linux.git/include/soc/mscc, branch v6.1.168

net: mscc: ocelot: treat 802.1ad tagged traffic as 802.1Q-untagged

2025-05-09T07:41:39+00:00

[ Upstream commit 36dd1141be70b5966906919714dc504a24c65ddf ]

I was revisiting the topic of 802.1ad treatment in the Ocelot switch [0]
and realized that not only is its basic VLAN classification pipeline
improper for offloading vlan_protocol 802.1ad bridges, but also improper
for offloading regular 802.1Q bridges already.

Namely, 802.1ad-tagged traffic should be treated as VLAN-untagged by
bridged ports, but this switch treats it as if it was 802.1Q-tagged with
the same VID as in the 802.1ad header. This is markedly different to
what the Linux bridge expects; see the "other_tpid()" function in
tools/testing/selftests/net/forwarding/bridge_vlan_aware.sh.

An idea came to me that the VCAP IS1 TCAM is more powerful than I'm
giving it credit for, and that it actually overwrites the classified VID
before the VLAN Table lookup takes place. In other words, it can be
used even to save a packet from being dropped on ingress due to VLAN
membership.

Add a sophisticated TCAM rule hardcoded into the driver to force the
switch to behave like a Linux bridge with vlan_filtering 1 vlan_protocol
802.1Q.

Regarding the lifetime of the filter: eventually the bridge will
disappear, and vlan_filtering on the port will be restored to 0 for
standalone mode. Then the filter will be deleted.

[0]: https://lore.kernel.org/netdev/20201009122947.nvhye4hvcha3tljh@skbuf/

Fixes: 7142529f1688 ("net: mscc: ocelot: add VLAN filtering")
Signed-off-by: Vladimir Oltean
Signed-off-by: David S. Miller
Stable-dep-of: 5ec6d7d737a4 ("net: mscc: ocelot: delete PVID VLAN when readding it as non-PVID")
Signed-off-by: Sasha Levin

net: mscc: ocelot: be resilient to loss of PTP packets during transmission

2024-12-19T17:08:54+00:00

[ Upstream commit b454abfab52543c44b581afc807b9f97fc1e7a3a ]

The Felix DSA driver presents unique challenges that make the simplistic
ocelot PTP TX timestamping procedure unreliable: any transmitted packet
may be lost in hardware before it ever leaves our local system.

This may happen because there is congestion on the DSA conduit, the
switch CPU port or even user port (Qdiscs like taprio may delay packets
indefinitely by design).

The technical problem is that the kernel, i.e. ocelot_port_add_txtstamp_skb(),
runs out of timestamp IDs eventually, because it never detects that
packets are lost, and keeps the IDs of the lost packets on hold
indefinitely. The manifestation of the issue once the entire timestamp
ID range becomes busy looks like this in dmesg:

mscc_felix 0000:00:00.5: port 0 delivering skb without TX timestamp
mscc_felix 0000:00:00.5: port 1 delivering skb without TX timestamp

At the surface level, we need a timeout timer so that the kernel knows a
timestamp ID is available again. But there is a deeper problem with the
implementation, which is the monotonically increasing ocelot_port->ts_id.
In the presence of packet loss, it will be impossible to detect that and
reuse one of the holes created in the range of free timestamp IDs.

What we actually need is a bitmap of 63 timestamp IDs tracking which one
is available. That is able to use up holes caused by packet loss, but
also gives us a unique opportunity to not implement an actual timer_list
for the timeout timer (very complicated in terms of locking).

We could only declare a timestamp ID stale on demand (lazily), aka when
there's no other timestamp ID available. There are pros and cons to this
approach: the implementation is much more simple than per-packet timers
would be, but most of the stale packets would be quasi-leaked - not
really leaked, but blocked in driver memory, since this algorithm sees
no reason to free them.

An improved technique would be to check for stale timestamp IDs every
time we allocate a new one. Assuming a constant flux of PTP packets,
this avoids stale packets being blocked in memory, but of course,
packets lost at the end of the flux are still blocked until the flux
resumes (nobody left to kick them out).

Since implementing per-packet timers is way too complicated, this should
be good enough.

Testing procedure:

Persistently block traffic class 5 and try to run PTP on it:
$ tc qdisc replace dev swp3 parent root taprio num_tc 8 \
	map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 \
	base-time 0 sched-entry S 0xdf 100000 flags 0x2
[  126.948141] mscc_felix 0000:00:00.5: port 3 tc 5 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS
$ ptp4l -i swp3 -2 -P -m --socket_priority 5 --fault_reset_interval ASAP --logSyncInterval -3
ptp4l[70.351]: port 1 (swp3): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[70.354]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[70.358]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE
[   70.394583] mscc_felix 0000:00:00.5: port 3 timestamp id 0
ptp4l[70.406]: timed out while polling for tx timestamp
ptp4l[70.406]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it
ptp4l[70.406]: port 1 (swp3): send peer delay response failed
ptp4l[70.407]: port 1 (swp3): clearing fault immediately
ptp4l[70.952]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1
[   71.394858] mscc_felix 0000:00:00.5: port 3 timestamp id 1
ptp4l[71.400]: timed out while polling for tx timestamp
ptp4l[71.400]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it
ptp4l[71.401]: port 1 (swp3): send peer delay response failed
ptp4l[71.401]: port 1 (swp3): clearing fault immediately
[   72.393616] mscc_felix 0000:00:00.5: port 3 timestamp id 2
ptp4l[72.401]: timed out while polling for tx timestamp
ptp4l[72.402]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it
ptp4l[72.402]: port 1 (swp3): send peer delay response failed
ptp4l[72.402]: port 1 (swp3): clearing fault immediately
ptp4l[72.952]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1
[   73.395291] mscc_felix 0000:00:00.5: port 3 timestamp id 3
ptp4l[73.400]: timed out while polling for tx timestamp
ptp4l[73.400]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it
ptp4l[73.400]: port 1 (swp3): send peer delay response failed
ptp4l[73.400]: port 1 (swp3): clearing fault immediately
[   74.394282] mscc_felix 0000:00:00.5: port 3 timestamp id 4
ptp4l[74.400]: timed out while polling for tx timestamp
ptp4l[74.401]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it
ptp4l[74.401]: port 1 (swp3): send peer delay response failed
ptp4l[74.401]: port 1 (swp3): clearing fault immediately
ptp4l[74.953]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1
[   75.396830] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 0 which seems lost
[   75.405760] mscc_felix 0000:00:00.5: port 3 timestamp id 0
ptp4l[75.410]: timed out while polling for tx timestamp
ptp4l[75.411]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it
ptp4l[75.411]: port 1 (swp3): send peer delay response failed
ptp4l[75.411]: port 1 (swp3): clearing fault immediately
(...)

Remove the blocking condition and see that the port recovers:
$ same tc command as above, but use "sched-entry S 0xff" instead
$ same ptp4l command as above
ptp4l[99.489]: port 1 (swp3): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[99.490]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[99.492]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE
[  100.403768] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 0 which seems lost
[  100.412545] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 1 which seems lost
[  100.421283] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 2 which seems lost
[  100.430015] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 3 which seems lost
[  100.438744] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 4 which seems lost
[  100.447470] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  100.505919] mscc_felix 0000:00:00.5: port 3 timestamp id 0
ptp4l[100.963]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1
[  101.405077] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  101.507953] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  102.405405] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  102.509391] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  103.406003] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  103.510011] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  104.405601] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  104.510624] mscc_felix 0000:00:00.5: port 3 timestamp id 0
ptp4l[104.965]: selected best master clock d858d7.fffe.00ca6d
ptp4l[104.966]: port 1 (swp3): assuming the grand master role
ptp4l[104.967]: port 1 (swp3): LISTENING to GRAND_MASTER on RS_GRAND_MASTER
[  105.106201] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.232420] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.359001] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.405500] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.485356] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.511220] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.610938] mscc_felix 0000:00:00.5: port 3 timestamp id 0
[  105.737237] mscc_felix 0000:00:00.5: port 3 timestamp id 0
(...)

Notice that in this new usage pattern, a non-congested port should
basically use timestamp ID 0 all the time, progressing to higher numbers
only if there are unacknowledged timestamps in flight. Compare this to
the old usage, where the timestamp ID used to monotonically increase
modulo OCELOT_MAX_PTP_ID.

In terms of implementation, this simplifies the bookkeeping of the
ocelot_port :: ts_id and ptp_skbs_in_flight. Since we need to traverse
the list of two-step timestampable skbs for each new packet anyway, the
information can already be computed and does not need to be stored.
Also, ocelot_port->tx_skbs is always accessed under the switch-wide
ocelot->ts_id_lock IRQ-unsafe spinlock, so we don't need the skb queue's
lock and can use the unlocked primitives safely.

This problem was actually detected using the tc-taprio offload, and is
causing trouble in TSN scenarios, which Felix (NXP LS1028A / VSC9959)
supports but Ocelot (VSC7514) does not. Thus, I've selected the commit
to blame as the one adding initial timestamping support for the Felix
switch.

Fixes: c0bcf537667c ("net: dsa: ocelot: add hardware timestamping support for Felix")
Signed-off-by: Vladimir Oltean 
Link: https://patch.msgid.link/20241205145519.1236778-5-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: mscc: ocelot: serialize access to the injection/extraction groups

2024-08-29T15:30:43+00:00

[ Upstream commit c5e12ac3beb0dd3a718296b2d8af5528e9ab728e ]

As explained by Horatiu Vultur in commit 603ead96582d ("net: sparx5: Add
spinlock for frame transmission from CPU") which is for a similar
hardware design, multiple CPUs can simultaneously perform injection
or extraction. There are only 2 register groups for injection and 2
for extraction, and the driver only uses one of each. So we'd better
serialize access using spin locks, otherwise frame corruption is
possible.

Note that unlike in sparx5, FDMA in ocelot does not have this issue
because struct ocelot_fdma_tx_ring already contains an xmit_lock.

I guess this is mostly a problem for NXP LS1028A, as that is dual core.
I don't think VSC7514 is. So I'm blaming the commit where LS1028A (aka
the felix DSA driver) started using register-based packet injection and
extraction.

Fixes: 0a6f17c6ae21 ("net: dsa: tag_ocelot_8021q: add support for PTP timestamping")
Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: mscc: ocelot: use ocelot_xmit_get_vlan_info() also for FDMA and register injection

2024-08-29T15:30:43+00:00

[ Upstream commit 67c3ca2c5cfe6a50772514e3349b5e7b3b0fac03 ]

Problem description
-------------------

On an NXP LS1028A (felix DSA driver) with the following configuration:

- ocelot-8021q tagging protocol
- VLAN-aware bridge (with STP) spanning at least swp0 and swp1
- 8021q VLAN upper interfaces on swp0 and swp1: swp0.700, swp1.700
- ptp4l on swp0.700 and swp1.700

we see that the ptp4l instances do not see each other's traffic,
and they all go to the grand master state due to the
ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES condition.

Jumping to the conclusion for the impatient
-------------------------------------------

There is a zero-day bug in the ocelot switchdev driver in the way it
handles VLAN-tagged packet injection. The correct logic already exists in
the source code, in function ocelot_xmit_get_vlan_info() added by commit
5ca721c54d86 ("net: dsa: tag_ocelot: set the classified VLAN during xmit").
But it is used only for normal NPI-based injection with the DSA "ocelot"
tagging protocol. The other injection code paths (register-based and
FDMA-based) roll their own wrong logic. This affects and was noticed on
the DSA "ocelot-8021q" protocol because it uses register-based injection.

By moving ocelot_xmit_get_vlan_info() to a place that's common for both
the DSA tagger and the ocelot switch library, it can also be called from
ocelot_port_inject_frame() in ocelot.c.

We need to touch the lines with ocelot_ifh_port_set()'s prototype
anyway, so let's rename it to something clearer regarding what it does,
and add a kernel-doc. ocelot_ifh_set_basic() should do.

Investigation notes
-------------------

Debugging reveals that PTP event (aka those carrying timestamps, like
Sync) frames injected into swp0.700 (but also swp1.700) hit the wire
with two VLAN tags:

00000000: 01 1b 19 00 00 00 00 01 02 03 04 05 81 00 02 bc
                                              ~~~~~~~~~~~
00000010: 81 00 02 bc 88 f7 00 12 00 2c 00 00 02 00 00 00
          ~~~~~~~~~~~
00000020: 00 00 00 00 00 00 00 00 00 00 00 01 02 ff fe 03
00000030: 04 05 00 01 00 04 00 00 00 00 00 00 00 00 00 00
00000040: 00 00

The second (unexpected) VLAN tag makes felix_check_xtr_pkt() ->
ptp_classify_raw() fail to see these as PTP packets at the link
partner's receiving end, and return PTP_CLASS_NONE (because the BPF
classifier is not written to expect 2 VLAN tags).

The reason why packets have 2 VLAN tags is because the transmission
code treats VLAN incorrectly.

Neither ocelot switchdev, nor felix DSA, declare the NETIF_F_HW_VLAN_CTAG_TX
feature. Therefore, at xmit time, all VLANs should be in the skb head,
and none should be in the hwaccel area. This is done by:

static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
					  netdev_features_t features)
{
	if (skb_vlan_tag_present(skb) &&
	    !vlan_hw_offload_capable(features, skb->vlan_proto))
		skb = __vlan_hwaccel_push_inside(skb);
	return skb;
}

But ocelot_port_inject_frame() handles things incorrectly:

	ocelot_ifh_port_set(ifh, port, rew_op, skb_vlan_tag_get(skb));

void ocelot_ifh_port_set(struct sk_buff *skb, void *ifh, int port, u32 rew_op)
{
	(...)
	if (vlan_tag)
		ocelot_ifh_set_vlan_tci(ifh, vlan_tag);
	(...)
}

The way __vlan_hwaccel_push_inside() pushes the tag inside the skb head
is by calling:

static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
{
	skb->vlan_present = 0;
}

which does _not_ zero out skb->vlan_tci as seen by skb_vlan_tag_get().
This means that ocelot, when it calls skb_vlan_tag_get(), sees
(and uses) a residual skb->vlan_tci, while the same VLAN tag is
_already_ in the skb head.

The trivial fix for double VLAN headers is to replace the content of
ocelot_ifh_port_set() with:

	if (skb_vlan_tag_present(skb))
		ocelot_ifh_set_vlan_tci(ifh, skb_vlan_tag_get(skb));

but this would not be correct either, because, as mentioned,
vlan_hw_offload_capable() is false for us, so we'd be inserting dead
code and we'd always transmit packets with VID=0 in the injection frame
header.

I can't actually test the ocelot switchdev driver and rely exclusively
on code inspection, but I don't think traffic from 8021q uppers has ever
been injected properly, and not double-tagged. Thus I'm blaming the
introduction of VLAN fields in the injection header - early driver code.

As hinted at in the early conclusion, what we _want_ to happen for
VLAN transmission was already described once in commit 5ca721c54d86
("net: dsa: tag_ocelot: set the classified VLAN during xmit").

ocelot_xmit_get_vlan_info() intends to ensure that if the port through
which we're transmitting is under a VLAN-aware bridge, the outer VLAN
tag from the skb head is stripped from there and inserted into the
injection frame header (so that the packet is processed in hardware
through that actual VLAN). And in all other cases, the packet is sent
with VID=0 in the injection frame header, since the port is VLAN-unaware
and has logic to strip this VID on egress (making it invisible to the
wire).

Fixes: 08d02364b12f ("net: mscc: fix the injection header")
Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: mscc: ocelot: don't keep PTP configuration of all ports in single structure

2023-07-19T14:22:01+00:00

[ Upstream commit 45d0fcb5bc9558d0bf3d2fa7fabc5d8a88d35439 ]

In a future change, the driver will need to determine whether PTP RX
timestamping is enabled on a port (including whether traps were set up
on that port in particular) and that is currently not possible.

The driver supports different RX filters (L2, L4) and kinds of TX
timestamping (one-step, two-step) on its ports, but it saves all
configuration in a single struct hwtstamp_config that is global to the
switch. So, the latest timestamping configuration on one port
(including a request to disable timestamping) affects what gets reported
for all ports, even though the configuration itself is still individual
to each port.

The port timestamping configurations are only coupled because of the
common structure, so replace the hwtstamp_config with a mask of trapped
protocols saved per port. We also have the ptp_cmd to distinguish
between one-step and two-step PTP timestamping, so with those 2 bits of
information we can fully reconstruct a descriptive struct
hwtstamp_config for each port, during the SIOCGHWTSTAMP ioctl.

Fixes: 4e3b0468e6d7 ("net: mscc: PTP Hardware Clock (PHC) support")
Fixes: 96ca08c05838 ("net: mscc: ocelot: set up traps for PTP packets")
Signed-off-by: Vladimir Oltean 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net: dsa: felix: add support for changing DSA master

2022-09-20T08:32:36+00:00

Changing the DSA master means different things depending on the tagging
protocol in use.

For NPI mode ("ocelot" and "seville"), there is a single port which can
be configured as NPI, but DSA only permits changing the CPU port
affinity of user ports one by one. So changing a user port to a
different NPI port globally changes what the NPI port is, and breaks the
user ports still using the old one.

To address this while still permitting the change of the NPI port,
require that the user ports which are still affine to the old NPI port
are down, and cannot be brought up until they are all affine to the same
NPI port.

The tag_8021q mode ("ocelot-8021q") is more flexible, in that each user
port can be freely assigned to one CPU port or to the other. This works
by filtering host addresses towards both tag_8021q CPU ports, and then
restricting the forwarding from a certain user port only to one of the
two tag_8021q CPU ports.

Additionally, the 2 tag_8021q CPU ports can be placed in a LAG. This
works by enabling forwarding via PGID_SRC from a certain user port
towards the logical port ID containing both tag_8021q CPU ports, but
then restricting forwarding per packet, via the LAG hash codes in
PGID_AGGR, to either one or the other.

When we change the DSA master to a LAG device, DSA guarantees us that
the LAG has at least one lower interface as a physical DSA master.
But DSA masters can come and go as lowers of that LAG, and
ds->ops->port_change_master() will not get called, because the DSA
master is still the same (the LAG). So we need to hook into the
ds->ops->port_lag_{join,leave} calls on the CPU ports and update the
logical port ID of the LAG that user ports are assigned to.

Signed-off-by: Vladimir Oltean 
Signed-off-by: Paolo Abeni

net: dsa: propagate extack to port_lag_join

2022-09-20T08:32:36+00:00

Drivers could refuse to offload a LAG configuration for a variety of
reasons, mainly having to do with its TX type. Additionally, since DSA
masters may now also be LAG interfaces, and this will translate into a
call to port_lag_join on the CPU ports, there may be extra restrictions
there. Propagate the netlink extack to this DSA method in order for
drivers to give a meaningful error message back to the user.

Signed-off-by: Vladimir Oltean 
Signed-off-by: Paolo Abeni

net: mscc: ocelot: share the common stat definitions between all drivers

2022-09-09T09:59:12+00:00

All switch families supported by the ocelot lib (ocelot, felix, seville)
export the same registers so far. But for example felix also has TSN
counters, while the others don't.

To reduce the bloat even further, create an OCELOT_COMMON_STATS() macro
which just lists all stats that are common between switches. The array
elements are still replicated among all of vsc9959_stats_layout,
vsc9953_stats_layout and ocelot_stats_layout.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

net: mscc: ocelot: minimize definitions for stats

2022-09-09T09:59:12+00:00

The current definition of struct ocelot_stat_layout is long-winded (4
lines per entry, and we have hundreds of entries), so we could make an
effort to use the C preprocessor and reduce the line count.

Create an implicit correspondence between enum ocelot_reg, which tells
us the register address (SYS_COUNT_RX_OCTETS etc) and enum ocelot_stat
which allows us to index the ocelot->stats array (OCELOT_STAT_RX_OCTETS
etc), and don't require us to specify both when we define what stats
each switch family has.

Create an OCELOT_STAT() macro that pairs only an enum ocelot_stat to an
enum ocelot_reg, and an OCELOT_STAT_ETHTOOL() macro which also contains
a name exported to the unstructured ethtool -S stringset API. For now,
we define all counters as having the OCELOT_STAT_ETHTOOL() kind, but we
will add more counters in the future which are not exported to the
unstructured ethtool -S.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

net: mscc: ocelot: harmonize names of SYS_COUNT_TX_AGING and OCELOT_STAT_TX_AGED

2022-09-09T09:59:12+00:00

The hardware counter is called C_TX_AGED, so rename SYS_COUNT_TX_AGING
to SYS_COUNT_TX_AGED. This will become important since we want to
minimize the way in which we declare struct ocelot_stat_layout elements,
using the C preprocessor.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller