On Tue, Sep 10, 2019 at 10:10:49AM -0700, Rob Clark wrote: > On Tue, Sep 10, 2019 at 9:34 AM Robin Murphy <robin.murphy@xxxxxxx> wrote: > > On 06/09/2019 22:44, Rob Clark wrote: > > > NOTE that in discussion of previous revisions, RMRR came up. This is > > > not really a replacement for RMRR (nor does RMRR really provide any > > > more information than we already get from EFI GOP, or DT in the > > > simplefb case). I also don't see how RMRR could help w/ SMMU handover > > > of CB/SMR config (Bjorn's patchset[1]) without defining new tables. > > > > The point of RMRR-like-things is that they identify not just the memory > > region but also the specific device accessing them, which means the > > IOMMU driver knows up-front which IDs etc. it must be careful not to > > disrupt. Obviously for SMMU that *would* be some new table (designed to > > encompass everything relevant) since literal RMRRs are specifically an > > Intel VT-d thing. > > Perhaps I'm not looking in the right place, but the extent of what I > could find about RMRR tables was: > > https://github.com/tianocore/edk2/blob/master/MdePkg/Include/IndustryStandard/DmaRemappingReportingTable.h#L122 > > I couldn't really see how that specifies the device. But entirely > possible that I'm not seeing the whole picture. I don't think anybody was planning to implement RMRR "as-is" for arm64, so you might be better off looking at the proposal from Thierry, although it has some issues that are still to be resolved: http://lkml.kernel.org/r/20190829111407.17191-1-thierry.reding@xxxxxxxxx Will _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
