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Commit 291d1e72 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: sja1105: Add support for FDB and MDB management 



Currently only the (more difficult) first generation E/T series is
supported. Here the TCAM is only 4-way associative, and to know where
the hardware will search for a FDB entry, we need to perform the same
hash algorithm in order to install the entry in the correct bin.

On P/Q/R/S, the TCAM should be fully associative. However the SPI
command interface is different, and because I don't have access to a
new-generation device at the moment, support for it is TODO.

Signed-off-by: default avatarVladimir Oltean <olteanv@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8aa9ebcc

drivers/net/dsa/sja1105/sja1105.h

+2 −0
Original line number Diff line number Diff line
@@ -123,6 +123,8 @@ int sja1105_dynamic_config_write(struct sja1105_private *priv, 
				 enum sja1105_blk_idx blk_idx,

				 int index, void *entry, bool keep);



u8 sja1105_fdb_hash(struct sja1105_private *priv, const u8 *addr, u16 vid);



/* Common implementations for the static and dynamic configs */

size_t sja1105_l2_forwarding_entry_packing(void *buf, void *entry_ptr,

					   enum packing_op op);

drivers/net/dsa/sja1105/sja1105_dynamic_config.c

+43 −0
Original line number Diff line number Diff line
@@ -487,3 +487,46 @@ int sja1105_dynamic_config_write(struct sja1105_private *priv, 


	return 0;

}



static u8 sja1105_crc8_add(u8 crc, u8 byte, u8 poly)

{

	int i;



	for (i = 0; i < 8; i++) {

		if ((crc ^ byte) & (1 << 7)) {

			crc <<= 1;

			crc ^= poly;

		} else {

			crc <<= 1;

		}

		byte <<= 1;

	}

	return crc;

}



/* CRC8 algorithm with non-reversed input, non-reversed output,

 * no input xor and no output xor. Code customized for receiving

 * the SJA1105 E/T FDB keys (vlanid, macaddr) as input. CRC polynomial

 * is also received as argument in the Koopman notation that the switch

 * hardware stores it in.

 */

u8 sja1105_fdb_hash(struct sja1105_private *priv, const u8 *addr, u16 vid)

{

	struct sja1105_l2_lookup_params_entry *l2_lookup_params =

		priv->static_config.tables[BLK_IDX_L2_LOOKUP_PARAMS].entries;

	u64 poly_koopman = l2_lookup_params->poly;

	/* Convert polynomial from Koopman to 'normal' notation */

	u8 poly = (u8)(1 + (poly_koopman << 1));

	u64 vlanid = l2_lookup_params->shared_learn ? 0 : vid;

	u64 input = (vlanid << 48) | ether_addr_to_u64(addr);

	u8 crc = 0; /* seed */

	int i;



	/* Mask the eight bytes starting from MSB one at a time */

	for (i = 56; i >= 0; i -= 8) {

		u8 byte = (input & (0xffull << i)) >> i;



		crc = sja1105_crc8_add(crc, byte, poly);

	}

	return crc;

}

drivers/net/dsa/sja1105/sja1105_main.c

+194 −0
Original line number Diff line number Diff line
@@ -179,6 +179,9 @@ static int sja1105_init_static_fdb(struct sja1105_private *priv) 


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



	/* We only populate the FDB table through dynamic

	 * L2 Address Lookup entries

	 */

	if (table->entry_count) {

		kfree(table->entries);

		table->entry_count = 0;
@@ -689,6 +692,191 @@ static void sja1105_adjust_link(struct dsa_switch *ds, int port, 
		sja1105_adjust_port_config(priv, port, phydev->speed, true);

}



/* First-generation switches have a 4-way set associative TCAM that

 * holds the FDB entries. An FDB index spans from 0 to 1023 and is comprised of

 * a "bin" (grouping of 4 entries) and a "way" (an entry within a bin).

 * For the placement of a newly learnt FDB entry, the switch selects the bin

 * based on a hash function, and the way within that bin incrementally.

 */

static inline int sja1105et_fdb_index(int bin, int way)

{

	return bin * SJA1105ET_FDB_BIN_SIZE + way;

}



static int sja1105_is_fdb_entry_in_bin(struct sja1105_private *priv, int bin,

				       const u8 *addr, u16 vid,

				       struct sja1105_l2_lookup_entry *match,

				       int *last_unused)

{

	int way;



	for (way = 0; way < SJA1105ET_FDB_BIN_SIZE; way++) {

		struct sja1105_l2_lookup_entry l2_lookup = {0};

		int index = sja1105et_fdb_index(bin, way);



		/* Skip unused entries, optionally marking them

		 * into the return value

		 */

		if (sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP,

						index, &l2_lookup)) {

			if (last_unused)

				*last_unused = way;

			continue;

		}



		if (l2_lookup.macaddr == ether_addr_to_u64(addr) &&

		    l2_lookup.vlanid == vid) {

			if (match)

				*match = l2_lookup;

			return way;

		}

	}

	/* Return an invalid entry index if not found */

	return -1;

}



static int sja1105_fdb_add(struct dsa_switch *ds, int port,

			   const unsigned char *addr, u16 vid)

{

	struct sja1105_l2_lookup_entry l2_lookup = {0};

	struct sja1105_private *priv = ds->priv;

	struct device *dev = ds->dev;

	int last_unused = -1;

	int bin, way;



	bin = sja1105_fdb_hash(priv, addr, vid);



	way = sja1105_is_fdb_entry_in_bin(priv, bin, addr, vid,

					  &l2_lookup, &last_unused);

	if (way >= 0) {

		/* We have an FDB entry. Is our port in the destination

		 * mask? If yes, we need to do nothing. If not, we need

		 * to rewrite the entry by adding this port to it.

		 */

		if (l2_lookup.destports & BIT(port))

			return 0;

		l2_lookup.destports |= BIT(port);

	} else {

		int index = sja1105et_fdb_index(bin, way);



		/* We don't have an FDB entry. We construct a new one and

		 * try to find a place for it within the FDB table.

		 */

		l2_lookup.macaddr = ether_addr_to_u64(addr);

		l2_lookup.destports = BIT(port);

		l2_lookup.vlanid = vid;



		if (last_unused >= 0) {

			way = last_unused;

		} else {

			/* Bin is full, need to evict somebody.

			 * Choose victim at random. If you get these messages

			 * often, you may need to consider changing the

			 * distribution function:

			 * static_config[BLK_IDX_L2_LOOKUP_PARAMS].entries->poly

			 */

			get_random_bytes(&way, sizeof(u8));

			way %= SJA1105ET_FDB_BIN_SIZE;

			dev_warn(dev, "Warning, FDB bin %d full while adding entry for %pM. Evicting entry %u.\n",

				 bin, addr, way);

			/* Evict entry */

			sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,

						     index, NULL, false);

		}

	}

	l2_lookup.index = sja1105et_fdb_index(bin, way);



	return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,

					    l2_lookup.index, &l2_lookup,

					    true);

}



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

			   const unsigned char *addr, u16 vid)

{

	struct sja1105_l2_lookup_entry l2_lookup = {0};

	struct sja1105_private *priv = ds->priv;

	int index, bin, way;

	bool keep;



	bin = sja1105_fdb_hash(priv, addr, vid);

	way = sja1105_is_fdb_entry_in_bin(priv, bin, addr, vid,

					  &l2_lookup, NULL);

	if (way < 0)

		return 0;

	index = sja1105et_fdb_index(bin, way);



	/* We have an FDB entry. Is our port in the destination mask? If yes,

	 * we need to remove it. If the resulting port mask becomes empty, we

	 * need to completely evict the FDB entry.

	 * Otherwise we just write it back.

	 */

	if (l2_lookup.destports & BIT(port))

		l2_lookup.destports &= ~BIT(port);

	if (l2_lookup.destports)

		keep = true;

	else

		keep = false;



	return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP,

					    index, &l2_lookup, keep);

}



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

			    dsa_fdb_dump_cb_t *cb, void *data)

{

	struct sja1105_private *priv = ds->priv;

	struct device *dev = ds->dev;

	int i;



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

		struct sja1105_l2_lookup_entry l2_lookup = {0};

		u8 macaddr[ETH_ALEN];

		int rc;



		rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP,

						 i, &l2_lookup);

		/* No fdb entry at i, not an issue */

		if (rc == -EINVAL)

			continue;

		if (rc) {

			dev_err(dev, "Failed to dump FDB: %d\n", rc);

			return rc;

		}



		/* FDB dump callback is per port. This means we have to

		 * disregard a valid entry if it's not for this port, even if

		 * only to revisit it later. This is inefficient because the

		 * 1024-sized FDB table needs to be traversed 4 times through

		 * SPI during a 'bridge fdb show' command.

		 */

		if (!(l2_lookup.destports & BIT(port)))

			continue;

		u64_to_ether_addr(l2_lookup.macaddr, macaddr);

		cb(macaddr, l2_lookup.vlanid, false, data);

	}

	return 0;

}



/* This callback needs to be present */

static int sja1105_mdb_prepare(struct dsa_switch *ds, int port,

			       const struct switchdev_obj_port_mdb *mdb)

{

	return 0;

}



static void sja1105_mdb_add(struct dsa_switch *ds, int port,

			    const struct switchdev_obj_port_mdb *mdb)

{

	sja1105_fdb_add(ds, port, mdb->addr, mdb->vid);

}



static int sja1105_mdb_del(struct dsa_switch *ds, int port,

			   const struct switchdev_obj_port_mdb *mdb)

{

	return sja1105_fdb_del(ds, port, mdb->addr, mdb->vid);

}



static int sja1105_bridge_member(struct dsa_switch *ds, int port,

				 struct net_device *br, bool member)

{
@@ -791,8 +979,14 @@ static const struct dsa_switch_ops sja1105_switch_ops = { 
	.get_tag_protocol	= sja1105_get_tag_protocol,

	.setup			= sja1105_setup,

	.adjust_link		= sja1105_adjust_link,

	.port_fdb_dump		= sja1105_fdb_dump,

	.port_fdb_add		= sja1105_fdb_add,

	.port_fdb_del		= sja1105_fdb_del,

	.port_bridge_join	= sja1105_bridge_join,

	.port_bridge_leave	= sja1105_bridge_leave,

	.port_mdb_prepare	= sja1105_mdb_prepare,

	.port_mdb_add		= sja1105_mdb_add,

	.port_mdb_del		= sja1105_mdb_del,

};



static int sja1105_check_device_id(struct sja1105_private *priv)