nsutils.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

			names_count = 2;
			break;


		/* Null_name */

		case 0:
			names_index = 0;
			names_count = 0;
			break;


		/* one 4-byte name */

		default:
			names_index = prefix_length;
			names_count = 1;
			break;
		}
	}

	/*
	 * Calculate the length of Converted_name, which equals the length
	 * of the prefix, length of all object names, length of any required
	 * punctuation ('.') between object names, plus the NULL terminator.
	 */
	*converted_name_length = prefix_length + (4 * names_count) +
			   ((names_count > 0) ? (names_count - 1) : 0) + 1;

	/*
	 * Check to see if we're still in bounds.  If not, there's a problem
	 * with Internal_name (invalid format).
	 */
	if (*converted_name_length > internal_name_length) {
		REPORT_ERROR (("Ns_externalize_name: Invalid internal name\n"));
		return_ACPI_STATUS (AE_BAD_PATHNAME);
	}

	/*
	 * Build Converted_name...
	 */

	(*converted_name) = ACPI_MEM_CALLOCATE (*converted_name_length);
	if (!(*converted_name)) {
		return_ACPI_STATUS (AE_NO_MEMORY);
	}

	j = 0;

	for (i = 0; i < prefix_length; i++) {
		(*converted_name)[j++] = internal_name[i];
	}

	if (names_count > 0) {
		for (i = 0; i < names_count; i++) {
			if (i > 0) {
				(*converted_name)[j++] = '.';
			}

			(*converted_name)[j++] = internal_name[names_index++];
			(*converted_name)[j++] = internal_name[names_index++];
			(*converted_name)[j++] = internal_name[names_index++];
			(*converted_name)[j++] = internal_name[names_index++];
		}
	}

	return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_map_handle_to_node
 *
 * PARAMETERS:  Handle          - Handle to be converted to an Node
 *
 * RETURN:      A Name table entry pointer
 *
 * DESCRIPTION: Convert a namespace handle to a real Node
 *
 ******************************************************************************/

acpi_namespace_node *
acpi_ns_map_handle_to_node (
	acpi_handle             handle)
{

	FUNCTION_ENTRY ();


	/*
	 * Simple implementation for now;
	 * TBD: [Future] Real integer handles allow for more verification
	 * and keep all pointers within this subsystem!
	 */
	if (!handle) {
		return (NULL);
	}

	if (handle == ACPI_ROOT_OBJECT) {
		return (acpi_gbl_root_node);
	}


	/* We can at least attempt to verify the handle */

	if (!VALID_DESCRIPTOR_TYPE (handle, ACPI_DESC_TYPE_NAMED)) {
		return (NULL);
	}

	return ((acpi_namespace_node *) handle);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_convert_entry_to_handle
 *
 * PARAMETERS:  Node          - Node to be converted to a Handle
 *
 * RETURN:      An USER acpi_handle
 *
 * DESCRIPTION: Convert a real Node to a namespace handle
 *
 ******************************************************************************/

acpi_handle
acpi_ns_convert_entry_to_handle (
	acpi_namespace_node         *node)
{


	/*
	 * Simple implementation for now;
	 * TBD: [Future] Real integer handles allow for more verification
	 * and keep all pointers within this subsystem!
	 */
	return ((acpi_handle) node);


/* ---------------------------------------------------

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

	if (Node == Acpi_gbl_Root_node)
	{
		return (ACPI_ROOT_OBJECT);
	}


	return ((acpi_handle) Node);
------------------------------------------------------*/
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_terminate
 *
 * PARAMETERS:  none
 *
 * RETURN:      none
 *
 * DESCRIPTION: free memory allocated for table storage.
 *
 ******************************************************************************/

void
acpi_ns_terminate (void)
{
	acpi_operand_object     *obj_desc;
	acpi_namespace_node     *this_node;


	FUNCTION_TRACE ("Ns_terminate");


	this_node = acpi_gbl_root_node;

	/*
	 * 1) Free the entire namespace -- all objects, tables, and stacks
	 *
	 * Delete all objects linked to the root
	 * (additional table descriptors)
	 */
	acpi_ns_delete_namespace_subtree (this_node);

	/* Detach any object(s) attached to the root */

	obj_desc = acpi_ns_get_attached_object (this_node);
	if (obj_desc) {
		acpi_ns_detach_object (this_node);
		acpi_ut_remove_reference (obj_desc);
	}

	acpi_ns_delete_children (this_node);
	ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Namespace freed\n"));


	/*
	 * 2) Now we can delete the ACPI tables
	 */
	acpi_tb_delete_acpi_tables ();
	ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "ACPI Tables freed\n"));

	return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_opens_scope
 *
 * PARAMETERS:  Type        - A valid namespace type
 *
 * RETURN:      NEWSCOPE if the passed type "opens a name scope" according
 *              to the ACPI specification, else 0
 *
 ******************************************************************************/

u32
acpi_ns_opens_scope (
	acpi_object_type8       type)
{
	FUNCTION_TRACE_U32 ("Ns_opens_scope", type);


	if (!acpi_ut_valid_object_type (type)) {
		/* type code out of range  */

		REPORT_WARNING (("Ns_opens_scope: Invalid Object Type\n"));
		return_VALUE (NSP_NORMAL);
	}

	return_VALUE (((u32) acpi_gbl_ns_properties[type]) & NSP_NEWSCOPE);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_get_node
 *
 * PARAMETERS:  *Pathname   - Name to be found, in external (ASL) format. The
 *                            \ (backslash) and ^ (carat) prefixes, and the
 *                            . (period) to separate segments are supported.
 *              Start_node  - Root of subtree to be searched, or NS_ALL for the
 *                            root of the name space.  If Name is fully
 *                            qualified (first s8 is '\'), the passed value
 *                            of Scope will not be accessed.
 *              Return_node - Where the Node is returned
 *
 * DESCRIPTION: Look up a name relative to a given scope and return the
 *              corresponding Node.  NOTE: Scope can be null.
 *
 * MUTEX:       Locks namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_get_node (
	NATIVE_CHAR             *pathname,
	acpi_namespace_node     *start_node,
	acpi_namespace_node     **return_node)
{
	acpi_generic_state      scope_info;
	acpi_status             status;
	NATIVE_CHAR             *internal_path = NULL;


	FUNCTION_TRACE_PTR ("Ns_get_node", pathname);


	/* Ensure that the namespace has been initialized */

	if (!acpi_gbl_root_node) {
		return_ACPI_STATUS (AE_NO_NAMESPACE);
	}

	if (!pathname) {
		return_ACPI_STATUS (AE_BAD_PARAMETER);
	}


	/* Convert path to internal representation */

	status = acpi_ns_internalize_name (pathname, &internal_path);
	if (ACPI_FAILURE (status)) {
		return_ACPI_STATUS (status);
	}


	acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);

	/* Setup lookup scope (search starting point) */

	scope_info.scope.node = start_node;

	/* Lookup the name in the namespace */

	status = acpi_ns_lookup (&scope_info, internal_path,
			 ACPI_TYPE_ANY, IMODE_EXECUTE,
			 NS_NO_UPSEARCH | NS_DONT_OPEN_SCOPE,
			 NULL, return_node);

	if (ACPI_FAILURE (status)) {
		ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "%s, %s\n",
				internal_path, acpi_format_exception (status)));
	}


	acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);

	/* Cleanup */

	ACPI_MEM_FREE (internal_path);
	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_find_parent_name
 *
 * PARAMETERS:  *Child_node            - Named Obj whose name is to be found
 *
 * RETURN:      The ACPI name
 *
 * DESCRIPTION: Search for the given obj in its parent scope and return the
 *              name segment, or "????" if the parent name can't be found
 *              (which "should not happen").
 *
 ******************************************************************************/

acpi_name
acpi_ns_find_parent_name (
	acpi_namespace_node     *child_node)
{
	acpi_namespace_node     *parent_node;


	FUNCTION_TRACE ("Ns_find_parent_name");


	if (child_node) {
		/* Valid entry.  Get the parent Node */

		parent_node = acpi_ns_get_parent_object (child_node);
		if (parent_node) {
			ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Parent of %p [%4.4s] is %p [%4.4s]\n",
				child_node, (char*)&child_node->name, parent_node, (char*)&parent_node->name));

			if (parent_node->name) {
				return_VALUE (parent_node->name);
			}
		}

		ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "unable to find parent of %p (%4.4s)\n",
			child_node, (char*)&child_node->name));
	}

	return_VALUE (ACPI_UNKNOWN_NAME);
}


#if defined(ACPI_DEBUG) || defined(ENABLE_DEBUGGER)

/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_exist_downstream_sibling
 *
 * PARAMETERS:  *Node          - pointer to first Node to examine
 *
 * RETURN:      TRUE if sibling is found, FALSE otherwise
 *
 * DESCRIPTION: Searches remainder of scope being processed to determine
 *              whether there is a downstream sibling to the current
 *              object.  This function is used to determine what type of
 *              line drawing character to use when displaying namespace
 *              trees.
 *
 ******************************************************************************/

u8
acpi_ns_exist_downstream_sibling (
	acpi_namespace_node     *node)
{

	if (!node) {
		return (FALSE);
	}

	if (node->name) {
		return (TRUE);
	}

	return (FALSE);
}

#endif /* ACPI_DEBUG */


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_get_parent_object
 *
 * PARAMETERS:  Node       - Current table entry
 *
 * RETURN:      Parent entry of the given entry
 *
 * DESCRIPTION: Obtain the parent entry for a given entry in the namespace.
 *
 ******************************************************************************/


acpi_namespace_node *
acpi_ns_get_parent_object (
	acpi_namespace_node     *node)
{


	FUNCTION_ENTRY ();


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

	/*
	 * Walk to the end of this peer list.
	 * The last entry is marked with a flag and the peer
	 * pointer is really a pointer back to the parent.
	 * This saves putting a parent back pointer in each and
	 * every named object!
	 */
	while (!(node->flags & ANOBJ_END_OF_PEER_LIST)) {
		node = node->peer;
	}


	return (node->peer);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ns_get_next_valid_node
 *
 * PARAMETERS:  Node       - Current table entry
 *
 * RETURN:      Next valid Node in the linked node list.  NULL if no more valid
 *              nodess
 *
 * DESCRIPTION: Find the next valid node within a name table.
 *              Useful for implementing NULL-end-of-list loops.
 *
 ******************************************************************************/


acpi_namespace_node *
acpi_ns_get_next_valid_node (
	acpi_namespace_node     *node)
{

	/* If we are at the end of this peer list, return NULL */

	if (node->flags & ANOBJ_END_OF_PEER_LIST) {
		return NULL;
	}

	/* Otherwise just return the next peer */

	return (node->peer);
}