iommu/arm-smmu: Implement DOMAIN_ATTR_PGTBL_INFO

The DOMAIN_ATTR_PGTBL_INFO attribute will be useful in implementing DMA
APIs that can leverage the fast page table mapping routines.  Implement
it.

CRs-Fixed: 997751
Change-Id: Id3acec0089b126e7d6ad44d8d322bf473614f716
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index cec4ef4..f38eb8e 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -2924,6 +2924,17 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
                                        & (1 << DOMAIN_ATTR_FAST));
                ret = 0;
                break;
+       case DOMAIN_ATTR_PGTBL_INFO: {
+               struct iommu_pgtbl_info *info = data;
+
+               if (!(smmu_domain->attributes & (1 << DOMAIN_ATTR_FAST))) {
+                       ret = -ENODEV;
+                       break;
+               }
+               info->pmds = smmu_domain->pgtbl_cfg.av8l_fast_cfg.pmds;
+               ret = 0;
+               break;
+       }
        default:
                ret = -ENODEV;
                break;