Re: [PATCH][POWERPC] Workaround for iommu page alignment

[Olof Johansson]

On Tue, Jan 08, 2008 at 08:45:59AM +1100, Benjamin Herrenschmidt wrote:
> Our iommu page size is currently always 4K. That means with our current
> code, drivers may do a dma_map_sg() of a 64K page and obtain a dma_addr_t
> that is only 4K aligned.
> 
> This works fine in most cases except some infiniband HW it seems, where
> they tell the HW about the page size and it ignores the low bits of the
> DMA address.
> 
> This works around it by making our IOMMU code enforce a PAGE_SIZE alignment
> for mappings of objects that are page aligned in the first place and whose
> size is larger or equal to a page.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

Acked-by: Olof Johansson <olof@xxxxxxxxx>


-Olof
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