Add support for Realtek RTL8366S switch tag
Signed-off-by: DENG Qingfang <dqf...@gmail.com>
---
include/net/dsa.h | 2 +
net/dsa/Kconfig | 6 +++
net/dsa/Makefile | 1 +
net/dsa/tag_rtl8366s.c | 98 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 107 insertions(+)
create mode 100644 net/dsa/tag_rtl8366s.c
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 83a933e563fe..14fedf832f27 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -49,6 +49,7 @@ 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_RTL8366S_VALUE 22
enum dsa_tag_protocol {
DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE,
@@ -73,6 +74,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_XRS700X = DSA_TAG_PROTO_XRS700X_VALUE,
DSA_TAG_PROTO_OCELOT_8021Q = DSA_TAG_PROTO_OCELOT_8021Q_VALUE,
DSA_TAG_PROTO_SEVILLE = DSA_TAG_PROTO_SEVILLE_VALUE,
+ DSA_TAG_PROTO_RTL8366S = DSA_TAG_PROTO_RTL8366S_VALUE,
};
struct packet_type;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index a45572cfb71a..303228e0ad8b 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -104,6 +104,12 @@ config NET_DSA_TAG_RTL4_A
Realtek switches with 4 byte protocol A tags, sich as found in
the Realtek RTL8366RB.
+config NET_DSA_TAG_RTL8366S
+ tristate "Tag driver for Realtek RTL8366S switch tags"
+ help
+ Say Y or M if you want to enable support for tagging frames for the
+ Realtek RTL8366S switch.
+
config NET_DSA_TAG_OCELOT
tristate "Tag driver for Ocelot family of switches, using NPI port"
select PACKING
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 44bc79952b8b..df158e73a30b 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o
obj-$(CONFIG_NET_DSA_TAG_HELLCREEK) += tag_hellcreek.o
obj-$(CONFIG_NET_DSA_TAG_KSZ) += tag_ksz.o
obj-$(CONFIG_NET_DSA_TAG_RTL4_A) += tag_rtl4_a.o
+obj-$(CONFIG_NET_DSA_TAG_RTL8366S) += tag_rtl8366s.o
obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
obj-$(CONFIG_NET_DSA_TAG_OCELOT) += tag_ocelot.o
diff --git a/net/dsa/tag_rtl8366s.c b/net/dsa/tag_rtl8366s.c
new file mode 100644
index 000000000000..6c6c66853e4c
--- /dev/null
+++ b/net/dsa/tag_rtl8366s.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Handler for Realtek RTL8366S switch tags
+ * Copyright (c) 2021 DENG, Qingfang <dqf...@gmail.com>
+ *
+ * This tag header looks like:
+ *
+ * -------------------------------------------------
+ * | MAC DA | MAC SA | 0x8899 | 2-byte tag | Type |
+ * -------------------------------------------------
+ *
+ * The 2-byte tag format in tag_rcv:
+ * +------+------+------+------+------+------+------+------+
+ * 15: 8 | Protocol number (0x9) | Priority | Reserved |
+ * +------+------+------+------+------+------+------+------+
+ * 7: 0 | Reserved | Source port number |
+ * +------+------+------+------+------+------+------+------+
+ *
+ * The 2-byte tag format in tag_xmit:
+ * +------+------+------+------+------+------+------+------+
+ * 15: 8 | Protocol number (0x9) | Priority | Reserved |
+ * +------+------+------+------+------+------+------+------+
+ * 7: 0 | Reserved | Destination port mask |
+ * +------+------+------+------+------+------+------+------+
+ */
+
+#include <linux/etherdevice.h>
+
+#include "dsa_priv.h"
+
+#define RTL8366S_HDR_LEN 4
+#define RTL8366S_ETHERTYPE 0x8899
+#define RTL8366S_PROTOCOL_SHIFT 12
+#define RTL8366S_PROTOCOL 0x9
+#define RTL8366S_TAG \
+ (RTL8366S_PROTOCOL << RTL8366S_PROTOCOL_SHIFT)
+
+static struct sk_buff *rtl8366s_tag_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct dsa_port *dp = dsa_slave_to_port(dev);
+ __be16 *tag;
+
+ /* Make sure the frame is at least 60 bytes long _before_
+ * inserting the CPU tag, or it will be dropped by the switch.
+ */
+ if (unlikely(eth_skb_pad(skb)))
+ return NULL;
+
+ skb_push(skb, RTL8366S_HDR_LEN);
+ memmove(skb->data, skb->data + RTL8366S_HDR_LEN,
+ 2 * ETH_ALEN);
+
+ tag = (__be16 *)(skb->data + 2 * ETH_ALEN);
+ tag[0] = htons(RTL8366S_ETHERTYPE);
+ tag[1] = htons(RTL8366S_TAG | BIT(dp->index));
+
+ return skb;
+}
+
+static struct sk_buff *rtl8366s_tag_rcv(struct sk_buff *skb,
+ struct net_device *dev,
+ struct packet_type *pt)
+{
+ u8 *tag;
+ u8 port;
+
+ if (unlikely(!pskb_may_pull(skb, RTL8366S_HDR_LEN)))
+ return NULL;
+
+ tag = skb->data - 2;
+ port = tag[3] & 0x7;
+
+ skb->dev = dsa_master_find_slave(dev, 0, port);
+ if (unlikely(!skb->dev))
+ return NULL;
+
+ skb_pull_rcsum(skb, RTL8366S_HDR_LEN);
+ memmove(skb->data - ETH_HLEN,
+ skb->data - ETH_HLEN - RTL8366S_HDR_LEN,
+ 2 * ETH_ALEN);
+
+ skb->offload_fwd_mark = 1;
+
+ return skb;
+}
+
+static const struct dsa_device_ops rtl8366s_netdev_ops = {
+ .name = "rtl8366s",
+ .proto = DSA_TAG_PROTO_RTL8366S,
+ .xmit = rtl8366s_tag_xmit,
+ .rcv = rtl8366s_tag_rcv,
+ .overhead = RTL8366S_HDR_LEN,
+};
+module_dsa_tag_driver(rtl8366s_netdev_ops);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_RTL8366S);
--
2.25.1
