200 Commits

Author SHA1 Message Date
Vladimir Oltean
8fbd24f3d1 net: mscc: ocelot: add TX timestamping statistics
Add an u64 hardware timestamping statistics structure for each ocelot
port. Export a function from the common switch library for reporting
them to ethtool. This is called by the ocelot switchdev front-end for
now.

Note that for the switchdev driver, we report the one-step PTP packets
as unconfirmed, even though in principle, for some transmission
mechanisms like FDMA, we may be able to confirm transmission and bump
the "pkts" counter in ocelot_fdma_tx_cleanup() instead. I don't have
access to hardware which uses the switchdev front-end, and I've kept the
implementation simple.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250116104628.123555-4-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-17 20:01:10 -08:00
Vladimir Oltean
b454abfab5 net: mscc: ocelot: be resilient to loss of PTP packets during transmission
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: c0bcf53766 ("net: dsa: ocelot: add hardware timestamping support for Felix")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241205145519.1236778-5-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-07 17:56:46 -08:00
Vladimir Oltean
36dd1141be net: mscc: ocelot: treat 802.1ad tagged traffic as 802.1Q-untagged
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: 7142529f16 ("net: mscc: ocelot: add VLAN filtering")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-16 09:59:32 +01:00
Vladimir Oltean
c5e12ac3be net: mscc: ocelot: serialize access to the injection/extraction groups
As explained by Horatiu Vultur in commit 603ead9658 ("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: 0a6f17c6ae ("net: dsa: tag_ocelot_8021q: add support for PTP timestamping")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-16 09:59:32 +01:00
Vladimir Oltean
67c3ca2c5c net: mscc: ocelot: use ocelot_xmit_get_vlan_info() also for FDMA and register injection
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
5ca721c54d ("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 5ca721c54d
("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: 08d02364b1 ("net: mscc: fix the injection header")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-16 09:59:32 +01:00
Kory Maincent
2111375b85 net: Add struct kernel_ethtool_ts_info
In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.

Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.

Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-15 08:02:26 -07:00
Yue Haibing
49e62a0462 net: mscc: ocelot: Remove unused declarations
Commit 6c30384eb1 ("net: mscc: ocelot: register devlink ports")
declared but never implemented ocelot_devlink_init() and
ocelot_devlink_teardown().
Commit 2096805497 ("net: mscc: ocelot: automatically detect VCAP constants")
declared but never implemented ocelot_detect_vcap_constants().
Commit 403ffc2c34 ("net: mscc: ocelot: add support for preemptible traffic classes")
declared but never implemented ocelot_port_update_preemptible_tcs().

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230821130218.19096-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-22 10:29:15 -07:00
Vladimir Oltean
c60819149b net: dsa: felix: make vsc9959_tas_guard_bands_update() visible to ocelot->ops
In a future change we will need to make
ocelot_port_update_active_preemptible_tcs() call
vsc9959_tas_guard_bands_update(), but that is currently not possible,
since the ocelot switch lib does not have access to functions private to
the DSA wrapper.

Move the pointer to vsc9959_tas_guard_bands_update() from felix->info
(which is private to the DSA driver) to ocelot->ops (which is also
visible to the ocelot switch lib).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Message-ID: <20230705104422.49025-3-vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-06 19:10:22 -07:00
Vladimir Oltean
009d30f1a7 net: mscc: ocelot: extend ocelot->fwd_domain_lock to cover ocelot->tas_lock
In a future commit we will have to call vsc9959_tas_guard_bands_update()
from ocelot_port_update_active_preemptible_tcs(), and that will be
impossible due to the AB/BA locking dependencies between
ocelot->tas_lock and ocelot->fwd_domain_lock.

Just like we did in commit 3ff468ef98 ("net: mscc: ocelot: remove
struct ocelot_mm_state :: lock"), the only solution is to expand the
scope of ocelot->fwd_domain_lock for it to also serialize changes made
to the Time-Aware Shaper, because those will have to result in a
recalculation of cut-through TCs, which is something that depends on the
forwarding domain.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Message-ID: <20230705104422.49025-2-vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-06 19:10:22 -07:00
Vladimir Oltean
45d0fcb5bc net: mscc: ocelot: don't keep PTP configuration of all ports in single structure
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: 4e3b0468e6 ("net: mscc: PTP Hardware Clock (PHC) support")
Fixes: 96ca08c058 ("net: mscc: ocelot: set up traps for PTP packets")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-06-29 12:40:27 +02:00
Vladimir Oltean
403ffc2c34 net: mscc: ocelot: add support for preemptible traffic classes
In order to not transmit (preemptible) frames which will be received by
the link partner as corrupted (because it doesn't support FP), the
hardware requires the driver to program the QSYS_PREEMPTION_CFG_P_QUEUES
register only after the MAC Merge layer becomes active (verification
succeeds, or was disabled).

There are some cases when FP is known (through experimentation) to be
broken. Give priority to FP over cut-through switching, and disable FP
for known broken link modes.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-17 19:01:19 -07:00
Vladimir Oltean
aac80140dc net: mscc: ocelot: add support for mqprio offload
This doesn't apply anything to hardware and in general doesn't do
anything that the software variant doesn't do, except for checking that
there isn't more than 1 TXQ per TC (TXQs for a DSA switch are a dubious
concept anyway). The reason we add this is to be able to parse one more
field added to struct tc_mqprio_qopt_offload, namely preemptible_tcs.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-17 19:01:19 -07:00
Vladimir Oltean
7bf4a5b071 net: mscc: ocelot: optimize ocelot_mm_irq()
The MAC Merge IRQ of all ports is shared with the PTP TX timestamp IRQ
of all ports, which means that currently, when a PTP TX timestamp is
generated, felix_irq_handler() also polls for the MAC Merge layer status
of all ports, looking for changes. This makes the kernel do more work,
and under certain circumstances may make ptp4l require a
tx_timestamp_timeout argument higher than before.

Changes to the MAC Merge layer status are only to be expected under
certain conditions - its TX direction needs to be enabled - so we can
check early if that is the case, and omit register access otherwise.

Make ocelot_mm_update_port_status() skip register access if
mm->tx_enabled is unset, and also call it once more, outside IRQ
context, from ocelot_port_set_mm(), when mm->tx_enabled transitions from
true to false, because an IRQ is also expected in that case.

Also, a port may have its MAC Merge layer enabled but it may not have
generated the interrupt. In that case, there's no point in writing to
DEV_MM_STATUS to acknowledge that IRQ. We can reduce the number of
register writes per port with MM enabled by keeping an "ack" variable
which writes the "write-one-to-clear" bits. Those are 3 in number:
PRMPT_ACTIVE_STICKY, UNEXP_RX_PFRM_STICKY and UNEXP_TX_PFRM_STICKY.
The other fields in DEV_MM_STATUS are read-only and it doesn't matter
what is written to them, so writing zero is just fine.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-17 19:01:18 -07:00
Vladimir Oltean
3ff468ef98 net: mscc: ocelot: remove struct ocelot_mm_state :: lock
Unfortunately, the workarounds for the hardware bugs make it pointless
to keep fine-grained locking for the MAC Merge state of each port.

Our vsc9959_cut_through_fwd() implementation requires
ocelot->fwd_domain_lock to be held, in order to serialize with changes
to the bridging domains and to port speed changes (which affect which
ports can be cut-through). Simultaneously, the traffic classes which can
be cut-through cannot be preemptible at the same time, and this will
depend on the MAC Merge layer state (which changes from threaded
interrupt context).

Since vsc9959_cut_through_fwd() would have to hold the mm->lock of all
ports for a correct and race-free implementation with respect to
ocelot_mm_irq(), in practice it means that any time a port's mm->lock is
held, it would potentially block holders of ocelot->fwd_domain_lock.

In the interest of simple locking rules, make all MAC Merge layer state
changes (and preemptible traffic class changes) be serialized by the
ocelot->fwd_domain_lock.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-17 19:01:18 -07:00
Vladimir Oltean
15f93f46f3 net: mscc: ocelot: export a single ocelot_mm_irq()
When the switch emits an IRQ, we don't know what caused it, and we
iterate through all ports to check the MAC Merge status.

Move that iteration inside the ocelot lib; we will change the locking in
a future change and it would be good to encapsulate that lock completely
within the ocelot lib.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-17 19:01:18 -07:00
Vladimir Oltean
9ecd05794b net: mscc: ocelot: strengthen type of "u32 reg" in I/O accessors
The "u32 reg" argument that is passed to these functions is not a plain
address, but rather a driver-specific encoding of another enum
ocelot_target target in the upper bits, and an index into the
u32 ocelot->map[target][] array in the lower bits. That encoded value
takes the type "enum ocelot_reg" and is what is passed to these I/O
functions, so let's actually use that to prevent type confusion.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-13 21:56:06 -07:00
Colin Foster
dfca93ed51 net: mscc: ocelot: expose serdes configuration function
During chip initialization, ports that use SGMII / QSGMII to interface to
external phys need to be configured on the VSC7513 and VSC7514. Expose this
configuration routine, so it can be used by DSA drivers.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-20 09:08:48 +00:00
Colin Foster
69f7f89c0d net: mscc: ocelot: expose generic phylink_mac_config routine
The ocelot-switch driver can utilize the phylink_mac_config routine. Move
this to the ocelot library location and export the symbol to make this
possible.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-20 09:08:48 +00:00
Colin Foster
fec53f4494 net: mscc: ocelot: expose ocelot_pll5_init routine
Ocelot chips have an internal PLL that must be used when communicating
through external phys. Expose the init routine, so it can be used by other
drivers.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-20 09:08:48 +00:00
Colin Foster
b1ca2f1b04 net: mscc: ocelot: un-export unused regmap symbols
There are no external users of the vsc7514_*_regmap[] symbols or
vsc7514_vcap_* functions. They were exported in commit 32ecd22ba6 ("net:
mscc: ocelot: split register definitions to a separate file") with the
intention of being used, but the actual structure used in commit
2efaca411c ("net: mscc: ocelot: expose vsc7514_regmap definition") ended
up being all that was needed.

Bury these unnecessary symbols.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230204182056.25502-1-colin.foster@in-advantage.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-06 22:33:15 -08:00
Colin Foster
2efaca411c net: mscc: ocelot: expose vsc7514_regmap definition
The VSC7514 target regmap is identical for ones shared with similar
hardware, specifically the VSC7512. Share this resource, and change the
name to match the pattern of other exported resources.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # regression
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-30 21:07:20 -08:00
Colin Foster
b67f550213 net: mscc: ocelot: expose ocelot_reset routine
Resetting the switch core is the same whether it is done internally or
externally. Move this routine to the ocelot library so it can be used by
other drivers.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # regression
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-30 21:07:20 -08:00
Colin Foster
beb9a74e0b net: mscc: ocelot: expose vcap_props structure
The vcap_props structure is common to other devices, specifically the
VSC7512 chip that can only be controlled externally. Export this structure
so it doesn't need to be recreated.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # regression
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-30 21:07:20 -08:00
Colin Foster
728d8019f1 net: mscc: ocelot: expose regfield definition to be used by other drivers
The ocelot_regfields struct is common between several different chips, some
of which can only be controlled externally. Export this structure so it
doesn't have to be duplicated in these other drivers.

Rename the structure as well, to follow the conventions of other shared
resources.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # regression
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-30 21:07:20 -08:00
Colin Foster
c6a9321b08 net: mscc: ocelot: expose ocelot wm functions
Expose ocelot_wm functions so they can be shared with other drivers.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # regression
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-30 21:07:20 -08:00