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author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2020-09-26 22:32:04 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-09-27 00:17:58 +0300 |
commit | 5124197ce58b5706bb60c2ecb3b79f4dfabab6e1 (patch) | |
tree | 700864b30af8895bb94cb90f5e3beafb82abe966 /drivers | |
parent | 707091eb26338c0d621171a8332fed11257a63f7 (diff) | |
download | linux-5124197ce58b5706bb60c2ecb3b79f4dfabab6e1.tar.xz |
net: dsa: tag_ocelot: use a short prefix on both ingress and egress
There are 2 goals that we follow:
- Reduce the header size
- Make the header size equal between RX and TX
The issue that required long prefix on RX was the fact that the ocelot
DSA tag, being put before Ethernet as it is, would overlap with the area
that a DSA master uses for RX filtering (destination MAC address
mainly).
Now that we can ask DSA to put the master in promiscuous mode, in theory
we could remove the prefix altogether and call it a day, but it looks
like we can't. Using no prefix on ingress, some packets (such as ICMP)
would be received, while others (such as PTP) would not be received.
This is because the DSA master we use (enetc) triggers parse errors
("MAC rx frame errors") presumably because it sees Ethernet frames with
a bad length. And indeed, when using no prefix, the EtherType (bytes
12-13 of the frame, bits 96-111) falls over the REW_VAL field from the
extraction header, aka the PTP timestamp.
When turning the short (32-bit) prefix on, the EtherType overlaps with
bits 64-79 of the extraction header, which are a reserved area
transmitted as zero by the switch. The packets are not dropped by the
DSA master with a short prefix. Actually, the frames look like this in
tcpdump (below is a PTP frame, with an extra dsa_8021q tag - dadb 0482 -
added by a downstream sja1105).
89:0c:a9:f2:01:00 > 88:80:00:0a:00:1d, 802.3, length 0: LLC, \
dsap Unknown (0x10) Individual, ssap ProWay NM (0x0e) Response, \
ctrl 0x0004: Information, send seq 2, rcv seq 0, \
Flags [Response], length 78
0x0000: 8880 000a 001d 890c a9f2 0100 0000 100f ................
0x0010: 0400 0000 0180 c200 000e 001f 7b63 0248 ............{c.H
0x0020: dadb 0482 88f7 1202 0036 0000 0000 0000 .........6......
0x0030: 0000 0000 0000 0000 0000 001f 7bff fe63 ............{..c
0x0040: 0248 0001 1f81 0500 0000 0000 0000 0000 .H..............
0x0050: 0000 0000 0000 0000 0000 0000 ............
So the short prefix is our new default: we've shortened our RX frames by
12 octets, increased TX by 4, and headers are now equal between RX and
TX. Note that we still need promiscuous mode for the DSA master to not
drop it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/dsa/ocelot/felix.c | 6 | ||||
-rw-r--r-- | drivers/net/dsa/ocelot/felix_vsc9959.c | 13 | ||||
-rw-r--r-- | drivers/net/dsa/ocelot/seville_vsc9953.c | 13 |
3 files changed, 23 insertions, 9 deletions
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c index b8e192374a32..ab3ee5c3fd02 100644 --- a/drivers/net/dsa/ocelot/felix.c +++ b/drivers/net/dsa/ocelot/felix.c @@ -439,8 +439,8 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports) ocelot->vcap_is2_actions= felix->info->vcap_is2_actions; ocelot->vcap = felix->info->vcap; ocelot->ops = felix->info->ops; - ocelot->inj_prefix = OCELOT_TAG_PREFIX_NONE; - ocelot->xtr_prefix = OCELOT_TAG_PREFIX_LONG; + ocelot->inj_prefix = OCELOT_TAG_PREFIX_SHORT; + ocelot->xtr_prefix = OCELOT_TAG_PREFIX_SHORT; port_phy_modes = kcalloc(num_phys_ports, sizeof(phy_interface_t), GFP_KERNEL); @@ -511,7 +511,7 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports) return PTR_ERR(target); } - template = devm_kzalloc(ocelot->dev, OCELOT_TAG_LEN, + template = devm_kzalloc(ocelot->dev, OCELOT_TOTAL_TAG_LEN, GFP_KERNEL); if (!template) { dev_err(ocelot->dev, diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index 3ab6d6847c5b..2e9270c00096 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -1155,6 +1155,8 @@ static void vsc9959_xmit_template_populate(struct ocelot *ocelot, int port) struct ocelot_port *ocelot_port = ocelot->ports[port]; u8 *template = ocelot_port->xmit_template; u64 bypass, dest, src; + __be32 *prefix; + u8 *injection; /* Set the source port as the CPU port module and not the * NPI port @@ -1163,9 +1165,14 @@ static void vsc9959_xmit_template_populate(struct ocelot *ocelot, int port) dest = BIT(port); bypass = true; - packing(template, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0); - packing(template, &dest, 68, 56, OCELOT_TAG_LEN, PACK, 0); - packing(template, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0); + injection = template + OCELOT_SHORT_PREFIX_LEN; + prefix = (__be32 *)template; + + packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0); + packing(injection, &dest, 68, 56, OCELOT_TAG_LEN, PACK, 0); + packing(injection, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0); + + *prefix = cpu_to_be32(0x8880000a); } static const struct felix_info felix_info_vsc9959 = { diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c index b0ff90c0ae16..e28dd600f464 100644 --- a/drivers/net/dsa/ocelot/seville_vsc9953.c +++ b/drivers/net/dsa/ocelot/seville_vsc9953.c @@ -1003,6 +1003,8 @@ static void vsc9953_xmit_template_populate(struct ocelot *ocelot, int port) struct ocelot_port *ocelot_port = ocelot->ports[port]; u8 *template = ocelot_port->xmit_template; u64 bypass, dest, src; + __be32 *prefix; + u8 *injection; /* Set the source port as the CPU port module and not the * NPI port @@ -1011,9 +1013,14 @@ static void vsc9953_xmit_template_populate(struct ocelot *ocelot, int port) dest = BIT(port); bypass = true; - packing(template, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0); - packing(template, &dest, 67, 57, OCELOT_TAG_LEN, PACK, 0); - packing(template, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0); + injection = template + OCELOT_SHORT_PREFIX_LEN; + prefix = (__be32 *)template; + + packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0); + packing(injection, &dest, 67, 57, OCELOT_TAG_LEN, PACK, 0); + packing(injection, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0); + + *prefix = cpu_to_be32(0x88800005); } static const struct felix_info seville_info_vsc9953 = { |