xref: /openbmc/linux/drivers/acpi/acpica/psargs.c (revision 12eb4683)
1 /******************************************************************************
2  *
3  * Module Name: psargs - Parse AML opcode arguments
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2013, 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
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 
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 
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_IS_ROOT_PREFIX(*end) || ACPI_IS_PARENT_PREFIX(*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
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
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 
484 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
485 						       *parser_state)
486 {
487 	u32 aml_offset;
488 	union acpi_parse_object *field;
489 	union acpi_parse_object *arg = NULL;
490 	u16 opcode;
491 	u32 name;
492 	u8 access_type;
493 	u8 access_attribute;
494 	u8 access_length;
495 	u32 pkg_length;
496 	u8 *pkg_end;
497 	u32 buffer_length;
498 
499 	ACPI_FUNCTION_TRACE(ps_get_next_field);
500 
501 	aml_offset =
502 	    (u32)ACPI_PTR_DIFF(parser_state->aml, parser_state->aml_start);
503 
504 	/* Determine field type */
505 
506 	switch (ACPI_GET8(parser_state->aml)) {
507 	case AML_FIELD_OFFSET_OP:
508 
509 		opcode = AML_INT_RESERVEDFIELD_OP;
510 		parser_state->aml++;
511 		break;
512 
513 	case AML_FIELD_ACCESS_OP:
514 
515 		opcode = AML_INT_ACCESSFIELD_OP;
516 		parser_state->aml++;
517 		break;
518 
519 	case AML_FIELD_CONNECTION_OP:
520 
521 		opcode = AML_INT_CONNECTION_OP;
522 		parser_state->aml++;
523 		break;
524 
525 	case AML_FIELD_EXT_ACCESS_OP:
526 
527 		opcode = AML_INT_EXTACCESSFIELD_OP;
528 		parser_state->aml++;
529 		break;
530 
531 	default:
532 
533 		opcode = AML_INT_NAMEDFIELD_OP;
534 		break;
535 	}
536 
537 	/* Allocate a new field op */
538 
539 	field = acpi_ps_alloc_op(opcode);
540 	if (!field) {
541 		return_PTR(NULL);
542 	}
543 
544 	field->common.aml_offset = aml_offset;
545 
546 	/* Decode the field type */
547 
548 	switch (opcode) {
549 	case AML_INT_NAMEDFIELD_OP:
550 
551 		/* Get the 4-character name */
552 
553 		ACPI_MOVE_32_TO_32(&name, parser_state->aml);
554 		acpi_ps_set_name(field, name);
555 		parser_state->aml += ACPI_NAME_SIZE;
556 
557 		/* Get the length which is encoded as a package length */
558 
559 		field->common.value.size =
560 		    acpi_ps_get_next_package_length(parser_state);
561 		break;
562 
563 	case AML_INT_RESERVEDFIELD_OP:
564 
565 		/* Get the length which is encoded as a package length */
566 
567 		field->common.value.size =
568 		    acpi_ps_get_next_package_length(parser_state);
569 		break;
570 
571 	case AML_INT_ACCESSFIELD_OP:
572 	case AML_INT_EXTACCESSFIELD_OP:
573 
574 		/*
575 		 * Get access_type and access_attrib and merge into the field Op
576 		 * access_type is first operand, access_attribute is second. stuff
577 		 * these bytes into the node integer value for convenience.
578 		 */
579 
580 		/* Get the two bytes (Type/Attribute) */
581 
582 		access_type = ACPI_GET8(parser_state->aml);
583 		parser_state->aml++;
584 		access_attribute = ACPI_GET8(parser_state->aml);
585 		parser_state->aml++;
586 
587 		field->common.value.integer = (u8)access_type;
588 		field->common.value.integer |= (u16)(access_attribute << 8);
589 
590 		/* This opcode has a third byte, access_length */
591 
592 		if (opcode == AML_INT_EXTACCESSFIELD_OP) {
593 			access_length = ACPI_GET8(parser_state->aml);
594 			parser_state->aml++;
595 
596 			field->common.value.integer |=
597 			    (u32)(access_length << 16);
598 		}
599 		break;
600 
601 	case AML_INT_CONNECTION_OP:
602 
603 		/*
604 		 * Argument for Connection operator can be either a Buffer
605 		 * (resource descriptor), or a name_string.
606 		 */
607 		if (ACPI_GET8(parser_state->aml) == AML_BUFFER_OP) {
608 			parser_state->aml++;
609 
610 			pkg_end = parser_state->aml;
611 			pkg_length =
612 			    acpi_ps_get_next_package_length(parser_state);
613 			pkg_end += pkg_length;
614 
615 			if (parser_state->aml < pkg_end) {
616 
617 				/* Non-empty list */
618 
619 				arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
620 				if (!arg) {
621 					acpi_ps_free_op(field);
622 					return_PTR(NULL);
623 				}
624 
625 				/* Get the actual buffer length argument */
626 
627 				opcode = ACPI_GET8(parser_state->aml);
628 				parser_state->aml++;
629 
630 				switch (opcode) {
631 				case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
632 
633 					buffer_length =
634 					    ACPI_GET8(parser_state->aml);
635 					parser_state->aml += 1;
636 					break;
637 
638 				case AML_WORD_OP:	/* AML_WORDDATA_ARG */
639 
640 					buffer_length =
641 					    ACPI_GET16(parser_state->aml);
642 					parser_state->aml += 2;
643 					break;
644 
645 				case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
646 
647 					buffer_length =
648 					    ACPI_GET32(parser_state->aml);
649 					parser_state->aml += 4;
650 					break;
651 
652 				default:
653 
654 					buffer_length = 0;
655 					break;
656 				}
657 
658 				/* Fill in bytelist data */
659 
660 				arg->named.value.size = buffer_length;
661 				arg->named.data = parser_state->aml;
662 			}
663 
664 			/* Skip to End of byte data */
665 
666 			parser_state->aml = pkg_end;
667 		} else {
668 			arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
669 			if (!arg) {
670 				acpi_ps_free_op(field);
671 				return_PTR(NULL);
672 			}
673 
674 			/* Get the Namestring argument */
675 
676 			arg->common.value.name =
677 			    acpi_ps_get_next_namestring(parser_state);
678 		}
679 
680 		/* Link the buffer/namestring to parent (CONNECTION_OP) */
681 
682 		acpi_ps_append_arg(field, arg);
683 		break;
684 
685 	default:
686 
687 		/* Opcode was set in previous switch */
688 		break;
689 	}
690 
691 	return_PTR(field);
692 }
693 
694 /*******************************************************************************
695  *
696  * FUNCTION:    acpi_ps_get_next_arg
697  *
698  * PARAMETERS:  walk_state          - Current state
699  *              parser_state        - Current parser state object
700  *              arg_type            - The argument type (AML_*_ARG)
701  *              return_arg          - Where the next arg is returned
702  *
703  * RETURN:      Status, and an op object containing the next argument.
704  *
705  * DESCRIPTION: Get next argument (including complex list arguments that require
706  *              pushing the parser stack)
707  *
708  ******************************************************************************/
709 
710 acpi_status
711 acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
712 		     struct acpi_parse_state *parser_state,
713 		     u32 arg_type, union acpi_parse_object **return_arg)
714 {
715 	union acpi_parse_object *arg = NULL;
716 	union acpi_parse_object *prev = NULL;
717 	union acpi_parse_object *field;
718 	u32 subop;
719 	acpi_status status = AE_OK;
720 
721 	ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
722 
723 	switch (arg_type) {
724 	case ARGP_BYTEDATA:
725 	case ARGP_WORDDATA:
726 	case ARGP_DWORDDATA:
727 	case ARGP_CHARLIST:
728 	case ARGP_NAME:
729 	case ARGP_NAMESTRING:
730 
731 		/* Constants, strings, and namestrings are all the same size */
732 
733 		arg = acpi_ps_alloc_op(AML_BYTE_OP);
734 		if (!arg) {
735 			return_ACPI_STATUS(AE_NO_MEMORY);
736 		}
737 		acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
738 		break;
739 
740 	case ARGP_PKGLENGTH:
741 
742 		/* Package length, nothing returned */
743 
744 		parser_state->pkg_end =
745 		    acpi_ps_get_next_package_end(parser_state);
746 		break;
747 
748 	case ARGP_FIELDLIST:
749 
750 		if (parser_state->aml < parser_state->pkg_end) {
751 
752 			/* Non-empty list */
753 
754 			while (parser_state->aml < parser_state->pkg_end) {
755 				field = acpi_ps_get_next_field(parser_state);
756 				if (!field) {
757 					return_ACPI_STATUS(AE_NO_MEMORY);
758 				}
759 
760 				if (prev) {
761 					prev->common.next = field;
762 				} else {
763 					arg = field;
764 				}
765 				prev = field;
766 			}
767 
768 			/* Skip to End of byte data */
769 
770 			parser_state->aml = parser_state->pkg_end;
771 		}
772 		break;
773 
774 	case ARGP_BYTELIST:
775 
776 		if (parser_state->aml < parser_state->pkg_end) {
777 
778 			/* Non-empty list */
779 
780 			arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
781 			if (!arg) {
782 				return_ACPI_STATUS(AE_NO_MEMORY);
783 			}
784 
785 			/* Fill in bytelist data */
786 
787 			arg->common.value.size = (u32)
788 			    ACPI_PTR_DIFF(parser_state->pkg_end,
789 					  parser_state->aml);
790 			arg->named.data = parser_state->aml;
791 
792 			/* Skip to End of byte data */
793 
794 			parser_state->aml = parser_state->pkg_end;
795 		}
796 		break;
797 
798 	case ARGP_TARGET:
799 	case ARGP_SUPERNAME:
800 	case ARGP_SIMPLENAME:
801 
802 		subop = acpi_ps_peek_opcode(parser_state);
803 		if (subop == 0 ||
804 		    acpi_ps_is_leading_char(subop) ||
805 		    ACPI_IS_ROOT_PREFIX(subop) ||
806 		    ACPI_IS_PARENT_PREFIX(subop)) {
807 
808 			/* null_name or name_string */
809 
810 			arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
811 			if (!arg) {
812 				return_ACPI_STATUS(AE_NO_MEMORY);
813 			}
814 
815 			/* To support super_name arg of Unload */
816 
817 			if (walk_state->opcode == AML_UNLOAD_OP) {
818 				status =
819 				    acpi_ps_get_next_namepath(walk_state,
820 							      parser_state, arg,
821 							      1);
822 
823 				/*
824 				 * If the super_name arg of Unload is a method call,
825 				 * we have restored the AML pointer, just free this Arg
826 				 */
827 				if (arg->common.aml_opcode ==
828 				    AML_INT_METHODCALL_OP) {
829 					acpi_ps_free_op(arg);
830 					arg = NULL;
831 				}
832 			} else {
833 				status =
834 				    acpi_ps_get_next_namepath(walk_state,
835 							      parser_state, arg,
836 							      0);
837 			}
838 		} else {
839 			/* Single complex argument, nothing returned */
840 
841 			walk_state->arg_count = 1;
842 		}
843 		break;
844 
845 	case ARGP_DATAOBJ:
846 	case ARGP_TERMARG:
847 
848 		/* Single complex argument, nothing returned */
849 
850 		walk_state->arg_count = 1;
851 		break;
852 
853 	case ARGP_DATAOBJLIST:
854 	case ARGP_TERMLIST:
855 	case ARGP_OBJLIST:
856 
857 		if (parser_state->aml < parser_state->pkg_end) {
858 
859 			/* Non-empty list of variable arguments, nothing returned */
860 
861 			walk_state->arg_count = ACPI_VAR_ARGS;
862 		}
863 		break;
864 
865 	default:
866 
867 		ACPI_ERROR((AE_INFO, "Invalid ArgType: 0x%X", arg_type));
868 		status = AE_AML_OPERAND_TYPE;
869 		break;
870 	}
871 
872 	*return_arg = arg;
873 	return_ACPI_STATUS(status);
874 }
875