xref: /freebsd/sys/contrib/dev/acpica/compiler/aslxref.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 - 2021, 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 BOOLEAN
184 XfObjectExists (
185     char                    *Name);
186 
187 static ACPI_STATUS
188 XfCompareOneNamespaceObject (
189     ACPI_HANDLE             ObjHandle,
190     UINT32                  Level,
191     void                    *Context,
192     void                    **ReturnValue);
193 
194 static void
195 XfCheckFieldRange (
196     ACPI_PARSE_OBJECT       *Op,
197     UINT32                  RegionBitLength,
198     UINT32                  FieldBitOffset,
199     UINT32                  FieldBitLength,
200     UINT32                  AccessBitWidth);
201 
202 static BOOLEAN
203 XfFindCondRefOfName (
204     ACPI_NAMESPACE_NODE     *Node,
205     ACPI_PARSE_OBJECT       *Op);
206 
207 static BOOLEAN
208 XfRefIsGuardedByIfCondRefOf (
209     ACPI_NAMESPACE_NODE     *Node,
210     ACPI_PARSE_OBJECT       *Op);
211 
212 
213 /*******************************************************************************
214  *
215  * FUNCTION:    XfCrossReferenceNamespace
216  *
217  * PARAMETERS:  None
218  *
219  * RETURN:      Status
220  *
221  * DESCRIPTION: Perform a cross reference check of the parse tree against the
222  *              namespace. Every named referenced within the parse tree
223  *              should be get resolved with a namespace lookup. If not, the
224  *              original reference in the ASL code is invalid -- i.e., refers
225  *              to a non-existent object.
226  *
227  * NOTE:  The ASL "External" operator causes the name to be inserted into the
228  *        namespace so that references to the external name will be resolved
229  *        correctly here.
230  *
231  ******************************************************************************/
232 
233 ACPI_STATUS
234 XfCrossReferenceNamespace (
235     void)
236 {
237     ACPI_WALK_STATE         *WalkState;
238 
239 
240     /*
241      * Create a new walk state for use when looking up names
242      * within the namespace (Passed as context to the callbacks)
243      */
244     WalkState = AcpiDsCreateWalkState (0, NULL, NULL, NULL);
245     if (!WalkState)
246     {
247         return (AE_NO_MEMORY);
248     }
249 
250     /* Walk the entire parse tree */
251 
252     TrWalkParseTree (AslGbl_ParseTreeRoot, ASL_WALK_VISIT_TWICE,
253         XfNamespaceLocateBegin, XfNamespaceLocateEnd, WalkState);
254 
255     ACPI_FREE (WalkState);
256     return (AE_OK);
257 }
258 
259 
260 /*******************************************************************************
261  *
262  * FUNCTION:    XfObjectExists
263  *
264  * PARAMETERS:  Name            - 4 char ACPI name
265  *
266  * RETURN:      TRUE if name exists in namespace
267  *
268  * DESCRIPTION: Walk the namespace to find an object
269  *
270  ******************************************************************************/
271 
272 static BOOLEAN
273 XfObjectExists (
274     char                    *Name)
275 {
276     ACPI_STATUS             Status;
277 
278 
279     /* Walk entire namespace from the supplied root */
280 
281     Status = AcpiNsWalkNamespace (ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
282         ACPI_UINT32_MAX, FALSE, XfCompareOneNamespaceObject, NULL,
283         Name, NULL);
284     if (Status == AE_CTRL_TRUE)
285     {
286         /* At least one instance of the name was found */
287 
288         return (TRUE);
289     }
290 
291     return (FALSE);
292 }
293 
294 
295 /*******************************************************************************
296  *
297  * FUNCTION:    XfCompareOneNamespaceObject
298  *
299  * PARAMETERS:  ACPI_WALK_CALLBACK
300  *
301  * RETURN:      Status
302  *
303  * DESCRIPTION: Compare name of one object.
304  *
305  ******************************************************************************/
306 
307 static ACPI_STATUS
308 XfCompareOneNamespaceObject (
309     ACPI_HANDLE             ObjHandle,
310     UINT32                  Level,
311     void                    *Context,
312     void                    **ReturnValue)
313 {
314     ACPI_NAMESPACE_NODE     *Node = (ACPI_NAMESPACE_NODE *) ObjHandle;
315 
316 
317     /* Simply check the name */
318 
319     if (*((UINT32 *) (Context)) == Node->Name.Integer)
320     {
321         /* Abort walk if we found one instance */
322 
323         return (AE_CTRL_TRUE);
324     }
325 
326     return (AE_OK);
327 }
328 
329 
330 /*******************************************************************************
331  *
332  * FUNCTION:    XfCheckFieldRange
333  *
334  * PARAMETERS:  RegionBitLength     - Length of entire parent region
335  *              FieldBitOffset      - Start of the field unit (within region)
336  *              FieldBitLength      - Entire length of field unit
337  *              AccessBitWidth      - Access width of the field unit
338  *
339  * RETURN:      None
340  *
341  * DESCRIPTION: Check one field unit to make sure it fits in the parent
342  *              op region.
343  *
344  * Note: AccessBitWidth must be either 8,16,32, or 64
345  *
346  ******************************************************************************/
347 
348 static void
349 XfCheckFieldRange (
350     ACPI_PARSE_OBJECT       *Op,
351     UINT32                  RegionBitLength,
352     UINT32                  FieldBitOffset,
353     UINT32                  FieldBitLength,
354     UINT32                  AccessBitWidth)
355 {
356     UINT32                  FieldEndBitOffset;
357 
358 
359     /*
360      * Check each field unit against the region size. The entire
361      * field unit (start offset plus length) must fit within the
362      * region.
363      */
364     FieldEndBitOffset = FieldBitOffset + FieldBitLength;
365 
366     if (FieldEndBitOffset > RegionBitLength)
367     {
368         /* Field definition itself is beyond the end-of-region */
369 
370         AslError (ASL_ERROR, ASL_MSG_FIELD_UNIT_OFFSET, Op, NULL);
371         return;
372     }
373 
374     /*
375      * Now check that the field plus AccessWidth doesn't go beyond
376      * the end-of-region. Assumes AccessBitWidth is a power of 2
377      */
378     FieldEndBitOffset = ACPI_ROUND_UP (FieldEndBitOffset, AccessBitWidth);
379 
380     if (FieldEndBitOffset > RegionBitLength)
381     {
382         /* Field definition combined with the access is beyond EOR */
383 
384         AslError (ASL_ERROR, ASL_MSG_FIELD_UNIT_ACCESS_WIDTH, Op, NULL);
385     }
386 }
387 
388 
389 /*******************************************************************************
390  *
391  * FUNCTION:    XfNamespaceLocateBegin
392  *
393  * PARAMETERS:  ASL_WALK_CALLBACK
394  *
395  * RETURN:      Status
396  *
397  * DESCRIPTION: Descending callback used during cross-reference. For named
398  *              object references, attempt to locate the name in the
399  *              namespace.
400  *
401  * NOTE: ASL references to named fields within resource descriptors are
402  *       resolved to integer values here. Therefore, this step is an
403  *       important part of the code generation. We don't know that the
404  *       name refers to a resource descriptor until now.
405  *
406  ******************************************************************************/
407 
408 static ACPI_STATUS
409 XfNamespaceLocateBegin (
410     ACPI_PARSE_OBJECT       *Op,
411     UINT32                  Level,
412     void                    *Context)
413 {
414     ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
415     ACPI_NAMESPACE_NODE     *Node;
416     ACPI_STATUS             Status;
417     ACPI_OBJECT_TYPE        ObjectType;
418     char                    *Path;
419     UINT8                   PassedArgs;
420     ACPI_PARSE_OBJECT       *NextOp;
421     ACPI_PARSE_OBJECT       *OwningOp;
422     ACPI_PARSE_OBJECT       *SpaceIdOp;
423     UINT32                  MinimumLength;
424     UINT32                  Offset;
425     UINT32                  FieldBitLength;
426     UINT32                  TagBitLength;
427     UINT8                   Message = 0;
428     const ACPI_OPCODE_INFO  *OpInfo;
429     UINT32                  Flags;
430     ASL_METHOD_LOCAL        *MethodLocals = NULL;
431     ASL_METHOD_LOCAL        *MethodArgs = NULL;
432     int                     RegisterNumber;
433     UINT32                  i;
434     ACPI_NAMESPACE_NODE     *DeclarationParentMethod;
435     ACPI_PARSE_OBJECT       *ReferenceParentMethod;
436     char                    *ExternalPath;
437 
438 
439     ACPI_FUNCTION_TRACE_PTR (XfNamespaceLocateBegin, Op);
440 
441 
442     if ((Op->Asl.AmlOpcode == AML_METHOD_OP) && Op->Asl.Node)
443     {
444         Node = Op->Asl.Node;
445 
446         /* Support for method LocalX/ArgX analysis */
447 
448         if (!Node->MethodLocals)
449         {
450             /* Create local/arg info blocks */
451 
452             MethodLocals = UtLocalCalloc (
453                 sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_LOCALS);
454             Node->MethodLocals = MethodLocals;
455 
456             MethodArgs = UtLocalCalloc (
457                 sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_ARGS);
458             Node->MethodArgs = MethodArgs;
459 
460             /*
461              * Get the method argument count
462              * First, get the name node
463              */
464             NextOp = Op->Asl.Child;
465 
466             /* Get the NumArguments node */
467 
468             NextOp = NextOp->Asl.Next;
469             Node->ArgCount = (UINT8)
470                 (((UINT8) NextOp->Asl.Value.Integer) & 0x07);
471 
472             /* We will track all possible ArgXs */
473 
474             for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++)
475             {
476                 if (i < Node->ArgCount)
477                 {
478                     /* Real Args are always "initialized" */
479 
480                     MethodArgs[i].Flags = ASL_ARG_INITIALIZED;
481                 }
482                 else
483                 {
484                     /* Other ArgXs can be used as locals */
485 
486                     MethodArgs[i].Flags = ASL_ARG_IS_LOCAL;
487                 }
488 
489                 MethodArgs[i].Op = Op;
490             }
491         }
492     }
493 
494     /*
495      * If this node is the actual declaration of a name
496      * [such as the XXXX name in "Method (XXXX)"],
497      * we are not interested in it here. We only care about names that are
498      * references to other objects within the namespace and the parent objects
499      * of name declarations
500      */
501     if (Op->Asl.CompileFlags & OP_IS_NAME_DECLARATION)
502     {
503         return_ACPI_STATUS (AE_OK);
504     }
505 
506     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
507 
508     /* Check method LocalX variables */
509 
510     if (OpInfo->Type == AML_TYPE_LOCAL_VARIABLE)
511     {
512         /* Find parent method Op */
513 
514         NextOp = UtGetParentMethodOp (Op);
515         if (!NextOp)
516         {
517             return_ACPI_STATUS (AE_OK);
518         }
519 
520         /* Get method node */
521 
522         Node = NextOp->Asl.Node;
523 
524         RegisterNumber = Op->Asl.AmlOpcode & 0x0007; /* 0x60 through 0x67 */
525         MethodLocals = Node->MethodLocals;
526 
527         if (Op->Asl.CompileFlags & OP_IS_TARGET)
528         {
529             /* Local is being initialized */
530 
531             MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_INITIALIZED;
532             MethodLocals[RegisterNumber].Op = Op;
533 
534             return_ACPI_STATUS (AE_OK);
535         }
536 
537         /* Mark this Local as referenced */
538 
539         MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_REFERENCED;
540         MethodLocals[RegisterNumber].Op = Op;
541 
542         return_ACPI_STATUS (AE_OK);
543     }
544 
545     /* Check method ArgX variables */
546 
547     if (OpInfo->Type == AML_TYPE_METHOD_ARGUMENT)
548     {
549         /* Find parent method Op */
550 
551         NextOp = UtGetParentMethodOp (Op);
552         if (!NextOp)
553         {
554             return_ACPI_STATUS (AE_OK);
555         }
556 
557         /* Get method node */
558 
559         Node = NextOp->Asl.Node;
560 
561         /* Get Arg # */
562 
563         RegisterNumber = Op->Asl.AmlOpcode - AML_ARG0; /* 0x68 through 0x6F */
564         MethodArgs = Node->MethodArgs;
565 
566         /* Mark this Arg as referenced */
567 
568         MethodArgs[RegisterNumber].Flags |= ASL_ARG_REFERENCED;
569         MethodArgs[RegisterNumber].Op = Op;
570 
571         if (Op->Asl.CompileFlags & OP_IS_TARGET)
572         {
573             /* Arg is being initialized */
574 
575             MethodArgs[RegisterNumber].Flags |= ASL_ARG_INITIALIZED;
576         }
577 
578         return_ACPI_STATUS (AE_OK);
579     }
580 
581     /*
582      * After method ArgX and LocalX, we are only interested in opcodes
583      * that have an associated name
584      */
585     if ((!(OpInfo->Flags & AML_NAMED)) &&
586         (!(OpInfo->Flags & AML_CREATE)) &&
587         (Op->Asl.ParseOpcode != PARSEOP_NAMESTRING) &&
588         (Op->Asl.ParseOpcode != PARSEOP_NAMESEG)    &&
589         (Op->Asl.ParseOpcode != PARSEOP_METHODCALL) &&
590         (Op->Asl.ParseOpcode != PARSEOP_EXTERNAL))
591     {
592         return_ACPI_STATUS (AE_OK);
593     }
594 
595     /*
596      * We must enable the "search-to-root" for single NameSegs, but
597      * we have to be very careful about opening up scopes
598      */
599     Flags = ACPI_NS_SEARCH_PARENT;
600     if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
601         (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
602         (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
603         (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL)   ||
604         (Op->Asl.ParseOpcode == PARSEOP_CONDREFOF))
605     {
606         /*
607          * These are name references, do not push the scope stack
608          * for them.
609          */
610         Flags |= ACPI_NS_DONT_OPEN_SCOPE;
611     }
612 
613     /* Get the NamePath from the appropriate place */
614 
615     if (OpInfo->Flags & AML_NAMED)
616     {
617         /* For nearly all NAMED operators, the name reference is the first child */
618 
619         Path = Op->Asl.Child->Asl.Value.String;
620         if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
621         {
622             /*
623              * ALIAS is the only oddball opcode, the name declaration
624              * (alias name) is the second operand
625              */
626             Path = Op->Asl.Child->Asl.Next->Asl.Value.String;
627         }
628     }
629     else if (OpInfo->Flags & AML_CREATE)
630     {
631         /* Name must appear as the last parameter */
632 
633         NextOp = Op->Asl.Child;
634         while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
635         {
636             NextOp = NextOp->Asl.Next;
637         }
638 
639         Path = NextOp->Asl.Value.String;
640     }
641     else
642     {
643         Path = Op->Asl.Value.String;
644     }
645 
646     ObjectType = AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode);
647     ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
648         "Type=%s\n", AcpiUtGetTypeName (ObjectType)));
649 
650     /*
651      * Lookup the name in the namespace. Name must exist at this point, or it
652      * is an invalid reference.
653      *
654      * The namespace is also used as a lookup table for references to resource
655      * descriptors and the fields within them.
656      */
657     AslGbl_NsLookupCount++;
658 
659     Status = AcpiNsLookup (WalkState->ScopeInfo, Path, ObjectType,
660         ACPI_IMODE_EXECUTE, Flags, WalkState, &Node);
661     if (ACPI_FAILURE (Status))
662     {
663         if (Status == AE_NOT_FOUND)
664         {
665             /*
666              * We didn't find the name reference by path -- we can qualify this
667              * a little better before we print an error message
668              */
669 
670             if ((Op->Asl.Parent) &&
671                 (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF))
672             {
673                 /*
674                  * One special case: CondRefOf operator - if the name doesn't
675                  * exist at this point, it means that there's no actual or
676                  * external declaration. If the name is not found, just ignore
677                  * it, the point of the operator is to determine if the name
678                  * exists at runtime. We wanted to see if this named object
679                  * exists to facilitate analysis to allow protected usage of
680                  * undeclared externals.
681                  */
682                 return_ACPI_STATUS (AE_OK);
683             }
684             else if (strlen (Path) == ACPI_NAMESEG_SIZE)
685             {
686                 /* A simple, one-segment ACPI name */
687 
688                 if (XfObjectExists (Path))
689                 {
690                     /*
691                      * There exists such a name, but we couldn't get to it
692                      * from this scope
693                      */
694                     AslError (ASL_ERROR, ASL_MSG_NOT_REACHABLE, Op,
695                         Op->Asl.ExternalName);
696                 }
697                 else
698                 {
699                     /* The name doesn't exist, period */
700 
701                     AslError (ASL_ERROR, ASL_MSG_NOT_EXIST,
702                         Op, Op->Asl.ExternalName);
703                 }
704             }
705             else
706             {
707                 /* The NamePath contains multiple NameSegs */
708 
709                 if ((OpInfo->Flags & AML_CREATE) ||
710                     (OpInfo->ObjectType == ACPI_TYPE_LOCAL_ALIAS))
711                 {
712                     /*
713                      * The new name is the last parameter. For the
714                      * CreateXXXXField and Alias operators
715                      */
716                     NextOp = Op->Asl.Child;
717                     while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
718                     {
719                         NextOp = NextOp->Asl.Next;
720                     }
721 
722                     AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, NextOp,
723                         NextOp->Asl.ExternalName);
724                 }
725                 else if (OpInfo->Flags & AML_NAMED)
726                 {
727                     /* The new name is the first parameter */
728 
729                     AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, Op,
730                         Op->Asl.ExternalName);
731                 }
732                 else if (Path[0] == AML_ROOT_PREFIX)
733                 {
734                     /* Full namepath from root, the object does not exist */
735 
736                     AslError (ASL_ERROR, ASL_MSG_NOT_EXIST, Op,
737                         Op->Asl.ExternalName);
738                 }
739                 else
740                 {
741                     /*
742                      * Generic "not found" error. Cannot determine whether it
743                      * doesn't exist or just can't be reached. However, we
744                      * can differentiate between a NameSeg vs. NamePath.
745                      */
746                     if (strlen (Op->Asl.ExternalName) == ACPI_NAMESEG_SIZE)
747                     {
748                         AslError (ASL_ERROR, ASL_MSG_NOT_FOUND, Op,
749                             Op->Asl.ExternalName);
750                     }
751                     else
752                     {
753                         AslError (ASL_ERROR, ASL_MSG_NAMEPATH_NOT_EXIST, Op,
754                             Op->Asl.ExternalName);
755                     }
756                 }
757             }
758 
759             Status = AE_OK;
760         }
761 
762         return_ACPI_STATUS (Status);
763     }
764 
765     /* Check for an attempt to access an object in another method */
766 
767     if (!XfValidateCrossReference (Op, OpInfo, Node))
768     {
769         AslError (ASL_ERROR, ASL_MSG_TEMPORARY_OBJECT, Op,
770             Op->Asl.ExternalName);
771         return_ACPI_STATUS (Status);
772     }
773 
774    /* Object was found above, check for an illegal forward reference */
775 
776     if (Op->Asl.CompileFlags & OP_NOT_FOUND_DURING_LOAD)
777     {
778         /*
779          * During the load phase, this Op was flagged as a possible
780          * illegal forward reference. In other words, Op is a name path or
781          * name segment that refers to a named object declared after the
782          * reference. In this scinario, Node refers to the actual declaration
783          * and Op is a parse node that references the named object.
784          *
785          * Note:
786          *
787          * Object references inside of control methods are allowed to
788          * refer to objects declared outside of control methods.
789          *
790          * If the declaration and reference are both contained inside of the
791          * same method or outside of any method, this is a forward reference
792          * and should be reported as a compiler error.
793          */
794         DeclarationParentMethod = UtGetParentMethodNode (Node);
795         ReferenceParentMethod = UtGetParentMethodOp (Op);
796 
797         /* case 1: declaration and reference are both outside of method */
798 
799         if (!ReferenceParentMethod && !DeclarationParentMethod)
800         {
801             AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
802                 Op->Asl.ExternalName);
803         }
804 
805         /* case 2: declaration and reference are both inside of the same method */
806 
807         else if (ReferenceParentMethod && DeclarationParentMethod &&
808             ReferenceParentMethod == DeclarationParentMethod->Op)
809         {
810              AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
811                 Op->Asl.ExternalName);
812         }
813     }
814 
815     /* Check for a reference vs. name declaration */
816 
817     if (!(OpInfo->Flags & AML_NAMED) &&
818         !(OpInfo->Flags & AML_CREATE))
819     {
820         /* This node has been referenced, mark it for reference check */
821 
822         Node->Flags |= ANOBJ_IS_REFERENCED;
823     }
824 
825     /*
826      * Attempt to optimize the NamePath
827      *
828      * One special case: CondRefOf operator - not all AML interpreter
829      * implementations expect optimized namepaths as a parameter to this
830      * operator. They require relative name paths with prefix operators or
831      * namepaths starting with the root scope.
832      *
833      * Other AML interpreter implementations do not perform the namespace
834      * search that starts at the current scope and recursively searching the
835      * parent scope until the root scope. The lack of search is only known to
836      * occur for the namestring parameter for the CondRefOf operator.
837      */
838     if ((Op->Asl.Parent) &&
839         (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_CONDREFOF))
840     {
841         OptOptimizeNamePath (Op, OpInfo->Flags, WalkState, Path, Node);
842     }
843 
844     /*
845      * 1) Dereference an alias (A name reference that is an alias)
846      *    Aliases are not nested, the alias always points to the final object
847      */
848     if ((Op->Asl.ParseOpcode != PARSEOP_ALIAS) &&
849         (Node->Type == ACPI_TYPE_LOCAL_ALIAS))
850     {
851         /* This node points back to the original PARSEOP_ALIAS */
852 
853         NextOp = Node->Op;
854 
855         /* The first child is the alias target op */
856 
857         NextOp = NextOp->Asl.Child;
858 
859         /* That in turn points back to original target alias node */
860 
861         if (NextOp->Asl.Node)
862         {
863             Node = NextOp->Asl.Node;
864         }
865 
866         /* Else - forward reference to alias, will be resolved later */
867     }
868 
869     /* 2) Check for a reference to a resource descriptor */
870 
871     if ((Node->Type == ACPI_TYPE_LOCAL_RESOURCE_FIELD) ||
872         (Node->Type == ACPI_TYPE_LOCAL_RESOURCE))
873     {
874         /*
875          * This was a reference to a field within a resource descriptor.
876          * Extract the associated field offset (either a bit or byte
877          * offset depending on the field type) and change the named
878          * reference into an integer for AML code generation
879          */
880         Offset = Node->Value;
881         TagBitLength = Node->Length;
882 
883         /*
884          * If a field is being created, generate the length (in bits) of
885          * the field. Note: Opcodes other than CreateXxxField and Index
886          * can come through here. For other opcodes, we just need to
887          * convert the resource tag reference to an integer offset.
888          */
889         switch (Op->Asl.Parent->Asl.AmlOpcode)
890         {
891         case AML_CREATE_FIELD_OP: /* Variable "Length" field, in bits */
892             /*
893              * We know the length operand is an integer constant because
894              * we know that it contains a reference to a resource
895              * descriptor tag.
896              */
897             FieldBitLength = (UINT32) Op->Asl.Next->Asl.Value.Integer;
898             break;
899 
900         case AML_CREATE_BIT_FIELD_OP:
901 
902             FieldBitLength = 1;
903             break;
904 
905         case AML_CREATE_BYTE_FIELD_OP:
906         case AML_INDEX_OP:
907 
908             FieldBitLength = 8;
909             break;
910 
911         case AML_CREATE_WORD_FIELD_OP:
912 
913             FieldBitLength = 16;
914             break;
915 
916         case AML_CREATE_DWORD_FIELD_OP:
917 
918             FieldBitLength = 32;
919             break;
920 
921         case AML_CREATE_QWORD_FIELD_OP:
922 
923             FieldBitLength = 64;
924             break;
925 
926         default:
927 
928             FieldBitLength = 0;
929             break;
930         }
931 
932         /* Check the field length against the length of the resource tag */
933 
934         if (FieldBitLength)
935         {
936             if (TagBitLength < FieldBitLength)
937             {
938                 Message = ASL_MSG_TAG_SMALLER;
939             }
940             else if (TagBitLength > FieldBitLength)
941             {
942                 Message = ASL_MSG_TAG_LARGER;
943             }
944 
945             if (Message)
946             {
947                 sprintf (AslGbl_MsgBuffer,
948                     "Size mismatch, Tag: %u bit%s, Field: %u bit%s",
949                     TagBitLength, (TagBitLength > 1) ? "s" : "",
950                     FieldBitLength, (FieldBitLength > 1) ? "s" : "");
951 
952                 AslError (ASL_WARNING, Message, Op, AslGbl_MsgBuffer);
953             }
954         }
955 
956         /* Convert the BitOffset to a ByteOffset for certain opcodes */
957 
958         switch (Op->Asl.Parent->Asl.AmlOpcode)
959         {
960         case AML_CREATE_BYTE_FIELD_OP:
961         case AML_CREATE_WORD_FIELD_OP:
962         case AML_CREATE_DWORD_FIELD_OP:
963         case AML_CREATE_QWORD_FIELD_OP:
964         case AML_INDEX_OP:
965 
966             Offset = ACPI_DIV_8 (Offset);
967             break;
968 
969         default:
970 
971             break;
972         }
973 
974         /* Now convert this node to an integer whose value is the field offset */
975 
976         Op->Asl.AmlLength = 0;
977         Op->Asl.ParseOpcode = PARSEOP_INTEGER;
978         Op->Asl.Value.Integer = (UINT64) Offset;
979         Op->Asl.CompileFlags |= OP_IS_RESOURCE_FIELD;
980 
981         OpcGenerateAmlOpcode (Op);
982     }
983 
984     /* 3) Check for a method invocation */
985 
986     else if ((((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) || (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)) &&
987                 (Node->Type == ACPI_TYPE_METHOD) &&
988                 (Op->Asl.Parent) &&
989                 (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_METHOD))   ||
990 
991                 (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
992     {
993         /*
994          * A reference to a method within one of these opcodes is not an
995          * invocation of the method, it is simply a reference to the method.
996          *
997          * September 2016: Removed DeRefOf from this list
998          * July 2020: Added Alias to this list
999          */
1000         if ((Op->Asl.Parent) &&
1001             ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_REFOF)     ||
1002             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_PACKAGE)    ||
1003             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_VAR_PACKAGE)||
1004             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_OBJECTTYPE) ||
1005             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_ALIAS)))
1006         {
1007             return_ACPI_STATUS (AE_OK);
1008         }
1009 
1010         /*
1011          * There are two types of method invocation:
1012          * 1) Invocation with arguments -- the parser recognizes this
1013          *    as a METHODCALL.
1014          * 2) Invocation with no arguments --the parser cannot determine that
1015          *    this is a method invocation, therefore we have to figure it out
1016          *    here.
1017          */
1018         if (Node->Type != ACPI_TYPE_METHOD)
1019         {
1020             sprintf (AslGbl_MsgBuffer, "%s is a %s",
1021                 Op->Asl.ExternalName, AcpiUtGetTypeName (Node->Type));
1022 
1023             AslError (ASL_ERROR, ASL_MSG_NOT_METHOD, Op, AslGbl_MsgBuffer);
1024             return_ACPI_STATUS (AE_OK);
1025         }
1026 
1027         /* Save the method node in the caller's op */
1028 
1029         Op->Asl.Node = Node;
1030         if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF)
1031         {
1032             return_ACPI_STATUS (AE_OK);
1033         }
1034 
1035         /*
1036          * This is a method invocation, with or without arguments.
1037          * Count the number of arguments, each appears as a child
1038          * under the parent node
1039          */
1040         Op->Asl.ParseOpcode = PARSEOP_METHODCALL;
1041         UtSetParseOpName (Op);
1042 
1043         PassedArgs = 0;
1044         NextOp = Op->Asl.Child;
1045 
1046         while (NextOp)
1047         {
1048             PassedArgs++;
1049             NextOp = NextOp->Asl.Next;
1050         }
1051 
1052         if (Node->Value != ASL_EXTERNAL_METHOD_UNKNOWN_PARAMS &&
1053             Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
1054         {
1055             /*
1056              * Check the parsed arguments with the number expected by the
1057              * method declaration itself
1058              */
1059             if (PassedArgs != Node->Value)
1060             {
1061                 if (Node->Flags & ANOBJ_IS_EXTERNAL)
1062                 {
1063                     sprintf (AslGbl_MsgBuffer,
1064                         "according to previous use, %s requires %u",
1065                         Op->Asl.ExternalName, Node->Value);
1066                 }
1067                 else
1068                 {
1069                     sprintf (AslGbl_MsgBuffer, "%s requires %u", Op->Asl.ExternalName,
1070                         Node->Value);
1071                 }
1072 
1073                 if (PassedArgs < Node->Value)
1074                 {
1075                     AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_LO, Op, AslGbl_MsgBuffer);
1076                 }
1077                 else
1078                 {
1079                     AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_HI, Op, AslGbl_MsgBuffer);
1080                 }
1081             }
1082         }
1083 
1084         /*
1085          * At this point, a method call to an external method has been
1086          * detected. As of 11/19/2019, iASL does not support parameter counts
1087          * for methods declared as external. Therefore, save the parameter
1088          * count of the first method call and use this count check other
1089          * method calls to ensure that the methods are being called with the
1090          * same amount of parameters.
1091          */
1092         else if (Node->Type == ACPI_TYPE_METHOD &&
1093             (Node->Flags & ANOBJ_IS_EXTERNAL) &&
1094             Node->Value == ASL_EXTERNAL_METHOD_UNKNOWN_PARAMS &&
1095             Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
1096         {
1097             Node->Value = PassedArgs;
1098         }
1099     }
1100 
1101     /* 4) Check for an ASL Field definition */
1102 
1103     else if ((Op->Asl.Parent) &&
1104             ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_FIELD)     ||
1105              (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_BANKFIELD)))
1106     {
1107         /*
1108          * Offset checking for fields. If the parent operation region has a
1109          * constant length (known at compile time), we can check fields
1110          * defined in that region against the region length. This will catch
1111          * fields and field units that cannot possibly fit within the region.
1112          *
1113          * Note: Index fields do not directly reference an operation region,
1114          * thus they are not included in this check.
1115          */
1116         if (Op == Op->Asl.Parent->Asl.Child)
1117         {
1118             /*
1119              * This is the first child of the field node, which is
1120              * the name of the region. Get the parse node for the
1121              * region -- which contains the length of the region.
1122              */
1123             OwningOp = Node->Op;
1124             Op->Asl.Parent->Asl.ExtraValue =
1125                 ACPI_MUL_8 ((UINT32) OwningOp->Asl.Value.Integer);
1126 
1127             /* Examine the field access width */
1128 
1129             switch ((UINT8) Op->Asl.Parent->Asl.Value.Integer)
1130             {
1131             case AML_FIELD_ACCESS_ANY:
1132             case AML_FIELD_ACCESS_BYTE:
1133             case AML_FIELD_ACCESS_BUFFER:
1134             default:
1135 
1136                 MinimumLength = 1;
1137                 break;
1138 
1139             case AML_FIELD_ACCESS_WORD:
1140 
1141                 MinimumLength = 2;
1142                 break;
1143 
1144             case AML_FIELD_ACCESS_DWORD:
1145 
1146                 MinimumLength = 4;
1147                 break;
1148 
1149             case AML_FIELD_ACCESS_QWORD:
1150 
1151                 MinimumLength = 8;
1152                 break;
1153             }
1154 
1155             /*
1156              * Is the region at least as big as the access width?
1157              * Note: DataTableRegions have 0 length
1158              */
1159             if (((UINT32) OwningOp->Asl.Value.Integer) &&
1160                 ((UINT32) OwningOp->Asl.Value.Integer < MinimumLength))
1161             {
1162                 AslError (ASL_ERROR, ASL_MSG_FIELD_ACCESS_WIDTH, Op, NULL);
1163             }
1164 
1165             /*
1166              * Check EC/CMOS/SMBUS fields to make sure that the correct
1167              * access type is used (BYTE for EC/CMOS, BUFFER for SMBUS)
1168              */
1169             SpaceIdOp = OwningOp->Asl.Child->Asl.Next;
1170             switch ((UINT32) SpaceIdOp->Asl.Value.Integer)
1171             {
1172             case ACPI_ADR_SPACE_EC:
1173             case ACPI_ADR_SPACE_CMOS:
1174             case ACPI_ADR_SPACE_GPIO:
1175 
1176                 if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
1177                     AML_FIELD_ACCESS_BYTE)
1178                 {
1179                     AslError (ASL_ERROR, ASL_MSG_REGION_BYTE_ACCESS, Op, NULL);
1180                 }
1181                 break;
1182 
1183             case ACPI_ADR_SPACE_SMBUS:
1184             case ACPI_ADR_SPACE_IPMI:
1185             case ACPI_ADR_SPACE_GSBUS:
1186 
1187                 if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
1188                     AML_FIELD_ACCESS_BUFFER)
1189                 {
1190                     AslError (ASL_ERROR, ASL_MSG_REGION_BUFFER_ACCESS, Op, NULL);
1191                 }
1192                 break;
1193 
1194             default:
1195 
1196                 /* Nothing to do for other address spaces */
1197 
1198                 break;
1199             }
1200         }
1201         else
1202         {
1203             /*
1204              * This is one element of the field list. Check to make sure
1205              * that it does not go beyond the end of the parent operation region.
1206              *
1207              * In the code below:
1208              *    Op->Asl.Parent->Asl.ExtraValue      - Region Length (bits)
1209              *    Op->Asl.ExtraValue                  - Field start offset (bits)
1210              *    Op->Asl.Child->Asl.Value.Integer32  - Field length (bits)
1211              *    Op->Asl.Child->Asl.ExtraValue       - Field access width (bits)
1212              */
1213             if (Op->Asl.Parent->Asl.ExtraValue && Op->Asl.Child)
1214             {
1215                 XfCheckFieldRange (Op,
1216                     Op->Asl.Parent->Asl.ExtraValue,
1217                     Op->Asl.ExtraValue,
1218                     (UINT32) Op->Asl.Child->Asl.Value.Integer,
1219                     Op->Asl.Child->Asl.ExtraValue);
1220             }
1221         }
1222     }
1223 
1224     /*
1225      * 5) Check for external resolution
1226      *
1227      * By this point, everything should be loaded in the namespace. If a
1228      * namespace lookup results in a namespace node that is an external, it
1229      * means that this named object was not defined in the input ASL. This
1230      * causes issues because there are plenty of incidents where developers
1231      * use the external keyword to suppress compiler errors about undefined
1232      * objects. Note: this only applies when compiling multiple definition
1233      * blocks.
1234      *
1235      * Do not check for external resolution in the following cases:
1236      *
1237      * case 1) External (ABCD)
1238      *
1239      *         This declares ABCD as an external so there is no requirement for
1240      *         ABCD to be loaded in the namespace when analyzing the actual
1241      *         External() statement.
1242      *
1243      * case 2) CondRefOf (ABCD)
1244      *
1245      *         This operator will query the ACPI namespace on the existence of
1246      *         ABCD. If ABCD does not exist, this operator will return a 0
1247      *         without incurring AML runtime errors. Therefore, ABCD is allowed
1248      *         to not exist when analyzing the CondRefOf operator.
1249      *
1250      * case 3) External (ABCD)
1251      *         if (CondRefOf (ABCD))
1252      *         {
1253      *             Store (0, ABCD)
1254      *         }
1255      *
1256      *         In this case, ABCD is accessed only if it exists due to the if
1257      *         statement so there is no need to flag the ABCD nested in the
1258      *         store operator.
1259      */
1260     if (AslGbl_ParseTreeRoot->Asl.Child && AslGbl_ParseTreeRoot->Asl.Child->Asl.Next &&
1261         (Node->Flags & ANOBJ_IS_EXTERNAL) &&
1262         Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL &&
1263         Op->Asl.ParseOpcode != PARSEOP_EXTERNAL &&
1264         Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_CONDREFOF &&
1265         !XfRefIsGuardedByIfCondRefOf (Node, Op))
1266     {
1267         ExternalPath = AcpiNsGetNormalizedPathname (Node, TRUE);
1268         sprintf (AslGbl_MsgBuffer, "full path of external object: %s",
1269             ExternalPath);
1270         AslDualParseOpError (ASL_ERROR, ASL_MSG_UNDEFINED_EXTERNAL, Op, NULL,
1271             ASL_MSG_EXTERNAL_FOUND_HERE, Node->Op, AslGbl_MsgBuffer);
1272         if (ExternalPath)
1273         {
1274             ACPI_FREE (ExternalPath);
1275         }
1276     }
1277 
1278     /* 5) Check for a connection object */
1279 #if 0
1280     else if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONNECTION)
1281     {
1282         return_ACPI_STATUS (Status);
1283     }
1284 #endif
1285 
1286     Op->Asl.Node = Node;
1287     return_ACPI_STATUS (Status);
1288 }
1289 
1290 
1291 /*******************************************************************************
1292  *
1293  * FUNCTION:    XfRefIsGuardedByIfCondRefOf
1294  *
1295  * PARAMETERS:  Node        - Named object reference node
1296  *              Op          - Named object reference parse node
1297  *
1298  * RETURN:      BOOLEAN
1299  *
1300  * DESCRIPTION: returns true if Op checked inside if (CondRefOf (...))
1301  *              refers to Node.
1302  *
1303  ******************************************************************************/
1304 
1305 static BOOLEAN
1306 XfRefIsGuardedByIfCondRefOf (
1307     ACPI_NAMESPACE_NODE     *Node,
1308     ACPI_PARSE_OBJECT       *Op)
1309 {
1310     ACPI_PARSE_OBJECT       *Parent = Op->Asl.Parent;
1311 
1312 
1313     while (Parent)
1314     {
1315         if (Parent->Asl.ParseOpcode == PARSEOP_IF &&
1316             XfFindCondRefOfName (Node, Parent->Asl.Child))
1317         {
1318             return (TRUE);
1319         }
1320 
1321         Parent = Parent->Asl.Parent;
1322     }
1323 
1324     return (FALSE);
1325 }
1326 
1327 
1328 /*******************************************************************************
1329  *
1330  * FUNCTION:    XfRefIsGuardedByIfCondRefOf
1331  *
1332  * PARAMETERS:  Node        - Named object reference node
1333  *              Op          - Named object reference parse node
1334  *
1335  * RETURN:      BOOLEAN
1336  *
1337  * DESCRIPTION: returns true if Op checked inside if (CondRefOf (...))
1338  *              refers to Node.
1339  *
1340  ******************************************************************************/
1341 
1342 static BOOLEAN
1343 XfFindCondRefOfName (
1344     ACPI_NAMESPACE_NODE     *Node,
1345     ACPI_PARSE_OBJECT       *Op)
1346 {
1347     BOOLEAN                 CondRefOfFound = FALSE;
1348 
1349 
1350     if (!Op)
1351     {
1352         return (FALSE);
1353     }
1354 
1355     switch (Op->Asl.ParseOpcode)
1356     {
1357     case PARSEOP_CONDREFOF:
1358 
1359         return (Op->Asl.Child->Common.Node == Node);
1360         break;
1361 
1362     case PARSEOP_LAND:
1363 
1364         CondRefOfFound = XfFindCondRefOfName (Node, Op->Asl.Child);
1365         if (CondRefOfFound)
1366         {
1367             return (TRUE);
1368         }
1369 
1370         return (XfFindCondRefOfName (Node, Op->Asl.Child->Asl.Next));
1371         break;
1372 
1373     default:
1374 
1375         return (FALSE);
1376         break;
1377     }
1378 }
1379 
1380 
1381 /*******************************************************************************
1382  *
1383  * FUNCTION:    XfNamespaceLocateEnd
1384  *
1385  * PARAMETERS:  ASL_WALK_CALLBACK
1386  *
1387  * RETURN:      Status
1388  *
1389  * DESCRIPTION: Ascending callback used during cross reference. We only
1390  *              need to worry about scope management here.
1391  *
1392  ******************************************************************************/
1393 
1394 static ACPI_STATUS
1395 XfNamespaceLocateEnd (
1396     ACPI_PARSE_OBJECT       *Op,
1397     UINT32                  Level,
1398     void                    *Context)
1399 {
1400     ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
1401     const ACPI_OPCODE_INFO  *OpInfo;
1402 
1403 
1404     ACPI_FUNCTION_TRACE (XfNamespaceLocateEnd);
1405 
1406 
1407     /* We are only interested in opcodes that have an associated name */
1408 
1409     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
1410     if (!(OpInfo->Flags & AML_NAMED))
1411     {
1412         return_ACPI_STATUS (AE_OK);
1413     }
1414 
1415     /* Not interested in name references, we did not open a scope for them */
1416 
1417     if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
1418         (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
1419         (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
1420         (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL))
1421     {
1422         return_ACPI_STATUS (AE_OK);
1423     }
1424 
1425     /* Pop the scope stack if necessary */
1426 
1427     if (AcpiNsOpensScope (AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode)))
1428     {
1429 
1430         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
1431             "%s: Popping scope for Op %p\n",
1432             AcpiUtGetTypeName (OpInfo->ObjectType), Op));
1433 
1434         (void) AcpiDsScopeStackPop (WalkState);
1435     }
1436 
1437     return_ACPI_STATUS (AE_OK);
1438 }
1439 
1440 
1441 /*******************************************************************************
1442  *
1443  * FUNCTION:    XfValidateCrossReference
1444  *
1445  * PARAMETERS:  Op                      - Parse Op that references the object
1446  *              OpInfo                  - Parse Op info struct
1447  *              Node                    - Node for the referenced object
1448  *
1449  * RETURN:      TRUE if the reference is legal, FALSE otherwise
1450  *
1451  * DESCRIPTION: Determine if a reference to another object is allowed.
1452  *
1453  * EXAMPLE:
1454  *      Method (A) {Name (INT1, 1)}     Declaration of object INT1
1455  *      Method (B) (Store (2, \A.INT1)} Illegal reference to object INT1
1456  *                                      (INT1 is temporary, valid only during
1457  *                                      execution of A)
1458  *
1459  * NOTES:
1460  *      A null pointer returned by either UtGetParentMethodOp or
1461  *      UtGetParentMethodNode indicates that the parameter object is not
1462  *      within a control method.
1463  *
1464  *      Five cases are handled: Case(Op, Node)
1465  *      1) Case(0,0): Op is not within a method, Node is not    --> OK
1466  *      2) Case(0,1): Op is not within a method, but Node is    --> Illegal
1467  *      3) Case(1,0): Op is within a method, Node is not        --> OK
1468  *      4) Case(1,1): Both are within the same method           --> OK
1469  *      5) Case(1,1): Both are in methods, but not same method  --> Illegal
1470  *
1471  ******************************************************************************/
1472 
1473 static BOOLEAN
1474 XfValidateCrossReference (
1475     ACPI_PARSE_OBJECT       *Op,
1476     const ACPI_OPCODE_INFO  *OpInfo,
1477     ACPI_NAMESPACE_NODE     *Node)
1478 {
1479     ACPI_PARSE_OBJECT       *ReferencingMethodOp;
1480     ACPI_NAMESPACE_NODE     *ReferencedMethodNode;
1481 
1482 
1483     /* Ignore actual named (and related) object declarations */
1484 
1485     if (OpInfo->Flags & (AML_NAMED | AML_CREATE | AML_DEFER | AML_HAS_ARGS))
1486     {
1487         return (TRUE);
1488     }
1489 
1490     /*
1491      * 1) Search upwards in parse tree for owner of the referencing object
1492      * 2) Search upwards in namespace to find the owner of the referenced object
1493      */
1494     ReferencingMethodOp = UtGetParentMethodOp (Op);
1495     ReferencedMethodNode = UtGetParentMethodNode (Node);
1496 
1497     if (!ReferencingMethodOp && !ReferencedMethodNode)
1498     {
1499         /*
1500          * 1) Case (0,0): Both Op and Node are not within methods
1501          * --> OK
1502          */
1503         return (TRUE);
1504     }
1505 
1506     if (!ReferencingMethodOp && ReferencedMethodNode)
1507     {
1508         /*
1509          * 2) Case (0,1): Op is not in a method, but Node is within a
1510          * method --> illegal
1511          */
1512         return (FALSE);
1513     }
1514     else if (ReferencingMethodOp && !ReferencedMethodNode)
1515     {
1516         /*
1517          * 3) Case (1,0): Op is within a method, but Node is not
1518          * --> OK
1519          */
1520         return (TRUE);
1521     }
1522     else if (ReferencingMethodOp->Asl.Node == ReferencedMethodNode)
1523     {
1524         /*
1525          * 4) Case (1,1): Both Op and Node are within the same method
1526          * --> OK
1527          */
1528         return (TRUE);
1529     }
1530     else
1531     {
1532         /*
1533          * 5) Case (1,1), Op and Node are in different methods
1534          * --> Illegal
1535          */
1536         return (FALSE);
1537     }
1538 }
1539