net/bnxt: fix Rx queue start/stop for Thor based NICs

Controller-specific handling is required for Thor-based NICs when
stopping or starting a receive queue, otherwise packet reception
may not be reliably resumed when a stopped receive queue is
restarted:
  - The VNIC default receive ring needs to be recomputed when a
    receive queue is stopped or started.
  - When stopping the last (or only) receive queue for a given
    VNIC, ensure that no packets can reach the default receive
    ring by temporarily setting the VNIC MRU to zero.

Fixes: f8168ca0e690 ("net/bnxt: support thor controller")
Cc: stable@dpdk.org
Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
index bb4dcf4..2cba007 100644 (file)
--- a/drivers/net/bnxt/bnxt_hwrm.c
+++ b/drivers/net/bnxt/bnxt_hwrm.c
@@ -1696,10 +1696,29 @@ int bnxt_hwrm_vnic_cfg(struct bnxt *bp, struct bnxt_vnic_info *vnic)
        HWRM_PREP(req, VNIC_CFG, BNXT_USE_CHIMP_MB);
 
        if (BNXT_CHIP_THOR(bp)) {
-               struct bnxt_rx_queue *rxq =
-                       bp->eth_dev->data->rx_queues[vnic->start_grp_id];
-               struct bnxt_rx_ring_info *rxr = rxq->rx_ring;
-               struct bnxt_cp_ring_info *cpr = rxq->cp_ring;
+               int dflt_rxq = vnic->start_grp_id;
+               struct bnxt_rx_ring_info *rxr;
+               struct bnxt_cp_ring_info *cpr;
+               struct bnxt_rx_queue *rxq;
+               int i;
+
+               /*
+                * The first active receive ring is used as the VNIC
+                * default receive ring. If there are no active receive
+                * rings (all corresponding receive queues are stopped),
+                * the first receive ring is used.
+                */
+               for (i = vnic->start_grp_id; i < vnic->end_grp_id; i++) {
+                       rxq = bp->eth_dev->data->rx_queues[i];
+                       if (rxq->rx_started) {
+                               dflt_rxq = i;
+                               break;
+                       }
+               }
+
+               rxq = bp->eth_dev->data->rx_queues[dflt_rxq];
+               rxr = rxq->rx_ring;
+               cpr = rxq->cp_ring;
 
                req.default_rx_ring_id =
                        rte_cpu_to_le_16(rxr->rx_ring_struct->fw_ring_id);

diff --git a/drivers/net/bnxt/bnxt_rxq.c b/drivers/net/bnxt/bnxt_rxq.c
index e82eda9..e7c012f 100644 (file)
--- a/drivers/net/bnxt/bnxt_rxq.c
+++ b/drivers/net/bnxt/bnxt_rxq.c
@@ -451,6 +451,10 @@ int bnxt_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id)
        if (rc)
                return rc;
 
+       if (BNXT_CHIP_THOR(bp)) {
+               /* Reconfigure default receive ring and MRU. */
+               bnxt_hwrm_vnic_cfg(bp, rxq->vnic);
+       }
        PMD_DRV_LOG(INFO, "Rx queue started %d\n", rx_queue_id);
 
        if (dev_conf->rxmode.mq_mode & ETH_MQ_RX_RSS_FLAG) {
@@ -491,7 +495,8 @@ int bnxt_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
        struct rte_eth_conf *dev_conf = &bp->eth_dev->data->dev_conf;
        struct bnxt_vnic_info *vnic = NULL;
        struct bnxt_rx_queue *rxq = NULL;
-       int rc = 0;
+       int active_queue_cnt = 0;
+       int i, rc = 0;
 
        rc = is_bnxt_in_error(bp);
        if (rc)
@@ -507,8 +512,9 @@ int bnxt_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
        }
 
        rxq = bp->rx_queues[rx_queue_id];
+       vnic = rxq->vnic;
 
-       if (rxq == NULL) {
+       if (!rxq || !vnic) {
                PMD_DRV_LOG(ERR, "Invalid Rx queue %d\n", rx_queue_id);
                return -EINVAL;
        }
@@ -518,7 +524,6 @@ int bnxt_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
        PMD_DRV_LOG(DEBUG, "Rx queue stopped\n");
 
        if (dev_conf->rxmode.mq_mode & ETH_MQ_RX_RSS_FLAG) {
-               vnic = rxq->vnic;
                if (BNXT_HAS_RING_GRPS(bp))
                        vnic->fw_grp_ids[rx_queue_id] = INVALID_HW_RING_ID;
 
@@ -526,6 +531,33 @@ int bnxt_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
                rc = bnxt_vnic_rss_configure(bp, vnic);
        }
 
+       if (BNXT_CHIP_THOR(bp)) {
+               /* Compute current number of active receive queues. */
+               for (i = vnic->start_grp_id; i < vnic->end_grp_id; i++)
+                       if (bp->rx_queues[i]->rx_started)
+                               active_queue_cnt++;
+
+               /*
+                * For Thor, we need to ensure that the VNIC default receive
+                * ring corresponds to an active receive queue. When no queue
+                * is active, we need to temporarily set the MRU to zero so
+                * that packets are dropped early in the receive pipeline in
+                * order to prevent the VNIC default receive ring from being
+                * accessed.
+                */
+               if (active_queue_cnt == 0) {
+                       uint16_t saved_mru = vnic->mru;
+
+                       vnic->mru = 0;
+                       /* Reconfigure default receive ring and MRU. */
+                       bnxt_hwrm_vnic_cfg(bp, vnic);
+                       vnic->mru = saved_mru;
+               } else {
+                       /* Reconfigure default receive ring. */
+                       bnxt_hwrm_vnic_cfg(bp, vnic);
+               }
+       }
+
        if (rc == 0)
                bnxt_rx_queue_release_mbufs(rxq);