xref: /haiku/src/add-ons/kernel/bus_managers/acpi/acpica/components/utilities/utosi.c (revision 6e82e428596071bbde44e296d04740f1f5d54d03)
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 
220     /* Feature Group Strings */
221 
222     {"Extended Address Space Descriptor", NULL, ACPI_OSI_FEATURE, 0},
223 
224     /*
225      * All "optional" feature group strings (features that are implemented
226      * by the host) should be dynamically modified to VALID by the host via
227      * AcpiInstallInterface or AcpiUpdateInterfaces. Such optional feature
228      * group strings are set as INVALID by default here.
229      */
230 
231     {"Module Device",               NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
232     {"Processor Device",            NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
233     {"3.0 Thermal Model",           NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
234     {"3.0 _SCP Extensions",         NULL, ACPI_OSI_OPTIONAL_FEATURE, 0},
235     {"Processor Aggregator Device", NULL, ACPI_OSI_OPTIONAL_FEATURE, 0}
236 };
237 
238 
239 /*******************************************************************************
240  *
241  * FUNCTION:    AcpiUtInitializeInterfaces
242  *
243  * PARAMETERS:  None
244  *
245  * RETURN:      Status
246  *
247  * DESCRIPTION: Initialize the global _OSI supported interfaces list
248  *
249  ******************************************************************************/
250 
251 ACPI_STATUS
252 AcpiUtInitializeInterfaces (
253     void)
254 {
255     ACPI_STATUS             Status;
256     UINT32                  i;
257 
258 
259     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
260     if (ACPI_FAILURE (Status))
261     {
262         return (Status);
263     }
264 
265     AcpiGbl_SupportedInterfaces = AcpiDefaultSupportedInterfaces;
266 
267     /* Link the static list of supported interfaces */
268 
269     for (i = 0;
270         i < (ACPI_ARRAY_LENGTH (AcpiDefaultSupportedInterfaces) - 1);
271         i++)
272     {
273         AcpiDefaultSupportedInterfaces[i].Next =
274             &AcpiDefaultSupportedInterfaces[(ACPI_SIZE) i + 1];
275     }
276 
277     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
278     return (AE_OK);
279 }
280 
281 
282 /*******************************************************************************
283  *
284  * FUNCTION:    AcpiUtInterfaceTerminate
285  *
286  * PARAMETERS:  None
287  *
288  * RETURN:      Status
289  *
290  * DESCRIPTION: Delete all interfaces in the global list. Sets
291  *              AcpiGbl_SupportedInterfaces to NULL.
292  *
293  ******************************************************************************/
294 
295 ACPI_STATUS
296 AcpiUtInterfaceTerminate (
297     void)
298 {
299     ACPI_STATUS             Status;
300     ACPI_INTERFACE_INFO     *NextInterface;
301 
302 
303     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
304     if (ACPI_FAILURE (Status))
305     {
306         return (Status);
307     }
308 
309     NextInterface = AcpiGbl_SupportedInterfaces;
310     while (NextInterface)
311     {
312         AcpiGbl_SupportedInterfaces = NextInterface->Next;
313 
314         if (NextInterface->Flags & ACPI_OSI_DYNAMIC)
315         {
316             /* Only interfaces added at runtime can be freed */
317 
318             ACPI_FREE (NextInterface->Name);
319             ACPI_FREE (NextInterface);
320         }
321         else
322         {
323             /* Interface is in static list. Reset it to invalid or valid. */
324 
325             if (NextInterface->Flags & ACPI_OSI_DEFAULT_INVALID)
326             {
327                 NextInterface->Flags |= ACPI_OSI_INVALID;
328             }
329             else
330             {
331                 NextInterface->Flags &= ~ACPI_OSI_INVALID;
332             }
333         }
334 
335         NextInterface = AcpiGbl_SupportedInterfaces;
336     }
337 
338     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
339     return (AE_OK);
340 }
341 
342 
343 /*******************************************************************************
344  *
345  * FUNCTION:    AcpiUtInstallInterface
346  *
347  * PARAMETERS:  InterfaceName       - The interface to install
348  *
349  * RETURN:      Status
350  *
351  * DESCRIPTION: Install the interface into the global interface list.
352  *              Caller MUST hold AcpiGbl_OsiMutex
353  *
354  ******************************************************************************/
355 
356 ACPI_STATUS
357 AcpiUtInstallInterface (
358     ACPI_STRING             InterfaceName)
359 {
360     ACPI_INTERFACE_INFO     *InterfaceInfo;
361 
362 
363     /* Allocate info block and space for the name string */
364 
365     InterfaceInfo = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_INTERFACE_INFO));
366     if (!InterfaceInfo)
367     {
368         return (AE_NO_MEMORY);
369     }
370 
371     InterfaceInfo->Name = ACPI_ALLOCATE_ZEROED (strlen (InterfaceName) + 1);
372     if (!InterfaceInfo->Name)
373     {
374         ACPI_FREE (InterfaceInfo);
375         return (AE_NO_MEMORY);
376     }
377 
378     /* Initialize new info and insert at the head of the global list */
379 
380     strcpy (InterfaceInfo->Name, InterfaceName);
381     InterfaceInfo->Flags = ACPI_OSI_DYNAMIC;
382     InterfaceInfo->Next = AcpiGbl_SupportedInterfaces;
383 
384     AcpiGbl_SupportedInterfaces = InterfaceInfo;
385     return (AE_OK);
386 }
387 
388 
389 /*******************************************************************************
390  *
391  * FUNCTION:    AcpiUtRemoveInterface
392  *
393  * PARAMETERS:  InterfaceName       - The interface to remove
394  *
395  * RETURN:      Status
396  *
397  * DESCRIPTION: Remove the interface from the global interface list.
398  *              Caller MUST hold AcpiGbl_OsiMutex
399  *
400  ******************************************************************************/
401 
402 ACPI_STATUS
403 AcpiUtRemoveInterface (
404     ACPI_STRING             InterfaceName)
405 {
406     ACPI_INTERFACE_INFO     *PreviousInterface;
407     ACPI_INTERFACE_INFO     *NextInterface;
408 
409 
410     PreviousInterface = NextInterface = AcpiGbl_SupportedInterfaces;
411     while (NextInterface)
412     {
413         if (!strcmp (InterfaceName, NextInterface->Name))
414         {
415             /*
416              * Found: name is in either the static list
417              * or was added at runtime
418              */
419             if (NextInterface->Flags & ACPI_OSI_DYNAMIC)
420             {
421                 /* Interface was added dynamically, remove and free it */
422 
423                 if (PreviousInterface == NextInterface)
424                 {
425                     AcpiGbl_SupportedInterfaces = NextInterface->Next;
426                 }
427                 else
428                 {
429                     PreviousInterface->Next = NextInterface->Next;
430                 }
431 
432                 ACPI_FREE (NextInterface->Name);
433                 ACPI_FREE (NextInterface);
434             }
435             else
436             {
437                 /*
438                  * Interface is in static list. If marked invalid, then
439                  * it does not actually exist. Else, mark it invalid.
440                  */
441                 if (NextInterface->Flags & ACPI_OSI_INVALID)
442                 {
443                     return (AE_NOT_EXIST);
444                 }
445 
446                 NextInterface->Flags |= ACPI_OSI_INVALID;
447             }
448 
449             return (AE_OK);
450         }
451 
452         PreviousInterface = NextInterface;
453         NextInterface = NextInterface->Next;
454     }
455 
456     /* Interface was not found */
457 
458     return (AE_NOT_EXIST);
459 }
460 
461 
462 /*******************************************************************************
463  *
464  * FUNCTION:    AcpiUtUpdateInterfaces
465  *
466  * PARAMETERS:  Action              - Actions to be performed during the
467  *                                    update
468  *
469  * RETURN:      Status
470  *
471  * DESCRIPTION: Update _OSI interface strings, disabling or enabling OS vendor
472  *              strings or/and feature group strings.
473  *              Caller MUST hold AcpiGbl_OsiMutex
474  *
475  ******************************************************************************/
476 
477 ACPI_STATUS
478 AcpiUtUpdateInterfaces (
479     UINT8                   Action)
480 {
481     ACPI_INTERFACE_INFO     *NextInterface;
482 
483 
484     NextInterface = AcpiGbl_SupportedInterfaces;
485     while (NextInterface)
486     {
487         if (((NextInterface->Flags & ACPI_OSI_FEATURE) &&
488              (Action & ACPI_FEATURE_STRINGS)) ||
489             (!(NextInterface->Flags & ACPI_OSI_FEATURE) &&
490              (Action & ACPI_VENDOR_STRINGS)))
491         {
492             if (Action & ACPI_DISABLE_INTERFACES)
493             {
494                 /* Mark the interfaces as invalid */
495 
496                 NextInterface->Flags |= ACPI_OSI_INVALID;
497             }
498             else
499             {
500                 /* Mark the interfaces as valid */
501 
502                 NextInterface->Flags &= ~ACPI_OSI_INVALID;
503             }
504         }
505 
506         NextInterface = NextInterface->Next;
507     }
508 
509     return (AE_OK);
510 }
511 
512 
513 /*******************************************************************************
514  *
515  * FUNCTION:    AcpiUtGetInterface
516  *
517  * PARAMETERS:  InterfaceName       - The interface to find
518  *
519  * RETURN:      ACPI_INTERFACE_INFO if found. NULL if not found.
520  *
521  * DESCRIPTION: Search for the specified interface name in the global list.
522  *              Caller MUST hold AcpiGbl_OsiMutex
523  *
524  ******************************************************************************/
525 
526 ACPI_INTERFACE_INFO *
527 AcpiUtGetInterface (
528     ACPI_STRING             InterfaceName)
529 {
530     ACPI_INTERFACE_INFO     *NextInterface;
531 
532 
533     NextInterface = AcpiGbl_SupportedInterfaces;
534     while (NextInterface)
535     {
536         if (!strcmp (InterfaceName, NextInterface->Name))
537         {
538             return (NextInterface);
539         }
540 
541         NextInterface = NextInterface->Next;
542     }
543 
544     return (NULL);
545 }
546 
547 
548 /*******************************************************************************
549  *
550  * FUNCTION:    AcpiUtOsiImplementation
551  *
552  * PARAMETERS:  WalkState           - Current walk state
553  *
554  * RETURN:      Status
555  *              Integer: TRUE (0) if input string is matched
556  *                       FALSE (-1) if string is not matched
557  *
558  * DESCRIPTION: Implementation of the _OSI predefined control method. When
559  *              an invocation of _OSI is encountered in the system AML,
560  *              control is transferred to this function.
561  *
562  * (August 2016)
563  * Note:  _OSI is now defined to return "Ones" to indicate a match, for
564  * compatibility with other ACPI implementations. On a 32-bit DSDT, Ones
565  * is 0xFFFFFFFF. On a 64-bit DSDT, Ones is 0xFFFFFFFFFFFFFFFF
566  * (ACPI_UINT64_MAX).
567  *
568  * This function always returns ACPI_UINT64_MAX for TRUE, and later code
569  * will truncate this to 32 bits if necessary.
570  *
571  ******************************************************************************/
572 
573 ACPI_STATUS
574 AcpiUtOsiImplementation (
575     ACPI_WALK_STATE         *WalkState)
576 {
577     ACPI_OPERAND_OBJECT     *StringDesc;
578     ACPI_OPERAND_OBJECT     *ReturnDesc;
579     ACPI_INTERFACE_INFO     *InterfaceInfo;
580     ACPI_INTERFACE_HANDLER  InterfaceHandler;
581     ACPI_STATUS             Status;
582     UINT64                  ReturnValue;
583 
584 
585     ACPI_FUNCTION_TRACE (UtOsiImplementation);
586 
587 
588     /* Validate the string input argument (from the AML caller) */
589 
590     StringDesc = WalkState->Arguments[0].Object;
591     if (!StringDesc ||
592         (StringDesc->Common.Type != ACPI_TYPE_STRING))
593     {
594         return_ACPI_STATUS (AE_TYPE);
595     }
596 
597     /* Create a return object */
598 
599     ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
600     if (!ReturnDesc)
601     {
602         return_ACPI_STATUS (AE_NO_MEMORY);
603     }
604 
605     /* Default return value is 0, NOT SUPPORTED */
606 
607     ReturnValue = 0;
608     Status = AcpiOsAcquireMutex (AcpiGbl_OsiMutex, ACPI_WAIT_FOREVER);
609     if (ACPI_FAILURE (Status))
610     {
611         AcpiUtRemoveReference (ReturnDesc);
612         return_ACPI_STATUS (Status);
613     }
614 
615     /* Lookup the interface in the global _OSI list */
616 
617     InterfaceInfo = AcpiUtGetInterface (StringDesc->String.Pointer);
618     if (InterfaceInfo &&
619         !(InterfaceInfo->Flags & ACPI_OSI_INVALID))
620     {
621         /*
622          * The interface is supported.
623          * Update the OsiData if necessary. We keep track of the latest
624          * version of Windows that has been requested by the BIOS.
625          */
626         if (InterfaceInfo->Value > AcpiGbl_OsiData)
627         {
628             AcpiGbl_OsiData = InterfaceInfo->Value;
629         }
630 
631         ReturnValue = ACPI_UINT64_MAX;
632     }
633 
634     AcpiOsReleaseMutex (AcpiGbl_OsiMutex);
635 
636     /*
637      * Invoke an optional _OSI interface handler. The host OS may wish
638      * to do some interface-specific handling. For example, warn about
639      * certain interfaces or override the true/false support value.
640      */
641     InterfaceHandler = AcpiGbl_InterfaceHandler;
642     if (InterfaceHandler)
643     {
644         if (InterfaceHandler (
645             StringDesc->String.Pointer, (UINT32) ReturnValue))
646         {
647             ReturnValue = ACPI_UINT64_MAX;
648         }
649     }
650 
651     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INFO,
652         "ACPI: BIOS _OSI(\"%s\") is %ssupported\n",
653         StringDesc->String.Pointer, ReturnValue == 0 ? "not " : ""));
654 
655     /* Complete the return object */
656 
657     ReturnDesc->Integer.Value = ReturnValue;
658     WalkState->ReturnDesc = ReturnDesc;
659     return_ACPI_STATUS (AE_OK);
660 }
661