[PATCH 4/7] v4l: videobuf2: add IOMMU based DMA memory allocator

On Monday 18 April 2011, Marek Szyprowski wrote:

From: Andrzej Pietrasiewicz <redacted>

This patch adds new videobuf2 memory allocator dedicated to devices that
supports IOMMU DMA mappings. A device with IOMMU module and a driver
with include/iommu.h compatible interface is required. This allocator
aquires memory with standard alloc_page() call and doesn't suffer from
memory fragmentation issues. The allocator support following page sizes:
4KiB, 64KiB, 1MiB and 16MiB to reduce iommu translation overhead.

My feeling is that this is not the right abstraction. Why can't you
just implement the regular dma-mapping.h interfaces for your IOMMU
so that the videobuf code can use the existing allocators?

	Arnd