iommu/arm-smmu: Add support for pagetable config domain attribute

Add support for domain attribute DOMAIN_ATTR_IO_PGTABLE_CFG
to get/set pagetable configuration data which initially will
be used to set quirks and later can be extended to include
other pagetable configuration data.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Link: https://lore.kernel.org/r/2ab52ced2f853115c32461259a075a2877feffa6.1606287059.git.saiprakash.ranjan@codeaurora.org
Signed-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm/arm-smmu/arm-smmu.c

@@ -789,6 +789,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 	if (smmu_domain->non_strict)
 		pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
 
+	if (smmu_domain->pgtbl_cfg.quirks)
+		pgtbl_cfg.quirks |= smmu_domain->pgtbl_cfg.quirks;
+
 	pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
 	if (!pgtbl_ops) {
 		ret = -ENOMEM;
@@ -1511,6 +1514,12 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
 		case DOMAIN_ATTR_NESTING:
 			*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
 			return 0;
+		case DOMAIN_ATTR_IO_PGTABLE_CFG: {
+			struct io_pgtable_domain_attr *pgtbl_cfg = data;
+			*pgtbl_cfg = smmu_domain->pgtbl_cfg;
+
+			return 0;
+		}
 		default:
 			return -ENODEV;
 		}
@@ -1551,6 +1560,17 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 			else
 				smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
 			break;
+		case DOMAIN_ATTR_IO_PGTABLE_CFG: {
+			struct io_pgtable_domain_attr *pgtbl_cfg = data;
+
+			if (smmu_domain->smmu) {
+				ret = -EPERM;
+				goto out_unlock;
+			}
+
+			smmu_domain->pgtbl_cfg = *pgtbl_cfg;
+			break;
+		}
 		default:
 			ret = -ENODEV;
 		}

drivers/iommu/arm/arm-smmu/arm-smmu.h

@@ -364,6 +364,7 @@ enum arm_smmu_domain_stage {
 struct arm_smmu_domain {
 	struct arm_smmu_device		*smmu;
 	struct io_pgtable_ops		*pgtbl_ops;
+	struct io_pgtable_domain_attr	pgtbl_cfg;
 	const struct iommu_flush_ops	*flush_ops;
 	struct arm_smmu_cfg		cfg;
 	enum arm_smmu_domain_stage	stage;