Re: [PATCH 00 of 14] swiotlb/x86: lay groundwork for xen dom0 use of swiotlb

Ingo Molnar
2008-12-19T08:19:21Z

* FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote:

> On Thu, 18 Dec 2008 12:17:54 -0600
> Becky Bruce <beckyb@kernel.crashing.org> wrote:
>
> > > Can you be more specific? What architecture is plan to use highmem
> > > support in swiotlb?
> >
> > 32-bit powerpc needs this support - I was actually about to push a
> > similar set of patches. We have several processors that support 36
> > bits of physical address space and do not have any iommu capability.
> > The rest of the kernel support for those processors is now in place,
> > so swiotlb is the last piece of the puzzle for that to be fully
> > functional. I need to take a closer look at this series to see
> > exactly what it's doing and how it differs from what I've been testing.
>
> Ah, thanks,
>
> Then I accept that highmem support in lib/swiotbl.c is generically
> useful and we have to live with the ugly complication due to it.

Great! And we of course want to make the best possible job here - so
whenever you notice any area that could be done better and less
intrusively, please mention it.

Ingo