[PATCH net-next] net: hns3: Add support to change MTU in hardware & netdev

From: Salil Mehta
Date: Fri Aug 18 2017 - 07:36:54 EST


This patch adds the following support to the HNS3 driver:
1. Support to change the Maximum Transmission Unit of a
netdevice and of a port in hardware .
2. Initializes the supported MTU range for the netdevice.

Signed-off-by: lipeng <lipeng321@xxxxxxxxxx>
Signed-off-by: Salil Mehta <salil.mehta@xxxxxxxxxx>
---
.../net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c | 46 ++++++++++++++++++++++
.../net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h | 1 +
2 files changed, 47 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
index e731f87..8e3711e 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.c
@@ -1278,11 +1278,53 @@ static int hns3_ndo_set_vf_vlan(struct net_device *netdev, int vf, u16 vlan,
return ret;
}

+static int hns3_nic_change_mtu(struct net_device *netdev, int new_mtu)
+{
+ struct hns3_nic_priv *priv = netdev_priv(netdev);
+ struct hnae3_handle *h = priv->ae_handle;
+ bool if_running = netif_running(netdev);
+ int ret;
+
+ /* no change in MTU */
+ if (new_mtu == netdev->mtu)
+ return 0;
+
+ if (!h->ae_algo->ops->set_mtu)
+ return -ENOTSUPP;
+
+ /* if this was called with netdev up then bring netdevice down */
+ if (if_running) {
+ (void)hns3_nic_net_stop(netdev);
+ msleep(100);
+ }
+
+ ret = h->ae_algo->ops->set_mtu(h, new_mtu);
+ if (ret) {
+ netdev_err(netdev, "failed to change MTU in hardware %d\n",
+ ret);
+ return ret;
+ }
+
+ /* assign newly changed mtu to netdevice as well */
+ netdev->mtu = new_mtu;
+
+ /* if the netdev was running earlier, bring it up again */
+ if (if_running) {
+ if (hns3_nic_net_open(netdev)) {
+ netdev_err(netdev, "MTU, couldnt up netdev again\n");
+ ret = -EINVAL;
+ }
+ }
+
+ return ret;
+}
+
static const struct net_device_ops hns3_nic_netdev_ops = {
.ndo_open = hns3_nic_net_open,
.ndo_stop = hns3_nic_net_stop,
.ndo_start_xmit = hns3_nic_net_xmit,
.ndo_set_mac_address = hns3_nic_net_set_mac_address,
+ .ndo_change_mtu = hns3_nic_change_mtu,
.ndo_set_features = hns3_nic_set_features,
.ndo_get_stats64 = hns3_nic_get_stats64,
.ndo_setup_tc = hns3_nic_setup_tc,
@@ -2752,6 +2794,10 @@ static int hns3_client_init(struct hnae3_handle *handle)
goto out_reg_netdev_fail;
}

+ /* MTU range: 68 - 9706 */
+ netdev->min_mtu = ETH_MIN_MTU;
+ netdev->max_mtu = HNS3_MAX_MTU - (ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN);
+
return ret;

out_reg_netdev_fail:
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
index a6e8f15..7e87461 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hns3_enet.h
@@ -76,6 +76,7 @@ enum hns3_nic_state {
#define HNS3_RING_NAME_LEN 16
#define HNS3_BUFFER_SIZE_2048 2048
#define HNS3_RING_MAX_PENDING 32768
+#define HNS3_MAX_MTU 9728

#define HNS3_BD_SIZE_512_TYPE 0
#define HNS3_BD_SIZE_1024_TYPE 1
--
2.7.4