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2021-09-15net: dsa: flush switchdev workqueue before tearing down CPU/DSA portsVladimir Oltean
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 <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20210914134726.2305133-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-23net: dsa: track unique bridge numbers across all DSA switch treesVladimir Oltean
Right now, cross-tree bridging setups work somewhat by mistake. In the case of cross-tree bridging with sja1105, all switch instances need to agree upon a common VLAN ID for forwarding a packet that belongs to a certain bridging domain. With TX forwarding offload, the VLAN ID is the bridge VLAN for VLAN-aware bridging, and the tag_8021q TX forwarding offload VID (a VLAN which has non-zero VBID bits) for VLAN-unaware bridging. The VBID for VLAN-unaware bridging is derived from the dp->bridge_num value calculated by DSA independently for each switch tree. If ports from one tree join one bridge, and ports from another tree join another bridge, DSA will assign them the same bridge_num, even though the bridges are different. If cross-tree bridging is supported, this is an issue. Modify DSA to calculate the bridge_num globally across all switch trees. This has the implication for a driver that the dp->bridge_num value that DSA will assign to its ports might not be contiguous, if there are boards with multiple DSA drivers instantiated. Additionally, all bridge_num values eat up towards each switch's ds->num_fwd_offloading_bridges maximum, which is potentially unfortunate, and can be seen as a limitation introduced by this patch. However, that is the lesser evil for now. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-12net: dsa: tag_8021q: don't broadcast during setup/teardownVladimir Oltean
Currently, on my board with multiple sja1105 switches in disjoint trees described in commit f66a6a69f97a ("net: dsa: permit cross-chip bridging between all trees in the system"), rebooting the board triggers the following benign warnings: [ 12.345566] sja1105 spi2.0: port 0 failed to notify tag_8021q VLAN 1088 deletion: -ENOENT [ 12.353804] sja1105 spi2.0: port 0 failed to notify tag_8021q VLAN 2112 deletion: -ENOENT [ 12.362019] sja1105 spi2.0: port 1 failed to notify tag_8021q VLAN 1089 deletion: -ENOENT [ 12.370246] sja1105 spi2.0: port 1 failed to notify tag_8021q VLAN 2113 deletion: -ENOENT [ 12.378466] sja1105 spi2.0: port 2 failed to notify tag_8021q VLAN 1090 deletion: -ENOENT [ 12.386683] sja1105 spi2.0: port 2 failed to notify tag_8021q VLAN 2114 deletion: -ENOENT Basically switch 1 calls dsa_tag_8021q_unregister, and switch 1's TX and RX VLANs cannot be found on switch 2's CPU port. But why would switch 2 even attempt to delete switch 1's TX and RX tag_8021q VLANs from its CPU port? Well, because we use dsa_broadcast, and it is supposed that it had added those VLANs in the first place (because in dsa_port_tag_8021q_vlan_match, all CPU ports match regardless of their tree index or switch index). The two trees probe asynchronously, and when switch 1 probed, it called dsa_broadcast which did not notify the tree of switch 2, because that didn't probe yet. But during unbind, switch 2's tree _is_ probed, so it _is_ notified of the deletion. Before jumping to introduce a synchronization mechanism between the probing across disjoint switch trees, let's take a step back and see whether we _need_ to do that in the first place. The RX and TX VLANs of switch 1 would be needed on switch 2's CPU port only if switch 1 and 2 were part of a cross-chip bridge. And dsa_tag_8021q_bridge_join takes care precisely of that (but if probing was synchronous, the bridge_join would just end up bumping the VLANs' refcount, because they are already installed by the setup path). Since by the time the ports are bridged, all DSA trees are already set up, and we don't need the tag_8021q VLANs of one switch installed on the other switches during probe time, the answer is that we don't need to fix the synchronization issue. So make the setup and teardown code paths call dsa_port_notify, which notifies only the local tree, and the bridge code paths call dsa_broadcast, which let the other trees know as well. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-09devlink: Set device as early as possibleLeon Romanovsky
All kernel devlink implementations call to devlink_alloc() during initialization routine for specific device which is used later as a parent device for devlink_register(). Such late device assignment causes to the situation which requires us to call to device_register() before setting other parameters, but that call opens devlink to the world and makes accessible for the netlink users. Any attempt to move devlink_register() to be the last call generates the following error due to access to the devlink->dev pointer. [ 8.758862] devlink_nl_param_fill+0x2e8/0xe50 [ 8.760305] devlink_param_notify+0x6d/0x180 [ 8.760435] __devlink_params_register+0x2f1/0x670 [ 8.760558] devlink_params_register+0x1e/0x20 The simple change of API to set devlink device in the devlink_alloc() instead of devlink_register() fixes all this above and ensures that prior to call to devlink_register() everything already set. Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05net: dsa: give preference to local CPU portsVladimir Oltean
Be there an "H" switch topology, where there are 2 switches connected as follows: eth0 eth1 | | CPU port CPU port | DSA link | sw0p0 sw0p1 sw0p2 sw0p3 sw0p4 -------- sw1p4 sw1p3 sw1p2 sw1p1 sw1p0 | | | | | | user user user user user user port port port port port port basically one where each switch has its own CPU port for termination, but there is also a DSA link in case packets need to be forwarded in hardware between one switch and another. DSA insists to see this as a daisy chain topology, basically registering all network interfaces as sw0p0@eth0, ... sw1p0@eth0 and disregarding eth1 as a valid DSA master. This is only half the story, since when asked using dsa_port_is_cpu(), DSA will respond that sw1p1 is a CPU port, however one which has no dp->cpu_dp pointing to it. So sw1p1 is enabled, but not used. Furthermore, be there a driver for switches which support only one upstream port. This driver iterates through its ports and checks using dsa_is_upstream_port() whether the current port is an upstream one. For switch 1, two ports pass the "is upstream port" checks: - sw1p4 is an upstream port because it is a routing port towards the dedicated CPU port assigned using dsa_tree_setup_default_cpu() - sw1p1 is also an upstream port because it is a CPU port, albeit one that is disabled. This is because dsa_upstream_port() returns: if (!cpu_dp) return port; which means that if @dp does not have a ->cpu_dp pointer (which is a characteristic of CPU ports themselves as well as unused ports), then @dp is its own upstream port. So the driver for switch 1 rightfully says: I have two upstream ports, but I don't support multiple upstream ports! So let me error out, I don't know which one to choose and what to do with the other one. Generally I am against enforcing any default policy in the kernel in terms of user to CPU port assignment (like round robin or such) but this case is different. To solve the conundrum, one would have to: - Disable sw1p1 in the device tree or mark it as "not a CPU port" in order to comply with DSA's view of this topology as a daisy chain, where the termination traffic from switch 1 must pass through switch 0. This is counter-productive because it wastes 1Gbps of termination throughput in switch 1. - Disable the DSA link between sw0p4 and sw1p4 and do software forwarding between switch 0 and 1, and basically treat the switches as part of disjoint switch trees. This is counter-productive because it wastes 1Gbps of autonomous forwarding throughput between switch 0 and 1. - Treat sw0p4 and sw1p4 as user ports instead of DSA links. This could work, but it makes cross-chip bridging impossible. In this setup we would need to have 2 separate bridges, br0 spanning the ports of switch 0, and br1 spanning the ports of switch 1, and the "DSA links treated as user ports" sw0p4 (part of br0) and sw1p4 (part of br1) are the gateway ports between one bridge and another. This is hard to manage from a user's perspective, who wants to have a unified view of the switching fabric and the ability to transparently add ports to the same bridge. VLANs would also need to be explicitly managed by the user on these gateway ports. So it seems that the only reasonable thing to do is to make DSA prefer CPU ports that are local to the switch. Meaning that by default, the user and DSA ports of switch 0 will get assigned to the CPU port from switch 0 (sw0p1) and the user and DSA ports of switch 1 will get assigned to the CPU port from switch 1. The way this solves the problem is that sw1p4 is no longer an upstream port as far as switch 1 is concerned (it no longer views sw0p1 as its dedicated CPU port). So here we are, the first multi-CPU port that DSA supports is also perhaps the most uneventful one: the individual switches don't support multiple CPUs, however the DSA switch tree as a whole does have multiple CPU ports. No user space assignment of user ports to CPU ports is desirable, necessary, or possible. Ports that do not have a local CPU port (say there was an extra switch hanging off of sw0p0) default to the standard implementation of getting assigned to the first CPU port of the DSA switch tree. Is that good enough? Probably not (if the downstream switch was hanging off of switch 1, we would most certainly prefer its CPU port to be sw1p1), but in order to support that use case too, we would need to traverse the dst->rtable in search of an optimum dedicated CPU port, one that has the smallest number of hops between dp->ds and dp->cpu_dp->ds. At the moment, the DSA routing table structure does not keep the number of hops between dl->dp and dl->link_dp, and while it is probably deducible, there is zero justification to write that code now. Let's hope DSA will never have to support that use case. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05net: dsa: rename teardown_default_cpu to teardown_cpu_portsVladimir Oltean
There is nothing specific to having a default CPU port to what dsa_tree_teardown_default_cpu() does. Even with multiple CPU ports, it would do the same thing: iterate through the ports of this switch tree and reset the ->cpu_dp pointer to NULL. So rename it accordingly. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-23net: dsa: add support for bridge TX forwarding offloadVladimir Oltean
For a DSA switch, to offload the forwarding process of a bridge device means to send the packets coming from the software bridge as data plane packets. This is contrary to everything that DSA has done so far, because the current taggers only know to send control packets (ones that target a specific destination port), whereas data plane packets are supposed to be forwarded according to the FDB lookup, much like packets ingressing on any regular ingress port. If the FDB lookup process returns multiple destination ports (flooding, multicast), then replication is also handled by the switch hardware - the bridge only sends a single packet and avoids the skb_clone(). DSA keeps for each bridge port a zero-based index (the number of the bridge). Multiple ports performing TX forwarding offload to the same bridge have the same dp->bridge_num value, and ports not offloading the TX data plane of a bridge have dp->bridge_num = -1. The tagger can check if the packet that is being transmitted on has skb->offload_fwd_mark = true or not. If it does, it can be sure that the packet belongs to the data plane of a bridge, further information about which can be obtained based on dp->bridge_dev and dp->bridge_num. It can then compose a DSA tag for injecting a data plane packet into that bridge number. For the switch driver side, we offer two new dsa_switch_ops methods, called .port_bridge_fwd_offload_{add,del}, which are modeled after .port_bridge_{join,leave}. These methods are provided in case the driver needs to configure the hardware to treat packets coming from that bridge software interface as data plane packets. The switchdev <-> bridge interaction happens during the netdev_master_upper_dev_link() call, so to switch drivers, the effect is that the .port_bridge_fwd_offload_add() method is called immediately after .port_bridge_join(). If the bridge number exceeds the number of bridges for which the switch driver can offload the TX data plane (and this includes the case where the driver can offload none), DSA falls back to simply returning tx_fwd_offload = false in the switchdev_bridge_port_offload() call. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-23net: dsa: track the number of switches in a treeVladimir Oltean
In preparation of supporting data plane forwarding on behalf of a software bridge, some drivers might need to view bridges as virtual switches behind the CPU port in a cross-chip topology. Give them some help and let them know how many physical switches there are in the tree, so that they can count the virtual switches starting from that number on. Note that the first dsa_switch_ops method where this information is reliably available is .setup(). This is because of how DSA works: in a tree with 3 switches, each calling dsa_register_switch(), the first 2 will advance until dsa_tree_setup() -> dsa_tree_setup_routing_table() and exit with error code 0 because the topology is not complete. Since probing is parallel at this point, one switch does not know about the existence of the other. Then the third switch comes, and for it, dsa_tree_setup_routing_table() returns complete = true. This switch goes ahead and calls dsa_tree_setup_switches() for everybody else, calling their .setup() methods too. This acts as the synchronization point. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29net: dsa: reference count the FDB addresses at the cross-chip notifier levelVladimir Oltean
The same concerns expressed for host MDB entries are valid for host FDBs just as well: - in the case of multiple bridges spanning the same switch chip, deleting a host FDB entry that belongs to one bridge will result in breakage to the other bridge - not deleting FDB entries across DSA links means that the switch's hardware tables will eventually run out, given enough wear&tear So do the same thing and introduce reference counting for CPU ports and DSA links using the same data structures as we have for MDB entries. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29net: dsa: reference count the MDB entries at the cross-chip notifier levelVladimir Oltean
Ever since the cross-chip notifiers were introduced, the design was meant to be simplistic and just get the job done without worrying too much about dangling resources left behind. For example, somebody installs an MDB entry on sw0p0 in this daisy chain topology. It gets installed using ds->ops->port_mdb_add() on sw0p0, sw1p4 and sw2p4. | sw0p0 sw0p1 sw0p2 sw0p3 sw0p4 [ user ] [ user ] [ user ] [ dsa ] [ cpu ] [ x ] [ ] [ ] [ ] [ ] | +---------+ | sw1p0 sw1p1 sw1p2 sw1p3 sw1p4 [ user ] [ user ] [ user ] [ dsa ] [ dsa ] [ ] [ ] [ ] [ ] [ x ] | +---------+ | sw2p0 sw2p1 sw2p2 sw2p3 sw2p4 [ user ] [ user ] [ user ] [ user ] [ dsa ] [ ] [ ] [ ] [ ] [ x ] Then the same person deletes that MDB entry. The cross-chip notifier for deletion only matches sw0p0: | sw0p0 sw0p1 sw0p2 sw0p3 sw0p4 [ user ] [ user ] [ user ] [ dsa ] [ cpu ] [ x ] [ ] [ ] [ ] [ ] | +---------+ | sw1p0 sw1p1 sw1p2 sw1p3 sw1p4 [ user ] [ user ] [ user ] [ dsa ] [ dsa ] [ ] [ ] [ ] [ ] [ ] | +---------+ | sw2p0 sw2p1 sw2p2 sw2p3 sw2p4 [ user ] [ user ] [ user ] [ user ] [ dsa ] [ ] [ ] [ ] [ ] [ ] Why? Because the DSA links are 'trunk' ports, if we just go ahead and delete the MDB from sw1p4 and sw2p4 directly, we might delete those multicast entries when they are still needed. Just consider the fact that somebody does: - add a multicast MAC address towards sw0p0 [ via the cross-chip notifiers it gets installed on the DSA links too ] - add the same multicast MAC address towards sw0p1 (another port of that same switch) - delete the same multicast MAC address from sw0p0. At this point, if we deleted the MAC address from the DSA links, it would be flooded, even though there is still an entry on switch 0 which needs it not to. So that is why deletions only match the targeted source port and nothing on DSA links. Of course, dangling resources means that the hardware tables will eventually run out given enough additions/removals, but hey, at least it's simple. But there is a bigger concern which needs to be addressed, and that is our support for SWITCHDEV_OBJ_ID_HOST_MDB. DSA simply translates such an object into a dsa_port_host_mdb_add() which ends up as ds->ops->port_mdb_add() on the upstream port, and a similar thing happens on deletion: dsa_port_host_mdb_del() will trigger ds->ops->port_mdb_del() on the upstream port. When there are 2 VLAN-unaware bridges spanning the same switch (which is a use case DSA proudly supports), each bridge will install its own SWITCHDEV_OBJ_ID_HOST_MDB entries. But upon deletion, DSA goes ahead and emits a DSA_NOTIFIER_MDB_DEL for dp->cpu_dp, which is shared between the user ports enslaved to br0 and the user ports enslaved to br1. Not good. The host-trapped multicast addresses installed by br1 will be deleted when any state changes in br0 (IGMP timers expire, or ports leave, etc). To avoid this, we could of course go the route of the zero-sum game and delete the DSA_NOTIFIER_MDB_DEL call for dp->cpu_dp. But the better design is to just admit that on shared ports like DSA links and CPU ports, we should be reference counting calls, even if this consumes some dynamic memory which DSA has traditionally avoided. On the flip side, the hardware tables of switches are limited in size, so it would be good if the OS managed them properly instead of having them eventually overflow. To address the memory usage concern, we only apply the refcounting of MDB entries on ports that are really shared (CPU ports and DSA links) and not on user ports. In a typical single-switch setup, this means only the CPU port (and the host MDB entries are not that many, really). The name of the newly introduced data structures (dsa_mac_addr) is chosen in such a way that will be reusable for host FDB entries (next patch). With this change, we can finally have the same matching logic for the MDB additions and deletions, as well as for their host-trapped variants. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-21net: dsa: export the dsa_port_is_{user,cpu,dsa} helpersVladimir Oltean
The difference between dsa_is_user_port and dsa_port_is_user is that the former needs to look up the list of ports of the DSA switch tree in order to find the struct dsa_port, while the latter directly receives it as an argument. dsa_is_user_port is already in widespread use and has its place, so there isn't any chance of converting all callers to a single form. But being able to do: dsa_port_is_user(dp) instead of dsa_is_user_port(dp->ds, dp->index) is much more efficient too, especially when the "dp" comes from an iterator over the DSA switch tree - this reduces the complexity from quadratic to linear. Move these helpers from dsa2.c to include/net/dsa.h so that others can use them too. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-21net: dsa: assert uniqueness of dsa,member propertiesVladimir Oltean
The cross-chip notifiers work by comparing each ds->index against the info->sw_index value from the notifier. The ds->index is retrieved from the device tree dsa,member property. If a single tree cross-chip topology does not declare unique switch IDs, this will result in hard-to-debug issues/voodoo effects such as the cross-chip notifier for one switch port also matching the port with the same number from another switch. Check in dsa_switch_parse_member_of() whether the DSA switch tree contains a DSA switch with the index we're preparing to add, before actually adding it. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-20net: dsa: Allow default tag protocol to be overridden from DTTobias Waldekranz
Some combinations of tag protocols and Ethernet controllers are incompatible, and it is hard for the driver to keep track of these. Therefore, allow the device tree author (typically the board vendor) to inform the driver of this fact by selecting an alternate protocol that is known to work. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-13of: net: pass the dst buffer to of_get_mac_address()Michael Walle
of_get_mac_address() returns a "const void*" pointer to a MAC address. Lately, support to fetch the MAC address by an NVMEM provider was added. But this will only work with platform devices. It will not work with PCI devices (e.g. of an integrated root complex) and esp. not with DSA ports. There is an of_* variant of the nvmem binding which works without devices. The returned data of a nvmem_cell_read() has to be freed after use. On the other hand the return of_get_mac_address() points to some static data without a lifetime. The trick for now, was to allocate a device resource managed buffer which is then returned. This will only work if we have an actual device. Change it, so that the caller of of_get_mac_address() has to supply a buffer where the MAC address is written to. Unfortunately, this will touch all drivers which use the of_get_mac_address(). Usually the code looks like: const char *addr; addr = of_get_mac_address(np); if (!IS_ERR(addr)) ether_addr_copy(ndev->dev_addr, addr); This can then be simply rewritten as: of_get_mac_address(np, ndev->dev_addr); Sometimes is_valid_ether_addr() is used to test the MAC address. of_get_mac_address() already makes sure, it just returns a valid MAC address. Thus we can just test its return code. But we have to be careful if there are still other sources for the MAC address before the of_get_mac_address(). In this case we have to keep the is_valid_ether_addr() call. The following coccinelle patch was used to convert common cases to the new style. Afterwards, I've manually gone over the drivers and fixed the return code variable: either used a new one or if one was already available use that. Mansour Moufid, thanks for that coccinelle patch! <spml> @a@ identifier x; expression y, z; @@ - x = of_get_mac_address(y); + x = of_get_mac_address(y, z); <... - ether_addr_copy(z, x); ...> @@ identifier a.x; @@ - if (<+... x ...+>) {} @@ identifier a.x; @@ if (<+... x ...+>) { ... } - else {} @@ identifier a.x; expression e; @@ - if (<+... x ...+>@e) - {} - else + if (!(e)) {...} @@ expression x, y, z; @@ - x = of_get_mac_address(y, z); + of_get_mac_address(y, z); ... when != x </spml> All drivers, except drivers/net/ethernet/aeroflex/greth.c, were compile-time tested. Suggested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Michael Walle <michael@walle.cc> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-29net: dsa: Fix type was not set for devlink portMaxim Kochetkov
If PHY is not available on DSA port (described at devicetree but absent or failed to detect) then kernel prints warning after 3700 secs: [ 3707.948771] ------------[ cut here ]------------ [ 3707.948784] Type was not set for devlink port. [ 3707.948894] WARNING: CPU: 1 PID: 17 at net/core/devlink.c:8097 0xc083f9d8 We should unregister the devlink port as a user port and re-register it as an unused port before executing "continue" in case of dsa_port_setup error. Fixes: 86f8b1c01a0a ("net: dsa: Do not make user port errors fatal") Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-22net: dsa: don't assign an error value to tag_opsGeorge McCollister
Use a temporary variable to hold the return value from dsa_tag_driver_get() instead of assigning it to dst->tag_ops. Leaving an error value in dst->tag_ops can result in deferencing an invalid pointer when a deferred switch configuration happens later. Fixes: 357f203bb3b5 ("net: dsa: keep a copy of the tagging protocol in the DSA switch tree") Signed-off-by: George McCollister <george.mccollister@gmail.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
2021-02-04net: dsa: call teardown method on probe failureVladimir Oltean
Since teardown is supposed to undo the effects of the setup method, it should be called in the error path for dsa_switch_setup, not just in dsa_switch_teardown. Fixes: 5e3f847a02aa ("net: dsa: Add teardown callback for drivers") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20210204163351.2929670-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29net: dsa: allow changing the tag protocol via the "tagging" device attributeVladimir Oltean
Currently DSA exposes the following sysfs: $ cat /sys/class/net/eno2/dsa/tagging ocelot which is a read-only device attribute, introduced in the kernel as commit 98cdb4807123 ("net: dsa: Expose tagging protocol to user-space"), and used by libpcap since its commit 993db3800d7d ("Add support for DSA link-layer types"). It would be nice if we could extend this device attribute by making it writable: $ echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging This is useful with DSA switches that can make use of more than one tagging protocol. It may be useful in dsa_loop in the future too, to perform offline testing of various taggers, or for changing between dsa and edsa on Marvell switches, if that is desirable. In terms of implementation, drivers can support this feature by implementing .change_tag_protocol, which should always leave the switch in a consistent state: either with the new protocol if things went well, or with the old one if something failed. Teardown of the old protocol, if necessary, must be handled by the driver. Some things remain as before: - The .get_tag_protocol is currently only called at probe time, to load the initial tagging protocol driver. Nonetheless, new drivers should report the tagging protocol in current use now. - The driver should manage by itself the initial setup of tagging protocol, no later than the .setup() method, as well as destroying resources used by the last tagger in use, no earlier than the .teardown() method. For multi-switch DSA trees, error handling is a bit more complicated, since e.g. the 5th out of 7 switches may fail to change the tag protocol. When that happens, a revert to the original tag protocol is attempted, but that may fail too, leaving the tree in an inconsistent state despite each individual switch implementing .change_tag_protocol transactionally. Since the intersection between drivers that implement .change_tag_protocol and drivers that support D in DSA is currently the empty set, the possibility for this error to happen is ignored for now. Testing: $ insmod mscc_felix.ko [ 79.549784] mscc_felix 0000:00:00.5: Adding to iommu group 14 [ 79.565712] mscc_felix 0000:00:00.5: Failed to register DSA switch: -517 $ insmod tag_ocelot.ko $ rmmod mscc_felix.ko $ insmod mscc_felix.ko [ 97.261724] libphy: VSC9959 internal MDIO bus: probed [ 97.267363] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 0 [ 97.274998] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 1 [ 97.282561] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 2 [ 97.289700] mscc_felix 0000:00:00.5: Found PCS at internal MDIO address 3 [ 97.599163] mscc_felix 0000:00:00.5 swp0 (uninitialized): PHY [0000:00:00.3:10] driver [Microsemi GE VSC8514 SyncE] (irq=POLL) [ 97.862034] mscc_felix 0000:00:00.5 swp1 (uninitialized): PHY [0000:00:00.3:11] driver [Microsemi GE VSC8514 SyncE] (irq=POLL) [ 97.950731] mscc_felix 0000:00:00.5 swp0: configuring for inband/qsgmii link mode [ 97.964278] 8021q: adding VLAN 0 to HW filter on device swp0 [ 98.146161] mscc_felix 0000:00:00.5 swp2 (uninitialized): PHY [0000:00:00.3:12] driver [Microsemi GE VSC8514 SyncE] (irq=POLL) [ 98.238649] mscc_felix 0000:00:00.5 swp1: configuring for inband/qsgmii link mode [ 98.251845] 8021q: adding VLAN 0 to HW filter on device swp1 [ 98.433916] mscc_felix 0000:00:00.5 swp3 (uninitialized): PHY [0000:00:00.3:13] driver [Microsemi GE VSC8514 SyncE] (irq=POLL) [ 98.485542] mscc_felix 0000:00:00.5: configuring for fixed/internal link mode [ 98.503584] mscc_felix 0000:00:00.5: Link is Up - 2.5Gbps/Full - flow control rx/tx [ 98.527948] device eno2 entered promiscuous mode [ 98.544755] DSA: tree 0 setup $ ping 10.0.0.1 PING 10.0.0.1 (10.0.0.1): 56 data bytes 64 bytes from 10.0.0.1: seq=0 ttl=64 time=2.337 ms 64 bytes from 10.0.0.1: seq=1 ttl=64 time=0.754 ms ^C - 10.0.0.1 ping statistics - 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.754/1.545/2.337 ms $ cat /sys/class/net/eno2/dsa/tagging ocelot $ cat ./test_ocelot_8021q.sh #!/bin/bash ip link set swp0 down ip link set swp1 down ip link set swp2 down ip link set swp3 down ip link set swp5 down ip link set eno2 down echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging ip link set eno2 up ip link set swp0 up ip link set swp1 up ip link set swp2 up ip link set swp3 up ip link set swp5 up $ ./test_ocelot_8021q.sh ./test_ocelot_8021q.sh: line 9: echo: write error: Protocol not available $ rmmod tag_ocelot.ko rmmod: can't unload module 'tag_ocelot': Resource temporarily unavailable $ insmod tag_ocelot_8021q.ko $ ./test_ocelot_8021q.sh $ cat /sys/class/net/eno2/dsa/tagging ocelot-8021q $ rmmod tag_ocelot.ko $ rmmod tag_ocelot_8021q.ko rmmod: can't unload module 'tag_ocelot_8021q': Resource temporarily unavailable $ ping 10.0.0.1 PING 10.0.0.1 (10.0.0.1): 56 data bytes 64 bytes from 10.0.0.1: seq=0 ttl=64 time=0.953 ms 64 bytes from 10.0.0.1: seq=1 ttl=64 time=0.787 ms 64 bytes from 10.0.0.1: seq=2 ttl=64 time=0.771 ms $ rmmod mscc_felix.ko [ 645.544426] mscc_felix 0000:00:00.5: Link is Down [ 645.838608] DSA: tree 0 torn down $ rmmod tag_ocelot_8021q.ko Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29net: dsa: keep a copy of the tagging protocol in the DSA switch treeVladimir Oltean
Cascading DSA switches can be done multiple ways. There is the brute force approach / tag stacking, where one upstream switch, located between leaf switches and the host Ethernet controller, will just happily transport the DSA header of those leaf switches as payload. For this kind of setups, DSA works without any special kind of treatment compared to a single switch - they just aren't aware of each other. Then there's the approach where the upstream switch understands the tags it transports from its leaves below, as it doesn't push a tag of its own, but it routes based on the source port & switch id information present in that tag (as opposed to DMAC & VID) and it strips the tag when egressing a front-facing port. Currently only Marvell implements the latter, and Marvell DSA trees contain only Marvell switches. So it is safe to say that DSA trees already have a single tag protocol shared by all switches, and in fact this is what makes the switches able to understand each other. This fact is also implied by the fact that currently, the tagging protocol is reported as part of a sysfs installed on the DSA master and not per port, so it must be the same for all the ports connected to that DSA master regardless of the switch that they belong to. It's time to make this official and enforce it (yes, this also means we won't have any "switch understands tag to some extent but is not able to speak it" hardware oddities that we'll support in the future). This is needed due to the imminent introduction of the dsa_switch_ops:: change_tag_protocol driver API. When that is introduced, we'll have to notify switches of the tagging protocol that they're configured to use. Currently the tag_ops structure pointer is held only for CPU ports. But there are switches which don't have CPU ports and nonetheless still need to be configured. These would be Marvell leaf switches whose upstream port is just a DSA link. How do we inform these of their tagging protocol setup/deletion? One answer to the above would be: iterate through the DSA switch tree's ports once, list the CPU ports, get their tag_ops, then iterate again now that we have it, and notify everybody of that tag_ops. But what to do if conflicts appear between one cpu_dp->tag_ops and another? There's no escaping the fact that conflict resolution needs to be done, so we can be upfront about it. Ease our work and just keep the master copy of the tag_ops inside the struct dsa_switch_tree. Reference counting is now moved to be per-tree too, instead of per-CPU port. There are many places in the data path that access master->dsa_ptr->tag_ops and we would introduce unnecessary performance penalty going through yet another indirection, so keep those right where they are. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-29net: dsa: document the existing switch tree notifiers and add a new oneVladimir Oltean
The existence of dsa_broadcast has generated some confusion in the past: https://www.mail-archive.com/netdev@vger.kernel.org/msg365042.html So let's document the existing dsa_port_notify and dsa_broadcast functions and explain when each of them should be used. Also, in fact, the in-between function has always been there but was lacking a name, and is the main reason for this patch: dsa_tree_notify. Refactor dsa_broadcast to use it. This patch also moves dsa_broadcast (a top-level function) to dsa2.c, where it really belonged in the first place, but had no companion so it stood with dsa_port_notify. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15net: dsa: add ops for devlink-sbVladimir Oltean
Switches that care about QoS might have hardware support for reserving buffer pools for individual ports or traffic classes, and configuring their sizes and thresholds. Through devlink-sb (shared buffers), this is all configurable, as well as their occupancy being viewable. Add the plumbing in DSA for these operations. Individual drivers still need to call devlink_sb_register() with the shared buffers they want to expose. A helper was not created in DSA for this purpose (unlike, say, dsa_devlink_params_register), since in my opinion it does not bring any benefit over plainly calling devlink_sb_register() directly. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15net: dsa: set configure_vlan_while_not_filtering to true by defaultVladimir Oltean
As explained in commit 54a0ed0df496 ("net: dsa: provide an option for drivers to always receive bridge VLANs"), DSA has historically been skipping VLAN switchdev operations when the bridge wasn't in vlan_filtering mode, but the reason why it was doing that has never been clear. So the configure_vlan_while_not_filtering option is there merely to preserve functionality for existing drivers. It isn't some behavior that drivers should opt into. Ideally, when all drivers leave this flag set, we can delete the dsa_port_skip_vlan_configuration() function. New drivers always seem to omit setting this flag, for some reason. So let's reverse the logic: the DSA core sets it by default to true before the .setup() callback, and legacy drivers can turn it off. This way, new drivers get the new behavior by default, unless they explicitly set the flag to false, which is more obvious during review. Remove the assignment from drivers which were setting it to true, and add the assignment to false for the drivers that didn't previously have it. This way, it should be easier to see how many we have left. The following drivers: lan9303, mv88e6060 were skipped from setting this flag to false, because they didn't have any VLAN offload ops in the first place. The Broadcom Starfighter 2 driver calls the common b53_switch_alloc and therefore also inherits the configure_vlan_while_not_filtering=true behavior. Also, print a message through netlink extack every time a VLAN has been skipped. This is mildly annoying on purpose, so that (a) it is at least clear that VLANs are being skipped - the legacy behavior in itself is confusing, and the extack should be much more difficult to miss, unlike kernel logs - and (b) people have one more incentive to convert to the new behavior. No behavior change except for the added prints is intended at this time. $ ip link add br0 type bridge vlan_filtering 0 $ ip link set sw0p2 master br0 [ 60.315148] br0: port 1(sw0p2) entered blocking state [ 60.320350] br0: port 1(sw0p2) entered disabled state [ 60.327839] device sw0p2 entered promiscuous mode [ 60.334905] br0: port 1(sw0p2) entered blocking state [ 60.340142] br0: port 1(sw0p2) entered forwarding state Warning: dsa_core: skipping configuration of VLAN. # This was the pvid $ bridge vlan add dev sw0p2 vid 100 Warning: dsa_core: skipping configuration of VLAN. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20210115231919.43834-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-14net: dsa: Link aggregation supportTobias Waldekranz
Monitor the following events and notify the driver when: - A DSA port joins/leaves a LAG. - A LAG, made up of DSA ports, joins/leaves a bridge. - A DSA port in a LAG is enabled/disabled (enabled meaning "distributing" in 802.3ad LACP terms). When a LAG joins a bridge, the DSA subsystem will treat that as each individual port joining the bridge. The driver may look at the port's LAG device pointer to see if it is associated with any LAG, if that is required. This is analogue to how switchdev events are replicated out to all lower devices when reaching e.g. a LAG. Drivers can optionally request that DSA maintain a linear mapping from a LAG ID to the corresponding netdev by setting ds->num_lag_ids to the desired size. In the event that the hardware is not capable of offloading a particular LAG for any reason (the typical case being use of exotic modes like broadcast), DSA will take a hands-off approach, allowing the LAG to be formed as a pure software construct. This is reported back through the extended ACK, but is otherwise transparent to the user. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-12net: dsa: clear devlink port type before unregistering slave netdevsVladimir Oltean
Florian reported a use-after-free bug in devlink_nl_port_fill found with KASAN: (devlink_nl_port_fill) (devlink_port_notify) (devlink_port_unregister) (dsa_switch_teardown.part.3) (dsa_tree_teardown_switches) (dsa_unregister_switch) (bcm_sf2_sw_remove) (platform_remove) (device_release_driver_internal) (device_links_unbind_consumers) (device_release_driver_internal) (device_driver_detach) (unbind_store) Allocated by task 31: alloc_netdev_mqs+0x5c/0x50c dsa_slave_create+0x110/0x9c8 dsa_register_switch+0xdb0/0x13a4 b53_switch_register+0x47c/0x6dc bcm_sf2_sw_probe+0xaa4/0xc98 platform_probe+0x90/0xf4 really_probe+0x184/0x728 driver_probe_device+0xa4/0x278 __device_attach_driver+0xe8/0x148 bus_for_each_drv+0x108/0x158 Freed by task 249: free_netdev+0x170/0x194 dsa_slave_destroy+0xac/0xb0 dsa_port_teardown.part.2+0xa0/0xb4 dsa_tree_teardown_switches+0x50/0xc4 dsa_unregister_switch+0x124/0x250 bcm_sf2_sw_remove+0x98/0x13c platform_remove+0x44/0x5c device_release_driver_internal+0x150/0x254 device_links_unbind_consumers+0xf8/0x12c device_release_driver_internal+0x84/0x254 device_driver_detach+0x30/0x34 unbind_store+0x90/0x134 What happens is that devlink_port_unregister emits a netlink DEVLINK_CMD_PORT_DEL message which associates the devlink port that is getting unregistered with the ifindex of its corresponding net_device. Only trouble is, the net_device has already been unregistered. It looks like we can stub out the search for a corresponding net_device if we clear the devlink_port's type. This looks like a bit of a hack, but also seems to be the reason why the devlink_port_type_clear function exists in the first place. Fixes: 3122433eb533 ("net: dsa: Register devlink ports before calling DSA driver setup()") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Florian fainelli <f.fainelli@gmail.com> Reported-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20210112004831.3778323-1-olteanv@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-06net: dsa: print error on invalid port indexRafał Miłecki
Looking for an -EINVAL all over the dsa code could take hours for inexperienced DSA users. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20210106090915.21439-1-zajec5@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-04net: dsa: Register devlink ports before calling DSA driver setup()Andrew Lunn
DSA drivers want to create regions on devlink ports as well as the devlink device instance, in order to export registers and other tables per port. To keep all this code together in the drivers, have the devlink ports registered early, so the setup() method can setup both device and port devlink regions. v3: Remove dp->setup Move common code out of switch statement. Fix wrong goto Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-04net: dsa: Make use of devlink port flavour unusedAndrew Lunn
If a port is unused, still create a devlink port for it, but set the flavour to unused. This allows us to attach devlink regions to the port, etc. Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-18net: dsa: wire up devlink info getAndrew Lunn
Allow the DSA drivers to implement the devlink call to get info info, e.g. driver name, firmware version, ASIC ID, etc. v2: Combine declaration and the assignment on a single line. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22net: dsa: of: Allow ethernet-ports as encapsulating nodeKurt Kanzenbach
Due to unified Ethernet Switch Device Tree Bindings allow for ethernet-ports as encapsulating node as well. Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-09devlink: Replace devlink_port_attrs_set parameters with a structDanielle Ratson
Currently, devlink_port_attrs_set accepts a long list of parameters, that most of them are devlink port's attributes. Use the devlink_port_attrs struct to replace the relevant parameters. Signed-off-by: Danielle Ratson <danieller@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-10net: dsa: introduce a dsa_switch_find functionVladimir Oltean
Somewhat similar to dsa_tree_find, dsa_switch_find returns a dsa_switch structure pointer by searching for its tree index and switch index (the parameters from dsa,member). To be used, for example, by drivers who implement .crosschip_bridge_join and need a reference to the other switch indicated to by the tree_index and sw_index arguments. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-04net: dsa: Do not make user port errors fatalFlorian Fainelli
Prior to 1d27732f411d ("net: dsa: setup and teardown ports"), we would not treat failures to set-up an user port as fatal, but after this commit we would, which is a regression for some systems where interfaces may be declared in the Device Tree, but the underlying hardware may not be present (pluggable daughter cards for instance). Fixes: 1d27732f411d ("net: dsa: setup and teardown ports") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-27net: dsa: implement auto-normalization of MTU for bridge hardware datapathVladimir Oltean
Many switches don't have an explicit knob for configuring the MTU (maximum transmission unit per interface). Instead, they do the length-based packet admission checks on the ingress interface, for reasons that are easy to understand (why would you accept a packet in the queuing subsystem if you know you're going to drop it anyway). So it is actually the MRU that these switches permit configuring. In Linux there only exists the IFLA_MTU netlink attribute and the associated dev_set_mtu function. The comments like to play blind and say that it's changing the "maximum transfer unit", which is to say that there isn't any directionality in the meaning of the MTU word. So that is the interpretation that this patch is giving to things: MTU == MRU. When 2 interfaces having different MTUs are bridged, the bridge driver MTU auto-adjustment logic kicks in: what br_mtu_auto_adjust() does is it adjusts the MTU of the bridge net device itself (and not that of the slave net devices) to the minimum value of all slave interfaces, in order for forwarded packets to not exceed the MTU regardless of the interface they are received and send on. The idea behind this behavior, and why the slave MTUs are not adjusted, is that normal termination from Linux over the L2 forwarding domain should happen over the bridge net device, which _is_ properly limited by the minimum MTU. And termination over individual slave devices is possible even if those are bridged. But that is not "forwarding", so there's no reason to do normalization there, since only a single interface sees that packet. The problem with those switches that can only control the MRU is with the offloaded data path, where a packet received on an interface with MRU 9000 would still be forwarded to an interface with MRU 1500. And the br_mtu_auto_adjust() function does not really help, since the MTU configured on the bridge net device is ignored. In order to enforce the de-facto MTU == MRU rule for these switches, we need to do MTU normalization, which means: in order for no packet larger than the MTU configured on this port to be sent, then we need to limit the MRU on all ports that this packet could possibly come from. AKA since we are configuring the MRU via MTU, it means that all ports within a bridge forwarding domain should have the same MTU. And that is exactly what this patch is trying to do. >From an implementation perspective, we try to follow the intent of the user, otherwise there is a risk that we might livelock them (they try to change the MTU on an already-bridged interface, but we just keep changing it back in an attempt to keep the MTU normalized). So the MTU that the bridge is normalized to is either: - The most recently changed one: ip link set dev swp0 master br0 ip link set dev swp1 master br0 ip link set dev swp0 mtu 1400 This sequence will make swp1 inherit MTU 1400 from swp0. - The one of the most recently added interface to the bridge: ip link set dev swp0 master br0 ip link set dev swp1 mtu 1400 ip link set dev swp1 master br0 The above sequence will make swp0 inherit MTU 1400 as well. Suggested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-27net: dsa: Fix use-after-free in probing of DSA switch treeVladimir Oltean
DSA sets up a switch tree little by little. Every switch of the N members of the tree calls dsa_register_switch, and (N - 1) will just touch the dst->ports list with their ports and quickly exit. Only the last switch that calls dsa_register_switch will find all DSA links complete in dsa_tree_setup_routing_table, and not return zero as a result but instead go ahead and set up the entire DSA switch tree (practically on behalf of the other switches too). The trouble is that the (N - 1) switches don't clean up after themselves after they get an error such as EPROBE_DEFER. Their footprint left in dst->ports by dsa_switch_touch_ports is still there. And switch N, the one responsible with actually setting up the tree, is going to work with those stale dp, dp->ds and dp->ds->dev pointers. In particular ds and ds->dev might get freed by the device driver. Be there a 2-switch tree and the following calling order: - Switch 1 calls dsa_register_switch - Calls dsa_switch_touch_ports, populates dst->ports - Calls dsa_port_parse_cpu, gets -EPROBE_DEFER, exits. - Switch 2 calls dsa_register_switch - Calls dsa_switch_touch_ports, populates dst->ports - Probe doesn't get deferred, so it goes ahead. - Calls dsa_tree_setup_routing_table, which returns "complete == true" due to Switch 1 having called dsa_switch_touch_ports before. - Because the DSA links are complete, it calls dsa_tree_setup_switches now. - dsa_tree_setup_switches iterates through dst->ports, initializing the Switch 1 ds structure (invalid) and the Switch 2 ds structure (valid). - Undefined behavior (use after free, sometimes NULL pointers, etc). Real example below (debugging prints added by me, as well as guards against NULL pointers): [ 5.477947] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.313002] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.319932] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.329693] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.339458] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.349226] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.358991] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.368758] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.378524] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.388291] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.398057] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803df0b980 (dev ffffff803f775c00) [ 6.407912] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.417682] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.427446] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.437212] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.446979] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.456744] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.466512] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.476277] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.486043] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.495810] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.505577] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803da02f80 (dev 0000000000000000) [ 6.515433] dsa_tree_setup_switches: Setting up port 0 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.354120] dsa_tree_setup_switches: Setting up port 1 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.361045] dsa_tree_setup_switches: Setting up port 2 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.370805] dsa_tree_setup_switches: Setting up port 3 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.380571] dsa_tree_setup_switches: Setting up port 4 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.390337] dsa_tree_setup_switches: Setting up port 5 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.400104] dsa_tree_setup_switches: Setting up port 6 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.409872] dsa_tree_setup_switches: Setting up port 7 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.419637] dsa_tree_setup_switches: Setting up port 8 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.429403] dsa_tree_setup_switches: Setting up port 9 of switch ffffff803db15b80 (dev ffffff803d8e4800) [ 7.439169] dsa_tree_setup_switches: Setting up port 10 of switch ffffff803db15b80 (dev ffffff803d8e4800) The solution is to recognize that the functions that call dsa_switch_touch_ports (dsa_switch_parse_of, dsa_switch_parse) have side effects, and therefore one should clean up their side effects on error path. The cleanup of dst->ports was taken from dsa_switch_remove and moved into a dedicated dsa_switch_release_ports function, which should really be per-switch (free only the members of dst->ports that are also members of ds, instead of all switch ports). Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08net: dsa: Get information about stacked DSA protocolFlorian Fainelli
It is possible to stack multiple DSA switches in a way that they are not part of the tree (disjoint) but the DSA master of a switch is a DSA slave of another. When that happens switch drivers may have to know this is the case so as to determine whether their tagging protocol has a remove chance of working. This is useful for specific switch drivers such as b53 where devices have been known to be stacked in the wild without the Broadcom tag protocol supporting that feature. This allows b53 to continue supporting those devices by forcing the disabling of Broadcom tags on the outermost switches if necessary. The get_tag_protocol() function is therefore updated to gain an additional enum dsa_tag_protocol argument which denotes the current tagging protocol used by the DSA master we are attached to, else DSA_TAG_PROTO_NONE for the top of the dsa_switch_tree. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17net: dsa: make unexported dsa_link_touch() staticBen Dooks (Codethink)
dsa_link_touch() is not exported, or defined outside of the file it is in so make it static to avoid the following warning: net/dsa/dsa2.c:127:17: warning: symbol 'dsa_link_touch' was not declared. Should it be static? Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-05net: dsa: Fix use after free in dsa_switch_remove()Florian Fainelli
The order in which the ports are deleted from the list and freed and the call to dsa_switch_remove() is done is reversed, which leads to an use after free condition. Reverse the two: first tear down the ports and switch from the fabric, then free the ports associated with that switch fabric. Fixes: 05f294a85235 ("net: dsa: allocate ports on touch") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31net: dsa: remove limitation of switch index valueVivien Didelot
Because there is no static array describing the links between switches anymore, we have no reason to force a limitation of the index value set by the device tree. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31net: dsa: remove tree functions related to switchesVivien Didelot
The DSA fabric setup code has been simplified a lot so get rid of the dsa_tree_remove_switch, dsa_tree_add_switch and dsa_switch_add helpers, and keep the code simple with only the dsa_switch_probe and dsa_switch_remove functions. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31net: dsa: remove the dst->ds arrayVivien Didelot
Now that the DSA ports are listed in the switch fabric, there is no need to store the dsa_switch structures from the drivers in the fabric anymore. So get rid of the dst->ds static array. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31net: dsa: remove switch routing table setup codeVivien Didelot
The dsa_switch structure has no routing table specific data to setup, so the switch fabric can directly walk its ports and initialize its routing table from them. This allows us to remove the dsa_switch_setup_routing_table function. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31net: dsa: remove ds->rtableVivien Didelot
Drivers do not use the ds->rtable static arrays anymore, get rid of it. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31net: dsa: list DSA links in the fabricVivien Didelot
Implement a new list of DSA links in the switch fabric itself, to provide an alterative to the ds->rtable static arrays. At the same time, provide a new dsa_routing_port() helper to abstract the usage of ds->rtable in drivers. If there's no port to reach a given device, return the first invalid port, ds->num_ports. This avoids potential signedness errors or the need to define special values. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28net: dsa: Add support for devlink device parametersAndrew Lunn
Add plumbing to allow DSA drivers to register parameters with devlink. To keep with the abstraction, the DSA drivers pass the ds structure to these helpers, and the DSA core then translates that to the devlink structure associated to the device. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28net: dsa: fix dereference on ds->dev before null check errorColin Ian King
Currently ds->dev is dereferenced on the assignments of pdata and np before ds->dev is null checked, hence there is a potential null pointer dereference on ds->dev. Fix this by assigning pdata and np after the ds->dev null pointer sanity check. Addresses-Coverity: ("Dereference before null check") Fixes: 7e99e3470172 ("net: dsa: remove dsa_switch_alloc helper") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-22net: dsa: remove dsa_switch_alloc helperVivien Didelot
Now that ports are dynamically listed in the fabric, there is no need to provide a special helper to allocate the dsa_switch structure. This will give more flexibility to drivers to embed this structure as they wish in their private structure. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22net: dsa: allocate ports on touchVivien Didelot
Allocate the struct dsa_port the first time it is accessed with dsa_port_touch, and remove the static dsa_port array from the dsa_switch structure. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22net: dsa: use ports list to setup default CPU portVivien Didelot
Use the new ports list instead of iterating over switches and their ports when setting up the default CPU port. Unassign it on teardown. Now that we can iterate over multiple CPU ports, remove dst->cpu_dp. At the same time, provide a better error message for CPU-less tree. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>