On Tue, Dec 07, 2021 at 12:48:13PM +0000, Robin Murphy wrote: > On 2021-12-07 12:28, John Garry via iommu wrote: > > On 07/12/2021 12:04, Robin Murphy wrote: > > > > > > > > > So is there some userspace part to go with this now? > > > > > > FWIW I've not looked into it - is it just a case of someone knocking > > > out some JSON from the MMU-600/700 TRMs, or is there still mroe to > > > do? > > > > That should just be it. Hope I didn't arrive too late :) Yes, I think we just missed two things: the DT binding for SMMUv3 PMU which is just addressed by this patchset; and the PMU event aliasing for SMMUv3 PMU, before I inquired with John and John said he would upstream the related patches after kernel can export a IIDR value via sysfs node. Seems to me, after this patchset for DT binding and PMU event alias patches are landed to the mainline kernel, it would be perfect. > > > I had the impression that *some* part of the process was stalled > > > until implementations can start providing meaningful IIDRs, but I > > > wasn't sure whether that was tooling or just data. I just work the > > > low-level enablement angle :) > > > > Tooling should be ok, but I would just like to see more of these JSONs > > so any tooling issues can be ironed out. > > Sounds good - Jean, Leo, is that something Linaro might like to pick up as > part of the PMCG interest, or shall I make a note on my to-do list for the > new year? I took a look for current patch for using PIDR to synthesize IIDR, it looks good to me. But I tested it on Hisilicon D06 board and observed the composed IIDR values are still zeros. I added a printk sentence to dump iidr value at the end of the function smmu_pmu_get_iidr(): leoy@ubuntu:~$ dmesg | grep iidr [ 28.674087] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.8.auto: iidr=0x0 [ 28.705239] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.9.auto: iidr=0x0 [ 28.729924] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.10.auto: iidr=0x0 [ 28.754855] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.11.auto: iidr=0x0 [ 28.779811] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.12.auto: iidr=0x0 [ 28.804755] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.13.auto: iidr=0x0 [ 28.829825] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.14.auto: iidr=0x0 [ 28.854767] arm-smmu-v3-pmcg arm-smmu-v3-pmcg.15.auto: iidr=0x0 Please confirm if this is expected or not? I think this might introduce difficulty for John for the PMU event alias patches, which is dependent on a non-zero IIDR. At last, very appreciate your (Jean-Philippe, Robin and John) help! Thanks, Leo
