net: dsa: sja1105: Add support for traffic through standalone ports

In order to support this, we are creating a make-shift switch tag out of
a VLAN trunk configured on the CPU port. Termination of normal traffic
on switch ports only works when not under a vlan_filtering bridge.
Termination of management (PTP, BPDU) traffic works under all
circumstances because it uses a different tagging mechanism
(incl_srcpt). We are making use of the generic CONFIG_NET_DSA_TAG_8021Q
code and leveraging it from our own CONFIG_NET_DSA_TAG_SJA1105.

There are two types of traffic: regular and link-local.

The link-local traffic received on the CPU port is trapped from the
switch's regular forwarding decisions because it matched one of the two
DMAC filters for management traffic.

On transmission, the switch requires special massaging for these
link-local frames. Due to a weird implementation of the switching IP, by
default it drops link-local frames that originate on the CPU port.
It needs to be told where to forward them to, through an SPI command
("management route") that is valid for only a single frame.
So when we're sending link-local traffic, we are using the
dsa_defer_xmit mechanism.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 28 insertions, 9 deletions

diff --git a/include/linux/dsa/sja1105.h b/include/linux/dsa/sja1105.h
index abf3977e34fd..603a02e5a8cb 100644
--- a/include/linux/dsa/sja1105.h
+++ b/include/linux/dsa/sja1105.h
@@ -2,22 +2,39 @@
  * Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
  */
 
-/* Included by drivers/net/dsa/sja1105/sja1105.h */
+/* Included by drivers/net/dsa/sja1105/sja1105.h and net/dsa/tag_sja1105.c */
 
 #ifndef _NET_DSA_SJA1105_H
 #define _NET_DSA_SJA1105_H
 
+#include <linux/skbuff.h>
 #include <linux/etherdevice.h>
+#include <net/dsa.h>
 
 #define ETH_P_SJA1105				ETH_P_DSA_8021Q
 
-/* The switch can only be convinced to stay in unmanaged mode and not trap any
- * link-local traffic by actually telling it to filter frames sent at the
- * 00:00:00:00:00:00 destination MAC.
- */
-#define SJA1105_LINKLOCAL_FILTER_A		0x000000000000ull
-#define SJA1105_LINKLOCAL_FILTER_A_MASK		0xFFFFFFFFFFFFull
-#define SJA1105_LINKLOCAL_FILTER_B		0x000000000000ull
-#define SJA1105_LINKLOCAL_FILTER_B_MASK		0xFFFFFFFFFFFFull
+/* IEEE 802.3 Annex 57A: Slow Protocols PDUs (01:80:C2:xx:xx:xx) */
+#define SJA1105_LINKLOCAL_FILTER_A		0x0180C2000000ull
+#define SJA1105_LINKLOCAL_FILTER_A_MASK		0xFFFFFF000000ull
+/* IEEE 1588 Annex F: Transport of PTP over Ethernet (01:1B:19:xx:xx:xx) */
+#define SJA1105_LINKLOCAL_FILTER_B		0x011B19000000ull
+#define SJA1105_LINKLOCAL_FILTER_B_MASK		0xFFFFFF000000ull
+
+enum sja1105_frame_type {
+	SJA1105_FRAME_TYPE_NORMAL = 0,
+	SJA1105_FRAME_TYPE_LINK_LOCAL,
+};
+
+struct sja1105_skb_cb {
+	enum sja1105_frame_type type;
+};
+
+#define SJA1105_SKB_CB(skb) \
+	((struct sja1105_skb_cb *)DSA_SKB_CB_PRIV(skb))
+
+struct sja1105_port {
+	struct dsa_port *dp;
+	int mgmt_slot;
+};
 
 #endif /* _NET_DSA_SJA1105_H */
diff --git a/include/net/dsa.h b/include/net/dsa.h
index e20be1ceb306..6aaaadd6a413 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -43,6 +43,7 @@ struct phylink_link_state;
 #define DSA_TAG_PROTO_QCA_VALUE			10
 #define DSA_TAG_PROTO_TRAILER_VALUE		11
 #define DSA_TAG_PROTO_8021Q_VALUE		12
+#define DSA_TAG_PROTO_SJA1105_VALUE		13
 
 enum dsa_tag_protocol {
 	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -58,6 +59,7 @@ enum dsa_tag_protocol {
 	DSA_TAG_PROTO_QCA		= DSA_TAG_PROTO_QCA_VALUE,
 	DSA_TAG_PROTO_TRAILER		= DSA_TAG_PROTO_TRAILER_VALUE,
 	DSA_TAG_PROTO_8021Q		= DSA_TAG_PROTO_8021Q_VALUE,
+	DSA_TAG_PROTO_SJA1105		= DSA_TAG_PROTO_SJA1105_VALUE,
 };
 
 struct packet_type;