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

FUJITA Tomonori
2008-12-19T02:48:35Z

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.