RDMA/nes: Forward packets for a new connection with stale APBVT entry

Under heavy traffic, there is a small windows when an APBVT entry is
not yet removed and a new connection is established.  Packets for the
new connection are dropped until APBVT entry is removed.  This patch
will forward the packets instead of dropping them.

Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Chien Tung <chien.tin.tung@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
index c259ddc..f34fa6f 100644 (file)
--- a/drivers/infiniband/hw/nes/nes_cm.c
+++ b/drivers/infiniband/hw/nes/nes_cm.c
@@ -86,7 +86,7 @@ static int mini_cm_accept(struct nes_cm_core *, struct ietf_mpa_frame *,
        struct nes_cm_node *);
 static int mini_cm_reject(struct nes_cm_core *, struct ietf_mpa_frame *,
        struct nes_cm_node *);
-static void mini_cm_recv_pkt(struct nes_cm_core *, struct nes_vnic *,
+static int mini_cm_recv_pkt(struct nes_cm_core *, struct nes_vnic *,
        struct sk_buff *);
 static int mini_cm_dealloc_core(struct nes_cm_core *);
 static int mini_cm_get(struct nes_cm_core *);
@@ -2076,7 +2076,7 @@ static int mini_cm_close(struct nes_cm_core *cm_core, struct nes_cm_node *cm_nod
  * recv_pkt - recv an ETHERNET packet, and process it through CM
  * node state machine
  */
-static void mini_cm_recv_pkt(struct nes_cm_core *cm_core,
+static int mini_cm_recv_pkt(struct nes_cm_core *cm_core,
        struct nes_vnic *nesvnic, struct sk_buff *skb)
 {
        struct nes_cm_node *cm_node = NULL;
@@ -2084,23 +2084,16 @@ static void mini_cm_recv_pkt(struct nes_cm_core *cm_core,
        struct iphdr *iph;
        struct tcphdr *tcph;
        struct nes_cm_info nfo;
+       int skb_handled = 1;
 
        if (!skb)
-               return;
+               return 0;
        if (skb->len < sizeof(struct iphdr) + sizeof(struct tcphdr)) {
-               dev_kfree_skb_any(skb);
-               return;
+               return 0;
        }
 
        iph = (struct iphdr *)skb->data;
        tcph = (struct tcphdr *)(skb->data + sizeof(struct iphdr));
-       skb_reset_network_header(skb);
-       skb_set_transport_header(skb, sizeof(*tcph));
-       if (!tcph) {
-               dev_kfree_skb_any(skb);
-               return;
-       }
-       skb->len = ntohs(iph->tot_len);
 
        nfo.loc_addr = ntohl(iph->daddr);
        nfo.loc_port = ntohs(tcph->dest);
@@ -2121,23 +2114,21 @@ static void mini_cm_recv_pkt(struct nes_cm_core *cm_core,
                        /* Only type of packet accepted are for */
                        /* the PASSIVE open (syn only) */
                        if ((!tcph->syn) || (tcph->ack)) {
-                               cm_packets_dropped++;
+                               skb_handled = 0;
                                break;
                        }
                        listener = find_listener(cm_core, nfo.loc_addr,
                                nfo.loc_port,
                                NES_CM_LISTENER_ACTIVE_STATE);
-                       if (listener) {
-                               nfo.cm_id = listener->cm_id;
-                               nfo.conn_type = listener->conn_type;
-                       } else {
-                               nes_debug(NES_DBG_CM, "Unable to find listener "
-                                       "for the pkt\n");
-                               cm_packets_dropped++;
-                               dev_kfree_skb_any(skb);
+                       if (!listener) {
+                               nfo.cm_id = NULL;
+                               nfo.conn_type = 0;
+                               nes_debug(NES_DBG_CM, "Unable to find listener for the pkt\n");
+                               skb_handled = 0;
                                break;
                        }
-
+                       nfo.cm_id = listener->cm_id;
+                       nfo.conn_type = listener->conn_type;
                        cm_node = make_cm_node(cm_core, nesvnic, &nfo,
                                listener);
                        if (!cm_node) {
@@ -2163,9 +2154,13 @@ static void mini_cm_recv_pkt(struct nes_cm_core *cm_core,
                        dev_kfree_skb_any(skb);
                        break;
                }
+               skb_reset_network_header(skb);
+               skb_set_transport_header(skb, sizeof(*tcph));
+               skb->len = ntohs(iph->tot_len);
                process_packet(cm_node, skb, cm_core);
                rem_ref_cm_node(cm_core, cm_node);
        } while (0);
+       return skb_handled;
 }
 
 
@@ -2985,15 +2980,16 @@ int nes_destroy_listen(struct iw_cm_id *cm_id)
  */
 int nes_cm_recv(struct sk_buff *skb, struct net_device *netdevice)
 {
+       int rc = 0;
        cm_packets_received++;
        if ((g_cm_core) && (g_cm_core->api)) {
-               g_cm_core->api->recv_pkt(g_cm_core, netdev_priv(netdevice), skb);
+               rc = g_cm_core->api->recv_pkt(g_cm_core, netdev_priv(netdevice), skb);
        } else {
                nes_debug(NES_DBG_CM, "Unable to process packet for CM,"
                                " cm is not setup properly.\n");
        }
 
-       return 0;
+       return rc;
 }
 
 

diff --git a/drivers/infiniband/hw/nes/nes_cm.h b/drivers/infiniband/hw/nes/nes_cm.h
index 25e2493..3a20a78 100644 (file)
--- a/drivers/infiniband/hw/nes/nes_cm.h
+++ b/drivers/infiniband/hw/nes/nes_cm.h
@@ -397,7 +397,7 @@ struct nes_cm_ops {
                        struct nes_cm_node *);
        int (*reject)(struct nes_cm_core *, struct ietf_mpa_frame *,
                        struct nes_cm_node *);
-       void (*recv_pkt)(struct nes_cm_core *, struct nes_vnic *,
+       int (*recv_pkt)(struct nes_cm_core *, struct nes_vnic *,
                        struct sk_buff *);
        int (*destroy_cm_core)(struct nes_cm_core *);
        int (*get)(struct nes_cm_core *);

diff --git a/drivers/infiniband/hw/nes/nes_hw.c b/drivers/infiniband/hw/nes/nes_hw.c
index 7c49cc8..8f70ff2 100644 (file)
--- a/drivers/infiniband/hw/nes/nes_hw.c
+++ b/drivers/infiniband/hw/nes/nes_hw.c
@@ -2700,27 +2700,33 @@ void nes_nic_ce_handler(struct nes_device *nesdev, struct nes_hw_nic_cq *cq)
                                                        pkt_type, (pkt_type & NES_PKT_TYPE_APBVT_MASK)); */
 
                                if ((pkt_type & NES_PKT_TYPE_APBVT_MASK) == NES_PKT_TYPE_APBVT_BITS) {
-                                       nes_cm_recv(rx_skb, nesvnic->netdev);
+                                       if (nes_cm_recv(rx_skb, nesvnic->netdev))
+                                               rx_skb = NULL;
+                               }
+                               if (rx_skb == NULL)
+                                       goto skip_rx_indicate0;
+
+
+                               if ((cqe_misc & NES_NIC_CQE_TAG_VALID) &&
+                                   (nesvnic->vlan_grp != NULL)) {
+                                       vlan_tag = (u16)(le32_to_cpu(
+                                                       cq->cq_vbase[head].cqe_words[NES_NIC_CQE_TAG_PKT_TYPE_IDX])
+                                                       >> 16);
+                                       nes_debug(NES_DBG_CQ, "%s: Reporting stripped VLAN packet. Tag = 0x%04X\n",
+                                                       nesvnic->netdev->name, vlan_tag);
+                                       if (nes_use_lro)
+                                               lro_vlan_hwaccel_receive_skb(&nesvnic->lro_mgr, rx_skb,
+                                                               nesvnic->vlan_grp, vlan_tag, NULL);
+                                       else
+                                               nes_vlan_rx(rx_skb, nesvnic->vlan_grp, vlan_tag);
                                } else {
-                                       if ((cqe_misc & NES_NIC_CQE_TAG_VALID) && (nesvnic->vlan_grp != NULL)) {
-                                               vlan_tag = (u16)(le32_to_cpu(
-                                                               cq->cq_vbase[head].cqe_words[NES_NIC_CQE_TAG_PKT_TYPE_IDX])
-                                                               >> 16);
-                                               nes_debug(NES_DBG_CQ, "%s: Reporting stripped VLAN packet. Tag = 0x%04X\n",
-                                                               nesvnic->netdev->name, vlan_tag);
-                                               if (nes_use_lro)
-                                                       lro_vlan_hwaccel_receive_skb(&nesvnic->lro_mgr, rx_skb,
-                                                                       nesvnic->vlan_grp, vlan_tag, NULL);
-                                               else
-                                                       nes_vlan_rx(rx_skb, nesvnic->vlan_grp, vlan_tag);
-                                       } else {
-                                               if (nes_use_lro)
-                                                       lro_receive_skb(&nesvnic->lro_mgr, rx_skb, NULL);
-                                               else
-                                                       nes_netif_rx(rx_skb);
-                                       }
+                                       if (nes_use_lro)
+                                               lro_receive_skb(&nesvnic->lro_mgr, rx_skb, NULL);
+                                       else
+                                               nes_netif_rx(rx_skb);
                                }
 
+skip_rx_indicate0:
                                nesvnic->netdev->last_rx = jiffies;
                                /* nesvnic->netstats.rx_packets++; */
                                /* nesvnic->netstats.rx_bytes += rx_pkt_size; */