From 0cf024ed12b5e44253c1498cb3265d2874a0c324 Mon Sep 17 00:00:00 2001
From: Alaa Hleihel <ahleihel@redhat.com>
Date: Tue, 12 May 2020 10:54:48 -0400
Subject: [PATCH 176/312] [netdrv] net/mlx5e: Change inline mode correctly when
 changing trust state

Message-id: <20200512105530.4207-83-ahleihel@redhat.com>
Patchwork-id: 306954
Patchwork-instance: patchwork
O-Subject: [RHEL8.3 BZ 1789382 082/124] net/mlx5e: Change inline mode correctly when changing trust state
Bugzilla: 1789382
RH-Acked-by: Tony Camuso <tcamuso@redhat.com>
RH-Acked-by: Kamal Heib <kheib@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>

Bugzilla: http://bugzilla.redhat.com/1789382
Upstream: v5.7-rc1

commit 6e0504c69811ae9df7e7e1284950befbe3e6f496
Author: Maxim Mikityanskiy <maximmi@mellanox.com>
Date:   Thu Nov 14 13:06:16 2019 +0200

    net/mlx5e: Change inline mode correctly when changing trust state

    The current steps that are performed when the trust state changes, if
    the channels are active:

    1. The trust state is changed in hardware.

    2. The new inline mode is calculated.

    3. If the new inline mode is different, the channels are recreated using
    the new inline mode.

    This approach has some issues:

    1. There is a time gap between changing trust state in hardware and
    starting sending enough inline headers (the latter happens after
    recreation of channels). It leads to failed transmissions and error
    CQEs.

    2. If the new channels fail to open, we'll be left with the old ones,
    but the hardware will be configured for the new trust state, so the
    interval when we can see TX errors never ends.

    This patch fixes the issues above by moving the trust state change into
    the preactivate hook that runs during the recreation of the channels
    when no channels are active, so it eliminates the gap of partially
    applied configuration. If the inline mode doesn't change with the change
    of the trust state, the channels won't be recreated, just like before
    this patch.

    Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
    Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
    Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Signed-off-by: Alaa Hleihel <ahleihel@redhat.com>
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c | 55 +++++++++++++---------
 1 file changed, 33 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
index 1375f6483a13..47874d34156b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
@@ -1098,49 +1098,59 @@ void mlx5e_dcbnl_delete_app(struct mlx5e_priv *priv)
 	mlx5e_dcbnl_dscp_app(priv, DELETE);
 }
 
-static void mlx5e_trust_update_tx_min_inline_mode(struct mlx5e_priv *priv,
-						  struct mlx5e_params *params)
+static void mlx5e_params_calc_trust_tx_min_inline_mode(struct mlx5_core_dev *mdev,
+						       struct mlx5e_params *params,
+						       u8 trust_state)
 {
-	mlx5_query_min_inline(priv->mdev, &params->tx_min_inline_mode);
-	if (priv->dcbx_dp.trust_state == MLX5_QPTS_TRUST_DSCP &&
+	mlx5_query_min_inline(mdev, &params->tx_min_inline_mode);
+	if (trust_state == MLX5_QPTS_TRUST_DSCP &&
 	    params->tx_min_inline_mode == MLX5_INLINE_MODE_L2)
 		params->tx_min_inline_mode = MLX5_INLINE_MODE_IP;
 }
 
-static void mlx5e_trust_update_sq_inline_mode(struct mlx5e_priv *priv)
+static int mlx5e_update_trust_state_hw(struct mlx5e_priv *priv, void *context)
+{
+	u8 *trust_state = context;
+	int err;
+
+	err = mlx5_set_trust_state(priv->mdev, *trust_state);
+	if (err)
+		return err;
+	priv->dcbx_dp.trust_state = *trust_state;
+
+	return 0;
+}
+
+static int mlx5e_set_trust_state(struct mlx5e_priv *priv, u8 trust_state)
 {
 	struct mlx5e_channels new_channels = {};
+	bool reset_channels = true;
+	int err = 0;
 
 	mutex_lock(&priv->state_lock);
 
 	new_channels.params = priv->channels.params;
-	mlx5e_trust_update_tx_min_inline_mode(priv, &new_channels.params);
+	mlx5e_params_calc_trust_tx_min_inline_mode(priv->mdev, &new_channels.params,
+						   trust_state);
 
 	if (!test_bit(MLX5E_STATE_OPENED, &priv->state)) {
 		priv->channels.params = new_channels.params;
-		goto out;
+		reset_channels = false;
 	}
 
 	/* Skip if tx_min_inline is the same */
 	if (new_channels.params.tx_min_inline_mode ==
 	    priv->channels.params.tx_min_inline_mode)
-		goto out;
+		reset_channels = false;
 
-	mlx5e_safe_switch_channels(priv, &new_channels, NULL, NULL);
+	if (reset_channels)
+		err = mlx5e_safe_switch_channels(priv, &new_channels,
+						 mlx5e_update_trust_state_hw,
+						 &trust_state);
+	else
+		err = mlx5e_update_trust_state_hw(priv, &trust_state);
 
-out:
 	mutex_unlock(&priv->state_lock);
-}
-
-static int mlx5e_set_trust_state(struct mlx5e_priv *priv, u8 trust_state)
-{
-	int err;
-
-	err = mlx5_set_trust_state(priv->mdev, trust_state);
-	if (err)
-		return err;
-	priv->dcbx_dp.trust_state = trust_state;
-	mlx5e_trust_update_sq_inline_mode(priv);
 
 	return err;
 }
@@ -1171,7 +1181,8 @@ static int mlx5e_trust_initialize(struct mlx5e_priv *priv)
 	if (err)
 		return err;
 
-	mlx5e_trust_update_tx_min_inline_mode(priv, &priv->channels.params);
+	mlx5e_params_calc_trust_tx_min_inline_mode(priv->mdev, &priv->channels.params,
+						   priv->dcbx_dp.trust_state);
 
 	err = mlx5_query_dscp2prio(priv->mdev, priv->dcbx_dp.dscp2prio);
 	if (err)
-- 
2.13.6