i40e: Enable/Disable PF switch LB on SR-IOV configure changes

The PF VSI was never updated to enable or disable internal switch loopback
when VFs were created or destroyed via the sysfs interface.  Add some
helper functions to take care of that.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -716,6 +716,76 @@ static bool i40e_vfs_are_assigned(struct i40e_pf *pf)
 
 	return false;
 }
+#ifdef CONFIG_PCI_IOV
+
+/**
+ * i40e_enable_pf_switch_lb
+ * @pf: pointer to the pf structure
+ *
+ * enable switch loop back or die - no point in a return value
+ **/
+static void i40e_enable_pf_switch_lb(struct i40e_pf *pf)
+{
+	struct i40e_vsi *vsi = pf->vsi[pf->lan_vsi];
+	struct i40e_vsi_context ctxt;
+	int aq_ret;
+
+	ctxt.seid = pf->main_vsi_seid;
+	ctxt.pf_num = pf->hw.pf_id;
+	ctxt.vf_num = 0;
+	aq_ret = i40e_aq_get_vsi_params(&pf->hw, &ctxt, NULL);
+	if (aq_ret) {
+		dev_info(&pf->pdev->dev,
+			 "%s couldn't get pf vsi config, err %d, aq_err %d\n",
+			 __func__, aq_ret, pf->hw.aq.asq_last_status);
+		return;
+	}
+	ctxt.flags = I40E_AQ_VSI_TYPE_PF;
+	ctxt.info.valid_sections = cpu_to_le16(I40E_AQ_VSI_PROP_SWITCH_VALID);
+	ctxt.info.switch_id |= cpu_to_le16(I40E_AQ_VSI_SW_ID_FLAG_ALLOW_LB);
+
+	aq_ret = i40e_aq_update_vsi_params(&vsi->back->hw, &ctxt, NULL);
+	if (aq_ret) {
+		dev_info(&pf->pdev->dev,
+			 "%s: update vsi switch failed, aq_err=%d\n",
+			 __func__, vsi->back->hw.aq.asq_last_status);
+	}
+}
+#endif
+
+/**
+ * i40e_disable_pf_switch_lb
+ * @pf: pointer to the pf structure
+ *
+ * disable switch loop back or die - no point in a return value
+ **/
+static void i40e_disable_pf_switch_lb(struct i40e_pf *pf)
+{
+	struct i40e_vsi *vsi = pf->vsi[pf->lan_vsi];
+	struct i40e_vsi_context ctxt;
+	int aq_ret;
+
+	ctxt.seid = pf->main_vsi_seid;
+	ctxt.pf_num = pf->hw.pf_id;
+	ctxt.vf_num = 0;
+	aq_ret = i40e_aq_get_vsi_params(&pf->hw, &ctxt, NULL);
+	if (aq_ret) {
+		dev_info(&pf->pdev->dev,
+			 "%s couldn't get pf vsi config, err %d, aq_err %d\n",
+			 __func__, aq_ret, pf->hw.aq.asq_last_status);
+		return;
+	}
+	ctxt.flags = I40E_AQ_VSI_TYPE_PF;
+	ctxt.info.valid_sections = cpu_to_le16(I40E_AQ_VSI_PROP_SWITCH_VALID);
+	ctxt.info.switch_id &= ~cpu_to_le16(I40E_AQ_VSI_SW_ID_FLAG_ALLOW_LB);
+
+	aq_ret = i40e_aq_update_vsi_params(&vsi->back->hw, &ctxt, NULL);
+	if (aq_ret) {
+		dev_info(&pf->pdev->dev,
+			 "%s: update vsi switch failed, aq_err=%d\n",
+			 __func__, vsi->back->hw.aq.asq_last_status);
+	}
+}
 
 /**
  * i40e_free_vfs
@@ -759,10 +829,11 @@ void i40e_free_vfs(struct i40e_pf *pf)
 			bit_idx = (hw->func_caps.vf_base_id + vf_id) % 32;
 			wr32(hw, I40E_GLGEN_VFLRSTAT(reg_idx), (1 << bit_idx));
 		}
-	}
-	else
+		i40e_disable_pf_switch_lb(pf);
+	} else {
 		dev_warn(&pf->pdev->dev,
 			 "unable to disable SR-IOV because VFs are assigned.\n");
+	}
 
 	/* Re-enable interrupt 0. */
 	i40e_irq_dynamic_enable_icr0(pf);
@@ -816,6 +887,7 @@ static int i40e_alloc_vfs(struct i40e_pf *pf, u16 num_alloc_vfs)
 	pf->vf = vfs;
 	pf->num_alloc_vfs = num_alloc_vfs;
 
+	i40e_enable_pf_switch_lb(pf);
 err_alloc:
 	if (ret)
 		i40e_free_vfs(pf);