xref: /illumos-gate/usr/src/common/acpica/tables/tbutils.c (revision 35786f6866ae52207d0f1a25fe7ca5f652f32ce0)
1 /******************************************************************************
2  *
3  * Module Name: tbutils - ACPI Table utilities
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2018, 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  * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
87  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
88  * PARTICULAR PURPOSE.
89  *
90  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
91  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
92  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
93  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
94  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
95  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
96  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
97  * LIMITED REMEDY.
98  *
99  * 4.3. Licensee shall not export, either directly or indirectly, any of this
100  * software or system incorporating such software without first obtaining any
101  * required license or other approval from the U. S. Department of Commerce or
102  * any other agency or department of the United States Government. In the
103  * event Licensee exports any such software from the United States or
104  * re-exports any such software from a foreign destination, Licensee shall
105  * ensure that the distribution and export/re-export of the software is in
106  * compliance with all laws, regulations, orders, or other restrictions of the
107  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
108  * any of its subsidiaries will export/re-export any technical data, process,
109  * software, or service, directly or indirectly, to any country for which the
110  * United States government or any agency thereof requires an export license,
111  * other governmental approval, or letter of assurance, without first obtaining
112  * such license, approval or letter.
113  *
114  *****************************************************************************
115  *
116  * Alternatively, you may choose to be licensed under the terms of the
117  * following license:
118  *
119  * Redistribution and use in source and binary forms, with or without
120  * modification, are permitted provided that the following conditions
121  * are met:
122  * 1. Redistributions of source code must retain the above copyright
123  *    notice, this list of conditions, and the following disclaimer,
124  *    without modification.
125  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
126  *    substantially similar to the "NO WARRANTY" disclaimer below
127  *    ("Disclaimer") and any redistribution must be conditioned upon
128  *    including a substantially similar Disclaimer requirement for further
129  *    binary redistribution.
130  * 3. Neither the names of the above-listed copyright holders nor the names
131  *    of any contributors may be used to endorse or promote products derived
132  *    from this software without specific prior written permission.
133  *
134  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
137  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
138  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
139  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
140  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
141  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
142  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
143  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
144  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
145  *
146  * Alternatively, you may choose to be licensed under the terms of the
147  * GNU General Public License ("GPL") version 2 as published by the Free
148  * Software Foundation.
149  *
150  *****************************************************************************/
151 
152 #include "acpi.h"
153 #include "accommon.h"
154 #include "actables.h"
155 
156 #define _COMPONENT          ACPI_TABLES
157         ACPI_MODULE_NAME    ("tbutils")
158 
159 
160 /* Local prototypes */
161 
162 static ACPI_PHYSICAL_ADDRESS
163 AcpiTbGetRootTableEntry (
164     UINT8                   *TableEntry,
165     UINT32                  TableEntrySize);
166 
167 
168 #if (!ACPI_REDUCED_HARDWARE)
169 /*******************************************************************************
170  *
171  * FUNCTION:    AcpiTbInitializeFacs
172  *
173  * PARAMETERS:  None
174  *
175  * RETURN:      Status
176  *
177  * DESCRIPTION: Create a permanent mapping for the FADT and save it in a global
178  *              for accessing the Global Lock and Firmware Waking Vector
179  *
180  ******************************************************************************/
181 
182 ACPI_STATUS
AcpiTbInitializeFacs(void)183 AcpiTbInitializeFacs (
184     void)
185 {
186     ACPI_TABLE_FACS         *Facs;
187 
188 
189     /* If Hardware Reduced flag is set, there is no FACS */
190 
191     if (AcpiGbl_ReducedHardware)
192     {
193         AcpiGbl_FACS = NULL;
194         return (AE_OK);
195     }
196     else if (AcpiGbl_FADT.XFacs &&
197          (!AcpiGbl_FADT.Facs || !AcpiGbl_Use32BitFacsAddresses))
198     {
199         (void) AcpiGetTableByIndex (AcpiGbl_XFacsIndex,
200             ACPI_CAST_INDIRECT_PTR (ACPI_TABLE_HEADER, &Facs));
201         AcpiGbl_FACS = Facs;
202     }
203     else if (AcpiGbl_FADT.Facs)
204     {
205         (void) AcpiGetTableByIndex (AcpiGbl_FacsIndex,
206             ACPI_CAST_INDIRECT_PTR (ACPI_TABLE_HEADER, &Facs));
207         AcpiGbl_FACS = Facs;
208     }
209 
210     /* If there is no FACS, just continue. There was already an error msg */
211 
212     return (AE_OK);
213 }
214 #endif /* !ACPI_REDUCED_HARDWARE */
215 
216 
217 /*******************************************************************************
218  *
219  * FUNCTION:    AcpiTbCheckDsdtHeader
220  *
221  * PARAMETERS:  None
222  *
223  * RETURN:      None
224  *
225  * DESCRIPTION: Quick compare to check validity of the DSDT. This will detect
226  *              if the DSDT has been replaced from outside the OS and/or if
227  *              the DSDT header has been corrupted.
228  *
229  ******************************************************************************/
230 
231 void
AcpiTbCheckDsdtHeader(void)232 AcpiTbCheckDsdtHeader (
233     void)
234 {
235 
236     /* Compare original length and checksum to current values */
237 
238     if (AcpiGbl_OriginalDsdtHeader.Length != AcpiGbl_DSDT->Length ||
239         AcpiGbl_OriginalDsdtHeader.Checksum != AcpiGbl_DSDT->Checksum)
240     {
241         ACPI_BIOS_ERROR ((AE_INFO,
242             "The DSDT has been corrupted or replaced - "
243             "old, new headers below"));
244 
245         AcpiTbPrintTableHeader (0, &AcpiGbl_OriginalDsdtHeader);
246         AcpiTbPrintTableHeader (0, AcpiGbl_DSDT);
247 
248         /* Disable further error messages */
249 
250         AcpiGbl_OriginalDsdtHeader.Length = AcpiGbl_DSDT->Length;
251         AcpiGbl_OriginalDsdtHeader.Checksum = AcpiGbl_DSDT->Checksum;
252     }
253 }
254 
255 
256 /*******************************************************************************
257  *
258  * FUNCTION:    AcpiTbCopyDsdt
259  *
260  * PARAMETERS:  TableIndex          - Index of installed table to copy
261  *
262  * RETURN:      The copied DSDT
263  *
264  * DESCRIPTION: Implements a subsystem option to copy the DSDT to local memory.
265  *              Some very bad BIOSs are known to either corrupt the DSDT or
266  *              install a new, bad DSDT. This copy works around the problem.
267  *
268  ******************************************************************************/
269 
270 ACPI_TABLE_HEADER *
AcpiTbCopyDsdt(UINT32 TableIndex)271 AcpiTbCopyDsdt (
272     UINT32                  TableIndex)
273 {
274     ACPI_TABLE_HEADER       *NewTable;
275     ACPI_TABLE_DESC         *TableDesc;
276 
277 
278     TableDesc = &AcpiGbl_RootTableList.Tables[TableIndex];
279 
280     NewTable = ACPI_ALLOCATE (TableDesc->Length);
281     if (!NewTable)
282     {
283         ACPI_ERROR ((AE_INFO, "Could not copy DSDT of length 0x%X",
284             TableDesc->Length));
285         return (NULL);
286     }
287 
288     memcpy (NewTable, TableDesc->Pointer, TableDesc->Length);
289     AcpiTbUninstallTable (TableDesc);
290 
291     AcpiTbInitTableDescriptor (
292         &AcpiGbl_RootTableList.Tables[AcpiGbl_DsdtIndex],
293         ACPI_PTR_TO_PHYSADDR (NewTable),
294         ACPI_TABLE_ORIGIN_INTERNAL_VIRTUAL, NewTable);
295 
296     ACPI_INFO ((
297         "Forced DSDT copy: length 0x%05X copied locally, original unmapped",
298         NewTable->Length));
299 
300     return (NewTable);
301 }
302 
303 
304 /*******************************************************************************
305  *
306  * FUNCTION:    AcpiTbGetRootTableEntry
307  *
308  * PARAMETERS:  TableEntry          - Pointer to the RSDT/XSDT table entry
309  *              TableEntrySize      - sizeof 32 or 64 (RSDT or XSDT)
310  *
311  * RETURN:      Physical address extracted from the root table
312  *
313  * DESCRIPTION: Get one root table entry. Handles 32-bit and 64-bit cases on
314  *              both 32-bit and 64-bit platforms
315  *
316  * NOTE:        ACPI_PHYSICAL_ADDRESS is 32-bit on 32-bit platforms, 64-bit on
317  *              64-bit platforms.
318  *
319  ******************************************************************************/
320 
321 static ACPI_PHYSICAL_ADDRESS
AcpiTbGetRootTableEntry(UINT8 * TableEntry,UINT32 TableEntrySize)322 AcpiTbGetRootTableEntry (
323     UINT8                   *TableEntry,
324     UINT32                  TableEntrySize)
325 {
326     UINT64                  Address64;
327 
328 
329     /*
330      * Get the table physical address (32-bit for RSDT, 64-bit for XSDT):
331      * Note: Addresses are 32-bit aligned (not 64) in both RSDT and XSDT
332      */
333     if (TableEntrySize == ACPI_RSDT_ENTRY_SIZE)
334     {
335         /*
336          * 32-bit platform, RSDT: Return 32-bit table entry
337          * 64-bit platform, RSDT: Expand 32-bit to 64-bit and return
338          */
339         return ((ACPI_PHYSICAL_ADDRESS) (*ACPI_CAST_PTR (
340             UINT32, TableEntry)));
341     }
342     else
343     {
344         /*
345          * 32-bit platform, XSDT: Truncate 64-bit to 32-bit and return
346          * 64-bit platform, XSDT: Move (unaligned) 64-bit to local,
347          *  return 64-bit
348          */
349         ACPI_MOVE_64_TO_64 (&Address64, TableEntry);
350 
351 #if ACPI_MACHINE_WIDTH == 32
352         if (Address64 > ACPI_UINT32_MAX)
353         {
354             /* Will truncate 64-bit address to 32 bits, issue warning */
355 
356             ACPI_BIOS_WARNING ((AE_INFO,
357                 "64-bit Physical Address in XSDT is too large (0x%8.8X%8.8X),"
358                 " truncating",
359                 ACPI_FORMAT_UINT64 (Address64)));
360         }
361 #endif
362         return ((ACPI_PHYSICAL_ADDRESS) (Address64));
363     }
364 }
365 
366 
367 /*******************************************************************************
368  *
369  * FUNCTION:    AcpiTbParseRootTable
370  *
371  * PARAMETERS:  RsdpAddress         - Pointer to the RSDP
372  *
373  * RETURN:      Status
374  *
375  * DESCRIPTION: This function is called to parse the Root System Description
376  *              Table (RSDT or XSDT)
377  *
378  * NOTE:        Tables are mapped (not copied) for efficiency. The FACS must
379  *              be mapped and cannot be copied because it contains the actual
380  *              memory location of the ACPI Global Lock.
381  *
382  ******************************************************************************/
383 
384 ACPI_STATUS ACPI_INIT_FUNCTION
AcpiTbParseRootTable(ACPI_PHYSICAL_ADDRESS RsdpAddress)385 AcpiTbParseRootTable (
386     ACPI_PHYSICAL_ADDRESS   RsdpAddress)
387 {
388     ACPI_TABLE_RSDP         *Rsdp;
389     UINT32                  TableEntrySize;
390     UINT32                  i;
391     UINT32                  TableCount;
392     ACPI_TABLE_HEADER       *Table;
393     ACPI_PHYSICAL_ADDRESS   Address;
394     UINT32                  Length;
395     UINT8                   *TableEntry;
396     ACPI_STATUS             Status;
397     UINT32                  TableIndex;
398 
399 
400     ACPI_FUNCTION_TRACE (TbParseRootTable);
401 
402 
403     /* Map the entire RSDP and extract the address of the RSDT or XSDT */
404 
405     Rsdp = AcpiOsMapMemory (RsdpAddress, sizeof (ACPI_TABLE_RSDP));
406     if (!Rsdp)
407     {
408         return_ACPI_STATUS (AE_NO_MEMORY);
409     }
410 
411     AcpiTbPrintTableHeader (RsdpAddress,
412         ACPI_CAST_PTR (ACPI_TABLE_HEADER, Rsdp));
413 
414     /* Use XSDT if present and not overridden. Otherwise, use RSDT */
415 
416     if ((Rsdp->Revision > 1) &&
417         Rsdp->XsdtPhysicalAddress &&
418         !AcpiGbl_DoNotUseXsdt)
419     {
420         /*
421          * RSDP contains an XSDT (64-bit physical addresses). We must use
422          * the XSDT if the revision is > 1 and the XSDT pointer is present,
423          * as per the ACPI specification.
424          */
425         Address = (ACPI_PHYSICAL_ADDRESS) Rsdp->XsdtPhysicalAddress;
426         TableEntrySize = ACPI_XSDT_ENTRY_SIZE;
427     }
428     else
429     {
430         /* Root table is an RSDT (32-bit physical addresses) */
431 
432         Address = (ACPI_PHYSICAL_ADDRESS) Rsdp->RsdtPhysicalAddress;
433         TableEntrySize = ACPI_RSDT_ENTRY_SIZE;
434     }
435 
436     /*
437      * It is not possible to map more than one entry in some environments,
438      * so unmap the RSDP here before mapping other tables
439      */
440     AcpiOsUnmapMemory (Rsdp, sizeof (ACPI_TABLE_RSDP));
441 
442     /* Map the RSDT/XSDT table header to get the full table length */
443 
444     Table = AcpiOsMapMemory (Address, sizeof (ACPI_TABLE_HEADER));
445     if (!Table)
446     {
447         return_ACPI_STATUS (AE_NO_MEMORY);
448     }
449 
450     AcpiTbPrintTableHeader (Address, Table);
451 
452     /*
453      * Validate length of the table, and map entire table.
454      * Minimum length table must contain at least one entry.
455      */
456     Length = Table->Length;
457     AcpiOsUnmapMemory (Table, sizeof (ACPI_TABLE_HEADER));
458 
459     if (Length < (sizeof (ACPI_TABLE_HEADER) + TableEntrySize))
460     {
461         ACPI_BIOS_ERROR ((AE_INFO,
462             "Invalid table length 0x%X in RSDT/XSDT", Length));
463         return_ACPI_STATUS (AE_INVALID_TABLE_LENGTH);
464     }
465 
466     Table = AcpiOsMapMemory (Address, Length);
467     if (!Table)
468     {
469         return_ACPI_STATUS (AE_NO_MEMORY);
470     }
471 
472     /* Validate the root table checksum */
473 
474     Status = AcpiTbVerifyChecksum (Table, Length);
475     if (ACPI_FAILURE (Status))
476     {
477         AcpiOsUnmapMemory (Table, Length);
478         return_ACPI_STATUS (Status);
479     }
480 
481     /* Get the number of entries and pointer to first entry */
482 
483     TableCount = (UINT32) ((Table->Length - sizeof (ACPI_TABLE_HEADER)) /
484         TableEntrySize);
485     TableEntry = ACPI_ADD_PTR (UINT8, Table, sizeof (ACPI_TABLE_HEADER));
486 
487     /* Initialize the root table array from the RSDT/XSDT */
488 
489     for (i = 0; i < TableCount; i++)
490     {
491         /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */
492 
493         Address = AcpiTbGetRootTableEntry (TableEntry, TableEntrySize);
494 
495         /* Skip NULL entries in RSDT/XSDT */
496 
497         if (!Address)
498         {
499             goto NextTable;
500         }
501 
502         Status = AcpiTbInstallStandardTable (Address,
503             ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL, FALSE, TRUE, &TableIndex);
504 
505         if (ACPI_SUCCESS (Status) &&
506             ACPI_COMPARE_NAME (
507                 &AcpiGbl_RootTableList.Tables[TableIndex].Signature,
508                 ACPI_SIG_FADT))
509         {
510             AcpiGbl_FadtIndex = TableIndex;
511             AcpiTbParseFadt ();
512         }
513 
514 NextTable:
515 
516         TableEntry += TableEntrySize;
517     }
518 
519     AcpiOsUnmapMemory (Table, Length);
520     return_ACPI_STATUS (AE_OK);
521 }
522 
523 
524 /*******************************************************************************
525  *
526  * FUNCTION:    AcpiTbGetTable
527  *
528  * PARAMETERS:  TableDesc           - Table descriptor
529  *              OutTable            - Where the pointer to the table is returned
530  *
531  * RETURN:      Status and pointer to the requested table
532  *
533  * DESCRIPTION: Increase a reference to a table descriptor and return the
534  *              validated table pointer.
535  *              If the table descriptor is an entry of the root table list,
536  *              this API must be invoked with ACPI_MTX_TABLES acquired.
537  *
538  ******************************************************************************/
539 
540 ACPI_STATUS
AcpiTbGetTable(ACPI_TABLE_DESC * TableDesc,ACPI_TABLE_HEADER ** OutTable)541 AcpiTbGetTable (
542     ACPI_TABLE_DESC        *TableDesc,
543     ACPI_TABLE_HEADER      **OutTable)
544 {
545     ACPI_STATUS            Status;
546 
547 
548     ACPI_FUNCTION_TRACE (AcpiTbGetTable);
549 
550 
551     if (TableDesc->ValidationCount == 0)
552     {
553         /* Table need to be "VALIDATED" */
554 
555         Status = AcpiTbValidateTable (TableDesc);
556         if (ACPI_FAILURE (Status))
557         {
558             return_ACPI_STATUS (Status);
559         }
560     }
561 
562     if (TableDesc->ValidationCount < ACPI_MAX_TABLE_VALIDATIONS)
563     {
564         TableDesc->ValidationCount++;
565 
566         /*
567          * Detect ValidationCount overflows to ensure that the warning
568          * message will only be printed once.
569          */
570         if (TableDesc->ValidationCount >= ACPI_MAX_TABLE_VALIDATIONS)
571         {
572             ACPI_WARNING((AE_INFO,
573                 "Table %p, Validation count overflows\n", TableDesc));
574         }
575     }
576 
577     *OutTable = TableDesc->Pointer;
578     return_ACPI_STATUS (AE_OK);
579 }
580 
581 
582 /*******************************************************************************
583  *
584  * FUNCTION:    AcpiTbPutTable
585  *
586  * PARAMETERS:  TableDesc           - Table descriptor
587  *
588  * RETURN:      None
589  *
590  * DESCRIPTION: Decrease a reference to a table descriptor and release the
591  *              validated table pointer if no references.
592  *              If the table descriptor is an entry of the root table list,
593  *              this API must be invoked with ACPI_MTX_TABLES acquired.
594  *
595  ******************************************************************************/
596 
597 void
AcpiTbPutTable(ACPI_TABLE_DESC * TableDesc)598 AcpiTbPutTable (
599     ACPI_TABLE_DESC        *TableDesc)
600 {
601 
602     ACPI_FUNCTION_TRACE (AcpiTbPutTable);
603 
604 
605     if (TableDesc->ValidationCount < ACPI_MAX_TABLE_VALIDATIONS)
606     {
607         TableDesc->ValidationCount--;
608 
609         /*
610          * Detect ValidationCount underflows to ensure that the warning
611          * message will only be printed once.
612          */
613         if (TableDesc->ValidationCount >= ACPI_MAX_TABLE_VALIDATIONS)
614         {
615             ACPI_WARNING ((AE_INFO,
616                 "Table %p, Validation count underflows\n", TableDesc));
617             return_VOID;
618         }
619     }
620 
621     if (TableDesc->ValidationCount == 0)
622     {
623         /* Table need to be "INVALIDATED" */
624 
625         AcpiTbInvalidateTable (TableDesc);
626     }
627 
628     return_VOID;
629 }
630