net: dsa: store CPU switch structure in the tree

Store a dsa_switch pointer to the CPU switch in the tree instead of only
its index. This avoids the need to initialize it to -1.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -124,7 +124,7 @@ struct dsa_switch_tree {
 	/*
 	 * The switch and port to which the CPU is attached.
 	 */
-	s8			cpu_switch;
+	struct dsa_switch	*cpu_switch;
 	s8			cpu_port;
 
 	/*
@@ -204,7 +204,7 @@ struct dsa_switch {
 
 static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
 {
-	return !!(ds->index == ds->dst->cpu_switch && p == ds->dst->cpu_port);
+	return !!(ds == ds->dst->cpu_switch && p == ds->dst->cpu_port);
 }
 
 static inline bool dsa_is_dsa_port(struct dsa_switch *ds, int p)
@@ -227,10 +227,10 @@ static inline u8 dsa_upstream_port(struct dsa_switch *ds)
 	 * Else return the (DSA) port number that connects to the
 	 * switch that is one hop closer to the cpu.
 	 */
-	if (dst->cpu_switch == ds->index)
+	if (dst->cpu_switch == ds)
 		return dst->cpu_port;
 	else
-		return ds->rtable[dst->cpu_switch];
+		return ds->rtable[dst->cpu_switch->index];
 }
 
 struct switchdev_trans;

net/dsa/dsa.c

@@ -225,12 +225,12 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
 			continue;
 
 		if (!strcmp(name, "cpu")) {
-			if (dst->cpu_switch != -1) {
+			if (!dst->cpu_switch) {
 				netdev_err(dst->master_netdev,
 					   "multiple cpu ports?!\n");
 				return -EINVAL;
 			}
-			dst->cpu_switch = index;
+			dst->cpu_switch = ds;
 			dst->cpu_port = i;
 			ds->cpu_port_mask |= 1 << i;
 		} else if (!strcmp(name, "dsa")) {
@@ -254,7 +254,7 @@ static int dsa_switch_setup_one(struct dsa_switch *ds, struct device *parent)
 	 * tagging protocol to the preferred tagging format of this
 	 * switch.
 	 */
-	if (dst->cpu_switch == index) {
+	if (dst->cpu_switch == ds) {
 		enum dsa_tag_protocol tag_protocol;
 
 		tag_protocol = ops->get_tag_protocol(ds);
@@ -757,7 +757,6 @@ static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
 
 	dst->pd = pd;
 	dst->master_netdev = dev;
-	dst->cpu_switch = -1;
 	dst->cpu_port = -1;
 
 	for (i = 0; i < pd->nr_chips; i++) {

net/dsa/dsa2.c

@@ -57,7 +57,6 @@ static struct dsa_switch_tree *dsa_add_dst(u32 tree)
 	if (!dst)
 		return NULL;
 	dst->tree = tree;
-	dst->cpu_switch = -1;
 	INIT_LIST_HEAD(&dst->list);
 	list_add_tail(&dsa_switch_trees, &dst->list);
 	kref_init(&dst->refcount);
@@ -448,8 +447,8 @@ static int dsa_cpu_parse(struct device_node *port, u32 index,
 	if (!dst->master_netdev)
 		dst->master_netdev = ethernet_dev;
 
-	if (dst->cpu_switch == -1) {
-		dst->cpu_switch = ds->index;
+	if (!dst->cpu_switch) {
+		dst->cpu_switch = ds;
 		dst->cpu_port = index;
 	}