From 964dbf186eaa84d409c359ddf09c827a3fbe8228 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= Date: Wed, 17 Mar 2021 11:29:26 +0100 Subject: [PATCH 1/2] net: dsa: tag_brcm: add support for legacy tags MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add support for legacy Broadcom tags, which are similar to DSA_TAG_PROTO_BRCM. These tags are used on BCM5325, BCM5365 and BCM63xx switches. Signed-off-by: Álvaro Fernández Rojas Signed-off-by: David S. Miller --- include/net/dsa.h | 2 + net/dsa/Kconfig | 7 +++ net/dsa/tag_brcm.c | 107 +++++++++++++++++++++++++++++++++++++++++++-- 3 files changed, 113 insertions(+), 3 deletions(-) --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -45,10 +45,12 @@ struct phylink_link_state; #define DSA_TAG_PROTO_OCELOT_VALUE 15 #define DSA_TAG_PROTO_AR9331_VALUE 16 #define DSA_TAG_PROTO_RTL4_A_VALUE 17 +#define DSA_TAG_PROTO_BRCM_LEGACY_VALUE 22 enum dsa_tag_protocol { DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE, DSA_TAG_PROTO_BRCM = DSA_TAG_PROTO_BRCM_VALUE, + DSA_TAG_PROTO_BRCM_LEGACY = DSA_TAG_PROTO_BRCM_LEGACY_VALUE, DSA_TAG_PROTO_BRCM_PREPEND = DSA_TAG_PROTO_BRCM_PREPEND_VALUE, DSA_TAG_PROTO_DSA = DSA_TAG_PROTO_DSA_VALUE, DSA_TAG_PROTO_EDSA = DSA_TAG_PROTO_EDSA_VALUE, --- a/net/dsa/Kconfig +++ b/net/dsa/Kconfig @@ -47,6 +47,13 @@ config NET_DSA_TAG_BRCM Say Y if you want to enable support for tagging frames for the Broadcom switches which place the tag after the MAC source address. +config NET_DSA_TAG_BRCM_LEGACY + tristate "Tag driver for Broadcom legacy switches using in-frame headers" + select NET_DSA_TAG_BRCM_COMMON + help + Say Y if you want to enable support for tagging frames for the + Broadcom legacy switches which place the tag after the MAC source + address. config NET_DSA_TAG_BRCM_PREPEND tristate "Tag driver for Broadcom switches using prepended headers" --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -11,9 +11,26 @@ #include "dsa_priv.h" -/* This tag length is 4 bytes, older ones were 6 bytes, we do not - * handle them - */ +/* Legacy Broadcom tag (6 bytes) */ +#define BRCM_LEG_TAG_LEN 6 + +/* Type fields */ +/* 1st byte in the tag */ +#define BRCM_LEG_TYPE_HI 0x88 +/* 2nd byte in the tag */ +#define BRCM_LEG_TYPE_LO 0x74 + +/* Tag fields */ +/* 3rd byte in the tag */ +#define BRCM_LEG_UNICAST (0 << 5) +#define BRCM_LEG_MULTICAST (1 << 5) +#define BRCM_LEG_EGRESS (2 << 5) +#define BRCM_LEG_INGRESS (3 << 5) + +/* 6th byte in the tag */ +#define BRCM_LEG_PORT_ID (0xf) + +/* Newer Broadcom tag (4 bytes) */ #define BRCM_TAG_LEN 4 /* Tag is constructed and desconstructed using byte by byte access @@ -194,6 +211,87 @@ DSA_TAG_DRIVER(brcm_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM); #endif +#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) +static struct sk_buff *brcm_leg_tag_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct dsa_port *dp = dsa_slave_to_port(dev); + u8 *brcm_tag; + + /* The Ethernet switch we are interfaced with needs packets to be at + * least 64 bytes (including FCS) otherwise they will be discarded when + * they enter the switch port logic. When Broadcom tags are enabled, we + * need to make sure that packets are at least 70 bytes + * (including FCS and tag) because the length verification is done after + * the Broadcom tag is stripped off the ingress packet. + * + * Let dsa_slave_xmit() free the SKB + */ + if (__skb_put_padto(skb, ETH_ZLEN + BRCM_LEG_TAG_LEN, false)) + return NULL; + + skb_push(skb, BRCM_LEG_TAG_LEN); + + memmove(skb->data, skb->data + BRCM_LEG_TAG_LEN, 2 * ETH_ALEN); + + brcm_tag = skb->data + 2 * ETH_ALEN; + + /* Broadcom tag type */ + brcm_tag[0] = BRCM_LEG_TYPE_HI; + brcm_tag[1] = BRCM_LEG_TYPE_LO; + + /* Broadcom tag value */ + brcm_tag[2] = BRCM_LEG_EGRESS; + brcm_tag[3] = 0; + brcm_tag[4] = 0; + brcm_tag[5] = dp->index & BRCM_LEG_PORT_ID; + + return skb; +} + +static struct sk_buff *brcm_leg_tag_rcv(struct sk_buff *skb, + struct net_device *dev, + struct packet_type *pt) +{ + int source_port; + u8 *brcm_tag; + + if (unlikely(!pskb_may_pull(skb, BRCM_LEG_PORT_ID))) + return NULL; + + brcm_tag = skb->data - 2; + + source_port = brcm_tag[5] & BRCM_LEG_PORT_ID; + + skb->dev = dsa_master_find_slave(dev, 0, source_port); + if (!skb->dev) + return NULL; + + /* Remove Broadcom tag and update checksum */ + skb_pull_rcsum(skb, BRCM_LEG_TAG_LEN); + + skb->offload_fwd_mark = 1; + + /* Move the Ethernet DA and SA */ + memmove(skb->data - ETH_HLEN, + skb->data - ETH_HLEN - BRCM_LEG_TAG_LEN, + 2 * ETH_ALEN); + + return skb; +} + +static const struct dsa_device_ops brcm_legacy_netdev_ops = { + .name = "brcm-legacy", + .proto = DSA_TAG_PROTO_BRCM_LEGACY, + .xmit = brcm_leg_tag_xmit, + .rcv = brcm_leg_tag_rcv, + .overhead = BRCM_LEG_TAG_LEN, +}; + +DSA_TAG_DRIVER(brcm_legacy_netdev_ops); +MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_BRCM_LEGACY); +#endif /* CONFIG_NET_DSA_TAG_BRCM_LEGACY */ + #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) static struct sk_buff *brcm_tag_xmit_prepend(struct sk_buff *skb, struct net_device *dev) @@ -226,6 +324,9 @@ static struct dsa_tag_driver *dsa_tag_dr #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) &DSA_TAG_DRIVER_NAME(brcm_netdev_ops), #endif +#if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_LEGACY) + &DSA_TAG_DRIVER_NAME(brcm_legacy_netdev_ops), +#endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM_PREPEND) &DSA_TAG_DRIVER_NAME(brcm_prepend_netdev_ops), #endif