to_tcf_csum
update_flags = rcu_dereference(to_tcf_csum(a)->params)->update_flags;
struct tcf_csum *p = to_tcf_csum(a);
const struct tcf_csum *p = to_tcf_csum(a);
struct tcf_csum *p = to_tcf_csum(a);
p = to_tcf_csum(*a);