xref: /openbmc/linux/drivers/acpi/acpica/psargs.c (revision 133f9794)
1 /******************************************************************************
2  *
3  * Module Name: psargs - Parse AML opcode arguments
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2018, 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 #include "acconvert.h"
51 
52 #define _COMPONENT          ACPI_PARSER
53 ACPI_MODULE_NAME("psargs")
54 
55 /* Local prototypes */
56 static u32
57 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state);
58 
59 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
60 						       *parser_state);
61 
62 /*******************************************************************************
63  *
64  * FUNCTION:    acpi_ps_get_next_package_length
65  *
66  * PARAMETERS:  parser_state        - Current parser state object
67  *
68  * RETURN:      Decoded package length. On completion, the AML pointer points
69  *              past the length byte or bytes.
70  *
71  * DESCRIPTION: Decode and return a package length field.
72  *              Note: Largest package length is 28 bits, from ACPI specification
73  *
74  ******************************************************************************/
75 
76 static u32
77 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
78 {
79 	u8 *aml = parser_state->aml;
80 	u32 package_length = 0;
81 	u32 byte_count;
82 	u8 byte_zero_mask = 0x3F;	/* Default [0:5] */
83 
84 	ACPI_FUNCTION_TRACE(ps_get_next_package_length);
85 
86 	/*
87 	 * Byte 0 bits [6:7] contain the number of additional bytes
88 	 * used to encode the package length, either 0,1,2, or 3
89 	 */
90 	byte_count = (aml[0] >> 6);
91 	parser_state->aml += ((acpi_size)byte_count + 1);
92 
93 	/* Get bytes 3, 2, 1 as needed */
94 
95 	while (byte_count) {
96 		/*
97 		 * Final bit positions for the package length bytes:
98 		 *      Byte3->[20:27]
99 		 *      Byte2->[12:19]
100 		 *      Byte1->[04:11]
101 		 *      Byte0->[00:03]
102 		 */
103 		package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
104 
105 		byte_zero_mask = 0x0F;	/* Use bits [0:3] of byte 0 */
106 		byte_count--;
107 	}
108 
109 	/* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
110 
111 	package_length |= (aml[0] & byte_zero_mask);
112 	return_UINT32(package_length);
113 }
114 
115 /*******************************************************************************
116  *
117  * FUNCTION:    acpi_ps_get_next_package_end
118  *
119  * PARAMETERS:  parser_state        - Current parser state object
120  *
121  * RETURN:      Pointer to end-of-package +1
122  *
123  * DESCRIPTION: Get next package length and return a pointer past the end of
124  *              the package. Consumes the package length field
125  *
126  ******************************************************************************/
127 
128 u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
129 {
130 	u8 *start = parser_state->aml;
131 	u32 package_length;
132 
133 	ACPI_FUNCTION_TRACE(ps_get_next_package_end);
134 
135 	/* Function below updates parser_state->Aml */
136 
137 	package_length = acpi_ps_get_next_package_length(parser_state);
138 
139 	return_PTR(start + package_length);	/* end of package */
140 }
141 
142 /*******************************************************************************
143  *
144  * FUNCTION:    acpi_ps_get_next_namestring
145  *
146  * PARAMETERS:  parser_state        - Current parser state object
147  *
148  * RETURN:      Pointer to the start of the name string (pointer points into
149  *              the AML.
150  *
151  * DESCRIPTION: Get next raw namestring within the AML stream. Handles all name
152  *              prefix characters. Set parser state to point past the string.
153  *              (Name is consumed from the AML.)
154  *
155  ******************************************************************************/
156 
157 char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
158 {
159 	u8 *start = parser_state->aml;
160 	u8 *end = parser_state->aml;
161 
162 	ACPI_FUNCTION_TRACE(ps_get_next_namestring);
163 
164 	/* Point past any namestring prefix characters (backslash or carat) */
165 
166 	while (ACPI_IS_ROOT_PREFIX(*end) || ACPI_IS_PARENT_PREFIX(*end)) {
167 		end++;
168 	}
169 
170 	/* Decode the path prefix character */
171 
172 	switch (*end) {
173 	case 0:
174 
175 		/* null_name */
176 
177 		if (end == start) {
178 			start = NULL;
179 		}
180 		end++;
181 		break;
182 
183 	case AML_DUAL_NAME_PREFIX:
184 
185 		/* Two name segments */
186 
187 		end += 1 + (2 * ACPI_NAME_SIZE);
188 		break;
189 
190 	case AML_MULTI_NAME_PREFIX:
191 
192 		/* Multiple name segments, 4 chars each, count in next byte */
193 
194 		end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
195 		break;
196 
197 	default:
198 
199 		/* Single name segment */
200 
201 		end += ACPI_NAME_SIZE;
202 		break;
203 	}
204 
205 	parser_state->aml = end;
206 	return_PTR((char *)start);
207 }
208 
209 /*******************************************************************************
210  *
211  * FUNCTION:    acpi_ps_get_next_namepath
212  *
213  * PARAMETERS:  parser_state        - Current parser state object
214  *              arg                 - Where the namepath will be stored
215  *              arg_count           - If the namepath points to a control method
216  *                                    the method's argument is returned here.
217  *              possible_method_call - Whether the namepath can possibly be the
218  *                                    start of a method call
219  *
220  * RETURN:      Status
221  *
222  * DESCRIPTION: Get next name (if method call, return # of required args).
223  *              Names are looked up in the internal namespace to determine
224  *              if the name represents a control method. If a method
225  *              is found, the number of arguments to the method is returned.
226  *              This information is critical for parsing to continue correctly.
227  *
228  ******************************************************************************/
229 
230 acpi_status
231 acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
232 			  struct acpi_parse_state *parser_state,
233 			  union acpi_parse_object *arg, u8 possible_method_call)
234 {
235 	acpi_status status;
236 	char *path;
237 	union acpi_parse_object *name_op;
238 	union acpi_operand_object *method_desc;
239 	struct acpi_namespace_node *node;
240 	u8 *start = parser_state->aml;
241 
242 	ACPI_FUNCTION_TRACE(ps_get_next_namepath);
243 
244 	path = acpi_ps_get_next_namestring(parser_state);
245 	acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
246 
247 	/* Null path case is allowed, just exit */
248 
249 	if (!path) {
250 		arg->common.value.name = path;
251 		return_ACPI_STATUS(AE_OK);
252 	}
253 
254 	/*
255 	 * Lookup the name in the internal namespace, starting with the current
256 	 * scope. We don't want to add anything new to the namespace here,
257 	 * however, so we use MODE_EXECUTE.
258 	 * Allow searching of the parent tree, but don't open a new scope -
259 	 * we just want to lookup the object (must be mode EXECUTE to perform
260 	 * the upsearch)
261 	 */
262 	status = acpi_ns_lookup(walk_state->scope_info, path,
263 				ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
264 				ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
265 				NULL, &node);
266 
267 	/*
268 	 * If this name is a control method invocation, we must
269 	 * setup the method call
270 	 */
271 	if (ACPI_SUCCESS(status) &&
272 	    possible_method_call && (node->type == ACPI_TYPE_METHOD)) {
273 		if ((GET_CURRENT_ARG_TYPE(walk_state->arg_types) ==
274 		     ARGP_SUPERNAME)
275 		    || (GET_CURRENT_ARG_TYPE(walk_state->arg_types) ==
276 			ARGP_TARGET)) {
277 			/*
278 			 * acpi_ps_get_next_namestring has increased the AML pointer past
279 			 * the method invocation namestring, so we need to restore the
280 			 * saved AML pointer back to the original method invocation
281 			 * namestring.
282 			 */
283 			walk_state->parser_state.aml = start;
284 			walk_state->arg_count = 1;
285 			acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
286 		}
287 
288 		/* This name is actually a control method invocation */
289 
290 		method_desc = acpi_ns_get_attached_object(node);
291 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
292 				  "Control Method invocation %4.4s - %p Desc %p Path=%p\n",
293 				  node->name.ascii, node, method_desc, path));
294 
295 		name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP, start);
296 		if (!name_op) {
297 			return_ACPI_STATUS(AE_NO_MEMORY);
298 		}
299 
300 		/* Change Arg into a METHOD CALL and attach name to it */
301 
302 		acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
303 		name_op->common.value.name = path;
304 
305 		/* Point METHODCALL/NAME to the METHOD Node */
306 
307 		name_op->common.node = node;
308 		acpi_ps_append_arg(arg, name_op);
309 
310 		if (!method_desc) {
311 			ACPI_ERROR((AE_INFO,
312 				    "Control Method %p has no attached object",
313 				    node));
314 			return_ACPI_STATUS(AE_AML_INTERNAL);
315 		}
316 
317 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
318 				  "Control Method - %p Args %X\n",
319 				  node, method_desc->method.param_count));
320 
321 		/* Get the number of arguments to expect */
322 
323 		walk_state->arg_count = method_desc->method.param_count;
324 		return_ACPI_STATUS(AE_OK);
325 	}
326 
327 	/*
328 	 * Special handling if the name was not found during the lookup -
329 	 * some not_found cases are allowed
330 	 */
331 	if (status == AE_NOT_FOUND) {
332 
333 		/* 1) not_found is ok during load pass 1/2 (allow forward references) */
334 
335 		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
336 		    ACPI_PARSE_EXECUTE) {
337 			status = AE_OK;
338 		}
339 
340 		/* 2) not_found during a cond_ref_of(x) is ok by definition */
341 
342 		else if (walk_state->op->common.aml_opcode ==
343 			 AML_CONDITIONAL_REF_OF_OP) {
344 			status = AE_OK;
345 		}
346 
347 		/*
348 		 * 3) not_found while building a Package is ok at this point, we
349 		 * may flag as an error later if slack mode is not enabled.
350 		 * (Some ASL code depends on allowing this behavior)
351 		 */
352 		else if ((arg->common.parent) &&
353 			 ((arg->common.parent->common.aml_opcode ==
354 			   AML_PACKAGE_OP)
355 			  || (arg->common.parent->common.aml_opcode ==
356 			      AML_VARIABLE_PACKAGE_OP))) {
357 			status = AE_OK;
358 		}
359 	}
360 
361 	/* Final exception check (may have been changed from code above) */
362 
363 	if (ACPI_FAILURE(status)) {
364 		ACPI_ERROR_NAMESPACE(walk_state->scope_info, path, status);
365 
366 		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
367 		    ACPI_PARSE_EXECUTE) {
368 
369 			/* Report a control method execution error */
370 
371 			status = acpi_ds_method_error(status, walk_state);
372 		}
373 	}
374 
375 	/* Save the namepath */
376 
377 	arg->common.value.name = path;
378 	return_ACPI_STATUS(status);
379 }
380 
381 /*******************************************************************************
382  *
383  * FUNCTION:    acpi_ps_get_next_simple_arg
384  *
385  * PARAMETERS:  parser_state        - Current parser state object
386  *              arg_type            - The argument type (AML_*_ARG)
387  *              arg                 - Where the argument is returned
388  *
389  * RETURN:      None
390  *
391  * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
392  *
393  ******************************************************************************/
394 
395 void
396 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
397 			    u32 arg_type, union acpi_parse_object *arg)
398 {
399 	u32 length;
400 	u16 opcode;
401 	u8 *aml = parser_state->aml;
402 
403 	ACPI_FUNCTION_TRACE_U32(ps_get_next_simple_arg, arg_type);
404 
405 	switch (arg_type) {
406 	case ARGP_BYTEDATA:
407 
408 		/* Get 1 byte from the AML stream */
409 
410 		opcode = AML_BYTE_OP;
411 		arg->common.value.integer = (u64) *aml;
412 		length = 1;
413 		break;
414 
415 	case ARGP_WORDDATA:
416 
417 		/* Get 2 bytes from the AML stream */
418 
419 		opcode = AML_WORD_OP;
420 		ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
421 		length = 2;
422 		break;
423 
424 	case ARGP_DWORDDATA:
425 
426 		/* Get 4 bytes from the AML stream */
427 
428 		opcode = AML_DWORD_OP;
429 		ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
430 		length = 4;
431 		break;
432 
433 	case ARGP_QWORDDATA:
434 
435 		/* Get 8 bytes from the AML stream */
436 
437 		opcode = AML_QWORD_OP;
438 		ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
439 		length = 8;
440 		break;
441 
442 	case ARGP_CHARLIST:
443 
444 		/* Get a pointer to the string, point past the string */
445 
446 		opcode = AML_STRING_OP;
447 		arg->common.value.string = ACPI_CAST_PTR(char, aml);
448 
449 		/* Find the null terminator */
450 
451 		length = 0;
452 		while (aml[length]) {
453 			length++;
454 		}
455 		length++;
456 		break;
457 
458 	case ARGP_NAME:
459 	case ARGP_NAMESTRING:
460 
461 		acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
462 		arg->common.value.name =
463 		    acpi_ps_get_next_namestring(parser_state);
464 		return_VOID;
465 
466 	default:
467 
468 		ACPI_ERROR((AE_INFO, "Invalid ArgType 0x%X", arg_type));
469 		return_VOID;
470 	}
471 
472 	acpi_ps_init_op(arg, opcode);
473 	parser_state->aml += length;
474 	return_VOID;
475 }
476 
477 /*******************************************************************************
478  *
479  * FUNCTION:    acpi_ps_get_next_field
480  *
481  * PARAMETERS:  parser_state        - Current parser state object
482  *
483  * RETURN:      A newly allocated FIELD op
484  *
485  * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
486  *
487  ******************************************************************************/
488 
489 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
490 						       *parser_state)
491 {
492 	u8 *aml;
493 	union acpi_parse_object *field;
494 	union acpi_parse_object *arg = NULL;
495 	u16 opcode;
496 	u32 name;
497 	u8 access_type;
498 	u8 access_attribute;
499 	u8 access_length;
500 	u32 pkg_length;
501 	u8 *pkg_end;
502 	u32 buffer_length;
503 
504 	ACPI_FUNCTION_TRACE(ps_get_next_field);
505 
506 	ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
507 	aml = parser_state->aml;
508 
509 	/* Determine field type */
510 
511 	switch (ACPI_GET8(parser_state->aml)) {
512 	case AML_FIELD_OFFSET_OP:
513 
514 		opcode = AML_INT_RESERVEDFIELD_OP;
515 		parser_state->aml++;
516 		break;
517 
518 	case AML_FIELD_ACCESS_OP:
519 
520 		opcode = AML_INT_ACCESSFIELD_OP;
521 		parser_state->aml++;
522 		break;
523 
524 	case AML_FIELD_CONNECTION_OP:
525 
526 		opcode = AML_INT_CONNECTION_OP;
527 		parser_state->aml++;
528 		break;
529 
530 	case AML_FIELD_EXT_ACCESS_OP:
531 
532 		opcode = AML_INT_EXTACCESSFIELD_OP;
533 		parser_state->aml++;
534 		break;
535 
536 	default:
537 
538 		opcode = AML_INT_NAMEDFIELD_OP;
539 		break;
540 	}
541 
542 	/* Allocate a new field op */
543 
544 	field = acpi_ps_alloc_op(opcode, aml);
545 	if (!field) {
546 		return_PTR(NULL);
547 	}
548 
549 	/* Decode the field type */
550 
551 	ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
552 	switch (opcode) {
553 	case AML_INT_NAMEDFIELD_OP:
554 
555 		/* Get the 4-character name */
556 
557 		ACPI_MOVE_32_TO_32(&name, parser_state->aml);
558 		acpi_ps_set_name(field, name);
559 		parser_state->aml += ACPI_NAME_SIZE;
560 
561 		ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
562 
563 #ifdef ACPI_ASL_COMPILER
564 		/*
565 		 * Because the package length isn't represented as a parse tree object,
566 		 * take comments surrounding this and add to the previously created
567 		 * parse node.
568 		 */
569 		if (field->common.inline_comment) {
570 			field->common.name_comment =
571 			    field->common.inline_comment;
572 		}
573 		field->common.inline_comment = acpi_gbl_current_inline_comment;
574 		acpi_gbl_current_inline_comment = NULL;
575 #endif
576 
577 		/* Get the length which is encoded as a package length */
578 
579 		field->common.value.size =
580 		    acpi_ps_get_next_package_length(parser_state);
581 		break;
582 
583 	case AML_INT_RESERVEDFIELD_OP:
584 
585 		/* Get the length which is encoded as a package length */
586 
587 		field->common.value.size =
588 		    acpi_ps_get_next_package_length(parser_state);
589 		break;
590 
591 	case AML_INT_ACCESSFIELD_OP:
592 	case AML_INT_EXTACCESSFIELD_OP:
593 
594 		/*
595 		 * Get access_type and access_attrib and merge into the field Op
596 		 * access_type is first operand, access_attribute is second. stuff
597 		 * these bytes into the node integer value for convenience.
598 		 */
599 
600 		/* Get the two bytes (Type/Attribute) */
601 
602 		access_type = ACPI_GET8(parser_state->aml);
603 		parser_state->aml++;
604 		access_attribute = ACPI_GET8(parser_state->aml);
605 		parser_state->aml++;
606 
607 		field->common.value.integer = (u8)access_type;
608 		field->common.value.integer |= (u16)(access_attribute << 8);
609 
610 		/* This opcode has a third byte, access_length */
611 
612 		if (opcode == AML_INT_EXTACCESSFIELD_OP) {
613 			access_length = ACPI_GET8(parser_state->aml);
614 			parser_state->aml++;
615 
616 			field->common.value.integer |=
617 			    (u32)(access_length << 16);
618 		}
619 		break;
620 
621 	case AML_INT_CONNECTION_OP:
622 
623 		/*
624 		 * Argument for Connection operator can be either a Buffer
625 		 * (resource descriptor), or a name_string.
626 		 */
627 		aml = parser_state->aml;
628 		if (ACPI_GET8(parser_state->aml) == AML_BUFFER_OP) {
629 			parser_state->aml++;
630 
631 			ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
632 			pkg_end = parser_state->aml;
633 			pkg_length =
634 			    acpi_ps_get_next_package_length(parser_state);
635 			pkg_end += pkg_length;
636 
637 			ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
638 			if (parser_state->aml < pkg_end) {
639 
640 				/* Non-empty list */
641 
642 				arg =
643 				    acpi_ps_alloc_op(AML_INT_BYTELIST_OP, aml);
644 				if (!arg) {
645 					acpi_ps_free_op(field);
646 					return_PTR(NULL);
647 				}
648 
649 				/* Get the actual buffer length argument */
650 
651 				opcode = ACPI_GET8(parser_state->aml);
652 				parser_state->aml++;
653 
654 				ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
655 				switch (opcode) {
656 				case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
657 
658 					buffer_length =
659 					    ACPI_GET8(parser_state->aml);
660 					parser_state->aml += 1;
661 					break;
662 
663 				case AML_WORD_OP:	/* AML_WORDDATA_ARG */
664 
665 					buffer_length =
666 					    ACPI_GET16(parser_state->aml);
667 					parser_state->aml += 2;
668 					break;
669 
670 				case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
671 
672 					buffer_length =
673 					    ACPI_GET32(parser_state->aml);
674 					parser_state->aml += 4;
675 					break;
676 
677 				default:
678 
679 					buffer_length = 0;
680 					break;
681 				}
682 
683 				/* Fill in bytelist data */
684 
685 				ASL_CV_CAPTURE_COMMENTS_ONLY(parser_state);
686 				arg->named.value.size = buffer_length;
687 				arg->named.data = parser_state->aml;
688 			}
689 
690 			/* Skip to End of byte data */
691 
692 			parser_state->aml = pkg_end;
693 		} else {
694 			arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP, aml);
695 			if (!arg) {
696 				acpi_ps_free_op(field);
697 				return_PTR(NULL);
698 			}
699 
700 			/* Get the Namestring argument */
701 
702 			arg->common.value.name =
703 			    acpi_ps_get_next_namestring(parser_state);
704 		}
705 
706 		/* Link the buffer/namestring to parent (CONNECTION_OP) */
707 
708 		acpi_ps_append_arg(field, arg);
709 		break;
710 
711 	default:
712 
713 		/* Opcode was set in previous switch */
714 		break;
715 	}
716 
717 	return_PTR(field);
718 }
719 
720 /*******************************************************************************
721  *
722  * FUNCTION:    acpi_ps_get_next_arg
723  *
724  * PARAMETERS:  walk_state          - Current state
725  *              parser_state        - Current parser state object
726  *              arg_type            - The argument type (AML_*_ARG)
727  *              return_arg          - Where the next arg is returned
728  *
729  * RETURN:      Status, and an op object containing the next argument.
730  *
731  * DESCRIPTION: Get next argument (including complex list arguments that require
732  *              pushing the parser stack)
733  *
734  ******************************************************************************/
735 
736 acpi_status
737 acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
738 		     struct acpi_parse_state *parser_state,
739 		     u32 arg_type, union acpi_parse_object **return_arg)
740 {
741 	union acpi_parse_object *arg = NULL;
742 	union acpi_parse_object *prev = NULL;
743 	union acpi_parse_object *field;
744 	u32 subop;
745 	acpi_status status = AE_OK;
746 
747 	ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
748 
749 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
750 			  "Expected argument type ARGP: %s (%2.2X)\n",
751 			  acpi_ut_get_argument_type_name(arg_type), arg_type));
752 
753 	switch (arg_type) {
754 	case ARGP_BYTEDATA:
755 	case ARGP_WORDDATA:
756 	case ARGP_DWORDDATA:
757 	case ARGP_CHARLIST:
758 	case ARGP_NAME:
759 	case ARGP_NAMESTRING:
760 
761 		/* Constants, strings, and namestrings are all the same size */
762 
763 		arg = acpi_ps_alloc_op(AML_BYTE_OP, parser_state->aml);
764 		if (!arg) {
765 			return_ACPI_STATUS(AE_NO_MEMORY);
766 		}
767 
768 		acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
769 		break;
770 
771 	case ARGP_PKGLENGTH:
772 
773 		/* Package length, nothing returned */
774 
775 		parser_state->pkg_end =
776 		    acpi_ps_get_next_package_end(parser_state);
777 		break;
778 
779 	case ARGP_FIELDLIST:
780 
781 		if (parser_state->aml < parser_state->pkg_end) {
782 
783 			/* Non-empty list */
784 
785 			while (parser_state->aml < parser_state->pkg_end) {
786 				field = acpi_ps_get_next_field(parser_state);
787 				if (!field) {
788 					return_ACPI_STATUS(AE_NO_MEMORY);
789 				}
790 
791 				if (prev) {
792 					prev->common.next = field;
793 				} else {
794 					arg = field;
795 				}
796 				prev = field;
797 			}
798 
799 			/* Skip to End of byte data */
800 
801 			parser_state->aml = parser_state->pkg_end;
802 		}
803 		break;
804 
805 	case ARGP_BYTELIST:
806 
807 		if (parser_state->aml < parser_state->pkg_end) {
808 
809 			/* Non-empty list */
810 
811 			arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP,
812 					       parser_state->aml);
813 			if (!arg) {
814 				return_ACPI_STATUS(AE_NO_MEMORY);
815 			}
816 
817 			/* Fill in bytelist data */
818 
819 			arg->common.value.size = (u32)
820 			    ACPI_PTR_DIFF(parser_state->pkg_end,
821 					  parser_state->aml);
822 			arg->named.data = parser_state->aml;
823 
824 			/* Skip to End of byte data */
825 
826 			parser_state->aml = parser_state->pkg_end;
827 		}
828 		break;
829 
830 	case ARGP_SIMPLENAME:
831 	case ARGP_NAME_OR_REF:
832 
833 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
834 				  "**** SimpleName/NameOrRef: %s (%2.2X)\n",
835 				  acpi_ut_get_argument_type_name(arg_type),
836 				  arg_type));
837 
838 		subop = acpi_ps_peek_opcode(parser_state);
839 		if (subop == 0 ||
840 		    acpi_ps_is_leading_char(subop) ||
841 		    ACPI_IS_ROOT_PREFIX(subop) ||
842 		    ACPI_IS_PARENT_PREFIX(subop)) {
843 
844 			/* null_name or name_string */
845 
846 			arg =
847 			    acpi_ps_alloc_op(AML_INT_NAMEPATH_OP,
848 					     parser_state->aml);
849 			if (!arg) {
850 				return_ACPI_STATUS(AE_NO_MEMORY);
851 			}
852 
853 			status =
854 			    acpi_ps_get_next_namepath(walk_state, parser_state,
855 						      arg,
856 						      ACPI_NOT_METHOD_CALL);
857 		} else {
858 			/* Single complex argument, nothing returned */
859 
860 			walk_state->arg_count = 1;
861 		}
862 		break;
863 
864 	case ARGP_TARGET:
865 	case ARGP_SUPERNAME:
866 
867 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
868 				  "**** Target/Supername: %s (%2.2X)\n",
869 				  acpi_ut_get_argument_type_name(arg_type),
870 				  arg_type));
871 
872 		subop = acpi_ps_peek_opcode(parser_state);
873 		if (subop == 0 ||
874 		    acpi_ps_is_leading_char(subop) ||
875 		    ACPI_IS_ROOT_PREFIX(subop) ||
876 		    ACPI_IS_PARENT_PREFIX(subop)) {
877 
878 			/* NULL target (zero). Convert to a NULL namepath */
879 
880 			arg =
881 			    acpi_ps_alloc_op(AML_INT_NAMEPATH_OP,
882 					     parser_state->aml);
883 			if (!arg) {
884 				return_ACPI_STATUS(AE_NO_MEMORY);
885 			}
886 
887 			status =
888 			    acpi_ps_get_next_namepath(walk_state, parser_state,
889 						      arg,
890 						      ACPI_POSSIBLE_METHOD_CALL);
891 
892 			if (arg->common.aml_opcode == AML_INT_METHODCALL_OP) {
893 				acpi_ps_free_op(arg);
894 				arg = NULL;
895 				walk_state->arg_count = 1;
896 			}
897 		} else {
898 			/* Single complex argument, nothing returned */
899 
900 			walk_state->arg_count = 1;
901 		}
902 		break;
903 
904 	case ARGP_DATAOBJ:
905 	case ARGP_TERMARG:
906 
907 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
908 				  "**** TermArg/DataObj: %s (%2.2X)\n",
909 				  acpi_ut_get_argument_type_name(arg_type),
910 				  arg_type));
911 
912 		/* Single complex argument, nothing returned */
913 
914 		walk_state->arg_count = 1;
915 		break;
916 
917 	case ARGP_DATAOBJLIST:
918 	case ARGP_TERMLIST:
919 	case ARGP_OBJLIST:
920 
921 		if (parser_state->aml < parser_state->pkg_end) {
922 
923 			/* Non-empty list of variable arguments, nothing returned */
924 
925 			walk_state->arg_count = ACPI_VAR_ARGS;
926 		}
927 		break;
928 
929 	default:
930 
931 		ACPI_ERROR((AE_INFO, "Invalid ArgType: 0x%X", arg_type));
932 		status = AE_AML_OPERAND_TYPE;
933 		break;
934 	}
935 
936 	*return_arg = arg;
937 	return_ACPI_STATUS(status);
938 }
939