From: Parav Pandit <parav@mellanox.com>
Date: Thu, 14 May 2020 05:12:56 -0500
Subject: net/mlx5: Disable reload while removing the device
Patch-mainline: v5.8-rc1
Git-commit: 60904cd349abc98cb888fc28d1ca55a8e2cf87b3
References: jsc#SLE-8464

While unregistration is in progress, user might be reloading the
interface.
This can race with unregistration in below flow which uses the
resources which are getting disabled by reload flow.

Hence, disable the devlink reloading first when removing the device.

     CPU0                                   CPU1
     ----                                   ----
local_pci_remove()                  devlink_mutex
  remove_one()                       devlink_nl_cmd_reload()
    mlx5_unregister_device()           devlink_reload()
                                       ops->reload_down()
                                         mlx5_unload_one()

Fixes: 4383cfcc65e7 ("net/mlx5: Add devlink reload")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/devlink.c |    2 --
 drivers/net/ethernet/mellanox/mlx5/core/main.c    |    2 ++
 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -256,7 +256,6 @@ int mlx5_devlink_register(struct devlink
 		goto params_reg_err;
 	mlx5_devlink_set_params_init_values(devlink);
 	devlink_params_publish(devlink);
-	devlink_reload_enable(devlink);
 	return 0;
 
 params_reg_err:
@@ -266,7 +265,6 @@ params_reg_err:
 
 void mlx5_devlink_unregister(struct devlink *devlink)
 {
-	devlink_reload_disable(devlink);
 	devlink_params_unregister(devlink, mlx5_devlink_params,
 				  ARRAY_SIZE(mlx5_devlink_params));
 	devlink_unregister(devlink);
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -1361,6 +1361,7 @@ static int init_one(struct pci_dev *pdev
 		dev_err(&pdev->dev, "mlx5_crdump_enable failed with error code %d\n", err);
 
 	pci_save_state(pdev);
+	devlink_reload_enable(devlink);
 	return 0;
 
 err_load_one:
@@ -1378,6 +1379,7 @@ static void remove_one(struct pci_dev *p
 	struct mlx5_core_dev *dev  = pci_get_drvdata(pdev);
 	struct devlink *devlink = priv_to_devlink(dev);
 
+	devlink_reload_disable(devlink);
 	mlx5_crdump_disable(dev);
 	mlx5_devlink_unregister(devlink);