Messages in this thread | | | Date | Fri, 24 Jan 2014 13:06:35 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH v2 2/5] x86: enable DMA CMA with swiotlb |
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On Fri, Jan 17, 2014 at 08:32:09AM +0900, Akinobu Mita wrote: > 2014/1/16 Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>: > > On Tue, Jan 14, 2014 at 11:13:47PM +0900, Akinobu Mita wrote: > >> The DMA Contiguous Memory Allocator support on x86 is disabled when > >> swiotlb config option is enabled. So DMA CMA is always disabled on > >> x86_64 because swiotlb is always enabled. This attempts to support > >> for DMA CMA with enabling swiotlb config option. > >> > >> The contiguous memory allocator on x86 is integrated in the function > >> dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops > >> for dma_alloc_coherent(). > >> > >> x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops > >> tries to allocate with dma_generic_alloc_coherent() firstly and then > >> swiotlb_alloc_coherent() is called as a fallback. > >> > >> The main part of supporting DMA CMA with swiotlb is that changing > >> x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops > >> for dma_free_coherent() so that it can distinguish memory allocated by > >> dma_generic_alloc_coherent() from one allocated by swiotlb_alloc_coherent() > >> and release it with dma_generic_free_coherent() which can handle contiguous > >> memory. This change requires making is_swiotlb_buffer() global function. > >> > >> This also needs to change .free callback in the dma_map_ops for amd_gart > >> and sta2x11, because these dma_ops are also using > >> dma_generic_alloc_coherent(). > >> > >> Cc: Marek Szyprowski <m.szyprowski@samsung.com> > >> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > >> Cc: David Woodhouse <dwmw2@infradead.org> > >> Cc: Don Dutile <ddutile@redhat.com> > >> Cc: Thomas Gleixner <tglx@linutronix.de> > >> Cc: Ingo Molnar <mingo@redhat.com> > >> Cc: "H. Peter Anvin" <hpa@zytor.com> > >> Cc: Andi Kleen <andi@firstfloor.org> > >> Cc: x86@kernel.org > >> Cc: iommu@lists.linux-foundation.org > >> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > >> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> > >> --- > >> No change from the previous version > >> > >> arch/x86/Kconfig | 2 +- > >> arch/x86/include/asm/swiotlb.h | 7 +++++++ > >> arch/x86/kernel/amd_gart_64.c | 2 +- > >> arch/x86/kernel/pci-swiotlb.c | 9 ++++++--- > >> arch/x86/pci/sta2x11-fixup.c | 6 ++---- > >> include/linux/swiotlb.h | 2 ++ > >> lib/swiotlb.c | 2 +- > > > > It looks reasonable from my perspective (as swiotlb maintainer). > > > > Not too thrilled about the 'is_swiotlb_buffer' but that code is > > quite small so it should be fast enough. > > Thanks. Can I get your Acked-by for this patch?
Yes. Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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