On Fri, 28 Feb 2020 10:50:25 +0000 Will Deacon <will@xxxxxxxxxx> wrote: > On Fri, Feb 28, 2020 at 10:25:56AM +0000, Andre Przywara wrote: > > On Fri, 28 Feb 2020 10:04:47 +0000 > > Will Deacon <will@xxxxxxxxxx> wrote: > > > > Hi, > > > > > On Tue, Feb 25, 2020 at 04:01:54PM -0600, Rob Herring wrote: > > > > On Tue, Feb 18, 2020 at 11:20 AM Will Deacon <will@xxxxxxxxxx> wrote: > > > > > > > > > > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote: > > > > > > Cc: Will Deacon <will@xxxxxxxxxx> > > > > > > Cc: Robin Murphy <robin.murphy@xxxxxxx> > > > > > > Cc: Joerg Roedel <joro@xxxxxxxxxx> > > > > > > Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > Signed-off-by: Rob Herring <robh@xxxxxxxxxx> > > > > > > --- > > > > > > Do not apply yet. > > > > > > > > > > Pleeeeease? ;) > > > > > > > > > > > drivers/iommu/arm-smmu-impl.c | 43 ----------------------------------- > > > > > > 1 file changed, 43 deletions(-) > > > > > > > > > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove > > > > > anything from 'struct arm_smmu_impl' because most implementations fall > > > > > just short of perfect. > > > > > > > > > > Anyway, let me know when I can push the button and I'll queue this in > > > > > the arm-smmu tree. > > > > > > > > Seems we're leaving the platform support for now, but I think we never > > > > actually enabled SMMU support. It's not in the dts either in mainline > > > > nor the version I have which should be close to what shipped in > > > > firmware. So as long as Andre agrees, this one is good to apply. > > > > > > Andre? Can I queue this one for 5.7, please? > > > > I was wondering how much of a pain it is to keep it in? AFAICS there are > > other users of the "impl" indirection. If those goes away, I would be > > happy to let Calxeda go. > > The impl stuff is new, so we'll keep it around. The concern is more about > testing (see below). > > > But Eric had the magic DT nodes to get the SMMU working, and I used that > > before, with updating the DT either on flash or dynamically via U-Boot. > > What did you actually use the SMMU for, though? The > 'arm_iommu_create_mapping()' interface isn't widely used and, given that > highbank doesn't support KVM, the use-cases for VFIO are pretty limited > too. AFAIK Highbank doesn't have the SMMU, probably mostly for that reason. I have a DT snippet for Midway, and that puts the MMIO base at ~36GB, which is not possible on Highbank. So I think that the quirk is really meant and needed for Midway. > > So I don't know exactly *how* desperate you are with removing this, or if > > there are other reasons than "negative diffstat", but if possible I would > > like to keep it in. > > It's more that we *do* make quite a lot of changes to the arm-smmu driver > and it's never tested with this quirk. If you're stepping up to run smmu > tests on my queue for each release on highbank, then great, but otherwise > I'd rather not carry the code for fun. The change in diffstat is minimal > (we're going to need to hooks for nvidia, who broke things in a different > way). I am about to set up some more sophisticated testing, and will include some SMMU bits in it. Cheers, Andre. > Also, since the hooks aren't going away, if you /do/ end up using the SMMU > in future, then we could re-add the driver quirk without any fuss. > > Will
