Commit ea32690d authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: sja1105: serialize sja1105_port_mcast_flood() with other FDB accesses 



sja1105_fdb_add() runs from the dsa_owq, and sja1105_port_mcast_flood()
runs from switchdev_deferred_process_work(). Prior to the blamed commit,
they used to be indirectly serialized through the rtnl_lock(), which
no longer holds true because dsa_owq dropped that.

So, it is now possible that we traverse the static config BLK_IDX_L2_LOOKUP
elements concurrently compared to when we change them, in
sja1105_static_fdb_change(). That is not ideal, since it might result in
data corruption.

Introduce a mutex which serializes accesses to the hardware FDB and to
the static config elements for the L2 Address Lookup table.

I can't find a good reason to add locking around sja1105_fdb_dump().
I'll add it later if needed.

Fixes: 0faf890f ("net: dsa: drop rtnl_lock from dsa_slave_switchdev_event_work")
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7cef293b

drivers/net/dsa/sja1105/sja1105.h

+2 −0
Original line number Diff line number Diff line
@@ -266,6 +266,8 @@ struct sja1105_private { 
	 * the switch doesn't confuse them with one another.

	 */

	struct mutex mgmt_lock;

	/* Serializes accesses to the FDB */

	struct mutex fdb_lock;

	/* PTP two-step TX timestamp ID, and its serialization lock */

	spinlock_t ts_id_lock;

	u8 ts_id;

drivers/net/dsa/sja1105/sja1105_main.c

+43 −13
Original line number Diff line number Diff line
@@ -1798,6 +1798,7 @@ static int sja1105_fdb_add(struct dsa_switch *ds, int port, 
			   struct dsa_db db)

{

	struct sja1105_private *priv = ds->priv;

	int rc;



	if (!vid) {

		switch (db.type) {
@@ -1812,10 +1813,14 @@ static int sja1105_fdb_add(struct dsa_switch *ds, int port, 
		}

	}



	return priv->info->fdb_add_cmd(ds, port, addr, vid);

	mutex_lock(&priv->fdb_lock);

	rc = priv->info->fdb_add_cmd(ds, port, addr, vid);

	mutex_unlock(&priv->fdb_lock);



	return rc;

}



static int sja1105_fdb_del(struct dsa_switch *ds, int port,

static int __sja1105_fdb_del(struct dsa_switch *ds, int port,

			     const unsigned char *addr, u16 vid,

			     struct dsa_db db)

{
@@ -1837,6 +1842,20 @@ static int sja1105_fdb_del(struct dsa_switch *ds, int port, 
	return priv->info->fdb_del_cmd(ds, port, addr, vid);

}



static int sja1105_fdb_del(struct dsa_switch *ds, int port,

			   const unsigned char *addr, u16 vid,

			   struct dsa_db db)

{

	struct sja1105_private *priv = ds->priv;

	int rc;



	mutex_lock(&priv->fdb_lock);

	rc = __sja1105_fdb_del(ds, port, addr, vid, db);

	mutex_unlock(&priv->fdb_lock);



	return rc;

}



static int sja1105_fdb_dump(struct dsa_switch *ds, int port,

			    dsa_fdb_dump_cb_t *cb, void *data)

{
@@ -1899,6 +1918,8 @@ static void sja1105_fast_age(struct dsa_switch *ds, int port) 
	};

	int i;



	mutex_lock(&priv->fdb_lock);



	for (i = 0; i < SJA1105_MAX_L2_LOOKUP_COUNT; i++) {

		struct sja1105_l2_lookup_entry l2_lookup = {0};

		u8 macaddr[ETH_ALEN];
@@ -1912,7 +1933,7 @@ static void sja1105_fast_age(struct dsa_switch *ds, int port) 
		if (rc) {

			dev_err(ds->dev, "Failed to read FDB: %pe\n",

				ERR_PTR(rc));

			return;

			break;

		}



		if (!(l2_lookup.destports & BIT(port)))
@@ -1924,14 +1945,16 @@ static void sja1105_fast_age(struct dsa_switch *ds, int port) 


		u64_to_ether_addr(l2_lookup.macaddr, macaddr);



		rc = sja1105_fdb_del(ds, port, macaddr, l2_lookup.vlanid, db);

		rc = __sja1105_fdb_del(ds, port, macaddr, l2_lookup.vlanid, db);

		if (rc) {

			dev_err(ds->dev,

				"Failed to delete FDB entry %pM vid %lld: %pe\n",

				macaddr, l2_lookup.vlanid, ERR_PTR(rc));

			return;

			break;

		}

	}



	mutex_unlock(&priv->fdb_lock);

}



static int sja1105_mdb_add(struct dsa_switch *ds, int port,
@@ -2955,7 +2978,9 @@ static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to, 
{

	struct sja1105_l2_lookup_entry *l2_lookup;

	struct sja1105_table *table;

	int match;

	int match, rc;



	mutex_lock(&priv->fdb_lock);



	table = &priv->static_config.tables[BLK_IDX_L2_LOOKUP];

	l2_lookup = table->entries;
@@ -2968,7 +2993,8 @@ static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to, 
	if (match == table->entry_count) {

		NL_SET_ERR_MSG_MOD(extack,

				   "Could not find FDB entry for unknown multicast");

		return -ENOSPC;

		rc = -ENOSPC;

		goto out;

	}



	if (flags.val & BR_MCAST_FLOOD)
@@ -2976,10 +3002,13 @@ static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to, 
	else

		l2_lookup[match].destports &= ~BIT(to);



	return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,

	rc = sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,

					  l2_lookup[match].index,

					    &l2_lookup[match],

					    true);

					  &l2_lookup[match], true);

out:

	mutex_unlock(&priv->fdb_lock);



	return rc;

}



static int sja1105_port_pre_bridge_flags(struct dsa_switch *ds, int port,
@@ -3349,6 +3378,7 @@ static int sja1105_probe(struct spi_device *spi) 
	mutex_init(&priv->ptp_data.lock);

	mutex_init(&priv->dynamic_config_lock);

	mutex_init(&priv->mgmt_lock);

	mutex_init(&priv->fdb_lock);

	spin_lock_init(&priv->ts_id_lock);



	rc = sja1105_parse_dt(priv);