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/******************************************************************************
*
* Module Name: pswalk - Parser routines to walk parsed op tree(s)
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2004, 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.
*/
#include <acpi/acpi.h>
#include <acpi/acparser.h>
#include <acpi/acdispat.h>
#define _COMPONENT ACPI_PARSER
ACPI_MODULE_NAME ("pswalk")
/*******************************************************************************
*
* FUNCTION: acpi_ps_get_next_walk_op
*
* PARAMETERS: walk_state - Current state of the walk
* Op - Current Op to be walked
* ascending_callback - Procedure called when Op is complete
*
* RETURN: Status
*
* DESCRIPTION: Get the next Op in a walk of the parse tree.
*
******************************************************************************/
acpi_status
acpi_ps_get_next_walk_op (
struct acpi_walk_state *walk_state,
union acpi_parse_object *op,
acpi_parse_upwards ascending_callback)
{
union acpi_parse_object *next;
union acpi_parse_object *parent;
union acpi_parse_object *grand_parent;
acpi_status status;
ACPI_FUNCTION_TRACE_PTR ("ps_get_next_walk_op", op);
/* Check for a argument only if we are descending in the tree */
if (walk_state->next_op_info != ACPI_NEXT_OP_UPWARD) {
/* Look for an argument or child of the current op */
next = acpi_ps_get_arg (op, 0);
if (next) {
/* Still going downward in tree (Op is not completed yet) */
walk_state->prev_op = op;
walk_state->next_op = next;
walk_state->next_op_info = ACPI_NEXT_OP_DOWNWARD;
return_ACPI_STATUS (AE_OK);
}
/*
* No more children, this Op is complete. Save Next and Parent
* in case the Op object gets deleted by the callback routine
*/
next = op->common.next;
parent = op->common.parent;
walk_state->op = op;
walk_state->op_info = acpi_ps_get_opcode_info (op->common.aml_opcode);
walk_state->opcode = op->common.aml_opcode;
status = ascending_callback (walk_state);
/*
* If we are back to the starting point, the walk is complete.
*/
if (op == walk_state->origin) {
/* Reached the point of origin, the walk is complete */
walk_state->prev_op = op;
walk_state->next_op = NULL;
return_ACPI_STATUS (status);
}
/*
* Check for a sibling to the current op. A sibling means
* we are still going "downward" in the tree.
*/
if (next) {
/* There is a sibling, it will be next */
walk_state->prev_op = op;
walk_state->next_op = next;
walk_state->next_op_info = ACPI_NEXT_OP_DOWNWARD;
/* Continue downward */
return_ACPI_STATUS (status);
}
/*
* Drop into the loop below because we are moving upwards in
* the tree
*/
}
else {
/*
* We are resuming a walk, and we were (are) going upward in the tree.
* So, we want to drop into the parent loop below.
*/
parent = op;
}
/*
* Look for a sibling of the current Op's parent
* Continue moving up the tree until we find a node that has not been
* visited, or we get back to where we started.
*/
while (parent) {
/* We are moving up the tree, therefore this parent Op is complete */
grand_parent = parent->common.parent;
next = parent->common.next;
walk_state->op = parent;
walk_state->op_info = acpi_ps_get_opcode_info (parent->common.aml_opcode);
walk_state->opcode = parent->common.aml_opcode;
status = ascending_callback (walk_state);
/*
* If we are back to the starting point, the walk is complete.
*/
if (parent == walk_state->origin) {
/* Reached the point of origin, the walk is complete */
walk_state->prev_op = parent;
walk_state->next_op = NULL;
return_ACPI_STATUS (status);
}
/*
* If there is a sibling to this parent (it is not the starting point
* Op), then we will visit it.
*/
if (next) {
/* found sibling of parent */
walk_state->prev_op = parent;
walk_state->next_op = next;
walk_state->next_op_info = ACPI_NEXT_OP_DOWNWARD;
return_ACPI_STATUS (status);
}
/* No siblings, no errors, just move up one more level in the tree */
op = parent;
parent = grand_parent;
walk_state->prev_op = op;
}
/*
* Got all the way to the top of the tree, we must be done!
* However, the code should have terminated in the loop above
*/
walk_state->next_op = NULL;
return_ACPI_STATUS (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_delete_completed_op
*
* PARAMETERS: State - Walk state
* Op - Completed op
*
* RETURN: AE_OK
*
* DESCRIPTION: Callback function for acpi_ps_get_next_walk_op(). Used during
* acpi_ps_delete_parse tree to delete Op objects when all sub-objects
* have been visited (and deleted.)
*
******************************************************************************/
acpi_status
acpi_ps_delete_completed_op (
struct acpi_walk_state *walk_state)
{
acpi_ps_free_op (walk_state->op);
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_delete_parse_tree
*
* PARAMETERS: subtree_root - Root of tree (or subtree) to delete
*
* RETURN: None
*
* DESCRIPTION: Delete a portion of or an entire parse tree.
*
******************************************************************************/
void
acpi_ps_delete_parse_tree (
union acpi_parse_object *subtree_root)
{
struct acpi_walk_state *walk_state;
struct acpi_thread_state *thread;
acpi_status status;
ACPI_FUNCTION_TRACE_PTR ("ps_delete_parse_tree", subtree_root);
if (!subtree_root) {
return_VOID;
}
/* Create and initialize a new walk list */
thread = acpi_ut_create_thread_state ();
if (!thread) {
return_VOID;
}
walk_state = acpi_ds_create_walk_state (0, NULL, NULL, thread);
if (!walk_state) {
return_VOID;
}
walk_state->parse_flags = 0;
walk_state->descending_callback = NULL;
walk_state->ascending_callback = NULL;
walk_state->origin = subtree_root;
walk_state->next_op = subtree_root;
/* Head downward in the tree */
walk_state->next_op_info = ACPI_NEXT_OP_DOWNWARD;
/* Visit all nodes in the subtree */
while (walk_state->next_op) {
status = acpi_ps_get_next_walk_op (walk_state, walk_state->next_op,
acpi_ps_delete_completed_op);
if (ACPI_FAILURE (status)) {
break;
}
}
/* We are done with this walk */
acpi_ut_delete_generic_state (ACPI_CAST_PTR (union acpi_generic_state, thread));
acpi_ds_delete_walk_state (walk_state);
return_VOID;
}