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Author SHA1 Message Date
Vladimir Oltean
2f5dc00f7a net: bridge: switchdev: let drivers inform which bridge ports are offloaded
On reception of an skb, the bridge checks if it was marked as 'already
forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it
is, it assigns the source hardware domain of that skb based on the
hardware domain of the ingress port. Then during forwarding, it enforces
that the egress port must have a different hardware domain than the
ingress one (this is done in nbp_switchdev_allowed_egress).

Non-switchdev drivers don't report any physical switch id (neither
through devlink nor .ndo_get_port_parent_id), therefore the bridge
assigns them a hardware domain of 0, and packets coming from them will
always have skb->offload_fwd_mark = 0. So there aren't any restrictions.

Problems appear due to the fact that DSA would like to perform software
fallback for bonding and team interfaces that the physical switch cannot
offload.

       +-- br0 ---+
      / /   |      \
     / /    |       \
    /  |    |      bond0
   /   |    |     /    \
 swp0 swp1 swp2 swp3 swp4

There, it is desirable that the presence of swp3 and swp4 under a
non-offloaded LAG does not preclude us from doing hardware bridging
beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high
enough that software bridging between {swp0,swp1,swp2} and bond0 is not
impractical.

But this creates an impossible paradox given the current way in which
port hardware domains are assigned. When the driver receives a packet
from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to
something.

- If we set it to 0, then the bridge will forward it towards swp1, swp2
  and bond0. But the switch has already forwarded it towards swp1 and
  swp2 (not to bond0, remember, that isn't offloaded, so as far as the
  switch is concerned, ports swp3 and swp4 are not looking up the FDB,
  and the entire bond0 is a destination that is strictly behind the
  CPU). But we don't want duplicated traffic towards swp1 and swp2, so
  it's not ok to set skb->offload_fwd_mark = 0.

- If we set it to 1, then the bridge will not forward the skb towards
  the ports with the same switchdev mark, i.e. not to swp1, swp2 and
  bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should
  have forwarded the skb there.

So the real issue is that bond0 will be assigned the same hardware
domain as {swp0,swp1,swp2}, because the function that assigns hardware
domains to bridge ports, nbp_switchdev_add(), recurses through bond0's
lower interfaces until it finds something that implements devlink (calls
dev_get_port_parent_id with bool recurse = true). This is a problem
because the fact that bond0 can be offloaded by swp3 and swp4 in our
example is merely an assumption.

A solution is to give the bridge explicit hints as to what hardware
domain it should use for each port.

Currently, the bridging offload is very 'silent': a driver registers a
netdevice notifier, which is put on the netns's notifier chain, and
which sniffs around for NETDEV_CHANGEUPPER events where the upper is a
bridge, and the lower is an interface it knows about (one registered by
this driver, normally). Then, from within that notifier, it does a bunch
of stuff behind the bridge's back, without the bridge necessarily
knowing that there's somebody offloading that port. It looks like this:

     ip link set swp0 master br0
                  |
                  v
 br_add_if() calls netdev_master_upper_dev_link()
                  |
                  v
        call_netdevice_notifiers
                  |
                  v
       dsa_slave_netdevice_event
                  |
                  v
        oh, hey! it's for me!
                  |
                  v
           .port_bridge_join

What we do to solve the conundrum is to be less silent, and change the
switchdev drivers to present themselves to the bridge. Something like this:

     ip link set swp0 master br0
                  |
                  v
 br_add_if() calls netdev_master_upper_dev_link()
                  |
                  v                    bridge: Aye! I'll use this
        call_netdevice_notifiers           ^  ppid as the
                  |                        |  hardware domain for
                  v                        |  this port, and zero
       dsa_slave_netdevice_event           |  if I got nothing.
                  |                        |
                  v                        |
        oh, hey! it's for me!              |
                  |                        |
                  v                        |
           .port_bridge_join               |
                  |                        |
                  +------------------------+
             switchdev_bridge_port_offload(swp0, swp0)

Then stacked interfaces (like bond0 on top of swp3/swp4) would be
treated differently in DSA, depending on whether we can or cannot
offload them.

The offload case:

    ip link set bond0 master br0
                  |
                  v
 br_add_if() calls netdev_master_upper_dev_link()
                  |
                  v                    bridge: Aye! I'll use this
        call_netdevice_notifiers           ^  ppid as the
                  |                        |  switchdev mark for
                  v                        |        bond0.
       dsa_slave_netdevice_event           | Coincidentally (or not),
                  |                        | bond0 and swp0, swp1, swp2
                  v                        | all have the same switchdev
        hmm, it's not quite for me,        | mark now, since the ASIC
         but my driver has already         | is able to forward towards
           called .port_lag_join           | all these ports in hw.
          for it, because I have           |
      a port with dp->lag_dev == bond0.    |
                  |                        |
                  v                        |
           .port_bridge_join               |
           for swp3 and swp4               |
                  |                        |
                  +------------------------+
            switchdev_bridge_port_offload(bond0, swp3)
            switchdev_bridge_port_offload(bond0, swp4)

And the non-offload case:

    ip link set bond0 master br0
                  |
                  v
 br_add_if() calls netdev_master_upper_dev_link()
                  |
                  v                    bridge waiting:
        call_netdevice_notifiers           ^  huh, switchdev_bridge_port_offload
                  |                        |  wasn't called, okay, I'll use a
                  v                        |  hwdom of zero for this one.
       dsa_slave_netdevice_event           :  Then packets received on swp0 will
                  |                        :  not be software-forwarded towards
                  v                        :  swp1, but they will towards bond0.
         it's not for me, but
       bond0 is an upper of swp3
      and swp4, but their dp->lag_dev
       is NULL because they couldn't
            offload it.

Basically we can draw the conclusion that the lowers of a bridge port
can come and go, so depending on the configuration of lowers for a
bridge port, it can dynamically toggle between offloaded and unoffloaded.
Therefore, we need an equivalent switchdev_bridge_port_unoffload too.

This patch changes the way any switchdev driver interacts with the
bridge. From now on, everybody needs to call switchdev_bridge_port_offload
and switchdev_bridge_port_unoffload, otherwise the bridge will treat the
port as non-offloaded and allow software flooding to other ports from
the same ASIC.

Note that these functions lay the ground for a more complex handshake
between switchdev drivers and the bridge in the future.

For drivers that will request a replay of the switchdev objects when
they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we
place the call to switchdev_bridge_port_unoffload() strategically inside
the NETDEV_PRECHANGEUPPER notifier's code path, and not inside
NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers
need the netdev adjacency lists to be valid, and that is only true in
NETDEV_PRECHANGEUPPER.

Cc: Vadym Kochan <vkochan@marvell.com>
Cc: Taras Chornyi <tchornyi@marvell.com>
Cc: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: Lars Povlsen <lars.povlsen@microchip.com>
Cc: Steen Hegelund <Steen.Hegelund@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression
Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch
Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:26:23 -07:00
Vladimir Oltean
bae33f2b5a net: switchdev: remove the transaction structure from port attributes
Since the introduction of the switchdev API, port attributes were
transmitted to drivers for offloading using a two-step transactional
model, with a prepare phase that was supposed to catch all errors, and a
commit phase that was supposed to never fail.

Some classes of failures can never be avoided, like hardware access, or
memory allocation. In the latter case, merely attempting to move the
memory allocation to the preparation phase makes it impossible to avoid
memory leaks, since commit 91cf8eceff ("switchdev: Remove unused
transaction item queue") which has removed the unused mechanism of
passing on the allocated memory between one phase and another.

It is time we admit that separating the preparation from the commit
phase is something that is best left for the driver to decide, and not
something that should be baked into the API, especially since there are
no switchdev callers that depend on this.

This patch removes the struct switchdev_trans member from switchdev port
attribute notifier structures, and converts drivers to not look at this
member.

In part, this patch contains a revert of my previous commit 2e554a7a5d
("net: dsa: propagate switchdev vlan_filtering prepare phase to
drivers").

For the most part, the conversion was trivial except for:
- Rocker's world implementation based on Broadcom OF-DPA had an odd
  implementation of ofdpa_port_attr_bridge_flags_set. The conversion was
  done mechanically, by pasting the implementation twice, then only
  keeping the code that would get executed during prepare phase on top,
  then only keeping the code that gets executed during the commit phase
  on bottom, then simplifying the resulting code until this was obtained.
- DSA's offloading of STP state, bridge flags, VLAN filtering and
  multicast router could be converted right away. But the ageing time
  could not, so a shim was introduced and this was left for a further
  commit.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> # hellcreek
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> # RTL8366RB
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-11 16:00:57 -08:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Florian Fainelli
610d2b601b rocker: Remove getting PORT_BRIDGE_FLAGS
There is no code that attempts to get the
SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS attribute, remove support for that.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-12 12:49:53 -05:00
Arkadi Sharshevsky
abfbf8a0b2 rocker: Remove support bridge bypass FDB
The FDB add/delete are now done through the notification chain. The FDBs
are synced with the bridge and there is no need for extra dumping.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:16:30 -04:00
Arkadi Sharshevsky
403caa7afc rocker: Remove support for bypass bridge port attributes/vlan set
The bridge port attributes/vlan for mlxsw devices should be set only
from bridge code. The vlans are synced totally with the bridge so
there is no need to special dump support.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:16:29 -04:00
Arkadi Sharshevsky
00fc0c51e3 rocker: Change world_ops API and implementation to be switchdev independant
Currently the switchdev_trans struct is embedded in the world_ops API.
In order to add support for adding FDB via a notfication chain the API should
be switchdev independent.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:16:29 -04:00
Arkadi Sharshevsky
96673a3044 rocker: Add support for querying supported bridge flags
Add support for querying supported bridge flags.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08 14:16:29 -04:00
Ido Schimmel
c1bb279cfa rocker: Create an ordered workqueue for FIB offload
As explained in the previous commits, we need to process FIB entries
addition / deletion events in FIFO order or otherwise we can have a
mismatch between the kernel's FIB table and the device's.

Create an ordered workqueue for rocker to which these work items will be
submitted to.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 19:29:35 -05:00
Jiri Pirko
936bd48656 rocker: use FIB notifications instead of switchdev calls
Until now, in order to offload a FIB entry to HW we use switchdev op.
Use the newly introduced FIB notifier infrasturucture to process
FIB entries to offload the in HW.
Abort mechanism is now handled within the rocker driver.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-28 04:48:00 -04:00
Jiri Pirko
3a8befcd78 rocker: move ageing_time from struct rocker to struct ofdpa
This is OF-DPA specific, used only there, similar to
ofdpa_port->ageing_time. So move it to OF-DPA code.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-12 20:11:13 -05:00
Ido Schimmel
88de1cd457 rocker: set FDB cleanup timer according to lowest ageing time
In rocker, ageing time is a per-port attribute, so the next time the FDB
cleanup timer fires should be set according to the lowest ageing time.

This will later allow us to delete the BR_MIN_AGEING_TIME macro, which was
added to guarantee minimum ageing time in the bridge layer, thereby breaking
existing behavior.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-11 14:58:58 -05:00
Jiri Pirko
3fbcdbf3f1 rocker: move OF-DPA stuff into separate file
Carve out OF-DPA would specific code from the common file to the world
file. This change required struct rocker and struct rocker_port split
into world specific struct ofdpa and struct ofdpa_port. Along with this
the world specific functions and defines were renamed from prefix
"rocker_" to "ofdpa_".

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 23:08:35 -05:00
Jiri Pirko
e420114eef rocker: introduce worlds infrastructure
This is another step on the way to per-world clean cut. Introduce world
ops hooks which each world can implement in world-specific way.
Also introduce world infrastructure along with OF-DPA world stub.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 23:08:34 -05:00
Jiri Pirko
0514c4e809 rocker: move rocker and rocker_port structs into header
And take some other related thing along. They are going to be pushed
into of-dpa part anyway.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 23:08:34 -05:00
Jiri Pirko
de1521923c rocker: push tlv processing into separate files
Carve out TLV processing helpers into separate files.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 23:08:34 -05:00
Jiri Pirko
0fe685f6a2 rocker: rename rocker.h to rocker_hw.h
Since "rocker.h" file is going to be used for different purpose,
rename the hardware-specific header to "rocker_hw.h".

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 23:08:34 -05:00
Scott Feldman
3f98a8e636 rocker: add offload_fwd_mark support
If device flags ingress packet as "fwd offload", mark the
skb->offlaod_fwd_mark using the ingress port's dev->offlaod_fwd_mark.  This
will be the hint to the kernel that this packet has already been forwarded
by device to egress ports matching skb->offlaod_fwd_mark.

For rocker, derive port dev->offlaod_fwd_mark based on device switch ID and
port ifindex.  If port is bridged, use the bridge ifindex rather than the
port ifindex.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 18:32:45 -07:00
Scott Feldman
77a58c741d rocker: add change MTU support
Implement ndo_change_mtu: on MTU change, reallocate Rx ring bufs and signal
HW of new port MTU value.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Tested-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09 00:31:14 -07:00
Scott Feldman
4725ceb9b7 rocker: make checkpatch -f clean
Well almost clean: ignore the CHECKs for space after cast operator and some
longer-than-80 char cases where for readability it's better to keep as-is.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-12 18:43:56 -04:00
David Ahern
db19170bc0 rocker: add support for phys_port_name
Implement the phys_port_name operation. Port names are pulled from the
rocker hardware model in qemu and default to the qemu name + port id.
e.g.,

sw1p1: flags=4098<BROADCAST,MULTICAST>  mtu 1500
        ether 52:54:00:12:35:01  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

where 'sw1' comes from the qemu command line -device rocker,name=sw1, and
'p1' is port 1.

Patch is adapted from Scott's phys_port_id patch.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18 22:30:35 -04:00
Scott Feldman
1b5ef07e3d rocker: sparse: fix dynamic allocation on stack warning
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 22:01:27 -05:00
Scott Feldman
4a6bb6d359 rocker: rename lport to pport
This is just a rename of physical ports from "lport" to "pport".  Not a
functional change.  OF-DPA uses logical ports (lport) for tunnels, but the
driver (and device) were using "lport" for physical ports.  Renaming physical
ports references to "pport", freeing up "lport" for use later with tunnels.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-26 11:21:57 -05:00
Scott Feldman
7eb344f873 rocker: fix non-portable err return codes
The rocker device returns error codes if something goes wrong with descriptor
processing.  Originally the device used standard errno codes for different
errors, but since those errno codes aren't portable across ARCHs, the device
now returns hard-coded error codes that stay constant across diff ARCHs.  Fix
driver to use those same hard-coded values.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-26 11:21:57 -05:00
David Ahern
9766e97af1 net: rocker: Add support for retrieving port level statistics
Add support for retrieving port level statistics from device.
Hook is added for ethtool's stats functionality. For example,

$ ethtool -S eth3
NIC statistics:
     rx_packets: 12
     rx_bytes: 2790
     rx_dropped: 0
     rx_errors: 0
     tx_packets: 8
     tx_bytes: 728
     tx_dropped: 0
     tx_errors: 0

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-01 23:17:39 -08:00
Scott Feldman
5111f80cbc rocker: add ndo_bridge_setlink/getlink support for learning policy
Rocker ports will use new "swdev" hwmode for bridge port offload policy.
Current supported policy settings are BR_LEARNING and BR_LEARNING_SYNC.
User can turn on/off device port FDB learning and syncing to bridge.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-02 20:01:26 -08:00
Jiri Pirko
4b8ac9660a rocker: introduce rocker switch driver
This patch introduces the first driver to benefit from the switchdev
infrastructure and to implement newly introduced switch ndos. This is a
driver for emulated switch chip implemented in qemu:
https://github.com/sfeldma/qemu-rocker/

This patch is a result of joint work with Scott Feldman.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-02 20:01:24 -08:00