if_ntb: MFV 2849b5d7: Reset transport QP link stats on down

Reset the link stats when the link goes down.  In particular, the TX and
RX index and count must be reset, or else the TX side will be sending
packets to the RX side where the RX side is not expecting them.  Reset
all the stats, to be consistent.

Authored by:	Allen Hubbe
Obtained from:	Linux (Dual BSD/GPL driver)
Sponsored by:	EMC / Isilon Storage Division

1 files changed, 22 insertions, 9 deletions

diff --git a/sys/dev/ntb/if_ntb/if_ntb.c b/sys/dev/ntb/if_ntb/if_ntb.c
index 81dcc80890ab..32642ddcaaaa 100644
--- a/sys/dev/ntb/if_ntb/if_ntb.c
+++ b/sys/dev/ntb/if_ntb/if_ntb.c
@@ -300,6 +300,7 @@ static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
 static void ntb_qp_link_work(void *arg);
 static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt);
 static void ntb_qp_link_down(struct ntb_transport_qp *qp);
+static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp);
 static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp);
 static void ntb_transport_link_down(struct ntb_transport_qp *qp);
 static void ntb_send_link_down(struct ntb_transport_qp *qp);
@@ -642,9 +643,9 @@ ntb_transport_init_queue(struct ntb_transport_ctx *nt, unsigned int qp_num)
 	qp->qp_num = qp_num;
 	qp->transport = nt;
 	qp->ntb = nt->ntb;
-	qp->link_is_up = false;
 	qp->client_ready = false;
 	qp->event_handler = NULL;
+	ntb_qp_link_down_reset(qp);
 
 	if (nt->qp_count % mw_count && mw_num + 1 < nt->qp_count / mw_count)
 		num_qps_mw = nt->qp_count / mw_count + 1;
@@ -1444,16 +1445,28 @@ ntb_qp_link_down(struct ntb_transport_qp *qp)
 }
 
 static void
+ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
+{
+
+	qp->link_is_up = false;
+
+	qp->tx_index = qp->rx_index = 0;
+	qp->tx_bytes = qp->rx_bytes = 0;
+	qp->tx_pkts = qp->rx_pkts = 0;
+
+	qp->rx_ring_empty = 0;
+	qp->tx_ring_full = 0;
+
+	qp->rx_err_no_buf = qp->rx_err_oflow = qp->rx_err_ver = 0;
+}
+
+static void
 ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 {
 	struct ntb_transport_ctx *nt = qp->transport;
 
-	if (!qp->link_is_up) {
-		callout_drain(&qp->link_work);
-		return;
-	}
-
-	qp->link_is_up = false;
+	callout_drain(&qp->link_work);
+	ntb_qp_link_down_reset(qp);
 
 	if (qp->event_handler != NULL)
 		qp->event_handler(qp->cb_data, NTB_LINK_DOWN);
@@ -1502,8 +1515,6 @@ ntb_send_link_down(struct ntb_transport_qp *qp)
 	if (!qp->link_is_up)
 		return;
 
-	qp->link_is_up = false;
-
 	for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
 		entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
 		if (entry != NULL)
@@ -1524,6 +1535,8 @@ ntb_send_link_down(struct ntb_transport_qp *qp)
 	if (rc != 0)
 		printf("ntb: Failed to send link down\n");
 	mtx_unlock(&qp->transport->tx_lock);
+
+	ntb_qp_link_down_reset(qp);
 }