xref: /openbmc/linux/drivers/acpi/acpica/rscalc.c (revision e00a844a)
1 /*******************************************************************************
2  *
3  * Module Name: rscalc - Calculate stream and list lengths
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, 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/acpi.h>
45 #include "accommon.h"
46 #include "acresrc.h"
47 #include "acnamesp.h"
48 
49 #define _COMPONENT          ACPI_RESOURCES
50 ACPI_MODULE_NAME("rscalc")
51 
52 /* Local prototypes */
53 static u8 acpi_rs_count_set_bits(u16 bit_field);
54 
55 static acpi_rs_length
56 acpi_rs_struct_option_length(struct acpi_resource_source *resource_source);
57 
58 static u32
59 acpi_rs_stream_option_length(u32 resource_length, u32 minimum_total_length);
60 
61 /*******************************************************************************
62  *
63  * FUNCTION:    acpi_rs_count_set_bits
64  *
65  * PARAMETERS:  bit_field       - Field in which to count bits
66  *
67  * RETURN:      Number of bits set within the field
68  *
69  * DESCRIPTION: Count the number of bits set in a resource field. Used for
70  *              (Short descriptor) interrupt and DMA lists.
71  *
72  ******************************************************************************/
73 
74 static u8 acpi_rs_count_set_bits(u16 bit_field)
75 {
76 	u8 bits_set;
77 
78 	ACPI_FUNCTION_ENTRY();
79 
80 	for (bits_set = 0; bit_field; bits_set++) {
81 
82 		/* Zero the least significant bit that is set */
83 
84 		bit_field &= (u16) (bit_field - 1);
85 	}
86 
87 	return (bits_set);
88 }
89 
90 /*******************************************************************************
91  *
92  * FUNCTION:    acpi_rs_struct_option_length
93  *
94  * PARAMETERS:  resource_source     - Pointer to optional descriptor field
95  *
96  * RETURN:      Status
97  *
98  * DESCRIPTION: Common code to handle optional resource_source_index and
99  *              resource_source fields in some Large descriptors. Used during
100  *              list-to-stream conversion
101  *
102  ******************************************************************************/
103 
104 static acpi_rs_length
105 acpi_rs_struct_option_length(struct acpi_resource_source *resource_source)
106 {
107 	ACPI_FUNCTION_ENTRY();
108 
109 	/*
110 	 * If the resource_source string is valid, return the size of the string
111 	 * (string_length includes the NULL terminator) plus the size of the
112 	 * resource_source_index (1).
113 	 */
114 	if (resource_source->string_ptr) {
115 		return ((acpi_rs_length)(resource_source->string_length + 1));
116 	}
117 
118 	return (0);
119 }
120 
121 /*******************************************************************************
122  *
123  * FUNCTION:    acpi_rs_stream_option_length
124  *
125  * PARAMETERS:  resource_length     - Length from the resource header
126  *              minimum_total_length - Minimum length of this resource, before
127  *                                    any optional fields. Includes header size
128  *
129  * RETURN:      Length of optional string (0 if no string present)
130  *
131  * DESCRIPTION: Common code to handle optional resource_source_index and
132  *              resource_source fields in some Large descriptors. Used during
133  *              stream-to-list conversion
134  *
135  ******************************************************************************/
136 
137 static u32
138 acpi_rs_stream_option_length(u32 resource_length,
139 			     u32 minimum_aml_resource_length)
140 {
141 	u32 string_length = 0;
142 
143 	ACPI_FUNCTION_ENTRY();
144 
145 	/*
146 	 * The resource_source_index and resource_source are optional elements of
147 	 * some Large-type resource descriptors.
148 	 */
149 
150 	/*
151 	 * If the length of the actual resource descriptor is greater than the
152 	 * ACPI spec-defined minimum length, it means that a resource_source_index
153 	 * exists and is followed by a (required) null terminated string. The
154 	 * string length (including the null terminator) is the resource length
155 	 * minus the minimum length, minus one byte for the resource_source_index
156 	 * itself.
157 	 */
158 	if (resource_length > minimum_aml_resource_length) {
159 
160 		/* Compute the length of the optional string */
161 
162 		string_length =
163 		    resource_length - minimum_aml_resource_length - 1;
164 	}
165 
166 	/*
167 	 * Round the length up to a multiple of the native word in order to
168 	 * guarantee that the entire resource descriptor is native word aligned
169 	 */
170 	return ((u32) ACPI_ROUND_UP_TO_NATIVE_WORD(string_length));
171 }
172 
173 /*******************************************************************************
174  *
175  * FUNCTION:    acpi_rs_get_aml_length
176  *
177  * PARAMETERS:  resource            - Pointer to the resource linked list
178  *              resource_list_size  - Size of the resource linked list
179  *              size_needed         - Where the required size is returned
180  *
181  * RETURN:      Status
182  *
183  * DESCRIPTION: Takes a linked list of internal resource descriptors and
184  *              calculates the size buffer needed to hold the corresponding
185  *              external resource byte stream.
186  *
187  ******************************************************************************/
188 
189 acpi_status
190 acpi_rs_get_aml_length(struct acpi_resource *resource,
191 		       acpi_size resource_list_size, acpi_size *size_needed)
192 {
193 	acpi_size aml_size_needed = 0;
194 	struct acpi_resource *resource_end;
195 	acpi_rs_length total_size;
196 
197 	ACPI_FUNCTION_TRACE(rs_get_aml_length);
198 
199 	/* Traverse entire list of internal resource descriptors */
200 
201 	resource_end =
202 	    ACPI_ADD_PTR(struct acpi_resource, resource, resource_list_size);
203 	while (resource < resource_end) {
204 
205 		/* Validate the descriptor type */
206 
207 		if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
208 			return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
209 		}
210 
211 		/* Sanity check the length. It must not be zero, or we loop forever */
212 
213 		if (!resource->length) {
214 			return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
215 		}
216 
217 		/* Get the base size of the (external stream) resource descriptor */
218 
219 		total_size = acpi_gbl_aml_resource_sizes[resource->type];
220 
221 		/*
222 		 * Augment the base size for descriptors with optional and/or
223 		 * variable-length fields
224 		 */
225 		switch (resource->type) {
226 		case ACPI_RESOURCE_TYPE_IRQ:
227 
228 			/* Length can be 3 or 2 */
229 
230 			if (resource->data.irq.descriptor_length == 2) {
231 				total_size--;
232 			}
233 			break;
234 
235 		case ACPI_RESOURCE_TYPE_START_DEPENDENT:
236 
237 			/* Length can be 1 or 0 */
238 
239 			if (resource->data.irq.descriptor_length == 0) {
240 				total_size--;
241 			}
242 			break;
243 
244 		case ACPI_RESOURCE_TYPE_VENDOR:
245 			/*
246 			 * Vendor Defined Resource:
247 			 * For a Vendor Specific resource, if the Length is between 1 and 7
248 			 * it will be created as a Small Resource data type, otherwise it
249 			 * is a Large Resource data type.
250 			 */
251 			if (resource->data.vendor.byte_length > 7) {
252 
253 				/* Base size of a Large resource descriptor */
254 
255 				total_size =
256 				    sizeof(struct aml_resource_large_header);
257 			}
258 
259 			/* Add the size of the vendor-specific data */
260 
261 			total_size = (acpi_rs_length)
262 			    (total_size + resource->data.vendor.byte_length);
263 			break;
264 
265 		case ACPI_RESOURCE_TYPE_END_TAG:
266 			/*
267 			 * End Tag:
268 			 * We are done -- return the accumulated total size.
269 			 */
270 			*size_needed = aml_size_needed + total_size;
271 
272 			/* Normal exit */
273 
274 			return_ACPI_STATUS(AE_OK);
275 
276 		case ACPI_RESOURCE_TYPE_ADDRESS16:
277 			/*
278 			 * 16-Bit Address Resource:
279 			 * Add the size of the optional resource_source info
280 			 */
281 			total_size = (acpi_rs_length)(total_size +
282 						      acpi_rs_struct_option_length
283 						      (&resource->data.
284 						       address16.
285 						       resource_source));
286 			break;
287 
288 		case ACPI_RESOURCE_TYPE_ADDRESS32:
289 			/*
290 			 * 32-Bit Address Resource:
291 			 * Add the size of the optional resource_source info
292 			 */
293 			total_size = (acpi_rs_length)(total_size +
294 						      acpi_rs_struct_option_length
295 						      (&resource->data.
296 						       address32.
297 						       resource_source));
298 			break;
299 
300 		case ACPI_RESOURCE_TYPE_ADDRESS64:
301 			/*
302 			 * 64-Bit Address Resource:
303 			 * Add the size of the optional resource_source info
304 			 */
305 			total_size = (acpi_rs_length)(total_size +
306 						      acpi_rs_struct_option_length
307 						      (&resource->data.
308 						       address64.
309 						       resource_source));
310 			break;
311 
312 		case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
313 			/*
314 			 * Extended IRQ Resource:
315 			 * Add the size of each additional optional interrupt beyond the
316 			 * required 1 (4 bytes for each u32 interrupt number)
317 			 */
318 			total_size = (acpi_rs_length)(total_size +
319 						      ((resource->data.
320 							extended_irq.
321 							interrupt_count -
322 							1) * 4) +
323 						      /* Add the size of the optional resource_source info */
324 						      acpi_rs_struct_option_length
325 						      (&resource->data.
326 						       extended_irq.
327 						       resource_source));
328 			break;
329 
330 		case ACPI_RESOURCE_TYPE_GPIO:
331 
332 			total_size = (acpi_rs_length)(total_size +
333 						      (resource->data.gpio.
334 						       pin_table_length * 2) +
335 						      resource->data.gpio.
336 						      resource_source.
337 						      string_length +
338 						      resource->data.gpio.
339 						      vendor_length);
340 
341 			break;
342 
343 		case ACPI_RESOURCE_TYPE_PIN_FUNCTION:
344 
345 			total_size = (acpi_rs_length)(total_size +
346 						      (resource->data.
347 						       pin_function.
348 						       pin_table_length * 2) +
349 						      resource->data.
350 						      pin_function.
351 						      resource_source.
352 						      string_length +
353 						      resource->data.
354 						      pin_function.
355 						      vendor_length);
356 
357 			break;
358 
359 		case ACPI_RESOURCE_TYPE_SERIAL_BUS:
360 
361 			total_size =
362 			    acpi_gbl_aml_resource_serial_bus_sizes[resource->
363 								   data.
364 								   common_serial_bus.
365 								   type];
366 
367 			total_size = (acpi_rs_length)(total_size +
368 						      resource->data.
369 						      i2c_serial_bus.
370 						      resource_source.
371 						      string_length +
372 						      resource->data.
373 						      i2c_serial_bus.
374 						      vendor_length);
375 
376 			break;
377 
378 		case ACPI_RESOURCE_TYPE_PIN_CONFIG:
379 
380 			total_size = (acpi_rs_length)(total_size +
381 						      (resource->data.
382 						       pin_config.
383 						       pin_table_length * 2) +
384 						      resource->data.pin_config.
385 						      resource_source.
386 						      string_length +
387 						      resource->data.pin_config.
388 						      vendor_length);
389 
390 			break;
391 
392 		case ACPI_RESOURCE_TYPE_PIN_GROUP:
393 
394 			total_size = (acpi_rs_length)(total_size +
395 						      (resource->data.pin_group.
396 						       pin_table_length * 2) +
397 						      resource->data.pin_group.
398 						      resource_label.
399 						      string_length +
400 						      resource->data.pin_group.
401 						      vendor_length);
402 
403 			break;
404 
405 		case ACPI_RESOURCE_TYPE_PIN_GROUP_FUNCTION:
406 
407 			total_size = (acpi_rs_length)(total_size +
408 						      resource->data.
409 						      pin_group_function.
410 						      resource_source.
411 						      string_length +
412 						      resource->data.
413 						      pin_group_function.
414 						      resource_source_label.
415 						      string_length +
416 						      resource->data.
417 						      pin_group_function.
418 						      vendor_length);
419 
420 			break;
421 
422 		case ACPI_RESOURCE_TYPE_PIN_GROUP_CONFIG:
423 
424 			total_size = (acpi_rs_length)(total_size +
425 						      resource->data.
426 						      pin_group_config.
427 						      resource_source.
428 						      string_length +
429 						      resource->data.
430 						      pin_group_config.
431 						      resource_source_label.
432 						      string_length +
433 						      resource->data.
434 						      pin_group_config.
435 						      vendor_length);
436 
437 			break;
438 
439 		default:
440 
441 			break;
442 		}
443 
444 		/* Update the total */
445 
446 		aml_size_needed += total_size;
447 
448 		/* Point to the next object */
449 
450 		resource =
451 		    ACPI_ADD_PTR(struct acpi_resource, resource,
452 				 resource->length);
453 	}
454 
455 	/* Did not find an end_tag resource descriptor */
456 
457 	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
458 }
459 
460 /*******************************************************************************
461  *
462  * FUNCTION:    acpi_rs_get_list_length
463  *
464  * PARAMETERS:  aml_buffer          - Pointer to the resource byte stream
465  *              aml_buffer_length   - Size of aml_buffer
466  *              size_needed         - Where the size needed is returned
467  *
468  * RETURN:      Status
469  *
470  * DESCRIPTION: Takes an external resource byte stream and calculates the size
471  *              buffer needed to hold the corresponding internal resource
472  *              descriptor linked list.
473  *
474  ******************************************************************************/
475 
476 acpi_status
477 acpi_rs_get_list_length(u8 *aml_buffer,
478 			u32 aml_buffer_length, acpi_size *size_needed)
479 {
480 	acpi_status status;
481 	u8 *end_aml;
482 	u8 *buffer;
483 	u32 buffer_size;
484 	u16 temp16;
485 	u16 resource_length;
486 	u32 extra_struct_bytes;
487 	u8 resource_index;
488 	u8 minimum_aml_resource_length;
489 	union aml_resource *aml_resource;
490 
491 	ACPI_FUNCTION_TRACE(rs_get_list_length);
492 
493 	*size_needed = ACPI_RS_SIZE_MIN;	/* Minimum size is one end_tag */
494 	end_aml = aml_buffer + aml_buffer_length;
495 
496 	/* Walk the list of AML resource descriptors */
497 
498 	while (aml_buffer < end_aml) {
499 
500 		/* Validate the Resource Type and Resource Length */
501 
502 		status =
503 		    acpi_ut_validate_resource(NULL, aml_buffer,
504 					      &resource_index);
505 		if (ACPI_FAILURE(status)) {
506 			/*
507 			 * Exit on failure. Cannot continue because the descriptor length
508 			 * may be bogus also.
509 			 */
510 			return_ACPI_STATUS(status);
511 		}
512 
513 		aml_resource = (void *)aml_buffer;
514 
515 		/* Get the resource length and base (minimum) AML size */
516 
517 		resource_length = acpi_ut_get_resource_length(aml_buffer);
518 		minimum_aml_resource_length =
519 		    acpi_gbl_resource_aml_sizes[resource_index];
520 
521 		/*
522 		 * Augment the size for descriptors with optional
523 		 * and/or variable length fields
524 		 */
525 		extra_struct_bytes = 0;
526 		buffer =
527 		    aml_buffer + acpi_ut_get_resource_header_length(aml_buffer);
528 
529 		switch (acpi_ut_get_resource_type(aml_buffer)) {
530 		case ACPI_RESOURCE_NAME_IRQ:
531 			/*
532 			 * IRQ Resource:
533 			 * Get the number of bits set in the 16-bit IRQ mask
534 			 */
535 			ACPI_MOVE_16_TO_16(&temp16, buffer);
536 			extra_struct_bytes = acpi_rs_count_set_bits(temp16);
537 			break;
538 
539 		case ACPI_RESOURCE_NAME_DMA:
540 			/*
541 			 * DMA Resource:
542 			 * Get the number of bits set in the 8-bit DMA mask
543 			 */
544 			extra_struct_bytes = acpi_rs_count_set_bits(*buffer);
545 			break;
546 
547 		case ACPI_RESOURCE_NAME_VENDOR_SMALL:
548 		case ACPI_RESOURCE_NAME_VENDOR_LARGE:
549 			/*
550 			 * Vendor Resource:
551 			 * Get the number of vendor data bytes
552 			 */
553 			extra_struct_bytes = resource_length;
554 
555 			/*
556 			 * There is already one byte included in the minimum
557 			 * descriptor size. If there are extra struct bytes,
558 			 * subtract one from the count.
559 			 */
560 			if (extra_struct_bytes) {
561 				extra_struct_bytes--;
562 			}
563 			break;
564 
565 		case ACPI_RESOURCE_NAME_END_TAG:
566 			/*
567 			 * End Tag: This is the normal exit
568 			 */
569 			return_ACPI_STATUS(AE_OK);
570 
571 		case ACPI_RESOURCE_NAME_ADDRESS32:
572 		case ACPI_RESOURCE_NAME_ADDRESS16:
573 		case ACPI_RESOURCE_NAME_ADDRESS64:
574 			/*
575 			 * Address Resource:
576 			 * Add the size of the optional resource_source
577 			 */
578 			extra_struct_bytes =
579 			    acpi_rs_stream_option_length(resource_length,
580 							 minimum_aml_resource_length);
581 			break;
582 
583 		case ACPI_RESOURCE_NAME_EXTENDED_IRQ:
584 			/*
585 			 * Extended IRQ Resource:
586 			 * Using the interrupt_table_length, add 4 bytes for each additional
587 			 * interrupt. Note: at least one interrupt is required and is
588 			 * included in the minimum descriptor size (reason for the -1)
589 			 */
590 			extra_struct_bytes = (buffer[1] - 1) * sizeof(u32);
591 
592 			/* Add the size of the optional resource_source */
593 
594 			extra_struct_bytes +=
595 			    acpi_rs_stream_option_length(resource_length -
596 							 extra_struct_bytes,
597 							 minimum_aml_resource_length);
598 			break;
599 
600 		case ACPI_RESOURCE_NAME_GPIO:
601 
602 			/* Vendor data is optional */
603 
604 			if (aml_resource->gpio.vendor_length) {
605 				extra_struct_bytes +=
606 				    aml_resource->gpio.vendor_offset -
607 				    aml_resource->gpio.pin_table_offset +
608 				    aml_resource->gpio.vendor_length;
609 			} else {
610 				extra_struct_bytes +=
611 				    aml_resource->large_header.resource_length +
612 				    sizeof(struct aml_resource_large_header) -
613 				    aml_resource->gpio.pin_table_offset;
614 			}
615 			break;
616 
617 		case ACPI_RESOURCE_NAME_PIN_FUNCTION:
618 
619 			/* Vendor data is optional */
620 
621 			if (aml_resource->pin_function.vendor_length) {
622 				extra_struct_bytes +=
623 				    aml_resource->pin_function.vendor_offset -
624 				    aml_resource->pin_function.
625 				    pin_table_offset +
626 				    aml_resource->pin_function.vendor_length;
627 			} else {
628 				extra_struct_bytes +=
629 				    aml_resource->large_header.resource_length +
630 				    sizeof(struct aml_resource_large_header) -
631 				    aml_resource->pin_function.pin_table_offset;
632 			}
633 			break;
634 
635 		case ACPI_RESOURCE_NAME_SERIAL_BUS:
636 
637 			minimum_aml_resource_length =
638 			    acpi_gbl_resource_aml_serial_bus_sizes
639 			    [aml_resource->common_serial_bus.type];
640 			extra_struct_bytes +=
641 			    aml_resource->common_serial_bus.resource_length -
642 			    minimum_aml_resource_length;
643 			break;
644 
645 		case ACPI_RESOURCE_NAME_PIN_CONFIG:
646 
647 			/* Vendor data is optional */
648 
649 			if (aml_resource->pin_config.vendor_length) {
650 				extra_struct_bytes +=
651 				    aml_resource->pin_config.vendor_offset -
652 				    aml_resource->pin_config.pin_table_offset +
653 				    aml_resource->pin_config.vendor_length;
654 			} else {
655 				extra_struct_bytes +=
656 				    aml_resource->large_header.resource_length +
657 				    sizeof(struct aml_resource_large_header) -
658 				    aml_resource->pin_config.pin_table_offset;
659 			}
660 			break;
661 
662 		case ACPI_RESOURCE_NAME_PIN_GROUP:
663 
664 			extra_struct_bytes +=
665 			    aml_resource->pin_group.vendor_offset -
666 			    aml_resource->pin_group.pin_table_offset +
667 			    aml_resource->pin_group.vendor_length;
668 
669 			break;
670 
671 		case ACPI_RESOURCE_NAME_PIN_GROUP_FUNCTION:
672 
673 			extra_struct_bytes +=
674 			    aml_resource->pin_group_function.vendor_offset -
675 			    aml_resource->pin_group_function.res_source_offset +
676 			    aml_resource->pin_group_function.vendor_length;
677 
678 			break;
679 
680 		case ACPI_RESOURCE_NAME_PIN_GROUP_CONFIG:
681 
682 			extra_struct_bytes +=
683 			    aml_resource->pin_group_config.vendor_offset -
684 			    aml_resource->pin_group_config.res_source_offset +
685 			    aml_resource->pin_group_config.vendor_length;
686 
687 			break;
688 
689 		default:
690 
691 			break;
692 		}
693 
694 		/*
695 		 * Update the required buffer size for the internal descriptor structs
696 		 *
697 		 * Important: Round the size up for the appropriate alignment. This
698 		 * is a requirement on IA64.
699 		 */
700 		if (acpi_ut_get_resource_type(aml_buffer) ==
701 		    ACPI_RESOURCE_NAME_SERIAL_BUS) {
702 			buffer_size =
703 			    acpi_gbl_resource_struct_serial_bus_sizes
704 			    [aml_resource->common_serial_bus.type] +
705 			    extra_struct_bytes;
706 		} else {
707 			buffer_size =
708 			    acpi_gbl_resource_struct_sizes[resource_index] +
709 			    extra_struct_bytes;
710 		}
711 
712 		buffer_size = (u32)ACPI_ROUND_UP_TO_NATIVE_WORD(buffer_size);
713 		*size_needed += buffer_size;
714 
715 		ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES,
716 				  "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
717 				  acpi_ut_get_resource_type(aml_buffer),
718 				  acpi_ut_get_descriptor_length(aml_buffer),
719 				  buffer_size));
720 
721 		/*
722 		 * Point to the next resource within the AML stream using the length
723 		 * contained in the resource descriptor header
724 		 */
725 		aml_buffer += acpi_ut_get_descriptor_length(aml_buffer);
726 	}
727 
728 	/* Did not find an end_tag resource descriptor */
729 
730 	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
731 }
732 
733 /*******************************************************************************
734  *
735  * FUNCTION:    acpi_rs_get_pci_routing_table_length
736  *
737  * PARAMETERS:  package_object          - Pointer to the package object
738  *              buffer_size_needed      - u32 pointer of the size buffer
739  *                                        needed to properly return the
740  *                                        parsed data
741  *
742  * RETURN:      Status
743  *
744  * DESCRIPTION: Given a package representing a PCI routing table, this
745  *              calculates the size of the corresponding linked list of
746  *              descriptions.
747  *
748  ******************************************************************************/
749 
750 acpi_status
751 acpi_rs_get_pci_routing_table_length(union acpi_operand_object *package_object,
752 				     acpi_size *buffer_size_needed)
753 {
754 	u32 number_of_elements;
755 	acpi_size temp_size_needed = 0;
756 	union acpi_operand_object **top_object_list;
757 	u32 index;
758 	union acpi_operand_object *package_element;
759 	union acpi_operand_object **sub_object_list;
760 	u8 name_found;
761 	u32 table_index;
762 
763 	ACPI_FUNCTION_TRACE(rs_get_pci_routing_table_length);
764 
765 	number_of_elements = package_object->package.count;
766 
767 	/*
768 	 * Calculate the size of the return buffer.
769 	 * The base size is the number of elements * the sizes of the
770 	 * structures. Additional space for the strings is added below.
771 	 * The minus one is to subtract the size of the u8 Source[1]
772 	 * member because it is added below.
773 	 *
774 	 * But each PRT_ENTRY structure has a pointer to a string and
775 	 * the size of that string must be found.
776 	 */
777 	top_object_list = package_object->package.elements;
778 
779 	for (index = 0; index < number_of_elements; index++) {
780 
781 		/* Dereference the subpackage */
782 
783 		package_element = *top_object_list;
784 
785 		/* We must have a valid Package object */
786 
787 		if (!package_element ||
788 		    (package_element->common.type != ACPI_TYPE_PACKAGE)) {
789 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
790 		}
791 
792 		/*
793 		 * The sub_object_list will now point to an array of the
794 		 * four IRQ elements: Address, Pin, Source and source_index
795 		 */
796 		sub_object_list = package_element->package.elements;
797 
798 		/* Scan the irq_table_elements for the Source Name String */
799 
800 		name_found = FALSE;
801 
802 		for (table_index = 0;
803 		     table_index < package_element->package.count
804 		     && !name_found; table_index++) {
805 			if (*sub_object_list &&	/* Null object allowed */
806 			    ((ACPI_TYPE_STRING ==
807 			      (*sub_object_list)->common.type) ||
808 			     ((ACPI_TYPE_LOCAL_REFERENCE ==
809 			       (*sub_object_list)->common.type) &&
810 			      ((*sub_object_list)->reference.class ==
811 			       ACPI_REFCLASS_NAME)))) {
812 				name_found = TRUE;
813 			} else {
814 				/* Look at the next element */
815 
816 				sub_object_list++;
817 			}
818 		}
819 
820 		temp_size_needed += (sizeof(struct acpi_pci_routing_table) - 4);
821 
822 		/* Was a String type found? */
823 
824 		if (name_found) {
825 			if ((*sub_object_list)->common.type == ACPI_TYPE_STRING) {
826 				/*
827 				 * The length String.Length field does not include the
828 				 * terminating NULL, add 1
829 				 */
830 				temp_size_needed += ((acpi_size)
831 						     (*sub_object_list)->string.
832 						     length + 1);
833 			} else {
834 				temp_size_needed += acpi_ns_get_pathname_length((*sub_object_list)->reference.node);
835 			}
836 		} else {
837 			/*
838 			 * If no name was found, then this is a NULL, which is
839 			 * translated as a u32 zero.
840 			 */
841 			temp_size_needed += sizeof(u32);
842 		}
843 
844 		/* Round up the size since each element must be aligned */
845 
846 		temp_size_needed = ACPI_ROUND_UP_TO_64BIT(temp_size_needed);
847 
848 		/* Point to the next union acpi_operand_object */
849 
850 		top_object_list++;
851 	}
852 
853 	/*
854 	 * Add an extra element to the end of the list, essentially a
855 	 * NULL terminator
856 	 */
857 	*buffer_size_needed =
858 	    temp_size_needed + sizeof(struct acpi_pci_routing_table);
859 	return_ACPI_STATUS(AE_OK);
860 }
861