/******************************************************************************
 *
 * Module Name: dswstate - Dispatcher parse tree walk management routines
 *
 *****************************************************************************/

/*
 * 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.
 */

#include <acpi/acpi.h>
#include <acpi/acparser.h>
#include <acpi/acdispat.h>
#include <acpi/acnamesp.h>

#define _COMPONENT          ACPI_DISPATCHER
ACPI_MODULE_NAME("dswstate")

/* Local prototypes */
#ifdef ACPI_OBSOLETE_FUNCTIONS
acpi_status
acpi_ds_result_insert(void *object,
                      u32 index, struct acpi_walk_state *walk_state);

acpi_status acpi_ds_obj_stack_delete_all(struct acpi_walk_state *walk_state);

acpi_status
acpi_ds_obj_stack_pop_object(union acpi_operand_object **object,
                             struct acpi_walk_state *walk_state);

void *acpi_ds_obj_stack_get_value(u32 index,
                                  struct acpi_walk_state *walk_state);
#endif

#ifdef ACPI_FUTURE_USAGE
/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_remove
 *
 * PARAMETERS:  Object              - Where to return the popped object
 *              Index               - Where to extract the object
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
 *              other words, this is a FIFO.
 *
 ******************************************************************************/

acpi_status
acpi_ds_result_remove(union acpi_operand_object **object,
                      u32 index, struct acpi_walk_state *walk_state)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_remove);

        state = walk_state->results;
        if (!state) {
                ACPI_ERROR((AE_INFO, "No result object pushed! State=%p",
                            walk_state));
                return (AE_NOT_EXIST);
        }

        if (index >= ACPI_OBJ_MAX_OPERAND) {
                ACPI_ERROR((AE_INFO,
                            "Index out of range: %X State=%p Num=%X",
                            index, walk_state, state->results.num_results));
        }

        /* Check for a valid result object */

        if (!state->results.obj_desc[index]) {
                ACPI_ERROR((AE_INFO,
                            "Null operand! State=%p #Ops=%X, Index=%X",
                            walk_state, state->results.num_results, index));
                return (AE_AML_NO_RETURN_VALUE);
        }

        /* Remove the object */

        state->results.num_results--;

        *object = state->results.obj_desc[index];
        state->results.obj_desc[index] = NULL;

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                          "Obj=%p [%s] Index=%X State=%p Num=%X\n",
                          *object,
                          (*object) ? acpi_ut_get_object_type_name(*object) :
                          "NULL", index, walk_state,
                          state->results.num_results));

        return (AE_OK);
}
#endif                          /*  ACPI_FUTURE_USAGE  */

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_pop
 *
 * PARAMETERS:  Object              - Where to return the popped object
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
 *              other words, this is a FIFO.
 *
 ******************************************************************************/

acpi_status
acpi_ds_result_pop(union acpi_operand_object ** object,
                   struct acpi_walk_state * walk_state)
{
        acpi_native_uint index;
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_pop);

        state = walk_state->results;
        if (!state) {
                return (AE_OK);
        }

        if (!state->results.num_results) {
                ACPI_ERROR((AE_INFO, "Result stack is empty! State=%p",
                            walk_state));
                return (AE_AML_NO_RETURN_VALUE);
        }

        /* Remove top element */

        state->results.num_results--;

        for (index = ACPI_OBJ_NUM_OPERANDS; index; index--) {

                /* Check for a valid result object */

                if (state->results.obj_desc[index - 1]) {
                        *object = state->results.obj_desc[index - 1];
                        state->results.obj_desc[index - 1] = NULL;

                        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                          "Obj=%p [%s] Index=%X State=%p Num=%X\n",
                                          *object,
                                          (*object) ?
                                          acpi_ut_get_object_type_name(*object)
                                          : "NULL", (u32) index - 1, walk_state,
                                          state->results.num_results));

                        return (AE_OK);
                }
        }

        ACPI_ERROR((AE_INFO, "No result objects! State=%p", walk_state));
        return (AE_AML_NO_RETURN_VALUE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_pop_from_bottom
 *
 * PARAMETERS:  Object              - Where to return the popped object
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop an object off the bottom of this walk's result stack.  In
 *              other words, this is a FIFO.
 *
 ******************************************************************************/

acpi_status
acpi_ds_result_pop_from_bottom(union acpi_operand_object ** object,
                               struct acpi_walk_state * walk_state)
{
        acpi_native_uint index;
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_pop_from_bottom);

        state = walk_state->results;
        if (!state) {
                ACPI_ERROR((AE_INFO,
                            "No result object pushed! State=%p", walk_state));
                return (AE_NOT_EXIST);
        }

        if (!state->results.num_results) {
                ACPI_ERROR((AE_INFO, "No result objects! State=%p",
                            walk_state));
                return (AE_AML_NO_RETURN_VALUE);
        }

        /* Remove Bottom element */

        *object = state->results.obj_desc[0];

        /* Push entire stack down one element */

        for (index = 0; index < state->results.num_results; index++) {
                state->results.obj_desc[index] =
                    state->results.obj_desc[index + 1];
        }

        state->results.num_results--;

        /* Check for a valid result object */

        if (!*object) {
                ACPI_ERROR((AE_INFO,
                            "Null operand! State=%p #Ops=%X Index=%X",
                            walk_state, state->results.num_results,
                            (u32) index));
                return (AE_AML_NO_RETURN_VALUE);
        }

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] Results=%p State=%p\n",
                          *object,
                          (*object) ? acpi_ut_get_object_type_name(*object) :
                          "NULL", state, walk_state));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_push
 *
 * PARAMETERS:  Object              - Where to return the popped object
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Push an object onto the current result stack
 *
 ******************************************************************************/

acpi_status
acpi_ds_result_push(union acpi_operand_object * object,
                    struct acpi_walk_state * walk_state)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_push);

        state = walk_state->results;
        if (!state) {
                ACPI_ERROR((AE_INFO, "No result stack frame during push"));
                return (AE_AML_INTERNAL);
        }

        if (state->results.num_results == ACPI_OBJ_NUM_OPERANDS) {
                ACPI_ERROR((AE_INFO,
                            "Result stack overflow: Obj=%p State=%p Num=%X",
                            object, walk_state, state->results.num_results));
                return (AE_STACK_OVERFLOW);
        }

        if (!object) {
                ACPI_ERROR((AE_INFO,
                            "Null Object! Obj=%p State=%p Num=%X",
                            object, walk_state, state->results.num_results));
                return (AE_BAD_PARAMETER);
        }

        state->results.obj_desc[state->results.num_results] = object;
        state->results.num_results++;

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
                          object,
                          object ?
                          acpi_ut_get_object_type_name((union
                                                        acpi_operand_object *)
                                                       object) : "NULL",
                          walk_state, state->results.num_results,
                          walk_state->current_result));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_stack_push
 *
 * PARAMETERS:  walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Push an object onto the walk_state result stack.
 *
 ******************************************************************************/

acpi_status acpi_ds_result_stack_push(struct acpi_walk_state * walk_state)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_stack_push);

        state = acpi_ut_create_generic_state();
        if (!state) {
                return (AE_NO_MEMORY);
        }

        state->common.descriptor_type = ACPI_DESC_TYPE_STATE_RESULT;
        acpi_ut_push_generic_state(&walk_state->results, state);

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Results=%p State=%p\n",
                          state, walk_state));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_stack_pop
 *
 * PARAMETERS:  walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop an object off of the walk_state result stack.
 *
 ******************************************************************************/

acpi_status acpi_ds_result_stack_pop(struct acpi_walk_state * walk_state)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_stack_pop);

        /* Check for stack underflow */

        if (walk_state->results == NULL) {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Underflow - State=%p\n",
                                  walk_state));
                return (AE_AML_NO_OPERAND);
        }

        state = acpi_ut_pop_generic_state(&walk_state->results);

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                          "Result=%p RemainingResults=%X State=%p\n",
                          state, state->results.num_results, walk_state));

        acpi_ut_delete_generic_state(state);

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_obj_stack_push
 *
 * PARAMETERS:  Object              - Object to push
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Push an object onto this walk's object/operand stack
 *
 ******************************************************************************/

acpi_status
acpi_ds_obj_stack_push(void *object, struct acpi_walk_state * walk_state)
{
        ACPI_FUNCTION_NAME(ds_obj_stack_push);

        /* Check for stack overflow */

        if (walk_state->num_operands >= ACPI_OBJ_NUM_OPERANDS) {
                ACPI_ERROR((AE_INFO,
                            "Object stack overflow! Obj=%p State=%p #Ops=%X",
                            object, walk_state, walk_state->num_operands));
                return (AE_STACK_OVERFLOW);
        }

        /* Put the object onto the stack */

        walk_state->operands[walk_state->num_operands] = object;
        walk_state->num_operands++;

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
                          object,
                          acpi_ut_get_object_type_name((union
                                                        acpi_operand_object *)
                                                       object), walk_state,
                          walk_state->num_operands));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_obj_stack_pop
 *
 * PARAMETERS:  pop_count           - Number of objects/entries to pop
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
 *              deleted by this routine.
 *
 ******************************************************************************/

acpi_status
acpi_ds_obj_stack_pop(u32 pop_count, struct acpi_walk_state * walk_state)
{
        u32 i;

        ACPI_FUNCTION_NAME(ds_obj_stack_pop);

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

                /* Check for stack underflow */

                if (walk_state->num_operands == 0) {
                        ACPI_ERROR((AE_INFO,
                                    "Object stack underflow! Count=%X State=%p #Ops=%X",
                                    pop_count, walk_state,
                                    walk_state->num_operands));
                        return (AE_STACK_UNDERFLOW);
                }

                /* Just set the stack entry to null */

                walk_state->num_operands--;
                walk_state->operands[walk_state->num_operands] = NULL;
        }

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
                          pop_count, walk_state, walk_state->num_operands));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_obj_stack_pop_and_delete
 *
 * PARAMETERS:  pop_count           - Number of objects/entries to pop
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop this walk's object stack and delete each object that is
 *              popped off.
 *
 ******************************************************************************/

acpi_status
acpi_ds_obj_stack_pop_and_delete(u32 pop_count,
                                 struct acpi_walk_state * walk_state)
{
        u32 i;
        union acpi_operand_object *obj_desc;

        ACPI_FUNCTION_NAME(ds_obj_stack_pop_and_delete);

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

                /* Check for stack underflow */

                if (walk_state->num_operands == 0) {
                        ACPI_ERROR((AE_INFO,
                                    "Object stack underflow! Count=%X State=%p #Ops=%X",
                                    pop_count, walk_state,
                                    walk_state->num_operands));
                        return (AE_STACK_UNDERFLOW);
                }

                /* Pop the stack and delete an object if present in this stack entry */

                walk_state->num_operands--;
                obj_desc = walk_state->operands[walk_state->num_operands];
                if (obj_desc) {
                        acpi_ut_remove_reference(walk_state->
                                                 operands[walk_state->
                                                          num_operands]);
                        walk_state->operands[walk_state->num_operands] = NULL;
                }
        }

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Count=%X State=%p #Ops=%X\n",
                          pop_count, walk_state, walk_state->num_operands));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_get_current_walk_state
 *
 * PARAMETERS:  Thread          - Get current active state for this Thread
 *
 * RETURN:      Pointer to the current walk state
 *
 * DESCRIPTION: Get the walk state that is at the head of the list (the "current"
 *              walk state.)
 *
 ******************************************************************************/

struct acpi_walk_state *acpi_ds_get_current_walk_state(struct acpi_thread_state
                                                       *thread)
{
        ACPI_FUNCTION_NAME(ds_get_current_walk_state);

        if (!thread) {
                return (NULL);
        }

        ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "Current WalkState %p\n",
                          thread->walk_state_list));

        return (thread->walk_state_list);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_push_walk_state
 *
 * PARAMETERS:  walk_state      - State to push
 *              Thread          - Thread state object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Place the Thread state at the head of the state list.
 *
 ******************************************************************************/

void
acpi_ds_push_walk_state(struct acpi_walk_state *walk_state,
                        struct acpi_thread_state *thread)
{
        ACPI_FUNCTION_TRACE(ds_push_walk_state);

        walk_state->next = thread->walk_state_list;
        thread->walk_state_list = walk_state;

        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_pop_walk_state
 *
 * PARAMETERS:  Thread      - Current thread state
 *
 * RETURN:      A walk_state object popped from the thread's stack
 *
 * DESCRIPTION: Remove and return the walkstate object that is at the head of
 *              the walk stack for the given walk list.  NULL indicates that
 *              the list is empty.
 *
 ******************************************************************************/

struct acpi_walk_state *acpi_ds_pop_walk_state(struct acpi_thread_state *thread)
{
        struct acpi_walk_state *walk_state;

        ACPI_FUNCTION_TRACE(ds_pop_walk_state);

        walk_state = thread->walk_state_list;

        if (walk_state) {

                /* Next walk state becomes the current walk state */

                thread->walk_state_list = walk_state->next;

                /*
                 * Don't clear the NEXT field, this serves as an indicator
                 * that there is a parent WALK STATE
                 * Do Not: walk_state->Next = NULL;
                 */
        }

        return_PTR(walk_state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_create_walk_state
 *
 * PARAMETERS:  owner_id        - ID for object creation
 *              Origin          - Starting point for this walk
 *              method_desc     - Method object
 *              Thread          - Current thread state
 *
 * RETURN:      Pointer to the new walk state.
 *
 * DESCRIPTION: Allocate and initialize a new walk state.  The current walk
 *              state is set to this new state.
 *
 ******************************************************************************/

struct acpi_walk_state *acpi_ds_create_walk_state(acpi_owner_id owner_id, union acpi_parse_object
                                                  *origin, union acpi_operand_object
                                                  *method_desc, struct acpi_thread_state
                                                  *thread)
{
        struct acpi_walk_state *walk_state;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ds_create_walk_state);

        walk_state = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_walk_state));
        if (!walk_state) {
                return_PTR(NULL);
        }

        walk_state->descriptor_type = ACPI_DESC_TYPE_WALK;
        walk_state->method_desc = method_desc;
        walk_state->owner_id = owner_id;
        walk_state->origin = origin;
        walk_state->thread = thread;

        walk_state->parser_state.start_op = origin;

        /* Init the method args/local */

#if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
        acpi_ds_method_data_init(walk_state);
#endif

        /* Create an initial result stack entry */

        status = acpi_ds_result_stack_push(walk_state);
        if (ACPI_FAILURE(status)) {
                ACPI_FREE(walk_state);
                return_PTR(NULL);
        }

        /* Put the new state at the head of the walk list */

        if (thread) {
                acpi_ds_push_walk_state(walk_state, thread);
        }

        return_PTR(walk_state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_init_aml_walk
 *
 * PARAMETERS:  walk_state      - New state to be initialized
 *              Op              - Current parse op
 *              method_node     - Control method NS node, if any
 *              aml_start       - Start of AML
 *              aml_length      - Length of AML
 *              Info            - Method info block (params, etc.)
 *              pass_number     - 1, 2, or 3
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize a walk state for a pass 1 or 2 parse tree walk
 *
 ******************************************************************************/

acpi_status
acpi_ds_init_aml_walk(struct acpi_walk_state *walk_state,
                      union acpi_parse_object *op,
                      struct acpi_namespace_node *method_node,
                      u8 * aml_start,
                      u32 aml_length,
                      struct acpi_evaluate_info *info, u8 pass_number)
{
        acpi_status status;
        struct acpi_parse_state *parser_state = &walk_state->parser_state;
        union acpi_parse_object *extra_op;

        ACPI_FUNCTION_TRACE(ds_init_aml_walk);

        walk_state->parser_state.aml =
            walk_state->parser_state.aml_start = aml_start;
        walk_state->parser_state.aml_end =
            walk_state->parser_state.pkg_end = aml_start + aml_length;

        /* The next_op of the next_walk will be the beginning of the method */

        walk_state->next_op = NULL;
        walk_state->pass_number = pass_number;

        if (info) {
                if (info->parameter_type == ACPI_PARAM_GPE) {
                        walk_state->gpe_event_info =
                            ACPI_CAST_PTR(struct acpi_gpe_event_info,
                                          info->parameters);
                } else {
                        walk_state->params = info->parameters;
                        walk_state->caller_return_desc = &info->return_object;
                }
        }

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

        if (method_node) {
                walk_state->parser_state.start_node = method_node;
                walk_state->walk_type = ACPI_WALK_METHOD;
                walk_state->method_node = method_node;
                walk_state->method_desc =
                    acpi_ns_get_attached_object(method_node);

                /* Push start scope on scope stack and make it current  */

                status =
                    acpi_ds_scope_stack_push(method_node, ACPI_TYPE_METHOD,
                                             walk_state);
                if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                }

                /* Init the method arguments */

                status = acpi_ds_method_data_init_args(walk_state->params,
                                                       ACPI_METHOD_NUM_ARGS,
                                                       walk_state);
                if (ACPI_FAILURE(status)) {
                        return_ACPI_STATUS(status);
                }
        } else {
                /*
                 * Setup the current scope.
                 * Find a Named Op that has a namespace node associated with it.
                 * search upwards from this Op.  Current scope is the first
                 * Op with a namespace node.
                 */
                extra_op = parser_state->start_op;
                while (extra_op && !extra_op->common.node) {
                        extra_op = extra_op->common.parent;
                }

                if (!extra_op) {
                        parser_state->start_node = NULL;
                } else {
                        parser_state->start_node = extra_op->common.node;
                }

                if (parser_state->start_node) {

                        /* Push start scope on scope stack and make it current  */

                        status =
                            acpi_ds_scope_stack_push(parser_state->start_node,
                                                     parser_state->start_node->
                                                     type, walk_state);
                        if (ACPI_FAILURE(status)) {
                                return_ACPI_STATUS(status);
                        }
                }
        }

        status = acpi_ds_init_callbacks(walk_state, pass_number);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_delete_walk_state
 *
 * PARAMETERS:  walk_state      - State to delete
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Delete a walk state including all internal data structures
 *
 ******************************************************************************/

void acpi_ds_delete_walk_state(struct acpi_walk_state *walk_state)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_TRACE_PTR(ds_delete_walk_state, walk_state);

        if (!walk_state) {
                return;
        }

        if (walk_state->descriptor_type != ACPI_DESC_TYPE_WALK) {
                ACPI_ERROR((AE_INFO, "%p is not a valid walk state",
                            walk_state));
                return;
        }

        /* There should not be any open scopes */

        if (walk_state->parser_state.scope) {
                ACPI_ERROR((AE_INFO, "%p walk still has a scope list",
                            walk_state));
                acpi_ps_cleanup_scope(&walk_state->parser_state);
        }

        /* Always must free any linked control states */

        while (walk_state->control_state) {
                state = walk_state->control_state;
                walk_state->control_state = state->common.next;

                acpi_ut_delete_generic_state(state);
        }

        /* Always must free any linked parse states */

        while (walk_state->scope_info) {
                state = walk_state->scope_info;
                walk_state->scope_info = state->common.next;

                acpi_ut_delete_generic_state(state);
        }

        /* Always must free any stacked result states */

        while (walk_state->results) {
                state = walk_state->results;
                walk_state->results = state->common.next;

                acpi_ut_delete_generic_state(state);
        }

        ACPI_FREE(walk_state);
        return_VOID;
}

#ifdef ACPI_OBSOLETE_FUNCTIONS
/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_result_insert
 *
 * PARAMETERS:  Object              - Object to push
 *              Index               - Where to insert the object
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Insert an object onto this walk's result stack
 *
 ******************************************************************************/

acpi_status
acpi_ds_result_insert(void *object,
                      u32 index, struct acpi_walk_state *walk_state)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_NAME(ds_result_insert);

        state = walk_state->results;
        if (!state) {
                ACPI_ERROR((AE_INFO, "No result object pushed! State=%p",
                            walk_state));
                return (AE_NOT_EXIST);
        }

        if (index >= ACPI_OBJ_NUM_OPERANDS) {
                ACPI_ERROR((AE_INFO,
                            "Index out of range: %X Obj=%p State=%p Num=%X",
                            index, object, walk_state,
                            state->results.num_results));
                return (AE_BAD_PARAMETER);
        }

        if (!object) {
                ACPI_ERROR((AE_INFO,
                            "Null Object! Index=%X Obj=%p State=%p Num=%X",
                            index, object, walk_state,
                            state->results.num_results));
                return (AE_BAD_PARAMETER);
        }

        state->results.obj_desc[index] = object;
        state->results.num_results++;

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                          "Obj=%p [%s] State=%p Num=%X Cur=%X\n",
                          object,
                          object ?
                          acpi_ut_get_object_type_name((union
                                                        acpi_operand_object *)
                                                       object) : "NULL",
                          walk_state, state->results.num_results,
                          walk_state->current_result));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_obj_stack_delete_all
 *
 * PARAMETERS:  walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Clear the object stack by deleting all objects that are on it.
 *              Should be used with great care, if at all!
 *
 ******************************************************************************/

acpi_status acpi_ds_obj_stack_delete_all(struct acpi_walk_state * walk_state)
{
        u32 i;

        ACPI_FUNCTION_TRACE_PTR(ds_obj_stack_delete_all, walk_state);

        /* The stack size is configurable, but fixed */

        for (i = 0; i < ACPI_OBJ_NUM_OPERANDS; i++) {
                if (walk_state->operands[i]) {
                        acpi_ut_remove_reference(walk_state->operands[i]);
                        walk_state->operands[i] = NULL;
                }
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_obj_stack_pop_object
 *
 * PARAMETERS:  Object              - Where to return the popped object
 *              walk_state          - Current Walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Pop this walk's object stack.  Objects on the stack are NOT
 *              deleted by this routine.
 *
 ******************************************************************************/

acpi_status
acpi_ds_obj_stack_pop_object(union acpi_operand_object **object,
                             struct acpi_walk_state *walk_state)
{
        ACPI_FUNCTION_NAME(ds_obj_stack_pop_object);

        /* Check for stack underflow */

        if (walk_state->num_operands == 0) {
                ACPI_ERROR((AE_INFO,
                            "Missing operand/stack empty! State=%p #Ops=%X",
                            walk_state, walk_state->num_operands));
                *object = NULL;
                return (AE_AML_NO_OPERAND);
        }

        /* Pop the stack */

        walk_state->num_operands--;

        /* Check for a valid operand */

        if (!walk_state->operands[walk_state->num_operands]) {
                ACPI_ERROR((AE_INFO,
                            "Null operand! State=%p #Ops=%X",
                            walk_state, walk_state->num_operands));
                *object = NULL;
                return (AE_AML_NO_OPERAND);
        }

        /* Get operand and set stack entry to null */

        *object = walk_state->operands[walk_state->num_operands];
        walk_state->operands[walk_state->num_operands] = NULL;

        ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Obj=%p [%s] State=%p #Ops=%X\n",
                          *object, acpi_ut_get_object_type_name(*object),
                          walk_state, walk_state->num_operands));

        return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_obj_stack_get_value
 *
 * PARAMETERS:  Index               - Stack index whose value is desired.  Based
 *                                    on the top of the stack (index=0 == top)
 *              walk_state          - Current Walk state
 *
 * RETURN:      Pointer to the requested operand
 *
 * DESCRIPTION: Retrieve an object from this walk's operand stack.  Index must
 *              be within the range of the current stack pointer.
 *
 ******************************************************************************/

void *acpi_ds_obj_stack_get_value(u32 index, struct acpi_walk_state *walk_state)
{

        ACPI_FUNCTION_TRACE_PTR(ds_obj_stack_get_value, walk_state);

        /* Can't do it if the stack is empty */

        if (walk_state->num_operands == 0) {
                return_PTR(NULL);
        }

        /* or if the index is past the top of the stack */

        if (index > (walk_state->num_operands - (u32) 1)) {
                return_PTR(NULL);
        }

        return_PTR(walk_state->
                   operands[(acpi_native_uint) (walk_state->num_operands - 1) -
                            index]);
}
#endif