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(-)
@@ -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;
}
@@ -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;
@@ -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;
}