xref: /freebsd/sys/contrib/dev/acpica/compiler/aslxref.c (revision 480093f4440d54b30b3025afeac24b48f2ba7a2e)
1 /******************************************************************************
2  *
3  * Module Name: aslxref - Namespace cross-reference
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2020, 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 <contrib/dev/acpica/compiler/aslcompiler.h>
153 #include "aslcompiler.y.h"
154 #include <contrib/dev/acpica/include/acparser.h>
155 #include <contrib/dev/acpica/include/amlcode.h>
156 #include <contrib/dev/acpica/include/acnamesp.h>
157 #include <contrib/dev/acpica/include/acdispat.h>
158 
159 
160 #define _COMPONENT          ACPI_COMPILER
161         ACPI_MODULE_NAME    ("aslxref")
162 
163 /* Local prototypes */
164 
165 static ACPI_STATUS
166 XfNamespaceLocateBegin (
167     ACPI_PARSE_OBJECT       *Op,
168     UINT32                  Level,
169     void                    *Context);
170 
171 static ACPI_STATUS
172 XfNamespaceLocateEnd (
173     ACPI_PARSE_OBJECT       *Op,
174     UINT32                  Level,
175     void                    *Context);
176 
177 static BOOLEAN
178 XfValidateCrossReference (
179     ACPI_PARSE_OBJECT       *Op,
180     const ACPI_OPCODE_INFO  *OpInfo,
181     ACPI_NAMESPACE_NODE     *Node);
182 
183 static ACPI_PARSE_OBJECT *
184 XfGetParentMethod (
185     ACPI_PARSE_OBJECT       *Op);
186 
187 static BOOLEAN
188 XfObjectExists (
189     char                    *Name);
190 
191 static ACPI_STATUS
192 XfCompareOneNamespaceObject (
193     ACPI_HANDLE             ObjHandle,
194     UINT32                  Level,
195     void                    *Context,
196     void                    **ReturnValue);
197 
198 static void
199 XfCheckFieldRange (
200     ACPI_PARSE_OBJECT       *Op,
201     UINT32                  RegionBitLength,
202     UINT32                  FieldBitOffset,
203     UINT32                  FieldBitLength,
204     UINT32                  AccessBitWidth);
205 
206 
207 /*******************************************************************************
208  *
209  * FUNCTION:    XfCrossReferenceNamespace
210  *
211  * PARAMETERS:  None
212  *
213  * RETURN:      Status
214  *
215  * DESCRIPTION: Perform a cross reference check of the parse tree against the
216  *              namespace. Every named referenced within the parse tree
217  *              should be get resolved with a namespace lookup. If not, the
218  *              original reference in the ASL code is invalid -- i.e., refers
219  *              to a non-existent object.
220  *
221  * NOTE:  The ASL "External" operator causes the name to be inserted into the
222  *        namespace so that references to the external name will be resolved
223  *        correctly here.
224  *
225  ******************************************************************************/
226 
227 ACPI_STATUS
228 XfCrossReferenceNamespace (
229     void)
230 {
231     ACPI_WALK_STATE         *WalkState;
232 
233 
234     /*
235      * Create a new walk state for use when looking up names
236      * within the namespace (Passed as context to the callbacks)
237      */
238     WalkState = AcpiDsCreateWalkState (0, NULL, NULL, NULL);
239     if (!WalkState)
240     {
241         return (AE_NO_MEMORY);
242     }
243 
244     /* Walk the entire parse tree */
245 
246     TrWalkParseTree (AslGbl_ParseTreeRoot, ASL_WALK_VISIT_TWICE,
247         XfNamespaceLocateBegin, XfNamespaceLocateEnd, WalkState);
248 
249     ACPI_FREE (WalkState);
250     return (AE_OK);
251 }
252 
253 
254 /*******************************************************************************
255  *
256  * FUNCTION:    XfObjectExists
257  *
258  * PARAMETERS:  Name            - 4 char ACPI name
259  *
260  * RETURN:      TRUE if name exists in namespace
261  *
262  * DESCRIPTION: Walk the namespace to find an object
263  *
264  ******************************************************************************/
265 
266 static BOOLEAN
267 XfObjectExists (
268     char                    *Name)
269 {
270     ACPI_STATUS             Status;
271 
272 
273     /* Walk entire namespace from the supplied root */
274 
275     Status = AcpiNsWalkNamespace (ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
276         ACPI_UINT32_MAX, FALSE, XfCompareOneNamespaceObject, NULL,
277         Name, NULL);
278     if (Status == AE_CTRL_TRUE)
279     {
280         /* At least one instance of the name was found */
281 
282         return (TRUE);
283     }
284 
285     return (FALSE);
286 }
287 
288 
289 /*******************************************************************************
290  *
291  * FUNCTION:    XfCompareOneNamespaceObject
292  *
293  * PARAMETERS:  ACPI_WALK_CALLBACK
294  *
295  * RETURN:      Status
296  *
297  * DESCRIPTION: Compare name of one object.
298  *
299  ******************************************************************************/
300 
301 static ACPI_STATUS
302 XfCompareOneNamespaceObject (
303     ACPI_HANDLE             ObjHandle,
304     UINT32                  Level,
305     void                    *Context,
306     void                    **ReturnValue)
307 {
308     ACPI_NAMESPACE_NODE     *Node = (ACPI_NAMESPACE_NODE *) ObjHandle;
309 
310 
311     /* Simply check the name */
312 
313     if (*((UINT32 *) (Context)) == Node->Name.Integer)
314     {
315         /* Abort walk if we found one instance */
316 
317         return (AE_CTRL_TRUE);
318     }
319 
320     return (AE_OK);
321 }
322 
323 
324 /*******************************************************************************
325  *
326  * FUNCTION:    XfCheckFieldRange
327  *
328  * PARAMETERS:  RegionBitLength     - Length of entire parent region
329  *              FieldBitOffset      - Start of the field unit (within region)
330  *              FieldBitLength      - Entire length of field unit
331  *              AccessBitWidth      - Access width of the field unit
332  *
333  * RETURN:      None
334  *
335  * DESCRIPTION: Check one field unit to make sure it fits in the parent
336  *              op region.
337  *
338  * Note: AccessBitWidth must be either 8,16,32, or 64
339  *
340  ******************************************************************************/
341 
342 static void
343 XfCheckFieldRange (
344     ACPI_PARSE_OBJECT       *Op,
345     UINT32                  RegionBitLength,
346     UINT32                  FieldBitOffset,
347     UINT32                  FieldBitLength,
348     UINT32                  AccessBitWidth)
349 {
350     UINT32                  FieldEndBitOffset;
351 
352 
353     /*
354      * Check each field unit against the region size. The entire
355      * field unit (start offset plus length) must fit within the
356      * region.
357      */
358     FieldEndBitOffset = FieldBitOffset + FieldBitLength;
359 
360     if (FieldEndBitOffset > RegionBitLength)
361     {
362         /* Field definition itself is beyond the end-of-region */
363 
364         AslError (ASL_ERROR, ASL_MSG_FIELD_UNIT_OFFSET, Op, NULL);
365         return;
366     }
367 
368     /*
369      * Now check that the field plus AccessWidth doesn't go beyond
370      * the end-of-region. Assumes AccessBitWidth is a power of 2
371      */
372     FieldEndBitOffset = ACPI_ROUND_UP (FieldEndBitOffset, AccessBitWidth);
373 
374     if (FieldEndBitOffset > RegionBitLength)
375     {
376         /* Field definition combined with the access is beyond EOR */
377 
378         AslError (ASL_ERROR, ASL_MSG_FIELD_UNIT_ACCESS_WIDTH, Op, NULL);
379     }
380 }
381 
382 
383 /*******************************************************************************
384  *
385  * FUNCTION:    XfGetParentMethod
386  *
387  * PARAMETERS:  Op                      - Parse Op to be checked
388  *
389  * RETURN:      Control method Op if found. NULL otherwise
390  *
391  * DESCRIPTION: Find the control method parent of a parse op. Returns NULL if
392  *              the input Op is not within a control method.
393  *
394  ******************************************************************************/
395 
396 static ACPI_PARSE_OBJECT *
397 XfGetParentMethod (
398     ACPI_PARSE_OBJECT       *Op)
399 {
400     ACPI_PARSE_OBJECT       *NextOp;
401 
402 
403     NextOp = Op->Asl.Parent;
404     while (NextOp)
405     {
406         if (NextOp->Asl.AmlOpcode == AML_METHOD_OP)
407         {
408             return (NextOp);
409         }
410 
411         NextOp = NextOp->Asl.Parent;
412     }
413 
414     return (NULL); /* No parent method found */
415 }
416 
417 
418 /*******************************************************************************
419  *
420  * FUNCTION:    XfNamespaceLocateBegin
421  *
422  * PARAMETERS:  ASL_WALK_CALLBACK
423  *
424  * RETURN:      Status
425  *
426  * DESCRIPTION: Descending callback used during cross-reference. For named
427  *              object references, attempt to locate the name in the
428  *              namespace.
429  *
430  * NOTE: ASL references to named fields within resource descriptors are
431  *       resolved to integer values here. Therefore, this step is an
432  *       important part of the code generation. We don't know that the
433  *       name refers to a resource descriptor until now.
434  *
435  ******************************************************************************/
436 
437 static ACPI_STATUS
438 XfNamespaceLocateBegin (
439     ACPI_PARSE_OBJECT       *Op,
440     UINT32                  Level,
441     void                    *Context)
442 {
443     ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
444     ACPI_NAMESPACE_NODE     *Node;
445     ACPI_STATUS             Status;
446     ACPI_OBJECT_TYPE        ObjectType;
447     char                    *Path;
448     UINT8                   PassedArgs;
449     ACPI_PARSE_OBJECT       *NextOp;
450     ACPI_PARSE_OBJECT       *OwningOp;
451     ACPI_PARSE_OBJECT       *SpaceIdOp;
452     UINT32                  MinimumLength;
453     UINT32                  Offset;
454     UINT32                  FieldBitLength;
455     UINT32                  TagBitLength;
456     UINT8                   Message = 0;
457     const ACPI_OPCODE_INFO  *OpInfo;
458     UINT32                  Flags;
459     ASL_METHOD_LOCAL        *MethodLocals = NULL;
460     ASL_METHOD_LOCAL        *MethodArgs = NULL;
461     int                     RegisterNumber;
462     UINT32                  i;
463     ACPI_NAMESPACE_NODE     *DeclarationParentMethod;
464     ACPI_PARSE_OBJECT       *ReferenceParentMethod;
465 
466 
467     ACPI_FUNCTION_TRACE_PTR (XfNamespaceLocateBegin, Op);
468 
469 
470     if ((Op->Asl.AmlOpcode == AML_METHOD_OP) && Op->Asl.Node)
471     {
472         Node = Op->Asl.Node;
473 
474         /* Support for method LocalX/ArgX analysis */
475 
476         if (!Node->MethodLocals)
477         {
478             /* Create local/arg info blocks */
479 
480             MethodLocals = UtLocalCalloc (
481                 sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_LOCALS);
482             Node->MethodLocals = MethodLocals;
483 
484             MethodArgs = UtLocalCalloc (
485                 sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_ARGS);
486             Node->MethodArgs = MethodArgs;
487 
488             /*
489              * Get the method argument count
490              * First, get the name node
491              */
492             NextOp = Op->Asl.Child;
493 
494             /* Get the NumArguments node */
495 
496             NextOp = NextOp->Asl.Next;
497             Node->ArgCount = (UINT8)
498                 (((UINT8) NextOp->Asl.Value.Integer) & 0x07);
499 
500             /* We will track all possible ArgXs */
501 
502             for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++)
503             {
504                 if (i < Node->ArgCount)
505                 {
506                     /* Real Args are always "initialized" */
507 
508                     MethodArgs[i].Flags = ASL_ARG_INITIALIZED;
509                 }
510                 else
511                 {
512                     /* Other ArgXs can be used as locals */
513 
514                     MethodArgs[i].Flags = ASL_ARG_IS_LOCAL;
515                 }
516 
517                 MethodArgs[i].Op = Op;
518             }
519         }
520     }
521 
522     /*
523      * If this node is the actual declaration of a name
524      * [such as the XXXX name in "Method (XXXX)"],
525      * we are not interested in it here. We only care about names that are
526      * references to other objects within the namespace and the parent objects
527      * of name declarations
528      */
529     if (Op->Asl.CompileFlags & OP_IS_NAME_DECLARATION)
530     {
531         return_ACPI_STATUS (AE_OK);
532     }
533 
534     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
535 
536     /* Check method LocalX variables */
537 
538     if (OpInfo->Type == AML_TYPE_LOCAL_VARIABLE)
539     {
540         /* Find parent method Op */
541 
542         NextOp = XfGetParentMethod (Op);
543         if (!NextOp)
544         {
545             return_ACPI_STATUS (AE_OK);
546         }
547 
548         /* Get method node */
549 
550         Node = NextOp->Asl.Node;
551 
552         RegisterNumber = Op->Asl.AmlOpcode & 0x0007; /* 0x60 through 0x67 */
553         MethodLocals = Node->MethodLocals;
554 
555         if (Op->Asl.CompileFlags & OP_IS_TARGET)
556         {
557             /* Local is being initialized */
558 
559             MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_INITIALIZED;
560             MethodLocals[RegisterNumber].Op = Op;
561 
562             return_ACPI_STATUS (AE_OK);
563         }
564 
565         /* Mark this Local as referenced */
566 
567         MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_REFERENCED;
568         MethodLocals[RegisterNumber].Op = Op;
569 
570         return_ACPI_STATUS (AE_OK);
571     }
572 
573     /* Check method ArgX variables */
574 
575     if (OpInfo->Type == AML_TYPE_METHOD_ARGUMENT)
576     {
577         /* Find parent method Op */
578 
579         NextOp = XfGetParentMethod (Op);
580         if (!NextOp)
581         {
582             return_ACPI_STATUS (AE_OK);
583         }
584 
585         /* Get method node */
586 
587         Node = NextOp->Asl.Node;
588 
589         /* Get Arg # */
590 
591         RegisterNumber = Op->Asl.AmlOpcode - AML_ARG0; /* 0x68 through 0x6F */
592         MethodArgs = Node->MethodArgs;
593 
594         /* Mark this Arg as referenced */
595 
596         MethodArgs[RegisterNumber].Flags |= ASL_ARG_REFERENCED;
597         MethodArgs[RegisterNumber].Op = Op;
598 
599         if (Op->Asl.CompileFlags & OP_IS_TARGET)
600         {
601             /* Arg is being initialized */
602 
603             MethodArgs[RegisterNumber].Flags |= ASL_ARG_INITIALIZED;
604         }
605 
606         return_ACPI_STATUS (AE_OK);
607     }
608 
609     /*
610      * After method ArgX and LocalX, we are only interested in opcodes
611      * that have an associated name
612      */
613     if ((!(OpInfo->Flags & AML_NAMED)) &&
614         (!(OpInfo->Flags & AML_CREATE)) &&
615         (Op->Asl.ParseOpcode != PARSEOP_NAMESTRING) &&
616         (Op->Asl.ParseOpcode != PARSEOP_NAMESEG)    &&
617         (Op->Asl.ParseOpcode != PARSEOP_METHODCALL) &&
618         (Op->Asl.ParseOpcode != PARSEOP_EXTERNAL))
619     {
620         return_ACPI_STATUS (AE_OK);
621     }
622 
623     /*
624      * One special case: CondRefOf operator - we don't care if the name exists
625      * or not at this point, just ignore it, the point of the operator is to
626      * determine if the name exists at runtime.
627      */
628     if ((Op->Asl.Parent) &&
629         (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF))
630     {
631         return_ACPI_STATUS (AE_OK);
632     }
633 
634     /*
635      * We must enable the "search-to-root" for single NameSegs, but
636      * we have to be very careful about opening up scopes
637      */
638     Flags = ACPI_NS_SEARCH_PARENT;
639     if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
640         (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
641         (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
642         (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL))
643     {
644         /*
645          * These are name references, do not push the scope stack
646          * for them.
647          */
648         Flags |= ACPI_NS_DONT_OPEN_SCOPE;
649     }
650 
651     /* Get the NamePath from the appropriate place */
652 
653     if (OpInfo->Flags & AML_NAMED)
654     {
655         /* For nearly all NAMED operators, the name reference is the first child */
656 
657         Path = Op->Asl.Child->Asl.Value.String;
658         if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
659         {
660             /*
661              * ALIAS is the only oddball opcode, the name declaration
662              * (alias name) is the second operand
663              */
664             Path = Op->Asl.Child->Asl.Next->Asl.Value.String;
665         }
666     }
667     else if (OpInfo->Flags & AML_CREATE)
668     {
669         /* Name must appear as the last parameter */
670 
671         NextOp = Op->Asl.Child;
672         while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
673         {
674             NextOp = NextOp->Asl.Next;
675         }
676 
677         Path = NextOp->Asl.Value.String;
678     }
679     else
680     {
681         Path = Op->Asl.Value.String;
682     }
683 
684     ObjectType = AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode);
685     ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
686         "Type=%s\n", AcpiUtGetTypeName (ObjectType)));
687 
688     /*
689      * Lookup the name in the namespace. Name must exist at this point, or it
690      * is an invalid reference.
691      *
692      * The namespace is also used as a lookup table for references to resource
693      * descriptors and the fields within them.
694      */
695     AslGbl_NsLookupCount++;
696 
697     Status = AcpiNsLookup (WalkState->ScopeInfo, Path, ObjectType,
698         ACPI_IMODE_EXECUTE, Flags, WalkState, &Node);
699     if (ACPI_FAILURE (Status))
700     {
701         if (Status == AE_NOT_FOUND)
702         {
703             /*
704              * We didn't find the name reference by path -- we can qualify this
705              * a little better before we print an error message
706              */
707             if (strlen (Path) == ACPI_NAMESEG_SIZE)
708             {
709                 /* A simple, one-segment ACPI name */
710 
711                 if (XfObjectExists (Path))
712                 {
713                     /*
714                      * There exists such a name, but we couldn't get to it
715                      * from this scope
716                      */
717                     AslError (ASL_ERROR, ASL_MSG_NOT_REACHABLE, Op,
718                         Op->Asl.ExternalName);
719                 }
720                 else
721                 {
722                     /* The name doesn't exist, period */
723 
724                     AslError (ASL_ERROR, ASL_MSG_NOT_EXIST,
725                         Op, Op->Asl.ExternalName);
726                 }
727             }
728             else
729             {
730                 /* The NamePath contains multiple NameSegs */
731 
732                 if ((OpInfo->Flags & AML_CREATE) ||
733                     (OpInfo->ObjectType == ACPI_TYPE_LOCAL_ALIAS))
734                 {
735                     /*
736                      * The new name is the last parameter. For the
737                      * CreateXXXXField and Alias operators
738                      */
739                     NextOp = Op->Asl.Child;
740                     while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
741                     {
742                         NextOp = NextOp->Asl.Next;
743                     }
744 
745                     AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, NextOp,
746                         NextOp->Asl.ExternalName);
747                 }
748                 else if (OpInfo->Flags & AML_NAMED)
749                 {
750                     /* The new name is the first parameter */
751 
752                     AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, Op,
753                         Op->Asl.ExternalName);
754                 }
755                 else if (Path[0] == AML_ROOT_PREFIX)
756                 {
757                     /* Full namepath from root, the object does not exist */
758 
759                     AslError (ASL_ERROR, ASL_MSG_NOT_EXIST, Op,
760                         Op->Asl.ExternalName);
761                 }
762                 else
763                 {
764                     /*
765                      * Generic "not found" error. Cannot determine whether it
766                      * doesn't exist or just can't be reached. However, we
767                      * can differentiate between a NameSeg vs. NamePath.
768                      */
769                     if (strlen (Op->Asl.ExternalName) == ACPI_NAMESEG_SIZE)
770                     {
771                         AslError (ASL_ERROR, ASL_MSG_NOT_FOUND, Op,
772                             Op->Asl.ExternalName);
773                     }
774                     else
775                     {
776                         AslError (ASL_ERROR, ASL_MSG_NAMEPATH_NOT_EXIST, Op,
777                             Op->Asl.ExternalName);
778                     }
779                 }
780             }
781 
782             Status = AE_OK;
783         }
784 
785         return_ACPI_STATUS (Status);
786     }
787 
788     /* Check for an attempt to access an object in another method */
789 
790     if (!XfValidateCrossReference (Op, OpInfo, Node))
791     {
792         AslError (ASL_ERROR, ASL_MSG_TEMPORARY_OBJECT, Op,
793             Op->Asl.ExternalName);
794         return_ACPI_STATUS (Status);
795     }
796 
797    /* Object was found above, check for an illegal forward reference */
798 
799     if (Op->Asl.CompileFlags & OP_NOT_FOUND_DURING_LOAD)
800     {
801         /*
802          * During the load phase, this Op was flagged as a possible
803          * illegal forward reference. In other words, Op is a name path or
804          * name segment that refers to a named object declared after the
805          * reference. In this scinario, Node refers to the actual declaration
806          * and Op is a parse node that references the named object.
807          *
808          * Note:
809          *
810          * Object references inside of control methods are allowed to
811          * refer to objects declared outside of control methods.
812          *
813          * If the declaration and reference are both contained inside of the
814          * same method or outside of any method, this is a forward reference
815          * and should be reported as a compiler error.
816          */
817         DeclarationParentMethod = UtGetParentMethod (Node);
818         ReferenceParentMethod = XfGetParentMethod (Op);
819 
820         /* case 1: declaration and refrence are both outside of method */
821 
822         if (!ReferenceParentMethod && !DeclarationParentMethod)
823         {
824             AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
825                 Op->Asl.ExternalName);
826         }
827 
828         /* case 2: declaration and reference are both inside of the same method */
829 
830         else if (ReferenceParentMethod && DeclarationParentMethod &&
831             ReferenceParentMethod == DeclarationParentMethod->Op)
832         {
833              AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
834                 Op->Asl.ExternalName);
835         }
836     }
837 
838     /* Check for a reference vs. name declaration */
839 
840     if (!(OpInfo->Flags & AML_NAMED) &&
841         !(OpInfo->Flags & AML_CREATE))
842     {
843         /* This node has been referenced, mark it for reference check */
844 
845         Node->Flags |= ANOBJ_IS_REFERENCED;
846     }
847 
848     /* Attempt to optimize the NamePath */
849 
850     OptOptimizeNamePath (Op, OpInfo->Flags, WalkState, Path, Node);
851 
852     /*
853      * 1) Dereference an alias (A name reference that is an alias)
854      *    Aliases are not nested, the alias always points to the final object
855      */
856     if ((Op->Asl.ParseOpcode != PARSEOP_ALIAS) &&
857         (Node->Type == ACPI_TYPE_LOCAL_ALIAS))
858     {
859         /* This node points back to the original PARSEOP_ALIAS */
860 
861         NextOp = Node->Op;
862 
863         /* The first child is the alias target op */
864 
865         NextOp = NextOp->Asl.Child;
866 
867         /* That in turn points back to original target alias node */
868 
869         if (NextOp->Asl.Node)
870         {
871             Node = NextOp->Asl.Node;
872         }
873 
874         /* Else - forward reference to alias, will be resolved later */
875     }
876 
877     /* 2) Check for a reference to a resource descriptor */
878 
879     if ((Node->Type == ACPI_TYPE_LOCAL_RESOURCE_FIELD) ||
880         (Node->Type == ACPI_TYPE_LOCAL_RESOURCE))
881     {
882         /*
883          * This was a reference to a field within a resource descriptor.
884          * Extract the associated field offset (either a bit or byte
885          * offset depending on the field type) and change the named
886          * reference into an integer for AML code generation
887          */
888         Offset = Node->Value;
889         TagBitLength = Node->Length;
890 
891         /*
892          * If a field is being created, generate the length (in bits) of
893          * the field. Note: Opcodes other than CreateXxxField and Index
894          * can come through here. For other opcodes, we just need to
895          * convert the resource tag reference to an integer offset.
896          */
897         switch (Op->Asl.Parent->Asl.AmlOpcode)
898         {
899         case AML_CREATE_FIELD_OP: /* Variable "Length" field, in bits */
900             /*
901              * We know the length operand is an integer constant because
902              * we know that it contains a reference to a resource
903              * descriptor tag.
904              */
905             FieldBitLength = (UINT32) Op->Asl.Next->Asl.Value.Integer;
906             break;
907 
908         case AML_CREATE_BIT_FIELD_OP:
909 
910             FieldBitLength = 1;
911             break;
912 
913         case AML_CREATE_BYTE_FIELD_OP:
914         case AML_INDEX_OP:
915 
916             FieldBitLength = 8;
917             break;
918 
919         case AML_CREATE_WORD_FIELD_OP:
920 
921             FieldBitLength = 16;
922             break;
923 
924         case AML_CREATE_DWORD_FIELD_OP:
925 
926             FieldBitLength = 32;
927             break;
928 
929         case AML_CREATE_QWORD_FIELD_OP:
930 
931             FieldBitLength = 64;
932             break;
933 
934         default:
935 
936             FieldBitLength = 0;
937             break;
938         }
939 
940         /* Check the field length against the length of the resource tag */
941 
942         if (FieldBitLength)
943         {
944             if (TagBitLength < FieldBitLength)
945             {
946                 Message = ASL_MSG_TAG_SMALLER;
947             }
948             else if (TagBitLength > FieldBitLength)
949             {
950                 Message = ASL_MSG_TAG_LARGER;
951             }
952 
953             if (Message)
954             {
955                 sprintf (AslGbl_MsgBuffer,
956                     "Size mismatch, Tag: %u bit%s, Field: %u bit%s",
957                     TagBitLength, (TagBitLength > 1) ? "s" : "",
958                     FieldBitLength, (FieldBitLength > 1) ? "s" : "");
959 
960                 AslError (ASL_WARNING, Message, Op, AslGbl_MsgBuffer);
961             }
962         }
963 
964         /* Convert the BitOffset to a ByteOffset for certain opcodes */
965 
966         switch (Op->Asl.Parent->Asl.AmlOpcode)
967         {
968         case AML_CREATE_BYTE_FIELD_OP:
969         case AML_CREATE_WORD_FIELD_OP:
970         case AML_CREATE_DWORD_FIELD_OP:
971         case AML_CREATE_QWORD_FIELD_OP:
972         case AML_INDEX_OP:
973 
974             Offset = ACPI_DIV_8 (Offset);
975             break;
976 
977         default:
978 
979             break;
980         }
981 
982         /* Now convert this node to an integer whose value is the field offset */
983 
984         Op->Asl.AmlLength = 0;
985         Op->Asl.ParseOpcode = PARSEOP_INTEGER;
986         Op->Asl.Value.Integer = (UINT64) Offset;
987         Op->Asl.CompileFlags |= OP_IS_RESOURCE_FIELD;
988 
989         OpcGenerateAmlOpcode (Op);
990     }
991 
992     /* 3) Check for a method invocation */
993 
994     else if ((((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) || (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)) &&
995                 (Node->Type == ACPI_TYPE_METHOD) &&
996                 (Op->Asl.Parent) &&
997                 (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_METHOD))   ||
998 
999                 (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
1000     {
1001         /*
1002          * A reference to a method within one of these opcodes is not an
1003          * invocation of the method, it is simply a reference to the method.
1004          *
1005          * September 2016: Removed DeRefOf from this list
1006          */
1007         if ((Op->Asl.Parent) &&
1008             ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_REFOF)     ||
1009             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_PACKAGE)    ||
1010             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_VAR_PACKAGE)||
1011             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_OBJECTTYPE)))
1012         {
1013             return_ACPI_STATUS (AE_OK);
1014         }
1015 
1016         /*
1017          * There are two types of method invocation:
1018          * 1) Invocation with arguments -- the parser recognizes this
1019          *    as a METHODCALL.
1020          * 2) Invocation with no arguments --the parser cannot determine that
1021          *    this is a method invocation, therefore we have to figure it out
1022          *    here.
1023          */
1024         if (Node->Type != ACPI_TYPE_METHOD)
1025         {
1026             sprintf (AslGbl_MsgBuffer, "%s is a %s",
1027                 Op->Asl.ExternalName, AcpiUtGetTypeName (Node->Type));
1028 
1029             AslError (ASL_ERROR, ASL_MSG_NOT_METHOD, Op, AslGbl_MsgBuffer);
1030             return_ACPI_STATUS (AE_OK);
1031         }
1032 
1033         /* Save the method node in the caller's op */
1034 
1035         Op->Asl.Node = Node;
1036         if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF)
1037         {
1038             return_ACPI_STATUS (AE_OK);
1039         }
1040 
1041         /*
1042          * This is a method invocation, with or without arguments.
1043          * Count the number of arguments, each appears as a child
1044          * under the parent node
1045          */
1046         Op->Asl.ParseOpcode = PARSEOP_METHODCALL;
1047         UtSetParseOpName (Op);
1048 
1049         PassedArgs = 0;
1050         NextOp = Op->Asl.Child;
1051 
1052         while (NextOp)
1053         {
1054             PassedArgs++;
1055             NextOp = NextOp->Asl.Next;
1056         }
1057 
1058         if (Node->Value != ASL_EXTERNAL_METHOD_UNKNOWN_PARAMS &&
1059             Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
1060         {
1061             /*
1062              * Check the parsed arguments with the number expected by the
1063              * method declaration itself
1064              */
1065             if (PassedArgs != Node->Value)
1066             {
1067                 if (Node->Flags & ANOBJ_IS_EXTERNAL)
1068                 {
1069                     sprintf (AslGbl_MsgBuffer,
1070                         "according to previous use, %s requires %u",
1071                         Op->Asl.ExternalName, Node->Value);
1072                 }
1073                 else
1074                 {
1075                     sprintf (AslGbl_MsgBuffer, "%s requires %u", Op->Asl.ExternalName,
1076                         Node->Value);
1077                 }
1078 
1079                 if (PassedArgs < Node->Value)
1080                 {
1081                     AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_LO, Op, AslGbl_MsgBuffer);
1082                 }
1083                 else
1084                 {
1085                     AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_HI, Op, AslGbl_MsgBuffer);
1086                 }
1087             }
1088         }
1089 
1090         /*
1091          * At this point, a method call to an external method has been
1092          * detected. As of 11/19/2019, iASL does not support parameter counts
1093          * for methods declared as external. Therefore, save the parameter
1094          * count of the first method call and use this count check other
1095          * method calls to ensure that the methods are being called with the
1096          * same amount of parameters.
1097          */
1098         else if (Node->Type == ACPI_TYPE_METHOD &&
1099             (Node->Flags & ANOBJ_IS_EXTERNAL) &&
1100             Node->Value == ASL_EXTERNAL_METHOD_UNKNOWN_PARAMS &&
1101             Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
1102         {
1103             Node->Value = PassedArgs;
1104         }
1105     }
1106 
1107     /* 4) Check for an ASL Field definition */
1108 
1109     else if ((Op->Asl.Parent) &&
1110             ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_FIELD)     ||
1111              (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_BANKFIELD)))
1112     {
1113         /*
1114          * Offset checking for fields. If the parent operation region has a
1115          * constant length (known at compile time), we can check fields
1116          * defined in that region against the region length. This will catch
1117          * fields and field units that cannot possibly fit within the region.
1118          *
1119          * Note: Index fields do not directly reference an operation region,
1120          * thus they are not included in this check.
1121          */
1122         if (Op == Op->Asl.Parent->Asl.Child)
1123         {
1124             /*
1125              * This is the first child of the field node, which is
1126              * the name of the region. Get the parse node for the
1127              * region -- which contains the length of the region.
1128              */
1129             OwningOp = Node->Op;
1130             Op->Asl.Parent->Asl.ExtraValue =
1131                 ACPI_MUL_8 ((UINT32) OwningOp->Asl.Value.Integer);
1132 
1133             /* Examine the field access width */
1134 
1135             switch ((UINT8) Op->Asl.Parent->Asl.Value.Integer)
1136             {
1137             case AML_FIELD_ACCESS_ANY:
1138             case AML_FIELD_ACCESS_BYTE:
1139             case AML_FIELD_ACCESS_BUFFER:
1140             default:
1141 
1142                 MinimumLength = 1;
1143                 break;
1144 
1145             case AML_FIELD_ACCESS_WORD:
1146 
1147                 MinimumLength = 2;
1148                 break;
1149 
1150             case AML_FIELD_ACCESS_DWORD:
1151 
1152                 MinimumLength = 4;
1153                 break;
1154 
1155             case AML_FIELD_ACCESS_QWORD:
1156 
1157                 MinimumLength = 8;
1158                 break;
1159             }
1160 
1161             /*
1162              * Is the region at least as big as the access width?
1163              * Note: DataTableRegions have 0 length
1164              */
1165             if (((UINT32) OwningOp->Asl.Value.Integer) &&
1166                 ((UINT32) OwningOp->Asl.Value.Integer < MinimumLength))
1167             {
1168                 AslError (ASL_ERROR, ASL_MSG_FIELD_ACCESS_WIDTH, Op, NULL);
1169             }
1170 
1171             /*
1172              * Check EC/CMOS/SMBUS fields to make sure that the correct
1173              * access type is used (BYTE for EC/CMOS, BUFFER for SMBUS)
1174              */
1175             SpaceIdOp = OwningOp->Asl.Child->Asl.Next;
1176             switch ((UINT32) SpaceIdOp->Asl.Value.Integer)
1177             {
1178             case ACPI_ADR_SPACE_EC:
1179             case ACPI_ADR_SPACE_CMOS:
1180             case ACPI_ADR_SPACE_GPIO:
1181 
1182                 if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
1183                     AML_FIELD_ACCESS_BYTE)
1184                 {
1185                     AslError (ASL_ERROR, ASL_MSG_REGION_BYTE_ACCESS, Op, NULL);
1186                 }
1187                 break;
1188 
1189             case ACPI_ADR_SPACE_SMBUS:
1190             case ACPI_ADR_SPACE_IPMI:
1191             case ACPI_ADR_SPACE_GSBUS:
1192 
1193                 if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
1194                     AML_FIELD_ACCESS_BUFFER)
1195                 {
1196                     AslError (ASL_ERROR, ASL_MSG_REGION_BUFFER_ACCESS, Op, NULL);
1197                 }
1198                 break;
1199 
1200             default:
1201 
1202                 /* Nothing to do for other address spaces */
1203 
1204                 break;
1205             }
1206         }
1207         else
1208         {
1209             /*
1210              * This is one element of the field list. Check to make sure
1211              * that it does not go beyond the end of the parent operation region.
1212              *
1213              * In the code below:
1214              *    Op->Asl.Parent->Asl.ExtraValue      - Region Length (bits)
1215              *    Op->Asl.ExtraValue                  - Field start offset (bits)
1216              *    Op->Asl.Child->Asl.Value.Integer32  - Field length (bits)
1217              *    Op->Asl.Child->Asl.ExtraValue       - Field access width (bits)
1218              */
1219             if (Op->Asl.Parent->Asl.ExtraValue && Op->Asl.Child)
1220             {
1221                 XfCheckFieldRange (Op,
1222                     Op->Asl.Parent->Asl.ExtraValue,
1223                     Op->Asl.ExtraValue,
1224                     (UINT32) Op->Asl.Child->Asl.Value.Integer,
1225                     Op->Asl.Child->Asl.ExtraValue);
1226             }
1227         }
1228     }
1229 
1230     /*
1231      * 5) Check for external resolution
1232      * By this point, everything should be loaded in the namespace. If a
1233      * namespace lookup results in a namespace node that is an external, it
1234      * means that this named object was not defined in the input ASL. This
1235      * causes issues because there are plenty of incidents where developers
1236      * use the external keyword to suppress compiler errors about undefined
1237      * objects. Note: this only applies when compiling multiple definition
1238      * blocks.
1239      */
1240     if (AslGbl_ParseTreeRoot->Asl.Child && AslGbl_ParseTreeRoot->Asl.Child->Asl.Next &&
1241         (Op->Asl.ParseOpcode != PARSEOP_EXTERNAL &&
1242         Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL) &&
1243         (Node->Flags & ANOBJ_IS_EXTERNAL))
1244     {
1245         AslError (ASL_ERROR, ASL_MSG_UNDEFINED_EXTERNAL, Op, NULL);
1246     }
1247 
1248     /* 5) Check for a connection object */
1249 #if 0
1250     else if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONNECTION)
1251     {
1252         return_ACPI_STATUS (Status);
1253     }
1254 #endif
1255 
1256     Op->Asl.Node = Node;
1257     return_ACPI_STATUS (Status);
1258 }
1259 
1260 
1261 /*******************************************************************************
1262  *
1263  * FUNCTION:    XfNamespaceLocateEnd
1264  *
1265  * PARAMETERS:  ASL_WALK_CALLBACK
1266  *
1267  * RETURN:      Status
1268  *
1269  * DESCRIPTION: Ascending callback used during cross reference. We only
1270  *              need to worry about scope management here.
1271  *
1272  ******************************************************************************/
1273 
1274 static ACPI_STATUS
1275 XfNamespaceLocateEnd (
1276     ACPI_PARSE_OBJECT       *Op,
1277     UINT32                  Level,
1278     void                    *Context)
1279 {
1280     ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
1281     const ACPI_OPCODE_INFO  *OpInfo;
1282 
1283 
1284     ACPI_FUNCTION_TRACE (XfNamespaceLocateEnd);
1285 
1286 
1287     /* We are only interested in opcodes that have an associated name */
1288 
1289     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
1290     if (!(OpInfo->Flags & AML_NAMED))
1291     {
1292         return_ACPI_STATUS (AE_OK);
1293     }
1294 
1295     /* Not interested in name references, we did not open a scope for them */
1296 
1297     if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
1298         (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
1299         (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
1300         (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL))
1301     {
1302         return_ACPI_STATUS (AE_OK);
1303     }
1304 
1305     /* Pop the scope stack if necessary */
1306 
1307     if (AcpiNsOpensScope (AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode)))
1308     {
1309 
1310         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
1311             "%s: Popping scope for Op %p\n",
1312             AcpiUtGetTypeName (OpInfo->ObjectType), Op));
1313 
1314         (void) AcpiDsScopeStackPop (WalkState);
1315     }
1316 
1317     return_ACPI_STATUS (AE_OK);
1318 }
1319 
1320 
1321 /*******************************************************************************
1322  *
1323  * FUNCTION:    XfValidateCrossReference
1324  *
1325  * PARAMETERS:  Op                      - Parse Op that references the object
1326  *              OpInfo                  - Parse Op info struct
1327  *              Node                    - Node for the referenced object
1328  *
1329  * RETURN:      TRUE if the reference is legal, FALSE otherwise
1330  *
1331  * DESCRIPTION: Determine if a reference to another object is allowed.
1332  *
1333  * EXAMPLE:
1334  *      Method (A) {Name (INT1, 1)}     Declaration of object INT1
1335  *      Method (B) (Store (2, \A.INT1)} Illegal reference to object INT1
1336  *                                      (INT1 is temporary, valid only during
1337  *                                      execution of A)
1338  *
1339  * NOTES:
1340  *      A null pointer returned by either XfGetParentMethod or
1341  *      UtGetParentMethod indicates that the parameter object is not
1342  *      within a control method.
1343  *
1344  *      Five cases are handled: Case(Op, Node)
1345  *      1) Case(0,0): Op is not within a method, Node is not    --> OK
1346  *      2) Case(0,1): Op is not within a method, but Node is    --> Illegal
1347  *      3) Case(1,0): Op is within a method, Node is not        --> OK
1348  *      4) Case(1,1): Both are within the same method           --> OK
1349  *      5) Case(1,1): Both are in methods, but not same method  --> Illegal
1350  *
1351  ******************************************************************************/
1352 
1353 static BOOLEAN
1354 XfValidateCrossReference (
1355     ACPI_PARSE_OBJECT       *Op,
1356     const ACPI_OPCODE_INFO  *OpInfo,
1357     ACPI_NAMESPACE_NODE     *Node)
1358 {
1359     ACPI_PARSE_OBJECT       *ReferencingMethodOp;
1360     ACPI_NAMESPACE_NODE     *ReferencedMethodNode;
1361 
1362 
1363     /* Ignore actual named (and related) object declarations */
1364 
1365     if (OpInfo->Flags & (AML_NAMED | AML_CREATE | AML_DEFER | AML_HAS_ARGS))
1366     {
1367         return (TRUE);
1368     }
1369 
1370     /*
1371      * 1) Search upwards in parse tree for owner of the referencing object
1372      * 2) Search upwards in namespace to find the owner of the referenced object
1373      */
1374     ReferencingMethodOp = XfGetParentMethod (Op);
1375     ReferencedMethodNode = UtGetParentMethod (Node);
1376 
1377     if (!ReferencingMethodOp && !ReferencedMethodNode)
1378     {
1379         /*
1380          * 1) Case (0,0): Both Op and Node are not within methods
1381          * --> OK
1382          */
1383         return (TRUE);
1384     }
1385 
1386     if (!ReferencingMethodOp && ReferencedMethodNode)
1387     {
1388         /*
1389          * 2) Case (0,1): Op is not in a method, but Node is within a
1390          * method --> illegal
1391          */
1392         return (FALSE);
1393     }
1394     else if (ReferencingMethodOp && !ReferencedMethodNode)
1395     {
1396         /*
1397          * 3) Case (1,0): Op is within a method, but Node is not
1398          * --> OK
1399          */
1400         return (TRUE);
1401     }
1402     else if (ReferencingMethodOp->Asl.Node == ReferencedMethodNode)
1403     {
1404         /*
1405          * 4) Case (1,1): Both Op and Node are within the same method
1406          * --> OK
1407          */
1408         return (TRUE);
1409     }
1410     else
1411     {
1412         /*
1413          * 5) Case (1,1), Op and Node are in different methods
1414          * --> Illegal
1415          */
1416         return (FALSE);
1417     }
1418 }
1419