net/sfc: restart RxQ in case of exception on event queue

Examples of recoverable exceptions are:
 - unexpected Rx event (Rx scatter abort with non-zero size,
   too big Rx descriptors batch completed)
 - Rx error due to invalid Rx descriptors push
 - Rx error due to Rx descriptor read error (e.g. unmapped Rx ring
   and denied by IOMMU)

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andrew Lee <alee@solarflare.com>
Reviewed-by: Robert Stonehouse <rstonehouse@solarflare.com>

diff --git a/drivers/net/sfc/sfc.h b/drivers/net/sfc/sfc.h
index 543c368..c6bb5e8 100644 (file)
--- a/drivers/net/sfc/sfc.h
+++ b/drivers/net/sfc/sfc.h
@@ -190,6 +190,12 @@ sfc_adapter_lock(struct sfc_adapter *sa)
        rte_spinlock_lock(&sa->lock);
 }
 
+static inline int
+sfc_adapter_trylock(struct sfc_adapter *sa)
+{
+       return rte_spinlock_trylock(&sa->lock);
+}
+
 static inline void
 sfc_adapter_unlock(struct sfc_adapter *sa)
 {

diff --git a/drivers/net/sfc/sfc_ev.c b/drivers/net/sfc/sfc_ev.c
index 96b95cc..36aede8 100644 (file)
--- a/drivers/net/sfc/sfc_ev.c
+++ b/drivers/net/sfc/sfc_ev.c
@@ -30,6 +30,7 @@
 #include <rte_debug.h>
 #include <rte_cycles.h>
 #include <rte_alarm.h>
+#include <rte_branch_prediction.h>
 
 #include "efx.h"
 
@@ -320,6 +321,31 @@ sfc_ev_qpoll(struct sfc_evq *evq)
 
        efx_ev_qpoll(evq->common, &evq->read_ptr, &sfc_ev_callbacks, evq);
 
+       if (unlikely(evq->exception) && sfc_adapter_trylock(evq->sa)) {
+               struct sfc_adapter *sa = evq->sa;
+               int rc;
+
+               if ((evq->rxq != NULL) && (evq->rxq->state & SFC_RXQ_RUNNING)) {
+                       unsigned int rxq_sw_index = sfc_rxq_sw_index(evq->rxq);
+
+                       sfc_warn(sa,
+                                "restart RxQ %u because of exception on its EvQ %u",
+                                rxq_sw_index, evq->evq_index);
+
+                       sfc_rx_qstop(sa, rxq_sw_index);
+                       rc = sfc_rx_qstart(sa, rxq_sw_index);
+                       if (rc != 0)
+                               sfc_err(sa, "cannot restart RxQ %u",
+                                       rxq_sw_index);
+               }
+
+               if (evq->exception)
+                       sfc_panic(sa, "unrecoverable exception on EvQ %u",
+                                 evq->evq_index);
+
+               sfc_adapter_unlock(sa);
+       }
+
        /* Poll-mode driver does not re-prime the event queue for interrupts */
 }