Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 805 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/dsfield.c b/drivers/acpi/acpica/dsfield.c
new file mode 100644
index 000000000..bcc6a7acc
--- /dev/null
+++ b/drivers/acpi/acpica/dsfield.c
@@ -0,0 +1,805 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: dsfield - Dispatcher field routines
+ *
+ * Copyright (C) 2000 - 2018, 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);
+	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);
+}