CIU3_IDT_IO
cvmx_write_csr(b + CIU3_IDT_IO(idt_ip2), 0);
cvmx_write_csr(b + CIU3_IDT_IO(idt_ip3), 0);
cvmx_write_csr(b + CIU3_IDT_IO(idt_ip4), 0);
cvmx_write_csr(b + CIU3_IDT_IO(unused_idt2), 0);