Messages in this thread | | | Date | Thu, 18 Dec 2008 12:09:13 -0800 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 00 of 14] swiotlb/x86: lay groundwork for xen dom0 use of swiotlb |
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Becky Bruce wrote: > 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. > > So there is another immediate use case, and I'd really hate to see > this code duplicated. It should be entirely possible to remove the > assumption that we can save off the VA of the original buffer, which > is the thing that precludes HIGHMEM support, and still have nice > readable, maintainable code.
Good, I'm glad I'm not just making things up ;)
The gist of the patch is to convert all the kernel virtual addresses into struct page+offset. It's a fairly generic way to handle highmem systems, so it should work for you too. Of course, if you have a cleaner patch to achieve the same result, then we evaluate that too.
J
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