The HiSilicon erratum 161010801 describes the limitation of HiSilicon platforms Hip06/Hip07 to support the SMMU mappings for MSI transactions.
On these platforms GICv3 ITS translator is presented with the deviceID by extending the MSI payload data to 64 bits to include the deviceID. Hence, the PCIe controller on this platforms has to differentiate the MSI payload against other DMA payload and has to modify the MSI payload. This basically makes it difficult for this platforms to have a SMMU translation for MSI. This patch implements a ACPI table based quirk to reserve the hw msi regions in the smmu-v3 driver which means these address regions will not be translated and will be excluded from iova allocations. Signed-off-by: shameer <[email protected]> --- drivers/iommu/arm-smmu-v3.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index abe4b88..f03c63b 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -597,6 +597,7 @@ struct arm_smmu_device { u32 features; #define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0) +#define ARM_SMMU_OPT_RESV_HW_MSI (1 << 1) u32 options; struct arm_smmu_cmdq cmdq; @@ -1904,14 +1905,31 @@ static void arm_smmu_get_resv_regions(struct device *dev, struct list_head *head) { struct iommu_resv_region *region; + struct arm_smmu_device *smmu; + struct iommu_fwspec *fwspec = dev->iommu_fwspec; int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; - region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, - prot, IOMMU_RESV_SW_MSI); - if (!region) - return; + smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); + + if (smmu && (smmu->options & ARM_SMMU_OPT_RESV_HW_MSI) && + dev_is_pci(dev)) { + int ret = -EINVAL; + + if (!is_of_node(smmu->dev->fwnode)) + ret = iort_iommu_its_get_resv_regions(dev, head); - list_add_tail(®ion->list, head); + if (ret) { + dev_warn(dev, "HW MSI region resv failed: %d\n", ret); + return; + } + } else { + region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, + prot, IOMMU_RESV_SW_MSI); + if (!region) + return; + + list_add_tail(®ion->list, head); + } iommu_dma_get_resv_regions(dev, head); } @@ -2611,6 +2629,7 @@ static void parse_driver_acpi_options(struct acpi_iort_smmu_v3 *iort_smmu, switch (iort_smmu->model) { case ACPI_IORT_SMMU_HISILICON_HI161X: smmu->options |= ARM_SMMU_OPT_SKIP_PREFETCH; + smmu->options |= ARM_SMMU_OPT_RESV_HW_MSI; break; default: break; -- 1.9.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
