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2021-01-07net: dsa: exit early in dsa_slave_switchdev_event if we can't program the FDBVladimir Oltean
Right now, the following would happen for a switch driver that does not implement .port_fdb_add or .port_fdb_del. dsa_slave_switchdev_event returns NOTIFY_OK and schedules: -> dsa_slave_switchdev_event_work -> dsa_port_fdb_add -> dsa_port_notify(DSA_NOTIFIER_FDB_ADD) -> dsa_switch_fdb_add -> if (!ds->ops->port_fdb_add) return -EOPNOTSUPP; -> an error is printed with dev_dbg, and dsa_fdb_offload_notify(switchdev_work) is not called. We can avoid scheduling the worker for nothing and say NOTIFY_DONE. Because we don't call dsa_fdb_offload_notify, the static FDB entry will remain just in the software bridge. 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: Jakub Kicinski <kuba@kernel.org>
2021-01-07net: dsa: move switchdev event implementation under the same switch/case ↵Vladimir Oltean
statement We'll need to start listening to SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE events even for interfaces where dsa_slave_dev_check returns false, so we need that check inside the switch-case statement for SWITCHDEV_FDB_*. This movement also avoids a useless allocation / free of switchdev_work on the untreated "default event" case. 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>
2021-01-07net: dsa: don't use switchdev_notifier_fdb_info in dsa_switchdev_event_workVladimir Oltean
Currently DSA doesn't add FDB entries on the CPU port, because it only does so through switchdev, which is associated with a net_device, and there are none of those for the CPU port. But actually FDB addresses on the CPU port have some use cases of their own, if the switchdev operations are initiated from within the DSA layer. There is just one problem with the existing code: it passes a structure in dsa_switchdev_event_work which was retrieved directly from switchdev, so it contains a net_device. We need to generalize the contents to something that covers the CPU port as well: the "ds, port" tuple is fine for that. Note that the new procedure for notifying the successful FDB offload is inspired from the rocker model. Also, nothing was being done if added_by_user was false. Let's check for that a lot earlier, and don't actually bother to schedule the worker for nothing. 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>
2021-01-07net: dsa: be louder when a non-legacy FDB operation failsVladimir Oltean
The dev_close() call was added in commit c9eb3e0f8701 ("net: dsa: Add support for learning FDB through notification") "to indicate inconsistent situation" when we could not delete an FDB entry from the port. bridge fdb del d8:58:d7:00:ca:6d dev swp0 self master It is a bit drastic and at the same time not helpful if the above fails to only print with netdev_dbg log level, but on the other hand to bring the interface down. So increase the verbosity of the error message, and drop dev_close(). 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>
2020-12-08net: dsa: print the MTU value that could not be setRasmus Villemoes
These warnings become somewhat more informative when they include the MTU value that could not be set and not just the errno. Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Link: https://lore.kernel.org/r/20201205133944.10182-1-rasmus.villemoes@prevas.dk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-20net: dsa: avoid potential use-after-free errorChristian Eggers
If dsa_switch_ops::port_txtstamp() returns false, clone will be freed immediately. Shouldn't store a pointer to freed memory. Signed-off-by: Christian Eggers <ceggers@arri.de> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20201119110906.25558-1-ceggers@arri.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-09net: dsa: use net core stats64 handlingHeiner Kallweit
Use netdev->tstats instead of a member of dsa_slave_priv for storing a pointer to the per-cpu counters. This allows us to use core functionality for statistics handling. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-05net: dsa: Give drivers the chance to veto certain upper devicesVladimir Oltean
Some switches rely on unique pvids to ensure port separation in standalone mode, because they don't have a port forwarding matrix configurable in hardware. So, setups like a group of 2 uppers with the same VLAN, swp0.100 and swp1.100, will cause traffic tagged with VLAN 100 to be autonomously forwarded between these switch ports, in spite of there being no bridge between swp0 and swp1. These drivers need to prevent this from happening. They need to have VLAN filtering enabled in standalone mode (so they'll drop frames tagged with unknown VLANs) and they can only accept an 8021q upper on a port as long as it isn't installed on any other port too. So give them the chance to veto bad user requests. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> [Kurt: Pass info instead of ptr] Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-02net: dsa: implement a central TX reallocation procedureVladimir Oltean
At the moment, taggers are left with the task of ensuring that the skb headers are writable (which they aren't, if the frames were cloned for TX timestamping, for flooding by the bridge, etc), and that there is enough space in the skb data area for the DSA tag to be pushed. Moreover, the life of tail taggers is even harder, because they need to ensure that short frames have enough padding, a problem that normal taggers don't have. The principle of the DSA framework is that everything except for the most intimate hardware specifics (like in this case, the actual packing of the DSA tag bits) should be done inside the core, to avoid having code paths that are very rarely tested. So provide a TX reallocation procedure that should cover the known needs of DSA today. Note that this patch also gives the network stack a good hint about the headroom/tailroom it's going to need. Up till now it wasn't doing that. So the reallocation procedure should really be there only for the exceptional cases, and for cloned packets which need to be unshared. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Christian Eggers <ceggers@arri.de> # For tail taggers only Tested-by: Kurt Kanzenbach <kurt@linutronix.de> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-13net: dsa: use new function dev_fetch_sw_netstatsHeiner Kallweit
Simplify the code by using new function dev_fetch_sw_netstats(). Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/b6047017-8226-6b7e-a3cd-064e69fdfa27@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-20net: dsa: install VLANs into the master's RX filter tooVladimir Oltean
Most DSA switch tags shift the EtherType to the right, causing the master to not parse the VLAN as VLAN. However, not all switches do that (example: tail tags, tag_8021q etc), and if the DSA master has "rx-vlan-filter: on" in ethtool -k, then we have a problem. Therefore, we could populate the VLAN table of the master, just in case (for some switches it will not make a difference), so that network I/O can work even with a VLAN filtering master. 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>
2020-09-20net: dsa: allow 8021q uppers while the bridge has vlan_filtering=0Vladimir Oltean
When the bridge has VLAN awareness disabled there isn't any duplication of functionality, since the bridge does not process VLAN. Don't deny adding 8021q uppers to DSA switch ports in that case. The switch is supposed to simply pass traffic leaving the VLAN tag as-is, and the stack will happily strip the VLAN tag for all 8021q uppers that exist. We need to ensure that there are no 8021q uppers when the user attempts to enable bridge vlan_filtering. 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>
2020-09-20net: dsa: convert denying bridge VLAN with existing 8021q upper to ↵Vladimir Oltean
PRECHANGEUPPER This is checking for the following order of operations, and makes sure to deny that configuration: ip link add link swp2 name swp2.100 type vlan id 100 ip link add br0 type bridge vlan_filtering 1 ip link set swp2 master br0 bridge vlan add dev swp2 vid 100 Instead of using vlan_for_each(), which looks at the VLAN filters installed with vlan_vid_add(), just track the 8021q uppers. This has the advantage of freeing up the vlan_vid_add() call for actual VLAN filtering. There is another change in this patch. The check is moved in slave.c, from switch.c. I don't think it makes sense to have this 8021q upper check for each switch port that gets notified of that VLAN addition (these include DSA links and CPU ports, we know those can't have 8021q uppers because they don't have a net_device registered for them), so just do it in slave.c, for that one slave interface. 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>
2020-09-20net: dsa: convert check for 802.1Q upper when bridged into PRECHANGEUPPERVladimir Oltean
DSA tries to prevent having a VLAN added by a bridge and by an 802.1Q upper at the same time. It does that by checking the VID in .ndo_vlan_rx_add_vid(), since that's something that the 8021q module calls, via vlan_vid_add(). When a VLAN matches in both subsystems, this check returns -EBUSY. However the vlan_vid_add() function isn't specific to the 8021q module in any way at all. It is simply the kernel's way to tell an interface to add a VLAN to its RX filter and not drop that VLAN. So there's no reason to return -EBUSY when somebody tries to call vlan_vid_add() for a VLAN that was installed by the bridge. The proper behavior is to accept that configuration. So what's wrong is how DSA checks that it has an 8021q upper. It should look at the actual uppers for that, not just assume that the 8021q module was somewhere in the call stack of .ndo_vlan_rx_add_vid(). 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>
2020-09-20net: dsa: rename dsa_slave_upper_vlan_check to something more suggestiveVladimir Oltean
We'll be adding a new check in the PRECHANGEUPPER notifier, where we'll need to check some VLAN uppers. It is hard to do that when there is already a function named dsa_slave_upper_vlan_check. So rename this one. Not to mention that this function probably shouldn't have started with "dsa_slave_" in the first place, since the struct net_device argument isn't a DSA slave, but an 8021q upper of one. 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>
2020-09-20net: dsa: deny enslaving 802.1Q upper to VLAN-aware bridge from PRECHANGEUPPERVladimir Oltean
There doesn't seem to be any strong technical reason for doing it this way, but we'll be adding more checks for invalid upper device configurations, and it will be easier to have them all grouped under PRECHANGEUPPER. Tested that it still works: ip link set br0 type bridge vlan_filtering 1 ip link add link swp2 name swp2.100 type vlan id 100 ip link set swp2.100 master br0 [ 20.321312] br0: port 5(swp2.100) entered blocking state [ 20.326711] br0: port 5(swp2.100) entered disabled state Error: dsa_core: Cannot enslave VLAN device into VLAN aware bridge. [ 20.346549] br0: port 5(swp2.100) entered blocking state [ 20.351957] br0: port 5(swp2.100) entered disabled state 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>
2020-09-11Revert "net: dsa: Add more convenient functions for installing port VLANs"Vladimir Oltean
This reverts commit 314f76d7a68bab0516aa52877944e6aacfa0fc3f. Citing that commit message, the call graph was: dsa_slave_vlan_rx_add_vid dsa_port_setup_8021q_tagging | | | | | +-------------+ | | v v dsa_port_vid_add dsa_slave_port_obj_add | | +-------+ +-------+ | | v v dsa_port_vlan_add Now that tag_8021q has its own ops structure, it no longer relies on dsa_port_vid_add, and therefore on the dsa_switch_ops to install its VLANs. So dsa_port_vid_add now only has one single caller. So we can simplify the call graph to what it was before, aka: dsa_slave_vlan_rx_add_vid dsa_slave_port_obj_add | | +-------+ +-------+ | | v v dsa_port_vlan_add 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>
2020-09-08net: dsa: link interfaces with the DSA master to get rid of lockdep warningsVladimir Oltean
Since commit 845e0ebb4408 ("net: change addr_list_lock back to static key"), cascaded DSA setups (DSA switch port as DSA master for another DSA switch port) are emitting this lockdep warning: ============================================ WARNING: possible recursive locking detected 5.8.0-rc1-00133-g923e4b5032dd-dirty #208 Not tainted -------------------------------------------- dhcpcd/323 is trying to acquire lock: ffff000066dd4268 (&dsa_master_addr_list_lock_key/1){+...}-{2:2}, at: dev_mc_sync+0x44/0x90 but task is already holding lock: ffff00006608c268 (&dsa_master_addr_list_lock_key/1){+...}-{2:2}, at: dev_mc_sync+0x44/0x90 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dsa_master_addr_list_lock_key/1); lock(&dsa_master_addr_list_lock_key/1); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by dhcpcd/323: #0: ffffdbd1381dda18 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x24/0x30 #1: ffff00006614b268 (_xmit_ETHER){+...}-{2:2}, at: dev_set_rx_mode+0x28/0x48 #2: ffff00006608c268 (&dsa_master_addr_list_lock_key/1){+...}-{2:2}, at: dev_mc_sync+0x44/0x90 stack backtrace: Call trace: dump_backtrace+0x0/0x1e0 show_stack+0x20/0x30 dump_stack+0xec/0x158 __lock_acquire+0xca0/0x2398 lock_acquire+0xe8/0x440 _raw_spin_lock_nested+0x64/0x90 dev_mc_sync+0x44/0x90 dsa_slave_set_rx_mode+0x34/0x50 __dev_set_rx_mode+0x60/0xa0 dev_mc_sync+0x84/0x90 dsa_slave_set_rx_mode+0x34/0x50 __dev_set_rx_mode+0x60/0xa0 dev_set_rx_mode+0x30/0x48 __dev_open+0x10c/0x180 __dev_change_flags+0x170/0x1c8 dev_change_flags+0x2c/0x70 devinet_ioctl+0x774/0x878 inet_ioctl+0x348/0x3b0 sock_do_ioctl+0x50/0x310 sock_ioctl+0x1f8/0x580 ksys_ioctl+0xb0/0xf0 __arm64_sys_ioctl+0x28/0x38 el0_svc_common.constprop.0+0x7c/0x180 do_el0_svc+0x2c/0x98 el0_sync_handler+0x9c/0x1b8 el0_sync+0x158/0x180 Since DSA never made use of the netdev API for describing links between upper devices and lower devices, the dev->lower_level value of a DSA switch interface would be 1, which would warn when it is a DSA master. We can use netdev_upper_dev_link() to describe the relationship between a DSA slave and a DSA master. To be precise, a DSA "slave" (switch port) is an "upper" to a DSA "master" (host port). The relationship is "many uppers to one lower", like in the case of VLAN. So, for that reason, we use the same function as VLAN uses. There might be a chance that somebody will try to take hold of this interface and use it immediately after register_netdev() and before netdev_upper_dev_link(). To avoid that, we do the registration and linkage while holding the RTNL, and we use the RTNL-locked cousin of register_netdev(), which is register_netdevice(). Since this warning was not there when lockdep was using dynamic keys for addr_list_lock, we are blaming the lockdep patch itself. The network stack _has_ been using static lockdep keys before, and it _is_ likely that stacked DSA setups have been triggering these lockdep warnings since forever, however I can't test very old kernels on this particular stacked DSA setup, to ensure I'm not in fact introducing regressions. Fixes: 845e0ebb4408 ("net: change addr_list_lock back to static key") Suggested-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-07net: dsa: don't print non-fatal MTU error if not supportedVladimir Oltean
Commit 72579e14a1d3 ("net: dsa: don't fail to probe if we couldn't set the MTU") changed, for some reason, the "err && err != -EOPNOTSUPP" check into a simple "err". This causes the MTU warning to be printed even for drivers that don't have the MTU operations implemented. Fix that. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-07net: dsa: change PHY error message againVladimir Oltean
slave_dev->name is only populated at this stage if it was specified through a label in the device tree. However that is not mandatory. When it isn't, the error message looks like this: [ 5.037057] fsl_enetc 0000:00:00.2 eth2: error -19 setting up slave PHY for eth%d [ 5.044672] fsl_enetc 0000:00:00.2 eth2: error -19 setting up slave PHY for eth%d [ 5.052275] fsl_enetc 0000:00:00.2 eth2: error -19 setting up slave PHY for eth%d [ 5.059877] fsl_enetc 0000:00:00.2 eth2: error -19 setting up slave PHY for eth%d which is especially confusing since the error gets printed on behalf of the DSA master (fsl_enetc in this case). Printing an error message that contains a valid reference to the DSA port's name is difficult at this point in the initialization stage, so at least we should print some info that is more reliable, even if less user-friendly. That may be the driver name and the hardware port index. After this change, the error is printed as: [ 6.051587] mscc_felix 0000:00:00.5: error -19 setting up PHY for tree 0, switch 0, port 0 [ 6.061192] mscc_felix 0000:00:00.5: error -19 setting up PHY for tree 0, switch 0, port 1 [ 6.070765] mscc_felix 0000:00:00.5: error -19 setting up PHY for tree 0, switch 0, port 2 [ 6.080324] mscc_felix 0000:00:00.5: error -19 setting up PHY for tree 0, switch 0, port 3 Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-20net: dsa: use the ETH_MIN_MTU and ETH_DATA_LEN default valuesVladimir Oltean
Now that DSA supports MTU configuration, undo the effects of commit 8b1efc0f83f1 ("net: remove MTU limits on a few ether_setup callers") and let DSA interfaces use the default min_mtu and max_mtu specified by ether_setup(). This is more important for min_mtu: since DSA is Ethernet, the minimum MTU is the same as of any other Ethernet interface, and definitely not zero. For the max_mtu, we have a callback through which drivers can override that, if they want to. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-30net: dsa: Improve subordinate PHY error messageFlorian Fainelli
It is not very informative to know the DSA master device when a subordinate network device fails to get its PHY setup. Provide the device name and capitalize PHY while we are it. 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>
2020-05-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
xdp_umem.c had overlapping changes between the 64-bit math fix for the calculation of npgs and the removal of the zerocopy memory type which got rid of the chunk_size_nohdr member. The mlx5 Kconfig conflict is a case where we just take the net-next copy of the Kconfig entry dependency as it takes on the ESWITCH dependency by one level of indirection which is what the 'net' conflicting change is trying to ensure. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-27net: dsa: declare lockless TX feature for slave portsVladimir Oltean
Be there a platform with the following layout: Regular NIC | +----> DSA master for switch port | +----> DSA master for another switch port After changing DSA back to static lockdep class keys in commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key changes"), this kernel splat can be seen: [ 13.361198] ============================================ [ 13.366524] WARNING: possible recursive locking detected [ 13.371851] 5.7.0-rc4-02121-gc32a05ecd7af-dirty #988 Not tainted [ 13.377874] -------------------------------------------- [ 13.383201] swapper/0/0 is trying to acquire lock: [ 13.388004] ffff0000668ff298 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.397879] [ 13.397879] but task is already holding lock: [ 13.403727] ffff0000661a1698 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.413593] [ 13.413593] other info that might help us debug this: [ 13.420140] Possible unsafe locking scenario: [ 13.420140] [ 13.426075] CPU0 [ 13.428523] ---- [ 13.430969] lock(&dsa_slave_netdev_xmit_lock_key); [ 13.435946] lock(&dsa_slave_netdev_xmit_lock_key); [ 13.440924] [ 13.440924] *** DEADLOCK *** [ 13.440924] [ 13.446860] May be due to missing lock nesting notation [ 13.446860] [ 13.453668] 6 locks held by swapper/0/0: [ 13.457598] #0: ffff800010003de0 ((&idev->mc_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x0/0x400 [ 13.466593] #1: ffffd4d3fb478700 (rcu_read_lock){....}-{1:2}, at: mld_sendpack+0x0/0x560 [ 13.474803] #2: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x64/0xb10 [ 13.483886] #3: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x6c/0xbe0 [ 13.492793] #4: ffff0000661a1698 (&dsa_slave_netdev_xmit_lock_key){+.-.}-{2:2}, at: __dev_queue_xmit+0x84c/0xbe0 [ 13.503094] #5: ffffd4d3fb478728 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x6c/0xbe0 [ 13.512000] [ 13.512000] stack backtrace: [ 13.516369] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc4-02121-gc32a05ecd7af-dirty #988 [ 13.530421] Call trace: [ 13.532871] dump_backtrace+0x0/0x1d8 [ 13.536539] show_stack+0x24/0x30 [ 13.539862] dump_stack+0xe8/0x150 [ 13.543271] __lock_acquire+0x1030/0x1678 [ 13.547290] lock_acquire+0xf8/0x458 [ 13.550873] _raw_spin_lock+0x44/0x58 [ 13.554543] __dev_queue_xmit+0x84c/0xbe0 [ 13.558562] dev_queue_xmit+0x24/0x30 [ 13.562232] dsa_slave_xmit+0xe0/0x128 [ 13.565988] dev_hard_start_xmit+0xf4/0x448 [ 13.570182] __dev_queue_xmit+0x808/0xbe0 [ 13.574200] dev_queue_xmit+0x24/0x30 [ 13.577869] neigh_resolve_output+0x15c/0x220 [ 13.582237] ip6_finish_output2+0x244/0xb10 [ 13.586430] __ip6_finish_output+0x1dc/0x298 [ 13.590709] ip6_output+0x84/0x358 [ 13.594116] mld_sendpack+0x2bc/0x560 [ 13.597786] mld_ifc_timer_expire+0x210/0x390 [ 13.602153] call_timer_fn+0xcc/0x400 [ 13.605822] run_timer_softirq+0x588/0x6e0 [ 13.609927] __do_softirq+0x118/0x590 [ 13.613597] irq_exit+0x13c/0x148 [ 13.616918] __handle_domain_irq+0x6c/0xc0 [ 13.621023] gic_handle_irq+0x6c/0x160 [ 13.624779] el1_irq+0xbc/0x180 [ 13.627927] cpuidle_enter_state+0xb4/0x4d0 [ 13.632120] cpuidle_enter+0x3c/0x50 [ 13.635703] call_cpuidle+0x44/0x78 [ 13.639199] do_idle+0x228/0x2c8 [ 13.642433] cpu_startup_entry+0x2c/0x48 [ 13.646363] rest_init+0x1ac/0x280 [ 13.649773] arch_call_rest_init+0x14/0x1c [ 13.653878] start_kernel+0x490/0x4bc Lockdep keys themselves were added in commit ab92d68fc22f ("net: core: add generic lockdep keys"), and it's very likely that this splat existed since then, but I have no real way to check, since this stacked platform wasn't supported by mainline back then. >From Taehee's own words: This patch was considered that all stackable devices have LLTX flag. But the dsa doesn't have LLTX, so this splat happened. After this patch, dsa shares the same lockdep class key. On the nested dsa interface architecture, which you illustrated, the same lockdep class key will be used in __dev_queue_xmit() because dsa doesn't have LLTX. So that lockdep detects deadlock because the same lockdep class key is used recursively although actually the different locks are used. There are some ways to fix this problem. 1. using NETIF_F_LLTX flag. If possible, using the LLTX flag is a very clear way for it. But I'm so sorry I don't know whether the dsa could have LLTX or not. 2. using dynamic lockdep again. It means that each interface uses a separate lockdep class key. So, lockdep will not detect recursive locking. But this way has a problem that it could consume lockdep class key too many. Currently, lockdep can have 8192 lockdep class keys. - you can see this number with the following command. cat /proc/lockdep_stats lock-classes: 1251 [max: 8192] ... The [max: 8192] means that the maximum number of lockdep class keys. If too many lockdep class keys are registered, lockdep stops to work. So, using a dynamic(separated) lockdep class key should be considered carefully. In addition, updating lockdep class key routine might have to be existing. (lockdep_register_key(), lockdep_set_class(), lockdep_unregister_key()) 3. Using lockdep subclass. A lockdep class key could have 8 subclasses. The different subclass is considered different locks by lockdep infrastructure. But "lock-classes" is not counted by subclasses. So, it could avoid stopping lockdep infrastructure by an overflow of lockdep class keys. This approach should also have an updating lockdep class key routine. (lockdep_set_subclass()) 4. Using nonvalidate lockdep class key. The lockdep infrastructure supports nonvalidate lockdep class key type. It means this lockdep is not validated by lockdep infrastructure. So, the splat will not happen but lockdep couldn't detect real deadlock case because lockdep really doesn't validate it. I think this should be used for really special cases. (lockdep_set_novalidate_class()) Further discussion here: https://patchwork.ozlabs.org/project/netdev/patch/20200503052220.4536-2-xiyou.wangcong@gmail.com/ There appears to be no negative side-effect to declaring lockless TX for the DSA virtual interfaces, which means they handle their own locking. So that's what we do to make the splat go away. Patch tested in a wide variety of cases: unicast, multicast, PTP, etc. Fixes: ab92d68fc22f ("net: core: add generic lockdep keys") Suggested-by: Taehee Yoo <ap420073@gmail.com> 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>
2020-05-12net: dsa: provide an option for drivers to always receive bridge VLANsRussell King
DSA assumes that a bridge which has vlan filtering disabled is not vlan aware, and ignores all vlan configuration. However, the kernel software bridge code allows configuration in this state. This causes the kernel's idea of the bridge vlan state and the hardware state to disagree, so "bridge vlan show" indicates a correct configuration but the hardware lacks all configuration. Even worse, enabling vlan filtering on a DSA bridge immediately blocks all traffic which, given the output of "bridge vlan show", is very confusing. Provide an option that drivers can set to indicate they want to receive vlan configuration even when vlan filtering is disabled. At the very least, this is safe for Marvell DSA bridges, which do not look up ingress traffic in the VTU if the port is in 8021Q disabled state. It is also safe for the Ocelot switch family. Whether this change is suitable for all DSA bridges is not known. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> 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>
2020-05-07netpoll: accept NULL np argument in netpoll_send_skb()Eric Dumazet
netpoll_send_skb() callers seem to leak skb if the np pointer is NULL. While this should not happen, we can make the code more robust. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-07net: remove newlines in NL_SET_ERR_MSG_MODJacob Keller
The NL_SET_ERR_MSG_MOD macro is used to report a string describing an error message to userspace via the netlink extended ACK structure. It should not have a trailing newline. Add a cocci script which catches cases where the newline marker is present. Using this script, fix the handful of cases which accidentally included a trailing new line. I couldn't figure out a way to get a patch mode working, so this script only implements context, report, and org. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Andy Whitcroft <apw@canonical.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Conflicts were all overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06net: dsa: remove duplicate assignment in dsa_slave_add_cls_matchall_mirredVladimir Oltean
This was caused by a poor merge conflict resolution on my side. The "act = &cls->rule->action.entries[0];" assignment was already present in the code prior to the patch mentioned below. Fixes: e13c2075280e ("net: dsa: refactor matchall mirred action to separate function") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net: partially revert dynamic lockdep key changesCong Wang
This patch reverts the folowing commits: commit 064ff66e2bef84f1153087612032b5b9eab005bd "bonding: add missing netdev_update_lockdep_key()" commit 53d374979ef147ab51f5d632dfe20b14aebeccd0 "net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()" commit 1f26c0d3d24125992ab0026b0dab16c08df947c7 "net: fix kernel-doc warning in <linux/netdevice.h>" commit ab92d68fc22f9afab480153bd82a20f6e2533769 "net: core: add generic lockdep keys" but keeps the addr_list_lock_key because we still lock addr_list_lock nestedly on stack devices, unlikely xmit_lock this is safe because we don't take addr_list_lock on any fast path. Reported-and-tested-by: syzbot+aaa6fa4949cc5d9b7b25@syzkaller.appspotmail.com Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Simple overlapping changes to linux/vermagic.h Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-24net: phylink, dsa: eliminate phylink_fixed_state_cb()Russell King
Move the callback into the phylink_config structure, rather than providing a callback to set this up. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-23net: dsa: add GRO support via gro_cellsAlexander Lobakin
gro_cells lib is used by different encapsulating netdevices, such as geneve, macsec, vxlan etc. to speed up decapsulated traffic processing. CPU tag is a sort of "encapsulation", and we can use the same mechs to greatly improve overall DSA performance. skbs are passed to the GRO layer after removing CPU tags, so we don't need any new packet offload types as it was firstly proposed by me in the first GRO-over-DSA variant [1]. The size of struct gro_cells is sizeof(void *), so hot struct dsa_slave_priv becomes only 4/8 bytes bigger, and all critical fields remain in one 32-byte cacheline. The other positive side effect is that drivers for network devices that can be shipped as CPU ports of DSA-driven switches can now use napi_gro_frags() to pass skbs to kernel. Packets built that way are completely non-linear and are likely being dropped without GRO. This was tested on to-be-mainlined-soon Ethernet driver that uses napi_gro_frags(), and the overall performance was on par with the variant from [1], sometimes even better due to minimal overhead. net.core.gro_normal_batch tuning may help to push it to the limit on particular setups and platforms. iperf3 IPoE VLAN NAT TCP forwarding (port1.218 -> port0) setup on 1.2 GHz MIPS board: 5.7-rc2 baseline: [ID] Interval Transfer Bitrate Retr [ 5] 0.00-120.01 sec 9.00 GBytes 644 Mbits/sec 413 sender [ 5] 0.00-120.00 sec 8.99 GBytes 644 Mbits/sec receiver Iface RX packets TX packets eth0 7097731 7097702 port0 426050 6671829 port1 6671681 425862 port1.218 6671677 425851 With this patch: [ID] Interval Transfer Bitrate Retr [ 5] 0.00-120.01 sec 12.2 GBytes 870 Mbits/sec 122 sender [ 5] 0.00-120.00 sec 12.2 GBytes 870 Mbits/sec receiver Iface RX packets TX packets eth0 9474792 9474777 port0 455200 353288 port1 9019592 455035 port1.218 353144 455024 v2: - Add some performance examples in the commit message; - No functional changes. [1] https://lore.kernel.org/netdev/20191230143028.27313-1-alobakin@dlink.ru/ Signed-off-by: Alexander Lobakin <bloodyreaper@yandex.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-22net: dsa: don't fail to probe if we couldn't set the MTUVladimir Oltean
There is no reason to fail the probing of the switch if the MTU couldn't be configured correctly (either the switch port itself, or the host port) for whatever reason. MTU-sized traffic probably won't work, sure, but we can still probably limp on and support some form of communication anyway, which the users would probably appreciate more. Fixes: bfcb813203e6 ("net: dsa: configure the MTU for switch ports") Reported-by: Oleksij Rempel <o.rempel@pengutronix.de> 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>
2020-04-02net: dsa: dsa_bridge_mtu_normalization() can be statickbuild test robot
Fixes: f41071407c85 ("net: dsa: implement auto-normalization of MTU for bridge hardware datapath") Signed-off-by: kbuild test robot <lkp@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-31net: dsa: fix oops while probing Marvell DSA switchesRussell King
Fix an oops in dsa_port_phylink_mac_change() caused by a combination of a20f997010c4 ("net: dsa: Don't instantiate phylink for CPU/DSA ports unless needed") and the net-dsa-improve-serdes-integration series of patches 65b7a2c8e369 ("Merge branch 'net-dsa-improve-serdes-integration'"). Unable to handle kernel NULL pointer dereference at virtual address 00000124 pgd = c0004000 [00000124] *pgd=00000000 Internal error: Oops: 805 [#1] SMP ARM Modules linked in: tag_edsa spi_nor mtd xhci_plat_hcd mv88e6xxx(+) xhci_hcd armada_thermal marvell_cesa dsa_core ehci_orion libdes phy_armada38x_comphy at24 mcp3021 sfp evbug spi_orion sff mdio_i2c CPU: 1 PID: 214 Comm: irq/55-mv88e6xx Not tainted 5.6.0+ #470 Hardware name: Marvell Armada 380/385 (Device Tree) PC is at phylink_mac_change+0x10/0x88 LR is at mv88e6352_serdes_irq_status+0x74/0x94 [mv88e6xxx] Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-30net: dsa: add port policersVladimir Oltean
The approach taken to pass the port policer methods on to drivers is pragmatic. It is similar to the port mirroring implementation (in that the DSA core does all of the filter block interaction and only passes simple operations for the driver to implement) and dissimilar to how flow-based policers are going to be implemented (where the driver has full control over the flow_cls_offload data structure). Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-30net: dsa: refactor matchall mirred action to separate functionVladimir Oltean
Make room for other actions for the matchall filter by keeping the mirred argument parsing self-contained in its own function. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> 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>
2020-03-27net: dsa: configure the MTU for switch portsVladimir Oltean
It is useful be able to configure port policers on a switch to accept frames of various sizes: - Increase the MTU for better throughput from the default of 1500 if it is known that there is no 10/100 Mbps device in the network. - Decrease the MTU to limit the latency of high-priority frames under congestion, or work around various network segments that add extra headers to packets which can't be fragmented. For DSA slave ports, this is mostly a pass-through callback, called through the regular ndo ops and at probe time (to ensure consistency across all supported switches). The CPU port is called with an MTU equal to the largest configured MTU of the slave ports. The assumption is that the user might want to sustain a bidirectional conversation with a partner over any switch port. The DSA master is configured the same as the CPU port, plus the tagger overhead. Since the MTU is by definition L2 payload (sans Ethernet header), it is up to each individual driver to figure out if it needs to do anything special for its frame tags on the CPU port (it shouldn't except in special cases). So the MTU does not contain the tagger overhead on the CPU port. However the MTU of the DSA master, minus the tagger overhead, is used as a proxy for the MTU of the CPU port, which does not have a net device. This is to avoid uselessly calling the .change_mtu function on the CPU port when nothing should change. So it is safe to assume that the DSA master and the CPU port MTUs are apart by exactly the tagger's overhead in bytes. Some changes were made around dsa_master_set_mtu(), function which was now removed, for 2 reasons: - dev_set_mtu() already calls dev_validate_mtu(), so it's redundant to do the same thing in DSA - __dev_set_mtu() returns 0 if ops->ndo_change_mtu is an absent method That is to say, there's no need for this function in DSA, we can safely call dev_set_mtu() directly, take the rtnl lock when necessary, and just propagate whatever errors get reported (since the user probably wants to be informed). Some inspiration (mainly in the MTU DSA notifier) was taken from a vaguely similar patch from Murali and Florian, who are credited as co-developers down below. Co-developed-by: Murali Krishna Policharla <murali.policharla@broadcom.com> Signed-off-by: Murali Krishna Policharla <murali.policharla@broadcom.com> Co-developed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-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>
2020-03-17net: rename flow_action_hw_stats_types* -> flow_action_hw_stats*Jakub Kicinski
flow_action_hw_stats_types_check() helper takes one of the FLOW_ACTION_HW_STATS_*_BIT values as input. If we align the arguments to the opening bracket of the helper there is no way to call this helper and stay under 80 characters. Remove the "types" part from the new flow_action helpers and enum values. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Minor overlapping changes, nothing serious. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-08flow_offload: check for basic action hw stats typeJiri Pirko
Introduce flow_action_basic_hw_stats_types_check() helper and use it in drivers. That sanitizes the drivers which do not have support for action HW stats types. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-03net: dsa: Add bypass operations for the flower classifier-action filterVladimir Oltean
Due to the immense variety of classification keys and actions available for tc-flower, as well as due to potentially very different DSA switch capabilities, it doesn't make a lot of sense for the DSA mid layer to even attempt to interpret these. So just pass them on to the underlying switch driver. DSA implements just the standard boilerplate for binding and unbinding flow blocks to ports, since nobody wants to deal with that. 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>
2020-03-03net: dsa: fix phylink_start()/phylink_stop() callsRussell King
Place phylink_start()/phylink_stop() inside dsa_port_enable() and dsa_port_disable(), which ensures that we call phylink_stop() before tearing down phylink - which is a documented requirement. Failure to do so can cause use-after-free bugs. Fixes: 0e27921816ad ("net: dsa: Use PHYLINK for the CPU/DSA ports") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> 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>
2020-01-05net: dsa: Make deferred_xmit private to sja1105Vladimir Oltean
There are 3 things that are wrong with the DSA deferred xmit mechanism: 1. Its introduction has made the DSA hotpath ever so slightly more inefficient for everybody, since DSA_SKB_CB(skb)->deferred_xmit needs to be initialized to false for every transmitted frame, in order to figure out whether the driver requested deferral or not (a very rare occasion, rare even for the only driver that does use this mechanism: sja1105). That was necessary to avoid kfree_skb from freeing the skb. 2. Because L2 PTP is a link-local protocol like STP, it requires management routes and deferred xmit with this switch. But as opposed to STP, the deferred work mechanism needs to schedule the packet rather quickly for the TX timstamp to be collected in time and sent to user space. But there is no provision for controlling the scheduling priority of this deferred xmit workqueue. Too bad this is a rather specific requirement for a feature that nobody else uses (more below). 3. Perhaps most importantly, it makes the DSA core adhere a bit too much to the NXP company-wide policy "Innovate Where It Doesn't Matter". The sja1105 is probably the only DSA switch that requires some frames sent from the CPU to be routed to the slave port via an out-of-band configuration (register write) rather than in-band (DSA tag). And there are indeed very good reasons to not want to do that: if that out-of-band register is at the other end of a slow bus such as SPI, then you limit that Ethernet flow's throughput to effectively the throughput of the SPI bus. So hardware vendors should definitely not be encouraged to design this way. We do _not_ want more widespread use of this mechanism. Luckily we have a solution for each of the 3 issues: For 1, we can just remove that variable in the skb->cb and counteract the effect of kfree_skb with skb_get, much to the same effect. The advantage, of course, being that anybody who doesn't use deferred xmit doesn't need to do any extra operation in the hotpath. For 2, we can create a kernel thread for each port's deferred xmit work. If the user switch ports are named swp0, swp1, swp2, the kernel threads will be named swp0_xmit, swp1_xmit, swp2_xmit (there appears to be a 15 character length limit on kernel thread names). With this, the user can change the scheduling priority with chrt $(pidof swp2_xmit). For 3, we can actually move the entire implementation to the sja1105 driver. So this patch deletes the generic implementation from the DSA core and adds a new one, more adequate to the requirements of PTP TX timestamping, in sja1105_main.c. Suggested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-04net: of_get_phy_mode: Change API to solve int/unit warningsAndrew Lunn
Before this change of_get_phy_mode() returned an enum, phy_interface_t. On error, -ENODEV etc, is returned. If the result of the function is stored in a variable of type phy_interface_t, and the compiler has decided to represent this as an unsigned int, comparision with -ENODEV etc, is a signed vs unsigned comparision. Fix this problem by changing the API. Make the function return an error, or 0 on success, and pass a pointer, of type phy_interface_t, where the phy mode should be stored. v2: Return with *interface set to PHY_INTERFACE_MODE_NA on error. Add error checks to all users of of_get_phy_mode() Fixup a few reverse christmas tree errors Fixup a few slightly malformed reverse christmas trees v3: Fix 0-day reported errors. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>