MCSX_PAB_RX_SLAVE_FIFO_SKID_CFGX
mcs_reg_write(mcs, MCSX_PAB_RX_SLAVE_FIFO_SKID_CFGX(req->port_id), val);
reg = MCSX_PAB_RX_SLAVE_FIFO_SKID_CFGX(req->port_id);
reg = MCSX_PAB_RX_SLAVE_FIFO_SKID_CFGX(lmac_id);