Re: [PATCH 5/7] MIPS: use the generic uncached segment support in dma-direct

[Christoph Hellwig]

On Tue, Apr 30, 2019 at 09:11:07PM +0000, Paul Burton wrote:
> Right but dma_direct_alloc_pages() already checks for the PageHighMem
> case & returns before ever calling arch_dma_prep_coherent(), no?

True.  And of course it can't be remapped into the uncached segment
anyway.  So yes, we should drop it.  Eventually I want to add generic
support for DMA_ATTR_NO_KERNEL_MAPPING, but that'll involved auditing
all instances anyway.