linux/drivers/net/ethernet/mscc
Vladimir Oltean 8e0341aefc net: mscc: ocelot: fix backwards compatibility with single-chain tc-flower offload
ACL rules can be offloaded to VCAP IS2 either through chain 0, or, since
the blamed commit, through a chain index whose number encodes a specific
PAG (Policy Action Group) and lookup number.

The chain number is translated through ocelot_chain_to_pag() into a PAG,
and through ocelot_chain_to_lookup() into a lookup number.

The problem with the blamed commit is that the above 2 functions don't
have special treatment for chain 0. So ocelot_chain_to_pag(0) returns
filter->pag = 224, which is in fact -32, but the "pag" field is an u8.

So we end up programming the hardware with VCAP IS2 entries having a PAG
of 224. But the way in which the PAG works is that it defines a subset
of VCAP IS2 filters which should match on a packet. The default PAG is
0, and previous VCAP IS1 rules (which we offload using 'goto') can
modify it. So basically, we are installing filters with a PAG on which
no packet will ever match. This is the hardware equivalent of adding
filters to a chain which has no 'goto' to it.

Restore the previous functionality by making ACL filters offloaded to
chain 0 go to PAG 0 and lookup number 0. The choice of PAG is clearly
correct, but the choice of lookup number isn't "as before" (which was to
leave the lookup a "don't care"). However, lookup 0 should be fine,
since even though there are ACL actions (policers) which have a
requirement to be used in a specific lookup, that lookup is 0.

Fixes: 226e9cd82a ("net: mscc: ocelot: only install TCAM entries into a specific lookup and PAG")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220316192117.2568261-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-17 09:34:52 -07:00
..
Kconfig of: net: move of_net under net/ 2021-10-07 13:39:51 +01:00
Makefile net: ocelot: add FDMA support 2021-12-10 20:56:58 -08:00
ocelot.c net: mscc: ocelot: fix use-after-free in ocelot_vlan_del() 2022-02-15 14:38:20 +00:00
ocelot.h net: ocelot: add support for ndo_change_mtu 2021-12-10 20:56:57 -08:00
ocelot_devlink.c net: update NXP copyright text 2021-09-17 13:52:17 +01:00
ocelot_fdma.c net: ocelot: use dma_unmap_addr to get tx buffer dma_addr 2021-12-13 14:51:21 +00:00
ocelot_fdma.h net: ocelot: add FDMA support 2021-12-10 20:56:58 -08:00
ocelot_flower.c net: mscc: ocelot: fix backwards compatibility with single-chain tc-flower offload 2022-03-17 09:34:52 -07:00
ocelot_io.c net: mscc: Fix non-GPL export of regmap APIs 2021-08-12 09:44:31 +01:00
ocelot_mrp.c net: mscc: ocelot: add the local station MAC addresses in VID 0 2021-10-21 12:14:29 +01:00
ocelot_net.c net: ocelot: Fix the call to switchdev_bridge_port_offload 2022-01-17 13:04:25 +00:00
ocelot_police.c
ocelot_police.h
ocelot_ptp.c time64.h: Consolidated PSEC_PER_SEC definition 2021-04-06 16:32:17 -07:00
ocelot_qs.h
ocelot_rew.h
ocelot_vcap.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-11-26 13:45:19 -08:00
ocelot_vcap.h net: dsa: felix: perform switch setup for tag_8021q 2021-01-29 21:25:27 -08:00
ocelot_vsc7514.c net: ocelot: add FDMA support 2021-12-10 20:56:58 -08:00
vsc7514_regs.c net: mscc: ocelot: split register definitions to a separate file 2021-12-07 21:44:49 -08:00