Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[wrt350n-kernel.git] / drivers / acpi / parser / psargs.c
blobc2b9835c890b892269e47079cf69a94fc6b9fe1e
1 /******************************************************************************
3 * Module Name: psargs - Parse AML opcode arguments
5 *****************************************************************************/
7 /*
8 * Copyright (C) 2000 - 2007, R. Byron Moore
9 * All rights reserved.
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.
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.
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.
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>
50 #define _COMPONENT ACPI_PARSER
51 ACPI_MODULE_NAME("psargs")
53 /* Local prototypes */
54 static u32
55 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state);
57 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
58 *parser_state);
60 /*******************************************************************************
62 * FUNCTION: acpi_ps_get_next_package_length
64 * PARAMETERS: parser_state - Current parser state object
66 * RETURN: Decoded package length. On completion, the AML pointer points
67 * past the length byte or bytes.
69 * DESCRIPTION: Decode and return a package length field.
70 * Note: Largest package length is 28 bits, from ACPI specification
72 ******************************************************************************/
74 static u32
75 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
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] */
82 ACPI_FUNCTION_TRACE(ps_get_next_package_length);
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
88 byte_count = (aml[0] >> 6);
89 parser_state->aml += (byte_count + 1);
91 /* Get bytes 3, 2, 1 as needed */
93 while (byte_count) {
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]
101 package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
103 byte_zero_mask = 0x0F; /* Use bits [0:3] of byte 0 */
104 byte_count--;
107 /* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
109 package_length |= (aml[0] & byte_zero_mask);
110 return_UINT32(package_length);
113 /*******************************************************************************
115 * FUNCTION: acpi_ps_get_next_package_end
117 * PARAMETERS: parser_state - Current parser state object
119 * RETURN: Pointer to end-of-package +1
121 * DESCRIPTION: Get next package length and return a pointer past the end of
122 * the package. Consumes the package length field
124 ******************************************************************************/
126 u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
128 u8 *start = parser_state->aml;
129 u32 package_length;
131 ACPI_FUNCTION_TRACE(ps_get_next_package_end);
133 /* Function below updates parser_state->Aml */
135 package_length = acpi_ps_get_next_package_length(parser_state);
137 return_PTR(start + package_length); /* end of package */
140 /*******************************************************************************
142 * FUNCTION: acpi_ps_get_next_namestring
144 * PARAMETERS: parser_state - Current parser state object
146 * RETURN: Pointer to the start of the name string (pointer points into
147 * the AML.
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.)
153 ******************************************************************************/
155 char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
157 u8 *start = parser_state->aml;
158 u8 *end = parser_state->aml;
160 ACPI_FUNCTION_TRACE(ps_get_next_namestring);
162 /* Point past any namestring prefix characters (backslash or carat) */
164 while (acpi_ps_is_prefix_char(*end)) {
165 end++;
168 /* Decode the path prefix character */
170 switch (*end) {
171 case 0:
173 /* null_name */
175 if (end == start) {
176 start = NULL;
178 end++;
179 break;
181 case AML_DUAL_NAME_PREFIX:
183 /* Two name segments */
185 end += 1 + (2 * ACPI_NAME_SIZE);
186 break;
188 case AML_MULTI_NAME_PREFIX_OP:
190 /* Multiple name segments, 4 chars each, count in next byte */
192 end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
193 break;
195 default:
197 /* Single name segment */
199 end += ACPI_NAME_SIZE;
200 break;
203 parser_state->aml = end;
204 return_PTR((char *)start);
207 /*******************************************************************************
209 * FUNCTION: acpi_ps_get_next_namepath
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
218 * RETURN: Status
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.
226 ******************************************************************************/
228 acpi_status
229 acpi_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)
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;
240 ACPI_FUNCTION_TRACE(ps_get_next_namepath);
242 path = acpi_ps_get_next_namestring(parser_state);
243 acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
245 /* Null path case is allowed, just exit */
247 if (!path) {
248 arg->common.value.name = path;
249 return_ACPI_STATUS(AE_OK);
252 /* Setup search scope info */
254 scope_info.scope.node = NULL;
255 node = parser_state->start_node;
256 if (node) {
257 scope_info.scope.node = node;
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)
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);
273 * If this name is a control method invocation, we must
274 * setup the method call
276 if (ACPI_SUCCESS(status) &&
277 possible_method_call && (node->type == ACPI_TYPE_METHOD)) {
279 /* This name is actually a control method invocation */
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));
286 name_op = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
287 if (!name_op) {
288 return_ACPI_STATUS(AE_NO_MEMORY);
291 /* Change Arg into a METHOD CALL and attach name to it */
293 acpi_ps_init_op(arg, AML_INT_METHODCALL_OP);
294 name_op->common.value.name = path;
296 /* Point METHODCALL/NAME to the METHOD Node */
298 name_op->common.node = node;
299 acpi_ps_append_arg(arg, name_op);
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);
308 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
309 "Control Method - %p Args %X\n",
310 node, method_desc->method.param_count));
312 /* Get the number of arguments to expect */
314 walk_state->arg_count = method_desc->method.param_count;
315 return_ACPI_STATUS(AE_OK);
319 * Special handling if the name was not found during the lookup -
320 * some not_found cases are allowed
322 if (status == AE_NOT_FOUND) {
324 /* 1) not_found is ok during load pass 1/2 (allow forward references) */
326 if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) !=
327 ACPI_PARSE_EXECUTE) {
328 status = AE_OK;
331 /* 2) not_found during a cond_ref_of(x) is ok by definition */
333 else if (walk_state->op->common.aml_opcode ==
334 AML_COND_REF_OF_OP) {
335 status = AE_OK;
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)
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;
352 /* Final exception check (may have been changed from code above) */
354 if (ACPI_FAILURE(status)) {
355 ACPI_ERROR_NAMESPACE(path, status);
357 if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
358 ACPI_PARSE_EXECUTE) {
360 /* Report a control method execution error */
362 status = acpi_ds_method_error(status, walk_state);
366 /* Save the namepath */
368 arg->common.value.name = path;
369 return_ACPI_STATUS(status);
372 /*******************************************************************************
374 * FUNCTION: acpi_ps_get_next_simple_arg
376 * PARAMETERS: parser_state - Current parser state object
377 * arg_type - The argument type (AML_*_ARG)
378 * Arg - Where the argument is returned
380 * RETURN: None
382 * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
384 ******************************************************************************/
386 void
387 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
388 u32 arg_type, union acpi_parse_object *arg)
390 u32 length;
391 u16 opcode;
392 u8 *aml = parser_state->aml;
394 ACPI_FUNCTION_TRACE_U32(ps_get_next_simple_arg, arg_type);
396 switch (arg_type) {
397 case ARGP_BYTEDATA:
399 /* Get 1 byte from the AML stream */
401 opcode = AML_BYTE_OP;
402 arg->common.value.integer = (acpi_integer) * aml;
403 length = 1;
404 break;
406 case ARGP_WORDDATA:
408 /* Get 2 bytes from the AML stream */
410 opcode = AML_WORD_OP;
411 ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
412 length = 2;
413 break;
415 case ARGP_DWORDDATA:
417 /* Get 4 bytes from the AML stream */
419 opcode = AML_DWORD_OP;
420 ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
421 length = 4;
422 break;
424 case ARGP_QWORDDATA:
426 /* Get 8 bytes from the AML stream */
428 opcode = AML_QWORD_OP;
429 ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
430 length = 8;
431 break;
433 case ARGP_CHARLIST:
435 /* Get a pointer to the string, point past the string */
437 opcode = AML_STRING_OP;
438 arg->common.value.string = ACPI_CAST_PTR(char, aml);
440 /* Find the null terminator */
442 length = 0;
443 while (aml[length]) {
444 length++;
446 length++;
447 break;
449 case ARGP_NAME:
450 case ARGP_NAMESTRING:
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;
457 default:
459 ACPI_ERROR((AE_INFO, "Invalid ArgType %X", arg_type));
460 return_VOID;
463 acpi_ps_init_op(arg, opcode);
464 parser_state->aml += length;
465 return_VOID;
468 /*******************************************************************************
470 * FUNCTION: acpi_ps_get_next_field
472 * PARAMETERS: parser_state - Current parser state object
474 * RETURN: A newly allocated FIELD op
476 * DESCRIPTION: Get next field (named_field, reserved_field, or access_field)
478 ******************************************************************************/
480 static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
481 *parser_state)
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;
490 ACPI_FUNCTION_TRACE(ps_get_next_field);
492 /* Determine field type */
494 switch (ACPI_GET8(parser_state->aml)) {
495 default:
497 opcode = AML_INT_NAMEDFIELD_OP;
498 break;
500 case 0x00:
502 opcode = AML_INT_RESERVEDFIELD_OP;
503 parser_state->aml++;
504 break;
506 case 0x01:
508 opcode = AML_INT_ACCESSFIELD_OP;
509 parser_state->aml++;
510 break;
513 /* Allocate a new field op */
515 field = acpi_ps_alloc_op(opcode);
516 if (!field) {
517 return_PTR(NULL);
520 field->common.aml_offset = aml_offset;
522 /* Decode the field type */
524 switch (opcode) {
525 case AML_INT_NAMEDFIELD_OP:
527 /* Get the 4-character name */
529 ACPI_MOVE_32_TO_32(&name, parser_state->aml);
530 acpi_ps_set_name(field, name);
531 parser_state->aml += ACPI_NAME_SIZE;
533 /* Get the length which is encoded as a package length */
535 field->common.value.size =
536 acpi_ps_get_next_package_length(parser_state);
537 break;
539 case AML_INT_RESERVEDFIELD_OP:
541 /* Get the length which is encoded as a package length */
543 field->common.value.size =
544 acpi_ps_get_next_package_length(parser_state);
545 break;
547 case AML_INT_ACCESSFIELD_OP:
550 * Get access_type and access_attrib and merge into the field Op
551 * access_type is first operand, access_attribute is second
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;
560 default:
562 /* Opcode was set in previous switch */
563 break;
566 return_PTR(field);
569 /*******************************************************************************
571 * FUNCTION: acpi_ps_get_next_arg
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
578 * RETURN: Status, and an op object containing the next argument.
580 * DESCRIPTION: Get next argument (including complex list arguments that require
581 * pushing the parser stack)
583 ******************************************************************************/
585 acpi_status
586 acpi_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)
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;
596 ACPI_FUNCTION_TRACE_PTR(ps_get_next_arg, parser_state);
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:
606 /* Constants, strings, and namestrings are all the same size */
608 arg = acpi_ps_alloc_op(AML_BYTE_OP);
609 if (!arg) {
610 return_ACPI_STATUS(AE_NO_MEMORY);
612 acpi_ps_get_next_simple_arg(parser_state, arg_type, arg);
613 break;
615 case ARGP_PKGLENGTH:
617 /* Package length, nothing returned */
619 parser_state->pkg_end =
620 acpi_ps_get_next_package_end(parser_state);
621 break;
623 case ARGP_FIELDLIST:
625 if (parser_state->aml < parser_state->pkg_end) {
627 /* Non-empty list */
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);
635 if (prev) {
636 prev->common.next = field;
637 } else {
638 arg = field;
640 prev = field;
643 /* Skip to End of byte data */
645 parser_state->aml = parser_state->pkg_end;
647 break;
649 case ARGP_BYTELIST:
651 if (parser_state->aml < parser_state->pkg_end) {
653 /* Non-empty list */
655 arg = acpi_ps_alloc_op(AML_INT_BYTELIST_OP);
656 if (!arg) {
657 return_ACPI_STATUS(AE_NO_MEMORY);
660 /* Fill in bytelist data */
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;
667 /* Skip to End of byte data */
669 parser_state->aml = parser_state->pkg_end;
671 break;
673 case ARGP_TARGET:
674 case ARGP_SUPERNAME:
675 case ARGP_SIMPLENAME:
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)) {
682 /* null_name or name_string */
684 arg = acpi_ps_alloc_op(AML_INT_NAMEPATH_OP);
685 if (!arg) {
686 return_ACPI_STATUS(AE_NO_MEMORY);
689 status =
690 acpi_ps_get_next_namepath(walk_state, parser_state,
691 arg, 0);
692 } else {
693 /* Single complex argument, nothing returned */
695 walk_state->arg_count = 1;
697 break;
699 case ARGP_DATAOBJ:
700 case ARGP_TERMARG:
702 /* Single complex argument, nothing returned */
704 walk_state->arg_count = 1;
705 break;
707 case ARGP_DATAOBJLIST:
708 case ARGP_TERMLIST:
709 case ARGP_OBJLIST:
711 if (parser_state->aml < parser_state->pkg_end) {
713 /* Non-empty list of variable arguments, nothing returned */
715 walk_state->arg_count = ACPI_VAR_ARGS;
717 break;
719 default:
721 ACPI_ERROR((AE_INFO, "Invalid ArgType: %X", arg_type));
722 status = AE_AML_OPERAND_TYPE;
723 break;
726 *return_arg = arg;
727 return_ACPI_STATUS(status);