xref: /titanic_41/usr/src/uts/intel/io/acpica/executer/exconfig.c (revision 500b1e787b108592a37e3d54dc9b5e676de5386d)
1 /******************************************************************************
2  *
3  * Module Name: exconfig - Namespace reconfiguration (Load/Unload opcodes)
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2009, Intel Corp.
12  * All rights reserved.
13  *
14  * 2. License
15  *
16  * 2.1. This is your license from Intel Corp. under its intellectual property
17  * rights.  You may have additional license terms from the party that provided
18  * you this software, covering your right to use that party's intellectual
19  * property rights.
20  *
21  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
22  * copy of the source code appearing in this file ("Covered Code") an
23  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
24  * base code distributed originally by Intel ("Original Intel Code") to copy,
25  * make derivatives, distribute, use and display any portion of the Covered
26  * Code in any form, with the right to sublicense such rights; and
27  *
28  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
29  * license (with the right to sublicense), under only those claims of Intel
30  * patents that are infringed by the Original Intel Code, to make, use, sell,
31  * offer to sell, and import the Covered Code and derivative works thereof
32  * solely to the minimum extent necessary to exercise the above copyright
33  * license, and in no event shall the patent license extend to any additions
34  * to or modifications of the Original Intel Code.  No other license or right
35  * is granted directly or by implication, estoppel or otherwise;
36  *
37  * The above copyright and patent license is granted only if the following
38  * conditions are met:
39  *
40  * 3. Conditions
41  *
42  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
43  * Redistribution of source code of any substantial portion of the Covered
44  * Code or modification with rights to further distribute source must include
45  * the above Copyright Notice, the above License, this list of Conditions,
46  * and the following Disclaimer and Export Compliance provision.  In addition,
47  * Licensee must cause all Covered Code to which Licensee contributes to
48  * contain a file documenting the changes Licensee made to create that Covered
49  * Code and the date of any change.  Licensee must include in that file the
50  * documentation of any changes made by any predecessor Licensee.  Licensee
51  * must include a prominent statement that the modification is derived,
52  * directly or indirectly, from Original Intel Code.
53  *
54  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
55  * Redistribution of source code of any substantial portion of the Covered
56  * Code or modification without rights to further distribute source must
57  * include the following Disclaimer and Export Compliance provision in the
58  * documentation and/or other materials provided with distribution.  In
59  * addition, Licensee may not authorize further sublicense of source of any
60  * portion of the Covered Code, and must include terms to the effect that the
61  * license from Licensee to its licensee is limited to the intellectual
62  * property embodied in the software Licensee provides to its licensee, and
63  * not to intellectual property embodied in modifications its licensee may
64  * make.
65  *
66  * 3.3. Redistribution of Executable. Redistribution in executable form of any
67  * substantial portion of the Covered Code or modification must reproduce the
68  * above Copyright Notice, and the following Disclaimer and Export Compliance
69  * provision in the documentation and/or other materials provided with the
70  * distribution.
71  *
72  * 3.4. Intel retains all right, title, and interest in and to the Original
73  * Intel Code.
74  *
75  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
76  * Intel shall be used in advertising or otherwise to promote the sale, use or
77  * other dealings in products derived from or relating to the Covered Code
78  * without prior written authorization from Intel.
79  *
80  * 4. Disclaimer and Export Compliance
81  *
82  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
83  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
84  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
85  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
86 
87  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
88  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
89  * PARTICULAR PURPOSE.
90  *
91  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
92  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
93  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
94  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
95  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
96  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
97  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
98  * LIMITED REMEDY.
99  *
100  * 4.3. Licensee shall not export, either directly or indirectly, any of this
101  * software or system incorporating such software without first obtaining any
102  * required license or other approval from the U. S. Department of Commerce or
103  * any other agency or department of the United States Government.  In the
104  * event Licensee exports any such software from the United States or
105  * re-exports any such software from a foreign destination, Licensee shall
106  * ensure that the distribution and export/re-export of the software is in
107  * compliance with all laws, regulations, orders, or other restrictions of the
108  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
109  * any of its subsidiaries will export/re-export any technical data, process,
110  * software, or service, directly or indirectly, to any country for which the
111  * United States government or any agency thereof requires an export license,
112  * other governmental approval, or letter of assurance, without first obtaining
113  * such license, approval or letter.
114  *
115  *****************************************************************************/
116 
117 #define __EXCONFIG_C__
118 
119 #include "acpi.h"
120 #include "accommon.h"
121 #include "acinterp.h"
122 #include "acnamesp.h"
123 #include "actables.h"
124 #include "acdispat.h"
125 #include "acevents.h"
126 
127 
128 #define _COMPONENT          ACPI_EXECUTER
129         ACPI_MODULE_NAME    ("exconfig")
130 
131 /* Local prototypes */
132 
133 static ACPI_STATUS
134 AcpiExAddTable (
135     UINT32                  TableIndex,
136     ACPI_NAMESPACE_NODE     *ParentNode,
137     ACPI_OPERAND_OBJECT     **DdbHandle);
138 
139 static ACPI_STATUS
140 AcpiExRegionRead (
141     ACPI_OPERAND_OBJECT     *ObjDesc,
142     UINT32                  Length,
143     UINT8                   *Buffer);
144 
145 
146 /*******************************************************************************
147  *
148  * FUNCTION:    AcpiExAddTable
149  *
150  * PARAMETERS:  Table               - Pointer to raw table
151  *              ParentNode          - Where to load the table (scope)
152  *              DdbHandle           - Where to return the table handle.
153  *
154  * RETURN:      Status
155  *
156  * DESCRIPTION: Common function to Install and Load an ACPI table with a
157  *              returned table handle.
158  *
159  ******************************************************************************/
160 
161 static ACPI_STATUS
162 AcpiExAddTable (
163     UINT32                  TableIndex,
164     ACPI_NAMESPACE_NODE     *ParentNode,
165     ACPI_OPERAND_OBJECT     **DdbHandle)
166 {
167     ACPI_STATUS             Status;
168     ACPI_OPERAND_OBJECT     *ObjDesc;
169 
170 
171     ACPI_FUNCTION_TRACE (ExAddTable);
172 
173 
174     /* Create an object to be the table handle */
175 
176     ObjDesc = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_REFERENCE);
177     if (!ObjDesc)
178     {
179         return_ACPI_STATUS (AE_NO_MEMORY);
180     }
181 
182     /* Init the table handle */
183 
184     ObjDesc->Common.Flags |= AOPOBJ_DATA_VALID;
185     ObjDesc->Reference.Class = ACPI_REFCLASS_TABLE;
186     *DdbHandle = ObjDesc;
187 
188     /* Install the new table into the local data structures */
189 
190     ObjDesc->Reference.Value = TableIndex;
191 
192     /* Add the table to the namespace */
193 
194     Status = AcpiNsLoadTable (TableIndex, ParentNode);
195     if (ACPI_FAILURE (Status))
196     {
197         AcpiUtRemoveReference (ObjDesc);
198         *DdbHandle = NULL;
199         return_ACPI_STATUS (Status);
200     }
201 
202     /* Execute any module-level code that was found in the table */
203 
204     AcpiExExitInterpreter ();
205     AcpiNsExecModuleCodeList ();
206     AcpiExEnterInterpreter ();
207 
208     return_ACPI_STATUS (Status);
209 }
210 
211 
212 /*******************************************************************************
213  *
214  * FUNCTION:    AcpiExLoadTableOp
215  *
216  * PARAMETERS:  WalkState           - Current state with operands
217  *              ReturnDesc          - Where to store the return object
218  *
219  * RETURN:      Status
220  *
221  * DESCRIPTION: Load an ACPI table from the RSDT/XSDT
222  *
223  ******************************************************************************/
224 
225 ACPI_STATUS
226 AcpiExLoadTableOp (
227     ACPI_WALK_STATE         *WalkState,
228     ACPI_OPERAND_OBJECT     **ReturnDesc)
229 {
230     ACPI_STATUS             Status;
231     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
232     ACPI_NAMESPACE_NODE     *ParentNode;
233     ACPI_NAMESPACE_NODE     *StartNode;
234     ACPI_NAMESPACE_NODE     *ParameterNode = NULL;
235     ACPI_OPERAND_OBJECT     *DdbHandle;
236     ACPI_TABLE_HEADER       *Table;
237     UINT32                  TableIndex;
238 
239 
240     ACPI_FUNCTION_TRACE (ExLoadTableOp);
241 
242 
243     /* Validate lengths for the SignatureString, OEMIDString, OEMTableID */
244 
245     if ((Operand[0]->String.Length > ACPI_NAME_SIZE) ||
246         (Operand[1]->String.Length > ACPI_OEM_ID_SIZE) ||
247         (Operand[2]->String.Length > ACPI_OEM_TABLE_ID_SIZE))
248     {
249         return_ACPI_STATUS (AE_BAD_PARAMETER);
250     }
251 
252     /* Find the ACPI table in the RSDT/XSDT */
253 
254     Status = AcpiTbFindTable (Operand[0]->String.Pointer,
255                               Operand[1]->String.Pointer,
256                               Operand[2]->String.Pointer, &TableIndex);
257     if (ACPI_FAILURE (Status))
258     {
259         if (Status != AE_NOT_FOUND)
260         {
261             return_ACPI_STATUS (Status);
262         }
263 
264         /* Table not found, return an Integer=0 and AE_OK */
265 
266         DdbHandle = AcpiUtCreateIntegerObject ((UINT64) 0);
267         if (!DdbHandle)
268         {
269             return_ACPI_STATUS (AE_NO_MEMORY);
270         }
271 
272         *ReturnDesc = DdbHandle;
273         return_ACPI_STATUS (AE_OK);
274     }
275 
276     /* Default nodes */
277 
278     StartNode = WalkState->ScopeInfo->Scope.Node;
279     ParentNode = AcpiGbl_RootNode;
280 
281     /* RootPath (optional parameter) */
282 
283     if (Operand[3]->String.Length > 0)
284     {
285         /*
286          * Find the node referenced by the RootPathString.  This is the
287          * location within the namespace where the table will be loaded.
288          */
289         Status = AcpiNsGetNode (StartNode, Operand[3]->String.Pointer,
290                     ACPI_NS_SEARCH_PARENT, &ParentNode);
291         if (ACPI_FAILURE (Status))
292         {
293             return_ACPI_STATUS (Status);
294         }
295     }
296 
297     /* ParameterPath (optional parameter) */
298 
299     if (Operand[4]->String.Length > 0)
300     {
301         if ((Operand[4]->String.Pointer[0] != '\\') &&
302             (Operand[4]->String.Pointer[0] != '^'))
303         {
304             /*
305              * Path is not absolute, so it will be relative to the node
306              * referenced by the RootPathString (or the NS root if omitted)
307              */
308             StartNode = ParentNode;
309         }
310 
311         /* Find the node referenced by the ParameterPathString */
312 
313         Status = AcpiNsGetNode (StartNode, Operand[4]->String.Pointer,
314                     ACPI_NS_SEARCH_PARENT, &ParameterNode);
315         if (ACPI_FAILURE (Status))
316         {
317             return_ACPI_STATUS (Status);
318         }
319     }
320 
321     /* Load the table into the namespace */
322 
323     Status = AcpiExAddTable (TableIndex, ParentNode, &DdbHandle);
324     if (ACPI_FAILURE (Status))
325     {
326         return_ACPI_STATUS (Status);
327     }
328 
329     /* Parameter Data (optional) */
330 
331     if (ParameterNode)
332     {
333         /* Store the parameter data into the optional parameter object */
334 
335         Status = AcpiExStore (Operand[5],
336                     ACPI_CAST_PTR (ACPI_OPERAND_OBJECT, ParameterNode),
337                     WalkState);
338         if (ACPI_FAILURE (Status))
339         {
340             (void) AcpiExUnloadTable (DdbHandle);
341 
342             AcpiUtRemoveReference (DdbHandle);
343             return_ACPI_STATUS (Status);
344         }
345     }
346 
347     Status = AcpiGetTableByIndex (TableIndex, &Table);
348     if (ACPI_SUCCESS (Status))
349     {
350         ACPI_INFO ((AE_INFO,
351             "Dynamic OEM Table Load - [%.4s] OemId [%.6s] OemTableId [%.8s]",
352             Table->Signature, Table->OemId, Table->OemTableId));
353     }
354 
355     /* Invoke table handler if present */
356 
357     if (AcpiGbl_TableHandler)
358     {
359         (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_LOAD, Table,
360                     AcpiGbl_TableHandlerContext);
361     }
362 
363     *ReturnDesc = DdbHandle;
364     return_ACPI_STATUS  (Status);
365 }
366 
367 
368 /*******************************************************************************
369  *
370  * FUNCTION:    AcpiExRegionRead
371  *
372  * PARAMETERS:  ObjDesc         - Region descriptor
373  *              Length          - Number of bytes to read
374  *              Buffer          - Pointer to where to put the data
375  *
376  * RETURN:      Status
377  *
378  * DESCRIPTION: Read data from an operation region. The read starts from the
379  *              beginning of the region.
380  *
381  ******************************************************************************/
382 
383 static ACPI_STATUS
384 AcpiExRegionRead (
385     ACPI_OPERAND_OBJECT     *ObjDesc,
386     UINT32                  Length,
387     UINT8                   *Buffer)
388 {
389     ACPI_STATUS             Status;
390     ACPI_INTEGER            Value;
391     UINT32                  RegionOffset = 0;
392     UINT32                  i;
393 
394 
395     /* Bytewise reads */
396 
397     for (i = 0; i < Length; i++)
398     {
399         Status = AcpiEvAddressSpaceDispatch (ObjDesc, ACPI_READ,
400                     RegionOffset, 8, &Value);
401         if (ACPI_FAILURE (Status))
402         {
403             return (Status);
404         }
405 
406         *Buffer = (UINT8) Value;
407         Buffer++;
408         RegionOffset++;
409     }
410 
411     return (AE_OK);
412 }
413 
414 
415 /*******************************************************************************
416  *
417  * FUNCTION:    AcpiExLoadOp
418  *
419  * PARAMETERS:  ObjDesc         - Region or Buffer/Field where the table will be
420  *                                obtained
421  *              Target          - Where a handle to the table will be stored
422  *              WalkState       - Current state
423  *
424  * RETURN:      Status
425  *
426  * DESCRIPTION: Load an ACPI table from a field or operation region
427  *
428  * NOTE: Region Fields (Field, BankField, IndexFields) are resolved to buffer
429  *       objects before this code is reached.
430  *
431  *       If source is an operation region, it must refer to SystemMemory, as
432  *       per the ACPI specification.
433  *
434  ******************************************************************************/
435 
436 ACPI_STATUS
437 AcpiExLoadOp (
438     ACPI_OPERAND_OBJECT     *ObjDesc,
439     ACPI_OPERAND_OBJECT     *Target,
440     ACPI_WALK_STATE         *WalkState)
441 {
442     ACPI_OPERAND_OBJECT     *DdbHandle;
443     ACPI_TABLE_HEADER       *Table;
444     ACPI_TABLE_DESC         TableDesc;
445     UINT32                  TableIndex;
446     ACPI_STATUS             Status;
447     UINT32                  Length;
448 
449 
450     ACPI_FUNCTION_TRACE (ExLoadOp);
451 
452 
453     ACPI_MEMSET (&TableDesc, 0, sizeof (ACPI_TABLE_DESC));
454 
455     /* Source Object can be either an OpRegion or a Buffer/Field */
456 
457     switch (ObjDesc->Common.Type)
458     {
459     case ACPI_TYPE_REGION:
460 
461         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
462             "Load table from Region %p\n", ObjDesc));
463 
464         /* Region must be SystemMemory (from ACPI spec) */
465 
466         if (ObjDesc->Region.SpaceId != ACPI_ADR_SPACE_SYSTEM_MEMORY)
467         {
468             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
469         }
470 
471         /*
472          * If the Region Address and Length have not been previously evaluated,
473          * evaluate them now and save the results.
474          */
475         if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
476         {
477             Status = AcpiDsGetRegionArguments (ObjDesc);
478             if (ACPI_FAILURE (Status))
479             {
480                 return_ACPI_STATUS (Status);
481             }
482         }
483 
484         /* Get the table header first so we can get the table length */
485 
486         Table = ACPI_ALLOCATE (sizeof (ACPI_TABLE_HEADER));
487         if (!Table)
488         {
489             return_ACPI_STATUS (AE_NO_MEMORY);
490         }
491 
492         Status = AcpiExRegionRead (ObjDesc, sizeof (ACPI_TABLE_HEADER),
493                     ACPI_CAST_PTR (UINT8, Table));
494         Length = Table->Length;
495         ACPI_FREE (Table);
496 
497         if (ACPI_FAILURE (Status))
498         {
499             return_ACPI_STATUS (Status);
500         }
501 
502         /* Must have at least an ACPI table header */
503 
504         if (Length < sizeof (ACPI_TABLE_HEADER))
505         {
506             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
507         }
508 
509         /*
510          * The original implementation simply mapped the table, with no copy.
511          * However, the memory region is not guaranteed to remain stable and
512          * we must copy the table to a local buffer. For example, the memory
513          * region is corrupted after suspend on some machines. Dynamically
514          * loaded tables are usually small, so this overhead is minimal.
515          *
516          * The latest implementation (5/2009) does not use a mapping at all.
517          * We use the low-level operation region interface to read the table
518          * instead of the obvious optimization of using a direct mapping.
519          * This maintains a consistent use of operation regions across the
520          * entire subsystem. This is important if additional processing must
521          * be performed in the (possibly user-installed) operation region
522          * handler. For example, AcpiExec and ASLTS depend on this.
523          */
524 
525         /* Allocate a buffer for the table */
526 
527         TableDesc.Pointer = ACPI_ALLOCATE (Length);
528         if (!TableDesc.Pointer)
529         {
530             return_ACPI_STATUS (AE_NO_MEMORY);
531         }
532 
533         /* Read the entire table */
534 
535         Status = AcpiExRegionRead (ObjDesc, Length,
536                     ACPI_CAST_PTR (UINT8, TableDesc.Pointer));
537         if (ACPI_FAILURE (Status))
538         {
539             ACPI_FREE (TableDesc.Pointer);
540             return_ACPI_STATUS (Status);
541         }
542 
543         TableDesc.Address = ObjDesc->Region.Address;
544         break;
545 
546 
547     case ACPI_TYPE_BUFFER: /* Buffer or resolved RegionField */
548 
549         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
550             "Load table from Buffer or Field %p\n", ObjDesc));
551 
552         /* Must have at least an ACPI table header */
553 
554         if (ObjDesc->Buffer.Length < sizeof (ACPI_TABLE_HEADER))
555         {
556             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
557         }
558 
559         /* Get the actual table length from the table header */
560 
561         Table = ACPI_CAST_PTR (ACPI_TABLE_HEADER, ObjDesc->Buffer.Pointer);
562         Length = Table->Length;
563 
564         /* Table cannot extend beyond the buffer */
565 
566         if (Length > ObjDesc->Buffer.Length)
567         {
568             return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
569         }
570         if (Length < sizeof (ACPI_TABLE_HEADER))
571         {
572             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
573         }
574 
575         /*
576          * Copy the table from the buffer because the buffer could be modified
577          * or even deleted in the future
578          */
579         TableDesc.Pointer = ACPI_ALLOCATE (Length);
580         if (!TableDesc.Pointer)
581         {
582             return_ACPI_STATUS (AE_NO_MEMORY);
583         }
584 
585         ACPI_MEMCPY (TableDesc.Pointer, Table, Length);
586         TableDesc.Address = ACPI_TO_INTEGER (TableDesc.Pointer);
587         break;
588 
589 
590     default:
591         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
592     }
593 
594     /* Validate table checksum (will not get validated in TbAddTable) */
595 
596     Status = AcpiTbVerifyChecksum (TableDesc.Pointer, Length);
597     if (ACPI_FAILURE (Status))
598     {
599         ACPI_FREE (TableDesc.Pointer);
600         return_ACPI_STATUS (Status);
601     }
602 
603     /* Complete the table descriptor */
604 
605     TableDesc.Length = Length;
606     TableDesc.Flags = ACPI_TABLE_ORIGIN_ALLOCATED;
607 
608     /* Install the new table into the local data structures */
609 
610     Status = AcpiTbAddTable (&TableDesc, &TableIndex);
611     if (ACPI_FAILURE (Status))
612     {
613         goto Cleanup;
614     }
615 
616     /*
617      * Add the table to the namespace.
618      *
619      * Note: Load the table objects relative to the root of the namespace.
620      * This appears to go against the ACPI specification, but we do it for
621      * compatibility with other ACPI implementations.
622      */
623     Status = AcpiExAddTable (TableIndex, AcpiGbl_RootNode, &DdbHandle);
624     if (ACPI_FAILURE (Status))
625     {
626         /* On error, TablePtr was deallocated above */
627 
628         return_ACPI_STATUS (Status);
629     }
630 
631     /* Store the DdbHandle into the Target operand */
632 
633     Status = AcpiExStore (DdbHandle, Target, WalkState);
634     if (ACPI_FAILURE (Status))
635     {
636         (void) AcpiExUnloadTable (DdbHandle);
637 
638         /* TablePtr was deallocated above */
639 
640         AcpiUtRemoveReference (DdbHandle);
641         return_ACPI_STATUS (Status);
642     }
643 
644     /* Remove the reference by added by AcpiExStore above */
645 
646     AcpiUtRemoveReference (DdbHandle);
647 
648     /* Invoke table handler if present */
649 
650     if (AcpiGbl_TableHandler)
651     {
652         (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_LOAD, TableDesc.Pointer,
653                     AcpiGbl_TableHandlerContext);
654     }
655 
656 Cleanup:
657     if (ACPI_FAILURE (Status))
658     {
659         /* Delete allocated table buffer */
660 
661         AcpiTbDeleteTable (&TableDesc);
662     }
663     return_ACPI_STATUS (Status);
664 }
665 
666 
667 /*******************************************************************************
668  *
669  * FUNCTION:    AcpiExUnloadTable
670  *
671  * PARAMETERS:  DdbHandle           - Handle to a previously loaded table
672  *
673  * RETURN:      Status
674  *
675  * DESCRIPTION: Unload an ACPI table
676  *
677  ******************************************************************************/
678 
679 ACPI_STATUS
680 AcpiExUnloadTable (
681     ACPI_OPERAND_OBJECT     *DdbHandle)
682 {
683     ACPI_STATUS             Status = AE_OK;
684     ACPI_OPERAND_OBJECT     *TableDesc = DdbHandle;
685     UINT32                  TableIndex;
686     ACPI_TABLE_HEADER       *Table;
687 
688 
689     ACPI_FUNCTION_TRACE (ExUnloadTable);
690 
691 
692     /*
693      * Validate the handle
694      * Although the handle is partially validated in AcpiExReconfiguration()
695      * when it calls AcpiExResolveOperands(), the handle is more completely
696      * validated here.
697      *
698      * Handle must be a valid operand object of type reference. Also, the
699      * DdbHandle must still be marked valid (table has not been previously
700      * unloaded)
701      */
702     if ((!DdbHandle) ||
703         (ACPI_GET_DESCRIPTOR_TYPE (DdbHandle) != ACPI_DESC_TYPE_OPERAND) ||
704         (DdbHandle->Common.Type != ACPI_TYPE_LOCAL_REFERENCE) ||
705         (!(DdbHandle->Common.Flags & AOPOBJ_DATA_VALID)))
706     {
707         return_ACPI_STATUS (AE_BAD_PARAMETER);
708     }
709 
710     /* Get the table index from the DdbHandle */
711 
712     TableIndex = TableDesc->Reference.Value;
713 
714     /* Ensure the table is still loaded */
715 
716     if (!AcpiTbIsTableLoaded (TableIndex))
717     {
718         return_ACPI_STATUS (AE_NOT_EXIST);
719     }
720 
721     /* Invoke table handler if present */
722 
723     if (AcpiGbl_TableHandler)
724     {
725         Status = AcpiGetTableByIndex (TableIndex, &Table);
726         if (ACPI_SUCCESS (Status))
727         {
728             (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_UNLOAD, Table,
729                         AcpiGbl_TableHandlerContext);
730         }
731     }
732 
733     /* Delete the portion of the namespace owned by this table */
734 
735     Status = AcpiTbDeleteNamespaceByOwner (TableIndex);
736     if (ACPI_FAILURE (Status))
737     {
738         return_ACPI_STATUS (Status);
739     }
740 
741     (void) AcpiTbReleaseOwnerId (TableIndex);
742     AcpiTbSetTableLoadedFlag (TableIndex, FALSE);
743 
744     /*
745      * Invalidate the handle. We do this because the handle may be stored
746      * in a named object and may not be actually deleted until much later.
747      */
748     DdbHandle->Common.Flags &= ~AOPOBJ_DATA_VALID;
749     return_ACPI_STATUS (AE_OK);
750 }
751 
752