Subject: [PATCH v3 18/32] iommu/s390: implement iova_to_phys_length

From: Guanghui Feng <[email-masked]>
Date: Wed, 3 Jun 2026 23:17:50 +0800

Implement iova_to_phys_length for s390 IOMMU driver,
returning the actual PTE mapping size.

Signed-off-by: Guanghui Feng <[email-masked]>
---
 drivers/iommu/s390-iommu.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index f148f559ac56..6cfcc55ef59f 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -986,22 +986,23 @@ static unsigned long *get_rto_from_iova(struct s390_domain *domain,
 	}
 }
 
-static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
-					   dma_addr_t iova)
+static phys_addr_t s390_iommu_iova_to_phys_length(struct iommu_domain *domain,
+						  dma_addr_t iova,
+						  size_t *mapped_length)
 {
 	struct s390_domain *s390_domain = to_s390_domain(domain);
 	unsigned long *rto, *sto, *pto;
 	unsigned long ste, pte, rte;
 	unsigned int rtx, sx, px;
-	phys_addr_t phys = 0;
+	phys_addr_t phys = PHYS_ADDR_MAX;
 
 	if (iova < domain->geometry.aperture_start ||
 	    iova > domain->geometry.aperture_end)
-		return 0;
+		return PHYS_ADDR_MAX;
 
 	rto = get_rto_from_iova(s390_domain, iova);
 	if (!rto)
-		return 0;
+		return PHYS_ADDR_MAX;
 
 	rtx = calc_rtx(iova);
 	sx = calc_sx(iova);
@@ -1014,8 +1015,11 @@ static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
 		if (reg_entry_isvalid(ste)) {
 			pto = get_st_pto(ste);
 			pte = READ_ONCE(pto[px]);
-			if (pt_entry_isvalid(pte))
+			if (pt_entry_isvalid(pte)) {
 				phys = pte & ZPCI_PTE_ADDR_MASK;
+				if (mapped_length)
+					*mapped_length = SZ_4K;
+			}
 		}
 	}
 
@@ -1183,7 +1187,7 @@ static struct iommu_domain blocking_domain = {
 		.flush_iotlb_all = s390_iommu_flush_iotlb_all, \
 		.iotlb_sync      = s390_iommu_iotlb_sync, \
 		.iotlb_sync_map  = s390_iommu_iotlb_sync_map, \
-		.iova_to_phys	= s390_iommu_iova_to_phys, \
+		.iova_to_phys_length	= s390_iommu_iova_to_phys_length, \
 		.free		= s390_domain_free, \
 	}
 
-- 
2.43.7