drivers/acpi/acpica/psloop.c - linux - Git at Google

 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
 /******************************************************************************
  *
  * Module Name: psloop - Main AML parse loop
  *
  * Copyright (C) 2000 - 2019, Intel Corp.
  *
  *****************************************************************************/

 /*
  * 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 "accommon.h"
 #include "acinterp.h"
 #include "acparser.h"
 #include "acdispat.h"
 #include "amlcode.h"
 #include "acconvert.h"
 #include "acnamesp.h"

 #define _COMPONENT          ACPI_PARSER
 ACPI_MODULE_NAME("psloop")

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

 /*******************************************************************************
  *
  * 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);

 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 			  "Get arguments for opcode [%s]\n",
 			  op->common.aml_op_name));

 	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,
 						   ACPI_POSSIBLE_METHOD_CALL);
 		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 = walk_state->parser_state.aml;

 			switch (op->common.aml_opcode) {
 			case AML_METHOD_OP:
 			case AML_BUFFER_OP:
 			case AML_PACKAGE_OP:
 			case AML_VARIABLE_PACKAGE_OP:
 			case AML_WHILE_OP:

 				break;

 			default:

 				ASL_CV_CAPTURE_COMMENTS(walk_state);
 				break;
 			}

 			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) {
 				acpi_ps_append_arg(op, arg);
 			}

 			INCREMENT_ARG_LIST(walk_state->arg_types);
 		}

 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 				  "Final argument count: %8.8X pass %u\n",
 				  walk_state->arg_count,
 				  walk_state->pass_number));

 		/* Special processing for certain opcodes */

 		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_VARIABLE_PACKAGE_OP:

 			if ((op->common.parent) &&
 			    (op->common.parent->common.aml_opcode ==
 			     AML_NAME_OP)
 			    && (walk_state->pass_number <=
 				ACPI_IMODE_LOAD_PASS2)) {
 				ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 						  "Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
 						  walk_state->pass_number,
 						  aml_op_start));

 				/*
 				 * 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_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;
 	union acpi_parse_object *op = NULL;	/* current op */
 	struct acpi_parse_state *parser_state;
 	u8 *aml_op_start = NULL;
 	u8 opcode_length;

 	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;

 #ifndef 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_EXCEPTION((AE_INFO, status,
 								"Invoked method did not return a value"));
 					}

 					ACPI_EXCEPTION((AE_INFO, status,
 							"GetPredicate Failed"));
 					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)) {
 		ASL_CV_CAPTURE_COMMENTS(walk_state);

 		aml_op_start = parser_state->aml;
 		if (!op) {
 			status =
 			    acpi_ps_create_op(walk_state, aml_op_start, &op);
 			if (ACPI_FAILURE(status)) {
 				/*
 				 * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
 				 * executing it as a control method. However, if we encounter
 				 * an error while loading the table, we need to keep trying to
 				 * load the table rather than aborting the table load. Set the
 				 * status to AE_OK to proceed with the table load.
 				 */
 				if ((walk_state->
 				     parse_flags & ACPI_PARSE_MODULE_LEVEL)
 				    && ((status == AE_ALREADY_EXISTS)
 					|| (status == AE_NOT_FOUND))) {
 					status = AE_OK;
 				}
 				if (status == AE_CTRL_PARSE_CONTINUE) {
 					continue;
 				}

 				if (status == AE_CTRL_PARSE_PENDING) {
 					status = AE_OK;
 				}

 				if (status == AE_CTRL_TERMINATE) {
 					return_ACPI_STATUS(status);
 				}

 				status =
 				    acpi_ps_complete_op(walk_state, &op,
 							status);
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}
 				if (acpi_ns_opens_scope
 				    (acpi_ps_get_opcode_info
 				     (walk_state->opcode)->object_type)) {
 					/*
 					 * If the scope/device op fails to parse, skip the body of
 					 * the scope op because the parse failure indicates that
 					 * the device may not exist.
 					 */
 					ACPI_INFO(("Skipping parse of AML opcode: %s (0x%4.4X)", acpi_ps_get_opcode_name(walk_state->opcode), walk_state->opcode));

 					/*
 					 * Determine the opcode length before skipping the opcode.
 					 * An opcode can be 1 byte or 2 bytes in length.
 					 */
 					opcode_length = 1;
 					if ((walk_state->opcode & 0xFF00) ==
 					    AML_EXTENDED_OPCODE) {
 						opcode_length = 2;
 					}
 					walk_state->parser_state.aml =
 					    walk_state->aml + opcode_length;

 					walk_state->parser_state.aml =
 					    acpi_ps_get_next_package_end
 					    (&walk_state->parser_state);
 					walk_state->aml =
 					    walk_state->parser_state.aml;
 				}

 				continue;
 			}

 			acpi_ex_start_trace_opcode(op, walk_state);
 		}

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

 		switch (op->common.aml_opcode) {
 		case AML_BYTE_OP:
 		case AML_WORD_OP:
 		case AML_DWORD_OP:
 		case AML_QWORD_OP:

 			break;

 		default:

 			ASL_CV_CAPTURE_COMMENTS(walk_state);
 			break;
 		}

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

 		if (walk_state->arg_types) {

 			/* Get arguments */

 			status =
 			    acpi_ps_get_arguments(walk_state, aml_op_start, op);
 			if (ACPI_FAILURE(status)) {
 				status =
 				    acpi_ps_complete_op(walk_state, &op,
 							status);
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}
 				if ((walk_state->control_state) &&
 				    ((walk_state->control_state->control.
 				      opcode == AML_IF_OP)
 				     || (walk_state->control_state->control.
 					 opcode == AML_WHILE_OP))) {
 					/*
 					 * If the if/while op fails to parse, we will skip parsing
 					 * the body of the op.
 					 */
 					parser_state->aml =
 					    walk_state->control_state->control.
 					    aml_predicate_start + 1;
 					parser_state->aml =
 					    acpi_ps_get_next_package_end
 					    (parser_state);
 					walk_state->aml = parser_state->aml;

 					ACPI_ERROR((AE_INFO,
 						    "Skipping While/If block"));
 					if (*walk_state->aml == AML_ELSE_OP) {
 						ACPI_ERROR((AE_INFO,
 							    "Skipping Else block"));
 						walk_state->parser_state.aml =
 						    walk_state->aml + 1;
 						walk_state->parser_state.aml =
 						    acpi_ps_get_next_package_end
 						    (parser_state);
 						walk_state->aml =
 						    parser_state->aml;
 					}
 					ACPI_FREE(acpi_ut_pop_generic_state
 						  (&walk_state->control_state));
 				}
 				op = NULL;
 				continue;
 			}
 		}

 		/* Check for arguments that need to be processed */

 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
 				  "Parseloop: argument count: %8.8X\n",
 				  walk_state->arg_count));

 		if (walk_state->arg_count) {
 			/*
 			 * There are arguments (complex ones), push Op and
 			 * prepare for argument
 			 */
 			status = acpi_ps_push_scope(parser_state, op,
 						    walk_state->arg_types,
 						    walk_state->arg_count);
 			if (ACPI_FAILURE(status)) {
 				status =
 				    acpi_ps_complete_op(walk_state, &op,
 							status);
 				if (ACPI_FAILURE(status)) {
 					return_ACPI_STATUS(status);
 				}

 				continue;
 			}

 			op = NULL;
 			continue;
 		}

 		/*
 		 * All arguments have been processed -- Op is complete,
 		 * prepare for next
 		 */
 		walk_state->op_info =
 		    acpi_ps_get_opcode_info(op->common.aml_opcode);
 		if (walk_state->op_info->flags & AML_NAMED) {
 			if (op->common.aml_opcode == AML_REGION_OP ||
 			    op->common.aml_opcode == AML_DATA_REGION_OP) {
 				/*
 				 * Skip parsing of control method or opregion body,
 				 * because we don't have enough info in the first pass
 				 * to parse them correctly.
 				 *
 				 * Completed parsing an op_region declaration, we now
 				 * know the length.
 				 */
 				op->named.length =
 				    (u32) (parser_state->aml - op->named.data);
 			}
 		}

 		if (walk_state->op_info->flags & AML_CREATE) {
 			/*
 			 * Backup to beginning of create_XXXfield declaration (1 for
 			 * Opcode)
 			 *
 			 * body_length is unknown until we parse the body
 			 */
 			op->named.length =
 			    (u32) (parser_state->aml - op->named.data);
 		}

 		if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
 			/*
 			 * Backup to beginning of bank_field declaration
 			 *
 			 * body_length is unknown until we parse the body
 			 */
 			op->named.length =
 			    (u32) (parser_state->aml - op->named.data);
 		}

 		/* This op complete, notify the dispatcher */

 		if (walk_state->ascending_callback != NULL) {
 			walk_state->op = op;
 			walk_state->opcode = op->common.aml_opcode;

 			status = walk_state->ascending_callback(walk_state);
 			status =
 			    acpi_ps_next_parse_state(walk_state, op, status);
 			if (status == AE_CTRL_PENDING) {
 				status = AE_OK;
 			} else
 			    if ((walk_state->
 				 parse_flags & ACPI_PARSE_MODULE_LEVEL)
 				&& (ACPI_AML_EXCEPTION(status)
 				    || status == AE_ALREADY_EXISTS
 				    || status == AE_NOT_FOUND)) {
 				/*
 				 * ACPI_PARSE_MODULE_LEVEL flag means that we
 				 * are currently loading a table by executing
 				 * it as a control method. However, if we
 				 * encounter an error while loading the table,
 				 * we need to keep trying to load the table
 				 * rather than aborting the table load (setting
 				 * the status to AE_OK continues the table
 				 * load). If we get a failure at this point, it
 				 * means that the dispatcher got an error while
 				 * trying to execute the Op.
 				 */
 				status = AE_OK;
 			}
 		}

 		status = acpi_ps_complete_op(walk_state, &op, status);
 		if (ACPI_FAILURE(status)) {
 			return_ACPI_STATUS(status);
 		}

 	}			/* while parser_state->Aml */

 	status = acpi_ps_complete_final_op(walk_state, op, status);
 	return_ACPI_STATUS(status);
 }
	// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
	/******************************************************************************
	*
	* Module Name: psloop - Main AML parse loop
	*
	* Copyright (C) 2000 - 2019, Intel Corp.
	*
	*****************************************************************************/

	/*
	* 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 "accommon.h"
	#include "acinterp.h"
	#include "acparser.h"
	#include "acdispat.h"
	#include "amlcode.h"
	#include "acconvert.h"
	#include "acnamesp.h"

	#define _COMPONENT ACPI_PARSER
	ACPI_MODULE_NAME("psloop")

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

	/*******************************************************************************
	*
	* 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);

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Get arguments for opcode [%s]\n",
	op->common.aml_op_name));

	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,
	ACPI_POSSIBLE_METHOD_CALL);
	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 = walk_state->parser_state.aml;

	switch (op->common.aml_opcode) {
	case AML_METHOD_OP:
	case AML_BUFFER_OP:
	case AML_PACKAGE_OP:
	case AML_VARIABLE_PACKAGE_OP:
	case AML_WHILE_OP:

	break;

	default:

	ASL_CV_CAPTURE_COMMENTS(walk_state);
	break;
	}

	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) {
	acpi_ps_append_arg(op, arg);
	}

	INCREMENT_ARG_LIST(walk_state->arg_types);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Final argument count: %8.8X pass %u\n",
	walk_state->arg_count,
	walk_state->pass_number));

	/* Special processing for certain opcodes */

	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_VARIABLE_PACKAGE_OP:

	if ((op->common.parent) &&
	(op->common.parent->common.aml_opcode ==
	AML_NAME_OP)
	&& (walk_state->pass_number <=
	ACPI_IMODE_LOAD_PASS2)) {
	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
	walk_state->pass_number,
	aml_op_start));

	/*
	* 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_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;
	union acpi_parse_object op = NULL; / current op */
	struct acpi_parse_state *parser_state;
	u8 *aml_op_start = NULL;
	u8 opcode_length;

	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;

	#ifndef 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_EXCEPTION((AE_INFO, status,
	"Invoked method did not return a value"));
	}

	ACPI_EXCEPTION((AE_INFO, status,
	"GetPredicate Failed"));
	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)) {
	ASL_CV_CAPTURE_COMMENTS(walk_state);

	aml_op_start = parser_state->aml;
	if (!op) {
	status =
	acpi_ps_create_op(walk_state, aml_op_start, &op);
	if (ACPI_FAILURE(status)) {
	/*
	* ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
	* executing it as a control method. However, if we encounter
	* an error while loading the table, we need to keep trying to
	* load the table rather than aborting the table load. Set the
	* status to AE_OK to proceed with the table load.
	*/
	if ((walk_state->
	parse_flags & ACPI_PARSE_MODULE_LEVEL)
	&& ((status == AE_ALREADY_EXISTS)
	\|\| (status == AE_NOT_FOUND))) {
	status = AE_OK;
	}
	if (status == AE_CTRL_PARSE_CONTINUE) {
	continue;
	}

	if (status == AE_CTRL_PARSE_PENDING) {
	status = AE_OK;
	}

	if (status == AE_CTRL_TERMINATE) {
	return_ACPI_STATUS(status);
	}

	status =
	acpi_ps_complete_op(walk_state, &op,
	status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	if (acpi_ns_opens_scope
	(acpi_ps_get_opcode_info
	(walk_state->opcode)->object_type)) {
	/*
	* If the scope/device op fails to parse, skip the body of
	* the scope op because the parse failure indicates that
	* the device may not exist.
	*/
	ACPI_INFO(("Skipping parse of AML opcode: %s (0x%4.4X)", acpi_ps_get_opcode_name(walk_state->opcode), walk_state->opcode));

	/*
	* Determine the opcode length before skipping the opcode.
	* An opcode can be 1 byte or 2 bytes in length.
	*/
	opcode_length = 1;
	if ((walk_state->opcode & 0xFF00) ==
	AML_EXTENDED_OPCODE) {
	opcode_length = 2;
	}
	walk_state->parser_state.aml =
	walk_state->aml + opcode_length;

	walk_state->parser_state.aml =
	acpi_ps_get_next_package_end
	(&walk_state->parser_state);
	walk_state->aml =
	walk_state->parser_state.aml;
	}

	continue;
	}

	acpi_ex_start_trace_opcode(op, walk_state);
	}

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

	switch (op->common.aml_opcode) {
	case AML_BYTE_OP:
	case AML_WORD_OP:
	case AML_DWORD_OP:
	case AML_QWORD_OP:

	break;

	default:

	ASL_CV_CAPTURE_COMMENTS(walk_state);
	break;
	}

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

	if (walk_state->arg_types) {

	/* Get arguments */

	status =
	acpi_ps_get_arguments(walk_state, aml_op_start, op);
	if (ACPI_FAILURE(status)) {
	status =
	acpi_ps_complete_op(walk_state, &op,
	status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	if ((walk_state->control_state) &&
	((walk_state->control_state->control.
	opcode == AML_IF_OP)
	\|\| (walk_state->control_state->control.
	opcode == AML_WHILE_OP))) {
	/*
	* If the if/while op fails to parse, we will skip parsing
	* the body of the op.
	*/
	parser_state->aml =
	walk_state->control_state->control.
	aml_predicate_start + 1;
	parser_state->aml =
	acpi_ps_get_next_package_end
	(parser_state);
	walk_state->aml = parser_state->aml;

	ACPI_ERROR((AE_INFO,
	"Skipping While/If block"));
	if (*walk_state->aml == AML_ELSE_OP) {
	ACPI_ERROR((AE_INFO,
	"Skipping Else block"));
	walk_state->parser_state.aml =
	walk_state->aml + 1;
	walk_state->parser_state.aml =
	acpi_ps_get_next_package_end
	(parser_state);
	walk_state->aml =
	parser_state->aml;
	}
	ACPI_FREE(acpi_ut_pop_generic_state
	(&walk_state->control_state));
	}
	op = NULL;
	continue;
	}
	}

	/* Check for arguments that need to be processed */

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
	"Parseloop: argument count: %8.8X\n",
	walk_state->arg_count));

	if (walk_state->arg_count) {
	/*
	* There are arguments (complex ones), push Op and
	* prepare for argument
	*/
	status = acpi_ps_push_scope(parser_state, op,
	walk_state->arg_types,
	walk_state->arg_count);
	if (ACPI_FAILURE(status)) {
	status =
	acpi_ps_complete_op(walk_state, &op,
	status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	continue;
	}

	op = NULL;
	continue;
	}

	/*
	* All arguments have been processed -- Op is complete,
	* prepare for next
	*/
	walk_state->op_info =
	acpi_ps_get_opcode_info(op->common.aml_opcode);
	if (walk_state->op_info->flags & AML_NAMED) {
	if (op->common.aml_opcode == AML_REGION_OP \|\|
	op->common.aml_opcode == AML_DATA_REGION_OP) {
	/*
	* Skip parsing of control method or opregion body,
	* because we don't have enough info in the first pass
	* to parse them correctly.
	*
	* Completed parsing an op_region declaration, we now
	* know the length.
	*/
	op->named.length =
	(u32) (parser_state->aml - op->named.data);
	}
	}

	if (walk_state->op_info->flags & AML_CREATE) {
	/*
	* Backup to beginning of create_XXXfield declaration (1 for
	* Opcode)
	*
	* body_length is unknown until we parse the body
	*/
	op->named.length =
	(u32) (parser_state->aml - op->named.data);
	}

	if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
	/*
	* Backup to beginning of bank_field declaration
	*
	* body_length is unknown until we parse the body
	*/
	op->named.length =
	(u32) (parser_state->aml - op->named.data);
	}

	/* This op complete, notify the dispatcher */

	if (walk_state->ascending_callback != NULL) {
	walk_state->op = op;
	walk_state->opcode = op->common.aml_opcode;

	status = walk_state->ascending_callback(walk_state);
	status =
	acpi_ps_next_parse_state(walk_state, op, status);
	if (status == AE_CTRL_PENDING) {
	status = AE_OK;
	} else
	if ((walk_state->
	parse_flags & ACPI_PARSE_MODULE_LEVEL)
	&& (ACPI_AML_EXCEPTION(status)
	\|\| status == AE_ALREADY_EXISTS
	\|\| status == AE_NOT_FOUND)) {
	/*
	* ACPI_PARSE_MODULE_LEVEL flag means that we
	* are currently loading a table by executing
	* it as a control method. However, if we
	* encounter an error while loading the table,
	* we need to keep trying to load the table
	* rather than aborting the table load (setting
	* the status to AE_OK continues the table
	* load). If we get a failure at this point, it
	* means that the dispatcher got an error while
	* trying to execute the Op.
	*/
	status = AE_OK;
	}
	}

	status = acpi_ps_complete_op(walk_state, &op, status);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	} /* while parser_state->Aml */

	status = acpi_ps_complete_final_op(walk_state, op, status);
	return_ACPI_STATUS(status);
	}