Commit graph

7 commits

Author SHA1 Message Date
Vladimir Oltean
e2f9a8fe73 net: mscc: ocelot: always pass skb clone to ocelot_port_add_txtstamp_skb
Currently, ocelot switchdev passes the skb directly to the function that
enqueues it to the list of skb's awaiting a TX timestamp. Whereas the
felix DSA driver first clones the skb, then passes the clone to this
queue.

This matters because in the case of felix, the common IRQ handler, which
is ocelot_get_txtstamp(), currently clones the clone, and frees the
original clone. This is useless and can be simplified by using
skb_complete_tx_timestamp() instead of skb_tstamp_tx().

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:47:56 -07:00
Vladimir Oltean
6565243c06 net: mscc: ocelot: add locking for the port TX timestamp ID
The ocelot_port->ts_id is used to:
(a) populate skb->cb[0] for matching the TX timestamp in the PTP IRQ
    with an skb.
(b) populate the REW_OP from the injection header of the ongoing skb.
Only then is ocelot_port->ts_id incremented.

This is a problem because, at least theoretically, another timestampable
skb might use the same ocelot_port->ts_id before that is incremented.
Normally all transmit calls are serialized by the netdev transmit
spinlock, but in this case, ocelot_port_add_txtstamp_skb() is also
called by DSA, which has started declaring the NETIF_F_LLTX feature
since commit 2b86cb8299 ("net: dsa: declare lockless TX feature for
slave ports").  So the logic of using and incrementing the timestamp id
should be atomic per port.

The solution is to use the global ocelot_port->ts_id only while
protected by the associated ocelot_port->ts_id_lock. That's where we
populate skb->cb[0]. Note that for ocelot, ocelot_port_add_txtstamp_skb
is called for the actual skb, but for felix, it is called for the skb's
clone. That is something which will also be changed in the future.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-18 13:52:33 -07:00
Vladimir Oltean
67c2404922 net: dsa: felix: create a template for the DSA tags on xmit
With this patch we try to kill 2 birds with 1 stone.

First of all, some switches that use tag_ocelot.c don't have the exact
same bitfield layout for the DSA tags. The destination ports field is
different for Seville VSC9953 for example. So the choices are to either
duplicate tag_ocelot.c into a new tag_seville.c (sub-optimal) or somehow
take into account a supposed ocelot->dest_ports_offset when packing this
field into the DSA injection header (again not ideal).

Secondly, tag_ocelot.c already needs to memset a 128-bit area to zero
and call some packing() functions of dubious performance in the
fastpath. And most of the values it needs to pack are pretty much
constant (BYPASS=1, SRC_PORT=CPU, DEST=port index). So it would be good
if we could improve that.

The proposed solution is to allocate a memory area per port at probe
time, initialize that with the statically defined bits as per chip
hardware revision, and just perform a simpler memcpy in the fastpath.

Other alternatives have been analyzed, such as:
- Create a separate tag_seville.c: too much code duplication for just 1
  bit field difference.
- Create a separate DSA_TAG_PROTO_SEVILLE under tag_ocelot.c, just like
  tag_brcm.c, which would have a separate .xmit function. Again, too
  much code duplication for just 1 bit field difference.
- Allocate the template from the init function of the tag_ocelot.c
  module, instead of from the driver: couldn't figure out a method of
  accessing the correct port template corresponding to the correct
  tagger in the .xmit function.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13 17:40:01 -07:00
Florian Fainelli
2fa3888bb7 net: dsa: ocelot: Constify dsa_device_ops
ocelot_netdev_ops should be const since that is what the DSA layer
expects.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-11 16:50:45 -07:00
Vladimir Oltean
69df578c5f net: mscc: ocelot: eliminate confusion between CPU and NPI port
Ocelot has the concept of a CPU port. The CPU port is represented in the
forwarding and the queueing system, but it is not a physical device. The
CPU port can either be accessed via register-based injection/extraction
(which is the case of Ocelot), via Frame-DMA (similar to the first one),
or "connected" to a physical Ethernet port (called NPI in the datasheet)
which is the case of the Felix DSA switch.

In Ocelot the CPU port is at index 11.
In Felix the CPU port is at index 6.

The CPU bit is treated special in the forwarding, as it is never cleared
from the forwarding port mask (once added to it). Other than that, it is
treated the same as a normal front port.

Both Felix and Ocelot should use the CPU port in the same way. This
means that Felix should not use the NPI port directly when forwarding to
the CPU, but instead use the CPU port.

This patch is fixing this such that Felix will use port 6 as its CPU
port, and just use the NPI port to carry the traffic.

Therefore, eliminate the "ocelot->cpu" variable which was holding the
index of the NPI port for Felix, and the index of the CPU port module
for Ocelot, so the variable was actually configuring different things
for different drivers and causing at least part of the confusion.

Also remove the "ocelot->num_cpu_ports" variable, which is the result of
another confusion. The 2 CPU ports mentioned in the datasheet are
because there are two frame extraction channels (register based or DMA
based). This is of no relevance to the driver at the moment, and
invisible to the analyzer module.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Suggested-by: Allan W. Nielsen <allan.nielsen@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-04 14:19:00 -08:00
Yangbo Lu
c0bcf53766 net: dsa: ocelot: add hardware timestamping support for Felix
This patch is to reuse ocelot functions as possible to enable PTP
clock and to support hardware timestamping on Felix.
On TX path, timestamping works on packet which requires timestamp.
The injection header will be configured accordingly, and skb clone
requires timestamp will be added into a list. The TX timestamp
is final handled in threaded interrupt handler when PTP timestamp
FIFO is ready.
On RX path, timestamping is always working. The RX timestamp could
be got from extraction header.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-21 14:39:02 -08:00
Vladimir Oltean
8dce89aa5f net: dsa: ocelot: add tagger for Ocelot/Felix switches
While it is entirely possible that this tagger format is in fact more
generic than just these 2 switch families, I don't have that knowledge.
The Seville switch in NXP T1040 has a similar frame format, but there
are enough differences (e.g. DEST field starts at bit 57 instead of 56)
that calling this file tag_vitesse.c is a bit of a stretch at the
moment. The frame format has been listed in a comment so that people who
add support for further Vitesse switches can rework this tagger while
keeping compatibility with Felix.

The "ocelot" name was chosen instead of "felix" because even the Ocelot
switch can act as a DSA device when it is used in NPI mode, and the Felix
tagger format is almost identical. Currently it is only used for the
Felix switch embedded in the NXP LS1028A chip.

The ABI for this tagger should be considered "not stable" at the moment.
The DSA tag is always placed before the Ethernet header and therefore,
we are using the long prefix for RX tags to avoid putting the DSA master
port in promiscuous mode. Once there will be an API in DSA for drivers
to request DSA masters to be in promiscuous mode unconditionally, we
will switch to the "no prefix" extraction frame header, which will save
16 padding bytes for each RX frame.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-15 12:32:16 -08:00