xref: /freebsd/sys/contrib/dev/acpica/compiler/aslxref.c (revision 4e99f45480598189d49d45a825533a6c9e12f02c)
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 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 
437 
438     ACPI_FUNCTION_TRACE_PTR (XfNamespaceLocateBegin, Op);
439 
440 
441     if ((Op->Asl.AmlOpcode == AML_METHOD_OP) && Op->Asl.Node)
442     {
443         Node = Op->Asl.Node;
444 
445         /* Support for method LocalX/ArgX analysis */
446 
447         if (!Node->MethodLocals)
448         {
449             /* Create local/arg info blocks */
450 
451             MethodLocals = UtLocalCalloc (
452                 sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_LOCALS);
453             Node->MethodLocals = MethodLocals;
454 
455             MethodArgs = UtLocalCalloc (
456                 sizeof (ASL_METHOD_LOCAL) * ACPI_METHOD_NUM_ARGS);
457             Node->MethodArgs = MethodArgs;
458 
459             /*
460              * Get the method argument count
461              * First, get the name node
462              */
463             NextOp = Op->Asl.Child;
464 
465             /* Get the NumArguments node */
466 
467             NextOp = NextOp->Asl.Next;
468             Node->ArgCount = (UINT8)
469                 (((UINT8) NextOp->Asl.Value.Integer) & 0x07);
470 
471             /* We will track all possible ArgXs */
472 
473             for (i = 0; i < ACPI_METHOD_NUM_ARGS; i++)
474             {
475                 if (i < Node->ArgCount)
476                 {
477                     /* Real Args are always "initialized" */
478 
479                     MethodArgs[i].Flags = ASL_ARG_INITIALIZED;
480                 }
481                 else
482                 {
483                     /* Other ArgXs can be used as locals */
484 
485                     MethodArgs[i].Flags = ASL_ARG_IS_LOCAL;
486                 }
487 
488                 MethodArgs[i].Op = Op;
489             }
490         }
491     }
492 
493     /*
494      * If this node is the actual declaration of a name
495      * [such as the XXXX name in "Method (XXXX)"],
496      * we are not interested in it here. We only care about names that are
497      * references to other objects within the namespace and the parent objects
498      * of name declarations
499      */
500     if (Op->Asl.CompileFlags & OP_IS_NAME_DECLARATION)
501     {
502         return_ACPI_STATUS (AE_OK);
503     }
504 
505     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
506 
507     /* Check method LocalX variables */
508 
509     if (OpInfo->Type == AML_TYPE_LOCAL_VARIABLE)
510     {
511         /* Find parent method Op */
512 
513         NextOp = UtGetParentMethodOp (Op);
514         if (!NextOp)
515         {
516             return_ACPI_STATUS (AE_OK);
517         }
518 
519         /* Get method node */
520 
521         Node = NextOp->Asl.Node;
522 
523         RegisterNumber = Op->Asl.AmlOpcode & 0x0007; /* 0x60 through 0x67 */
524         MethodLocals = Node->MethodLocals;
525 
526         if (Op->Asl.CompileFlags & OP_IS_TARGET)
527         {
528             /* Local is being initialized */
529 
530             MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_INITIALIZED;
531             MethodLocals[RegisterNumber].Op = Op;
532 
533             return_ACPI_STATUS (AE_OK);
534         }
535 
536         /* Mark this Local as referenced */
537 
538         MethodLocals[RegisterNumber].Flags |= ASL_LOCAL_REFERENCED;
539         MethodLocals[RegisterNumber].Op = Op;
540 
541         return_ACPI_STATUS (AE_OK);
542     }
543 
544     /* Check method ArgX variables */
545 
546     if (OpInfo->Type == AML_TYPE_METHOD_ARGUMENT)
547     {
548         /* Find parent method Op */
549 
550         NextOp = UtGetParentMethodOp (Op);
551         if (!NextOp)
552         {
553             return_ACPI_STATUS (AE_OK);
554         }
555 
556         /* Get method node */
557 
558         Node = NextOp->Asl.Node;
559 
560         /* Get Arg # */
561 
562         RegisterNumber = Op->Asl.AmlOpcode - AML_ARG0; /* 0x68 through 0x6F */
563         MethodArgs = Node->MethodArgs;
564 
565         /* Mark this Arg as referenced */
566 
567         MethodArgs[RegisterNumber].Flags |= ASL_ARG_REFERENCED;
568         MethodArgs[RegisterNumber].Op = Op;
569 
570         if (Op->Asl.CompileFlags & OP_IS_TARGET)
571         {
572             /* Arg is being initialized */
573 
574             MethodArgs[RegisterNumber].Flags |= ASL_ARG_INITIALIZED;
575         }
576 
577         return_ACPI_STATUS (AE_OK);
578     }
579 
580     /*
581      * After method ArgX and LocalX, we are only interested in opcodes
582      * that have an associated name
583      */
584     if ((!(OpInfo->Flags & AML_NAMED)) &&
585         (!(OpInfo->Flags & AML_CREATE)) &&
586         (Op->Asl.ParseOpcode != PARSEOP_NAMESTRING) &&
587         (Op->Asl.ParseOpcode != PARSEOP_NAMESEG)    &&
588         (Op->Asl.ParseOpcode != PARSEOP_METHODCALL) &&
589         (Op->Asl.ParseOpcode != PARSEOP_EXTERNAL))
590     {
591         return_ACPI_STATUS (AE_OK);
592     }
593 
594     /*
595      * We must enable the "search-to-root" for single NameSegs, but
596      * we have to be very careful about opening up scopes
597      */
598     Flags = ACPI_NS_SEARCH_PARENT;
599     if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
600         (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
601         (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
602         (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL)   ||
603         (Op->Asl.ParseOpcode == PARSEOP_CONDREFOF))
604     {
605         /*
606          * These are name references, do not push the scope stack
607          * for them.
608          */
609         Flags |= ACPI_NS_DONT_OPEN_SCOPE;
610     }
611 
612     /* Get the NamePath from the appropriate place */
613 
614     if (OpInfo->Flags & AML_NAMED)
615     {
616         /* For nearly all NAMED operators, the name reference is the first child */
617 
618         Path = Op->Asl.Child->Asl.Value.String;
619         if (Op->Asl.AmlOpcode == AML_ALIAS_OP)
620         {
621             /*
622              * ALIAS is the only oddball opcode, the name declaration
623              * (alias name) is the second operand
624              */
625             Path = Op->Asl.Child->Asl.Next->Asl.Value.String;
626         }
627     }
628     else if (OpInfo->Flags & AML_CREATE)
629     {
630         /* Name must appear as the last parameter */
631 
632         NextOp = Op->Asl.Child;
633         while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
634         {
635             NextOp = NextOp->Asl.Next;
636         }
637 
638         Path = NextOp->Asl.Value.String;
639     }
640     else
641     {
642         Path = Op->Asl.Value.String;
643     }
644 
645     ObjectType = AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode);
646     ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
647         "Type=%s\n", AcpiUtGetTypeName (ObjectType)));
648 
649     /*
650      * Lookup the name in the namespace. Name must exist at this point, or it
651      * is an invalid reference.
652      *
653      * The namespace is also used as a lookup table for references to resource
654      * descriptors and the fields within them.
655      */
656     AslGbl_NsLookupCount++;
657 
658     Status = AcpiNsLookup (WalkState->ScopeInfo, Path, ObjectType,
659         ACPI_IMODE_EXECUTE, Flags, WalkState, &Node);
660     if (ACPI_FAILURE (Status))
661     {
662         if (Status == AE_NOT_FOUND)
663         {
664             /*
665              * We didn't find the name reference by path -- we can qualify this
666              * a little better before we print an error message
667              */
668 
669             if ((Op->Asl.Parent) &&
670                 (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF))
671             {
672                 /*
673                  * One special case: CondRefOf operator - if the name doesn't
674                  * exist at this point, it means that there's no actual or
675                  * external declaration. If the name is not found, just ignore
676                  * it, the point of the operator is to determine if the name
677                  * exists at runtime. We wanted to see if this named object
678                  * exists to facilitate analysis to allow protected usage of
679                  * undeclared externals.
680                  */
681                 return_ACPI_STATUS (AE_OK);
682             }
683             else if (strlen (Path) == ACPI_NAMESEG_SIZE)
684             {
685                 /* A simple, one-segment ACPI name */
686 
687                 if (XfObjectExists (Path))
688                 {
689                     /*
690                      * There exists such a name, but we couldn't get to it
691                      * from this scope
692                      */
693                     AslError (ASL_ERROR, ASL_MSG_NOT_REACHABLE, Op,
694                         Op->Asl.ExternalName);
695                 }
696                 else
697                 {
698                     /* The name doesn't exist, period */
699 
700                     AslError (ASL_ERROR, ASL_MSG_NOT_EXIST,
701                         Op, Op->Asl.ExternalName);
702                 }
703             }
704             else
705             {
706                 /* The NamePath contains multiple NameSegs */
707 
708                 if ((OpInfo->Flags & AML_CREATE) ||
709                     (OpInfo->ObjectType == ACPI_TYPE_LOCAL_ALIAS))
710                 {
711                     /*
712                      * The new name is the last parameter. For the
713                      * CreateXXXXField and Alias operators
714                      */
715                     NextOp = Op->Asl.Child;
716                     while (!(NextOp->Asl.CompileFlags & OP_IS_NAME_DECLARATION))
717                     {
718                         NextOp = NextOp->Asl.Next;
719                     }
720 
721                     AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, NextOp,
722                         NextOp->Asl.ExternalName);
723                 }
724                 else if (OpInfo->Flags & AML_NAMED)
725                 {
726                     /* The new name is the first parameter */
727 
728                     AslError (ASL_ERROR, ASL_MSG_PREFIX_NOT_EXIST, Op,
729                         Op->Asl.ExternalName);
730                 }
731                 else if (Path[0] == AML_ROOT_PREFIX)
732                 {
733                     /* Full namepath from root, the object does not exist */
734 
735                     AslError (ASL_ERROR, ASL_MSG_NOT_EXIST, Op,
736                         Op->Asl.ExternalName);
737                 }
738                 else
739                 {
740                     /*
741                      * Generic "not found" error. Cannot determine whether it
742                      * doesn't exist or just can't be reached. However, we
743                      * can differentiate between a NameSeg vs. NamePath.
744                      */
745                     if (strlen (Op->Asl.ExternalName) == ACPI_NAMESEG_SIZE)
746                     {
747                         AslError (ASL_ERROR, ASL_MSG_NOT_FOUND, Op,
748                             Op->Asl.ExternalName);
749                     }
750                     else
751                     {
752                         AslError (ASL_ERROR, ASL_MSG_NAMEPATH_NOT_EXIST, Op,
753                             Op->Asl.ExternalName);
754                     }
755                 }
756             }
757 
758             Status = AE_OK;
759         }
760 
761         return_ACPI_STATUS (Status);
762     }
763 
764     /* Check for an attempt to access an object in another method */
765 
766     if (!XfValidateCrossReference (Op, OpInfo, Node))
767     {
768         AslError (ASL_ERROR, ASL_MSG_TEMPORARY_OBJECT, Op,
769             Op->Asl.ExternalName);
770         return_ACPI_STATUS (Status);
771     }
772 
773    /* Object was found above, check for an illegal forward reference */
774 
775     if (Op->Asl.CompileFlags & OP_NOT_FOUND_DURING_LOAD)
776     {
777         /*
778          * During the load phase, this Op was flagged as a possible
779          * illegal forward reference. In other words, Op is a name path or
780          * name segment that refers to a named object declared after the
781          * reference. In this scinario, Node refers to the actual declaration
782          * and Op is a parse node that references the named object.
783          *
784          * Note:
785          *
786          * Object references inside of control methods are allowed to
787          * refer to objects declared outside of control methods.
788          *
789          * If the declaration and reference are both contained inside of the
790          * same method or outside of any method, this is a forward reference
791          * and should be reported as a compiler error.
792          */
793         DeclarationParentMethod = UtGetParentMethodNode (Node);
794         ReferenceParentMethod = UtGetParentMethodOp (Op);
795 
796         /* case 1: declaration and reference are both outside of method */
797 
798         if (!ReferenceParentMethod && !DeclarationParentMethod)
799         {
800             AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
801                 Op->Asl.ExternalName);
802         }
803 
804         /* case 2: declaration and reference are both inside of the same method */
805 
806         else if (ReferenceParentMethod && DeclarationParentMethod &&
807             ReferenceParentMethod == DeclarationParentMethod->Op)
808         {
809              AslError (ASL_ERROR, ASL_MSG_ILLEGAL_FORWARD_REF, Op,
810                 Op->Asl.ExternalName);
811         }
812     }
813 
814     /* Check for a reference vs. name declaration */
815 
816     if (!(OpInfo->Flags & AML_NAMED) &&
817         !(OpInfo->Flags & AML_CREATE))
818     {
819         /* This node has been referenced, mark it for reference check */
820 
821         Node->Flags |= ANOBJ_IS_REFERENCED;
822     }
823 
824     /*
825      * Attempt to optimize the NamePath
826      *
827      * One special case: CondRefOf operator - not all AML interpreter
828      * implementations expect optimized namepaths as a parameter to this
829      * operator. They require relative name paths with prefix operators or
830      * namepaths starting with the root scope.
831      *
832      * Other AML interpreter implementations do not perform the namespace
833      * search that starts at the current scope and recursively searching the
834      * parent scope until the root scope. The lack of search is only known to
835      * occur for the namestring parameter for the CondRefOf operator.
836      */
837     if ((Op->Asl.Parent) &&
838         (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_CONDREFOF))
839     {
840         OptOptimizeNamePath (Op, OpInfo->Flags, WalkState, Path, Node);
841     }
842 
843     /*
844      * 1) Dereference an alias (A name reference that is an alias)
845      *    Aliases are not nested, the alias always points to the final object
846      */
847     if ((Op->Asl.ParseOpcode != PARSEOP_ALIAS) &&
848         (Node->Type == ACPI_TYPE_LOCAL_ALIAS))
849     {
850         /* This node points back to the original PARSEOP_ALIAS */
851 
852         NextOp = Node->Op;
853 
854         /* The first child is the alias target op */
855 
856         NextOp = NextOp->Asl.Child;
857 
858         /* That in turn points back to original target alias node */
859 
860         if (NextOp->Asl.Node)
861         {
862             Node = NextOp->Asl.Node;
863         }
864 
865         /* Else - forward reference to alias, will be resolved later */
866     }
867 
868     /* 2) Check for a reference to a resource descriptor */
869 
870     if ((Node->Type == ACPI_TYPE_LOCAL_RESOURCE_FIELD) ||
871         (Node->Type == ACPI_TYPE_LOCAL_RESOURCE))
872     {
873         /*
874          * This was a reference to a field within a resource descriptor.
875          * Extract the associated field offset (either a bit or byte
876          * offset depending on the field type) and change the named
877          * reference into an integer for AML code generation
878          */
879         Offset = Node->Value;
880         TagBitLength = Node->Length;
881 
882         /*
883          * If a field is being created, generate the length (in bits) of
884          * the field. Note: Opcodes other than CreateXxxField and Index
885          * can come through here. For other opcodes, we just need to
886          * convert the resource tag reference to an integer offset.
887          */
888         switch (Op->Asl.Parent->Asl.AmlOpcode)
889         {
890         case AML_CREATE_FIELD_OP: /* Variable "Length" field, in bits */
891             /*
892              * We know the length operand is an integer constant because
893              * we know that it contains a reference to a resource
894              * descriptor tag.
895              */
896             FieldBitLength = (UINT32) Op->Asl.Next->Asl.Value.Integer;
897             break;
898 
899         case AML_CREATE_BIT_FIELD_OP:
900 
901             FieldBitLength = 1;
902             break;
903 
904         case AML_CREATE_BYTE_FIELD_OP:
905         case AML_INDEX_OP:
906 
907             FieldBitLength = 8;
908             break;
909 
910         case AML_CREATE_WORD_FIELD_OP:
911 
912             FieldBitLength = 16;
913             break;
914 
915         case AML_CREATE_DWORD_FIELD_OP:
916 
917             FieldBitLength = 32;
918             break;
919 
920         case AML_CREATE_QWORD_FIELD_OP:
921 
922             FieldBitLength = 64;
923             break;
924 
925         default:
926 
927             FieldBitLength = 0;
928             break;
929         }
930 
931         /* Check the field length against the length of the resource tag */
932 
933         if (FieldBitLength)
934         {
935             if (TagBitLength < FieldBitLength)
936             {
937                 Message = ASL_MSG_TAG_SMALLER;
938             }
939             else if (TagBitLength > FieldBitLength)
940             {
941                 Message = ASL_MSG_TAG_LARGER;
942             }
943 
944             if (Message)
945             {
946                 sprintf (AslGbl_MsgBuffer,
947                     "Size mismatch, Tag: %u bit%s, Field: %u bit%s",
948                     TagBitLength, (TagBitLength > 1) ? "s" : "",
949                     FieldBitLength, (FieldBitLength > 1) ? "s" : "");
950 
951                 AslError (ASL_WARNING, Message, Op, AslGbl_MsgBuffer);
952             }
953         }
954 
955         /* Convert the BitOffset to a ByteOffset for certain opcodes */
956 
957         switch (Op->Asl.Parent->Asl.AmlOpcode)
958         {
959         case AML_CREATE_BYTE_FIELD_OP:
960         case AML_CREATE_WORD_FIELD_OP:
961         case AML_CREATE_DWORD_FIELD_OP:
962         case AML_CREATE_QWORD_FIELD_OP:
963         case AML_INDEX_OP:
964 
965             Offset = ACPI_DIV_8 (Offset);
966             break;
967 
968         default:
969 
970             break;
971         }
972 
973         /* Now convert this node to an integer whose value is the field offset */
974 
975         Op->Asl.AmlLength = 0;
976         Op->Asl.ParseOpcode = PARSEOP_INTEGER;
977         Op->Asl.Value.Integer = (UINT64) Offset;
978         Op->Asl.CompileFlags |= OP_IS_RESOURCE_FIELD;
979 
980         OpcGenerateAmlOpcode (Op);
981     }
982 
983     /* 3) Check for a method invocation */
984 
985     else if ((((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) || (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)) &&
986                 (Node->Type == ACPI_TYPE_METHOD) &&
987                 (Op->Asl.Parent) &&
988                 (Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_METHOD))   ||
989 
990                 (Op->Asl.ParseOpcode == PARSEOP_METHODCALL))
991     {
992         /*
993          * A reference to a method within one of these opcodes is not an
994          * invocation of the method, it is simply a reference to the method.
995          *
996          * September 2016: Removed DeRefOf from this list
997          */
998         if ((Op->Asl.Parent) &&
999             ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_REFOF)     ||
1000             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_PACKAGE)    ||
1001             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_VAR_PACKAGE)||
1002             (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_OBJECTTYPE)))
1003         {
1004             return_ACPI_STATUS (AE_OK);
1005         }
1006 
1007         /*
1008          * There are two types of method invocation:
1009          * 1) Invocation with arguments -- the parser recognizes this
1010          *    as a METHODCALL.
1011          * 2) Invocation with no arguments --the parser cannot determine that
1012          *    this is a method invocation, therefore we have to figure it out
1013          *    here.
1014          */
1015         if (Node->Type != ACPI_TYPE_METHOD)
1016         {
1017             sprintf (AslGbl_MsgBuffer, "%s is a %s",
1018                 Op->Asl.ExternalName, AcpiUtGetTypeName (Node->Type));
1019 
1020             AslError (ASL_ERROR, ASL_MSG_NOT_METHOD, Op, AslGbl_MsgBuffer);
1021             return_ACPI_STATUS (AE_OK);
1022         }
1023 
1024         /* Save the method node in the caller's op */
1025 
1026         Op->Asl.Node = Node;
1027         if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONDREFOF)
1028         {
1029             return_ACPI_STATUS (AE_OK);
1030         }
1031 
1032         /*
1033          * This is a method invocation, with or without arguments.
1034          * Count the number of arguments, each appears as a child
1035          * under the parent node
1036          */
1037         Op->Asl.ParseOpcode = PARSEOP_METHODCALL;
1038         UtSetParseOpName (Op);
1039 
1040         PassedArgs = 0;
1041         NextOp = Op->Asl.Child;
1042 
1043         while (NextOp)
1044         {
1045             PassedArgs++;
1046             NextOp = NextOp->Asl.Next;
1047         }
1048 
1049         if (Node->Value != ASL_EXTERNAL_METHOD_UNKNOWN_PARAMS &&
1050             Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
1051         {
1052             /*
1053              * Check the parsed arguments with the number expected by the
1054              * method declaration itself
1055              */
1056             if (PassedArgs != Node->Value)
1057             {
1058                 if (Node->Flags & ANOBJ_IS_EXTERNAL)
1059                 {
1060                     sprintf (AslGbl_MsgBuffer,
1061                         "according to previous use, %s requires %u",
1062                         Op->Asl.ExternalName, Node->Value);
1063                 }
1064                 else
1065                 {
1066                     sprintf (AslGbl_MsgBuffer, "%s requires %u", Op->Asl.ExternalName,
1067                         Node->Value);
1068                 }
1069 
1070                 if (PassedArgs < Node->Value)
1071                 {
1072                     AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_LO, Op, AslGbl_MsgBuffer);
1073                 }
1074                 else
1075                 {
1076                     AslError (ASL_ERROR, ASL_MSG_ARG_COUNT_HI, Op, AslGbl_MsgBuffer);
1077                 }
1078             }
1079         }
1080 
1081         /*
1082          * At this point, a method call to an external method has been
1083          * detected. As of 11/19/2019, iASL does not support parameter counts
1084          * for methods declared as external. Therefore, save the parameter
1085          * count of the first method call and use this count check other
1086          * method calls to ensure that the methods are being called with the
1087          * same amount of parameters.
1088          */
1089         else if (Node->Type == ACPI_TYPE_METHOD &&
1090             (Node->Flags & ANOBJ_IS_EXTERNAL) &&
1091             Node->Value == ASL_EXTERNAL_METHOD_UNKNOWN_PARAMS &&
1092             Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL)
1093         {
1094             Node->Value = PassedArgs;
1095         }
1096     }
1097 
1098     /* 4) Check for an ASL Field definition */
1099 
1100     else if ((Op->Asl.Parent) &&
1101             ((Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_FIELD)     ||
1102              (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_BANKFIELD)))
1103     {
1104         /*
1105          * Offset checking for fields. If the parent operation region has a
1106          * constant length (known at compile time), we can check fields
1107          * defined in that region against the region length. This will catch
1108          * fields and field units that cannot possibly fit within the region.
1109          *
1110          * Note: Index fields do not directly reference an operation region,
1111          * thus they are not included in this check.
1112          */
1113         if (Op == Op->Asl.Parent->Asl.Child)
1114         {
1115             /*
1116              * This is the first child of the field node, which is
1117              * the name of the region. Get the parse node for the
1118              * region -- which contains the length of the region.
1119              */
1120             OwningOp = Node->Op;
1121             Op->Asl.Parent->Asl.ExtraValue =
1122                 ACPI_MUL_8 ((UINT32) OwningOp->Asl.Value.Integer);
1123 
1124             /* Examine the field access width */
1125 
1126             switch ((UINT8) Op->Asl.Parent->Asl.Value.Integer)
1127             {
1128             case AML_FIELD_ACCESS_ANY:
1129             case AML_FIELD_ACCESS_BYTE:
1130             case AML_FIELD_ACCESS_BUFFER:
1131             default:
1132 
1133                 MinimumLength = 1;
1134                 break;
1135 
1136             case AML_FIELD_ACCESS_WORD:
1137 
1138                 MinimumLength = 2;
1139                 break;
1140 
1141             case AML_FIELD_ACCESS_DWORD:
1142 
1143                 MinimumLength = 4;
1144                 break;
1145 
1146             case AML_FIELD_ACCESS_QWORD:
1147 
1148                 MinimumLength = 8;
1149                 break;
1150             }
1151 
1152             /*
1153              * Is the region at least as big as the access width?
1154              * Note: DataTableRegions have 0 length
1155              */
1156             if (((UINT32) OwningOp->Asl.Value.Integer) &&
1157                 ((UINT32) OwningOp->Asl.Value.Integer < MinimumLength))
1158             {
1159                 AslError (ASL_ERROR, ASL_MSG_FIELD_ACCESS_WIDTH, Op, NULL);
1160             }
1161 
1162             /*
1163              * Check EC/CMOS/SMBUS fields to make sure that the correct
1164              * access type is used (BYTE for EC/CMOS, BUFFER for SMBUS)
1165              */
1166             SpaceIdOp = OwningOp->Asl.Child->Asl.Next;
1167             switch ((UINT32) SpaceIdOp->Asl.Value.Integer)
1168             {
1169             case ACPI_ADR_SPACE_EC:
1170             case ACPI_ADR_SPACE_CMOS:
1171             case ACPI_ADR_SPACE_GPIO:
1172 
1173                 if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
1174                     AML_FIELD_ACCESS_BYTE)
1175                 {
1176                     AslError (ASL_ERROR, ASL_MSG_REGION_BYTE_ACCESS, Op, NULL);
1177                 }
1178                 break;
1179 
1180             case ACPI_ADR_SPACE_SMBUS:
1181             case ACPI_ADR_SPACE_IPMI:
1182             case ACPI_ADR_SPACE_GSBUS:
1183 
1184                 if ((UINT8) Op->Asl.Parent->Asl.Value.Integer !=
1185                     AML_FIELD_ACCESS_BUFFER)
1186                 {
1187                     AslError (ASL_ERROR, ASL_MSG_REGION_BUFFER_ACCESS, Op, NULL);
1188                 }
1189                 break;
1190 
1191             default:
1192 
1193                 /* Nothing to do for other address spaces */
1194 
1195                 break;
1196             }
1197         }
1198         else
1199         {
1200             /*
1201              * This is one element of the field list. Check to make sure
1202              * that it does not go beyond the end of the parent operation region.
1203              *
1204              * In the code below:
1205              *    Op->Asl.Parent->Asl.ExtraValue      - Region Length (bits)
1206              *    Op->Asl.ExtraValue                  - Field start offset (bits)
1207              *    Op->Asl.Child->Asl.Value.Integer32  - Field length (bits)
1208              *    Op->Asl.Child->Asl.ExtraValue       - Field access width (bits)
1209              */
1210             if (Op->Asl.Parent->Asl.ExtraValue && Op->Asl.Child)
1211             {
1212                 XfCheckFieldRange (Op,
1213                     Op->Asl.Parent->Asl.ExtraValue,
1214                     Op->Asl.ExtraValue,
1215                     (UINT32) Op->Asl.Child->Asl.Value.Integer,
1216                     Op->Asl.Child->Asl.ExtraValue);
1217             }
1218         }
1219     }
1220 
1221     /*
1222      * 5) Check for external resolution
1223      *
1224      * By this point, everything should be loaded in the namespace. If a
1225      * namespace lookup results in a namespace node that is an external, it
1226      * means that this named object was not defined in the input ASL. This
1227      * causes issues because there are plenty of incidents where developers
1228      * use the external keyword to suppress compiler errors about undefined
1229      * objects. Note: this only applies when compiling multiple definition
1230      * blocks.
1231      *
1232      * Do not check for external resolution in the following cases:
1233      *
1234      * case 1) External (ABCD)
1235      *
1236      *         This declares ABCD as an external so there is no requirement for
1237      *         ABCD to be loaded in the namespace when analyzing the actual
1238      *         External() statement.
1239      *
1240      * case 2) CondRefOf (ABCD)
1241      *
1242      *         This operator will query the ACPI namespace on the existence of
1243      *         ABCD. If ABCD does not exist, this operator will return a 0
1244      *         without incurring AML runtime errors. Therefore, ABCD is allowed
1245      *         to not exist when analyzing the CondRefOf operator.
1246      *
1247      * case 3) External (ABCD)
1248      *         if (CondRefOf (ABCD))
1249      *         {
1250      *             Store (0, ABCD)
1251      *         }
1252      *
1253      *         In this case, ABCD is accessed only if it exists due to the if
1254      *         statement so there is no need to flag the ABCD nested in the
1255      *         store operator.
1256      */
1257     if (AslGbl_ParseTreeRoot->Asl.Child && AslGbl_ParseTreeRoot->Asl.Child->Asl.Next &&
1258         (Node->Flags & ANOBJ_IS_EXTERNAL) &&
1259         Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_EXTERNAL &&
1260         Op->Asl.ParseOpcode != PARSEOP_EXTERNAL &&
1261         Op->Asl.Parent->Asl.ParseOpcode != PARSEOP_CONDREFOF &&
1262         !XfRefIsGuardedByIfCondRefOf (Node, Op))
1263     {
1264         AslError (ASL_ERROR, ASL_MSG_UNDEFINED_EXTERNAL, Op, NULL);
1265     }
1266 
1267     /* 5) Check for a connection object */
1268 #if 0
1269     else if (Op->Asl.Parent->Asl.ParseOpcode == PARSEOP_CONNECTION)
1270     {
1271         return_ACPI_STATUS (Status);
1272     }
1273 #endif
1274 
1275     Op->Asl.Node = Node;
1276     return_ACPI_STATUS (Status);
1277 }
1278 
1279 
1280 /*******************************************************************************
1281  *
1282  * FUNCTION:    XfRefIsGuardedByIfCondRefOf
1283  *
1284  * PARAMETERS:  Node        - Named object reference node
1285  *              Op          - Named object reference parse node
1286  *
1287  * RETURN:      BOOLEAN
1288  *
1289  * DESCRIPTION: returns true if Op checked inside if (CondRefOf (...))
1290  *              refers to Node.
1291  *
1292  ******************************************************************************/
1293 
1294 static BOOLEAN
1295 XfRefIsGuardedByIfCondRefOf (
1296     ACPI_NAMESPACE_NODE     *Node,
1297     ACPI_PARSE_OBJECT       *Op)
1298 {
1299     ACPI_PARSE_OBJECT       *Parent = Op->Asl.Parent;
1300 
1301 
1302     while (Parent)
1303     {
1304         if (Parent->Asl.ParseOpcode == PARSEOP_IF &&
1305             XfFindCondRefOfName (Node, Parent->Asl.Child))
1306         {
1307             return (TRUE);
1308         }
1309 
1310         Parent = Parent->Asl.Parent;
1311     }
1312 
1313     return (FALSE);
1314 }
1315 
1316 
1317 /*******************************************************************************
1318  *
1319  * FUNCTION:    XfRefIsGuardedByIfCondRefOf
1320  *
1321  * PARAMETERS:  Node        - Named object reference node
1322  *              Op          - Named object reference parse node
1323  *
1324  * RETURN:      BOOLEAN
1325  *
1326  * DESCRIPTION: returns true if Op checked inside if (CondRefOf (...))
1327  *              refers to Node.
1328  *
1329  ******************************************************************************/
1330 
1331 static BOOLEAN
1332 XfFindCondRefOfName (
1333     ACPI_NAMESPACE_NODE     *Node,
1334     ACPI_PARSE_OBJECT       *Op)
1335 {
1336     BOOLEAN                 CondRefOfFound = FALSE;
1337 
1338 
1339     if (!Op)
1340     {
1341         return (FALSE);
1342     }
1343 
1344     switch (Op->Asl.ParseOpcode)
1345     {
1346     case PARSEOP_CONDREFOF:
1347 
1348         return (Op->Asl.Child->Common.Node == Node);
1349         break;
1350 
1351     case PARSEOP_LAND:
1352 
1353         CondRefOfFound = XfFindCondRefOfName (Node, Op->Asl.Child);
1354         if (CondRefOfFound)
1355         {
1356             return (TRUE);
1357         }
1358 
1359         return (XfFindCondRefOfName (Node, Op->Asl.Child->Asl.Next));
1360         break;
1361 
1362     default:
1363 
1364         return (FALSE);
1365         break;
1366     }
1367 }
1368 
1369 
1370 /*******************************************************************************
1371  *
1372  * FUNCTION:    XfNamespaceLocateEnd
1373  *
1374  * PARAMETERS:  ASL_WALK_CALLBACK
1375  *
1376  * RETURN:      Status
1377  *
1378  * DESCRIPTION: Ascending callback used during cross reference. We only
1379  *              need to worry about scope management here.
1380  *
1381  ******************************************************************************/
1382 
1383 static ACPI_STATUS
1384 XfNamespaceLocateEnd (
1385     ACPI_PARSE_OBJECT       *Op,
1386     UINT32                  Level,
1387     void                    *Context)
1388 {
1389     ACPI_WALK_STATE         *WalkState = (ACPI_WALK_STATE *) Context;
1390     const ACPI_OPCODE_INFO  *OpInfo;
1391 
1392 
1393     ACPI_FUNCTION_TRACE (XfNamespaceLocateEnd);
1394 
1395 
1396     /* We are only interested in opcodes that have an associated name */
1397 
1398     OpInfo = AcpiPsGetOpcodeInfo (Op->Asl.AmlOpcode);
1399     if (!(OpInfo->Flags & AML_NAMED))
1400     {
1401         return_ACPI_STATUS (AE_OK);
1402     }
1403 
1404     /* Not interested in name references, we did not open a scope for them */
1405 
1406     if ((Op->Asl.ParseOpcode == PARSEOP_NAMESTRING) ||
1407         (Op->Asl.ParseOpcode == PARSEOP_NAMESEG)    ||
1408         (Op->Asl.ParseOpcode == PARSEOP_METHODCALL) ||
1409         (Op->Asl.ParseOpcode == PARSEOP_EXTERNAL))
1410     {
1411         return_ACPI_STATUS (AE_OK);
1412     }
1413 
1414     /* Pop the scope stack if necessary */
1415 
1416     if (AcpiNsOpensScope (AslMapNamedOpcodeToDataType (Op->Asl.AmlOpcode)))
1417     {
1418 
1419         ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
1420             "%s: Popping scope for Op %p\n",
1421             AcpiUtGetTypeName (OpInfo->ObjectType), Op));
1422 
1423         (void) AcpiDsScopeStackPop (WalkState);
1424     }
1425 
1426     return_ACPI_STATUS (AE_OK);
1427 }
1428 
1429 
1430 /*******************************************************************************
1431  *
1432  * FUNCTION:    XfValidateCrossReference
1433  *
1434  * PARAMETERS:  Op                      - Parse Op that references the object
1435  *              OpInfo                  - Parse Op info struct
1436  *              Node                    - Node for the referenced object
1437  *
1438  * RETURN:      TRUE if the reference is legal, FALSE otherwise
1439  *
1440  * DESCRIPTION: Determine if a reference to another object is allowed.
1441  *
1442  * EXAMPLE:
1443  *      Method (A) {Name (INT1, 1)}     Declaration of object INT1
1444  *      Method (B) (Store (2, \A.INT1)} Illegal reference to object INT1
1445  *                                      (INT1 is temporary, valid only during
1446  *                                      execution of A)
1447  *
1448  * NOTES:
1449  *      A null pointer returned by either UtGetParentMethodOp or
1450  *      UtGetParentMethodNode indicates that the parameter object is not
1451  *      within a control method.
1452  *
1453  *      Five cases are handled: Case(Op, Node)
1454  *      1) Case(0,0): Op is not within a method, Node is not    --> OK
1455  *      2) Case(0,1): Op is not within a method, but Node is    --> Illegal
1456  *      3) Case(1,0): Op is within a method, Node is not        --> OK
1457  *      4) Case(1,1): Both are within the same method           --> OK
1458  *      5) Case(1,1): Both are in methods, but not same method  --> Illegal
1459  *
1460  ******************************************************************************/
1461 
1462 static BOOLEAN
1463 XfValidateCrossReference (
1464     ACPI_PARSE_OBJECT       *Op,
1465     const ACPI_OPCODE_INFO  *OpInfo,
1466     ACPI_NAMESPACE_NODE     *Node)
1467 {
1468     ACPI_PARSE_OBJECT       *ReferencingMethodOp;
1469     ACPI_NAMESPACE_NODE     *ReferencedMethodNode;
1470 
1471 
1472     /* Ignore actual named (and related) object declarations */
1473 
1474     if (OpInfo->Flags & (AML_NAMED | AML_CREATE | AML_DEFER | AML_HAS_ARGS))
1475     {
1476         return (TRUE);
1477     }
1478 
1479     /*
1480      * 1) Search upwards in parse tree for owner of the referencing object
1481      * 2) Search upwards in namespace to find the owner of the referenced object
1482      */
1483     ReferencingMethodOp = UtGetParentMethodOp (Op);
1484     ReferencedMethodNode = UtGetParentMethodNode (Node);
1485 
1486     if (!ReferencingMethodOp && !ReferencedMethodNode)
1487     {
1488         /*
1489          * 1) Case (0,0): Both Op and Node are not within methods
1490          * --> OK
1491          */
1492         return (TRUE);
1493     }
1494 
1495     if (!ReferencingMethodOp && ReferencedMethodNode)
1496     {
1497         /*
1498          * 2) Case (0,1): Op is not in a method, but Node is within a
1499          * method --> illegal
1500          */
1501         return (FALSE);
1502     }
1503     else if (ReferencingMethodOp && !ReferencedMethodNode)
1504     {
1505         /*
1506          * 3) Case (1,0): Op is within a method, but Node is not
1507          * --> OK
1508          */
1509         return (TRUE);
1510     }
1511     else if (ReferencingMethodOp->Asl.Node == ReferencedMethodNode)
1512     {
1513         /*
1514          * 4) Case (1,1): Both Op and Node are within the same method
1515          * --> OK
1516          */
1517         return (TRUE);
1518     }
1519     else
1520     {
1521         /*
1522          * 5) Case (1,1), Op and Node are in different methods
1523          * --> Illegal
1524          */
1525         return (FALSE);
1526     }
1527 }
1528