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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-06-11 22:01:24 +0300
committerDavid S. Miller <davem@davemloft.net>2021-06-11 12:45:38 -0700
commit4e50025129efabb07714c1f27a80526897da374b (patch)
treebef1017e42111f0e3ffc5d6119ea58a677b6aa35 /net/dsa/dsa_priv.h
parent6c0de59b3d735f4c8c704dae30db540204b496ec (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/dsa_priv.h')
-rw-r--r--net/dsa/dsa_priv.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 92282de54230..b8b17474b72b 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -154,6 +154,11 @@ const struct dsa_device_ops *dsa_find_tagger_by_name(const char *buf);
bool dsa_schedule_work(struct work_struct *work);
const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops);
+static inline int dsa_tag_protocol_overhead(const struct dsa_device_ops *ops)
+{
+ return ops->needed_headroom + ops->needed_tailroom;
+}
+
/* master.c */
int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp);
void dsa_master_teardown(struct net_device *dev);