On Tue, 30 Apr 2024 at 01:26, Robin Murphy <robin.murphy@xxxxxxx> wrote: > > On 2024-04-29 5:31 pm, Dmitry Baryshkov wrote: > > On Fri, Apr 19, 2024 at 05:54:45PM +0100, Robin Murphy wrote: > >> It's somewhat hard to see, but arm64's arch_setup_dma_ops() should only > >> ever call iommu_setup_dma_ops() after a successful iommu_probe_device(), > >> which means there should be no harm in achieving the same order of > >> operations by running it off the back of iommu_probe_device() itself. > >> This then puts it in line with the x86 and s390 .probe_finalize bodges, > >> letting us pull it all into the main flow properly. As a bonus this lets > >> us fold in and de-scope the PCI workaround setup as well. > >> > >> At this point we can also then pull the call up inside the group mutex, > >> and avoid having to think about whether iommu_group_store_type() could > >> theoretically race and free the domain if iommu_setup_dma_ops() ran just > >> *before* iommu_device_use_default_domain() claims it... Furthermore we > >> replace one .probe_finalize call completely, since the only remaining > >> implementations are now one which only needs to run once for the initial > >> boot-time probe, and two which themselves render that path unreachable. > >> > >> This leaves us a big step closer to realistically being able to unpick > >> the variety of different things that iommu_setup_dma_ops() has been > >> muddling together, and further streamline iommu-dma into core API flows > >> in future. > >> > >> Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> # For Intel IOMMU > >> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> > >> Tested-by: Hanjun Guo <guohanjun@xxxxxxxxxx> > >> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> > >> --- > >> v2: Shuffle around to make sure the iommu_group_do_probe_finalize() case > >> is covered as well, with bonus side-effects as above. > >> v3: *Really* do that, remembering the other two probe_finalize sites too. > >> --- > >> arch/arm64/mm/dma-mapping.c | 2 -- > >> drivers/iommu/amd/iommu.c | 8 -------- > >> drivers/iommu/dma-iommu.c | 18 ++++++------------ > >> drivers/iommu/dma-iommu.h | 14 ++++++-------- > >> drivers/iommu/intel/iommu.c | 7 ------- > >> drivers/iommu/iommu.c | 20 +++++++------------- > >> drivers/iommu/s390-iommu.c | 6 ------ > >> drivers/iommu/virtio-iommu.c | 10 ---------- > >> include/linux/iommu.h | 7 ------- > >> 9 files changed, 19 insertions(+), 73 deletions(-) > > > > This patch breaks UFS on Qualcomm SC8180X Primus platform: > > > > > > [ 3.846856] arm-smmu 15000000.iommu: Unhandled context fault: fsr=0x402, iova=0x1032db3e0, fsynr=0x130000, cbfrsynra=0x300, cb=4 > > Hmm, a context fault implies that the device did get attached to a DMA > domain, thus has successfully been through __iommu_probe_device(), yet > somehow still didn't get the right DMA ops (since that "IOVA" looks more > like a PA to me). Do you see the "Adding to IOMMU group..." message for > this device, and/or any other relevant messages or errors before this > point? No, nothing relevant. [ 8.372395] ufshcd-qcom 1d84000.ufshc: Adding to iommu group 6 (please ignore the timestamp, it comes before ufshc being probed). > I'm guessing there's a fair chance probe deferral might be > involved as well. I'd like to understand what path(s) this ends up > taking through __iommu_probe_device() and of_dma_configure(), or at > least the number and order of probe attempts between the UFS and SMMU > drivers. __iommu_probe_device() gets called twice and returns early because ops is NULL. Then finally of_dma_configure_id() is called. The following branches are taken: np == dev->of_node of_dma_get_range() returned 0 bus_dma_limit and dma_range_map are set __iommu_probe_device() is called, using the `!group->default_domain && !group_lis` case, then group->default_domain() is not NULL, In the end, iommu_setup_dma_ops() is called. Then the ufshc probe defers (most likely the PHY is not present or some other device is not there yet). On the next (succeeding) try, of_dma_configure_id() is called again. The call trace is more or less the same, except that __iommu_probe_device() is not called > I'll stare at the code in the morning and see if I can spot any > overlooked ways in which what I think might be happening could happen, > but any more info to help narrow it down would be much appreciated. > > Thanks, > Robin. > > > [ 3.846880] ufshcd-qcom 1d84000.ufshc: ufshcd_check_errors: saved_err 0x20000 saved_uic_err 0x0 > > [ 3.846929] host_regs: 00000000: 1587031f 00000000 00000300 00000000 > > [ 3.846935] host_regs: 00000010: 01000000 00010217 00000000 00000000 > > [ 3.846941] host_regs: 00000020: 00000000 00070ef5 00000000 00000000 > > [ 3.846946] host_regs: 00000030: 0000000f 00000001 00000000 00000000 > > [ 3.846951] host_regs: 00000040: 00000000 00000000 00000000 00000000 > > [ 3.846956] host_regs: 00000050: 032db000 00000001 00000000 00000000 > > [ 3.846962] host_regs: 00000060: 00000000 80000000 00000000 00000000 > > [ 3.846967] host_regs: 00000070: 032dd000 00000001 00000000 00000000 > > [ 3.846972] host_regs: 00000080: 00000000 00000000 00000000 00000000 > > [ 3.846977] host_regs: 00000090: 00000016 00000000 00000000 0000000c > > [ 3.847074] ufshcd-qcom 1d84000.ufshc: ufshcd_err_handler started; HBA state eh_fatal; powered 1; shutting down 0; saved_err = 131072; saved_uic_err = 0; force_reset = 0 > > [ 4.406550] ufshcd-qcom 1d84000.ufshc: ufshcd_verify_dev_init: NOP OUT failed -11 > > [ 4.417953] ufshcd-qcom 1d84000.ufshc: ufshcd_async_scan failed: -11 > > -- With best wishes Dmitry
