diff options
Diffstat (limited to 'drivers/iommu/arm')
| -rw-r--r-- | drivers/iommu/arm/arm-smmu/arm-smmu.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index 719fbca1fe52..443bc517277b 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1316,8 +1316,14 @@ static bool arm_smmu_capable(struct device *dev, enum iommu_cap cap) switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: - /* Assume that a coherent TCU implies coherent TBUs */ - return cfg->smmu->features & ARM_SMMU_FEAT_COHERENT_WALK; + /* + * It's overwhelmingly the case in practice that when the pagetable + * walk interface is connected to a coherent interconnect, all the + * translation interfaces are too. Furthermore if the device is + * natively coherent, then its translation interface must also be. + */ + return cfg->smmu->features & ARM_SMMU_FEAT_COHERENT_WALK || + device_get_dma_attr(dev) == DEV_DMA_COHERENT; case IOMMU_CAP_NOEXEC: return true; default: |