net: dsa: Refactor selection of tag ops into a function

Replace the two switch statements with an array lookup, and store the
result in the dsa tree structure. The drivers no longer need to know
the selected tag protocol, so remove it from the dsa switch structure.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 45 insertions, 26 deletions

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 7140de475c07..221ebde4318d 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -29,6 +29,33 @@
 
 char dsa_driver_version[] = "0.1";
 
+static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
+					    struct net_device *dev)
+{
+	/* Just return the original SKB */
+	return skb;
+}
+
+static const struct dsa_device_ops none_ops = {
+	.xmit	= dsa_slave_notag_xmit,
+	.rcv	= NULL,
+};
+
+const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
+#ifdef CONFIG_NET_DSA_TAG_DSA
+	[DSA_TAG_PROTO_DSA] = &dsa_netdev_ops,
+#endif
+#ifdef CONFIG_NET_DSA_TAG_EDSA
+	[DSA_TAG_PROTO_EDSA] = &edsa_netdev_ops,
+#endif
+#ifdef CONFIG_NET_DSA_TAG_TRAILER
+	[DSA_TAG_PROTO_TRAILER] = &trailer_netdev_ops,
+#endif
+#ifdef CONFIG_NET_DSA_TAG_BRCM
+	[DSA_TAG_PROTO_BRCM] = &brcm_netdev_ops,
+#endif
+	[DSA_TAG_PROTO_NONE] = &none_ops,
+};
 
 /* switch driver registration ***********************************************/
 static DEFINE_MUTEX(dsa_switch_drivers_mutex);
@@ -225,6 +252,20 @@ static int dsa_cpu_dsa_setups(struct dsa_switch *ds, struct device *dev)
 	return 0;
 }
 
+const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol)
+{
+	const struct dsa_device_ops *ops;
+
+	if (tag_protocol >= DSA_TAG_LAST)
+		return ERR_PTR(-EINVAL);
+	ops = dsa_device_ops[tag_protocol];
+
+	if (!ops)
+		return ERR_PTR(-ENOPROTOOPT);
+
+	return ops;
+}
+
 static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
 {
 	struct dsa_switch_driver *drv = ds->drv;
@@ -277,35 +318,13 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
 	 * switch.
 	 */
 	if (dst->cpu_switch == index) {
-		switch (drv->tag_protocol) {
-#ifdef CONFIG_NET_DSA_TAG_DSA
-		case DSA_TAG_PROTO_DSA:
-			dst->rcv = dsa_netdev_ops.rcv;
-			break;
-#endif
-#ifdef CONFIG_NET_DSA_TAG_EDSA
-		case DSA_TAG_PROTO_EDSA:
-			dst->rcv = edsa_netdev_ops.rcv;
-			break;
-#endif
-#ifdef CONFIG_NET_DSA_TAG_TRAILER
-		case DSA_TAG_PROTO_TRAILER:
-			dst->rcv = trailer_netdev_ops.rcv;
-			break;
-#endif
-#ifdef CONFIG_NET_DSA_TAG_BRCM
-		case DSA_TAG_PROTO_BRCM:
-			dst->rcv = brcm_netdev_ops.rcv;
-			break;
-#endif
-		case DSA_TAG_PROTO_NONE:
-			break;
-		default:
-			ret = -ENOPROTOOPT;
+		dst->tag_ops = dsa_resolve_tag_protocol(drv->tag_protocol);
+		if (IS_ERR(dst->tag_ops)) {
+			ret = PTR_ERR(dst->tag_ops);
 			goto out;
 		}
 
-		dst->tag_protocol = drv->tag_protocol;
+		dst->rcv = dst->tag_ops->rcv;
 	}
 
 	memcpy(ds->rtable, cd->rtable, sizeof(ds->rtable));