IOAT_MMIO_BAR
err = pcim_iomap_regions(pdev, 1 << IOAT_MMIO_BAR, DRV_NAME);
version = readb(iomap[IOAT_MMIO_BAR] + IOAT_VER_OFFSET);
device = alloc_ioatdma(pdev, iomap[IOAT_MMIO_BAR]);