dma_unmap_len_set  300 include/linux/dma-mapping.h #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
dma_unmap_len_set  307 include/linux/dma-mapping.h #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)