// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: dsfield - Dispatcher field routines
 *
 * Copyright (C) 2000 - 2019, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "amlcode.h"
#include "acdispat.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "acparser.h"

#ifdef ACPI_EXEC_APP
#include "aecommon.h"
#endif

#define _COMPONENT          ACPI_DISPATCHER
ACPI_MODULE_NAME("dsfield")

/* Local prototypes */
#ifdef ACPI_ASL_COMPILER
#include "acdisasm.h"
static acpi_status
acpi_ds_create_external_region(acpi_status lookup_status,
                               union acpi_parse_object *op,
                               char *path,
                               struct acpi_walk_state *walk_state,
                               struct acpi_namespace_node **node);
#endif

static acpi_status
acpi_ds_get_field_names(struct acpi_create_field_info *info,
                        struct acpi_walk_state *walk_state,
                        union acpi_parse_object *arg);

#ifdef ACPI_ASL_COMPILER
/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_create_external_region (iASL Disassembler only)
 *
 * PARAMETERS:  lookup_status   - Status from ns_lookup operation
 *              op              - Op containing the Field definition and args
 *              path            - Pathname of the region
 *  `           walk_state      - Current method state
 *              node            - Where the new region node is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Add region to the external list if NOT_FOUND. Create a new
 *              region node/object.
 *
 ******************************************************************************/

static acpi_status
acpi_ds_create_external_region(acpi_status lookup_status,
                               union acpi_parse_object *op,
                               char *path,
                               struct acpi_walk_state *walk_state,
                               struct acpi_namespace_node **node)
{
        acpi_status status;
        union acpi_operand_object *obj_desc;

        if (lookup_status != AE_NOT_FOUND) {
                return (lookup_status);
        }

        /*
         * Table disassembly:
         * operation_region not found. Generate an External for it, and
         * insert the name into the namespace.
         */
        acpi_dm_add_op_to_external_list(op, path, ACPI_TYPE_REGION, 0, 0);

        status = acpi_ns_lookup(walk_state->scope_info, path, ACPI_TYPE_REGION,
                                ACPI_IMODE_LOAD_PASS1, ACPI_NS_SEARCH_PARENT,
                                walk_state, node);
        if (ACPI_FAILURE(status)) {
                return (status);
        }

        /* Must create and install a region object for the new node */

        obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_REGION);
        if (!obj_desc) {
                return (AE_NO_MEMORY);
        }

        obj_desc->region.node = *node;
        status = acpi_ns_attach_object(*node, obj_desc, ACPI_TYPE_REGION);
        return (status);
}
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_create_buffer_field
 *
 * PARAMETERS:  op                  - Current parse op (create_XXField)
 *              walk_state          - Current state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute the create_field operators:
 *              create_bit_field_op,
 *              create_byte_field_op,
 *              create_word_field_op,
 *              create_dword_field_op,
 *              create_qword_field_op,
 *              create_field_op     (all of which define a field in a buffer)
 *
 ******************************************************************************/

acpi_status
acpi_ds_create_buffer_field(union acpi_parse_object *op,
                            struct acpi_walk_state *walk_state)
{
        union acpi_parse_object *arg;
        struct acpi_namespace_node *node;
        acpi_status status;
        union acpi_operand_object *obj_desc;
        union acpi_operand_object *second_desc = NULL;
        u32 flags;

        ACPI_FUNCTION_TRACE(ds_create_buffer_field);

        /*
         * Get the name_string argument (name of the new buffer_field)
         */
        if (op->common.aml_opcode == AML_CREATE_FIELD_OP) {

                /* For create_field, name is the 4th argument */

                arg = acpi_ps_get_arg(op, 3);
        } else {
                /* For all other create_XXXField operators, name is the 3rd argument */

                arg = acpi_ps_get_arg(op, 2);
        }

        if (!arg) {
                return_ACPI_STATUS(AE_AML_NO_OPERAND);
        }

        if (walk_state->deferred_node) {
                node = walk_state->deferred_node;
                status = AE_OK;
        } else {
                /* Execute flag should always be set when this function is entered */

                if (!(walk_state->parse_flags & ACPI_PARSE_EXECUTE)) {
                        ACPI_ERROR((AE_INFO, "Parse execute mode is not set"));
                        return_ACPI_STATUS(AE_AML_INTERNAL);
                }

                /* Creating new namespace node, should not already exist */

                flags = ACPI_NS_NO_UPSEARCH | ACPI_NS_DONT_OPEN_SCOPE |
                    ACPI_NS_ERROR_IF_FOUND;

                /*
                 * Mark node temporary if we are executing a normal control
                 * method. (Don't mark if this is a module-level code method)
                 */
                if (walk_state->method_node &&
                    !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
                        flags |= ACPI_NS_TEMPORARY;
                }

                /* Enter the name_string into the namespace */

                status = acpi_ns_lookup(walk_state->scope_info,
                                        arg->common.value.string, ACPI_TYPE_ANY,
                                        ACPI_IMODE_LOAD_PASS1, flags,
                                        walk_state, &node);
                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                             arg->common.value.string, status);
                        return_ACPI_STATUS(status);
                }
        }

        /*
         * We could put the returned object (Node) on the object stack for later,
         * but for now, we will put it in the "op" object that the parser uses,
         * so we can get it again at the end of this scope.
         */
        op->common.node = node;

        /*
         * If there is no object attached to the node, this node was just created
         * and we need to create the field object. Otherwise, this was a lookup
         * of an existing node and we don't want to create the field object again.
         */
        obj_desc = acpi_ns_get_attached_object(node);
        if (obj_desc) {
                return_ACPI_STATUS(AE_OK);
        }

        /*
         * The Field definition is not fully parsed at this time.
         * (We must save the address of the AML for the buffer and index operands)
         */

        /* Create the buffer field object */

        obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_BUFFER_FIELD);
        if (!obj_desc) {
                status = AE_NO_MEMORY;
                goto cleanup;
        }

        /*
         * Remember location in AML stream of the field unit opcode and operands
         * -- since the buffer and index operands must be evaluated.
         */
        second_desc = obj_desc->common.next_object;
        second_desc->extra.aml_start = op->named.data;
        second_desc->extra.aml_length = op->named.length;
        obj_desc->buffer_field.node = node;

        /* Attach constructed field descriptors to parent node */

        status = acpi_ns_attach_object(node, obj_desc, ACPI_TYPE_BUFFER_FIELD);
        if (ACPI_FAILURE(status)) {
                goto cleanup;
        }

cleanup:

        /* Remove local reference to the object */

        acpi_ut_remove_reference(obj_desc);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_get_field_names
 *
 * PARAMETERS:  info            - create_field info structure
 *  `           walk_state      - Current method state
 *              arg             - First parser arg for the field name list
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Process all named fields in a field declaration. Names are
 *              entered into the namespace.
 *
 ******************************************************************************/

static acpi_status
acpi_ds_get_field_names(struct acpi_create_field_info *info,
                        struct acpi_walk_state *walk_state,
                        union acpi_parse_object *arg)
{
        acpi_status status;
        u64 position;
        union acpi_parse_object *child;

#ifdef ACPI_EXEC_APP
        u64 value = 0;
        union acpi_operand_object *result_desc;
        union acpi_operand_object *obj_desc;
        char *name_path;
#endif

        ACPI_FUNCTION_TRACE_PTR(ds_get_field_names, info);

        /* First field starts at bit zero */

        info->field_bit_position = 0;

        /* Process all elements in the field list (of parse nodes) */

        while (arg) {
                /*
                 * Four types of field elements are handled:
                 * 1) name - Enters a new named field into the namespace
                 * 2) offset - specifies a bit offset
                 * 3) access_as - changes the access mode/attributes
                 * 4) connection - Associate a resource template with the field
                 */
                switch (arg->common.aml_opcode) {
                case AML_INT_RESERVEDFIELD_OP:

                        position = (u64)info->field_bit_position +
                            (u64)arg->common.value.size;

                        if (position > ACPI_UINT32_MAX) {
                                ACPI_ERROR((AE_INFO,
                                            "Bit offset within field too large (> 0xFFFFFFFF)"));
                                return_ACPI_STATUS(AE_SUPPORT);
                        }

                        info->field_bit_position = (u32) position;
                        break;

                case AML_INT_ACCESSFIELD_OP:
                case AML_INT_EXTACCESSFIELD_OP:
                        /*
                         * Get new access_type, access_attribute, and access_length fields
                         * -- to be used for all field units that follow, until the
                         * end-of-field or another access_as keyword is encountered.
                         * NOTE. These three bytes are encoded in the integer value
                         * of the parseop for convenience.
                         *
                         * In field_flags, preserve the flag bits other than the
                         * ACCESS_TYPE bits.
                         */

                        /* access_type (byte_acc, word_acc, etc.) */

                        info->field_flags = (u8)
                            ((info->
                              field_flags & ~(AML_FIELD_ACCESS_TYPE_MASK)) |
                             ((u8)((u32)(arg->common.value.integer & 0x07))));

                        /* access_attribute (attrib_quick, attrib_byte, etc.) */

                        info->attribute = (u8)
                            ((arg->common.value.integer >> 8) & 0xFF);

                        /* access_length (for serial/buffer protocols) */

                        info->access_length = (u8)
                            ((arg->common.value.integer >> 16) & 0xFF);
                        break;

                case AML_INT_CONNECTION_OP:
                        /*
                         * Clear any previous connection. New connection is used for all
                         * fields that follow, similar to access_as
                         */
                        info->resource_buffer = NULL;
                        info->connection_node = NULL;
                        info->pin_number_index = 0;

                        /*
                         * A Connection() is either an actual resource descriptor (buffer)
                         * or a named reference to a resource template
                         */
                        child = arg->common.value.arg;
                        if (child->common.aml_opcode == AML_INT_BYTELIST_OP) {
                                info->resource_buffer = child->named.data;
                                info->resource_length =
                                    (u16)child->named.value.integer;
                        } else {
                                /* Lookup the Connection() namepath, it should already exist */

                                status = acpi_ns_lookup(walk_state->scope_info,
                                                        child->common.value.
                                                        name, ACPI_TYPE_ANY,
                                                        ACPI_IMODE_EXECUTE,
                                                        ACPI_NS_DONT_OPEN_SCOPE,
                                                        walk_state,
                                                        &info->connection_node);
                                if (ACPI_FAILURE(status)) {
                                        ACPI_ERROR_NAMESPACE(walk_state->
                                                             scope_info,
                                                             child->common.
                                                             value.name,
                                                             status);
                                        return_ACPI_STATUS(status);
                                }
                        }
                        break;

                case AML_INT_NAMEDFIELD_OP:

                        /* Lookup the name, it should already exist */

                        status = acpi_ns_lookup(walk_state->scope_info,
                                                (char *)&arg->named.name,
                                                info->field_type,
                                                ACPI_IMODE_EXECUTE,
                                                ACPI_NS_DONT_OPEN_SCOPE,
                                                walk_state, &info->field_node);
                        if (ACPI_FAILURE(status)) {
                                ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                                     (char *)&arg->named.name,
                                                     status);
                                return_ACPI_STATUS(status);
                        } else {
                                arg->common.node = info->field_node;
                                info->field_bit_length = arg->common.value.size;

                                /*
                                 * If there is no object attached to the node, this node was
                                 * just created and we need to create the field object.
                                 * Otherwise, this was a lookup of an existing node and we
                                 * don't want to create the field object again.
                                 */
                                if (!acpi_ns_get_attached_object
                                    (info->field_node)) {
                                        status = acpi_ex_prep_field_value(info);
                                        if (ACPI_FAILURE(status)) {
                                                return_ACPI_STATUS(status);
                                        }
#ifdef ACPI_EXEC_APP
                                        name_path =
                                            acpi_ns_get_external_pathname(info->
                                                                          field_node);
                                        obj_desc =
                                            acpi_ut_create_integer_object
                                            (value);
                                        if (ACPI_SUCCESS
                                            (ae_lookup_init_file_entry
                                             (name_path, &value))) {
                                                acpi_ex_write_data_to_field
                                                    (obj_desc,
                                                     acpi_ns_get_attached_object
                                                     (info->field_node),
                                                     &result_desc);
                                        }
                                        acpi_ut_remove_reference(obj_desc);
                                        ACPI_FREE(name_path);
#endif
                                }
                        }

                        /* Keep track of bit position for the next field */

                        position = (u64)info->field_bit_position +
                            (u64)arg->common.value.size;

                        if (position > ACPI_UINT32_MAX) {
                                ACPI_ERROR((AE_INFO,
                                            "Field [%4.4s] bit offset too large (> 0xFFFFFFFF)",
                                            ACPI_CAST_PTR(char,
                                                          &info->field_node->
                                                          name)));
                                return_ACPI_STATUS(AE_SUPPORT);
                        }

                        info->field_bit_position += info->field_bit_length;
                        info->pin_number_index++;       /* Index relative to previous Connection() */
                        break;

                default:

                        ACPI_ERROR((AE_INFO,
                                    "Invalid opcode in field list: 0x%X",
                                    arg->common.aml_opcode));
                        return_ACPI_STATUS(AE_AML_BAD_OPCODE);
                }

                arg = arg->common.next;
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_create_field
 *
 * PARAMETERS:  op              - Op containing the Field definition and args
 *              region_node     - Object for the containing Operation Region
 *  `           walk_state      - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create a new field in the specified operation region
 *
 ******************************************************************************/

acpi_status
acpi_ds_create_field(union acpi_parse_object *op,
                     struct acpi_namespace_node *region_node,
                     struct acpi_walk_state *walk_state)
{
        acpi_status status;
        union acpi_parse_object *arg;
        struct acpi_create_field_info info;

        ACPI_FUNCTION_TRACE_PTR(ds_create_field, op);

        /* First arg is the name of the parent op_region (must already exist) */

        arg = op->common.value.arg;

        if (!region_node) {
                status =
                    acpi_ns_lookup(walk_state->scope_info,
                                   arg->common.value.name, ACPI_TYPE_REGION,
                                   ACPI_IMODE_EXECUTE, ACPI_NS_SEARCH_PARENT,
                                   walk_state, &region_node);
#ifdef ACPI_ASL_COMPILER
                status = acpi_ds_create_external_region(status, arg,
                                                        arg->common.value.name,
                                                        walk_state,
                                                        &region_node);
#endif
                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                             arg->common.value.name, status);
                        return_ACPI_STATUS(status);
                }
        }

        memset(&info, 0, sizeof(struct acpi_create_field_info));

        /* Second arg is the field flags */

        arg = arg->common.next;
        info.field_flags = (u8) arg->common.value.integer;
        info.attribute = 0;

        /* Each remaining arg is a Named Field */

        info.field_type = ACPI_TYPE_LOCAL_REGION_FIELD;
        info.region_node = region_node;

        status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
        if (info.region_node->object->region.space_id ==
            ACPI_ADR_SPACE_PLATFORM_COMM
            && !(region_node->object->field.internal_pcc_buffer =
                 ACPI_ALLOCATE_ZEROED(info.region_node->object->region.
                                      length))) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_init_field_objects
 *
 * PARAMETERS:  op              - Op containing the Field definition and args
 *  `           walk_state      - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: For each "Field Unit" name in the argument list that is
 *              part of the field declaration, enter the name into the
 *              namespace.
 *
 ******************************************************************************/

acpi_status
acpi_ds_init_field_objects(union acpi_parse_object *op,
                           struct acpi_walk_state *walk_state)
{
        acpi_status status;
        union acpi_parse_object *arg = NULL;
        struct acpi_namespace_node *node;
        u8 type = 0;
        u32 flags;

        ACPI_FUNCTION_TRACE_PTR(ds_init_field_objects, op);

        /* Execute flag should always be set when this function is entered */

        if (!(walk_state->parse_flags & ACPI_PARSE_EXECUTE)) {
                if (walk_state->parse_flags & ACPI_PARSE_DEFERRED_OP) {

                        /* bank_field Op is deferred, just return OK */

                        return_ACPI_STATUS(AE_OK);
                }

                ACPI_ERROR((AE_INFO, "Parse deferred mode is not set"));
                return_ACPI_STATUS(AE_AML_INTERNAL);
        }

        /*
         * Get the field_list argument for this opcode. This is the start of the
         * list of field elements.
         */
        switch (walk_state->opcode) {
        case AML_FIELD_OP:

                arg = acpi_ps_get_arg(op, 2);
                type = ACPI_TYPE_LOCAL_REGION_FIELD;
                break;

        case AML_BANK_FIELD_OP:

                arg = acpi_ps_get_arg(op, 4);
                type = ACPI_TYPE_LOCAL_BANK_FIELD;
                break;

        case AML_INDEX_FIELD_OP:

                arg = acpi_ps_get_arg(op, 3);
                type = ACPI_TYPE_LOCAL_INDEX_FIELD;
                break;

        default:

                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /* Creating new namespace node(s), should not already exist */

        flags = ACPI_NS_NO_UPSEARCH | ACPI_NS_DONT_OPEN_SCOPE |
            ACPI_NS_ERROR_IF_FOUND;

        /*
         * Mark node(s) temporary if we are executing a normal control
         * method. (Don't mark if this is a module-level code method)
         */
        if (walk_state->method_node &&
            !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
                flags |= ACPI_NS_TEMPORARY;
        }
#ifdef ACPI_EXEC_APP
        flags |= ACPI_NS_OVERRIDE_IF_FOUND;
#endif
        /*
         * Walk the list of entries in the field_list
         * Note: field_list can be of zero length. In this case, Arg will be NULL.
         */
        while (arg) {
                /*
                 * Ignore OFFSET/ACCESSAS/CONNECTION terms here; we are only interested
                 * in the field names in order to enter them into the namespace.
                 */
                if (arg->common.aml_opcode == AML_INT_NAMEDFIELD_OP) {
                        status = acpi_ns_lookup(walk_state->scope_info,
                                                (char *)&arg->named.name, type,
                                                ACPI_IMODE_LOAD_PASS1, flags,
                                                walk_state, &node);
                        if (ACPI_FAILURE(status)) {
                                ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                                     (char *)&arg->named.name,
                                                     status);
                                if (status != AE_ALREADY_EXISTS) {
                                        return_ACPI_STATUS(status);
                                }

                                /* Name already exists, just ignore this error */

                                status = AE_OK;
                        }

                        arg->common.node = node;
                }

                /* Get the next field element in the list */

                arg = arg->common.next;
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_create_bank_field
 *
 * PARAMETERS:  op              - Op containing the Field definition and args
 *              region_node     - Object for the containing Operation Region
 *              walk_state      - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create a new bank field in the specified operation region
 *
 ******************************************************************************/

acpi_status
acpi_ds_create_bank_field(union acpi_parse_object *op,
                          struct acpi_namespace_node *region_node,
                          struct acpi_walk_state *walk_state)
{
        acpi_status status;
        union acpi_parse_object *arg;
        struct acpi_create_field_info info;

        ACPI_FUNCTION_TRACE_PTR(ds_create_bank_field, op);

        /* First arg is the name of the parent op_region (must already exist) */

        arg = op->common.value.arg;
        if (!region_node) {
                status =
                    acpi_ns_lookup(walk_state->scope_info,
                                   arg->common.value.name, ACPI_TYPE_REGION,
                                   ACPI_IMODE_EXECUTE, ACPI_NS_SEARCH_PARENT,
                                   walk_state, &region_node);
#ifdef ACPI_ASL_COMPILER
                status = acpi_ds_create_external_region(status, arg,
                                                        arg->common.value.name,
                                                        walk_state,
                                                        &region_node);
#endif
                if (ACPI_FAILURE(status)) {
                        ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                             arg->common.value.name, status);
                        return_ACPI_STATUS(status);
                }
        }

        /* Second arg is the Bank Register (Field) (must already exist) */

        arg = arg->common.next;
        status =
            acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
                           ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
                           ACPI_NS_SEARCH_PARENT, walk_state,
                           &info.register_node);
        if (ACPI_FAILURE(status)) {
                ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                     arg->common.value.string, status);
                return_ACPI_STATUS(status);
        }

        /*
         * Third arg is the bank_value
         * This arg is a term_arg, not a constant
         * It will be evaluated later, by acpi_ds_eval_bank_field_operands
         */
        arg = arg->common.next;

        /* Fourth arg is the field flags */

        arg = arg->common.next;
        info.field_flags = (u8) arg->common.value.integer;

        /* Each remaining arg is a Named Field */

        info.field_type = ACPI_TYPE_LOCAL_BANK_FIELD;
        info.region_node = region_node;

        /*
         * Use Info.data_register_node to store bank_field Op
         * It's safe because data_register_node will never be used when create
         * bank field \we store aml_start and aml_length in the bank_field Op for
         * late evaluation. Used in acpi_ex_prep_field_value(Info)
         *
         * TBD: Or, should we add a field in struct acpi_create_field_info, like
         * "void *ParentOp"?
         */
        info.data_register_node = (struct acpi_namespace_node *)op;

        status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_create_index_field
 *
 * PARAMETERS:  op              - Op containing the Field definition and args
 *              region_node     - Object for the containing Operation Region
 *  `           walk_state      - Current method state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create a new index field in the specified operation region
 *
 ******************************************************************************/

acpi_status
acpi_ds_create_index_field(union acpi_parse_object *op,
                           struct acpi_namespace_node *region_node,
                           struct acpi_walk_state *walk_state)
{
        acpi_status status;
        union acpi_parse_object *arg;
        struct acpi_create_field_info info;

        ACPI_FUNCTION_TRACE_PTR(ds_create_index_field, op);

        /* First arg is the name of the Index register (must already exist) */

        arg = op->common.value.arg;
        status =
            acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
                           ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
                           ACPI_NS_SEARCH_PARENT, walk_state,
                           &info.register_node);
        if (ACPI_FAILURE(status)) {
                ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                     arg->common.value.string, status);
                return_ACPI_STATUS(status);
        }

        /* Second arg is the data register (must already exist) */

        arg = arg->common.next;
        status =
            acpi_ns_lookup(walk_state->scope_info, arg->common.value.string,
                           ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
                           ACPI_NS_SEARCH_PARENT, walk_state,
                           &info.data_register_node);
        if (ACPI_FAILURE(status)) {
                ACPI_ERROR_NAMESPACE(walk_state->scope_info,
                                     arg->common.value.string, status);
                return_ACPI_STATUS(status);
        }

        /* Next arg is the field flags */

        arg = arg->common.next;
        info.field_flags = (u8) arg->common.value.integer;

        /* Each remaining arg is a Named Field */

        info.field_type = ACPI_TYPE_LOCAL_INDEX_FIELD;
        info.region_node = region_node;

        status = acpi_ds_get_field_names(&info, walk_state, arg->common.next);
        return_ACPI_STATUS(status);
}