Subject: Re: [PATCH] 8xx: map_page() skip pinned region and tlbie debugging aid

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 28 Jun 2005 16:30:07 +1000

> 
> You see, this just keeps growing in features and complexity :-)
> It would be nice for ioremap() to consider multiple, dynamic 8M
> pages on 8xx like it does BATs on traditional PPC.  It will do
> this .... someday soon.

You should consider 8Mb pages the way we do BATs yes, that is have
something like an array of those or use 2 PMD entries to represent them,
and then, have ioremap treat them like it does with BATs. Such 8Mb pages
could then be setup using io_block_mapping().

Note that I'll soon send the patch I told you about that makes the
virtual address picked by io_block_mapping() dynamic, so we no longer
have to do crappy assumptions all over the place :)

> Perhaps I should go back and push some of this dynamic 8M
> page stuff.  It would eliminate the tlbie() problems, give us
> more flexibility.  Damn, not enough hours in a day ....

Looks like a good idea though :)

Ben.