On Fri, 10 Jul 2009 07:12:36 +0200 Ingo Molnar <mi...@elte.hu> wrote:
> > * FUJITA Tomonori <fujita.tomon...@lab.ntt.co.jp> wrote: > > > - removes unused (and unnecessary) hooks in swiotlb. > > > > - adds dma_capable() and converts swiotlb to use it. It can be used to > > know if a memory area is dma capable or not. I added > > is_buffer_dma_capable() for the same purpose long ago but it turned > > out that the function doesn't work on POWERPC. > > > > This can be applied cleanly to linux-next, -mm, and mainline. This > > patchset touches multiple architectures (ia64, powerpc, x86) so I > > guess that -mm is appropriate for this patchset (I don't care much > > what tree would merge this though). > > > > This is tested on x86 but only compile tested on POWERPC and IA64. > > > > Thanks, > > > > = > > arch/ia64/include/asm/dma-mapping.h | 18 ++++++ > > arch/powerpc/include/asm/dma-mapping.h | 23 +++++++ > > arch/powerpc/kernel/dma-swiotlb.c | 48 +--------------- > > arch/x86/include/asm/dma-mapping.h | 18 ++++++ > > arch/x86/kernel/pci-dma.c | 2 +- > > arch/x86/kernel/pci-gart_64.c | 5 +- > > arch/x86/kernel/pci-nommu.c | 2 +- > > arch/x86/kernel/pci-swiotlb.c | 25 -------- > > include/linux/dma-mapping.h | 5 -- > > include/linux/swiotlb.h | 11 ---- > > lib/swiotlb.c | 102 > > +++++++++----------------------- > > 11 files changed, 92 insertions(+), 167 deletions(-) > > Hm, the functions and facilities you remove here were added as part > of preparatory patches for Xen guest support. You were aware of > them, you were involved in discussions about those aspects with Ian > and Jeremy but still you chose not to Cc: either of them and you > failed to address that aspect in the changelogs. > > I'd like the Xen code to become cleaner more than anyone else here i > guess, but patch submission methods like this are not really > helpful. A far better method is to be open about such disagreements, > to declare them, to Cc: everyone who disagrees, and to line out the > arguments in the changelogs as well - instead of just curtly > declaring those APIs 'unused' and failing to Cc: involved parties. > > Alas, on the technical level the cleanups themselves look mostly > fine to me. Ian, Jeremy, the changes will alter Xen's use of > swiotlb, but can the Xen side still live with these new methods - in > particular is dma_capable() sufficient as a mechanism and can the > Xen side filter out DMA allocations to make them physically > continuous? dma_capable() doesn't work for Xen in the way that Ian hopes. As I said to him again and again, he tries to use arch code in the very original way, and it's unacceptable (of course, he disagreed with it). I don't think that we need to take account of dom0 support; we don't have a clear idea about an acceptable dom0 design (it needs to use swiotlb code? I don't know yet), we don't even know we will have dom0 support in mainline. That's why I didn't CC this patchset to Xen camp. I think that it's more reasonable to think about how the code can works for dom0 support when Xen people come with the new dom0 code. > Ben, Tony, Becky, any objections wrt. the PowerPC / IA64 impact? If > everyone agrees i can apply them to the IOMMU tree, test it and push > it out to -next, etc. > > Ingo > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
