Re: [RFC PATCH v3 4/6] swiotlb: Add restricted DMA alloc/free support.

[Christoph Hellwig <hch@xxxxxx>]

On Wed, Jan 13, 2021 at 06:27:08PM +0000, Robin Murphy wrote:
>> Can we hook in somewhat lower level in the dma-direct code so that all
>> the remapping in dma-direct can be reused instead of duplicated?  That
>> also becomes important if we want to use non-remapping uncached support,
>> e.g. on mips or x86, or the direct changing of the attributes that Will
>> planned to look into for arm64.
>
> Indeed, AFAICS this ought to boil down to a direct equivalent of 
> __dma_direct_alloc_pages() - other than the address there should be no 
> conceptual difference between pages from the restricted pool and those from 
> the regular page allocator, so this probably deserves to be plumbed in as 
> an alternative to that.

Yes, that's what I mean.  You managed to word it much better, though.