dsa_switch_find
ds = dsa_switch_find(dst->index, dev);
struct dsa_switch *dsa_switch_find(int tree_index, int sw_index);
if (dsa_switch_find(ds->dst->index, ds->index)) {
EXPORT_SYMBOL_GPL(dsa_switch_find);
ds = dsa_switch_find(cpu_dp->dst->index, switch_id);