dma-direct: remove the mapping_error dma_map_ops method

The dma-direct code already returns (~(dma_addr_t)0x0) on mapping
failures, so we can switch over to returning DMA_MAPPING_ERROR and let
the core dma-mapping code handle the rest.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/kernel/dma-swiotlb.c

@@ -59,7 +59,6 @@ const struct dma_map_ops powerpc_swiotlb_dma_ops = {
 	.sync_single_for_device = swiotlb_sync_single_for_device,
 	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 	.sync_sg_for_device = swiotlb_sync_sg_for_device,
-	.mapping_error = dma_direct_mapping_error,
 	.get_required_mask = swiotlb_powerpc_get_required,
 };
 

include/linux/dma-direct.h

@@ -5,8 +5,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/mem_encrypt.h>
 
-#define DIRECT_MAPPING_ERROR		(~(dma_addr_t)0)
-
 #ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
 #include <asm/dma-direct.h>
 #else
@@ -76,5 +74,4 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
 int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 		enum dma_data_direction dir, unsigned long attrs);
 int dma_direct_supported(struct device *dev, u64 mask);
-int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr);
 #endif /* _LINUX_DMA_DIRECT_H */

kernel/dma/direct.c

@@ -289,7 +289,7 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
 	dma_addr_t dma_addr = phys_to_dma(dev, phys);
 
 	if (!check_addr(dev, dma_addr, size, __func__))
-		return DIRECT_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		dma_direct_sync_single_for_device(dev, dma_addr, size, dir);
@@ -336,11 +336,6 @@ int dma_direct_supported(struct device *dev, u64 mask)
 	return mask >= phys_to_dma(dev, min_mask);
 }
 
-int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
-	return dma_addr == DIRECT_MAPPING_ERROR;
-}
-
 const struct dma_map_ops dma_direct_ops = {
 	.alloc			= dma_direct_alloc,
 	.free			= dma_direct_free,
@@ -359,7 +354,6 @@ const struct dma_map_ops dma_direct_ops = {
 #endif
 	.get_required_mask	= dma_direct_get_required_mask,
 	.dma_supported		= dma_direct_supported,
-	.mapping_error		= dma_direct_mapping_error,
 	.cache_sync		= arch_dma_cache_sync,
 };
 EXPORT_SYMBOL(dma_direct_ops);

kernel/dma/swiotlb.c

@@ -631,21 +631,21 @@ static dma_addr_t swiotlb_bounce_page(struct device *dev, phys_addr_t *phys,
 	if (unlikely(swiotlb_force == SWIOTLB_NO_FORCE)) {
 		dev_warn_ratelimited(dev,
 			"Cannot do DMA to address %pa\n", phys);
-		return DIRECT_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 	}
 
 	/* Oh well, have to allocate and map a bounce buffer. */
 	*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),
 			*phys, size, dir, attrs);
 	if (*phys == SWIOTLB_MAP_ERROR)
-		return DIRECT_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 
 	/* Ensure that the address returned is DMA'ble */
 	dma_addr = __phys_to_dma(dev, *phys);
 	if (unlikely(!dma_capable(dev, dma_addr, size))) {
 		swiotlb_tbl_unmap_single(dev, *phys, size, dir,
 			attrs | DMA_ATTR_SKIP_CPU_SYNC);
-		return DIRECT_MAPPING_ERROR;
+		return DMA_MAPPING_ERROR;
 	}
 
 	return dma_addr;
@@ -680,7 +680,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 
 	if (!dev_is_dma_coherent(dev) &&
 	    (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0 &&
-	    dev_addr != DIRECT_MAPPING_ERROR)
+	    dev_addr != DMA_MAPPING_ERROR)
 		arch_sync_dma_for_device(dev, phys, size, dir);
 
 	return dev_addr;
@@ -789,7 +789,7 @@ swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, int nelems,
 	for_each_sg(sgl, sg, nelems, i) {
 		sg->dma_address = swiotlb_map_page(dev, sg_page(sg), sg->offset,
 				sg->length, dir, attrs);
-		if (sg->dma_address == DIRECT_MAPPING_ERROR)
+		if (sg->dma_address == DMA_MAPPING_ERROR)
 			goto out_error;
 		sg_dma_len(sg) = sg->length;
 	}
@@ -869,7 +869,6 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask)
 }
 
 const struct dma_map_ops swiotlb_dma_ops = {
-	.mapping_error		= dma_direct_mapping_error,
 	.alloc			= dma_direct_alloc,
 	.free			= dma_direct_free,
 	.sync_single_for_cpu	= swiotlb_sync_single_for_cpu,