// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: psscope - Parser scope stack management routines
 *
 * Copyright (C) 2000 - 2020, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acparser.h"

#define _COMPONENT          ACPI_PARSER
ACPI_MODULE_NAME("psscope")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_parent_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Pointer to an Op object
 *
 * DESCRIPTION: Get parent of current op being parsed
 *
 ******************************************************************************/
union acpi_parse_object *acpi_ps_get_parent_scope(struct acpi_parse_state
                                                  *parser_state)
{

        return (parser_state->scope->parse_scope.op);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_has_completed_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Boolean, TRUE = scope completed.
 *
 * DESCRIPTION: Is parsing of current argument complete?  Determined by
 *              1) AML pointer is at or beyond the end of the scope
 *              2) The scope argument count has reached zero.
 *
 ******************************************************************************/

u8 acpi_ps_has_completed_scope(struct acpi_parse_state * parser_state)
{

        return ((u8)
                ((parser_state->aml >= parser_state->scope->parse_scope.arg_end
                  || !parser_state->scope->parse_scope.arg_count)));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_init_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              root                - the Root Node of this new scope
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate and init a new scope object
 *
 ******************************************************************************/

acpi_status
acpi_ps_init_scope(struct acpi_parse_state * parser_state,
                   union acpi_parse_object * root_op)
{
        union acpi_generic_state *scope;

        ACPI_FUNCTION_TRACE_PTR(ps_init_scope, root_op);

        scope = acpi_ut_create_generic_state();
        if (!scope) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        scope->common.descriptor_type = ACPI_DESC_TYPE_STATE_RPSCOPE;
        scope->parse_scope.op = root_op;
        scope->parse_scope.arg_count = ACPI_VAR_ARGS;
        scope->parse_scope.arg_end = parser_state->aml_end;
        scope->parse_scope.pkg_end = parser_state->aml_end;

        parser_state->scope = scope;
        parser_state->start_op = root_op;

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_push_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              op                  - Current op to be pushed
 *              remaining_args      - List of args remaining
 *              arg_count           - Fixed or variable number of args
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Push current op to begin parsing its argument
 *
 ******************************************************************************/

acpi_status
acpi_ps_push_scope(struct acpi_parse_state *parser_state,
                   union acpi_parse_object *op,
                   u32 remaining_args, u32 arg_count)
{
        union acpi_generic_state *scope;

        ACPI_FUNCTION_TRACE_PTR(ps_push_scope, op);

        scope = acpi_ut_create_generic_state();
        if (!scope) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        scope->common.descriptor_type = ACPI_DESC_TYPE_STATE_PSCOPE;
        scope->parse_scope.op = op;
        scope->parse_scope.arg_list = remaining_args;
        scope->parse_scope.arg_count = arg_count;
        scope->parse_scope.pkg_end = parser_state->pkg_end;

        /* Push onto scope stack */

        acpi_ut_push_generic_state(&parser_state->scope, scope);

        if (arg_count == ACPI_VAR_ARGS) {

                /* Multiple arguments */

                scope->parse_scope.arg_end = parser_state->pkg_end;
        } else {
                /* Single argument */

                scope->parse_scope.arg_end = ACPI_TO_POINTER(ACPI_MAX_PTR);
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_pop_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              op                  - Where the popped op is returned
 *              arg_list            - Where the popped "next argument" is
 *                                    returned
 *              arg_count           - Count of objects in arg_list
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Return to parsing a previous op
 *
 ******************************************************************************/

void
acpi_ps_pop_scope(struct acpi_parse_state *parser_state,
                  union acpi_parse_object **op, u32 * arg_list, u32 * arg_count)
{
        union acpi_generic_state *scope = parser_state->scope;

        ACPI_FUNCTION_TRACE(ps_pop_scope);

        /* Only pop the scope if there is in fact a next scope */

        if (scope->common.next) {
                scope = acpi_ut_pop_generic_state(&parser_state->scope);

                /* Return to parsing previous op */

                *op = scope->parse_scope.op;
                *arg_list = scope->parse_scope.arg_list;
                *arg_count = scope->parse_scope.arg_count;
                parser_state->pkg_end = scope->parse_scope.pkg_end;

                /* All done with this scope state structure */

                acpi_ut_delete_generic_state(scope);
        } else {
                /* Empty parse stack, prepare to fetch next opcode */

                *op = NULL;
                *arg_list = 0;
                *arg_count = 0;
        }

        ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
                          "Popped Op %p Args %X\n", *op, *arg_count));
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_cleanup_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Destroy available list, remaining stack levels, and return
 *              root scope
 *
 ******************************************************************************/

void acpi_ps_cleanup_scope(struct acpi_parse_state *parser_state)
{
        union acpi_generic_state *scope;

        ACPI_FUNCTION_TRACE_PTR(ps_cleanup_scope, parser_state);

        if (!parser_state) {
                return_VOID;
        }

        /* Delete anything on the scope stack */

        while (parser_state->scope) {
                scope = acpi_ut_pop_generic_state(&parser_state->scope);
                acpi_ut_delete_generic_state(scope);
        }

        return_VOID;
}