dma-mapping: remove unused map_page callback

After conversion of arch code to use physical address mapping,
there are no users of .map_page() and .unmap_page() callbacks,
so let's remove them.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251015-remove-map-page-v5-14-3bbfe3a25cdf@kernel.org

Author: rleon

include/linux/dma-map-ops.h

@@ -31,13 +31,6 @@ struct dma_map_ops {
 			void *cpu_addr, dma_addr_t dma_addr, size_t size,
 			unsigned long attrs);
 
-	dma_addr_t (*map_page)(struct device *dev, struct page *page,
-			unsigned long offset, size_t size,
-			enum dma_data_direction dir, unsigned long attrs);
-	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);

kernel/dma/mapping.c

@@ -171,16 +171,6 @@ dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
 		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 && ops->map_page) {
-		struct page *page = phys_to_page(phys);
-		size_t offset = offset_in_page(phys);
-
-		/*
-		 * The dma_ops API contract for ops->map_page() requires
-		 * kmappable memory.
-		 */
-		addr = ops->map_page(dev, page, offset, size, dir, attrs);
-	}
 
 	if (!is_mmio)
 		kmsan_handle_dma(phys, size, dir);
@@ -222,8 +212,6 @@ void dma_unmap_phys(struct device *dev, dma_addr_t addr, size_t size,
 		iommu_dma_unmap_phys(dev, addr, size, dir, attrs);
 	else if (ops->unmap_phys)
 		ops->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);
 	debug_dma_unmap_phys(dev, addr, size, dir);
 }

kernel/dma/ops_helpers.c

@@ -76,11 +76,8 @@ struct page *dma_common_alloc_pages(struct device *dev, size_t size,
 	if (use_dma_iommu(dev))
 		*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_handle = ops->map_phys(dev, phys, size, dir,
 					    DMA_ATTR_SKIP_CPU_SYNC);
 	if (*dma_handle == DMA_MAPPING_ERROR) {
 		dma_free_contiguous(dev, page, size);
@@ -102,8 +99,5 @@ void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
 	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);
 	dma_free_contiguous(dev, page, size);
 }