i40e: Add support FEC configuration for Fortville 25G

This patch adds support for setting/getting FEC configuration
using ethtool options:
       set/show-priv-flags rs-fec/base-r-fec
       set/show-fec off/rs/baser/auto for kernels version >= 4.14
Signed-off-by: Damian Dybek <damian.dybek@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -524,6 +524,8 @@ struct i40e_pf {
 #define I40E_FLAG_FD_SB_INACTIVE		BIT(22)
 #define I40E_FLAG_FD_SB_TO_CLOUD_FILTER		BIT(23)
 #define I40E_FLAG_DISABLE_FW_LLDP		BIT(24)
+#define I40E_FLAG_RS_FEC			BIT(25)
+#define I40E_FLAG_BASE_R_FEC			BIT(26)
 
 	struct i40e_client_instance *cinst;
 	bool stat_offsets_loaded;
@@ -1087,6 +1089,8 @@ i40e_status i40e_set_partition_bw_setting(struct i40e_pf *pf);
 i40e_status i40e_commit_partition_bw_setting(struct i40e_pf *pf);
 void i40e_print_link_message(struct i40e_vsi *vsi, bool isup);
 
+void i40e_set_fec_in_flags(u8 fec_cfg, u32 *flags);
+
 static inline bool i40e_enabled_xdp_vsi(struct i40e_vsi *vsi)
 {
 	return !!vsi->xdp_prog;

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -13860,6 +13860,29 @@ static void i40e_get_platform_mac_addr(struct pci_dev *pdev, struct i40e_pf *pf)
 		i40e_get_mac_addr(&pf->hw, pf->hw.mac.addr);
 }
 
+/**
+ * i40e_set_fec_in_flags - helper function for setting FEC options in flags
+ * @fec_cfg: FEC option to set in flags
+ * @flags: ptr to flags in which we set FEC option
+ **/
+void i40e_set_fec_in_flags(u8 fec_cfg, u32 *flags)
+{
+	if (fec_cfg & I40E_AQ_SET_FEC_AUTO)
+		*flags |= I40E_FLAG_RS_FEC | I40E_FLAG_BASE_R_FEC;
+	if ((fec_cfg & I40E_AQ_SET_FEC_REQUEST_RS) ||
+	    (fec_cfg & I40E_AQ_SET_FEC_ABILITY_RS)) {
+		*flags |= I40E_FLAG_RS_FEC;
+		*flags &= ~I40E_FLAG_BASE_R_FEC;
+	}
+	if ((fec_cfg & I40E_AQ_SET_FEC_REQUEST_KR) ||
+	    (fec_cfg & I40E_AQ_SET_FEC_ABILITY_KR)) {
+		*flags |= I40E_FLAG_BASE_R_FEC;
+		*flags &= ~I40E_FLAG_RS_FEC;
+	}
+	if (fec_cfg == 0)
+		*flags &= ~(I40E_FLAG_RS_FEC | I40E_FLAG_BASE_R_FEC);
+}
+
 /**
  * i40e_probe - Device initialization routine
  * @pdev: PCI device information struct
@@ -14351,6 +14374,9 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			i40e_aq_str(&pf->hw, pf->hw.aq.asq_last_status));
 	pf->hw.phy.link_info.requested_speeds = abilities.link_speed;
 
+	/* set the FEC config due to the board capabilities */
+	i40e_set_fec_in_flags(abilities.fec_cfg_curr_mod_ext_info, &pf->flags);
+
 	/* get the supported phy types from the fw */
 	err = i40e_aq_get_phy_capabilities(hw, false, true, &abilities, NULL);
 	if (err)