net/nfp: make sure MTU is never larger than mbuf size

Setting a MTU larger than mbuf size is not supported by the device but
not prohibited by the driver. This change adds a restriction to the
driver to prevent setting an MTU that is too large.

While at it define the minimum MTU in the device information to describe
the complete supported MTU range.

Fixes: d4a27a3 ("nfp: add basic features")
Cc: stable@dpdk.org
Signed-off-by: Peng Zhang <peng.zhang@corigine.com>
Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Reviewed-by: Walter Heymans <walter.heymans@corigine.com>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>

diff --git a/drivers/net/nfp/nfp_common.c b/drivers/net/nfp/nfp_common.c
index 52fbda1a79de0a181fd9c9b54c39e86ebb72581f..be68c25fb8d4edf4e021e29cf6f105f45bab4624 100644 (file)
--- a/drivers/net/nfp/nfp_common.c
+++ b/drivers/net/nfp/nfp_common.c
@@ -176,6 +176,13 @@ nfp_net_configure(struct rte_eth_dev *dev)
                return -EINVAL;
        }
 
+       /* Checking MTU set */
+       if (rxmode->mtu > hw->flbufsz) {
+               PMD_INIT_LOG(INFO, "MTU (%u) larger then current mbufsize (%u) not supported",
+                                   rxmode->mtu, hw->flbufsz);
+               return -ERANGE;
+       }
+
        return 0;
 }
 
@@ -702,6 +709,7 @@ nfp_net_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
         */
        dev_info->max_rx_pktlen = NFP_FRAME_SIZE_MAX;
        dev_info->max_mtu = hw->max_mtu;
+       dev_info->min_mtu = RTE_ETHER_MIN_MTU;
        /* Next should change when PF support is implemented */
        dev_info->max_mac_addrs = 1;
 
@@ -961,6 +969,13 @@ nfp_net_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
                return -EBUSY;
        }
 
+       /* MTU larger then current mbufsize not supported */
+       if (mtu > hw->flbufsz) {
+               PMD_DRV_LOG(ERR, "MTU (%u) larger then current mbufsize (%u) not supported",
+                           mtu, hw->flbufsz);
+               return -ERANGE;
+       }
+
        /* writing to configuration space */
        nn_cfg_writel(hw, NFP_NET_CFG_MTU, mtu);