Messages in this thread | | | Date | Thu, 14 Aug 2008 05:46:34 +0900 | Subject | Re: [PATCH 1/7] x86: add alloc_coherent dma_ops callback to GART driver | From | FUJITA Tomonori <> |
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On Wed, 13 Aug 2008 14:46:36 +0200 Joerg Roedel <joerg.roedel@amd.com> wrote:
> On Wed, Aug 13, 2008 at 09:45:54AM +0900, FUJITA Tomonori wrote: > > On Tue, 12 Aug 2008 17:24:11 +0200 > > Joerg Roedel <joerg.roedel@amd.com> wrote: > > > > > Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> > > > --- > > > arch/x86/kernel/pci-gart_64.c | 21 +++++++++++++++++++++ > > > 1 files changed, 21 insertions(+), 0 deletions(-) > > > > > > diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c > > > index cdab678..55cc388 100644 > > > --- a/arch/x86/kernel/pci-gart_64.c > > > +++ b/arch/x86/kernel/pci-gart_64.c > > > @@ -499,6 +499,26 @@ error: > > > return 0; > > > } > > > > > > +/* allocate and map a coherent mapping */ > > > +static void * > > > +gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, > > > + gfp_t flag) > > > +{ > > > + void *vaddr; > > > + > > > + vaddr = (void *)__get_free_pages(flag, get_order(size)); > > > + if (!vaddr) > > > + return NULL; > > > + > > > + *dma_addr = gart_map_single(dev, __pa(vaddr), size, DMA_BIDIRECTIONAL); > > > + if (*dma_addr != bad_dma_address) > > > + return vaddr; > > > + > > > + free_pages((unsigned long)vaddr, get_order(size)); > > > + > > > + return NULL; > > > +} > > > + > > > static int no_agp; > > > > It would be better to return a size-aligned memory as DMA-mapping.txt > > says (though I don't think that it doesn't matter much): > > > > http://lkml.org/lkml/2008/8/8/555 > > Agreed. I try to change the patchset so it returns size aligned dma > addresses. > > > I also think that x86 IOMMUs need to handle DMA_*BIT_MASK properly, > > don't we? > > Shouldn't this be done by the IOMMUs using your iommu_area_alloc() > function? Or do I misunderstand something?
iommu_area_alloc works but IOMMUs need to use it properly. arch/powerpc/kernel/iommu.c is a good example.
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