net/mlx: enhance Rx scatter mode detection

Toggle Rx scatter mode based on the scatter_enable flag and the maximum
packet size only instead of deriving this information from the jumbo_frame
setting and the MTU configuration.

Signed-off-by: Vasily Philipov <vasilyf@mellanox.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index 4427ca3..45b5269 100644 (file)
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -3433,7 +3433,7 @@ rxq_rehash(struct rte_eth_dev *dev, struct rxq *rxq)
        }
        /* Enable scattered packets support for this queue if necessary. */
        assert(mb_len >= RTE_PKTMBUF_HEADROOM);
-       if ((dev->data->dev_conf.rxmode.jumbo_frame) &&
+       if (dev->data->dev_conf.rxmode.enable_scatter &&
            (dev->data->dev_conf.rxmode.max_rx_pkt_len >
             (mb_len - RTE_PKTMBUF_HEADROOM))) {
                tmpl.sp = 1;
@@ -3655,11 +3655,19 @@ rxq_setup(struct rte_eth_dev *dev, struct rxq *rxq, uint16_t desc,
                tmpl.csum_l2tun = !!dev->data->dev_conf.rxmode.hw_ip_checksum;
        /* Enable scattered packets support for this queue if necessary. */
        assert(mb_len >= RTE_PKTMBUF_HEADROOM);
-       if ((dev->data->dev_conf.rxmode.jumbo_frame) &&
-           (dev->data->dev_conf.rxmode.max_rx_pkt_len >
-            (mb_len - RTE_PKTMBUF_HEADROOM))) {
+       if (dev->data->dev_conf.rxmode.max_rx_pkt_len <=
+           (mb_len - RTE_PKTMBUF_HEADROOM)) {
+               tmpl.sp = 0;
+       } else if (dev->data->dev_conf.rxmode.enable_scatter) {
                tmpl.sp = 1;
                desc /= MLX4_PMD_SGE_WR_N;
+       } else {
+               WARN("%p: the requested maximum Rx packet size (%u) is"
+                    " larger than a single mbuf (%u) and scattered"
+                    " mode has not been requested",
+                    (void *)dev,
+                    dev->data->dev_conf.rxmode.max_rx_pkt_len,
+                    mb_len - RTE_PKTMBUF_HEADROOM);
        }
        DEBUG("%p: %s scattered packets support (%u WRs)",
              (void *)dev, (tmpl.sp ? "enabling" : "disabling"), desc);
@@ -4768,21 +4776,16 @@ mlx4_dev_set_mtu(struct rte_eth_dev *dev, uint16_t mtu)
        /* Reconfigure each RX queue. */
        for (i = 0; (i != priv->rxqs_n); ++i) {
                struct rxq *rxq = (*priv->rxqs)[i];
-               unsigned int mb_len;
                unsigned int max_frame_len;
-               int sp;
 
                if (rxq == NULL)
                        continue;
-               /* Calculate new maximum frame length according to MTU and
-                * toggle scattered support (sp) if necessary. */
+               /* Calculate new maximum frame length according to MTU. */
                max_frame_len = (priv->mtu + ETHER_HDR_LEN +
                                 (ETHER_MAX_VLAN_FRAME_LEN - ETHER_MAX_LEN));
-               mb_len = rte_pktmbuf_data_room_size(rxq->mp);
-               assert(mb_len >= RTE_PKTMBUF_HEADROOM);
-               sp = (max_frame_len > (mb_len - RTE_PKTMBUF_HEADROOM));
                /* Provide new values to rxq_setup(). */
-               dev->data->dev_conf.rxmode.jumbo_frame = sp;
+               dev->data->dev_conf.rxmode.jumbo_frame =
+                       (max_frame_len > ETHER_MAX_LEN);
                dev->data->dev_conf.rxmode.max_rx_pkt_len = max_frame_len;
                ret = rxq_rehash(dev, rxq);
                if (ret) {

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index dd5fe5c..766fb72 100644 (file)
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -995,7 +995,6 @@ recover:
                struct rxq *rxq = (*priv->rxqs)[i];
                struct rxq_ctrl *rxq_ctrl =
                        container_of(rxq, struct rxq_ctrl, rxq);
-               int sp;
                unsigned int mb_len;
                unsigned int tmp;
 
@@ -1003,10 +1002,9 @@ recover:
                        continue;
                mb_len = rte_pktmbuf_data_room_size(rxq->mp);
                assert(mb_len >= RTE_PKTMBUF_HEADROOM);
-               /* Toggle scattered support (sp) if necessary. */
-               sp = (max_frame_len > (mb_len - RTE_PKTMBUF_HEADROOM));
                /* Provide new values to rxq_setup(). */
-               dev->data->dev_conf.rxmode.jumbo_frame = sp;
+               dev->data->dev_conf.rxmode.jumbo_frame =
+                       (max_frame_len > ETHER_MAX_LEN);
                dev->data->dev_conf.rxmode.max_rx_pkt_len = max_frame_len;
                if (rehash)
                        ret = rxq_rehash(dev, rxq_ctrl);

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 98fa050..d5825fd 100644 (file)
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -950,14 +950,10 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl *rxq_ctrl,
        (void)conf; /* Thresholds configuration (ignored). */
        /* Enable scattered packets support for this queue if necessary. */
        assert(mb_len >= RTE_PKTMBUF_HEADROOM);
-       /* If smaller than MRU, multi-segment support must be enabled. */
-       if (mb_len < (priv->mtu > dev->data->dev_conf.rxmode.max_rx_pkt_len ?
-                    dev->data->dev_conf.rxmode.max_rx_pkt_len :
-                    priv->mtu))
-               dev->data->dev_conf.rxmode.jumbo_frame = 1;
-       if ((dev->data->dev_conf.rxmode.jumbo_frame) &&
-           (dev->data->dev_conf.rxmode.max_rx_pkt_len >
-            (mb_len - RTE_PKTMBUF_HEADROOM))) {
+       if (dev->data->dev_conf.rxmode.max_rx_pkt_len <=
+           (mb_len - RTE_PKTMBUF_HEADROOM)) {
+               tmpl.rxq.sges_n = 0;
+       } else if (dev->data->dev_conf.rxmode.enable_scatter) {
                unsigned int size =
                        RTE_PKTMBUF_HEADROOM +
                        dev->data->dev_conf.rxmode.max_rx_pkt_len;
@@ -980,6 +976,13 @@ rxq_ctrl_setup(struct rte_eth_dev *dev, struct rxq_ctrl *rxq_ctrl,
                              dev->data->dev_conf.rxmode.max_rx_pkt_len);
                        return EOVERFLOW;
                }
+       } else {
+               WARN("%p: the requested maximum Rx packet size (%u) is"
+                    " larger than a single mbuf (%u) and scattered"
+                    " mode has not been requested",
+                    (void *)dev,
+                    dev->data->dev_conf.rxmode.max_rx_pkt_len,
+                    mb_len - RTE_PKTMBUF_HEADROOM);
        }
        DEBUG("%p: maximum number of segments per packet: %u",
              (void *)dev, 1 << tmpl.rxq.sges_n);