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| author |   Jean-Philippe Brucker <jean-philippe@linaro.org> | 2020-09-18 12:18:48 +0200 |
|---|---|---|
| committer |   Will Deacon <will@kernel.org> | 2020-09-28 23:48:06 +0100 |
| commit | 3f1ce8e85ee06dbe6a8b2e037e9b35f6b32e9ab3 (patch) | |
| tree | f2b600a4219ce2e22a38a2892d2d64a4e9266542 /drivers/iommu/Kconfig | |
| parent | iommu/arm-smmu-v3: Move definitions to a header (diff) | |
| download | linux-dev-3f1ce8e85ee06dbe6a8b2e037e9b35f6b32e9ab3.tar.xz linux-dev-3f1ce8e85ee06dbe6a8b2e037e9b35f6b32e9ab3.zip | |
iommu/arm-smmu-v3: Share process page tables
With Shared Virtual Addressing (SVA), we need to mirror CPU TTBR, TCR,
MAIR and ASIDs in SMMU contexts. Each SMMU has a single ASID space split
into two sets, shared and private. Shared ASIDs correspond to those
obtained from the arch ASID allocator, and private ASIDs are used for
"classic" map/unmap DMA.
A possible conflict happens when trying to use a shared ASID that has
already been allocated for private use by the SMMU driver. This will be
addressed in a later patch by replacing the private ASID. At the
moment we return -EBUSY.
Each mm_struct shared with the SMMU will have a single context
descriptor. Add a refcount to keep track of this. It will be protected
by the global SVA lock.
Introduce a new arm-smmu-v3-sva.c file and the CONFIG_ARM_SMMU_V3_SVA
option to let users opt in SVA support.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-9-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu/Kconfig')
| -rw-r--r-- | drivers/iommu/Kconfig | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index bef5d75e306b..82fa56238c96 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -308,6 +308,16 @@ config ARM_SMMU_V3 Say Y here if your system includes an IOMMU device implementing the ARM SMMUv3 architecture. +config ARM_SMMU_V3_SVA + bool "Shared Virtual Addressing support for the ARM SMMUv3" + depends on ARM_SMMU_V3 + help + Support for sharing process address spaces with devices using the + SMMUv3. + + Say Y here if your system supports SVA extensions such as PCIe PASID + and PRI. + config S390_IOMMU def_bool y if S390 && PCI depends on S390 && PCI |