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author | 2022-03-02 22:52:34 -0300 | |
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committer | 2022-03-05 11:04:25 +0000 | |
commit | cd87fecdedd7b54c61f5d7c2b7237b43126ac50a (patch) | |
tree | 93f1f6bd47d794e6f7e07016848529e560b1c936 /net/dsa | |
parent | dt-bindings: net: dsa: add rtl8_4 and rtl8_4t tag formats (diff) | |
download | linux-cd87fecdedd7b54c61f5d7c2b7237b43126ac50a.tar.gz linux-cd87fecdedd7b54c61f5d7c2b7237b43126ac50a.tar.bz2 linux-cd87fecdedd7b54c61f5d7c2b7237b43126ac50a.zip |
net: dsa: tag_rtl8_4: add rtl8_4t trailing variant
Realtek switches supports the same tag both before ethertype or between
payload and the CRC.
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa')
-rw-r--r-- | net/dsa/tag_rtl8_4.c | 152 |
1 files changed, 116 insertions, 36 deletions
diff --git a/net/dsa/tag_rtl8_4.c b/net/dsa/tag_rtl8_4.c index 02686ad4045d..71fec45fd0ea 100644 --- a/net/dsa/tag_rtl8_4.c +++ b/net/dsa/tag_rtl8_4.c @@ -7,13 +7,8 @@ * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence * named tag_rtl8_4. * - * This tag header has the following format: + * This tag has the following format: * - * ------------------------------------------- - * | MAC DA | MAC SA | 8 byte tag | Type | ... - * ------------------------------------------- - * _______________/ \______________________________________ - * / \ * 0 7|8 15 * |-----------------------------------+-----------------------------------|--- * | (16-bit) | ^ @@ -58,6 +53,24 @@ * TX/RX | TX (switch->CPU): port number the packet was received on * | RX (CPU->switch): forwarding port mask (if ALLOW=0) * | allowance port mask (if ALLOW=1) + * + * The tag can be positioned before Ethertype, using tag "rtl8_4": + * + * +--------+--------+------------+------+----- + * | MAC DA | MAC SA | 8 byte tag | Type | ... + * +--------+--------+------------+------+----- + * + * The tag can also appear between the end of the payload and before the CRC, + * using tag "rtl8_4t": + * + * +--------+--------+------+-----+---------+------------+-----+ + * | MAC DA | MAC SA | TYPE | ... | payload | 8-byte tag | CRC | + * +--------+--------+------+-----+---------+------------+-----+ + * + * The added bytes after the payload will break most checksums, either in + * software or hardware. To avoid this issue, if the checksum is still pending, + * this tagger checksums the packet in software before adding the tag. + * */ #include <linux/bitfield.h> @@ -84,87 +97,133 @@ #define RTL8_4_TX GENMASK(3, 0) #define RTL8_4_RX GENMASK(10, 0) -static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb, - struct net_device *dev) +static void rtl8_4_write_tag(struct sk_buff *skb, struct net_device *dev, + void *tag) { struct dsa_port *dp = dsa_slave_to_port(dev); - __be16 *tag; - - skb_push(skb, RTL8_4_TAG_LEN); - - dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN); - tag = dsa_etype_header_pos_tx(skb); + __be16 tag16[RTL8_4_TAG_LEN / 2]; /* Set Realtek EtherType */ - tag[0] = htons(ETH_P_REALTEK); + tag16[0] = htons(ETH_P_REALTEK); /* Set Protocol; zero REASON */ - tag[1] = htons(FIELD_PREP(RTL8_4_PROTOCOL, RTL8_4_PROTOCOL_RTL8365MB)); + tag16[1] = htons(FIELD_PREP(RTL8_4_PROTOCOL, RTL8_4_PROTOCOL_RTL8365MB)); /* Zero FID_EN, FID, PRI_EN, PRI, KEEP; set LEARN_DIS */ - tag[2] = htons(FIELD_PREP(RTL8_4_LEARN_DIS, 1)); + tag16[2] = htons(FIELD_PREP(RTL8_4_LEARN_DIS, 1)); /* Zero ALLOW; set RX (CPU->switch) forwarding port mask */ - tag[3] = htons(FIELD_PREP(RTL8_4_RX, BIT(dp->index))); + tag16[3] = htons(FIELD_PREP(RTL8_4_RX, BIT(dp->index))); + + memcpy(tag, tag16, RTL8_4_TAG_LEN); +} + +static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + skb_push(skb, RTL8_4_TAG_LEN); + + dsa_alloc_etype_header(skb, RTL8_4_TAG_LEN); + + rtl8_4_write_tag(skb, dev, dsa_etype_header_pos_tx(skb)); return skb; } -static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, - struct net_device *dev) +static struct sk_buff *rtl8_4t_tag_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + /* Calculate the checksum here if not done yet as trailing tags will + * break either software or hardware based checksum + */ + if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) + return NULL; + + rtl8_4_write_tag(skb, dev, skb_put(skb, RTL8_4_TAG_LEN)); + + return skb; +} + +static int rtl8_4_read_tag(struct sk_buff *skb, struct net_device *dev, + void *tag) { - __be16 *tag; + __be16 tag16[RTL8_4_TAG_LEN / 2]; u16 etype; u8 reason; u8 proto; u8 port; - if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) - return NULL; - - tag = dsa_etype_header_pos_rx(skb); + memcpy(tag16, tag, RTL8_4_TAG_LEN); /* Parse Realtek EtherType */ - etype = ntohs(tag[0]); + etype = ntohs(tag16[0]); if (unlikely(etype != ETH_P_REALTEK)) { dev_warn_ratelimited(&dev->dev, "non-realtek ethertype 0x%04x\n", etype); - return NULL; + return -EPROTO; } /* Parse Protocol */ - proto = FIELD_GET(RTL8_4_PROTOCOL, ntohs(tag[1])); + proto = FIELD_GET(RTL8_4_PROTOCOL, ntohs(tag16[1])); if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) { dev_warn_ratelimited(&dev->dev, "unknown realtek protocol 0x%02x\n", proto); - return NULL; + return -EPROTO; } /* Parse REASON */ - reason = FIELD_GET(RTL8_4_REASON, ntohs(tag[1])); + reason = FIELD_GET(RTL8_4_REASON, ntohs(tag16[1])); /* Parse TX (switch->CPU) */ - port = FIELD_GET(RTL8_4_TX, ntohs(tag[3])); + port = FIELD_GET(RTL8_4_TX, ntohs(tag16[3])); skb->dev = dsa_master_find_slave(dev, 0, port); if (!skb->dev) { dev_warn_ratelimited(&dev->dev, "could not find slave for port %d\n", port); - return NULL; + return -ENOENT; } + if (reason != RTL8_4_REASON_TRAP) + dsa_default_offload_fwd_mark(skb); + + return 0; +} + +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, + struct net_device *dev) +{ + if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN))) + return NULL; + + if (unlikely(rtl8_4_read_tag(skb, dev, dsa_etype_header_pos_rx(skb)))) + return NULL; + /* Remove tag and recalculate checksum */ skb_pull_rcsum(skb, RTL8_4_TAG_LEN); dsa_strip_etype_header(skb, RTL8_4_TAG_LEN); - if (reason != RTL8_4_REASON_TRAP) - dsa_default_offload_fwd_mark(skb); + return skb; +} + +static struct sk_buff *rtl8_4t_tag_rcv(struct sk_buff *skb, + struct net_device *dev) +{ + if (skb_linearize(skb)) + return NULL; + + if (unlikely(rtl8_4_read_tag(skb, dev, skb_tail_pointer(skb) - RTL8_4_TAG_LEN))) + return NULL; + + if (pskb_trim_rcsum(skb, skb->len - RTL8_4_TAG_LEN)) + return NULL; return skb; } +/* Ethertype version */ static const struct dsa_device_ops rtl8_4_netdev_ops = { .name = "rtl8_4", .proto = DSA_TAG_PROTO_RTL8_4, @@ -172,7 +231,28 @@ static const struct dsa_device_ops rtl8_4_netdev_ops = { .rcv = rtl8_4_tag_rcv, .needed_headroom = RTL8_4_TAG_LEN, }; -module_dsa_tag_driver(rtl8_4_netdev_ops); -MODULE_LICENSE("GPL"); +DSA_TAG_DRIVER(rtl8_4_netdev_ops); + MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4); + +/* Tail version */ +static const struct dsa_device_ops rtl8_4t_netdev_ops = { + .name = "rtl8_4t", + .proto = DSA_TAG_PROTO_RTL8_4T, + .xmit = rtl8_4t_tag_xmit, + .rcv = rtl8_4t_tag_rcv, + .needed_tailroom = RTL8_4_TAG_LEN, +}; + +DSA_TAG_DRIVER(rtl8_4t_netdev_ops); + +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8_4L); + +static struct dsa_tag_driver *dsa_tag_drivers[] = { + &DSA_TAG_DRIVER_NAME(rtl8_4_netdev_ops), + &DSA_TAG_DRIVER_NAME(rtl8_4t_netdev_ops), +}; +module_dsa_tag_drivers(dsa_tag_drivers); + +MODULE_LICENSE("GPL"); |