Merge tag 'dma-mapping-7.1-2026-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

Pull dma-mapping fix from Marek Szyprowski:
 "Three more fixes for the DMA-mapping code, related to PCI P2PDMA, DMA
  debug and DMA link ranges API (Li RongQing and Jason Gunthorpe)"

* tag 'dma-mapping-7.1-2026-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  iommu/dma: Do not try to iommu_map a 0 length region in swiotlb
  dma-debug: fix physical address retrieval in debug_dma_sync_sg_for_device
  dma-mapping: direct: fix missing mapping for THRU_HOST_BRIDGE segments

kernel/dma/debug.c

@@ -1556,7 +1556,7 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 		struct dma_debug_entry ref = {
 			.type           = dma_debug_sg,
 			.dev            = dev,
-			.paddr		= sg_phys(sg),
+			.paddr		= sg_phys(s),
 			.dev_addr       = sg_dma_address(s),
 			.size           = sg_dma_len(s),
 			.direction      = direction,

kernel/dma/direct.c

@@ -476,7 +476,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 			 * must be mapped with CPU physical address and not PCI
 			 * bus addresses.
 			 */
-			break;
+			fallthrough;
 		case PCI_P2PDMA_MAP_NONE:
 			need_sync = true;
 			sg->dma_address = dma_direct_map_phys(dev, sg_phys(sg),