net/core: use __vlan_hwaccel helpers

This removes assumptions about VLAN_TAG_PRESENT bit.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -4889,7 +4889,7 @@ static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc,
 		 * and set skb->priority like in vlan_do_receive()
 		 * For the time being, just ignore Priority Code Point
 		 */
-		skb->vlan_tci = 0;
+		__vlan_hwaccel_clear_tag(skb);
 	}
 
 	type = skb->protocol;
@@ -5386,6 +5386,8 @@ static struct list_head *gro_list_prepare(struct napi_struct *napi,
 		}
 
 		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
+		diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb);
+		if (skb_vlan_tag_present(p))
 			diffs |= p->vlan_tci ^ skb->vlan_tci;
 		diffs |= skb_metadata_dst_cmp(p, skb);
 		diffs |= skb_metadata_differs(p, skb);
@@ -5652,7 +5654,7 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
 	__skb_pull(skb, skb_headlen(skb));
 	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
-	skb->vlan_tci = 0;
+	__vlan_hwaccel_clear_tag(skb);
 	skb->dev = napi->dev;
 	skb->skb_iif = 0;
 	skb->encapsulation = 0;

net/core/skbuff.c

@@ -5166,7 +5166,7 @@ int skb_vlan_pop(struct sk_buff *skb)
 	int err;
 
 	if (likely(skb_vlan_tag_present(skb))) {
-		skb->vlan_tci = 0;
+		__vlan_hwaccel_clear_tag(skb);
 	} else {
 		if (unlikely(!eth_type_vlan(skb->protocol)))
 			return 0;

net/sched/act_vlan.c

@@ -63,7 +63,7 @@ static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
 		/* extract existing tag (and guarantee no hw-accel tag) */
 		if (skb_vlan_tag_present(skb)) {
 			tci = skb_vlan_tag_get(skb);
-			skb->vlan_tci = 0;
+			__vlan_hwaccel_clear_tag(skb);
 		} else {
 			/* in-payload vlan tag, pop it */
 			err = __skb_vlan_pop(skb, &tci);