xref: /freebsd/sys/contrib/dev/acpica/components/resources/rscreate.c (revision d5b0e70f7e04d971691517ce1304d86a1e367e2e)
1 /*******************************************************************************
2  *
3  * Module Name: rscreate - Create resource lists/tables
4  *
5  ******************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2022, 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/include/acpi.h>
153 #include <contrib/dev/acpica/include/accommon.h>
154 #include <contrib/dev/acpica/include/acresrc.h>
155 #include <contrib/dev/acpica/include/acnamesp.h>
156 
157 #define _COMPONENT          ACPI_RESOURCES
158         ACPI_MODULE_NAME    ("rscreate")
159 
160 
161 /*******************************************************************************
162  *
163  * FUNCTION:    AcpiBufferToResource
164  *
165  * PARAMETERS:  AmlBuffer           - Pointer to the resource byte stream
166  *              AmlBufferLength     - Length of the AmlBuffer
167  *              ResourcePtr         - Where the converted resource is returned
168  *
169  * RETURN:      Status
170  *
171  * DESCRIPTION: Convert a raw AML buffer to a resource list
172  *
173  ******************************************************************************/
174 
175 ACPI_STATUS
176 AcpiBufferToResource (
177     UINT8                   *AmlBuffer,
178     UINT16                  AmlBufferLength,
179     ACPI_RESOURCE           **ResourcePtr)
180 {
181     ACPI_STATUS             Status;
182     ACPI_SIZE               ListSizeNeeded;
183     void                    *Resource;
184     void                    *CurrentResourcePtr;
185 
186 
187     ACPI_FUNCTION_TRACE (AcpiBufferToResource);
188 
189 
190     /*
191      * Note: we allow AE_AML_NO_RESOURCE_END_TAG, since an end tag
192      * is not required here.
193      */
194 
195     /* Get the required length for the converted resource */
196 
197     Status = AcpiRsGetListLength (
198         AmlBuffer, AmlBufferLength, &ListSizeNeeded);
199     if (Status == AE_AML_NO_RESOURCE_END_TAG)
200     {
201         Status = AE_OK;
202     }
203     if (ACPI_FAILURE (Status))
204     {
205         return_ACPI_STATUS (Status);
206     }
207 
208     /* Allocate a buffer for the converted resource */
209 
210     Resource = ACPI_ALLOCATE_ZEROED (ListSizeNeeded);
211     CurrentResourcePtr = Resource;
212     if (!Resource)
213     {
214         return_ACPI_STATUS (AE_NO_MEMORY);
215     }
216 
217     /* Perform the AML-to-Resource conversion */
218 
219     Status = AcpiUtWalkAmlResources (NULL, AmlBuffer, AmlBufferLength,
220         AcpiRsConvertAmlToResources, &CurrentResourcePtr);
221     if (Status == AE_AML_NO_RESOURCE_END_TAG)
222     {
223         Status = AE_OK;
224     }
225     if (ACPI_FAILURE (Status))
226     {
227         ACPI_FREE (Resource);
228     }
229     else
230     {
231         *ResourcePtr = Resource;
232     }
233 
234     return_ACPI_STATUS (Status);
235 }
236 
237 ACPI_EXPORT_SYMBOL (AcpiBufferToResource)
238 
239 
240 /*******************************************************************************
241  *
242  * FUNCTION:    AcpiRsCreateResourceList
243  *
244  * PARAMETERS:  AmlBuffer           - Pointer to the resource byte stream
245  *              OutputBuffer        - Pointer to the user's buffer
246  *
247  * RETURN:      Status: AE_OK if okay, else a valid ACPI_STATUS code
248  *              If OutputBuffer is not large enough, OutputBufferLength
249  *              indicates how large OutputBuffer should be, else it
250  *              indicates how may UINT8 elements of OutputBuffer are valid.
251  *
252  * DESCRIPTION: Takes the byte stream returned from a _CRS, _PRS control method
253  *              execution and parses the stream to create a linked list
254  *              of device resources.
255  *
256  ******************************************************************************/
257 
258 ACPI_STATUS
259 AcpiRsCreateResourceList (
260     ACPI_OPERAND_OBJECT     *AmlBuffer,
261     ACPI_BUFFER             *OutputBuffer)
262 {
263 
264     ACPI_STATUS             Status;
265     UINT8                   *AmlStart;
266     ACPI_SIZE               ListSizeNeeded = 0;
267     UINT32                  AmlBufferLength;
268     void                    *Resource;
269 
270 
271     ACPI_FUNCTION_TRACE (RsCreateResourceList);
272 
273 
274     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "AmlBuffer = %p\n",
275         AmlBuffer));
276 
277     /* Params already validated, so we don't re-validate here */
278 
279     AmlBufferLength = AmlBuffer->Buffer.Length;
280     AmlStart = AmlBuffer->Buffer.Pointer;
281 
282     /*
283      * Pass the AmlBuffer into a module that can calculate
284      * the buffer size needed for the linked list
285      */
286     Status = AcpiRsGetListLength (AmlStart, AmlBufferLength,
287                 &ListSizeNeeded);
288 
289     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Status=%X ListSizeNeeded=%X\n",
290         Status, (UINT32) ListSizeNeeded));
291     if (ACPI_FAILURE (Status))
292     {
293         return_ACPI_STATUS (Status);
294     }
295 
296     /* Validate/Allocate/Clear caller buffer */
297 
298     Status = AcpiUtInitializeBuffer (OutputBuffer, ListSizeNeeded);
299     if (ACPI_FAILURE (Status))
300     {
301         return_ACPI_STATUS (Status);
302     }
303 
304     /* Do the conversion */
305 
306     Resource = OutputBuffer->Pointer;
307     Status = AcpiUtWalkAmlResources (NULL, AmlStart, AmlBufferLength,
308         AcpiRsConvertAmlToResources, &Resource);
309     if (ACPI_FAILURE (Status))
310     {
311         return_ACPI_STATUS (Status);
312     }
313 
314     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "OutputBuffer %p Length %X\n",
315         OutputBuffer->Pointer, (UINT32) OutputBuffer->Length));
316     return_ACPI_STATUS (AE_OK);
317 }
318 
319 
320 /*******************************************************************************
321  *
322  * FUNCTION:    AcpiRsCreatePciRoutingTable
323  *
324  * PARAMETERS:  PackageObject           - Pointer to a package containing one
325  *                                        of more ACPI_OPERAND_OBJECTs
326  *              OutputBuffer            - Pointer to the user's buffer
327  *
328  * RETURN:      Status  AE_OK if okay, else a valid ACPI_STATUS code.
329  *              If the OutputBuffer is too small, the error will be
330  *              AE_BUFFER_OVERFLOW and OutputBuffer->Length will point
331  *              to the size buffer needed.
332  *
333  * DESCRIPTION: Takes the ACPI_OPERAND_OBJECT package and creates a
334  *              linked list of PCI interrupt descriptions
335  *
336  * NOTE: It is the caller's responsibility to ensure that the start of the
337  * output buffer is aligned properly (if necessary).
338  *
339  ******************************************************************************/
340 
341 ACPI_STATUS
342 AcpiRsCreatePciRoutingTable (
343     ACPI_OPERAND_OBJECT     *PackageObject,
344     ACPI_BUFFER             *OutputBuffer)
345 {
346     UINT8                   *Buffer;
347     ACPI_OPERAND_OBJECT     **TopObjectList;
348     ACPI_OPERAND_OBJECT     **SubObjectList;
349     ACPI_OPERAND_OBJECT     *ObjDesc;
350     ACPI_SIZE               BufferSizeNeeded = 0;
351     UINT32                  NumberOfElements;
352     UINT32                  Index;
353     ACPI_PCI_ROUTING_TABLE  *UserPrt;
354     ACPI_NAMESPACE_NODE     *Node;
355     ACPI_STATUS             Status;
356     ACPI_BUFFER             PathBuffer;
357 
358 
359     ACPI_FUNCTION_TRACE (RsCreatePciRoutingTable);
360 
361 
362     /* Params already validated, so we don't re-validate here */
363 
364     /* Get the required buffer length */
365 
366     Status = AcpiRsGetPciRoutingTableLength (
367         PackageObject,&BufferSizeNeeded);
368     if (ACPI_FAILURE (Status))
369     {
370         return_ACPI_STATUS (Status);
371     }
372 
373     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "BufferSizeNeeded = %X\n",
374         (UINT32) BufferSizeNeeded));
375 
376     /* Validate/Allocate/Clear caller buffer */
377 
378     Status = AcpiUtInitializeBuffer (OutputBuffer, BufferSizeNeeded);
379     if (ACPI_FAILURE (Status))
380     {
381         return_ACPI_STATUS (Status);
382     }
383 
384     /*
385      * Loop through the ACPI_INTERNAL_OBJECTS - Each object should be a
386      * package that in turn contains an UINT64 Address, a UINT8 Pin,
387      * a Name, and a UINT8 SourceIndex.
388      */
389     TopObjectList = PackageObject->Package.Elements;
390     NumberOfElements = PackageObject->Package.Count;
391     Buffer = OutputBuffer->Pointer;
392     UserPrt = ACPI_CAST_PTR (ACPI_PCI_ROUTING_TABLE, Buffer);
393 
394     for (Index = 0; Index < NumberOfElements; Index++)
395     {
396         /*
397          * Point UserPrt past this current structure
398          *
399          * NOTE: On the first iteration, UserPrt->Length will
400          * be zero because we cleared the return buffer earlier
401          */
402         Buffer += UserPrt->Length;
403         UserPrt = ACPI_CAST_PTR (ACPI_PCI_ROUTING_TABLE, Buffer);
404 
405         /*
406          * Fill in the Length field with the information we have at this
407          * point. The minus four is to subtract the size of the UINT8
408          * Source[4] member because it is added below.
409          */
410         UserPrt->Length = (sizeof (ACPI_PCI_ROUTING_TABLE) - 4);
411 
412         /* Each subpackage must be of length 4 */
413 
414         if ((*TopObjectList)->Package.Count != 4)
415         {
416             ACPI_ERROR ((AE_INFO,
417                 "(PRT[%u]) Need package of length 4, found length %u",
418                 Index, (*TopObjectList)->Package.Count));
419             return_ACPI_STATUS (AE_AML_PACKAGE_LIMIT);
420         }
421 
422         /*
423          * Dereference the subpackage.
424          * The SubObjectList will now point to an array of the four IRQ
425          * elements: [Address, Pin, Source, SourceIndex]
426          */
427         SubObjectList = (*TopObjectList)->Package.Elements;
428 
429         /* 1) First subobject: Dereference the PRT.Address */
430 
431         ObjDesc = SubObjectList[0];
432         if (!ObjDesc || ObjDesc->Common.Type != ACPI_TYPE_INTEGER)
433         {
434             ACPI_ERROR ((AE_INFO,
435                 "(PRT[%u].Address) Need Integer, found %s",
436                 Index, AcpiUtGetObjectTypeName (ObjDesc)));
437             return_ACPI_STATUS (AE_BAD_DATA);
438         }
439 
440         UserPrt->Address = ObjDesc->Integer.Value;
441 
442         /* 2) Second subobject: Dereference the PRT.Pin */
443 
444         ObjDesc = SubObjectList[1];
445         if (!ObjDesc || ObjDesc->Common.Type != ACPI_TYPE_INTEGER)
446         {
447             ACPI_ERROR ((AE_INFO, "(PRT[%u].Pin) Need Integer, found %s",
448                 Index, AcpiUtGetObjectTypeName (ObjDesc)));
449             return_ACPI_STATUS (AE_BAD_DATA);
450         }
451 
452         UserPrt->Pin = (UINT32) ObjDesc->Integer.Value;
453 
454         /*
455          * 3) Third subobject: Dereference the PRT.SourceName
456          * The name may be unresolved (slack mode), so allow a null object
457          */
458         ObjDesc = SubObjectList[2];
459         if (ObjDesc)
460         {
461             switch (ObjDesc->Common.Type)
462             {
463             case ACPI_TYPE_LOCAL_REFERENCE:
464 
465                 if (ObjDesc->Reference.Class != ACPI_REFCLASS_NAME)
466                 {
467                     ACPI_ERROR ((AE_INFO,
468                         "(PRT[%u].Source) Need name, found Reference Class 0x%X",
469                         Index, ObjDesc->Reference.Class));
470                     return_ACPI_STATUS (AE_BAD_DATA);
471                 }
472 
473                 Node = ObjDesc->Reference.Node;
474 
475                 /* Use *remaining* length of the buffer as max for pathname */
476 
477                 PathBuffer.Length = OutputBuffer->Length -
478                     (UINT32) ((UINT8 *) UserPrt->Source -
479                     (UINT8 *) OutputBuffer->Pointer);
480                 PathBuffer.Pointer = UserPrt->Source;
481 
482                 Status = AcpiNsHandleToPathname (
483                     (ACPI_HANDLE) Node, &PathBuffer, FALSE);
484                 if (ACPI_FAILURE (Status))
485                 {
486                     return_ACPI_STATUS (Status);
487                 }
488 
489                 /* +1 to include null terminator */
490 
491                 UserPrt->Length += (UINT32) strlen (UserPrt->Source) + 1;
492                 break;
493 
494             case ACPI_TYPE_STRING:
495 
496                 strcpy (UserPrt->Source, ObjDesc->String.Pointer);
497 
498                 /*
499                  * Add to the Length field the length of the string
500                  * (add 1 for terminator)
501                  */
502                 UserPrt->Length += ObjDesc->String.Length + 1;
503                 break;
504 
505             case ACPI_TYPE_INTEGER:
506                 /*
507                  * If this is a number, then the Source Name is NULL, since
508                  * the entire buffer was zeroed out, we can leave this alone.
509                  *
510                  * Add to the Length field the length of the UINT32 NULL
511                  */
512                 UserPrt->Length += sizeof (UINT32);
513                 break;
514 
515             default:
516 
517                ACPI_ERROR ((AE_INFO,
518                    "(PRT[%u].Source) Need Ref/String/Integer, found %s",
519                    Index, AcpiUtGetObjectTypeName (ObjDesc)));
520                return_ACPI_STATUS (AE_BAD_DATA);
521             }
522         }
523 
524         /* Now align the current length */
525 
526         UserPrt->Length = (UINT32) ACPI_ROUND_UP_TO_64BIT (UserPrt->Length);
527 
528         /* 4) Fourth subobject: Dereference the PRT.SourceIndex */
529 
530         ObjDesc = SubObjectList[3];
531         if (!ObjDesc || ObjDesc->Common.Type != ACPI_TYPE_INTEGER)
532         {
533             ACPI_ERROR ((AE_INFO,
534                 "(PRT[%u].SourceIndex) Need Integer, found %s",
535                 Index, AcpiUtGetObjectTypeName (ObjDesc)));
536             return_ACPI_STATUS (AE_BAD_DATA);
537         }
538 
539         UserPrt->SourceIndex = (UINT32) ObjDesc->Integer.Value;
540 
541         /* Point to the next ACPI_OPERAND_OBJECT in the top level package */
542 
543         TopObjectList++;
544     }
545 
546     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "OutputBuffer %p Length %X\n",
547         OutputBuffer->Pointer, (UINT32) OutputBuffer->Length));
548     return_ACPI_STATUS (AE_OK);
549 }
550 
551 
552 /*******************************************************************************
553  *
554  * FUNCTION:    AcpiRsCreateAmlResources
555  *
556  * PARAMETERS:  ResourceList            - Pointer to the resource list buffer
557  *              OutputBuffer            - Where the AML buffer is returned
558  *
559  * RETURN:      Status  AE_OK if okay, else a valid ACPI_STATUS code.
560  *              If the OutputBuffer is too small, the error will be
561  *              AE_BUFFER_OVERFLOW and OutputBuffer->Length will point
562  *              to the size buffer needed.
563  *
564  * DESCRIPTION: Converts a list of device resources to an AML bytestream
565  *              to be used as input for the _SRS control method.
566  *
567  ******************************************************************************/
568 
569 ACPI_STATUS
570 AcpiRsCreateAmlResources (
571     ACPI_BUFFER             *ResourceList,
572     ACPI_BUFFER             *OutputBuffer)
573 {
574     ACPI_STATUS             Status;
575     ACPI_SIZE               AmlSizeNeeded = 0;
576 
577 
578     ACPI_FUNCTION_TRACE (RsCreateAmlResources);
579 
580 
581     /* Params already validated, no need to re-validate here */
582 
583     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "ResourceList Buffer = %p\n",
584         ResourceList->Pointer));
585 
586     /* Get the buffer size needed for the AML byte stream */
587 
588     Status = AcpiRsGetAmlLength (
589         ResourceList->Pointer, ResourceList->Length, &AmlSizeNeeded);
590 
591     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "AmlSizeNeeded=%X, %s\n",
592         (UINT32) AmlSizeNeeded, AcpiFormatException (Status)));
593     if (ACPI_FAILURE (Status))
594     {
595         return_ACPI_STATUS (Status);
596     }
597 
598     /* Validate/Allocate/Clear caller buffer */
599 
600     Status = AcpiUtInitializeBuffer (OutputBuffer, AmlSizeNeeded);
601     if (ACPI_FAILURE (Status))
602     {
603         return_ACPI_STATUS (Status);
604     }
605 
606     /* Do the conversion */
607 
608     Status = AcpiRsConvertResourcesToAml (ResourceList->Pointer,
609         AmlSizeNeeded, OutputBuffer->Pointer);
610     if (ACPI_FAILURE (Status))
611     {
612         return_ACPI_STATUS (Status);
613     }
614 
615     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "OutputBuffer %p Length %X\n",
616         OutputBuffer->Pointer, (UINT32) OutputBuffer->Length));
617     return_ACPI_STATUS (AE_OK);
618 }
619