dma-mapping: remove unused mapping resource callbacks

After ARM and XEN conversions to use physical addresses for the mapping,
there are no in-kernel users for map_resource/unmap_resource callbacks,
so 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-v5-6-3bbfe3a25cdf@kernel.org

Author: rleon

include/linux/dma-map-ops.h

@@ -53,12 +53,6 @@ struct dma_map_ops {
 			enum dma_data_direction dir, unsigned long attrs);
 	void (*unmap_sg)(struct device *dev, struct scatterlist *sg, int nents,
 			enum dma_data_direction dir, unsigned long attrs);
-	dma_addr_t (*map_resource)(struct device *dev, phys_addr_t phys_addr,
-			size_t size, enum dma_data_direction dir,
-			unsigned long attrs);
-	void (*unmap_resource)(struct device *dev, dma_addr_t dma_handle,
-			size_t size, enum dma_data_direction dir,
-			unsigned long attrs);
 	void (*sync_single_for_cpu)(struct device *dev, dma_addr_t dma_handle,
 			size_t size, enum dma_data_direction dir);
 	void (*sync_single_for_device)(struct device *dev,

kernel/dma/mapping.c

@@ -157,7 +157,7 @@ dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	bool is_mmio = attrs & DMA_ATTR_MMIO;
-	dma_addr_t addr;
+	dma_addr_t addr = DMA_MAPPING_ERROR;
 
 	BUG_ON(!valid_dma_direction(dir));
 
@@ -171,18 +171,13 @@ 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) {
-		if (!ops->map_resource)
-			return DMA_MAPPING_ERROR;
-
-		addr = ops->map_resource(dev, phys, size, dir, attrs);
-	} else {
+	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, while ops->map_resource() does not.
+		 * kmappable memory.
 		 */
 		addr = ops->map_page(dev, page, offset, size, dir, attrs);
 	}
@@ -227,10 +222,7 @@ 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 if (is_mmio) {
-		if (ops->unmap_resource)
-			ops->unmap_resource(dev, addr, size, dir, attrs);
-	} else
+	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);