On Tue, Jan 10, 2017 at 09:39:39PM +0800, Hanjun Guo wrote:

[...]

quoted

What you can do is create a wrapper, say iort_node_map_platform_id()
(whose signature is equivalent to iort_node_map_rid() minus rid_in)
that carries out the two steps outlined above.

To do that I suggest the following:

(1) I send a patch to "fix" iort_node_get_id() (ie index issue you
   reported)

I prepared two simple patches, one is for fix the indentation and
the other is adding the missing kernel-doc comment, how about
sending the out for 4.10-rcx?

For me it is fine depending on how Rafael wants to handle them,
ie if he can batch those with the eg iort_node_get_id() fix I have
just sent:

https://patchwork.kernel.org/patch/9507041/

quoted

(2) We remove type_mask handling from iort_node_get_id()

iort_node_get_id() for now only supports id single mappings,
Do we need to extend it for multi id mappings? seems Sinan's
platform have such cases.

I am not really sure I understand what you mean here.

quoted

(3) We create iort_node_map_platform_id() that (pseudo-code, I can
   write the patch if it is clearer):

struct acpi_iort_node *iort_node_map_platform_id(u8 type_mask, int index,
					 ...)
{
u32 id, id_out;
struct acpi_iort_node *parent = iort_node_get_id(&id, index);

if (!parent)
	return NULL;

/* we should probably rename iort_node_map_rid() too */
if (!(IORT_TYPE_MASK(parent->type) & type_mask)
	parent = iort_node_map_rid(parent, id, &id_out, type_mask);

return parent;
}

(4) we update current iort_node_get_id() users and move them over
   to iort_node_map_platform_id()

I think we need to prepare one patch for the above steps, or it
have functional changes for iort_node_get_id(), for example we
removed the type_mask handling from iort_node_get_id() and it
will break the case for SMMU if we only have requester id entries.

If the question is "should we apply this change as a single logical
patch" the answer is yes, it looks a simple one to me (basically
it implies writing the function above and update the iort_node_get_id()
existing callers with it). Does this answer your question ?

Thanks !
Lorenzo