i40e: Implement an ethtool private flag to stop LLDP in FW

Implement the private flag disable-fw-lldp for ethtool
to disable the processing of LLDP packets by the FW.
This will stop the FW from consuming LLDPDU and cause
them to be sent up the stack.

The FW is also being configured to apply a default DCB
configuration on link up.

Toggling the value of this flag will also cause a PF reset.

Disabling FW DCB will also disable DCBx.
Signed-off-by: Dave Ertman <david.m.ertman@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_ethtool.c

@@ -233,6 +233,7 @@ static const struct i40e_priv_flags i40e_gstrings_priv_flags[] = {
 	I40E_PRIV_FLAG("legacy-rx", I40E_FLAG_LEGACY_RX, 0),
 	I40E_PRIV_FLAG("disable-source-pruning",
 		       I40E_FLAG_SOURCE_PRUNING_DISABLED, 0),
+	I40E_PRIV_FLAG("disable-fw-lldp", I40E_FLAG_DISABLE_FW_LLDP, 0),
 };
 
 #define I40E_PRIV_FLAGS_STR_LEN ARRAY_SIZE(i40e_gstrings_priv_flags)
@@ -4317,6 +4318,25 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
 	    !(pf->hw_features & I40E_HW_ATR_EVICT_CAPABLE))
 		return -EOPNOTSUPP;
 
+	/* Disable FW LLDP not supported if NPAR active or if FW
+	 * API version < 1.7
+	 */
+	if (new_flags & I40E_FLAG_DISABLE_FW_LLDP) {
+		if (pf->hw.func_caps.npar_enable) {
+			dev_warn(&pf->pdev->dev,
+				 "Unable to stop FW LLDP if NPAR active\n");
+			return -EOPNOTSUPP;
+		}
+
+		if (pf->hw.aq.api_maj_ver < 1 ||
+		    (pf->hw.aq.api_maj_ver == 1 &&
+		     pf->hw.aq.api_min_ver < 7)) {
+			dev_warn(&pf->pdev->dev,
+				 "FW ver does not support stopping FW LLDP\n");
+			return -EOPNOTSUPP;
+		}
+	}
+
 	/* Compare and exchange the new flags into place. If we failed, that
 	 * is if cmpxchg returns anything but the old value, this means that
 	 * something else has modified the flags variable since we copied it
@@ -4362,12 +4382,37 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
 		}
 	}
 
+	if (changed_flags & I40E_FLAG_DISABLE_FW_LLDP) {
+		if (pf->flags & I40E_FLAG_DISABLE_FW_LLDP) {
+			struct i40e_dcbx_config *dcbcfg;
+			int i;
+
+			i40e_aq_stop_lldp(&pf->hw, true, NULL);
+			i40e_aq_set_dcb_parameters(&pf->hw, true, NULL);
+			/* reset local_dcbx_config to default */
+			dcbcfg = &pf->hw.local_dcbx_config;
+			dcbcfg->etscfg.willing = 1;
+			dcbcfg->etscfg.maxtcs = 0;
+			dcbcfg->etscfg.tcbwtable[0] = 100;
+			for (i = 1; i < I40E_MAX_TRAFFIC_CLASS; i++)
+				dcbcfg->etscfg.tcbwtable[i] = 0;
+			for (i = 0; i < I40E_MAX_USER_PRIORITY; i++)
+				dcbcfg->etscfg.prioritytable[i] = 0;
+			dcbcfg->etscfg.tsatable[0] = I40E_IEEE_TSA_ETS;
+			dcbcfg->pfc.willing = 1;
+			dcbcfg->pfc.pfccap = I40E_MAX_TRAFFIC_CLASS;
+		} else {
+			i40e_aq_start_lldp(&pf->hw, NULL);
+		}
+	}
+
 	/* Issue reset to cause things to take effect, as additional bits
 	 * are added we will need to create a mask of bits requiring reset
 	 */
 	if (changed_flags & (I40E_FLAG_VEB_STATS_ENABLED |
 			     I40E_FLAG_LEGACY_RX |
-			     I40E_FLAG_SOURCE_PRUNING_DISABLED))
+			     I40E_FLAG_SOURCE_PRUNING_DISABLED |
+			     I40E_FLAG_DISABLE_FW_LLDP))
 		i40e_do_reset(pf, BIT(__I40E_PF_RESET_REQUESTED), true);
 
 	return 0;

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

@@ -6320,8 +6320,11 @@ static int i40e_init_pf_dcb(struct i40e_pf *pf)
 	struct i40e_hw *hw = &pf->hw;
 	int err = 0;
 
-	/* Do not enable DCB for SW1 and SW2 images even if the FW is capable */
-	if (pf->hw_features & I40E_HW_NO_DCB_SUPPORT)
+	/* Do not enable DCB for SW1 and SW2 images even if the FW is capable
+	 * Also do not enable DCBx if FW LLDP agent is disabled
+	 */
+	if ((pf->hw_features & I40E_HW_NO_DCB_SUPPORT) ||
+	    (pf->flags & I40E_FLAG_DISABLE_FW_LLDP))
 		goto out;
 
 	/* Get the initial DCB configuration */
@@ -9221,6 +9224,9 @@ static void i40e_rebuild(struct i40e_pf *pf, bool reinit, bool lock_acquired)
 		goto end_core_reset;
 	}
 
+	/* Enable FW to write a default DCB config on link-up */
+	i40e_aq_set_dcb_parameters(hw, true, NULL);
+
 #ifdef CONFIG_I40E_DCB
 	ret = i40e_init_pf_dcb(pf);
 	if (ret) {
@@ -13543,6 +13549,10 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_drvdata(pdev, pf);
 	pci_save_state(pdev);
+
+	/* Enable FW to write default DCB config on link-up */
+	i40e_aq_set_dcb_parameters(hw, true, NULL);
+
 #ifdef CONFIG_I40E_DCB
 	err = i40e_init_pf_dcb(pf);
 	if (err) {