<feed xmlns='http://www.w3.org/2005/Atom'>
<title>blaster4385/linux-IllusionX/drivers/net/ethernet/mscc, branch v6.12.10</title>
<subtitle>Linux kernel with personal config changes for arch linux</subtitle>
<id>http://git.tablaster.dev/blaster4385/linux-IllusionX/atom?h=v6.12.10</id>
<link rel='self' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/atom?h=v6.12.10'/>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/'/>
<updated>2024-12-27T13:02:02Z</updated>
<entry>
<title>net: mscc: ocelot: fix incorrect IFH SRC_PORT field in ocelot_ifh_set_basic()</title>
<updated>2024-12-27T13:02:02Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-12-12T16:55:45Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=a8836eae3288c351acd3b2743d2fad2a4ee2bd56'/>
<id>urn:sha1:a8836eae3288c351acd3b2743d2fad2a4ee2bd56</id>
<content type='text'>
[ Upstream commit 2d5df3a680ffdaf606baa10636bdb1daf757832e ]

Packets injected by the CPU should have a SRC_PORT field equal to the
CPU port module index in the Analyzer block (ocelot-&gt;num_phys_ports).

The blamed commit copied the ocelot_ifh_set_basic() call incorrectly
from ocelot_xmit_common() in net/dsa/tag_ocelot.c. Instead of calling
with "x", it calls with BIT_ULL(x), but the field is not a port mask,
but rather a single port index.

[ side note: this is the technical debt of code duplication :( ]

The error used to be silent and doesn't appear to have other
user-visible manifestations, but with new changes in the packing
library, it now fails loudly as follows:

------------[ cut here ]------------
Cannot store 0x40 inside bits 46-43 - will truncate
sja1105 spi2.0: xmit timed out
WARNING: CPU: 1 PID: 102 at lib/packing.c:98 __pack+0x90/0x198
sja1105 spi2.0: timed out polling for tstamp
CPU: 1 UID: 0 PID: 102 Comm: felix_xmit
Tainted: G        W        N 6.13.0-rc1-00372-gf706b85d972d-dirty #2605
Call trace:
 __pack+0x90/0x198 (P)
 __pack+0x90/0x198 (L)
 packing+0x78/0x98
 ocelot_ifh_set_basic+0x260/0x368
 ocelot_port_inject_frame+0xa8/0x250
 felix_port_deferred_xmit+0x14c/0x258
 kthread_worker_fn+0x134/0x350
 kthread+0x114/0x138

The code path pertains to the ocelot switchdev driver and to the felix
secondary DSA tag protocol, ocelot-8021q. Here seen with ocelot-8021q.

The messenger (packing) is not really to blame, so fix the original
commit instead.

Fixes: e1b9e80236c5 ("net: mscc: ocelot: fix QoS class for injected packets with "ocelot-8021q"")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Link: https://patch.msgid.link/20241212165546.879567-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: perform error cleanup in ocelot_hwstamp_set()</title>
<updated>2024-12-19T17:13:14Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-12-05T14:55:19Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=6a4c7173a64551f0dccb89f27f84cf073677ed6b'/>
<id>urn:sha1:6a4c7173a64551f0dccb89f27f84cf073677ed6b</id>
<content type='text'>
[ Upstream commit 43a4166349a254446e7a3db65f721c6a30daccf3 ]

An unsupported RX filter will leave the port with TX timestamping still
applied as per the new request, rather than the old setting. When
parsing the tx_type, don't apply it just yet, but delay that until after
we've parsed the rx_filter as well (and potentially returned -ERANGE for
that).

Similarly, copy_to_user() may fail, which is a rare occurrence, but
should still be treated by unwinding what was done.

Fixes: 96ca08c05838 ("net: mscc: ocelot: set up traps for PTP packets")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20241205145519.1236778-6-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: be resilient to loss of PTP packets during transmission</title>
<updated>2024-12-19T17:13:14Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-12-05T14:55:18Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=266ac61e59119a9d4c74fe2d35341e7babb6b68a'/>
<id>urn:sha1:266ac61e59119a9d4c74fe2d35341e7babb6b68a</id>
<content type='text'>
[ 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-&gt;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-&gt;tx_skbs is always accessed under the switch-wide
ocelot-&gt;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 &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20241205145519.1236778-5-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: ocelot-&gt;ts_id_lock and ocelot_port-&gt;tx_skbs.lock are IRQ-safe</title>
<updated>2024-12-19T17:13:13Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-12-05T14:55:17Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=2a80ea8b2541ebb6e710500a4adfe788052e5361'/>
<id>urn:sha1:2a80ea8b2541ebb6e710500a4adfe788052e5361</id>
<content type='text'>
[ Upstream commit 0c53cdb95eb4a604062e326636971d96dd9b1b26 ]

ocelot_get_txtstamp() is a threaded IRQ handler, requested explicitly as
such by both ocelot_ptp_rdy_irq_handler() and vsc9959_irq_handler().

As such, it runs with IRQs enabled, and not in hardirq context. Thus,
ocelot_port_add_txtstamp_skb() has no reason to turn off IRQs, it cannot
be preempted by ocelot_get_txtstamp(). For the same reason,
dev_kfree_skb_any_reason() will always evaluate as kfree_skb_reason() in
this calling context, so just simplify the dev_kfree_skb_any() call to
kfree_skb().

Also, ocelot_port_txtstamp_request() runs from NET_TX softirq context,
not with hardirqs enabled. Thus, ocelot_get_txtstamp() which shares the
ocelot_port-&gt;tx_skbs.lock lock with it, has no reason to disable hardirqs.

This is part of a larger rework of the TX timestamping procedure.
A logical subportion of the rework has been split into a separate
change.

Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20241205145519.1236778-4-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Stable-dep-of: b454abfab525 ("net: mscc: ocelot: be resilient to loss of PTP packets during transmission")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: improve handling of TX timestamp for unknown skb</title>
<updated>2024-12-19T17:13:13Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-12-05T14:55:16Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=123515f97cab450b42bdd61fb5e22d09deaccf3e'/>
<id>urn:sha1:123515f97cab450b42bdd61fb5e22d09deaccf3e</id>
<content type='text'>
[ Upstream commit b6fba4b3f0becb794e274430f3a0839d8ba31262 ]

This condition, theoretically impossible to trigger, is not really
handled well. By "continuing", we are skipping the write to SYS_PTP_NXT
which advances the timestamp FIFO to the next entry. So we are reading
the same FIFO entry all over again, printing stack traces and eventually
killing the kernel.

No real problem has been observed here. This is part of a larger rework
of the timestamp IRQ procedure, with this logical change split out into
a patch of its own. We will need to "goto next_ts" for other conditions
as well.

Fixes: 9fde506e0c53 ("net: mscc: ocelot: warn when a PTP IRQ is raised for an unknown skb")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20241205145519.1236778-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: fix memory leak on ocelot_port_add_txtstamp_skb()</title>
<updated>2024-12-19T17:13:13Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-12-05T14:55:15Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=b12cdb8f2e9c72f5f6d07d00ff44f5564c22856e'/>
<id>urn:sha1:b12cdb8f2e9c72f5f6d07d00ff44f5564c22856e</id>
<content type='text'>
[ Upstream commit 4b01bec25bef62544228bce06db6a3afa5d3d6bb ]

If ocelot_port_add_txtstamp_skb() fails, for example due to a full PTP
timestamp FIFO, we must undo the skb_clone_sk() call with kfree_skb().
Otherwise, the reference to the skb clone is lost.

Fixes: 52849bcf0029 ("net: mscc: ocelot: avoid overflowing the PTP timestamp FIFO")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Link: https://patch.msgid.link/20241205145519.1236778-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: Remove setting of RX software timestamp</title>
<updated>2024-09-10T00:44:41Z</updated>
<author>
<name>Gal Pressman</name>
<email>gal@nvidia.com</email>
</author>
<published>2024-09-06T14:46:26Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=0de3c713e9b8b1085a1454122268f16aeeb3ee9b'/>
<id>urn:sha1:0de3c713e9b8b1085a1454122268f16aeeb3ee9b</id>
<content type='text'>
The responsibility for reporting of RX software timestamp has moved to
the core layer (see __ethtool_get_ts_info()), remove usage from the
device drivers.

Reviewed-by: Carolina Jubran &lt;cjubran@nvidia.com&gt;
Reviewed-by: Rahul Rameshbabu &lt;rrameshbabu@nvidia.com&gt;
Signed-off-by: Gal Pressman &lt;gal@nvidia.com&gt;
Link: https://patch.msgid.link/20240906144632.404651-11-gal@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: treat 802.1ad tagged traffic as 802.1Q-untagged</title>
<updated>2024-08-16T08:59:32Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-08-15T00:07:07Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=36dd1141be70b5966906919714dc504a24c65ddf'/>
<id>urn:sha1:36dd1141be70b5966906919714dc504a24c65ddf</id>
<content type='text'>
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 &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: serialize access to the injection/extraction groups</title>
<updated>2024-08-16T08:59:32Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-08-15T00:07:04Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=c5e12ac3beb0dd3a718296b2d8af5528e9ab728e'/>
<id>urn:sha1:c5e12ac3beb0dd3a718296b2d8af5528e9ab728e</id>
<content type='text'>
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 &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: mscc: ocelot: fix QoS class for injected packets with "ocelot-8021q"</title>
<updated>2024-08-16T08:59:32Z</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2024-08-15T00:07:03Z</published>
<link rel='alternate' type='text/html' href='http://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=e1b9e80236c540fa85d76e2d510d1b38e1968c5d'/>
<id>urn:sha1:e1b9e80236c540fa85d76e2d510d1b38e1968c5d</id>
<content type='text'>
There are 2 distinct code paths (listed below) in the source code which
set up an injection header for Ocelot(-like) switches. Code path (2)
lacks the QoS class and source port being set correctly. Especially the
improper QoS classification is a problem for the "ocelot-8021q"
alternative DSA tagging protocol, because we support tc-taprio and each
packet needs to be scheduled precisely through its time slot. This
includes PTP, which is normally assigned to a traffic class other than
0, but would be sent through TC 0 nonetheless.

The code paths are:

(1) ocelot_xmit_common() from net/dsa/tag_ocelot.c - called only by the
    standard "ocelot" DSA tagging protocol which uses NPI-based
    injection - sets up bit fields in the tag manually to account for
    a small difference (destination port offset) between Ocelot and
    Seville. Namely, ocelot_ifh_set_dest() is omitted out of
    ocelot_xmit_common(), because there's also seville_ifh_set_dest().

(2) ocelot_ifh_set_basic(), called by:
    - ocelot_fdma_prepare_skb() for FDMA transmission of the ocelot
      switchdev driver
    - ocelot_port_xmit() -&gt; ocelot_port_inject_frame() for
      register-based transmission of the ocelot switchdev driver
    - felix_port_deferred_xmit() -&gt; ocelot_port_inject_frame() for the
      DSA tagger ocelot-8021q when it must transmit PTP frames (also
      through register-based injection).
    sets the bit fields according to its own logic.

The problem is that (2) doesn't call ocelot_ifh_set_qos_class().
Copying that logic from ocelot_xmit_common() fixes that.

Unfortunately, although desirable, it is not easily possible to
de-duplicate code paths (1) and (2), and make net/dsa/tag_ocelot.c
directly call ocelot_ifh_set_basic()), because of the ocelot/seville
difference. This is the "minimal" fix with some logic duplicated (but
at least more consolidated).

Fixes: 0a6f17c6ae21 ("net: dsa: tag_ocelot_8021q: add support for PTP timestamping")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
</feed>
