1 files changed, 475 insertions, 0 deletions

diff --git a/net/dsa/master.c b/net/dsa/master.c
new file mode 100644
index 0000000000..6be89ab0cc
--- /dev/null
+++ b/net/dsa/master.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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>
+ */
+
+#include <linux/ethtool.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <net/dsa.h>
+
+#include "dsa.h"
+#include "master.h"
+#include "port.h"
+#include "tag.h"
+
+static int dsa_master_get_regs_len(struct net_device *dev)
+{
+	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 ret = 0;
+	int len;
+
+	if (ops->get_regs_len) {
+		len = ops->get_regs_len(dev);
+		if (len < 0)
+			return len;
+		ret += len;
+	}
+
+	ret += sizeof(struct ethtool_drvinfo);
+	ret += sizeof(struct ethtool_regs);
+
+	if (ds->ops->get_regs_len) {
+		len = ds->ops->get_regs_len(ds, port);
+		if (len < 0)
+			return len;
+		ret += len;
+	}
+
+	return ret;
+}
+
+static void dsa_master_get_regs(struct net_device *dev,
+				struct ethtool_regs *regs, void *data)
+{
+	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;
+	struct ethtool_drvinfo *cpu_info;
+	struct ethtool_regs *cpu_regs;
+	int port = cpu_dp->index;
+	int len;
+
+	if (ops->get_regs_len && ops->get_regs) {
+		len = ops->get_regs_len(dev);
+		if (len < 0)
+			return;
+		regs->len = len;
+		ops->get_regs(dev, regs, data);
+		data += regs->len;
+	}
+
+	cpu_info = (struct ethtool_drvinfo *)data;
+	strscpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver));
+	data += sizeof(*cpu_info);
+	cpu_regs = (struct ethtool_regs *)data;
+	data += sizeof(*cpu_regs);
+
+	if (ds->ops->get_regs_len && ds->ops->get_regs) {
+		len = ds->ops->get_regs_len(ds, port);
+		if (len < 0)
+			return;
+		cpu_regs->len = len;
+		ds->ops->get_regs(ds, port, cpu_regs, data);
+	}
+}
+
+static void dsa_master_get_ethtool_stats(struct net_device *dev,
+					 struct ethtool_stats *stats,
+					 uint64_t *data)
+{
+	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 count = 0;
+
+	if (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, data + count);
+}
+
+static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
+					     struct ethtool_stats *stats,
+					     uint64_t *data)
+{
+	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 count = 0;
+
+	if (dev->phydev && !ops->get_ethtool_phy_stats) {
+		count = phy_ethtool_get_sset_count(dev->phydev);
+		if (count >= 0)
+			phy_ethtool_get_stats(dev->phydev, stats, data);
+	} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
+		count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
+		ops->get_ethtool_phy_stats(dev, stats, data);
+	}
+
+	if (count < 0)
+		count = 0;
+
+	if (ds->ops->get_ethtool_phy_stats)
+		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
+}
+
+static int dsa_master_get_sset_count(struct net_device *dev, int sset)
+{
+	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 count = 0;
+
+	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
+	    !ops->get_ethtool_phy_stats)
+		count = phy_ethtool_get_sset_count(dev->phydev);
+	else if (ops->get_sset_count)
+		count = ops->get_sset_count(dev, sset);
+
+	if (count < 0)
+		count = 0;
+
+	if (ds->ops->get_sset_count)
+		count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
+
+	return count;
+}
+
+static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
+				   uint8_t *data)
+{
+	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;
+	uint8_t pfx[4];
+	uint8_t *ndata;
+
+	snprintf(pfx, sizeof(pfx), "p%.2d", port);
+	/* We do not want to be NULL-terminated, since this is a prefix */
+	pfx[sizeof(pfx) - 1] = '_';
+
+	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
+	    !ops->get_ethtool_phy_stats) {
+		mcount = phy_ethtool_get_sset_count(dev->phydev);
+		if (mcount < 0)
+			mcount = 0;
+		else
+			phy_ethtool_get_strings(dev->phydev, data);
+	} else if (ops->get_sset_count && ops->get_strings) {
+		mcount = ops->get_sset_count(dev, stringset);
+		if (mcount < 0)
+			mcount = 0;
+		ops->get_strings(dev, stringset, data);
+	}
+
+	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);
+		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));
+		}
+	}
+}
+
+/* Deny PTP operations on master if there is at least one switch in the tree
+ * that is PTP capable.
+ */
+int __dsa_master_hwtstamp_validate(struct net_device *dev,
+				   const struct kernel_hwtstamp_config *config,
+				   struct netlink_ext_ack *extack)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct dsa_switch_tree *dst;
+	struct dsa_port *dp;
+
+	dst = ds->dst;
+
+	list_for_each_entry(dp, &dst->ports, list) {
+		if (dsa_port_supports_hwtstamp(dp)) {
+			NL_SET_ERR_MSG(extack,
+				       "HW timestamping not allowed on DSA master when switch supports the operation");
+			return -EBUSY;
+		}
+	}
+
+	return 0;
+}
+
+static int dsa_master_ethtool_setup(struct net_device *dev)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct ethtool_ops *ops;
+
+	if (netif_is_lag_master(dev))
+		return 0;
+
+	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return -ENOMEM;
+
+	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
+	if (cpu_dp->orig_ethtool_ops)
+		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
+
+	ops->get_regs_len = dsa_master_get_regs_len;
+	ops->get_regs = dsa_master_get_regs;
+	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;
+	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
+
+	dev->ethtool_ops = ops;
+
+	return 0;
+}
+
+static void dsa_master_ethtool_teardown(struct net_device *dev)
+{
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+
+	if (netif_is_lag_master(dev))
+		return;
+
+	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
+	cpu_dp->orig_ethtool_ops = NULL;
+}
+
+/* Keep the master always promiscuous if the tagging protocol requires that
+ * (garbles MAC DA) or if it doesn't support unicast filtering, case in which
+ * it would revert to promiscuous mode as soon as we call dev_uc_add() on it
+ * anyway.
+ */
+static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
+{
+	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
+
+	if ((dev->priv_flags & IFF_UNICAST_FLT) && !ops->promisc_on_master)
+		return;
+
+	ASSERT_RTNL();
+
+	dev_set_promiscuity(dev, inc);
+}
+
+static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
+			    char *buf)
+{
+	struct net_device *dev = to_net_dev(d);
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+
+	return sysfs_emit(buf, "%s\n",
+		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
+}
+
+static ssize_t tagging_store(struct device *d, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	const struct dsa_device_ops *new_tag_ops, *old_tag_ops;
+	const char *end = strchrnul(buf, '\n'), *name;
+	struct net_device *dev = to_net_dev(d);
+	struct dsa_port *cpu_dp = dev->dsa_ptr;
+	size_t len = end - buf;
+	int err;
+
+	/* Empty string passed */
+	if (!len)
+		return -ENOPROTOOPT;
+
+	name = kstrndup(buf, len, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	old_tag_ops = cpu_dp->tag_ops;
+	new_tag_ops = dsa_tag_driver_get_by_name(name);
+	kfree(name);
+	/* Bad tagger name? */
+	if (IS_ERR(new_tag_ops))
+		return PTR_ERR(new_tag_ops);
+
+	if (new_tag_ops == old_tag_ops)
+		/* Drop the temporarily held duplicate reference, since
+		 * the DSA switch tree uses this tagger.
+		 */
+		goto out;
+
+	err = dsa_tree_change_tag_proto(cpu_dp->ds->dst, new_tag_ops,
+					old_tag_ops);
+	if (err) {
+		/* On failure the old tagger is restored, so we don't need the
+		 * driver for the new one.
+		 */
+		dsa_tag_driver_put(new_tag_ops);
+		return err;
+	}
+
+	/* On success we no longer need the module for the old tagging protocol
+	 */
+out:
+	dsa_tag_driver_put(old_tag_ops);
+	return count;
+}
+static DEVICE_ATTR_RW(tagging);
+
+static struct attribute *dsa_slave_attrs[] = {
+	&dev_attr_tagging.attr,
+	NULL
+};
+
+static const struct attribute_group dsa_group = {
+	.name	= "dsa",
+	.attrs	= dsa_slave_attrs,
+};
+
+static void dsa_master_reset_mtu(struct net_device *dev)
+{
+	int err;
+
+	err = dev_set_mtu(dev, ETH_DATA_LEN);
+	if (err)
+		netdev_dbg(dev,
+			   "Unable to reset MTU to exclude DSA overheads\n");
+}
+
+int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
+{
+	const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops;
+	struct dsa_switch *ds = cpu_dp->ds;
+	struct device_link *consumer_link;
+	int mtu, ret;
+
+	mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops);
+
+	/* The DSA master must use SET_NETDEV_DEV for this to work. */
+	if (!netif_is_lag_master(dev)) {
+		consumer_link = device_link_add(ds->dev, dev->dev.parent,
+						DL_FLAG_AUTOREMOVE_CONSUMER);
+		if (!consumer_link)
+			netdev_err(dev,
+				   "Failed to create a device link to DSA switch %s\n",
+				   dev_name(ds->dev));
+	}
+
+	/* The switch driver may not implement ->port_change_mtu(), case in
+	 * which dsa_slave_change_mtu() will not update the master MTU either,
+	 * so we need to do that here.
+	 */
+	ret = dev_set_mtu(dev, mtu);
+	if (ret)
+		netdev_warn(dev, "error %d setting MTU to %d to include DSA overhead\n",
+			    ret, mtu);
+
+	/* If we use a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point on get
+	 * sent to the tag format's receive function.
+	 */
+	wmb();
+
+	dev->dsa_ptr = cpu_dp;
+
+	dsa_master_set_promiscuity(dev, 1);
+
+	ret = dsa_master_ethtool_setup(dev);
+	if (ret)
+		goto out_err_reset_promisc;
+
+	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
+	if (ret)
+		goto out_err_ethtool_teardown;
+
+	return ret;
+
+out_err_ethtool_teardown:
+	dsa_master_ethtool_teardown(dev);
+out_err_reset_promisc:
+	dsa_master_set_promiscuity(dev, -1);
+	return ret;
+}
+
+void dsa_master_teardown(struct net_device *dev)
+{
+	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
+	dsa_master_ethtool_teardown(dev);
+	dsa_master_reset_mtu(dev);
+	dsa_master_set_promiscuity(dev, -1);
+
+	dev->dsa_ptr = NULL;
+
+	/* If we used a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point get sent
+	 * without the tag and go through the regular receive path.
+	 */
+	wmb();
+}
+
+int dsa_master_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp,
+			 struct netdev_lag_upper_info *uinfo,
+			 struct netlink_ext_ack *extack)
+{
+	bool master_setup = false;
+	int err;
+
+	if (!netdev_uses_dsa(lag_dev)) {
+		err = dsa_master_setup(lag_dev, cpu_dp);
+		if (err)
+			return err;
+
+		master_setup = true;
+	}
+
+	err = dsa_port_lag_join(cpu_dp, lag_dev, uinfo, extack);
+	if (err) {
+		NL_SET_ERR_MSG_WEAK_MOD(extack, "CPU port failed to join LAG");
+		goto out_master_teardown;
+	}
+
+	return 0;
+
+out_master_teardown:
+	if (master_setup)
+		dsa_master_teardown(lag_dev);
+	return err;
+}
+
+/* Tear down a master if there isn't any other user port on it,
+ * optionally also destroying LAG information.
+ */
+void dsa_master_lag_teardown(struct net_device *lag_dev,
+			     struct dsa_port *cpu_dp)
+{
+	struct net_device *upper;
+	struct list_head *iter;
+
+	dsa_port_lag_leave(cpu_dp, lag_dev);
+
+	netdev_for_each_upper_dev_rcu(lag_dev, upper, iter)
+		if (dsa_slave_dev_check(upper))
+			return;
+
+	dsa_master_teardown(lag_dev);
+}