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nsxfname.c revision 1.8
      1 /******************************************************************************
      2  *
      3  * Module Name: nsxfname - Public interfaces to the ACPI subsystem
      4  *                         ACPI Namespace oriented interfaces
      5  *
      6  *****************************************************************************/
      7 
      8 /*
      9  * Copyright (C) 2000 - 2016, Intel Corp.
     10  * All rights reserved.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions, and the following disclaimer,
     17  *    without modification.
     18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
     19  *    substantially similar to the "NO WARRANTY" disclaimer below
     20  *    ("Disclaimer") and any redistribution must be conditioned upon
     21  *    including a substantially similar Disclaimer requirement for further
     22  *    binary redistribution.
     23  * 3. Neither the names of the above-listed copyright holders nor the names
     24  *    of any contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * Alternatively, this software may be distributed under the terms of the
     28  * GNU General Public License ("GPL") version 2 as published by the Free
     29  * Software Foundation.
     30  *
     31  * NO WARRANTY
     32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
     35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     42  * POSSIBILITY OF SUCH DAMAGES.
     43  */
     44 
     45 #define EXPORT_ACPI_INTERFACES
     46 
     47 #include "acpi.h"
     48 #include "accommon.h"
     49 #include "acnamesp.h"
     50 #include "acparser.h"
     51 #include "amlcode.h"
     52 
     53 
     54 #define _COMPONENT          ACPI_NAMESPACE
     55         ACPI_MODULE_NAME    ("nsxfname")
     56 
     57 /* Local prototypes */
     58 
     59 static char *
     60 AcpiNsCopyDeviceId (
     61     ACPI_PNP_DEVICE_ID      *Dest,
     62     ACPI_PNP_DEVICE_ID      *Source,
     63     char                    *StringArea);
     64 
     65 
     66 /******************************************************************************
     67  *
     68  * FUNCTION:    AcpiGetHandle
     69  *
     70  * PARAMETERS:  Parent          - Object to search under (search scope).
     71  *              Pathname        - Pointer to an asciiz string containing the
     72  *                                name
     73  *              RetHandle       - Where the return handle is returned
     74  *
     75  * RETURN:      Status
     76  *
     77  * DESCRIPTION: This routine will search for a caller specified name in the
     78  *              name space. The caller can restrict the search region by
     79  *              specifying a non NULL parent. The parent value is itself a
     80  *              namespace handle.
     81  *
     82  ******************************************************************************/
     83 
     84 ACPI_STATUS
     85 AcpiGetHandle (
     86     ACPI_HANDLE             Parent,
     87     ACPI_CONST_STRING       Pathname,
     88     ACPI_HANDLE             *RetHandle)
     89 {
     90     ACPI_STATUS             Status;
     91     ACPI_NAMESPACE_NODE     *Node = NULL;
     92     ACPI_NAMESPACE_NODE     *PrefixNode = NULL;
     93     ACPI_STRING             UPathname = __UNCONST(Pathname);
     94 
     95 
     96     ACPI_FUNCTION_ENTRY ();
     97 
     98 
     99     /* Parameter Validation */
    100 
    101     if (!RetHandle || !Pathname)
    102     {
    103         return (AE_BAD_PARAMETER);
    104     }
    105 
    106     /* Convert a parent handle to a prefix node */
    107 
    108     if (Parent)
    109     {
    110         PrefixNode = AcpiNsValidateHandle (Parent);
    111         if (!PrefixNode)
    112         {
    113             return (AE_BAD_PARAMETER);
    114         }
    115     }
    116 
    117     /*
    118      * Valid cases are:
    119      * 1) Fully qualified pathname
    120      * 2) Parent + Relative pathname
    121      *
    122      * Error for <null Parent + relative path>
    123      */
    124     if (ACPI_IS_ROOT_PREFIX (Pathname[0]))
    125     {
    126         /* Pathname is fully qualified (starts with '\') */
    127 
    128         /* Special case for root-only, since we can't search for it */
    129 
    130         if (!strcmp (Pathname, ACPI_NS_ROOT_PATH))
    131         {
    132             *RetHandle = ACPI_CAST_PTR (ACPI_HANDLE, AcpiGbl_RootNode);
    133             return (AE_OK);
    134         }
    135     }
    136     else if (!PrefixNode)
    137     {
    138         /* Relative path with null prefix is disallowed */
    139 
    140         return (AE_BAD_PARAMETER);
    141     }
    142 
    143     /* Find the Node and convert to a handle */
    144 
    145     Status = AcpiNsGetNode (PrefixNode, UPathname, ACPI_NS_NO_UPSEARCH, &Node);
    146     if (ACPI_SUCCESS (Status))
    147     {
    148         *RetHandle = ACPI_CAST_PTR (ACPI_HANDLE, Node);
    149     }
    150 
    151     return (Status);
    152 }
    153 
    154 ACPI_EXPORT_SYMBOL (AcpiGetHandle)
    155 
    156 
    157 /******************************************************************************
    158  *
    159  * FUNCTION:    AcpiGetName
    160  *
    161  * PARAMETERS:  Handle          - Handle to be converted to a pathname
    162  *              NameType        - Full pathname or single segment
    163  *              Buffer          - Buffer for returned path
    164  *
    165  * RETURN:      Pointer to a string containing the fully qualified Name.
    166  *
    167  * DESCRIPTION: This routine returns the fully qualified name associated with
    168  *              the Handle parameter. This and the AcpiPathnameToHandle are
    169  *              complementary functions.
    170  *
    171  ******************************************************************************/
    172 
    173 ACPI_STATUS
    174 AcpiGetName (
    175     ACPI_HANDLE             Handle,
    176     UINT32                  NameType,
    177     ACPI_BUFFER             *Buffer)
    178 {
    179     ACPI_STATUS             Status;
    180     ACPI_NAMESPACE_NODE     *Node;
    181     const char              *NodeName;
    182 
    183 
    184     /* Parameter validation */
    185 
    186     if (NameType > ACPI_NAME_TYPE_MAX)
    187     {
    188         return (AE_BAD_PARAMETER);
    189     }
    190 
    191     Status = AcpiUtValidateBuffer (Buffer);
    192     if (ACPI_FAILURE (Status))
    193     {
    194         return (Status);
    195     }
    196 
    197     if (NameType == ACPI_FULL_PATHNAME ||
    198         NameType == ACPI_FULL_PATHNAME_NO_TRAILING)
    199     {
    200         /* Get the full pathname (From the namespace root) */
    201 
    202         Status = AcpiNsHandleToPathname (Handle, Buffer,
    203             NameType == ACPI_FULL_PATHNAME ? FALSE : TRUE);
    204         return (Status);
    205     }
    206 
    207     /*
    208      * Wants the single segment ACPI name.
    209      * Validate handle and convert to a namespace Node
    210      */
    211     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
    212     if (ACPI_FAILURE (Status))
    213     {
    214         return (Status);
    215     }
    216 
    217     Node = AcpiNsValidateHandle (Handle);
    218     if (!Node)
    219     {
    220         Status = AE_BAD_PARAMETER;
    221         goto UnlockAndExit;
    222     }
    223 
    224     /* Validate/Allocate/Clear caller buffer */
    225 
    226     Status = AcpiUtInitializeBuffer (Buffer, ACPI_PATH_SEGMENT_LENGTH);
    227     if (ACPI_FAILURE (Status))
    228     {
    229         goto UnlockAndExit;
    230     }
    231 
    232     /* Just copy the ACPI name from the Node and zero terminate it */
    233 
    234     NodeName = __UNCONST(AcpiUtGetNodeName (Node));
    235     ACPI_MOVE_NAME (Buffer->Pointer, NodeName);
    236     ((char *) Buffer->Pointer) [ACPI_NAME_SIZE] = 0;
    237     Status = AE_OK;
    238 
    239 
    240 UnlockAndExit:
    241 
    242     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
    243     return (Status);
    244 }
    245 
    246 ACPI_EXPORT_SYMBOL (AcpiGetName)
    247 
    248 
    249 /******************************************************************************
    250  *
    251  * FUNCTION:    AcpiNsCopyDeviceId
    252  *
    253  * PARAMETERS:  Dest                - Pointer to the destination PNP_DEVICE_ID
    254  *              Source              - Pointer to the source PNP_DEVICE_ID
    255  *              StringArea          - Pointer to where to copy the dest string
    256  *
    257  * RETURN:      Pointer to the next string area
    258  *
    259  * DESCRIPTION: Copy a single PNP_DEVICE_ID, including the string data.
    260  *
    261  ******************************************************************************/
    262 
    263 static char *
    264 AcpiNsCopyDeviceId (
    265     ACPI_PNP_DEVICE_ID      *Dest,
    266     ACPI_PNP_DEVICE_ID      *Source,
    267     char                    *StringArea)
    268 {
    269     /* Create the destination PNP_DEVICE_ID */
    270 
    271     Dest->String = StringArea;
    272     Dest->Length = Source->Length;
    273 
    274     /* Copy actual string and return a pointer to the next string area */
    275 
    276     memcpy (StringArea, Source->String, Source->Length);
    277     return (StringArea + Source->Length);
    278 }
    279 
    280 
    281 /******************************************************************************
    282  *
    283  * FUNCTION:    AcpiGetObjectInfo
    284  *
    285  * PARAMETERS:  Handle              - Object Handle
    286  *              ReturnBuffer        - Where the info is returned
    287  *
    288  * RETURN:      Status
    289  *
    290  * DESCRIPTION: Returns information about an object as gleaned from the
    291  *              namespace node and possibly by running several standard
    292  *              control methods (Such as in the case of a device.)
    293  *
    294  * For Device and Processor objects, run the Device _HID, _UID, _CID, _STA,
    295  * _CLS, _ADR, _SxW, and _SxD methods.
    296  *
    297  * Note: Allocates the return buffer, must be freed by the caller.
    298  *
    299  * Note: This interface is intended to be used during the initial device
    300  * discovery namespace traversal. Therefore, no complex methods can be
    301  * executed, especially those that access operation regions. Therefore, do
    302  * not add any additional methods that could cause problems in this area.
    303  * this was the fate of the _SUB method which was found to cause such
    304  * problems and was removed (11/2015).
    305  *
    306  ******************************************************************************/
    307 
    308 ACPI_STATUS
    309 AcpiGetObjectInfo (
    310     ACPI_HANDLE             Handle,
    311     ACPI_DEVICE_INFO        **ReturnBuffer)
    312 {
    313     ACPI_NAMESPACE_NODE     *Node;
    314     ACPI_DEVICE_INFO        *Info;
    315     ACPI_PNP_DEVICE_ID_LIST *CidList = NULL;
    316     ACPI_PNP_DEVICE_ID      *Hid = NULL;
    317     ACPI_PNP_DEVICE_ID      *Uid = NULL;
    318     ACPI_PNP_DEVICE_ID      *Cls = NULL;
    319     char                    *NextIdString;
    320     ACPI_OBJECT_TYPE        Type;
    321     ACPI_NAME               Name;
    322     UINT8                   ParamCount= 0;
    323     UINT16                  Valid = 0;
    324     UINT32                  InfoSize;
    325     UINT32                  i;
    326     ACPI_STATUS             Status;
    327 
    328 
    329     /* Parameter validation */
    330 
    331     if (!Handle || !ReturnBuffer)
    332     {
    333         return (AE_BAD_PARAMETER);
    334     }
    335 
    336     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
    337     if (ACPI_FAILURE (Status))
    338     {
    339         return (Status);
    340     }
    341 
    342     Node = AcpiNsValidateHandle (Handle);
    343     if (!Node)
    344     {
    345         (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
    346         return (AE_BAD_PARAMETER);
    347     }
    348 
    349     /* Get the namespace node data while the namespace is locked */
    350 
    351     InfoSize = sizeof (ACPI_DEVICE_INFO);
    352     Type = Node->Type;
    353     Name = Node->Name.Integer;
    354 
    355     if (Node->Type == ACPI_TYPE_METHOD)
    356     {
    357         ParamCount = Node->Object->Method.ParamCount;
    358     }
    359 
    360     Status = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
    361     if (ACPI_FAILURE (Status))
    362     {
    363         return (Status);
    364     }
    365 
    366     if ((Type == ACPI_TYPE_DEVICE) ||
    367         (Type == ACPI_TYPE_PROCESSOR))
    368     {
    369         /*
    370          * Get extra info for ACPI Device/Processor objects only:
    371          * Run the Device _HID, _UID, _CLS, and _CID methods.
    372          *
    373          * Note: none of these methods are required, so they may or may
    374          * not be present for this device. The Info->Valid bitfield is used
    375          * to indicate which methods were found and run successfully.
    376          */
    377 
    378         /* Execute the Device._HID method */
    379 
    380         Status = AcpiUtExecute_HID (Node, &Hid);
    381         if (ACPI_SUCCESS (Status))
    382         {
    383             InfoSize += Hid->Length;
    384             Valid |= ACPI_VALID_HID;
    385         }
    386 
    387         /* Execute the Device._UID method */
    388 
    389         Status = AcpiUtExecute_UID (Node, &Uid);
    390         if (ACPI_SUCCESS (Status))
    391         {
    392             InfoSize += Uid->Length;
    393             Valid |= ACPI_VALID_UID;
    394         }
    395 
    396         /* Execute the Device._CID method */
    397 
    398         Status = AcpiUtExecute_CID (Node, &CidList);
    399         if (ACPI_SUCCESS (Status))
    400         {
    401             /* Add size of CID strings and CID pointer array */
    402 
    403             InfoSize += (CidList->ListSize - sizeof (ACPI_PNP_DEVICE_ID_LIST));
    404             Valid |= ACPI_VALID_CID;
    405         }
    406 
    407         /* Execute the Device._CLS method */
    408 
    409         Status = AcpiUtExecute_CLS (Node, &Cls);
    410         if (ACPI_SUCCESS (Status))
    411         {
    412             InfoSize += Cls->Length;
    413             Valid |= ACPI_VALID_CLS;
    414         }
    415     }
    416 
    417     /*
    418      * Now that we have the variable-length data, we can allocate the
    419      * return buffer
    420      */
    421     Info = ACPI_ALLOCATE_ZEROED (InfoSize);
    422     if (!Info)
    423     {
    424         Status = AE_NO_MEMORY;
    425         goto Cleanup;
    426     }
    427 
    428     /* Get the fixed-length data */
    429 
    430     if ((Type == ACPI_TYPE_DEVICE) ||
    431         (Type == ACPI_TYPE_PROCESSOR))
    432     {
    433         /*
    434          * Get extra info for ACPI Device/Processor objects only:
    435          * Run the _STA, _ADR and, SxW, and _SxD methods.
    436          *
    437          * Notes: none of these methods are required, so they may or may
    438          * not be present for this device. The Info->Valid bitfield is used
    439          * to indicate which methods were found and run successfully.
    440          *
    441          * For _STA, if the method does not exist, then (as per the ACPI
    442          * specification), the returned CurrentStatus flags will indicate
    443          * that the device is present/functional/enabled. Otherwise, the
    444          * CurrentStatus flags reflect the value returned from _STA.
    445          */
    446 
    447         /* Execute the Device._STA method */
    448 
    449         Status = AcpiUtExecute_STA (Node, &Info->CurrentStatus);
    450         if (ACPI_SUCCESS (Status))
    451         {
    452             Valid |= ACPI_VALID_STA;
    453         }
    454 
    455         /* Execute the Device._ADR method */
    456 
    457         Status = AcpiUtEvaluateNumericObject (METHOD_NAME__ADR, Node,
    458             &Info->Address);
    459         if (ACPI_SUCCESS (Status))
    460         {
    461             Valid |= ACPI_VALID_ADR;
    462         }
    463 
    464         /* Execute the Device._SxW methods */
    465 
    466         Status = AcpiUtExecutePowerMethods (Node,
    467             AcpiGbl_LowestDstateNames, ACPI_NUM_SxW_METHODS,
    468             Info->LowestDstates);
    469         if (ACPI_SUCCESS (Status))
    470         {
    471             Valid |= ACPI_VALID_SXWS;
    472         }
    473 
    474         /* Execute the Device._SxD methods */
    475 
    476         Status = AcpiUtExecutePowerMethods (Node,
    477             AcpiGbl_HighestDstateNames, ACPI_NUM_SxD_METHODS,
    478             Info->HighestDstates);
    479         if (ACPI_SUCCESS (Status))
    480         {
    481             Valid |= ACPI_VALID_SXDS;
    482         }
    483     }
    484 
    485     /*
    486      * Create a pointer to the string area of the return buffer.
    487      * Point to the end of the base ACPI_DEVICE_INFO structure.
    488      */
    489     NextIdString = ACPI_CAST_PTR (char, Info->CompatibleIdList.Ids);
    490     if (CidList)
    491     {
    492         /* Point past the CID PNP_DEVICE_ID array */
    493 
    494         NextIdString += ((ACPI_SIZE) CidList->Count * sizeof (ACPI_PNP_DEVICE_ID));
    495     }
    496 
    497     /*
    498      * Copy the HID, UID, and CIDs to the return buffer. The variable-length
    499      * strings are copied to the reserved area at the end of the buffer.
    500      *
    501      * For HID and CID, check if the ID is a PCI Root Bridge.
    502      */
    503     if (Hid)
    504     {
    505         NextIdString = AcpiNsCopyDeviceId (&Info->HardwareId,
    506             Hid, NextIdString);
    507 
    508         if (AcpiUtIsPciRootBridge (Hid->String))
    509         {
    510             Info->Flags |= ACPI_PCI_ROOT_BRIDGE;
    511         }
    512     }
    513 
    514     if (Uid)
    515     {
    516         NextIdString = AcpiNsCopyDeviceId (&Info->UniqueId,
    517             Uid, NextIdString);
    518     }
    519 
    520     if (CidList)
    521     {
    522         Info->CompatibleIdList.Count = CidList->Count;
    523         Info->CompatibleIdList.ListSize = CidList->ListSize;
    524 
    525         /* Copy each CID */
    526 
    527         for (i = 0; i < CidList->Count; i++)
    528         {
    529             NextIdString = AcpiNsCopyDeviceId (&Info->CompatibleIdList.Ids[i],
    530                 &CidList->Ids[i], NextIdString);
    531 
    532             if (AcpiUtIsPciRootBridge (CidList->Ids[i].String))
    533             {
    534                 Info->Flags |= ACPI_PCI_ROOT_BRIDGE;
    535             }
    536         }
    537     }
    538 
    539     if (Cls)
    540     {
    541         NextIdString = AcpiNsCopyDeviceId (&Info->ClassCode,
    542             Cls, NextIdString);
    543     }
    544 
    545     /* Copy the fixed-length data */
    546 
    547     Info->InfoSize = InfoSize;
    548     Info->Type = Type;
    549     Info->Name = Name;
    550     Info->ParamCount = ParamCount;
    551     Info->Valid = Valid;
    552 
    553     *ReturnBuffer = Info;
    554     Status = AE_OK;
    555 
    556 
    557 Cleanup:
    558     if (Hid)
    559     {
    560         ACPI_FREE (Hid);
    561     }
    562     if (Uid)
    563     {
    564         ACPI_FREE (Uid);
    565     }
    566     if (CidList)
    567     {
    568         ACPI_FREE (CidList);
    569     }
    570     if (Cls)
    571     {
    572         ACPI_FREE (Cls);
    573     }
    574     return (Status);
    575 }
    576 
    577 ACPI_EXPORT_SYMBOL (AcpiGetObjectInfo)
    578 
    579 
    580 /******************************************************************************
    581  *
    582  * FUNCTION:    AcpiInstallMethod
    583  *
    584  * PARAMETERS:  Buffer         - An ACPI table containing one control method
    585  *
    586  * RETURN:      Status
    587  *
    588  * DESCRIPTION: Install a control method into the namespace. If the method
    589  *              name already exists in the namespace, it is overwritten. The
    590  *              input buffer must contain a valid DSDT or SSDT containing a
    591  *              single control method.
    592  *
    593  ******************************************************************************/
    594 
    595 ACPI_STATUS
    596 AcpiInstallMethod (
    597     UINT8                   *Buffer)
    598 {
    599     ACPI_TABLE_HEADER       *Table = ACPI_CAST_PTR (ACPI_TABLE_HEADER, Buffer);
    600     UINT8                   *AmlBuffer;
    601     UINT8                   *AmlStart;
    602     char                    *Path;
    603     ACPI_NAMESPACE_NODE     *Node;
    604     ACPI_OPERAND_OBJECT     *MethodObj;
    605     ACPI_PARSE_STATE        ParserState;
    606     UINT32                  AmlLength;
    607     UINT16                  Opcode;
    608     UINT8                   MethodFlags;
    609     ACPI_STATUS             Status;
    610 
    611 
    612     /* Parameter validation */
    613 
    614     if (!Buffer)
    615     {
    616         return (AE_BAD_PARAMETER);
    617     }
    618 
    619     /* Table must be a DSDT or SSDT */
    620 
    621     if (!ACPI_COMPARE_NAME (Table->Signature, ACPI_SIG_DSDT) &&
    622         !ACPI_COMPARE_NAME (Table->Signature, ACPI_SIG_SSDT))
    623     {
    624         return (AE_BAD_HEADER);
    625     }
    626 
    627     /* First AML opcode in the table must be a control method */
    628 
    629     ParserState.Aml = Buffer + sizeof (ACPI_TABLE_HEADER);
    630     Opcode = AcpiPsPeekOpcode (&ParserState);
    631     if (Opcode != AML_METHOD_OP)
    632     {
    633         return (AE_BAD_PARAMETER);
    634     }
    635 
    636     /* Extract method information from the raw AML */
    637 
    638     ParserState.Aml += AcpiPsGetOpcodeSize (Opcode);
    639     ParserState.PkgEnd = AcpiPsGetNextPackageEnd (&ParserState);
    640     Path = AcpiPsGetNextNamestring (&ParserState);
    641 
    642     MethodFlags = *ParserState.Aml++;
    643     AmlStart = ParserState.Aml;
    644     AmlLength = ACPI_PTR_DIFF (ParserState.PkgEnd, AmlStart);
    645 
    646     /*
    647      * Allocate resources up-front. We don't want to have to delete a new
    648      * node from the namespace if we cannot allocate memory.
    649      */
    650     AmlBuffer = ACPI_ALLOCATE (AmlLength);
    651     if (!AmlBuffer)
    652     {
    653         return (AE_NO_MEMORY);
    654     }
    655 
    656     MethodObj = AcpiUtCreateInternalObject (ACPI_TYPE_METHOD);
    657     if (!MethodObj)
    658     {
    659         ACPI_FREE (AmlBuffer);
    660         return (AE_NO_MEMORY);
    661     }
    662 
    663     /* Lock namespace for AcpiNsLookup, we may be creating a new node */
    664 
    665     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
    666     if (ACPI_FAILURE (Status))
    667     {
    668         goto ErrorExit;
    669     }
    670 
    671     /* The lookup either returns an existing node or creates a new one */
    672 
    673     Status = AcpiNsLookup (NULL, Path, ACPI_TYPE_METHOD, ACPI_IMODE_LOAD_PASS1,
    674         ACPI_NS_DONT_OPEN_SCOPE | ACPI_NS_ERROR_IF_FOUND, NULL, &Node);
    675 
    676     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
    677 
    678     if (ACPI_FAILURE (Status)) /* NsLookup */
    679     {
    680         if (Status != AE_ALREADY_EXISTS)
    681         {
    682             goto ErrorExit;
    683         }
    684 
    685         /* Node existed previously, make sure it is a method node */
    686 
    687         if (Node->Type != ACPI_TYPE_METHOD)
    688         {
    689             Status = AE_TYPE;
    690             goto ErrorExit;
    691         }
    692     }
    693 
    694     /* Copy the method AML to the local buffer */
    695 
    696     memcpy (AmlBuffer, AmlStart, AmlLength);
    697 
    698     /* Initialize the method object with the new method's information */
    699 
    700     MethodObj->Method.AmlStart = AmlBuffer;
    701     MethodObj->Method.AmlLength = AmlLength;
    702 
    703     MethodObj->Method.ParamCount = (UINT8)
    704         (MethodFlags & AML_METHOD_ARG_COUNT);
    705 
    706     if (MethodFlags & AML_METHOD_SERIALIZED)
    707     {
    708         MethodObj->Method.InfoFlags = ACPI_METHOD_SERIALIZED;
    709 
    710         MethodObj->Method.SyncLevel = (UINT8)
    711             ((MethodFlags & AML_METHOD_SYNC_LEVEL) >> 4);
    712     }
    713 
    714     /*
    715      * Now that it is complete, we can attach the new method object to
    716      * the method Node (detaches/deletes any existing object)
    717      */
    718     Status = AcpiNsAttachObject (Node, MethodObj, ACPI_TYPE_METHOD);
    719 
    720     /*
    721      * Flag indicates AML buffer is dynamic, must be deleted later.
    722      * Must be set only after attach above.
    723      */
    724     Node->Flags |= ANOBJ_ALLOCATED_BUFFER;
    725 
    726     /* Remove local reference to the method object */
    727 
    728     AcpiUtRemoveReference (MethodObj);
    729     return (Status);
    730 
    731 
    732 ErrorExit:
    733 
    734     ACPI_FREE (AmlBuffer);
    735     ACPI_FREE (MethodObj);
    736     return (Status);
    737 }
    738 
    739 ACPI_EXPORT_SYMBOL (AcpiInstallMethod)
    740