net: dsa: remove copy of master ethtool_ops

There is no need to store a copy of the master ethtool ops, storing the
original pointer in DSA and the new one in the master netdev itself is
enough.

In the meantime, set orig_ethtool_ops to NULL when restoring the master
ethtool ops and check the presence of the master original ethtool ops as
well as its needed functions before calling them.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -188,7 +188,6 @@ struct dsa_port {
 	/*
 	 * Original copy of the master netdev ethtool_ops
 	 */
-	struct ethtool_ops	ethtool_ops;
 	const struct ethtool_ops *orig_ethtool_ops;
 };
 

net/dsa/dsa.c

@@ -124,11 +124,10 @@ int dsa_cpu_port_ethtool_setup(struct dsa_port *cpu_dp)
 	if (!cpu_ops)
 		return -ENOMEM;
 
-	memcpy(&cpu_dp->ethtool_ops, master->ethtool_ops,
-	       sizeof(struct ethtool_ops));
 	cpu_dp->orig_ethtool_ops = master->ethtool_ops;
-	memcpy(cpu_ops, &cpu_dp->ethtool_ops,
-	       sizeof(struct ethtool_ops));
+	if (cpu_dp->orig_ethtool_ops)
+		memcpy(cpu_ops, cpu_dp->orig_ethtool_ops, sizeof(*cpu_ops));
+
 	dsa_cpu_port_ethtool_init(cpu_ops);
 	master->ethtool_ops = cpu_ops;
 
@@ -138,6 +137,7 @@ int dsa_cpu_port_ethtool_setup(struct dsa_port *cpu_dp)
 void dsa_cpu_port_ethtool_restore(struct dsa_port *cpu_dp)
 {
 	cpu_dp->netdev->ethtool_ops = cpu_dp->orig_ethtool_ops;
+	cpu_dp->orig_ethtool_ops = NULL;
 }
 
 void dsa_cpu_dsa_destroy(struct dsa_port *port)

net/dsa/slave.c

@@ -574,12 +574,13 @@ static void dsa_cpu_port_get_ethtool_stats(struct net_device *dev,
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
 	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
 	struct dsa_switch *ds = cpu_dp->ds;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 	s8 cpu_port = cpu_dp->index;
 	int count = 0;
 
-	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 (ops && ops->get_sset_count && ops->get_ethtool_stats) {
+		count = ops->get_sset_count(dev, ETH_SS_STATS);
+		ops->get_ethtool_stats(dev, stats, data);
 	}
 
 	if (ds->ops->get_ethtool_stats)
@@ -591,10 +592,11 @@ static int dsa_cpu_port_get_sset_count(struct net_device *dev, int sset)
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
 	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
 	struct dsa_switch *ds = cpu_dp->ds;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 	int count = 0;
 
-	if (cpu_dp->ethtool_ops.get_sset_count)
-		count += cpu_dp->ethtool_ops.get_sset_count(dev, sset);
+	if (ops && ops->get_sset_count)
+		count += ops->get_sset_count(dev, sset);
 
 	if (sset == ETH_SS_STATS && ds->ops->get_sset_count)
 		count += ds->ops->get_sset_count(ds);
@@ -608,6 +610,7 @@ static void dsa_cpu_port_get_strings(struct net_device *dev,
 	struct dsa_switch_tree *dst = dev->dsa_ptr;
 	struct dsa_port *cpu_dp = dsa_get_cpu_port(dst);
 	struct dsa_switch *ds = cpu_dp->ds;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
 	s8 cpu_port = cpu_dp->index;
 	int len = ETH_GSTRING_LEN;
 	int mcount = 0, count;
@@ -619,9 +622,9 @@ 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 (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 (ops && ops->get_sset_count && ops->get_strings) {
+		mcount = ops->get_sset_count(dev, ETH_SS_STATS);
+		ops->get_strings(dev, stringset, data);
 	}
 
 	if (stringset == ETH_SS_STATS && ds->ops->get_strings) {