Re: [PATCH v3 0/6] Prerequisites for NXP LS104xA SMMU enablement

[Robin Murphy]

On 31/05/2019 17:33, Christoph Hellwig wrote:
> On Thu, May 30, 2019 at 03:08:44PM -0700, David Miller wrote:
> > From: laurentiu.tudor@xxxxxxx
> > Date: Thu, 30 May 2019 17:19:45 +0300
> >
> > > Depends on this pull request:
> > >
> > >   http://lists.infradead.org/pipermail/linux-arm-kernel/2019-May/653554.html
> >
> > I'm not sure how you want me to handle this.
>
> The thing needs to be completely redone as it abuses parts of the
> iommu API in a completely unacceptable way.

`git grep iommu_iova_to_phys drivers/{crypto,gpu,net}`

:(

I guess one alternative is for the offending drivers to maintain their 
own lookup tables of mapped DMA addresses - I think at least some of 
these things allow storing some kind of token in a descriptor, which 
even if it's not big enough for a virtual address might be sufficient 
for an index.

Robin.