[Design] iommu/arm-smmu-v3: Implementing set_dev_pasid for other domain types

[Jean-Philippe Brucker]

On Sat, Mar 25, 2023 at 01:42:22PM +0800, Michael Shavit wrote:
> On Fri, Mar 24, 2023 at 8:31 PM Jean-Philippe Brucker
> <jean-philippe at linaro.org> wrote:
> 
> > > As a first order consequence, when multiple devices share a domain:
> > >     1. We’ll use more memory than we would have before.
> >
> > I wonder if we could save some memory by reducing the allocation size for
> > single-entry context tables: it looks like dma_direct_alloc() gives us a
> > full page at the moment even though we only need 64 bytes per CD
> > (and S1ContextPtr alignment is 64B).
> 
> Oh interesting, I can give that a try. I'm guessing you mean by
> allocating from a pool when a master with ssid=1 needs to allocate its
> cd table?

Yes, adding a dma_pool for this particular case could work

Thanks,
Jean