iommu/arm-smmu: Clean up DMA API usage

With the correct DMA API calls now integrated into the io-pgtable code,
let that handle the flushing of non-coherent page table updates.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 6 insertions, 16 deletions

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 0583ed2f33c0..5770ab98fa38 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -611,24 +611,13 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 static void arm_smmu_flush_pgtable(void *addr, size_t size, void *cookie)
 {
         struct arm_smmu_domain *smmu_domain = cookie;
-        struct arm_smmu_device *smmu = smmu_domain->smmu;
-        unsigned long offset = (unsigned long)addr & ~PAGE_MASK;
-
 
-        /* Ensure new page tables are visible to the hardware walker */
-        if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK) {
+        /*
+         * Ensure new page tables are visible to a coherent hardware walker.
+         * The page table code deals with flushing for the non-coherent case.
+         */
+        if (smmu_domain->smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
                 dsb(ishst);
-        } else {
-                /*
-                 * If the SMMU can't walk tables in the CPU caches, treat them
-                 * like non-coherent DMA since we need to flush the new entries
-                 * all the way out to memory. There's no possibility of
-                 * recursion here as the SMMU table walker will not be wired
-                 * through another SMMU.
-                 */
-                dma_map_page(smmu->dev, virt_to_page(addr), offset, size,
-                             DMA_TO_DEVICE);
-        }
 }
 
 static struct iommu_gather_ops arm_smmu_gather_ops = {
@@ -899,6 +888,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
                 .ias            = ias,
                 .oas            = oas,
                 .tlb            = &arm_smmu_gather_ops,
+                .iommu_dev      = smmu->dev,
         };
 
         smmu_domain->smmu = smmu;