bnx2x: allow adding VLANs while interface is down

Since implementing VLAN filtering in commit 05cc5a39ddb74
("bnx2x: add vlan filtering offload") bnx2x refuses to add a VLAN while
the interface is down:

  # ip link add link enp3s0f0 enp3s0f0_10 type vlan id 10
  RTNETLINK answers: Bad address

and in dmesg (with bnx2x.debug=0x20):
  bnx2x: [bnx2x_vlan_rx_add_vid:12941(enp3s0f0)]Ignoring VLAN
  configuration the interface is down

Other drivers have no problem with this.
Fix this peculiar behavior in the following way:
 - Accept requests to add/kill VID regardless of the device state.
   Maintain the requested list of VIDs in the bp->vlan_reg list.
 - If the device is up, try to configure the VID list into the hardware.
   If we run out of VLAN credits or encounter a failure configuring an
   entry, fall back to accepting all VLANs.
   If we successfully configure all entries from the list, turn the
   fallback off.
 - Use the same code for reconfiguring VLANs during NIC load.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Acked-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -12895,52 +12895,71 @@ static int __bnx2x_vlan_configure_vid(struct bnx2x *bp, u16 vid, bool add)
 	return rc;
 }
 
-int bnx2x_vlan_reconfigure_vid(struct bnx2x *bp)
+static int bnx2x_vlan_configure_vid_list(struct bnx2x *bp)
 {
 	struct bnx2x_vlan_entry *vlan;
 	int rc = 0;
 
-	if (!bp->vlan_cnt) {
-		DP(NETIF_MSG_IFUP, "No need to re-configure vlan filters\n");
-		return 0;
-	}
-
+	/* Configure all non-configured entries */
 	list_for_each_entry(vlan, &bp->vlan_reg, link) {
-		/* Prepare for cleanup in case of errors */
-		if (rc) {
-			vlan->hw = false;
-			continue;
-		}
-
-		if (!vlan->hw)
+		if (vlan->hw)
 			continue;
 
-		DP(NETIF_MSG_IFUP, "Re-configuring vlan 0x%04x\n", vlan->vid);
+		if (bp->vlan_cnt >= bp->vlan_credit)
+			return -ENOBUFS;
 
 		rc = __bnx2x_vlan_configure_vid(bp, vlan->vid, true);
 		if (rc) {
-			BNX2X_ERR("Unable to configure VLAN %d\n", vlan->vid);
-			vlan->hw = false;
-			rc = -EINVAL;
-			continue;
+			BNX2X_ERR("Unable to config VLAN %d\n", vlan->vid);
+			return rc;
 		}
+
+		DP(NETIF_MSG_IFUP, "HW configured for VLAN %d\n", vlan->vid);
+		vlan->hw = true;
+		bp->vlan_cnt++;
 	}
 
-	return rc;
+	return 0;
+}
+
+static void bnx2x_vlan_configure(struct bnx2x *bp, bool set_rx_mode)
+{
+	bool need_accept_any_vlan;
+
+	need_accept_any_vlan = !!bnx2x_vlan_configure_vid_list(bp);
+
+	if (bp->accept_any_vlan != need_accept_any_vlan) {
+		bp->accept_any_vlan = need_accept_any_vlan;
+		DP(NETIF_MSG_IFUP, "Accept all VLAN %s\n",
+		   bp->accept_any_vlan ? "raised" : "cleared");
+		if (set_rx_mode) {
+			if (IS_PF(bp))
+				bnx2x_set_rx_mode_inner(bp);
+			else
+				bnx2x_vfpf_storm_rx_mode(bp);
+		}
+	}
+}
+
+int bnx2x_vlan_reconfigure_vid(struct bnx2x *bp)
+{
+	struct bnx2x_vlan_entry *vlan;
+
+	/* The hw forgot all entries after reload */
+	list_for_each_entry(vlan, &bp->vlan_reg, link)
+		vlan->hw = false;
+	bp->vlan_cnt = 0;
+
+	/* Don't set rx mode here. Our caller will do it. */
+	bnx2x_vlan_configure(bp, false);
+
+	return 0;
 }
 
 static int bnx2x_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid)
 {
 	struct bnx2x *bp = netdev_priv(dev);
 	struct bnx2x_vlan_entry *vlan;
-	bool hw = false;
-	int rc = 0;
-
-	if (!netif_running(bp->dev)) {
-		DP(NETIF_MSG_IFUP,
-		   "Ignoring VLAN configuration the interface is down\n");
-		return -EFAULT;
-	}
 
 	DP(NETIF_MSG_IFUP, "Adding VLAN %d\n", vid);
 
@@ -12948,93 +12967,47 @@ static int bnx2x_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid)
 	if (!vlan)
 		return -ENOMEM;
 
-	bp->vlan_cnt++;
-	if (bp->vlan_cnt > bp->vlan_credit && !bp->accept_any_vlan) {
-		DP(NETIF_MSG_IFUP, "Accept all VLAN raised\n");
-		bp->accept_any_vlan = true;
-		if (IS_PF(bp))
-			bnx2x_set_rx_mode_inner(bp);
-		else
-			bnx2x_vfpf_storm_rx_mode(bp);
-	} else if (bp->vlan_cnt <= bp->vlan_credit) {
-		rc = __bnx2x_vlan_configure_vid(bp, vid, true);
-		hw = true;
-	}
-
 	vlan->vid = vid;
-	vlan->hw = hw;
+	vlan->hw = false;
+	list_add_tail(&vlan->link, &bp->vlan_reg);
 
-	if (!rc) {
-		list_add(&vlan->link, &bp->vlan_reg);
-	} else {
-		bp->vlan_cnt--;
-		kfree(vlan);
-	}
-
-	DP(NETIF_MSG_IFUP, "Adding VLAN result %d\n", rc);
+	if (netif_running(dev))
+		bnx2x_vlan_configure(bp, true);
 
-	return rc;
+	return 0;
 }
 
 static int bnx2x_vlan_rx_kill_vid(struct net_device *dev, __be16 proto, u16 vid)
 {
 	struct bnx2x *bp = netdev_priv(dev);
 	struct bnx2x_vlan_entry *vlan;
+	bool found = false;
 	int rc = 0;
 
-	if (!netif_running(bp->dev)) {
-		DP(NETIF_MSG_IFUP,
-		   "Ignoring VLAN configuration the interface is down\n");
-		return -EFAULT;
-	}
-
 	DP(NETIF_MSG_IFUP, "Removing VLAN %d\n", vid);
 
-	if (!bp->vlan_cnt) {
-		BNX2X_ERR("Unable to kill VLAN %d\n", vid);
-		return -EINVAL;
-	}
-
 	list_for_each_entry(vlan, &bp->vlan_reg, link)
-		if (vlan->vid == vid)
+		if (vlan->vid == vid) {
+			found = true;
 			break;
+		}
 
-	if (vlan->vid != vid) {
+	if (!found) {
 		BNX2X_ERR("Unable to kill VLAN %d - not found\n", vid);
 		return -EINVAL;
 	}
 
-	if (vlan->hw)
+	if (netif_running(dev) && vlan->hw) {
 		rc = __bnx2x_vlan_configure_vid(bp, vid, false);
+		DP(NETIF_MSG_IFUP, "HW deconfigured for VLAN %d\n", vid);
+		bp->vlan_cnt--;
+	}
 
 	list_del(&vlan->link);
 	kfree(vlan);
 
-	bp->vlan_cnt--;
-
-	if (bp->vlan_cnt <= bp->vlan_credit && bp->accept_any_vlan) {
-		/* Configure all non-configured entries */
-		list_for_each_entry(vlan, &bp->vlan_reg, link) {
-			if (vlan->hw)
-				continue;
-
-			rc = __bnx2x_vlan_configure_vid(bp, vlan->vid, true);
-			if (rc) {
-				BNX2X_ERR("Unable to config VLAN %d\n",
-					  vlan->vid);
-				continue;
-			}
-			DP(NETIF_MSG_IFUP, "HW configured for VLAN %d\n",
-			   vlan->vid);
-			vlan->hw = true;
-		}
-		DP(NETIF_MSG_IFUP, "Accept all VLAN Removed\n");
-		bp->accept_any_vlan = false;
-		if (IS_PF(bp))
-			bnx2x_set_rx_mode_inner(bp);
-		else
-			bnx2x_vfpf_storm_rx_mode(bp);
-	}
+	if (netif_running(dev))
+		bnx2x_vlan_configure(bp, true);
 
 	DP(NETIF_MSG_IFUP, "Removing VLAN result %d\n", rc);