[PATCH 3/8] iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys

[Leon Romanovsky]

From: Leon Romanovsky <leonro at nvidia.com>

Rename the IOMMU DMA mapping functions to better reflect their actual
calling convention. The functions iommu_dma_map_page() and
iommu_dma_unmap_page() are renamed to iommu_dma_map_phys() and
iommu_dma_unmap_phys() respectively, as they already operate on physical
addresses rather than page structures.

The calling convention changes from accepting (struct page *page,
unsigned long offset) to (phys_addr_t phys), which eliminates the need
for page-to-physical address conversion within the functions. This
renaming prepares for the broader DMA API conversion from page-based
to physical address-based mapping throughout the kernel.

All callers are updated to pass physical addresses directly, including
dma_map_page_attrs(), scatterlist mapping functions, and DMA page
allocation helpers. The change simplifies the code by removing the
page_to_phys() + offset calculation that was previously done inside
the IOMMU functions.

Signed-off-by: Leon Romanovsky <leonro at nvidia.com>
---
 drivers/iommu/dma-iommu.c | 14 ++++++--------
 include/linux/iommu-dma.h |  7 +++----
 kernel/dma/mapping.c      |  4 ++--
 kernel/dma/ops_helpers.c  |  6 +++---
 4 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index ea2ef53bd4fe..cd4bc22efa96 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1190,11 +1190,9 @@ static inline size_t iova_unaligned(struct iova_domain *iovad, phys_addr_t phys,
 	return iova_offset(iovad, phys | size);
 }
 
-dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
-	      unsigned long offset, size_t size, enum dma_data_direction dir,
-	      unsigned long attrs)
+dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
+		enum dma_data_direction dir, unsigned long attrs)
 {
-	phys_addr_t phys = page_to_phys(page) + offset;
 	bool coherent = dev_is_dma_coherent(dev);
 	int prot = dma_info_to_prot(dir, coherent, attrs);
 	struct iommu_domain *domain = iommu_get_dma_domain(dev);
@@ -1222,7 +1220,7 @@ dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
 	return iova;
 }
 
-void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+void iommu_dma_unmap_phys(struct device *dev, dma_addr_t dma_handle,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	struct iommu_domain *domain = iommu_get_dma_domain(dev);
@@ -1341,7 +1339,7 @@ static void iommu_dma_unmap_sg_swiotlb(struct device *dev, struct scatterlist *s
 	int i;
 
 	for_each_sg(sg, s, nents, i)
-		iommu_dma_unmap_page(dev, sg_dma_address(s),
+		iommu_dma_unmap_phys(dev, sg_dma_address(s),
 				sg_dma_len(s), dir, attrs);
 }
 
@@ -1354,8 +1352,8 @@ static int iommu_dma_map_sg_swiotlb(struct device *dev, struct scatterlist *sg,
 	sg_dma_mark_swiotlb(sg);
 
 	for_each_sg(sg, s, nents, i) {
-		sg_dma_address(s) = iommu_dma_map_page(dev, sg_page(s),
-				s->offset, s->length, dir, attrs);
+		sg_dma_address(s) = iommu_dma_map_phys(dev, sg_phys(s),
+				s->length, dir, attrs);
 		if (sg_dma_address(s) == DMA_MAPPING_ERROR)
 			goto out_unmap;
 		sg_dma_len(s) = s->length;
diff --git a/include/linux/iommu-dma.h b/include/linux/iommu-dma.h
index 508beaa44c39..485bdffed988 100644
--- a/include/linux/iommu-dma.h
+++ b/include/linux/iommu-dma.h
@@ -21,10 +21,9 @@ static inline bool use_dma_iommu(struct device *dev)
 }
 #endif /* CONFIG_IOMMU_DMA */
 
-dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
-		unsigned long offset, size_t size, enum dma_data_direction dir,
-		unsigned long attrs);
-void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+dma_addr_t iommu_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
+		enum dma_data_direction dir, unsigned long attrs);
+void iommu_dma_unmap_phys(struct device *dev, dma_addr_t dma_handle,
 		size_t size, enum dma_data_direction dir, unsigned long attrs);
 int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		enum dma_data_direction dir, unsigned long attrs);
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index fe1f0da6dc50..58482536db9b 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -169,7 +169,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
 	    arch_dma_map_page_direct(dev, phys + size))
 		addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
 	else if (use_dma_iommu(dev))
-		addr = iommu_dma_map_page(dev, page, offset, size, dir, attrs);
+		addr = iommu_dma_map_phys(dev, phys, size, dir, attrs);
 	else
 		addr = ops->map_page(dev, page, offset, size, dir, attrs);
 	kmsan_handle_dma(page, offset, size, dir);
@@ -190,7 +190,7 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
 	    arch_dma_unmap_page_direct(dev, addr + size))
 		dma_direct_unmap_page(dev, addr, size, dir, attrs);
 	else if (use_dma_iommu(dev))
-		iommu_dma_unmap_page(dev, addr, size, dir, attrs);
+		iommu_dma_unmap_phys(dev, addr, size, dir, attrs);
 	else
 		ops->unmap_page(dev, addr, size, dir, attrs);
 	trace_dma_unmap_phys(dev, addr, size, dir, attrs);
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c
index 9afd569eadb9..6f9d604d9d40 100644
--- a/kernel/dma/ops_helpers.c
+++ b/kernel/dma/ops_helpers.c
@@ -72,8 +72,8 @@ struct page *dma_common_alloc_pages(struct device *dev, size_t size,
 		return NULL;
 
 	if (use_dma_iommu(dev))
-		*dma_handle = iommu_dma_map_page(dev, page, 0, size, dir,
-						 DMA_ATTR_SKIP_CPU_SYNC);
+		*dma_handle = iommu_dma_map_phys(dev, page_to_phys(page), size,
+						 dir, DMA_ATTR_SKIP_CPU_SYNC);
 	else
 		*dma_handle = ops->map_page(dev, page, 0, size, dir,
 					    DMA_ATTR_SKIP_CPU_SYNC);
@@ -92,7 +92,7 @@ void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	if (use_dma_iommu(dev))
-		iommu_dma_unmap_page(dev, dma_handle, size, dir,
+		iommu_dma_unmap_phys(dev, dma_handle, size, dir,
 				     DMA_ATTR_SKIP_CPU_SYNC);
 	else if (ops->unmap_page)
 		ops->unmap_page(dev, dma_handle, size, dir,
-- 
2.49.0