linux/net/dsa
Vladimir Oltean 3eaae1d05f net: dsa: tag_8021q: support up to 8 VLANs per port using sub-VLANs
For switches that support VLAN retagging, such as sja1105, we extend
dsa_8021q by encoding a "sub-VLAN" into the remaining 3 free bits in the
dsa_8021q tag.

A sub-VLAN is nothing more than a number in the range 0-7, which serves
as an index into a per-port driver lookup table. The sub-VLAN value of
zero means that traffic is untagged (this is also backwards-compatible
with dsa_8021q without retagging).

The switch should be configured to retag VLAN-tagged traffic that gets
transmitted towards the CPU port (and towards the CPU only). Example:

bridge vlan add dev sw1p0 vid 100

The switch retags frames received on port 0, going to the CPU, and
having VID 100, to the VID of 1104 (0x0450). In dsa_8021q language:

 | 11  | 10  |  9  |  8  |  7  |  6  |  5  |  4  |  3  |  2  |  1  |  0  |
 +-----------+-----+-----------------+-----------+-----------------------+
 |    DIR    | SVL |    SWITCH_ID    |  SUBVLAN  |          PORT         |
 +-----------+-----+-----------------+-----------+-----------------------+

0x0450 means:
 - DIR = 0b01: this is an RX VLAN
 - SUBVLAN = 0b001: this is subvlan #1
 - SWITCH_ID = 0b001: this is switch 1 (see the name "sw1p0")
 - PORT = 0b0000: this is port 0 (see the name "sw1p0")

The driver also remembers the "1 -> 100" mapping. In the hotpath, if the
sub-VLAN from the tag encodes a non-untagged frame, this mapping is used
to create a VLAN hwaccel tag, with the value of 100.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-12 13:08:08 -07:00
..
dsa2.c net: dsa: introduce a dsa_switch_find function 2020-05-10 19:52:33 -07:00
dsa_priv.h net: dsa: provide an option for drivers to always receive bridge VLANs 2020-05-12 13:08:07 -07:00
dsa.c net: dsa: introduce a dsa_port_from_netdev public helper 2020-05-07 17:31:57 -07:00
Kconfig net: dsa: add GRO support via gro_cells 2020-04-23 12:32:13 -07:00
Makefile net: dsa: add support for Atheros AR9331 TAG format 2019-12-20 17:05:47 -08:00
master.c net: dsa: Do not leave DSA master with NULL netdev_ops 2020-05-06 17:31:54 -07:00
port.c net: dsa: provide an option for drivers to always receive bridge VLANs 2020-05-12 13:08:07 -07:00
slave.c net: dsa: provide an option for drivers to always receive bridge VLANs 2020-05-12 13:08:07 -07:00
switch.c net: dsa: permit cross-chip bridging between all trees in the system 2020-05-10 19:52:33 -07:00
tag_8021q.c net: dsa: tag_8021q: support up to 8 VLANs per port using sub-VLANs 2020-05-12 13:08:08 -07:00
tag_ar9331.c net: dsa: tag_ar9331: Make sure there is headroom for tag 2020-02-14 07:34:51 -08:00
tag_brcm.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
tag_dsa.c dsa: Cleanup unneeded table and make tag structures static 2019-04-28 19:41:01 -04:00
tag_edsa.c dsa: Cleanup unneeded table and make tag structures static 2019-04-28 19:41:01 -04:00
tag_gswip.c net: dsa: tag_gswip: fix typo in tagger name 2020-01-16 13:58:26 +01:00
tag_ksz.c net: dsa: ksz: use common define for tag len 2019-12-20 21:06:49 -08:00
tag_lan9303.c dsa: Cleanup unneeded table and make tag structures static 2019-04-28 19:41:01 -04:00
tag_mtk.c dsa: Cleanup unneeded table and make tag structures static 2019-04-28 19:41:01 -04:00
tag_ocelot.c net: dsa: ocelot: Constify dsa_device_ops 2020-05-11 16:50:45 -07:00
tag_qca.c net: dsa: tag_qca: Make sure there is headroom for tag 2020-02-14 07:34:51 -08:00
tag_sja1105.c net: dsa: sja1105: prepare tagger for handling DSA tags and VLAN simultaneously 2020-05-12 13:08:08 -07:00
tag_trailer.c dsa: Cleanup unneeded table and make tag structures static 2019-04-28 19:41:01 -04:00