path: root/net/dsa/port.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Handling of a single switch port
 *
 * Copyright (c) 2017 Savoir-faire Linux Inc.
 *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 */

#include <linux/if_bridge.h>
#include <linux/notifier.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>

#include "dsa_priv.h"

/**
 * dsa_port_notify - Notify the switching fabric of changes to a port
 * @dp: port on which change occurred
 * @e: event, must be of type DSA_NOTIFIER_*
 * @v: event-specific value.
 *
 * Notify all switches in the DSA tree that this port's switch belongs to,
 * including this switch itself, of an event. Allows the other switches to
 * reconfigure themselves for cross-chip operations. Can also be used to
 * reconfigure ports without net_devices (CPU ports, DSA links) whenever
 * a user port's state changes.
 */
static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)
{
	return dsa_tree_notify(dp->ds->dst, e, v);
}

static void dsa_port_notify_bridge_fdb_flush(const struct dsa_port *dp)
{
	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
	struct switchdev_notifier_fdb_info info = {
		/* flush all VLANs */
		.vid = 0,
	};

	/* When the port becomes standalone it has already left the bridge.
	 * Don't notify the bridge in that case.
	 */
	if (!brport_dev)
		return;

	call_switchdev_notifiers(SWITCHDEV_FDB_FLUSH_TO_BRIDGE,
				 brport_dev, &info.info, NULL);
}

static void dsa_port_fast_age(const struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;

	if (!ds->ops->port_fast_age)
		return;

	ds->ops->port_fast_age(ds, dp->index);

	dsa_port_notify_bridge_fdb_flush(dp);
}

static bool dsa_port_can_configure_learning(struct dsa_port *dp)
{
	struct switchdev_brport_flags flags = {
		.mask = BR_LEARNING,
	};
	struct dsa_switch *ds = dp->ds;
	int err;

	if (!ds->ops->port_bridge_flags || !ds->ops->port_pre_bridge_flags)
		return false;

	err = ds->ops->port_pre_bridge_flags(ds, dp->index, flags, NULL);
	return !err;
}

int dsa_port_set_state(struct dsa_port *dp, u8 state, bool do_fast_age)
{
	struct dsa_switch *ds = dp->ds;
	int port = dp->index;

	if (!ds->ops->port_stp_state_set)
		return -EOPNOTSUPP;

	ds->ops->port_stp_state_set(ds, port, state);

	if (!dsa_port_can_configure_learning(dp) ||
	    (do_fast_age && dp->learning)) {
		/* Fast age FDB entries or flush appropriate forwarding database
		 * for the given port, if we are moving it from Learning or
		 * Forwarding state, to Disabled or Blocking or Listening state.
		 * Ports that were standalone before the STP state change don't
		 * need to fast age the FDB, since address learning is off in
		 * standalone mode.
		 */

		if ((dp->stp_state == BR_STATE_LEARNING ||
		     dp->stp_state == BR_STATE_FORWARDING) &&
		    (state == BR_STATE_DISABLED ||
		     state == BR_STATE_BLOCKING ||
		     state == BR_STATE_LISTENING))
			dsa_port_fast_age(dp);
	}

	dp->stp_state = state;

	return 0;
}

static void dsa_port_set_state_now(struct dsa_port *dp, u8 state,
				   bool do_fast_age)
{
	int err;

	err = dsa_port_set_state(dp, state, do_fast_age);
	if (err)
		pr_err("DSA: failed to set STP state %u (%d)\n", state, err);
}

int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy)
{
	struct dsa_switch *ds = dp->ds;
	int port = dp->index;
	int err;

	if (ds->ops->port_enable) {
		err = ds->ops->port_enable(ds, port, phy);
		if (err)
			return err;
	}

	if (!dp->bridge)
		dsa_port_set_state_now(dp, BR_STATE_FORWARDING, false);

	if (dp->pl)
		phylink_start(dp->pl);

	return 0;
}

int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
{
	int err;

	rtnl_lock();
	err = dsa_port_enable_rt(dp, phy);
	rtnl_unlock();

	return err;
}

void dsa_port_disable_rt(struct dsa_port *dp)
{
	struct dsa_switch *ds = dp->ds;
	int port = dp->index;

	if (dp->pl)
		phylink_stop(dp->pl);

	if (!dp->bridge)
		dsa_port_set_state_now(dp, BR_STATE_DISABLED, false);

	if (ds->ops->port_disable)
		ds->ops->port_disable(ds, port);
}

void dsa_port_disable(struct dsa_port *dp)
{
	rtnl_lock();
	dsa_port_disable_rt(dp);
	rtnl_unlock();
}

static int dsa_port_inherit_brport_flags(struct dsa_port *dp,
					 struct netlink_ext_ack *extack)
{
	const unsigned long mask = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD |
				   BR_BCAST_FLOOD | BR_PORT_LOCKED;
	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
	int flag, err;

	for_each_set_bit(flag, &mask, 32) {
		struct switchdev_brport_flags flags = {0};

		flags.mask = BIT(flag);

		if (br_port_flag_is_set(brport_dev, BIT(flag)))
			flags.val = BIT(flag);

		err = dsa_port_bridge_flags(dp, flags, extack);
		if (err && err != -EOPNOTSUPP)
			return err;
	}

	return 0;
}

static void dsa_port_clear_brport_flags(struct dsa_port *dp)
{
	const unsigned long val = BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
	const unsigned long mask = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD |
				   BR_BCAST_FLOOD | BR_PORT_LOCKED;
	int flag, err;

	for_each_set_bit(flag, &mask, 32) {
		struct switchdev_brport_flags flags = {0};

		flags.mask = BIT(flag);
		flags.val = val & BIT(flag);

		err = dsa_port_bridge_flags(dp, flags, NULL);
		if (err && err != -EOPNOTSUPP)
			dev_err(dp->ds->dev,
				"failed to clear bridge port flag %lu: %pe\n",
				flags.val, ERR_PTR(err));
	}
}

static int dsa_port_switchdev_sync_attrs(struct dsa_port *dp,
					 struct netlink_ext_ack *extack)
{
	struct net_device *brport_dev = dsa_port_to_bridge_port(dp);
	struct net_device *br = dsa_port_bridge_dev_get(dp);
	int err;

	err = dsa_port_inherit_brport_flags(dp, extack);
	if (err)
		return err;

	err = dsa_port_set_state(dp, br_port_get_stp_state(brport_dev), false);
	if (err && err != -EOPNOTSUPP)
		return err;

	err = dsa_port_vlan_filtering(dp, br_vlan_enabled(br), extack);
	if (err && err != -EOPNOTSUPP)
		return err;

	err = dsa_port_ageing_time(dp, br_get_ageing_time(br));
	if (err && err != -EOPNOTSUPP)
		return err;

	return 0;
}

static void dsa_port_switchdev_unsync_attrs(struct dsa_port *dp)
{
	/* Configure the port for standalone mode (no address learning,
	 * flood everything).
	 * The bridge only emits SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS events
	 * when the user requests it through netlink or sysfs, but not
	 * automatically at port join or leave, so we need to handle resetting
	 * the brport flags ourselves. But we even prefer it that way, because
	 * otherwise, some setups might never get the notification they need,
	 * for example, when a port leaves a LAG that offloads the bridge,
	 * it becomes standalone, but as far as the bridge is concerned, no
	 * port ever left.
	 */
	dsa_port_clear_brport_flags(dp);

	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
	 */
	dsa_port_set_state_now(dp, BR_STATE_FORWARDING, true);

	/* VLAN filtering is handled by dsa_switch_bridge_leave */

	/* Ageing time may be global to the switch chip, so don't change it
	 * here because we have no good reason (or value) to change it to.
	 */
}

static int dsa_port_bridge_create(struct dsa_port *dp,
				  struct net_device *br,
				  struct netlink_ext_ack *extack)
{
	struct dsa_switch *ds = dp->ds;
	struct dsa_bridge *