Subject: [PATCH v3 21/32] iommu/tegra-smmu: implement iova_to_phys_length

From: Guanghui Feng <[email-masked]>
Date: Wed, 3 Jun 2026 23:17:53 +0800

Implement iova_to_phys_length for Tegra SMMU IOMMU driver,
returning the actual PTE mapping size.

Signed-off-by: Guanghui Feng <[email-masked]>
---
 drivers/iommu/tegra-smmu.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 67e7a7b925f0..12f9bb623d87 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -803,8 +803,8 @@ static size_t tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
 	return size;
 }
 
-static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
-					   dma_addr_t iova)
+static phys_addr_t tegra_smmu_iova_to_phys_length(struct iommu_domain *domain,
+					   dma_addr_t iova, size_t *mapped_length)
 {
 	struct tegra_smmu_as *as = to_smmu_as(domain);
 	unsigned long pfn;
@@ -813,10 +813,13 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
 
 	pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
 	if (!pte || !*pte)
-		return 0;
+		return PHYS_ADDR_MAX;
 
 	pfn = *pte & as->smmu->pfn_mask;
 
+	if (mapped_length)
+		*mapped_length = SZ_4K;
+
 	return SMMU_PFN_PHYS(pfn) + SMMU_OFFSET_IN_PAGE(iova);
 }
 
@@ -1007,7 +1010,7 @@ static const struct iommu_ops tegra_smmu_ops = {
 		.attach_dev	= tegra_smmu_attach_dev,
 		.map_pages	= tegra_smmu_map,
 		.unmap_pages	= tegra_smmu_unmap,
-		.iova_to_phys	= tegra_smmu_iova_to_phys,
+		.iova_to_phys_length = tegra_smmu_iova_to_phys_length,
 		.free		= tegra_smmu_domain_free,
 	}
 };
-- 
2.43.7