net: dsa: Introduce dsa_get_cpu_port()

Introduce a helper function which will return a reference to the CPU
port used in a dsa_switch_tree. Right now this is a singleton, but this
will change once we introduce multi-CPU port support, so ease the
transition by converting the affected code paths.
Reviewed-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/dsa/dsa_priv.h

@@ -188,4 +188,9 @@ static inline struct net_device *dsa_master_netdev(struct dsa_slave_priv *p)
 	return p->dp->cpu_dp->netdev;
 }
 
+static inline struct dsa_port *dsa_get_cpu_port(struct dsa_switch_tree *dst)
+{
+	return dst->cpu_dp;
+}
+
 #endif

net/dsa/slave.c

@@ -520,14 +520,14 @@ static void dsa_cpu_port_get_ethtool_stats(struct net_device *dev,
 					   uint64_t *data)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds = dst->cpu_dp->ds;
-	s8 cpu_port = dst->cpu_dp->index;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
+	struct dsa_switch *ds = cpu_dp->ds;
+	s8 cpu_port = cpu_dp->index;
 	int count = 0;
 
-	if (dst->cpu_dp->ethtool_ops.get_sset_count) {
-		count = dst->cpu_dp->ethtool_ops.get_sset_count(dev,
-							       ETH_SS_STATS);
-		dst->cpu_dp->ethtool_ops.get_ethtool_stats(dev, stats, data);
+	if (cpu_dp->ethtool_ops.get_sset_count) {
+		count = cpu_dp->ethtool_ops.get_sset_count(dev, ETH_SS_STATS);
+		cpu_dp->ethtool_ops.get_ethtool_stats(dev, stats, data);
 	}
 
 	if (ds->ops->get_ethtool_stats)
@@ -537,11 +537,12 @@ static void dsa_cpu_port_get_ethtool_stats(struct net_device *dev,
 static int dsa_cpu_port_get_sset_count(struct net_device *dev, int sset)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds = dst->cpu_dp->ds;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
+	struct dsa_switch *ds = cpu_dp->ds;
 	int count = 0;
 
-	if (dst->cpu_dp->ethtool_ops.get_sset_count)
-		count += dst->cpu_dp->ethtool_ops.get_sset_count(dev, sset);
+	if (cpu_dp->ethtool_ops.get_sset_count)
+		count += cpu_dp->ethtool_ops.get_sset_count(dev, sset);
 
 	if (sset == ETH_SS_STATS && ds->ops->get_sset_count)
 		count += ds->ops->get_sset_count(ds);
@@ -553,8 +554,9 @@ static void dsa_cpu_port_get_strings(struct net_device *dev,
 				     uint32_t stringset, uint8_t *data)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds = dst->cpu_dp->ds;
-	s8 cpu_port = dst->cpu_dp->index;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
+	struct dsa_switch *ds = cpu_dp->ds;
+	s8 cpu_port = cpu_dp->index;
 	int len = ETH_GSTRING_LEN;
 	int mcount = 0, count;
 	unsigned int i;
@@ -565,10 +567,9 @@ static void dsa_cpu_port_get_strings(struct net_device *dev,
 	/* We do not want to be NULL-terminated, since this is a prefix */
 	pfx[sizeof(pfx) - 1] = '_';
 
-	if (dst->cpu_dp->ethtool_ops.get_sset_count) {
-		mcount = dst->cpu_dp->ethtool_ops.get_sset_count(dev,
-								ETH_SS_STATS);
-		dst->cpu_dp->ethtool_ops.get_strings(dev, stringset, data);
+	if (cpu_dp->ethtool_ops.get_sset_count) {
+		mcount = cpu_dp->ethtool_ops.get_sset_count(dev, ETH_SS_STATS);
+		cpu_dp->ethtool_ops.get_strings(dev, stringset, data);
 	}
 
 	if (stringset == ETH_SS_STATS && ds->ops->get_strings) {

net/dsa/tag_brcm.c

@@ -93,12 +93,11 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 				    struct net_device *orig_dev)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
+	struct dsa_switch *ds = cpu_dp->ds;
 	int source_port;
 	u8 *brcm_tag;
 
-	ds = dst->cpu_dp->ds;
-
 	if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN)))
 		return NULL;
 

net/dsa/tag_ksz.c

@@ -75,12 +75,11 @@ static struct sk_buff *ksz_rcv(struct sk_buff *skb, struct net_device *dev,
 			       struct net_device *orig_dev)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
+	struct dsa_switch *ds = cpu_dp->ds;
 	u8 *tag;
 	int source_port;
 
-	ds = dst->cpu_dp->ds;
-
 	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
 
 	source_port = tag[0] & 7;

net/dsa/tag_qca.c

@@ -67,6 +67,7 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 				   struct net_device *orig_dev)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
 	struct dsa_switch *ds;
 	u8 ver;
 	int port;
@@ -95,7 +96,7 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
 	/* This protocol doesn't support cascading multiple switches so it's
 	 * safe to assume the switch is first in the tree
 	 */
-	ds = dst->cpu_dp->ds;
+	ds = cpu_dp->ds;
 	if (!ds)
 		return NULL;
 

net/dsa/tag_trailer.c

@@ -61,12 +61,11 @@ static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 				   struct net_device *orig_dev)
 {
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
-	struct dsa_switch *ds;
+	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
+	struct dsa_switch *ds = cpu_dp->ds;
 	u8 *trailer;
 	int source_port;
 
-	ds = dst->cpu_dp->ds;
-
 	if (skb_linearize(skb))
 		return NULL;