Merge tag 'dma-mapping-6.18-2025-11-12' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

Pull dma-mapping fixes from Marek Szyprowski:

 - two minor fixes for DMA API infrastructure: restoring proper
   structure padding used in benchmark tests (Qinxin Xia) and global
   DMA_BIT_MASK macro rework to make it a bit more clang friendly (James
   Clark)

* tag 'dma-mapping-6.18-2025-11-12' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  dma-mapping: Allow use of DMA_BIT_MASK(64) in global scope
  dma-mapping: benchmark: Restore padding to ensure uABI remained consistent

Author: torvalds

include/linux/dma-mapping.h

@@ -90,7 +90,7 @@
  */
 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
 
-#define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
+#define DMA_BIT_MASK(n)	GENMASK_ULL(n - 1, 0)
 
 struct dma_iova_state {
 	dma_addr_t addr;

include/linux/map_benchmark.h

@@ -27,5 +27,6 @@ struct map_benchmark {
 	__u32 dma_dir; /* DMA data direction */
 	__u32 dma_trans_ns; /* time for DMA transmission in ns */
 	__u32 granule;  /* how many PAGE_SIZE will do map/unmap once a time */
+	__u8 expansion[76]; /* For future use */
 };
 #endif /* _KERNEL_DMA_BENCHMARK_H */