openvswitch: Unionize ovs_key_ct_label with a u32 array.

Make the array of labels in struct ovs_key_ct_label an union, adding a
u32 array of the same byte size as the existing u8 array.  It is
faster to loop through the labels 32 bits at the time, which is also
the alignment of netlink attributes.
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/openvswitch.h

@@ -446,9 +446,13 @@ struct ovs_key_nd {
 	__u8	nd_tll[ETH_ALEN];
 };
 
-#define OVS_CT_LABELS_LEN	16
+#define OVS_CT_LABELS_LEN_32	4
+#define OVS_CT_LABELS_LEN	(OVS_CT_LABELS_LEN_32 * sizeof(__u32))
 struct ovs_key_ct_labels {
+	union {
 		__u8	ct_labels[OVS_CT_LABELS_LEN];
+		__u32	ct_labels_32[OVS_CT_LABELS_LEN_32];
+	};
 };
 
 /* OVS_KEY_ATTR_CT_STATE flags */

net/openvswitch/conntrack.c

@@ -281,20 +281,21 @@ static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
 		/* Triggers a change event, which makes sense only for
 		 * confirmed connections.
 		 */
-		int err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
-						OVS_CT_LABELS_LEN / sizeof(u32));
+		int err = nf_connlabels_replace(ct, labels->ct_labels_32,
+						mask->ct_labels_32,
+						OVS_CT_LABELS_LEN_32);
 		if (err)
 			return err;
 	} else {
 		u32 *dst = (u32 *)cl->bits;
-		const u32 *msk = (const u32 *)mask->ct_labels;
-		const u32 *lbl = (const u32 *)labels->ct_labels;
+		const u32 *msk = mask->ct_labels_32;
+		const u32 *lbl = labels->ct_labels_32;
 		int i;
 
 		/* No-one else has access to the non-confirmed entry, copy
 		 * labels over, keeping any bits we are not explicitly setting.
 		 */
-		for (i = 0; i < OVS_CT_LABELS_LEN / sizeof(u32); i++)
+		for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
 			dst[i] = (dst[i] & ~msk[i]) | (lbl[i] & msk[i]);
 	}
 
@@ -866,8 +867,8 @@ static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
 {
 	size_t i;
 
-	for (i = 0; i < sizeof(*labels); i++)
-		if (labels->ct_labels[i])
+	for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
+		if (labels->ct_labels_32[i])
 			return true;
 
 	return false;