This effectively reverts commit 60724d4b ("net: dsa: Add support for
DSA specific notifiers"). The reason is that since commit 2f1e8ea7
("net: dsa: link interfaces with the DSA master to get rid of lockdep
warnings"), it appears that there is a generic way to achieve the same
purpose. The only user thus far, the Broadcom SYSTEMPORT driver, was
converted to use the generic notifiers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The SYSTEMPORT driver maps each port of the embedded Broadcom DSA switch
port to a certain queue of the master Ethernet controller. For that it
currently uses a dedicated notifier infrastructure which was added in
commit 60724d4b ("net: dsa: Add support for DSA specific notifiers").

However, since commit 2f1e8ea7 ("net: dsa: link interfaces with the
DSA master to get rid of lockdep warnings"), DSA is actually an upper of
the Broadcom SYSTEMPORT as far as the netdevice adjacency lists are
concerned. So naturally, the plain NETDEV_CHANGEUPPER net device notifiers
are emitted. It looks like there is enough API exposed by DSA to the
outside world already to make the call_dsa_notifiers API redundant. So
let's convert its only user to plain netdev notifiers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Using the NETDEV_CHANGEUPPER notifications, drivers can be aware when
they are enslaved to e.g. a bridge by calling netif_is_bridge_master().

Export this helper from DSA to get the equivalent functionality of
determining whether the upper interface of a CHANGEUPPER notifier is a
DSA switch interface or not.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

It is a bit strange to see something as specific as Broadcom SYSTEMPORT
bits in the main DSA include file. Move these away into a separate
header, and have the tagger and the SYSTEMPORT driver include them.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Vladimir Oltean says:

====================
Offload software learnt bridge addresses to DSA

This series tries to make DSA behave a bit more sanely when bridged with
"foreign" (non-DSA) interfaces and source address learning is not
supported on the hardware CPU port (which would make things work more
seamlessly without software intervention). When a station A connected to
a DSA switch port needs to talk to another station B connected to a
non-DSA port through the Linux bridge, DSA must explicitly add a route
for station B towards its CPU port.

Initial RFC was posted here:
https://patchwork.ozlabs.org/project/netdev/cover/20201108131953.2462644-1-olteanv@gmail.com/

v2 was posted here:
https://patchwork.kernel.org/project/netdevbpf/cover/20201213024018.772586-1-vladimir.oltean@nxp.com/

v3 was posted here:
https://patchwork.kernel.org/project/netdevbpf/cover/20201213140710.1198050-1-vladimir.oltean@nxp.com/

This is a resend of the previous v3 with some added Reviewed-by tags.
====================

Link: https://lore.kernel.org/r/20210106095136.224739-1-olteanv@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Given the following setup:

ip link add br0 type bridge
ip link set eno0 master br0
ip link set swp0 master br0
ip link set swp1 master br0
ip link set swp2 master br0
ip link set swp3 master br0

Currently, packets received on a DSA slave interface (such as swp0)
which should be routed by the software bridge towards a non-switch port
(such as eno0) are also flooded towards the other switch ports (swp1,
swp2, swp3) because the destination is unknown to the hardware switch.

This patch addresses the issue by monitoring the addresses learnt by the
software bridge on eno0, and adding/deleting them as static FDB entries
on the CPU port accordingly.
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>

Some DSA switches (and not only) cannot learn source MAC addresses from
packets injected from the CPU. They only perform hardware address
learning from inbound traffic.

This can be problematic when we have a bridge spanning some DSA switch
ports and some non-DSA ports (which we'll call "foreign interfaces" from
DSA's perspective).

There are 2 classes of problems created by the lack of learning on
CPU-injected traffic:
- excessive flooding, due to the fact that DSA treats those addresses as
  unknown
- the risk of stale routes, which can lead to temporary packet loss

To illustrate the second class, consider the following situation, which
is common in production equipment (wireless access points, where there
is a WLAN interface and an Ethernet switch, and these form a single
bridging domain).

 AP 1:
 +------------------------------------------------------------------------+
 |                                          br0                           |
 +------------------------------------------------------------------------+
 +------------+ +------------+ +------------+ +------------+ +------------+
 |    swp0    | |    swp1    | |    swp2    | |    swp3    | |    wlan0   |
 +------------+ +------------+ +------------+ +------------+ +------------+
       |                                                       ^        ^
       |                                                       |        |
       |                                                       |        |
       |                                                    Client A  Client B
       |
       |
       |
 +------------+ +------------+ +------------+ +------------+ +------------+
 |    swp0    | |    swp1    | |    swp2    | |    swp3    | |    wlan0   |
 +------------+ +------------+ +------------+ +------------+ +------------+
 +------------------------------------------------------------------------+
 |                                          br0                           |
 +------------------------------------------------------------------------+
 AP 2

- br0 of AP 1 will know that Clients A and B are reachable via wlan0
- the hardware fdb of a DSA switch driver today is not kept in sync with
  the software entries on other bridge ports, so it will not know that
  clients A and B are reachable via the CPU port UNLESS the hardware
  switch itself performs SA learning from traffic injected from the CPU.
  Nonetheless, a substantial number of switches don't.
- the hardware fdb of the DSA switch on AP 2 may autonomously learn that
  Client A and B are reachable through swp0. Therefore, the software br0
  of AP 2 also may or may not learn this. In the example we're
  illustrating, some Ethernet traffic has been going on, and br0 from AP
  2 has indeed learnt that it can reach Client B through swp0.

One of the wireless clients, say Client B, disconnects from AP 1 and
roams to AP 2. The topology now looks like this:

 AP 1:
 +------------------------------------------------------------------------+
 |                                          br0                           |
 +------------------------------------------------------------------------+
 +------------+ +------------+ +------------+ +------------+ +------------+
 |    swp0    | |    swp1    | |    swp2    | |    swp3    | |    wlan0   |
 +------------+ +------------+ +------------+ +------------+ +------------+
       |                                                            ^
       |                                                            |
       |                                                         Client A
       |
       |
       |                                                         Client B
       |                                                            |
       |                                                            v
 +------------+ +------------+ +------------+ +------------+ +------------+
 |    swp0    | |    swp1    | |    swp2    | |    swp3    | |    wlan0   |
 +------------+ +------------+ +------------+ +------------+ +------------+
 +------------------------------------------------------------------------+
 |                                          br0                           |
 +------------------------------------------------------------------------+
 AP 2

- br0 of AP 1 still knows that Client A is reachable via wlan0 (no change)
- br0 of AP 1 will (possibly) know that Client B has left wlan0. There
  are cases where it might never find out though. Either way, DSA today
  does not process that notification in any way.
- the hardware FDB of the DSA switch on AP 1 may learn autonomously that
  Client B can be reached via swp0, if it receives any packet with
  Client 1's source MAC address over Ethernet.
- the hardware FDB of the DSA switch on AP 2 still thinks that Client B
  can be reached via swp0. It does not know that it has roamed to wlan0,
  because it doesn't perform SA learning from the CPU port.

Now Client A contacts Client B.
AP 1 routes the packet fine towards swp0 and delivers it on the Ethernet
segment.
AP 2 sees a frame on swp0 and its fdb says that the destination is swp0.
Hairpinning is disabled => drop.

This problem comes from the fact that these switches have a 'blind spot'
for addresses coming from software bridging. The generic solution is not
to assume that hardware learning can be enabled somehow, but to listen
to more bridge learning events. It turns out that the bridge driver does
learn in software from all inbound frames, in __br_handle_local_finish.
A proper SWITCHDEV_FDB_ADD_TO_DEVICE notification is emitted for the
addresses serviced by the bridge on 'foreign' interfaces. The software
bridge also does the right thing on migration, by notifying that the old
entry is deleted, so that does not need to be special-cased in DSA. When
it is deleted, we just need to delete our static FDB entry towards the
CPU too, and wait.

The problem is that DSA currently only cares about SWITCHDEV_FDB_ADD_TO_DEVICE
events received on its own interfaces, such as static FDB entries.

Luckily we can change that, and DSA can listen to all switchdev FDB
add/del events in the system and figure out if those events were emitted
by a bridge that spans at least one of DSA's own ports. In case that is
true, DSA will also offload that address towards its own CPU port, in
the eventuality that there might be bridge clients attached to the DSA
switch who want to talk to the station connected to the foreign
interface.

In terms of implementation, we need to keep the fdb_info->added_by_user
check for the case where the switchdev event was targeted directly at a
DSA switch port. But we don't need to look at that flag for snooped
events. So the check is currently too late, we need to move it earlier.
This also simplifies the code a bit, since we avoid uselessly allocating
and freeing switchdev_work.

We could probably do some improvements in the future. For example,
multi-bridge support is rudimentary at the moment. If there are two
bridges spanning a DSA switch's ports, and both of them need to service
the same MAC address, then what will happen is that the migration of one
of those stations will trigger the deletion of the FDB entry from the
CPU port while it is still used by other bridge. That could be improved
with reference counting but is left for another time.

This behavior needs to be enabled at driver level by setting
ds->assisted_learning_on_cpu_port = true. This is because we don't want
to inflict a potential performance penalty (accesses through
MDIO/I2C/SPI are expensive) to hardware that really doesn't need it
because address learning on the CPU port works there.
Reported-by: DENG Qingfang <dqfext@gmail.com>
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>

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>

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>

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>

The dev_close() call was added in commit c9eb3e0f ("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>

Currently the bridge emits atomic switchdev notifications for
dynamically learnt FDB entries. Monitoring these notifications works
wonders for switchdev drivers that want to keep their hardware FDB in
sync with the bridge's FDB.

For example station A wants to talk to station B in the diagram below,
and we are concerned with the behavior of the bridge on the DUT device:

                   DUT
 +-------------------------------------+
 |                 br0                 |
 | +------+ +------+ +------+ +------+ |
 | |      | |      | |      | |      | |
 | | swp0 | | swp1 | | swp2 | | eth0 | |
 +-------------------------------------+
      |        |                  |
  Station A    |                  |
               |                  |
         +--+------+--+    +--+------+--+
         |  |      |  |    |  |      |  |
         |  | swp0 |  |    |  | swp0 |  |
 Another |  +------+  |    |  +------+  | Another
  switch |     br0    |    |     br0    | switch
         |  +------+  |    |  +------+  |
         |  |      |  |    |  |      |  |
         |  | swp1 |  |    |  | swp1 |  |
         +--+------+--+    +--+------+--+
                                  |
                              Station B

Interfaces swp0, swp1, swp2 are handled by a switchdev driver that has
the following property: frames injected from its control interface bypass
the internal address analyzer logic, and therefore, this hardware does
not learn from the source address of packets transmitted by the network
stack through it. So, since bridging between eth0 (where Station B is
attached) and swp0 (where Station A is attached) is done in software,
the switchdev hardware will never learn the source address of Station B.
So the traffic towards that destination will be treated as unknown, i.e.
flooded.

This is where the bridge notifications come in handy. When br0 on the
DUT sees frames with Station B's MAC address on eth0, the switchdev
driver gets these notifications and can install a rule to send frames
towards Station B's address that are incoming from swp0, swp1, swp2,
only towards the control interface. This is all switchdev driver private
business, which the notification makes possible.

All is fine until someone unplugs Station B's cable and moves it to the
other switch:

                   DUT
 +-------------------------------------+
 |                 br0                 |
 | +------+ +------+ +------+ +------+ |
 | |      | |      | |      | |      | |
 | | swp0 | | swp1 | | swp2 | | eth0 | |
 +-------------------------------------+
      |        |                  |
  Station A    |                  |
               |                  |
         +--+------+--+    +--+------+--+
         |  |      |  |    |  |      |  |
         |  | swp0 |  |    |  | swp0 |  |
 Another |  +------+  |    |  +------+  | Another
  switch |     br0    |    |     br0    | switch
         |  +------+  |    |  +------+  |
         |  |      |  |    |  |      |  |
         |  | swp1 |  |    |  | swp1 |  |
         +--+------+--+    +--+------+--+
               |
           Station B

Luckily for the use cases we care about, Station B is noisy enough that
the DUT hears it (on swp1 this time). swp1 receives the frames and
delivers them to the bridge, who enters the unlikely path in br_fdb_update
of updating an existing entry. It moves the entry in the software bridge
to swp1 and emits an addition notification towards that.

As far as the switchdev driver is concerned, all that it needs to ensure
is that traffic between Station A and Station B is not forever broken.
If it does nothing, then the stale rule to send frames for Station B
towards the control interface remains in place. But Station B is no
longer reachable via the control interface, but via a port that can
offload the bridge port learning attribute. It's just that the port is
prevented from learning this address, since the rule overrides FDB
updates. So the rule needs to go. The question is via what mechanism.

It sure would be possible for this switchdev driver to keep track of all
addresses which are sent to the control interface, and then also listen
for bridge notifier events on its own ports, searching for the ones that
have a MAC address which was previously sent to the control interface.
But this is cumbersome and inefficient. Instead, with one small change,
the bridge could notify of the address deletion from the old port, in a
symmetrical manner with how it did for the insertion. Then the switchdev
driver would not be required to monitor learn/forget events for its own
ports. It could just delete the rule towards the control interface upon
bridge entry migration. This would make hardware address learning be
possible again. Then it would take a few more packets until the hardware
and software FDB would be in sync again.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Heiner Kallweit says:

====================
r8169: improve RTL8168g PHY suspend quirk

According to Realtek the ERI register 0x1a8 quirk is needed to work
around a hw issue with the PHY on RTL8168g. The register needs to be
changed before powering down the PHY. Currently we don't meet this
requirement, however I'm not aware of any problems caused by this.
Therefore I see the change as an improvement.

The PHY driver has no means to access the chip ERI registers,
therefore we have to intercept MDIO writes to the BMCR register.
If the BMCR_PDOWN bit is going to be set, then let's apply the
quirk before actually powering down the PHY.
====================

Link: https://lore.kernel.org/r/9303c2cf-c521-beea-c09f-63b5dfa91b9c@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

According to Realtek the ERI register 0x1a8 quirk is needed to work
around a hw issue with the PHY on RTL8168g. The register needs to be
changed before powering down the PHY. Currently we don't meet this
requirement, however I'm not aware of any problems caused by this.
Therefore I see the change as an improvement.

The PHY driver has no means to access the chip ERI registers,
therefore we have to intercept MDIO writes to BMCR register.
If the BMCR_PDOWN bit is going to be set, then let's apply the
quirk before actually powering down the PHY.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

No functional change here. We just move a code block to avoid a
function forward declaration in a subsequent change.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Switch to lockdep_assert_held(_once), similar to what is being done
in other subsystems. One advantage is that there's zero runtime
overhead if lockdep support isn't enabled.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/ccc40b9d-8ee0-43a1-5009-2cc95ca79c85@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

BCM72116 features a 28nm integrated EPHY, add an entry to match this PHY
OUI.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210106170944.1253046-1-f.fainelli@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

udp_tunnel_nic: post conversion cleanup

It has been two releases since we added the common infra for UDP
tunnel port offload, and we have not heard of any major issues.
Remove the old direct driver NDOs completely, and perform minor
simplifications in the tunnel drivers.

Link: https://lore.kernel.org/r/20210106210637.1839662-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Move the NETIF_F_RX_UDP_TUNNEL_PORT feature check into
udp_tunnel_nic_*_port() helpers, since they're always
done right before the call.

Add similar checks before calling the notifier.
udp_tunnel_nic invokes the notifier without checking
features which could result in some wasted cycles.
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

All UDP tunnel port management is now routed via udp_tunnel_nic
infra directly. Remove the old callbacks.
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

udp_tunnel_nic handles REGISTER and UNREGISTER event, now that all
drivers use that infra we can drop the event handling in the tunnel
drivers.
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

All drivers use udp_tunnel_nic_*_port() helpers, prepare for
NDO removal by invoking those helpers directly.

The helpers are safe to call on all devices, they check if
device has the UDP tunnel state initialized.
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

All of the OF code that is used has stubbed and will compile and link
just fine, keeping COMPILE_TEST is enough.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210106191546.1358324-1-f.fainelli@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Sieng Piaw Liew says:

====================
bcm63xx_enet: major makeover of driver

This patch series aim to improve the bcm63xx_enet driver by integrating the
latest networking features, i.e. batched rx processing, BQL, build_skb,
etc.

The newer enetsw SoCs are found to be able to do unaligned rx DMA by adding
NET_IP_ALIGN padding which, combined with these patches, improved packet
processing performance by ~50% on BCM6328.

Older non-enetsw SoCs still benefit mainly from rx batching. Performance
improvement of ~30% is observed on BCM6333.

The BCM63xx SoCs are designed for routers. As such, having BQL is
beneficial as well as trivial to add.

v3:
* Simplify xmit_more patch by not moving around the code needlessly.
* Fix indentation in xmit_more patch.
* Fix indentation in build_skb patch.
* Split rx ring cleanup patch from build_skb patch and precede build_skb
  patch for better understanding, as suggested by Florian Fainelli.

v2:
* Add xmit_more support and rx loop improvisation patches.
* Moved BQL netdev_reset_queue() to bcm_enet_stop()/bcm_enetsw_stop()
  functions as suggested by Florian Fainelli.
* Improved commit messages.
====================

Link: https://lore.kernel.org/r/20210106144208.1935-1-liew.s.piaw@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Use existing rx processed count to track against budget, thereby making
budget decrement operation redundant.

rx_desc_count can be calculated outside the rx loop, making the loop a
bit smaller.
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We can increase the efficiency of rx path by using buffers to receive
packets then build SKBs around them just before passing into the network
stack. In contrast, preallocating SKBs too early reduces CPU cache
efficiency.

Check if we're in NAPI context when refilling RX. Normally we're almost
always running in NAPI context. Dispatch to napi_alloc_frag directly
instead of relying on netdev_alloc_frag which does the same but
with the overhead of local_bh_disable/enable.

Tested on BCM6328 320 MHz and iperf3 -M 512 to measure packet/sec
performance. Included netif_receive_skb_list and NET_IP_ALIGN
optimizations.

Before:
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-10.00  sec  49.9 MBytes  41.9 Mbits/sec  197         sender
[  4]   0.00-10.00  sec  49.3 MBytes  41.3 Mbits/sec            receiver

After:
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-30.00  sec   171 MBytes  47.8 Mbits/sec  272         sender
[  4]   0.00-30.00  sec   170 MBytes  47.6 Mbits/sec            receiver
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The rx SKB ring use the same code for cleanup at various points.
Combine them into a function to reduce lines of code.
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Use netdev_alloc_skb_ip_align on newer SoCs with integrated switch
(enetsw) when refilling RX. Increases packet processing performance
by 30% (with netif_receive_skb_list).

Non-enetsw SoCs cannot function with the extra pad so continue to use
the regular netdev_alloc_skb.

Tested on BCM6328 320 MHz and iperf3 -M 512 to measure packet/sec
performance.

Before:
[ ID] Interval Transfer Bandwidth Retr
[ 4] 0.00-30.00 sec 120 MBytes 33.7 Mbits/sec 277 sender
[ 4] 0.00-30.00 sec 120 MBytes 33.5 Mbits/sec receiver

After (+netif_receive_skb_list):
[ 4] 0.00-30.00 sec 155 MBytes 43.3 Mbits/sec 354 sender
[ 4] 0.00-30.00 sec 154 MBytes 43.1 Mbits/sec receiver
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Support bulking hardware TX queue by using netdev_xmit_more().
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add Byte Queue Limits support to reduce/remove bufferbloat in
bcm63xx_enet.
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Use netif_receive_skb_list to batch process rx skb.
Tested on BCM6328 320 MHz using iperf3 -M 512, increasing performance
by 12.5%.

Before:
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-30.00  sec   120 MBytes  33.7 Mbits/sec  277         sender
[  4]   0.00-30.00  sec   120 MBytes  33.5 Mbits/sec            receiver

After:
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-30.00  sec   136 MBytes  37.9 Mbits/sec  203         sender
[  4]   0.00-30.00  sec   135 MBytes  37.7 Mbits/sec            receiver
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When measuring the throughput (iperf3 + TCP) while routing on a
not-so-powerful device (Mediatek MT7621, 880MHz CPU), I noticed that I
achieved significantly lower speeds with QMI-based modems than for
example a USB LAN dongle. The CPU was saturated in all of my tests.

With the dongle I got ~300 Mbit/s, while I only measured ~200 Mbit/s
with the modems. All offloads, etc.  were switched off for the dongle,
and I configured the modems to use QMAP (16k aggregation). The tests
with the dongle were performed in my local (gigabit) network, while the
LTE network the modems were connected to delivers 700-800 Mbit/s.

Profiling the kernel revealed the cause of the performance difference.
In qmimux_rx_fixup(), an SKB is allocated for each packet contained in
the URB. This SKB has too little headroom, causing the check in
skb_cow() (called from ip_forward()) to fail. pskb_expand_head() is then
called and the SKB is reallocated. In the output from perf, I see that a
significant amount of time is spent in pskb_expand_head() + support
functions.

In order to ensure that the SKB has enough headroom, this commit
increases the amount of memory allocated in qmimux_rx_fixup() by
LL_MAX_HEADER. The reason for using LL_MAX_HEADER and not a more
accurate value, is that we do not know the type of the outgoing network
interface. After making this change, I achieve the same throughput with
the modems as with the dongle.
Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Link: https://lore.kernel.org/r/20210106122403.1321180-1-kristian.evensen@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Merge tag 'linux-can-next-for-5.12-20210106' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2021-01-06

The first 16 patches are by me and target the tcan4x5x SPI glue driver for the
m_can CAN driver. First there are a several cleanup commits, then the SPI
regmap part is converted to 8 bits per word, to make it possible to use that
driver on SPI controllers that only support the 8 bit per word mode (such as
the SPI cores on the raspberry pi).

Oliver Hartkopp contributes a patch for the CAN_RAW protocol. The getsockopt()
for CAN_RAW_FILTER is changed to return -ERANGE if the filterset does not fit
into the provided user space buffer.

The last two patches are by Joakim Zhang and add wakeup support to the flexcan
driver for the i.MX8QM SoC. The dt-bindings docs are extended to describe the
added property.

* tag 'linux-can-next-for-5.12-20210106' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next:
  can: flexcan: add CAN wakeup function for i.MX8QM
  dt-bindings: can: fsl,flexcan: add fsl,scu-index property to indicate a resource
  can: raw: return -ERANGE when filterset does not fit into user space buffer
  can: tcan4x5x: add support for half-duplex controllers
  can: tcan4x5x: rework SPI access
  can: tcan4x5x: add {wr,rd}_table
  can: tcan4x5x: add max_raw_{read,write} of 256
  can: tcan4x5x: tcan4x5x_regmap: set reg_stride to 4
  can: tcan4x5x: fix max register value
  can: tcan4x5x: tcan4x5x_regmap_init(): use spi as context pointer
  can: tcan4x5x: tcan4x5x_regmap_write(): remove not needed casts and replace 4 by sizeof
  can: tcan4x5x: rename regmap_spi_gather_write() -> tcan4x5x_regmap_gather_write()
  can: tcan4x5x: remove regmap async support
  can: tcan4x5x: tcan4x5x_bus: remove not needed read_flag_mask
  can: tcan4x5x: mark struct regmap_bus tcan4x5x_bus as constant
  can: tcan4x5x: move regmap code into seperate file
  can: tcan4x5x: rename tcan4x5x.c -> tcan4x5x-core.c
  can: tcan4x5x: beautify indention of tcan4x5x_of_match and tcan4x5x_id_table
  can: tcan4x5x: replace DEVICE_NAME by KBUILD_MODNAME
====================

Link: https://lore.kernel.org/r/20210107094900.173046-1-mkl@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

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.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The System Controller Firmware (SCFW) is a low-level system function
which runs on a dedicated Cortex-M core to provide power, clock, and
resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
(QM, QP), and i.MX8QX (QXP, DX). SCU driver manages the IPC interface
between host CPU and the SCU firmware running on M4.

For i.MX8QM, stop mode request is controlled by System Controller Unit(SCU)
firmware, this patch introduces FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW quirk
for this function.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201106105627.31061-6-qiangqing.zhang@nxp.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

For SoCs with SCU support, need setup stop mode via SCU firmware, so this
property can help indicate a resource in SCU firmware.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20201106105627.31061-3-qiangqing.zhang@nxp.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Multiple filters (struct can_filter) can be set with the setsockopt()
function, which was originally intended as a write-only operation.

As getsockopt() also provides a CAN_RAW_FILTER option to read back the
given filters, the caller has to provide an appropriate user space buffer.
In the case this buffer is too small the getsockopt() silently truncates
the filter information and gives no information about the needed space.
This is safe but not convenient for the programmer.

In net/core/sock.c the SO_PEERGROUPS sockopt had a similar requirement
and solved it by returning -ERANGE in the case that the provided data
does not fit into the given user space buffer and fills the required size
into optlen, so that the caller can retry with a matching buffer length.

This patch adopts this approach for CAN_RAW_FILTER getsockopt().
Reported-by: Phillip Schichtel <phillip@schich.tel>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-By: Phillip Schichtel <phillip@schich.tel>
Link: https://lore.kernel.org/r/20201216174928.21663-1-socketcan@hartkopp.netSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch adds back support for half-duplex controllers, which was removed in
the last patch.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-17-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch reworks the SPI access and fixes several probems:
- tcan4x5x_regmap_gather_write(), tcan4x5x_regmap_read():
  Do not place variable "addr" on stack and use it as buffer for SPI
  transfer. Buffers for SPI transfers must be allocated from DMA save
  memory.
- tcan4x5x_regmap_gather_write(), tcan4x5x_regmap_read():
  Halfe number of SPI transfers by using a single buffer + memcpy().
  This improves the performance, especially on SPI controllers, which
  use interrupt based transfers.
- Use "8" bits per word, not "32". This makes it possible to use this
  driver on SoCs like the Raspberry Pi, which SPI host controller
  drivers only support 8 bits per word.

Note: this breaks half duplex only controllers. Support for them will be
re-added in the next patch.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-16-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The memory space of the chip is not fully populated, so add a regmap range
table to document this.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-15-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>