[PATCH] iommu: Decouple iommu_map_sg from CPU page size

[joro@8bytes.org (Joerg Roedel)]

On Tue, Nov 25, 2014 at 05:50:55PM +0000, Robin Murphy wrote:
> If the IOMMU supports pages smaller than the CPU page size, segments
> which lie at offsets within the CPU page may be mapped based on the
> finer-grained IOMMU page boundaries. This minimises the amount of
> non-buffer memory between the CPU page boundary and the start of the
> segment which must be mapped and therefore exposed to the device, and
> brings the default iommu_map_sg implementation in line with
> iommu_map/unmap with respect to alignment.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> 
> Hi Joerg,
> 
> I noticed this whilst wiring up DMA mapping to this new API - on arm64
> we anticipate running 4k IOMMU pages with 64k CPU pages, in which case
> the alignment check ends up being unnecessarily strict.

Applied to the core branch, thanks.


	Joerg