With the introduction of explicit offloading API in switchdev in commit
2f5dc00f ("net: bridge: switchdev: let drivers inform which bridge
ports are offloaded"), we started having Ethernet switch drivers calling
directly into a function exported by net/bridge/br_switchdev.c, which is
a function exported by the bridge driver.

This means that drivers that did not have an explicit dependency on the
bridge before, like cpsw and am65-cpsw, now do - otherwise it is not
possible to call a symbol exported by a driver that can be built as
module unless you are a module too.

There was an attempt to solve the dependency issue in the form of commit
b0e81817 ("net: build all switchdev drivers as modules when the
bridge is a module"). Grygorii Strashko, however, says about it:

| In my opinion, the problem is a bit bigger here than just fixing the
| build :(
|
| In case, of ^cpsw the switchdev mode is kinda optional and in many
| cases (especially for testing purposes, NFS) the multi-mac mode is
| still preferable mode.
|
| There were no such tight dependency between switchdev drivers and
| bridge core before and switchdev serviced as independent, notification
| based layer between them, so ^cpsw still can be "Y" and bridge can be
| "M". Now for mostly every kernel build configuration the CONFIG_BRIDGE
| will need to be set as "Y", or we will have to update drivers to
| support build with BRIDGE=n and maintain separate builds for
| networking vs non-networking testing.  But is this enough?  Wouldn't
| it cause 'chain reaction' required to add more and more "Y" options
| (like CONFIG_VLAN_8021Q)?
|
| PS. Just to be sure we on the same page - ARM builds will be forced
| (with this patch) to have CONFIG_TI_CPSW_SWITCHDEV=m and so all our
| automation testing will just fail with omap2plus_defconfig.

In the light of this, it would be desirable for some configurations to
avoid dependencies between switchdev drivers and the bridge, and have
the switchdev mode as completely optional within the driver.

Arnd Bergmann also tried to write a patch which better expressed the
build time dependency for Ethernet switch drivers where the switchdev
support is optional, like cpsw/am65-cpsw, and this made the drivers
follow the bridge (compile as module if the bridge is a module) only if
the optional switchdev support in the driver was enabled in the first
place:
https://patchwork.kernel.org/project/netdevbpf/patch/20210802144813.1152762-1-arnd@kernel.org/

but this still did not solve the fact that cpsw and am65-cpsw now must
be built as modules when the bridge is a module - it just expressed
correctly that optional dependency. But the new behavior is an apparent
regression from Grygorii's perspective.

So to support the use case where the Ethernet driver is built-in,
NET_SWITCHDEV (a bool option) is enabled, and the bridge is a module, we
need a framework that can handle the possible absence of the bridge from
the running system, i.e. runtime bloatware as opposed to build-time
bloatware.

Luckily we already have this framework, since switchdev has been using
it extensively. Events from the bridge side are transmitted to the
driver side using notifier chains - this was originally done so that
unrelated drivers could snoop for events emitted by the bridge towards
ports that are implemented by other drivers (think of a switch driver
with LAG offload that listens for switchdev events on a bonding/team
interface that it offloads).

There are also events which are transmitted from the driver side to the
bridge side, which again are modeled using notifiers.
SWITCHDEV_FDB_ADD_TO_BRIDGE is an example of this, and deals with
notifying the bridge that a MAC address has been dynamically learned.
So there is a precedent we can use for modeling the new framework.

The difference compared to SWITCHDEV_FDB_ADD_TO_BRIDGE is that the work
that the bridge needs to do when a port becomes offloaded is blocking in
its nature: replay VLANs, MDBs etc. The calling context is indeed
blocking (we are under rtnl_mutex), but the existing switchdev
notification chain that the bridge is subscribed to is only the atomic
one. So we need to subscribe the bridge to the blocking switchdev
notification chain too.

This patch:
- keeps the driver-side perception of the switchdev_bridge_port_{,un}offload
  unchanged
- moves the implementation of switchdev_bridge_port_{,un}offload from
  the bridge module into the switchdev module.
- makes everybody that is subscribed to the switchdev blocking notifier
  chain "hear" offload & unoffload events
- makes the bridge driver subscribe and handle those events
- moves the bridge driver's handling of those events into 2 new
  functions called br_switchdev_port_{,un}offload. These functions
  contain in fact the core of the logic that was previously in
  switchdev_bridge_port_{,un}offload, just that now we go through an
  extra indirection layer to reach them.

Unlike all the other switchdev notification structures, the structure
used to carry the bridge port information, struct
switchdev_notifier_brport_info, does not contain a "bool handled".
This is because in the current usage pattern, we always know that a
switchdev bridge port offloading event will be handled by the bridge,
because the switchdev_bridge_port_offload() call was initiated by a
NETDEV_CHANGEUPPER event in the first place, where info->upper_dev is a
bridge. So if the bridge wasn't loaded, then the CHANGEUPPER event
couldn't have happened.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'linux-can-next-for-5.15-20210804' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2021-08-04

this is a pull request of 5 patches for net-next/master.

The first patch is by me and fixes a typo in a comment in the CAN
J1939 protocol.

The next 2 patches are by Oleksij Rempel and update the CAN J1939
protocol to send RX status updates via the error queue mechanism.

The next patch is by me and adds a missing variable initialization to
the flexcan driver (the problem was introduced in the current net-next
cycle).

The last patch is by Aswath Govindraju and adds power-domains to the
Bosch m_can DT binding documentation.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Document power-domains property for adding the Power domain provider.

Link: https://lore.kernel.org/r/20210802091822.16407-1-a-govindraju@ti.comSigned-off-by: Aswath Govindraju <a-govindraju@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch adds the missing initialization of the "err" variable in
the flexcan_clks_enable() function.

Fixes: d9cead75 ("can: flexcan: add mcf5441x support")
Link: https://lore.kernel.org/r/20210728075428.1493568-1-mkl@pengutronix.deReported-by: kernel test robot <lkp@intel.com>
Cc: Angelo Dureghello <angelo@kernel-space.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

To be able to create applications with user friendly feedback, we need be
able to provide receive status information.

Typical ETP transfer may take seconds or even hours. To give user some
clue or show a progress bar, the stack should push status updates.
Same as for the TX information, the socket error queue will be used with
following new signals:
- J1939_EE_INFO_RX_RTS   - received and accepted request to send signal.
- J1939_EE_INFO_RX_DPO   - received data package offset signal
- J1939_EE_INFO_RX_ABORT - RX session was aborted

Instead of completion signal, user will get data package.
To activate this signals, application should set
SOF_TIMESTAMPING_RX_SOFTWARE to the SO_TIMESTAMPING socket option. This
will avoid unpredictable application behavior for the old software.

Link: https://lore.kernel.org/r/20210707094854.30781-3-o.rempel@pengutronix.deSigned-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Prepare the world for the J1939_ERRQUEUE_RX_ version

Link: https://lore.kernel.org/r/20210707094854.30781-2-o.rempel@pengutronix.deSigned-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

As presented last month in our "BIG TCP" talk at netdev 0x15,
we plan using IPv6 jumbograms.

One of the minor problem we talked about is the fact that
ip6_parse_tlv() is currently using tables to list known tlvs,
thus using potentially expensive indirect calls.

While we could mitigate this cost using macros from
indirect_call_wrapper.h, we also can get rid of the tables
and let the compiler emit optimized code.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Justin Iurman <justin.iurman@uliege.be>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

DENG Qingfang says:

====================
mt7530 software fallback bridging fix

DSA core has gained software fallback support since commit 2f5dc00f,
but it does not work properly on mt7530. This patch series fixes the
issues.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 7e777021 ("mt7530 mt7530_fdb_write only set ivl
bit vid larger than 1").

Before this series, the default value of all ports' PVID is 1, which is
copied into the FDB entry, even if the ports are VLAN unaware. So
`bridge fdb show` will show entries like `dev swp0 vlan 1 self` even on
a VLAN-unaware bridge.

The blamed commit does not solve that issue completely, instead it may
cause a new issue that FDB is inaccessible in a VLAN-aware bridge with
PVID 1.

This series sets PVID to 0 on VLAN-unaware ports, so `bridge fdb show`
will no longer print `vlan 1` on VLAN-unaware bridges, and that special
case in fdb_write is not required anymore.

Set FDB entries' filter ID to 1 to match the VLAN table.
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As filter ID 1 is the only one used for bridges, set STP state on it.
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Consider the following bridge configuration, where bond0 is not
offloaded:

         +-- br0 --+
        / /   |     \
       / /    |      \
      /  |    |     bond0
     /   |    |     /   \
   swp0 swp1 swp2 swp3 swp4
     .        .       .
     .        .       .
     A        B       C

Ideally, when the switch receives a packet from swp3 or swp4, it should
forward the packet to the CPU, according to the port matrix and unknown
unicast flood settings.

But packet loss will happen if the destination address is at one of the
offloaded ports (swp0~2). For example, when client C sends a packet to
A, the FDB lookup will indicate that it should be forwarded to swp0, but
the port matrix of swp3 and swp4 is configured to only allow the CPU to
be its destination, so it is dropped.

However, this issue does not happen if the bridge is VLAN-aware. That is
because VLAN-aware bridges use independent VLAN learning, i.e. use VID
for FDB lookup, on offloaded ports. As swp3 and swp4 are not offloaded,
shared VLAN learning with default filter ID of 0 is used instead. So the
lookup for A with filter ID 0 never hits and the packet can be forwarded
to the CPU.

In the current code, only two combinations were used to toggle user
ports' VLAN awareness: one is PCR.PORT_VLAN set to port matrix mode with
PVC.VLAN_ATTR set to transparent port, the other is PCR.PORT_VLAN set to
security mode with PVC.VLAN_ATTR set to user port.

It turns out that only PVC.VLAN_ATTR contributes to VLAN awareness, and
port matrix mode just skips the VLAN table lookup. The reference manual
is somehow misleading when describing PORT_VLAN modes. It states that
PORT_MEM (VLAN port member) is used for destination if the VLAN table
lookup hits, but actually **PORT_MEM & PORT_MATRIX** (bitwise AND of
VLAN port member and port matrix) is used instead, which means we can
have two or more separate VLAN-aware bridges with the same PVID and
traffic won't leak between them.

Therefore, to solve this, enable independent VLAN learning with PVID 0
on VLAN-unaware bridges, by setting their PCR.PORT_VLAN to fallback
mode, while leaving standalone ports in port matrix mode. The CPU port
is always set to fallback mode to serve those bridges.

During testing, it is found that FDB lookup with filter ID of 0 will
also hit entries with VID 0 even with independent VLAN learning. To
avoid that, install all VLANs with filter ID of 1.
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Consider the following bridge configuration, where bond0 is not
offloaded:

         +-- br0 --+
        / /   |     \
       / /    |      \
      /  |    |     bond0
     /   |    |     /   \
   swp0 swp1 swp2 swp3 swp4
     .        .       .
     .        .       .
     A        B       C

Address learning is enabled on offloaded ports (swp0~2) and the CPU
port, so when client A sends a packet to C, the following will happen:

1. The switch learns that client A can be reached at swp0.
2. The switch probably already knows that client C can be reached at the
   CPU port, so it forwards the packet to the CPU.
3. The bridge core knows client C can be reached at bond0, so it
   forwards the packet back to the switch.
4. The switch learns that client A can be reached at the CPU port.
5. The switch forwards the packet to either swp3 or swp4, according to
   the packet's tag.

That makes client A's MAC address flap between swp0 and the CPU port. If
client B sends a packet to A, it is possible that the packet is
forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't
forward it back to the switch, resulting in packet loss.

As we have the assisted_learning_on_cpu_port in DSA core now, enable
that and disable hardware learning on the CPU port.
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Vladimir Oltean <oltean@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alex Elder says:

====================
net: ipa: prepare GSI interrupts for runtime PM

The last patch in this series arranges for GSI interrupts to be
disabled when the IPA hardware is suspended.  This ensures the clock
is always operational when a GSI interrupt fires.  Leading up to
that are patches that rearrange the code a bit to allow this to
be done.

The first two patches aren't *directly* related.  They remove some
flag arguments to some GSI suspend/resume related functions, using
the version field now present in the GSI structure.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce new functions gsi_suspend() and gsi_resume(), which will
disable the GSI interrupt handler after all endpoints are suspended
and re-enable it before endpoints are resumed.  This will ensure no
GSI interrupt handler will fire when the hardware is suspended.

Here's a little further explanation.  There are seven GSI interrupt
types, and most are disabled except when needed.
  - These two are not used (never enabled):
      GSI_INTER_EE_CH_CTRL
      GSI_INTER_EE_EV_CTRL
  - These two are only used to implement channel and event ring
    commands, and are only enabled while a command is underway:
      GSI_CH_CTRL
      GSI_EV_CTRL
  - The IEOB interrupt signals I/O completion.  It will not fire
    when a channel is stopped (or "suspended").
      GSI_IEOB
  - This interrupt is used to allocate or halt modem channels,
    and is only enabled while such a command is underway.
      GSI_GLOB_EE
    However it also is used to signal certain errors, and this could
    occur at any time.
  - The general interrupt signals general errors, and could occur at
    any time.
      GSI_GENERAL

The purpose for this change is to ensure no global or general
interrupts fire due to errors while the hardware is suspended.
We enable the clock on resume, and at that time we can "handle"
(at least report) these error conditions.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The GSI IRQ handler could be triggered as soon as it is registered
with request_irq().  The handler function, gsi_isr(), touches
hardware, meaning the IPA clock must be operational.  The IPA clock
is not operating when the handler is registered (in gsi_irq_init()),
so this is a problem.

Move the call to request_irq() for the GSI interrupt handler into
gsi_irq_setup(), which is called when the IPA clock is known to be
operational (and furthermore, the GSI firmware will have been
loaded).  Request the IRQ at the end of that function, after all
interrupt types have been disabled and masked.

Move the matching free_irq() call into gsi_irq_teardown(), and get
rid of the now empty gsi_irq_exit(),
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change gsi_irq_setup() so it returns an error value, and introduce
gsi_irq_teardown() as its inverse.  Set the interrupt type (IRQ
rather than MSI) in gsi_irq_setup().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move gsi_irq_setup() and gsi_ring_setup() so they're defined right
above gsi_setup() where they're called.  This is a trivial movement
of code to prepare for upcoming patches.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change the Boolean flags passed to __gsi_channel_start() and
__gsi_channel_stop() so they represent whether the request is being
made to implement suspend (versus stop) or resume (versus start).

Then stop or start the channel for suspend/resume requests only if
the hardware version indicates it should be done.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The GSI layer has the IPA version now, so there's no need for
version-specific flags to be passed from IPA.  One instance of
this is in gsi_channel_suspend() and gsi_channel_resume(), which
indicate whether or not the endpoint suspend is implemented by
GSI stopping the channel.  We can make that determination based
on gsi->version, eliminating the need for a Boolean flag in those
functions.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Loic Poulain says:

====================
net: mhi: move MBIM to WWAN

Implement a proper WWAN driver for MBIM network protocol, with multi link
management supported through the WWAN framework (wwan rtnetlink).

Until now, MBIM over MHI was supported directly in the mhi_net driver, via
some protocol rx/tx fixup callbacks, but with only one session supported
(no multilink muxing). We can then remove that part from mhi_net and restore
the driver to a simpler version for 'raw' ip transfer (or QMAP via rmnet link).

Note that a wwan0 link is created by default for session-id 0. Additional links
can be managed via ip tool:

    $ ip link add dev wwan0mms parentdev wwan0 type wwan linkid 1
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The MBIM protocol has now been integrated in a proper WWAN driver. We
can then revert back to a simpler driver for mhi_net, which is used
for raw IP or QMAP protocol (via rmnet link).

- Remove protocol management
- Remove WWAN framework usage (only valid for mbim)
- Remove net/mhi directory for simpler mhi_net.c file
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add new wwan driver for MBIM over MHI. MBIM is a transport protocol
for IP packets, allowing packet aggregation and muxing. Initially
designed for USB bus, it is also exposed through MHI bus for QCOM
based PCIe wwan modems.

This driver supports the new wwan rtnetlink interface for multi-link
management and has been tested with Quectel EM120R-GL M2 module.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
net: add netif_set_real_num_queues() for device reconfig

This short set adds a helper to make the implementation of
two-phase NIC reconfig easier.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Avoid reconfig problems due to failures in netif_set_real_num_tx_queues()
by using netif_set_real_num_queues().
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

netif_set_real_num_rx_queues() and netif_set_real_num_tx_queues()
can fail which breaks drivers trying to implement reconfiguration
in a way that can't leave the device half-broken. In other words
those functions are incompatible with prepare/commit approach.

Luckily setting real number of queues can fail only if the number
is increased, meaning that if we order operations correctly we
can guarantee ending up with either new config (success), or
the old one (on error).

Provide a helper implementing such logic so that drivers don't
have to duplicate it.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pass extack arg to validate_linkmsg and validate_link_af callbacks.
If a netlink attribute has a reject_message, use the extended ack
mechanism to carry the message back to user space.
Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds OOB support for AF_UNIX sockets.
The semantics is same as TCP.

The last byte of a message with the OOB flag is
treated as the OOB byte. The byte is separated into
a skb and a pointer to the skb is stored in unix_sock.
The pointer is used to enforce OOB semantics.
Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ioana Ciornei says:

====================
dpaa2-switch: integrate the MAC endpoint support

This patch set integrates the already available MAC support into the
dpaa2-switch driver as well.

The first 4 patches are fixing up some minor problems or optimizing the
code, while the remaining ones are actually integrating the dpaa2-mac
support into the switch driver by calling the dpaa2_mac_* provided
functions. While at it, we also export the MAC statistics in ethtool
like we do for dpaa2-eth.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

If a switch port is connected to a MAC, use the common dpaa2-mac support
for exporting the available MAC statistics.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the next patch, we'll add support for also exporting the MAC
statistics in the ethtool stats. Annotate already present HW stats with
a suggestive prefix.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Integrate the common MAC endpoint management support into the
dpaa2-switch driver as well. Nothing special happens here, just that the
already available dpaa2-mac functions are also called from dpaa2-switch.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In case of a switch DPAA2 object, the interface ID is also needed when
querying for the object endpoint. Extend fsl_mc_get_endpoint() so that
users can also pass the interface ID that are interested in.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The call to dpaa2_switch_port_link_state_update is a leftover from the
time when on DPAA2 platforms the PHYs were started at boot time so when
an ifconfig was issued on the associated interface, the link status
needed to be checked directly from the ndo_open() callback.  This is not
needed anymore since we are now properly integrated with the PHY layer
thus a link interrupt will come directly from the PHY eventually without
the need to call the sync function.
Fix this up by removing the call to dpaa2_switch_port_link_state_update.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We should not enable the switch interfaces at probe time since this is
trigged by the open callback. Remove the call dpsw_enable() which does
exactly this.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The MC firmware supplies us the switch interface index for which an
interrupt was triggered. Use this to our advantage instead of looping
through all the switch ports and doing unnecessary work.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Request all interrupt sources to be read and then cleared on the DPSW
object. In the next patches we'll also add support for treating other
interrupts.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch intends to fix MAC internal delay doesn't work, due to use
of_property_read_u32() incorrectly, and improve this feature a bit:
1) check the delay value if valid, only program register when it's 2000ps.
2) only enable "enet_2x_txclk" clock when require MAC internal delay.

Fixes: fc539459 ("net: fec: add MAC internal delayed clock feature support")
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20210803052424.19008-1-qiangqing.zhang@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Dan Carpenter's smatch tests report that the "vid" variable, populated
by sja1105_vlan_rcv when an skb is received by the tagger that has a
VLAN ID which cannot be decoded by tag_8021q, may be uninitialized when
used here:

	if (source_port == -1 || switch_id == -1)
		skb->dev = dsa_find_designated_bridge_port_by_vid(netdev, vid);

The sja1105 driver, by construction, sets up the switch in a way that
all data plane packets sent towards the CPU port are VLAN-tagged. So it
is practically impossible, in a functional system, for a packet to be
processed by sja1110_rcv() which is not a control packet and does not
have a VLAN header either.

However, it would be nice if the sja1105 tagging driver could
consistently do something valid, for example fail, even if presented with
packets that do not hold valid sja1105 tags. Currently it is a bit hard
to argue that it does that, given the fact that a data plane packet with
no VLAN tag will trigger a call to dsa_find_designated_bridge_port_by_vid
with a vid argument that is an uninitialized stack variable.

To fix this, we can initialize the u16 vid variable with 0, a value that
can never be a bridge VLAN, so dsa_find_designated_bridge_port_by_vid
will always return a NULL skb->dev.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210802195137.303625-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Nikolay points out that it is incorrect to assume that it is impossible
to have an fdb entry with fdb->dst == NULL and the BR_FDB_LOCAL bit in
fdb->flags not set. This is because there are reader-side places that
test_bit(BR_FDB_LOCAL, &fdb->flags) without the br->hash_lock, and if
the updating of the FDB entry happens on another CPU, there are no
memory barriers at writer or reader side which would ensure that the
reader sees the updates to both fdb->flags and fdb->dst in the same
order, i.e. the reader will not see an inconsistent FDB entry.

So we must be prepared to deal with FDB entries where fdb->dst and
fdb->flags are in a potentially inconsistent state, and that means that
fdb->dst == NULL should remain a condition to pick the net_device that
we report to switchdev as being the bridge device, which is what the
code did prior to the blamed patch.

Fixes: 52e4bec1 ("net: bridge: switchdev: treat local FDBs the same as entries towards the bridge")
Suggested-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20210802113633.189831-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit b79c6fba, reversing
these changes made to 0ac26271:

  commit 6a0eb6c9 ("dt-bindings: net: qcom,ipa: make imem interconnect
                       optional")
  commit f8bd3c82 ("arm64: dts: qcom: sc7280: add IPA information")
  commit fd0f72c3 ("arm64: dts: qcom: sc7180: define ipa_fw_mem node")

I intend for these commits to go through the Qualcomm repository, to
avoid conflicting with other activity being merged there.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20210802233019.800250-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>