i40e: restore workaround for removing default MAC filter

A previous commit 53cb6e9e8949 ("i40e: Removal of workaround for simple
MAC address filter deletion") removed a workaround for some
firmware versions which was reported to not be necessary in production
NICs. Unfortunately this workaround is necessary in some configurations,
specifically the Ethernet Controller XL710 for 40GbE QSFP+ (8086:1583).

Without this patch, the mentioned NICs with current firmware exhibit
issues when adding VLANs, as outlined by the following reproduction:

  $modprobe i40e
  $ip link set <device> up
  $ip link add link <device> vlan100 type vlan id 100
  $dmesg | tail
  <snip>
  kernel: i40e 0000:82:00.0: Error I40E_AQ_RC_EINVAL adding RX
filters on PF, promiscuous mode forced on

This results in filters being marked as FAILED and setting the device in
promiscuous mode.

The root cause of receiving the -EINVAL error response appears to be due
to a conflict with the default MAC filter which still exists on the
default firmware for this device. Attempting to add a new VLAN filter on
the default MAC address conflicts with the IGNORE_VLAN setting on the
default rule.

Change-ID: I4d8f6d48ac5f60cfe981b3baad30eb4d7c170d61
Signed-off-by: Jacob Keller <jacob.e.keller@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_main.c

@@ -1225,6 +1225,39 @@ bool i40e_is_vsi_in_vlan(struct i40e_vsi *vsi)
 	return vsi->has_vlan_filter;
 }
 
+/**
+ * i40e_rm_default_mac_filter - Remove the default MAC filter set by NVM
+ * @vsi: the PF Main VSI - inappropriate for any other VSI
+ * @macaddr: the MAC address
+ *
+ * Remove whatever filter the firmware set up so the driver can manage
+ * its own filtering intelligently.
+ **/
+static void i40e_rm_default_mac_filter(struct i40e_vsi *vsi, u8 *macaddr)
+{
+	struct i40e_aqc_remove_macvlan_element_data element;
+	struct i40e_pf *pf = vsi->back;
+
+	/* Only appropriate for the PF main VSI */
+	if (vsi->type != I40E_VSI_MAIN)
+		return;
+
+	memset(&element, 0, sizeof(element));
+	ether_addr_copy(element.mac_addr, macaddr);
+	element.vlan_tag = 0;
+	/* Ignore error returns, some firmware does it this way... */
+	element.flags = I40E_AQC_MACVLAN_DEL_PERFECT_MATCH;
+	i40e_aq_remove_macvlan(&pf->hw, vsi->seid, &element, 1, NULL);
+
+	memset(&element, 0, sizeof(element));
+	ether_addr_copy(element.mac_addr, macaddr);
+	element.vlan_tag = 0;
+	/* ...and some firmware does it this way. */
+	element.flags = I40E_AQC_MACVLAN_DEL_PERFECT_MATCH |
+			I40E_AQC_MACVLAN_DEL_IGNORE_VLAN;
+	i40e_aq_remove_macvlan(&pf->hw, vsi->seid, &element, 1, NULL);
+}
+
 /**
  * i40e_add_filter - Add a mac/vlan filter to the VSI
  * @vsi: the VSI to be searched
@@ -9295,6 +9328,12 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 	if (vsi->type == I40E_VSI_MAIN) {
 		SET_NETDEV_DEV(netdev, &pf->pdev->dev);
 		ether_addr_copy(mac_addr, hw->mac.perm_addr);
+		/* The following steps are necessary to prevent reception
+		 * of tagged packets - some older NVM configurations load a
+		 * default a MAC-VLAN filter that accepts any tagged packet
+		 * which must be replaced by a normal filter.
+		 */
+		i40e_rm_default_mac_filter(vsi, mac_addr);
 		spin_lock_bh(&vsi->mac_filter_hash_lock);
 		i40e_add_filter(vsi, mac_addr, I40E_VLAN_ANY);
 		spin_unlock_bh(&vsi->mac_filter_hash_lock);
@@ -9828,6 +9867,8 @@ static struct i40e_vsi *i40e_vsi_reinit_setup(struct i40e_vsi *vsi)
 	pf->vsi[pf->lan_vsi]->tc_config.enabled_tc = 0;
 	pf->vsi[pf->lan_vsi]->seid = pf->main_vsi_seid;
 	i40e_vsi_config_tc(pf->vsi[pf->lan_vsi], enabled_tc);
+	if (vsi->type == I40E_VSI_MAIN)
+		i40e_rm_default_mac_filter(vsi, pf->hw.mac.perm_addr);
 
 	/* assign it some queues */
 	ret = i40e_alloc_rings(vsi);