xref: /linux/drivers/acpi/acpica/psargs.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /******************************************************************************
2  *
3  * Module Name: psargs - Parse AML opcode arguments
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, 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, start);
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 	u8 *aml;
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 = parser_state->aml;
502 
503 	/* Determine field type */
504 
505 	switch (ACPI_GET8(parser_state->aml)) {
506 	case AML_FIELD_OFFSET_OP:
507 
508 		opcode = AML_INT_RESERVEDFIELD_OP;
509 		parser_state->aml++;
510 		break;
511 
512 	case AML_FIELD_ACCESS_OP:
513 
514 		opcode = AML_INT_ACCESSFIELD_OP;
515 		parser_state->aml++;
516 		break;
517 
518 	case AML_FIELD_CONNECTION_OP:
519 
520 		opcode = AML_INT_CONNECTION_OP;
521 		parser_state->aml++;
522 		break;
523 
524 	case AML_FIELD_EXT_ACCESS_OP:
525 
526 		opcode = AML_INT_EXTACCESSFIELD_OP;
527 		parser_state->aml++;
528 		break;
529 
530 	default:
531 
532 		opcode = AML_INT_NAMEDFIELD_OP;
533 		break;
534 	}
535 
536 	/* Allocate a new field op */
537 
538 	field = acpi_ps_alloc_op(opcode, aml);
539 	if (!field) {
540 		return_PTR(NULL);
541 	}
542 
543 	/* Decode the field type */
544 
545 	switch (opcode) {
546 	case AML_INT_NAMEDFIELD_OP:
547 
548 		/* Get the 4-character name */
549 
550 		ACPI_MOVE_32_TO_32(&name, parser_state->aml);
551 		acpi_ps_set_name(field, name);
552 		parser_state->aml += ACPI_NAME_SIZE;
553 
554 		/* Get the length which is encoded as a package length */
555 
556 		field->common.value.size =
557 		    acpi_ps_get_next_package_length(parser_state);
558 		break;
559 
560 	case AML_INT_RESERVEDFIELD_OP:
561 
562 		/* Get the length which is encoded as a package length */
563 
564 		field->common.value.size =
565 		    acpi_ps_get_next_package_length(parser_state);
566 		break;
567 
568 	case AML_INT_ACCESSFIELD_OP:
569 	case AML_INT_EXTACCESSFIELD_OP:
570 
571 		/*
572 		 * Get access_type and access_attrib and merge into the field Op
573 		 * access_type is first operand, access_attribute is second. stuff
574 		 * these bytes into the node integer value for convenience.
575 		 */
576 
577 		/* Get the two bytes (Type/Attribute) */
578 
579 		access_type = ACPI_GET8(parser_state->aml);
580 		parser_state->aml++;
581 		access_attribute = ACPI_GET8(parser_state->aml);
582 		parser_state->aml++;
583 
584 		field->common.value.integer = (u8)access_type;
585 		field->common.value.integer |= (u16)(access_attribute << 8);
586 
587 		/* This opcode has a third byte, access_length */
588 
589 		if (opcode == AML_INT_EXTACCESSFIELD_OP) {
590 			access_length = ACPI_GET8(parser_state->aml);
591 			parser_state->aml++;
592 
593 			field->common.value.integer |=
594 			    (u32)(access_length << 16);
595 		}
596 		break;
597 
598 	case AML_INT_CONNECTION_OP:
599 
600 		/*
601 		 * Argument for Connection operator can be either a Buffer
602 		 * (resource descriptor), or a name_string.
603 		 */
604 		aml = parser_state->aml;
605 		if (ACPI_GET8(parser_state->aml) == AML_BUFFER_OP) {
606 			parser_state->aml++;
607 
608 			pkg_end = parser_state->aml;
609 			pkg_length =
610 			    acpi_ps_get_next_package_length(parser_state);
611 			pkg_end += pkg_length;
612 
613 			if (parser_state->aml < pkg_end) {
614 
615 				/* Non-empty list */
616 
617 				arg =
618 				    acpi_ps_alloc_op(AML_INT_BYTELIST_OP, aml);
619 				if (!arg) {
620 					acpi_ps_free_op(field);
621 					return_PTR(NULL);
622 				}
623 
624 				/* Get the actual buffer length argument */
625 
626 				opcode = ACPI_GET8(parser_state->aml);
627 				parser_state->aml++;
628 
629 				switch (opcode) {
630 				case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
631 
632 					buffer_length =
633 					    ACPI_GET8(parser_state->aml);
634 					parser_state->aml += 1;
635 					break;
636 
637 				case AML_WORD_OP:	/* AML_WORDDATA_ARG */
638 
639 					buffer_length =
640 					    ACPI_GET16(parser_state->aml);
641 					parser_state->aml += 2;
642 					break;
643 
644 				case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
645 
646 					buffer_length =
647 					    ACPI_GET32(parser_state->aml);
648 					parser_state->aml += 4;
649 					break;
650 
651 				default:
652 
653 					buffer_length = 0;
654 					break;
655 				}
656 
657 				/* Fill in bytelist data */
658 
659 				arg->named.value.size = buffer_length;
660 				arg->named.data = parser_state->aml;
661 			}
662 
663 			/* Skip to End of byte data */
664 
665 			parser_state->aml = pkg_end;
666 		} else {
667 			arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP, aml);
668 			if (!arg) {
669 				acpi_ps_free_op(field);
670 				return_PTR(NULL);
671 			}
672 
673 			/* Get the Namestring argument */
674 
675 			arg->common.value.name =
676 			    acpi_ps_get_next_namestring(parser_state);
677 		}
678 
679 		/* Link the buffer/namestring to parent (CONNECTION_OP) */
680 
681 		acpi_ps_append_arg(field, arg);
682 		break;
683 
684 	default:
685 
686 		/* Opcode was set in previous switch */
687 		break;
688 	}
689 
690 	return_PTR(field);
691 }
692 
693 /*******************************************************************************
694  *
695  * FUNCTION:    acpi_ps_get_next_arg
696  *
697  * PARAMETERS:  walk_state          - Current state
698  *              parser_state        - Current parser state object
699  *              arg_type            - The argument type (AML_*_ARG)
700  *              return_arg          - Where the next arg is returned
701  *
702  * RETURN:      Status, and an op object containing the next argument.
703  *
704  * DESCRIPTION: Get next argument (including complex list arguments that require
705  *              pushing the parser stack)
706  *
707  ******************************************************************************/
708 
709 acpi_status
710 acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
711 		     struct acpi_parse_state *parser_state,
712 		     u32 arg_type, union acpi_parse_object **return_arg)
713 {
714 	union acpi_parse_object *arg = NULL;
715 	union acpi_parse_object *prev = NULL;
716 	union acpi_parse_object *field;
717 	u32 subop;
718 	acpi_status status = AE_OK;
719 
720 	ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
721 
722 	switch (arg_type) {
723 	case ARGP_BYTEDATA:
724 	case ARGP_WORDDATA:
725 	case ARGP_DWORDDATA:
726 	case ARGP_CHARLIST:
727 	case ARGP_NAME:
728 	case ARGP_NAMESTRING:
729 
730 		/* Constants, strings, and namestrings are all the same size */
731 
732 		arg = acpi_ps_alloc_op(AML_BYTE_OP, parser_state->aml);
733 		if (!arg) {
734 			return_ACPI_STATUS(AE_NO_MEMORY);
735 		}
736 		acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
737 		break;
738 
739 	case ARGP_PKGLENGTH:
740 
741 		/* Package length, nothing returned */
742 
743 		parser_state->pkg_end =
744 		    acpi_ps_get_next_package_end(parser_state);
745 		break;
746 
747 	case ARGP_FIELDLIST:
748 
749 		if (parser_state->aml < parser_state->pkg_end) {
750 
751 			/* Non-empty list */
752 
753 			while (parser_state->aml < parser_state->pkg_end) {
754 				field = acpi_ps_get_next_field(parser_state);
755 				if (!field) {
756 					return_ACPI_STATUS(AE_NO_MEMORY);
757 				}
758 
759 				if (prev) {
760 					prev->common.next = field;
761 				} else {
762 					arg = field;
763 				}
764 				prev = field;
765 			}
766 
767 			/* Skip to End of byte data */
768 
769 			parser_state->aml = parser_state->pkg_end;
770 		}
771 		break;
772 
773 	case ARGP_BYTELIST:
774 
775 		if (parser_state->aml < parser_state->pkg_end) {
776 
777 			/* Non-empty list */
778 
779 			arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP,
780 					       parser_state->aml);
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 =
811 			    acpi_ps_alloc_op(AML_INT_NAMEPATH_OP,
812 					     parser_state->aml);
813 			if (!arg) {
814 				return_ACPI_STATUS(AE_NO_MEMORY);
815 			}
816 
817 			/* To support super_name arg of Unload */
818 
819 			if (walk_state->opcode == AML_UNLOAD_OP) {
820 				status =
821 				    acpi_ps_get_next_namepath(walk_state,
822 							      parser_state, arg,
823 							      1);
824 
825 				/*
826 				 * If the super_name arg of Unload is a method call,
827 				 * we have restored the AML pointer, just free this Arg
828 				 */
829 				if (arg->common.aml_opcode ==
830 				    AML_INT_METHODCALL_OP) {
831 					acpi_ps_free_op(arg);
832 					arg = NULL;
833 				}
834 			} else {
835 				status =
836 				    acpi_ps_get_next_namepath(walk_state,
837 							      parser_state, arg,
838 							      0);
839 			}
840 		} else {
841 			/* Single complex argument, nothing returned */
842 
843 			walk_state->arg_count = 1;
844 		}
845 		break;
846 
847 	case ARGP_DATAOBJ:
848 	case ARGP_TERMARG:
849 
850 		/* Single complex argument, nothing returned */
851 
852 		walk_state->arg_count = 1;
853 		break;
854 
855 	case ARGP_DATAOBJLIST:
856 	case ARGP_TERMLIST:
857 	case ARGP_OBJLIST:
858 
859 		if (parser_state->aml < parser_state->pkg_end) {
860 
861 			/* Non-empty list of variable arguments, nothing returned */
862 
863 			walk_state->arg_count = ACPI_VAR_ARGS;
864 		}
865 		break;
866 
867 	default:
868 
869 		ACPI_ERROR((AE_INFO, "Invalid ArgType: 0x%X", arg_type));
870 		status = AE_AML_OPERAND_TYPE;
871 		break;
872 	}
873 
874 	*return_arg = arg;
875 	return_ACPI_STATUS(status);
876 }
877