+static int napi_poll(struct napi_struct *n, struct list_head *repoll)
+{
+ void *have;
+ int work, weight;
+
+ list_del_init(&n->poll_list);
+
+ have = netpoll_poll_lock(n);
+
+ weight = n->weight;
+
+ /* This NAPI_STATE_SCHED test is for avoiding a race
+ * with netpoll's poll_napi(). Only the entity which
+ * obtains the lock and sees NAPI_STATE_SCHED set will
+ * actually make the ->poll() call. Therefore we avoid
+ * accidentally calling ->poll() when NAPI is not scheduled.
+ */
+ work = 0;
+ if (test_bit(NAPI_STATE_SCHED, &n->state)) {
+ work = n->poll(n, weight);
+ trace_napi_poll(n);
+ }
+
+ WARN_ON_ONCE(work > weight);
+
+ if (likely(work < weight))
+ goto out_unlock;
+
+ /* Drivers must not modify the NAPI state if they
+ * consume the entire weight. In such cases this code
+ * still "owns" the NAPI instance and therefore can
+ * move the instance around on the list at-will.
+ */
+ if (unlikely(napi_disable_pending(n))) {
+ napi_complete(n);
+ goto out_unlock;
+ }
+
+ if (n->gro_list) {
+ /* flush too old packets
+ * If HZ < 1000, flush all packets.
+ */
+ napi_gro_flush(n, HZ >= 1000);
+ }
+
+ /* Some drivers may have called napi_schedule
+ * prior to exhausting their budget.
+ */
+ if (unlikely(!list_empty(&n->poll_list))) {
+ pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
+ n->dev ? n->dev->name : "backlog");
+ goto out_unlock;
+ }
+
+ list_add_tail(&n->poll_list, repoll);
+
+out_unlock:
+ netpoll_poll_unlock(have);
+
+ return work;
+}
+