kernel/linux.git/net/dsa/switch.h, branch v6.19.11

net: dsa: Use conduit and user terms

2023-10-24T20:08:14+00:00

Use more inclusive terms throughout the DSA subsystem by moving away from "master" which is replaced by "conduit" and "slave" which is replaced by "user". No functional changes. Acked-by: Rob Herring Acked-by: Stephen Hemminger Reviewed-by: Vladimir Oltean Signed-off-by: Florian Fainelli Link: https://lore.kernel.org/r/20231023181729.1191071-2-florian.fainelli@broadcom.com Signed-off-by: Jakub Kicinski

net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses

2023-06-27T16:37:41+00:00

When using the felix driver (the only one which supports UC filtering and MC filtering) as a DSA master for a random other DSA switch, one can see the following stack trace when the downstream switch ports join a VLAN-aware bridge: ============================= WARNING: suspicious RCU usage ----------------------------- net/8021q/vlan_core.c:238 suspicious rcu_dereference_protected() usage! stack backtrace: Workqueue: dsa_ordered dsa_slave_switchdev_event_work Call trace: lockdep_rcu_suspicious+0x170/0x210 vlan_for_each+0x8c/0x188 dsa_slave_sync_uc+0x128/0x178 __hw_addr_sync_dev+0x138/0x158 dsa_slave_set_rx_mode+0x58/0x70 __dev_set_rx_mode+0x88/0xa8 dev_uc_add+0x74/0xa0 dsa_port_bridge_host_fdb_add+0xec/0x180 dsa_slave_switchdev_event_work+0x7c/0x1c8 process_one_work+0x290/0x568 What it's saying is that vlan_for_each() expects rtnl_lock() context and it's not getting it, when it's called from the DSA master's ndo_set_rx_mode(). The caller of that - dsa_slave_set_rx_mode() - is the slave DSA interface's dsa_port_bridge_host_fdb_add() which comes from the deferred dsa_slave_switchdev_event_work(). We went to great lengths to avoid the rtnl_lock() context in that call path in commit 0faf890fc519 ("net: dsa: drop rtnl_lock from dsa_slave_switchdev_event_work"), and calling rtnl_lock() is simply not an option due to the possibility of deadlocking when calling dsa_flush_workqueue() from the call paths that do hold rtnl_lock() - basically all of them. So, when the DSA master calls vlan_for_each() from its ndo_set_rx_mode(), the state of the 8021q driver on this device is really not protected from concurrent access by anything. Looking at net/8021q/, I don't think that vlan_info->vid_list was particularly designed with RCU traversal in mind, so introducing an RCU read-side form of vlan_for_each() - vlan_for_each_rcu() - won't be so easy, and it also wouldn't be exactly what we need anyway. In general I believe that the solution isn't in net/8021q/ anyway; vlan_for_each() is not cut out for this task. DSA doesn't need rtnl_lock() to be held per se - since it's not a netdev state change that we're blocking, but rather, just concurrent additions/removals to a VLAN list. We don't even need sleepable context - the callback of vlan_for_each() just schedules deferred work. The proposed escape is to remove the dependency on vlan_for_each() and to open-code a non-sleepable, rtnl-free alternative to that, based on copies of the VLAN list modified from .ndo_vlan_rx_add_vid() and .ndo_vlan_rx_kill_vid(). Fixes: 64fdc5f341db ("net: dsa: sync unicast and multicast addresses for VLAN filters too") Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20230626154402.3154454-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski

net: dsa: move notifier definitions to switch.h

2022-11-23T04:41:52+00:00

Reduce bloat in dsa_priv.h by moving the cross-chip notifier data structures to switch.h. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski

net: dsa: move dsa_tree_notify() and dsa_broadcast() to switch.c

2022-11-23T04:41:51+00:00

There isn't an intuitive place for these 2 cross-chip notifier functions according to the function-to-file classification based on names (dsa_switch_*() goes to switch.c), but I consider these to be part of the cross-chip notifier handling, therefore part of switch.c. Move them there to reduce bloat in dsa2.c (the place where all code with no better place to go goes). Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski

net: dsa: move headers exported by switch.c to switch.h

2022-11-23T04:41:51+00:00

Reduce code bloat in dsa_priv.h by moving the prototypes exported by switch.h into their own header file. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Jakub Kicinski