xref: /illumos-gate/usr/src/common/acpica/utilities/utosi.c (revision 3ce5372277f4657ad0e52d36c979527c4ca22de2)
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 - 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 
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 
221     /* Feature Group Strings */
222 
223     {"Extended Address Space Descriptor", NULL, ACPI_OSI_FEATURE, 0},
224 
225     /*
226      * All "optional" feature group strings (features that are implemented
227      * by the host) should be dynamically modified to VALID by the host via
228      * AcpiInstallInterface or AcpiUpdateInterfaces. Such optional feature
229      * group strings are set as INVALID by default here.
230      */
231 
232     {"Module Device",               NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
233     {"Processor Device",            NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
234     {"3.0 Thermal Model",           NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
235     {"3.0 _SCP Extensions",         NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
236     {"Processor Aggregator Device", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0}
237 };
238 
239 
240 /*******************************************************************************
241  *
242  * FUNCTION:    AcpiUtInitializeInterfaces
243  *
244  * PARAMETERS:  None
245  *
246  * RETURN:      Status
247  *
248  * DESCRIPTION: Initialize the global _OSI supported interfaces list
249  *
250  ******************************************************************************/
251 
252 ACPI_STATUS
253 AcpiUtInitializeInterfaces (
254     void)
255 {
256     ACPI_STATUS             Status;
257     UINT32                  i;
258 
259 
260     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
261     if (ACPI_FAILURE (Status))
262     {
263         return (Status);
264     }
265 
266     AcpiGbl_SupportedInterfaces = AcpiDefaultSupportedInterfaces;
267 
268     /* Link the static list of supported interfaces */
269 
270     for (i = 0;
271         i < (ACPI_ARRAY_LENGTH (AcpiDefaultSupportedInterfaces) - 1);
272         i++)
273     {
274         AcpiDefaultSupportedInterfaces[i].Next =
275             &AcpiDefaultSupportedInterfaces[(ACPI_SIZE) i + 1];
276     }
277 
278     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
279     return (AE_OK);
280 }
281 
282 
283 /*******************************************************************************
284  *
285  * FUNCTION:    AcpiUtInterfaceTerminate
286  *
287  * PARAMETERS:  None
288  *
289  * RETURN:      Status
290  *
291  * DESCRIPTION: Delete all interfaces in the global list. Sets
292  *              AcpiGbl_SupportedInterfaces to NULL.
293  *
294  ******************************************************************************/
295 
296 ACPI_STATUS
297 AcpiUtInterfaceTerminate (
298     void)
299 {
300     ACPI_STATUS             Status;
301     ACPI_INTERFACE_INFO     *NextInterface;
302 
303 
304     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
305     if (ACPI_FAILURE (Status))
306     {
307         return (Status);
308     }
309 
310     NextInterface = AcpiGbl_SupportedInterfaces;
311     while (NextInterface)
312     {
313         AcpiGbl_SupportedInterfaces = NextInterface->Next;
314 
315         if (NextInterface->Flags & ACPI_OSI_DYNAMIC)
316         {
317             /* Only interfaces added at runtime can be freed */
318 
319             ACPI_FREE (NextInterface->Name);
320             ACPI_FREE (NextInterface);
321         }
322         else
323         {
324             /* Interface is in static list. Reset it to invalid or valid. */
325 
326             if (NextInterface->Flags & ACPI_OSI_DEFAULT_INVALID)
327             {
328                 NextInterface->Flags |= ACPI_OSI_INVALID;
329             }
330             else
331             {
332                 NextInterface->Flags &= ~ACPI_OSI_INVALID;
333             }
334         }
335 
336         NextInterface = AcpiGbl_SupportedInterfaces;
337     }
338 
339     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
340     return (AE_OK);
341 }
342 
343 
344 /*******************************************************************************
345  *
346  * FUNCTION:    AcpiUtInstallInterface
347  *
348  * PARAMETERS:  InterfaceName       - The interface to install
349  *
350  * RETURN:      Status
351  *
352  * DESCRIPTION: Install the interface into the global interface list.
353  *              Caller MUST hold AcpiGbl_OsiMutex
354  *
355  ******************************************************************************/
356 
357 ACPI_STATUS
358 AcpiUtInstallInterface (
359     ACPI_STRING             InterfaceName)
360 {
361     ACPI_INTERFACE_INFO     *InterfaceInfo;
362 
363 
364     /* Allocate info block and space for the name string */
365 
366     InterfaceInfo = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_INTERFACE_INFO));
367     if (!InterfaceInfo)
368     {
369         return (AE_NO_MEMORY);
370     }
371 
372     InterfaceInfo->Name = ACPI_ALLOCATE_ZEROED (strlen (InterfaceName) + 1);
373     if (!InterfaceInfo->Name)
374     {
375         ACPI_FREE (InterfaceInfo);
376         return (AE_NO_MEMORY);
377     }
378 
379     /* Initialize new info and insert at the head of the global list */
380 
381     strcpy (InterfaceInfo->Name, InterfaceName);
382     InterfaceInfo->Flags = ACPI_OSI_DYNAMIC;
383     InterfaceInfo->Next = AcpiGbl_SupportedInterfaces;
384 
385     AcpiGbl_SupportedInterfaces = InterfaceInfo;
386     return (AE_OK);
387 }
388 
389 
390 /*******************************************************************************
391  *
392  * FUNCTION:    AcpiUtRemoveInterface
393  *
394  * PARAMETERS:  InterfaceName       - The interface to remove
395  *
396  * RETURN:      Status
397  *
398  * DESCRIPTION: Remove the interface from the global interface list.
399  *              Caller MUST hold AcpiGbl_OsiMutex
400  *
401  ******************************************************************************/
402 
403 ACPI_STATUS
404 AcpiUtRemoveInterface (
405     ACPI_STRING             InterfaceName)
406 {
407     ACPI_INTERFACE_INFO     *PreviousInterface;
408     ACPI_INTERFACE_INFO     *NextInterface;
409 
410 
411     PreviousInterface = NextInterface = AcpiGbl_SupportedInterfaces;
412     while (NextInterface)
413     {
414         if (!strcmp (InterfaceName, NextInterface->Name))
415         {
416             /*
417              * Found: name is in either the static list
418              * or was added at runtime
419              */
420             if (NextInterface->Flags & ACPI_OSI_DYNAMIC)
421             {
422                 /* Interface was added dynamically, remove and free it */
423 
424                 if (PreviousInterface == NextInterface)
425                 {
426                     AcpiGbl_SupportedInterfaces = NextInterface->Next;
427                 }
428                 else
429                 {
430                     PreviousInterface->Next = NextInterface->Next;
431                 }
432 
433                 ACPI_FREE (NextInterface->Name);
434                 ACPI_FREE (NextInterface);
435             }
436             else
437             {
438                 /*
439                  * Interface is in static list. If marked invalid, then
440                  * it does not actually exist. Else, mark it invalid.
441                  */
442                 if (NextInterface->Flags & ACPI_OSI_INVALID)
443                 {
444                     return (AE_NOT_EXIST);
445                 }
446 
447                 NextInterface->Flags |= ACPI_OSI_INVALID;
448             }
449 
450             return (AE_OK);
451         }
452 
453         PreviousInterface = NextInterface;
454         NextInterface = NextInterface->Next;
455     }
456 
457     /* Interface was not found */
458 
459     return (AE_NOT_EXIST);
460 }
461 
462 
463 /*******************************************************************************
464  *
465  * FUNCTION:    AcpiUtUpdateInterfaces
466  *
467  * PARAMETERS:  Action              - Actions to be performed during the
468  *                                    update
469  *
470  * RETURN:      Status
471  *
472  * DESCRIPTION: Update _OSI interface strings, disabling or enabling OS vendor
473  *              strings or/and feature group strings.
474  *              Caller MUST hold AcpiGbl_OsiMutex
475  *
476  ******************************************************************************/
477 
478 ACPI_STATUS
479 AcpiUtUpdateInterfaces (
480     UINT8                   Action)
481 {
482     ACPI_INTERFACE_INFO     *NextInterface;
483 
484 
485     NextInterface = AcpiGbl_SupportedInterfaces;
486     while (NextInterface)
487     {
488         if (((NextInterface->Flags & ACPI_OSI_FEATURE) &&
489              (Action & ACPI_FEATURE_STRINGS)) ||
490             (!(NextInterface->Flags & ACPI_OSI_FEATURE) &&
491              (Action & ACPI_VENDOR_STRINGS)))
492         {
493             if (Action & ACPI_DISABLE_INTERFACES)
494             {
495                 /* Mark the interfaces as invalid */
496 
497                 NextInterface->Flags |= ACPI_OSI_INVALID;
498             }
499             else
500             {
501                 /* Mark the interfaces as valid */
502 
503                 NextInterface->Flags &= ~ACPI_OSI_INVALID;
504             }
505         }
506 
507         NextInterface = NextInterface->Next;
508     }
509 
510     return (AE_OK);
511 }
512 
513 
514 /*******************************************************************************
515  *
516  * FUNCTION:    AcpiUtGetInterface
517  *
518  * PARAMETERS:  InterfaceName       - The interface to find
519  *
520  * RETURN:      ACPI_INTERFACE_INFO if found. NULL if not found.
521  *
522  * DESCRIPTION: Search for the specified interface name in the global list.
523  *              Caller MUST hold AcpiGbl_OsiMutex
524  *
525  ******************************************************************************/
526 
527 ACPI_INTERFACE_INFO *
528 AcpiUtGetInterface (
529     ACPI_STRING             InterfaceName)
530 {
531     ACPI_INTERFACE_INFO     *NextInterface;
532 
533 
534     NextInterface = AcpiGbl_SupportedInterfaces;
535     while (NextInterface)
536     {
537         if (!strcmp (InterfaceName, NextInterface->Name))
538         {
539             return (NextInterface);
540         }
541 
542         NextInterface = NextInterface->Next;
543     }
544 
545     return (NULL);
546 }
547 
548 
549 /*******************************************************************************
550  *
551  * FUNCTION:    AcpiUtOsiImplementation
552  *
553  * PARAMETERS:  WalkState           - Current walk state
554  *
555  * RETURN:      Status
556  *              Integer: TRUE (0) if input string is matched
557  *                       FALSE (-1) if string is not matched
558  *
559  * DESCRIPTION: Implementation of the _OSI predefined control method. When
560  *              an invocation of _OSI is encountered in the system AML,
561  *              control is transferred to this function.
562  *
563  * (August 2016)
564  * Note:  _OSI is now defined to return "Ones" to indicate a match, for
565  * compatibility with other ACPI implementations. On a 32-bit DSDT, Ones
566  * is 0xFFFFFFFF. On a 64-bit DSDT, Ones is 0xFFFFFFFFFFFFFFFF
567  * (ACPI_UINT64_MAX).
568  *
569  * This function always returns ACPI_UINT64_MAX for TRUE, and later code
570  * will truncate this to 32 bits if necessary.
571  *
572  ******************************************************************************/
573 
574 ACPI_STATUS
575 AcpiUtOsiImplementation (
576     ACPI_WALK_STATE         *WalkState)
577 {
578     ACPI_OPERAND_OBJECT     *StringDesc;
579     ACPI_OPERAND_OBJECT     *ReturnDesc;
580     ACPI_INTERFACE_INFO     *InterfaceInfo;
581     ACPI_INTERFACE_HANDLER  InterfaceHandler;
582     ACPI_STATUS             Status;
583     UINT64                  ReturnValue;
584 
585 
586     ACPI_FUNCTION_TRACE (UtOsiImplementation);
587 
588 
589     /* Validate the string input argument (from the AML caller) */
590 
591     StringDesc = WalkState->Arguments[0].Object;
592     if (!StringDesc ||
593         (StringDesc->Common.Type != ACPI_TYPE_STRING))
594     {
595         return_ACPI_STATUS (AE_TYPE);
596     }
597 
598     /* Create a return object */
599 
600     ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
601     if (!ReturnDesc)
602     {
603         return_ACPI_STATUS (AE_NO_MEMORY);
604     }
605 
606     /* Default return value is 0, NOT SUPPORTED */
607 
608     ReturnValue = 0;
609     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
610     if (ACPI_FAILURE (Status))
611     {
612         AcpiUtRemoveReference (ReturnDesc);
613         return_ACPI_STATUS (Status);
614     }
615 
616     /* Lookup the interface in the global _OSI list */
617 
618     InterfaceInfo = AcpiUtGetInterface (StringDesc->String.Pointer);
619     if (InterfaceInfo &&
620         !(InterfaceInfo->Flags & ACPI_OSI_INVALID))
621     {
622         /*
623          * The interface is supported.
624          * Update the OsiData if necessary. We keep track of the latest
625          * version of Windows that has been requested by the BIOS.
626          */
627         if (InterfaceInfo->Value > AcpiGbl_OsiData)
628         {
629             AcpiGbl_OsiData = InterfaceInfo->Value;
630         }
631 
632         ReturnValue = ACPI_UINT64_MAX;
633     }
634 
635     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
636 
637     /*
638      * Invoke an optional _OSI interface handler. The host OS may wish
639      * to do some interface-specific handling. For example, warn about
640      * certain interfaces or override the true/false support value.
641      */
642     InterfaceHandler = AcpiGbl_InterfaceHandler;
643     if (InterfaceHandler)
644     {
645         if (InterfaceHandler (
646             StringDesc->String.Pointer, (UINT32) ReturnValue))
647         {
648             ReturnValue = ACPI_UINT64_MAX;
649         }
650     }
651 
652     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INFO,
653         "ACPI: BIOS _OSI(\"%s\") is %ssupported\n",
654         StringDesc->String.Pointer, ReturnValue == 0 ? "not " : ""));
655 
656     /* Complete the return object */
657 
658     ReturnDesc->Integer.Value = ReturnValue;
659     WalkState->ReturnDesc = ReturnDesc;
660     return_ACPI_STATUS (AE_OK);
661 }
662