On Thu, Jun 17, 2021 at 05:30:11PM +0900, Tomasz Figa wrote:

We still have use cases for dma_alloc_coherent() and DMA_ATTR_NO_KERNEL_MAPPING.

dma_alloc_coherent does not take a flags argument, so you can't use
DMA_ATTR_NO_KERNEL_MAPPING with it.  What would your use case be here
anyway?  In general DMA_ATTR_NO_KERNEL_MAPPING is rather misnamed, as
usually there is a kernel mapping, just not one that is coherent and
should be used.