xref: /titanic_41/usr/src/uts/intel/io/acpica/executer/exconfig.c (revision 299d957d28501350bcae7fa4333ff183c062c427)
1 /******************************************************************************
2  *
3  * Module Name: exconfig - Namespace reconfiguration (Load/Unload opcodes)
4  *              $Revision: 1.113 $
5  *
6  *****************************************************************************/
7 
8 /******************************************************************************
9  *
10  * 1. Copyright Notice
11  *
12  * Some or all of this work - Copyright (c) 1999 - 2008, Intel Corp.
13  * All rights reserved.
14  *
15  * 2. License
16  *
17  * 2.1. This is your license from Intel Corp. under its intellectual property
18  * rights.  You may have additional license terms from the party that provided
19  * you this software, covering your right to use that party's intellectual
20  * property rights.
21  *
22  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
23  * copy of the source code appearing in this file ("Covered Code") an
24  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
25  * base code distributed originally by Intel ("Original Intel Code") to copy,
26  * make derivatives, distribute, use and display any portion of the Covered
27  * Code in any form, with the right to sublicense such rights; and
28  *
29  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
30  * license (with the right to sublicense), under only those claims of Intel
31  * patents that are infringed by the Original Intel Code, to make, use, sell,
32  * offer to sell, and import the Covered Code and derivative works thereof
33  * solely to the minimum extent necessary to exercise the above copyright
34  * license, and in no event shall the patent license extend to any additions
35  * to or modifications of the Original Intel Code.  No other license or right
36  * is granted directly or by implication, estoppel or otherwise;
37  *
38  * The above copyright and patent license is granted only if the following
39  * conditions are met:
40  *
41  * 3. Conditions
42  *
43  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
44  * Redistribution of source code of any substantial portion of the Covered
45  * Code or modification with rights to further distribute source must include
46  * the above Copyright Notice, the above License, this list of Conditions,
47  * and the following Disclaimer and Export Compliance provision.  In addition,
48  * Licensee must cause all Covered Code to which Licensee contributes to
49  * contain a file documenting the changes Licensee made to create that Covered
50  * Code and the date of any change.  Licensee must include in that file the
51  * documentation of any changes made by any predecessor Licensee.  Licensee
52  * must include a prominent statement that the modification is derived,
53  * directly or indirectly, from Original Intel Code.
54  *
55  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
56  * Redistribution of source code of any substantial portion of the Covered
57  * Code or modification without rights to further distribute source must
58  * include the following Disclaimer and Export Compliance provision in the
59  * documentation and/or other materials provided with distribution.  In
60  * addition, Licensee may not authorize further sublicense of source of any
61  * portion of the Covered Code, and must include terms to the effect that the
62  * license from Licensee to its licensee is limited to the intellectual
63  * property embodied in the software Licensee provides to its licensee, and
64  * not to intellectual property embodied in modifications its licensee may
65  * make.
66  *
67  * 3.3. Redistribution of Executable. Redistribution in executable form of any
68  * substantial portion of the Covered Code or modification must reproduce the
69  * above Copyright Notice, and the following Disclaimer and Export Compliance
70  * provision in the documentation and/or other materials provided with the
71  * distribution.
72  *
73  * 3.4. Intel retains all right, title, and interest in and to the Original
74  * Intel Code.
75  *
76  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
77  * Intel shall be used in advertising or otherwise to promote the sale, use or
78  * other dealings in products derived from or relating to the Covered Code
79  * without prior written authorization from Intel.
80  *
81  * 4. Disclaimer and Export Compliance
82  *
83  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
84  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
85  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
86  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
87 
88  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
89  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
90  * PARTICULAR PURPOSE.
91  *
92  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
93  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
94  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
95  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
96  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
97  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
98  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
99  * LIMITED REMEDY.
100  *
101  * 4.3. Licensee shall not export, either directly or indirectly, any of this
102  * software or system incorporating such software without first obtaining any
103  * required license or other approval from the U. S. Department of Commerce or
104  * any other agency or department of the United States Government.  In the
105  * event Licensee exports any such software from the United States or
106  * re-exports any such software from a foreign destination, Licensee shall
107  * ensure that the distribution and export/re-export of the software is in
108  * compliance with all laws, regulations, orders, or other restrictions of the
109  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
110  * any of its subsidiaries will export/re-export any technical data, process,
111  * software, or service, directly or indirectly, to any country for which the
112  * United States government or any agency thereof requires an export license,
113  * other governmental approval, or letter of assurance, without first obtaining
114  * such license, approval or letter.
115  *
116  *****************************************************************************/
117 
118 #define __EXCONFIG_C__
119 
120 #include "acpi.h"
121 #include "acinterp.h"
122 #include "acnamesp.h"
123 #include "actables.h"
124 #include "acdispat.h"
125 
126 
127 #define _COMPONENT          ACPI_EXECUTER
128         ACPI_MODULE_NAME    ("exconfig")
129 
130 /* Local prototypes */
131 
132 static ACPI_STATUS
133 AcpiExAddTable (
134     UINT32                  TableIndex,
135     ACPI_NAMESPACE_NODE     *ParentNode,
136     ACPI_OPERAND_OBJECT     **DdbHandle);
137 
138 
139 /*******************************************************************************
140  *
141  * FUNCTION:    AcpiExAddTable
142  *
143  * PARAMETERS:  Table               - Pointer to raw table
144  *              ParentNode          - Where to load the table (scope)
145  *              DdbHandle           - Where to return the table handle.
146  *
147  * RETURN:      Status
148  *
149  * DESCRIPTION: Common function to Install and Load an ACPI table with a
150  *              returned table handle.
151  *
152  ******************************************************************************/
153 
154 static ACPI_STATUS
155 AcpiExAddTable (
156     UINT32                  TableIndex,
157     ACPI_NAMESPACE_NODE     *ParentNode,
158     ACPI_OPERAND_OBJECT     **DdbHandle)
159 {
160     ACPI_STATUS             Status;
161     ACPI_OPERAND_OBJECT     *ObjDesc;
162 
163 
164     ACPI_FUNCTION_TRACE (ExAddTable);
165 
166 
167     /* Create an object to be the table handle */
168 
169     ObjDesc = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_REFERENCE);
170     if (!ObjDesc)
171     {
172         return_ACPI_STATUS (AE_NO_MEMORY);
173     }
174 
175     /* Init the table handle */
176 
177     ObjDesc->Reference.Class = ACPI_REFCLASS_TABLE;
178     *DdbHandle = ObjDesc;
179 
180     /* Install the new table into the local data structures */
181 
182     ObjDesc->Reference.Value = TableIndex;
183 
184     /* Add the table to the namespace */
185 
186     Status = AcpiNsLoadTable (TableIndex, ParentNode);
187     if (ACPI_FAILURE (Status))
188     {
189         AcpiUtRemoveReference (ObjDesc);
190         *DdbHandle = NULL;
191     }
192 
193     return_ACPI_STATUS (Status);
194 }
195 
196 
197 /*******************************************************************************
198  *
199  * FUNCTION:    AcpiExLoadTableOp
200  *
201  * PARAMETERS:  WalkState           - Current state with operands
202  *              ReturnDesc          - Where to store the return object
203  *
204  * RETURN:      Status
205  *
206  * DESCRIPTION: Load an ACPI table from the RSDT/XSDT
207  *
208  ******************************************************************************/
209 
210 ACPI_STATUS
211 AcpiExLoadTableOp (
212     ACPI_WALK_STATE         *WalkState,
213     ACPI_OPERAND_OBJECT     **ReturnDesc)
214 {
215     ACPI_STATUS             Status;
216     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
217     ACPI_NAMESPACE_NODE     *ParentNode;
218     ACPI_NAMESPACE_NODE     *StartNode;
219     ACPI_NAMESPACE_NODE     *ParameterNode = NULL;
220     ACPI_OPERAND_OBJECT     *DdbHandle;
221     ACPI_TABLE_HEADER       *Table;
222     UINT32                  TableIndex;
223 
224 
225     ACPI_FUNCTION_TRACE (ExLoadTableOp);
226 
227 
228     /* Validate lengths for the SignatureString, OEMIDString, OEMTableID */
229 
230     if ((Operand[0]->String.Length > ACPI_NAME_SIZE) ||
231         (Operand[1]->String.Length > ACPI_OEM_ID_SIZE) ||
232         (Operand[2]->String.Length > ACPI_OEM_TABLE_ID_SIZE))
233     {
234         return_ACPI_STATUS (AE_BAD_PARAMETER);
235     }
236 
237     /* Find the ACPI table in the RSDT/XSDT */
238 
239     Status = AcpiTbFindTable (Operand[0]->String.Pointer,
240                               Operand[1]->String.Pointer,
241                               Operand[2]->String.Pointer, &TableIndex);
242     if (ACPI_FAILURE (Status))
243     {
244         if (Status != AE_NOT_FOUND)
245         {
246             return_ACPI_STATUS (Status);
247         }
248 
249         /* Table not found, return an Integer=0 and AE_OK */
250 
251         DdbHandle = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
252         if (!DdbHandle)
253         {
254             return_ACPI_STATUS (AE_NO_MEMORY);
255         }
256 
257         DdbHandle->Integer.Value = 0;
258         *ReturnDesc = DdbHandle;
259 
260         return_ACPI_STATUS (AE_OK);
261     }
262 
263     /* Default nodes */
264 
265     StartNode = WalkState->ScopeInfo->Scope.Node;
266     ParentNode = AcpiGbl_RootNode;
267 
268     /* RootPath (optional parameter) */
269 
270     if (Operand[3]->String.Length > 0)
271     {
272         /*
273          * Find the node referenced by the RootPathString.  This is the
274          * location within the namespace where the table will be loaded.
275          */
276         Status = AcpiNsGetNode (StartNode, Operand[3]->String.Pointer,
277                     ACPI_NS_SEARCH_PARENT, &ParentNode);
278         if (ACPI_FAILURE (Status))
279         {
280             return_ACPI_STATUS (Status);
281         }
282     }
283 
284     /* ParameterPath (optional parameter) */
285 
286     if (Operand[4]->String.Length > 0)
287     {
288         if ((Operand[4]->String.Pointer[0] != '\\') &&
289             (Operand[4]->String.Pointer[0] != '^'))
290         {
291             /*
292              * Path is not absolute, so it will be relative to the node
293              * referenced by the RootPathString (or the NS root if omitted)
294              */
295             StartNode = ParentNode;
296         }
297 
298         /* Find the node referenced by the ParameterPathString */
299 
300         Status = AcpiNsGetNode (StartNode, Operand[4]->String.Pointer,
301                     ACPI_NS_SEARCH_PARENT, &ParameterNode);
302         if (ACPI_FAILURE (Status))
303         {
304             return_ACPI_STATUS (Status);
305         }
306     }
307 
308     /* Load the table into the namespace */
309 
310     Status = AcpiExAddTable (TableIndex, ParentNode, &DdbHandle);
311     if (ACPI_FAILURE (Status))
312     {
313         return_ACPI_STATUS (Status);
314     }
315 
316     /* Parameter Data (optional) */
317 
318     if (ParameterNode)
319     {
320         /* Store the parameter data into the optional parameter object */
321 
322         Status = AcpiExStore (Operand[5],
323                     ACPI_CAST_PTR (ACPI_OPERAND_OBJECT, ParameterNode),
324                     WalkState);
325         if (ACPI_FAILURE (Status))
326         {
327             (void) AcpiExUnloadTable (DdbHandle);
328             return_ACPI_STATUS (Status);
329         }
330     }
331 
332     Status = AcpiGetTableByIndex (TableIndex, &Table);
333     if (ACPI_SUCCESS (Status))
334     {
335         ACPI_INFO ((AE_INFO,
336             "Dynamic OEM Table Load - [%.4s] OemId [%.6s] OemTableId [%.8s]",
337             Table->Signature, Table->OemId, Table->OemTableId));
338     }
339 
340     /* Invoke table handler if present */
341 
342     if (AcpiGbl_TableHandler)
343     {
344         (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_LOAD, Table,
345                     AcpiGbl_TableHandlerContext);
346     }
347 
348     *ReturnDesc = DdbHandle;
349     return_ACPI_STATUS  (Status);
350 }
351 
352 
353 /*******************************************************************************
354  *
355  * FUNCTION:    AcpiExLoadOp
356  *
357  * PARAMETERS:  ObjDesc         - Region or Buffer/Field where the table will be
358  *                                obtained
359  *              Target          - Where a handle to the table will be stored
360  *              WalkState       - Current state
361  *
362  * RETURN:      Status
363  *
364  * DESCRIPTION: Load an ACPI table from a field or operation region
365  *
366  * NOTE: Region Fields (Field, BankField, IndexFields) are resolved to buffer
367  *       objects before this code is reached.
368  *
369  *       If source is an operation region, it must refer to SystemMemory, as
370  *       per the ACPI specification.
371  *
372  ******************************************************************************/
373 
374 ACPI_STATUS
375 AcpiExLoadOp (
376     ACPI_OPERAND_OBJECT     *ObjDesc,
377     ACPI_OPERAND_OBJECT     *Target,
378     ACPI_WALK_STATE         *WalkState)
379 {
380     ACPI_OPERAND_OBJECT     *DdbHandle;
381     ACPI_TABLE_HEADER       *Table;
382     ACPI_TABLE_DESC         TableDesc;
383     UINT32                  TableIndex;
384     ACPI_STATUS             Status;
385     UINT32                  Length;
386 
387 
388     ACPI_FUNCTION_TRACE (ExLoadOp);
389 
390 
391     ACPI_MEMSET (&TableDesc, 0, sizeof (ACPI_TABLE_DESC));
392 
393     /* Source Object can be either an OpRegion or a Buffer/Field */
394 
395     switch (ACPI_GET_OBJECT_TYPE (ObjDesc))
396     {
397     case ACPI_TYPE_REGION:
398 
399         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
400             "Load table from Region %p\n", ObjDesc));
401 
402         /* Region must be SystemMemory (from ACPI spec) */
403 
404         if (ObjDesc->Region.SpaceId != ACPI_ADR_SPACE_SYSTEM_MEMORY)
405         {
406             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
407         }
408 
409         /*
410          * If the Region Address and Length have not been previously evaluated,
411          * evaluate them now and save the results.
412          */
413         if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
414         {
415             Status = AcpiDsGetRegionArguments (ObjDesc);
416             if (ACPI_FAILURE (Status))
417             {
418                 return_ACPI_STATUS (Status);
419             }
420         }
421 
422         /*
423          * Map the table header and get the actual table length. The region
424          * length is not guaranteed to be the same as the table length.
425          */
426         Table = AcpiOsMapMemory (ObjDesc->Region.Address,
427                     sizeof (ACPI_TABLE_HEADER));
428         if (!Table)
429         {
430             return_ACPI_STATUS (AE_NO_MEMORY);
431         }
432 
433         Length = Table->Length;
434         AcpiOsUnmapMemory (Table, sizeof (ACPI_TABLE_HEADER));
435 
436         /* Must have at least an ACPI table header */
437 
438         if (Length < sizeof (ACPI_TABLE_HEADER))
439         {
440             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
441         }
442 
443         /*
444          * The memory region is not guaranteed to remain stable and we must
445          * copy the table to a local buffer. For example, the memory region
446          * is corrupted after suspend on some machines. Dynamically loaded
447          * tables are usually small, so this overhead is minimal.
448          */
449 
450         /* Allocate a buffer for the table */
451 
452         TableDesc.Pointer = ACPI_ALLOCATE (Length);
453         if (!TableDesc.Pointer)
454         {
455             return_ACPI_STATUS (AE_NO_MEMORY);
456         }
457 
458         /* Map the entire table and copy it */
459 
460         Table = AcpiOsMapMemory (ObjDesc->Region.Address, Length);
461         if (!Table)
462         {
463             ACPI_FREE (TableDesc.Pointer);
464             return_ACPI_STATUS (AE_NO_MEMORY);
465         }
466 
467         ACPI_MEMCPY (TableDesc.Pointer, Table, Length);
468         AcpiOsUnmapMemory (Table, Length);
469 
470         TableDesc.Address = ObjDesc->Region.Address;
471         break;
472 
473 
474     case ACPI_TYPE_BUFFER: /* Buffer or resolved RegionField */
475 
476         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
477             "Load table from Buffer or Field %p\n", ObjDesc));
478 
479         /* Must have at least an ACPI table header */
480 
481         if (ObjDesc->Buffer.Length < sizeof (ACPI_TABLE_HEADER))
482         {
483             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
484         }
485 
486         /* Get the actual table length from the table header */
487 
488         Table = ACPI_CAST_PTR (ACPI_TABLE_HEADER, ObjDesc->Buffer.Pointer);
489         Length = Table->Length;
490 
491         /* Table cannot extend beyond the buffer */
492 
493         if (Length > ObjDesc->Buffer.Length)
494         {
495             return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
496         }
497         if (Length < sizeof (ACPI_TABLE_HEADER))
498         {
499             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
500         }
501 
502         /*
503          * Copy the table from the buffer because the buffer could be modified
504          * or even deleted in the future
505          */
506         TableDesc.Pointer = ACPI_ALLOCATE (Length);
507         if (!TableDesc.Pointer)
508         {
509             return_ACPI_STATUS (AE_NO_MEMORY);
510         }
511 
512         ACPI_MEMCPY (TableDesc.Pointer, Table, Length);
513         TableDesc.Address = ACPI_TO_INTEGER (TableDesc.Pointer);
514         break;
515 
516 
517     default:
518         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
519     }
520 
521     /* Validate table checksum (will not get validated in TbAddTable) */
522 
523     Status = AcpiTbVerifyChecksum (TableDesc.Pointer, Length);
524     if (ACPI_FAILURE (Status))
525     {
526         ACPI_FREE (TableDesc.Pointer);
527         return_ACPI_STATUS (Status);
528     }
529 
530     /* Complete the table descriptor */
531 
532     TableDesc.Length = Length;
533     TableDesc.Flags = ACPI_TABLE_ORIGIN_ALLOCATED;
534 
535     /* Install the new table into the local data structures */
536 
537     Status = AcpiTbAddTable (&TableDesc, &TableIndex);
538     if (ACPI_FAILURE (Status))
539     {
540         goto Cleanup;
541     }
542 
543     /*
544      * Add the table to the namespace.
545      *
546      * Note: Load the table objects relative to the root of the namespace.
547      * This appears to go against the ACPI specification, but we do it for
548      * compatibility with other ACPI implementations.
549      */
550     Status = AcpiExAddTable (TableIndex, AcpiGbl_RootNode, &DdbHandle);
551     if (ACPI_FAILURE (Status))
552     {
553         /* On error, TablePtr was deallocated above */
554 
555         return_ACPI_STATUS (Status);
556     }
557 
558     /* Store the DdbHandle into the Target operand */
559 
560     Status = AcpiExStore (DdbHandle, Target, WalkState);
561     if (ACPI_FAILURE (Status))
562     {
563         (void) AcpiExUnloadTable (DdbHandle);
564 
565         /* TablePtr was deallocated above */
566 
567         AcpiUtRemoveReference (DdbHandle);
568         return_ACPI_STATUS (Status);
569     }
570 
571     /* Invoke table handler if present */
572 
573     if (AcpiGbl_TableHandler)
574     {
575         (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_LOAD, TableDesc.Pointer,
576                     AcpiGbl_TableHandlerContext);
577     }
578 
579 Cleanup:
580     if (ACPI_FAILURE (Status))
581     {
582         /* Delete allocated table buffer */
583 
584         AcpiTbDeleteTable (&TableDesc);
585     }
586     return_ACPI_STATUS (Status);
587 }
588 
589 
590 /*******************************************************************************
591  *
592  * FUNCTION:    AcpiExUnloadTable
593  *
594  * PARAMETERS:  DdbHandle           - Handle to a previously loaded table
595  *
596  * RETURN:      Status
597  *
598  * DESCRIPTION: Unload an ACPI table
599  *
600  ******************************************************************************/
601 
602 ACPI_STATUS
603 AcpiExUnloadTable (
604     ACPI_OPERAND_OBJECT     *DdbHandle)
605 {
606     ACPI_STATUS             Status = AE_OK;
607     ACPI_OPERAND_OBJECT     *TableDesc = DdbHandle;
608     UINT32                  TableIndex;
609     ACPI_TABLE_HEADER       *Table;
610 
611 
612     ACPI_FUNCTION_TRACE (ExUnloadTable);
613 
614 
615     /*
616      * Validate the handle
617      * Although the handle is partially validated in AcpiExReconfiguration(),
618      * when it calls AcpiExResolveOperands(), the handle is more completely
619      * validated here.
620      */
621     if ((!DdbHandle) ||
622         (ACPI_GET_DESCRIPTOR_TYPE (DdbHandle) != ACPI_DESC_TYPE_OPERAND) ||
623         (ACPI_GET_OBJECT_TYPE (DdbHandle) != ACPI_TYPE_LOCAL_REFERENCE))
624     {
625         return_ACPI_STATUS (AE_BAD_PARAMETER);
626     }
627 
628     /* Get the table index from the DdbHandle */
629 
630     TableIndex = TableDesc->Reference.Value;
631 
632     /* Invoke table handler if present */
633 
634     if (AcpiGbl_TableHandler)
635     {
636         Status = AcpiGetTableByIndex (TableIndex, &Table);
637         if (ACPI_SUCCESS (Status))
638         {
639             (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_UNLOAD, Table,
640                         AcpiGbl_TableHandlerContext);
641         }
642     }
643 
644     /*
645      * Delete the entire namespace under this table Node
646      * (Offset contains the TableId)
647      */
648     AcpiTbDeleteNamespaceByOwner (TableIndex);
649     (void) AcpiTbReleaseOwnerId (TableIndex);
650 
651     AcpiTbSetTableLoadedFlag (TableIndex, FALSE);
652 
653     /* Table unloaded, remove a reference to the DdbHandle object */
654 
655     AcpiUtRemoveReference (DdbHandle);
656     return_ACPI_STATUS (AE_OK);
657 }
658 
659