net/mlx5: Serialize module cleanup with reload and remove

Currently, remove and reload flows can run in parallel to module cleanup.
This design is error prone. For example: aux_drivers callbacks are called
from both cleanup and remove flows with different lockings, which can
cause a deadlock[1].
Hence, serialize module cleanup with reload and remove.

[1]
       cleanup                        remove
       -------                        ------
   auxiliary_driver_unregister();
                                     devl_lock()
                                      auxiliary_device_delete(mlx5e_aux)
    device_lock(mlx5e_aux)
     devl_lock()
                                       device_lock(mlx5e_aux)

Fixes: 912cebf420 ("net/mlx5e: Connect ethernet part to auxiliary bus")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/main.c

@@ -2110,7 +2110,7 @@ static int __init mlx5_init(void)
 	mlx5_core_verify_params();
 	mlx5_register_debugfs();
 
-	err = pci_register_driver(&mlx5_core_driver);
+	err = mlx5e_init();
 	if (err)
 		goto err_debug;
 
@@ -2118,16 +2118,16 @@ static int __init mlx5_init(void)
 	if (err)
 		goto err_sf;
 
-	err = mlx5e_init();
+	err = pci_register_driver(&mlx5_core_driver);
 	if (err)
-		goto err_en;
+		goto err_pci;
 
 	return 0;
 
-err_en:
+err_pci:
 	mlx5_sf_driver_unregister();
 err_sf:
-	pci_unregister_driver(&mlx5_core_driver);
+	mlx5e_cleanup();
 err_debug:
 	mlx5_unregister_debugfs();
 	return err;
@@ -2135,9 +2135,9 @@ err_debug:
 
 static void __exit mlx5_cleanup(void)
 {
-	mlx5e_cleanup();
-	mlx5_sf_driver_unregister();
 	pci_unregister_driver(&mlx5_core_driver);
+	mlx5_sf_driver_unregister();
+	mlx5e_cleanup();
 	mlx5_unregister_debugfs();
 }