net: dsa: sja1105: Add FDB operations for P/Q/R/S series

This adds support for manipulating the L2 forwarding database (dump,
add, delete) for the second generation of NXP SJA1105 switches.

At the moment only FDB entries installed statically through 'bridge fdb'
are visible in the dump callback - the dynamically learned ones are
still under investigation.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105.h

@@ -147,6 +147,11 @@ int sja1105_dynamic_config_write(struct sja1105_private *priv,
 				 enum sja1105_blk_idx blk_idx,
 				 int index, void *entry, bool keep);
 
+enum sja1105_iotag {
+	SJA1105_C_TAG = 0, /* Inner VLAN header */
+	SJA1105_S_TAG = 1, /* Outer VLAN header */
+};
+
 u8 sja1105et_fdb_hash(struct sja1105_private *priv, const u8 *addr, u16 vid);
 int sja1105et_fdb_add(struct dsa_switch *ds, int port,
 		      const unsigned char *addr, u16 vid);

drivers/net/dsa/sja1105/sja1105_main.c

@@ -210,6 +210,8 @@ static int sja1105_init_l2_lookup_params(struct sja1105_private *priv)
 		.maxage = SJA1105_AGEING_TIME_MS(300000),
 		/* All entries within a FDB bin are available for learning */
 		.dyn_tbsz = SJA1105ET_FDB_BIN_SIZE,
+		/* And the P/Q/R/S equivalent setting: */
+		.start_dynspc = 0,
 		/* 2^8 + 2^5 + 2^3 + 2^2 + 2^1 + 1 in Koopman notation */
 		.poly = 0x97,
 		/* This selects between Independent VLAN Learning (IVL) and
@@ -225,6 +227,13 @@ static int sja1105_init_l2_lookup_params(struct sja1105_private *priv)
 		 * Maybe correlate with no_linklocal_learn from bridge driver?
 		 */
 		.no_mgmt_learn = true,
+		/* P/Q/R/S only */
+		.use_static = true,
+		/* Dynamically learned FDB entries can overwrite other (older)
+		 * dynamic FDB entries
+		 */
+		.owr_dyn = true,
+		.drpnolearn = true,
 	};
 
 	table = &priv->static_config.tables[BLK_IDX_L2_LOOKUP_PARAMS];
@@ -908,13 +917,89 @@ int sja1105et_fdb_del(struct dsa_switch *ds, int port,
 int sja1105pqrs_fdb_add(struct dsa_switch *ds, int port,
 			const unsigned char *addr, u16 vid)
 {
-	return -EOPNOTSUPP;
+	struct sja1105_l2_lookup_entry l2_lookup = {0};
+	struct sja1105_private *priv = ds->priv;
+	int rc, i;
+
+	/* Search for an existing entry in the FDB table */
+	l2_lookup.macaddr = ether_addr_to_u64(addr);
+	l2_lookup.vlanid = vid;
+	l2_lookup.iotag = SJA1105_S_TAG;
+	l2_lookup.mask_macaddr = GENMASK_ULL(ETH_ALEN * 8 - 1, 0);
+	l2_lookup.mask_vlanid = VLAN_VID_MASK;
+	l2_lookup.mask_iotag = BIT(0);
+	l2_lookup.destports = BIT(port);
+
+	rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP,
+					 SJA1105_SEARCH, &l2_lookup);
+	if (rc == 0) {
+		/* Found and this port is already in the entry's
+		 * port mask => job done
+		 */
+		if (l2_lookup.destports & BIT(port))
+			return 0;
+		/* l2_lookup.index is populated by the switch in case it
+		 * found something.
+		 */
+		l2_lookup.destports |= BIT(port);
+		goto skip_finding_an_index;
+	}
+
+	/* Not found, so try to find an unused spot in the FDB.
+	 * This is slightly inefficient because the strategy is knock-knock at
+	 * every possible position from 0 to 1023.
+	 */
+	for (i = 0; i < SJA1105_MAX_L2_LOOKUP_COUNT; i++) {
+		rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP,
+						 i, NULL);
+		if (rc < 0)
+			break;
+	}
+	if (i == SJA1105_MAX_L2_LOOKUP_COUNT) {
+		dev_err(ds->dev, "FDB is full, cannot add entry.\n");
+		return -EINVAL;
+	}
+	l2_lookup.index = i;
+
+skip_finding_an_index:
+	return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,
+					    l2_lookup.index, &l2_lookup,
+					    true);
 }
 
 int sja1105pqrs_fdb_del(struct dsa_switch *ds, int port,
 			const unsigned char *addr, u16 vid)
 {
-	return -EOPNOTSUPP;
+	struct sja1105_l2_lookup_entry l2_lookup = {0};
+	struct sja1105_private *priv = ds->priv;
+	bool keep;
+	int rc;
+
+	l2_lookup.macaddr = ether_addr_to_u64(addr);
+	l2_lookup.vlanid = vid;
+	l2_lookup.iotag = SJA1105_S_TAG;
+	l2_lookup.mask_macaddr = GENMASK_ULL(ETH_ALEN * 8 - 1, 0);
+	l2_lookup.mask_vlanid = VLAN_VID_MASK;
+	l2_lookup.mask_iotag = BIT(0);
+	l2_lookup.destports = BIT(port);
+
+	rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP,
+					 SJA1105_SEARCH, &l2_lookup);
+	if (rc < 0)
+		return 0;
+
+	l2_lookup.destports &= ~BIT(port);
+
+	/* Decide whether we remove just this port from the FDB entry,
+	 * or if we remove it completely.
+	 */
+	if (l2_lookup.destports)
+		keep = true;
+	else
+		keep = false;
+
+	return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,
+					    l2_lookup.index, &l2_lookup, keep);
 }
 
 static int sja1105_fdb_add(struct dsa_switch *ds, int port,