Subversion Repositories Kolibri OS

/*******************************************************************************

 *

 * Module Name: dsutils - Dispatcher utilities

 *

 ******************************************************************************/

/*

 * Copyright (C) 2000 - 2015, Intel Corp.

 * 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.

 */

#include 

#include "accommon.h"

#include "acparser.h"

#include "amlcode.h"

#include "acdispat.h"

#include "acinterp.h"

#include "acnamesp.h"

#include "acdebug.h"

#define _COMPONENT          ACPI_DISPATCHER

ACPI_MODULE_NAME("dsutils")

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_clear_implicit_return

 *

 * PARAMETERS:  walk_state          - Current State

 *

 * RETURN:      None.

 *

 * DESCRIPTION: Clear and remove a reference on an implicit return value. Used

 *              to delete "stale" return values (if enabled, the return value

 *              from every operator is saved at least momentarily, in case the

 *              parent method exits.)

 *

 ******************************************************************************/

void acpi_ds_clear_implicit_return(struct acpi_walk_state *walk_state)

{

	ACPI_FUNCTION_NAME(ds_clear_implicit_return);

	/*

	 * Slack must be enabled for this feature

	 */

	if (!acpi_gbl_enable_interpreter_slack) {

		return;

	}

	if (walk_state->implicit_return_obj) {

		/*

		 * Delete any "stale" implicit return. However, in

		 * complex statements, the implicit return value can be

		 * bubbled up several levels.

		 */

		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

				  "Removing reference on stale implicit return obj %p\n",

				  walk_state->implicit_return_obj));

		acpi_ut_remove_reference(walk_state->implicit_return_obj);

		walk_state->implicit_return_obj = NULL;

	}

}

#ifndef ACPI_NO_METHOD_EXECUTION

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_do_implicit_return

 *

 * PARAMETERS:  return_desc         - The return value

 *              walk_state          - Current State

 *              add_reference       - True if a reference should be added to the

 *                                    return object

 *

 * RETURN:      TRUE if implicit return enabled, FALSE otherwise

 *

 * DESCRIPTION: Implements the optional "implicit return".  We save the result

 *              of every ASL operator and control method invocation in case the

 *              parent method exit. Before storing a new return value, we

 *              delete the previous return value.

 *

 ******************************************************************************/

u8

acpi_ds_do_implicit_return(union acpi_operand_object *return_desc,

			   struct acpi_walk_state *walk_state, u8 add_reference)

{

	ACPI_FUNCTION_NAME(ds_do_implicit_return);

	/*

	 * Slack must be enabled for this feature, and we must

	 * have a valid return object

	 */

	if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {

		return (FALSE);

	}

	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

			  "Result %p will be implicitly returned; Prev=%p\n",

			  return_desc, walk_state->implicit_return_obj));

	/*

	 * Delete any "stale" implicit return value first. However, in

	 * complex statements, the implicit return value can be

	 * bubbled up several levels, so we don't clear the value if it

	 * is the same as the return_desc.

	 */

	if (walk_state->implicit_return_obj) {

		if (walk_state->implicit_return_obj == return_desc) {

			return (TRUE);

		}

		acpi_ds_clear_implicit_return(walk_state);

	}

	/* Save the implicit return value, add a reference if requested */

	walk_state->implicit_return_obj = return_desc;

	if (add_reference) {

		acpi_ut_add_reference(return_desc);

	}

	return (TRUE);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_is_result_used

 *

 * PARAMETERS:  op                  - Current Op

 *              walk_state          - Current State

 *

 * RETURN:      TRUE if result is used, FALSE otherwise

 *

 * DESCRIPTION: Check if a result object will be used by the parent

 *

 ******************************************************************************/

u8

acpi_ds_is_result_used(union acpi_parse_object * op,

		       struct acpi_walk_state * walk_state)

{

	const struct acpi_opcode_info *parent_info;

	ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);

	/* Must have both an Op and a Result Object */

	if (!op) {

		ACPI_ERROR((AE_INFO, "Null Op"));

		return_UINT8(TRUE);

	}

	/*

	 * We know that this operator is not a

	 * Return() operator (would not come here.) The following code is the

	 * optional support for a so-called "implicit return". Some AML code

	 * assumes that the last value of the method is "implicitly" returned

	 * to the caller. Just save the last result as the return value.

	 * NOTE: this is optional because the ASL language does not actually

	 * support this behavior.

	 */

	(void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,

					 TRUE);

	/*

	 * Now determine if the parent will use the result

	 *

	 * If there is no parent, or the parent is a scope_op, we are executing

	 * at the method level. An executing method typically has no parent,

	 * since each method is parsed separately. A method invoked externally

	 * via execute_control_method has a scope_op as the parent.

	 */

	if ((!op->common.parent) ||

	    (op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {

		/* No parent, the return value cannot possibly be used */

		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

				  "At Method level, result of [%s] not used\n",

				  acpi_ps_get_opcode_name(op->common.

							  aml_opcode)));

		return_UINT8(FALSE);

	}

	/* Get info on the parent. The root_op is AML_SCOPE */

	parent_info =

	    acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);

	if (parent_info->class == AML_CLASS_UNKNOWN) {

		ACPI_ERROR((AE_INFO, "Unknown parent opcode Op=%p", op));

		return_UINT8(FALSE);

	}

	/*

	 * Decide what to do with the result based on the parent. If

	 * the parent opcode will not use the result, delete the object.

	 * Otherwise leave it as is, it will be deleted when it is used

	 * as an operand later.

	 */

	switch (parent_info->class) {

	case AML_CLASS_CONTROL:

		switch (op->common.parent->common.aml_opcode) {

		case AML_RETURN_OP:

			/* Never delete the return value associated with a return opcode */

			goto result_used;

		case AML_IF_OP:

		case AML_WHILE_OP:

			/*

			 * If we are executing the predicate AND this is the predicate op,

			 * we will use the return value

			 */

			if ((walk_state->control_state->common.state ==

			     ACPI_CONTROL_PREDICATE_EXECUTING)

			    && (walk_state->control_state->control.

				predicate_op == op)) {

				goto result_used;

			}

			break;

		default:

			/* Ignore other control opcodes */

			break;

		}

		/* The general control opcode returns no result */

		goto result_not_used;

	case AML_CLASS_CREATE:

		/*

		 * These opcodes allow term_arg(s) as operands and therefore

		 * the operands can be method calls. The result is used.

		 */

		goto result_used;

	case AML_CLASS_NAMED_OBJECT:

		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_PACKAGE_OP)

		    || (op->common.parent->common.aml_opcode ==

			AML_VAR_PACKAGE_OP)

		    || (op->common.parent->common.aml_opcode == AML_BUFFER_OP)

		    || (op->common.parent->common.aml_opcode ==

			AML_INT_EVAL_SUBTREE_OP)

		    || (op->common.parent->common.aml_opcode ==

			AML_BANK_FIELD_OP)) {

			/*

			 * These opcodes allow term_arg(s) as operands and therefore

			 * the operands can be method calls. The result is used.

			 */

			goto result_used;

		}

		goto result_not_used;

	default:

		/*

		 * In all other cases. the parent will actually use the return

		 * object, so keep it.

		 */

		goto result_used;

	}

result_used:

	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

			  "Result of [%s] used by Parent [%s] Op=%p\n",

			  acpi_ps_get_opcode_name(op->common.aml_opcode),

			  acpi_ps_get_opcode_name(op->common.parent->common.

						  aml_opcode), op));

	return_UINT8(TRUE);

result_not_used:

	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

			  "Result of [%s] not used by Parent [%s] Op=%p\n",

			  acpi_ps_get_opcode_name(op->common.aml_opcode),

			  acpi_ps_get_opcode_name(op->common.parent->common.

						  aml_opcode), op));

	return_UINT8(FALSE);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_delete_result_if_not_used

 *

 * PARAMETERS:  op              - Current parse Op

 *              result_obj      - Result of the operation

 *              walk_state      - Current state

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Used after interpretation of an opcode. If there is an internal

 *              result descriptor, check if the parent opcode will actually use

 *              this result. If not, delete the result now so that it will

 *              not become orphaned.

 *

 ******************************************************************************/

void

acpi_ds_delete_result_if_not_used(union acpi_parse_object *op,

				  union acpi_operand_object *result_obj,

				  struct acpi_walk_state *walk_state)

{

	union acpi_operand_object *obj_desc;

	acpi_status status;

	ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);

	if (!op) {

		ACPI_ERROR((AE_INFO, "Null Op"));

		return_VOID;

	}

	if (!result_obj) {

		return_VOID;

	}

	if (!acpi_ds_is_result_used(op, walk_state)) {

		/* Must pop the result stack (obj_desc should be equal to result_obj) */

		status = acpi_ds_result_pop(&obj_desc, walk_state);

		if (ACPI_SUCCESS(status)) {

			acpi_ut_remove_reference(result_obj);

		}

	}

	return_VOID;

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_resolve_operands

 *

 * PARAMETERS:  walk_state          - Current walk state with operands on stack

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Resolve all operands to their values. Used to prepare

 *              arguments to a control method invocation (a call from one

 *              method to another.)

 *

 ******************************************************************************/

acpi_status acpi_ds_resolve_operands(struct acpi_walk_state *walk_state)

{

	u32 i;

	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);

	/*

	 * Attempt to resolve each of the valid operands

	 * Method arguments are passed by reference, not by value. This means

	 * that the actual objects are passed, not copies of the objects.

	 */

	for (i = 0; i < walk_state->num_operands; i++) {

		status =

		    acpi_ex_resolve_to_value(&walk_state->operands[i],

					     walk_state);

		if (ACPI_FAILURE(status)) {

			break;

		}

	}

	return_ACPI_STATUS(status);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_clear_operands

 *

 * PARAMETERS:  walk_state          - Current walk state with operands on stack

 *

 * RETURN:      None

 *

 * DESCRIPTION: Clear all operands on the current walk state operand stack.

 *

 ******************************************************************************/

void acpi_ds_clear_operands(struct acpi_walk_state *walk_state)

{

	u32 i;

	ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);

	/* Remove a reference on each operand on the stack */

	for (i = 0; i < walk_state->num_operands; i++) {

		/*

		 * Remove a reference to all operands, including both

		 * "Arguments" and "Targets".

		 */

		acpi_ut_remove_reference(walk_state->operands[i]);

		walk_state->operands[i] = NULL;

	}

	walk_state->num_operands = 0;

	return_VOID;

}

#endif

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_create_operand

 *

 * PARAMETERS:  walk_state      - Current walk state

 *              arg             - Parse object for the argument

 *              arg_index       - Which argument (zero based)

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Translate a parse tree object that is an argument to an AML

 *              opcode to the equivalent interpreter object. This may include

 *              looking up a name or entering a new name into the internal

 *              namespace.

 *

 ******************************************************************************/

acpi_status

acpi_ds_create_operand(struct acpi_walk_state *walk_state,

		       union acpi_parse_object *arg, u32 arg_index)

{

	acpi_status status = AE_OK;

	char *name_string;

	u32 name_length;

	union acpi_operand_object *obj_desc;

	union acpi_parse_object *parent_op;

	u16 opcode;

	acpi_interpreter_mode interpreter_mode;

	const struct acpi_opcode_info *op_info;

	ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);

	/* A valid name must be looked up in the namespace */

	if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&

	    (arg->common.value.string) &&

	    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {

		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Getting a name: Arg=%p\n",

				  arg));

		/* Get the entire name string from the AML stream */

		status =

		    acpi_ex_get_name_string(ACPI_TYPE_ANY,

					    arg->common.value.buffer,

					    &name_string, &name_length);

		if (ACPI_FAILURE(status)) {

			return_ACPI_STATUS(status);

		}

		/* All prefixes have been handled, and the name is in name_string */

		/*

		 * Special handling for buffer_field declarations. This is a deferred

		 * opcode that unfortunately defines the field name as the last

		 * parameter instead of the first. We get here when we are performing

		 * the deferred execution, so the actual name of the field is already

		 * in the namespace. We don't want to attempt to look it up again

		 * because we may be executing in a different scope than where the

		 * actual opcode exists.

		 */

		if ((walk_state->deferred_node) &&

		    (walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)

		    && (arg_index ==

			(u32) ((walk_state->opcode ==

				AML_CREATE_FIELD_OP) ? 3 : 2))) {

			obj_desc =

			    ACPI_CAST_PTR(union acpi_operand_object,

					  walk_state->deferred_node);

			status = AE_OK;

		} else {	/* All other opcodes */

			/*

			 * Differentiate between a namespace "create" operation

			 * versus a "lookup" operation (IMODE_LOAD_PASS2 vs.

			 * IMODE_EXECUTE) in order to support the creation of

			 * namespace objects during the execution of control methods.

			 */

			parent_op = arg->common.parent;

			op_info =

			    acpi_ps_get_opcode_info(parent_op->common.

						    aml_opcode);

			if ((op_info->flags & AML_NSNODE)

			    && (parent_op->common.aml_opcode !=

				AML_INT_METHODCALL_OP)

			    && (parent_op->common.aml_opcode != AML_REGION_OP)

			    && (parent_op->common.aml_opcode !=

				AML_INT_NAMEPATH_OP)) {

				/* Enter name into namespace if not found */

				interpreter_mode = ACPI_IMODE_LOAD_PASS2;

			} else {

				/* Return a failure if name not found */

				interpreter_mode = ACPI_IMODE_EXECUTE;

			}

			status =

			    acpi_ns_lookup(walk_state->scope_info, name_string,

					   ACPI_TYPE_ANY, interpreter_mode,

					   ACPI_NS_SEARCH_PARENT |

					   ACPI_NS_DONT_OPEN_SCOPE, walk_state,

					   ACPI_CAST_INDIRECT_PTR(struct

								  acpi_namespace_node,

								  &obj_desc));

			/*

			 * The only case where we pass through (ignore) a NOT_FOUND

			 * error is for the cond_ref_of opcode.

			 */

			if (status == AE_NOT_FOUND) {

				if (parent_op->common.aml_opcode ==

				    AML_COND_REF_OF_OP) {

					/*

					 * For the Conditional Reference op, it's OK if

					 * the name is not found;  We just need a way to

					 * indicate this to the interpreter, set the

					 * object to the root

					 */

					obj_desc =

					    ACPI_CAST_PTR(union

								 acpi_operand_object,

								 acpi_gbl_root_node);

					status = AE_OK;

				} else if (parent_op->common.aml_opcode ==

					   AML_EXTERNAL_OP) {

					/* TBD: May only be temporary */

					obj_desc =

					    acpi_ut_create_string_object((acpi_size) name_length);

					strncpy(obj_desc->string.pointer,

						name_string, name_length);

					status = AE_OK;

				} else {

					/*

					 * We just plain didn't find it -- which is a

					 * very serious error at this point

					 */

					status = AE_AML_NAME_NOT_FOUND;

				}

			}

			if (ACPI_FAILURE(status)) {

				ACPI_ERROR_NAMESPACE(name_string, status);

			}

		}

		/* Free the namestring created above */

		ACPI_FREE(name_string);

		/* Check status from the lookup */

		if (ACPI_FAILURE(status)) {

			return_ACPI_STATUS(status);

		}

		/* Put the resulting object onto the current object stack */

		status = acpi_ds_obj_stack_push(obj_desc, walk_state);

		if (ACPI_FAILURE(status)) {

			return_ACPI_STATUS(status);

		}

		ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object

				   (obj_desc, walk_state));

	} else {

		/* Check for null name case */

		if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&

		    !(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {

			/*

			 * If the name is null, this means that this is an

			 * optional result parameter that was not specified

			 * in the original ASL. Create a Zero Constant for a

			 * placeholder. (Store to a constant is a Noop.)

			 */

			opcode = AML_ZERO_OP;	/* Has no arguments! */

			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

					  "Null namepath: Arg=%p\n", arg));

		} else {

			opcode = arg->common.aml_opcode;

		}

		/* Get the object type of the argument */

		op_info = acpi_ps_get_opcode_info(opcode);

		if (op_info->object_type == ACPI_TYPE_INVALID) {

			return_ACPI_STATUS(AE_NOT_IMPLEMENTED);

		}

		if ((op_info->flags & AML_HAS_RETVAL)

		    || (arg->common.flags & ACPI_PARSEOP_IN_STACK)) {

			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

					  "Argument previously created, already stacked\n"));

			ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object

					   (walk_state->

					    operands[walk_state->num_operands -

						     1], walk_state));

			/*

			 * Use value that was already previously returned

			 * by the evaluation of this argument

			 */

			status = acpi_ds_result_pop(&obj_desc, walk_state);

			if (ACPI_FAILURE(status)) {

				/*

				 * Only error is underflow, and this indicates

				 * a missing or null operand!

				 */

				ACPI_EXCEPTION((AE_INFO, status,

						"Missing or null operand"));

				return_ACPI_STATUS(status);

			}

		} else {

			/* Create an ACPI_INTERNAL_OBJECT for the argument */

			obj_desc =

			    acpi_ut_create_internal_object(op_info->

							   object_type);

			if (!obj_desc) {

				return_ACPI_STATUS(AE_NO_MEMORY);

			}

			/* Initialize the new object */

			status =

			    acpi_ds_init_object_from_op(walk_state, arg, opcode,

							&obj_desc);

			if (ACPI_FAILURE(status)) {

				acpi_ut_delete_object_desc(obj_desc);

				return_ACPI_STATUS(status);

			}

		}

		/* Put the operand object on the object stack */

		status = acpi_ds_obj_stack_push(obj_desc, walk_state);

		if (ACPI_FAILURE(status)) {

			return_ACPI_STATUS(status);

		}

		ACPI_DEBUGGER_EXEC(acpi_db_display_argument_object

				   (obj_desc, walk_state));

	}

	return_ACPI_STATUS(AE_OK);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_ds_create_operands

 *

 * PARAMETERS:  walk_state          - Current state

 *              first_arg           - First argument of a parser argument tree

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Convert an operator's arguments from a parse tree format to

 *              namespace objects and place those argument object on the object

 *              stack in preparation for evaluation by the interpreter.

 *

 ******************************************************************************/

acpi_status

acpi_ds_create_operands(struct acpi_walk_state *walk_state,

			union acpi_parse_object *first_arg)

{

	acpi_status status = AE_OK;

	union acpi_parse_object *arg;

	union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];

	u32 arg_count = 0;

	u32 index = walk_state->num_operands;

	u32 i;

	ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);

	/* Get all arguments in the list */

	arg = first_arg;

	while (arg) {

		if (index >= ACPI_OBJ_NUM_OPERANDS) {

			return_ACPI_STATUS(AE_BAD_DATA);

		}

		arguments[index] = arg;

		walk_state->operands[index] = NULL;

		/* Move on to next argument, if any */

		arg = arg->common.next;

		arg_count++;

		index++;

	}

	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

			  "NumOperands %d, ArgCount %d, Index %d\n",

			  walk_state->num_operands, arg_count, index));

	/* Create the interpreter arguments, in reverse order */

	index--;

	for (i = 0; i < arg_count; i++) {

		arg = arguments[index];

		walk_state->operand_index = (u8)index;

		status = acpi_ds_create_operand(walk_state, arg, index);

		if (ACPI_FAILURE(status)) {

			goto cleanup;

		}

		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,

				  "Created Arg #%u (%p) %u args total\n",

				  index, arg, arg_count));

		index--;

	}

	return_ACPI_STATUS(status);

cleanup:

	/*

	 * We must undo everything done above; meaning that we must

	 * pop everything off of the operand stack and delete those

	 * objects

	 */

	acpi_ds_obj_stack_pop_and_delete(arg_count, walk_state);

	ACPI_EXCEPTION((AE_INFO, status, "While creating Arg %u", index));

	return_ACPI_STATUS(status);

}

/*****************************************************************************

 *

 * FUNCTION:    acpi_ds_evaluate_name_path

 *

 * PARAMETERS:  walk_state      - Current state of the parse tree walk,

 *                                the opcode of current operation should be

 *                                AML_INT_NAMEPATH_OP

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Translate the -name_path- parse tree object to the equivalent

 *              interpreter object, convert it to value, if needed, duplicate

 *              it, if needed, and push it onto the current result stack.

 *

 ****************************************************************************/

acpi_status acpi_ds_evaluate_name_path(struct acpi_walk_state *walk_state)

{

	acpi_status status = AE_OK;

	union acpi_parse_object *op = walk_state->op;

	union acpi_operand_object **operand = &walk_state->operands[0];

	union acpi_operand_object *new_obj_desc;

	u8 type;

	ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);

	if (!op->common.parent) {

		/* This happens after certain exception processing */

		goto exit;

	}

	if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||

	    (op->common.parent->common.aml_opcode == AML_VAR_PACKAGE_OP) ||

	    (op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {

		/* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */

		goto exit;

	}

	status = acpi_ds_create_operand(walk_state, op, 0);

	if (ACPI_FAILURE(status)) {

		goto exit;

	}

	if (op->common.flags & ACPI_PARSEOP_TARGET) {

		new_obj_desc = *operand;

		goto push_result;

	}

	type = (*operand)->common.type;

	status = acpi_ex_resolve_to_value(operand, walk_state);

	if (ACPI_FAILURE(status)) {

		goto exit;

	}

	if (type == ACPI_TYPE_INTEGER) {

		/* It was incremented by acpi_ex_resolve_to_value */

		acpi_ut_remove_reference(*operand);

		status =

		    acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,

						    walk_state);

		if (ACPI_FAILURE(status)) {

			goto exit;

		}

	} else {

		/*

		 * The object either was anew created or is

		 * a Namespace node - don't decrement it.

		 */

		new_obj_desc = *operand;

	}

	/* Cleanup for name-path operand */

	status = acpi_ds_obj_stack_pop(1, walk_state);

	if (ACPI_FAILURE(status)) {

		walk_state->result_obj = new_obj_desc;

		goto exit;

	}

push_result:

	walk_state->result_obj = new_obj_desc;

	status = acpi_ds_result_push(walk_state->result_obj, walk_state);

	if (ACPI_SUCCESS(status)) {

		/* Force to take it from stack */

		op->common.flags |= ACPI_PARSEOP_IN_STACK;

	}

exit:

	return_ACPI_STATUS(status);

}