Subject: [PATCH v2 03/30] iommu/io-pgtable-arm-v7s: introduce iova_to_phys_length in io_pgtable_ops

From: Guanghui Feng <[email-masked]>
Date: Tue, 2 Jun 2026 18:46:10 +0800

Implement iova_to_phys_length in ARM v7s backend: returns block size
derived from level mask. The old iova_to_phys is kept as a thin wrapper.

Signed-off-by: Guanghui Feng <[email-masked]>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 34 ++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 1dbef8c55007..5868d68e8a85 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -641,13 +641,27 @@ static size_t arm_v7s_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova
 	return unmapped;
 }
 
+static phys_addr_t arm_v7s_iova_to_phys_length(struct io_pgtable_ops *ops,
+						unsigned long iova,
+						size_t *mapped_length);
+
 static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops,
 					unsigned long iova)
+{
+	phys_addr_t phys = arm_v7s_iova_to_phys_length(ops, iova, NULL);
+
+	return (phys == PHYS_ADDR_MAX) ? 0 : phys;
+}
+
+static phys_addr_t arm_v7s_iova_to_phys_length(struct io_pgtable_ops *ops,
+						unsigned long iova,
+						size_t *mapped_length)
 {
 	struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
 	arm_v7s_iopte *ptep = data->pgd, pte;
 	int lvl = 0;
 	u32 mask;
+	size_t blk_size;
 
 	do {
 		ptep += ARM_V7S_LVL_IDX(iova, ++lvl, &data->iop.cfg);
@@ -656,11 +670,16 @@ static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops,
 	} while (ARM_V7S_PTE_IS_TABLE(pte, lvl));
 
 	if (!ARM_V7S_PTE_IS_VALID(pte))
-		return 0;
+		return PHYS_ADDR_MAX;
 
 	mask = ARM_V7S_LVL_MASK(lvl);
 	if (arm_v7s_pte_is_cont(pte, lvl))
 		mask *= ARM_V7S_CONT_PAGES;
+
+	blk_size = ~mask + 1U;
+	if (mapped_length)
+		*mapped_length = blk_size;
+
 	return iopte_to_paddr(pte, lvl, &data->iop.cfg) | (iova & ~mask);
 }
 
@@ -714,6 +733,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
 		.map_pages	= arm_v7s_map_pages,
 		.unmap_pages	= arm_v7s_unmap_pages,
 		.iova_to_phys	= arm_v7s_iova_to_phys,
+		.iova_to_phys_length	= arm_v7s_iova_to_phys_length,
 	};
 
 	/* We have to do this early for __arm_v7s_alloc_table to work... */
@@ -843,13 +863,13 @@ static int __init arm_v7s_do_selftests(void)
 	 * Initial sanity checks.
 	 * Empty page tables shouldn't provide any translations.
 	 */
-	if (ops->iova_to_phys(ops, 42))
+	if (ops->iova_to_phys_length(ops, 42, NULL) != PHYS_ADDR_MAX)
 		return __FAIL(ops);
 
-	if (ops->iova_to_phys(ops, SZ_1G + 42))
+	if (ops->iova_to_phys_length(ops, SZ_1G + 42, NULL) != PHYS_ADDR_MAX)
 		return __FAIL(ops);
 
-	if (ops->iova_to_phys(ops, SZ_2G + 42))
+	if (ops->iova_to_phys_length(ops, SZ_2G + 42, NULL) != PHYS_ADDR_MAX)
 		return __FAIL(ops);
 
 	/*
@@ -870,7 +890,7 @@ static int __init arm_v7s_do_selftests(void)
 				    &mapped))
 			return __FAIL(ops);
 
-		if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
+		if (ops->iova_to_phys_length(ops, iova + 42, NULL) != (iova + 42))
 			return __FAIL(ops);
 
 		iova += SZ_16M;
@@ -884,7 +904,7 @@ static int __init arm_v7s_do_selftests(void)
 		if (ops->unmap_pages(ops, iova, size, 1, NULL) != size)
 			return __FAIL(ops);
 
-		if (ops->iova_to_phys(ops, iova + 42))
+		if (ops->iova_to_phys_length(ops, iova + 42, NULL) != PHYS_ADDR_MAX)
 			return __FAIL(ops);
 
 		/* Remap full block */
@@ -892,7 +912,7 @@ static int __init arm_v7s_do_selftests(void)
 				   GFP_KERNEL, &mapped))
 			return __FAIL(ops);
 
-		if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
+		if (ops->iova_to_phys_length(ops, iova + 42, NULL) != (iova + 42))
 			return __FAIL(ops);
 
 		iova += SZ_16M;
-- 
2.43.7