bad1a21944
commit ac9c5e92dd15b9927e7355ccf79df76a58b44344 upstream.
Although it's vanishingly unlikely that anyone would integrate an SMMU
within a coherent interconnect without also making the pagetable walk
interface coherent, the same effect happens if a coherent SMMU fails to
advertise CTTW correctly. This turns out to be the case on some popular
NXP SoCs, where VFIO started failing the IOMMU_CAP_CACHE_COHERENCY test,
even though IOMMU_CACHE *was* previously achieving the desired effect
anyway thanks to the underlying integration.
While those SoCs stand to gain some more general benefits from a
firmware update to override CTTW correctly in DT/ACPI, it's also easy
to work around this in Linux as well, to avoid imposing too much on
affected users - since the upstream client devices *are* correctly
marked as coherent, we can trivially infer their coherent paths through
the SMMU as well.
Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Fixes:
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||
|---|---|---|
| .. | ||
| amd | ||
| arm | ||
| intel | ||
| apple-dart.c | ||
| dma-iommu.c | ||
| dma-iommu.h | ||
| exynos-iommu.c | ||
| fsl_pamu_domain.c | ||
| fsl_pamu_domain.h | ||
| fsl_pamu.c | ||
| fsl_pamu.h | ||
| hyperv-iommu.c | ||
| io-pgfault.c | ||
| io-pgtable-arm-v7s.c | ||
| io-pgtable-arm.c | ||
| io-pgtable-arm.h | ||
| io-pgtable-dart.c | ||
| io-pgtable.c | ||
| ioasid.c | ||
| iommu-debugfs.c | ||
| iommu-sva-lib.c | ||
| iommu-sva-lib.h | ||
| iommu-sysfs.c | ||
| iommu-traces.c | ||
| iommu.c | ||
| iova.c | ||
| ipmmu-vmsa.c | ||
| irq_remapping.c | ||
| irq_remapping.h | ||
| Kconfig | ||
| Makefile | ||
| msm_iommu_hw-8xxx.h | ||
| msm_iommu.c | ||
| msm_iommu.h | ||
| mtk_iommu_v1.c | ||
| mtk_iommu.c | ||
| of_iommu.c | ||
| omap-iommu-debug.c | ||
| omap-iommu.c | ||
| omap-iommu.h | ||
| omap-iopgtable.h | ||
| rockchip-iommu.c | ||
| s390-iommu.c | ||
| sprd-iommu.c | ||
| sun50i-iommu.c | ||
| tegra-gart.c | ||
| tegra-smmu.c | ||
| virtio-iommu.c | ||