Hi, On 03.06.2021 18:46, Thierry Reding wrote: > From: Thierry Reding <treding@xxxxxxxxxx> > > Implement a ->probe_finalize() callback that can be used by vendor > implementations to perform extra programming necessary after devices > have been attached to the SMMU. > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> This patch landed recently in linux-next as commit 0d97174aeadf ("iommu/arm-smmu: Implement ->probe_finalize()"). It causes the following issue on ARM Juno R1 board: arm-smmu 2b500000.iommu: probing hardware configuration... arm-smmu 2b500000.iommu: SMMUv1 with: arm-smmu 2b500000.iommu: stage 2 translation arm-smmu 2b500000.iommu: coherent table walk arm-smmu 2b500000.iommu: stream matching with 32 register groups arm-smmu 2b500000.iommu: 4 context banks (4 stage-2 only) arm-smmu 2b500000.iommu: Supported page sizes: 0x60211000 arm-smmu 2b500000.iommu: Stage-2: 40-bit IPA -> 40-bit PA arm-smmu 7fb00000.iommu: probing hardware configuration... arm-smmu 7fb00000.iommu: SMMUv1 with: arm-smmu 7fb00000.iommu: stage 2 translation arm-smmu 7fb00000.iommu: coherent table walk arm-smmu 7fb00000.iommu: stream matching with 16 register groups arm-smmu 7fb00000.iommu: 4 context banks (4 stage-2 only) arm-smmu 7fb00000.iommu: Supported page sizes: 0x60211000 arm-smmu 7fb00000.iommu: Stage-2: 40-bit IPA -> 40-bit PA arm-smmu 7fb10000.iommu: probing hardware configuration... arm-smmu 7fb10000.iommu: SMMUv1 with: arm-smmu 7fb10000.iommu: stage 2 translation arm-smmu 7fb10000.iommu: non-coherent table walk arm-smmu 7fb10000.iommu: (IDR0.CTTW overridden by FW configuration) arm-smmu 7fb10000.iommu: stream matching with 2 register groups arm-smmu 7fb10000.iommu: 1 context banks (1 stage-2 only) arm-smmu 7fb10000.iommu: Supported page sizes: 0x60211000 arm-smmu 7fb10000.iommu: Stage-2: 40-bit IPA -> 40-bit PA arm-smmu 7fb20000.iommu: probing hardware configuration... arm-smmu 7fb20000.iommu: SMMUv1 with: arm-smmu 7fb20000.iommu: stage 2 translation arm-smmu 7fb20000.iommu: non-coherent table walk arm-smmu 7fb20000.iommu: (IDR0.CTTW overridden by FW configuration) arm-smmu 7fb20000.iommu: stream matching with 2 register groups arm-smmu 7fb20000.iommu: 1 context banks (1 stage-2 only) arm-smmu 7fb20000.iommu: Supported page sizes: 0x60211000 arm-smmu 7fb20000.iommu: Stage-2: 40-bit IPA -> 40-bit PA arm-smmu 7fb30000.iommu: probing hardware configuration... arm-smmu 7fb30000.iommu: SMMUv1 with: arm-smmu 7fb30000.iommu: stage 2 translation arm-smmu 7fb30000.iommu: coherent table walk arm-smmu 7fb30000.iommu: stream matching with 2 register groups arm-smmu 7fb30000.iommu: 1 context banks (1 stage-2 only) arm-smmu 7fb30000.iommu: Supported page sizes: 0x60211000 arm-smmu 7fb30000.iommu: Stage-2: 40-bit IPA -> 40-bit PA tda998x 0-0070: found TDA19988 tda998x 0-0071: found TDA19988 brd: module loaded loop: module loaded megasas: 07.714.04.00-rc1 sata_sil24 0000:03:00.0: Adding to iommu group 0 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070 Mem abort info: ESR = 0x96000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 [0000000000000070] user address but active_mm is swapper Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc1+ #3466 Hardware name: ARM Juno development board (r1) (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO BTYPE=--) pc : arm_smmu_probe_finalize+0x14/0x48 lr : iommu_probe_device+0x74/0x120 ... Call trace: arm_smmu_probe_finalize+0x14/0x48 of_iommu_configure+0xe4/0x1b8 of_dma_configure_id+0xf8/0x2d8 pci_dma_configure+0x44/0x88 really_probe+0xc0/0x3c0 driver_probe_device+0x60/0xc0 device_driver_attach+0x6c/0x78 __driver_attach+0xc0/0x100 bus_for_each_dev+0x68/0xc8 driver_attach+0x20/0x28 bus_add_driver+0x168/0x1f8 driver_register+0x60/0x110 __pci_register_driver+0x5c/0x68 sil24_pci_driver_init+0x20/0x28 do_one_initcall+0x84/0x450 kernel_init_freeable+0x2dc/0x334 kernel_init+0x10/0x110 ret_from_fork+0x10/0x18 Code: b40001e1 f9405821 f9400023 f9401461 (f9403822) ---[ end trace 561eda4b855861d1 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b SMP: stopping secondary CPUs Kernel Offset: disabled CPU features: 0x00240022,25006086 Memory Limit: none ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]--- > --- > Changes in v2: > - remove unnecessarily paranoid check > > drivers/iommu/arm/arm-smmu/arm-smmu.c | 13 +++++++++++++ > drivers/iommu/arm/arm-smmu/arm-smmu.h | 1 + > 2 files changed, 14 insertions(+) > > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c > index 6f72c4d208ca..d20ce4d57df2 100644 > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c > @@ -1450,6 +1450,18 @@ static void arm_smmu_release_device(struct device *dev) > iommu_fwspec_free(dev); > } > > +static void arm_smmu_probe_finalize(struct device *dev) > +{ > + struct arm_smmu_master_cfg *cfg; > + struct arm_smmu_device *smmu; > + > + cfg = dev_iommu_priv_get(dev); > + smmu = cfg->smmu; > + > + if (smmu->impl->probe_finalize) > + smmu->impl->probe_finalize(smmu, dev); > +} > + > static struct iommu_group *arm_smmu_device_group(struct device *dev) > { > struct arm_smmu_master_cfg *cfg = dev_iommu_priv_get(dev); > @@ -1569,6 +1581,7 @@ static struct iommu_ops arm_smmu_ops = { > .iova_to_phys = arm_smmu_iova_to_phys, > .probe_device = arm_smmu_probe_device, > .release_device = arm_smmu_release_device, > + .probe_finalize = arm_smmu_probe_finalize, > .device_group = arm_smmu_device_group, > .enable_nesting = arm_smmu_enable_nesting, > .set_pgtable_quirks = arm_smmu_set_pgtable_quirks, > diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h > index c31a59d35c64..147c95e7c59c 100644 > --- a/drivers/iommu/arm/arm-smmu/arm-smmu.h > +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h > @@ -439,6 +439,7 @@ struct arm_smmu_impl { > struct device *dev, int start); > void (*write_s2cr)(struct arm_smmu_device *smmu, int idx); > void (*write_sctlr)(struct arm_smmu_device *smmu, int idx, u32 reg); > + void (*probe_finalize)(struct arm_smmu_device *smmu, struct device *dev); > }; > > #define INVALID_SMENDX -1 Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland