This series introduces the ability for certain devices on s390 to bypass a layer of IOMMU via the iommu.passthrough=1 option. In order to enable this, the concept of an identity domain is added to s390-iommu. On s390, IOMMU passthrough is only allowed if indicated via a special bit in s390 CLP data for the associated device group, otherwise we must fall back to dma-iommu. Changes for v2: - Remove ARCH_HAS_PHYS_TO_DMA, use bus_dma_region - Remove use of def_domain_type, use 1 of 2 ops chosen at init Matthew Rosato (3): s390/pci: check for relaxed translation capability s390/pci: store DMA offset in bus_dma_region iommu/s390: implement iommu passthrough via identity domain arch/s390/include/asm/pci.h | 2 +- arch/s390/include/asm/pci_clp.h | 4 +- arch/s390/pci/pci.c | 6 ++- arch/s390/pci/pci_bus.c | 18 +++++++ arch/s390/pci/pci_clp.c | 1 + drivers/iommu/s390-iommu.c | 95 +++++++++++++++++++++++++-------- 6 files changed, 99 insertions(+), 27 deletions(-) -- 2.47.1
