net/mlx5: Remove devl_unlock from mlx5_eswtich_mode_callback_enter

The function mlx5_eswtich_mode_callback_enter() was added as a temporary
workaround once devlink instance lock was added to devlink eswitch
callbacks. However, code review and testing show that all the callbacks
part to eswitch_mode_set don't take devlink instance lock in any flow
and so unlocking devlink instance lock while entering these functions is
not needed.

Remove devl_lock from mlx5_eswtich_mode_callback_enter() and devl_unlock
from mlx5_eswtich_mode_callback_exit(). Also remove the functions
mlx5_eswtich_mode_callback_enter()/exit() as they are not needed any
more. The callback eswitch_mode_set will be treated separately in the
following patches.

Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
index e224ec7005a64436b47ce401a3fbf1d2dbc7d214..3bd843e6d66a5c35288487d8a068700378a570a8 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
@@ -3342,27 +3342,6 @@ static int esw_inline_mode_to_devlink(u8 mlx5_mode, u8 *mode)
        return 0;
 }
 
-/* FIXME: devl_unlock() followed by devl_lock() inside driver callback
- * is never correct and prone to races. It's a transitional workaround,
- * never repeat this pattern.
- *
- * This code MUST be fixed before removing devlink_mutex as it is safe
- * to do only because of that mutex.
- */
-static void mlx5_eswtich_mode_callback_enter(struct devlink *devlink,
-                                            struct mlx5_eswitch *esw)
-{
-       devl_unlock(devlink);
-       down_write(&esw->mode_lock);
-}
-
-static void mlx5_eswtich_mode_callback_exit(struct devlink *devlink,
-                                           struct mlx5_eswitch *esw)
-{
-       up_write(&esw->mode_lock);
-       devl_lock(devlink);
-}
-
 int mlx5_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode,
                                  struct netlink_ext_ack *extack)
 {
@@ -3431,9 +3410,9 @@ int mlx5_devlink_eswitch_mode_get(struct devlink *devlink, u16 *mode)
        if (IS_ERR(esw))
                return PTR_ERR(esw);
 
-       mlx5_eswtich_mode_callback_enter(devlink, esw);
+       down_write(&esw->mode_lock);
        err = esw_mode_to_devlink(esw->mode, mode);
-       mlx5_eswtich_mode_callback_exit(devlink, esw);
+       up_write(&esw->mode_lock);
        return err;
 }
 
@@ -3480,7 +3459,7 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode,
        if (IS_ERR(esw))
                return PTR_ERR(esw);
 
-       mlx5_eswtich_mode_callback_enter(devlink, esw);
+       down_write(&esw->mode_lock);
 
        switch (MLX5_CAP_ETH(dev, wqe_inline_mode)) {
        case MLX5_CAP_INLINE_MODE_NOT_REQUIRED:
@@ -3514,11 +3493,11 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode,
                goto out;
 
        esw->offloads.inline_mode = mlx5_mode;
-       mlx5_eswtich_mode_callback_exit(devlink, esw);
+       up_write(&esw->mode_lock);
        return 0;
 
 out:
-       mlx5_eswtich_mode_callback_exit(devlink, esw);
+       up_write(&esw->mode_lock);
        return err;
 }
 
@@ -3531,9 +3510,9 @@ int mlx5_devlink_eswitch_inline_mode_get(struct devlink *devlink, u8 *mode)
        if (IS_ERR(esw))
                return PTR_ERR(esw);
 
-       mlx5_eswtich_mode_callback_enter(devlink, esw);
+       down_write(&esw->mode_lock);
        err = esw_inline_mode_to_devlink(esw->offloads.inline_mode, mode);
-       mlx5_eswtich_mode_callback_exit(devlink, esw);
+       up_write(&esw->mode_lock);
        return err;
 }
 
@@ -3549,7 +3528,7 @@ int mlx5_devlink_eswitch_encap_mode_set(struct devlink *devlink,
        if (IS_ERR(esw))
                return PTR_ERR(esw);
 
-       mlx5_eswtich_mode_callback_enter(devlink, esw);
+       down_write(&esw->mode_lock);
 
        if (encap != DEVLINK_ESWITCH_ENCAP_MODE_NONE &&
            (!MLX5_CAP_ESW_FLOWTABLE_FDB(dev, reformat) ||
@@ -3592,7 +3571,7 @@ int mlx5_devlink_eswitch_encap_mode_set(struct devlink *devlink,
        }
 
 unlock:
-       mlx5_eswtich_mode_callback_exit(devlink, esw);
+       up_write(&esw->mode_lock);
        return err;
 }
 
@@ -3605,9 +3584,9 @@ int mlx5_devlink_eswitch_encap_mode_get(struct devlink *devlink,
        if (IS_ERR(esw))
                return PTR_ERR(esw);
 
-       mlx5_eswtich_mode_callback_enter(devlink, esw);
+       down_write(&esw->mode_lock);
        *encap = esw->offloads.encap;
-       mlx5_eswtich_mode_callback_exit(devlink, esw);
+       up_write(&esw->mode_lock);
        return 0;
 }