psloop.c

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

/*
 * Copyright (C) 2000 - 2007, 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, (such as
 * Perl) do. Parsing is done by hand rather than with a YACC generated parser
 * to tightly constrain stack and dynamic memory usage. 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;

/* Local prototypes */

static acpi_status acpi_ps_get_aml_opcode(struct acpi_walk_state *walk_state);

static acpi_status
acpi_ps_build_named_op(struct acpi_walk_state *walk_state,
		       u8 * aml_op_start,
		       union acpi_parse_object *unnamed_op,
		       union acpi_parse_object **op);

static acpi_status
acpi_ps_create_op(struct acpi_walk_state *walk_state,
		  u8 * aml_op_start, union acpi_parse_object **new_op);

static acpi_status
acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
		      u8 * aml_op_start, union acpi_parse_object *op);

static acpi_status
acpi_ps_complete_op(struct acpi_walk_state *walk_state,
		    union acpi_parse_object **op, acpi_status status);

static acpi_status
acpi_ps_complete_final_op(struct acpi_walk_state *walk_state,
			  union acpi_parse_object *op, acpi_status status);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_aml_opcode
 *
 * PARAMETERS:  walk_state          - Current state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Extract the next AML opcode from the input stream.
 *
 ******************************************************************************/

static acpi_status acpi_ps_get_aml_opcode(struct acpi_walk_state *walk_state)
{

	ACPI_FUNCTION_TRACE_PTR(ps_get_aml_opcode, walk_state);

	walk_state->aml_offset =
	    (u32) ACPI_PTR_DIFF(walk_state->parser_state.aml,
				walk_state->parser_state.aml_start);
	walk_state->opcode = acpi_ps_peek_opcode(&(walk_state->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_ERROR((AE_INFO,
			    "Found unknown opcode %X at AML address %p offset %X, ignoring",
			    walk_state->opcode, walk_state->parser_state.aml,
			    walk_state->aml_offset));

		ACPI_DUMP_BUFFER(walk_state->parser_state.aml, 128);

		/* Assume one-byte bad opcode */

		walk_state->parser_state.aml++;
		return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);

	default:

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

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

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_build_named_op
 *
 * PARAMETERS:  walk_state          - Current state
 *              aml_op_start        - Begin of named Op in AML
 *              unnamed_op          - Early Op (not a named Op)
 *              Op                  - Returned Op
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Parse a named Op
 *
 ******************************************************************************/

static acpi_status
acpi_ps_build_named_op(struct acpi_walk_state *walk_state,
		       u8 * aml_op_start,
		       union acpi_parse_object *unnamed_op,
		       union acpi_parse_object **op)
{
	acpi_status status = AE_OK;
	union acpi_parse_object *arg = NULL;

	ACPI_FUNCTION_TRACE_PTR(ps_build_named_op, walk_state);

	unnamed_op->common.value.arg = NULL;
	unnamed_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,
					 &(walk_state->parser_state),
					 GET_CURRENT_ARG_TYPE(walk_state->
							      arg_types), &arg);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}

		acpi_ps_append_arg(unnamed_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)) {
		return_ACPI_STATUS(AE_AML_NO_OPERAND);
	}

	/* 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_EXCEPTION((AE_INFO, status, "During name lookup/catalog"));
		return_ACPI_STATUS(status);
	}

	if (!*op) {
		return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
	}

	status = acpi_ps_next_parse_state(walk_state, *op, status);
	if (ACPI_FAILURE(status)) {
		if (status == AE_CTRL_PENDING) {
			return_ACPI_STATUS(AE_CTRL_PARSE_PENDING);
		}
		return_ACPI_STATUS(status);
	}

	acpi_ps_append_arg(*op, unnamed_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;
	}

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_create_op
 *
 * PARAMETERS:  walk_state          - Current state
 *              aml_op_start        - Op start in AML
 *              new_op              - Returned Op
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get Op from AML
 *
 ******************************************************************************/

static acpi_status
acpi_ps_create_op(struct acpi_walk_state *walk_state,
		  u8 * aml_op_start, union acpi_parse_object **new_op)
{
	acpi_status status = AE_OK;
	union acpi_parse_object *op;
	union acpi_parse_object *named_op = NULL;

	ACPI_FUNCTION_TRACE_PTR(ps_create_op, walk_state);

	status = acpi_ps_get_aml_opcode(walk_state);
	if (status == AE_CTRL_PARSE_CONTINUE) {
		return_ACPI_STATUS(AE_CTRL_PARSE_CONTINUE);
	}

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

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

	if (walk_state->op_info->flags & AML_NAMED) {
		status =
		    acpi_ps_build_named_op(walk_state, aml_op_start, op,
					   &named_op);
		acpi_ps_free_op(op);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}

		*new_op = named_op;
		return_ACPI_STATUS(AE_OK);
	}

	/* Not a named opcode, just allocate Op and append to parent */

	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
			   (&(walk_state->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 = *new_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_CTRL_PARSE_PENDING;
		}
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_arguments
 *
 * PARAMETERS:  walk_state          - Current state
 *              aml_op_start        - Op start in AML
 *              Op                  - Current Op
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get arguments for passed Op.
 *
 ******************************************************************************/

static acpi_status
acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
		      u8 * aml_op_start, union acpi_parse_object *op)
{
	acpi_status status = AE_OK;
	union acpi_parse_object *arg = NULL;

	ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);

	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(&(walk_state->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,
					      &(walk_state->parser_state), op,
					      1);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}

		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(walk_state->parser_state.aml,
						walk_state->parser_state.
						aml_start);

			status =
			    acpi_ps_get_next_arg(walk_state,
						 &(walk_state->parser_state),
						 GET_CURRENT_ARG_TYPE
						 (walk_state->arg_types), &arg);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}

			if (arg) {
				arg->common.aml_offset = walk_state->aml_offset;
				acpi_ps_append_arg(op, arg);
			}

			INCREMENT_ARG_LIST(walk_state->arg_types);
		}

		/* Special processing for certain opcodes */

		/* TBD (remove): Temporary mechanism to disable this code if needed */

#ifdef ACPI_ENABLE_MODULE_LEVEL_CODE

		if ((walk_state->pass_number <= ACPI_IMODE_LOAD_PASS1) &&
		    ((walk_state->parse_flags & ACPI_PARSE_DISASSEMBLE) == 0)) {
			/*
			 * We want to skip If/Else/While constructs during Pass1 because we
			 * want to actually conditionally execute the code during Pass2.
			 *
			 * Except for disassembly, where we always want to walk the
			 * If/Else/While packages
			 */
			switch (op->common.aml_opcode) {
			case AML_IF_OP:
			case AML_ELSE_OP:
			case AML_WHILE_OP:

				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
						  "Pass1: Skipping an If/Else/While body\n"));

				/* Skip body of if/else/while in pass 1 */

				walk_state->parser_state.aml =
				    walk_state->parser_state.pkg_end;
				walk_state->arg_count = 0;
				break;

			default:
				break;
			}
		}
#endif

		switch (op->common.aml_opcode) {
		case AML_METHOD_OP:
			/*
			 * Skip parsing of control method because we don't have enough
			 * info in the first pass to parse it correctly.
			 *
			 * Save the length and address of the body
			 */
			op->named.data = walk_state->parser_state.aml;
			op->named.length = (u32)
			    (walk_state->parser_state.pkg_end -
			     walk_state->parser_state.aml);

			/* Skip body of method */

			walk_state->parser_state.aml =
			    walk_state->parser_state.pkg_end;
			walk_state->arg_count = 0;
			break;

		case AML_BUFFER_OP:
		case AML_PACKAGE_OP:
		case AML_VAR_PACKAGE_OP:

			if ((op->common.parent) &&
			    (op->common.parent->common.aml_opcode ==
			     AML_NAME_OP)
			    && (walk_state->pass_number <=
				ACPI_IMODE_LOAD_PASS2)) {
				/*
				 * Skip parsing of Buffers and Packages because we don't have
				 * enough info in the first pass to parse them correctly.
				 */
				op->named.data = aml_op_start;
				op->named.length = (u32)
				    (walk_state->parser_state.pkg_end -
				     aml_op_start);

				/* Skip body */

				walk_state->parser_state.aml =
				    walk_state->parser_state.pkg_end;
				walk_state->arg_count = 0;
			}
			break;

		case AML_WHILE_OP:

			if (walk_state->control_state) {
				walk_state->control_state->control.package_end =
				    walk_state->parser_state.pkg_end;
			}
			break;

		default:

			/* No action for all other opcodes */
			break;
		}

		break;
	}

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_complete_op
 *
 * PARAMETERS:  walk_state          - Current state
 *              Op                  - Returned Op