Lino reports that on his system with bcmgenet as DSA master and KSZ9897
as a switch, rebooting or shutting down never works properly.
What does the bcmgenet driver have special to trigger this, that other
DSA masters do not? It has an implementation of ->shutdown which simply
calls its ->remove implementation. Otherwise said, it unregisters its
network interface on shutdown.
This message can be seen in a loop, and it hangs the reboot process there:
unregister_netdevice: waiting for eth0 to become free. Usage count = 3
So why 3?
A usage count of 1 is normal for a registered network interface, and any
virtual interface which links itself as an upper of that will increment
it via dev_hold. In the case of DSA, this is the call path:
dsa_slave_create
-> netdev_upper_dev_link
-> __netdev_upper_dev_link
-> __netdev_adjacent_dev_insert
-> dev_hold
So a DSA switch with 3 interfaces will result in a usage count elevated
by two, and netdev_wait_allrefs will wait until they have gone away.
Other stacked interfaces, like VLAN, watch NETDEV_UNREGISTER events and
delete themselves, but DSA cannot just vanish and go poof, at most it
can unbind itself from the switch devices, but that must happen strictly
earlier compared to when the DSA master unregisters its net_device, so
reacting on the NETDEV_UNREGISTER event is way too late.
It seems that it is a pretty established pattern to have a driver's
->shutdown hook redirect to its ->remove hook, so the same code is
executed regardless of whether the driver is unbound from the device, or
the system is just shutting down. As Florian puts it, it is quite a big
hammer for bcmgenet to unregister its net_device during shutdown, but
having a common code path with the driver unbind helps ensure it is well
tested.
So DSA, for better or for worse, has to live with that and engage in an
arms race of implementing the ->shutdown hook too, from all individual
drivers, and do something sane when paired with masters that unregister
their net_device there. The only sane thing to do, of course, is to
unlink from the master.
However, complications arise really quickly.
The pattern of redirecting ->shutdown to ->remove is not unique to
bcmgenet or even to net_device drivers. In fact, SPI controllers do it
too (see dspi_shutdown -> dspi_remove), and presumably, I2C controllers
and MDIO controllers do it too (this is something I have not researched
too deeply, but even if this is not the case today, it is certainly
plausible to happen in the future, and must be taken into consideration).
Since DSA switches might be SPI devices, I2C devices, MDIO devices, the
insane implication is that for the exact same DSA switch device, we
might have both ->shutdown and ->remove getting called.
So we need to do something with that insane environment. The pattern
I've come up with is "if this, then not that", so if either ->shutdown
or ->remove gets called, we set the device's drvdata to NULL, and in the
other hook, we check whether the drvdata is NULL and just do nothing.
This is probably not necessary for platform devices, just for devices on
buses, but I would really insist for consistency among drivers, because
when code is copy-pasted, it is not always copy-pasted from the best
sources.
So depending on whether the DSA switch's ->remove or ->shutdown will get
called first, we cannot really guarantee even for the same driver if
rebooting will result in the same code path on all platforms. But
nonetheless, we need to do something minimally reasonable on ->shutdown
too to fix the bug. Of course, the ->remove will do more (a full
teardown of the tree, with all data structures freed, and this is why
the bug was not caught for so long). The new ->shutdown method is kept
separate from dsa_unregister_switch not because we couldn't have
unregistered the switch, but simply in the interest of doing something
quick and to the point.
The big question is: does the DSA switch's ->shutdown get called earlier
than the DSA master's ->shutdown? If not, there is still a risk that we
might still trigger the WARN_ON in unregister_netdevice that says we are
attempting to unregister a net_device which has uppers. That's no good.
Although the reference to the master net_device won't physically go away
even if DSA's ->shutdown comes afterwards, remember we have a dev_hold
on it.
The answer to that question lies in this comment above device_link_add:
* A side effect of the link creation is re-ordering of dpm_list and the
* devices_kset list by moving the consumer device and all devices depending
* on it to the ends of these lists (that does not happen to devices that have
* not been registered when this function is called).
so the fact that DSA uses device_link_add towards its master is not
exactly for nothing. device_shutdown() walks devices_kset from the back,
so this is our guarantee that DSA's shutdown happens before the master's
shutdown.
Fixes: 2f1e8ea726 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/
Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ocelot tagger is a hot mess currently, it relies on memory
initialized by the attached driver for basic frame transmission.
This is against all that DSA tagging protocols stand for, which is that
the transmission and reception of a DSA-tagged frame, the data path,
should be independent from the switch control path, because the tag
protocol is in principle hot-pluggable and reusable across switches
(even if in practice it wasn't until very recently). But if another
driver like dsa_loop wants to make use of tag_ocelot, it couldn't.
This was done to have common code between Felix and Ocelot, which have
one bit difference in the frame header format. Quoting from commit
67c2404922 ("net: dsa: felix: create a template for the DSA tags on
xmit"):
Other alternatives have been analyzed, such as:
- Create a separate tag_seville.c: too much code duplication for just 1
bit field difference.
- Create a separate DSA_TAG_PROTO_SEVILLE under tag_ocelot.c, just like
tag_brcm.c, which would have a separate .xmit function. Again, too
much code duplication for just 1 bit field difference.
- Allocate the template from the init function of the tag_ocelot.c
module, instead of from the driver: couldn't figure out a method of
accessing the correct port template corresponding to the correct
tagger in the .xmit function.
The really interesting part is that Seville should have had its own
tagging protocol defined - it is not compatible on the wire with Ocelot,
even for that single bit. In principle, a packet generated by
DSA_TAG_PROTO_OCELOT when booted on NXP LS1028A would look in a certain
way, but when booted on NXP T1040 it would look differently. The reverse
is also true: a packet generated by a Seville switch would be
interpreted incorrectly by Wireshark if it was told it was generated by
an Ocelot switch.
Actually things are a bit more nuanced. If we concentrate only on the
DSA tag, what I said above is true, but Ocelot/Seville also support an
optional DSA tag prefix, which can be short or long, and it is possible
to distinguish the two taggers based on an integer constant put in that
prefix. Nonetheless, creating a separate tagger is still justified,
since the tag prefix is optional, and without it, there is again no way
to distinguish.
Claiming backwards binary compatibility is a bit more tough, since I've
already changed the format of tag_ocelot once, in commit 5124197ce5
("net: dsa: tag_ocelot: use a short prefix on both ingress and egress").
Therefore I am not very concerned with treating this as a bugfix and
backporting it to stable kernels (which would be another mess due to the
fact that there would be lots of conflicts with the other DSA_TAG_PROTO*
definitions). It's just simpler to say that the string values of the
taggers have ABI value starting with kernel 5.12, which will be when the
changing of tag protocol via /sys/class/net/<dsa-master>/dsa/tagging
goes live.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Injection Frame Header and Extraction Frame Header that the switch
prepends to frames over the NPI port is also prepended to frames
delivered over the CPU port module's queues.
Let's unify the handling of the frame headers by making the ocelot
driver call some helpers exported by the DSA tagger. Among other things,
this allows us to get rid of the strange cpu_to_be32 when transmitting
the Injection Frame Header on ocelot, since the packing API uses
network byte order natively (when "quirks" is 0).
The comments above ocelot_gen_ifh talk about setting pop_cnt to 3, and
the cpu extraction queue mask to something, but the code doesn't do it,
so we don't do it either.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In expectation of the new tag_ocelot_8021q tagger implementation, we
need to be able to do runtime switchover between one tagger and another.
So we must structure the existing code for the current NPI-based tagger
in a certain way.
We move the felix_npi_port_init function in expectation of the future
driver configuration necessary for tag_ocelot_8021q: we would like to
not have the NPI-related bits interspersed with the tag_8021q bits.
The conversion from this:
ocelot_write_rix(ocelot,
ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)),
ANA_PGID_PGID, PGID_UC);
to this:
cpu_flood = ANA_PGID_PGID_PGID(BIT(ocelot->num_phys_ports));
ocelot_rmw_rix(ocelot, cpu_flood, cpu_flood, ANA_PGID_PGID, PGID_UC);
is perhaps non-trivial, but is nonetheless non-functional. The PGID_UC
(replicator for unknown unicast) is already configured out of hardware
reset to flood to all ports except ocelot->num_phys_ports (the CPU port
module). All we change is that we use a read-modify-write to only add
the CPU port module to the unknown unicast replicator, as opposed to
doing a full write to the register.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We should be moving anything that isn't DSA-specific or SoC-specific out
of the felix DSA driver, and into the common mscc_ocelot switch library.
The number of traffic classes is one of the aspects that is common
between all ocelot switches, so it belongs in the library.
This patch also makes seville use 8 TX queues, and therefore enables
prioritization via the QOS_CLASS field in the NPI injection header.
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>
We'll need to read back the watermark thresholds and occupancy from
hardware (for devlink-sb integration), not only to write them as we did
so far in ocelot_port_set_maxlen. So introduce 2 new functions in struct
ocelot_ops, similar to wm_enc, and implement them for the 3 supported
mscc_ocelot switches.
Remove the INUSE and MAXUSE unpacking helpers for the QSYS_RES_STAT
register, because that doesn't scale with the number of switches that
mscc_ocelot supports now. They have different bit widths for the
watermarks, and we need function pointers to abstract that difference
away.
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>
Instead of reading these values from the reference manual and writing
them down into the driver, it appears that the hardware gives us the
option of detecting them dynamically.
The number of frame references corresponds to what the reference manual
notes, however it seems that the frame buffers are reported as slightly
less than the books would indicate. On VSC9959 (Felix), the books say it
should have 128KB of packet buffer, but the registers indicate only
129840 bytes (126.79 KB). Also, the unit of measurement for FREECNT from
the documentation of all these devices is incorrect (taken from an older
generation). This was confirmed by Younes Leroul from Microchip support.
Not having anything better to do with these values at the moment* (this
will change soon), let's just print them.
*The frame buffer size is, in fact, used to calculate the tail dropping
watermarks.
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 current assumption is that the felix DSA driver has flooding knobs
per traffic class, while ocelot switchdev has a single flooding knob.
This was correct for felix VSC9959 and ocelot VSC7514, but with the
introduction of seville VSC9953, we see a switch driven by felix.c which
has a single flooding knob.
So it is clear that we must do what should have been done from the
beginning, which is not to overwrite the configuration done by ocelot.c
in felix, but instead to teach the common ocelot library about the
differences in our switches, and set up the flooding PGIDs centrally.
The effect that the bogus iteration through FELIX_NUM_TC has upon
seville is quite dramatic. ANA_FLOODING is located at 0x00b548, and
ANA_FLOODING_IPMC is located at 0x00b54c. So the bogus iteration will
actually overwrite ANA_FLOODING_IPMC when attempting to write
ANA_FLOODING[1]. There is no ANA_FLOODING[1] in sevile, just ANA_FLOODING.
And when ANA_FLOODING_IPMC is overwritten with a bogus value, the effect
is that ANA_FLOODING_IPMC gets the value of 0x0003CF7D:
MC6_DATA = 61,
MC6_CTRL = 61,
MC4_DATA = 60,
MC4_CTRL = 0.
Because MC4_CTRL is zero, this means that IPv4 multicast control packets
are not flooded, but dropped. An invalid configuration, and this is how
the issue was actually spotted.
Reported-by: Eldar Gasanov <eldargasanov2@gmail.com>
Reported-by: Maxim Kochetkov <fido_max@inbox.ru>
Tested-by: Eldar Gasanov <eldargasanov2@gmail.com>
Fixes: 84705fc165 ("net: dsa: felix: introduce support for Seville VSC9953 switch")
Fixes: 3c7b51bd39 ("net: dsa: felix: allow flooding for all traffic classes")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201204175416.1445937-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The VSC9953 Seville switch has 2 megabits of buffer split into 4360
words of 60 bytes each. 2048 * 1024 is 2 megabytes instead of 2 megabits.
2 megabits is (2048 / 8) * 1024 = 256 * 1024.
Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Fixes: a63ed92d21 ("net: dsa: seville: fix buffer size of the queue system")
Link: https://lore.kernel.org/r/20201019050625.21533-1-fido_max@inbox.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Small conflict around locking in rxrpc_process_event() -
channel_lock moved to bundle in next, while state lock
needs _bh() from net.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is an upper bound to the value that a watermark may hold. That
upper bound is not immediately obvious during configuration, and it
might be possible to have accidental truncation.
Actually this has happened already, add a warning to prevent it from
happening again.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rejecting non-native endian BTF overlapped with the addition
of support for it.
The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the mscc_ocelot_switch_lib is common between a pure switchdev and
a DSA driver, the procedure of retrieving a net_device for a certain
port index differs, as those are registered by their individual
front-ends.
Up to now that has been dealt with by always passing the port index to
the switch library, but now, we're going to need to work with net_device
pointers from the tc-flower offload, for things like indev, or mirred.
It is not desirable to refactor that, so let's make sure that the flower
offload core has the ability to translate between a net_device and a
port index properly.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we are deriving these from the constants exposed by the
hardware, we can delete the static info we're keeping in the driver.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The numbers in struct vcap_props are not intuitive to derive, because
they are not a straightforward copy-and-paste from the reference manual
but instead rely on a fairly detailed level of understanding of the
layout of an entry in the TCAM and in the action RAM. For this reason,
bugs are very easy to introduce here.
Ease the work of hardware porters and read from hardware the constants
that were exported for this particular purpose. Note that this implies
that struct vcap_props can no longer be const.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As a preparation step for the offloading to ES0, let's create the
infrastructure for talking with this hardware block.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As a preparation step for the offloading to IS1, let's create the
infrastructure for talking with this hardware block.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the Ocelot switches there are 3 TCAMs: VCAP ES0, IS1 and IS2, which
have the same configuration interface, but different sets of keys and
actions. The driver currently only supports VCAP IS2.
In preparation of VCAP IS1 and ES0 support, the existing code must be
generalized to work with any VCAP.
In that direction, we should move the structures that depend upon VCAP
instantiation, like vcap_is2_keys and vcap_is2_actions, out of struct
ocelot and into struct vcap_props .keys and .actions, a structure that
is replicated 3 times, once per VCAP. We'll pass that structure as an
argument to each function that does the key and action packing - only
the control logic needs to distinguish between ocelot->vcap[VCAP_IS2]
or IS1 or ES0.
Another change is to make use of the newly introduced ocelot_target_read
and ocelot_target_write API, since the 3 VCAPs have the same registers
but put at different addresses.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since the actions are packed together in the action RAM, an incorrect
action width means that no action except the first one would behave
correctly.
The tc-flower offload has probably not been tested on this hardware
since its introduction.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are 2 goals that we follow:
- Reduce the header size
- Make the header size equal between RX and TX
The issue that required long prefix on RX was the fact that the ocelot
DSA tag, being put before Ethernet as it is, would overlap with the area
that a DSA master uses for RX filtering (destination MAC address
mainly).
Now that we can ask DSA to put the master in promiscuous mode, in theory
we could remove the prefix altogether and call it a day, but it looks
like we can't. Using no prefix on ingress, some packets (such as ICMP)
would be received, while others (such as PTP) would not be received.
This is because the DSA master we use (enetc) triggers parse errors
("MAC rx frame errors") presumably because it sees Ethernet frames with
a bad length. And indeed, when using no prefix, the EtherType (bytes
12-13 of the frame, bits 96-111) falls over the REW_VAL field from the
extraction header, aka the PTP timestamp.
When turning the short (32-bit) prefix on, the EtherType overlaps with
bits 64-79 of the extraction header, which are a reserved area
transmitted as zero by the switch. The packets are not dropped by the
DSA master with a short prefix. Actually, the frames look like this in
tcpdump (below is a PTP frame, with an extra dsa_8021q tag - dadb 0482 -
added by a downstream sja1105).
89:0c:a9:f2:01:00 > 88:80:00:0a:00:1d, 802.3, length 0: LLC, \
dsap Unknown (0x10) Individual, ssap ProWay NM (0x0e) Response, \
ctrl 0x0004: Information, send seq 2, rcv seq 0, \
Flags [Response], length 78
0x0000: 8880 000a 001d 890c a9f2 0100 0000 100f ................
0x0010: 0400 0000 0180 c200 000e 001f 7b63 0248 ............{c.H
0x0020: dadb 0482 88f7 1202 0036 0000 0000 0000 .........6......
0x0030: 0000 0000 0000 0000 0000 001f 7bff fe63 ............{..c
0x0040: 0248 0001 1f81 0500 0000 0000 0000 0000 .H..............
0x0050: 0000 0000 0000 0000 0000 0000 ............
So the short prefix is our new default: we've shortened our RX frames by
12 octets, increased TX by 4, and headers are now equal between RX and
TX. Note that we still need promiscuous mode for the DSA master to not
drop it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Two minor conflicts:
1) net/ipv4/route.c, adding a new local variable while
moving another local variable and removing it's
initial assignment.
2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
One pretty prints the port mode differently, whilst another
changes the driver to try and obtain the port mode from
the port node rather than the switch node.
Signed-off-by: David S. Miller <davem@davemloft.net>
Since these were copied from the Felix VCAP IS2 code, and only the
offsets were adjusted, the order of the bit fields is still wrong.
Fix it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Seville does not need to depend on PCI or on the ENETC MDIO controller.
There will also be other compile-time differences in the future.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While we don't plan on making any changes to this function, currently
this is the only remaining dependency between felix and seville, after
the PCS has been refactored out into pcs-lynx.c.
Duplicate this function in seville to break the dependency completely.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reindent these definitions to be in line with the rest of the driver.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some definitions were likely copied from
drivers/net/mdio/mdio-mscc-miim.c.
They are not necessary, remove them.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The overall idea (issue soft reset, enable memories, initialize
memories, enable core) is the same, so it would make sense that an
attempt is made to unify the procedures.
It is not immediately obvious that the fields are not part of the same
register targets, though. So add a comment.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As per documentation, proper startup sequence is:
* Enable memories
* Initialize memories
* Enable core
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is another one of these right above the readx_poll_status.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The VSC9953 Seville switch has 2 megabits of buffer split into 4360
words of 60 bytes each.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the helper functions introduced by the newly added
Lynx PCS MDIO module in the Felix VSC9959 and Seville VSC9953.
Instead of representing the PCS as a phy_device, a mdio_device structure
will be passed to the Lynx module which is now actually implementing all
the PCS configuration and status reporting.
All code previously used for PCS monitoring and runtime configuration
is removed and replaced will calls to the Lynx PCS operations.
Tested on the following SERDES protocols of LS1028A: 0x7777
(2500Base-X), 0x85bb (QSGMII), 0x9999 (SGMII) and 0x13bb (USXGMII).
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is another switch from Vitesse / Microsemi / Microchip, that has
10 ports (8 external, 2 internal) and is integrated into the Freescale /
NXP T1040 PowerPC SoC. It is very similar to Felix from NXP LS1028A,
except that this is a platform device and Felix is a PCI device, and it
doesn't support IEEE 1588 and TSN.
Like Felix, this driver configures its own PCS on the internal MDIO bus
using a phy_device abstraction for it (yes, it will be refactored to use
a raw mdio_device, like other phylink drivers do, but let's keep it like
that for now). But unlike Felix, the MDIO bus and the PCS are not from
the same vendor. The PCS is the same QorIQ/Layerscape PCS as found in
Felix/ENETC/DPAA*, but the internal MDIO bus that is used to access it
is actually an instantiation of drivers/net/phy/mdio-mscc-miim.c. But it
would be difficult to reuse that driver (it doesn't even use regmap, and
it's less than 200 lines of code), so we hand-roll here some internal
MDIO bus accessors within seville_vsc9953.c, which serves the purpose of
driving the PCS absolutely fine.
Also, same as Felix, the PCS doesn't support dynamic reconfiguration of
SerDes protocol, so we need to do pre-validation of PHY mode from device
tree and not let phylink change it.
Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>