git: c31002454ea4 - main - mlx5en: Add sysctl variable mapping driver name to IF name

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=c31002454ea466d09071050d5467540727301fb0

commit c31002454ea466d09071050d5467540727301fb0
Author:     Vag Singh <vag.singh@oneconvergence.com>
AuthorDate: 2025-08-14 05:40:56 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-09-16 14:12:07 +0000

    mlx5en: Add sysctl variable mapping driver name to IF name
    
    PATCH 09/31] FreeBSD OFED support for DPDK MLX5 PMD
    
    HyperV is not enabling ROCE by default causing the OFED to
    not create few SYSCTL variables that publish kernel interface
    name. Due to this MLX5 PMD is not able to read kernel
    interface name to get MAC address.
    
    Added new sysctl variable in MLX5_EN driver to map the device
    name to the interface name.
    
    Differential revision:  https://reviews.freebsd.org/D32183
    MFC after:      1 month
---
 sys/dev/mlx5/mlx5_en/mlx5_en_main.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
index 4d94ddf6a391..7c03a1fcea6b 100644
--- a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
+++ b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
@@ -4123,6 +4123,18 @@ mlx5e_priv_static_destroy(struct mlx5e_priv *priv, struct mlx5_core_dev *mdev,
 	sx_destroy(&priv->state_lock);
 }
 
+static int
+sysctl_ifname(SYSCTL_HANDLER_ARGS)
+{
+	struct mlx5e_priv *priv = arg1;
+	char name[IFNAMSIZ];
+	int error;
+
+	strncpy(name, if_name(priv->ifp), sizeof(name));
+	error = sysctl_handle_string(oidp, name, sizeof(name), req);
+	return (error);
+}
+
 static int
 sysctl_firmware(SYSCTL_HANDLER_ARGS)
 {
@@ -4955,6 +4967,11 @@ mlx5e_create_ifp(struct mlx5_core_dev *mdev)
 	}
 	PRIV_UNLOCK(priv);
 
+	SYSCTL_ADD_PROC(&priv->sysctl_ctx,
+			SYSCTL_CHILDREN(device_get_sysctl_tree(mdev->pdev->dev.bsddev)),
+			OID_AUTO, "ifname", CTLTYPE_STRING | CTLFLAG_RD, priv, 0,
+			sysctl_ifname, "A", "ifname managed by driver");
+
 	return (priv);
 
 err_open_flow_tables: