[PATCH net 1/3] net/mlx5: Fix Unbinding uplink-netdev in switchdev mode
From: Tariq Toukan <tariqt@nvidia.com>
Date: 2026-01-26 07:15:44
Also in:
linux-rdma, lkml
Subsystem:
mellanox ethernet driver (mlx5e), mellanox mlx5 core vpi driver, networking drivers, the rest · Maintainers:
Saeed Mahameed, Tariq Toukan, Mark Bloch, Leon Romanovsky, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Shay Drory <redacted>
It is possible to unbind the uplink ETH driver while the E-Switch is
in switchdev mode. This leads to netdevice reference counting issues[1],
as the driver removal path was not designed to clean up from this state.
During uplink ETH driver removal (_mlx5e_remove), the code now waits for
any concurrent E-Switch mode transition to finish. It then removes the
REPs auxiliary device, if exists. This ensures a graceful cleanup.
[1]
unregister_netdevice: waiting for eth2 to become free. Usage count = 2
ref_tracker: netdev@00000000c912e04b has 1/1 users at
ib_device_set_netdev+0x130/0x270 [ib_core]
mlx5_ib_vport_rep_load+0xf4/0x3e0 [mlx5_ib]
mlx5_esw_offloads_rep_load+0xc7/0xe0 [mlx5_core]
esw_offloads_enable+0x583/0x900 [mlx5_core]
mlx5_eswitch_enable_locked+0x1b2/0x290 [mlx5_core]
mlx5_devlink_eswitch_mode_set+0x107/0x3e0 [mlx5_core]
devlink_nl_eswitch_set_doit+0x60/0xd0
genl_family_rcv_msg_doit+0xe0/0x130
genl_rcv_msg+0x183/0x290
netlink_rcv_skb+0x4b/0xf0
genl_rcv+0x24/0x40
netlink_unicast+0x255/0x380
netlink_sendmsg+0x1f3/0x420
__sock_sendmsg+0x38/0x60
__sys_sendto+0x119/0x180
__x64_sys_sendto+0x20/0x30
Fixes: 7a9fb35e8c3a ("net/mlx5e: Do not reload ethernet ports when changing eswitch mode")
Signed-off-by: Shay Drory <redacted>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
drivers/net/ethernet/mellanox/mlx5/core/dev.c | 14 ++++++++++
.../net/ethernet/mellanox/mlx5/core/en_main.c | 1 +
.../net/ethernet/mellanox/mlx5/core/eswitch.h | 4 +++
.../mellanox/mlx5/core/eswitch_offloads.c | 26 +++++++++++++++++++
.../ethernet/mellanox/mlx5/core/mlx5_core.h | 1 +
5 files changed, 46 insertions(+)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/dev.c b/drivers/net/ethernet/mellanox/mlx5/core/dev.c
index 64c04f52990f..781e39b5aa1d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/dev.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/dev.c@@ -575,3 +575,17 @@ bool mlx5_same_hw_devs(struct mlx5_core_dev *dev, struct mlx5_core_dev *peer_dev return plen && flen && flen == plen && !memcmp(fsystem_guid, psystem_guid, flen); } + +void mlx5_core_reps_aux_devs_remove(struct mlx5_core_dev *dev) +{ + struct mlx5_priv *priv = &dev->priv; + + if (priv->adev[MLX5_INTERFACE_PROTOCOL_ETH]) + device_lock_assert(&priv->adev[MLX5_INTERFACE_PROTOCOL_ETH]->adev.dev); + else + mlx5_core_err(dev, "ETH driver already removed\n"); + if (priv->adev[MLX5_INTERFACE_PROTOCOL_IB_REP]) + del_adev(&priv->adev[MLX5_INTERFACE_PROTOCOL_IB_REP]->adev); + if (priv->adev[MLX5_INTERFACE_PROTOCOL_ETH_REP]) + del_adev(&priv->adev[MLX5_INTERFACE_PROTOCOL_ETH_REP]->adev); +}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 9042c8a388e4..f83359f7fdea 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c@@ -6842,6 +6842,7 @@ static void _mlx5e_remove(struct auxiliary_device *adev) struct mlx5e_priv *priv = netdev_priv(netdev); struct mlx5_core_dev *mdev = edev->mdev; + mlx5_eswitch_safe_aux_devs_remove(mdev); mlx5_core_uplink_netdev_set(mdev, NULL); if (priv->profile)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index e7fe43799b23..714ad28e8445 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h@@ -929,6 +929,7 @@ int mlx5_esw_ipsec_vf_packet_offload_set(struct mlx5_eswitch *esw, struct mlx5_v int mlx5_esw_ipsec_vf_packet_offload_supported(struct mlx5_core_dev *dev, u16 vport_num); bool mlx5_esw_host_functions_enabled(const struct mlx5_core_dev *dev); +void mlx5_eswitch_safe_aux_devs_remove(struct mlx5_core_dev *dev); #else /* CONFIG_MLX5_ESWITCH */ /* eswitch API stubs */ static inline int mlx5_eswitch_init(struct mlx5_core_dev *dev) { return 0; }
@@ -1012,6 +1013,9 @@ mlx5_esw_vport_vhca_id(struct mlx5_eswitch *esw, u16 vportn, u16 *vhca_id) return false; } +static inline void +mlx5_eswitch_safe_aux_devs_remove(struct mlx5_core_dev *dev) {} + #endif /* CONFIG_MLX5_ESWITCH */ #endif /* __MLX5_ESWITCH_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
index ea94a727633f..02b7e474586d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c@@ -3981,6 +3981,32 @@ static bool mlx5_devlink_switchdev_active_mode_change(struct mlx5_eswitch *esw, return true; } +#define MLX5_ESW_HOLD_TIMEOUT_MS 7000 +#define MLX5_ESW_HOLD_RETRY_DELAY_MS 500 + +void mlx5_eswitch_safe_aux_devs_remove(struct mlx5_core_dev *dev) +{ + unsigned long timeout; + bool hold_esw = true; + + /* Wait for any concurrent eswitch mode transition to complete. */ + if (!mlx5_esw_hold(dev)) { + timeout = jiffies + msecs_to_jiffies(MLX5_ESW_HOLD_TIMEOUT_MS); + while (!mlx5_esw_hold(dev)) { + if (!time_before(jiffies, timeout)) { + hold_esw = false; + break; + } + msleep(MLX5_ESW_HOLD_RETRY_DELAY_MS); + } + } + if (hold_esw) { + if (mlx5_eswitch_mode(dev) == MLX5_ESWITCH_OFFLOADS) + mlx5_core_reps_aux_devs_remove(dev); + mlx5_esw_release(dev); + } +} + int mlx5_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode, struct netlink_ext_ack *extack) {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index cfebc110c02f..99b0a25054ef 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h@@ -290,6 +290,7 @@ int mlx5_register_device(struct mlx5_core_dev *dev); void mlx5_unregister_device(struct mlx5_core_dev *dev); void mlx5_dev_set_lightweight(struct mlx5_core_dev *dev); bool mlx5_dev_is_lightweight(struct mlx5_core_dev *dev); +void mlx5_core_reps_aux_devs_remove(struct mlx5_core_dev *dev); void mlx5_fw_reporters_create(struct mlx5_core_dev *dev); int mlx5_query_mtpps(struct mlx5_core_dev *dev, u32 *mtpps, u32 mtpps_size);
--
2.40.1