[dpdk-dev] [PATCH v2 4/7] net/ixgbe: set min and max MTU for ixgbe devices

[Ian Stokes <ian.stokes@intel.com>]

This commit sets the min and max supported MTU values for ixgbe devices
via the ixgbe_dev_info_get() function. Min MTU supported is set to
ETHER_MIN_MTU and max mtu is calculated as the max packet length
supported minus the transport overhead. To aid in these calculations
a new MACRO 'IXGBE_ETH_OVERHEAD' has been introduced to consolidate
overhead calculation and avoid duplication.

Signed-off-by: Ian Stokes <ian.stokes@intel.com>
---
 drivers/net/ixgbe/ixgbe_ethdev.c | 4 +++-
 drivers/net/ixgbe/ixgbe_ethdev.h | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index 97e10217d..60da3508c 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -3748,6 +3748,8 @@ ixgbe_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 		dev_info->max_vmdq_pools = ETH_16_POOLS;
 	else
 		dev_info->max_vmdq_pools = ETH_64_POOLS;
+	dev_info->max_mtu =  dev_info->max_rx_pktlen - IXGBE_ETH_OVERHEAD;
+	dev_info->min_mtu = ETHER_MIN_MTU;
 	dev_info->vmdq_queue_num = dev_info->max_rx_queues;
 	dev_info->rx_queue_offload_capa = ixgbe_get_rx_queue_offloads(dev);
 	dev_info->rx_offload_capa = (ixgbe_get_rx_port_offloads(dev) |
@@ -4939,7 +4941,7 @@ ixgbe_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 	uint32_t maxfrs;
 	struct ixgbe_hw *hw;
 	struct rte_eth_dev_info dev_info;
-	uint32_t frame_size = mtu + ETHER_HDR_LEN + ETHER_CRC_LEN;
+	uint32_t frame_size = mtu + IXGBE_ETH_OVERHEAD;
 	struct rte_eth_dev_data *dev_data = dev->data;
 
 	ixgbe_dev_info_get(dev, &dev_info);
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
index 3fec61352..d1f61e85e 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/ixgbe/ixgbe_ethdev.h
@@ -101,6 +101,9 @@
 #define IXGBE_5TUPLE_MAX_PRI            7
 #define IXGBE_5TUPLE_MIN_PRI            1
 
+/* The overhead from MTU to max frame size. */
+#define IXGBE_ETH_OVERHEAD (ETHER_HDR_LEN + ETHER_CRC_LEN)
+
 /* bit of VXLAN tunnel type | 7 bits of zeros  | 8 bits of zeros*/
 #define IXGBE_FDIR_VXLAN_TUNNEL_TYPE    0x8000
 /* bit of NVGRE tunnel type | 7 bits of zeros  | 8 bits of zeros*/
-- 
2.13.6