[3/3] net/bnx2x: fix to sync fastpath Rx queue access
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Message ID 20200114003920.17705-3-rmody@marvell.com
State Changes Requested, archived
Delegated to: Jerin Jacob
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Series
  • [1/3] net/bnx2x: fix to use required mem barriers in Rx path
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Commit Message

Rasesh Mody Jan. 14, 2020, 12:39 a.m. UTC
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")
Cc: stable@dpdk.org

Signed-off-by: Rasesh Mody <rmody@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(-)

Patch
diff mbox series

diff --git a/drivers/net/bnx2x/bnx2x.c b/drivers/net/bnx2x/bnx2x.c
index d38da4f60..7ea98b936 100644
--- a/drivers/net/bnx2x/bnx2x.c
+++ b/drivers/net/bnx2x/bnx2x.c
@@ -1167,6 +1167,10 @@  static int bnx2x_has_rx_work(struct bnx2x_fastpath *fp)
 	if (unlikely((rx_cq_cons_sb & MAX_RCQ_ENTRIES(rxq)) ==
 		     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;
 }
 
@@ -1249,9 +1253,12 @@  static uint8_t bnx2x_rxeof(struct bnx2x_softc *sc, struct bnx2x_fastpath *fp)
 	uint16_t bd_cons, bd_prod, bd_prod_fw, comp_ring_cons;
 	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;
 	}
 
@@ -1326,9 +1333,14 @@  static uint8_t bnx2x_rxeof(struct bnx2x_softc *sc, struct bnx2x_fastpath *fp)
 	rxq->rx_cq_head = sw_cq_cons;
 	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 3383c7675..1dbc98197 100644
--- a/drivers/net/bnx2x/bnx2x.h
+++ b/drivers/net/bnx2x/bnx2x.h
@@ -360,6 +360,9 @@  struct bnx2x_fastpath {
 	/* pointer back to parent structure */
 	struct bnx2x_softc *sc;
 
+	/* Used to synchronize fastpath Rx access */
+	rte_spinlock_t rx_mtx;
+
 	/* status block */
 	struct bnx2x_dma                 sb_dma;
 	union bnx2x_host_hc_status_block status_block;
diff --git a/drivers/net/bnx2x/bnx2x_rxtx.c b/drivers/net/bnx2x/bnx2x_rxtx.c
index b52f023ea..c8bb202d6 100644
--- a/drivers/net/bnx2x/bnx2x_rxtx.c
+++ b/drivers/net/bnx2x/bnx2x_rxtx.c
@@ -357,6 +357,8 @@  bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	uint16_t len, pad;
 	struct rte_mbuf *rx_mb = NULL;
 
+	rte_spinlock_lock(&(fp)->rx_mtx);
+
 	/* Add memory barrier as status block fields can change. This memory
 	 * barrier will flush out all the read/write operations to status block
 	 * generated before the barrier. It will ensure stale data is not read
@@ -379,8 +381,10 @@  bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	 */
 	rmb();
 
-	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) {
 
@@ -461,6 +465,8 @@  bnx2x_recv_pkts(void *p_rxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 
 	bnx2x_upd_rx_prod_fast(sc, fp, bd_prod, sw_cq_prod);
 
+	rte_spinlock_unlock(&(fp)->rx_mtx);
+
 	return nb_rx;
 }