This definition will be used when adding support for scanning and defines
the content of a beacon frame header as in the 802.15.4 specification.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230103165644.432209-3-miquel.raynal@bootlin.comSigned-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

The ieee802154 layer should be able to scan a set of channels in order
to look for beacons advertizing PANs. Supporting this involves adding
two user commands: triggering scans and aborting scans. The user should
also be notified when a new beacon is received and also upon scan
termination.

A scan request structure is created to list the requirements and to be
accessed asynchronously when changing channels or receiving beacons.

Mac layers may now implement the ->trigger_scan() and ->abort_scan()
hooks.
Co-developed-by: David Girault <david.girault@qorvo.com>
Signed-off-by: David Girault <david.girault@qorvo.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230103165644.432209-2-miquel.raynal@bootlin.comSigned-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

Roger Quadros says:

====================
net: ethernet: ti: am65-cpsw: Fix set channel operation

This contains a critical bug fix for the recently merged suspend/resume
support [1] that broke set channel operation. (ethtool -L eth0 tx <n>)

As there were 2 dependent patches on top of the offending commit [1]
first revert them and then apply them back after the correct fix.

[1] fd23df72 ("net: ethernet: ti: am65-cpsw: Add suspend/resume support")
====================

Link: https://lore.kernel.org/r/20221206094419.19478-1-rogerq@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

On low power during system suspend the ALE table context is lost.
Save the ALE context before suspend and restore it after resume.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

During suspend resume the context of PORT_VLAN_REG is lost so
save it during suspend and restore it during resume for
host port and slave ports.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add PM handlers for System suspend/resume.

As DMA driver doesn't yet support suspend/resume we free up
the DMA channels at suspend and acquire and initialize them
at resume.

In this revised approach we do not free the TX/RX IRQs at
am65_cpsw_nuss_common_stop() as it causes problems.
We will now free them only on .suspend() as we need to release
the DMA channels (as DMA looses context) and re-acquiring
them on .resume() may not necessarily give us the same
IRQs.

To make this easier:
- introduce am65_cpsw_nuss_remove_rx_chns() which is
   similar to am65_cpsw_nuss_remove_tx_chns(). These will
   be invoked in pm.suspend() to release the DMA channels
   and free up the IRQs.
- move napi_add() and request_irq() calls to
   am65_cpsw_nuss_init_rx/tx_chns() so we can invoke them
   in pm.resume() to acquire the DMA channels and IRQs.

As CPTS looses contect during suspend/resume, invoke the
necessary CPTS suspend/resume helpers.

ALE_CLEAR command is issued in cpsw_ale_start() so no need
to issue it before the call to cpsw_ale_start().
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit fd23df72.

This commit broke set channel operation. Revert this and
implement it with a different approach in a separate patch.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit 643cf0e3.

This is to make it easier to revert the offending commit
fd23df72 ("net: ethernet: ti: am65-cpsw: Add suspend/resume support")
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit 1af3cb37.

This is to make it easier to revert the offending commit
fd23df72 ("net: ethernet: ti: am65-cpsw: Add suspend/resume support")
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Shay Drory says:

====================
devlink: Add port function attribute to enable/disable Roce and migratable

This series is a complete rewrite of the series "devlink: Add port
function attribute to enable/disable roce"
link:
https://lore.kernel.org/netdev/20221102163954.279266-1-danielj@nvidia.com/

Currently mlx5 PCI VF and SF are enabled by default for RoCE
functionality. And mlx5 PCI VF is disable by dafault for migratable
functionality.

Currently a user does not have the ability to disable RoCE for a PCI
VF/SF device before such device is enumerated by the driver.

User is also incapable to do such setting from smartnic scenario for a
VF from the smartnic.

Current 'enable_roce' device knob is limited to do setting only at
driverinit time. By this time device is already created and firmware has
already allocated necessary system memory for supporting RoCE.

Also, Currently a user does not have the ability to enable migratable
for a PCI VF.

The above are a hyper visor level control, to set the functionality of
devices passed through to guests.

This is achieved by extending existing 'port function' object to control
capabilities of a function. This enables users to control capability of
the device before enumeration.

Examples when user prefers to disable RoCE for a VF when using switchdev
mode:

$ devlink port show pci/0000:06:00.0/1
pci/0000:06:00.0/1: type eth netdev pf0vf0 flavour pcivf controller 0
pfnum 0 vfnum 0 external false splittable false
  function:
    hw_addr 00:00:00:00:00:00 roce enable

$ devlink port function set pci/0000:06:00.0/1 roce disable

$ devlink port show pci/0000:06:00.0/1
pci/0000:06:00.0/1: type eth netdev pf0vf0 flavour pcivf controller 0
pfnum 0 vfnum 0 external false splittable false
  function:
    hw_addr 00:00:00:00:00:00 roce disable

FAQs:
-----
1. What does roce enable/disable do?
Ans: It disables RoCE capability of the function before its enumerated,
so when driver reads the capability from the device firmware, it is
disabled.
At this point RDMA stack will not be able to create UD, QP1, RC, XRC
type of QPs. When RoCE is disabled, the GID table of all ports of the
device is disabled in the device and software stack.

2. How is the roce 'port function' option different from existing
devlink param?
Ans: RoCE attribute at the port function level disables the RoCE
capability at the specific function level; while enable_roce only does
at the software level.

3. Why is this option for disabling only RoCE and not the whole RDMA
device?
Ans: Because user still wants to use the RDMA device for non RoCE
commands in more memory efficient way.
====================

Link: https://lore.kernel.org/r/20221206185119.380138-1-shayd@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Implement devlink port function commands to enable / disable migratable.
This is used to control the migratable capability of the device.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Acked-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Expose port function commands to enable / disable migratable
capability, this is used to set the port function as migratable.

Live migration is the process of transferring a live virtual machine
from one physical host to another without disrupting its normal
operation.

In order for a VM to be able to perform LM, all the VM components must
be able to perform migration. e.g.: to be migratable.
In order for VF to be migratable, VF must be bound to VFIO driver with
migration support.

When migratable capability is enabled for a function of the port, the
device is making the necessary preparations for the function to be
migratable, which might include disabling features which cannot be
migrated.

Example of LM with migratable function configuration:
Set migratable of the VF's port function.

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 migratable disable

$ devlink port function set pci/0000:06:00.0/2 migratable enable

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 migratable enable

Bind VF to VFIO driver with migration support:
$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/unbind
$ echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:08:00.0/driver_override
$ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/bind

Attach VF to the VM.
Start the VM.
Perform LM.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Implement devlink port function commands to enable / disable RoCE.
This is used to control the RoCE device capabilities.

This patch implement infrastructure which will be used by downstream
patches that will add additional capabilities.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Daniel Jurgens <danielj@nvidia.com>
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Acked-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Downstream patch requires to get other function GENERAL2 caps while
mlx5_vport_get_other_func_cap() gets only one type of caps (general).
Rename it to represent this and introduce a generic implementation
of mlx5_vport_get_other_func_cap().
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Acked-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Expose port function commands to enable / disable RoCE, this is used to
control the port RoCE device capabilities.

When RoCE is disabled for a function of the port, function cannot create
any RoCE specific resources (e.g GID table).
It also saves system memory utilization. For example disabling RoCE enable a
VF/SF saves 1 Mbytes of system memory per function.

Example of a PCI VF port which supports function configuration:
Set RoCE of the VF's port function.

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 roce enable

$ devlink port function set pci/0000:06:00.0/2 roce disable

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0
vfnum 1
    function:
        hw_addr 00:00:00:00:00:00 roce disable
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

devlink port function hw_addr attr documentation is in mlx5 specific
file while there is nothing mlx5 specific about it.
Move it to devlink-port.rst.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In order to avoid partial request processing, validate the request
before processing it.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Introduce IFC related capabilities to enable setting VF to be able to
perform live migration. e.g.: to be migratable.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Acked-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Ido Schimmel says:

====================
bridge: mcast: Preparations for EVPN extensions

This patchset was split from [1] and includes non-functional changes
aimed at making it easier to add additional netlink attributes later on.
Future extensions are available here [2].

The idea behind these patches is to create an MDB configuration
structure into which netlink messages are parsed into. The structure is
then passed in the entry creation / deletion call chain instead of
passing the netlink attributes themselves. The same pattern is used by
other rtnetlink objects such as routes and nexthops.

I initially tried to extend the current code, but it proved to be too
difficult, which is why I decided to refactor it to the extensible and
familiar pattern used by other rtnetlink objects.

Tested using existing selftests and using a new selftest that will be
submitted together with the planned extensions.

[1] https://lore.kernel.org/netdev/20221018120420.561846-1-idosch@nvidia.com/
[2] https://github.com/idosch/linux/commits/submit/mdb_v1
====================

Link: https://lore.kernel.org/r/20221206105809.363767-1-idosch@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The 'group' argument is not modified, so mark it as 'const'. It will
allow us to constify arguments of the callers of this function in future
patches.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Drop the first three arguments and instead extract them from the MDB
configuration structure.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The checks only require information parsed from the RTM_NEWMDB netlink
message and do not rely on any state stored in the bridge driver.
Therefore, there is no need to perform the checks in the critical
section under the multicast lock.

Move the checks out of the critical section.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The parsing of the netlink messages and the validity checks are now
performed in br_mdb_config_init() so we can remove br_mdb_parse().

This finally allows us to stop passing netlink attributes deep in the
MDB control path and only use the MDB configuration structure.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The MDB group key (i.e., {source, destination, protocol, VID}) is
currently determined under the multicast lock from the netlink
attributes. Instead, use the group key from the MDB configuration
structure that was prepared before acquiring the lock.

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As an intermediate step towards only using the new MDB configuration
structure, pass it further in the control path instead of passing
individual attributes.

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The MDB configuration structure (i.e., struct br_mdb_config) now
includes all the necessary information from the parsed RTM_{NEW,DEL}MDB
netlink messages, so use it.

This will later allow us to delete the calls to br_mdb_parse() from
br_mdb_add() and br_mdb_del().

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

These checks are now redundant as they are performed by
br_mdb_config_init() while parsing the RTM_{NEW,DEL}MDB messages.

Remove them.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Netlink attributes are currently passed deep in the MDB creation call
chain, making it difficult to add new attributes. In addition, some
validity checks are performed under the multicast lock although they can
be performed before it is ever acquired.

As a first step towards solving these issues, parse the RTM_{NEW,DEL}MDB
messages into a configuration structure, relieving other functions from
the need to handle raw netlink attributes.

Subsequent patches will convert the MDB code to use this configuration
structure.

This is consistent with how other rtnetlink objects are handled, such as
routes and nexthops.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/202212051918564721658@zte.com.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Merge tag 'ieee802154-for-net-next-2022-12-05' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan-next

Stefan Schmidt says:

====================
ieee802154-next 2022-12-05

Miquel continued his work towards full scanning support. For this,
we now allow the creation of dedicated coordinator interfaces
to allow a PAN coordinator to serve in the network and set
the needed address filters with the hardware.

On top of this we have the first part to allow scanning for available
15.4 networks. A new netlink scan group, within the existing nl802154
API, was added.

In addition Miquel fixed two issues that have been introduced in the former
patches to free an skb correctly and clarifying an expression in the stack.

From David Girault we got tracing support when registering new PANs.

* tag 'ieee802154-for-net-next-2022-12-05' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan-next:
  mac802154: Trace the registration of new PANs
  ieee802154: Advertize coordinators discovery
  mac802154: Allow the creation of coordinator interfaces
  mac802154: Clarify an expression
  mac802154: Move an skb free within the rx path
====================

Link: https://lore.kernel.org/r/20221205131909.1871790-1-stefan@datenfreihafen.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add ASIX based USB 10Base-T1L adapter support:
https://linux-automation.com/en/products/usb-t1l.htmlSigned-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20221205132102.2941732-1-o.rempel@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Hariprasad Kelam says:

====================
CN10KB MAC block support

OcteonTx2's next gen platform the CN10KB has RPM_USX MAC which has a
different serdes when compared to RPM MAC. Though the underlying
HW is different, the CSR interface has been designed largely inline
with RPM MAC, with few exceptions though. So we are using the same
CGX driver for RPM_USX MAC as well and will have a different set of APIs
for RPM_USX where ever necessary.

The RPM and RPM_USX blocks support a different number of LMACS.
RPM_USX support 8 LMACS per MAC block whereas legacy RPM supports only 4
LMACS per MAC. with this RPM_USX support double the number of DMAC filters
and fifo size.

This patchset adds initial support for CN10KB's RPM_USX  MAC i.e
registering the driver and defining MAC operations (mac_ops). With these
changes PF and VF netdev packet path will work and PF and VF netdev drivers
are able to configure MAC features like pause frames,PFC and loopback etc.

Also implements FEC stats for CN10K Mac block RPM and CN10KB Mac block
RPM_USX and extends ethtool support for PF and VF drivers by defining
get_fec_stats API to display FEC stats.
====================

Link: https://lore.kernel.org/r/20221205070521.21860-1-hkelam@marvell.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

CN10K silicon MAC block RPM and CN10KB silicon MAC block RPM_USX
both support BASER and RSFEC modes.

Also MAC (CGX) on OcteonTx2 silicon variants and MAC (RPM) on
OcteonTx3 CN10K are different and FEC stats need to be read
differently. CN10KB MAC block (RPM_USX) fec csr offsets are same
as CN10K MAC block (RPM) mac_ops points to same fn(). Upper layer
interface between  RVU AF and PF netdev is  kept same. Based on
silicon variant appropriate fn() pointer is called to  read FEC stats
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This patch registers a callback for get_fec_stats such that
FEC stats can be queried from the below command

"ethtool -I --show-fec eth0"
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

OcteonTx2's next gen platform the CN10KB has RPM_USX MAC which has a
different serdes when compared to RPM MAC. Though the underlying
HW is different, the CSR interface has been designed largely inline
with RPM MAC, with few exceptions though. So we are using the same
CGX driver for RPM_USX MAC as well and will have a different set of APIs
for RPM_USX where ever necessary.

The RPM and RPM_USX blocks support a different number of LMACS.
RPM_USX support 8 LMACS per MAC block whereas legacy RPM supports only 4
LMACS per MAC. with this RPM_USX support double the number of DMAC filters
and fifo size.

This patch adds initial support for CN10KB's RPM_USX  MAC i.e registering
the driver and defining MAC operations (mac_ops). Adds the logic to
configure internal loopback and pause frames and assign FIFO length to
LMACS.

Kernel reads lmac features like lmac type, autoneg, etc from shared
firmware data this structure only supports 4 lmacs per MAC, this patch
extends this structure to accommodate 8 lmacs.
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Most of the code in CGX/RPM driver assumes that max lmacs per
given MAC as always, 4 and the number of MAC blocks also as 4.
With this assumption, the max number of interfaces supported is
hardcoded to 16. This creates a problem as next gen CN10KB silicon
MAC supports 8 lmacs per MAC block.

This patch solves the problem by using "max lmac per MAC block"
value from constant csrs and uses cgx_cnt_max value which is
populated based number of MAC blocks supported by silicon.
Signed-off-by: Rakesh Babu Saladi <rsaladi2@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Oleksij Rempel says:

====================
net: dsa: microchip: add MTU support for KSZ8 series
====================

Link: https://lore.kernel.org/r/20221205052232.2834166-1-o.rempel@pengutronix.deSigned-off-by: Paolo Abeni <pabeni@redhat.com>

To make the code more comparable to KSZ9477 code, move DSA
configurations to the same location.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

KSZ8795 and KSZ9477 compatible series of switches use global max frame
size configuration register. So, enable MTU normalization for this reason.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Make MTU configurable on KSZ87xx and KSZ88xx series of switches.

Before this patch, pre-configured behavior was different on different
switch series, due to opposite meaning of the same bit:
- KSZ87xx: Reg 4, Bit 1 - if 1, max frame size is 1532; if 0 - 1514
- KSZ88xx: Reg 4, Bit 1 - if 1, max frame size is 1514; if 0 - 1532

Since the code was telling "... SW_LEGAL_PACKET_DISABLE, true)", I
assume, the idea was to set max frame size to 1532.

With this patch, by setting MTU size 1500, both switch series will be
configured to the 1532 frame limit.

This patch was tested on KSZ8873.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>