4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon <will.deacon@xxxxxxx> commit 7d321bd3542500caf125249f44dc37cb4e738013 upstream. The IO-pgtable code relies on the driver TLB invalidation callbacks to ensure that all page-table updates are visible to the IOMMU page-table walker. In the case that the page-table walker is cache-coherent, we cannot rely on an implicit DSB from the DMA-mapping code, so we must ensure that we execute a DSB in our tlb_add_flush() callback prior to triggering the invalidation. Cc: <stable@xxxxxxxxxxxxxxx> Cc: Robin Murphy <robin.murphy@xxxxxxx> Fixes: 2df7a25ce4a7 ("iommu/arm-smmu: Clean up DMA API usage") Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iommu/arm-smmu.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -469,6 +469,9 @@ static void arm_smmu_tlb_inv_range_nosyn bool stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS; void __iomem *reg = ARM_SMMU_CB(smmu_domain->smmu, cfg->cbndx); + if (smmu_domain->smmu->features & ARM_SMMU_FEAT_COHERENT_WALK) + wmb(); + if (stage1) { reg += leaf ? ARM_SMMU_CB_S1_TLBIVAL : ARM_SMMU_CB_S1_TLBIVA; @@ -510,6 +513,9 @@ static void arm_smmu_tlb_inv_vmid_nosync struct arm_smmu_domain *smmu_domain = cookie; void __iomem *base = ARM_SMMU_GR0(smmu_domain->smmu); + if (smmu_domain->smmu->features & ARM_SMMU_FEAT_COHERENT_WALK) + wmb(); + writel_relaxed(smmu_domain->cfg.vmid, base + ARM_SMMU_GR0_TLBIVMID); }