iommu/dma: Add support for DMA_ATTR_FORCE_CONTIGUOUS
Add support for DMA_ATTR_FORCE_CONTIGUOUS to the generic IOMMU DMA code.
This allows to allocate physically contiguous DMA buffers on arm64
systems with an IOMMU.
Note that as this uses the CMA allocator, setting this attribute has a
runtime-dependency on CONFIG_DMA_CMA, just like on arm32.
For arm64 systems using swiotlb, no changes are needed to support the
allocation of physically contiguous DMA buffers:
- swiotlb always uses physically contiguous buffers (up to
IO_TLB_SEGSIZE = 128 pages),
- arm64's __dma_alloc_coherent() already calls
dma_alloc_from_contiguous() when CMA is available.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
3 files changed
