
663 
664             /* Walk the CID list */
665 
666             Found = FALSE;
667             for (i = 0; i < Cid->Count; i++)
668             {
669                 if (ACPI_STRCMP (Cid->Ids[i].String, Info->Hid) == 0)
670                 {
671                     /* Found a matching CID */
672 
673                     Found = TRUE;
674                     break;
675                 }
676             }
677 
678             ACPI_FREE (Cid);
679             if (!Found)
680             {
681                 return (AE_OK);
682             }
683         }
684     }
685 
686     /* Run _STA to determine if device is present */
687 
688     Status = AcpiUtExecute_STA (Node, &Flags);
689     if (ACPI_FAILURE (Status))
690     {
691         return (AE_CTRL_DEPTH);
692     }
693 
694     if (!(Flags & ACPI_STA_DEVICE_PRESENT) &&
695         !(Flags & ACPI_STA_DEVICE_FUNCTIONING))
696     {
697         /*
698          * Don't examine the children of the device only when the
699          * device is neither present nor functional. See ACPI spec,
700          * description of _STA for more information.
701          */
702         return (AE_CTRL_DEPTH);
703     }
704 
705     /* We have a valid device, invoke the user function */
706 
707     Status = Info->UserFunction (ObjHandle, NestingLevel, Info->Context,
708                 ReturnValue);
709     return (Status);
710 }
711 
712 
713 /*******************************************************************************
714  *
715  * FUNCTION:    AcpiGetDevices
716  *
717  * PARAMETERS:  HID                 - HID to search for. Can be NULL.
718  *              UserFunction        - Called when a matching object is found
719  *              Context             - Passed to user function
720  *              ReturnValue         - Location where return value of
721  *                                    UserFunction is put if terminated early
722  *
723  * RETURNS      Return value from the UserFunction if terminated early.
724  *              Otherwise, returns NULL.
725  *
726  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
727  *              starting (and ending) at the object specified by StartHandle.
728  *              The UserFunction is called whenever an object of type
729  *              Device is found.  If the user function returns
730  *              a non-zero value, the search is terminated immediately and this
731  *              value is returned to the caller.
732  *
733  *              This is a wrapper for WalkNamespace, but the callback performs
734  *              additional filtering. Please see AcpiNsGetDeviceCallback.
735  *
736  ******************************************************************************/
737 
738 ACPI_STATUS
739 AcpiGetDevices (
740     char                    *HID,
741     ACPI_WALK_CALLBACK      UserFunction,
742     void                    *Context,
743     void                    **ReturnValue)
744 {
745     ACPI_STATUS             Status;
746     ACPI_GET_DEVICES_INFO   Info;
747 
748 
749     ACPI_FUNCTION_TRACE (AcpiGetDevices);
750 
751 
752     /* Parameter validation */
753 
754     if (!UserFunction)
755     {
756         return_ACPI_STATUS (AE_BAD_PARAMETER);
757     }
758 
759     /*
760      * We're going to call their callback from OUR callback, so we need
761      * to know what it is, and their context parameter.
762      */
763     Info.Hid          = HID;
764     Info.Context      = Context;
765     Info.UserFunction = UserFunction;
766 
767     /*
768      * Lock the namespace around the walk.
769      * The namespace will be unlocked/locked around each call
770      * to the user function - since this function
771      * must be allowed to make Acpi calls itself.
772      */
773     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
774     if (ACPI_FAILURE (Status))
775     {
776         return_ACPI_STATUS (Status);
777     }
778 
779     Status = AcpiNsWalkNamespace (ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
780                 ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
781                 AcpiNsGetDeviceCallback, NULL, &Info, ReturnValue);
782 
783     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
784     return_ACPI_STATUS (Status);
785 }
786 
787 ACPI_EXPORT_SYMBOL (AcpiGetDevices)
788 
789 
790 /*******************************************************************************
791  *
792  * FUNCTION:    AcpiAttachData
793  *
794  * PARAMETERS:  ObjHandle           - Namespace node
795  *              Handler             - Handler for this attachment
796  *              Data                - Pointer to data to be attached
797  *
798  * RETURN:      Status
799  *
800  * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
801  *
802  ******************************************************************************/
803 
804 ACPI_STATUS
805 AcpiAttachData (
806     ACPI_HANDLE             ObjHandle,
807     ACPI_OBJECT_HANDLER     Handler,
808     void                    *Data)
809 {
810     ACPI_NAMESPACE_NODE     *Node;
811     ACPI_STATUS             Status;
812 
813 
814     /* Parameter validation */
815 
816     if (!ObjHandle  ||
817         !Handler    ||
818         !Data)
819     {
820         return (AE_BAD_PARAMETER);
821     }
822 
823     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
824     if (ACPI_FAILURE (Status))
825     {
826         return (Status);
827     }
828 
829     /* Convert and validate the handle */
830 
831     Node = AcpiNsValidateHandle (ObjHandle);
832     if (!Node)
833     {
834         Status = AE_BAD_PARAMETER;
835         goto UnlockAndExit;
836     }
837 
838     Status = AcpiNsAttachData (Node, Handler, Data);
839 
840 UnlockAndExit:
841     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
842     return (Status);
843 }
844 
845 ACPI_EXPORT_SYMBOL (AcpiAttachData)
846 
847 
848 /*******************************************************************************
849  *
850  * FUNCTION:    AcpiDetachData
851  *
852  * PARAMETERS:  ObjHandle           - Namespace node handle
853  *              Handler             - Handler used in call to AcpiAttachData
854  *
855  * RETURN:      Status
856  *
857  * DESCRIPTION: Remove data that was previously attached to a node.
858  *
859  ******************************************************************************/
860 
861 ACPI_STATUS
862 AcpiDetachData (
863     ACPI_HANDLE             ObjHandle,
864     ACPI_OBJECT_HANDLER     Handler)
865 {
866     ACPI_NAMESPACE_NODE     *Node;
867     ACPI_STATUS             Status;
868 
869 
870     /* Parameter validation */
871 
872     if (!ObjHandle  ||
873         !Handler)
874     {
875         return (AE_BAD_PARAMETER);
876     }
877 
878     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
879     if (ACPI_FAILURE (Status))
880     {
881         return (Status);
882     }
883 
884     /* Convert and validate the handle */
885 
886     Node = AcpiNsValidateHandle (ObjHandle);
887     if (!Node)
888     {
889         Status = AE_BAD_PARAMETER;
890         goto UnlockAndExit;
891     }
892 
893     Status = AcpiNsDetachData (Node, Handler);
894 
895 UnlockAndExit:
896     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
897     return (Status);
898 }
899 
900 ACPI_EXPORT_SYMBOL (AcpiDetachData)
901 
902 
903 /*******************************************************************************
904  *
905  * FUNCTION:    AcpiGetData
906  *
907  * PARAMETERS:  ObjHandle           - Namespace node
908  *              Handler             - Handler used in call to AttachData
909  *              Data                - Where the data is returned
910  *
911  * RETURN:      Status
912  *
913  * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
914  *
915  ******************************************************************************/
916 
917 ACPI_STATUS
918 AcpiGetData (
919     ACPI_HANDLE             ObjHandle,
920     ACPI_OBJECT_HANDLER     Handler,
921     void                    **Data)
922 {
923     ACPI_NAMESPACE_NODE     *Node;
924     ACPI_STATUS             Status;
925 
926 
927     /* Parameter validation */
928 
929     if (!ObjHandle  ||
930         !Handler    ||
931         !Data)
932     {
933         return (AE_BAD_PARAMETER);
934     }
935 
936     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
937     if (ACPI_FAILURE (Status))
938     {
939         return (Status);
940     }
941 
942     /* Convert and validate the handle */
943 
944     Node = AcpiNsValidateHandle (ObjHandle);
945     if (!Node)
946     {
947         Status = AE_BAD_PARAMETER;
948         goto UnlockAndExit;
949     }
950 
951     Status = AcpiNsGetAttachedData (Node, Handler, Data);
952 
953 UnlockAndExit:
954     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
955     return (Status);
956 }
957 
958 ACPI_EXPORT_SYMBOL (AcpiGetData)
959 
960 
961