nsalloc.c

h内核

	 * Increment the reference count(s) of all parents up to
	 * the root!
	 */
	while ((node = acpi_ns_get_parent_node (node)) != NULL) {
		node->reference_count++;
	}

	return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_children
 *
 * PARAMETERS:  parent_node     - Delete this objects children
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Delete all children of the parent object. In other words,
 *              deletes a "scope".
 *
 ******************************************************************************/

void
acpi_ns_delete_children (
	struct acpi_namespace_node      *parent_node)
{
	struct acpi_namespace_node      *child_node;
	struct acpi_namespace_node      *next_node;
	struct acpi_namespace_node      *node;
	u8                              flags;


	ACPI_FUNCTION_TRACE_PTR ("ns_delete_children", parent_node);


	if (!parent_node) {
		return_VOID;
	}

	/* If no children, all done! */

	child_node = parent_node->child;
	if (!child_node) {
		return_VOID;
	}

	/*
	 * Deallocate all children at this level
	 */
	do {
		/* Get the things we need */

		next_node   = child_node->peer;
		flags       = child_node->flags;

		/* Grandchildren should have all been deleted already */

		if (child_node->child) {
			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Found a grandchild! P=%p C=%p\n",
				parent_node, child_node));
		}

		/* Now we can free this child object */

		ACPI_MEM_TRACKING (acpi_gbl_memory_lists[ACPI_MEM_LIST_NSNODE].total_freed++);

		ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Object %p, Remaining %X\n",
			child_node, acpi_gbl_current_node_count));

		/*
		 * Detach an object if there is one, then free the child node
		 */
		acpi_ns_detach_object (child_node);

		/*
		 * Decrement the reference count(s) of all parents up to
		 * the root! (counts were incremented when the node was created)
		 */
		node = child_node;
		while ((node = acpi_ns_get_parent_node (node)) != NULL) {
			node->reference_count--;
		}

		/* There should be only one reference remaining on this node */

		if (child_node->reference_count != 1) {
			ACPI_REPORT_WARNING (("Existing references (%d) on node being deleted (%p)\n",
				child_node->reference_count, child_node));
		}

		/* Now we can delete the node */

		ACPI_MEM_FREE (child_node);

		/* And move on to the next child in the list */

		child_node = next_node;

	} while (!(flags & ANOBJ_END_OF_PEER_LIST));


	/* Clear the parent's child pointer */

	parent_node->child = NULL;

	return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_namespace_subtree
 *
 * PARAMETERS:  parent_node     - Root of the subtree to be deleted
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Delete a subtree of the namespace.  This includes all objects
 *              stored within the subtree.
 *
 ******************************************************************************/

void
acpi_ns_delete_namespace_subtree (
	struct acpi_namespace_node      *parent_node)
{
	struct acpi_namespace_node      *child_node = NULL;
	u32                             level = 1;


	ACPI_FUNCTION_TRACE ("ns_delete_namespace_subtree");


	if (!parent_node) {
		return_VOID;
	}

	/*
	 * Traverse the tree of objects until we bubble back up
	 * to where we started.
	 */
	while (level > 0) {
		/* Get the next node in this scope (NULL if none) */

		child_node = acpi_ns_get_next_node (ACPI_TYPE_ANY, parent_node,
				 child_node);
		if (child_node) {
			/* Found a child node - detach any attached object */

			acpi_ns_detach_object (child_node);

			/* Check if this node has any children */

			if (acpi_ns_get_next_node (ACPI_TYPE_ANY, child_node, NULL)) {
				/*
				 * There is at least one child of this node,
				 * visit the node
				 */
				level++;
				parent_node = child_node;
				child_node = NULL;
			}
		}
		else {
			/*
			 * No more children of this parent node.
			 * Move up to the grandparent.
			 */
			level--;

			/*
			 * Now delete all of the children of this parent
			 * all at the same time.
			 */
			acpi_ns_delete_children (parent_node);

			/* New "last child" is this parent node */

			child_node = parent_node;

			/* Move up the tree to the grandparent */

			parent_node = acpi_ns_get_parent_node (parent_node);
		}
	}

	return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_remove_reference
 *
 * PARAMETERS:  Node           - Named node whose reference count is to be
 *                               decremented
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Remove a Node reference.  Decrements the reference count
 *              of all parent Nodes up to the root.  Any node along
 *              the way that reaches zero references is freed.
 *
 ******************************************************************************/

void
acpi_ns_remove_reference (
	struct acpi_namespace_node      *node)
{
	struct acpi_namespace_node      *parent_node;
	struct acpi_namespace_node      *this_node;


	ACPI_FUNCTION_ENTRY ();


	/*
	 * Decrement the reference count(s) of this node and all
	 * nodes up to the root,  Delete anything with zero remaining references.
	 */
	this_node = node;
	while (this_node) {
		/* Prepare to move up to parent */

		parent_node = acpi_ns_get_parent_node (this_node);

		/* Decrement the reference count on this node */

		this_node->reference_count--;

		/* Delete the node if no more references */

		if (!this_node->reference_count) {
			/* Delete all children and delete the node */

			acpi_ns_delete_children (this_node);
			acpi_ns_delete_node (this_node);
		}

		this_node = parent_node;
	}
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_namespace_by_owner
 *
 * PARAMETERS:  owner_id    - All nodes with this owner will be deleted
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Delete entries within the namespace that are owned by a
 *              specific ID.  Used to delete entire ACPI tables.  All
 *              reference counts are updated.
 *
 ******************************************************************************/

void
acpi_ns_delete_namespace_by_owner (
	u16                             owner_id)
{
	struct acpi_namespace_node      *child_node;
	struct acpi_namespace_node      *deletion_node;
	u32                             level;
	struct acpi_namespace_node      *parent_node;


	ACPI_FUNCTION_TRACE_U32 ("ns_delete_namespace_by_owner", owner_id);


	parent_node   = acpi_gbl_root_node;
	child_node    = NULL;
	deletion_node = NULL;
	level         = 1;

	/*
	 * Traverse the tree of nodes until we bubble back up
	 * to where we started.
	 */
	while (level > 0) {
		/*
		 * Get the next child of this parent node. When child_node is NULL,
		 * the first child of the parent is returned
		 */
		child_node = acpi_ns_get_next_node (ACPI_TYPE_ANY, parent_node, child_node);

		if (deletion_node) {
			acpi_ns_remove_reference (deletion_node);
			deletion_node = NULL;
		}

		if (child_node) {
			if (child_node->owner_id == owner_id) {
				/* Found a matching child node - detach any attached object */

				acpi_ns_detach_object (child_node);
			}

			/* Check if this node has any children */

			if (acpi_ns_get_next_node (ACPI_TYPE_ANY, child_node, NULL)) {
				/*
				 * There is at least one child of this node,
				 * visit the node
				 */
				level++;
				parent_node = child_node;
				child_node = NULL;
			}
			else if (child_node->owner_id == owner_id) {
				deletion_node = child_node;
			}
		}
		else {
			/*
			 * No more children of this parent node.
			 * Move up to the grandparent.
			 */
			level--;
			if (level != 0) {
				if (parent_node->owner_id == owner_id) {
					deletion_node = parent_node;
				}
			}

			/* New "last child" is this parent node */

			child_node = parent_node;

			/* Move up the tree to the grandparent */

			parent_node = acpi_ns_get_parent_node (parent_node);
		}
	}

	return_VOID;
}