From: Vivek Pernamitta <vivek.pernamitta@oss.qualcomm.com>

Add support to configure a new client as Ethernet type over MHI by
setting "mhi_device_info.ethernet_if = true". Create a new Ethernet
interface named eth%d. This complements existing NET driver support.

Introduce IP_SW1, ETH0, and ETH1 network interfaces required for
M-plane, NETCONF, and S-plane components.

M-plane:
Implement DU M-Plane software for non-real-time O-RAN management
between O-DU and O-RU using NETCONF/YANG and O-RAN WG4 M-Plane YANG
models. Provide capability exchange, configuration management,
performance monitoring, and fault management per O-RAN.WG4.TS.MP.0-
R004-v18.00.

NETCONF:
Use NETCONF protocol for configuration operations such as fetching,
modifying, and deleting network device configurations.

S-plane:
Support frequency and time synchronization between O-DUs and O-RUs
using Synchronous Ethernet and IEEE 1588. Assume PTP transport over
L2 Ethernet (ITU-T G.8275.1) for full timing support; allow PTP over
UDP/IP (ITU-T G.8275.2) with reduced reliability. as per ORAN spec
O-RAN.WG4.CUS.0-R003-v12.00.

Signed-off-by: Vivek Pernamitta <vivek.pernamitta@oss.qualcomm.com>
---
 drivers/net/mhi_net.c | 75 ++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 62 insertions(+), 13 deletions(-)

diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c
index ae169929a9d8e449b5a427993abf68e8d032fae2..d0713e1eb7b024667f8f3f00ed3cf38d91a75708 100644
--- a/drivers/net/mhi_net.c
+++ b/drivers/net/mhi_net.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2020 Linaro Ltd <loic.poulain@linaro.org>
  */
 
+#include <linux/etherdevice.h>
 #include <linux/if_arp.h>
 #include <linux/mhi.h>
 #include <linux/mod_devicetable.h>
@@ -38,10 +39,12 @@ struct mhi_net_dev {
 	u32 rx_queue_sz;
 	int msg_enable;
 	unsigned int mru;
+	bool ethernet_if;
 };
 
 struct mhi_device_info {
 	const char *netname;
+	bool ethernet_if;
 };
 
 static int mhi_ndo_open(struct net_device *ndev)
@@ -119,11 +122,29 @@ static void mhi_ndo_get_stats64(struct net_device *ndev,
 	} while (u64_stats_fetch_retry(&mhi_netdev->stats.tx_syncp, start));
 }
 
+static int mhi_mac_address(struct net_device *dev, void *p)
+{
+	if (dev->type == ARPHRD_ETHER)
+		return eth_mac_addr(dev, p);
+
+	return 0;
+}
+
+static int mhi_validate_address(struct net_device *dev)
+{
+	if (dev->type == ARPHRD_ETHER)
+		return eth_validate_addr(dev);
+
+	return 0;
+}
+
 static const struct net_device_ops mhi_netdev_ops = {
 	.ndo_open               = mhi_ndo_open,
 	.ndo_stop               = mhi_ndo_stop,
 	.ndo_start_xmit         = mhi_ndo_xmit,
 	.ndo_get_stats64	= mhi_ndo_get_stats64,
+	.ndo_set_mac_address    = mhi_mac_address,
+	.ndo_validate_addr      = mhi_validate_address,
 };
 
 static void mhi_net_setup(struct net_device *ndev)
@@ -140,6 +161,13 @@ static void mhi_net_setup(struct net_device *ndev)
 	ndev->tx_queue_len = 1000;
 }
 
+static void mhi_ethernet_setup(struct net_device *ndev)
+{
+	ndev->netdev_ops = &mhi_netdev_ops;
+	ether_setup(ndev);
+	ndev->max_mtu = ETH_MAX_MTU;
+}
+
 static struct sk_buff *mhi_net_skb_agg(struct mhi_net_dev *mhi_netdev,
 				       struct sk_buff *skb)
 {
@@ -209,16 +237,22 @@ static void mhi_net_dl_callback(struct mhi_device *mhi_dev,
 			mhi_netdev->skbagg_head = NULL;
 		}
 
-		switch (skb->data[0] & 0xf0) {
-		case 0x40:
-			skb->protocol = htons(ETH_P_IP);
-			break;
-		case 0x60:
-			skb->protocol = htons(ETH_P_IPV6);
-			break;
-		default:
-			skb->protocol = htons(ETH_P_MAP);
-			break;
+		if (mhi_netdev->ethernet_if) {
+			skb_copy_to_linear_data(skb, skb->data,
+						mhi_res->bytes_xferd);
+			skb->protocol = eth_type_trans(skb, mhi_netdev->ndev);
+		} else {
+			switch (skb->data[0] & 0xf0) {
+			case 0x40:
+				skb->protocol = htons(ETH_P_IP);
+				break;
+			case 0x60:
+				skb->protocol = htons(ETH_P_IPV6);
+				break;
+			default:
+				skb->protocol = htons(ETH_P_MAP);
+				break;
+			}
 		}
 
 		u64_stats_update_begin(&mhi_netdev->stats.rx_syncp);
@@ -301,11 +335,14 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
 		schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2);
 }
 
-static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
+static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev, bool eth_dev)
 {
 	struct mhi_net_dev *mhi_netdev;
 	int err;
 
+	if (eth_dev)
+		eth_hw_addr_random(ndev);
+
 	mhi_netdev = netdev_priv(ndev);
 
 	dev_set_drvdata(&mhi_dev->dev, mhi_netdev);
@@ -313,6 +350,7 @@ static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
 	mhi_netdev->mdev = mhi_dev;
 	mhi_netdev->skbagg_head = NULL;
 	mhi_netdev->mru = mhi_dev->mhi_cntrl->mru;
+	mhi_netdev->ethernet_if = eth_dev;
 
 	INIT_DELAYED_WORK(&mhi_netdev->rx_refill, mhi_net_rx_refill_work);
 	u64_stats_init(&mhi_netdev->stats.rx_syncp);
@@ -356,13 +394,14 @@ static int mhi_net_probe(struct mhi_device *mhi_dev,
 	int err;
 
 	ndev = alloc_netdev(sizeof(struct mhi_net_dev), info->netname,
-			    NET_NAME_PREDICTABLE, mhi_net_setup);
+			    NET_NAME_PREDICTABLE, info->ethernet_if ?
+			    mhi_ethernet_setup : mhi_net_setup);
 	if (!ndev)
 		return -ENOMEM;
 
 	SET_NETDEV_DEV(ndev, &mhi_dev->dev);
 
-	err = mhi_net_newlink(mhi_dev, ndev);
+	err = mhi_net_newlink(mhi_dev, ndev, info->ethernet_if);
 	if (err) {
 		free_netdev(ndev);
 		return err;
@@ -380,10 +419,17 @@ static void mhi_net_remove(struct mhi_device *mhi_dev)
 
 static const struct mhi_device_info mhi_hwip0 = {
 	.netname = "mhi_hwip%d",
+	.ethernet_if = false,
 };
 
 static const struct mhi_device_info mhi_swip0 = {
 	.netname = "mhi_swip%d",
+	.ethernet_if = false,
+};
+
+static const struct mhi_device_info mhi_eth0 = {
+	.netname = "eth%d",
+	.ethernet_if = true,
 };
 
 static const struct mhi_device_id mhi_net_id_table[] = {
@@ -391,6 +437,9 @@ static const struct mhi_device_id mhi_net_id_table[] = {
 	{ .chan = "IP_HW0", .driver_data = (kernel_ulong_t)&mhi_hwip0 },
 	/* Software data PATH (to modem CPU) */
 	{ .chan = "IP_SW0", .driver_data = (kernel_ulong_t)&mhi_swip0 },
+	{ .chan = "IP_SW1", .driver_data = (kernel_ulong_t)&mhi_swip0 },
+	{ .chan = "IP_ETH0", .driver_data = (kernel_ulong_t)&mhi_eth0 },
+	{ .chan = "IP_ETH1", .driver_data = (kernel_ulong_t)&mhi_eth0 },
 	{}
 };
 MODULE_DEVICE_TABLE(mhi, mhi_net_id_table);

-- 
2.34.1

On Tue, 09 Dec 2025 16:55:38 +0530 Vivek Pernamitta wrote:
> Add support to configure a new client as Ethernet type over MHI by
> setting "mhi_device_info.ethernet_if = true". Create a new Ethernet
> interface named eth%d. This complements existing NET driver support.
> 
> Introduce IP_SW1, ETH0, and ETH1 network interfaces required for
> M-plane, NETCONF, and S-plane components.
> 
> M-plane:
> Implement DU M-Plane software for non-real-time O-RAN management
> between O-DU and O-RU using NETCONF/YANG and O-RAN WG4 M-Plane YANG
> models. Provide capability exchange, configuration management,
> performance monitoring, and fault management per O-RAN.WG4.TS.MP.0-
> R004-v18.00.

Noob question perhaps, what does any of this have to do with Ethernet?
You need Ethernet to exchange NETCONF messages?

On 12/10/2025 3:08 PM, Jakub Kicinski wrote:
> On Tue, 09 Dec 2025 16:55:38 +0530 Vivek Pernamitta wrote:
>> Add support to configure a new client as Ethernet type over MHI by
>> setting "mhi_device_info.ethernet_if = true". Create a new Ethernet
>> interface named eth%d. This complements existing NET driver support.
>>
>> Introduce IP_SW1, ETH0, and ETH1 network interfaces required for
>> M-plane, NETCONF, and S-plane components.
>>
>> M-plane:
>> Implement DU M-Plane software for non-real-time O-RAN management
>> between O-DU and O-RU using NETCONF/YANG and O-RAN WG4 M-Plane YANG
>> models. Provide capability exchange, configuration management,
>> performance monitoring, and fault management per O-RAN.WG4.TS.MP.0-
>> R004-v18.00.
> 
> Noob question perhaps, what does any of this have to do with Ethernet?
> You need Ethernet to exchange NETCONF messages?

The patch primarily addresses host-to-DU communication. However, the
NETCONF/M-Plane packets originating from the host will eventually be
transmitted from the DU to the RU over the fronthaul, which uses
Ethernet. Bridging is therefore required to forward packets received
from the host towards the fronthaul Ethernet interface.
For additional details on this architecture and data flow, please
refer to the O-RAN Management Plane Specification:

O-RAN.WG4.MP.0-v07.00
O-RAN Alliance Working Group 4 – Management Plane Specification
Chapter 4: O-RU to O-DU Interface Management

-Vivek

On Mon, Dec 22, 2025 at 04:13:11PM +0530, vivek pernamitta wrote:
> 
> 
> On 12/10/2025 3:08 PM, Jakub Kicinski wrote:
> > On Tue, 09 Dec 2025 16:55:38 +0530 Vivek Pernamitta wrote:
> > > Add support to configure a new client as Ethernet type over MHI by
> > > setting "mhi_device_info.ethernet_if = true". Create a new Ethernet
> > > interface named eth%d. This complements existing NET driver support.
> > > 
> > > Introduce IP_SW1, ETH0, and ETH1 network interfaces required for
> > > M-plane, NETCONF, and S-plane components.
> > > 
> > > M-plane:
> > > Implement DU M-Plane software for non-real-time O-RAN management
> > > between O-DU and O-RU using NETCONF/YANG and O-RAN WG4 M-Plane YANG
> > > models. Provide capability exchange, configuration management,
> > > performance monitoring, and fault management per O-RAN.WG4.TS.MP.0-
> > > R004-v18.00.
> > 
> > Noob question perhaps, what does any of this have to do with Ethernet?
> > You need Ethernet to exchange NETCONF messages?
> 
> The patch primarily addresses host-to-DU communication. However, the
> NETCONF/M-Plane packets originating from the host will eventually be
> transmitted from the DU to the RU over the fronthaul, which uses
> Ethernet. Bridging is therefore required to forward packets received
> from the host towards the fronthaul Ethernet interface.
> For additional details on this architecture and data flow, please
> refer to the O-RAN Management Plane Specification:
> 

You missed one obvious point. The actual link between the device (QDU100) and
the host is PCIe/MHI. The device has the Etherent inteface and is exposed as the
MHI channel to the host. So this patch creates the Ethernet interface on the
host based on the 'IP_ETH' channel so that the host can use this interface for
exchaning the NETCONF packets.

All the rest of the O-RAN management details are irrelevant.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

>  	ndev = alloc_netdev(sizeof(struct mhi_net_dev), info->netname,
> -			    NET_NAME_PREDICTABLE, mhi_net_setup);
> +			    NET_NAME_PREDICTABLE, info->ethernet_if ?
> +			    mhi_ethernet_setup : mhi_net_setup);

Is the name predictable? I thought "eth%d" was considered
NET_NAME_ENUM?

https://elixir.bootlin.com/linux/v6.18/source/net/ethernet/eth.c#L382

	Andrew

On 12/9/2025 7:06 PM, Andrew Lunn wrote:
>>   	ndev = alloc_netdev(sizeof(struct mhi_net_dev), info->netname,
>> -			    NET_NAME_PREDICTABLE, mhi_net_setup);
>> +			    NET_NAME_PREDICTABLE, info->ethernet_if ?
>> +			    mhi_ethernet_setup : mhi_net_setup);
> 
> Is the name predictable? I thought "eth%d" was considered
> NET_NAME_ENUM?
> 
> https://elixir.bootlin.com/linux/v6.18/source/net/ethernet/eth.c#L382
> 
> 	Andrew
For Ethernet-type devices, the interface name will follow the standard
convention: eth%d, For normal IP interfaces, the interface will be
created as mhi_swip%d/mhi_hwip%d.The naming will depend on the details
provided through |struct mhi_device_info.|