+
+/**
+ * i40e_detect_recover_hung_queue - Function to detect and recover hung_queue
+ * @q_idx: TX queue number
+ * @vsi: Pointer to VSI struct
+ *
+ * This function checks specified queue for given VSI. Detects hung condition.
+ * Sets hung bit since it is two step process. Before next run of service task
+ * if napi_poll runs, it reset 'hung' bit for respective q_vector. If not,
+ * hung condition remain unchanged and during subsequent run, this function
+ * issues SW interrupt to recover from hung condition.
+ **/
+static void i40e_detect_recover_hung_queue(int q_idx, struct i40e_vsi *vsi)
+{
+ struct i40e_ring *tx_ring = NULL;
+ struct i40e_pf *pf;
+ u32 head, val, tx_pending;
+ int i;
+
+ pf = vsi->back;
+
+ /* now that we have an index, find the tx_ring struct */
+ for (i = 0; i < vsi->num_queue_pairs; i++) {
+ if (vsi->tx_rings[i] && vsi->tx_rings[i]->desc) {
+ if (q_idx == vsi->tx_rings[i]->queue_index) {
+ tx_ring = vsi->tx_rings[i];
+ break;
+ }
+ }
+ }
+
+ if (!tx_ring)
+ return;
+
+ /* Read interrupt register */
+ if (pf->flags & I40E_FLAG_MSIX_ENABLED)
+ val = rd32(&pf->hw,
+ I40E_PFINT_DYN_CTLN(tx_ring->q_vector->v_idx +
+ tx_ring->vsi->base_vector - 1));
+ else
+ val = rd32(&pf->hw, I40E_PFINT_DYN_CTL0);
+
+ head = i40e_get_head(tx_ring);
+
+ tx_pending = i40e_get_tx_pending(tx_ring);
+
+ /* Interrupts are disabled and TX pending is non-zero,
+ * trigger the SW interrupt (don't wait). Worst case
+ * there will be one extra interrupt which may result
+ * into not cleaning any queues because queues are cleaned.
+ */
+ if (tx_pending && (!(val & I40E_PFINT_DYN_CTLN_INTENA_MASK)))
+ i40e_force_wb(vsi, tx_ring->q_vector);
+}
+
+/**
+ * i40e_detect_recover_hung - Function to detect and recover hung_queues
+ * @pf: pointer to PF struct
+ *
+ * LAN VSI has netdev and netdev has TX queues. This function is to check
+ * each of those TX queues if they are hung, trigger recovery by issuing
+ * SW interrupt.
+ **/
+static void i40e_detect_recover_hung(struct i40e_pf *pf)
+{
+ struct net_device *netdev;
+ struct i40e_vsi *vsi;
+ int i;
+
+ /* Only for LAN VSI */
+ vsi = pf->vsi[pf->lan_vsi];
+
+ if (!vsi)
+ return;
+
+ /* Make sure, VSI state is not DOWN/RECOVERY_PENDING */
+ if (test_bit(__I40E_DOWN, &vsi->back->state) ||
+ test_bit(__I40E_RESET_RECOVERY_PENDING, &vsi->back->state))
+ return;
+
+ /* Make sure type is MAIN VSI */
+ if (vsi->type != I40E_VSI_MAIN)
+ return;
+
+ netdev = vsi->netdev;
+ if (!netdev)
+ return;
+
+ /* Bail out if netif_carrier is not OK */
+ if (!netif_carrier_ok(netdev))
+ return;
+
+ /* Go thru' TX queues for netdev */
+ for (i = 0; i < netdev->num_tx_queues; i++) {
+ struct netdev_queue *q;
+
+ q = netdev_get_tx_queue(netdev, i);
+ if (q)
+ i40e_detect_recover_hung_queue(i, vsi);
+ }
+}
+