From 291d1e72b756424eac7b1ea2be326a59f004a580 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Thu, 2 May 2019 23:23:31 +0300 Subject: [PATCH] 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: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/dsa/sja1105/sja1105.h | 2 + drivers/net/dsa/sja1105/sja1105_dynamic_config.c | 43 +++++ drivers/net/dsa/sja1105/sja1105_main.c | 194 +++++++++++++++++++++++ 3 files changed, 239 insertions(+) diff --git a/drivers/net/dsa/sja1105/sja1105.h b/drivers/net/dsa/sja1105/sja1105.h index e01cb85..50ab928 100644 --- a/drivers/net/dsa/sja1105/sja1105.h +++ b/drivers/net/dsa/sja1105/sja1105.h @@ -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); diff --git a/drivers/net/dsa/sja1105/sja1105_dynamic_config.c b/drivers/net/dsa/sja1105/sja1105_dynamic_config.c index d8f1454..e73ab28 100644 --- a/drivers/net/dsa/sja1105/sja1105_dynamic_config.c +++ b/drivers/net/dsa/sja1105/sja1105_dynamic_config.c @@ -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; +} diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 7d2ad2d..ec8137e 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -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) -- 2.7.4