reactos/drivers/bus/acpi/acpica/namespace/nsaccess.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2016, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include "acpi.h"
  45 #include "accommon.h"
  46 #include "amlcode.h"
  47 #include "acnamesp.h"
  48 #include "acdispat.h"
  49
  50
  51 #define _COMPONENT          ACPI_NAMESPACE
  52         ACPI_MODULE_NAME    ("nsaccess")
  53
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    AcpiNsRootInitialize
  58  *
  59  * PARAMETERS:  None
  60  *
  61  * RETURN:      Status
  62  *
  63  * DESCRIPTION: Allocate and initialize the default root named objects
  64  *
  65  * MUTEX:       Locks namespace for entire execution
  66  *
  67  ******************************************************************************/
  68
  69 ACPI_STATUS
  70 AcpiNsRootInitialize (
  71     void)
  72 {
  73     ACPI_STATUS                 Status;
  74     const ACPI_PREDEFINED_NAMES *InitVal = NULL;
  75     ACPI_NAMESPACE_NODE         *NewNode;
  76     ACPI_OPERAND_OBJECT         *ObjDesc;
  77     ACPI_STRING                 Val = NULL;
  78
  79
  80     ACPI_FUNCTION_TRACE (NsRootInitialize);
  81
  82
  83     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
  84     if (ACPI_FAILURE (Status))
  85     {
  86         return_ACPI_STATUS (Status);
  87     }
  88
  89     /*
  90      * The global root ptr is initially NULL, so a non-NULL value indicates
  91      * that AcpiNsRootInitialize() has already been called; just return.
  92      */
  93     if (AcpiGbl_RootNode)
  94     {
  95         Status = AE_OK;
  96         goto UnlockAndExit;
  97     }
  98
  99     /*
 100      * Tell the rest of the subsystem that the root is initialized
 101      * (This is OK because the namespace is locked)
 102      */
 103     AcpiGbl_RootNode = &AcpiGbl_RootNodeStruct;
 104
 105     /* Enter the pre-defined names in the name table */
 106
 107     ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 108         "Entering predefined entries into namespace\n"));
 109
 110     for (InitVal = AcpiGbl_PreDefinedNames; InitVal->Name; InitVal++)
 111     {
 112         /* _OSI is optional for now, will be permanent later */
 113
 114         if (!strcmp (InitVal->Name, "_OSI") && !AcpiGbl_CreateOsiMethod)
 115         {
 116             continue;
 117         }
 118
 119         Status = AcpiNsLookup (NULL, ACPI_CAST_PTR (char, InitVal->Name),
 120             InitVal->Type, ACPI_IMODE_LOAD_PASS2, ACPI_NS_NO_UPSEARCH,
 121             NULL, &NewNode);
 122         if (ACPI_FAILURE (Status))
 123         {
 124             ACPI_EXCEPTION ((AE_INFO, Status,
 125                 "Could not create predefined name %s",
 126                 InitVal->Name));
 127             continue;
 128         }
 129
 130         /*
 131          * Name entered successfully. If entry in PreDefinedNames[] specifies
 132          * an initial value, create the initial value.
 133          */
 134         if (InitVal->Val)
 135         {
 136             Status = AcpiOsPredefinedOverride (InitVal, &Val);
 137             if (ACPI_FAILURE (Status))
 138             {
 139                 ACPI_ERROR ((AE_INFO,
 140                     "Could not override predefined %s",
 141                     InitVal->Name));
 142             }
 143
 144             if (!Val)
 145             {
 146                 Val = InitVal->Val;
 147             }
 148
 149             /*
 150              * Entry requests an initial value, allocate a
 151              * descriptor for it.
 152              */
 153             ObjDesc = AcpiUtCreateInternalObject (InitVal->Type);
 154             if (!ObjDesc)
 155             {
 156                 Status = AE_NO_MEMORY;
 157                 goto UnlockAndExit;
 158             }
 159
 160             /*
 161              * Convert value string from table entry to
 162              * internal representation. Only types actually
 163              * used for initial values are implemented here.
 164              */
 165             switch (InitVal->Type)
 166             {
 167             case ACPI_TYPE_METHOD:
 168
 169                 ObjDesc->Method.ParamCount = (UINT8) ACPI_TO_INTEGER (Val);
 170                 ObjDesc->Common.Flags |= AOPOBJ_DATA_VALID;
 171
 172 #if defined (ACPI_ASL_COMPILER)
 173
 174                 /* Save the parameter count for the iASL compiler */
 175
 176                 NewNode->Value = ObjDesc->Method.ParamCount;
 177 #else
 178                 /* Mark this as a very SPECIAL method */
 179
 180                 ObjDesc->Method.InfoFlags = ACPI_METHOD_INTERNAL_ONLY;
 181                 ObjDesc->Method.Dispatch.Implementation = AcpiUtOsiImplementation;
 182 #endif
 183                 break;
 184
 185             case ACPI_TYPE_INTEGER:
 186
 187                 ObjDesc->Integer.Value = ACPI_TO_INTEGER (Val);
 188                 break;
 189
 190             case ACPI_TYPE_STRING:
 191
 192                 /* Build an object around the static string */
 193
 194                 ObjDesc->String.Length = (UINT32) strlen (Val);
 195                 ObjDesc->String.Pointer = Val;
 196                 ObjDesc->Common.Flags |= AOPOBJ_STATIC_POINTER;
 197                 break;
 198
 199             case ACPI_TYPE_MUTEX:
 200
 201                 ObjDesc->Mutex.Node = NewNode;
 202                 ObjDesc->Mutex.SyncLevel = (UINT8) (ACPI_TO_INTEGER (Val) - 1);
 203
 204                 /* Create a mutex */
 205
 206                 Status = AcpiOsCreateMutex (&ObjDesc->Mutex.OsMutex);
 207                 if (ACPI_FAILURE (Status))
 208                 {
 209                     AcpiUtRemoveReference (ObjDesc);
 210                     goto UnlockAndExit;
 211                 }
 212
 213                 /* Special case for ACPI Global Lock */
 214
 215                 if (strcmp (InitVal->Name, "_GL_") == 0)
 216                 {
 217                     AcpiGbl_GlobalLockMutex = ObjDesc;
 218
 219                     /* Create additional counting semaphore for global lock */
 220
 221                     Status = AcpiOsCreateSemaphore (
 222                         1, 0, &AcpiGbl_GlobalLockSemaphore);
 223                     if (ACPI_FAILURE (Status))
 224                     {
 225                         AcpiUtRemoveReference (ObjDesc);
 226                         goto UnlockAndExit;
 227                     }
 228                 }
 229                 break;
 230
 231             default:
 232
 233                 ACPI_ERROR ((AE_INFO, "Unsupported initial type value 0x%X",
 234                     InitVal->Type));
 235                 AcpiUtRemoveReference (ObjDesc);
 236                 ObjDesc = NULL;
 237                 continue;
 238             }
 239
 240             /* Store pointer to value descriptor in the Node */
 241
 242             Status = AcpiNsAttachObject (NewNode, ObjDesc,
 243                 ObjDesc->Common.Type);
 244
 245             /* Remove local reference to the object */
 246
 247             AcpiUtRemoveReference (ObjDesc);
 248         }
 249     }
 250
 251
 252 UnlockAndExit:
 253     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
 254
 255     /* Save a handle to "_GPE", it is always present */
 256
 257     if (ACPI_SUCCESS (Status))
 258     {
 259         Status = AcpiNsGetNode (NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
 260             &AcpiGbl_FadtGpeDevice);
 261     }
 262
 263     return_ACPI_STATUS (Status);
 264 }
 265
 266
 267 /*******************************************************************************
 268  *
 269  * FUNCTION:    AcpiNsLookup
 270  *
 271  * PARAMETERS:  ScopeInfo       - Current scope info block
 272  *              Pathname        - Search pathname, in internal format
 273  *                                (as represented in the AML stream)
 274  *              Type            - Type associated with name
 275  *              InterpreterMode - IMODE_LOAD_PASS2 => add name if not found
 276  *              Flags           - Flags describing the search restrictions
 277  *              WalkState       - Current state of the walk
 278  *              ReturnNode      - Where the Node is placed (if found
 279  *                                or created successfully)
 280  *
 281  * RETURN:      Status
 282  *
 283  * DESCRIPTION: Find or enter the passed name in the name space.
 284  *              Log an error if name not found in Exec mode.
 285  *
 286  * MUTEX:       Assumes namespace is locked.
 287  *
 288  ******************************************************************************/
 289
 290 ACPI_STATUS
 291 AcpiNsLookup (
 292     ACPI_GENERIC_STATE      *ScopeInfo,
 293     char                    *Pathname,
 294     ACPI_OBJECT_TYPE        Type,
 295     ACPI_INTERPRETER_MODE   InterpreterMode,
 296     UINT32                  Flags,
 297     ACPI_WALK_STATE         *WalkState,
 298     ACPI_NAMESPACE_NODE     **ReturnNode)
 299 {
 300     ACPI_STATUS             Status;
 301     char                    *Path = Pathname;
 302     ACPI_NAMESPACE_NODE     *PrefixNode;
 303     ACPI_NAMESPACE_NODE     *CurrentNode = NULL;
 304     ACPI_NAMESPACE_NODE     *ThisNode = NULL;
 305     UINT32                  NumSegments;
 306     UINT32                  NumCarats;
 307     ACPI_NAME               SimpleName;
 308     ACPI_OBJECT_TYPE        TypeToCheckFor;
 309     ACPI_OBJECT_TYPE        ThisSearchType;
 310     UINT32                  SearchParentFlag = ACPI_NS_SEARCH_PARENT;
 311     UINT32                  LocalFlags;
 312
 313
 314     ACPI_FUNCTION_TRACE (NsLookup);
 315
 316
 317     if (!ReturnNode)
 318     {
 319         return_ACPI_STATUS (AE_BAD_PARAMETER);
 320     }
 321
 322     LocalFlags = Flags &
 323         ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
 324           ACPI_NS_SEARCH_PARENT);
 325     *ReturnNode = ACPI_ENTRY_NOT_FOUND;
 326     AcpiGbl_NsLookupCount++;
 327
 328     if (!AcpiGbl_RootNode)
 329     {
 330         return_ACPI_STATUS (AE_NO_NAMESPACE);
 331     }
 332
 333     /* Get the prefix scope. A null scope means use the root scope */
 334
 335     if ((!ScopeInfo) ||
 336         (!ScopeInfo->Scope.Node))
 337     {
 338         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 339             "Null scope prefix, using root node (%p)\n",
 340             AcpiGbl_RootNode));
 341
 342         PrefixNode = AcpiGbl_RootNode;
 343     }
 344     else
 345     {
 346         PrefixNode = ScopeInfo->Scope.Node;
 347         if (ACPI_GET_DESCRIPTOR_TYPE (PrefixNode) != ACPI_DESC_TYPE_NAMED)
 348         {
 349             ACPI_ERROR ((AE_INFO, "%p is not a namespace node [%s]",
 350                 PrefixNode, AcpiUtGetDescriptorName (PrefixNode)));
 351             return_ACPI_STATUS (AE_AML_INTERNAL);
 352         }
 353
 354         if (!(Flags & ACPI_NS_PREFIX_IS_SCOPE))
 355         {
 356             /*
 357              * This node might not be a actual "scope" node (such as a
 358              * Device/Method, etc.)  It could be a Package or other object
 359              * node. Backup up the tree to find the containing scope node.
 360              */
 361             while (!AcpiNsOpensScope (PrefixNode->Type) &&
 362                     PrefixNode->Type != ACPI_TYPE_ANY)
 363             {
 364                 PrefixNode = PrefixNode->Parent;
 365             }
 366         }
 367     }
 368
 369     /* Save type. TBD: may be no longer necessary */
 370
 371     TypeToCheckFor = Type;
 372
 373     /*
 374      * Begin examination of the actual pathname
 375      */
 376     if (!Pathname)
 377     {
 378         /* A Null NamePath is allowed and refers to the root */
 379
 380         NumSegments = 0;
 381         ThisNode = AcpiGbl_RootNode;
 382         Path = "";
 383
 384         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 385             "Null Pathname (Zero segments), Flags=%X\n", Flags));
 386     }
 387     else
 388     {
 389         /*
 390          * Name pointer is valid (and must be in internal name format)
 391          *
 392          * Check for scope prefixes:
 393          *
 394          * As represented in the AML stream, a namepath consists of an
 395          * optional scope prefix followed by a name segment part.
 396          *
 397          * If present, the scope prefix is either a Root Prefix (in
 398          * which case the name is fully qualified), or one or more
 399          * Parent Prefixes (in which case the name's scope is relative
 400          * to the current scope).
 401          */
 402         if (*Path == (UINT8) AML_ROOT_PREFIX)
 403         {
 404             /* Pathname is fully qualified, start from the root */
 405
 406             ThisNode = AcpiGbl_RootNode;
 407             SearchParentFlag = ACPI_NS_NO_UPSEARCH;
 408
 409             /* Point to name segment part */
 410
 411             Path++;
 412
 413             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 414                 "Path is absolute from root [%p]\n", ThisNode));
 415         }
 416         else
 417         {
 418             /* Pathname is relative to current scope, start there */
 419
 420             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 421                 "Searching relative to prefix scope [%4.4s] (%p)\n",
 422                 AcpiUtGetNodeName (PrefixNode), PrefixNode));
 423
 424             /*
 425              * Handle multiple Parent Prefixes (carat) by just getting
 426              * the parent node for each prefix instance.
 427              */
 428             ThisNode = PrefixNode;
 429             NumCarats = 0;
 430             while (*Path == (UINT8) AML_PARENT_PREFIX)
 431             {
 432                 /* Name is fully qualified, no search rules apply */
 433
 434                 SearchParentFlag = ACPI_NS_NO_UPSEARCH;
 435
 436                 /*
 437                  * Point past this prefix to the name segment
 438                  * part or the next Parent Prefix
 439                  */
 440                 Path++;
 441
 442                 /* Backup to the parent node */
 443
 444                 NumCarats++;
 445                 ThisNode = ThisNode->Parent;
 446                 if (!ThisNode)
 447                 {
 448                     /* Current scope has no parent scope */
 449
 450                     ACPI_ERROR ((AE_INFO,
 451                         "%s: Path has too many parent prefixes (^) "
 452                         "- reached beyond root node", Pathname));
 453                     return_ACPI_STATUS (AE_NOT_FOUND);
 454                 }
 455             }
 456
 457             if (SearchParentFlag == ACPI_NS_NO_UPSEARCH)
 458             {
 459                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 460                     "Search scope is [%4.4s], path has %u carat(s)\n",
 461                     AcpiUtGetNodeName (ThisNode), NumCarats));
 462             }
 463         }
 464
 465         /*
 466          * Determine the number of ACPI name segments in this pathname.
 467          *
 468          * The segment part consists of either:
 469          *  - A Null name segment (0)
 470          *  - A DualNamePrefix followed by two 4-byte name segments
 471          *  - A MultiNamePrefix followed by a byte indicating the
 472          *      number of segments and the segments themselves.
 473          *  - A single 4-byte name segment
 474          *
 475          * Examine the name prefix opcode, if any, to determine the number of
 476          * segments.
 477          */
 478         switch (*Path)
 479         {
 480         case 0:
 481             /*
 482              * Null name after a root or parent prefixes. We already
 483              * have the correct target node and there are no name segments.
 484              */
 485             NumSegments  = 0;
 486             Type = ThisNode->Type;
 487
 488             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 489                 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
 490                 Flags));
 491             break;
 492
 493         case AML_DUAL_NAME_PREFIX:
 494
 495             /* More than one NameSeg, search rules do not apply */
 496
 497             SearchParentFlag = ACPI_NS_NO_UPSEARCH;
 498
 499             /* Two segments, point to first name segment */
 500
 501             NumSegments = 2;
 502             Path++;
 503
 504             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 505                 "Dual Pathname (2 segments, Flags=%X)\n", Flags));
 506             break;
 507
 508         case AML_MULTI_NAME_PREFIX_OP:
 509
 510             /* More than one NameSeg, search rules do not apply */
 511
 512             SearchParentFlag = ACPI_NS_NO_UPSEARCH;
 513
 514             /* Extract segment count, point to first name segment */
 515
 516             Path++;
 517             NumSegments = (UINT32) (UINT8) *Path;
 518             Path++;
 519
 520             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 521                 "Multi Pathname (%u Segments, Flags=%X)\n",
 522                 NumSegments, Flags));
 523             break;
 524
 525         default:
 526             /*
 527              * Not a Null name, no Dual or Multi prefix, hence there is
 528              * only one name segment and Pathname is already pointing to it.
 529              */
 530             NumSegments = 1;
 531
 532             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 533                 "Simple Pathname (1 segment, Flags=%X)\n", Flags));
 534             break;
 535         }
 536
 537         ACPI_DEBUG_EXEC (AcpiNsPrintPathname (NumSegments, Path));
 538     }
 539
 540
 541     /*
 542      * Search namespace for each segment of the name. Loop through and
 543      * verify (or add to the namespace) each name segment.
 544      *
 545      * The object type is significant only at the last name
 546      * segment. (We don't care about the types along the path, only
 547      * the type of the final target object.)
 548      */
 549     ThisSearchType = ACPI_TYPE_ANY;
 550     CurrentNode = ThisNode;
 551     while (NumSegments && CurrentNode)
 552     {
 553         NumSegments--;
 554         if (!NumSegments)
 555         {
 556             /* This is the last segment, enable typechecking */
 557
 558             ThisSearchType = Type;
 559
 560             /*
 561              * Only allow automatic parent search (search rules) if the caller
 562              * requested it AND we have a single, non-fully-qualified NameSeg
 563              */
 564             if ((SearchParentFlag != ACPI_NS_NO_UPSEARCH) &&
 565                 (Flags & ACPI_NS_SEARCH_PARENT))
 566             {
 567                 LocalFlags |= ACPI_NS_SEARCH_PARENT;
 568             }
 569
 570             /* Set error flag according to caller */
 571
 572             if (Flags & ACPI_NS_ERROR_IF_FOUND)
 573             {
 574                 LocalFlags |= ACPI_NS_ERROR_IF_FOUND;
 575             }
 576
 577             /* Set override flag according to caller */
 578
 579             if (Flags & ACPI_NS_OVERRIDE_IF_FOUND)
 580             {
 581                 LocalFlags |= ACPI_NS_OVERRIDE_IF_FOUND;
 582             }
 583         }
 584
 585         /* Extract one ACPI name from the front of the pathname */
 586
 587         ACPI_MOVE_32_TO_32 (&SimpleName, Path);
 588
 589         /* Try to find the single (4 character) ACPI name */
 590
 591         Status = AcpiNsSearchAndEnter (SimpleName, WalkState, CurrentNode,
 592             InterpreterMode, ThisSearchType, LocalFlags, &ThisNode);
 593         if (ACPI_FAILURE (Status))
 594         {
 595             if (Status == AE_NOT_FOUND)
 596             {
 597                 /* Name not found in ACPI namespace */
 598
 599                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
 600                     "Name [%4.4s] not found in scope [%4.4s] %p\n",
 601                     (char *) &SimpleName, (char *) &CurrentNode->Name,
 602                     CurrentNode));
 603             }
 604
 605             *ReturnNode = ThisNode;
 606             return_ACPI_STATUS (Status);
 607         }
 608
 609         /* More segments to follow? */
 610
 611         if (NumSegments > 0)
 612         {
 613             /*
 614              * If we have an alias to an object that opens a scope (such as a
 615              * device or processor), we need to dereference the alias here so
 616              * that we can access any children of the original node (via the
 617              * remaining segments).
 618              */
 619             if (ThisNode->Type == ACPI_TYPE_LOCAL_ALIAS)
 620             {
 621                 if (!ThisNode->Object)
 622                 {
 623                     return_ACPI_STATUS (AE_NOT_EXIST);
 624                 }
 625
 626                 if (AcpiNsOpensScope (((ACPI_NAMESPACE_NODE *)
 627                         ThisNode->Object)->Type))
 628                 {
 629                     ThisNode = (ACPI_NAMESPACE_NODE *) ThisNode->Object;
 630                 }
 631             }
 632         }
 633
 634         /* Special handling for the last segment (NumSegments == 0) */
 635
 636         else
 637         {
 638             /*
 639              * Sanity typecheck of the target object:
 640              *
 641              * If 1) This is the last segment (NumSegments == 0)
 642              *    2) And we are looking for a specific type
 643              *       (Not checking for TYPE_ANY)
 644              *    3) Which is not an alias
 645              *    4) Which is not a local type (TYPE_SCOPE)
 646              *    5) And the type of target object is known (not TYPE_ANY)
 647              *    6) And target object does not match what we are looking for
 648              *
 649              * Then we have a type mismatch. Just warn and ignore it.
 650              */
 651             if ((TypeToCheckFor != ACPI_TYPE_ANY)                   &&
 652                 (TypeToCheckFor != ACPI_TYPE_LOCAL_ALIAS)           &&
 653                 (TypeToCheckFor != ACPI_TYPE_LOCAL_METHOD_ALIAS)    &&
 654                 (TypeToCheckFor != ACPI_TYPE_LOCAL_SCOPE)           &&
 655                 (ThisNode->Type != ACPI_TYPE_ANY)                   &&
 656                 (ThisNode->Type != TypeToCheckFor))
 657             {
 658                 /* Complain about a type mismatch */
 659
 660                 ACPI_WARNING ((AE_INFO,
 661                     "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
 662                     ACPI_CAST_PTR (char, &SimpleName),
 663                     AcpiUtGetTypeName (ThisNode->Type),
 664                     AcpiUtGetTypeName (TypeToCheckFor)));
 665             }
 666
 667             /*
 668              * If this is the last name segment and we are not looking for a
 669              * specific type, but the type of found object is known, use that
 670              * type to (later) see if it opens a scope.
 671              */
 672             if (Type == ACPI_TYPE_ANY)
 673             {
 674                 Type = ThisNode->Type;
 675             }
 676         }
 677
 678         /* Point to next name segment and make this node current */
 679
 680         Path += ACPI_NAME_SIZE;
 681         CurrentNode = ThisNode;
 682     }
 683
 684     /* Always check if we need to open a new scope */
 685
 686     if (!(Flags & ACPI_NS_DONT_OPEN_SCOPE) && (WalkState))
 687     {
 688         /*
 689          * If entry is a type which opens a scope, push the new scope on the
 690          * scope stack.
 691          */
 692         if (AcpiNsOpensScope (Type))
 693         {
 694             Status = AcpiDsScopeStackPush (ThisNode, Type, WalkState);
 695             if (ACPI_FAILURE (Status))
 696             {
 697                 return_ACPI_STATUS (Status);
 698             }
 699         }
 700     }
 701
 702     *ReturnNode = ThisNode;
 703     return_ACPI_STATUS (AE_OK);
 704 }