v5 --> v6: 1. give up adding boot option iommu.dma_mode v4 --> v5: As Hanjun and Thomas Gleixner's suggestion: 1. Keep the old ARCH specific boot options no change. 2. Keep build option CONFIG_IOMMU_DEFAULT_PASSTHROUGH no change. v4: As Robin Murphy's suggestion: "It's also not necessarily obvious to the user how this interacts with IOMMU_DEFAULT_PASSTHROUGH, so if we really do go down this route, maybe it would be better to refactor the whole lot into a single selection of something like IOMMU_DEFAULT_MODE anyway." In this version, I tried to normalize the IOMMU dma mode boot options for all ARCHs. When IOMMU is enabled, there are 3 dma modes: paasthrough(bypass), lazy(mapping but defer the IOTLB invalidation), strict. But currently each ARCHs defined their private boot options, different with each other. For example, to enable/disable "passthrough", ARM64 use iommu.passthrough=1/0, X86 use iommu=pt/nopt, PPC/POWERNV use iommu=nobypass. Zhen Lei (1): iommu: enhance IOMMU dma mode build options arch/ia64/kernel/pci-dma.c | 2 +- arch/powerpc/platforms/powernv/pci-ioda.c | 3 ++- arch/s390/pci/pci_dma.c | 2 +- arch/x86/kernel/pci-dma.c | 7 ++--- drivers/iommu/Kconfig | 44 ++++++++++++++++++++++++++----- drivers/iommu/amd_iommu_init.c | 3 ++- drivers/iommu/intel-iommu.c | 2 +- drivers/iommu/iommu.c | 3 ++- 8 files changed, 48 insertions(+), 18 deletions(-) -- 1.8.3
