Jean-Philippe has post a patchset for Adding PCIe SVM support to ARM SMMUv3: https://www.spinics.net/lists/arm-kernel/msg565155.html But for some platform devices(aka on-chip integrated devices), there is also SVM requirement, which works based on the SMMU stall mode. Jean-Philippe has prepared a prototype patchset to support it: git://linux-arm.org/linux-jpb.git svm/stall We tested this patchset with some fixes on a on-chip integrated device. The basic function is ok, so I just send them out for review, although this patchset heavily depends on the former patchset (PCIe SVM support for ARM SMMUv3), which is still under discussion. Patch Overview: *1 to 3 prepare for device tree or acpi get the device stall ability and pasid bits *4 is to realise the SVM function for platform device *5 is fix a bug when test SVM function while SMMU donnot support this feature *6 avoid ILLEGAL setting of STE and CD entry about stall Acctually here, I also have a question about SVM on SMMUv3: 1. Why the SVM feature on SMMUv3 depends on BTM feature? when bind a task to device, it will register a mmu_notify. Therefore, when a page range is invalid, we can send TLBI or ATC invalid without BTM? 2. According to ACPI IORT spec, named component specific data has a node flags field whoes bit0 is for Stall support. However, it do not have any field for pasid bit. Can we use other 5 bits[5:1] for pasid bit numbers, so we can have 32 pasid bit for a single platform device which should be enough, because SMMU only support 20 bit pasid 3. Presently, the pasid is allocate for a task but not for a context, if a task is trying to bind to 2 device A and B: a) A support 5 pasid bits b) B support 2 pasid bits c) when the task bind to device A, it allocate pasid = 16 d) then it must be fail when trying to bind to task B, for its highest pasid is 4. So it should allocate a single pasid for a context to avoid this? Jean-Philippe Brucker (3): dt-bindings: document stall and PASID properties for IOMMU masters iommu/of: Add stall and pasid properties to iommu_fwspec iommu/arm-smmu-v3: Add SVM support for platform devices Yisheng Xie (3): ACPI: IORT: Add stall and pasid properties to iommu_fwspec iommu/arm-smmu-v3: fix panic when handle stall mode irq iommu/arm-smmu-v3: Avoid ILLEGAL setting of STE.S1STALLD and CD.S Documentation/devicetree/bindings/iommu/iommu.txt | 13 ++ drivers/acpi/arm64/iort.c | 20 ++ drivers/iommu/arm-smmu-v3.c | 230 ++++++++++++++++++---- drivers/iommu/of_iommu.c | 11 + include/acpi/actbl2.h | 5 + include/linux/iommu.h | 2 + 6 files changed, 244 insertions(+), 37 deletions(-) -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
