Re: 4MB pages and framebuffer access, x11perf results, 2.1.125

David S. Miller (davem@dm.cobaltmicro.com)
Tue, 27 Oct 1998 20:16:30 -0800


Date: Wed, 28 Oct 1998 05:13:44 +0100 (CET)
From: MOLNAR Ingo <mingo@chiara.csoma.elte.hu>

On Tue, 27 Oct 1998, David S. Miller wrote:

> Post your patches so we can actually have a chance to figure something
> like that out :-)

uhm, was too embarrased to do that :) Be prepared, it's Really Ugly. The
main goal was to get a prototype working fast ...

Ok, here is one suggestion.

Arguably mmap_mem() could be dealing with either real memory or I/O
memory, the latter is the case we care about here.

So what we could do is introduce macros to test this attribute for a
physical page. Using this we could also instroduce the rule that you
can't mmap memory which half straddles physical real memory and I/O
space.

Anyways, if the macro says this is I/O space we can call
ioremap_page_range() or whatever, which is completely implemented
already in per-architecture MM support files.

Go from there.

Just an idea.

Later,
David S. Miller
davem@dm.cobaltmicro.com

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