xref: /freebsd/sys/contrib/dev/acpica/components/utilities/utosi.c (revision 3b2324c3a800d7599f348c408f01908d0cef05a0)
1 /******************************************************************************
2  *
3  * Module Name: utosi - Support for the _OSI predefined control method
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2019, 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 <contrib/dev/acpica/include/acpi.h>
153 #include <contrib/dev/acpica/include/accommon.h>
154 
155 
156 #define _COMPONENT          ACPI_UTILITIES
157         ACPI_MODULE_NAME    ("utosi")
158 
159 
160 /******************************************************************************
161  *
162  * ACPICA policy for new _OSI strings:
163  *
164  * It is the stated policy of ACPICA that new _OSI strings will be integrated
165  * into this module as soon as possible after they are defined. It is strongly
166  * recommended that all ACPICA hosts mirror this policy and integrate any
167  * changes to this module as soon as possible. There are several historical
168  * reasons behind this policy:
169  *
170  * 1) New BIOSs tend to test only the case where the host responds TRUE to
171  *    the latest version of Windows, which would respond to the latest/newest
172  *    _OSI string. Not responding TRUE to the latest version of Windows will
173  *    risk executing untested code paths throughout the DSDT and SSDTs.
174  *
175  * 2) If a new _OSI string is recognized only after a significant delay, this
176  *    has the potential to cause problems on existing working machines because
177  *    of the possibility that a new and different path through the ASL code
178  *    will be executed.
179  *
180  * 3) New _OSI strings are tending to come out about once per year. A delay
181  *    in recognizing a new string for a significant amount of time risks the
182  *    release of another string which only compounds the initial problem.
183  *
184  *****************************************************************************/
185 
186 
187 /*
188  * Strings supported by the _OSI predefined control method (which is
189  * implemented internally within this module.)
190  *
191  * March 2009: Removed "Linux" as this host no longer wants to respond true
192  * for this string. Basically, the only safe OS strings are windows-related
193  * and in many or most cases represent the only test path within the
194  * BIOS-provided ASL code.
195  *
196  * The last element of each entry is used to track the newest version of
197  * Windows that the BIOS has requested.
198  */
199 static ACPI_INTERFACE_INFO    AcpiDefaultSupportedInterfaces[] =
200 {
201     /* Operating System Vendor Strings */
202 
203     {"Windows 2000",        NULL, 0, ACPI_OSI_WIN_2000},         /* Windows 2000 */
204     {"Windows 2001",        NULL, 0, ACPI_OSI_WIN_XP},           /* Windows XP */
205     {"Windows 2001 SP1",    NULL, 0, ACPI_OSI_WIN_XP_SP1},       /* Windows XP SP1 */
206     {"Windows 2001.1",      NULL, 0, ACPI_OSI_WINSRV_2003},      /* Windows Server 2003 */
207     {"Windows 2001 SP2",    NULL, 0, ACPI_OSI_WIN_XP_SP2},       /* Windows XP SP2 */
208     {"Windows 2001.1 SP1",  NULL, 0, ACPI_OSI_WINSRV_2003_SP1},  /* Windows Server 2003 SP1 - Added 03/2006 */
209     {"Windows 2006",        NULL, 0, ACPI_OSI_WIN_VISTA},        /* Windows Vista - Added 03/2006 */
210     {"Windows 2006.1",      NULL, 0, ACPI_OSI_WINSRV_2008},      /* Windows Server 2008 - Added 09/2009 */
211     {"Windows 2006 SP1",    NULL, 0, ACPI_OSI_WIN_VISTA_SP1},    /* Windows Vista SP1 - Added 09/2009 */
212     {"Windows 2006 SP2",    NULL, 0, ACPI_OSI_WIN_VISTA_SP2},    /* Windows Vista SP2 - Added 09/2010 */
213     {"Windows 2009",        NULL, 0, ACPI_OSI_WIN_7},            /* Windows 7 and Server 2008 R2 - Added 09/2009 */
214     {"Windows 2012",        NULL, 0, ACPI_OSI_WIN_8},            /* Windows 8 and Server 2012 - Added 08/2012 */
215     {"Windows 2013",        NULL, 0, ACPI_OSI_WIN_8},            /* Windows 8.1 and Server 2012 R2 - Added 01/2014 */
216     {"Windows 2015",        NULL, 0, ACPI_OSI_WIN_10},           /* Windows 10 - Added 03/2015 */
217     {"Windows 2016",        NULL, 0, ACPI_OSI_WIN_10_RS1},       /* Windows 10 version 1607 - Added 12/2017 */
218     {"Windows 2017",        NULL, 0, ACPI_OSI_WIN_10_RS2},       /* Windows 10 version 1703 - Added 12/2017 */
219     {"Windows 2017.2",      NULL, 0, ACPI_OSI_WIN_10_RS3},       /* Windows 10 version 1709 - Added 02/2018 */
220     {"Windows 2018",        NULL, 0, ACPI_OSI_WIN_10_RS4},       /* Windows 10 version 1803 - Added 11/2018 */
221     {"Windows 2018.2",      NULL, 0, ACPI_OSI_WIN_10_RS5},       /* Windows 10 version 1809 - Added 11/2018 */
222 
223     /* Feature Group Strings */
224 
225     {"Extended Address Space Descriptor", NULL, ACPI_OSI_FEATURE, 0},
226 
227     /*
228      * All "optional" feature group strings (features that are implemented
229      * by the host) should be dynamically modified to VALID by the host via
230      * AcpiInstallInterface or AcpiUpdateInterfaces. Such optional feature
231      * group strings are set as INVALID by default here.
232      */
233 
234     {"Module Device",               NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
235     {"Processor Device",            NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
236     {"3.0 Thermal Model",           NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
237     {"3.0 _SCP Extensions",         NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
238     {"Processor Aggregator Device", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0}
239 };
240 
241 
242 /*******************************************************************************
243  *
244  * FUNCTION:    AcpiUtInitializeInterfaces
245  *
246  * PARAMETERS:  None
247  *
248  * RETURN:      Status
249  *
250  * DESCRIPTION: Initialize the global _OSI supported interfaces list
251  *
252  ******************************************************************************/
253 
254 ACPI_STATUS
255 AcpiUtInitializeInterfaces (
256     void)
257 {
258     ACPI_STATUS             Status;
259     UINT32                  i;
260 
261 
262     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
263     if (ACPI_FAILURE (Status))
264     {
265         return (Status);
266     }
267 
268     AcpiGbl_SupportedInterfaces = AcpiDefaultSupportedInterfaces;
269 
270     /* Link the static list of supported interfaces */
271 
272     for (i = 0;
273         i < (ACPI_ARRAY_LENGTH (AcpiDefaultSupportedInterfaces) - 1);
274         i++)
275     {
276         AcpiDefaultSupportedInterfaces[i].Next =
277             &AcpiDefaultSupportedInterfaces[(ACPI_SIZE) i + 1];
278     }
279 
280     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
281     return (AE_OK);
282 }
283 
284 
285 /*******************************************************************************
286  *
287  * FUNCTION:    AcpiUtInterfaceTerminate
288  *
289  * PARAMETERS:  None
290  *
291  * RETURN:      Status
292  *
293  * DESCRIPTION: Delete all interfaces in the global list. Sets
294  *              AcpiGbl_SupportedInterfaces to NULL.
295  *
296  ******************************************************************************/
297 
298 ACPI_STATUS
299 AcpiUtInterfaceTerminate (
300     void)
301 {
302     ACPI_STATUS             Status;
303     ACPI_INTERFACE_INFO     *NextInterface;
304 
305 
306     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
307     if (ACPI_FAILURE (Status))
308     {
309         return (Status);
310     }
311 
312     NextInterface = AcpiGbl_SupportedInterfaces;
313     while (NextInterface)
314     {
315         AcpiGbl_SupportedInterfaces = NextInterface->Next;
316 
317         if (NextInterface->Flags & ACPI_OSI_DYNAMIC)
318         {
319             /* Only interfaces added at runtime can be freed */
320 
321             ACPI_FREE (NextInterface->Name);
322             ACPI_FREE (NextInterface);
323         }
324         else
325         {
326             /* Interface is in static list. Reset it to invalid or valid. */
327 
328             if (NextInterface->Flags & ACPI_OSI_DEFAULT_INVALID)
329             {
330                 NextInterface->Flags |= ACPI_OSI_INVALID;
331             }
332             else
333             {
334                 NextInterface->Flags &= ~ACPI_OSI_INVALID;
335             }
336         }
337 
338         NextInterface = AcpiGbl_SupportedInterfaces;
339     }
340 
341     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
342     return (AE_OK);
343 }
344 
345 
346 /*******************************************************************************
347  *
348  * FUNCTION:    AcpiUtInstallInterface
349  *
350  * PARAMETERS:  InterfaceName       - The interface to install
351  *
352  * RETURN:      Status
353  *
354  * DESCRIPTION: Install the interface into the global interface list.
355  *              Caller MUST hold AcpiGbl_OsiMutex
356  *
357  ******************************************************************************/
358 
359 ACPI_STATUS
360 AcpiUtInstallInterface (
361     ACPI_STRING             InterfaceName)
362 {
363     ACPI_INTERFACE_INFO     *InterfaceInfo;
364 
365 
366     /* Allocate info block and space for the name string */
367 
368     InterfaceInfo = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_INTERFACE_INFO));
369     if (!InterfaceInfo)
370     {
371         return (AE_NO_MEMORY);
372     }
373 
374     InterfaceInfo->Name = ACPI_ALLOCATE_ZEROED (strlen (InterfaceName) + 1);
375     if (!InterfaceInfo->Name)
376     {
377         ACPI_FREE (InterfaceInfo);
378         return (AE_NO_MEMORY);
379     }
380 
381     /* Initialize new info and insert at the head of the global list */
382 
383     strcpy (InterfaceInfo->Name, InterfaceName);
384     InterfaceInfo->Flags = ACPI_OSI_DYNAMIC;
385     InterfaceInfo->Next = AcpiGbl_SupportedInterfaces;
386 
387     AcpiGbl_SupportedInterfaces = InterfaceInfo;
388     return (AE_OK);
389 }
390 
391 
392 /*******************************************************************************
393  *
394  * FUNCTION:    AcpiUtRemoveInterface
395  *
396  * PARAMETERS:  InterfaceName       - The interface to remove
397  *
398  * RETURN:      Status
399  *
400  * DESCRIPTION: Remove the interface from the global interface list.
401  *              Caller MUST hold AcpiGbl_OsiMutex
402  *
403  ******************************************************************************/
404 
405 ACPI_STATUS
406 AcpiUtRemoveInterface (
407     ACPI_STRING             InterfaceName)
408 {
409     ACPI_INTERFACE_INFO     *PreviousInterface;
410     ACPI_INTERFACE_INFO     *NextInterface;
411 
412 
413     PreviousInterface = NextInterface = AcpiGbl_SupportedInterfaces;
414     while (NextInterface)
415     {
416         if (!strcmp (InterfaceName, NextInterface->Name))
417         {
418             /*
419              * Found: name is in either the static list
420              * or was added at runtime
421              */
422             if (NextInterface->Flags & ACPI_OSI_DYNAMIC)
423             {
424                 /* Interface was added dynamically, remove and free it */
425 
426                 if (PreviousInterface == NextInterface)
427                 {
428                     AcpiGbl_SupportedInterfaces = NextInterface->Next;
429                 }
430                 else
431                 {
432                     PreviousInterface->Next = NextInterface->Next;
433                 }
434 
435                 ACPI_FREE (NextInterface->Name);
436                 ACPI_FREE (NextInterface);
437             }
438             else
439             {
440                 /*
441                  * Interface is in static list. If marked invalid, then
442                  * it does not actually exist. Else, mark it invalid.
443                  */
444                 if (NextInterface->Flags & ACPI_OSI_INVALID)
445                 {
446                     return (AE_NOT_EXIST);
447                 }
448 
449                 NextInterface->Flags |= ACPI_OSI_INVALID;
450             }
451 
452             return (AE_OK);
453         }
454 
455         PreviousInterface = NextInterface;
456         NextInterface = NextInterface->Next;
457     }
458 
459     /* Interface was not found */
460 
461     return (AE_NOT_EXIST);
462 }
463 
464 
465 /*******************************************************************************
466  *
467  * FUNCTION:    AcpiUtUpdateInterfaces
468  *
469  * PARAMETERS:  Action              - Actions to be performed during the
470  *                                    update
471  *
472  * RETURN:      Status
473  *
474  * DESCRIPTION: Update _OSI interface strings, disabling or enabling OS vendor
475  *              strings or/and feature group strings.
476  *              Caller MUST hold AcpiGbl_OsiMutex
477  *
478  ******************************************************************************/
479 
480 ACPI_STATUS
481 AcpiUtUpdateInterfaces (
482     UINT8                   Action)
483 {
484     ACPI_INTERFACE_INFO     *NextInterface;
485 
486 
487     NextInterface = AcpiGbl_SupportedInterfaces;
488     while (NextInterface)
489     {
490         if (((NextInterface->Flags & ACPI_OSI_FEATURE) &&
491              (Action & ACPI_FEATURE_STRINGS)) ||
492             (!(NextInterface->Flags & ACPI_OSI_FEATURE) &&
493              (Action & ACPI_VENDOR_STRINGS)))
494         {
495             if (Action & ACPI_DISABLE_INTERFACES)
496             {
497                 /* Mark the interfaces as invalid */
498 
499                 NextInterface->Flags |= ACPI_OSI_INVALID;
500             }
501             else
502             {
503                 /* Mark the interfaces as valid */
504 
505                 NextInterface->Flags &= ~ACPI_OSI_INVALID;
506             }
507         }
508 
509         NextInterface = NextInterface->Next;
510     }
511 
512     return (AE_OK);
513 }
514 
515 
516 /*******************************************************************************
517  *
518  * FUNCTION:    AcpiUtGetInterface
519  *
520  * PARAMETERS:  InterfaceName       - The interface to find
521  *
522  * RETURN:      ACPI_INTERFACE_INFO if found. NULL if not found.
523  *
524  * DESCRIPTION: Search for the specified interface name in the global list.
525  *              Caller MUST hold AcpiGbl_OsiMutex
526  *
527  ******************************************************************************/
528 
529 ACPI_INTERFACE_INFO *
530 AcpiUtGetInterface (
531     ACPI_STRING             InterfaceName)
532 {
533     ACPI_INTERFACE_INFO     *NextInterface;
534 
535 
536     NextInterface = AcpiGbl_SupportedInterfaces;
537     while (NextInterface)
538     {
539         if (!strcmp (InterfaceName, NextInterface->Name))
540         {
541             return (NextInterface);
542         }
543 
544         NextInterface = NextInterface->Next;
545     }
546 
547     return (NULL);
548 }
549 
550 
551 /*******************************************************************************
552  *
553  * FUNCTION:    AcpiUtOsiImplementation
554  *
555  * PARAMETERS:  WalkState           - Current walk state
556  *
557  * RETURN:      Status
558  *              Integer: TRUE (0) if input string is matched
559  *                       FALSE (-1) if string is not matched
560  *
561  * DESCRIPTION: Implementation of the _OSI predefined control method. When
562  *              an invocation of _OSI is encountered in the system AML,
563  *              control is transferred to this function.
564  *
565  * (August 2016)
566  * Note:  _OSI is now defined to return "Ones" to indicate a match, for
567  * compatibility with other ACPI implementations. On a 32-bit DSDT, Ones
568  * is 0xFFFFFFFF. On a 64-bit DSDT, Ones is 0xFFFFFFFFFFFFFFFF
569  * (ACPI_UINT64_MAX).
570  *
571  * This function always returns ACPI_UINT64_MAX for TRUE, and later code
572  * will truncate this to 32 bits if necessary.
573  *
574  ******************************************************************************/
575 
576 ACPI_STATUS
577 AcpiUtOsiImplementation (
578     ACPI_WALK_STATE         *WalkState)
579 {
580     ACPI_OPERAND_OBJECT     *StringDesc;
581     ACPI_OPERAND_OBJECT     *ReturnDesc;
582     ACPI_INTERFACE_INFO     *InterfaceInfo;
583     ACPI_INTERFACE_HANDLER  InterfaceHandler;
584     ACPI_STATUS             Status;
585     UINT64                  ReturnValue;
586 
587 
588     ACPI_FUNCTION_TRACE (UtOsiImplementation);
589 
590 
591     /* Validate the string input argument (from the AML caller) */
592 
593     StringDesc = WalkState->Arguments[0].Object;
594     if (!StringDesc ||
595         (StringDesc->Common.Type != ACPI_TYPE_STRING))
596     {
597         return_ACPI_STATUS (AE_TYPE);
598     }
599 
600     /* Create a return object */
601 
602     ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
603     if (!ReturnDesc)
604     {
605         return_ACPI_STATUS (AE_NO_MEMORY);
606     }
607 
608     /* Default return value is 0, NOT SUPPORTED */
609 
610     ReturnValue = 0;
611     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
612     if (ACPI_FAILURE (Status))
613     {
614         AcpiUtRemoveReference (ReturnDesc);
615         return_ACPI_STATUS (Status);
616     }
617 
618     /* Lookup the interface in the global _OSI list */
619 
620     InterfaceInfo = AcpiUtGetInterface (StringDesc->String.Pointer);
621     if (InterfaceInfo &&
622         !(InterfaceInfo->Flags & ACPI_OSI_INVALID))
623     {
624         /*
625          * The interface is supported.
626          * Update the OsiData if necessary. We keep track of the latest
627          * version of Windows that has been requested by the BIOS.
628          */
629         if (InterfaceInfo->Value > AcpiGbl_OsiData)
630         {
631             AcpiGbl_OsiData = InterfaceInfo->Value;
632         }
633 
634         ReturnValue = ACPI_UINT64_MAX;
635     }
636 
637     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
638 
639     /*
640      * Invoke an optional _OSI interface handler. The host OS may wish
641      * to do some interface-specific handling. For example, warn about
642      * certain interfaces or override the true/false support value.
643      */
644     InterfaceHandler = AcpiGbl_InterfaceHandler;
645     if (InterfaceHandler)
646     {
647         if (InterfaceHandler (
648             StringDesc->String.Pointer, (UINT32) ReturnValue))
649         {
650             ReturnValue = ACPI_UINT64_MAX;
651         }
652     }
653 
654     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INFO,
655         "ACPI: BIOS _OSI(\"%s\") is %ssupported\n",
656         StringDesc->String.Pointer, ReturnValue == 0 ? "not " : ""));
657 
658     /* Complete the return object */
659 
660     ReturnDesc->Integer.Value = ReturnValue;
661     WalkState->ReturnDesc = ReturnDesc;
662     return_ACPI_STATUS (AE_OK);
663 }
664