net: dsa: move master ethtool code

DSA overrides the master device ethtool ops, so that it can inject stats
from its dedicated switch CPU port as well.

The related code is currently split in dsa.c and slave.c, but it only
scopes the master net device. Move it to a new master.c DSA core file.

This file will be later extented with master net device specific code.

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>

1 files changed, 120 insertions, 0 deletions

diff --git a/net/dsa/master.c b/net/dsa/master.c
new file mode 100644
index 000000000000..5e5147ec5a44
--- /dev/null
+++ b/net/dsa/master.c
@@ -0,0 +1,120 @@
+/*
+ * Handling of a master device, switching frames via its switch fabric CPU port
+ *
+ * Copyright (c) 2017 Savoir-faire Linux Inc.
+ *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include "dsa_priv.h"
+
+static void dsa_master_get_ethtool_stats(struct net_device *dev,
+					 struct ethtool_stats *stats,
+					 uint64_t *data)
+{
+	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *port = dst->cpu_dp;
+	struct dsa_switch *ds = port->ds;
+	const struct ethtool_ops *ops = port->orig_ethtool_ops;
+	int count = 0;
+
+	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)
+		ds->ops->get_ethtool_stats(ds, port->index, data + count);
+}
+
+static int dsa_master_get_sset_count(struct net_device *dev, int sset)
+{
+	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *port = dst->cpu_dp;
+	struct dsa_switch *ds = port->ds;
+	const struct ethtool_ops *ops = port->orig_ethtool_ops;
+	int count = 0;
+
+	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);
+
+	return count;
+}
+
+static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
+				   uint8_t *data)
+{
+	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *port = dst->cpu_dp;
+	struct dsa_switch *ds = port->ds;
+	const struct ethtool_ops *ops = port->orig_ethtool_ops;
+	int len = ETH_GSTRING_LEN;
+	int mcount = 0, count;
+	unsigned int i;
+	uint8_t pfx[4];
+	uint8_t *ndata;
+
+	snprintf(pfx, sizeof(pfx), "p%.2d", port->index);
+	/* We do not want to be NULL-terminated, since this is a prefix */
+	pfx[sizeof(pfx) - 1] = '_';
+
+	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) {
+		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->index, ndata);
+		count = ds->ops->get_sset_count(ds);
+		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));
+		}
+	}
+}
+
+int dsa_master_ethtool_setup(struct net_device *dev)
+{
+	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *port = dst->cpu_dp;
+	struct dsa_switch *ds = port->ds;
+	struct ethtool_ops *ops;
+
+	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return -ENOMEM;
+
+	port->orig_ethtool_ops = dev->ethtool_ops;
+	if (port->orig_ethtool_ops)
+		memcpy(ops, port->orig_ethtool_ops, sizeof(*ops));
+
+	ops->get_sset_count = dsa_master_get_sset_count;
+	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
+	ops->get_strings = dsa_master_get_strings;
+
+	dev->ethtool_ops = ops;
+
+	return 0;
+}
+
+void dsa_master_ethtool_restore(struct net_device *dev)
+{
+	struct dsa_switch_tree *dst = dev->dsa_ptr;
+	struct dsa_port *port = dst->cpu_dp;
+
+	dev->ethtool_ops = port->orig_ethtool_ops;
+	port->orig_ethtool_ops = NULL;
+}