Commit graph

21 commits

Author SHA1 Message Date
Daniel Golle
bcb3b83146 net: dsa: mxl862xx: fix use-after-free of DSA ports in crc_err_work
Upon an MDIO CRC error mxl862xx_crc_err_work_fn() walks the DSA ports
and closes the CPU port conduits:

	dsa_switch_for_each_cpu_port(dp, priv->ds)
		dev_close(dp->conduit);

mxl862xx_remove() unregisters the switch before cancelling this work:

	set_bit(MXL862XX_FLAG_WORK_STOPPED, &priv->flags);
	cancel_delayed_work_sync(&priv->stats_work);
	dsa_unregister_switch(ds);
	mxl862xx_host_shutdown(priv);

dsa_unregister_switch() frees the dsa_port objects. If a CRC error
schedules the work during teardown it can run after the ports have been
freed and dereference freed memory.

Guard the port walk with MXL862XX_FLAG_WORK_STOPPED, which is already set
before dsa_unregister_switch(). DSA tears the ports down under
rtnl_lock(), so checking the flag under rtnl_lock() means the work either
runs before teardown and sees valid ports, or runs afterwards, observes
the flag and skips the walk. This mirrors the host_flood_work handler,
which skips torn-down ports under rtnl_lock().

Link: https://sashiko.dev/#/patchset/cover.1780968180.git.daniel%40makrotopia.org?part=2
Fixes: a319d0c8c8 ("net: dsa: mxl862xx: add CRC for MDIO communication")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/5e55169926c02f2b914e5ada529d7453b943cda4.1781702256.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-24 17:51:11 -07:00
Daniel Golle
6b3f7af578 net: dsa: mxl862xx: avoid unaligned 16-bit access in api_wrap
The MXL862XX_API_* macros pass the address of a stack-allocated, __packed
firmware-ABI struct to mxl862xx_api_wrap() as a void *. The struct has an
alignment of 1, so the compiler is free to place it at an odd address.

mxl862xx_api_wrap() reinterprets that buffer as a __le16 * and accesses it
with data[i], for which the compiler assumes the natural 2-byte alignment
of __le16 and emits aligned 16-bit loads/stores (e.g. lhu/sh on MIPS).
When the buffer lands on an odd address these fault on architectures that
do not support unaligned access, such as MIPS32.

-Waddress-of-packed-member does not catch this: the packed origin is
laundered through the void * parameter, so the cast inside api_wrap looks
alignment-safe to the compiler and no warning is emitted.

Use get_unaligned_le16()/put_unaligned_le16() for the three 16-bit word
accesses. The byte accesses (*(u8 *)&data[i], crc16()) are already safe
and are left unchanged.

Link: https://sashiko.dev/#/patchset/cover.1781319534.git.daniel%40makrotopia.org?part=4
Fixes: 23794bec1c ("net: dsa: add basic initial driver for MxL862xx switches")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/599327521db465a534d277de53ab9b6cac01928b.1781702256.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-24 17:51:11 -07:00
Daniel Golle
13ea4d4888 net: dsa: mxl862xx: add support for SerDes ports
The MxL862xx has two XPCS/SerDes interfaces (XPCS0 for ports 9-12,
XPCS1 for ports 13-16). Each can operate in various single-lane modes
(SGMII, 1000Base-X, 2500Base-X, 10GBase-R, 10GBase-KR, USXGMII) or as
QSGMII or 10G_QXGMII providing four sub-ports per interface.

Implement phylink PCS operations using the firmware's XPCS API:

  - pcs_enable/pcs_disable: refcount the sub-ports sharing an XPCS
    and power it down once the last sub-port is released.
  - pcs_config: configure negotiation mode and CL37/SGMII advertising.
  - pcs_get_state: read link state and the link-partner ability word
    from firmware and decode using phylink's standard CL37, SGMII, and
    USXGMII decoders.
  - pcs_an_restart: restart CL37 or CL73 auto-negotiation.
  - pcs_link_up: force speed/duplex for SGMII.
  - pcs_inband_caps: report per-mode in-band status capabilities.

Register a PCS instance for each SerDes interface and
QSGMII/10G_QXGMII sub-ports during setup. Advertise the supported
interface modes in phylink_get_caps based on port number.

Firmware older than 1.0.84 lacks the XPCS API and instead configures
the SerDes itself, using defaults stored in flash. mac_select_pcs()
returns NULL in that case while the single-lane interface modes stay
advertised, so a CPU port keeps working in the firmware-configured
mode.

Lacking support for expressing PHY-side role modes in Linux only the
MAC-side of SGMII, QSGMII, USXGMII and 10G_QXGMII are implemented for
now.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/736e4df02e4cb8c530c1670cbe7efac20b5d696d.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:01 -07:00
Daniel Golle
7dab839724 net: dsa: mxl862xx: move API macros to mxl862xx-host.h
Move the MXL862XX_API_WRITE, MXL862XX_API_READ and
MXL862XX_API_READ_QUIET convenience macros from mxl862xx.c to
mxl862xx-host.h next to the mxl862xx_api_wrap() prototype they wrap.
This makes them available to other compilation units that include
mxl862xx-host.h, which is needed once the SerDes PCS code in
mxl862xx-phylink.c also calls firmware commands.

No functional change.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/914f57931e79cc3932a9f32813465c08d29cf4bf.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:01 -07:00
Daniel Golle
c103433200 net: dsa: mxl862xx: move phylink stubs to mxl862xx-phylink.c
Move the phylink MAC operations and get_caps callback from mxl862xx.c
into a dedicated mxl862xx-phylink.c file. This prepares for the SerDes
PCS implementation which adds substantial phylink/PCS code -- keeping
it in a separate file avoids function-position churn in the main
driver file.

No functional change.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/fb9336de94bef47a0834287cbca87954e5e4c795.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:00 -07:00
Daniel Golle
937137db79 net: dsa: mxl862xx: store firmware version for feature gating
Query the firmware version at init (already done in wait_ready),
cache it in priv->fw_version, and provide MXL862XX_FW_VER_MIN()
for version-gated code paths throughout the driver.

MXL862XX_FW_VER() packs major/minor/revision into a u32 with
bitwise shifts so that versions compare with natural ordering,
independent of host endianness.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/91a26a8ffeaa2ce1729f98347e93e779973976bb.1781319534.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-15 17:18:00 -07:00
Daniel Golle
a21d33a526 net: dsa: mxl862xx: implement .get_stats64
Poll free-running firmware RMON counters every 2 seconds and accumulate
deltas into 64-bit per-port statistics. 32-bit packet counters wrap
in ~220s at 10 Gbps line rate with minimum-size frames; the 2s polling
interval provides a comfortable margin. The .get_stats64 callback
forces a fresh poll so that counters are always up to date when queried.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/fa38548ba05866879e8912721edc91947ce4ff12.1775951347.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-13 16:46:43 -07:00
Daniel Golle
e6295d1246 net: dsa: mxl862xx: add ethtool statistics support
The MxL862xx firmware exposes per-port RMON counters through the
RMON_PORT_GET command, covering standard IEEE 802.3 MAC statistics
(unicast/multicast/broadcast packet and byte counts, collision
counters, pause frames) as well as hardware-specific counters such
as extended VLAN discard and MTU exceed events.

Add the RMON counter firmware API structures and command definitions.
Implement .get_strings, .get_sset_count, and .get_ethtool_stats for
legacy ethtool -S support. Implement .get_eth_mac_stats,
.get_eth_ctrl_stats, and .get_pause_stats for the standardized
IEEE 802.3 statistics interface.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/480be14d5ed51f3db7b1681b298044dbf8e87494.1775951347.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-13 16:46:43 -07:00
Daniel Golle
d587f9b6dc net: dsa: mxl862xx: implement VLAN functionality
Add VLAN support using both the Extended VLAN (EVLAN) engine and the
VLAN Filter (VF) engine in a hybrid architecture that allows a higher
number of VIDs than either engine could achieve alone.

The VLAN Filter engine handles per-port VID membership checks with
discard-unmatched semantics. The Extended VLAN engine handles PVID
insertion on ingress (via fixed catchall rules) and tag stripping on
egress (2 rules per untagged VID). Tagged-only VIDs need no EVLAN
egress rules at all, so they consume only a VF entry.

Both engines draw from shared 1024-entry hardware pools. The VF pool
is divided equally among user ports for VID membership, while the
EVLAN pool is partitioned into small fixed-size ingress blocks (7
entries of catchall rules per port) and fixed-size egress blocks for
tag stripping.

With 5 user ports this yields up to 204 VIDs per port (limited by VF),
of which up to 98 can be untagged (limited by EVLAN egress budget).
With 9 user ports the numbers are 113 total and 53 untagged.

Wire up .port_vlan_add, .port_vlan_del, and .port_vlan_filtering.
Reprogram all EVLAN rules when the PVID or filtering mode changes.
Detach blocks from the bridge port before freeing them on bridge leave
to satisfy the firmware's internal refcount.

Future optimizations could increase VID capacity by dynamically sizing
the egress EVLAN blocks based on actual per-port untagged VID counts
rather than worst-case pre-allocation, or by sharing EVLAN egress and
VLAN Filter blocks across ports with identical VID sets.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/9be29637675342b109a85fa08f5378800d9f7b78.1775581804.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-10 16:03:44 -07:00
Daniel Golle
71934b9e6f net: dsa: mxl862xx: don't skip early bridge port configuration
mxl862xx_bridge_port_set() is currently guarded by the
mxl8622_port->setup_done flag, as the early call to
mxl862xx_bridge_port_set() from mxl862xx_port_stp_state_set() would
otherwise cause a NULL-pointer dereference on unused ports which don't
have dp->cpu_dp despite not being a CPU port.

Using the setup_done flag (which is never set for unused ports),
however, also prevents mxl862xx_bridge_port_set() from configuring
user ports' single-port bridges early, which was unintended.

Fix this by returning early from mxl862xx_bridge_port_set() in case
dsa_port_is_unused().

Fixes: 340bdf9846 ("net: dsa: mxl862xx: implement bridge offloading")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/15962aac29ebe0a6eb77565451acff880c41ef33.1775581804.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-10 16:03:44 -07:00
Daniel Golle
3a4056ec7e net: dsa: mxl862xx: reject DSA_PORT_TYPE_DSA
DSA links aren't supported by the mxl862xx driver.

Instead of returning early from .port_setup when called for
DSA_PORT_TYPE_DSA ports rather return -EOPNOTSUPP and show an error
message.

The desired side-effect is that the framework will switch the port to
DSA_PORT_TYPE_UNUSED, so we can stop caring about DSA_PORT_TYPE_DSA in
all other places.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/b686f3a22d8a6e7d470e7aa98da811a996a229b9.1775581804.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-10 16:03:44 -07:00
Daniel Golle
340bdf9846 net: dsa: mxl862xx: implement bridge offloading
Implement joining and leaving bridges as well as add, delete and dump
operations on isolated FDBs, port MDB membership management, and
setting a port's STP state.

The switch supports a maximum of 63 bridges, however, up to 12 may
be used as "single-port bridges" to isolate standalone ports.
Allowing up to 48 bridges to be offloaded seems more than enough on
that hardware, hence that is set as max_num_bridges.

A total of 128 bridge ports are supported in the bridge portmap, and
virtual bridge ports have to be used eg. for link-aggregation, hence
potentially exceeding the number of hardware ports.

The firmware-assigned bridge identifier (FID) for each offloaded bridge
is stored in an array used to map DSA bridge num to firmware bridge ID,
avoiding the need for a driver-private bridge tracking structure.
Bridge member portmaps are rebuilt on join/leave using
dsa_switch_for_each_bridge_member().

As there are now more users of the BRIDGEPORT_CONFIG_SET API and the
state of each port is cached locally, introduce a helper function
mxl862xx_set_bridge_port(struct dsa_switch *ds, int port) which
applies the cached per-port state to hardware. For standalone user
ports (dp->bridge == NULL), it additionally resets the port to
single-port bridge state: CPU-only portmap, learning and flooding
disabled. The CPU port path sets its state explicitly before calling
this helper and is therefore not affected by the reset.

Note that MASK_VLAN_BASED_MAC_LEARNING is intentionally absent from
the firmware write mask. After mxl862xx_reset(), the firmware
initialises all VLAN-based MAC learning fields to 0 (disabled), so
SVL is the active mode by default without having to set it explicitly.

Note that there is no convenient way to control flooding on per-port
level, so the driver is using a 0-rate QoS meter setup as a stopper in
lack of any better option. In order to be perfect the firmware-enforced
minimum bucket size is bypassed by directly writing 0s to the relevant
registers -- without that at least one 64-byte packet could still
pass before the meter would change from 'yellow' into 'red' state.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/dd079180e2098e5f9626fcd149b9bad9a1b5a1b2.1775049897.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-06 18:30:33 -07:00
Daniel Golle
e9abf1da0a net: dsa: mxl862xx: cancel pending work on probe error
Call mxl862xx_host_shutdown() in case dsa_register_switch() returns
an error, so any still pending crc_err_work get canceled.

Fixes: a319d0c8c8 ("net: dsa: mxl862xx: add CRC for MDIO communication")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/3fd163f5bb88de426ca9847549f94b4296170ef0.1774911025.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-31 19:16:31 -07:00
Daniel Golle
7c20f6c1cf net: dsa: mxl862xx: use RST_DATA to skip writing zero words
Issue the firmware's RST_DATA command before writing data payloads that
contain many zero words. RST_DATA zeroes both the firmware's internal
buffer and the MMD data registers in a single command, allowing the
driver to skip individual MDIO writes for zero-valued words. This
reduces bus traffic for the common case where API structs have many
unused or default-zero fields.

The optimization is applied when at least 5 zero words are found in the
payload, roughly the break-even point against the cost of the extra
RST_DATA command round-trip.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/d10bd6ad5df062d0da342c3e0d330550b3d2432b.1774185953.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-24 20:47:21 -07:00
Daniel Golle
a319d0c8c8 net: dsa: mxl862xx: add CRC for MDIO communication
Enable the firmware's opt-in CRC validation on the MDIO/MMD command
interface to detect bit errors on the bus. The firmware bundles CRC-6
and CRC-16 under a single enable flag, so both are implemented
together.

CRC-6 protects the ctrl and len_ret command registers using a table-
driven 3GPP algorithm. It is applied to every command exchange
including SET_DATA/GET_DATA batch transfers. With CRC enabled, the
firmware encodes its return value as a signed 11-bit integer within
the CRC- protected register fields, replacing the previous 16-bit
interpretation.

CRC-16 protects the data payload using the kernel's crc16() library.
The driver appends a CRC-16 checksum to outgoing data and verifies the
firmware-appended checksum on responses. The checksum is placed at the
exact byte offset where the struct data ends, correctly handling
packed structs with odd sizes by splitting the checksum across word
boundaries. SET_DATA/GET_DATA sub-commands carry only CRC-6.

Upon detection of a CRC error on either side all conduit interfaces
are taken down, triggering all user ports to go down as well. This is
the most feasible option: CRC errors are likely caused either by
broken hardware, or are symptom of overheating. In either case, trying
to resume normal operation isn't reasonable.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/620453b9a150bbe5b7ea4224331cb5dc5e57263b.1774185953.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-24 20:47:21 -07:00
Daniel Golle
6b5f49176a net: dsa: mxl862xx: don't read out-of-bounds
The write loop in mxl862xx_api_wrap() computes the word count as
(size + 1) / 2, rounding up for odd-sized structs.

On the last iteration of an odd-sized buffer it reads a full __le16
from data[i], accessing one byte past the end of the caller's struct.
KASAN catches this as a stack-out-of-bounds read during probe (e.g.
from mxl862xx_bridge_config_fwd() because of the odd length of
sizeof(struct mxl862xx_bridge_config) == 49).

The read-back loop already handles this case, it writes only a single
byte when (i * 2 + 1) == size. The write loop lacked the same guard.

In practice the over-read is harmless: the extra stack byte is sent to
the firmware which ignores trailing data beyond the command's declared
payload size.

Apply the same odd-size last-byte handling to the write path: when the
final word contains only one valid byte, send *(u8 *)&data[i] instead
of le16_to_cpu(data[i]). This is endian-safe because data is
__le16-encoded and the low byte is always at the lowest address
regardless of host byte order.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/83356ad9c9a4470dd49b6b3d661c2a8dd85cc6a1.1773803190.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-20 18:27:09 -07:00
Jakub Kicinski
72374257ed Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-7.0-rc4).

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
  db25c42c2e ("net/mlx5e: RX, Fix XDP multi-buf frag counting for striding RQ")
  dff1c3164a ("net/mlx5e: SHAMPO, Always calculate page size")
https://lore.kernel.org/aa7ORohmf67EKihj@sirena.org.uk

drivers/net/ethernet/ti/am65-cpsw-nuss.c
  840c9d13cb ("net: ethernet: ti: am65-cpsw-nuss: Fix rx_filter value for PTP support")
  a23c657e33 ("net: ethernet: ti: am65-cpsw: Use also port number to identify timestamps")
https://lore.kernel.org/abK3EkIXuVgMyGI7@sirena.org.uk

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-12 12:53:34 -07:00
Daniel Golle
f441b489cc net: dsa: mxl862xx: don't set user_mii_bus
The PHY addresses in the MII bus are not equal to the port addresses,
so the bus cannot be assigned as user_mii_bus. Falling back on the
user_mii_bus in case a PHY isn't declared in device tree will result in
using the wrong (in this case: off-by-+1) PHY.
Remove the wrong assignment.

Fixes: 23794bec1c ("net: dsa: add basic initial driver for MxL862xx switches")
Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/0f0df310fd8cab57e0e5e3d0831dd057fd05bcd5.1773103271.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-10 19:18:13 -07:00
Daniel Golle
aefa52a28a net: dsa: mxl862xx: rename MDIO op arguments
The use of the 'port' argument name for functions implementing the MDIO
bus operations is misleading as the port address isn't equal to the
PHY address.

Rename the MDIO operation argument name to match the prototypes of
mdiobus_write, mdiobus_read, mdiobus_c45_read and mdiobus_c45_write.

Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/e1f4cb3bcffc7df9af0f2c9b673b14c7e1201c9a.1772507674.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-04 16:41:19 -08:00
Arnd Bergmann
458c95de5c net: dsa: MxL862xx: don't force-enable MAXLINEAR_GPHY
The newly added dsa driver attempts to enable the corresponding PHY driver,
but that one has additional dependencies that may not be available:

WARNING: unmet direct dependencies detected for MAXLINEAR_GPHY
  Depends on [m]: NETDEVICES [=y] && PHYLIB [=y] && (HWMON [=m] || HWMON [=m]=n [=n])
  Selected by [y]:
  - NET_DSA_MXL862 [=y] && NETDEVICES [=y] && NET_DSA [=y]
aarch64-linux-ld: drivers/net/phy/mxl-gpy.o: in function `gpy_probe':
mxl-gpy.c:(.text.gpy_probe+0x13c): undefined reference to `devm_hwmon_device_register_with_info'
aarch64-linux-ld: drivers/net/phy/mxl-gpy.o: in function `gpy_hwmon_read':
mxl-gpy.c:(.text.gpy_hwmon_read+0x48): undefined reference to `polynomial_calc'

There is actually no compile-time dependency, as DSA correctly uses the
PHY abstractions. Remove the 'select' statement to reduce the complexity.

Fixes: 23794bec1c ("net: dsa: add basic initial driver for MxL862xx switches")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/20260216105522.2382373-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-17 17:10:28 -08:00
Daniel Golle
23794bec1c net: dsa: add basic initial driver for MxL862xx switches
Add very basic DSA driver for MaxLinear's MxL862xx switches.

In contrast to previous MaxLinear switches the MxL862xx has a built-in
processor that runs a sophisticated firmware based on Zephyr RTOS.
Interaction between the host and the switch hence is organized using a
software API of that firmware rather than accessing hardware registers
directly.

Add descriptions of the most basic firmware API calls to access the
built-in MDIO bus hosting the 2.5GE PHYs, basic port control as well as
setting up the CPU port.

Implement a very basic DSA driver using that API which is sufficient to
get packets flowing between the user ports and the CPU port.

The firmware offers all features one would expect from a modern switch
hardware, they are going to be added one by one in follow-up patch
series.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/ccde07e8cf33d8ae243000013b57cfaa2695e0a9.1770433307.git.daniel@makrotopia.org
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-11 11:27:58 +01:00