On Mon, Mar 16, 2020 at 10:41:42AM +0100, Christian König wrote: > Well I would prefer if the drivers can somehow express their requirements > and get IOVA structures already in the form they need. > > Converting the IOVA data from one form to another is sometimes quite costly. > Especially when it is only temporarily needed.
We basically have two ways to generate the IOVA: - a linear translation for the direct mapping case or some dumb IOMMU drivers - in that case case there is a 1:1 mapping between input segments and output segments in DMA mapping - a non-trivial IOMMU where all aligned segments are merged into a single IOVA range So I don't really see how the dma layer could help much with any limitation beyond existing max size and dma boundary ones. _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx