net/mlx5e: Extract checking of FEC support for a link mode

The check of whether a given FEC mode is supported in a given link mode
is about to get more complicated, so extract it in a separate function
to avoid code duplication.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20240404173357.123307-2-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlx5/core/en/port.c

@@ -308,6 +308,14 @@ enum mlx5e_fec_supported_link_mode {
 			*_policy = MLX5_GET(pplm_reg, _buf, fec_override_admin_##link);	\
 	} while (0)
 
+/* Returns true if FEC can be set for a given link mode. */
+static bool mlx5e_is_fec_supported_link_mode(struct mlx5_core_dev *dev,
+					     enum mlx5e_fec_supported_link_mode link_mode)
+{
+	return link_mode < MLX5E_FEC_FIRST_50G_PER_LANE_MODE ||
+	       MLX5_CAP_PCAM_FEATURE(dev, fec_50G_per_lane_in_pplm);
+}
+
 /* get/set FEC admin field for a given speed */
 static int mlx5e_fec_admin_field(u32 *pplm, u16 *fec_policy, bool write,
 				 enum mlx5e_fec_supported_link_mode link_mode)
@@ -389,7 +397,6 @@ static int mlx5e_get_fec_cap_field(u32 *pplm, u16 *fec_cap,
 
 bool mlx5e_fec_in_caps(struct mlx5_core_dev *dev, int fec_policy)
 {
-	bool fec_50g_per_lane = MLX5_CAP_PCAM_FEATURE(dev, fec_50G_per_lane_in_pplm);
 	u32 out[MLX5_ST_SZ_DW(pplm_reg)] = {};
 	u32 in[MLX5_ST_SZ_DW(pplm_reg)] = {};
 	int sz = MLX5_ST_SZ_BYTES(pplm_reg);
@@ -407,7 +414,7 @@ bool mlx5e_fec_in_caps(struct mlx5_core_dev *dev, int fec_policy)
 	for (i = 0; i < MLX5E_MAX_FEC_SUPPORTED_LINK_MODE; i++) {
 		u16 fec_caps;
 
-		if (i >= MLX5E_FEC_FIRST_50G_PER_LANE_MODE && !fec_50g_per_lane)
+		if (!mlx5e_is_fec_supported_link_mode(dev, i))
 			break;
 
 		mlx5e_get_fec_cap_field(out, &fec_caps, i);
@@ -420,7 +427,6 @@ bool mlx5e_fec_in_caps(struct mlx5_core_dev *dev, int fec_policy)
 int mlx5e_get_fec_mode(struct mlx5_core_dev *dev, u32 *fec_mode_active,
 		       u16 *fec_configured_mode)
 {
-	bool fec_50g_per_lane = MLX5_CAP_PCAM_FEATURE(dev, fec_50G_per_lane_in_pplm);
 	u32 out[MLX5_ST_SZ_DW(pplm_reg)] = {};
 	u32 in[MLX5_ST_SZ_DW(pplm_reg)] = {};
 	int sz = MLX5_ST_SZ_BYTES(pplm_reg);
@@ -445,7 +451,7 @@ int mlx5e_get_fec_mode(struct mlx5_core_dev *dev, u32 *fec_mode_active,
 
 	*fec_configured_mode = 0;
 	for (i = 0; i < MLX5E_MAX_FEC_SUPPORTED_LINK_MODE; i++) {
-		if (i >= MLX5E_FEC_FIRST_50G_PER_LANE_MODE && !fec_50g_per_lane)
+		if (!mlx5e_is_fec_supported_link_mode(dev, i))
 			break;
 
 		mlx5e_fec_admin_field(out, fec_configured_mode, 0, i);
@@ -489,7 +495,7 @@ int mlx5e_set_fec_mode(struct mlx5_core_dev *dev, u16 fec_policy)
 		u16 conf_fec = fec_policy;
 		u16 fec_caps = 0;
 
-		if (i >= MLX5E_FEC_FIRST_50G_PER_LANE_MODE && !fec_50g_per_lane)
+		if (!mlx5e_is_fec_supported_link_mode(dev, i))
 			break;
 
 		/* RS fec in ethtool is mapped to MLX5E_FEC_RS_528_514