On Thu, Nov 26, 2020 at 06:09:26PM +0000, Robin Murphy wrote: > On 2020-11-12 12:55, Jean-Philippe Brucker wrote: > > Copy the dma-can-stall property into the fwspec structure. > > Can't we just handle this as a regular device property? It's not part of the > actual IOMMU specifier, it doesn't need to be translated in any way, and > AFAICS it's used a grand total of once, in a slow path. Simply treating it > as the per-device property that it is should require zero additional code > for DT, and a simple device_add_properties() call for IORT. > > TBH that appears to be true of pasid-num-bits as well. Right I think that's better, thanks for the pointer. I'll take care of pasid-num-bits too. The Huawei quirk (fake PCIe supporting stall) is a little worse this way, but it should work. Thanks, Jean --- Diff untested on ACPI: diff --git a/include/linux/iommu.h b/include/linux/iommu.h index e7b40e569488..ad5c55bc45b2 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -591,8 +591,6 @@ struct iommu_group *fsl_mc_device_group(struct device *dev); struct iommu_fwspec { const struct iommu_ops *ops; struct fwnode_handle *iommu_fwnode; - u32 num_pasid_bits; - bool can_stall; unsigned int num_ids; u32 ids[]; }; diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index aa76e775bd6d..1582f6585741 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -960,16 +960,19 @@ static int iort_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data) static void iort_named_component_init(struct device *dev, struct acpi_iort_node *node) { + struct property_entry props[3] = {}; struct acpi_iort_named_component *nc; - struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); - - if (!fwspec) - return; nc = (struct acpi_iort_named_component *)node->node_data; - fwspec->num_pasid_bits = FIELD_GET(ACPI_IORT_NC_PASID_BITS, - nc->node_flags); - fwspec->can_stall = (nc->node_flags & ACPI_IORT_NC_STALL_SUPPORTED); + + props[0] = PROPERTY_ENTRY_U32("pasid-num-bits", + FIELD_GET(ACPI_IORT_NC_PASID_BITS, + nc->node_flags)); + if (nc->node_flags & ACPI_IORT_NC_STALL_SUPPORTED) + props[1] = PROPERTY_ENTRY_BOOL("dma-can-stall"); + + if (device_add_properties(dev, props)) + dev_warn(dev, "Could not register device properties\n"); } static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node *node) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 521ec7f0b2a0..571bd7c35a62 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2842,7 +2842,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev) if (ret) goto err_free_master; - master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); + device_property_read_u32(dev, "pasid-num-bits", &master->ssid_bits); + master->ssid_bits = min(smmu->ssid_bits, master->ssid_bits); /* * Note that PASID must be enabled before, and disabled after ATS: @@ -2858,7 +2859,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev) master->ssid_bits = min_t(u8, master->ssid_bits, CTXDESC_LINEAR_CDMAX); - if ((smmu->features & ARM_SMMU_FEAT_STALLS && fwspec->can_stall) || + if ((smmu->features & ARM_SMMU_FEAT_STALLS && + device_property_read_bool(dev, "dma-can-stall")) || smmu->features & ARM_SMMU_FEAT_STALL_FORCE) master->stall_enabled = true; diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index d6255ca823d8..a9d2df001149 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -210,14 +210,6 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, of_pci_iommu_init, &info); } else { err = of_iommu_configure_device(master_np, dev, id); - - fwspec = dev_iommu_fwspec_get(dev); - if (!err && fwspec) { - of_property_read_u32(master_np, "pasid-num-bits", - &fwspec->num_pasid_bits); - fwspec->can_stall = of_property_read_bool(master_np, - "dma-can-stall"); - } } /* diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 324dbe55836c..13a43a3d6347 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1828,12 +1828,17 @@ DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_HUAWEI, 0x1610, PCI_CLASS_BRIDGE_PCI static void quirk_huawei_pcie_sva(struct pci_dev *pdev) { - struct iommu_fwspec *fwspec; + struct property_entry properties[] = { + PROPERTY_ENTRY_BOOL("dma-can-stall"), + {}, + }; pdev->eetlp_prefix_path = 1; - fwspec = dev_iommu_fwspec_get(&pdev->dev); - if (fwspec) - fwspec->can_stall = 1; + + /* Device-tree can set the stall property */ + if (!pdev->dev.of_node && + device_add_properties(&pdev->dev, properties)) + pci_warn(pdev, "could not add stall property"); } DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0xa250, quirk_huawei_pcie_sva);