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 */
199static 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
254ACPI_STATUS
255AcpiUtInitializeInterfaces (
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
298ACPI_STATUS
299AcpiUtInterfaceTerminate (
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
359ACPI_STATUS
360AcpiUtInstallInterface (
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
405ACPI_STATUS
406AcpiUtRemoveInterface (
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
480ACPI_STATUS
481AcpiUtUpdateInterfaces (
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
529ACPI_INTERFACE_INFO *
530AcpiUtGetInterface (
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
576ACPI_STATUS
577AcpiUtOsiImplementation (
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