xref: /titanic_52/usr/src/uts/intel/io/acpica/resources/rscalc.c (revision 385cc6b4ad1792caef3f84eb61eed3f27085801f)
1 /*******************************************************************************
2  *
3  * Module Name: rscalc - Calculate stream and list lengths
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include "acpi.h"
45 #include "accommon.h"
46 #include "acresrc.h"
47 #include "acnamesp.h"
48 
49 
50 #define _COMPONENT          ACPI_RESOURCES
51         ACPI_MODULE_NAME    ("rscalc")
52 
53 
54 /* Local prototypes */
55 
56 static UINT8
57 AcpiRsCountSetBits (
58     UINT16                  BitField);
59 
60 static ACPI_RS_LENGTH
61 AcpiRsStructOptionLength (
62     ACPI_RESOURCE_SOURCE    *ResourceSource);
63 
64 static UINT32
65 AcpiRsStreamOptionLength (
66     UINT32                  ResourceLength,
67     UINT32                  MinimumTotalLength);
68 
69 
70 /*******************************************************************************
71  *
72  * FUNCTION:    AcpiRsCountSetBits
73  *
74  * PARAMETERS:  BitField        - Field in which to count bits
75  *
76  * RETURN:      Number of bits set within the field
77  *
78  * DESCRIPTION: Count the number of bits set in a resource field. Used for
79  *              (Short descriptor) interrupt and DMA lists.
80  *
81  ******************************************************************************/
82 
83 static UINT8
84 AcpiRsCountSetBits (
85     UINT16                  BitField)
86 {
87     UINT8                   BitsSet;
88 
89 
90     ACPI_FUNCTION_ENTRY ();
91 
92 
93     for (BitsSet = 0; BitField; BitsSet++)
94     {
95         /* Zero the least significant bit that is set */
96 
97         BitField &= (UINT16) (BitField - 1);
98     }
99 
100     return (BitsSet);
101 }
102 
103 
104 /*******************************************************************************
105  *
106  * FUNCTION:    AcpiRsStructOptionLength
107  *
108  * PARAMETERS:  ResourceSource      - Pointer to optional descriptor field
109  *
110  * RETURN:      Status
111  *
112  * DESCRIPTION: Common code to handle optional ResourceSourceIndex and
113  *              ResourceSource fields in some Large descriptors. Used during
114  *              list-to-stream conversion
115  *
116  ******************************************************************************/
117 
118 static ACPI_RS_LENGTH
119 AcpiRsStructOptionLength (
120     ACPI_RESOURCE_SOURCE    *ResourceSource)
121 {
122     ACPI_FUNCTION_ENTRY ();
123 
124 
125     /*
126      * If the ResourceSource string is valid, return the size of the string
127      * (StringLength includes the NULL terminator) plus the size of the
128      * ResourceSourceIndex (1).
129      */
130     if (ResourceSource->StringPtr)
131     {
132         return ((ACPI_RS_LENGTH) (ResourceSource->StringLength + 1));
133     }
134 
135     return (0);
136 }
137 
138 
139 /*******************************************************************************
140  *
141  * FUNCTION:    AcpiRsStreamOptionLength
142  *
143  * PARAMETERS:  ResourceLength      - Length from the resource header
144  *              MinimumTotalLength  - Minimum length of this resource, before
145  *                                    any optional fields. Includes header size
146  *
147  * RETURN:      Length of optional string (0 if no string present)
148  *
149  * DESCRIPTION: Common code to handle optional ResourceSourceIndex and
150  *              ResourceSource fields in some Large descriptors. Used during
151  *              stream-to-list conversion
152  *
153  ******************************************************************************/
154 
155 static UINT32
156 AcpiRsStreamOptionLength (
157     UINT32                  ResourceLength,
158     UINT32                  MinimumAmlResourceLength)
159 {
160     UINT32                  StringLength = 0;
161 
162 
163     ACPI_FUNCTION_ENTRY ();
164 
165 
166     /*
167      * The ResourceSourceIndex and ResourceSource are optional elements of
168      * some Large-type resource descriptors.
169      */
170 
171     /*
172      * If the length of the actual resource descriptor is greater than the
173      * ACPI spec-defined minimum length, it means that a ResourceSourceIndex
174      * exists and is followed by a (required) null terminated string. The
175      * string length (including the null terminator) is the resource length
176      * minus the minimum length, minus one byte for the ResourceSourceIndex
177      * itself.
178      */
179     if (ResourceLength > MinimumAmlResourceLength)
180     {
181         /* Compute the length of the optional string */
182 
183         StringLength = ResourceLength - MinimumAmlResourceLength - 1;
184     }
185 
186     /*
187      * Round the length up to a multiple of the native word in order to
188      * guarantee that the entire resource descriptor is native word aligned
189      */
190     return ((UINT32) ACPI_ROUND_UP_TO_NATIVE_WORD (StringLength));
191 }
192 
193 
194 /*******************************************************************************
195  *
196  * FUNCTION:    AcpiRsGetAmlLength
197  *
198  * PARAMETERS:  Resource            - Pointer to the resource linked list
199  *              ResourceListSize    - Size of the resource linked list
200  *              SizeNeeded          - Where the required size is returned
201  *
202  * RETURN:      Status
203  *
204  * DESCRIPTION: Takes a linked list of internal resource descriptors and
205  *              calculates the size buffer needed to hold the corresponding
206  *              external resource byte stream.
207  *
208  ******************************************************************************/
209 
210 ACPI_STATUS
211 AcpiRsGetAmlLength (
212     ACPI_RESOURCE           *Resource,
213     ACPI_SIZE               ResourceListSize,
214     ACPI_SIZE               *SizeNeeded)
215 {
216     ACPI_SIZE               AmlSizeNeeded = 0;
217     ACPI_RESOURCE           *ResourceEnd;
218     ACPI_RS_LENGTH          TotalSize;
219 
220 
221     ACPI_FUNCTION_TRACE (RsGetAmlLength);
222 
223 
224     /* Traverse entire list of internal resource descriptors */
225 
226     ResourceEnd = ACPI_ADD_PTR (ACPI_RESOURCE, Resource, ResourceListSize);
227     while (Resource < ResourceEnd)
228     {
229         /* Validate the descriptor type */
230 
231         if (Resource->Type > ACPI_RESOURCE_TYPE_MAX)
232         {
233             return_ACPI_STATUS (AE_AML_INVALID_RESOURCE_TYPE);
234         }
235 
236         /* Sanity check the length. It must not be zero, or we loop forever */
237 
238         if (!Resource->Length)
239         {
240             return_ACPI_STATUS (AE_AML_BAD_RESOURCE_LENGTH);
241         }
242 
243         /* Get the base size of the (external stream) resource descriptor */
244 
245         TotalSize = AcpiGbl_AmlResourceSizes [Resource->Type];
246 
247         /*
248          * Augment the base size for descriptors with optional and/or
249          * variable-length fields
250          */
251         switch (Resource->Type)
252         {
253         case ACPI_RESOURCE_TYPE_IRQ:
254 
255             /* Length can be 3 or 2 */
256 
257             if (Resource->Data.Irq.DescriptorLength == 2)
258             {
259                 TotalSize--;
260             }
261             break;
262 
263 
264         case ACPI_RESOURCE_TYPE_START_DEPENDENT:
265 
266             /* Length can be 1 or 0 */
267 
268             if (Resource->Data.Irq.DescriptorLength == 0)
269             {
270                 TotalSize--;
271             }
272             break;
273 
274 
275         case ACPI_RESOURCE_TYPE_VENDOR:
276             /*
277              * Vendor Defined Resource:
278              * For a Vendor Specific resource, if the Length is between 1 and 7
279              * it will be created as a Small Resource data type, otherwise it
280              * is a Large Resource data type.
281              */
282             if (Resource->Data.Vendor.ByteLength > 7)
283             {
284                 /* Base size of a Large resource descriptor */
285 
286                 TotalSize = sizeof (AML_RESOURCE_LARGE_HEADER);
287             }
288 
289             /* Add the size of the vendor-specific data */
290 
291             TotalSize = (ACPI_RS_LENGTH)
292                 (TotalSize + Resource->Data.Vendor.ByteLength);
293             break;
294 
295 
296         case ACPI_RESOURCE_TYPE_END_TAG:
297             /*
298              * End Tag:
299              * We are done -- return the accumulated total size.
300              */
301             *SizeNeeded = AmlSizeNeeded + TotalSize;
302 
303             /* Normal exit */
304 
305             return_ACPI_STATUS (AE_OK);
306 
307 
308         case ACPI_RESOURCE_TYPE_ADDRESS16:
309             /*
310              * 16-Bit Address Resource:
311              * Add the size of the optional ResourceSource info
312              */
313             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
314                 AcpiRsStructOptionLength (
315                     &Resource->Data.Address16.ResourceSource));
316             break;
317 
318 
319         case ACPI_RESOURCE_TYPE_ADDRESS32:
320             /*
321              * 32-Bit Address Resource:
322              * Add the size of the optional ResourceSource info
323              */
324             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
325                 AcpiRsStructOptionLength (
326                     &Resource->Data.Address32.ResourceSource));
327             break;
328 
329 
330         case ACPI_RESOURCE_TYPE_ADDRESS64:
331             /*
332              * 64-Bit Address Resource:
333              * Add the size of the optional ResourceSource info
334              */
335             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
336                 AcpiRsStructOptionLength (
337                     &Resource->Data.Address64.ResourceSource));
338             break;
339 
340 
341         case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
342             /*
343              * Extended IRQ Resource:
344              * Add the size of each additional optional interrupt beyond the
345              * required 1 (4 bytes for each UINT32 interrupt number)
346              */
347             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
348                 ((Resource->Data.ExtendedIrq.InterruptCount - 1) * 4) +
349 
350                 /* Add the size of the optional ResourceSource info */
351 
352                 AcpiRsStructOptionLength (
353                     &Resource->Data.ExtendedIrq.ResourceSource));
354             break;
355 
356 
357         case ACPI_RESOURCE_TYPE_GPIO:
358 
359             TotalSize = (ACPI_RS_LENGTH) (TotalSize +
360                 (Resource->Data.Gpio.PinTableLength * 2) +
361                 Resource->Data.Gpio.ResourceSource.StringLength +
362                 Resource->Data.Gpio.VendorLength);
363 
364             break;
365 
366 
367         case ACPI_RESOURCE_TYPE_SERIAL_BUS:
368 
369             TotalSize = AcpiGbl_AmlResourceSerialBusSizes [
370                 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 +=
550                     AmlResource->Gpio.VendorOffset -
551                     AmlResource->Gpio.PinTableOffset +
552                     AmlResource->Gpio.VendorLength;
553             }
554             else
555             {
556                 ExtraStructBytes +=
557                     AmlResource->LargeHeader.ResourceLength +
558                     sizeof (AML_RESOURCE_LARGE_HEADER) -
559                     AmlResource->Gpio.PinTableOffset;
560             }
561             break;
562 
563         case ACPI_RESOURCE_NAME_SERIAL_BUS:
564 
565             MinimumAmlResourceLength = AcpiGbl_ResourceAmlSerialBusSizes[
566                 AmlResource->CommonSerialBus.Type];
567             ExtraStructBytes +=
568                 AmlResource->CommonSerialBus.ResourceLength -
569                 MinimumAmlResourceLength;
570             break;
571 
572         default:
573 
574             break;
575         }
576 
577         /*
578          * Update the required buffer size for the internal descriptor structs
579          *
580          * Important: Round the size up for the appropriate alignment. This
581          * is a requirement on IA64.
582          */
583         if (AcpiUtGetResourceType (AmlBuffer) ==
584             ACPI_RESOURCE_NAME_SERIAL_BUS)
585         {
586             BufferSize = AcpiGbl_ResourceStructSerialBusSizes[
587                 AmlResource->CommonSerialBus.Type] + ExtraStructBytes;
588         }
589         else
590         {
591             BufferSize = AcpiGbl_ResourceStructSizes[ResourceIndex] +
592                 ExtraStructBytes;
593         }
594 
595         BufferSize = (UINT32) ACPI_ROUND_UP_TO_NATIVE_WORD (BufferSize);
596         *SizeNeeded += BufferSize;
597 
598         ACPI_DEBUG_PRINT ((ACPI_DB_RESOURCES,
599             "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
600             AcpiUtGetResourceType (AmlBuffer),
601             AcpiUtGetDescriptorLength (AmlBuffer), BufferSize));
602 
603         /*
604          * Point to the next resource within the AML stream using the length
605          * contained in the resource descriptor header
606          */
607         AmlBuffer += AcpiUtGetDescriptorLength (AmlBuffer);
608     }
609 
610     /* Did not find an EndTag resource descriptor */
611 
612     return_ACPI_STATUS (AE_AML_NO_RESOURCE_END_TAG);
613 }
614 
615 
616 /*******************************************************************************
617  *
618  * FUNCTION:    AcpiRsGetPciRoutingTableLength
619  *
620  * PARAMETERS:  PackageObject           - Pointer to the package object
621  *              BufferSizeNeeded        - UINT32 pointer of the size buffer
622  *                                        needed to properly return the
623  *                                        parsed data
624  *
625  * RETURN:      Status
626  *
627  * DESCRIPTION: Given a package representing a PCI routing table, this
628  *              calculates the size of the corresponding linked list of
629  *              descriptions.
630  *
631  ******************************************************************************/
632 
633 ACPI_STATUS
634 AcpiRsGetPciRoutingTableLength (
635     ACPI_OPERAND_OBJECT     *PackageObject,
636     ACPI_SIZE               *BufferSizeNeeded)
637 {
638     UINT32                  NumberOfElements;
639     ACPI_SIZE               TempSizeNeeded = 0;
640     ACPI_OPERAND_OBJECT     **TopObjectList;
641     UINT32                  Index;
642     ACPI_OPERAND_OBJECT     *PackageElement;
643     ACPI_OPERAND_OBJECT     **SubObjectList;
644     BOOLEAN                 NameFound;
645     UINT32                  TableIndex;
646 
647 
648     ACPI_FUNCTION_TRACE (RsGetPciRoutingTableLength);
649 
650 
651     NumberOfElements = PackageObject->Package.Count;
652 
653     /*
654      * Calculate the size of the return buffer.
655      * The base size is the number of elements * the sizes of the
656      * structures. Additional space for the strings is added below.
657      * The minus one is to subtract the size of the UINT8 Source[1]
658      * member because it is added below.
659      *
660      * But each PRT_ENTRY structure has a pointer to a string and
661      * the size of that string must be found.
662      */
663     TopObjectList = PackageObject->Package.Elements;
664 
665     for (Index = 0; Index < NumberOfElements; Index++)
666     {
667         /* Dereference the subpackage */
668 
669         PackageElement = *TopObjectList;
670 
671         /* We must have a valid Package object */
672 
673         if (!PackageElement ||
674             (PackageElement->Common.Type != ACPI_TYPE_PACKAGE))
675         {
676             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
677         }
678 
679         /*
680          * The SubObjectList will now point to an array of the
681          * four IRQ elements: Address, Pin, Source and SourceIndex
682          */
683         SubObjectList = PackageElement->Package.Elements;
684 
685         /* Scan the IrqTableElements for the Source Name String */
686 
687         NameFound = FALSE;
688 
689         for (TableIndex = 0;
690              TableIndex < PackageElement->Package.Count && !NameFound;
691              TableIndex++)
692         {
693             if (*SubObjectList && /* Null object allowed */
694 
695                 ((ACPI_TYPE_STRING ==
696                     (*SubObjectList)->Common.Type) ||
697 
698                 ((ACPI_TYPE_LOCAL_REFERENCE ==
699                     (*SubObjectList)->Common.Type) &&
700 
701                     ((*SubObjectList)->Reference.Class ==
702                         ACPI_REFCLASS_NAME))))
703             {
704                 NameFound = TRUE;
705             }
706             else
707             {
708                 /* Look at the next element */
709 
710                 SubObjectList++;
711             }
712         }
713 
714         TempSizeNeeded += (sizeof (ACPI_PCI_ROUTING_TABLE) - 4);
715 
716         /* Was a String type found? */
717 
718         if (NameFound)
719         {
720             if ((*SubObjectList)->Common.Type == ACPI_TYPE_STRING)
721             {
722                 /*
723                  * The length String.Length field does not include the
724                  * terminating NULL, add 1
725                  */
726                 TempSizeNeeded += ((ACPI_SIZE)
727                     (*SubObjectList)->String.Length + 1);
728             }
729             else
730             {
731                 TempSizeNeeded += AcpiNsGetPathnameLength (
732                     (*SubObjectList)->Reference.Node);
733             }
734         }
735         else
736         {
737             /*
738              * If no name was found, then this is a NULL, which is
739              * translated as a UINT32 zero.
740              */
741             TempSizeNeeded += sizeof (UINT32);
742         }
743 
744         /* Round up the size since each element must be aligned */
745 
746         TempSizeNeeded = ACPI_ROUND_UP_TO_64BIT (TempSizeNeeded);
747 
748         /* Point to the next ACPI_OPERAND_OBJECT */
749 
750         TopObjectList++;
751     }
752 
753     /*
754      * Add an extra element to the end of the list, essentially a
755      * NULL terminator
756      */
757     *BufferSizeNeeded = TempSizeNeeded + sizeof (ACPI_PCI_ROUTING_TABLE);
758     return_ACPI_STATUS (AE_OK);
759 }
760