[net-next 6/8] net/mlx5e: Ethtool driver callback for query/set FEC policy

[Saeed Mahameed <saeedm@mellanox.com>]

From: Shay Agroskin <shayag@mellanox.com>

Driver callback function for 'ethtool --show-fec',
'ethtool --set-fec' commands.

The query function returns active and configured FEC policy
for current link speed.

The set function sets FEC policy for all supported link
speeds.
1) If current link speed doesn't support requested FEC policy,
   the function fails.
2) If a different link speed doesn't support requested FEC
   policy, FEC capbilities for this speed are turned off.

Signed-off-by: Shay Agroskin <shayag@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---
 .../ethernet/mellanox/mlx5/core/en_ethtool.c  | 128 +++++++++++++++++-
 1 file changed, 126 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index c61f6302cde2..3e770abfd802 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -547,6 +547,70 @@ static void ptys2ethtool_adver_link(unsigned long *advertising_modes,
 			  __ETHTOOL_LINK_MODE_MASK_NBITS);
 }
 
+static const u32 pplm_fec_2_ethtool[] = {
+	[MLX5E_FEC_NOFEC] = ETHTOOL_FEC_OFF,
+	[MLX5E_FEC_FIRECODE] = ETHTOOL_FEC_BASER,
+	[MLX5E_FEC_RS_528_514] = ETHTOOL_FEC_RS,
+};
+
+static u32 pplm2ethtool_fec(u_long fec_mode, unsigned long size)
+{
+	int mode = 0;
+
+	if (!fec_mode)
+		return ETHTOOL_FEC_AUTO;
+
+	mode = find_first_bit(&fec_mode, size);
+
+	if (mode < ARRAY_SIZE(pplm_fec_2_ethtool))
+		return pplm_fec_2_ethtool[mode];
+
+	return 0;
+}
+
+/* we use ETHTOOL_FEC_* offset and apply it to ETHTOOL_LINK_MODE_FEC_*_BIT */
+static u32 ethtool_fec2ethtool_caps(u_long ethtool_fec_code)
+{
+	u32 offset;
+
+	offset = find_first_bit(&ethtool_fec_code, sizeof(u32));
+	offset -= ETHTOOL_FEC_OFF_BIT;
+	offset += ETHTOOL_LINK_MODE_FEC_NONE_BIT;
+
+	return offset;
+}
+
+static int get_fec_supported_advertised(struct mlx5_core_dev *dev,
+					struct ethtool_link_ksettings *link_ksettings)
+{
+	u_long fec_caps = 0;
+	u32 active_fec = 0;
+	u32 offset;
+	u32 bitn;
+	int err;
+
+	err = mlx5e_get_fec_caps(dev, (u8 *)&fec_caps);
+	if (err)
+		return (err == -EOPNOTSUPP) ? 0 : err;
+
+	err = mlx5e_get_fec_mode(dev, &active_fec, NULL);
+	if (err)
+		return err;
+
+	for_each_set_bit(bitn, &fec_caps, ARRAY_SIZE(pplm_fec_2_ethtool)) {
+		u_long ethtool_bitmask = pplm_fec_2_ethtool[bitn];
+
+		offset = ethtool_fec2ethtool_caps(ethtool_bitmask);
+		__set_bit(offset, link_ksettings->link_modes.supported);
+	}
+
+	active_fec = pplm2ethtool_fec(active_fec, sizeof(u32) * BITS_PER_BYTE);
+	offset = ethtool_fec2ethtool_caps(active_fec);
+	__set_bit(offset, link_ksettings->link_modes.advertising);
+
+	return 0;
+}
+
 static void ptys2ethtool_supported_advertised_port(struct ethtool_link_ksettings *link_ksettings,
 						   u32 eth_proto_cap,
 						   u8 connector_type)
@@ -742,7 +806,7 @@ static int mlx5e_get_link_ksettings(struct net_device *netdev,
 	if (err) {
 		netdev_err(netdev, "%s: query port ptys failed: %d\n",
 			   __func__, err);
-		goto err_query_ptys;
+		goto err_query_regs;
 	}
 
 	eth_proto_cap    = MLX5_GET(ptys_reg, out, eth_proto_capability);
@@ -778,11 +842,17 @@ static int mlx5e_get_link_ksettings(struct net_device *netdev,
 							  AUTONEG_ENABLE;
 	ethtool_link_ksettings_add_link_mode(link_ksettings, supported,
 					     Autoneg);
+
+	err = get_fec_supported_advertised(mdev, link_ksettings);
+	if (err)
+		netdev_dbg(netdev, "%s: FEC caps query failed: %d\n",
+			   __func__, err);
+
 	if (!an_disable_admin)
 		ethtool_link_ksettings_add_link_mode(link_ksettings,
 						     advertising, Autoneg);
 
-err_query_ptys:
+err_query_regs:
 	return err;
 }
 
@@ -1277,6 +1347,58 @@ static int mlx5e_set_wol(struct net_device *netdev, struct ethtool_wolinfo *wol)
 	return mlx5_set_port_wol(mdev, mlx5_wol_mode);
 }
 
+static int mlx5e_get_fecparam(struct net_device *netdev,
+			      struct ethtool_fecparam *fecparam)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	u8 fec_configured = 0;
+	u32 fec_active = 0;
+	int err;
+
+	err = mlx5e_get_fec_mode(mdev, &fec_active, &fec_configured);
+
+	if (err)
+		return err;
+
+	fecparam->active_fec = pplm2ethtool_fec((u_long)fec_active,
+						sizeof(u32) * BITS_PER_BYTE);
+
+	if (!fecparam->active_fec)
+		return -EOPNOTSUPP;
+
+	fecparam->fec = pplm2ethtool_fec((u_long)fec_configured,
+					 sizeof(u8) * BITS_PER_BYTE);
+
+	return 0;
+}
+
+static int mlx5e_set_fecparam(struct net_device *netdev,
+			      struct ethtool_fecparam *fecparam)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	u8 fec_policy = 0;
+	int mode;
+	int err;
+
+	for (mode = 0; mode < ARRAY_SIZE(pplm_fec_2_ethtool); mode++) {
+		if (!(pplm_fec_2_ethtool[mode] & fecparam->fec))
+			continue;
+		fec_policy |= (1 << mode);
+		break;
+	}
+
+	err = mlx5e_set_fec_mode(mdev, fec_policy);
+
+	if (err)
+		return err;
+
+	mlx5_toggle_port_link(mdev);
+
+	return 0;
+}
+
 static u32 mlx5e_get_msglevel(struct net_device *dev)
 {
 	return ((struct mlx5e_priv *)netdev_priv(dev))->msglevel;
@@ -1699,4 +1821,6 @@ const struct ethtool_ops mlx5e_ethtool_ops = {
 	.self_test         = mlx5e_self_test,
 	.get_msglevel      = mlx5e_get_msglevel,
 	.set_msglevel      = mlx5e_set_msglevel,
+	.get_fecparam      = mlx5e_get_fecparam,
+	.set_fecparam      = mlx5e_set_fecparam,
 };
-- 
2.17.2