[PATCH 11/33] dma-mapping: move swiotlb arch helpers to a new header

[Robin Murphy]

On 10/01/18 08:00, Christoph Hellwig wrote:
> phys_to_dma, dma_to_phys and dma_capable are helpers published by
> architecture code for use of swiotlb and xen-swiotlb only.  Drivers are
> not supposed to use these directly, but use the DMA API instead.
> 
> Move these to a new asm/dma-direct.h helper, included by a
> linux/dma-direct.h wrapper that provides the default linear mapping
> unless the architecture wants to override it.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
[...]
>   drivers/crypto/marvell/cesa.c                      |  1 +
>   drivers/mtd/nand/qcom_nandc.c                      |  1 +

I took a look at these, and it seems their phys_to_dma() usage is doing 
the thing which we subsequently formalised as dma_map_resource(). I've 
had a crack at a quick patch to update the CESA driver; qcom_nandc looks 
slightly more complex in that the changes probably need to span the BAM 
dmaengine driver as well.

In the process, though, I stumbled across gen_pool_dma_alloc() - yuck, 
something needs doing there, for sure...

Robin.