1 /******************************************************************************
2  *
3  * Module Name: psargs - Parse AML opcode arguments
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2011, 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 "acparser.h"
47 #include "amlcode.h"
48 #include "acnamesp.h"
49 #include "acdispat.h"
50 
51 #define _COMPONENT          ACPI_PARSER
52 ACPI_MODULE_NAME("psargs")
53 
54 /* Local prototypes */
55 static u32
56 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state);
57 
58 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
59 						       *parser_state);
60 
61 /*******************************************************************************
62  *
63  * FUNCTION:    acpi_ps_get_next_package_length
64  *
65  * PARAMETERS:  parser_state        - Current parser state object
66  *
67  * RETURN:      Decoded package length. On completion, the AML pointer points
68  *              past the length byte or bytes.
69  *
70  * DESCRIPTION: Decode and return a package length field.
71  *              Note: Largest package length is 28 bits, from ACPI specification
72  *
73  ******************************************************************************/
74 
75 static u32
acpi_ps_get_next_package_length(struct acpi_parse_state * parser_state)76 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
77 {
78 	u8 *aml = parser_state->aml;
79 	u32 package_length = 0;
80 	u32 byte_count;
81 	u8 byte_zero_mask = 0x3F;	/* Default [0:5] */
82 
83 	ACPI_FUNCTION_TRACE(ps_get_next_package_length);
84 
85 	/*
86 	 * Byte 0 bits [6:7] contain the number of additional bytes
87 	 * used to encode the package length, either 0,1,2, or 3
88 	 */
89 	byte_count = (aml[0] >> 6);
90 	parser_state->aml += ((acpi_size) byte_count + 1);
91 
92 	/* Get bytes 3, 2, 1 as needed */
93 
94 	while (byte_count) {
95 		/*
96 		 * Final bit positions for the package length bytes:
97 		 *      Byte3->[20:27]
98 		 *      Byte2->[12:19]
99 		 *      Byte1->[04:11]
100 		 *      Byte0->[00:03]
101 		 */
102 		package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
103 
104 		byte_zero_mask = 0x0F;	/* Use bits [0:3] of byte 0 */
105 		byte_count--;
106 	}
107 
108 	/* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
109 
110 	package_length |= (aml[0] & byte_zero_mask);
111 	return_UINT32(package_length);
112 }
113 
114 /*******************************************************************************
115  *
116  * FUNCTION:    acpi_ps_get_next_package_end
117  *
118  * PARAMETERS:  parser_state        - Current parser state object
119  *
120  * RETURN:      Pointer to end-of-package +1
121  *
122  * DESCRIPTION: Get next package length and return a pointer past the end of
123  *              the package.  Consumes the package length field
124  *
125  ******************************************************************************/
126 
acpi_ps_get_next_package_end(struct acpi_parse_state * parser_state)127 u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
128 {
129 	u8 *start = parser_state->aml;
130 	u32 package_length;
131 
132 	ACPI_FUNCTION_TRACE(ps_get_next_package_end);
133 
134 	/* Function below updates parser_state->Aml */
135 
136 	package_length = acpi_ps_get_next_package_length(parser_state);
137 
138 	return_PTR(start + package_length);	/* end of package */
139 }
140 
141 /*******************************************************************************
142  *
143  * FUNCTION:    acpi_ps_get_next_namestring
144  *
145  * PARAMETERS:  parser_state        - Current parser state object
146  *
147  * RETURN:      Pointer to the start of the name string (pointer points into
148  *              the AML.
149  *
150  * DESCRIPTION: Get next raw namestring within the AML stream.  Handles all name
151  *              prefix characters.  Set parser state to point past the string.
152  *              (Name is consumed from the AML.)
153  *
154  ******************************************************************************/
155 
acpi_ps_get_next_namestring(struct acpi_parse_state * parser_state)156 char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
157 {
158 	u8 *start = parser_state->aml;
159 	u8 *end = parser_state->aml;
160 
161 	ACPI_FUNCTION_TRACE(ps_get_next_namestring);
162 
163 	/* Point past any namestring prefix characters (backslash or carat) */
164 
165 	while (acpi_ps_is_prefix_char(*end)) {
166 		end++;
167 	}
168 
169 	/* Decode the path prefix character */
170 
171 	switch (*end) {
172 	case 0:
173 
174 		/* null_name */
175 
176 		if (end == start) {
177 			start = NULL;
178 		}
179 		end++;
180 		break;
181 
182 	case AML_DUAL_NAME_PREFIX:
183 
184 		/* Two name segments */
185 
186 		end += 1 + (2 * ACPI_NAME_SIZE);
187 		break;
188 
189 	case AML_MULTI_NAME_PREFIX_OP:
190 
191 		/* Multiple name segments, 4 chars each, count in next byte */
192 
193 		end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
194 		break;
195 
196 	default:
197 
198 		/* Single name segment */
199 
200 		end += ACPI_NAME_SIZE;
201 		break;
202 	}
203 
204 	parser_state->aml = end;
205 	return_PTR((char *)start);
206 }
207 
208 /*******************************************************************************
209  *
210  * FUNCTION:    acpi_ps_get_next_namepath
211  *
212  * PARAMETERS:  parser_state        - Current parser state object
213  *              Arg                 - Where the namepath will be stored
214  *              arg_count           - If the namepath points to a control method
215  *                                    the method's argument is returned here.
216  *              possible_method_call - Whether the namepath can possibly be the
217  *                                    start of a method call
218  *
219  * RETURN:      Status
220  *
221  * DESCRIPTION: Get next name (if method call, return # of required args).
222  *              Names are looked up in the internal namespace to determine
223  *              if the name represents a control method.  If a method
224  *              is found, the number of arguments to the method is returned.
225  *              This information is critical for parsing to continue correctly.
226  *
227  ******************************************************************************/
228 
229 acpi_status
acpi_ps_get_next_namepath(struct acpi_walk_state * walk_state,struct acpi_parse_state * parser_state,union acpi_parse_object * arg,u8 possible_method_call)230 acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
231 			  struct acpi_parse_state *parser_state,
232 			  union acpi_parse_object *arg, u8 possible_method_call)
233 {
234 	acpi_status status;
235 	char *path;
236 	union acpi_parse_object *name_op;
237 	union acpi_operand_object *method_desc;
238 	struct acpi_namespace_node *node;
239 	u8 *start = parser_state->aml;
240 
241 	ACPI_FUNCTION_TRACE(ps_get_next_namepath);
242 
243 	path = acpi_ps_get_next_namestring(parser_state);
244 	acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
245 
246 	/* Null path case is allowed, just exit */
247 
248 	if (!path) {
249 		arg->common.value.name = path;
250 		return_ACPI_STATUS(AE_OK);
251 	}
252 
253 	/*
254 	 * Lookup the name in the internal namespace, starting with the current
255 	 * scope. We don't want to add anything new to the namespace here,
256 	 * however, so we use MODE_EXECUTE.
257 	 * Allow searching of the parent tree, but don't open a new scope -
258 	 * we just want to lookup the object (must be mode EXECUTE to perform
259 	 * the upsearch)
260 	 */
261 	status = acpi_ns_lookup(walk_state->scope_info, path,
262 				ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
263 				ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
264 				NULL, &node);
265 
266 	/*
267 	 * If this name is a control method invocation, we must
268 	 * setup the method call
269 	 */
270 	if (ACPI_SUCCESS(status) &&
271 	    possible_method_call && (node->type == ACPI_TYPE_METHOD)) {
272 		if (walk_state->opcode == AML_UNLOAD_OP) {
273 			/*
274 			 * acpi_ps_get_next_namestring has increased the AML pointer,
275 			 * so we need to restore the saved AML pointer for method call.
276 			 */
277 			walk_state->parser_state.aml = start;
278 			walk_state->arg_count = 1;
279 			acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
280 			return_ACPI_STATUS(AE_OK);
281 		}
282 
283 		/* This name is actually a control method invocation */
284 
285 		method_desc = acpi_ns_get_attached_object(node);
286 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
287 				  "Control Method - %p Desc %p Path=%p\n", node,
288 				  method_desc, path));
289 
290 		name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
291 		if (!name_op) {
292 			return_ACPI_STATUS(AE_NO_MEMORY);
293 		}
294 
295 		/* Change Arg into a METHOD CALL and attach name to it */
296 
297 		acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
298 		name_op->common.value.name = path;
299 
300 		/* Point METHODCALL/NAME to the METHOD Node */
301 
302 		name_op->common.node = node;
303 		acpi_ps_append_arg(arg, name_op);
304 
305 		if (!method_desc) {
306 			ACPI_ERROR((AE_INFO,
307 				    "Control Method %p has no attached object",
308 				    node));
309 			return_ACPI_STATUS(AE_AML_INTERNAL);
310 		}
311 
312 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
313 				  "Control Method - %p Args %X\n",
314 				  node, method_desc->method.param_count));
315 
316 		/* Get the number of arguments to expect */
317 
318 		walk_state->arg_count = method_desc->method.param_count;
319 		return_ACPI_STATUS(AE_OK);
320 	}
321 
322 	/*
323 	 * Special handling if the name was not found during the lookup -
324 	 * some not_found cases are allowed
325 	 */
326 	if (status == AE_NOT_FOUND) {
327 
328 		/* 1) not_found is ok during load pass 1/2 (allow forward references) */
329 
330 		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
331 		    ACPI_PARSE_EXECUTE) {
332 			status = AE_OK;
333 		}
334 
335 		/* 2) not_found during a cond_ref_of(x) is ok by definition */
336 
337 		else if (walk_state->op->common.aml_opcode ==
338 			 AML_COND_REF_OF_OP) {
339 			status = AE_OK;
340 		}
341 
342 		/*
343 		 * 3) not_found while building a Package is ok at this point, we
344 		 * may flag as an error later if slack mode is not enabled.
345 		 * (Some ASL code depends on allowing this behavior)
346 		 */
347 		else if ((arg->common.parent) &&
348 			 ((arg->common.parent->common.aml_opcode ==
349 			   AML_PACKAGE_OP)
350 			  || (arg->common.parent->common.aml_opcode ==
351 			      AML_VAR_PACKAGE_OP))) {
352 			status = AE_OK;
353 		}
354 	}
355 
356 	/* Final exception check (may have been changed from code above) */
357 
358 	if (ACPI_FAILURE(status)) {
359 		ACPI_ERROR_NAMESPACE(path, status);
360 
361 		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
362 		    ACPI_PARSE_EXECUTE) {
363 
364 			/* Report a control method execution error */
365 
366 			status = acpi_ds_method_error(status, walk_state);
367 		}
368 	}
369 
370 	/* Save the namepath */
371 
372 	arg->common.value.name = path;
373 	return_ACPI_STATUS(status);
374 }
375 
376 /*******************************************************************************
377  *
378  * FUNCTION:    acpi_ps_get_next_simple_arg
379  *
380  * PARAMETERS:  parser_state        - Current parser state object
381  *              arg_type            - The argument type (AML_*_ARG)
382  *              Arg                 - Where the argument is returned
383  *
384  * RETURN:      None
385  *
386  * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
387  *
388  ******************************************************************************/
389 
390 void
acpi_ps_get_next_simple_arg(struct acpi_parse_state * parser_state,u32 arg_type,union acpi_parse_object * arg)391 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
392 			    u32 arg_type, union acpi_parse_object *arg)
393 {
394 	u32 length;
395 	u16 opcode;
396 	u8 *aml = parser_state->aml;
397 
398 	ACPI_FUNCTION_TRACE_U32(ps_get_next_simple_arg, arg_type);
399 
400 	switch (arg_type) {
401 	case ARGP_BYTEDATA:
402 
403 		/* Get 1 byte from the AML stream */
404 
405 		opcode = AML_BYTE_OP;
406 		arg->common.value.integer = (u64) *aml;
407 		length = 1;
408 		break;
409 
410 	case ARGP_WORDDATA:
411 
412 		/* Get 2 bytes from the AML stream */
413 
414 		opcode = AML_WORD_OP;
415 		ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
416 		length = 2;
417 		break;
418 
419 	case ARGP_DWORDDATA:
420 
421 		/* Get 4 bytes from the AML stream */
422 
423 		opcode = AML_DWORD_OP;
424 		ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
425 		length = 4;
426 		break;
427 
428 	case ARGP_QWORDDATA:
429 
430 		/* Get 8 bytes from the AML stream */
431 
432 		opcode = AML_QWORD_OP;
433 		ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
434 		length = 8;
435 		break;
436 
437 	case ARGP_CHARLIST:
438 
439 		/* Get a pointer to the string, point past the string */
440 
441 		opcode = AML_STRING_OP;
442 		arg->common.value.string = ACPI_CAST_PTR(char, aml);
443 
444 		/* Find the null terminator */
445 
446 		length = 0;
447 		while (aml[length]) {
448 			length++;
449 		}
450 		length++;
451 		break;
452 
453 	case ARGP_NAME:
454 	case ARGP_NAMESTRING:
455 
456 		acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
457 		arg->common.value.name =
458 		    acpi_ps_get_next_namestring(parser_state);
459 		return_VOID;
460 
461 	default:
462 
463 		ACPI_ERROR((AE_INFO, "Invalid ArgType 0x%X", arg_type));
464 		return_VOID;
465 	}
466 
467 	acpi_ps_init_op(arg, opcode);
468 	parser_state->aml += length;
469 	return_VOID;
470 }
471 
472 /*******************************************************************************
473  *
474  * FUNCTION:    acpi_ps_get_next_field
475  *
476  * PARAMETERS:  parser_state        - Current parser state object
477  *
478  * RETURN:      A newly allocated FIELD op
479  *
480  * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
481  *
482  ******************************************************************************/
483 
acpi_ps_get_next_field(struct acpi_parse_state * parser_state)484 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
485 						       *parser_state)
486 {
487 	u32 aml_offset = (u32)
488 	    ACPI_PTR_DIFF(parser_state->aml,
489 			  parser_state->aml_start);
490 	union acpi_parse_object *field;
491 	u16 opcode;
492 	u32 name;
493 
494 	ACPI_FUNCTION_TRACE(ps_get_next_field);
495 
496 	/* Determine field type */
497 
498 	switch (ACPI_GET8(parser_state->aml)) {
499 	default:
500 
501 		opcode = AML_INT_NAMEDFIELD_OP;
502 		break;
503 
504 	case 0x00:
505 
506 		opcode = AML_INT_RESERVEDFIELD_OP;
507 		parser_state->aml++;
508 		break;
509 
510 	case 0x01:
511 
512 		opcode = AML_INT_ACCESSFIELD_OP;
513 		parser_state->aml++;
514 		break;
515 	}
516 
517 	/* Allocate a new field op */
518 
519 	field = acpi_ps_alloc_op(opcode);
520 	if (!field) {
521 		return_PTR(NULL);
522 	}
523 
524 	field->common.aml_offset = aml_offset;
525 
526 	/* Decode the field type */
527 
528 	switch (opcode) {
529 	case AML_INT_NAMEDFIELD_OP:
530 
531 		/* Get the 4-character name */
532 
533 		ACPI_MOVE_32_TO_32(&name, parser_state->aml);
534 		acpi_ps_set_name(field, name);
535 		parser_state->aml += ACPI_NAME_SIZE;
536 
537 		/* Get the length which is encoded as a package length */
538 
539 		field->common.value.size =
540 		    acpi_ps_get_next_package_length(parser_state);
541 		break;
542 
543 	case AML_INT_RESERVEDFIELD_OP:
544 
545 		/* Get the length which is encoded as a package length */
546 
547 		field->common.value.size =
548 		    acpi_ps_get_next_package_length(parser_state);
549 		break;
550 
551 	case AML_INT_ACCESSFIELD_OP:
552 
553 		/*
554 		 * Get access_type and access_attrib and merge into the field Op
555 		 * access_type is first operand, access_attribute is second
556 		 */
557 		field->common.value.integer =
558 		    (((u32) ACPI_GET8(parser_state->aml) << 8));
559 		parser_state->aml++;
560 		field->common.value.integer |= ACPI_GET8(parser_state->aml);
561 		parser_state->aml++;
562 		break;
563 
564 	default:
565 
566 		/* Opcode was set in previous switch */
567 		break;
568 	}
569 
570 	return_PTR(field);
571 }
572 
573 /*******************************************************************************
574  *
575  * FUNCTION:    acpi_ps_get_next_arg
576  *
577  * PARAMETERS:  walk_state          - Current state
578  *              parser_state        - Current parser state object
579  *              arg_type            - The argument type (AML_*_ARG)
580  *              return_arg          - Where the next arg is returned
581  *
582  * RETURN:      Status, and an op object containing the next argument.
583  *
584  * DESCRIPTION: Get next argument (including complex list arguments that require
585  *              pushing the parser stack)
586  *
587  ******************************************************************************/
588 
589 acpi_status
acpi_ps_get_next_arg(struct acpi_walk_state * walk_state,struct acpi_parse_state * parser_state,u32 arg_type,union acpi_parse_object ** return_arg)590 acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
591 		     struct acpi_parse_state *parser_state,
592 		     u32 arg_type, union acpi_parse_object **return_arg)
593 {
594 	union acpi_parse_object *arg = NULL;
595 	union acpi_parse_object *prev = NULL;
596 	union acpi_parse_object *field;
597 	u32 subop;
598 	acpi_status status = AE_OK;
599 
600 	ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
601 
602 	switch (arg_type) {
603 	case ARGP_BYTEDATA:
604 	case ARGP_WORDDATA:
605 	case ARGP_DWORDDATA:
606 	case ARGP_CHARLIST:
607 	case ARGP_NAME:
608 	case ARGP_NAMESTRING:
609 
610 		/* Constants, strings, and namestrings are all the same size */
611 
612 		arg = acpi_ps_alloc_op(AML_BYTE_OP);
613 		if (!arg) {
614 			return_ACPI_STATUS(AE_NO_MEMORY);
615 		}
616 		acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
617 		break;
618 
619 	case ARGP_PKGLENGTH:
620 
621 		/* Package length, nothing returned */
622 
623 		parser_state->pkg_end =
624 		    acpi_ps_get_next_package_end(parser_state);
625 		break;
626 
627 	case ARGP_FIELDLIST:
628 
629 		if (parser_state->aml < parser_state->pkg_end) {
630 
631 			/* Non-empty list */
632 
633 			while (parser_state->aml < parser_state->pkg_end) {
634 				field = acpi_ps_get_next_field(parser_state);
635 				if (!field) {
636 					return_ACPI_STATUS(AE_NO_MEMORY);
637 				}
638 
639 				if (prev) {
640 					prev->common.next = field;
641 				} else {
642 					arg = field;
643 				}
644 				prev = field;
645 			}
646 
647 			/* Skip to End of byte data */
648 
649 			parser_state->aml = parser_state->pkg_end;
650 		}
651 		break;
652 
653 	case ARGP_BYTELIST:
654 
655 		if (parser_state->aml < parser_state->pkg_end) {
656 
657 			/* Non-empty list */
658 
659 			arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
660 			if (!arg) {
661 				return_ACPI_STATUS(AE_NO_MEMORY);
662 			}
663 
664 			/* Fill in bytelist data */
665 
666 			arg->common.value.size = (u32)
667 			    ACPI_PTR_DIFF(parser_state->pkg_end,
668 					  parser_state->aml);
669 			arg->named.data = parser_state->aml;
670 
671 			/* Skip to End of byte data */
672 
673 			parser_state->aml = parser_state->pkg_end;
674 		}
675 		break;
676 
677 	case ARGP_TARGET:
678 	case ARGP_SUPERNAME:
679 	case ARGP_SIMPLENAME:
680 
681 		subop = acpi_ps_peek_opcode(parser_state);
682 		if (subop == 0 ||
683 		    acpi_ps_is_leading_char(subop) ||
684 		    acpi_ps_is_prefix_char(subop)) {
685 
686 			/* null_name or name_string */
687 
688 			arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
689 			if (!arg) {
690 				return_ACPI_STATUS(AE_NO_MEMORY);
691 			}
692 
693 			/* To support super_name arg of Unload */
694 
695 			if (walk_state->opcode == AML_UNLOAD_OP) {
696 				status =
697 				    acpi_ps_get_next_namepath(walk_state,
698 							      parser_state, arg,
699 							      1);
700 
701 				/*
702 				 * If the super_name arg of Unload is a method call,
703 				 * we have restored the AML pointer, just free this Arg
704 				 */
705 				if (arg->common.aml_opcode ==
706 				    AML_INT_METHODCALL_OP) {
707 					acpi_ps_free_op(arg);
708 					arg = NULL;
709 				}
710 			} else {
711 				status =
712 				    acpi_ps_get_next_namepath(walk_state,
713 							      parser_state, arg,
714 							      0);
715 			}
716 		} else {
717 			/* Single complex argument, nothing returned */
718 
719 			walk_state->arg_count = 1;
720 		}
721 		break;
722 
723 	case ARGP_DATAOBJ:
724 	case ARGP_TERMARG:
725 
726 		/* Single complex argument, nothing returned */
727 
728 		walk_state->arg_count = 1;
729 		break;
730 
731 	case ARGP_DATAOBJLIST:
732 	case ARGP_TERMLIST:
733 	case ARGP_OBJLIST:
734 
735 		if (parser_state->aml < parser_state->pkg_end) {
736 
737 			/* Non-empty list of variable arguments, nothing returned */
738 
739 			walk_state->arg_count = ACPI_VAR_ARGS;
740 		}
741 		break;
742 
743 	default:
744 
745 		ACPI_ERROR((AE_INFO, "Invalid ArgType: 0x%X", arg_type));
746 		status = AE_AML_OPERAND_TYPE;
747 		break;
748 	}
749 
750 	*return_arg = arg;
751 	return_ACPI_STATUS(status);
752 }
753