[RFC PATCH net-next 1/2] net: dcb: add new pcp selector to app object

Daniel Machon
2022-09-08T11:56:29Z

Add new PCP selector for the 8021Qaz APP managed object.

The purpose of adding the PCP selector, is to be able to offload
PCP-based queue classification to the 8021Q Priority Code Point table,
see 6.9.3 of IEEE Std 802.1Q-2018.

PCP and DEI is encoded in the protocol field as 8*dei+pcp, so that a
mapping of PCP 2 and DEI 1 to priority 3 is encoded as {255, 10, 3}.

While PCP is not a standard 8021Qaz selector, it seems very convenient
to add it to the APP object, as this is where similar priority mapping
is handled, and it perfectly fits the {selector, protocol, priority}
triplet.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
---
include/uapi/linux/dcbnl.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/dcbnl.h b/include/uapi/linux/dcbnl.h
index a791a94013a6..8eab16e5bc13 100644
--- a/include/uapi/linux/dcbnl.h
+++ b/include/uapi/linux/dcbnl.h
@@ -217,6 +217,7 @@ struct cee_pfc {
#define IEEE_8021QAZ_APP_SEL_DGRAM 3
#define IEEE_8021QAZ_APP_SEL_ANY 4
#define IEEE_8021QAZ_APP_SEL_DSCP 5
+#define IEEE_8021QAZ_APP_SEL_PCP 255

/* This structure contains the IEEE 802.1Qaz APP managed object. This
* object is also used for the CEE std as well.
--
2.34.1