xref: /haiku/src/add-ons/kernel/bus_managers/acpi/acpica/components/executer/exconfig.c (revision 97dfeb96704e5dbc5bec32ad7b21379d0125e031)
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 - 2016, 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 #include "acpi.h"
118 #include "accommon.h"
119 #include "acinterp.h"
120 #include "acnamesp.h"
121 #include "actables.h"
122 #include "acdispat.h"
123 #include "acevents.h"
124 #include "amlcode.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 static ACPI_STATUS
139 AcpiExRegionRead (
140     ACPI_OPERAND_OBJECT     *ObjDesc,
141     UINT32                  Length,
142     UINT8                   *Buffer);
143 
144 
145 /*******************************************************************************
146  *
147  * FUNCTION:    AcpiExAddTable
148  *
149  * PARAMETERS:  Table               - Pointer to raw table
150  *              ParentNode          - Where to load the table (scope)
151  *              DdbHandle           - Where to return the table handle.
152  *
153  * RETURN:      Status
154  *
155  * DESCRIPTION: Common function to Install and Load an ACPI table with a
156  *              returned table handle.
157  *
158  ******************************************************************************/
159 
160 static ACPI_STATUS
161 AcpiExAddTable (
162     UINT32                  TableIndex,
163     ACPI_NAMESPACE_NODE     *ParentNode,
164     ACPI_OPERAND_OBJECT     **DdbHandle)
165 {
166     ACPI_OPERAND_OBJECT     *ObjDesc;
167     ACPI_STATUS             Status;
168     ACPI_OWNER_ID           OwnerId;
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     /*
209      * Update GPEs for any new _Lxx/_Exx methods. Ignore errors. The host is
210      * responsible for discovering any new wake GPEs by running _PRW methods
211      * that may have been loaded by this table.
212      */
213     Status = AcpiTbGetOwnerId (TableIndex, &OwnerId);
214     if (ACPI_SUCCESS (Status))
215     {
216         AcpiEvUpdateGpes (OwnerId);
217     }
218 
219     return_ACPI_STATUS (AE_OK);
220 }
221 
222 
223 /*******************************************************************************
224  *
225  * FUNCTION:    AcpiExLoadTableOp
226  *
227  * PARAMETERS:  WalkState           - Current state with operands
228  *              ReturnDesc          - Where to store the return object
229  *
230  * RETURN:      Status
231  *
232  * DESCRIPTION: Load an ACPI table from the RSDT/XSDT
233  *
234  ******************************************************************************/
235 
236 ACPI_STATUS
237 AcpiExLoadTableOp (
238     ACPI_WALK_STATE         *WalkState,
239     ACPI_OPERAND_OBJECT     **ReturnDesc)
240 {
241     ACPI_STATUS             Status;
242     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
243     ACPI_NAMESPACE_NODE     *ParentNode;
244     ACPI_NAMESPACE_NODE     *StartNode;
245     ACPI_NAMESPACE_NODE     *ParameterNode = NULL;
246     ACPI_OPERAND_OBJECT     *DdbHandle;
247     ACPI_TABLE_HEADER       *Table;
248     UINT32                  TableIndex;
249 
250 
251     ACPI_FUNCTION_TRACE (ExLoadTableOp);
252 
253 
254     /* Find the ACPI table in the RSDT/XSDT */
255 
256     Status = AcpiTbFindTable (
257         Operand[0]->String.Pointer,
258         Operand[1]->String.Pointer,
259         Operand[2]->String.Pointer, &TableIndex);
260     if (ACPI_FAILURE (Status))
261     {
262         if (Status != AE_NOT_FOUND)
263         {
264             return_ACPI_STATUS (Status);
265         }
266 
267         /* Table not found, return an Integer=0 and AE_OK */
268 
269         DdbHandle = AcpiUtCreateIntegerObject ((UINT64) 0);
270         if (!DdbHandle)
271         {
272             return_ACPI_STATUS (AE_NO_MEMORY);
273         }
274 
275         *ReturnDesc = DdbHandle;
276         return_ACPI_STATUS (AE_OK);
277     }
278 
279     /* Default nodes */
280 
281     StartNode = WalkState->ScopeInfo->Scope.Node;
282     ParentNode = AcpiGbl_RootNode;
283 
284     /* RootPath (optional parameter) */
285 
286     if (Operand[3]->String.Length > 0)
287     {
288         /*
289          * Find the node referenced by the RootPathString. This is the
290          * location within the namespace where the table will be loaded.
291          */
292         Status = AcpiNsGetNode (StartNode, Operand[3]->String.Pointer,
293             ACPI_NS_SEARCH_PARENT, &ParentNode);
294         if (ACPI_FAILURE (Status))
295         {
296             return_ACPI_STATUS (Status);
297         }
298     }
299 
300     /* ParameterPath (optional parameter) */
301 
302     if (Operand[4]->String.Length > 0)
303     {
304         if ((Operand[4]->String.Pointer[0] != AML_ROOT_PREFIX) &&
305             (Operand[4]->String.Pointer[0] != AML_PARENT_PREFIX))
306         {
307             /*
308              * Path is not absolute, so it will be relative to the node
309              * referenced by the RootPathString (or the NS root if omitted)
310              */
311             StartNode = ParentNode;
312         }
313 
314         /* Find the node referenced by the ParameterPathString */
315 
316         Status = AcpiNsGetNode (StartNode, Operand[4]->String.Pointer,
317             ACPI_NS_SEARCH_PARENT, &ParameterNode);
318         if (ACPI_FAILURE (Status))
319         {
320             return_ACPI_STATUS (Status);
321         }
322     }
323 
324     /* Load the table into the namespace */
325 
326     Status = AcpiExAddTable (TableIndex, ParentNode, &DdbHandle);
327     if (ACPI_FAILURE (Status))
328     {
329         return_ACPI_STATUS (Status);
330     }
331 
332     /* Parameter Data (optional) */
333 
334     if (ParameterNode)
335     {
336         /* Store the parameter data into the optional parameter object */
337 
338         Status = AcpiExStore (Operand[5],
339             ACPI_CAST_PTR (ACPI_OPERAND_OBJECT, ParameterNode), WalkState);
340         if (ACPI_FAILURE (Status))
341         {
342             (void) AcpiExUnloadTable (DdbHandle);
343 
344             AcpiUtRemoveReference (DdbHandle);
345             return_ACPI_STATUS (Status);
346         }
347     }
348 
349     Status = AcpiGetTableByIndex (TableIndex, &Table);
350     if (ACPI_SUCCESS (Status))
351     {
352         ACPI_INFO ((AE_INFO, "Dynamic OEM Table Load:"));
353         AcpiTbPrintTableHeader (0, Table);
354     }
355 
356     /* Invoke table handler if present */
357 
358     if (AcpiGbl_TableHandler)
359     {
360         (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_LOAD, Table,
361             AcpiGbl_TableHandlerContext);
362     }
363 
364     *ReturnDesc = DdbHandle;
365     return_ACPI_STATUS (Status);
366 }
367 
368 
369 /*******************************************************************************
370  *
371  * FUNCTION:    AcpiExRegionRead
372  *
373  * PARAMETERS:  ObjDesc         - Region descriptor
374  *              Length          - Number of bytes to read
375  *              Buffer          - Pointer to where to put the data
376  *
377  * RETURN:      Status
378  *
379  * DESCRIPTION: Read data from an operation region. The read starts from the
380  *              beginning of the region.
381  *
382  ******************************************************************************/
383 
384 static ACPI_STATUS
385 AcpiExRegionRead (
386     ACPI_OPERAND_OBJECT     *ObjDesc,
387     UINT32                  Length,
388     UINT8                   *Buffer)
389 {
390     ACPI_STATUS             Status;
391     UINT64                  Value;
392     UINT32                  RegionOffset = 0;
393     UINT32                  i;
394 
395 
396     /* Bytewise reads */
397 
398     for (i = 0; i < Length; i++)
399     {
400         Status = AcpiEvAddressSpaceDispatch (ObjDesc, NULL, ACPI_READ,
401             RegionOffset, 8, &Value);
402         if (ACPI_FAILURE (Status))
403         {
404             return (Status);
405         }
406 
407         *Buffer = (UINT8) Value;
408         Buffer++;
409         RegionOffset++;
410     }
411 
412     return (AE_OK);
413 }
414 
415 
416 /*******************************************************************************
417  *
418  * FUNCTION:    AcpiExLoadOp
419  *
420  * PARAMETERS:  ObjDesc         - Region or Buffer/Field where the table will be
421  *                                obtained
422  *              Target          - Where a handle to the table will be stored
423  *              WalkState       - Current state
424  *
425  * RETURN:      Status
426  *
427  * DESCRIPTION: Load an ACPI table from a field or operation region
428  *
429  * NOTE: Region Fields (Field, BankField, IndexFields) are resolved to buffer
430  *       objects before this code is reached.
431  *
432  *       If source is an operation region, it must refer to SystemMemory, as
433  *       per the ACPI specification.
434  *
435  ******************************************************************************/
436 
437 ACPI_STATUS
438 AcpiExLoadOp (
439     ACPI_OPERAND_OBJECT     *ObjDesc,
440     ACPI_OPERAND_OBJECT     *Target,
441     ACPI_WALK_STATE         *WalkState)
442 {
443     ACPI_OPERAND_OBJECT     *DdbHandle;
444     ACPI_TABLE_HEADER       *TableHeader;
445     ACPI_TABLE_HEADER       *Table;
446     UINT32                  TableIndex;
447     ACPI_STATUS             Status;
448     UINT32                  Length;
449 
450 
451     ACPI_FUNCTION_TRACE (ExLoadOp);
452 
453 
454     /* Source Object can be either an OpRegion or a Buffer/Field */
455 
456     switch (ObjDesc->Common.Type)
457     {
458     case ACPI_TYPE_REGION:
459 
460         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
461             "Load table from Region %p\n", ObjDesc));
462 
463         /* Region must be SystemMemory (from ACPI spec) */
464 
465         if (ObjDesc->Region.SpaceId != ACPI_ADR_SPACE_SYSTEM_MEMORY)
466         {
467             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
468         }
469 
470         /*
471          * If the Region Address and Length have not been previously
472          * evaluated, evaluate them now and save the results.
473          */
474         if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
475         {
476             Status = AcpiDsGetRegionArguments (ObjDesc);
477             if (ACPI_FAILURE (Status))
478             {
479                 return_ACPI_STATUS (Status);
480             }
481         }
482 
483         /* Get the table header first so we can get the table length */
484 
485         TableHeader = ACPI_ALLOCATE (sizeof (ACPI_TABLE_HEADER));
486         if (!TableHeader)
487         {
488             return_ACPI_STATUS (AE_NO_MEMORY);
489         }
490 
491         Status = AcpiExRegionRead (ObjDesc, sizeof (ACPI_TABLE_HEADER),
492             ACPI_CAST_PTR (UINT8, TableHeader));
493         Length = TableHeader->Length;
494         ACPI_FREE (TableHeader);
495 
496         if (ACPI_FAILURE (Status))
497         {
498             return_ACPI_STATUS (Status);
499         }
500 
501         /* Must have at least an ACPI table header */
502 
503         if (Length < sizeof (ACPI_TABLE_HEADER))
504         {
505             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
506         }
507 
508         /*
509          * The original implementation simply mapped the table, with no copy.
510          * However, the memory region is not guaranteed to remain stable and
511          * we must copy the table to a local buffer. For example, the memory
512          * region is corrupted after suspend on some machines. Dynamically
513          * loaded tables are usually small, so this overhead is minimal.
514          *
515          * The latest implementation (5/2009) does not use a mapping at all.
516          * We use the low-level operation region interface to read the table
517          * instead of the obvious optimization of using a direct mapping.
518          * This maintains a consistent use of operation regions across the
519          * entire subsystem. This is important if additional processing must
520          * be performed in the (possibly user-installed) operation region
521          * handler. For example, AcpiExec and ASLTS depend on this.
522          */
523 
524         /* Allocate a buffer for the table */
525 
526         Table = ACPI_ALLOCATE (Length);
527         if (!Table)
528         {
529             return_ACPI_STATUS (AE_NO_MEMORY);
530         }
531 
532         /* Read the entire table */
533 
534         Status = AcpiExRegionRead (ObjDesc, Length,
535             ACPI_CAST_PTR (UINT8, Table));
536         if (ACPI_FAILURE (Status))
537         {
538             ACPI_FREE (Table);
539             return_ACPI_STATUS (Status);
540         }
541         break;
542 
543     case ACPI_TYPE_BUFFER: /* Buffer or resolved RegionField */
544 
545         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
546             "Load table from Buffer or Field %p\n", ObjDesc));
547 
548         /* Must have at least an ACPI table header */
549 
550         if (ObjDesc->Buffer.Length < sizeof (ACPI_TABLE_HEADER))
551         {
552             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
553         }
554 
555         /* Get the actual table length from the table header */
556 
557         TableHeader = ACPI_CAST_PTR (
558             ACPI_TABLE_HEADER, ObjDesc->Buffer.Pointer);
559         Length = TableHeader->Length;
560 
561         /* Table cannot extend beyond the buffer */
562 
563         if (Length > ObjDesc->Buffer.Length)
564         {
565             return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
566         }
567         if (Length < sizeof (ACPI_TABLE_HEADER))
568         {
569             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
570         }
571 
572         /*
573          * Copy the table from the buffer because the buffer could be
574          * modified or even deleted in the future
575          */
576         Table = ACPI_ALLOCATE (Length);
577         if (!Table)
578         {
579             return_ACPI_STATUS (AE_NO_MEMORY);
580         }
581 
582         memcpy (Table, TableHeader, Length);
583         break;
584 
585     default:
586 
587         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
588     }
589 
590     /* Install the new table into the local data structures */
591 
592     ACPI_INFO ((AE_INFO, "Dynamic OEM Table Load:"));
593     (void) AcpiUtAcquireMutex (ACPI_MTX_TABLES);
594 
595     Status = AcpiTbInstallStandardTable (ACPI_PTR_TO_PHYSADDR (Table),
596         ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL, TRUE, TRUE,
597         &TableIndex);
598 
599     (void) AcpiUtReleaseMutex (ACPI_MTX_TABLES);
600     if (ACPI_FAILURE (Status))
601     {
602         /* Delete allocated table buffer */
603 
604         ACPI_FREE (Table);
605         return_ACPI_STATUS (Status);
606     }
607 
608     /*
609      * Note: Now table is "INSTALLED", it must be validated before
610      * loading.
611      */
612     Status = AcpiTbValidateTable (
613         &AcpiGbl_RootTableList.Tables[TableIndex]);
614     if (ACPI_FAILURE (Status))
615     {
616         return_ACPI_STATUS (Status);
617     }
618 
619     /*
620      * Add the table to the namespace.
621      *
622      * Note: Load the table objects relative to the root of the namespace.
623      * This appears to go against the ACPI specification, but we do it for
624      * compatibility with other ACPI implementations.
625      */
626     Status = AcpiExAddTable (TableIndex, AcpiGbl_RootNode, &DdbHandle);
627     if (ACPI_FAILURE (Status))
628     {
629         /* On error, TablePtr was deallocated above */
630 
631         return_ACPI_STATUS (Status);
632     }
633 
634     /* Store the DdbHandle into the Target operand */
635 
636     Status = AcpiExStore (DdbHandle, Target, WalkState);
637     if (ACPI_FAILURE (Status))
638     {
639         (void) AcpiExUnloadTable (DdbHandle);
640 
641         /* TablePtr was deallocated above */
642 
643         AcpiUtRemoveReference (DdbHandle);
644         return_ACPI_STATUS (Status);
645     }
646 
647     /* Remove the reference by added by AcpiExStore above */
648 
649     AcpiUtRemoveReference (DdbHandle);
650 
651     /* Invoke table handler if present */
652 
653     if (AcpiGbl_TableHandler)
654     {
655         (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_LOAD, Table,
656             AcpiGbl_TableHandlerContext);
657     }
658 
659     return_ACPI_STATUS (Status);
660 }
661 
662 
663 /*******************************************************************************
664  *
665  * FUNCTION:    AcpiExUnloadTable
666  *
667  * PARAMETERS:  DdbHandle           - Handle to a previously loaded table
668  *
669  * RETURN:      Status
670  *
671  * DESCRIPTION: Unload an ACPI table
672  *
673  ******************************************************************************/
674 
675 ACPI_STATUS
676 AcpiExUnloadTable (
677     ACPI_OPERAND_OBJECT     *DdbHandle)
678 {
679     ACPI_STATUS             Status = AE_OK;
680     ACPI_OPERAND_OBJECT     *TableDesc = DdbHandle;
681     UINT32                  TableIndex;
682     ACPI_TABLE_HEADER       *Table;
683 
684 
685     ACPI_FUNCTION_TRACE (ExUnloadTable);
686 
687 
688     /*
689      * Temporarily emit a warning so that the ASL for the machine can be
690      * hopefully obtained. This is to say that the Unload() operator is
691      * extremely rare if not completely unused.
692      */
693     ACPI_WARNING ((AE_INFO,
694         "Received request to unload an ACPI table"));
695 
696     /*
697      * Validate the handle
698      * Although the handle is partially validated in AcpiExReconfiguration()
699      * when it calls AcpiExResolveOperands(), the handle is more completely
700      * validated here.
701      *
702      * Handle must be a valid operand object of type reference. Also, the
703      * DdbHandle must still be marked valid (table has not been previously
704      * unloaded)
705      */
706     if ((!DdbHandle) ||
707         (ACPI_GET_DESCRIPTOR_TYPE (DdbHandle) != ACPI_DESC_TYPE_OPERAND) ||
708         (DdbHandle->Common.Type != ACPI_TYPE_LOCAL_REFERENCE) ||
709         (!(DdbHandle->Common.Flags & AOPOBJ_DATA_VALID)))
710     {
711         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
712     }
713 
714     /* Get the table index from the DdbHandle */
715 
716     TableIndex = TableDesc->Reference.Value;
717 
718     /* Ensure the table is still loaded */
719 
720     if (!AcpiTbIsTableLoaded (TableIndex))
721     {
722         return_ACPI_STATUS (AE_NOT_EXIST);
723     }
724 
725     /* Invoke table handler if present */
726 
727     if (AcpiGbl_TableHandler)
728     {
729         Status = AcpiGetTableByIndex (TableIndex, &Table);
730         if (ACPI_SUCCESS (Status))
731         {
732             (void) AcpiGbl_TableHandler (ACPI_TABLE_EVENT_UNLOAD, Table,
733                 AcpiGbl_TableHandlerContext);
734         }
735     }
736 
737     /* Delete the portion of the namespace owned by this table */
738 
739     Status = AcpiTbDeleteNamespaceByOwner (TableIndex);
740     if (ACPI_FAILURE (Status))
741     {
742         return_ACPI_STATUS (Status);
743     }
744 
745     (void) AcpiTbReleaseOwnerId (TableIndex);
746     AcpiTbSetTableLoadedFlag (TableIndex, FALSE);
747 
748     /*
749      * Invalidate the handle. We do this because the handle may be stored
750      * in a named object and may not be actually deleted until much later.
751      */
752     DdbHandle->Common.Flags &= ~AOPOBJ_DATA_VALID;
753     return_ACPI_STATUS (AE_OK);
754 }
755