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? 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.
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
