On Wed, Aug 23, 2023 at 01:47:34PM -0300, Jason Gunthorpe wrote: > At this point every iommu driver will cause a default_domain to be > selected, so we can finally remove this gap from the core code. > > The following table explains what each driver supports and what the > resulting default_domain will be: > > ops->defaut_domain > IDENTITY DMA PLATFORM v ARM32 dma-iommu ARCH > amd/iommu.c Y Y N/A either > apple-dart.c Y Y N/A either > arm-smmu.c Y Y IDENTITY either > qcom_iommu.c G Y IDENTITY either > arm-smmu-v3.c Y Y N/A either > exynos-iommu.c G Y IDENTITY either > fsl_pamu_domain.c Y Y N/A N/A PLATFORM > intel/iommu.c Y Y N/A either > ipmmu-vmsa.c G Y IDENTITY either > msm_iommu.c G IDENTITY N/A > mtk_iommu.c G Y IDENTITY either > mtk_iommu_v1.c G IDENTITY N/A > omap-iommu.c G IDENTITY N/A > rockchip-iommu.c G Y IDENTITY either > s390-iommu.c Y Y N/A N/A PLATFORM > sprd-iommu.c Y N/A DMA > sun50i-iommu.c G Y IDENTITY either > tegra-smmu.c G Y IDENTITY IDENTITY > virtio-iommu.c Y Y N/A either > spapr Y Y N/A N/A PLATFORM > * G means ops->identity_domain is used > * N/A means the driver will not compile in this configuration > > ARM32 drivers select an IDENTITY default domain through either the > ops->identity_domain or directly requesting an IDENTIY domain through > alloc_domain(). > > In ARM64 mode tegra-smmu will still block the use of dma-iommu.c and > forces an IDENTITY domain. > > S390 uses a PLATFORM domain to represent when the dma_ops are set to the > s390 iommu code. > > fsl_pamu uses an PLATFORM domain. > > POWER SPAPR uses PLATFORM and blocking to enable its weird VFIO mode. > > The x86 drivers continue unchanged. > > After this patch group->default_domain is only NULL for a short period > during bus iommu probing while all the groups are constituted. Otherwise > it is always !NULL. > > This completes changing the iommu subsystem driver contract to a system > where the current iommu_domain always represents some form of translation > and the driver is continuously asserting a definable translation mode. > > It resolves the confusion that the original ops->detach_dev() caused > around what translation, exactly, is the IOMMU performing after > detach. There were at least three different answers to that question in > the tree, they are all now clearly named with domain types. > > Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> > Tested-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> > Tested-by: Steven Price <steven.price@xxxxxxx> > Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > Tested-by: Nicolin Chen <nicolinc@xxxxxxxxxx> > Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> > --- > drivers/iommu/iommu.c | 22 +++++++--------------- > 1 file changed, 7 insertions(+), 15 deletions(-) > Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
