On Thu, Aug 13, 2020 at 07:40:55PM -0700, Rob Clark wrote: > From: Rob Clark <robdcl...@chromium.org> > > NOTE: Since Jordan was out today, and I wanted to keep things moving on > this, I took the liberty of respinning his series (originally > titled "iommu/arm-smmu: Add Adreno SMMU specific implementation") > with updates based on Will's review comments, and some fixes and > extra bits that I found in stress testing the series. Original > commit msg and updated version history below. > > In general I like the private interface between adreno-smmu and > the GPU driver. It should make for a more straightforward way > to extend things to optimize TLB invalidation in the future, for > example, rather than shoe-horning everything thru domain attrs. > And it lets us describe the get_ttbr1_cfg/set_ttrb0_cfg dance > more clearly. Although it is going to make landing this via > iommu vs drm tree a bit more difficult. Maybe there are some > arm-smmu parts of this series that could be pulled out to make > it not conflicty to land the private interface and adreno-smmu > bits via the drm tree? (But I'm jumping a bit ahead here. Just > wanted to point out that issue.) > > The complete series can be found at: > https://gitlab.freedesktop.org/drm/msm/-/commits/msm-next-pgtables > > This series adds an Adreno SMMU implementation to arm-smmu to allow GPU > hardware > pagetable switching. > > The Adreno GPU has built in capabilities to switch the TTBR0 pagetable during > runtime to allow each individual instance or application to have its own > pagetable. In order to take advantage of the HW capabilities there are > certain > requirements needed of the SMMU hardware. > > This series adds support for an Adreno specific arm-smmu implementation. The > new > implementation 1) ensures that the GPU domain is always assigned context bank > 0, > 2) enables split pagetable support (TTBR1) so that the instance specific > pagetable can be swapped while the global memory remains in place and 3) > shares > the current pagetable configuration with the GPU driver to allow it to create > its own io-pgtable instances. > > The series then adds the drm/msm code to enable these features. For targets > that > support it allocate new pagetables using the io-pgtable configuration shared > by > the arm-smmu driver and swap them in during runtime. > > This version of the series merges the previous patchset(s) [1] and [2] > with the following improvements: > > v13: (Respin by Rob) > - Switch to a private interface between adreno-smmu and GPU driver, > dropping the custom domain attr (Will Deacon) > - Rework the SCTLR.HUPCF patch to add new fields in smmu_domain->cfg > rather than adding new impl hook (Will Deacon) > - Drop for_each_cfg_sme() in favor of plain for() loop (Will Deacon) > - Fix context refcnt'ing issue which was causing problems with GPU > crash recover stress testing. > - Spiff up $debugfs/gem to show process information associated with > VMAs
I'll add the tags to Rob's code but in general I ack all these changes. I also like the private interface - it gives us the most flexibility without either changing the IOMMU API or giving up entirely and making an internal SMMU implementation inside drm/msm. <snip> Jordan -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
