ISA_DMA_BIT_MASK   19 arch/x86/include/asm/dma-mapping.h # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
ISA_DMA_BIT_MASK   21 arch/x86/include/asm/dma-mapping.h # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)