diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2021-06-11 22:01:24 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-06-11 12:45:38 -0700 |
| commit | 4e50025129efabb07714c1f27a80526897da374b (patch) | |
| tree | bef1017e42111f0e3ffc5d6119ea58a677b6aa35 /net/dsa/master.c | |
| parent | 6c0de59b3d735f4c8c704dae30db540204b496ec (diff) | |
net: dsa: generalize overhead for taggers that use both headers and trailers
Some really really weird switches just couldn't decide whether to use a
normal or a tail tagger, so they just did both.
This creates problems for DSA, because we only have the concept of an
'overhead' which can be applied to the headroom or to the tailroom of
the skb (like for example during the central TX reallocation procedure),
depending on the value of bool tail_tag, but not to both.
We need to generalize DSA to cater for these odd switches by
transforming the 'overhead / tail_tag' pair into 'needed_headroom /
needed_tailroom'.
The DSA master's MTU is increased to account for both.
The flow dissector code is modified such that it only calls the DSA
adjustment callback if the tagger has a non-zero header length.
Taggers are trivially modified to declare either needed_headroom or
needed_tailroom, based on the tail_tag value that they currently
declare.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa/master.c')
| -rw-r--r-- | net/dsa/master.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/dsa/master.c b/net/dsa/master.c index 63adbc21a735..3fc90e36772d 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -346,10 +346,12 @@ static struct lock_class_key dsa_master_addr_list_lock_key; int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp) { - int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead; + const struct dsa_device_ops *tag_ops = cpu_dp->tag_ops; struct dsa_switch *ds = cpu_dp->ds; struct device_link *consumer_link; - int ret; + int mtu, ret; + + mtu = ETH_DATA_LEN + dsa_tag_protocol_overhead(tag_ops); /* The DSA master must use SET_NETDEV_DEV for this to work. */ consumer_link = device_link_add(ds->dev, dev->dev.parent, |