From: Vladimir Oltean vladimir.oltean@nxp.com
stable inclusion from stable-5.10.58 commit 00bf923dce2abe69cc6b7d6b24f844df894d8104 bugzilla: 176984 https://gitee.com/openeuler/kernel/issues/I4E2P4
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 6c5fc159e0927531707895709eee1f8bfa04289f ]
The procedure to add a static FDB entry in sja1105 is concurrent with dynamic learning performed on all bridge ports and the CPU port.
The switch looks up the FDB from left to right, and also learns dynamically from left to right, so it is possible that between the moment when we pick up a free slot to install an FDB entry, another slot to the left of that one becomes free due to an address ageing out, and that other slot is then immediately used by the switch to learn dynamically the same address as we're trying to add statically.
The result is that we succeeded to add our static FDB entry, but it is being shadowed by a dynamic FDB entry to its left, and the switch will behave as if our static FDB entry did not exist.
We cannot really prevent this from happening unless we make the entire process to add a static FDB entry a huge critical section where address learning is temporarily disabled on _all_ ports, and then re-enabled according to the configuration done by sja1105_port_set_learning. However, that is kind of disruptive for the operation of the network.
What we can do alternatively is to simply read back the FDB for dynamic entries located before our newly added static one, and delete them. This will guarantee that our static FDB entry is now operational. It will still not guarantee that there aren't dynamic FDB entries to the _right_ of that static FDB entry, but at least those entries will age out by themselves since they aren't hit, and won't bother anyone.
Fixes: 291d1e72b756 ("net: dsa: sja1105: Add support for FDB and MDB management") Fixes: 1da73821343c ("net: dsa: sja1105: Add FDB operations for P/Q/R/S series") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- drivers/net/dsa/sja1105/sja1105_main.c | 57 +++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 2 deletions(-)
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 469d123772a6..52d8cc1a95fa 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -1260,10 +1260,11 @@ static int sja1105et_is_fdb_entry_in_bin(struct sja1105_private *priv, int bin, int sja1105et_fdb_add(struct dsa_switch *ds, int port, const unsigned char *addr, u16 vid) { - struct sja1105_l2_lookup_entry l2_lookup = {0}; + struct sja1105_l2_lookup_entry l2_lookup = {0}, tmp; struct sja1105_private *priv = ds->priv; struct device *dev = ds->dev; int last_unused = -1; + int start, end, i; int bin, way, rc;
bin = sja1105et_fdb_hash(priv, addr, vid); @@ -1315,6 +1316,29 @@ int sja1105et_fdb_add(struct dsa_switch *ds, int port, if (rc < 0) return rc;
+ /* Invalidate a dynamically learned entry if that exists */ + start = sja1105et_fdb_index(bin, 0); + end = sja1105et_fdb_index(bin, way); + + for (i = start; i < end; i++) { + rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP, + i, &tmp); + if (rc == -ENOENT) + continue; + if (rc) + return rc; + + if (tmp.macaddr != ether_addr_to_u64(addr) || tmp.vlanid != vid) + continue; + + rc = sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP, + i, NULL, false); + if (rc) + return rc; + + break; + } + return sja1105_static_fdb_change(priv, port, &l2_lookup, true); }
@@ -1356,7 +1380,7 @@ 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) { - struct sja1105_l2_lookup_entry l2_lookup = {0}; + struct sja1105_l2_lookup_entry l2_lookup = {0}, tmp; struct sja1105_private *priv = ds->priv; int rc, i;
@@ -1414,6 +1438,35 @@ int sja1105pqrs_fdb_add(struct dsa_switch *ds, int port, if (rc < 0) return rc;
+ /* The switch learns dynamic entries and looks up the FDB left to + * right. It is possible that our addition was concurrent with the + * dynamic learning of the same address, so now that the static entry + * has been installed, we are certain that address learning for this + * particular address has been turned off, so the dynamic entry either + * is in the FDB at an index smaller than the static one, or isn't (it + * can also be at a larger index, but in that case it is inactive + * because the static FDB entry will match first, and the dynamic one + * will eventually age out). Search for a dynamically learned address + * prior to our static one and invalidate it. + */ + tmp = l2_lookup; + + rc = sja1105_dynamic_config_read(priv, BLK_IDX_L2_LOOKUP, + SJA1105_SEARCH, &tmp); + if (rc < 0) { + dev_err(ds->dev, + "port %d failed to read back entry for %pM vid %d: %pe\n", + port, addr, vid, ERR_PTR(rc)); + return rc; + } + + if (tmp.index < l2_lookup.index) { + rc = sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP, + tmp.index, NULL, false); + if (rc < 0) + return rc; + } + return sja1105_static_fdb_change(priv, port, &l2_lookup, true); }