[PATCH net-next v2 08/12] net: dsa: add support for DSA rx offloading via metadata dst

Felix Fietkau
2022-11-09T16:34:53Z

If a metadata dst is present with the type METADATA_HW_PORT_MUX on a dsa cpu
port netdev, assume that it carries the port number and that there is no DSA
tag present in the skb data.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
net/core/flow_dissector.c | 4 +++-
net/dsa/dsa.c | 18 +++++++++++++++++-
2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 25cd35f5922e..1f476abc25e1 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -972,11 +972,13 @@ bool __skb_flow_dissect(const struct net *net,
if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
proto == htons(ETH_P_XDSA))) {
const struct dsa_device_ops *ops;
+ struct metadata_dst *md_dst = skb_metadata_dst(skb);
int offset = 0;

ops = skb->dev->dsa_ptr->tag_ops;
/* Only DSA header taggers break flow dissection */
- if (ops->needed_headroom) {
+ if (ops->needed_headroom &&
+ (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
if (ops->flow_dissect)
ops->flow_dissect(skb, &proto, &offset);
else
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 64b14f655b23..a20440e82dec 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -11,6 +11,7 @@
#include <linux/netdevice.h>
#include <linux/sysfs.h>
#include <linux/ptp_classify.h>
+#include <net/dst_metadata.h>

#include "dsa_priv.h"

@@ -216,6 +217,7 @@ static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *unused)
{
+ struct metadata_dst *md_dst = skb_metadata_dst(skb);
struct dsa_port *cpu_dp = dev->dsa_ptr;
struct sk_buff *nskb = NULL;
struct dsa_slave_priv *p;
@@ -229,7 +231,21 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
if (!skb)
return 0;

- nskb = cpu_dp->rcv(skb, dev);
+ if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
+ unsigned int port = md_dst->u.port_info.port_id;
+
+ dsa_default_offload_fwd_mark(skb);
+ skb_dst_set(skb, NULL);
+ if (!skb_has_extensions(skb))
+ skb->slow_gro = 0;
+
+ skb->dev = dsa_master_find_slave(dev, 0, port);
+ if (skb->dev)
+ nskb = skb;
+ } else {
+ nskb = cpu_dp->rcv(skb, dev);
+ }
+
if (!nskb) {
kfree_skb(skb);
return 0;
--
2.38.1