swiotlb: remove SWIOTLB_MAP_ERROR

We can use DMA_MAPPING_ERROR instead, which already maps to the same
value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>

drivers/xen/swiotlb-xen.c

@@ -403,7 +403,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
 
 	map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
 				     attrs);
-	if (map == SWIOTLB_MAP_ERROR)
+	if (map == DMA_MAPPING_ERROR)
 		return DMA_MAPPING_ERROR;
 
 	dev_addr = xen_phys_to_bus(map);
@@ -572,7 +572,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
 								 sg_phys(sg),
 								 sg->length,
 								 dir, attrs);
-			if (map == SWIOTLB_MAP_ERROR) {
+			if (map == DMA_MAPPING_ERROR) {
 				dev_warn(hwdev, "swiotlb buffer is full\n");
 				/* Don't panic here, we expect map_sg users
 				   to do proper error handling. */

include/linux/swiotlb.h

@@ -46,9 +46,6 @@ enum dma_sync_target {
 	SYNC_FOR_DEVICE = 1,
 };
 
-/* define the last possible byte of physical address space as a mapping error */
-#define SWIOTLB_MAP_ERROR (~(phys_addr_t)0x0)
-
 extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
 					  dma_addr_t tbl_dma_addr,
 					  phys_addr_t phys, size_t size,

kernel/dma/swiotlb.c

@@ -526,7 +526,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
 	spin_unlock_irqrestore(&io_tlb_lock, flags);
 	if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
 		dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size);
-	return SWIOTLB_MAP_ERROR;
+	return DMA_MAPPING_ERROR;
 found:
 	spin_unlock_irqrestore(&io_tlb_lock, flags);
 
@@ -637,7 +637,7 @@ static dma_addr_t swiotlb_bounce_page(struct device *dev, phys_addr_t *phys,
 	/* 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)
+	if (*phys == DMA_MAPPING_ERROR)
 		return DMA_MAPPING_ERROR;
 
 	/* Ensure that the address returned is DMA'ble */