net: dsa: tag_brcm: add support for legacy tags

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 <noltari@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Álvaro Fernández Rojas 2021-03-17 11:29:26 +01:00 committed by David S. Miller
parent 73a2218cb2
commit 964dbf186e
3 changed files with 113 additions and 3 deletions

View File

@ -49,10 +49,12 @@ struct phylink_link_state;
#define DSA_TAG_PROTO_XRS700X_VALUE 19
#define DSA_TAG_PROTO_OCELOT_8021Q_VALUE 20
#define DSA_TAG_PROTO_SEVILLE_VALUE 21
#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,

View File

@ -48,6 +48,13 @@ 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"

View File

@ -12,9 +12,26 @@
#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
@ -195,6 +212,87 @@ 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)
@ -227,6 +325,9 @@ static struct dsa_tag_driver *dsa_tag_driver_array[] = {
#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