1/******************************************************************************
2 *
3 * Module Name: psargs - Parse AML opcode arguments
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2007, R. Byron Moore
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 <acpi/acparser.h>
46#include <acpi/amlcode.h>
47#include <acpi/acnamesp.h>
48#include <acpi/acdispat.h>
49
50#define _COMPONENT          ACPI_PARSER
51ACPI_MODULE_NAME("psargs")
52
53/* Local prototypes */
54static u32
55acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state);
56
57static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
58						       *parser_state);
59
60/*******************************************************************************
61 *
62 * FUNCTION:    acpi_ps_get_next_package_length
63 *
64 * PARAMETERS:  parser_state        - Current parser state object
65 *
66 * RETURN:      Decoded package length. On completion, the AML pointer points
67 *              past the length byte or bytes.
68 *
69 * DESCRIPTION: Decode and return a package length field.
70 *              Note: Largest package length is 28 bits, from ACPI specification
71 *
72 ******************************************************************************/
73
74static u32
75acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
76{
77	u8 *aml = parser_state->aml;
78	u32 package_length = 0;
79	acpi_native_uint byte_count;
80	u8 byte_zero_mask = 0x3F;	/* Default [0:5] */
81
82	ACPI_FUNCTION_TRACE(ps_get_next_package_length);
83
84	/*
85	 * Byte 0 bits [6:7] contain the number of additional bytes
86	 * used to encode the package length, either 0,1,2, or 3
87	 */
88	byte_count = (aml[0] >> 6);
89	parser_state->aml += (byte_count + 1);
90
91	/* Get bytes 3, 2, 1 as needed */
92
93	while (byte_count) {
94		/*
95		 * Final bit positions for the package length bytes:
96		 *      Byte3->[20:27]
97		 *      Byte2->[12:19]
98		 *      Byte1->[04:11]
99		 *      Byte0->[00:03]
100		 */
101		package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
102
103		byte_zero_mask = 0x0F;	/* Use bits [0:3] of byte 0 */
104		byte_count--;
105	}
106
107	/* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
108
109	package_length |= (aml[0] & byte_zero_mask);
110	return_UINT32(package_length);
111}
112
113/*******************************************************************************
114 *
115 * FUNCTION:    acpi_ps_get_next_package_end
116 *
117 * PARAMETERS:  parser_state        - Current parser state object
118 *
119 * RETURN:      Pointer to end-of-package +1
120 *
121 * DESCRIPTION: Get next package length and return a pointer past the end of
122 *              the package.  Consumes the package length field
123 *
124 ******************************************************************************/
125
126u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
127{
128	u8 *start = parser_state->aml;
129	u32 package_length;
130
131	ACPI_FUNCTION_TRACE(ps_get_next_package_end);
132
133	/* Function below updates parser_state->Aml */
134
135	package_length = acpi_ps_get_next_package_length(parser_state);
136
137	return_PTR(start + package_length);	/* end of package */
138}
139
140/*******************************************************************************
141 *
142 * FUNCTION:    acpi_ps_get_next_namestring
143 *
144 * PARAMETERS:  parser_state        - Current parser state object
145 *
146 * RETURN:      Pointer to the start of the name string (pointer points into
147 *              the AML.
148 *
149 * DESCRIPTION: Get next raw namestring within the AML stream.  Handles all name
150 *              prefix characters.  Set parser state to point past the string.
151 *              (Name is consumed from the AML.)
152 *
153 ******************************************************************************/
154
155char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
156{
157	u8 *start = parser_state->aml;
158	u8 *end = parser_state->aml;
159
160	ACPI_FUNCTION_TRACE(ps_get_next_namestring);
161
162	/* Point past any namestring prefix characters (backslash or carat) */
163
164	while (acpi_ps_is_prefix_char(*end)) {
165		end++;
166	}
167
168	/* Decode the path prefix character */
169
170	switch (*end) {
171	case 0:
172
173		/* null_name */
174
175		if (end == start) {
176			start = NULL;
177		}
178		end++;
179		break;
180
181	case AML_DUAL_NAME_PREFIX:
182
183		/* Two name segments */
184
185		end += 1 + (2 * ACPI_NAME_SIZE);
186		break;
187
188	case AML_MULTI_NAME_PREFIX_OP:
189
190		/* Multiple name segments, 4 chars each, count in next byte */
191
192		end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
193		break;
194
195	default:
196
197		/* Single name segment */
198
199		end += ACPI_NAME_SIZE;
200		break;
201	}
202
203	parser_state->aml = end;
204	return_PTR((char *)start);
205}
206
207/*******************************************************************************
208 *
209 * FUNCTION:    acpi_ps_get_next_namepath
210 *
211 * PARAMETERS:  parser_state        - Current parser state object
212 *              Arg                 - Where the namepath will be stored
213 *              arg_count           - If the namepath points to a control method
214 *                                    the method's argument is returned here.
215 *              possible_method_call - Whether the namepath can possibly be the
216 *                                    start of a method call
217 *
218 * RETURN:      Status
219 *
220 * DESCRIPTION: Get next name (if method call, return # of required args).
221 *              Names are looked up in the internal namespace to determine
222 *              if the name represents a control method.  If a method
223 *              is found, the number of arguments to the method is returned.
224 *              This information is critical for parsing to continue correctly.
225 *
226 ******************************************************************************/
227
228acpi_status
229acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
230			  struct acpi_parse_state *parser_state,
231			  union acpi_parse_object *arg, u8 possible_method_call)
232{
233	char *path;
234	union acpi_parse_object *name_op;
235	acpi_status status;
236	union acpi_operand_object *method_desc;
237	struct acpi_namespace_node *node;
238	union acpi_generic_state scope_info;
239
240	ACPI_FUNCTION_TRACE(ps_get_next_namepath);
241
242	path = acpi_ps_get_next_namestring(parser_state);
243	acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
244
245	/* Null path case is allowed, just exit */
246
247	if (!path) {
248		arg->common.value.name = path;
249		return_ACPI_STATUS(AE_OK);
250	}
251
252	/* Setup search scope info */
253
254	scope_info.scope.node = NULL;
255	node = parser_state->start_node;
256	if (node) {
257		scope_info.scope.node = node;
258	}
259
260	/*
261	 * Lookup the name in the internal namespace. We don't want to add
262	 * anything new to the namespace here, however, so we use MODE_EXECUTE.
263	 * Allow searching of the parent tree, but don't open a new scope -
264	 * we just want to lookup the object (must be mode EXECUTE to perform
265	 * the upsearch)
266	 */
267	status =
268	    acpi_ns_lookup(&scope_info, path, ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
269			   ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE,
270			   NULL, &node);
271
272	/*
273	 * If this name is a control method invocation, we must
274	 * setup the method call
275	 */
276	if (ACPI_SUCCESS(status) &&
277	    possible_method_call && (node->type == ACPI_TYPE_METHOD)) {
278
279		/* This name is actually a control method invocation */
280
281		method_desc = acpi_ns_get_attached_object(node);
282		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
283				  "Control Method - %p Desc %p Path=%p\n", node,
284				  method_desc, path));
285
286		name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
287		if (!name_op) {
288			return_ACPI_STATUS(AE_NO_MEMORY);
289		}
290
291		/* Change Arg into a METHOD CALL and attach name to it */
292
293		acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
294		name_op->common.value.name = path;
295
296		/* Point METHODCALL/NAME to the METHOD Node */
297
298		name_op->common.node = node;
299		acpi_ps_append_arg(arg, name_op);
300
301		if (!method_desc) {
302			ACPI_ERROR((AE_INFO,
303				    "Control Method %p has no attached object",
304				    node));
305			return_ACPI_STATUS(AE_AML_INTERNAL);
306		}
307
308		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
309				  "Control Method - %p Args %X\n",
310				  node, method_desc->method.param_count));
311
312		/* Get the number of arguments to expect */
313
314		walk_state->arg_count = method_desc->method.param_count;
315		return_ACPI_STATUS(AE_OK);
316	}
317
318	/*
319	 * Special handling if the name was not found during the lookup -
320	 * some not_found cases are allowed
321	 */
322	if (status == AE_NOT_FOUND) {
323
324		/* 1) not_found is ok during load pass 1/2 (allow forward references) */
325
326		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
327		    ACPI_PARSE_EXECUTE) {
328			status = AE_OK;
329		}
330
331		/* 2) not_found during a cond_ref_of(x) is ok by definition */
332
333		else if (walk_state->op->common.aml_opcode ==
334			 AML_COND_REF_OF_OP) {
335			status = AE_OK;
336		}
337
338		/*
339		 * 3) not_found while building a Package is ok at this point, we
340		 * may flag as an error later if slack mode is not enabled.
341		 * (Some ASL code depends on allowing this behavior)
342		 */
343		else if ((arg->common.parent) &&
344			 ((arg->common.parent->common.aml_opcode ==
345			   AML_PACKAGE_OP)
346			  || (arg->common.parent->common.aml_opcode ==
347			      AML_VAR_PACKAGE_OP))) {
348			status = AE_OK;
349		}
350	}
351
352	/* Final exception check (may have been changed from code above) */
353
354	if (ACPI_FAILURE(status)) {
355		ACPI_ERROR_NAMESPACE(path, status);
356
357		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
358		    ACPI_PARSE_EXECUTE) {
359
360			/* Report a control method execution error */
361
362			status = acpi_ds_method_error(status, walk_state);
363		}
364	}
365
366	/* Save the namepath */
367
368	arg->common.value.name = path;
369	return_ACPI_STATUS(status);
370}
371
372/*******************************************************************************
373 *
374 * FUNCTION:    acpi_ps_get_next_simple_arg
375 *
376 * PARAMETERS:  parser_state        - Current parser state object
377 *              arg_type            - The argument type (AML_*_ARG)
378 *              Arg                 - Where the argument is returned
379 *
380 * RETURN:      None
381 *
382 * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
383 *
384 ******************************************************************************/
385
386void
387acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
388			    u32 arg_type, union acpi_parse_object *arg)
389{
390	u32 length;
391	u16 opcode;
392	u8 *aml = parser_state->aml;
393
394	ACPI_FUNCTION_TRACE_U32(ps_get_next_simple_arg, arg_type);
395
396	switch (arg_type) {
397	case ARGP_BYTEDATA:
398
399		/* Get 1 byte from the AML stream */
400
401		opcode = AML_BYTE_OP;
402		arg->common.value.integer = (acpi_integer) * aml;
403		length = 1;
404		break;
405
406	case ARGP_WORDDATA:
407
408		/* Get 2 bytes from the AML stream */
409
410		opcode = AML_WORD_OP;
411		ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
412		length = 2;
413		break;
414
415	case ARGP_DWORDDATA:
416
417		/* Get 4 bytes from the AML stream */
418
419		opcode = AML_DWORD_OP;
420		ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
421		length = 4;
422		break;
423
424	case ARGP_QWORDDATA:
425
426		/* Get 8 bytes from the AML stream */
427
428		opcode = AML_QWORD_OP;
429		ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
430		length = 8;
431		break;
432
433	case ARGP_CHARLIST:
434
435		/* Get a pointer to the string, point past the string */
436
437		opcode = AML_STRING_OP;
438		arg->common.value.string = ACPI_CAST_PTR(char, aml);
439
440		/* Find the null terminator */
441
442		length = 0;
443		while (aml[length]) {
444			length++;
445		}
446		length++;
447		break;
448
449	case ARGP_NAME:
450	case ARGP_NAMESTRING:
451
452		acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
453		arg->common.value.name =
454		    acpi_ps_get_next_namestring(parser_state);
455		return_VOID;
456
457	default:
458
459		ACPI_ERROR((AE_INFO, "Invalid ArgType %X", arg_type));
460		return_VOID;
461	}
462
463	acpi_ps_init_op(arg, opcode);
464	parser_state->aml += length;
465	return_VOID;
466}
467
468/*******************************************************************************
469 *
470 * FUNCTION:    acpi_ps_get_next_field
471 *
472 * PARAMETERS:  parser_state        - Current parser state object
473 *
474 * RETURN:      A newly allocated FIELD op
475 *
476 * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
477 *
478 ******************************************************************************/
479
480static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
481						       *parser_state)
482{
483	u32 aml_offset = (u32)
484	    ACPI_PTR_DIFF(parser_state->aml,
485			  parser_state->aml_start);
486	union acpi_parse_object *field;
487	u16 opcode;
488	u32 name;
489
490	ACPI_FUNCTION_TRACE(ps_get_next_field);
491
492	/* Determine field type */
493
494	switch (ACPI_GET8(parser_state->aml)) {
495	default:
496
497		opcode = AML_INT_NAMEDFIELD_OP;
498		break;
499
500	case 0x00:
501
502		opcode = AML_INT_RESERVEDFIELD_OP;
503		parser_state->aml++;
504		break;
505
506	case 0x01:
507
508		opcode = AML_INT_ACCESSFIELD_OP;
509		parser_state->aml++;
510		break;
511	}
512
513	/* Allocate a new field op */
514
515	field = acpi_ps_alloc_op(opcode);
516	if (!field) {
517		return_PTR(NULL);
518	}
519
520	field->common.aml_offset = aml_offset;
521
522	/* Decode the field type */
523
524	switch (opcode) {
525	case AML_INT_NAMEDFIELD_OP:
526
527		/* Get the 4-character name */
528
529		ACPI_MOVE_32_TO_32(&name, parser_state->aml);
530		acpi_ps_set_name(field, name);
531		parser_state->aml += ACPI_NAME_SIZE;
532
533		/* Get the length which is encoded as a package length */
534
535		field->common.value.size =
536		    acpi_ps_get_next_package_length(parser_state);
537		break;
538
539	case AML_INT_RESERVEDFIELD_OP:
540
541		/* Get the length which is encoded as a package length */
542
543		field->common.value.size =
544		    acpi_ps_get_next_package_length(parser_state);
545		break;
546
547	case AML_INT_ACCESSFIELD_OP:
548
549		/*
550		 * Get access_type and access_attrib and merge into the field Op
551		 * access_type is first operand, access_attribute is second
552		 */
553		field->common.value.integer =
554		    (((u32) ACPI_GET8(parser_state->aml) << 8));
555		parser_state->aml++;
556		field->common.value.integer |= ACPI_GET8(parser_state->aml);
557		parser_state->aml++;
558		break;
559
560	default:
561
562		/* Opcode was set in previous switch */
563		break;
564	}
565
566	return_PTR(field);
567}
568
569/*******************************************************************************
570 *
571 * FUNCTION:    acpi_ps_get_next_arg
572 *
573 * PARAMETERS:  walk_state          - Current state
574 *              parser_state        - Current parser state object
575 *              arg_type            - The argument type (AML_*_ARG)
576 *              return_arg          - Where the next arg is returned
577 *
578 * RETURN:      Status, and an op object containing the next argument.
579 *
580 * DESCRIPTION: Get next argument (including complex list arguments that require
581 *              pushing the parser stack)
582 *
583 ******************************************************************************/
584
585acpi_status
586acpi_ps_get_next_arg(struct acpi_walk_state *walk_state,
587		     struct acpi_parse_state *parser_state,
588		     u32 arg_type, union acpi_parse_object **return_arg)
589{
590	union acpi_parse_object *arg = NULL;
591	union acpi_parse_object *prev = NULL;
592	union acpi_parse_object *field;
593	u32 subop;
594	acpi_status status = AE_OK;
595
596	ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
597
598	switch (arg_type) {
599	case ARGP_BYTEDATA:
600	case ARGP_WORDDATA:
601	case ARGP_DWORDDATA:
602	case ARGP_CHARLIST:
603	case ARGP_NAME:
604	case ARGP_NAMESTRING:
605
606		/* Constants, strings, and namestrings are all the same size */
607
608		arg = acpi_ps_alloc_op(AML_BYTE_OP);
609		if (!arg) {
610			return_ACPI_STATUS(AE_NO_MEMORY);
611		}
612		acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
613		break;
614
615	case ARGP_PKGLENGTH:
616
617		/* Package length, nothing returned */
618
619		parser_state->pkg_end =
620		    acpi_ps_get_next_package_end(parser_state);
621		break;
622
623	case ARGP_FIELDLIST:
624
625		if (parser_state->aml < parser_state->pkg_end) {
626
627			/* Non-empty list */
628
629			while (parser_state->aml < parser_state->pkg_end) {
630				field = acpi_ps_get_next_field(parser_state);
631				if (!field) {
632					return_ACPI_STATUS(AE_NO_MEMORY);
633				}
634
635				if (prev) {
636					prev->common.next = field;
637				} else {
638					arg = field;
639				}
640				prev = field;
641			}
642
643			/* Skip to End of byte data */
644
645			parser_state->aml = parser_state->pkg_end;
646		}
647		break;
648
649	case ARGP_BYTELIST:
650
651		if (parser_state->aml < parser_state->pkg_end) {
652
653			/* Non-empty list */
654
655			arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
656			if (!arg) {
657				return_ACPI_STATUS(AE_NO_MEMORY);
658			}
659
660			/* Fill in bytelist data */
661
662			arg->common.value.size = (u32)
663			    ACPI_PTR_DIFF(parser_state->pkg_end,
664					  parser_state->aml);
665			arg->named.data = parser_state->aml;
666
667			/* Skip to End of byte data */
668
669			parser_state->aml = parser_state->pkg_end;
670		}
671		break;
672
673	case ARGP_TARGET:
674	case ARGP_SUPERNAME:
675	case ARGP_SIMPLENAME:
676
677		subop = acpi_ps_peek_opcode(parser_state);
678		if (subop == 0 ||
679		    acpi_ps_is_leading_char(subop) ||
680		    acpi_ps_is_prefix_char(subop)) {
681
682			/* null_name or name_string */
683
684			arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
685			if (!arg) {
686				return_ACPI_STATUS(AE_NO_MEMORY);
687			}
688
689			status =
690			    acpi_ps_get_next_namepath(walk_state, parser_state,
691						      arg, 0);
692		} else {
693			/* Single complex argument, nothing returned */
694
695			walk_state->arg_count = 1;
696		}
697		break;
698
699	case ARGP_DATAOBJ:
700	case ARGP_TERMARG:
701
702		/* Single complex argument, nothing returned */
703
704		walk_state->arg_count = 1;
705		break;
706
707	case ARGP_DATAOBJLIST:
708	case ARGP_TERMLIST:
709	case ARGP_OBJLIST:
710
711		if (parser_state->aml < parser_state->pkg_end) {
712
713			/* Non-empty list of variable arguments, nothing returned */
714
715			walk_state->arg_count = ACPI_VAR_ARGS;
716		}
717		break;
718
719	default:
720
721		ACPI_ERROR((AE_INFO, "Invalid ArgType: %X", arg_type));
722		status = AE_AML_OPERAND_TYPE;
723		break;
724	}
725
726	*return_arg = arg;
727	return_ACPI_STATUS(status);
728}
729