dma-direct: make uncached_kernel_address more general
Christoph Hellwig authored

Rename the symbol to arch_dma_set_uncached, and pass a size to it as
well as allow an error return.  That will allow reusing this hook for
in-place pagetable remapping.

As the in-place remap doesn't always require an explicit cache flush,
also detangle ARCH_HAS_DMA_PREP_COHERENT from ARCH_HAS_DMA_SET_UNCACHED.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
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