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 <nolt...@gmail.com>
---
include/net/dsa.h | 2 +
net/dsa/Kconfig | 7 ++++
net/dsa/tag_brcm.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 105 insertions(+)
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 83a933e563fe..dac303edd33d 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -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,
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 58b8fc82cd3c..aaf8a452fd5b 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -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"
diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
index e2577a7dcbca..9dbff771c9b3 100644
--- a/net/dsa/tag_brcm.c
+++ b/net/dsa/tag_brcm.c
@@ -9,9 +9,23 @@
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/slab.h>
+#include <linux/types.h>
#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
*/
@@ -195,6 +209,85 @@ 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)
@@ -227,6 +320,9 @@ 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
--
2.20.1
