1 /*******************************************************************************
2  *
3  * Module Name: rscalc - Calculate stream and list lengths
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2014, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #define __RSCALC_C__
45 
46 #include "acpi.h"
47 #include "accommon.h"
48 #include "acresrc.h"
49 #include "acnamesp.h"
50 
51 
52 #define _COMPONENT          ACPI_RESOURCES
53         ACPI_MODULE_NAME    ("rscalc")
54 
55 
56 /* Local prototypes */
57 
58 static UINT8
59 AcpiRsCountSetBits (
60     UINT16                  BitField);
61 
62 static ACPI_RS_LENGTH
63 AcpiRsStructOptionLength (
64     ACPI_RESOURCE_SOURCE    *ResourceSource);
65 
66 static UINT32
67 AcpiRsStreamOptionLength (
68     UINT32                  ResourceLength,
69     UINT32                  MinimumTotalLength);
70 
71 
72 /*******************************************************************************
73  *
74  * FUNCTION:    AcpiRsCountSetBits
75  *
76  * PARAMETERS:  BitField        - Field in which to count bits
77  *
78  * RETURN:      Number of bits set within the field
79  *
80  * DESCRIPTION: Count the number of bits set in a resource field. Used for
81  *              (Short descriptor) interrupt and DMA lists.
82  *
83  ******************************************************************************/
84 
85 static UINT8
86 AcpiRsCountSetBits (
87     UINT16                  BitField)
88 {
89     UINT8                   BitsSet;
90 
91 
92     ACPI_FUNCTION_ENTRY ();
93 
94 
95     for (BitsSet = 0; BitField; BitsSet++)
96     {
97         /* Zero the least significant bit that is set */
98 
99         BitField &= (UINT16) (BitField - 1);
100     }
101 
102     return (BitsSet);
103 }
104 
105 
106 /*******************************************************************************
107  *
108  * FUNCTION:    AcpiRsStructOptionLength
109  *
110  * PARAMETERS:  ResourceSource      - Pointer to optional descriptor field
111  *
112  * RETURN:      Status
113  *
114  * DESCRIPTION: Common code to handle optional ResourceSourceIndex and
115  *              ResourceSource fields in some Large descriptors. Used during
116  *              list-to-stream conversion
117  *
118  ******************************************************************************/
119 
120 static ACPI_RS_LENGTH
121 AcpiRsStructOptionLength (
122     ACPI_RESOURCE_SOURCE    *ResourceSource)
123 {
124     ACPI_FUNCTION_ENTRY ();
125 
126 
127     /*
128      * If the ResourceSource string is valid, return the size of the string
129      * (StringLength includes the NULL terminator) plus the size of the
130      * ResourceSourceIndex (1).
131      */
132     if (ResourceSource->StringPtr)
133     {
134         return ((ACPI_RS_LENGTH) (ResourceSource->StringLength + 1));
135     }
136 
137     return (0);
138 }
139 
140 
141 /*******************************************************************************
142  *
143  * FUNCTION:    AcpiRsStreamOptionLength
144  *
145  * PARAMETERS:  ResourceLength      - Length from the resource header
146  *              MinimumTotalLength  - Minimum length of this resource, before
147  *                                    any optional fields. Includes header size
148  *
149  * RETURN:      Length of optional string (0 if no string present)
150  *
151  * DESCRIPTION: Common code to handle optional ResourceSourceIndex and
152  *              ResourceSource fields in some Large descriptors. Used during
153  *              stream-to-list conversion
154  *
155  ******************************************************************************/
156 
157 static UINT32
158 AcpiRsStreamOptionLength (
159     UINT32                  ResourceLength,
160     UINT32                  MinimumAmlResourceLength)
161 {
162     UINT32                  StringLength = 0;
163 
164 
165     ACPI_FUNCTION_ENTRY ();
166 
167 
168     /*
169      * The ResourceSourceIndex and ResourceSource are optional elements of some
170      * Large-type resource descriptors.
171      */
172 
173     /*
174      * If the length of the actual resource descriptor is greater than the ACPI
175      * spec-defined minimum length, it means that a ResourceSourceIndex exists
176      * and is followed by a (required) null terminated string. The string length
177      * (including the null terminator) is the resource length minus the minimum
178      * length, minus one byte for the ResourceSourceIndex itself.
179      */
180     if (ResourceLength > MinimumAmlResourceLength)
181     {
182         /* Compute the length of the optional string */
183 
184         StringLength = ResourceLength - MinimumAmlResourceLength - 1;
185     }
186 
187     /*
188      * Round the length up to a multiple of the native word in order to
189      * guarantee that the entire resource descriptor is native word aligned
190      */
191     return ((UINT32) ACPI_ROUND_UP_TO_NATIVE_WORD (StringLength));
192 }
193 
194 
195 /*******************************************************************************
196  *
197  * FUNCTION:    AcpiRsGetAmlLength
198  *
199  * PARAMETERS:  Resource            - Pointer to the resource linked list
200  *              ResourceListSize    - Size of the resource linked list
201  *              SizeNeeded          - Where the required size is returned
202  *
203  * RETURN:      Status
204  *
205  * DESCRIPTION: Takes a linked list of internal resource descriptors and
206  *              calculates the size buffer needed to hold the corresponding
207  *              external resource byte stream.
208  *
209  ******************************************************************************/
210 
211 ACPI_STATUS
212 AcpiRsGetAmlLength (
213     ACPI_RESOURCE           *Resource,
214     ACPI_SIZE               ResourceListSize,
215     ACPI_SIZE               *SizeNeeded)
216 {
217     ACPI_SIZE               AmlSizeNeeded = 0;
218     ACPI_RESOURCE           *ResourceEnd;
219     ACPI_RS_LENGTH          TotalSize;
220 
221 
222     ACPI_FUNCTION_TRACE (RsGetAmlLength);
223 
224 
225     /* Traverse entire list of internal resource descriptors */
226 
227     ResourceEnd = ACPI_ADD_PTR (ACPI_RESOURCE, Resource, ResourceListSize);
228     while (Resource < ResourceEnd)
229     {
230         /* Validate the descriptor type */
231 
232         if (Resource->Type > ACPI_RESOURCE_TYPE_MAX)
233         {
234             return_ACPI_STATUS (AE_AML_INVALID_RESOURCE_TYPE);
235         }
236 
237         /* Sanity check the length. It must not be zero, or we loop forever */
238 
239         if (!Resource->Length)
240         {
241             return_ACPI_STATUS (AE_AML_BAD_RESOURCE_LENGTH);
242         }
243 
244         /* Get the base size of the (external stream) resource descriptor */
245 
246         TotalSize = AcpiGbl_AmlResourceSizes [Resource->Type];
247 
248         /*
249          * Augment the base size for descriptors with optional and/or
250          * variable-length fields
251          */
252         switch (Resource->Type)
253         {
254         case ACPI_RESOURCE_TYPE_IRQ:
255 
256             /* Length can be 3 or 2 */
257 
258             if (Resource->Data.Irq.DescriptorLength == 2)
259             {
260                 TotalSize--;
261             }
262             break;
263 
264 
265         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
266 
267             /* Length can be 1 or 0 */
268 
269             if (Resource->Data.Irq.DescriptorLength == 0)
270             {
271                 TotalSize--;
272             }
273             break;
274 
275 
276         case ACPI_RESOURCE_TYPE_VENDOR:
277             /*
278              * Vendor Defined Resource:
279              * For a Vendor Specific resource, if the Length is between 1 and 7
280              * it will be created as a Small Resource data type, otherwise it
281              * is a Large Resource data type.
282              */
283             if (Resource->Data.Vendor.ByteLength > 7)
284             {
285                 /* Base size of a Large resource descriptor */
286 
287                 TotalSize = sizeof (AML_RESOURCE_LARGE_HEADER);
288             }
289 
290             /* Add the size of the vendor-specific data */
291 
292             TotalSize = (ACPI_RS_LENGTH)
293                 (TotalSize + Resource->Data.Vendor.ByteLength);
294             break;
295 
296 
297         case ACPI_RESOURCE_TYPE_END_TAG:
298             /*
299              * End Tag:
300              * We are done -- return the accumulated total size.
301              */
302             *SizeNeeded = AmlSizeNeeded + TotalSize;
303 
304             /* Normal exit */
305 
306             return_ACPI_STATUS (AE_OK);
307 
308 
309         case ACPI_RESOURCE_TYPE_ADDRESS16:
310             /*
311              * 16-Bit Address Resource:
312              * Add the size of the optional ResourceSource info
313              */
314             TotalSize = (ACPI_RS_LENGTH)
315                 (TotalSize + AcpiRsStructOptionLength (
316                                 &Resource->Data.Address16.ResourceSource));
317             break;
318 
319 
320         case ACPI_RESOURCE_TYPE_ADDRESS32:
321             /*
322              * 32-Bit Address Resource:
323              * Add the size of the optional ResourceSource info
324              */
325             TotalSize = (ACPI_RS_LENGTH)
326                 (TotalSize + AcpiRsStructOptionLength (
327                                 &Resource->Data.Address32.ResourceSource));
328             break;
329 
330 
331         case ACPI_RESOURCE_TYPE_ADDRESS64:
332             /*
333              * 64-Bit Address Resource:
334              * Add the size of the optional ResourceSource info
335              */
336             TotalSize = (ACPI_RS_LENGTH)
337                 (TotalSize + AcpiRsStructOptionLength (
338                                 &Resource->Data.Address64.ResourceSource));
339             break;
340 
341 
342         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
343             /*
344              * Extended IRQ Resource:
345              * Add the size of each additional optional interrupt beyond the
346              * required 1 (4 bytes for each UINT32 interrupt number)
347              */
348             TotalSize = (ACPI_RS_LENGTH)
349                 (TotalSize +
350                 ((Resource->Data.ExtendedIrq.InterruptCount - 1) * 4) +
351 
352                 /* Add the size of the optional ResourceSource info */
353 
354                 AcpiRsStructOptionLength (
355                     &Resource->Data.ExtendedIrq.ResourceSource));
356             break;
357 
358 
359         case ACPI_RESOURCE_TYPE_GPIO:
360 
361             TotalSize = (ACPI_RS_LENGTH) (TotalSize + (Resource->Data.Gpio.PinTableLength * 2) +
362                 Resource->Data.Gpio.ResourceSource.StringLength +
363                 Resource->Data.Gpio.VendorLength);
364 
365             break;
366 
367 
368         case ACPI_RESOURCE_TYPE_SERIAL_BUS:
369 
370             TotalSize = AcpiGbl_AmlResourceSerialBusSizes [Resource->Data.CommonSerialBus.Type];
371 
372             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
373                 Resource->Data.I2cSerialBus.ResourceSource.StringLength +
374                 Resource->Data.I2cSerialBus.VendorLength);
375 
376             break;
377 
378         default:
379 
380             break;
381         }
382 
383         /* Update the total */
384 
385         AmlSizeNeeded += TotalSize;
386 
387         /* Point to the next object */
388 
389         Resource = ACPI_ADD_PTR (ACPI_RESOURCE, Resource, Resource->Length);
390     }
391 
392     /* Did not find an EndTag resource descriptor */
393 
394     return_ACPI_STATUS (AE_AML_NO_RESOURCE_END_TAG);
395 }
396 
397 
398 /*******************************************************************************
399  *
400  * FUNCTION:    AcpiRsGetListLength
401  *
402  * PARAMETERS:  AmlBuffer           - Pointer to the resource byte stream
403  *              AmlBufferLength     - Size of AmlBuffer
404  *              SizeNeeded          - Where the size needed is returned
405  *
406  * RETURN:      Status
407  *
408  * DESCRIPTION: Takes an external resource byte stream and calculates the size
409  *              buffer needed to hold the corresponding internal resource
410  *              descriptor linked list.
411  *
412  ******************************************************************************/
413 
414 ACPI_STATUS
415 AcpiRsGetListLength (
416     UINT8                   *AmlBuffer,
417     UINT32                  AmlBufferLength,
418     ACPI_SIZE               *SizeNeeded)
419 {
420     ACPI_STATUS             Status;
421     UINT8                   *EndAml;
422     UINT8                   *Buffer;
423     UINT32                  BufferSize;
424     UINT16                  Temp16;
425     UINT16                  ResourceLength;
426     UINT32                  ExtraStructBytes;
427     UINT8                   ResourceIndex;
428     UINT8                   MinimumAmlResourceLength;
429     AML_RESOURCE            *AmlResource;
430 
431 
432     ACPI_FUNCTION_TRACE (RsGetListLength);
433 
434 
435     *SizeNeeded = ACPI_RS_SIZE_MIN;         /* Minimum size is one EndTag */
436     EndAml = AmlBuffer + AmlBufferLength;
437 
438     /* Walk the list of AML resource descriptors */
439 
440     while (AmlBuffer < EndAml)
441     {
442         /* Validate the Resource Type and Resource Length */
443 
444         Status = AcpiUtValidateResource (NULL, AmlBuffer, &ResourceIndex);
445         if (ACPI_FAILURE (Status))
446         {
447             /*
448              * Exit on failure. Cannot continue because the descriptor length
449              * may be bogus also.
450              */
451             return_ACPI_STATUS (Status);
452         }
453 
454         AmlResource = (void *) AmlBuffer;
455 
456         /* Get the resource length and base (minimum) AML size */
457 
458         ResourceLength = AcpiUtGetResourceLength (AmlBuffer);
459         MinimumAmlResourceLength = AcpiGbl_ResourceAmlSizes[ResourceIndex];
460 
461         /*
462          * Augment the size for descriptors with optional
463          * and/or variable length fields
464          */
465         ExtraStructBytes = 0;
466         Buffer = AmlBuffer + AcpiUtGetResourceHeaderLength (AmlBuffer);
467 
468         switch (AcpiUtGetResourceType (AmlBuffer))
469         {
470         case ACPI_RESOURCE_NAME_IRQ:
471             /*
472              * IRQ Resource:
473              * Get the number of bits set in the 16-bit IRQ mask
474              */
475             ACPI_MOVE_16_TO_16 (&Temp16, Buffer);
476             ExtraStructBytes = AcpiRsCountSetBits (Temp16);
477             break;
478 
479 
480         case ACPI_RESOURCE_NAME_DMA:
481             /*
482              * DMA Resource:
483              * Get the number of bits set in the 8-bit DMA mask
484              */
485             ExtraStructBytes = AcpiRsCountSetBits (*Buffer);
486             break;
487 
488 
489         case ACPI_RESOURCE_NAME_VENDOR_SMALL:
490         case ACPI_RESOURCE_NAME_VENDOR_LARGE:
491             /*
492              * Vendor Resource:
493              * Get the number of vendor data bytes
494              */
495             ExtraStructBytes = ResourceLength;
496 
497             /*
498              * There is already one byte included in the minimum
499              * descriptor size. If there are extra struct bytes,
500              * subtract one from the count.
501              */
502             if (ExtraStructBytes)
503             {
504                 ExtraStructBytes--;
505             }
506             break;
507 
508 
509         case ACPI_RESOURCE_NAME_END_TAG:
510             /*
511              * End Tag: This is the normal exit
512              */
513             return_ACPI_STATUS (AE_OK);
514 
515 
516         case ACPI_RESOURCE_NAME_ADDRESS32:
517         case ACPI_RESOURCE_NAME_ADDRESS16:
518         case ACPI_RESOURCE_NAME_ADDRESS64:
519             /*
520              * Address Resource:
521              * Add the size of the optional ResourceSource
522              */
523             ExtraStructBytes = AcpiRsStreamOptionLength (
524                 ResourceLength, MinimumAmlResourceLength);
525             break;
526 
527 
528         case ACPI_RESOURCE_NAME_EXTENDED_IRQ:
529             /*
530              * Extended IRQ Resource:
531              * Using the InterruptTableLength, add 4 bytes for each additional
532              * interrupt. Note: at least one interrupt is required and is
533              * included in the minimum descriptor size (reason for the -1)
534              */
535             ExtraStructBytes = (Buffer[1] - 1) * sizeof (UINT32);
536 
537             /* Add the size of the optional ResourceSource */
538 
539             ExtraStructBytes += AcpiRsStreamOptionLength (
540                 ResourceLength - ExtraStructBytes, MinimumAmlResourceLength);
541             break;
542 
543         case ACPI_RESOURCE_NAME_GPIO:
544 
545             /* Vendor data is optional */
546 
547             if (AmlResource->Gpio.VendorLength)
548             {
549                 ExtraStructBytes += AmlResource->Gpio.VendorOffset -
550                     AmlResource->Gpio.PinTableOffset + AmlResource->Gpio.VendorLength;
551             }
552             else
553             {
554                 ExtraStructBytes += AmlResource->LargeHeader.ResourceLength +
555                     sizeof (AML_RESOURCE_LARGE_HEADER) -
556                     AmlResource->Gpio.PinTableOffset;
557             }
558             break;
559 
560         case ACPI_RESOURCE_NAME_SERIAL_BUS:
561 
562             MinimumAmlResourceLength = AcpiGbl_ResourceAmlSerialBusSizes[
563                 AmlResource->CommonSerialBus.Type];
564             ExtraStructBytes += AmlResource->CommonSerialBus.ResourceLength -
565                 MinimumAmlResourceLength;
566             break;
567 
568         default:
569 
570             break;
571         }
572 
573         /*
574          * Update the required buffer size for the internal descriptor structs
575          *
576          * Important: Round the size up for the appropriate alignment. This
577          * is a requirement on IA64.
578          */
579         if (AcpiUtGetResourceType (AmlBuffer) == ACPI_RESOURCE_NAME_SERIAL_BUS)
580         {
581             BufferSize = AcpiGbl_ResourceStructSerialBusSizes[
582                 AmlResource->CommonSerialBus.Type] + ExtraStructBytes;
583         }
584         else
585         {
586             BufferSize = AcpiGbl_ResourceStructSizes[ResourceIndex] +
587                         ExtraStructBytes;
588         }
589         BufferSize = (UINT32) ACPI_ROUND_UP_TO_NATIVE_WORD (BufferSize);
590 
591         *SizeNeeded += BufferSize;
592 
593         ACPI_DEBUG_PRINT ((ACPI_DB_RESOURCES,
594             "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
595             AcpiUtGetResourceType (AmlBuffer),
596             AcpiUtGetDescriptorLength (AmlBuffer), BufferSize));
597 
598         /*
599          * Point to the next resource within the AML stream using the length
600          * contained in the resource descriptor header
601          */
602         AmlBuffer += AcpiUtGetDescriptorLength (AmlBuffer);
603     }
604 
605     /* Did not find an EndTag resource descriptor */
606 
607     return_ACPI_STATUS (AE_AML_NO_RESOURCE_END_TAG);
608 }
609 
610 
611 /*******************************************************************************
612  *
613  * FUNCTION:    AcpiRsGetPciRoutingTableLength
614  *
615  * PARAMETERS:  PackageObject           - Pointer to the package object
616  *              BufferSizeNeeded        - UINT32 pointer of the size buffer
617  *                                        needed to properly return the
618  *                                        parsed data
619  *
620  * RETURN:      Status
621  *
622  * DESCRIPTION: Given a package representing a PCI routing table, this
623  *              calculates the size of the corresponding linked list of
624  *              descriptions.
625  *
626  ******************************************************************************/
627 
628 ACPI_STATUS
629 AcpiRsGetPciRoutingTableLength (
630     ACPI_OPERAND_OBJECT     *PackageObject,
631     ACPI_SIZE               *BufferSizeNeeded)
632 {
633     UINT32                  NumberOfElements;
634     ACPI_SIZE               TempSizeNeeded = 0;
635     ACPI_OPERAND_OBJECT     **TopObjectList;
636     UINT32                  Index;
637     ACPI_OPERAND_OBJECT     *PackageElement;
638     ACPI_OPERAND_OBJECT     **SubObjectList;
639     BOOLEAN                 NameFound;
640     UINT32                  TableIndex;
641 
642 
643     ACPI_FUNCTION_TRACE (RsGetPciRoutingTableLength);
644 
645 
646     NumberOfElements = PackageObject->Package.Count;
647 
648     /*
649      * Calculate the size of the return buffer.
650      * The base size is the number of elements * the sizes of the
651      * structures. Additional space for the strings is added below.
652      * The minus one is to subtract the size of the UINT8 Source[1]
653      * member because it is added below.
654      *
655      * But each PRT_ENTRY structure has a pointer to a string and
656      * the size of that string must be found.
657      */
658     TopObjectList = PackageObject->Package.Elements;
659 
660     for (Index = 0; Index < NumberOfElements; Index++)
661     {
662         /* Dereference the subpackage */
663 
664         PackageElement = *TopObjectList;
665 
666         /* We must have a valid Package object */
667 
668         if (!PackageElement ||
669             (PackageElement->Common.Type != ACPI_TYPE_PACKAGE))
670         {
671             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
672         }
673 
674         /*
675          * The SubObjectList will now point to an array of the
676          * four IRQ elements: Address, Pin, Source and SourceIndex
677          */
678         SubObjectList = PackageElement->Package.Elements;
679 
680         /* Scan the IrqTableElements for the Source Name String */
681 
682         NameFound = FALSE;
683 
684         for (TableIndex = 0;
685              TableIndex < PackageElement->Package.Count && !NameFound;
686              TableIndex++)
687         {
688             if (*SubObjectList && /* Null object allowed */
689 
690                 ((ACPI_TYPE_STRING ==
691                     (*SubObjectList)->Common.Type) ||
692 
693                 ((ACPI_TYPE_LOCAL_REFERENCE ==
694                     (*SubObjectList)->Common.Type) &&
695 
696                     ((*SubObjectList)->Reference.Class ==
697                         ACPI_REFCLASS_NAME))))
698             {
699                 NameFound = TRUE;
700             }
701             else
702             {
703                 /* Look at the next element */
704 
705                 SubObjectList++;
706             }
707         }
708 
709         TempSizeNeeded += (sizeof (ACPI_PCI_ROUTING_TABLE) - 4);
710 
711         /* Was a String type found? */
712 
713         if (NameFound)
714         {
715             if ((*SubObjectList)->Common.Type == ACPI_TYPE_STRING)
716             {
717                 /*
718                  * The length String.Length field does not include the
719                  * terminating NULL, add 1
720                  */
721                 TempSizeNeeded += ((ACPI_SIZE)
722                     (*SubObjectList)->String.Length + 1);
723             }
724             else
725             {
726                 TempSizeNeeded += AcpiNsGetPathnameLength (
727                                     (*SubObjectList)->Reference.Node);
728             }
729         }
730         else
731         {
732             /*
733              * If no name was found, then this is a NULL, which is
734              * translated as a UINT32 zero.
735              */
736             TempSizeNeeded += sizeof (UINT32);
737         }
738 
739         /* Round up the size since each element must be aligned */
740 
741         TempSizeNeeded = ACPI_ROUND_UP_TO_64BIT (TempSizeNeeded);
742 
743         /* Point to the next ACPI_OPERAND_OBJECT */
744 
745         TopObjectList++;
746     }
747 
748     /*
749      * Add an extra element to the end of the list, essentially a
750      * NULL terminator
751      */
752     *BufferSizeNeeded = TempSizeNeeded + sizeof (ACPI_PCI_ROUTING_TABLE);
753     return_ACPI_STATUS (AE_OK);
754 }
755