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authorVladimir Oltean <vladimir.oltean@nxp.com>2021-10-01 18:15:26 +0300
committerDavid S. Miller <davem@davemloft.net>2021-10-02 14:15:57 +0100
commitde5bbb6f7e4ce1357d6d3d46222dea70720a7998 (patch)
treeb18a70c9091de0f0684750d15ccca80a964858a4 /include/soc
parentf533bc14e21a0941b5b878ce5dda90cae65e81c3 (diff)
net: mscc: ocelot: support egress VLAN rewriting via VCAP ES0
Currently the ocelot driver does support the 'vlan modify' action, but in the ingress chain, and it is offloaded to VCAP IS1. This action changes the classified VLAN before the packet enters the bridging service, and the bridging works with the classified VLAN modified by VCAP IS1. That is good for some use cases, but there are others where the VLAN must be modified at the stage of the egress port, after the packet has exited the bridging service. One example is simulating IEEE 802.1CB active stream identification filters ("active" means that not only the rule matches on a packet flow, but it is also able to change some headers). For example, a stream is replicated on two egress ports, but they must have different VLAN IDs on egress ports A and B. This seems like a task for the VCAP ES0, but that currently only supports pushing the ES0 tag A, which is specified in the rule. Pushing another VLAN header is not what we want, but rather overwriting the existing one. It looks like when we push the ES0 tag A, it is actually possible to not only take the ES0 tag A's value from the rule itself (VID_A_VAL), but derive it from the following formula: ES0_TAG_A = Classified VID + VID_A_VAL Otherwise said, ES0_TAG_A can be used to increment with a given value the VLAN ID that the packet was already classified to, and the packet will have this value as an outer VLAN tag. This new VLAN ID value then gets stripped on egress (or not) according to the value of the native VLAN from the bridging service. While the hardware will happily increment the classified VLAN ID for all packets that match the ES0 rule, in practice this would be rather insane, so we only allow this kind of ES0 action if the ES0 filter contains a VLAN ID too, so as to restrict the matching on a known classified VLAN. If we program VID_A_VAL with the delta between the desired final VLAN (ES0_TAG_A) and the classified VLAN, we obtain the desired behavior. It doesn't look like it is possible with the tc-vlan action to modify the VLAN ID but not the PCP. In hardware it is possible to leave the PCP to the classified value, but we unconditionally program it to overwrite it with the PCP value from the rule. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/soc')
-rw-r--r--include/soc/mscc/ocelot_vcap.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/include/soc/mscc/ocelot_vcap.h b/include/soc/mscc/ocelot_vcap.h
index 25fd525aaf92..d45608fc4baf 100644
--- a/include/soc/mscc/ocelot_vcap.h
+++ b/include/soc/mscc/ocelot_vcap.h
@@ -576,6 +576,16 @@ enum ocelot_mask_mode {
OCELOT_MASK_MODE_REDIRECT,
};
+enum ocelot_es0_vid_sel {
+ OCELOT_ES0_VID_PLUS_CLASSIFIED_VID = 0,
+ OCELOT_ES0_VID = 1,
+};
+
+enum ocelot_es0_pcp_sel {
+ OCELOT_CLASSIFIED_PCP = 0,
+ OCELOT_ES0_PCP = 1,
+};
+
enum ocelot_es0_tag {
OCELOT_NO_ES0_TAG,
OCELOT_ES0_TAG,