net: dsa: append ethtool counters of all hidden ports to conduit

Currently there is no way to see packet counters on cascade ports, and
no clarity on how the API for that would look like.

Because it's something that is currently needed, just extend the hack
where ethtool -S on the conduit interface dumps CPU port counters, and
also use it to dump counters of cascade ports.

Note that the "pXX_" naming convention changes to "sXX_pYY", to
distinguish between ports having the same index but belonging to
different switches. This has a slight chance of causing regressions to
existing tooling:

- grepping for "p04_counter_name" still works, but might return more
  than one string now
- grepping for "    p04_counter_name" no longer works

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NipaLocal <nipa@local>

Author: vladimiroltean

net/dsa/conduit.c

@@ -87,25 +87,51 @@ static void dsa_conduit_get_regs(struct net_device *dev,
 	}
 }
 
+static ssize_t dsa_conduit_append_port_stats(struct dsa_switch *ds, int port,
+					     u64 *data, size_t start)
+{
+	int count;
+
+	if (!ds->ops->get_sset_count)
+		return 0;
+
+	count = ds->ops->get_sset_count(ds, port, ETH_SS_STATS);
+	if (count < 0)
+		return count;
+
+	if (ds->ops->get_ethtool_stats)
+		ds->ops->get_ethtool_stats(ds, port, data + start);
+
+	return count;
+}
+
 static void dsa_conduit_get_ethtool_stats(struct net_device *dev,
 					  struct ethtool_stats *stats,
 					  u64 *data)
 {
-	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_port *dp, *cpu_dp = dev->dsa_ptr;
 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
-	struct dsa_switch *ds = cpu_dp->ds;
-	int port = cpu_dp->index;
-	int count = 0;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	int count, mcount = 0;
 
 	if (ops && ops->get_sset_count && ops->get_ethtool_stats) {
 		netdev_lock_ops(dev);
-		count = ops->get_sset_count(dev, ETH_SS_STATS);
+		mcount = ops->get_sset_count(dev, ETH_SS_STATS);
 		ops->get_ethtool_stats(dev, stats, data);
 		netdev_unlock_ops(dev);
 	}
 
-	if (ds->ops->get_ethtool_stats)
-		ds->ops->get_ethtool_stats(ds, port, data + count);
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp))
+			continue;
+
+		count = dsa_conduit_append_port_stats(dp->ds, dp->index,
+						      data, mcount);
+		if (count < 0)
+			return;
+
+		mcount += count;
+	}
 }
 
 static void dsa_conduit_get_ethtool_phy_stats(struct net_device *dev,
@@ -136,11 +162,18 @@ static void dsa_conduit_get_ethtool_phy_stats(struct net_device *dev,
 		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
 }
 
+static void dsa_conduit_append_port_sset_count(struct dsa_switch *ds, int port,
+					       int sset, int *count)
+{
+	if (ds->ops->get_sset_count)
+		*count += ds->ops->get_sset_count(ds, port, sset);
+}
+
 static int dsa_conduit_get_sset_count(struct net_device *dev, int sset)
 {
-	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_port *dp, *cpu_dp = dev->dsa_ptr;
 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
-	struct dsa_switch *ds = cpu_dp->ds;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
 	int count = 0;
 
 	netdev_lock_ops(dev);
@@ -154,26 +187,57 @@ static int dsa_conduit_get_sset_count(struct net_device *dev, int sset)
 	if (count < 0)
 		count = 0;
 
-	if (ds->ops->get_sset_count)
-		count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp))
+			continue;
+
+		dsa_conduit_append_port_sset_count(dp->ds, dp->index, sset,
+						   &count);
+	}
 
 	return count;
 }
 
-static void dsa_conduit_get_strings(struct net_device *dev, u32 stringset,
-				    u8 *data)
+static ssize_t dsa_conduit_append_port_strings(struct dsa_switch *ds, int port,
+					       u32 stringset, u8 *data,
+					       size_t start)
 {
-	struct dsa_port *cpu_dp = dev->dsa_ptr;
-	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
-	struct dsa_switch *ds = cpu_dp->ds;
-	int port = cpu_dp->index;
 	int len = ETH_GSTRING_LEN;
-	int mcount = 0, count, i;
-	u8 pfx[4], *ndata;
+	u8 pfx[8], *ndata;
+	int count, i;
+
+	if (!ds->ops->get_strings)
+		return 0;
 
-	snprintf(pfx, sizeof(pfx), "p%.2d", port);
+	snprintf(pfx, sizeof(pfx), "s%.2d_p%.2d", ds->index, port);
 	/* We do not want to be NULL-terminated, since this is a prefix */
 	pfx[sizeof(pfx) - 1] = '_';
+	ndata = data + start * len;
+	/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
+	 * the output after to prepend our CPU port prefix we
+	 * constructed earlier
+	 */
+	ds->ops->get_strings(ds, port, stringset, ndata);
+	count = ds->ops->get_sset_count(ds, port, stringset);
+	if (count < 0)
+		return count;
+
+	for (i = 0; i < count; i++) {
+		memmove(ndata + (i * len + sizeof(pfx)),
+			ndata + i * len, len - sizeof(pfx));
+		memcpy(ndata + i * len, pfx, sizeof(pfx));
+	}
+
+	return count;
+}
+
+static void dsa_conduit_get_strings(struct net_device *dev, u32 stringset,
+				    u8 *data)
+{
+	struct dsa_port *dp, *cpu_dp = dev->dsa_ptr;
+	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
+	struct dsa_switch_tree *dst = cpu_dp->dst;
+	int count, mcount = 0;
 
 	netdev_lock_ops(dev);
 	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
@@ -191,21 +255,17 @@ static void dsa_conduit_get_strings(struct net_device *dev, u32 stringset,
 	}
 	netdev_unlock_ops(dev);
 
-	if (ds->ops->get_strings) {
-		ndata = data + mcount * len;
-		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
-		 * the output after to prepend our CPU port prefix we
-		 * constructed earlier
-		 */
-		ds->ops->get_strings(ds, port, stringset, ndata);
-		count = ds->ops->get_sset_count(ds, port, stringset);
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp))
+			continue;
+
+		count = dsa_conduit_append_port_strings(dp->ds, dp->index,
+							stringset, data,
+							mcount);
 		if (count < 0)
 			return;
-		for (i = 0; i < count; i++) {
-			memmove(ndata + (i * len + sizeof(pfx)),
-				ndata + i * len, len - sizeof(pfx));
-			memcpy(ndata + i * len, pfx, sizeof(pfx));
-		}
+
+		mcount += count;
 	}
 }