Hi, Currently, the MSI_IOVA_BASE address is hard-coded to 0x80000000, assuming that all platforms have this address available for MSI IOVA reservation. However, this is not always the case, as some platforms reserve this address for other purposes. Consequently, these platforms cannot reserve the MSI_IOVA_BASE address for MSI. There was an [1] attempt to fix this problem by passing the MSI IOVA base as a kernel command line parameter. In the previous attempt, Will suggested reserving the MSI IOVA at runtime whenever there is a conflict with the default MSI_IOVA_BASE. However, dynamically reserving this address has debuggability concerns, as it becomes difficult to track IOMMU mapping failures. This patch series aims to address the issue by introducing a new DTS property, "arm,smmu-pci-msi-iova-data". This property allows the configuration of MSI IOVA with a custom MSI base address and a custom length for IOMMU/SMMU drivers. It accommodates platforms that do not have the default MSI base address available for MSI reservation. [1]: https://lore.kernel.org/lkml/20200914181307.117792-1-vemegava@xxxxxxxxxxxxxxxxxxx/ Thanks, Shyam Shyam Saini (3): dt-bindings: iommu: add "arm,smmu-pci-msi-iova-data" property iommu: consolidate MSI_IOVA macro definitions arm-smmu: use dts passed MSI IOVA address and length .../bindings/iommu/arm,smmu-v3.yaml | 12 +++++ .../devicetree/bindings/iommu/arm,smmu.yaml | 12 +++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++++- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 3 -- drivers/iommu/arm/arm-smmu/arm-smmu.c | 11 +++-- drivers/iommu/virtio-iommu.c | 8 ++-- include/linux/iommu.h | 44 +++++++++++++++++++ 7 files changed, 86 insertions(+), 14 deletions(-) -- 2.34.1
