From 3bc3d79efdff6e29b80bf35f7a56baaa36e4d8fe Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= Date: Fri, 12 Mar 2021 12:35:39 +0100 Subject: [PATCH] net: dsa: b53: support tags for legacy switches MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Álvaro Fernández Rojas --- drivers/net/dsa/b53/Kconfig | 1 + drivers/net/dsa/b53/b53_common.c | 6 +++ include/net/dsa.h | 2 + net/dsa/Kconfig | 7 +++ net/dsa/tag_brcm.c | 93 ++++++++++++++++++++++++++++++++ 5 files changed, 109 insertions(+) --- a/drivers/net/dsa/b53/Kconfig +++ b/drivers/net/dsa/b53/Kconfig @@ -3,6 +3,7 @@ menuconfig B53 tristate "Broadcom BCM53xx managed switch support" depends on NET_DSA select NET_DSA_TAG_BRCM + select NET_DSA_TAG_BRCM_LEGACY select NET_DSA_TAG_BRCM_PREPEND help This driver adds support for Broadcom managed switch chips. It supports --- a/drivers/net/dsa/b53/b53_common.c +++ b/drivers/net/dsa/b53/b53_common.c @@ -1992,6 +1992,7 @@ static bool b53_can_enable_brcm_tags(str switch (tag_protocol) { case DSA_TAG_PROTO_BRCM: + case DSA_TAG_PROTO_BRCM_LEGACY: case DSA_TAG_PROTO_BRCM_PREPEND: dev_warn(ds->dev, "Port %d is stacked to Broadcom tag switch\n", port); @@ -2013,12 +2014,16 @@ enum dsa_tag_protocol b53_get_tag_protoc /* Older models (5325, 5365) support a different tag format that we do * not support in net/dsa/tag_brcm.c yet. */ - if (is5325(dev) || is5365(dev) || - !b53_can_enable_brcm_tags(ds, port, mprot)) { + if (!b53_can_enable_brcm_tags(ds, port, mprot)) { dev->tag_protocol = DSA_TAG_PROTO_NONE; goto out; } + if (is5325(dev) || is5365(dev) || is63xx(dev)) { + dev->tag_protocol = DSA_TAG_PROTO_BRCM_LEGACY; + goto out; + } + /* Broadcom BCM58xx chips have a flow accelerator on Port 8 * which requires us to use the prepended Broadcom tag type */ --- 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 @@ -8,9 +8,23 @@ #include #include #include +#include #include "dsa_priv.h" +struct bcm_legacy_tag { + uint16_t type; +#define BRCM_LEG_TYPE 0x8874 + + uint32_t tag; +#define BRCM_LEG_TAG_PORT_ID (0xf) +#define BRCM_LEG_TAG_MULTICAST (1 << 29) +#define BRCM_LEG_TAG_EGRESS (2 << 29) +#define BRCM_LEG_TAG_INGRESS (3 << 29) +} __attribute__((packed)); + +#define BRCM_LEG_TAG_LEN sizeof(struct bcm_legacy_tag) + /* This tag length is 4 bytes, older ones were 6 bytes, we do not * handle them */ @@ -197,6 +211,85 @@ 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); + struct bcm_legacy_tag *brcm_tag; + + if (skb_cow_head(skb, BRCM_LEG_TAG_LEN) < 0) + return NULL; + + /* 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 = (struct bcm_legacy_tag *) (skb->data + 2 * ETH_ALEN); + + brcm_tag->type = BRCM_LEG_TYPE; + brcm_tag->tag = BRCM_LEG_TAG_EGRESS; + brcm_tag->tag |= dp->index & BRCM_LEG_TAG_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; + struct bcm_legacy_tag *brcm_tag; + + if (unlikely(!pskb_may_pull(skb, BRCM_LEG_TAG_LEN))) + return NULL; + + brcm_tag = (struct bcm_legacy_tag *) (skb->data - 2); + + source_port = brcm_tag->tag & BRCM_LEG_TAG_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) @@ -229,6 +322,9 @@ 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