net/mlx5: Fix Unbinding uplink-netdev in switchdev mode

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 <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/1769411695-18820-2-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/dev.c b/drivers/net/ethernet/mellanox/mlx5/core/dev.c
index 64c04f52990fe07735c21b3025557b10579ba15e..781e39b5aa1deff558611dcb271c3f1229e3121d 100644 (file)
--- 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 9042c8a388e42bcaf72946323020a5ddfe69d267..f83359f7fdeae6f2dcc8c4b3a893de8323e2cbd1 100644 (file)
--- 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 e7fe43799b23effa2f74d00542278bf4cc2c8bfe..714ad28e8445b43b11aa0a77e814d40a9f200db6 100644 (file)
--- 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 ea94a727633f1f0ecf5a8f0d3153bdcb38812a29..02b7e474586d9c95dbed204ddab134172ca7353a 100644 (file)
--- 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 cfebc110c02fd94d7f3b7796f6f0702e999e8c76..99b0a25054efd8948894c8e5a549456770534d9d 100644 (file)
--- 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);