nfp: flower: prioritize stats updates

Previously it was possible to interrupt processing stats updates because
they were handled in a work queue. Interrupting the stats updates could
lead to a situation where we backup the control message queue. This patch
moves the stats update processing out of the work queue to be processed as
soon as hardware sends a request.

Reported-by: Louis Peens <louis.peens@netronome.com>
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 11 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/flower/cmsg.c b/drivers/net/ethernet/netronome/nfp/flower/cmsg.c
index 615314d9e7c6..baaea6f1a9d8 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/cmsg.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/cmsg.c
@@ -211,12 +211,6 @@ nfp_flower_cmsg_process_one_rx(struct nfp_app *app, struct sk_buff *skb)
 
         cmsg_hdr = nfp_flower_cmsg_get_hdr(skb);
 
-        if (unlikely(cmsg_hdr->version != NFP_FLOWER_CMSG_VER1)) {
-                nfp_flower_cmsg_warn(app, "Cannot handle repr control version %u\n",
-                                     cmsg_hdr->version);
-                goto out;
-        }
-
         type = cmsg_hdr->type;
         switch (type) {
         case NFP_FLOWER_CMSG_TYPE_PORT_REIFY:
@@ -225,9 +219,6 @@ nfp_flower_cmsg_process_one_rx(struct nfp_app *app, struct sk_buff *skb)
         case NFP_FLOWER_CMSG_TYPE_PORT_MOD:
                 nfp_flower_cmsg_portmod_rx(app, skb);
                 break;
-        case NFP_FLOWER_CMSG_TYPE_FLOW_STATS:
-                nfp_flower_rx_flow_stats(app, skb);
-                break;
         case NFP_FLOWER_CMSG_TYPE_NO_NEIGH:
                 nfp_tunnel_request_route(app, skb);
                 break;
@@ -263,7 +254,23 @@ void nfp_flower_cmsg_process_rx(struct work_struct *work)
 void nfp_flower_cmsg_rx(struct nfp_app *app, struct sk_buff *skb)
 {
         struct nfp_flower_priv *priv = app->priv;
+        struct nfp_flower_cmsg_hdr *cmsg_hdr;
+
+        cmsg_hdr = nfp_flower_cmsg_get_hdr(skb);
+
+        if (unlikely(cmsg_hdr->version != NFP_FLOWER_CMSG_VER1)) {
+                nfp_flower_cmsg_warn(app, "Cannot handle repr control version %u\n",
+                                     cmsg_hdr->version);
+                dev_kfree_skb_any(skb);
+                return;
+        }
 
-        skb_queue_tail(&priv->cmsg_skbs, skb);
-        schedule_work(&priv->cmsg_work);
+        if (cmsg_hdr->type == NFP_FLOWER_CMSG_TYPE_FLOW_STATS) {
+                /* We need to deal with stats updates from HW asap */
+                nfp_flower_rx_flow_stats(app, skb);
+                dev_consume_skb_any(skb);
+        } else {
+                skb_queue_tail(&priv->cmsg_skbs, skb);
+                schedule_work(&priv->cmsg_work);
+        }
 }