psloop.c

linux-2.6.15.6

/******************************************************************************
 *
 * Module Name: psloop - Main AML parse loop
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2005, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

/*
 * Parse the AML and build an operation tree as most interpreters,
 * like Perl, do.  Parsing is done by hand rather than with a YACC
 * generated parser to tightly constrain stack and dynamic memory
 * usage.  At the same time, parsing is kept flexible and the code
 * fairly compact by parsing based on a list of AML opcode
 * templates in aml_op_info[]
 */

#include <acpi/acpi.h>
#include <acpi/acparser.h>
#include <acpi/acdispat.h>
#include <acpi/amlcode.h>

#define _COMPONENT          ACPI_PARSER
ACPI_MODULE_NAME("psloop")

static u32 acpi_gbl_depth = 0;

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_parse_loop
 *
 * PARAMETERS:  walk_state          - Current state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
 *              a tree of ops.
 *
 ******************************************************************************/

acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
{
	acpi_status status = AE_OK;
	acpi_status status2;
	union acpi_parse_object *op = NULL;	/* current op */
	union acpi_parse_object *arg = NULL;
	union acpi_parse_object *pre_op = NULL;
	struct acpi_parse_state *parser_state;
	u8 *aml_op_start = NULL;

	ACPI_FUNCTION_TRACE_PTR("ps_parse_loop", walk_state);

	if (walk_state->descending_callback == NULL) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	parser_state = &walk_state->parser_state;
	walk_state->arg_types = 0;

#if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))

	if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
		/* We are restarting a preempted control method */

		if (acpi_ps_has_completed_scope(parser_state)) {
			/*
			 * We must check if a predicate to an IF or WHILE statement
			 * was just completed
			 */
			if ((parser_state->scope->parse_scope.op) &&
			    ((parser_state->scope->parse_scope.op->common.
			      aml_opcode == AML_IF_OP)
			     || (parser_state->scope->parse_scope.op->common.
				 aml_opcode == AML_WHILE_OP))
			    && (walk_state->control_state)
			    && (walk_state->control_state->common.state ==
				ACPI_CONTROL_PREDICATE_EXECUTING)) {
				/*
				 * A predicate was just completed, get the value of the
				 * predicate and branch based on that value
				 */
				walk_state->op = NULL;
				status =
				    acpi_ds_get_predicate_value(walk_state,
								ACPI_TO_POINTER
								(TRUE));
				if (ACPI_FAILURE(status)
				    && ((status & AE_CODE_MASK) !=
					AE_CODE_CONTROL)) {
					if (status == AE_AML_NO_RETURN_VALUE) {
						ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
								  "Invoked method did not return a value, %s\n",
								  acpi_format_exception
								  (status)));

					}
					ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
							  "get_predicate Failed, %s\n",
							  acpi_format_exception
							  (status)));
					return_ACPI_STATUS(status);
				}

				status =
				    acpi_ps_next_parse_state(walk_state, op,
							     status);
			}

			acpi_ps_pop_scope(parser_state, &op,
					  &walk_state->arg_types,
					  &walk_state->arg_count);
			ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
					  "Popped scope, Op=%p\n", op));
		} else if (walk_state->prev_op) {
			/* We were in the middle of an op */

			op = walk_state->prev_op;
			walk_state->arg_types = walk_state->prev_arg_types;
		}
	}
#endif

	/* Iterative parsing loop, while there is more AML to process: */

	while ((parser_state->aml < parser_state->aml_end) || (op)) {
		aml_op_start = parser_state->aml;
		if (!op) {
			/* Get the next opcode from the AML stream */

			walk_state->aml_offset =
			    (u32) ACPI_PTR_DIFF(parser_state->aml,
						parser_state->aml_start);
			walk_state->opcode = acpi_ps_peek_opcode(parser_state);

			/*
			 * First cut to determine what we have found:
			 * 1) A valid AML opcode
			 * 2) A name string
			 * 3) An unknown/invalid opcode
			 */
			walk_state->op_info =
			    acpi_ps_get_opcode_info(walk_state->opcode);
			switch (walk_state->op_info->class) {
			case AML_CLASS_ASCII:
			case AML_CLASS_PREFIX:
				/*
				 * Starts with a valid prefix or ASCII char, this is a name
				 * string.  Convert the bare name string to a namepath.
				 */
				walk_state->opcode = AML_INT_NAMEPATH_OP;
				walk_state->arg_types = ARGP_NAMESTRING;
				break;

			case AML_CLASS_UNKNOWN:

				/* The opcode is unrecognized.  Just skip unknown opcodes */

				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
						  "Found unknown opcode %X at AML address %p offset %X, ignoring\n",
						  walk_state->opcode,
						  parser_state->aml,
						  walk_state->aml_offset));

				ACPI_DUMP_BUFFER(parser_state->aml, 128);

				/* Assume one-byte bad opcode */

				parser_state->aml++;
				continue;

			default:

				/* Found opcode info, this is a normal opcode */

				parser_state->aml +=
				    acpi_ps_get_opcode_size(walk_state->opcode);
				walk_state->arg_types =
				    walk_state->op_info->parse_args;
				break;
			}

			/* Create Op structure and append to parent's argument list */

			if (walk_state->op_info->flags & AML_NAMED) {
				/* Allocate a new pre_op if necessary */

				if (!pre_op) {
					pre_op =
					    acpi_ps_alloc_op(walk_state->
							     opcode);
					if (!pre_op) {
						status = AE_NO_MEMORY;
						goto close_this_op;
					}
				}

				pre_op->common.value.arg = NULL;
				pre_op->common.aml_opcode = walk_state->opcode;

				/*
				 * Get and append arguments until we find the node that contains
				 * the name (the type ARGP_NAME).
				 */
				while (GET_CURRENT_ARG_TYPE
				       (walk_state->arg_types)
				       &&
				       (GET_CURRENT_ARG_TYPE
					(walk_state->arg_types) != ARGP_NAME)) {
					status =
					    acpi_ps_get_next_arg(walk_state,
								 parser_state,
								 GET_CURRENT_ARG_TYPE
								 (walk_state->
								  arg_types),
								 &arg);
					if (ACPI_FAILURE(status)) {
						goto close_this_op;
					}

					acpi_ps_append_arg(pre_op, arg);
					INCREMENT_ARG_LIST(walk_state->
							   arg_types);
				}

				/*
				 * Make sure that we found a NAME and didn't run out of
				 * arguments
				 */
				if (!GET_CURRENT_ARG_TYPE
				    (walk_state->arg_types)) {
					status = AE_AML_NO_OPERAND;
					goto close_this_op;
				}

				/* We know that this arg is a name, move to next arg */

				INCREMENT_ARG_LIST(walk_state->arg_types);

				/*
				 * Find the object.  This will either insert the object into
				 * the namespace or simply look it up
				 */
				walk_state->op = NULL;

				status =
				    walk_state->descending_callback(walk_state,
								    &op);
				if (ACPI_FAILURE(status)) {
					ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
							  "During name lookup/catalog, %s\n",
							  acpi_format_exception
							  (status)));
					goto close_this_op;
				}

				if (!op) {
					continue;
				}

				status =
				    acpi_ps_next_parse_state(walk_state, op,
							     status);
				if (status == AE_CTRL_PENDING) {
					status = AE_OK;
					goto close_this_op;
				}

				if (ACPI_FAILURE(status)) {
					goto close_this_op;
				}

				acpi_ps_append_arg(op,
						   pre_op->common.value.arg);
				acpi_gbl_depth++;

				if (op->common.aml_opcode == AML_REGION_OP) {
					/*
					 * Defer final parsing of an operation_region body,
					 * because we don't have enough info in the first pass
					 * to parse it correctly (i.e., there may be method
					 * calls within the term_arg elements of the body.)
					 *
					 * However, we must continue parsing because
					 * the opregion is not a standalone package --
					 * we don't know where the end is at this point.
					 *
					 * (Length is unknown until parse of the body complete)
					 */
					op->named.data = aml_op_start;
					op->named.length = 0;
				}
			} else {
				/* Not a named opcode, just allocate Op and append to parent */

				walk_state->op_info =
				    acpi_ps_get_opcode_info(walk_state->opcode);
				op = acpi_ps_alloc_op(walk_state->opcode);
				if (!op) {
					status = AE_NO_MEMORY;
					goto close_this_op;
				}

				if (walk_state->op_info->flags & AML_CREATE) {
					/*
					 * Backup to beginning of create_xXXfield declaration
					 * body_length is unknown until we parse the body
					 */
					op->named.data = aml_op_start;
					op->named.length = 0;
				}

				acpi_ps_append_arg(acpi_ps_get_parent_scope
						   (parser_state), op);

				if ((walk_state->descending_callback != NULL)) {
					/*
					 * Find the object. This will either insert the object into
					 * the namespace or simply look it up
					 */
					walk_state->op = op;

					status =
					    walk_state->
					    descending_callback(walk_state,
								&op);
					status =
					    acpi_ps_next_parse_state(walk_state,
								     op,
								     status);
					if (status == AE_CTRL_PENDING) {
						status = AE_OK;
						goto close_this_op;
					}

					if (ACPI_FAILURE(status)) {
						goto close_this_op;
					}
				}
			}

			op->common.aml_offset = walk_state->aml_offset;

			if (walk_state->op_info) {
				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
						  "Opcode %4.4X [%s] Op %p Aml %p aml_offset %5.5X\n",
						  (u32) op->common.aml_opcode,
						  walk_state->op_info->name, op,
						  parser_state->aml,
						  op->common.aml_offset));
			}
		}

		/*
		 * Start arg_count at zero because we don't know if there are
		 * any args yet
		 */
		walk_state->arg_count = 0;

		/* Are there any arguments that must be processed? */

		if (walk_state->arg_types) {
			/* Get arguments */

			switch (op->common.aml_opcode) {
			case AML_BYTE_OP:	/* AML_BYTEDATA_ARG */
			case AML_WORD_OP:	/* AML_WORDDATA_ARG */
			case AML_DWORD_OP:	/* AML_DWORDATA_ARG */
			case AML_QWORD_OP:	/* AML_QWORDATA_ARG */
			case AML_STRING_OP:	/* AML_ASCIICHARLIST_ARG */

				/* Fill in constant or string argument directly */

				acpi_ps_get_next_simple_arg(parser_state,
							    GET_CURRENT_ARG_TYPE
							    (walk_state->
							     arg_types), op);
				break;

			case AML_INT_NAMEPATH_OP:	/* AML_NAMESTRING_ARG */

				status =
				    acpi_ps_get_next_namepath(walk_state,
							      parser_state, op,
							      1);
				if (ACPI_FAILURE(status)) {
					goto close_this_op;
				}

				walk_state->arg_types = 0;
				break;

			default:
				/*
				 * Op is not a constant or string, append each argument
				 * to the Op
				 */
				while (GET_CURRENT_ARG_TYPE
				       (walk_state->arg_types)
				       && !walk_state->arg_count) {
					walk_state->aml_offset = (u32)
					    ACPI_PTR_DIFF(parser_state->aml,
							  parser_state->
							  aml_start);