kernel/linux.git/net/dsa/dsa.c, branch v6.1

net: dsa: allow the DSA master to be seen and changed through rtnetlink

2022-09-20T08:32:35+00:00

Some DSA switches have multiple CPU ports, which can be used to improve CPU termination throughput, but DSA, through dsa_tree_setup_cpu_ports(), sets up only the first one, leading to suboptimal use of hardware. The desire is to not change the default configuration but to permit the user to create a dynamic mapping between individual user ports and the CPU port that they are served by, configurable through rtnetlink. It is also intended to permit load balancing between CPU ports, and in that case, the foreseen model is for the DSA master to be a bonding interface whose lowers are the physical DSA masters. To that end, we create a struct rtnl_link_ops for DSA user ports with the "dsa" kind. We expose the IFLA_DSA_MASTER link attribute that contains the ifindex of the newly desired DSA master. Signed-off-by: Vladimir Oltean Signed-off-by: Paolo Abeni

net: dsa: delete dsa_port_walk_{fdbs,mdbs}

2022-05-07T04:00:12+00:00

All the users of these functions are gone, delete them before they gain new ones. Signed-off-by: Vladimir Oltean Signed-off-by: Jakub Kicinski

net: dsa: remove unused headers

2022-04-25T11:08:40+00:00

Reduce a number of included headers to a necessary minimum. Signed-off-by: Marcin Wojtas Signed-off-by: David S. Miller

net: dsa: felix: avoid early deletion of host FDB entries

2022-03-09T11:12:10+00:00

The Felix driver declares FDB isolation but puts all standalone ports in VID 0. This is mostly problem-free as discussed with Alvin here: https://patchwork.kernel.org/project/netdevbpf/cover/20220302191417.1288145-1-vladimir.oltean@nxp.com/#24763870 however there is one catch. DSA still thinks that FDB entries are installed on the CPU port as many times as there are user ports, and this is problematic when multiple user ports share the same MAC address. Consider the default case where all user ports inherit their MAC address from the DSA master, and then the user runs: ip link set swp0 address 00:01:02:03:04:05 The above will make dsa_slave_set_mac_address() call dsa_port_standalone_host_fdb_add() for 00:01:02:03:04:05 in port 0's standalone database, and dsa_port_standalone_host_fdb_del() for the old address of swp0, again in swp0's standalone database. Both the ->port_fdb_add() and ->port_fdb_del() will be propagated down to the felix driver, which will end up deleting the old MAC address from the CPU port. But this is still in use by other user ports, so we end up breaking unicast termination for them. There isn't a problem in the fact that DSA keeps track of host standalone addresses in the individual database of each user port: some drivers like sja1105 need this. There also isn't a problem in the fact that some drivers choose the same VID/FID for all standalone ports. It is just that the deletion of these host addresses must be delayed until they are known to not be in use any longer, and only the driver has this knowledge. Since DSA keeps these addresses in &cpu_dp->fdbs and &cpu_db->mdbs, it is just a matter of walking over those lists and see whether the same MAC address is present on the CPU port in the port db of another user port. I have considered reusing the generic dsa_port_walk_fdbs() and dsa_port_walk_mdbs() schemes for this, but locking makes it difficult. In the ->port_fdb_add() method and co, &dp->addr_lists_lock is held, but dsa_port_walk_fdbs() also acquires that lock. Also, even assuming that we introduce an unlocked variant of the address iterator, we'd still need some relatively complex data structures, and a void *ctx in the dsa_fdb_walk_cb_t which we don't currently pass, such that drivers are able to figure out, after iterating, whether the same MAC address is or isn't present in the port db of another port. All the above, plus the fact that I expect other drivers to follow the same model as felix where all standalone ports use the same FID, made me conclude that a generic method provided by DSA is necessary: dsa_fdb_present_in_other_db() and the mdb equivalent. Felix calls this from the ->port_fdb_del() handler for the CPU port, when the database was classified to either a port db, or a LAG db. For symmetry, we also call this from ->port_fdb_add(), because if the address was installed once, then installing it a second time serves no purpose: it's already in hardware in VID 0 and it affects all standalone ports. This change moves dsa_db_equal() from switch.c to dsa.c, since it now has one more caller. Fixes: 54c319846086 ("net: mscc: ocelot: enforce FDB isolation when VLAN-unaware") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: return success if there was nothing to do

2022-03-07T12:25:59+00:00

Clang static analysis reports this representative issue dsa.c:486:2: warning: Undefined or garbage value returned to caller return err; ^~~~~~~~~~ err is only set in the loop. If the loop is empty, garbage will be returned. So initialize err to 0 to handle this noop case. Signed-off-by: Tom Rix Reviewed-by: Andrew Lunn Reviewed-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: felix: migrate host FDB and MDB entries when changing tag proto

2022-03-03T14:15:31+00:00

The "ocelot" and "ocelot-8021q" tagging protocols make use of different hardware resources, and host FDB entries have different destination ports in the switch analyzer module, practically speaking. So when the user requests a tagging protocol change, the driver must migrate all host FDB and MDB entries from the NPI port (in fact CPU port module) towards the same physical port, but this time used as a regular port. It is pointless for the felix driver to keep a copy of the host addresses, when we can create and export DSA helpers for walking through the addresses that it already needs to keep on the CPU port, for refcounting purposes. felix_classify_db() is moved up to avoid a forward declaration. We pass "bool change" because dp->fdbs and dp->mdbs are uninitialized lists when felix_setup() first calls felix_set_tag_protocol(), so we need to avoid calling dsa_port_walk_fdbs() during probe time. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: mv88e6xxx: flush switchdev FDB workqueue before removing VLAN

2022-02-14T13:31:12+00:00

mv88e6xxx is special among DSA drivers in that it requires the VTU to contain the VID of the FDB entry it modifies in mv88e6xxx_port_db_load_purge(), otherwise it will return -EOPNOTSUPP. Sometimes due to races this is not always satisfied even if external code does everything right (first deletes the FDB entries, then the VLAN), because DSA commits to hardware FDB entries asynchronously since commit c9eb3e0f8701 ("net: dsa: Add support for learning FDB through notification"). Therefore, the mv88e6xxx driver must close this race condition by itself, by asking DSA to flush the switchdev workqueue of any FDB deletions in progress, prior to exiting a VLAN. Fixes: c9eb3e0f8701 ("net: dsa: Add support for learning FDB through notification") Reported-by: Rafael Richter Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

devlink: Simplify devlink resources unregister call

2021-11-30T12:23:32+00:00

The devlink_resources_unregister() used second parameter as an entry point for the recursive removal of devlink resources. None of the callers outside of devlink core needed to use this field, so let's remove it. As part of this removal, the "struct devlink_resource" was moved from .h to .c file as it is not possible to use in any place in the code except devlink.c. Signed-off-by: Leon Romanovsky Signed-off-by: David S. Miller

net: dsa: remove the "dsa_to_port in a loop" antipattern from the core

2021-10-21T11:44:06+00:00

Ever since Vivien's conversion of the ds->ports array into a dst->ports list, and the introduction of dsa_to_port, iterations through the ports of a switch became quadratic whenever dsa_to_port was needed. dsa_to_port can either be called directly, or indirectly through the dsa_is_{user,cpu,dsa,unused}_port helpers. Use the newly introduced dsa_switch_for_each_port() iteration macro that works with the iterator variable being a struct dsa_port *dp directly, and not an int i. It is an expensive variable to go from i to dp, but cheap to go from dp to i. This macro iterates through the entire ds->dst->ports list and filters by the ports belonging just to the switch provided as argument. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports

2021-09-15T22:09:46+00:00

Sometimes when unbinding the mv88e6xxx driver on Turris MOX, these error messages appear: mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete be:79:b4:9e:9e:96 vid 1 from fdb: -2 mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete be:79:b4:9e:9e:96 vid 0 from fdb: -2 mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 100 from fdb: -2 mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 1 from fdb: -2 mv88e6085 d0032004.mdio-mii:12: port 1 failed to delete d8:58:d7:00:ca:6d vid 0 from fdb: -2 (and similarly for other ports) What happens is that DSA has a policy "even if there are bugs, let's at least not leak memory" and dsa_port_teardown() clears the dp->fdbs and dp->mdbs lists, which are supposed to be empty. But deleting that cleanup code, the warnings go away. => the FDB and MDB lists (used for refcounting on shared ports, aka CPU and DSA ports) will eventually be empty, but are not empty by the time we tear down those ports. Aka we are deleting them too soon. The addresses that DSA complains about are host-trapped addresses: the local addresses of the ports, and the MAC address of the bridge device. The problem is that offloading those entries happens from a deferred work item scheduled by the SWITCHDEV_FDB_DEL_TO_DEVICE handler, and this races with the teardown of the CPU and DSA ports where the refcounting is kept. In fact, not only it races, but fundamentally speaking, if we iterate through the port list linearly, we might end up tearing down the shared ports even before we delete a DSA user port which has a bridge upper. So as it turns out, we need to first tear down the user ports (and the unused ones, for no better place of doing that), then the shared ports (the CPU and DSA ports). In between, we need to ensure that all work items scheduled by our switchdev handlers (which only run for user ports, hence the reason why we tear them down first) have finished. Fixes: 161ca59d39e9 ("net: dsa: reference count the MDB entries at the cross-chip notifier level") Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/20210914134726.2305133-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski