swiotlb_dma_mapping_error 22 arch/x86/kernel/pci-swiotlb_64.c .mapping_error = swiotlb_dma_mapping_error, swiotlb_dma_mapping_error 38 include/asm-x86/swiotlb.h extern int swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);