remove default fallbacks in dma_map_ops
hch at lst.de
Thu Jul 25 16:33:56 AEST 2019
we have a few places where the DMA mapping layer has non-trivial default
actions that are questionable and/or dangerous.
This series instead wires up the mmap, get_sgtable and get_required_mask
methods explicitly and cleans up some surrounding areas. This also means
we could get rid of the ARCH_NO_COHERENT_DMA_MMAP kconfig option, as we
now require a mmap method wired up, or in case of non-coherent dma-direct
the presence of the arch_dma_coherent_to_pfn hook. The only interesting
case is that the sound code also checked the ARCH_NO_COHERENT_DMA_MMAP
symbol in somewhat odd ways, so I'd like to see a review of the sound
situation before going forward with that patch.
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