Re: [PATCH] of: property: Add device link support for "iommu-map"

From: Will Deacon
Date: Mon Nov 25 2019 - 02:49:16 EST


On Fri, Nov 22, 2019 at 02:16:31PM -0600, Rob Herring wrote:
> On Fri, Nov 22, 2019 at 10:13 AM Ard Biesheuvel
> <ard.biesheuvel@xxxxxxxxxx> wrote:
> >
> > On Fri, 22 Nov 2019 at 17:01, Rob Herring <robh@xxxxxxxxxx> wrote:
> > >
> > > On Fri, Nov 22, 2019 at 8:55 AM Will Deacon <will@xxxxxxxxxx> wrote:
> > > >
> > > > [+Ard]
> > > >
> > > > Hi Rob,
> > > >
> > > > On Fri, Nov 22, 2019 at 08:47:46AM -0600, Rob Herring wrote:
> > > > > On Wed, Nov 20, 2019 at 1:00 PM Will Deacon <will@xxxxxxxxxx> wrote:
> > > > > >
> > > > > > Commit 8e12257dead7 ("of: property: Add device link support for iommus,
> > > > > > mboxes and io-channels") added device link support for IOMMU linkages
> > > > > > described using the "iommus" property. For PCI devices, this property
> > > > > > is not present and instead the "iommu-map" property is used on the host
> > > > > > bridge node to map the endpoint RequesterIDs to their corresponding
> > > > > > IOMMU instance.
> > > > > >
> > > > > > Add support for "iommu-map" to the device link supplier bindings so that
> > > > > > probing of PCI devices can be deferred until after the IOMMU is
> > > > > > available.
> > > > > >
> > > > > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > > > > Cc: Rob Herring <robh@xxxxxxxxxx>
> > > > > > Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
> > > > > > Cc: Robin Murphy <robin.murphy@xxxxxxx>
> > > > > > Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> > > > > > ---
> > > > > >
> > > > > > Applies against driver-core/driver-core-next.
> > > > > > Tested on AMD Seattle (arm64).
> > > > >
> > > > > Guess that answers my question whether anyone uses Seattle with DT.
> > > > > Seattle uses the old SMMU binding, and there's not even an IOMMU
> > > > > associated with the PCI host. I raise this mainly because the dts
> > > > > files for Seattle either need some love or perhaps should be removed.
> > > >
> > > > I'm using the new DT bindings on my Seattle, thanks to the firmware fairy
> > > > (Ard) visiting my flat with a dediprog. The patches I've posted to enable
> > > > modular builds of the arm-smmu driver require that the old binding is
> > > > disabled [1].
> > >
> > > Going to post those dts changes?
> > >
> >
> > Last time I tried upstreaming seattle DT changes I got zero response,
> > so I didn't bother since.
>
> I leave most dts reviews up to sub-arch maintainers and I'm pretty
> sure AMD doesn't care about it anymore, so we need a new maintainer or
> just send a pull request to Arnd/Olof.

Feel free to add my:

Tested-by: Will Deacon <will@xxxxxxxxxx>

If it's the same as the DT exposed by the firmware I have.

Will