1 files changed, 64 insertions, 0 deletions
diff --git a/net/dsa/tag_xrs700x.c b/net/dsa/tag_xrs700x.c
new file mode 100644
index 000000000000..ff442b8af636
--- /dev/null
+++ b/net/dsa/tag_xrs700x.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * XRS700x tag format handling
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2020 NovaTech LLC
+ */
+
+#include <linux/bitops.h>
+
+#include "dsa_priv.h"
+
+static struct sk_buff *xrs700x_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct dsa_port *partner, *dp = dsa_slave_to_port(dev);
+	u8 *trailer;
+
+	trailer = skb_put(skb, 1);
+	trailer[0] = BIT(dp->index);
+
+	if (dp->hsr_dev)
+		dsa_hsr_foreach_port(partner, dp->ds, dp->hsr_dev)
+			if (partner != dp)
+				trailer[0] |= BIT(partner->index);
+
+	return skb;
+}
+
+static struct sk_buff *xrs700x_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	int source_port;
+	u8 *trailer;
+
+	trailer = skb_tail_pointer(skb) - 1;
+
+	source_port = ffs((int)trailer[0]) - 1;
+
+	if (source_port < 0)
+		return NULL;
+
+	skb->dev = dsa_master_find_slave(dev, 0, source_port);
+	if (!skb->dev)
+		return NULL;
+
+	if (pskb_trim_rcsum(skb, skb->len - 1))
+		return NULL;
+
+	/* Frame is forwarded by hardware, don't forward in software. */
+	dsa_default_offload_fwd_mark(skb);
+
+	return skb;
+}
+
+static const struct dsa_device_ops xrs700x_netdev_ops = {
+	.name	= "xrs700x",
+	.proto	= DSA_TAG_PROTO_XRS700X,
+	.xmit	= xrs700x_xmit,
+	.rcv	= xrs700x_rcv,
+	.needed_tailroom = 1,
+};
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_XRS700X);
+
+module_dsa_tag_driver(xrs700x_netdev_ops);