kernel.git/drivers/net/dsa/b53/b53_priv.h, branch linux-5.16.y

net: dsa: b53: serialize access to the ARL table

2021-10-25T11:59:41Z

The b53 driver performs non-atomic transactions to the ARL table when adding, deleting and reading FDB and MDB entries. Traditionally these were all serialized by the rtnl_lock(), but now it is possible that DSA calls ->port_fdb_add and ->port_fdb_del without holding that lock. So the driver must have its own serialization logic. Add a mutex and hold it from all entry points (->port_fdb_{add,del,dump}, ->port_mdb_{add,del}). Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller

Revert "Merge branch 'dsa-rtnl'"

2021-10-25T11:59:25Z

This reverts commit 965e6b262f48257dbdb51b565ecfd84877a0ab5f, reversing changes made to 4d98bb0d7ec2d0b417df6207b0bafe1868bad9f8.

net: dsa: b53: serialize access to the ARL table

2021-10-24T12:47:44Z

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-09-23T18:19:49Z

net/mptcp/protocol.c 977d293e23b4 ("mptcp: ensure tx skbs always have the MPTCP ext") efe686ffce01 ("mptcp: ensure tx skbs always have the MPTCP ext") same patch merged in both trees, keep net-next. Signed-off-by: Jakub Kicinski

net: dsa: be compatible with masters which unregister on shutdown

2021-09-19T11:08:37Z

Lino reports that on his system with bcmgenet as DSA master and KSZ9897 as a switch, rebooting or shutting down never works properly. What does the bcmgenet driver have special to trigger this, that other DSA masters do not? It has an implementation of ->shutdown which simply calls its ->remove implementation. Otherwise said, it unregisters its network interface on shutdown. This message can be seen in a loop, and it hangs the reboot process there: unregister_netdevice: waiting for eth0 to become free. Usage count = 3 So why 3? A usage count of 1 is normal for a registered network interface, and any virtual interface which links itself as an upper of that will increment it via dev_hold. In the case of DSA, this is the call path: dsa_slave_create -> netdev_upper_dev_link -> __netdev_upper_dev_link -> __netdev_adjacent_dev_insert -> dev_hold So a DSA switch with 3 interfaces will result in a usage count elevated by two, and netdev_wait_allrefs will wait until they have gone away. Other stacked interfaces, like VLAN, watch NETDEV_UNREGISTER events and delete themselves, but DSA cannot just vanish and go poof, at most it can unbind itself from the switch devices, but that must happen strictly earlier compared to when the DSA master unregisters its net_device, so reacting on the NETDEV_UNREGISTER event is way too late. It seems that it is a pretty established pattern to have a driver's ->shutdown hook redirect to its ->remove hook, so the same code is executed regardless of whether the driver is unbound from the device, or the system is just shutting down. As Florian puts it, it is quite a big hammer for bcmgenet to unregister its net_device during shutdown, but having a common code path with the driver unbind helps ensure it is well tested. So DSA, for better or for worse, has to live with that and engage in an arms race of implementing the ->shutdown hook too, from all individual drivers, and do something sane when paired with masters that unregister their net_device there. The only sane thing to do, of course, is to unlink from the master. However, complications arise really quickly. The pattern of redirecting ->shutdown to ->remove is not unique to bcmgenet or even to net_device drivers. In fact, SPI controllers do it too (see dspi_shutdown -> dspi_remove), and presumably, I2C controllers and MDIO controllers do it too (this is something I have not researched too deeply, but even if this is not the case today, it is certainly plausible to happen in the future, and must be taken into consideration). Since DSA switches might be SPI devices, I2C devices, MDIO devices, the insane implication is that for the exact same DSA switch device, we might have both ->shutdown and ->remove getting called. So we need to do something with that insane environment. The pattern I've come up with is "if this, then not that", so if either ->shutdown or ->remove gets called, we set the device's drvdata to NULL, and in the other hook, we check whether the drvdata is NULL and just do nothing. This is probably not necessary for platform devices, just for devices on buses, but I would really insist for consistency among drivers, because when code is copy-pasted, it is not always copy-pasted from the best sources. So depending on whether the DSA switch's ->remove or ->shutdown will get called first, we cannot really guarantee even for the same driver if rebooting will result in the same code path on all platforms. But nonetheless, we need to do something minimally reasonable on ->shutdown too to fix the bug. Of course, the ->remove will do more (a full teardown of the tree, with all data structures freed, and this is why the bug was not caught for so long). The new ->shutdown method is kept separate from dsa_unregister_switch not because we couldn't have unregistered the switch, but simply in the interest of doing something quick and to the point. The big question is: does the DSA switch's ->shutdown get called earlier than the DSA master's ->shutdown? If not, there is still a risk that we might still trigger the WARN_ON in unregister_netdevice that says we are attempting to unregister a net_device which has uppers. That's no good. Although the reference to the master net_device won't physically go away even if DSA's ->shutdown comes afterwards, remember we have a dev_hold on it. The answer to that question lies in this comment above device_link_add: * A side effect of the link creation is re-ordering of dpm_list and the * devices_kset list by moving the consumer device and all devices depending * on it to the ends of these lists (that does not happen to devices that have * not been registered when this function is called). so the fact that DSA uses device_link_add towards its master is not exactly for nothing. device_shutdown() walks devices_kset from the back, so this is our guarantee that DSA's shutdown happens before the master's shutdown. Fixes: 2f1e8ea726e9 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings") Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/ Reported-by: Lino Sanfilippo Signed-off-by: Vladimir Oltean Tested-by: Andrew Lunn Signed-off-by: David S. Miller

net: dsa: b53: Drop unused "cpu_port" field

2021-09-17T02:06:36Z

It's set but never used anymore. Signed-off-by: Rafał Miłecki Reviewed-by: Florian Fainelli Tested-by: Florian Fainelli Signed-off-by: Jakub Kicinski

net: dsa: b53: Fix IMP port setup on BCM5301x

2021-09-05T18:02:38Z

Broadcom's b53 switches have one IMP (Inband Management Port) that needs to be programmed using its own designed register. IMP port may be different than CPU port - especially on devices with multiple CPU ports. For that reason it's required to explicitly note IMP port index and check for it when choosing a register to use. This commit fixes BCM5301x support. Those switches use CPU port 5 while their IMP port is 8. Before this patch b53 was trying to program port 5 with B53_PORT_OVERRIDE_CTRL instead of B53_GMII_PORT_OVERRIDE_CTRL(5). It may be possible to also replace "cpu_port" usages with dsa_is_cpu_port() but that is out of the scope of thix BCM5301x fix. Fixes: 967dd82ffc52 ("net: dsa: b53: Add support for Broadcom RoboSwitch") Signed-off-by: Rafał Miłecki Signed-off-by: David S. Miller

net: dsa: don't disable multicast flooding to the CPU even without an IGMP querier

2021-08-06T10:11:13Z

Commit 08cc83cc7fd8 ("net: dsa: add support for BRIDGE_MROUTER attribute") added an option for users to turn off multicast flooding towards the CPU if they turn off the IGMP querier on a bridge which already has enslaved ports (echo 0 > /sys/class/net/br0/bridge/multicast_router). And commit a8b659e7ff75 ("net: dsa: act as passthrough for bridge port flags") simply papered over that issue, because it moved the decision to flood the CPU with multicast (or not) from the DSA core down to individual drivers, instead of taking a more radical position then. The truth is that disabling multicast flooding to the CPU is simply something we are not prepared to do now, if at all. Some reasons: - ICMP6 neighbor solicitation messages are unregistered multicast packets as far as the bridge is concerned. So if we stop flooding multicast, the outside world cannot ping the bridge device's IPv6 link-local address. - There might be foreign interfaces bridged with our DSA switch ports (sending a packet towards the host does not necessarily equal termination, but maybe software forwarding). So if there is no one interested in that multicast traffic in the local network stack, that doesn't mean nobody is. - PTP over L4 (IPv4, IPv6) is multicast, but is unregistered as far as the bridge is concerned. This should reach the CPU port. - The switch driver might not do FDB partitioning. And since we don't even bother to do more fine-grained flood disabling (such as "disable flooding _from_port_N_ towards the CPU port" as opposed to "disable flooding _from_any_port_ towards the CPU port"), this breaks standalone ports, or even multiple bridges where one has an IGMP querier and one doesn't. Reverting the logic makes all of the above work. Fixes: a8b659e7ff75 ("net: dsa: act as passthrough for bridge port flags") Fixes: 08cc83cc7fd8 ("net: dsa: add support for BRIDGE_MROUTER attribute") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: dsa: b53: relax is63xx() condition

2021-03-17T19:05:46Z

BCM63xx switches are present on bcm63xx and bmips devices. Signed-off-by: Álvaro Fernández Rojas Acked-by: Florian Fainelli Signed-off-by: David S. Miller

net: dsa: bcm_sf2: Wire-up br_flags_pre, br_flags and set_mrouter

2021-02-23T20:23:00Z

Because bcm_sf2 implements its own dsa_switch_ops we need to export the b53_br_flags_pre(), b53_br_flags() and b53_set_mrouter so we can wire-up them up like they used to be with the former b53_br_egress_floods(). Fixes: a8b659e7ff75 ("net: dsa: act as passthrough for bridge port flags") Signed-off-by: Florian Fainelli Reviewed-by: Vladimir Oltean Signed-off-by: Jakub Kicinski