[PATCHv8 2/8] iommu/arm-smmu: Add domain attribute for pagetable configuration

[Sai Prakash Ranjan]

Add iommu domain attribute for pagetable configuration which
initially will be used to set quirks like for system cache aka
last level cache to be used by client drivers like GPU to set
right attributes for caching the hardware pagetables into the
system cache and later can be extended to include other page
table configuration data.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
---
 drivers/iommu/arm/arm-smmu/arm-smmu.c | 25 +++++++++++++++++++++++++
 drivers/iommu/arm/arm-smmu/arm-smmu.h |  1 +
 include/linux/io-pgtable.h            |  4 ++++
 include/linux/iommu.h                 |  1 +
 4 files changed, 31 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 0f28a8614da3..7b05782738e2 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/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 domain_attr_io_pgtbl_cfg *pgtbl_cfg = data;
+			*pgtbl_cfg = smmu_domain->pgtbl_cfg;
+
+			return 0;
+		}
 		default:
 			return -ENODEV;
 		}
@@ -1551,6 +1560,22 @@ 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 domain_attr_io_pgtbl_cfg *pgtbl_cfg = data;
+
+			if (smmu_domain->smmu) {
+				ret = -EPERM;
+				goto out_unlock;
+			}
+
+			if (!pgtbl_cfg) {
+				ret = -ENODEV;
+				goto out_unlock;
+			}
+
+			smmu_domain->pgtbl_cfg = *pgtbl_cfg;
+			break;
+		}
 		default:
 			ret = -ENODEV;
 		}
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index 04288b6fc619..18fbed376afb 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/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 domain_attr_io_pgtbl_cfg	pgtbl_cfg;
 	const struct iommu_flush_ops	*flush_ops;
 	struct arm_smmu_cfg		cfg;
 	enum arm_smmu_domain_stage	stage;
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index a9a2c59fab37..686b37d48743 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -212,6 +212,10 @@ struct io_pgtable {
 
 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
 
+struct domain_attr_io_pgtbl_cfg {
+	unsigned long quirks;
+};
+
 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
 {
 	iop->cfg.tlb->tlb_flush_all(iop->cookie);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b95a6f8db6ff..ffaa389ea128 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -118,6 +118,7 @@ enum iommu_attr {
 	DOMAIN_ATTR_FSL_PAMUV1,
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
 	DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
+	DOMAIN_ATTR_IO_PGTABLE_CFG,
 	DOMAIN_ATTR_MAX,
 };
 
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