Re: [PATCH 2/2] iommu: add Unisoc iommu basic driver

[Chunyan Zhang]

On Wed, 3 Feb 2021 at 02:02, Robin Murphy <robin.murphy@xxxxxxx> wrote:
>
> On 2021-02-02 14:41, Joerg Roedel wrote:
> > On Tue, Feb 02, 2021 at 02:34:34PM +0000, Robin Murphy wrote:
> >> Nope, I believe if Arm Ltd. had any involvement in this I'd know about it :)
> >
> > Okay, got confused by thinking of ARM as the CPU architecture, not the
> > company :)
> > But given the intel/ and amd/ subdirectories refer to company names as
> > well, the same is true for arm/.
>
> Right, trying to group IOMMU drivers by supposed CPU architecture is
> already a demonstrable non-starter; does intel-iommu count as x86, or
> IA-64, or do you want two copies? :P
>
> I somehow doubt anyone would license one of Arm's SMMUs to go in a
> RISC-V/MIPS/etc. based SoC, but in principle, they *could*. In fact it's
> precisely cases like this one - where silicon vendors come up with their
> own little scatter-gather unit to go with their own display controller
> etc. - that I imagine are most likely to get reused if the vendor
> decides to experiment with different CPUs to reach new market segments.

Yes, I agree, I believe this iommu unit along with Unisoc's
multi-media modules can be used on other architecture SoCs, not only
ARM based.

>
> Robin.