Messages in this thread | | | Date | Thu, 21 Aug 2008 17:17:24 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH 1/8] x86: add alloc_coherent dma_ops callback to GART driver |
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On Thu, Aug 21, 2008 at 11:16:49PM +0900, FUJITA Tomonori wrote: > On Tue, 19 Aug 2008 16:32:39 +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 4d8efb0..44a75a6 100644 > > --- a/arch/x86/kernel/pci-gart_64.c > > +++ b/arch/x86/kernel/pci-gart_64.c > > @@ -506,6 +506,26 @@ 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; > > I'm not sure a rule is documented or not, but I think that IOMMUs > return zeroed memory wrt dma_alloc_coherent. The current pci-dma.c > does, so I think that it would be better to keep the current behavior.
Ok, true. I will send and update patch to add this. Thanks.
Joerg
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