mlx5: reduce stack usage in mlx5_setup_tc

Clang warns about excessive stack usage on 32-bit targets:

drivers/net/ethernet/mellanox/mlx5/core/en_main.c:3597:12: error: stack frame size (1184) exceeds limit (1024) in 'mlx5e_setup_tc' [-Werror,-Wframe-larger-than]
static int mlx5e_setup_tc(struct net_device *dev, enum tc_setup_type type,

It turns out that both the mlx5e_setup_tc_mqprio_dcb() function and
the mlx5e_safe_switch_params() function it calls have a copy of
'struct mlx5e_params' on the stack, and this structure is fairly
large.

Use dynamic allocation for the inner one.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 3973d86905e843702f4e54347b8a319521be2a7f..6b9267c19e00f27658b36eb2ca24cfd90fa88ac0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3002,32 +3002,37 @@ int mlx5e_safe_switch_params(struct mlx5e_priv *priv,
                             mlx5e_fp_preactivate preactivate,
                             void *context, bool reset)
 {
-       struct mlx5e_channels new_chs = {};
+       struct mlx5e_channels *new_chs;
        int err;
 
        reset &= test_bit(MLX5E_STATE_OPENED, &priv->state);
        if (!reset)
                return mlx5e_switch_priv_params(priv, params, preactivate, context);
 
-       new_chs.params = *params;
+       new_chs = kzalloc(sizeof(*new_chs), GFP_KERNEL);
+       if (!new_chs)
+               return -ENOMEM;
+       new_chs->params = *params;
 
-       mlx5e_selq_prepare_params(&priv->selq, &new_chs.params);
+       mlx5e_selq_prepare_params(&priv->selq, &new_chs->params);
 
-       err = mlx5e_open_channels(priv, &new_chs);
+       err = mlx5e_open_channels(priv, new_chs);
        if (err)
                goto err_cancel_selq;
 
-       err = mlx5e_switch_priv_channels(priv, &new_chs, preactivate, context);
+       err = mlx5e_switch_priv_channels(priv, new_chs, preactivate, context);
        if (err)
                goto err_close;
 
+       kfree(new_chs);
        return 0;
 
 err_close:
-       mlx5e_close_channels(&new_chs);
+       mlx5e_close_channels(new_chs);
 
 err_cancel_selq:
        mlx5e_selq_cancel(&priv->selq);
+       kfree(new_chs);
        return err;
 }