1 files changed, 111 insertions, 0 deletions
diff --git a/net/dsa/tag_gswip.c b/net/dsa/tag_gswip.c
new file mode 100644
index 000000000..df7140984
--- /dev/null
+++ b/net/dsa/tag_gswip.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel / Lantiq GSWIP V2.0 PMAC tag support
+ *
+ * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
+ */
+
+#include <linux/bitops.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <net/dsa.h>
+
+#include "dsa_priv.h"
+
+#define GSWIP_TX_HEADER_LEN		4
+
+/* special tag in TX path header */
+/* Byte 0 */
+#define GSWIP_TX_SLPID_SHIFT		0	/* source port ID */
+#define  GSWIP_TX_SLPID_CPU		2
+#define  GSWIP_TX_SLPID_APP1		3
+#define  GSWIP_TX_SLPID_APP2		4
+#define  GSWIP_TX_SLPID_APP3		5
+#define  GSWIP_TX_SLPID_APP4		6
+#define  GSWIP_TX_SLPID_APP5		7
+
+/* Byte 1 */
+#define GSWIP_TX_CRCGEN_DIS		BIT(7)
+#define GSWIP_TX_DPID_SHIFT		0	/* destination group ID */
+#define  GSWIP_TX_DPID_ELAN		0
+#define  GSWIP_TX_DPID_EWAN		1
+#define  GSWIP_TX_DPID_CPU		2
+#define  GSWIP_TX_DPID_APP1		3
+#define  GSWIP_TX_DPID_APP2		4
+#define  GSWIP_TX_DPID_APP3		5
+#define  GSWIP_TX_DPID_APP4		6
+#define  GSWIP_TX_DPID_APP5		7
+
+/* Byte 2 */
+#define GSWIP_TX_PORT_MAP_EN		BIT(7)
+#define GSWIP_TX_PORT_MAP_SEL		BIT(6)
+#define GSWIP_TX_LRN_DIS		BIT(5)
+#define GSWIP_TX_CLASS_EN		BIT(4)
+#define GSWIP_TX_CLASS_SHIFT		0
+#define GSWIP_TX_CLASS_MASK		GENMASK(3, 0)
+
+/* Byte 3 */
+#define GSWIP_TX_DPID_EN		BIT(0)
+#define GSWIP_TX_PORT_MAP_SHIFT		1
+#define GSWIP_TX_PORT_MAP_MASK		GENMASK(6, 1)
+
+#define GSWIP_RX_HEADER_LEN	8
+
+/* special tag in RX path header */
+/* Byte 7 */
+#define GSWIP_RX_SPPID_SHIFT		4
+#define GSWIP_RX_SPPID_MASK		GENMASK(6, 4)
+
+static struct sk_buff *gswip_tag_xmit(struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+	u8 *gswip_tag;
+
+	skb_push(skb, GSWIP_TX_HEADER_LEN);
+
+	gswip_tag = skb->data;
+	gswip_tag[0] = GSWIP_TX_SLPID_CPU;
+	gswip_tag[1] = GSWIP_TX_DPID_ELAN;
+	gswip_tag[2] = GSWIP_TX_PORT_MAP_EN | GSWIP_TX_PORT_MAP_SEL;
+	gswip_tag[3] = BIT(dp->index + GSWIP_TX_PORT_MAP_SHIFT) & GSWIP_TX_PORT_MAP_MASK;
+	gswip_tag[3] |= GSWIP_TX_DPID_EN;
+
+	return skb;
+}
+
+static struct sk_buff *gswip_tag_rcv(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	int port;
+	u8 *gswip_tag;
+
+	if (unlikely(!pskb_may_pull(skb, GSWIP_RX_HEADER_LEN)))
+		return NULL;
+
+	gswip_tag = skb->data - ETH_HLEN;
+
+	/* Get source port information */
+	port = (gswip_tag[7] & GSWIP_RX_SPPID_MASK) >> GSWIP_RX_SPPID_SHIFT;
+	skb->dev = dsa_master_find_slave(dev, 0, port);
+	if (!skb->dev)
+		return NULL;
+
+	/* remove GSWIP tag */
+	skb_pull_rcsum(skb, GSWIP_RX_HEADER_LEN);
+
+	return skb;
+}
+
+static const struct dsa_device_ops gswip_netdev_ops = {
+	.name = "gswip",
+	.proto	= DSA_TAG_PROTO_GSWIP,
+	.xmit = gswip_tag_xmit,
+	.rcv = gswip_tag_rcv,
+	.needed_headroom = GSWIP_RX_HEADER_LEN,
+};
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_GSWIP);
+
+module_dsa_tag_driver(gswip_netdev_ops);