Subject: [PATCH v5 01/14] dma-mapping: prepare dma_map_ops to conversion to physical address

From: Leon Romanovsky <[email-masked]>
Date: Wed, 15 Oct 2025 12:12:47 +0300

From: Leon Romanovsky <[email-masked]>

Add new .map_phys() and .unmap_phys() callbacks to dma_map_ops as a
preparation to replace .map_page() and .unmap_page() respectively.

Reviewed-by: Jason Gunthorpe <[email-masked]>
Signed-off-by: Leon Romanovsky <[email-masked]>
---
 include/linux/dma-map-ops.h |  7 +++++++
 kernel/dma/mapping.c        |  4 ++++
 kernel/dma/ops_helpers.c    | 12 ++++++++++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index 10882d00cb17..79d2a74d4b49 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -37,6 +37,13 @@ struct dma_map_ops {
 	void (*unmap_page)(struct device *dev, dma_addr_t dma_handle,
 			size_t size, enum dma_data_direction dir,
 			unsigned long attrs);
+
+	dma_addr_t (*map_phys)(struct device *dev, phys_addr_t phys,
+			size_t size, enum dma_data_direction dir,
+			unsigned long attrs);
+	void (*unmap_phys)(struct device *dev, dma_addr_t dma_handle,
+			size_t size, enum dma_data_direction dir,
+			unsigned long attrs);
 	/*
 	 * map_sg should return a negative error code on error. See
 	 * dma_map_sgtable() for a list of appropriate error codes
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index fe7472f13b10..4080aebe5deb 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -169,6 +169,8 @@ dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
 		addr = dma_direct_map_phys(dev, phys, size, dir, attrs);
 	else if (use_dma_iommu(dev))
 		addr = iommu_dma_map_phys(dev, phys, size, dir, attrs);
+	else if (ops->map_phys)
+		addr = ops->map_phys(dev, phys, size, dir, attrs);
 	else if (is_mmio) {
 		if (!ops->map_resource)
 			return DMA_MAPPING_ERROR;
@@ -223,6 +225,8 @@ void dma_unmap_phys(struct device *dev, dma_addr_t addr, size_t size,
 		dma_direct_unmap_phys(dev, addr, size, dir, attrs);
 	else if (use_dma_iommu(dev))
 		iommu_dma_unmap_phys(dev, addr, size, dir, attrs);
+	else if (ops->unmap_phys)
+		ops->unmap_phys(dev, addr, size, dir, attrs);
 	else if (is_mmio) {
 		if (ops->unmap_resource)
 			ops->unmap_resource(dev, addr, size, dir, attrs);
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c
index 6f9d604d9d40..1eccbdbc99c1 100644
--- a/kernel/dma/ops_helpers.c
+++ b/kernel/dma/ops_helpers.c
@@ -64,6 +64,7 @@ struct page *dma_common_alloc_pages(struct device *dev, size_t size,
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct page *page;
+	phys_addr_t phys;
 
 	page = dma_alloc_contiguous(dev, size, gfp);
 	if (!page)
@@ -71,9 +72,13 @@ struct page *dma_common_alloc_pages(struct device *dev, size_t size,
 	if (!page)
 		return NULL;
 
+	phys = page_to_phys(page);
 	if (use_dma_iommu(dev))
-		*dma_handle = iommu_dma_map_phys(dev, page_to_phys(page), size,
-						 dir, DMA_ATTR_SKIP_CPU_SYNC);
+		*dma_handle = iommu_dma_map_phys(dev, phys, size, dir,
+						 DMA_ATTR_SKIP_CPU_SYNC);
+	else if (ops->map_phys)
+		*dma_handle = ops->map_phys(dev, phys, size, dir,
+					    DMA_ATTR_SKIP_CPU_SYNC);
 	else
 		*dma_handle = ops->map_page(dev, page, 0, size, dir,
 					    DMA_ATTR_SKIP_CPU_SYNC);
@@ -94,6 +99,9 @@ void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
 	if (use_dma_iommu(dev))
 		iommu_dma_unmap_phys(dev, dma_handle, size, dir,
 				     DMA_ATTR_SKIP_CPU_SYNC);
+	else if (ops->unmap_phys)
+		ops->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,
 				DMA_ATTR_SKIP_CPU_SYNC);

-- 
2.51.0