GEN3_IMBAR1XLMT_OFFSET
iowrite64(bar_addr, mmio + GEN3_IMBAR1XLMT_OFFSET);
bar_addr = ioread64(mmio + GEN3_IMBAR1XLMT_OFFSET);
u.v64 = ioread64(mmio + GEN3_IMBAR1XLMT_OFFSET);
.bar2_limit = GEN3_IMBAR1XLMT_OFFSET,