[dpdk-stable] patch 'net/bnx2x: fix to sync fastpath Rx queue access' has been queued to LTS release 18.11.7

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.7

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/20/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/c7afc147a41e78e89a1f86f27337e35593d38cd0

Thanks.

Kevin.

---
>From c7afc147a41e78e89a1f86f27337e35593d38cd0 Mon Sep 17 00:00:00 2001
From: Rasesh Mody <rmody at marvell.com>
Date: Sun, 26 Jan 2020 14:54:19 -0800
Subject: [PATCH] net/bnx2x: fix to sync fastpath Rx queue access

[ upstream commit 141c86f55f734c4f8b9ad3129b6e58807b5c4577 ]

PMD handles fast path completions in the Rx handler and control path
completions in the interrupt handler. They both are processing
completions from the same fastpath completion queue. There is a
potential for race condition when these two paths are processing
the completions from the same queue and trying to updating Rx Producer.

Add a fastpath Rx lock between these two paths to close this race.

Fixes: 540a211084a7 ("bnx2x: driver core")

Signed-off-by: Rasesh Mody <rmody at marvell.com>
---
 drivers/net/bnx2x/bnx2x.c      | 12 ++++++++++++
 drivers/net/bnx2x/bnx2x.h      |  3 +++
 drivers/net/bnx2x/bnx2x_rxtx.c |  8 +++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bnx2x/bnx2x.c b/drivers/net/bnx2x/bnx2x.c
index ab18fe2e56..b217a9f655 100644
--- a/drivers/net/bnx2x/bnx2x.c
+++ b/drivers/net/bnx2x/bnx2x.c
@@ -1168,4 +1168,8 @@ static int bnx2x_has_rx_work(struct bnx2x_fastpath *fp)
 		     MAX_RCQ_ENTRIES(rxq)))
 		rx_cq_cons_sb++;
+
+	PMD_RX_LOG(DEBUG, "hw CQ cons = %d, sw CQ cons = %d",
+		   rx_cq_cons_sb, rxq->rx_cq_head);
+
 	return rxq->rx_cq_head != rx_cq_cons_sb;
 }
@@ -1250,7 +1254,10 @@ static uint8_t bnx2x_rxeof(struct bnx2x_softc *sc, struct bnx2x_fastpath *fp)
 	uint16_t hw_cq_cons, sw_cq_cons, sw_cq_prod;
 
+	rte_spinlock_lock(&(fp)->rx_mtx);
+
 	rxq = sc->rx_queues[fp->index];
 	if (!rxq) {
 		PMD_RX_LOG(ERR, "RX queue %d is NULL", fp->index);
+		rte_spinlock_unlock(&(fp)->rx_mtx);
 		return 0;
 	}
@@ -1322,7 +1329,12 @@ next_cqe:
 	rxq->rx_cq_tail = sw_cq_prod;
 
+	PMD_RX_LOG(DEBUG, "BD prod = %d, sw CQ prod = %d",
+		   bd_prod_fw, sw_cq_prod);
+
 	/* Update producers */
 	bnx2x_update_rx_prod(sc, fp, bd_prod_fw, sw_cq_prod);
 
+	rte_spinlock_unlock(&(fp)->rx_mtx);
+
 	return sw_cq_cons != hw_cq_cons;
 }
diff --git a/drivers/net/bnx2x/bnx2x.h b/drivers/net/bnx2x/bnx2x.h
index ceaecb031f..fd49b9a3af 100644
--- a/drivers/net/bnx2x/bnx2x.h
+++ b/drivers/net/bnx2x/bnx2x.h
@@ -375,4 +375,7 @@ struct bnx2x_fastpath {
 	struct bnx2x_softc *sc;
 
+	/* Used to synchronize fastpath Rx access */
+	rte_spinlock_t rx_mtx;
+
 	/* status block */
 	struct bnx2x_dma                 sb_dma;
diff --git a/drivers/net/bnx2x/bnx2x_rxtx.c b/drivers/net/bnx2x/bnx2x_rxtx.c
index e5a2b25b56..71ebdf3f6b 100644
--- a/drivers/net/bnx2x/bnx2x_rxtx.c
+++ b/drivers/net/bnx2x/bnx2x_rxtx.c
@@ -345,4 +345,6 @@ bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	struct rte_mbuf *rx_mb = NULL;
 
+	rte_spinlock_lock(&(fp)->rx_mtx);
+
 	hw_cq_cons = le16toh(*fp->rx_cq_cons_sb);
 	if ((hw_cq_cons & USABLE_RCQ_ENTRIES_PER_PAGE) ==
@@ -356,6 +358,8 @@ bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	sw_cq_prod = rxq->rx_cq_tail;
 
-	if (sw_cq_cons == hw_cq_cons)
+	if (sw_cq_cons == hw_cq_cons) {
+		rte_spinlock_unlock(&(fp)->rx_mtx);
 		return 0;
+	}
 
 	while (nb_rx < nb_pkts && sw_cq_cons != hw_cq_cons) {
@@ -438,4 +442,6 @@ next_rx:
 	bnx2x_upd_rx_prod_fast(sc, fp, bd_prod, sw_cq_prod);
 
+	rte_spinlock_unlock(&(fp)->rx_mtx);
+
 	return nb_rx;
 }
-- 
2.21.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-02-14 17:02:38.206272383 +0000
+++ 0021-net-bnx2x-fix-to-sync-fastpath-Rx-queue-access.patch	2020-02-14 17:02:36.983407271 +0000
@@ -1 +1 @@
-From 141c86f55f734c4f8b9ad3129b6e58807b5c4577 Mon Sep 17 00:00:00 2001
+From c7afc147a41e78e89a1f86f27337e35593d38cd0 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 141c86f55f734c4f8b9ad3129b6e58807b5c4577 ]
+
@@ -15 +16,0 @@
-Cc: stable at dpdk.org
@@ -25 +26 @@
-index 50e289b286..0b4030e2b9 100644
+index ab18fe2e56..b217a9f655 100644
@@ -62 +63 @@
-index 3383c76759..1dbc98197d 100644
+index ceaecb031f..fd49b9a3af 100644
@@ -65 +66 @@
-@@ -361,4 +361,7 @@ struct bnx2x_fastpath {
+@@ -375,4 +375,7 @@ struct bnx2x_fastpath {
@@ -74 +75 @@
-index ae97dfee36..0d77035844 100644
+index e5a2b25b56..71ebdf3f6b 100644
@@ -77 +78 @@
-@@ -347,4 +347,6 @@ bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
+@@ -345,4 +345,6 @@ bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
@@ -84 +85 @@
-@@ -358,6 +360,8 @@ bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
+@@ -356,6 +358,8 @@ bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
@@ -94 +95 @@
-@@ -440,4 +444,6 @@ next_rx:
+@@ -438,4 +442,6 @@ next_rx: