ARM_V7S_LVL_IDX
tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl, cfg);
ptep += ARM_V7S_LVL_IDX(iova, lvl, cfg);
idx = ARM_V7S_LVL_IDX(iova, lvl, &iop->cfg);
ptep += ARM_V7S_LVL_IDX(iova, ++lvl, &data->iop.cfg);