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 - 2017, 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  * Alternatively, you may choose to be licensed under the terms of the
118  * following license:
119  *
120  * Redistribution and use in source and binary forms, with or without
121  * modification, are permitted provided that the following conditions
122  * are met:
123  * 1. Redistributions of source code must retain the above copyright
124  *    notice, this list of conditions, and the following disclaimer,
125  *    without modification.
126  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
127  *    substantially similar to the "NO WARRANTY" disclaimer below
128  *    ("Disclaimer") and any redistribution must be conditioned upon
129  *    including a substantially similar Disclaimer requirement for further
130  *    binary redistribution.
131  * 3. Neither the names of the above-listed copyright holders nor the names
132  *    of any contributors may be used to endorse or promote products derived
133  *    from this software without specific prior written permission.
134  *
135  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
136  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
137  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
138  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
139  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
140  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
141  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
142  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
143  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
144  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
145  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
146  *
147  * Alternatively, you may choose to be licensed under the terms of the
148  * GNU General Public License ("GPL") version 2 as published by the Free
149  * Software Foundation.
150  *
151  *****************************************************************************/
152 
153 #include "acpi.h"
154 #include "accommon.h"
155 #include "acinterp.h"
156 #include "acnamesp.h"
157 #include "actables.h"
158 #include "acdispat.h"
159 #include "acevents.h"
160 #include "amlcode.h"
161 
162 
163 #define _COMPONENT          ACPI_EXECUTER
164         ACPI_MODULE_NAME    ("exconfig")
165 
166 /* Local prototypes */
167 
168 static ACPI_STATUS
169 AcpiExAddTable (
170     UINT32                  TableIndex,
171     ACPI_OPERAND_OBJECT     **DdbHandle);
172 
173 static ACPI_STATUS
174 AcpiExRegionRead (
175     ACPI_OPERAND_OBJECT     *ObjDesc,
176     UINT32                  Length,
177     UINT8                   *Buffer);
178 
179 
180 /*******************************************************************************
181  *
182  * FUNCTION:    AcpiExAddTable
183  *
184  * PARAMETERS:  Table               - Pointer to raw table
185  *              ParentNode          - Where to load the table (scope)
186  *              DdbHandle           - Where to return the table handle.
187  *
188  * RETURN:      Status
189  *
190  * DESCRIPTION: Common function to Install and Load an ACPI table with a
191  *              returned table handle.
192  *
193  ******************************************************************************/
194 
195 static ACPI_STATUS
196 AcpiExAddTable (
197     UINT32                  TableIndex,
198     ACPI_OPERAND_OBJECT     **DdbHandle)
199 {
200     ACPI_OPERAND_OBJECT     *ObjDesc;
201 
202 
203     ACPI_FUNCTION_TRACE (ExAddTable);
204 
205 
206     /* Create an object to be the table handle */
207 
208     ObjDesc = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_REFERENCE);
209     if (!ObjDesc)
210     {
211         return_ACPI_STATUS (AE_NO_MEMORY);
212     }
213 
214     /* Init the table handle */
215 
216     ObjDesc->Common.Flags |= AOPOBJ_DATA_VALID;
217     ObjDesc->Reference.Class = ACPI_REFCLASS_TABLE;
218     ObjDesc->Reference.Value = TableIndex;
219     *DdbHandle = ObjDesc;
220     return_ACPI_STATUS (AE_OK);
221 }
222 
223 
224 /*******************************************************************************
225  *
226  * FUNCTION:    AcpiExLoadTableOp
227  *
228  * PARAMETERS:  WalkState           - Current state with operands
229  *              ReturnDesc          - Where to store the return object
230  *
231  * RETURN:      Status
232  *
233  * DESCRIPTION: Load an ACPI table from the RSDT/XSDT
234  *
235  ******************************************************************************/
236 
237 ACPI_STATUS
238 AcpiExLoadTableOp (
239     ACPI_WALK_STATE         *WalkState,
240     ACPI_OPERAND_OBJECT     **ReturnDesc)
241 {
242     ACPI_STATUS             Status;
243     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
244     ACPI_NAMESPACE_NODE     *ParentNode;
245     ACPI_NAMESPACE_NODE     *StartNode;
246     ACPI_NAMESPACE_NODE     *ParameterNode = NULL;
247     ACPI_OPERAND_OBJECT     *DdbHandle;
248     UINT32                  TableIndex;
249 
250 
251     ACPI_FUNCTION_TRACE (ExLoadTableOp);
252 
253 
254     /* Find the ACPI table in the RSDT/XSDT */
255 
256     AcpiExExitInterpreter ();
257     Status = AcpiTbFindTable (
258         Operand[0]->String.Pointer,
259         Operand[1]->String.Pointer,
260         Operand[2]->String.Pointer, &TableIndex);
261     AcpiExEnterInterpreter ();
262     if (ACPI_FAILURE (Status))
263     {
264         if (Status != AE_NOT_FOUND)
265         {
266             return_ACPI_STATUS (Status);
267         }
268 
269         /* Table not found, return an Integer=0 and AE_OK */
270 
271         DdbHandle = AcpiUtCreateIntegerObject ((UINT64) 0);
272         if (!DdbHandle)
273         {
274             return_ACPI_STATUS (AE_NO_MEMORY);
275         }
276 
277         *ReturnDesc = DdbHandle;
278         return_ACPI_STATUS (AE_OK);
279     }
280 
281     /* Default nodes */
282 
283     StartNode = WalkState->ScopeInfo->Scope.Node;
284     ParentNode = AcpiGbl_RootNode;
285 
286     /* RootPath (optional parameter) */
287 
288     if (Operand[3]->String.Length > 0)
289     {
290         /*
291          * Find the node referenced by the RootPathString. This is the
292          * location within the namespace where the table will be loaded.
293          */
294         Status = AcpiNsGetNodeUnlocked (StartNode,
295             Operand[3]->String.Pointer, ACPI_NS_SEARCH_PARENT,
296             &ParentNode);
297         if (ACPI_FAILURE (Status))
298         {
299             return_ACPI_STATUS (Status);
300         }
301     }
302 
303     /* ParameterPath (optional parameter) */
304 
305     if (Operand[4]->String.Length > 0)
306     {
307         if ((Operand[4]->String.Pointer[0] != AML_ROOT_PREFIX) &&
308             (Operand[4]->String.Pointer[0] != AML_PARENT_PREFIX))
309         {
310             /*
311              * Path is not absolute, so it will be relative to the node
312              * referenced by the RootPathString (or the NS root if omitted)
313              */
314             StartNode = ParentNode;
315         }
316 
317         /* Find the node referenced by the ParameterPathString */
318 
319         Status = AcpiNsGetNodeUnlocked (StartNode,
320             Operand[4]->String.Pointer, ACPI_NS_SEARCH_PARENT,
321             &ParameterNode);
322         if (ACPI_FAILURE (Status))
323         {
324             return_ACPI_STATUS (Status);
325         }
326     }
327 
328     /* Load the table into the namespace */
329 
330     ACPI_INFO (("Dynamic OEM Table Load:"));
331     AcpiExExitInterpreter ();
332     Status = AcpiTbLoadTable (TableIndex, ParentNode);
333     AcpiExEnterInterpreter ();
334     if (ACPI_FAILURE (Status))
335     {
336         return_ACPI_STATUS (Status);
337     }
338 
339     Status = AcpiExAddTable (TableIndex, &DdbHandle);
340     if (ACPI_FAILURE (Status))
341     {
342         return_ACPI_STATUS (Status);
343     }
344 
345     /* Parameter Data (optional) */
346 
347     if (ParameterNode)
348     {
349         /* Store the parameter data into the optional parameter object */
350 
351         Status = AcpiExStore (Operand[5],
352             ACPI_CAST_PTR (ACPI_OPERAND_OBJECT, ParameterNode), WalkState);
353         if (ACPI_FAILURE (Status))
354         {
355             (void) AcpiExUnloadTable (DdbHandle);
356 
357             AcpiUtRemoveReference (DdbHandle);
358             return_ACPI_STATUS (Status);
359         }
360     }
361 
362     *ReturnDesc = DdbHandle;
363     return_ACPI_STATUS (Status);
364 }
365 
366 
367 /*******************************************************************************
368  *
369  * FUNCTION:    AcpiExRegionRead
370  *
371  * PARAMETERS:  ObjDesc         - Region descriptor
372  *              Length          - Number of bytes to read
373  *              Buffer          - Pointer to where to put the data
374  *
375  * RETURN:      Status
376  *
377  * DESCRIPTION: Read data from an operation region. The read starts from the
378  *              beginning of the region.
379  *
380  ******************************************************************************/
381 
382 static ACPI_STATUS
383 AcpiExRegionRead (
384     ACPI_OPERAND_OBJECT     *ObjDesc,
385     UINT32                  Length,
386     UINT8                   *Buffer)
387 {
388     ACPI_STATUS             Status;
389     UINT64                  Value;
390     UINT32                  RegionOffset = 0;
391     UINT32                  i;
392 
393 
394     /* Bytewise reads */
395 
396     for (i = 0; i < Length; i++)
397     {
398         Status = AcpiEvAddressSpaceDispatch (ObjDesc, NULL, ACPI_READ,
399             RegionOffset, 8, &Value);
400         if (ACPI_FAILURE (Status))
401         {
402             return (Status);
403         }
404 
405         *Buffer = (UINT8) Value;
406         Buffer++;
407         RegionOffset++;
408     }
409 
410     return (AE_OK);
411 }
412 
413 
414 /*******************************************************************************
415  *
416  * FUNCTION:    AcpiExLoadOp
417  *
418  * PARAMETERS:  ObjDesc         - Region or Buffer/Field where the table will be
419  *                                obtained
420  *              Target          - Where a handle to the table will be stored
421  *              WalkState       - Current state
422  *
423  * RETURN:      Status
424  *
425  * DESCRIPTION: Load an ACPI table from a field or operation region
426  *
427  * NOTE: Region Fields (Field, BankField, IndexFields) are resolved to buffer
428  *       objects before this code is reached.
429  *
430  *       If source is an operation region, it must refer to SystemMemory, as
431  *       per the ACPI specification.
432  *
433  ******************************************************************************/
434 
435 ACPI_STATUS
436 AcpiExLoadOp (
437     ACPI_OPERAND_OBJECT     *ObjDesc,
438     ACPI_OPERAND_OBJECT     *Target,
439     ACPI_WALK_STATE         *WalkState)
440 {
441     ACPI_OPERAND_OBJECT     *DdbHandle;
442     ACPI_TABLE_HEADER       *TableHeader;
443     ACPI_TABLE_HEADER       *Table;
444     UINT32                  TableIndex;
445     ACPI_STATUS             Status;
446     UINT32                  Length;
447 
448 
449     ACPI_FUNCTION_TRACE (ExLoadOp);
450 
451 
452     /* Source Object can be either an OpRegion or a Buffer/Field */
453 
454     switch (ObjDesc->Common.Type)
455     {
456     case ACPI_TYPE_REGION:
457 
458         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
459             "Load table from Region %p\n", ObjDesc));
460 
461         /* Region must be SystemMemory (from ACPI spec) */
462 
463         if (ObjDesc->Region.SpaceId != ACPI_ADR_SPACE_SYSTEM_MEMORY)
464         {
465             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
466         }
467 
468         /*
469          * If the Region Address and Length have not been previously
470          * evaluated, evaluate them now and save the results.
471          */
472         if (!(ObjDesc->Common.Flags & AOPOBJ_DATA_VALID))
473         {
474             Status = AcpiDsGetRegionArguments (ObjDesc);
475             if (ACPI_FAILURE (Status))
476             {
477                 return_ACPI_STATUS (Status);
478             }
479         }
480 
481         /* Get the table header first so we can get the table length */
482 
483         TableHeader = ACPI_ALLOCATE (sizeof (ACPI_TABLE_HEADER));
484         if (!TableHeader)
485         {
486             return_ACPI_STATUS (AE_NO_MEMORY);
487         }
488 
489         Status = AcpiExRegionRead (ObjDesc, sizeof (ACPI_TABLE_HEADER),
490             ACPI_CAST_PTR (UINT8, TableHeader));
491         Length = TableHeader->Length;
492         ACPI_FREE (TableHeader);
493 
494         if (ACPI_FAILURE (Status))
495         {
496             return_ACPI_STATUS (Status);
497         }
498 
499         /* Must have at least an ACPI table header */
500 
501         if (Length < sizeof (ACPI_TABLE_HEADER))
502         {
503             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
504         }
505 
506         /*
507          * The original implementation simply mapped the table, with no copy.
508          * However, the memory region is not guaranteed to remain stable and
509          * we must copy the table to a local buffer. For example, the memory
510          * region is corrupted after suspend on some machines. Dynamically
511          * loaded tables are usually small, so this overhead is minimal.
512          *
513          * The latest implementation (5/2009) does not use a mapping at all.
514          * We use the low-level operation region interface to read the table
515          * instead of the obvious optimization of using a direct mapping.
516          * This maintains a consistent use of operation regions across the
517          * entire subsystem. This is important if additional processing must
518          * be performed in the (possibly user-installed) operation region
519          * handler. For example, AcpiExec and ASLTS depend on this.
520          */
521 
522         /* Allocate a buffer for the table */
523 
524         Table = ACPI_ALLOCATE (Length);
525         if (!Table)
526         {
527             return_ACPI_STATUS (AE_NO_MEMORY);
528         }
529 
530         /* Read the entire table */
531 
532         Status = AcpiExRegionRead (ObjDesc, Length,
533             ACPI_CAST_PTR (UINT8, Table));
534         if (ACPI_FAILURE (Status))
535         {
536             ACPI_FREE (Table);
537             return_ACPI_STATUS (Status);
538         }
539         break;
540 
541     case ACPI_TYPE_BUFFER: /* Buffer or resolved RegionField */
542 
543         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
544             "Load table from Buffer or Field %p\n", ObjDesc));
545 
546         /* Must have at least an ACPI table header */
547 
548         if (ObjDesc->Buffer.Length < sizeof (ACPI_TABLE_HEADER))
549         {
550             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
551         }
552 
553         /* Get the actual table length from the table header */
554 
555         TableHeader = ACPI_CAST_PTR (
556             ACPI_TABLE_HEADER, ObjDesc->Buffer.Pointer);
557         Length = TableHeader->Length;
558 
559         /* Table cannot extend beyond the buffer */
560 
561         if (Length > ObjDesc->Buffer.Length)
562         {
563             return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
564         }
565         if (Length < sizeof (ACPI_TABLE_HEADER))
566         {
567             return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
568         }
569 
570         /*
571          * Copy the table from the buffer because the buffer could be
572          * modified or even deleted in the future
573          */
574         Table = ACPI_ALLOCATE (Length);
575         if (!Table)
576         {
577             return_ACPI_STATUS (AE_NO_MEMORY);
578         }
579 
580         memcpy (Table, TableHeader, Length);
581         break;
582 
583     default:
584 
585         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
586     }
587 
588     /* Install the new table into the local data structures */
589 
590     ACPI_INFO (("Dynamic OEM Table Load:"));
591     AcpiExExitInterpreter ();
592     Status = AcpiTbInstallAndLoadTable (ACPI_PTR_TO_PHYSADDR (Table),
593         ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL, TRUE, &TableIndex);
594     AcpiExEnterInterpreter ();
595     if (ACPI_FAILURE (Status))
596     {
597         /* Delete allocated table buffer */
598 
599         ACPI_FREE (Table);
600         return_ACPI_STATUS (Status);
601     }
602 
603     /*
604      * Add the table to the namespace.
605      *
606      * Note: Load the table objects relative to the root of the namespace.
607      * This appears to go against the ACPI specification, but we do it for
608      * compatibility with other ACPI implementations.
609      */
610     Status = AcpiExAddTable (TableIndex, &DdbHandle);
611     if (ACPI_FAILURE (Status))
612     {
613         /* On error, TablePtr was deallocated above */
614 
615         return_ACPI_STATUS (Status);
616     }
617 
618     /* Store the DdbHandle into the Target operand */
619 
620     Status = AcpiExStore (DdbHandle, Target, WalkState);
621     if (ACPI_FAILURE (Status))
622     {
623         (void) AcpiExUnloadTable (DdbHandle);
624 
625         /* TablePtr was deallocated above */
626 
627         AcpiUtRemoveReference (DdbHandle);
628         return_ACPI_STATUS (Status);
629     }
630 
631     /* Remove the reference by added by AcpiExStore above */
632 
633     AcpiUtRemoveReference (DdbHandle);
634     return_ACPI_STATUS (Status);
635 }
636 
637 
638 /*******************************************************************************
639  *
640  * FUNCTION:    AcpiExUnloadTable
641  *
642  * PARAMETERS:  DdbHandle           - Handle to a previously loaded table
643  *
644  * RETURN:      Status
645  *
646  * DESCRIPTION: Unload an ACPI table
647  *
648  ******************************************************************************/
649 
650 ACPI_STATUS
651 AcpiExUnloadTable (
652     ACPI_OPERAND_OBJECT     *DdbHandle)
653 {
654     ACPI_STATUS             Status = AE_OK;
655     ACPI_OPERAND_OBJECT     *TableDesc = DdbHandle;
656     UINT32                  TableIndex;
657 
658 
659     ACPI_FUNCTION_TRACE (ExUnloadTable);
660 
661 
662     /*
663      * Temporarily emit a warning so that the ASL for the machine can be
664      * hopefully obtained. This is to say that the Unload() operator is
665      * extremely rare if not completely unused.
666      */
667     ACPI_WARNING ((AE_INFO,
668         "Received request to unload an ACPI table"));
669 
670     /*
671      * Validate the handle
672      * Although the handle is partially validated in AcpiExReconfiguration()
673      * when it calls AcpiExResolveOperands(), the handle is more completely
674      * validated here.
675      *
676      * Handle must be a valid operand object of type reference. Also, the
677      * DdbHandle must still be marked valid (table has not been previously
678      * unloaded)
679      */
680     if ((!DdbHandle) ||
681         (ACPI_GET_DESCRIPTOR_TYPE (DdbHandle) != ACPI_DESC_TYPE_OPERAND) ||
682         (DdbHandle->Common.Type != ACPI_TYPE_LOCAL_REFERENCE) ||
683         (!(DdbHandle->Common.Flags & AOPOBJ_DATA_VALID)))
684     {
685         return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
686     }
687 
688     /* Get the table index from the DdbHandle */
689 
690     TableIndex = TableDesc->Reference.Value;
691 
692     /*
693      * Release the interpreter lock so that the table lock won't have
694      * strict order requirement against it.
695      */
696     AcpiExExitInterpreter ();
697     Status = AcpiTbUnloadTable (TableIndex);
698     AcpiExEnterInterpreter ();
699 
700     /*
701      * Invalidate the handle. We do this because the handle may be stored
702      * in a named object and may not be actually deleted until much later.
703      */
704     if (ACPI_SUCCESS (Status))
705     {
706         DdbHandle->Common.Flags &= ~AOPOBJ_DATA_VALID;
707     }
708     return_ACPI_STATUS (Status);
709 }
710