valid_dma_direction
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));
BUG_ON(!valid_dma_direction(dir));