psparse.c

h内核

/******************************************************************************
 *
 * Module Name: psparse - Parser top level AML parse routines
 *
 *****************************************************************************/

/*
 * 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>
#include <acpi/acnamesp.h>
#include <acpi/acinterp.h>

#define _COMPONENT          ACPI_PARSER
	 ACPI_MODULE_NAME    ("psparse")


static u32                          acpi_gbl_depth = 0;


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_opcode_size
 *
 * PARAMETERS:  Opcode          - An AML opcode
 *
 * RETURN:      Size of the opcode, in bytes (1 or 2)
 *
 * DESCRIPTION: Get the size of the current opcode.
 *
 ******************************************************************************/

u32
acpi_ps_get_opcode_size (
	u32                             opcode)
{

	/* Extended (2-byte) opcode if > 255 */

	if (opcode > 0x00FF) {
		return (2);
	}

	/* Otherwise, just a single byte opcode */

	return (1);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_peek_opcode
 *
 * PARAMETERS:  parser_state        - A parser state object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
 *
 ******************************************************************************/

u16
acpi_ps_peek_opcode (
	struct acpi_parse_state         *parser_state)
{
	u8                              *aml;
	u16                             opcode;


	aml = parser_state->aml;
	opcode = (u16) ACPI_GET8 (aml);


	if (opcode == AML_EXTOP) {
		/* Extended opcode */

		aml++;
		opcode = (u16) ((opcode << 8) | ACPI_GET8 (aml));
	}

	return (opcode);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_complete_this_op
 *
 * PARAMETERS:  walk_state      - Current State
 *              Op              - Op to complete
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Perform any cleanup at the completion of an Op.
 *
 ******************************************************************************/

void
acpi_ps_complete_this_op (
	struct acpi_walk_state          *walk_state,
	union acpi_parse_object         *op)
{
	union acpi_parse_object         *prev;
	union acpi_parse_object         *next;
	const struct acpi_opcode_info   *parent_info;
	union acpi_parse_object         *replacement_op = NULL;


	ACPI_FUNCTION_TRACE_PTR ("ps_complete_this_op", op);


	/* Check for null Op, can happen if AML code is corrupt */

	if (!op) {
		return_VOID;
	}

	/* Delete this op and the subtree below it if asked to */

	if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) != ACPI_PARSE_DELETE_TREE) ||
		 (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
		return_VOID;
	}

	/* Make sure that we only delete this subtree */

	if (op->common.parent) {
		/*
		 * Check if we need to replace the operator and its subtree
		 * with a return value op (placeholder op)
		 */
		parent_info = acpi_ps_get_opcode_info (op->common.parent->common.aml_opcode);

		switch (parent_info->class) {
		case AML_CLASS_CONTROL:
			break;

		case AML_CLASS_CREATE:

			/*
			 * These opcodes contain term_arg operands. The current
			 * op must be replaced by a placeholder return op
			 */
			replacement_op = acpi_ps_alloc_op (AML_INT_RETURN_VALUE_OP);
			if (!replacement_op) {
				goto cleanup;
			}
			break;

		case AML_CLASS_NAMED_OBJECT:

			/*
			 * These opcodes contain term_arg operands. The current
			 * op must be replaced by a placeholder return op
			 */
			if ((op->common.parent->common.aml_opcode == AML_REGION_OP)      ||
				(op->common.parent->common.aml_opcode == AML_DATA_REGION_OP) ||
				(op->common.parent->common.aml_opcode == AML_BUFFER_OP)      ||
				(op->common.parent->common.aml_opcode == AML_PACKAGE_OP)     ||
				(op->common.parent->common.aml_opcode == AML_VAR_PACKAGE_OP)) {
				replacement_op = acpi_ps_alloc_op (AML_INT_RETURN_VALUE_OP);
				if (!replacement_op) {
					goto cleanup;
				}
			}

			if ((op->common.parent->common.aml_opcode == AML_NAME_OP) &&
				(walk_state->descending_callback != acpi_ds_exec_begin_op)) {
				if ((op->common.aml_opcode == AML_BUFFER_OP) ||
					(op->common.aml_opcode == AML_PACKAGE_OP) ||
					(op->common.aml_opcode == AML_VAR_PACKAGE_OP)) {
					replacement_op = acpi_ps_alloc_op (op->common.aml_opcode);
					if (!replacement_op) {
						goto cleanup;
					}

					replacement_op->named.data = op->named.data;
					replacement_op->named.length = op->named.length;
				}
			}
			break;

		default:
			replacement_op = acpi_ps_alloc_op (AML_INT_RETURN_VALUE_OP);
			if (!replacement_op) {
				goto cleanup;
			}
		}

		/* We must unlink this op from the parent tree */

		prev = op->common.parent->common.value.arg;
		if (prev == op) {
			/* This op is the first in the list */

			if (replacement_op) {
				replacement_op->common.parent       = op->common.parent;
				replacement_op->common.value.arg    = NULL;
				replacement_op->common.node         = op->common.node;
				op->common.parent->common.value.arg = replacement_op;
				replacement_op->common.next         = op->common.next;
			}
			else {
				op->common.parent->common.value.arg = op->common.next;
			}
		}

		/* Search the parent list */

		else while (prev) {
			/* Traverse all siblings in the parent's argument list */

			next = prev->common.next;
			if (next == op) {
				if (replacement_op) {
					replacement_op->common.parent   = op->common.parent;
					replacement_op->common.value.arg = NULL;
					replacement_op->common.node     = op->common.node;
					prev->common.next               = replacement_op;
					replacement_op->common.next     = op->common.next;
					next = NULL;
				}
				else {
					prev->common.next = op->common.next;
					next = NULL;
				}
			}

			prev = next;
		}
	}


cleanup:

	/* Now we can actually delete the subtree rooted at op */

	acpi_ps_delete_parse_tree (op);
	return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_next_parse_state
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Update the parser state based upon the return exception from
 *              the parser callback.
 *
 ******************************************************************************/

acpi_status
acpi_ps_next_parse_state (
	struct acpi_walk_state          *walk_state,
	union acpi_parse_object         *op,
	acpi_status                     callback_status)
{
	struct acpi_parse_state         *parser_state = &walk_state->parser_state;
	acpi_status                     status = AE_CTRL_PENDING;


	ACPI_FUNCTION_TRACE_PTR ("ps_next_parse_state", op);


	switch (callback_status) {
	case AE_CTRL_TERMINATE:

		/*
		 * A control method was terminated via a RETURN statement.
		 * The walk of this method is complete.
		 */
		parser_state->aml = parser_state->aml_end;
		status = AE_CTRL_TERMINATE;
		break;


	case AE_CTRL_BREAK:

		parser_state->aml = walk_state->aml_last_while;
		walk_state->control_state->common.value = FALSE;
		status = AE_CTRL_BREAK;
		break;

	case AE_CTRL_CONTINUE:


		parser_state->aml = walk_state->aml_last_while;
		status = AE_CTRL_CONTINUE;
		break;

	case AE_CTRL_PENDING:

		parser_state->aml = walk_state->aml_last_while;
		break;

#if 0
	case AE_CTRL_SKIP:

		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
		status = AE_OK;
		break;
#endif

	case AE_CTRL_TRUE:

		/*
		 * Predicate of an IF was true, and we are at the matching ELSE.
		 * Just close out this package
		 */
		parser_state->aml = acpi_ps_get_next_package_end (parser_state);
		break;


	case AE_CTRL_FALSE:

		/*
		 * Either an IF/WHILE Predicate was false or we encountered a BREAK
		 * opcode.  In both cases, we do not execute the rest of the
		 * package;  We simply close out the parent (finishing the walk of
		 * this branch of the tree) and continue execution at the parent
		 * level.
		 */
		parser_state->aml = parser_state->scope->parse_scope.pkg_end;

		/* In the case of a BREAK, just force a predicate (if any) to FALSE */

		walk_state->control_state->common.value = FALSE;
		status = AE_CTRL_END;
		break;


	case AE_CTRL_TRANSFER:

		/*
		 * A method call (invocation) -- transfer control
		 */
		status = AE_CTRL_TRANSFER;
		walk_state->prev_op = op;
		walk_state->method_call_op = op;
		walk_state->method_call_node = (op->common.value.arg)->common.node;

		/* Will return value (if any) be used by the caller? */

		walk_state->return_used = acpi_ds_is_result_used (op, walk_state);
		break;


	default:
		status = callback_status;
		if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
			status = AE_OK;
		}
		break;
	}

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_parse_loop
 *