net: dsa: sja1105: offload bridge port flags to device

The chip can configure unicast flooding, broadcast flooding and learning.
Learning is per port, while flooding is per {ingress, egress} port pair
and we need to configure the same value for all possible ingress ports
towards the requested one.

While multicast flooding is not officially supported, we can hack it by
using a feature of the second generation (P/Q/R/S) devices, which is that
FDB entries are maskable, and multicast addresses always have an odd
first octet. So by putting a match-all for 00:01:00:00:00:00 addr and
00:01:00:00:00:00 mask at the end of the FDB, we make sure that it is
always checked last, and does not take precedence in front of any other
MDB. So it behaves effectively as an unknown multicast entry.

For the first generation switches, this feature is not available, so
unknown multicast will always be treated the same as unknown unicast.
So the only thing we can do is request the user to offload the settings
for these 2 flags in tandem, i.e.

ip link set swp2 type bridge_slave flood off
Error: sja1105: This chip cannot configure multicast flooding independently of unicast.
ip link set swp2 type bridge_slave flood off mcast_flood off
ip link set swp2 type bridge_slave mcast_flood on
Error: sja1105: This chip cannot configure multicast flooding independently of unicast.

Signed-off-by: Vladimir Oltean <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: vladimiroltean

drivers/net/dsa/sja1105/sja1105.h

@@ -94,6 +94,7 @@ struct sja1105_info {
 	 * pop it when it's equal to TPID2.
 	 */
 	u16 qinq_tpid;
+	bool can_limit_mcast_flood;
 	int (*reset_cmd)(struct dsa_switch *ds);
 	int (*setup_rgmii_delay)(const void *ctx, int port);
 	/* Prototypes from include/net/dsa.h */
@@ -204,6 +205,7 @@ struct sja1105_private {
 	bool rgmii_rx_delay[SJA1105_NUM_PORTS];
 	bool rgmii_tx_delay[SJA1105_NUM_PORTS];
 	bool best_effort_vlan_filtering;
+	unsigned long learn_ena;
 	const struct sja1105_info *info;
 	struct gpio_desc *reset_gpio;
 	struct spi_device *spidev;

drivers/net/dsa/sja1105/sja1105_main.c

@@ -25,6 +25,8 @@
 #include "sja1105_sgmii.h"
 #include "sja1105_tas.h"
 
+#define SJA1105_UNKNOWN_MULTICAST	0x010000000000ull
+
 static const struct dsa_switch_ops sja1105_switch_ops;
 
 static void sja1105_hw_reset(struct gpio_desc *gpio, unsigned int pulse_len,
@@ -42,15 +44,10 @@ static void
 sja1105_port_allow_traffic(struct sja1105_l2_forwarding_entry *l2_fwd,
 			   int from, int to, bool allow)
 {
-	if (allow) {
-		l2_fwd[from].bc_domain  |= BIT(to);
+	if (allow)
 		l2_fwd[from].reach_port |= BIT(to);
-		l2_fwd[from].fl_domain  |= BIT(to);
-	} else {
-		l2_fwd[from].bc_domain  &= ~BIT(to);
+	else
 		l2_fwd[from].reach_port &= ~BIT(to);
-		l2_fwd[from].fl_domain  &= ~BIT(to);
-	}
 }
 
 /* Structure used to temporarily transport device tree
@@ -220,17 +217,43 @@ static int sja1105_init_mii_settings(struct sja1105_private *priv,
 
 static int sja1105_init_static_fdb(struct sja1105_private *priv)
 {
+	struct sja1105_l2_lookup_entry *l2_lookup;
 	struct sja1105_table *table;
+	int port;
 
 	table = &priv->static_config.tables[BLK_IDX_L2_LOOKUP];
 
-	/* We only populate the FDB table through dynamic
-	 * L2 Address Lookup entries
+	/* We only populate the FDB table through dynamic L2 Address Lookup
+	 * entries, except for a special entry at the end which is a catch-all
+	 * for unknown multicast and will be used to control flooding domain.
 	 */
 	if (table->entry_count) {
 		kfree(table->entries);
 		table->entry_count = 0;
 	}
+
+	if (!priv->info->can_limit_mcast_flood)
+		return 0;
+
+	table->entries = kcalloc(1, table->ops->unpacked_entry_size,
+				 GFP_KERNEL);
+	if (!table->entries)
+		return -ENOMEM;
+
+	table->entry_count = 1;
+	l2_lookup = table->entries;
+
+	/* All L2 multicast addresses have an odd first octet */
+	l2_lookup[0].macaddr = SJA1105_UNKNOWN_MULTICAST;
+	l2_lookup[0].mask_macaddr = SJA1105_UNKNOWN_MULTICAST;
+	l2_lookup[0].lockeds = true;
+	l2_lookup[0].index = SJA1105_MAX_L2_LOOKUP_COUNT - 1;
+
+	/* Flood multicast to every port by default */
+	for (port = 0; port < priv->ds->num_ports; port++)
+		if (!dsa_is_unused_port(priv->ds, port))
+			l2_lookup[0].destports |= BIT(port);
+
 	return 0;
 }
 
@@ -390,6 +413,12 @@ static int sja1105_init_l2_forwarding(struct sja1105_private *priv)
 
 		sja1105_port_allow_traffic(l2fwd, i, upstream, true);
 		sja1105_port_allow_traffic(l2fwd, upstream, i, true);
+
+		l2fwd[i].bc_domain = BIT(upstream);
+		l2fwd[i].fl_domain = BIT(upstream);
+
+		l2fwd[upstream].bc_domain |= BIT(i);
+		l2fwd[upstream].fl_domain |= BIT(i);
 	}
 	/* Next 8 entries define VLAN PCP mapping from ingress to egress.
 	 * Create a one-to-one mapping.
@@ -1514,6 +1543,12 @@ static int sja1105_fdb_dump(struct dsa_switch *ds, int port,
 		 */
 		if (!(l2_lookup.destports & BIT(port)))
 			continue;
+
+		/* We need to hide the FDB entry for unknown multicast */
+		if (l2_lookup.macaddr == SJA1105_UNKNOWN_MULTICAST &&
+		    l2_lookup.mask_macaddr == SJA1105_UNKNOWN_MULTICAST)
+			continue;
+
 		u64_to_ether_addr(l2_lookup.macaddr, macaddr);
 
 		/* We need to hide the dsa_8021q VLANs from the user. */
@@ -1605,12 +1640,12 @@ static void sja1105_bridge_stp_state_set(struct dsa_switch *ds, int port,
 	case BR_STATE_LEARNING:
 		mac[port].ingress   = true;
 		mac[port].egress    = false;
-		mac[port].dyn_learn = true;
+		mac[port].dyn_learn = !!(priv->learn_ena & BIT(port));
 		break;
 	case BR_STATE_FORWARDING:
 		mac[port].ingress   = true;
 		mac[port].egress    = true;
-		mac[port].dyn_learn = true;
+		mac[port].dyn_learn = !!(priv->learn_ena & BIT(port));
 		break;
 	default:
 		dev_err(ds->dev, "invalid STP state: %d\n", state);
@@ -3239,6 +3274,169 @@ static void sja1105_port_policer_del(struct dsa_switch *ds, int port)
 	sja1105_static_config_reload(priv, SJA1105_BEST_EFFORT_POLICING);
 }
 
+static int sja1105_port_set_learning(struct sja1105_private *priv, int port,
+				     bool enabled)
+{
+	struct sja1105_mac_config_entry *mac;
+	int rc;
+
+	mac = priv->static_config.tables[BLK_IDX_MAC_CONFIG].entries;
+
+	mac[port].dyn_learn = !!(priv->learn_ena & BIT(port));
+
+	rc = sja1105_dynamic_config_write(priv, BLK_IDX_MAC_CONFIG, port,
+					  &mac[port], true);
+	if (rc)
+		return rc;
+
+	if (enabled)
+		priv->learn_ena |= BIT(port);
+	else
+		priv->learn_ena &= ~BIT(port);
+
+	return 0;
+}
+
+/* Common function for unicast and broadcast flood configuration.
+ * Flooding is configured between each {ingress, egress} port pair, and since
+ * the bridge's semantics are those of "egress flooding", it means we must
+ * enable flooding towards this port from all ingress ports that are in the
+ * same bridge. In practice, we just enable flooding from all possible ingress
+ * ports regardless of whether they're in the same bridge or not, since the
+ * reach_port configuration will not allow flooded frames to leak across
+ * bridging domains anyway.
+ */
+static int sja1105_port_ucast_bcast_flood(struct sja1105_private *priv, int to,
+					  struct switchdev_brport_flags flags)
+{
+	struct sja1105_l2_forwarding_entry *l2_fwd;
+	int from, rc;
+
+	l2_fwd = priv->static_config.tables[BLK_IDX_L2_FORWARDING].entries;
+
+	for (from = 0; from < priv->ds->num_ports; from++) {
+		if (dsa_is_unused_port(priv->ds, from))
+			continue;
+		if (from == to)
+			continue;
+
+		/* Unicast */
+		if (flags.mask & BR_FLOOD) {
+			if (flags.val & BR_FLOOD)
+				l2_fwd[from].fl_domain |= BIT(to);
+			else
+				l2_fwd[from].fl_domain &= ~BIT(to);
+		}
+		/* Broadcast */
+		if (flags.mask & BR_BCAST_FLOOD) {
+			if (flags.val & BR_BCAST_FLOOD)
+				l2_fwd[from].bc_domain |= BIT(to);
+			else
+				l2_fwd[from].bc_domain &= ~BIT(to);
+		}
+
+		rc = sja1105_dynamic_config_write(priv, BLK_IDX_L2_FORWARDING,
+						  from, &l2_fwd[from], true);
+		if (rc < 0)
+			return rc;
+	}
+
+	return 0;
+}
+
+static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to,
+				    struct switchdev_brport_flags flags,
+				    struct netlink_ext_ack *extack)
+{
+	struct sja1105_l2_lookup_entry *l2_lookup;
+	struct sja1105_table *table;
+	int match;
+
+	table = &priv->static_config.tables[BLK_IDX_L2_LOOKUP];
+	l2_lookup = table->entries;
+
+	for (match = 0; match < table->entry_count; match++)
+		if (l2_lookup[match].macaddr == SJA1105_UNKNOWN_MULTICAST &&
+		    l2_lookup[match].mask_macaddr == SJA1105_UNKNOWN_MULTICAST)
+			break;
+
+	if (match == table->entry_count) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Could not find FDB entry for unknown multicast");
+		return -ENOSPC;
+	}
+
+	if (flags.val & BR_MCAST_FLOOD)
+		l2_lookup[match].destports |= BIT(to);
+	else
+		l2_lookup[match].destports &= ~BIT(to);
+
+	return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,
+					    l2_lookup[match].index,
+					    &l2_lookup[match],
+					    true);
+}
+
+static int sja1105_port_pre_bridge_flags(struct dsa_switch *ds, int port,
+					 struct switchdev_brport_flags flags,
+					 struct netlink_ext_ack *extack)
+{
+	struct sja1105_private *priv = ds->priv;
+
+	if (flags.mask & ~(BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD |
+			   BR_BCAST_FLOOD))
+		return -EINVAL;
+
+	if (flags.mask & (BR_FLOOD | BR_MCAST_FLOOD) &&
+	    !priv->info->can_limit_mcast_flood) {
+		bool multicast = !!(flags.val & BR_MCAST_FLOOD);
+		bool unicast = !!(flags.val & BR_FLOOD);
+
+		if (unicast != multicast) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "This chip cannot configure multicast flooding independently of unicast");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int sja1105_port_bridge_flags(struct dsa_switch *ds, int port,
+				     struct switchdev_brport_flags flags,
+				     struct netlink_ext_ack *extack)
+{
+	struct sja1105_private *priv = ds->priv;
+	int rc;
+
+	if (flags.mask & BR_LEARNING) {
+		bool learn_ena = !!(flags.val & BR_LEARNING);
+
+		rc = sja1105_port_set_learning(priv, port, learn_ena);
+		if (rc)
+			return rc;
+	}
+
+	if (flags.mask & (BR_FLOOD | BR_BCAST_FLOOD)) {
+		rc = sja1105_port_ucast_bcast_flood(priv, port, flags);
+		if (rc)
+			return rc;
+	}
+
+	/* For chips that can't offload BR_MCAST_FLOOD independently, there
+	 * is nothing to do here, we ensured the configuration is in sync by
+	 * offloading BR_FLOOD.
+	 */
+	if (flags.mask & BR_MCAST_FLOOD && priv->info->can_limit_mcast_flood) {
+		rc = sja1105_port_mcast_flood(priv, port, flags,
+					      extack);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
 static const struct dsa_switch_ops sja1105_switch_ops = {
 	.get_tag_protocol	= sja1105_get_tag_protocol,
 	.setup			= sja1105_setup,
@@ -3262,6 +3460,8 @@ static const struct dsa_switch_ops sja1105_switch_ops = {
 	.port_fdb_del		= sja1105_fdb_del,
 	.port_bridge_join	= sja1105_bridge_join,
 	.port_bridge_leave	= sja1105_bridge_leave,
+	.port_pre_bridge_flags	= sja1105_port_pre_bridge_flags,
+	.port_bridge_flags	= sja1105_port_bridge_flags,
 	.port_stp_state_set	= sja1105_bridge_stp_state_set,
 	.port_vlan_filtering	= sja1105_vlan_filtering,
 	.port_vlan_add		= sja1105_vlan_add,

drivers/net/dsa/sja1105/sja1105_spi.c

@@ -512,6 +512,7 @@ const struct sja1105_info sja1105e_info = {
 	.static_ops		= sja1105e_table_ops,
 	.dyn_ops		= sja1105et_dyn_ops,
 	.qinq_tpid		= ETH_P_8021Q,
+	.can_limit_mcast_flood	= false,
 	.ptp_ts_bits		= 24,
 	.ptpegr_ts_bytes	= 4,
 	.num_cbs_shapers	= SJA1105ET_MAX_CBS_COUNT,
@@ -529,6 +530,7 @@ const struct sja1105_info sja1105t_info = {
 	.static_ops		= sja1105t_table_ops,
 	.dyn_ops		= sja1105et_dyn_ops,
 	.qinq_tpid		= ETH_P_8021Q,
+	.can_limit_mcast_flood	= false,
 	.ptp_ts_bits		= 24,
 	.ptpegr_ts_bytes	= 4,
 	.num_cbs_shapers	= SJA1105ET_MAX_CBS_COUNT,
@@ -546,6 +548,7 @@ const struct sja1105_info sja1105p_info = {
 	.static_ops		= sja1105p_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
 	.qinq_tpid		= ETH_P_8021AD,
+	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
 	.ptpegr_ts_bytes	= 8,
 	.num_cbs_shapers	= SJA1105PQRS_MAX_CBS_COUNT,
@@ -564,6 +567,7 @@ const struct sja1105_info sja1105q_info = {
 	.static_ops		= sja1105q_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
 	.qinq_tpid		= ETH_P_8021AD,
+	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
 	.ptpegr_ts_bytes	= 8,
 	.num_cbs_shapers	= SJA1105PQRS_MAX_CBS_COUNT,
@@ -582,6 +586,7 @@ const struct sja1105_info sja1105r_info = {
 	.static_ops		= sja1105r_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
 	.qinq_tpid		= ETH_P_8021AD,
+	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
 	.ptpegr_ts_bytes	= 8,
 	.num_cbs_shapers	= SJA1105PQRS_MAX_CBS_COUNT,
@@ -601,6 +606,7 @@ const struct sja1105_info sja1105s_info = {
 	.dyn_ops		= sja1105pqrs_dyn_ops,
 	.regs			= &sja1105pqrs_regs,
 	.qinq_tpid		= ETH_P_8021AD,
+	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
 	.ptpegr_ts_bytes	= 8,
 	.num_cbs_shapers	= SJA1105PQRS_MAX_CBS_COUNT,