net/mlx5e: Read ETS settings directly from firmware

Issue description:
Current implementation saves the ETS settings from user in
a temporal soft copy and returns this settings when user
queries the ETS settings.

With the new DCBX firmware, the ETS settings can be changed
by firmware when the DCBX is in firmware controlled mode. Therefore,
user will obtain wrong values from the temporal soft copy.

Solution:
1. Read the ETS settings directly from firmware.
2. For tc_tsa:
   a. Initialize tc_tsa to vendor IEEE_8021QAZ_TSA_VENDOR at netdev
      creation.
   b. When reading ETS setting from FW, if the traffic class bandwidth
      is less than 100, set tc_tsa to IEEE_8021QAZ_TSA_ETS. This
      implementation solves the scenarios when the DCBX is in FW control
      and willing bit is on which means the ETS setting is dictated
      by remote switch.

Also check ETS capability where needed.

Signed-off-by: Huy Nguyen <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

drivers/net/ethernet/mellanox/mlx5/core/en.h

@@ -214,9 +214,6 @@ struct mlx5e_params {
 	u8  toeplitz_hash_key[40];
 	u32 indirection_rqt[MLX5E_INDIR_RQT_SIZE];
 	bool vlan_strip_disable;
-#ifdef CONFIG_MLX5_CORE_EN_DCB
-	struct ieee_ets ets;
-#endif
 	bool rx_am_enabled;
 	u32 lro_timeout;
 };
@@ -238,6 +235,9 @@ enum {
 
 struct mlx5e_dcbx {
 	struct mlx5e_cee_config    cee_cfg; /* pending configuration */
+
+	/* The only setting that cannot be read from FW */
+	u8                         tc_tsa[IEEE_8021QAZ_MAX_TCS];
 };
 #endif
 

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

@@ -45,12 +45,31 @@ static int mlx5e_dcbnl_ieee_getets(struct net_device *netdev,
 				   struct ieee_ets *ets)
 {
 	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	int err = 0;
+	int i;
 
 	if (!MLX5_CAP_GEN(priv->mdev, ets))
 		return -ENOTSUPP;
 
-	memcpy(ets, &priv->params.ets, sizeof(*ets));
-	return 0;
+	ets->ets_cap = mlx5_max_tc(priv->mdev) + 1;
+	for (i = 0; i < ets->ets_cap; i++) {
+		err = mlx5_query_port_prio_tc(mdev, i, &ets->prio_tc[i]);
+		if (err)
+			return err;
+	}
+
+	for (i = 0; i < ets->ets_cap; i++) {
+		err = mlx5_query_port_tc_bw_alloc(mdev, i, &ets->tc_tx_bw[i]);
+		if (err)
+			return err;
+		if (ets->tc_tx_bw[i] < MLX5E_MAX_BW_ALLOC)
+			priv->dcbx.tc_tsa[i] = IEEE_8021QAZ_TSA_ETS;
+	}
+
+	memcpy(ets->tc_tsa, priv->dcbx.tc_tsa, sizeof(ets->tc_tsa));
+
+	return err;
 }
 
 enum {
@@ -113,9 +132,6 @@ int mlx5e_dcbnl_ieee_setets_core(struct mlx5e_priv *priv, struct ieee_ets *ets)
 	int max_tc = mlx5_max_tc(mdev);
 	int err;
 
-	if (!MLX5_CAP_GEN(mdev, ets))
-		return -ENOTSUPP;
-
 	mlx5e_build_tc_group(ets, tc_group, max_tc);
 	mlx5e_build_tc_tx_bw(ets, tc_tx_bw, tc_group, max_tc);
 
@@ -127,7 +143,14 @@ int mlx5e_dcbnl_ieee_setets_core(struct mlx5e_priv *priv, struct ieee_ets *ets)
 	if (err)
 		return err;
 
-	return mlx5_set_port_tc_bw_alloc(mdev, tc_tx_bw);
+	err = mlx5_set_port_tc_bw_alloc(mdev, tc_tx_bw);
+
+	if (err)
+		return err;
+
+	memcpy(priv->dcbx.tc_tsa, ets->tc_tsa, sizeof(ets->tc_tsa));
+
+	return err;
 }
 
 static int mlx5e_dbcnl_validate_ets(struct net_device *netdev,
@@ -173,6 +196,9 @@ static int mlx5e_dcbnl_ieee_setets(struct net_device *netdev,
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 	int err;
 
+	if (!MLX5_CAP_GEN(priv->mdev, ets))
+		return -ENOTSUPP;
+
 	err = mlx5e_dbcnl_validate_ets(netdev, ets);
 	if (err)
 		return err;
@@ -181,9 +207,6 @@ static int mlx5e_dcbnl_ieee_setets(struct net_device *netdev,
 	if (err)
 		return err;
 
-	memcpy(&priv->params.ets, ets, sizeof(*ets));
-	priv->params.ets.ets_cap = mlx5_max_tc(priv->mdev) + 1;
-
 	return 0;
 }
 
@@ -316,9 +339,12 @@ static u8 mlx5e_dcbnl_setall(struct net_device *netdev)
 	struct mlx5_core_dev *mdev = priv->mdev;
 	struct ieee_ets ets;
 	struct ieee_pfc pfc;
-	int err;
+	int err = -ENOTSUPP;
 	int i;
 
+	if (!MLX5_CAP_GEN(mdev, ets))
+		goto out;
+
 	memset(&ets, 0, sizeof(ets));
 	memset(&pfc, 0, sizeof(pfc));
 

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

@@ -3328,18 +3328,27 @@ u16 mlx5e_get_max_inline_cap(struct mlx5_core_dev *mdev)
 #ifdef CONFIG_MLX5_CORE_EN_DCB
 static void mlx5e_ets_init(struct mlx5e_priv *priv)
 {
+	struct ieee_ets ets;
 	int i;
 
-	priv->params.ets.ets_cap = mlx5_max_tc(priv->mdev) + 1;
-	for (i = 0; i < priv->params.ets.ets_cap; i++) {
-		priv->params.ets.tc_tx_bw[i] = MLX5E_MAX_BW_ALLOC;
-		priv->params.ets.tc_tsa[i] = IEEE_8021QAZ_TSA_VENDOR;
-		priv->params.ets.prio_tc[i] = i;
+	if (!MLX5_CAP_GEN(priv->mdev, ets))
+		return;
+
+	memset(&ets, 0, sizeof(ets));
+	ets.ets_cap = mlx5_max_tc(priv->mdev) + 1;
+	for (i = 0; i < ets.ets_cap; i++) {
+		ets.tc_tx_bw[i] = MLX5E_MAX_BW_ALLOC;
+		ets.tc_tsa[i] = IEEE_8021QAZ_TSA_VENDOR;
+		ets.prio_tc[i] = i;
 	}
 
+	memcpy(priv->dcbx.tc_tsa, ets.tc_tsa, sizeof(ets.tc_tsa));
+
 	/* tclass[prio=0]=1, tclass[prio=1]=0, tclass[prio=i]=i (for i>1) */
-	priv->params.ets.prio_tc[0] = 1;
-	priv->params.ets.prio_tc[1] = 0;
+	ets.prio_tc[0] = 1;
+	ets.prio_tc[1] = 0;
+
+	mlx5e_dcbnl_ieee_setets_core(priv, &ets);
 }
 #endif
 
@@ -3509,10 +3518,6 @@ static void mlx5e_build_nic_netdev_priv(struct mlx5_core_dev *mdev,
 	MLX5E_SET_PRIV_FLAG(priv, MLX5E_PFLAG_RX_CQE_BASED_MODER,
 			    priv->params.rx_cq_period_mode == MLX5_CQ_PERIOD_MODE_START_FROM_CQE);
 
-#ifdef CONFIG_MLX5_CORE_EN_DCB
-	mlx5e_ets_init(priv);
-#endif
-
 	mutex_init(&priv->state_lock);
 
 	INIT_WORK(&priv->update_carrier_work, mlx5e_update_carrier_work);
@@ -3789,7 +3794,7 @@ static int mlx5e_init_nic_tx(struct mlx5e_priv *priv)
 	}
 
 #ifdef CONFIG_MLX5_CORE_EN_DCB
-	mlx5e_dcbnl_ieee_setets_core(priv, &priv->params.ets);
+	mlx5e_ets_init(priv);
 #endif
 	return 0;
 }